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diff --git a/security/Kconfig b/security/Kconfig new file mode 100644 index 000000000..e6db09a77 --- /dev/null +++ b/security/Kconfig @@ -0,0 +1,264 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +# Security configuration +# + +menu "Security options" + +source "security/keys/Kconfig" + +config SECURITY_DMESG_RESTRICT + bool "Restrict unprivileged access to the kernel syslog" + default n + help + This enforces restrictions on unprivileged users reading the kernel + syslog via dmesg(8). + + If this option is not selected, no restrictions will be enforced + unless the dmesg_restrict sysctl is explicitly set to (1). + + If you are unsure how to answer this question, answer N. + +config SECURITY + bool "Enable different security models" + depends on SYSFS + depends on MULTIUSER + help + This allows you to choose different security modules to be + configured into your kernel. + + If this option is not selected, the default Linux security + model will be used. + + If you are unsure how to answer this question, answer N. + +config SECURITY_WRITABLE_HOOKS + depends on SECURITY + bool + default n + +config SECURITYFS + bool "Enable the securityfs filesystem" + help + This will build the securityfs filesystem. It is currently used by + various security modules (AppArmor, IMA, SafeSetID, TOMOYO, TPM). + + If you are unsure how to answer this question, answer N. + +config SECURITY_NETWORK + bool "Socket and Networking Security Hooks" + depends on SECURITY + help + This enables the socket and networking security hooks. + If enabled, a security module can use these hooks to + implement socket and networking access controls. + If you are unsure how to answer this question, answer N. + +config SECURITY_INFINIBAND + bool "Infiniband Security Hooks" + depends on SECURITY && INFINIBAND + help + This enables the Infiniband security hooks. + If enabled, a security module can use these hooks to + implement Infiniband access controls. + If you are unsure how to answer this question, answer N. + +config SECURITY_NETWORK_XFRM + bool "XFRM (IPSec) Networking Security Hooks" + depends on XFRM && SECURITY_NETWORK + help + This enables the XFRM (IPSec) networking security hooks. + If enabled, a security module can use these hooks to + implement per-packet access controls based on labels + derived from IPSec policy. Non-IPSec communications are + designated as unlabelled, and only sockets authorized + to communicate unlabelled data can send without using + IPSec. + If you are unsure how to answer this question, answer N. + +config SECURITY_PATH + bool "Security hooks for pathname based access control" + depends on SECURITY + help + This enables the security hooks for pathname based access control. + If enabled, a security module can use these hooks to + implement pathname based access controls. + If you are unsure how to answer this question, answer N. + +config INTEL_TXT + bool "Enable Intel(R) Trusted Execution Technology (Intel(R) TXT)" + depends on HAVE_INTEL_TXT + help + This option enables support for booting the kernel with the + Trusted Boot (tboot) module. This will utilize + Intel(R) Trusted Execution Technology to perform a measured launch + of the kernel. If the system does not support Intel(R) TXT, this + will have no effect. + + Intel TXT will provide higher assurance of system configuration and + initial state as well as data reset protection. This is used to + create a robust initial kernel measurement and verification, which + helps to ensure that kernel security mechanisms are functioning + correctly. This level of protection requires a root of trust outside + of the kernel itself. + + Intel TXT also helps solve real end user concerns about having + confidence that their hardware is running the VMM or kernel that + it was configured with, especially since they may be responsible for + providing such assurances to VMs and services running on it. + + See <https://www.intel.com/technology/security/> for more information + about Intel(R) TXT. + See <http://tboot.sourceforge.net> for more information about tboot. + See Documentation/x86/intel_txt.rst for a description of how to enable + Intel TXT support in a kernel boot. + + If you are unsure as to whether this is required, answer N. + +config LSM_MMAP_MIN_ADDR + int "Low address space for LSM to protect from user allocation" + depends on SECURITY && SECURITY_SELINUX + default 32768 if ARM || (ARM64 && COMPAT) + default 65536 + help + This is the portion of low virtual memory which should be protected + from userspace allocation. Keeping a user from writing to low pages + can help reduce the impact of kernel NULL pointer bugs. + + For most ia64, ppc64 and x86 users with lots of address space + a value of 65536 is reasonable and should cause no problems. + On arm and other archs it should not be higher than 32768. + Programs which use vm86 functionality or have some need to map + this low address space will need the permission specific to the + systems running LSM. + +config HAVE_HARDENED_USERCOPY_ALLOCATOR + bool + help + The heap allocator implements __check_heap_object() for + validating memory ranges against heap object sizes in + support of CONFIG_HARDENED_USERCOPY. + +config HARDENED_USERCOPY + bool "Harden memory copies between kernel and userspace" + depends on HAVE_HARDENED_USERCOPY_ALLOCATOR + imply STRICT_DEVMEM + help + This option checks for obviously wrong memory regions when + copying memory to/from the kernel (via copy_to_user() and + copy_from_user() functions) by rejecting memory ranges that + are larger than the specified heap object, span multiple + separately allocated pages, are not on the process stack, + or are part of the kernel text. This prevents entire classes + of heap overflow exploits and similar kernel memory exposures. + +config FORTIFY_SOURCE + bool "Harden common str/mem functions against buffer overflows" + depends on ARCH_HAS_FORTIFY_SOURCE + # https://bugs.llvm.org/show_bug.cgi?id=41459 + depends on !CC_IS_CLANG || CLANG_VERSION >= 120001 + # https://github.com/llvm/llvm-project/issues/53645 + depends on !CC_IS_CLANG || !X86_32 + help + Detect overflows of buffers in common string and memory functions + where the compiler can determine and validate the buffer sizes. + +config STATIC_USERMODEHELPER + bool "Force all usermode helper calls through a single binary" + help + By default, the kernel can call many different userspace + binary programs through the "usermode helper" kernel + interface. Some of these binaries are statically defined + either in the kernel code itself, or as a kernel configuration + option. However, some of these are dynamically created at + runtime, or can be modified after the kernel has started up. + To provide an additional layer of security, route all of these + calls through a single executable that can not have its name + changed. + + Note, it is up to this single binary to then call the relevant + "real" usermode helper binary, based on the first argument + passed to it. If desired, this program can filter and pick + and choose what real programs are called. + + If you wish for all usermode helper programs are to be + disabled, choose this option and then set + STATIC_USERMODEHELPER_PATH to an empty string. + +config STATIC_USERMODEHELPER_PATH + string "Path to the static usermode helper binary" + depends on STATIC_USERMODEHELPER + default "/sbin/usermode-helper" + help + The binary called by the kernel when any usermode helper + program is wish to be run. The "real" application's name will + be in the first argument passed to this program on the command + line. + + If you wish for all usermode helper programs to be disabled, + specify an empty string here (i.e. ""). + +source "security/selinux/Kconfig" +source "security/smack/Kconfig" +source "security/tomoyo/Kconfig" +source "security/apparmor/Kconfig" +source "security/loadpin/Kconfig" +source "security/yama/Kconfig" +source "security/safesetid/Kconfig" +source "security/lockdown/Kconfig" +source "security/landlock/Kconfig" + +source "security/integrity/Kconfig" + +choice + prompt "First legacy 'major LSM' to be initialized" + default DEFAULT_SECURITY_SELINUX if SECURITY_SELINUX + default DEFAULT_SECURITY_SMACK if SECURITY_SMACK + default DEFAULT_SECURITY_TOMOYO if SECURITY_TOMOYO + default DEFAULT_SECURITY_APPARMOR if SECURITY_APPARMOR + default DEFAULT_SECURITY_DAC + + help + This choice is there only for converting CONFIG_DEFAULT_SECURITY + in old kernel configs to CONFIG_LSM in new kernel configs. Don't + change this choice unless you are creating a fresh kernel config, + for this choice will be ignored after CONFIG_LSM has been set. + + Selects the legacy "major security module" that will be + initialized first. Overridden by non-default CONFIG_LSM. + + config DEFAULT_SECURITY_SELINUX + bool "SELinux" if SECURITY_SELINUX=y + + config DEFAULT_SECURITY_SMACK + bool "Simplified Mandatory Access Control" if SECURITY_SMACK=y + + config DEFAULT_SECURITY_TOMOYO + bool "TOMOYO" if SECURITY_TOMOYO=y + + config DEFAULT_SECURITY_APPARMOR + bool "AppArmor" if SECURITY_APPARMOR=y + + config DEFAULT_SECURITY_DAC + bool "Unix Discretionary Access Controls" + +endchoice + +config LSM + string "Ordered list of enabled LSMs" + default "landlock,lockdown,yama,loadpin,safesetid,integrity,smack,selinux,tomoyo,apparmor,bpf" if DEFAULT_SECURITY_SMACK + default "landlock,lockdown,yama,loadpin,safesetid,integrity,apparmor,selinux,smack,tomoyo,bpf" if DEFAULT_SECURITY_APPARMOR + default "landlock,lockdown,yama,loadpin,safesetid,integrity,tomoyo,bpf" if DEFAULT_SECURITY_TOMOYO + default "landlock,lockdown,yama,loadpin,safesetid,integrity,bpf" if DEFAULT_SECURITY_DAC + default "landlock,lockdown,yama,loadpin,safesetid,integrity,selinux,smack,tomoyo,apparmor,bpf" + help + A comma-separated list of LSMs, in initialization order. + Any LSMs left off this list will be ignored. This can be + controlled at boot with the "lsm=" parameter. + + If unsure, leave this as the default. + +source "security/Kconfig.hardening" + +endmenu + diff --git a/security/Kconfig.hardening b/security/Kconfig.hardening new file mode 100644 index 000000000..0f295961e --- /dev/null +++ b/security/Kconfig.hardening @@ -0,0 +1,358 @@ +# SPDX-License-Identifier: GPL-2.0-only +menu "Kernel hardening options" + +config GCC_PLUGIN_STRUCTLEAK + bool + help + While the kernel is built with warnings enabled for any missed + stack variable initializations, this warning is silenced for + anything passed by reference to another function, under the + occasionally misguided assumption that the function will do + the initialization. As this regularly leads to exploitable + flaws, this plugin is available to identify and zero-initialize + such variables, depending on the chosen level of coverage. + + This plugin was originally ported from grsecurity/PaX. More + information at: + * https://grsecurity.net/ + * https://pax.grsecurity.net/ + +menu "Memory initialization" + +config CC_HAS_AUTO_VAR_INIT_PATTERN + def_bool $(cc-option,-ftrivial-auto-var-init=pattern) + +config CC_HAS_AUTO_VAR_INIT_ZERO_BARE + def_bool $(cc-option,-ftrivial-auto-var-init=zero) + +config CC_HAS_AUTO_VAR_INIT_ZERO_ENABLER + # Clang 16 and later warn about using the -enable flag, but it + # is required before then. + def_bool $(cc-option,-ftrivial-auto-var-init=zero -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang) + depends on !CC_HAS_AUTO_VAR_INIT_ZERO_BARE + +config CC_HAS_AUTO_VAR_INIT_ZERO + def_bool CC_HAS_AUTO_VAR_INIT_ZERO_BARE || CC_HAS_AUTO_VAR_INIT_ZERO_ENABLER + +choice + prompt "Initialize kernel stack variables at function entry" + default GCC_PLUGIN_STRUCTLEAK_BYREF_ALL if COMPILE_TEST && GCC_PLUGINS + default INIT_STACK_ALL_PATTERN if COMPILE_TEST && CC_HAS_AUTO_VAR_INIT_PATTERN + default INIT_STACK_ALL_ZERO if CC_HAS_AUTO_VAR_INIT_ZERO + default INIT_STACK_NONE + help + This option enables initialization of stack variables at + function entry time. This has the possibility to have the + greatest coverage (since all functions can have their + variables initialized), but the performance impact depends + on the function calling complexity of a given workload's + syscalls. + + This chooses the level of coverage over classes of potentially + uninitialized variables. The selected class of variable will be + initialized before use in a function. + + config INIT_STACK_NONE + bool "no automatic stack variable initialization (weakest)" + help + Disable automatic stack variable initialization. + This leaves the kernel vulnerable to the standard + classes of uninitialized stack variable exploits + and information exposures. + + config GCC_PLUGIN_STRUCTLEAK_USER + bool "zero-init structs marked for userspace (weak)" + # Plugin can be removed once the kernel only supports GCC 12+ + depends on GCC_PLUGINS && !CC_HAS_AUTO_VAR_INIT_ZERO + select GCC_PLUGIN_STRUCTLEAK + help + Zero-initialize any structures on the stack containing + a __user attribute. This can prevent some classes of + uninitialized stack variable exploits and information + exposures, like CVE-2013-2141: + https://git.kernel.org/linus/b9e146d8eb3b9eca + + config GCC_PLUGIN_STRUCTLEAK_BYREF + bool "zero-init structs passed by reference (strong)" + # Plugin can be removed once the kernel only supports GCC 12+ + depends on GCC_PLUGINS && !CC_HAS_AUTO_VAR_INIT_ZERO + depends on !(KASAN && KASAN_STACK) + select GCC_PLUGIN_STRUCTLEAK + help + Zero-initialize any structures on the stack that may + be passed by reference and had not already been + explicitly initialized. This can prevent most classes + of uninitialized stack variable exploits and information + exposures, like CVE-2017-1000410: + https://git.kernel.org/linus/06e7e776ca4d3654 + + As a side-effect, this keeps a lot of variables on the + stack that can otherwise be optimized out, so combining + this with CONFIG_KASAN_STACK can lead to a stack overflow + and is disallowed. + + config GCC_PLUGIN_STRUCTLEAK_BYREF_ALL + bool "zero-init everything passed by reference (very strong)" + # Plugin can be removed once the kernel only supports GCC 12+ + depends on GCC_PLUGINS && !CC_HAS_AUTO_VAR_INIT_ZERO + depends on !(KASAN && KASAN_STACK) + select GCC_PLUGIN_STRUCTLEAK + help + Zero-initialize any stack variables that may be passed + by reference and had not already been explicitly + initialized. This is intended to eliminate all classes + of uninitialized stack variable exploits and information + exposures. + + As a side-effect, this keeps a lot of variables on the + stack that can otherwise be optimized out, so combining + this with CONFIG_KASAN_STACK can lead to a stack overflow + and is disallowed. + + config INIT_STACK_ALL_PATTERN + bool "pattern-init everything (strongest)" + depends on CC_HAS_AUTO_VAR_INIT_PATTERN + depends on !KMSAN + help + Initializes everything on the stack (including padding) + with a specific debug value. This is intended to eliminate + all classes of uninitialized stack variable exploits and + information exposures, even variables that were warned about + having been left uninitialized. + + Pattern initialization is known to provoke many existing bugs + related to uninitialized locals, e.g. pointers receive + non-NULL values, buffer sizes and indices are very big. The + pattern is situation-specific; Clang on 64-bit uses 0xAA + repeating for all types and padding except float and double + which use 0xFF repeating (-NaN). Clang on 32-bit uses 0xFF + repeating for all types and padding. + + config INIT_STACK_ALL_ZERO + bool "zero-init everything (strongest and safest)" + depends on CC_HAS_AUTO_VAR_INIT_ZERO + depends on !KMSAN + help + Initializes everything on the stack (including padding) + with a zero value. This is intended to eliminate all + classes of uninitialized stack variable exploits and + information exposures, even variables that were warned + about having been left uninitialized. + + Zero initialization provides safe defaults for strings + (immediately NUL-terminated), pointers (NULL), indices + (index 0), and sizes (0 length), so it is therefore more + suitable as a production security mitigation than pattern + initialization. + +endchoice + +config GCC_PLUGIN_STRUCTLEAK_VERBOSE + bool "Report forcefully initialized variables" + depends on GCC_PLUGIN_STRUCTLEAK + depends on !COMPILE_TEST # too noisy + help + This option will cause a warning to be printed each time the + structleak plugin finds a variable it thinks needs to be + initialized. Since not all existing initializers are detected + by the plugin, this can produce false positive warnings. + +config GCC_PLUGIN_STACKLEAK + bool "Poison kernel stack before returning from syscalls" + depends on GCC_PLUGINS + depends on HAVE_ARCH_STACKLEAK + help + This option makes the kernel erase the kernel stack before + returning from system calls. This has the effect of leaving + the stack initialized to the poison value, which both reduces + the lifetime of any sensitive stack contents and reduces + potential for uninitialized stack variable exploits or information + exposures (it does not cover functions reaching the same stack + depth as prior functions during the same syscall). This blocks + most uninitialized stack variable attacks, with the performance + impact being driven by the depth of the stack usage, rather than + the function calling complexity. + + The performance impact on a single CPU system kernel compilation + sees a 1% slowdown, other systems and workloads may vary and you + are advised to test this feature on your expected workload before + deploying it. + + This plugin was ported from grsecurity/PaX. More information at: + * https://grsecurity.net/ + * https://pax.grsecurity.net/ + +config GCC_PLUGIN_STACKLEAK_VERBOSE + bool "Report stack depth analysis instrumentation" if EXPERT + depends on GCC_PLUGIN_STACKLEAK + depends on !COMPILE_TEST # too noisy + help + This option will cause a warning to be printed each time the + stackleak plugin finds a function it thinks needs to be + instrumented. This is useful for comparing coverage between + builds. + +config STACKLEAK_TRACK_MIN_SIZE + int "Minimum stack frame size of functions tracked by STACKLEAK" + default 100 + range 0 4096 + depends on GCC_PLUGIN_STACKLEAK + help + The STACKLEAK gcc plugin instruments the kernel code for tracking + the lowest border of the kernel stack (and for some other purposes). + It inserts the stackleak_track_stack() call for the functions with + a stack frame size greater than or equal to this parameter. + If unsure, leave the default value 100. + +config STACKLEAK_METRICS + bool "Show STACKLEAK metrics in the /proc file system" + depends on GCC_PLUGIN_STACKLEAK + depends on PROC_FS + help + If this is set, STACKLEAK metrics for every task are available in + the /proc file system. In particular, /proc/<pid>/stack_depth + shows the maximum kernel stack consumption for the current and + previous syscalls. Although this information is not precise, it + can be useful for estimating the STACKLEAK performance impact for + your workloads. + +config STACKLEAK_RUNTIME_DISABLE + bool "Allow runtime disabling of kernel stack erasing" + depends on GCC_PLUGIN_STACKLEAK + help + This option provides 'stack_erasing' sysctl, which can be used in + runtime to control kernel stack erasing for kernels built with + CONFIG_GCC_PLUGIN_STACKLEAK. + +config INIT_ON_ALLOC_DEFAULT_ON + bool "Enable heap memory zeroing on allocation by default" + depends on !KMSAN + help + This has the effect of setting "init_on_alloc=1" on the kernel + command line. This can be disabled with "init_on_alloc=0". + When "init_on_alloc" is enabled, all page allocator and slab + allocator memory will be zeroed when allocated, eliminating + many kinds of "uninitialized heap memory" flaws, especially + heap content exposures. The performance impact varies by + workload, but most cases see <1% impact. Some synthetic + workloads have measured as high as 7%. + +config INIT_ON_FREE_DEFAULT_ON + bool "Enable heap memory zeroing on free by default" + depends on !KMSAN + help + This has the effect of setting "init_on_free=1" on the kernel + command line. This can be disabled with "init_on_free=0". + Similar to "init_on_alloc", when "init_on_free" is enabled, + all page allocator and slab allocator memory will be zeroed + when freed, eliminating many kinds of "uninitialized heap memory" + flaws, especially heap content exposures. The primary difference + with "init_on_free" is that data lifetime in memory is reduced, + as anything freed is wiped immediately, making live forensics or + cold boot memory attacks unable to recover freed memory contents. + The performance impact varies by workload, but is more expensive + than "init_on_alloc" due to the negative cache effects of + touching "cold" memory areas. Most cases see 3-5% impact. Some + synthetic workloads have measured as high as 8%. + +config CC_HAS_ZERO_CALL_USED_REGS + def_bool $(cc-option,-fzero-call-used-regs=used-gpr) + # https://github.com/ClangBuiltLinux/linux/issues/1766 + # https://github.com/llvm/llvm-project/issues/59242 + depends on !CC_IS_CLANG || CLANG_VERSION > 150006 + +config ZERO_CALL_USED_REGS + bool "Enable register zeroing on function exit" + depends on CC_HAS_ZERO_CALL_USED_REGS + help + At the end of functions, always zero any caller-used register + contents. This helps ensure that temporary values are not + leaked beyond the function boundary. This means that register + contents are less likely to be available for side channels + and information exposures. Additionally, this helps reduce the + number of useful ROP gadgets by about 20% (and removes compiler + generated "write-what-where" gadgets) in the resulting kernel + image. This has a less than 1% performance impact on most + workloads. Image size growth depends on architecture, and should + be evaluated for suitability. For example, x86_64 grows by less + than 1%, and arm64 grows by about 5%. + +endmenu + +config CC_HAS_RANDSTRUCT + def_bool $(cc-option,-frandomize-layout-seed-file=/dev/null) + # Randstruct was first added in Clang 15, but it isn't safe to use until + # Clang 16 due to https://github.com/llvm/llvm-project/issues/60349 + depends on !CC_IS_CLANG || CLANG_VERSION >= 160000 + +choice + prompt "Randomize layout of sensitive kernel structures" + default RANDSTRUCT_FULL if COMPILE_TEST && (GCC_PLUGINS || CC_HAS_RANDSTRUCT) + default RANDSTRUCT_NONE + help + If you enable this, the layouts of structures that are entirely + function pointers (and have not been manually annotated with + __no_randomize_layout), or structures that have been explicitly + marked with __randomize_layout, will be randomized at compile-time. + This can introduce the requirement of an additional information + exposure vulnerability for exploits targeting these structure + types. + + Enabling this feature will introduce some performance impact, + slightly increase memory usage, and prevent the use of forensic + tools like Volatility against the system (unless the kernel + source tree isn't cleaned after kernel installation). + + The seed used for compilation is in scripts/basic/randomize.seed. + It remains after a "make clean" to allow for external modules to + be compiled with the existing seed and will be removed by a + "make mrproper" or "make distclean". This file should not be made + public, or the structure layout can be determined. + + config RANDSTRUCT_NONE + bool "Disable structure layout randomization" + help + Build normally: no structure layout randomization. + + config RANDSTRUCT_FULL + bool "Fully randomize structure layout" + depends on CC_HAS_RANDSTRUCT || GCC_PLUGINS + select MODVERSIONS if MODULES + help + Fully randomize the member layout of sensitive + structures as much as possible, which may have both a + memory size and performance impact. + + One difference between the Clang and GCC plugin + implementations is the handling of bitfields. The GCC + plugin treats them as fully separate variables, + introducing sometimes significant padding. Clang tries + to keep adjacent bitfields together, but with their bit + ordering randomized. + + config RANDSTRUCT_PERFORMANCE + bool "Limit randomization of structure layout to cache-lines" + depends on GCC_PLUGINS + select MODVERSIONS if MODULES + help + Randomization of sensitive kernel structures will make a + best effort at restricting randomization to cacheline-sized + groups of members. It will further not randomize bitfields + in structures. This reduces the performance hit of RANDSTRUCT + at the cost of weakened randomization. +endchoice + +config RANDSTRUCT + def_bool !RANDSTRUCT_NONE + +config GCC_PLUGIN_RANDSTRUCT + def_bool GCC_PLUGINS && RANDSTRUCT + help + Use GCC plugin to randomize structure layout. + + This plugin was ported from grsecurity/PaX. More + information at: + * https://grsecurity.net/ + * https://pax.grsecurity.net/ + +endmenu diff --git a/security/Makefile b/security/Makefile new file mode 100644 index 000000000..18121f8f8 --- /dev/null +++ b/security/Makefile @@ -0,0 +1,29 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Makefile for the kernel security code +# + +obj-$(CONFIG_KEYS) += keys/ + +# always enable default capabilities +obj-y += commoncap.o +obj-$(CONFIG_MMU) += min_addr.o + +# Object file lists +obj-$(CONFIG_SECURITY) += security.o +obj-$(CONFIG_SECURITYFS) += inode.o +obj-$(CONFIG_SECURITY_SELINUX) += selinux/ +obj-$(CONFIG_SECURITY_SMACK) += smack/ +obj-$(CONFIG_SECURITY) += lsm_audit.o +obj-$(CONFIG_SECURITY_TOMOYO) += tomoyo/ +obj-$(CONFIG_SECURITY_APPARMOR) += apparmor/ +obj-$(CONFIG_SECURITY_YAMA) += yama/ +obj-$(CONFIG_SECURITY_LOADPIN) += loadpin/ +obj-$(CONFIG_SECURITY_SAFESETID) += safesetid/ +obj-$(CONFIG_SECURITY_LOCKDOWN_LSM) += lockdown/ +obj-$(CONFIG_CGROUPS) += device_cgroup.o +obj-$(CONFIG_BPF_LSM) += bpf/ +obj-$(CONFIG_SECURITY_LANDLOCK) += landlock/ + +# Object integrity file lists +obj-$(CONFIG_INTEGRITY) += integrity/ diff --git a/security/apparmor/.gitignore b/security/apparmor/.gitignore new file mode 100644 index 000000000..6d1eb1c15 --- /dev/null +++ b/security/apparmor/.gitignore @@ -0,0 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0-only +net_names.h +capability_names.h +rlim_names.h diff --git a/security/apparmor/Kconfig b/security/apparmor/Kconfig new file mode 100644 index 000000000..f334e7ccc --- /dev/null +++ b/security/apparmor/Kconfig @@ -0,0 +1,123 @@ +# SPDX-License-Identifier: GPL-2.0-only +config SECURITY_APPARMOR + bool "AppArmor support" + depends on SECURITY && NET + select AUDIT + select SECURITY_PATH + select SECURITYFS + select SECURITY_NETWORK + default n + help + This enables the AppArmor security module. + Required userspace tools (if they are not included in your + distribution) and further information may be found at + http://apparmor.wiki.kernel.org + + If you are unsure how to answer this question, answer N. + +config SECURITY_APPARMOR_DEBUG + bool "Build AppArmor with debug code" + depends on SECURITY_APPARMOR + default n + help + Build apparmor with debugging logic in apparmor. Not all + debugging logic will necessarily be enabled. A submenu will + provide fine grained control of the debug options that are + available. + +config SECURITY_APPARMOR_DEBUG_ASSERTS + bool "Build AppArmor with debugging asserts" + depends on SECURITY_APPARMOR_DEBUG + default y + help + Enable code assertions made with AA_BUG. These are primarily + function entry preconditions but also exist at other key + points. If the assert is triggered it will trigger a WARN + message. + +config SECURITY_APPARMOR_DEBUG_MESSAGES + bool "Debug messages enabled by default" + depends on SECURITY_APPARMOR_DEBUG + default n + help + Set the default value of the apparmor.debug kernel parameter. + When enabled, various debug messages will be logged to + the kernel message buffer. + +config SECURITY_APPARMOR_INTROSPECT_POLICY + bool "Allow loaded policy to be introspected" + depends on SECURITY_APPARMOR + default y + help + This option selects whether introspection of loaded policy + is available to userspace via the apparmor filesystem. This + adds to kernel memory usage. It is required for introspection + of loaded policy, and check point and restore support. It + can be disabled for embedded systems where reducing memory and + cpu is paramount. + +config SECURITY_APPARMOR_HASH + bool "Enable introspection of sha1 hashes for loaded profiles" + depends on SECURITY_APPARMOR_INTROSPECT_POLICY + select CRYPTO + select CRYPTO_SHA1 + default y + help + This option selects whether introspection of loaded policy + hashes is available to userspace via the apparmor + filesystem. This option provides a light weight means of + checking loaded policy. This option adds to policy load + time and can be disabled for small embedded systems. + +config SECURITY_APPARMOR_HASH_DEFAULT + bool "Enable policy hash introspection by default" + depends on SECURITY_APPARMOR_HASH + default y + help + This option selects whether sha1 hashing of loaded policy + is enabled by default. The generation of sha1 hashes for + loaded policy provide system administrators a quick way + to verify that policy in the kernel matches what is expected, + however it can slow down policy load on some devices. In + these cases policy hashing can be disabled by default and + enabled only if needed. + +config SECURITY_APPARMOR_EXPORT_BINARY + bool "Allow exporting the raw binary policy" + depends on SECURITY_APPARMOR_INTROSPECT_POLICY + select ZLIB_INFLATE + select ZLIB_DEFLATE + default y + help + This option allows reading back binary policy as it was loaded. + It increases the amount of kernel memory needed by policy and + also increases policy load time. This option is required for + checkpoint and restore support, and debugging of loaded policy. + +config SECURITY_APPARMOR_PARANOID_LOAD + bool "Perform full verification of loaded policy" + depends on SECURITY_APPARMOR + default y + help + This options allows controlling whether apparmor does a full + verification of loaded policy. This should not be disabled + except for embedded systems where the image is read only, + includes policy, and has some form of integrity check. + Disabling the check will speed up policy loads. + +config SECURITY_APPARMOR_KUNIT_TEST + tristate "Build KUnit tests for policy_unpack.c" if !KUNIT_ALL_TESTS + depends on KUNIT && SECURITY_APPARMOR + default KUNIT_ALL_TESTS + help + This builds the AppArmor KUnit tests. + + KUnit tests run during boot and output the results to the debug log + in TAP format (https://testanything.org/). Only useful for kernel devs + running KUnit test harness and are not for inclusion into a + production build. + + For more information on KUnit and unit tests in general please refer + to the KUnit documentation in Documentation/dev-tools/kunit/. + + If unsure, say N. diff --git a/security/apparmor/Makefile b/security/apparmor/Makefile new file mode 100644 index 000000000..065f4e346 --- /dev/null +++ b/security/apparmor/Makefile @@ -0,0 +1,113 @@ +# SPDX-License-Identifier: GPL-2.0 +# Makefile for AppArmor Linux Security Module +# +obj-$(CONFIG_SECURITY_APPARMOR) += apparmor.o + +apparmor-y := apparmorfs.o audit.o capability.o task.o ipc.o lib.o match.o \ + path.o domain.o policy.o policy_unpack.o procattr.o lsm.o \ + resource.o secid.o file.o policy_ns.o label.o mount.o net.o +apparmor-$(CONFIG_SECURITY_APPARMOR_HASH) += crypto.o + +obj-$(CONFIG_SECURITY_APPARMOR_KUNIT_TEST) += apparmor_policy_unpack_test.o +apparmor_policy_unpack_test-objs += policy_unpack_test.o + +clean-files := capability_names.h rlim_names.h net_names.h + +# Build a lower case string table of address family names +# Transform lines from +# #define AF_LOCAL 1 /* POSIX name for AF_UNIX */ +# #define AF_INET 2 /* Internet IP Protocol */ +# to +# [1] = "local", +# [2] = "inet", +# +# and build the securityfs entries for the mapping. +# Transforms lines from +# #define AF_INET 2 /* Internet IP Protocol */ +# to +# #define AA_SFS_AF_MASK "local inet" +quiet_cmd_make-af = GEN $@ +cmd_make-af = echo "static const char *address_family_names[] = {" > $@ ;\ + sed $< >>$@ -r -n -e "/AF_MAX/d" -e "/AF_LOCAL/d" -e "/AF_ROUTE/d" -e \ + 's/^\#define[ \t]+AF_([A-Z0-9_]+)[ \t]+([0-9]+)(.*)/[\2] = "\L\1",/p';\ + echo "};" >> $@ ;\ + printf '%s' '\#define AA_SFS_AF_MASK "' >> $@ ;\ + sed -r -n -e "/AF_MAX/d" -e "/AF_LOCAL/d" -e "/AF_ROUTE/d" -e \ + 's/^\#define[ \t]+AF_([A-Z0-9_]+)[ \t]+([0-9]+)(.*)/\L\1/p'\ + $< | tr '\n' ' ' | sed -e 's/ $$/"\n/' >> $@ + +# Build a lower case string table of sock type names +# Transform lines from +# SOCK_STREAM = 1, +# to +# [1] = "stream", +quiet_cmd_make-sock = GEN $@ +cmd_make-sock = echo "static const char *sock_type_names[] = {" >> $@ ;\ + sed $^ >>$@ -r -n \ + -e 's/^\tSOCK_([A-Z0-9_]+)[\t]+=[ \t]+([0-9]+)(.*)/[\2] = "\L\1",/p';\ + echo "};" >> $@ + +# Build a lower case string table of capability names +# Transforms lines from +# #define CAP_DAC_OVERRIDE 1 +# to +# [1] = "dac_override", +quiet_cmd_make-caps = GEN $@ +cmd_make-caps = echo "static const char *const capability_names[] = {" > $@ ;\ + sed $< >>$@ -r -n -e '/CAP_FS_MASK/d' \ + -e 's/^\#define[ \t]+CAP_([A-Z0-9_]+)[ \t]+([0-9]+)/[\2] = "\L\1",/p';\ + echo "};" >> $@ ;\ + printf '%s' '\#define AA_SFS_CAPS_MASK "' >> $@ ;\ + sed $< -r -n -e '/CAP_FS_MASK/d' \ + -e 's/^\#define[ \t]+CAP_([A-Z0-9_]+)[ \t]+([0-9]+)/\L\1/p' | \ + tr '\n' ' ' | sed -e 's/ $$/"\n/' >> $@ + + +# Build a lower case string table of rlimit names. +# Transforms lines from +# #define RLIMIT_STACK 3 /* max stack size */ +# to +# [RLIMIT_STACK] = "stack", +# +# and build a second integer table (with the second sed cmd), that maps +# RLIMIT defines to the order defined in asm-generic/resource.h This is +# required by policy load to map policy ordering of RLIMITs to internal +# ordering for architectures that redefine an RLIMIT. +# Transforms lines from +# #define RLIMIT_STACK 3 /* max stack size */ +# to +# RLIMIT_STACK, +# +# and build the securityfs entries for the mapping. +# Transforms lines from +# #define RLIMIT_FSIZE 1 /* Maximum filesize */ +# #define RLIMIT_STACK 3 /* max stack size */ +# to +# #define AA_SFS_RLIMIT_MASK "fsize stack" +quiet_cmd_make-rlim = GEN $@ +cmd_make-rlim = echo "static const char *const rlim_names[RLIM_NLIMITS] = {" \ + > $@ ;\ + sed $< >> $@ -r -n \ + -e 's/^\# ?define[ \t]+(RLIMIT_([A-Z0-9_]+)).*/[\1] = "\L\2",/p';\ + echo "};" >> $@ ;\ + echo "static const int rlim_map[RLIM_NLIMITS] = {" >> $@ ;\ + sed -r -n "s/^\# ?define[ \t]+(RLIMIT_[A-Z0-9_]+).*/\1,/p" $< >> $@ ;\ + echo "};" >> $@ ; \ + printf '%s' '\#define AA_SFS_RLIMIT_MASK "' >> $@ ;\ + sed -r -n 's/^\# ?define[ \t]+RLIMIT_([A-Z0-9_]+).*/\L\1/p' $< | \ + tr '\n' ' ' | sed -e 's/ $$/"\n/' >> $@ + +$(obj)/capability.o : $(obj)/capability_names.h +$(obj)/net.o : $(obj)/net_names.h +$(obj)/resource.o : $(obj)/rlim_names.h +$(obj)/capability_names.h : $(srctree)/include/uapi/linux/capability.h \ + $(src)/Makefile + $(call cmd,make-caps) +$(obj)/rlim_names.h : $(srctree)/include/uapi/asm-generic/resource.h \ + $(src)/Makefile + $(call cmd,make-rlim) +$(obj)/net_names.h : $(srctree)/include/linux/socket.h \ + $(srctree)/include/linux/net.h \ + $(src)/Makefile + $(call cmd,make-af) + $(call cmd,make-sock) diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c new file mode 100644 index 000000000..7160e7aa5 --- /dev/null +++ b/security/apparmor/apparmorfs.c @@ -0,0 +1,2682 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * AppArmor security module + * + * This file contains AppArmor /sys/kernel/security/apparmor interface functions + * + * Copyright (C) 1998-2008 Novell/SUSE + * Copyright 2009-2010 Canonical Ltd. + */ + +#include <linux/ctype.h> +#include <linux/security.h> +#include <linux/vmalloc.h> +#include <linux/init.h> +#include <linux/seq_file.h> +#include <linux/uaccess.h> +#include <linux/mount.h> +#include <linux/namei.h> +#include <linux/capability.h> +#include <linux/rcupdate.h> +#include <linux/fs.h> +#include <linux/fs_context.h> +#include <linux/poll.h> +#include <linux/zlib.h> +#include <uapi/linux/major.h> +#include <uapi/linux/magic.h> + +#include "include/apparmor.h" +#include "include/apparmorfs.h" +#include "include/audit.h" +#include "include/cred.h" +#include "include/crypto.h" +#include "include/ipc.h" +#include "include/label.h" +#include "include/policy.h" +#include "include/policy_ns.h" +#include "include/resource.h" +#include "include/policy_unpack.h" +#include "include/task.h" + +/* + * The apparmor filesystem interface used for policy load and introspection + * The interface is split into two main components based on their function + * a securityfs component: + * used for static files that are always available, and which allows + * userspace to specificy the location of the security filesystem. + * + * fns and data are prefixed with + * aa_sfs_ + * + * an apparmorfs component: + * used loaded policy content and introspection. It is not part of a + * regular mounted filesystem and is available only through the magic + * policy symlink in the root of the securityfs apparmor/ directory. + * Tasks queries will be magically redirected to the correct portion + * of the policy tree based on their confinement. + * + * fns and data are prefixed with + * aafs_ + * + * The aa_fs_ prefix is used to indicate the fn is used by both the + * securityfs and apparmorfs filesystems. + */ + + +/* + * support fns + */ + +struct rawdata_f_data { + struct aa_loaddata *loaddata; +}; + +#ifdef CONFIG_SECURITY_APPARMOR_EXPORT_BINARY +#define RAWDATA_F_DATA_BUF(p) (char *)(p + 1) + +static void rawdata_f_data_free(struct rawdata_f_data *private) +{ + if (!private) + return; + + aa_put_loaddata(private->loaddata); + kvfree(private); +} + +static struct rawdata_f_data *rawdata_f_data_alloc(size_t size) +{ + struct rawdata_f_data *ret; + + if (size > SIZE_MAX - sizeof(*ret)) + return ERR_PTR(-EINVAL); + + ret = kvzalloc(sizeof(*ret) + size, GFP_KERNEL); + if (!ret) + return ERR_PTR(-ENOMEM); + + return ret; +} +#endif + +/** + * mangle_name - mangle a profile name to std profile layout form + * @name: profile name to mangle (NOT NULL) + * @target: buffer to store mangled name, same length as @name (MAYBE NULL) + * + * Returns: length of mangled name + */ +static int mangle_name(const char *name, char *target) +{ + char *t = target; + + while (*name == '/' || *name == '.') + name++; + + if (target) { + for (; *name; name++) { + if (*name == '/') + *(t)++ = '.'; + else if (isspace(*name)) + *(t)++ = '_'; + else if (isalnum(*name) || strchr("._-", *name)) + *(t)++ = *name; + } + + *t = 0; + } else { + int len = 0; + for (; *name; name++) { + if (isalnum(*name) || isspace(*name) || + strchr("/._-", *name)) + len++; + } + + return len; + } + + return t - target; +} + + +/* + * aafs - core fns and data for the policy tree + */ + +#define AAFS_NAME "apparmorfs" +static struct vfsmount *aafs_mnt; +static int aafs_count; + + +static int aafs_show_path(struct seq_file *seq, struct dentry *dentry) +{ + seq_printf(seq, "%s:[%lu]", AAFS_NAME, d_inode(dentry)->i_ino); + return 0; +} + +static void aafs_free_inode(struct inode *inode) +{ + if (S_ISLNK(inode->i_mode)) + kfree(inode->i_link); + free_inode_nonrcu(inode); +} + +static const struct super_operations aafs_super_ops = { + .statfs = simple_statfs, + .free_inode = aafs_free_inode, + .show_path = aafs_show_path, +}; + +static int apparmorfs_fill_super(struct super_block *sb, struct fs_context *fc) +{ + static struct tree_descr files[] = { {""} }; + int error; + + error = simple_fill_super(sb, AAFS_MAGIC, files); + if (error) + return error; + sb->s_op = &aafs_super_ops; + + return 0; +} + +static int apparmorfs_get_tree(struct fs_context *fc) +{ + return get_tree_single(fc, apparmorfs_fill_super); +} + +static const struct fs_context_operations apparmorfs_context_ops = { + .get_tree = apparmorfs_get_tree, +}; + +static int apparmorfs_init_fs_context(struct fs_context *fc) +{ + fc->ops = &apparmorfs_context_ops; + return 0; +} + +static struct file_system_type aafs_ops = { + .owner = THIS_MODULE, + .name = AAFS_NAME, + .init_fs_context = apparmorfs_init_fs_context, + .kill_sb = kill_anon_super, +}; + +/** + * __aafs_setup_d_inode - basic inode setup for apparmorfs + * @dir: parent directory for the dentry + * @dentry: dentry we are seting the inode up for + * @mode: permissions the file should have + * @data: data to store on inode.i_private, available in open() + * @link: if symlink, symlink target string + * @fops: struct file_operations that should be used + * @iops: struct of inode_operations that should be used + */ +static int __aafs_setup_d_inode(struct inode *dir, struct dentry *dentry, + umode_t mode, void *data, char *link, + const struct file_operations *fops, + const struct inode_operations *iops) +{ + struct inode *inode = new_inode(dir->i_sb); + + AA_BUG(!dir); + AA_BUG(!dentry); + + if (!inode) + return -ENOMEM; + + inode->i_ino = get_next_ino(); + inode->i_mode = mode; + inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode); + inode->i_private = data; + if (S_ISDIR(mode)) { + inode->i_op = iops ? iops : &simple_dir_inode_operations; + inode->i_fop = &simple_dir_operations; + inc_nlink(inode); + inc_nlink(dir); + } else if (S_ISLNK(mode)) { + inode->i_op = iops ? iops : &simple_symlink_inode_operations; + inode->i_link = link; + } else { + inode->i_fop = fops; + } + d_instantiate(dentry, inode); + dget(dentry); + + return 0; +} + +/** + * aafs_create - create a dentry in the apparmorfs filesystem + * + * @name: name of dentry to create + * @mode: permissions the file should have + * @parent: parent directory for this dentry + * @data: data to store on inode.i_private, available in open() + * @link: if symlink, symlink target string + * @fops: struct file_operations that should be used for + * @iops: struct of inode_operations that should be used + * + * This is the basic "create a xxx" function for apparmorfs. + * + * Returns a pointer to a dentry if it succeeds, that must be free with + * aafs_remove(). Will return ERR_PTR on failure. + */ +static struct dentry *aafs_create(const char *name, umode_t mode, + struct dentry *parent, void *data, void *link, + const struct file_operations *fops, + const struct inode_operations *iops) +{ + struct dentry *dentry; + struct inode *dir; + int error; + + AA_BUG(!name); + AA_BUG(!parent); + + if (!(mode & S_IFMT)) + mode = (mode & S_IALLUGO) | S_IFREG; + + error = simple_pin_fs(&aafs_ops, &aafs_mnt, &aafs_count); + if (error) + return ERR_PTR(error); + + dir = d_inode(parent); + + inode_lock(dir); + dentry = lookup_one_len(name, parent, strlen(name)); + if (IS_ERR(dentry)) { + error = PTR_ERR(dentry); + goto fail_lock; + } + + if (d_really_is_positive(dentry)) { + error = -EEXIST; + goto fail_dentry; + } + + error = __aafs_setup_d_inode(dir, dentry, mode, data, link, fops, iops); + if (error) + goto fail_dentry; + inode_unlock(dir); + + return dentry; + +fail_dentry: + dput(dentry); + +fail_lock: + inode_unlock(dir); + simple_release_fs(&aafs_mnt, &aafs_count); + + return ERR_PTR(error); +} + +/** + * aafs_create_file - create a file in the apparmorfs filesystem + * + * @name: name of dentry to create + * @mode: permissions the file should have + * @parent: parent directory for this dentry + * @data: data to store on inode.i_private, available in open() + * @fops: struct file_operations that should be used for + * + * see aafs_create + */ +static struct dentry *aafs_create_file(const char *name, umode_t mode, + struct dentry *parent, void *data, + const struct file_operations *fops) +{ + return aafs_create(name, mode, parent, data, NULL, fops, NULL); +} + +/** + * aafs_create_dir - create a directory in the apparmorfs filesystem + * + * @name: name of dentry to create + * @parent: parent directory for this dentry + * + * see aafs_create + */ +static struct dentry *aafs_create_dir(const char *name, struct dentry *parent) +{ + return aafs_create(name, S_IFDIR | 0755, parent, NULL, NULL, NULL, + NULL); +} + +/** + * aafs_remove - removes a file or directory from the apparmorfs filesystem + * + * @dentry: dentry of the file/directory/symlink to removed. + */ +static void aafs_remove(struct dentry *dentry) +{ + struct inode *dir; + + if (!dentry || IS_ERR(dentry)) + return; + + dir = d_inode(dentry->d_parent); + inode_lock(dir); + if (simple_positive(dentry)) { + if (d_is_dir(dentry)) + simple_rmdir(dir, dentry); + else + simple_unlink(dir, dentry); + d_delete(dentry); + dput(dentry); + } + inode_unlock(dir); + simple_release_fs(&aafs_mnt, &aafs_count); +} + + +/* + * aa_fs - policy load/replace/remove + */ + +/** + * aa_simple_write_to_buffer - common routine for getting policy from user + * @userbuf: user buffer to copy data from (NOT NULL) + * @alloc_size: size of user buffer (REQUIRES: @alloc_size >= @copy_size) + * @copy_size: size of data to copy from user buffer + * @pos: position write is at in the file (NOT NULL) + * + * Returns: kernel buffer containing copy of user buffer data or an + * ERR_PTR on failure. + */ +static struct aa_loaddata *aa_simple_write_to_buffer(const char __user *userbuf, + size_t alloc_size, + size_t copy_size, + loff_t *pos) +{ + struct aa_loaddata *data; + + AA_BUG(copy_size > alloc_size); + + if (*pos != 0) + /* only writes from pos 0, that is complete writes */ + return ERR_PTR(-ESPIPE); + + /* freed by caller to simple_write_to_buffer */ + data = aa_loaddata_alloc(alloc_size); + if (IS_ERR(data)) + return data; + + data->size = copy_size; + if (copy_from_user(data->data, userbuf, copy_size)) { + aa_put_loaddata(data); + return ERR_PTR(-EFAULT); + } + + return data; +} + +static ssize_t policy_update(u32 mask, const char __user *buf, size_t size, + loff_t *pos, struct aa_ns *ns) +{ + struct aa_loaddata *data; + struct aa_label *label; + ssize_t error; + + label = begin_current_label_crit_section(); + + /* high level check about policy management - fine grained in + * below after unpack + */ + error = aa_may_manage_policy(label, ns, mask); + if (error) + goto end_section; + + data = aa_simple_write_to_buffer(buf, size, size, pos); + error = PTR_ERR(data); + if (!IS_ERR(data)) { + error = aa_replace_profiles(ns, label, mask, data); + aa_put_loaddata(data); + } +end_section: + end_current_label_crit_section(label); + + return error; +} + +/* .load file hook fn to load policy */ +static ssize_t profile_load(struct file *f, const char __user *buf, size_t size, + loff_t *pos) +{ + struct aa_ns *ns = aa_get_ns(f->f_inode->i_private); + int error = policy_update(AA_MAY_LOAD_POLICY, buf, size, pos, ns); + + aa_put_ns(ns); + + return error; +} + +static const struct file_operations aa_fs_profile_load = { + .write = profile_load, + .llseek = default_llseek, +}; + +/* .replace file hook fn to load and/or replace policy */ +static ssize_t profile_replace(struct file *f, const char __user *buf, + size_t size, loff_t *pos) +{ + struct aa_ns *ns = aa_get_ns(f->f_inode->i_private); + int error = policy_update(AA_MAY_LOAD_POLICY | AA_MAY_REPLACE_POLICY, + buf, size, pos, ns); + aa_put_ns(ns); + + return error; +} + +static const struct file_operations aa_fs_profile_replace = { + .write = profile_replace, + .llseek = default_llseek, +}; + +/* .remove file hook fn to remove loaded policy */ +static ssize_t profile_remove(struct file *f, const char __user *buf, + size_t size, loff_t *pos) +{ + struct aa_loaddata *data; + struct aa_label *label; + ssize_t error; + struct aa_ns *ns = aa_get_ns(f->f_inode->i_private); + + label = begin_current_label_crit_section(); + /* high level check about policy management - fine grained in + * below after unpack + */ + error = aa_may_manage_policy(label, ns, AA_MAY_REMOVE_POLICY); + if (error) + goto out; + + /* + * aa_remove_profile needs a null terminated string so 1 extra + * byte is allocated and the copied data is null terminated. + */ + data = aa_simple_write_to_buffer(buf, size + 1, size, pos); + + error = PTR_ERR(data); + if (!IS_ERR(data)) { + data->data[size] = 0; + error = aa_remove_profiles(ns, label, data->data, size); + aa_put_loaddata(data); + } + out: + end_current_label_crit_section(label); + aa_put_ns(ns); + return error; +} + +static const struct file_operations aa_fs_profile_remove = { + .write = profile_remove, + .llseek = default_llseek, +}; + +struct aa_revision { + struct aa_ns *ns; + long last_read; +}; + +/* revision file hook fn for policy loads */ +static int ns_revision_release(struct inode *inode, struct file *file) +{ + struct aa_revision *rev = file->private_data; + + if (rev) { + aa_put_ns(rev->ns); + kfree(rev); + } + + return 0; +} + +static ssize_t ns_revision_read(struct file *file, char __user *buf, + size_t size, loff_t *ppos) +{ + struct aa_revision *rev = file->private_data; + char buffer[32]; + long last_read; + int avail; + + mutex_lock_nested(&rev->ns->lock, rev->ns->level); + last_read = rev->last_read; + if (last_read == rev->ns->revision) { + mutex_unlock(&rev->ns->lock); + if (file->f_flags & O_NONBLOCK) + return -EAGAIN; + if (wait_event_interruptible(rev->ns->wait, + last_read != + READ_ONCE(rev->ns->revision))) + return -ERESTARTSYS; + mutex_lock_nested(&rev->ns->lock, rev->ns->level); + } + + avail = sprintf(buffer, "%ld\n", rev->ns->revision); + if (*ppos + size > avail) { + rev->last_read = rev->ns->revision; + *ppos = 0; + } + mutex_unlock(&rev->ns->lock); + + return simple_read_from_buffer(buf, size, ppos, buffer, avail); +} + +static int ns_revision_open(struct inode *inode, struct file *file) +{ + struct aa_revision *rev = kzalloc(sizeof(*rev), GFP_KERNEL); + + if (!rev) + return -ENOMEM; + + rev->ns = aa_get_ns(inode->i_private); + if (!rev->ns) + rev->ns = aa_get_current_ns(); + file->private_data = rev; + + return 0; +} + +static __poll_t ns_revision_poll(struct file *file, poll_table *pt) +{ + struct aa_revision *rev = file->private_data; + __poll_t mask = 0; + + if (rev) { + mutex_lock_nested(&rev->ns->lock, rev->ns->level); + poll_wait(file, &rev->ns->wait, pt); + if (rev->last_read < rev->ns->revision) + mask |= EPOLLIN | EPOLLRDNORM; + mutex_unlock(&rev->ns->lock); + } + + return mask; +} + +void __aa_bump_ns_revision(struct aa_ns *ns) +{ + WRITE_ONCE(ns->revision, READ_ONCE(ns->revision) + 1); + wake_up_interruptible(&ns->wait); +} + +static const struct file_operations aa_fs_ns_revision_fops = { + .owner = THIS_MODULE, + .open = ns_revision_open, + .poll = ns_revision_poll, + .read = ns_revision_read, + .llseek = generic_file_llseek, + .release = ns_revision_release, +}; + +static void profile_query_cb(struct aa_profile *profile, struct aa_perms *perms, + const char *match_str, size_t match_len) +{ + struct aa_perms tmp = { }; + struct aa_dfa *dfa; + unsigned int state = 0; + + if (profile_unconfined(profile)) + return; + if (profile->file.dfa && *match_str == AA_CLASS_FILE) { + dfa = profile->file.dfa; + state = aa_dfa_match_len(dfa, profile->file.start, + match_str + 1, match_len - 1); + if (state) { + struct path_cond cond = { }; + + tmp = aa_compute_fperms(dfa, state, &cond); + } + } else if (profile->policy.dfa) { + if (!PROFILE_MEDIATES(profile, *match_str)) + return; /* no change to current perms */ + dfa = profile->policy.dfa; + state = aa_dfa_match_len(dfa, profile->policy.start[0], + match_str, match_len); + if (state) + aa_compute_perms(dfa, state, &tmp); + } + aa_apply_modes_to_perms(profile, &tmp); + aa_perms_accum_raw(perms, &tmp); +} + + +/** + * query_data - queries a policy and writes its data to buf + * @buf: the resulting data is stored here (NOT NULL) + * @buf_len: size of buf + * @query: query string used to retrieve data + * @query_len: size of query including second NUL byte + * + * The buffers pointed to by buf and query may overlap. The query buffer is + * parsed before buf is written to. + * + * The query should look like "<LABEL>\0<KEY>\0", where <LABEL> is the name of + * the security confinement context and <KEY> is the name of the data to + * retrieve. <LABEL> and <KEY> must not be NUL-terminated. + * + * Don't expect the contents of buf to be preserved on failure. + * + * Returns: number of characters written to buf or -errno on failure + */ +static ssize_t query_data(char *buf, size_t buf_len, + char *query, size_t query_len) +{ + char *out; + const char *key; + struct label_it i; + struct aa_label *label, *curr; + struct aa_profile *profile; + struct aa_data *data; + u32 bytes, blocks; + __le32 outle32; + + if (!query_len) + return -EINVAL; /* need a query */ + + key = query + strnlen(query, query_len) + 1; + if (key + 1 >= query + query_len) + return -EINVAL; /* not enough space for a non-empty key */ + if (key + strnlen(key, query + query_len - key) >= query + query_len) + return -EINVAL; /* must end with NUL */ + + if (buf_len < sizeof(bytes) + sizeof(blocks)) + return -EINVAL; /* not enough space */ + + curr = begin_current_label_crit_section(); + label = aa_label_parse(curr, query, GFP_KERNEL, false, false); + end_current_label_crit_section(curr); + if (IS_ERR(label)) + return PTR_ERR(label); + + /* We are going to leave space for two numbers. The first is the total + * number of bytes we are writing after the first number. This is so + * users can read the full output without reallocation. + * + * The second number is the number of data blocks we're writing. An + * application might be confined by multiple policies having data in + * the same key. + */ + memset(buf, 0, sizeof(bytes) + sizeof(blocks)); + out = buf + sizeof(bytes) + sizeof(blocks); + + blocks = 0; + label_for_each_confined(i, label, profile) { + if (!profile->data) + continue; + + data = rhashtable_lookup_fast(profile->data, &key, + profile->data->p); + + if (data) { + if (out + sizeof(outle32) + data->size > buf + + buf_len) { + aa_put_label(label); + return -EINVAL; /* not enough space */ + } + outle32 = __cpu_to_le32(data->size); + memcpy(out, &outle32, sizeof(outle32)); + out += sizeof(outle32); + memcpy(out, data->data, data->size); + out += data->size; + blocks++; + } + } + aa_put_label(label); + + outle32 = __cpu_to_le32(out - buf - sizeof(bytes)); + memcpy(buf, &outle32, sizeof(outle32)); + outle32 = __cpu_to_le32(blocks); + memcpy(buf + sizeof(bytes), &outle32, sizeof(outle32)); + + return out - buf; +} + +/** + * query_label - queries a label and writes permissions to buf + * @buf: the resulting permissions string is stored here (NOT NULL) + * @buf_len: size of buf + * @query: binary query string to match against the dfa + * @query_len: size of query + * @view_only: only compute for querier's view + * + * The buffers pointed to by buf and query may overlap. The query buffer is + * parsed before buf is written to. + * + * The query should look like "LABEL_NAME\0DFA_STRING" where LABEL_NAME is + * the name of the label, in the current namespace, that is to be queried and + * DFA_STRING is a binary string to match against the label(s)'s DFA. + * + * LABEL_NAME must be NUL terminated. DFA_STRING may contain NUL characters + * but must *not* be NUL terminated. + * + * Returns: number of characters written to buf or -errno on failure + */ +static ssize_t query_label(char *buf, size_t buf_len, + char *query, size_t query_len, bool view_only) +{ + struct aa_profile *profile; + struct aa_label *label, *curr; + char *label_name, *match_str; + size_t label_name_len, match_len; + struct aa_perms perms; + struct label_it i; + + if (!query_len) + return -EINVAL; + + label_name = query; + label_name_len = strnlen(query, query_len); + if (!label_name_len || label_name_len == query_len) + return -EINVAL; + + /** + * The extra byte is to account for the null byte between the + * profile name and dfa string. profile_name_len is greater + * than zero and less than query_len, so a byte can be safely + * added or subtracted. + */ + match_str = label_name + label_name_len + 1; + match_len = query_len - label_name_len - 1; + + curr = begin_current_label_crit_section(); + label = aa_label_parse(curr, label_name, GFP_KERNEL, false, false); + end_current_label_crit_section(curr); + if (IS_ERR(label)) + return PTR_ERR(label); + + perms = allperms; + if (view_only) { + label_for_each_in_ns(i, labels_ns(label), label, profile) { + profile_query_cb(profile, &perms, match_str, match_len); + } + } else { + label_for_each(i, label, profile) { + profile_query_cb(profile, &perms, match_str, match_len); + } + } + aa_put_label(label); + + return scnprintf(buf, buf_len, + "allow 0x%08x\ndeny 0x%08x\naudit 0x%08x\nquiet 0x%08x\n", + perms.allow, perms.deny, perms.audit, perms.quiet); +} + +/* + * Transaction based IO. + * The file expects a write which triggers the transaction, and then + * possibly a read(s) which collects the result - which is stored in a + * file-local buffer. Once a new write is performed, a new set of results + * are stored in the file-local buffer. + */ +struct multi_transaction { + struct kref count; + ssize_t size; + char data[]; +}; + +#define MULTI_TRANSACTION_LIMIT (PAGE_SIZE - sizeof(struct multi_transaction)) + +static void multi_transaction_kref(struct kref *kref) +{ + struct multi_transaction *t; + + t = container_of(kref, struct multi_transaction, count); + free_page((unsigned long) t); +} + +static struct multi_transaction * +get_multi_transaction(struct multi_transaction *t) +{ + if (t) + kref_get(&(t->count)); + + return t; +} + +static void put_multi_transaction(struct multi_transaction *t) +{ + if (t) + kref_put(&(t->count), multi_transaction_kref); +} + +/* does not increment @new's count */ +static void multi_transaction_set(struct file *file, + struct multi_transaction *new, size_t n) +{ + struct multi_transaction *old; + + AA_BUG(n > MULTI_TRANSACTION_LIMIT); + + new->size = n; + spin_lock(&file->f_lock); + old = (struct multi_transaction *) file->private_data; + file->private_data = new; + spin_unlock(&file->f_lock); + put_multi_transaction(old); +} + +static struct multi_transaction *multi_transaction_new(struct file *file, + const char __user *buf, + size_t size) +{ + struct multi_transaction *t; + + if (size > MULTI_TRANSACTION_LIMIT - 1) + return ERR_PTR(-EFBIG); + + t = (struct multi_transaction *)get_zeroed_page(GFP_KERNEL); + if (!t) + return ERR_PTR(-ENOMEM); + kref_init(&t->count); + if (copy_from_user(t->data, buf, size)) { + put_multi_transaction(t); + return ERR_PTR(-EFAULT); + } + + return t; +} + +static ssize_t multi_transaction_read(struct file *file, char __user *buf, + size_t size, loff_t *pos) +{ + struct multi_transaction *t; + ssize_t ret; + + spin_lock(&file->f_lock); + t = get_multi_transaction(file->private_data); + spin_unlock(&file->f_lock); + + if (!t) + return 0; + + ret = simple_read_from_buffer(buf, size, pos, t->data, t->size); + put_multi_transaction(t); + + return ret; +} + +static int multi_transaction_release(struct inode *inode, struct file *file) +{ + put_multi_transaction(file->private_data); + + return 0; +} + +#define QUERY_CMD_LABEL "label\0" +#define QUERY_CMD_LABEL_LEN 6 +#define QUERY_CMD_PROFILE "profile\0" +#define QUERY_CMD_PROFILE_LEN 8 +#define QUERY_CMD_LABELALL "labelall\0" +#define QUERY_CMD_LABELALL_LEN 9 +#define QUERY_CMD_DATA "data\0" +#define QUERY_CMD_DATA_LEN 5 + +/** + * aa_write_access - generic permissions and data query + * @file: pointer to open apparmorfs/access file + * @ubuf: user buffer containing the complete query string (NOT NULL) + * @count: size of ubuf + * @ppos: position in the file (MUST BE ZERO) + * + * Allows for one permissions or data query per open(), write(), and read() + * sequence. The only queries currently supported are label-based queries for + * permissions or data. + * + * For permissions queries, ubuf must begin with "label\0", followed by the + * profile query specific format described in the query_label() function + * documentation. + * + * For data queries, ubuf must have the form "data\0<LABEL>\0<KEY>\0", where + * <LABEL> is the name of the security confinement context and <KEY> is the + * name of the data to retrieve. + * + * Returns: number of bytes written or -errno on failure + */ +static ssize_t aa_write_access(struct file *file, const char __user *ubuf, + size_t count, loff_t *ppos) +{ + struct multi_transaction *t; + ssize_t len; + + if (*ppos) + return -ESPIPE; + + t = multi_transaction_new(file, ubuf, count); + if (IS_ERR(t)) + return PTR_ERR(t); + + if (count > QUERY_CMD_PROFILE_LEN && + !memcmp(t->data, QUERY_CMD_PROFILE, QUERY_CMD_PROFILE_LEN)) { + len = query_label(t->data, MULTI_TRANSACTION_LIMIT, + t->data + QUERY_CMD_PROFILE_LEN, + count - QUERY_CMD_PROFILE_LEN, true); + } else if (count > QUERY_CMD_LABEL_LEN && + !memcmp(t->data, QUERY_CMD_LABEL, QUERY_CMD_LABEL_LEN)) { + len = query_label(t->data, MULTI_TRANSACTION_LIMIT, + t->data + QUERY_CMD_LABEL_LEN, + count - QUERY_CMD_LABEL_LEN, true); + } else if (count > QUERY_CMD_LABELALL_LEN && + !memcmp(t->data, QUERY_CMD_LABELALL, + QUERY_CMD_LABELALL_LEN)) { + len = query_label(t->data, MULTI_TRANSACTION_LIMIT, + t->data + QUERY_CMD_LABELALL_LEN, + count - QUERY_CMD_LABELALL_LEN, false); + } else if (count > QUERY_CMD_DATA_LEN && + !memcmp(t->data, QUERY_CMD_DATA, QUERY_CMD_DATA_LEN)) { + len = query_data(t->data, MULTI_TRANSACTION_LIMIT, + t->data + QUERY_CMD_DATA_LEN, + count - QUERY_CMD_DATA_LEN); + } else + len = -EINVAL; + + if (len < 0) { + put_multi_transaction(t); + return len; + } + + multi_transaction_set(file, t, len); + + return count; +} + +static const struct file_operations aa_sfs_access = { + .write = aa_write_access, + .read = multi_transaction_read, + .release = multi_transaction_release, + .llseek = generic_file_llseek, +}; + +static int aa_sfs_seq_show(struct seq_file *seq, void *v) +{ + struct aa_sfs_entry *fs_file = seq->private; + + if (!fs_file) + return 0; + + switch (fs_file->v_type) { + case AA_SFS_TYPE_BOOLEAN: + seq_printf(seq, "%s\n", fs_file->v.boolean ? "yes" : "no"); + break; + case AA_SFS_TYPE_STRING: + seq_printf(seq, "%s\n", fs_file->v.string); + break; + case AA_SFS_TYPE_U64: + seq_printf(seq, "%#08lx\n", fs_file->v.u64); + break; + default: + /* Ignore unpritable entry types. */ + break; + } + + return 0; +} + +static int aa_sfs_seq_open(struct inode *inode, struct file *file) +{ + return single_open(file, aa_sfs_seq_show, inode->i_private); +} + +const struct file_operations aa_sfs_seq_file_ops = { + .owner = THIS_MODULE, + .open = aa_sfs_seq_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +/* + * profile based file operations + * policy/profiles/XXXX/profiles/ * + */ + +#define SEQ_PROFILE_FOPS(NAME) \ +static int seq_profile_ ##NAME ##_open(struct inode *inode, struct file *file)\ +{ \ + return seq_profile_open(inode, file, seq_profile_ ##NAME ##_show); \ +} \ + \ +static const struct file_operations seq_profile_ ##NAME ##_fops = { \ + .owner = THIS_MODULE, \ + .open = seq_profile_ ##NAME ##_open, \ + .read = seq_read, \ + .llseek = seq_lseek, \ + .release = seq_profile_release, \ +} \ + +static int seq_profile_open(struct inode *inode, struct file *file, + int (*show)(struct seq_file *, void *)) +{ + struct aa_proxy *proxy = aa_get_proxy(inode->i_private); + int error = single_open(file, show, proxy); + + if (error) { + file->private_data = NULL; + aa_put_proxy(proxy); + } + + return error; +} + +static int seq_profile_release(struct inode *inode, struct file *file) +{ + struct seq_file *seq = (struct seq_file *) file->private_data; + if (seq) + aa_put_proxy(seq->private); + return single_release(inode, file); +} + +static int seq_profile_name_show(struct seq_file *seq, void *v) +{ + struct aa_proxy *proxy = seq->private; + struct aa_label *label = aa_get_label_rcu(&proxy->label); + struct aa_profile *profile = labels_profile(label); + seq_printf(seq, "%s\n", profile->base.name); + aa_put_label(label); + + return 0; +} + +static int seq_profile_mode_show(struct seq_file *seq, void *v) +{ + struct aa_proxy *proxy = seq->private; + struct aa_label *label = aa_get_label_rcu(&proxy->label); + struct aa_profile *profile = labels_profile(label); + seq_printf(seq, "%s\n", aa_profile_mode_names[profile->mode]); + aa_put_label(label); + + return 0; +} + +static int seq_profile_attach_show(struct seq_file *seq, void *v) +{ + struct aa_proxy *proxy = seq->private; + struct aa_label *label = aa_get_label_rcu(&proxy->label); + struct aa_profile *profile = labels_profile(label); + if (profile->attach) + seq_printf(seq, "%s\n", profile->attach); + else if (profile->xmatch) + seq_puts(seq, "<unknown>\n"); + else + seq_printf(seq, "%s\n", profile->base.name); + aa_put_label(label); + + return 0; +} + +static int seq_profile_hash_show(struct seq_file *seq, void *v) +{ + struct aa_proxy *proxy = seq->private; + struct aa_label *label = aa_get_label_rcu(&proxy->label); + struct aa_profile *profile = labels_profile(label); + unsigned int i, size = aa_hash_size(); + + if (profile->hash) { + for (i = 0; i < size; i++) + seq_printf(seq, "%.2x", profile->hash[i]); + seq_putc(seq, '\n'); + } + aa_put_label(label); + + return 0; +} + +SEQ_PROFILE_FOPS(name); +SEQ_PROFILE_FOPS(mode); +SEQ_PROFILE_FOPS(attach); +SEQ_PROFILE_FOPS(hash); + +/* + * namespace based files + * several root files and + * policy/ * + */ + +#define SEQ_NS_FOPS(NAME) \ +static int seq_ns_ ##NAME ##_open(struct inode *inode, struct file *file) \ +{ \ + return single_open(file, seq_ns_ ##NAME ##_show, inode->i_private); \ +} \ + \ +static const struct file_operations seq_ns_ ##NAME ##_fops = { \ + .owner = THIS_MODULE, \ + .open = seq_ns_ ##NAME ##_open, \ + .read = seq_read, \ + .llseek = seq_lseek, \ + .release = single_release, \ +} \ + +static int seq_ns_stacked_show(struct seq_file *seq, void *v) +{ + struct aa_label *label; + + label = begin_current_label_crit_section(); + seq_printf(seq, "%s\n", label->size > 1 ? "yes" : "no"); + end_current_label_crit_section(label); + + return 0; +} + +static int seq_ns_nsstacked_show(struct seq_file *seq, void *v) +{ + struct aa_label *label; + struct aa_profile *profile; + struct label_it it; + int count = 1; + + label = begin_current_label_crit_section(); + + if (label->size > 1) { + label_for_each(it, label, profile) + if (profile->ns != labels_ns(label)) { + count++; + break; + } + } + + seq_printf(seq, "%s\n", count > 1 ? "yes" : "no"); + end_current_label_crit_section(label); + + return 0; +} + +static int seq_ns_level_show(struct seq_file *seq, void *v) +{ + struct aa_label *label; + + label = begin_current_label_crit_section(); + seq_printf(seq, "%d\n", labels_ns(label)->level); + end_current_label_crit_section(label); + + return 0; +} + +static int seq_ns_name_show(struct seq_file *seq, void *v) +{ + struct aa_label *label = begin_current_label_crit_section(); + seq_printf(seq, "%s\n", labels_ns(label)->base.name); + end_current_label_crit_section(label); + + return 0; +} + +SEQ_NS_FOPS(stacked); +SEQ_NS_FOPS(nsstacked); +SEQ_NS_FOPS(level); +SEQ_NS_FOPS(name); + + +/* policy/raw_data/ * file ops */ +#ifdef CONFIG_SECURITY_APPARMOR_EXPORT_BINARY +#define SEQ_RAWDATA_FOPS(NAME) \ +static int seq_rawdata_ ##NAME ##_open(struct inode *inode, struct file *file)\ +{ \ + return seq_rawdata_open(inode, file, seq_rawdata_ ##NAME ##_show); \ +} \ + \ +static const struct file_operations seq_rawdata_ ##NAME ##_fops = { \ + .owner = THIS_MODULE, \ + .open = seq_rawdata_ ##NAME ##_open, \ + .read = seq_read, \ + .llseek = seq_lseek, \ + .release = seq_rawdata_release, \ +} \ + +static int seq_rawdata_open(struct inode *inode, struct file *file, + int (*show)(struct seq_file *, void *)) +{ + struct aa_loaddata *data = __aa_get_loaddata(inode->i_private); + int error; + + if (!data) + /* lost race this ent is being reaped */ + return -ENOENT; + + error = single_open(file, show, data); + if (error) { + AA_BUG(file->private_data && + ((struct seq_file *)file->private_data)->private); + aa_put_loaddata(data); + } + + return error; +} + +static int seq_rawdata_release(struct inode *inode, struct file *file) +{ + struct seq_file *seq = (struct seq_file *) file->private_data; + + if (seq) + aa_put_loaddata(seq->private); + + return single_release(inode, file); +} + +static int seq_rawdata_abi_show(struct seq_file *seq, void *v) +{ + struct aa_loaddata *data = seq->private; + + seq_printf(seq, "v%d\n", data->abi); + + return 0; +} + +static int seq_rawdata_revision_show(struct seq_file *seq, void *v) +{ + struct aa_loaddata *data = seq->private; + + seq_printf(seq, "%ld\n", data->revision); + + return 0; +} + +static int seq_rawdata_hash_show(struct seq_file *seq, void *v) +{ + struct aa_loaddata *data = seq->private; + unsigned int i, size = aa_hash_size(); + + if (data->hash) { + for (i = 0; i < size; i++) + seq_printf(seq, "%.2x", data->hash[i]); + seq_putc(seq, '\n'); + } + + return 0; +} + +static int seq_rawdata_compressed_size_show(struct seq_file *seq, void *v) +{ + struct aa_loaddata *data = seq->private; + + seq_printf(seq, "%zu\n", data->compressed_size); + + return 0; +} + +SEQ_RAWDATA_FOPS(abi); +SEQ_RAWDATA_FOPS(revision); +SEQ_RAWDATA_FOPS(hash); +SEQ_RAWDATA_FOPS(compressed_size); + +static int deflate_decompress(char *src, size_t slen, char *dst, size_t dlen) +{ +#ifdef CONFIG_SECURITY_APPARMOR_EXPORT_BINARY + if (aa_g_rawdata_compression_level != 0) { + int error = 0; + struct z_stream_s strm; + + memset(&strm, 0, sizeof(strm)); + + strm.workspace = kvzalloc(zlib_inflate_workspacesize(), GFP_KERNEL); + if (!strm.workspace) + return -ENOMEM; + + strm.next_in = src; + strm.avail_in = slen; + + error = zlib_inflateInit(&strm); + if (error != Z_OK) { + error = -ENOMEM; + goto fail_inflate_init; + } + + strm.next_out = dst; + strm.avail_out = dlen; + + error = zlib_inflate(&strm, Z_FINISH); + if (error != Z_STREAM_END) + error = -EINVAL; + else + error = 0; + + zlib_inflateEnd(&strm); +fail_inflate_init: + kvfree(strm.workspace); + + return error; + } +#endif + + if (dlen < slen) + return -EINVAL; + memcpy(dst, src, slen); + return 0; +} + +static ssize_t rawdata_read(struct file *file, char __user *buf, size_t size, + loff_t *ppos) +{ + struct rawdata_f_data *private = file->private_data; + + return simple_read_from_buffer(buf, size, ppos, + RAWDATA_F_DATA_BUF(private), + private->loaddata->size); +} + +static int rawdata_release(struct inode *inode, struct file *file) +{ + rawdata_f_data_free(file->private_data); + + return 0; +} + +static int rawdata_open(struct inode *inode, struct file *file) +{ + int error; + struct aa_loaddata *loaddata; + struct rawdata_f_data *private; + + if (!aa_current_policy_view_capable(NULL)) + return -EACCES; + + loaddata = __aa_get_loaddata(inode->i_private); + if (!loaddata) + /* lost race: this entry is being reaped */ + return -ENOENT; + + private = rawdata_f_data_alloc(loaddata->size); + if (IS_ERR(private)) { + error = PTR_ERR(private); + goto fail_private_alloc; + } + + private->loaddata = loaddata; + + error = deflate_decompress(loaddata->data, loaddata->compressed_size, + RAWDATA_F_DATA_BUF(private), + loaddata->size); + if (error) + goto fail_decompress; + + file->private_data = private; + return 0; + +fail_decompress: + rawdata_f_data_free(private); + return error; + +fail_private_alloc: + aa_put_loaddata(loaddata); + return error; +} + +static const struct file_operations rawdata_fops = { + .open = rawdata_open, + .read = rawdata_read, + .llseek = generic_file_llseek, + .release = rawdata_release, +}; + +static void remove_rawdata_dents(struct aa_loaddata *rawdata) +{ + int i; + + for (i = 0; i < AAFS_LOADDATA_NDENTS; i++) { + if (!IS_ERR_OR_NULL(rawdata->dents[i])) { + /* no refcounts on i_private */ + aafs_remove(rawdata->dents[i]); + rawdata->dents[i] = NULL; + } + } +} + +void __aa_fs_remove_rawdata(struct aa_loaddata *rawdata) +{ + AA_BUG(rawdata->ns && !mutex_is_locked(&rawdata->ns->lock)); + + if (rawdata->ns) { + remove_rawdata_dents(rawdata); + list_del_init(&rawdata->list); + aa_put_ns(rawdata->ns); + rawdata->ns = NULL; + } +} + +int __aa_fs_create_rawdata(struct aa_ns *ns, struct aa_loaddata *rawdata) +{ + struct dentry *dent, *dir; + + AA_BUG(!ns); + AA_BUG(!rawdata); + AA_BUG(!mutex_is_locked(&ns->lock)); + AA_BUG(!ns_subdata_dir(ns)); + + /* + * just use ns revision dir was originally created at. This is + * under ns->lock and if load is successful revision will be + * bumped and is guaranteed to be unique + */ + rawdata->name = kasprintf(GFP_KERNEL, "%ld", ns->revision); + if (!rawdata->name) + return -ENOMEM; + + dir = aafs_create_dir(rawdata->name, ns_subdata_dir(ns)); + if (IS_ERR(dir)) + /* ->name freed when rawdata freed */ + return PTR_ERR(dir); + rawdata->dents[AAFS_LOADDATA_DIR] = dir; + + dent = aafs_create_file("abi", S_IFREG | 0444, dir, rawdata, + &seq_rawdata_abi_fops); + if (IS_ERR(dent)) + goto fail; + rawdata->dents[AAFS_LOADDATA_ABI] = dent; + + dent = aafs_create_file("revision", S_IFREG | 0444, dir, rawdata, + &seq_rawdata_revision_fops); + if (IS_ERR(dent)) + goto fail; + rawdata->dents[AAFS_LOADDATA_REVISION] = dent; + + if (aa_g_hash_policy) { + dent = aafs_create_file("sha1", S_IFREG | 0444, dir, + rawdata, &seq_rawdata_hash_fops); + if (IS_ERR(dent)) + goto fail; + rawdata->dents[AAFS_LOADDATA_HASH] = dent; + } + + dent = aafs_create_file("compressed_size", S_IFREG | 0444, dir, + rawdata, + &seq_rawdata_compressed_size_fops); + if (IS_ERR(dent)) + goto fail; + rawdata->dents[AAFS_LOADDATA_COMPRESSED_SIZE] = dent; + + dent = aafs_create_file("raw_data", S_IFREG | 0444, + dir, rawdata, &rawdata_fops); + if (IS_ERR(dent)) + goto fail; + rawdata->dents[AAFS_LOADDATA_DATA] = dent; + d_inode(dent)->i_size = rawdata->size; + + rawdata->ns = aa_get_ns(ns); + list_add(&rawdata->list, &ns->rawdata_list); + /* no refcount on inode rawdata */ + + return 0; + +fail: + remove_rawdata_dents(rawdata); + + return PTR_ERR(dent); +} +#endif /* CONFIG_SECURITY_APPARMOR_EXPORT_BINARY */ + + +/** fns to setup dynamic per profile/namespace files **/ + +/* + * + * Requires: @profile->ns->lock held + */ +void __aafs_profile_rmdir(struct aa_profile *profile) +{ + struct aa_profile *child; + int i; + + if (!profile) + return; + + list_for_each_entry(child, &profile->base.profiles, base.list) + __aafs_profile_rmdir(child); + + for (i = AAFS_PROF_SIZEOF - 1; i >= 0; --i) { + struct aa_proxy *proxy; + if (!profile->dents[i]) + continue; + + proxy = d_inode(profile->dents[i])->i_private; + aafs_remove(profile->dents[i]); + aa_put_proxy(proxy); + profile->dents[i] = NULL; + } +} + +/* + * + * Requires: @old->ns->lock held + */ +void __aafs_profile_migrate_dents(struct aa_profile *old, + struct aa_profile *new) +{ + int i; + + AA_BUG(!old); + AA_BUG(!new); + AA_BUG(!mutex_is_locked(&profiles_ns(old)->lock)); + + for (i = 0; i < AAFS_PROF_SIZEOF; i++) { + new->dents[i] = old->dents[i]; + if (new->dents[i]) + new->dents[i]->d_inode->i_mtime = current_time(new->dents[i]->d_inode); + old->dents[i] = NULL; + } +} + +static struct dentry *create_profile_file(struct dentry *dir, const char *name, + struct aa_profile *profile, + const struct file_operations *fops) +{ + struct aa_proxy *proxy = aa_get_proxy(profile->label.proxy); + struct dentry *dent; + + dent = aafs_create_file(name, S_IFREG | 0444, dir, proxy, fops); + if (IS_ERR(dent)) + aa_put_proxy(proxy); + + return dent; +} + +#ifdef CONFIG_SECURITY_APPARMOR_EXPORT_BINARY +static int profile_depth(struct aa_profile *profile) +{ + int depth = 0; + + rcu_read_lock(); + for (depth = 0; profile; profile = rcu_access_pointer(profile->parent)) + depth++; + rcu_read_unlock(); + + return depth; +} + +static char *gen_symlink_name(int depth, const char *dirname, const char *fname) +{ + char *buffer, *s; + int error; + int size = depth * 6 + strlen(dirname) + strlen(fname) + 11; + + s = buffer = kmalloc(size, GFP_KERNEL); + if (!buffer) + return ERR_PTR(-ENOMEM); + + for (; depth > 0; depth--) { + strcpy(s, "../../"); + s += 6; + size -= 6; + } + + error = snprintf(s, size, "raw_data/%s/%s", dirname, fname); + if (error >= size || error < 0) { + kfree(buffer); + return ERR_PTR(-ENAMETOOLONG); + } + + return buffer; +} + +static void rawdata_link_cb(void *arg) +{ + kfree(arg); +} + +static const char *rawdata_get_link_base(struct dentry *dentry, + struct inode *inode, + struct delayed_call *done, + const char *name) +{ + struct aa_proxy *proxy = inode->i_private; + struct aa_label *label; + struct aa_profile *profile; + char *target; + int depth; + + if (!dentry) + return ERR_PTR(-ECHILD); + + label = aa_get_label_rcu(&proxy->label); + profile = labels_profile(label); + depth = profile_depth(profile); + target = gen_symlink_name(depth, profile->rawdata->name, name); + aa_put_label(label); + + if (IS_ERR(target)) + return target; + + set_delayed_call(done, rawdata_link_cb, target); + + return target; +} + +static const char *rawdata_get_link_sha1(struct dentry *dentry, + struct inode *inode, + struct delayed_call *done) +{ + return rawdata_get_link_base(dentry, inode, done, "sha1"); +} + +static const char *rawdata_get_link_abi(struct dentry *dentry, + struct inode *inode, + struct delayed_call *done) +{ + return rawdata_get_link_base(dentry, inode, done, "abi"); +} + +static const char *rawdata_get_link_data(struct dentry *dentry, + struct inode *inode, + struct delayed_call *done) +{ + return rawdata_get_link_base(dentry, inode, done, "raw_data"); +} + +static const struct inode_operations rawdata_link_sha1_iops = { + .get_link = rawdata_get_link_sha1, +}; + +static const struct inode_operations rawdata_link_abi_iops = { + .get_link = rawdata_get_link_abi, +}; +static const struct inode_operations rawdata_link_data_iops = { + .get_link = rawdata_get_link_data, +}; +#endif /* CONFIG_SECURITY_APPARMOR_EXPORT_BINARY */ + +/* + * Requires: @profile->ns->lock held + */ +int __aafs_profile_mkdir(struct aa_profile *profile, struct dentry *parent) +{ + struct aa_profile *child; + struct dentry *dent = NULL, *dir; + int error; + + AA_BUG(!profile); + AA_BUG(!mutex_is_locked(&profiles_ns(profile)->lock)); + + if (!parent) { + struct aa_profile *p; + p = aa_deref_parent(profile); + dent = prof_dir(p); + /* adding to parent that previously didn't have children */ + dent = aafs_create_dir("profiles", dent); + if (IS_ERR(dent)) + goto fail; + prof_child_dir(p) = parent = dent; + } + + if (!profile->dirname) { + int len, id_len; + len = mangle_name(profile->base.name, NULL); + id_len = snprintf(NULL, 0, ".%ld", profile->ns->uniq_id); + + profile->dirname = kmalloc(len + id_len + 1, GFP_KERNEL); + if (!profile->dirname) { + error = -ENOMEM; + goto fail2; + } + + mangle_name(profile->base.name, profile->dirname); + sprintf(profile->dirname + len, ".%ld", profile->ns->uniq_id++); + } + + dent = aafs_create_dir(profile->dirname, parent); + if (IS_ERR(dent)) + goto fail; + prof_dir(profile) = dir = dent; + + dent = create_profile_file(dir, "name", profile, + &seq_profile_name_fops); + if (IS_ERR(dent)) + goto fail; + profile->dents[AAFS_PROF_NAME] = dent; + + dent = create_profile_file(dir, "mode", profile, + &seq_profile_mode_fops); + if (IS_ERR(dent)) + goto fail; + profile->dents[AAFS_PROF_MODE] = dent; + + dent = create_profile_file(dir, "attach", profile, + &seq_profile_attach_fops); + if (IS_ERR(dent)) + goto fail; + profile->dents[AAFS_PROF_ATTACH] = dent; + + if (profile->hash) { + dent = create_profile_file(dir, "sha1", profile, + &seq_profile_hash_fops); + if (IS_ERR(dent)) + goto fail; + profile->dents[AAFS_PROF_HASH] = dent; + } + +#ifdef CONFIG_SECURITY_APPARMOR_EXPORT_BINARY + if (profile->rawdata) { + if (aa_g_hash_policy) { + dent = aafs_create("raw_sha1", S_IFLNK | 0444, dir, + profile->label.proxy, NULL, NULL, + &rawdata_link_sha1_iops); + if (IS_ERR(dent)) + goto fail; + aa_get_proxy(profile->label.proxy); + profile->dents[AAFS_PROF_RAW_HASH] = dent; + } + dent = aafs_create("raw_abi", S_IFLNK | 0444, dir, + profile->label.proxy, NULL, NULL, + &rawdata_link_abi_iops); + if (IS_ERR(dent)) + goto fail; + aa_get_proxy(profile->label.proxy); + profile->dents[AAFS_PROF_RAW_ABI] = dent; + + dent = aafs_create("raw_data", S_IFLNK | 0444, dir, + profile->label.proxy, NULL, NULL, + &rawdata_link_data_iops); + if (IS_ERR(dent)) + goto fail; + aa_get_proxy(profile->label.proxy); + profile->dents[AAFS_PROF_RAW_DATA] = dent; + } +#endif /*CONFIG_SECURITY_APPARMOR_EXPORT_BINARY */ + + list_for_each_entry(child, &profile->base.profiles, base.list) { + error = __aafs_profile_mkdir(child, prof_child_dir(profile)); + if (error) + goto fail2; + } + + return 0; + +fail: + error = PTR_ERR(dent); + +fail2: + __aafs_profile_rmdir(profile); + + return error; +} + +static int ns_mkdir_op(struct user_namespace *mnt_userns, struct inode *dir, + struct dentry *dentry, umode_t mode) +{ + struct aa_ns *ns, *parent; + /* TODO: improve permission check */ + struct aa_label *label; + int error; + + label = begin_current_label_crit_section(); + error = aa_may_manage_policy(label, NULL, AA_MAY_LOAD_POLICY); + end_current_label_crit_section(label); + if (error) + return error; + + parent = aa_get_ns(dir->i_private); + AA_BUG(d_inode(ns_subns_dir(parent)) != dir); + + /* we have to unlock and then relock to get locking order right + * for pin_fs + */ + inode_unlock(dir); + error = simple_pin_fs(&aafs_ops, &aafs_mnt, &aafs_count); + mutex_lock_nested(&parent->lock, parent->level); + inode_lock_nested(dir, I_MUTEX_PARENT); + if (error) + goto out; + + error = __aafs_setup_d_inode(dir, dentry, mode | S_IFDIR, NULL, + NULL, NULL, NULL); + if (error) + goto out_pin; + + ns = __aa_find_or_create_ns(parent, READ_ONCE(dentry->d_name.name), + dentry); + if (IS_ERR(ns)) { + error = PTR_ERR(ns); + ns = NULL; + } + + aa_put_ns(ns); /* list ref remains */ +out_pin: + if (error) + simple_release_fs(&aafs_mnt, &aafs_count); +out: + mutex_unlock(&parent->lock); + aa_put_ns(parent); + + return error; +} + +static int ns_rmdir_op(struct inode *dir, struct dentry *dentry) +{ + struct aa_ns *ns, *parent; + /* TODO: improve permission check */ + struct aa_label *label; + int error; + + label = begin_current_label_crit_section(); + error = aa_may_manage_policy(label, NULL, AA_MAY_LOAD_POLICY); + end_current_label_crit_section(label); + if (error) + return error; + + parent = aa_get_ns(dir->i_private); + /* rmdir calls the generic securityfs functions to remove files + * from the apparmor dir. It is up to the apparmor ns locking + * to avoid races. + */ + inode_unlock(dir); + inode_unlock(dentry->d_inode); + + mutex_lock_nested(&parent->lock, parent->level); + ns = aa_get_ns(__aa_findn_ns(&parent->sub_ns, dentry->d_name.name, + dentry->d_name.len)); + if (!ns) { + error = -ENOENT; + goto out; + } + AA_BUG(ns_dir(ns) != dentry); + + __aa_remove_ns(ns); + aa_put_ns(ns); + +out: + mutex_unlock(&parent->lock); + inode_lock_nested(dir, I_MUTEX_PARENT); + inode_lock(dentry->d_inode); + aa_put_ns(parent); + + return error; +} + +static const struct inode_operations ns_dir_inode_operations = { + .lookup = simple_lookup, + .mkdir = ns_mkdir_op, + .rmdir = ns_rmdir_op, +}; + +static void __aa_fs_list_remove_rawdata(struct aa_ns *ns) +{ + struct aa_loaddata *ent, *tmp; + + AA_BUG(!mutex_is_locked(&ns->lock)); + + list_for_each_entry_safe(ent, tmp, &ns->rawdata_list, list) + __aa_fs_remove_rawdata(ent); +} + +/* + * + * Requires: @ns->lock held + */ +void __aafs_ns_rmdir(struct aa_ns *ns) +{ + struct aa_ns *sub; + struct aa_profile *child; + int i; + + if (!ns) + return; + AA_BUG(!mutex_is_locked(&ns->lock)); + + list_for_each_entry(child, &ns->base.profiles, base.list) + __aafs_profile_rmdir(child); + + list_for_each_entry(sub, &ns->sub_ns, base.list) { + mutex_lock_nested(&sub->lock, sub->level); + __aafs_ns_rmdir(sub); + mutex_unlock(&sub->lock); + } + + __aa_fs_list_remove_rawdata(ns); + + if (ns_subns_dir(ns)) { + sub = d_inode(ns_subns_dir(ns))->i_private; + aa_put_ns(sub); + } + if (ns_subload(ns)) { + sub = d_inode(ns_subload(ns))->i_private; + aa_put_ns(sub); + } + if (ns_subreplace(ns)) { + sub = d_inode(ns_subreplace(ns))->i_private; + aa_put_ns(sub); + } + if (ns_subremove(ns)) { + sub = d_inode(ns_subremove(ns))->i_private; + aa_put_ns(sub); + } + if (ns_subrevision(ns)) { + sub = d_inode(ns_subrevision(ns))->i_private; + aa_put_ns(sub); + } + + for (i = AAFS_NS_SIZEOF - 1; i >= 0; --i) { + aafs_remove(ns->dents[i]); + ns->dents[i] = NULL; + } +} + +/* assumes cleanup in caller */ +static int __aafs_ns_mkdir_entries(struct aa_ns *ns, struct dentry *dir) +{ + struct dentry *dent; + + AA_BUG(!ns); + AA_BUG(!dir); + + dent = aafs_create_dir("profiles", dir); + if (IS_ERR(dent)) + return PTR_ERR(dent); + ns_subprofs_dir(ns) = dent; + + dent = aafs_create_dir("raw_data", dir); + if (IS_ERR(dent)) + return PTR_ERR(dent); + ns_subdata_dir(ns) = dent; + + dent = aafs_create_file("revision", 0444, dir, ns, + &aa_fs_ns_revision_fops); + if (IS_ERR(dent)) + return PTR_ERR(dent); + aa_get_ns(ns); + ns_subrevision(ns) = dent; + + dent = aafs_create_file(".load", 0640, dir, ns, + &aa_fs_profile_load); + if (IS_ERR(dent)) + return PTR_ERR(dent); + aa_get_ns(ns); + ns_subload(ns) = dent; + + dent = aafs_create_file(".replace", 0640, dir, ns, + &aa_fs_profile_replace); + if (IS_ERR(dent)) + return PTR_ERR(dent); + aa_get_ns(ns); + ns_subreplace(ns) = dent; + + dent = aafs_create_file(".remove", 0640, dir, ns, + &aa_fs_profile_remove); + if (IS_ERR(dent)) + return PTR_ERR(dent); + aa_get_ns(ns); + ns_subremove(ns) = dent; + + /* use create_dentry so we can supply private data */ + dent = aafs_create("namespaces", S_IFDIR | 0755, dir, ns, NULL, NULL, + &ns_dir_inode_operations); + if (IS_ERR(dent)) + return PTR_ERR(dent); + aa_get_ns(ns); + ns_subns_dir(ns) = dent; + + return 0; +} + +/* + * Requires: @ns->lock held + */ +int __aafs_ns_mkdir(struct aa_ns *ns, struct dentry *parent, const char *name, + struct dentry *dent) +{ + struct aa_ns *sub; + struct aa_profile *child; + struct dentry *dir; + int error; + + AA_BUG(!ns); + AA_BUG(!parent); + AA_BUG(!mutex_is_locked(&ns->lock)); + + if (!name) + name = ns->base.name; + + if (!dent) { + /* create ns dir if it doesn't already exist */ + dent = aafs_create_dir(name, parent); + if (IS_ERR(dent)) + goto fail; + } else + dget(dent); + ns_dir(ns) = dir = dent; + error = __aafs_ns_mkdir_entries(ns, dir); + if (error) + goto fail2; + + /* profiles */ + list_for_each_entry(child, &ns->base.profiles, base.list) { + error = __aafs_profile_mkdir(child, ns_subprofs_dir(ns)); + if (error) + goto fail2; + } + + /* subnamespaces */ + list_for_each_entry(sub, &ns->sub_ns, base.list) { + mutex_lock_nested(&sub->lock, sub->level); + error = __aafs_ns_mkdir(sub, ns_subns_dir(ns), NULL, NULL); + mutex_unlock(&sub->lock); + if (error) + goto fail2; + } + + return 0; + +fail: + error = PTR_ERR(dent); + +fail2: + __aafs_ns_rmdir(ns); + + return error; +} + +/** + * __next_ns - find the next namespace to list + * @root: root namespace to stop search at (NOT NULL) + * @ns: current ns position (NOT NULL) + * + * Find the next namespace from @ns under @root and handle all locking needed + * while switching current namespace. + * + * Returns: next namespace or NULL if at last namespace under @root + * Requires: ns->parent->lock to be held + * NOTE: will not unlock root->lock + */ +static struct aa_ns *__next_ns(struct aa_ns *root, struct aa_ns *ns) +{ + struct aa_ns *parent, *next; + + AA_BUG(!root); + AA_BUG(!ns); + AA_BUG(ns != root && !mutex_is_locked(&ns->parent->lock)); + + /* is next namespace a child */ + if (!list_empty(&ns->sub_ns)) { + next = list_first_entry(&ns->sub_ns, typeof(*ns), base.list); + mutex_lock_nested(&next->lock, next->level); + return next; + } + + /* check if the next ns is a sibling, parent, gp, .. */ + parent = ns->parent; + while (ns != root) { + mutex_unlock(&ns->lock); + next = list_next_entry(ns, base.list); + if (!list_entry_is_head(next, &parent->sub_ns, base.list)) { + mutex_lock_nested(&next->lock, next->level); + return next; + } + ns = parent; + parent = parent->parent; + } + + return NULL; +} + +/** + * __first_profile - find the first profile in a namespace + * @root: namespace that is root of profiles being displayed (NOT NULL) + * @ns: namespace to start in (NOT NULL) + * + * Returns: unrefcounted profile or NULL if no profile + * Requires: profile->ns.lock to be held + */ +static struct aa_profile *__first_profile(struct aa_ns *root, + struct aa_ns *ns) +{ + AA_BUG(!root); + AA_BUG(ns && !mutex_is_locked(&ns->lock)); + + for (; ns; ns = __next_ns(root, ns)) { + if (!list_empty(&ns->base.profiles)) + return list_first_entry(&ns->base.profiles, + struct aa_profile, base.list); + } + return NULL; +} + +/** + * __next_profile - step to the next profile in a profile tree + * @p: current profile in tree (NOT NULL) + * + * Perform a depth first traversal on the profile tree in a namespace + * + * Returns: next profile or NULL if done + * Requires: profile->ns.lock to be held + */ +static struct aa_profile *__next_profile(struct aa_profile *p) +{ + struct aa_profile *parent; + struct aa_ns *ns = p->ns; + + AA_BUG(!mutex_is_locked(&profiles_ns(p)->lock)); + + /* is next profile a child */ + if (!list_empty(&p->base.profiles)) + return list_first_entry(&p->base.profiles, typeof(*p), + base.list); + + /* is next profile a sibling, parent sibling, gp, sibling, .. */ + parent = rcu_dereference_protected(p->parent, + mutex_is_locked(&p->ns->lock)); + while (parent) { + p = list_next_entry(p, base.list); + if (!list_entry_is_head(p, &parent->base.profiles, base.list)) + return p; + p = parent; + parent = rcu_dereference_protected(parent->parent, + mutex_is_locked(&parent->ns->lock)); + } + + /* is next another profile in the namespace */ + p = list_next_entry(p, base.list); + if (!list_entry_is_head(p, &ns->base.profiles, base.list)) + return p; + + return NULL; +} + +/** + * next_profile - step to the next profile in where ever it may be + * @root: root namespace (NOT NULL) + * @profile: current profile (NOT NULL) + * + * Returns: next profile or NULL if there isn't one + */ +static struct aa_profile *next_profile(struct aa_ns *root, + struct aa_profile *profile) +{ + struct aa_profile *next = __next_profile(profile); + if (next) + return next; + + /* finished all profiles in namespace move to next namespace */ + return __first_profile(root, __next_ns(root, profile->ns)); +} + +/** + * p_start - start a depth first traversal of profile tree + * @f: seq_file to fill + * @pos: current position + * + * Returns: first profile under current namespace or NULL if none found + * + * acquires first ns->lock + */ +static void *p_start(struct seq_file *f, loff_t *pos) +{ + struct aa_profile *profile = NULL; + struct aa_ns *root = aa_get_current_ns(); + loff_t l = *pos; + f->private = root; + + /* find the first profile */ + mutex_lock_nested(&root->lock, root->level); + profile = __first_profile(root, root); + + /* skip to position */ + for (; profile && l > 0; l--) + profile = next_profile(root, profile); + + return profile; +} + +/** + * p_next - read the next profile entry + * @f: seq_file to fill + * @p: profile previously returned + * @pos: current position + * + * Returns: next profile after @p or NULL if none + * + * may acquire/release locks in namespace tree as necessary + */ +static void *p_next(struct seq_file *f, void *p, loff_t *pos) +{ + struct aa_profile *profile = p; + struct aa_ns *ns = f->private; + (*pos)++; + + return next_profile(ns, profile); +} + +/** + * p_stop - stop depth first traversal + * @f: seq_file we are filling + * @p: the last profile writen + * + * Release all locking done by p_start/p_next on namespace tree + */ +static void p_stop(struct seq_file *f, void *p) +{ + struct aa_profile *profile = p; + struct aa_ns *root = f->private, *ns; + + if (profile) { + for (ns = profile->ns; ns && ns != root; ns = ns->parent) + mutex_unlock(&ns->lock); + } + mutex_unlock(&root->lock); + aa_put_ns(root); +} + +/** + * seq_show_profile - show a profile entry + * @f: seq_file to file + * @p: current position (profile) (NOT NULL) + * + * Returns: error on failure + */ +static int seq_show_profile(struct seq_file *f, void *p) +{ + struct aa_profile *profile = (struct aa_profile *)p; + struct aa_ns *root = f->private; + + aa_label_seq_xprint(f, root, &profile->label, + FLAG_SHOW_MODE | FLAG_VIEW_SUBNS, GFP_KERNEL); + seq_putc(f, '\n'); + + return 0; +} + +static const struct seq_operations aa_sfs_profiles_op = { + .start = p_start, + .next = p_next, + .stop = p_stop, + .show = seq_show_profile, +}; + +static int profiles_open(struct inode *inode, struct file *file) +{ + if (!aa_current_policy_view_capable(NULL)) + return -EACCES; + + return seq_open(file, &aa_sfs_profiles_op); +} + +static int profiles_release(struct inode *inode, struct file *file) +{ + return seq_release(inode, file); +} + +static const struct file_operations aa_sfs_profiles_fops = { + .open = profiles_open, + .read = seq_read, + .llseek = seq_lseek, + .release = profiles_release, +}; + + +/** Base file system setup **/ +static struct aa_sfs_entry aa_sfs_entry_file[] = { + AA_SFS_FILE_STRING("mask", + "create read write exec append mmap_exec link lock"), + { } +}; + +static struct aa_sfs_entry aa_sfs_entry_ptrace[] = { + AA_SFS_FILE_STRING("mask", "read trace"), + { } +}; + +static struct aa_sfs_entry aa_sfs_entry_signal[] = { + AA_SFS_FILE_STRING("mask", AA_SFS_SIG_MASK), + { } +}; + +static struct aa_sfs_entry aa_sfs_entry_attach[] = { + AA_SFS_FILE_BOOLEAN("xattr", 1), + { } +}; +static struct aa_sfs_entry aa_sfs_entry_domain[] = { + AA_SFS_FILE_BOOLEAN("change_hat", 1), + AA_SFS_FILE_BOOLEAN("change_hatv", 1), + AA_SFS_FILE_BOOLEAN("change_onexec", 1), + AA_SFS_FILE_BOOLEAN("change_profile", 1), + AA_SFS_FILE_BOOLEAN("stack", 1), + AA_SFS_FILE_BOOLEAN("fix_binfmt_elf_mmap", 1), + AA_SFS_FILE_BOOLEAN("post_nnp_subset", 1), + AA_SFS_FILE_BOOLEAN("computed_longest_left", 1), + AA_SFS_DIR("attach_conditions", aa_sfs_entry_attach), + AA_SFS_FILE_STRING("version", "1.2"), + { } +}; + +static struct aa_sfs_entry aa_sfs_entry_versions[] = { + AA_SFS_FILE_BOOLEAN("v5", 1), + AA_SFS_FILE_BOOLEAN("v6", 1), + AA_SFS_FILE_BOOLEAN("v7", 1), + AA_SFS_FILE_BOOLEAN("v8", 1), + AA_SFS_FILE_BOOLEAN("v9", 1), + { } +}; + +static struct aa_sfs_entry aa_sfs_entry_policy[] = { + AA_SFS_DIR("versions", aa_sfs_entry_versions), + AA_SFS_FILE_BOOLEAN("set_load", 1), + /* number of out of band transitions supported */ + AA_SFS_FILE_U64("outofband", MAX_OOB_SUPPORTED), + { } +}; + +static struct aa_sfs_entry aa_sfs_entry_mount[] = { + AA_SFS_FILE_STRING("mask", "mount umount pivot_root"), + { } +}; + +static struct aa_sfs_entry aa_sfs_entry_ns[] = { + AA_SFS_FILE_BOOLEAN("profile", 1), + AA_SFS_FILE_BOOLEAN("pivot_root", 0), + { } +}; + +static struct aa_sfs_entry aa_sfs_entry_query_label[] = { + AA_SFS_FILE_STRING("perms", "allow deny audit quiet"), + AA_SFS_FILE_BOOLEAN("data", 1), + AA_SFS_FILE_BOOLEAN("multi_transaction", 1), + { } +}; + +static struct aa_sfs_entry aa_sfs_entry_query[] = { + AA_SFS_DIR("label", aa_sfs_entry_query_label), + { } +}; +static struct aa_sfs_entry aa_sfs_entry_features[] = { + AA_SFS_DIR("policy", aa_sfs_entry_policy), + AA_SFS_DIR("domain", aa_sfs_entry_domain), + AA_SFS_DIR("file", aa_sfs_entry_file), + AA_SFS_DIR("network_v8", aa_sfs_entry_network), + AA_SFS_DIR("mount", aa_sfs_entry_mount), + AA_SFS_DIR("namespaces", aa_sfs_entry_ns), + AA_SFS_FILE_U64("capability", VFS_CAP_FLAGS_MASK), + AA_SFS_DIR("rlimit", aa_sfs_entry_rlimit), + AA_SFS_DIR("caps", aa_sfs_entry_caps), + AA_SFS_DIR("ptrace", aa_sfs_entry_ptrace), + AA_SFS_DIR("signal", aa_sfs_entry_signal), + AA_SFS_DIR("query", aa_sfs_entry_query), + { } +}; + +static struct aa_sfs_entry aa_sfs_entry_apparmor[] = { + AA_SFS_FILE_FOPS(".access", 0666, &aa_sfs_access), + AA_SFS_FILE_FOPS(".stacked", 0444, &seq_ns_stacked_fops), + AA_SFS_FILE_FOPS(".ns_stacked", 0444, &seq_ns_nsstacked_fops), + AA_SFS_FILE_FOPS(".ns_level", 0444, &seq_ns_level_fops), + AA_SFS_FILE_FOPS(".ns_name", 0444, &seq_ns_name_fops), + AA_SFS_FILE_FOPS("profiles", 0444, &aa_sfs_profiles_fops), + AA_SFS_DIR("features", aa_sfs_entry_features), + { } +}; + +static struct aa_sfs_entry aa_sfs_entry = + AA_SFS_DIR("apparmor", aa_sfs_entry_apparmor); + +/** + * entry_create_file - create a file entry in the apparmor securityfs + * @fs_file: aa_sfs_entry to build an entry for (NOT NULL) + * @parent: the parent dentry in the securityfs + * + * Use entry_remove_file to remove entries created with this fn. + */ +static int __init entry_create_file(struct aa_sfs_entry *fs_file, + struct dentry *parent) +{ + int error = 0; + + fs_file->dentry = securityfs_create_file(fs_file->name, + S_IFREG | fs_file->mode, + parent, fs_file, + fs_file->file_ops); + if (IS_ERR(fs_file->dentry)) { + error = PTR_ERR(fs_file->dentry); + fs_file->dentry = NULL; + } + return error; +} + +static void __init entry_remove_dir(struct aa_sfs_entry *fs_dir); +/** + * entry_create_dir - recursively create a directory entry in the securityfs + * @fs_dir: aa_sfs_entry (and all child entries) to build (NOT NULL) + * @parent: the parent dentry in the securityfs + * + * Use entry_remove_dir to remove entries created with this fn. + */ +static int __init entry_create_dir(struct aa_sfs_entry *fs_dir, + struct dentry *parent) +{ + struct aa_sfs_entry *fs_file; + struct dentry *dir; + int error; + + dir = securityfs_create_dir(fs_dir->name, parent); + if (IS_ERR(dir)) + return PTR_ERR(dir); + fs_dir->dentry = dir; + + for (fs_file = fs_dir->v.files; fs_file && fs_file->name; ++fs_file) { + if (fs_file->v_type == AA_SFS_TYPE_DIR) + error = entry_create_dir(fs_file, fs_dir->dentry); + else + error = entry_create_file(fs_file, fs_dir->dentry); + if (error) + goto failed; + } + + return 0; + +failed: + entry_remove_dir(fs_dir); + + return error; +} + +/** + * entry_remove_file - drop a single file entry in the apparmor securityfs + * @fs_file: aa_sfs_entry to detach from the securityfs (NOT NULL) + */ +static void __init entry_remove_file(struct aa_sfs_entry *fs_file) +{ + if (!fs_file->dentry) + return; + + securityfs_remove(fs_file->dentry); + fs_file->dentry = NULL; +} + +/** + * entry_remove_dir - recursively drop a directory entry from the securityfs + * @fs_dir: aa_sfs_entry (and all child entries) to detach (NOT NULL) + */ +static void __init entry_remove_dir(struct aa_sfs_entry *fs_dir) +{ + struct aa_sfs_entry *fs_file; + + for (fs_file = fs_dir->v.files; fs_file && fs_file->name; ++fs_file) { + if (fs_file->v_type == AA_SFS_TYPE_DIR) + entry_remove_dir(fs_file); + else + entry_remove_file(fs_file); + } + + entry_remove_file(fs_dir); +} + +/** + * aa_destroy_aafs - cleanup and free aafs + * + * releases dentries allocated by aa_create_aafs + */ +void __init aa_destroy_aafs(void) +{ + entry_remove_dir(&aa_sfs_entry); +} + + +#define NULL_FILE_NAME ".null" +struct path aa_null; + +static int aa_mk_null_file(struct dentry *parent) +{ + struct vfsmount *mount = NULL; + struct dentry *dentry; + struct inode *inode; + int count = 0; + int error = simple_pin_fs(parent->d_sb->s_type, &mount, &count); + + if (error) + return error; + + inode_lock(d_inode(parent)); + dentry = lookup_one_len(NULL_FILE_NAME, parent, strlen(NULL_FILE_NAME)); + if (IS_ERR(dentry)) { + error = PTR_ERR(dentry); + goto out; + } + inode = new_inode(parent->d_inode->i_sb); + if (!inode) { + error = -ENOMEM; + goto out1; + } + + inode->i_ino = get_next_ino(); + inode->i_mode = S_IFCHR | S_IRUGO | S_IWUGO; + inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode); + init_special_inode(inode, S_IFCHR | S_IRUGO | S_IWUGO, + MKDEV(MEM_MAJOR, 3)); + d_instantiate(dentry, inode); + aa_null.dentry = dget(dentry); + aa_null.mnt = mntget(mount); + + error = 0; + +out1: + dput(dentry); +out: + inode_unlock(d_inode(parent)); + simple_release_fs(&mount, &count); + return error; +} + + + +static const char *policy_get_link(struct dentry *dentry, + struct inode *inode, + struct delayed_call *done) +{ + struct aa_ns *ns; + struct path path; + int error; + + if (!dentry) + return ERR_PTR(-ECHILD); + + ns = aa_get_current_ns(); + path.mnt = mntget(aafs_mnt); + path.dentry = dget(ns_dir(ns)); + error = nd_jump_link(&path); + aa_put_ns(ns); + + return ERR_PTR(error); +} + +static int policy_readlink(struct dentry *dentry, char __user *buffer, + int buflen) +{ + char name[32]; + int res; + + res = snprintf(name, sizeof(name), "%s:[%lu]", AAFS_NAME, + d_inode(dentry)->i_ino); + if (res > 0 && res < sizeof(name)) + res = readlink_copy(buffer, buflen, name); + else + res = -ENOENT; + + return res; +} + +static const struct inode_operations policy_link_iops = { + .readlink = policy_readlink, + .get_link = policy_get_link, +}; + + +/** + * aa_create_aafs - create the apparmor security filesystem + * + * dentries created here are released by aa_destroy_aafs + * + * Returns: error on failure + */ +static int __init aa_create_aafs(void) +{ + struct dentry *dent; + int error; + + if (!apparmor_initialized) + return 0; + + if (aa_sfs_entry.dentry) { + AA_ERROR("%s: AppArmor securityfs already exists\n", __func__); + return -EEXIST; + } + + /* setup apparmorfs used to virtualize policy/ */ + aafs_mnt = kern_mount(&aafs_ops); + if (IS_ERR(aafs_mnt)) + panic("can't set apparmorfs up\n"); + aafs_mnt->mnt_sb->s_flags &= ~SB_NOUSER; + + /* Populate fs tree. */ + error = entry_create_dir(&aa_sfs_entry, NULL); + if (error) + goto error; + + dent = securityfs_create_file(".load", 0666, aa_sfs_entry.dentry, + NULL, &aa_fs_profile_load); + if (IS_ERR(dent)) + goto dent_error; + ns_subload(root_ns) = dent; + + dent = securityfs_create_file(".replace", 0666, aa_sfs_entry.dentry, + NULL, &aa_fs_profile_replace); + if (IS_ERR(dent)) + goto dent_error; + ns_subreplace(root_ns) = dent; + + dent = securityfs_create_file(".remove", 0666, aa_sfs_entry.dentry, + NULL, &aa_fs_profile_remove); + if (IS_ERR(dent)) + goto dent_error; + ns_subremove(root_ns) = dent; + + dent = securityfs_create_file("revision", 0444, aa_sfs_entry.dentry, + NULL, &aa_fs_ns_revision_fops); + if (IS_ERR(dent)) + goto dent_error; + ns_subrevision(root_ns) = dent; + + /* policy tree referenced by magic policy symlink */ + mutex_lock_nested(&root_ns->lock, root_ns->level); + error = __aafs_ns_mkdir(root_ns, aafs_mnt->mnt_root, ".policy", + aafs_mnt->mnt_root); + mutex_unlock(&root_ns->lock); + if (error) + goto error; + + /* magic symlink similar to nsfs redirects based on task policy */ + dent = securityfs_create_symlink("policy", aa_sfs_entry.dentry, + NULL, &policy_link_iops); + if (IS_ERR(dent)) + goto dent_error; + + error = aa_mk_null_file(aa_sfs_entry.dentry); + if (error) + goto error; + + /* TODO: add default profile to apparmorfs */ + + /* Report that AppArmor fs is enabled */ + aa_info_message("AppArmor Filesystem Enabled"); + return 0; + +dent_error: + error = PTR_ERR(dent); +error: + aa_destroy_aafs(); + AA_ERROR("Error creating AppArmor securityfs\n"); + return error; +} + +fs_initcall(aa_create_aafs); diff --git a/security/apparmor/audit.c b/security/apparmor/audit.c new file mode 100644 index 000000000..704b0c895 --- /dev/null +++ b/security/apparmor/audit.c @@ -0,0 +1,247 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * AppArmor security module + * + * This file contains AppArmor auditing functions + * + * Copyright (C) 1998-2008 Novell/SUSE + * Copyright 2009-2010 Canonical Ltd. + */ + +#include <linux/audit.h> +#include <linux/socket.h> + +#include "include/apparmor.h" +#include "include/audit.h" +#include "include/policy.h" +#include "include/policy_ns.h" +#include "include/secid.h" + +const char *const audit_mode_names[] = { + "normal", + "quiet_denied", + "quiet", + "noquiet", + "all" +}; + +static const char *const aa_audit_type[] = { + "AUDIT", + "ALLOWED", + "DENIED", + "HINT", + "STATUS", + "ERROR", + "KILLED", + "AUTO" +}; + +/* + * Currently AppArmor auditing is fed straight into the audit framework. + * + * TODO: + * netlink interface for complain mode + * user auditing, - send user auditing to netlink interface + * system control of whether user audit messages go to system log + */ + +/** + * audit_base - core AppArmor function. + * @ab: audit buffer to fill (NOT NULL) + * @ca: audit structure containing data to audit (NOT NULL) + * + * Record common AppArmor audit data from @sa + */ +static void audit_pre(struct audit_buffer *ab, void *ca) +{ + struct common_audit_data *sa = ca; + + if (aa_g_audit_header) { + audit_log_format(ab, "apparmor=\"%s\"", + aa_audit_type[aad(sa)->type]); + } + + if (aad(sa)->op) { + audit_log_format(ab, " operation=\"%s\"", aad(sa)->op); + } + + if (aad(sa)->info) { + audit_log_format(ab, " info=\"%s\"", aad(sa)->info); + if (aad(sa)->error) + audit_log_format(ab, " error=%d", aad(sa)->error); + } + + if (aad(sa)->label) { + struct aa_label *label = aad(sa)->label; + + if (label_isprofile(label)) { + struct aa_profile *profile = labels_profile(label); + + if (profile->ns != root_ns) { + audit_log_format(ab, " namespace="); + audit_log_untrustedstring(ab, + profile->ns->base.hname); + } + audit_log_format(ab, " profile="); + audit_log_untrustedstring(ab, profile->base.hname); + } else { + audit_log_format(ab, " label="); + aa_label_xaudit(ab, root_ns, label, FLAG_VIEW_SUBNS, + GFP_ATOMIC); + } + } + + if (aad(sa)->name) { + audit_log_format(ab, " name="); + audit_log_untrustedstring(ab, aad(sa)->name); + } +} + +/** + * aa_audit_msg - Log a message to the audit subsystem + * @sa: audit event structure (NOT NULL) + * @cb: optional callback fn for type specific fields (MAYBE NULL) + */ +void aa_audit_msg(int type, struct common_audit_data *sa, + void (*cb) (struct audit_buffer *, void *)) +{ + aad(sa)->type = type; + common_lsm_audit(sa, audit_pre, cb); +} + +/** + * aa_audit - Log a profile based audit event to the audit subsystem + * @type: audit type for the message + * @profile: profile to check against (NOT NULL) + * @sa: audit event (NOT NULL) + * @cb: optional callback fn for type specific fields (MAYBE NULL) + * + * Handle default message switching based off of audit mode flags + * + * Returns: error on failure + */ +int aa_audit(int type, struct aa_profile *profile, struct common_audit_data *sa, + void (*cb) (struct audit_buffer *, void *)) +{ + AA_BUG(!profile); + + if (type == AUDIT_APPARMOR_AUTO) { + if (likely(!aad(sa)->error)) { + if (AUDIT_MODE(profile) != AUDIT_ALL) + return 0; + type = AUDIT_APPARMOR_AUDIT; + } else if (COMPLAIN_MODE(profile)) + type = AUDIT_APPARMOR_ALLOWED; + else + type = AUDIT_APPARMOR_DENIED; + } + if (AUDIT_MODE(profile) == AUDIT_QUIET || + (type == AUDIT_APPARMOR_DENIED && + AUDIT_MODE(profile) == AUDIT_QUIET_DENIED)) + return aad(sa)->error; + + if (KILL_MODE(profile) && type == AUDIT_APPARMOR_DENIED) + type = AUDIT_APPARMOR_KILL; + + aad(sa)->label = &profile->label; + + aa_audit_msg(type, sa, cb); + + if (aad(sa)->type == AUDIT_APPARMOR_KILL) + (void)send_sig_info(SIGKILL, NULL, + sa->type == LSM_AUDIT_DATA_TASK && sa->u.tsk ? + sa->u.tsk : current); + + if (aad(sa)->type == AUDIT_APPARMOR_ALLOWED) + return complain_error(aad(sa)->error); + + return aad(sa)->error; +} + +struct aa_audit_rule { + struct aa_label *label; +}; + +void aa_audit_rule_free(void *vrule) +{ + struct aa_audit_rule *rule = vrule; + + if (rule) { + if (!IS_ERR(rule->label)) + aa_put_label(rule->label); + kfree(rule); + } +} + +int aa_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule) +{ + struct aa_audit_rule *rule; + + switch (field) { + case AUDIT_SUBJ_ROLE: + if (op != Audit_equal && op != Audit_not_equal) + return -EINVAL; + break; + default: + return -EINVAL; + } + + rule = kzalloc(sizeof(struct aa_audit_rule), GFP_KERNEL); + + if (!rule) + return -ENOMEM; + + /* Currently rules are treated as coming from the root ns */ + rule->label = aa_label_parse(&root_ns->unconfined->label, rulestr, + GFP_KERNEL, true, false); + if (IS_ERR(rule->label)) { + int err = PTR_ERR(rule->label); + aa_audit_rule_free(rule); + return err; + } + + *vrule = rule; + return 0; +} + +int aa_audit_rule_known(struct audit_krule *rule) +{ + int i; + + for (i = 0; i < rule->field_count; i++) { + struct audit_field *f = &rule->fields[i]; + + switch (f->type) { + case AUDIT_SUBJ_ROLE: + return 1; + } + } + + return 0; +} + +int aa_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule) +{ + struct aa_audit_rule *rule = vrule; + struct aa_label *label; + int found = 0; + + label = aa_secid_to_label(sid); + + if (!label) + return -ENOENT; + + if (aa_label_is_subset(label, rule->label)) + found = 1; + + switch (field) { + case AUDIT_SUBJ_ROLE: + switch (op) { + case Audit_equal: + return found; + case Audit_not_equal: + return !found; + } + } + return 0; +} diff --git a/security/apparmor/capability.c b/security/apparmor/capability.c new file mode 100644 index 000000000..deccea865 --- /dev/null +++ b/security/apparmor/capability.c @@ -0,0 +1,158 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * AppArmor security module + * + * This file contains AppArmor capability mediation functions + * + * Copyright (C) 1998-2008 Novell/SUSE + * Copyright 2009-2010 Canonical Ltd. + */ + +#include <linux/capability.h> +#include <linux/errno.h> +#include <linux/gfp.h> +#include <linux/security.h> + +#include "include/apparmor.h" +#include "include/capability.h" +#include "include/cred.h" +#include "include/policy.h" +#include "include/audit.h" + +/* + * Table of capability names: we generate it from capabilities.h. + */ +#include "capability_names.h" + +struct aa_sfs_entry aa_sfs_entry_caps[] = { + AA_SFS_FILE_STRING("mask", AA_SFS_CAPS_MASK), + { } +}; + +struct audit_cache { + struct aa_profile *profile; + kernel_cap_t caps; +}; + +static DEFINE_PER_CPU(struct audit_cache, audit_cache); + +/** + * audit_cb - call back for capability components of audit struct + * @ab - audit buffer (NOT NULL) + * @va - audit struct to audit data from (NOT NULL) + */ +static void audit_cb(struct audit_buffer *ab, void *va) +{ + struct common_audit_data *sa = va; + + audit_log_format(ab, " capname="); + audit_log_untrustedstring(ab, capability_names[sa->u.cap]); +} + +/** + * audit_caps - audit a capability + * @sa: audit data + * @profile: profile being tested for confinement (NOT NULL) + * @cap: capability tested + * @error: error code returned by test + * + * Do auditing of capability and handle, audit/complain/kill modes switching + * and duplicate message elimination. + * + * Returns: 0 or sa->error on success, error code on failure + */ +static int audit_caps(struct common_audit_data *sa, struct aa_profile *profile, + int cap, int error) +{ + struct audit_cache *ent; + int type = AUDIT_APPARMOR_AUTO; + + aad(sa)->error = error; + + if (likely(!error)) { + /* test if auditing is being forced */ + if (likely((AUDIT_MODE(profile) != AUDIT_ALL) && + !cap_raised(profile->caps.audit, cap))) + return 0; + type = AUDIT_APPARMOR_AUDIT; + } else if (KILL_MODE(profile) || + cap_raised(profile->caps.kill, cap)) { + type = AUDIT_APPARMOR_KILL; + } else if (cap_raised(profile->caps.quiet, cap) && + AUDIT_MODE(profile) != AUDIT_NOQUIET && + AUDIT_MODE(profile) != AUDIT_ALL) { + /* quiet auditing */ + return error; + } + + /* Do simple duplicate message elimination */ + ent = &get_cpu_var(audit_cache); + if (profile == ent->profile && cap_raised(ent->caps, cap)) { + put_cpu_var(audit_cache); + if (COMPLAIN_MODE(profile)) + return complain_error(error); + return error; + } else { + aa_put_profile(ent->profile); + ent->profile = aa_get_profile(profile); + cap_raise(ent->caps, cap); + } + put_cpu_var(audit_cache); + + return aa_audit(type, profile, sa, audit_cb); +} + +/** + * profile_capable - test if profile allows use of capability @cap + * @profile: profile being enforced (NOT NULL, NOT unconfined) + * @cap: capability to test if allowed + * @opts: CAP_OPT_NOAUDIT bit determines whether audit record is generated + * @sa: audit data (MAY BE NULL indicating no auditing) + * + * Returns: 0 if allowed else -EPERM + */ +static int profile_capable(struct aa_profile *profile, int cap, + unsigned int opts, struct common_audit_data *sa) +{ + int error; + + if (cap_raised(profile->caps.allow, cap) && + !cap_raised(profile->caps.denied, cap)) + error = 0; + else + error = -EPERM; + + if (opts & CAP_OPT_NOAUDIT) { + if (!COMPLAIN_MODE(profile)) + return error; + /* audit the cap request in complain mode but note that it + * should be optional. + */ + aad(sa)->info = "optional: no audit"; + } + + return audit_caps(sa, profile, cap, error); +} + +/** + * aa_capable - test permission to use capability + * @label: label being tested for capability (NOT NULL) + * @cap: capability to be tested + * @opts: CAP_OPT_NOAUDIT bit determines whether audit record is generated + * + * Look up capability in profile capability set. + * + * Returns: 0 on success, or else an error code. + */ +int aa_capable(struct aa_label *label, int cap, unsigned int opts) +{ + struct aa_profile *profile; + int error = 0; + DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_CAP, OP_CAPABLE); + + sa.u.cap = cap; + error = fn_for_each_confined(label, profile, + profile_capable(profile, cap, opts, &sa)); + + return error; +} diff --git a/security/apparmor/crypto.c b/security/apparmor/crypto.c new file mode 100644 index 000000000..b498ed302 --- /dev/null +++ b/security/apparmor/crypto.c @@ -0,0 +1,123 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * AppArmor security module + * + * This file contains AppArmor policy loading interface function definitions. + * + * Copyright 2013 Canonical Ltd. + * + * Fns to provide a checksum of policy that has been loaded this can be + * compared to userspace policy compiles to check loaded policy is what + * it should be. + */ + +#include <crypto/hash.h> + +#include "include/apparmor.h" +#include "include/crypto.h" + +static unsigned int apparmor_hash_size; + +static struct crypto_shash *apparmor_tfm; + +unsigned int aa_hash_size(void) +{ + return apparmor_hash_size; +} + +char *aa_calc_hash(void *data, size_t len) +{ + SHASH_DESC_ON_STACK(desc, apparmor_tfm); + char *hash = NULL; + int error = -ENOMEM; + + if (!apparmor_tfm) + return NULL; + + hash = kzalloc(apparmor_hash_size, GFP_KERNEL); + if (!hash) + goto fail; + + desc->tfm = apparmor_tfm; + + error = crypto_shash_init(desc); + if (error) + goto fail; + error = crypto_shash_update(desc, (u8 *) data, len); + if (error) + goto fail; + error = crypto_shash_final(desc, hash); + if (error) + goto fail; + + return hash; + +fail: + kfree(hash); + + return ERR_PTR(error); +} + +int aa_calc_profile_hash(struct aa_profile *profile, u32 version, void *start, + size_t len) +{ + SHASH_DESC_ON_STACK(desc, apparmor_tfm); + int error = -ENOMEM; + __le32 le32_version = cpu_to_le32(version); + + if (!aa_g_hash_policy) + return 0; + + if (!apparmor_tfm) + return 0; + + profile->hash = kzalloc(apparmor_hash_size, GFP_KERNEL); + if (!profile->hash) + goto fail; + + desc->tfm = apparmor_tfm; + + error = crypto_shash_init(desc); + if (error) + goto fail; + error = crypto_shash_update(desc, (u8 *) &le32_version, 4); + if (error) + goto fail; + error = crypto_shash_update(desc, (u8 *) start, len); + if (error) + goto fail; + error = crypto_shash_final(desc, profile->hash); + if (error) + goto fail; + + return 0; + +fail: + kfree(profile->hash); + profile->hash = NULL; + + return error; +} + +static int __init init_profile_hash(void) +{ + struct crypto_shash *tfm; + + if (!apparmor_initialized) + return 0; + + tfm = crypto_alloc_shash("sha1", 0, 0); + if (IS_ERR(tfm)) { + int error = PTR_ERR(tfm); + AA_ERROR("failed to setup profile sha1 hashing: %d\n", error); + return error; + } + apparmor_tfm = tfm; + apparmor_hash_size = crypto_shash_digestsize(apparmor_tfm); + + aa_info_message("AppArmor sha1 policy hashing enabled"); + + return 0; +} + +late_initcall(init_profile_hash); diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c new file mode 100644 index 000000000..91689d34d --- /dev/null +++ b/security/apparmor/domain.c @@ -0,0 +1,1458 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * AppArmor security module + * + * This file contains AppArmor policy attachment and domain transitions + * + * Copyright (C) 2002-2008 Novell/SUSE + * Copyright 2009-2010 Canonical Ltd. + */ + +#include <linux/errno.h> +#include <linux/fdtable.h> +#include <linux/fs.h> +#include <linux/file.h> +#include <linux/mount.h> +#include <linux/syscalls.h> +#include <linux/personality.h> +#include <linux/xattr.h> +#include <linux/user_namespace.h> + +#include "include/audit.h" +#include "include/apparmorfs.h" +#include "include/cred.h" +#include "include/domain.h" +#include "include/file.h" +#include "include/ipc.h" +#include "include/match.h" +#include "include/path.h" +#include "include/policy.h" +#include "include/policy_ns.h" + +/** + * aa_free_domain_entries - free entries in a domain table + * @domain: the domain table to free (MAYBE NULL) + */ +void aa_free_domain_entries(struct aa_domain *domain) +{ + int i; + if (domain) { + if (!domain->table) + return; + + for (i = 0; i < domain->size; i++) + kfree_sensitive(domain->table[i]); + kfree_sensitive(domain->table); + domain->table = NULL; + } +} + +/** + * may_change_ptraced_domain - check if can change profile on ptraced task + * @to_label: profile to change to (NOT NULL) + * @info: message if there is an error + * + * Check if current is ptraced and if so if the tracing task is allowed + * to trace the new domain + * + * Returns: %0 or error if change not allowed + */ +static int may_change_ptraced_domain(struct aa_label *to_label, + const char **info) +{ + struct task_struct *tracer; + struct aa_label *tracerl = NULL; + int error = 0; + + rcu_read_lock(); + tracer = ptrace_parent(current); + if (tracer) + /* released below */ + tracerl = aa_get_task_label(tracer); + + /* not ptraced */ + if (!tracer || unconfined(tracerl)) + goto out; + + error = aa_may_ptrace(tracerl, to_label, PTRACE_MODE_ATTACH); + +out: + rcu_read_unlock(); + aa_put_label(tracerl); + + if (error) + *info = "ptrace prevents transition"; + return error; +} + +/**** TODO: dedup to aa_label_match - needs perm and dfa, merging + * specifically this is an exact copy of aa_label_match except + * aa_compute_perms is replaced with aa_compute_fperms + * and policy.dfa with file.dfa + ****/ +/* match a profile and its associated ns component if needed + * Assumes visibility test has already been done. + * If a subns profile is not to be matched should be prescreened with + * visibility test. + */ +static inline unsigned int match_component(struct aa_profile *profile, + struct aa_profile *tp, + bool stack, unsigned int state) +{ + const char *ns_name; + + if (stack) + state = aa_dfa_match(profile->file.dfa, state, "&"); + if (profile->ns == tp->ns) + return aa_dfa_match(profile->file.dfa, state, tp->base.hname); + + /* try matching with namespace name and then profile */ + ns_name = aa_ns_name(profile->ns, tp->ns, true); + state = aa_dfa_match_len(profile->file.dfa, state, ":", 1); + state = aa_dfa_match(profile->file.dfa, state, ns_name); + state = aa_dfa_match_len(profile->file.dfa, state, ":", 1); + return aa_dfa_match(profile->file.dfa, state, tp->base.hname); +} + +/** + * label_compound_match - find perms for full compound label + * @profile: profile to find perms for + * @label: label to check access permissions for + * @stack: whether this is a stacking request + * @state: state to start match in + * @subns: whether to do permission checks on components in a subns + * @request: permissions to request + * @perms: perms struct to set + * + * Returns: 0 on success else ERROR + * + * For the label A//&B//&C this does the perm match for A//&B//&C + * @perms should be preinitialized with allperms OR a previous permission + * check to be stacked. + */ +static int label_compound_match(struct aa_profile *profile, + struct aa_label *label, bool stack, + unsigned int state, bool subns, u32 request, + struct aa_perms *perms) +{ + struct aa_profile *tp; + struct label_it i; + struct path_cond cond = { }; + + /* find first subcomponent that is visible */ + label_for_each(i, label, tp) { + if (!aa_ns_visible(profile->ns, tp->ns, subns)) + continue; + state = match_component(profile, tp, stack, state); + if (!state) + goto fail; + goto next; + } + + /* no component visible */ + *perms = allperms; + return 0; + +next: + label_for_each_cont(i, label, tp) { + if (!aa_ns_visible(profile->ns, tp->ns, subns)) + continue; + state = aa_dfa_match(profile->file.dfa, state, "//&"); + state = match_component(profile, tp, false, state); + if (!state) + goto fail; + } + *perms = aa_compute_fperms(profile->file.dfa, state, &cond); + aa_apply_modes_to_perms(profile, perms); + if ((perms->allow & request) != request) + return -EACCES; + + return 0; + +fail: + *perms = nullperms; + return -EACCES; +} + +/** + * label_components_match - find perms for all subcomponents of a label + * @profile: profile to find perms for + * @label: label to check access permissions for + * @stack: whether this is a stacking request + * @start: state to start match in + * @subns: whether to do permission checks on components in a subns + * @request: permissions to request + * @perms: an initialized perms struct to add accumulation to + * + * Returns: 0 on success else ERROR + * + * For the label A//&B//&C this does the perm match for each of A and B and C + * @perms should be preinitialized with allperms OR a previous permission + * check to be stacked. + */ +static int label_components_match(struct aa_profile *profile, + struct aa_label *label, bool stack, + unsigned int start, bool subns, u32 request, + struct aa_perms *perms) +{ + struct aa_profile *tp; + struct label_it i; + struct aa_perms tmp; + struct path_cond cond = { }; + unsigned int state = 0; + + /* find first subcomponent to test */ + label_for_each(i, label, tp) { + if (!aa_ns_visible(profile->ns, tp->ns, subns)) + continue; + state = match_component(profile, tp, stack, start); + if (!state) + goto fail; + goto next; + } + + /* no subcomponents visible - no change in perms */ + return 0; + +next: + tmp = aa_compute_fperms(profile->file.dfa, state, &cond); + aa_apply_modes_to_perms(profile, &tmp); + aa_perms_accum(perms, &tmp); + label_for_each_cont(i, label, tp) { + if (!aa_ns_visible(profile->ns, tp->ns, subns)) + continue; + state = match_component(profile, tp, stack, start); + if (!state) + goto fail; + tmp = aa_compute_fperms(profile->file.dfa, state, &cond); + aa_apply_modes_to_perms(profile, &tmp); + aa_perms_accum(perms, &tmp); + } + + if ((perms->allow & request) != request) + return -EACCES; + + return 0; + +fail: + *perms = nullperms; + return -EACCES; +} + +/** + * label_match - do a multi-component label match + * @profile: profile to match against (NOT NULL) + * @label: label to match (NOT NULL) + * @stack: whether this is a stacking request + * @state: state to start in + * @subns: whether to match subns components + * @request: permission request + * @perms: Returns computed perms (NOT NULL) + * + * Returns: the state the match finished in, may be the none matching state + */ +static int label_match(struct aa_profile *profile, struct aa_label *label, + bool stack, unsigned int state, bool subns, u32 request, + struct aa_perms *perms) +{ + int error; + + *perms = nullperms; + error = label_compound_match(profile, label, stack, state, subns, + request, perms); + if (!error) + return error; + + *perms = allperms; + return label_components_match(profile, label, stack, state, subns, + request, perms); +} + +/******* end TODO: dedup *****/ + +/** + * change_profile_perms - find permissions for change_profile + * @profile: the current profile (NOT NULL) + * @target: label to transition to (NOT NULL) + * @stack: whether this is a stacking request + * @request: requested perms + * @start: state to start matching in + * + * + * Returns: permission set + * + * currently only matches full label A//&B//&C or individual components A, B, C + * not arbitrary combinations. Eg. A//&B, C + */ +static int change_profile_perms(struct aa_profile *profile, + struct aa_label *target, bool stack, + u32 request, unsigned int start, + struct aa_perms *perms) +{ + if (profile_unconfined(profile)) { + perms->allow = AA_MAY_CHANGE_PROFILE | AA_MAY_ONEXEC; + perms->audit = perms->quiet = perms->kill = 0; + return 0; + } + + /* TODO: add profile in ns screening */ + return label_match(profile, target, stack, start, true, request, perms); +} + +/** + * aa_xattrs_match - check whether a file matches the xattrs defined in profile + * @bprm: binprm struct for the process to validate + * @profile: profile to match against (NOT NULL) + * @state: state to start match in + * + * Returns: number of extended attributes that matched, or < 0 on error + */ +static int aa_xattrs_match(const struct linux_binprm *bprm, + struct aa_profile *profile, unsigned int state) +{ + int i; + ssize_t size; + struct dentry *d; + char *value = NULL; + int value_size = 0, ret = profile->xattr_count; + + if (!bprm || !profile->xattr_count) + return 0; + might_sleep(); + + /* transition from exec match to xattr set */ + state = aa_dfa_outofband_transition(profile->xmatch, state); + d = bprm->file->f_path.dentry; + + for (i = 0; i < profile->xattr_count; i++) { + size = vfs_getxattr_alloc(&init_user_ns, d, profile->xattrs[i], + &value, value_size, GFP_KERNEL); + if (size >= 0) { + u32 perm; + + /* + * Check the xattr presence before value. This ensure + * that not present xattr can be distinguished from a 0 + * length value or rule that matches any value + */ + state = aa_dfa_null_transition(profile->xmatch, state); + /* Check xattr value */ + state = aa_dfa_match_len(profile->xmatch, state, value, + size); + perm = dfa_user_allow(profile->xmatch, state); + if (!(perm & MAY_EXEC)) { + ret = -EINVAL; + goto out; + } + } + /* transition to next element */ + state = aa_dfa_outofband_transition(profile->xmatch, state); + if (size < 0) { + /* + * No xattr match, so verify if transition to + * next element was valid. IFF so the xattr + * was optional. + */ + if (!state) { + ret = -EINVAL; + goto out; + } + /* don't count missing optional xattr as matched */ + ret--; + } + } + +out: + kfree(value); + return ret; +} + +/** + * find_attach - do attachment search for unconfined processes + * @bprm - binprm structure of transitioning task + * @ns: the current namespace (NOT NULL) + * @head - profile list to walk (NOT NULL) + * @name - to match against (NOT NULL) + * @info - info message if there was an error (NOT NULL) + * + * Do a linear search on the profiles in the list. There is a matching + * preference where an exact match is preferred over a name which uses + * expressions to match, and matching expressions with the greatest + * xmatch_len are preferred. + * + * Requires: @head not be shared or have appropriate locks held + * + * Returns: label or NULL if no match found + */ +static struct aa_label *find_attach(const struct linux_binprm *bprm, + struct aa_ns *ns, struct list_head *head, + const char *name, const char **info) +{ + int candidate_len = 0, candidate_xattrs = 0; + bool conflict = false; + struct aa_profile *profile, *candidate = NULL; + + AA_BUG(!name); + AA_BUG(!head); + + rcu_read_lock(); +restart: + list_for_each_entry_rcu(profile, head, base.list) { + if (profile->label.flags & FLAG_NULL && + &profile->label == ns_unconfined(profile->ns)) + continue; + + /* Find the "best" matching profile. Profiles must + * match the path and extended attributes (if any) + * associated with the file. A more specific path + * match will be preferred over a less specific one, + * and a match with more matching extended attributes + * will be preferred over one with fewer. If the best + * match has both the same level of path specificity + * and the same number of matching extended attributes + * as another profile, signal a conflict and refuse to + * match. + */ + if (profile->xmatch) { + unsigned int state, count; + u32 perm; + + state = aa_dfa_leftmatch(profile->xmatch, DFA_START, + name, &count); + perm = dfa_user_allow(profile->xmatch, state); + /* any accepting state means a valid match. */ + if (perm & MAY_EXEC) { + int ret = 0; + + if (count < candidate_len) + continue; + + if (bprm && profile->xattr_count) { + long rev = READ_ONCE(ns->revision); + + if (!aa_get_profile_not0(profile)) + goto restart; + rcu_read_unlock(); + ret = aa_xattrs_match(bprm, profile, + state); + rcu_read_lock(); + aa_put_profile(profile); + if (rev != + READ_ONCE(ns->revision)) + /* policy changed */ + goto restart; + /* + * Fail matching if the xattrs don't + * match + */ + if (ret < 0) + continue; + } + /* + * TODO: allow for more flexible best match + * + * The new match isn't more specific + * than the current best match + */ + if (count == candidate_len && + ret <= candidate_xattrs) { + /* Match is equivalent, so conflict */ + if (ret == candidate_xattrs) + conflict = true; + continue; + } + + /* Either the same length with more matching + * xattrs, or a longer match + */ + candidate = profile; + candidate_len = max(count, profile->xmatch_len); + candidate_xattrs = ret; + conflict = false; + } + } else if (!strcmp(profile->base.name, name)) { + /* + * old exact non-re match, without conditionals such + * as xattrs. no more searching required + */ + candidate = profile; + goto out; + } + } + + if (!candidate || conflict) { + if (conflict) + *info = "conflicting profile attachments"; + rcu_read_unlock(); + return NULL; + } + +out: + candidate = aa_get_newest_profile(candidate); + rcu_read_unlock(); + + return &candidate->label; +} + +static const char *next_name(int xtype, const char *name) +{ + return NULL; +} + +/** + * x_table_lookup - lookup an x transition name via transition table + * @profile: current profile (NOT NULL) + * @xindex: index into x transition table + * @name: returns: name tested to find label (NOT NULL) + * + * Returns: refcounted label, or NULL on failure (MAYBE NULL) + */ +struct aa_label *x_table_lookup(struct aa_profile *profile, u32 xindex, + const char **name) +{ + struct aa_label *label = NULL; + u32 xtype = xindex & AA_X_TYPE_MASK; + int index = xindex & AA_X_INDEX_MASK; + + AA_BUG(!name); + + /* index is guaranteed to be in range, validated at load time */ + /* TODO: move lookup parsing to unpack time so this is a straight + * index into the resultant label + */ + for (*name = profile->file.trans.table[index]; !label && *name; + *name = next_name(xtype, *name)) { + if (xindex & AA_X_CHILD) { + struct aa_profile *new_profile; + /* release by caller */ + new_profile = aa_find_child(profile, *name); + if (new_profile) + label = &new_profile->label; + continue; + } + label = aa_label_parse(&profile->label, *name, GFP_KERNEL, + true, false); + if (IS_ERR(label)) + label = NULL; + } + + /* released by caller */ + + return label; +} + +/** + * x_to_label - get target label for a given xindex + * @profile: current profile (NOT NULL) + * @bprm: binprm structure of transitioning task + * @name: name to lookup (NOT NULL) + * @xindex: index into x transition table + * @lookupname: returns: name used in lookup if one was specified (NOT NULL) + * + * find label for a transition index + * + * Returns: refcounted label or NULL if not found available + */ +static struct aa_label *x_to_label(struct aa_profile *profile, + const struct linux_binprm *bprm, + const char *name, u32 xindex, + const char **lookupname, + const char **info) +{ + struct aa_label *new = NULL; + struct aa_ns *ns = profile->ns; + u32 xtype = xindex & AA_X_TYPE_MASK; + const char *stack = NULL; + + switch (xtype) { + case AA_X_NONE: + /* fail exec unless ix || ux fallback - handled by caller */ + *lookupname = NULL; + break; + case AA_X_TABLE: + /* TODO: fix when perm mapping done at unload */ + stack = profile->file.trans.table[xindex & AA_X_INDEX_MASK]; + if (*stack != '&') { + /* released by caller */ + new = x_table_lookup(profile, xindex, lookupname); + stack = NULL; + break; + } + fallthrough; /* to X_NAME */ + case AA_X_NAME: + if (xindex & AA_X_CHILD) + /* released by caller */ + new = find_attach(bprm, ns, &profile->base.profiles, + name, info); + else + /* released by caller */ + new = find_attach(bprm, ns, &ns->base.profiles, + name, info); + *lookupname = name; + break; + } + + if (!new) { + if (xindex & AA_X_INHERIT) { + /* (p|c|n)ix - don't change profile but do + * use the newest version + */ + *info = "ix fallback"; + /* no profile && no error */ + new = aa_get_newest_label(&profile->label); + } else if (xindex & AA_X_UNCONFINED) { + new = aa_get_newest_label(ns_unconfined(profile->ns)); + *info = "ux fallback"; + } + } + + if (new && stack) { + /* base the stack on post domain transition */ + struct aa_label *base = new; + + new = aa_label_parse(base, stack, GFP_KERNEL, true, false); + if (IS_ERR(new)) + new = NULL; + aa_put_label(base); + } + + /* released by caller */ + return new; +} + +static struct aa_label *profile_transition(struct aa_profile *profile, + const struct linux_binprm *bprm, + char *buffer, struct path_cond *cond, + bool *secure_exec) +{ + struct aa_label *new = NULL; + const char *info = NULL, *name = NULL, *target = NULL; + unsigned int state = profile->file.start; + struct aa_perms perms = {}; + bool nonewprivs = false; + int error = 0; + + AA_BUG(!profile); + AA_BUG(!bprm); + AA_BUG(!buffer); + + error = aa_path_name(&bprm->file->f_path, profile->path_flags, buffer, + &name, &info, profile->disconnected); + if (error) { + if (profile_unconfined(profile) || + (profile->label.flags & FLAG_IX_ON_NAME_ERROR)) { + AA_DEBUG("name lookup ix on error"); + error = 0; + new = aa_get_newest_label(&profile->label); + } + name = bprm->filename; + goto audit; + } + + if (profile_unconfined(profile)) { + new = find_attach(bprm, profile->ns, + &profile->ns->base.profiles, name, &info); + if (new) { + AA_DEBUG("unconfined attached to new label"); + return new; + } + AA_DEBUG("unconfined exec no attachment"); + return aa_get_newest_label(&profile->label); + } + + /* find exec permissions for name */ + state = aa_str_perms(profile->file.dfa, state, name, cond, &perms); + if (perms.allow & MAY_EXEC) { + /* exec permission determine how to transition */ + new = x_to_label(profile, bprm, name, perms.xindex, &target, + &info); + if (new && new->proxy == profile->label.proxy && info) { + /* hack ix fallback - improve how this is detected */ + goto audit; + } else if (!new) { + error = -EACCES; + info = "profile transition not found"; + /* remove MAY_EXEC to audit as failure */ + perms.allow &= ~MAY_EXEC; + } + } else if (COMPLAIN_MODE(profile)) { + /* no exec permission - learning mode */ + struct aa_profile *new_profile = NULL; + + new_profile = aa_new_null_profile(profile, false, name, + GFP_KERNEL); + if (!new_profile) { + error = -ENOMEM; + info = "could not create null profile"; + } else { + error = -EACCES; + new = &new_profile->label; + } + perms.xindex |= AA_X_UNSAFE; + } else + /* fail exec */ + error = -EACCES; + + if (!new) + goto audit; + + + if (!(perms.xindex & AA_X_UNSAFE)) { + if (DEBUG_ON) { + dbg_printk("apparmor: scrubbing environment variables" + " for %s profile=", name); + aa_label_printk(new, GFP_KERNEL); + dbg_printk("\n"); + } + *secure_exec = true; + } + +audit: + aa_audit_file(profile, &perms, OP_EXEC, MAY_EXEC, name, target, new, + cond->uid, info, error); + if (!new || nonewprivs) { + aa_put_label(new); + return ERR_PTR(error); + } + + return new; +} + +static int profile_onexec(struct aa_profile *profile, struct aa_label *onexec, + bool stack, const struct linux_binprm *bprm, + char *buffer, struct path_cond *cond, + bool *secure_exec) +{ + unsigned int state = profile->file.start; + struct aa_perms perms = {}; + const char *xname = NULL, *info = "change_profile onexec"; + int error = -EACCES; + + AA_BUG(!profile); + AA_BUG(!onexec); + AA_BUG(!bprm); + AA_BUG(!buffer); + + if (profile_unconfined(profile)) { + /* change_profile on exec already granted */ + /* + * NOTE: Domain transitions from unconfined are allowed + * even when no_new_privs is set because this aways results + * in a further reduction of permissions. + */ + return 0; + } + + error = aa_path_name(&bprm->file->f_path, profile->path_flags, buffer, + &xname, &info, profile->disconnected); + if (error) { + if (profile_unconfined(profile) || + (profile->label.flags & FLAG_IX_ON_NAME_ERROR)) { + AA_DEBUG("name lookup ix on error"); + error = 0; + } + xname = bprm->filename; + goto audit; + } + + /* find exec permissions for name */ + state = aa_str_perms(profile->file.dfa, state, xname, cond, &perms); + if (!(perms.allow & AA_MAY_ONEXEC)) { + info = "no change_onexec valid for executable"; + goto audit; + } + /* test if this exec can be paired with change_profile onexec. + * onexec permission is linked to exec with a standard pairing + * exec\0change_profile + */ + state = aa_dfa_null_transition(profile->file.dfa, state); + error = change_profile_perms(profile, onexec, stack, AA_MAY_ONEXEC, + state, &perms); + if (error) { + perms.allow &= ~AA_MAY_ONEXEC; + goto audit; + } + + if (!(perms.xindex & AA_X_UNSAFE)) { + if (DEBUG_ON) { + dbg_printk("apparmor: scrubbing environment " + "variables for %s label=", xname); + aa_label_printk(onexec, GFP_KERNEL); + dbg_printk("\n"); + } + *secure_exec = true; + } + +audit: + return aa_audit_file(profile, &perms, OP_EXEC, AA_MAY_ONEXEC, xname, + NULL, onexec, cond->uid, info, error); +} + +/* ensure none ns domain transitions are correctly applied with onexec */ + +static struct aa_label *handle_onexec(struct aa_label *label, + struct aa_label *onexec, bool stack, + const struct linux_binprm *bprm, + char *buffer, struct path_cond *cond, + bool *unsafe) +{ + struct aa_profile *profile; + struct aa_label *new; + int error; + + AA_BUG(!label); + AA_BUG(!onexec); + AA_BUG(!bprm); + AA_BUG(!buffer); + + if (!stack) { + error = fn_for_each_in_ns(label, profile, + profile_onexec(profile, onexec, stack, + bprm, buffer, cond, unsafe)); + if (error) + return ERR_PTR(error); + new = fn_label_build_in_ns(label, profile, GFP_KERNEL, + aa_get_newest_label(onexec), + profile_transition(profile, bprm, buffer, + cond, unsafe)); + + } else { + /* TODO: determine how much we want to loosen this */ + error = fn_for_each_in_ns(label, profile, + profile_onexec(profile, onexec, stack, bprm, + buffer, cond, unsafe)); + if (error) + return ERR_PTR(error); + new = fn_label_build_in_ns(label, profile, GFP_KERNEL, + aa_label_merge(&profile->label, onexec, + GFP_KERNEL), + profile_transition(profile, bprm, buffer, + cond, unsafe)); + } + + if (new) + return new; + + /* TODO: get rid of GLOBAL_ROOT_UID */ + error = fn_for_each_in_ns(label, profile, + aa_audit_file(profile, &nullperms, OP_CHANGE_ONEXEC, + AA_MAY_ONEXEC, bprm->filename, NULL, + onexec, GLOBAL_ROOT_UID, + "failed to build target label", -ENOMEM)); + return ERR_PTR(error); +} + +/** + * apparmor_bprm_creds_for_exec - Update the new creds on the bprm struct + * @bprm: binprm for the exec (NOT NULL) + * + * Returns: %0 or error on failure + * + * TODO: once the other paths are done see if we can't refactor into a fn + */ +int apparmor_bprm_creds_for_exec(struct linux_binprm *bprm) +{ + struct aa_task_ctx *ctx; + struct aa_label *label, *new = NULL; + struct aa_profile *profile; + char *buffer = NULL; + const char *info = NULL; + int error = 0; + bool unsafe = false; + kuid_t i_uid = i_uid_into_mnt(file_mnt_user_ns(bprm->file), + file_inode(bprm->file)); + struct path_cond cond = { + i_uid, + file_inode(bprm->file)->i_mode + }; + + ctx = task_ctx(current); + AA_BUG(!cred_label(bprm->cred)); + AA_BUG(!ctx); + + label = aa_get_newest_label(cred_label(bprm->cred)); + + /* + * Detect no new privs being set, and store the label it + * occurred under. Ideally this would happen when nnp + * is set but there isn't a good way to do that yet. + * + * Testing for unconfined must be done before the subset test + */ + if ((bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS) && !unconfined(label) && + !ctx->nnp) + ctx->nnp = aa_get_label(label); + + /* buffer freed below, name is pointer into buffer */ + buffer = aa_get_buffer(false); + if (!buffer) { + error = -ENOMEM; + goto done; + } + + /* Test for onexec first as onexec override other x transitions. */ + if (ctx->onexec) + new = handle_onexec(label, ctx->onexec, ctx->token, + bprm, buffer, &cond, &unsafe); + else + new = fn_label_build(label, profile, GFP_KERNEL, + profile_transition(profile, bprm, buffer, + &cond, &unsafe)); + + AA_BUG(!new); + if (IS_ERR(new)) { + error = PTR_ERR(new); + goto done; + } else if (!new) { + error = -ENOMEM; + goto done; + } + + /* Policy has specified a domain transitions. If no_new_privs and + * confined ensure the transition is to confinement that is subset + * of the confinement when the task entered no new privs. + * + * NOTE: Domain transitions from unconfined and to stacked + * subsets are allowed even when no_new_privs is set because this + * aways results in a further reduction of permissions. + */ + if ((bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS) && + !unconfined(label) && + !aa_label_is_unconfined_subset(new, ctx->nnp)) { + error = -EPERM; + info = "no new privs"; + goto audit; + } + + if (bprm->unsafe & LSM_UNSAFE_SHARE) { + /* FIXME: currently don't mediate shared state */ + ; + } + + if (bprm->unsafe & (LSM_UNSAFE_PTRACE)) { + /* TODO: test needs to be profile of label to new */ + error = may_change_ptraced_domain(new, &info); + if (error) + goto audit; + } + + if (unsafe) { + if (DEBUG_ON) { + dbg_printk("scrubbing environment variables for %s " + "label=", bprm->filename); + aa_label_printk(new, GFP_KERNEL); + dbg_printk("\n"); + } + bprm->secureexec = 1; + } + + if (label->proxy != new->proxy) { + /* when transitioning clear unsafe personality bits */ + if (DEBUG_ON) { + dbg_printk("apparmor: clearing unsafe personality " + "bits. %s label=", bprm->filename); + aa_label_printk(new, GFP_KERNEL); + dbg_printk("\n"); + } + bprm->per_clear |= PER_CLEAR_ON_SETID; + } + aa_put_label(cred_label(bprm->cred)); + /* transfer reference, released when cred is freed */ + set_cred_label(bprm->cred, new); + +done: + aa_put_label(label); + aa_put_buffer(buffer); + + return error; + +audit: + error = fn_for_each(label, profile, + aa_audit_file(profile, &nullperms, OP_EXEC, MAY_EXEC, + bprm->filename, NULL, new, + i_uid, info, error)); + aa_put_label(new); + goto done; +} + +/* + * Functions for self directed profile change + */ + + +/* helper fn for change_hat + * + * Returns: label for hat transition OR ERR_PTR. Does NOT return NULL + */ +static struct aa_label *build_change_hat(struct aa_profile *profile, + const char *name, bool sibling) +{ + struct aa_profile *root, *hat = NULL; + const char *info = NULL; + int error = 0; + + if (sibling && PROFILE_IS_HAT(profile)) { + root = aa_get_profile_rcu(&profile->parent); + } else if (!sibling && !PROFILE_IS_HAT(profile)) { + root = aa_get_profile(profile); + } else { + info = "conflicting target types"; + error = -EPERM; + goto audit; + } + + hat = aa_find_child(root, name); + if (!hat) { + error = -ENOENT; + if (COMPLAIN_MODE(profile)) { + hat = aa_new_null_profile(profile, true, name, + GFP_KERNEL); + if (!hat) { + info = "failed null profile create"; + error = -ENOMEM; + } + } + } + aa_put_profile(root); + +audit: + aa_audit_file(profile, &nullperms, OP_CHANGE_HAT, AA_MAY_CHANGEHAT, + name, hat ? hat->base.hname : NULL, + hat ? &hat->label : NULL, GLOBAL_ROOT_UID, info, + error); + if (!hat || (error && error != -ENOENT)) + return ERR_PTR(error); + /* if hat && error - complain mode, already audited and we adjust for + * complain mode allow by returning hat->label + */ + return &hat->label; +} + +/* helper fn for changing into a hat + * + * Returns: label for hat transition or ERR_PTR. Does not return NULL + */ +static struct aa_label *change_hat(struct aa_label *label, const char *hats[], + int count, int flags) +{ + struct aa_profile *profile, *root, *hat = NULL; + struct aa_label *new; + struct label_it it; + bool sibling = false; + const char *name, *info = NULL; + int i, error; + + AA_BUG(!label); + AA_BUG(!hats); + AA_BUG(count < 1); + + if (PROFILE_IS_HAT(labels_profile(label))) + sibling = true; + + /*find first matching hat */ + for (i = 0; i < count && !hat; i++) { + name = hats[i]; + label_for_each_in_ns(it, labels_ns(label), label, profile) { + if (sibling && PROFILE_IS_HAT(profile)) { + root = aa_get_profile_rcu(&profile->parent); + } else if (!sibling && !PROFILE_IS_HAT(profile)) { + root = aa_get_profile(profile); + } else { /* conflicting change type */ + info = "conflicting targets types"; + error = -EPERM; + goto fail; + } + hat = aa_find_child(root, name); + aa_put_profile(root); + if (!hat) { + if (!COMPLAIN_MODE(profile)) + goto outer_continue; + /* complain mode succeed as if hat */ + } else if (!PROFILE_IS_HAT(hat)) { + info = "target not hat"; + error = -EPERM; + aa_put_profile(hat); + goto fail; + } + aa_put_profile(hat); + } + /* found a hat for all profiles in ns */ + goto build; +outer_continue: + ; + } + /* no hats that match, find appropriate error + * + * In complain mode audit of the failure is based off of the first + * hat supplied. This is done due how userspace interacts with + * change_hat. + */ + name = NULL; + label_for_each_in_ns(it, labels_ns(label), label, profile) { + if (!list_empty(&profile->base.profiles)) { + info = "hat not found"; + error = -ENOENT; + goto fail; + } + } + info = "no hats defined"; + error = -ECHILD; + +fail: + label_for_each_in_ns(it, labels_ns(label), label, profile) { + /* + * no target as it has failed to be found or built + * + * change_hat uses probing and should not log failures + * related to missing hats + */ + /* TODO: get rid of GLOBAL_ROOT_UID */ + if (count > 1 || COMPLAIN_MODE(profile)) { + aa_audit_file(profile, &nullperms, OP_CHANGE_HAT, + AA_MAY_CHANGEHAT, name, NULL, NULL, + GLOBAL_ROOT_UID, info, error); + } + } + return ERR_PTR(error); + +build: + new = fn_label_build_in_ns(label, profile, GFP_KERNEL, + build_change_hat(profile, name, sibling), + aa_get_label(&profile->label)); + if (!new) { + info = "label build failed"; + error = -ENOMEM; + goto fail; + } /* else if (IS_ERR) build_change_hat has logged error so return new */ + + return new; +} + +/** + * aa_change_hat - change hat to/from subprofile + * @hats: vector of hat names to try changing into (MAYBE NULL if @count == 0) + * @count: number of hat names in @hats + * @token: magic value to validate the hat change + * @flags: flags affecting behavior of the change + * + * Returns %0 on success, error otherwise. + * + * Change to the first profile specified in @hats that exists, and store + * the @hat_magic in the current task context. If the count == 0 and the + * @token matches that stored in the current task context, return to the + * top level profile. + * + * change_hat only applies to profiles in the current ns, and each profile + * in the ns must make the same transition otherwise change_hat will fail. + */ +int aa_change_hat(const char *hats[], int count, u64 token, int flags) +{ + const struct cred *cred; + struct aa_task_ctx *ctx = task_ctx(current); + struct aa_label *label, *previous, *new = NULL, *target = NULL; + struct aa_profile *profile; + struct aa_perms perms = {}; + const char *info = NULL; + int error = 0; + + /* released below */ + cred = get_current_cred(); + label = aa_get_newest_cred_label(cred); + previous = aa_get_newest_label(ctx->previous); + + /* + * Detect no new privs being set, and store the label it + * occurred under. Ideally this would happen when nnp + * is set but there isn't a good way to do that yet. + * + * Testing for unconfined must be done before the subset test + */ + if (task_no_new_privs(current) && !unconfined(label) && !ctx->nnp) + ctx->nnp = aa_get_label(label); + + if (unconfined(label)) { + info = "unconfined can not change_hat"; + error = -EPERM; + goto fail; + } + + if (count) { + new = change_hat(label, hats, count, flags); + AA_BUG(!new); + if (IS_ERR(new)) { + error = PTR_ERR(new); + new = NULL; + /* already audited */ + goto out; + } + + error = may_change_ptraced_domain(new, &info); + if (error) + goto fail; + + /* + * no new privs prevents domain transitions that would + * reduce restrictions. + */ + if (task_no_new_privs(current) && !unconfined(label) && + !aa_label_is_unconfined_subset(new, ctx->nnp)) { + /* not an apparmor denial per se, so don't log it */ + AA_DEBUG("no_new_privs - change_hat denied"); + error = -EPERM; + goto out; + } + + if (flags & AA_CHANGE_TEST) + goto out; + + target = new; + error = aa_set_current_hat(new, token); + if (error == -EACCES) + /* kill task in case of brute force attacks */ + goto kill; + } else if (previous && !(flags & AA_CHANGE_TEST)) { + /* + * no new privs prevents domain transitions that would + * reduce restrictions. + */ + if (task_no_new_privs(current) && !unconfined(label) && + !aa_label_is_unconfined_subset(previous, ctx->nnp)) { + /* not an apparmor denial per se, so don't log it */ + AA_DEBUG("no_new_privs - change_hat denied"); + error = -EPERM; + goto out; + } + + /* Return to saved label. Kill task if restore fails + * to avoid brute force attacks + */ + target = previous; + error = aa_restore_previous_label(token); + if (error) { + if (error == -EACCES) + goto kill; + goto fail; + } + } /* else ignore @flags && restores when there is no saved profile */ + +out: + aa_put_label(new); + aa_put_label(previous); + aa_put_label(label); + put_cred(cred); + + return error; + +kill: + info = "failed token match"; + perms.kill = AA_MAY_CHANGEHAT; + +fail: + fn_for_each_in_ns(label, profile, + aa_audit_file(profile, &perms, OP_CHANGE_HAT, + AA_MAY_CHANGEHAT, NULL, NULL, target, + GLOBAL_ROOT_UID, info, error)); + + goto out; +} + + +static int change_profile_perms_wrapper(const char *op, const char *name, + struct aa_profile *profile, + struct aa_label *target, bool stack, + u32 request, struct aa_perms *perms) +{ + const char *info = NULL; + int error = 0; + + if (!error) + error = change_profile_perms(profile, target, stack, request, + profile->file.start, perms); + if (error) + error = aa_audit_file(profile, perms, op, request, name, + NULL, target, GLOBAL_ROOT_UID, info, + error); + + return error; +} + +/** + * aa_change_profile - perform a one-way profile transition + * @fqname: name of profile may include namespace (NOT NULL) + * @flags: flags affecting change behavior + * + * Change to new profile @name. Unlike with hats, there is no way + * to change back. If @name isn't specified the current profile name is + * used. + * If @onexec then the transition is delayed until + * the next exec. + * + * Returns %0 on success, error otherwise. + */ +int aa_change_profile(const char *fqname, int flags) +{ + struct aa_label *label, *new = NULL, *target = NULL; + struct aa_profile *profile; + struct aa_perms perms = {}; + const char *info = NULL; + const char *auditname = fqname; /* retain leading & if stack */ + bool stack = flags & AA_CHANGE_STACK; + struct aa_task_ctx *ctx = task_ctx(current); + int error = 0; + char *op; + u32 request; + + label = aa_get_current_label(); + + /* + * Detect no new privs being set, and store the label it + * occurred under. Ideally this would happen when nnp + * is set but there isn't a good way to do that yet. + * + * Testing for unconfined must be done before the subset test + */ + if (task_no_new_privs(current) && !unconfined(label) && !ctx->nnp) + ctx->nnp = aa_get_label(label); + + if (!fqname || !*fqname) { + aa_put_label(label); + AA_DEBUG("no profile name"); + return -EINVAL; + } + + if (flags & AA_CHANGE_ONEXEC) { + request = AA_MAY_ONEXEC; + if (stack) + op = OP_STACK_ONEXEC; + else + op = OP_CHANGE_ONEXEC; + } else { + request = AA_MAY_CHANGE_PROFILE; + if (stack) + op = OP_STACK; + else + op = OP_CHANGE_PROFILE; + } + + if (*fqname == '&') { + stack = true; + /* don't have label_parse() do stacking */ + fqname++; + } + target = aa_label_parse(label, fqname, GFP_KERNEL, true, false); + if (IS_ERR(target)) { + struct aa_profile *tprofile; + + info = "label not found"; + error = PTR_ERR(target); + target = NULL; + /* + * TODO: fixme using labels_profile is not right - do profile + * per complain profile + */ + if ((flags & AA_CHANGE_TEST) || + !COMPLAIN_MODE(labels_profile(label))) + goto audit; + /* released below */ + tprofile = aa_new_null_profile(labels_profile(label), false, + fqname, GFP_KERNEL); + if (!tprofile) { + info = "failed null profile create"; + error = -ENOMEM; + goto audit; + } + target = &tprofile->label; + goto check; + } + + /* + * self directed transitions only apply to current policy ns + * TODO: currently requiring perms for stacking and straight change + * stacking doesn't strictly need this. Determine how much + * we want to loosen this restriction for stacking + * + * if (!stack) { + */ + error = fn_for_each_in_ns(label, profile, + change_profile_perms_wrapper(op, auditname, + profile, target, stack, + request, &perms)); + if (error) + /* auditing done in change_profile_perms_wrapper */ + goto out; + + /* } */ + +check: + /* check if tracing task is allowed to trace target domain */ + error = may_change_ptraced_domain(target, &info); + if (error && !fn_for_each_in_ns(label, profile, + COMPLAIN_MODE(profile))) + goto audit; + + /* TODO: add permission check to allow this + * if ((flags & AA_CHANGE_ONEXEC) && !current_is_single_threaded()) { + * info = "not a single threaded task"; + * error = -EACCES; + * goto audit; + * } + */ + if (flags & AA_CHANGE_TEST) + goto out; + + /* stacking is always a subset, so only check the nonstack case */ + if (!stack) { + new = fn_label_build_in_ns(label, profile, GFP_KERNEL, + aa_get_label(target), + aa_get_label(&profile->label)); + /* + * no new privs prevents domain transitions that would + * reduce restrictions. + */ + if (task_no_new_privs(current) && !unconfined(label) && + !aa_label_is_unconfined_subset(new, ctx->nnp)) { + /* not an apparmor denial per se, so don't log it */ + AA_DEBUG("no_new_privs - change_hat denied"); + error = -EPERM; + goto out; + } + } + + if (!(flags & AA_CHANGE_ONEXEC)) { + /* only transition profiles in the current ns */ + if (stack) + new = aa_label_merge(label, target, GFP_KERNEL); + if (IS_ERR_OR_NULL(new)) { + info = "failed to build target label"; + if (!new) + error = -ENOMEM; + else + error = PTR_ERR(new); + new = NULL; + perms.allow = 0; + goto audit; + } + error = aa_replace_current_label(new); + } else { + if (new) { + aa_put_label(new); + new = NULL; + } + + /* full transition will be built in exec path */ + error = aa_set_current_onexec(target, stack); + } + +audit: + error = fn_for_each_in_ns(label, profile, + aa_audit_file(profile, &perms, op, request, auditname, + NULL, new ? new : target, + GLOBAL_ROOT_UID, info, error)); + +out: + aa_put_label(new); + aa_put_label(target); + aa_put_label(label); + + return error; +} diff --git a/security/apparmor/file.c b/security/apparmor/file.c new file mode 100644 index 000000000..e1b7e9360 --- /dev/null +++ b/security/apparmor/file.c @@ -0,0 +1,711 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * AppArmor security module + * + * This file contains AppArmor mediation of files + * + * Copyright (C) 1998-2008 Novell/SUSE + * Copyright 2009-2010 Canonical Ltd. + */ + +#include <linux/tty.h> +#include <linux/fdtable.h> +#include <linux/file.h> +#include <linux/fs.h> +#include <linux/mount.h> + +#include "include/apparmor.h" +#include "include/audit.h" +#include "include/cred.h" +#include "include/file.h" +#include "include/match.h" +#include "include/net.h" +#include "include/path.h" +#include "include/policy.h" +#include "include/label.h" + +static u32 map_mask_to_chr_mask(u32 mask) +{ + u32 m = mask & PERMS_CHRS_MASK; + + if (mask & AA_MAY_GETATTR) + m |= MAY_READ; + if (mask & (AA_MAY_SETATTR | AA_MAY_CHMOD | AA_MAY_CHOWN)) + m |= MAY_WRITE; + + return m; +} + +/** + * file_audit_cb - call back for file specific audit fields + * @ab: audit_buffer (NOT NULL) + * @va: audit struct to audit values of (NOT NULL) + */ +static void file_audit_cb(struct audit_buffer *ab, void *va) +{ + struct common_audit_data *sa = va; + kuid_t fsuid = current_fsuid(); + char str[10]; + + if (aad(sa)->request & AA_AUDIT_FILE_MASK) { + aa_perm_mask_to_str(str, sizeof(str), aa_file_perm_chrs, + map_mask_to_chr_mask(aad(sa)->request)); + audit_log_format(ab, " requested_mask=\"%s\"", str); + } + if (aad(sa)->denied & AA_AUDIT_FILE_MASK) { + aa_perm_mask_to_str(str, sizeof(str), aa_file_perm_chrs, + map_mask_to_chr_mask(aad(sa)->denied)); + audit_log_format(ab, " denied_mask=\"%s\"", str); + } + if (aad(sa)->request & AA_AUDIT_FILE_MASK) { + audit_log_format(ab, " fsuid=%d", + from_kuid(&init_user_ns, fsuid)); + audit_log_format(ab, " ouid=%d", + from_kuid(&init_user_ns, aad(sa)->fs.ouid)); + } + + if (aad(sa)->peer) { + audit_log_format(ab, " target="); + aa_label_xaudit(ab, labels_ns(aad(sa)->label), aad(sa)->peer, + FLAG_VIEW_SUBNS, GFP_KERNEL); + } else if (aad(sa)->fs.target) { + audit_log_format(ab, " target="); + audit_log_untrustedstring(ab, aad(sa)->fs.target); + } +} + +/** + * aa_audit_file - handle the auditing of file operations + * @profile: the profile being enforced (NOT NULL) + * @perms: the permissions computed for the request (NOT NULL) + * @op: operation being mediated + * @request: permissions requested + * @name: name of object being mediated (MAYBE NULL) + * @target: name of target (MAYBE NULL) + * @tlabel: target label (MAY BE NULL) + * @ouid: object uid + * @info: extra information message (MAYBE NULL) + * @error: 0 if operation allowed else failure error code + * + * Returns: %0 or error on failure + */ +int aa_audit_file(struct aa_profile *profile, struct aa_perms *perms, + const char *op, u32 request, const char *name, + const char *target, struct aa_label *tlabel, + kuid_t ouid, const char *info, int error) +{ + int type = AUDIT_APPARMOR_AUTO; + DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_TASK, op); + + sa.u.tsk = NULL; + aad(&sa)->request = request; + aad(&sa)->name = name; + aad(&sa)->fs.target = target; + aad(&sa)->peer = tlabel; + aad(&sa)->fs.ouid = ouid; + aad(&sa)->info = info; + aad(&sa)->error = error; + sa.u.tsk = NULL; + + if (likely(!aad(&sa)->error)) { + u32 mask = perms->audit; + + if (unlikely(AUDIT_MODE(profile) == AUDIT_ALL)) + mask = 0xffff; + + /* mask off perms that are not being force audited */ + aad(&sa)->request &= mask; + + if (likely(!aad(&sa)->request)) + return 0; + type = AUDIT_APPARMOR_AUDIT; + } else { + /* only report permissions that were denied */ + aad(&sa)->request = aad(&sa)->request & ~perms->allow; + AA_BUG(!aad(&sa)->request); + + if (aad(&sa)->request & perms->kill) + type = AUDIT_APPARMOR_KILL; + + /* quiet known rejects, assumes quiet and kill do not overlap */ + if ((aad(&sa)->request & perms->quiet) && + AUDIT_MODE(profile) != AUDIT_NOQUIET && + AUDIT_MODE(profile) != AUDIT_ALL) + aad(&sa)->request &= ~perms->quiet; + + if (!aad(&sa)->request) + return aad(&sa)->error; + } + + aad(&sa)->denied = aad(&sa)->request & ~perms->allow; + return aa_audit(type, profile, &sa, file_audit_cb); +} + +/** + * is_deleted - test if a file has been completely unlinked + * @dentry: dentry of file to test for deletion (NOT NULL) + * + * Returns: true if deleted else false + */ +static inline bool is_deleted(struct dentry *dentry) +{ + if (d_unlinked(dentry) && d_backing_inode(dentry)->i_nlink == 0) + return true; + return false; +} + +static int path_name(const char *op, struct aa_label *label, + const struct path *path, int flags, char *buffer, + const char **name, struct path_cond *cond, u32 request) +{ + struct aa_profile *profile; + const char *info = NULL; + int error; + + error = aa_path_name(path, flags, buffer, name, &info, + labels_profile(label)->disconnected); + if (error) { + fn_for_each_confined(label, profile, + aa_audit_file(profile, &nullperms, op, request, *name, + NULL, NULL, cond->uid, info, error)); + return error; + } + + return 0; +} + +/** + * map_old_perms - map old file perms layout to the new layout + * @old: permission set in old mapping + * + * Returns: new permission mapping + */ +static u32 map_old_perms(u32 old) +{ + u32 new = old & 0xf; + if (old & MAY_READ) + new |= AA_MAY_GETATTR | AA_MAY_OPEN; + if (old & MAY_WRITE) + new |= AA_MAY_SETATTR | AA_MAY_CREATE | AA_MAY_DELETE | + AA_MAY_CHMOD | AA_MAY_CHOWN | AA_MAY_OPEN; + if (old & 0x10) + new |= AA_MAY_LINK; + /* the old mapping lock and link_subset flags where overlaid + * and use was determined by part of a pair that they were in + */ + if (old & 0x20) + new |= AA_MAY_LOCK | AA_LINK_SUBSET; + if (old & 0x40) /* AA_EXEC_MMAP */ + new |= AA_EXEC_MMAP; + + return new; +} + +/** + * aa_compute_fperms - convert dfa compressed perms to internal perms + * @dfa: dfa to compute perms for (NOT NULL) + * @state: state in dfa + * @cond: conditions to consider (NOT NULL) + * + * TODO: convert from dfa + state to permission entry, do computation conversion + * at load time. + * + * Returns: computed permission set + */ +struct aa_perms aa_compute_fperms(struct aa_dfa *dfa, unsigned int state, + struct path_cond *cond) +{ + /* FIXME: change over to new dfa format + * currently file perms are encoded in the dfa, new format + * splits the permissions from the dfa. This mapping can be + * done at profile load + */ + struct aa_perms perms = { }; + + if (uid_eq(current_fsuid(), cond->uid)) { + perms.allow = map_old_perms(dfa_user_allow(dfa, state)); + perms.audit = map_old_perms(dfa_user_audit(dfa, state)); + perms.quiet = map_old_perms(dfa_user_quiet(dfa, state)); + perms.xindex = dfa_user_xindex(dfa, state); + } else { + perms.allow = map_old_perms(dfa_other_allow(dfa, state)); + perms.audit = map_old_perms(dfa_other_audit(dfa, state)); + perms.quiet = map_old_perms(dfa_other_quiet(dfa, state)); + perms.xindex = dfa_other_xindex(dfa, state); + } + perms.allow |= AA_MAY_GETATTR; + + /* change_profile wasn't determined by ownership in old mapping */ + if (ACCEPT_TABLE(dfa)[state] & 0x80000000) + perms.allow |= AA_MAY_CHANGE_PROFILE; + if (ACCEPT_TABLE(dfa)[state] & 0x40000000) + perms.allow |= AA_MAY_ONEXEC; + + return perms; +} + +/** + * aa_str_perms - find permission that match @name + * @dfa: to match against (MAYBE NULL) + * @state: state to start matching in + * @name: string to match against dfa (NOT NULL) + * @cond: conditions to consider for permission set computation (NOT NULL) + * @perms: Returns - the permissions found when matching @name + * + * Returns: the final state in @dfa when beginning @start and walking @name + */ +unsigned int aa_str_perms(struct aa_dfa *dfa, unsigned int start, + const char *name, struct path_cond *cond, + struct aa_perms *perms) +{ + unsigned int state; + state = aa_dfa_match(dfa, start, name); + *perms = aa_compute_fperms(dfa, state, cond); + + return state; +} + +int __aa_path_perm(const char *op, struct aa_profile *profile, const char *name, + u32 request, struct path_cond *cond, int flags, + struct aa_perms *perms) +{ + int e = 0; + + if (profile_unconfined(profile)) + return 0; + aa_str_perms(profile->file.dfa, profile->file.start, name, cond, perms); + if (request & ~perms->allow) + e = -EACCES; + return aa_audit_file(profile, perms, op, request, name, NULL, NULL, + cond->uid, NULL, e); +} + + +static int profile_path_perm(const char *op, struct aa_profile *profile, + const struct path *path, char *buffer, u32 request, + struct path_cond *cond, int flags, + struct aa_perms *perms) +{ + const char *name; + int error; + + if (profile_unconfined(profile)) + return 0; + + error = path_name(op, &profile->label, path, + flags | profile->path_flags, buffer, &name, cond, + request); + if (error) + return error; + return __aa_path_perm(op, profile, name, request, cond, flags, + perms); +} + +/** + * aa_path_perm - do permissions check & audit for @path + * @op: operation being checked + * @label: profile being enforced (NOT NULL) + * @path: path to check permissions of (NOT NULL) + * @flags: any additional path flags beyond what the profile specifies + * @request: requested permissions + * @cond: conditional info for this request (NOT NULL) + * + * Returns: %0 else error if access denied or other error + */ +int aa_path_perm(const char *op, struct aa_label *label, + const struct path *path, int flags, u32 request, + struct path_cond *cond) +{ + struct aa_perms perms = {}; + struct aa_profile *profile; + char *buffer = NULL; + int error; + + flags |= PATH_DELEGATE_DELETED | (S_ISDIR(cond->mode) ? PATH_IS_DIR : + 0); + buffer = aa_get_buffer(false); + if (!buffer) + return -ENOMEM; + error = fn_for_each_confined(label, profile, + profile_path_perm(op, profile, path, buffer, request, + cond, flags, &perms)); + + aa_put_buffer(buffer); + + return error; +} + +/** + * xindex_is_subset - helper for aa_path_link + * @link: link permission set + * @target: target permission set + * + * test target x permissions are equal OR a subset of link x permissions + * this is done as part of the subset test, where a hardlink must have + * a subset of permissions that the target has. + * + * Returns: true if subset else false + */ +static inline bool xindex_is_subset(u32 link, u32 target) +{ + if (((link & ~AA_X_UNSAFE) != (target & ~AA_X_UNSAFE)) || + ((link & AA_X_UNSAFE) && !(target & AA_X_UNSAFE))) + return false; + + return true; +} + +static int profile_path_link(struct aa_profile *profile, + const struct path *link, char *buffer, + const struct path *target, char *buffer2, + struct path_cond *cond) +{ + const char *lname, *tname = NULL; + struct aa_perms lperms = {}, perms; + const char *info = NULL; + u32 request = AA_MAY_LINK; + unsigned int state; + int error; + + error = path_name(OP_LINK, &profile->label, link, profile->path_flags, + buffer, &lname, cond, AA_MAY_LINK); + if (error) + goto audit; + + /* buffer2 freed below, tname is pointer in buffer2 */ + error = path_name(OP_LINK, &profile->label, target, profile->path_flags, + buffer2, &tname, cond, AA_MAY_LINK); + if (error) + goto audit; + + error = -EACCES; + /* aa_str_perms - handles the case of the dfa being NULL */ + state = aa_str_perms(profile->file.dfa, profile->file.start, lname, + cond, &lperms); + + if (!(lperms.allow & AA_MAY_LINK)) + goto audit; + + /* test to see if target can be paired with link */ + state = aa_dfa_null_transition(profile->file.dfa, state); + aa_str_perms(profile->file.dfa, state, tname, cond, &perms); + + /* force audit/quiet masks for link are stored in the second entry + * in the link pair. + */ + lperms.audit = perms.audit; + lperms.quiet = perms.quiet; + lperms.kill = perms.kill; + + if (!(perms.allow & AA_MAY_LINK)) { + info = "target restricted"; + lperms = perms; + goto audit; + } + + /* done if link subset test is not required */ + if (!(perms.allow & AA_LINK_SUBSET)) + goto done_tests; + + /* Do link perm subset test requiring allowed permission on link are + * a subset of the allowed permissions on target. + */ + aa_str_perms(profile->file.dfa, profile->file.start, tname, cond, + &perms); + + /* AA_MAY_LINK is not considered in the subset test */ + request = lperms.allow & ~AA_MAY_LINK; + lperms.allow &= perms.allow | AA_MAY_LINK; + + request |= AA_AUDIT_FILE_MASK & (lperms.allow & ~perms.allow); + if (request & ~lperms.allow) { + goto audit; + } else if ((lperms.allow & MAY_EXEC) && + !xindex_is_subset(lperms.xindex, perms.xindex)) { + lperms.allow &= ~MAY_EXEC; + request |= MAY_EXEC; + info = "link not subset of target"; + goto audit; + } + +done_tests: + error = 0; + +audit: + return aa_audit_file(profile, &lperms, OP_LINK, request, lname, tname, + NULL, cond->uid, info, error); +} + +/** + * aa_path_link - Handle hard link permission check + * @label: the label being enforced (NOT NULL) + * @old_dentry: the target dentry (NOT NULL) + * @new_dir: directory the new link will be created in (NOT NULL) + * @new_dentry: the link being created (NOT NULL) + * + * Handle the permission test for a link & target pair. Permission + * is encoded as a pair where the link permission is determined + * first, and if allowed, the target is tested. The target test + * is done from the point of the link match (not start of DFA) + * making the target permission dependent on the link permission match. + * + * The subset test if required forces that permissions granted + * on link are a subset of the permission granted to target. + * + * Returns: %0 if allowed else error + */ +int aa_path_link(struct aa_label *label, struct dentry *old_dentry, + const struct path *new_dir, struct dentry *new_dentry) +{ + struct path link = { .mnt = new_dir->mnt, .dentry = new_dentry }; + struct path target = { .mnt = new_dir->mnt, .dentry = old_dentry }; + struct path_cond cond = { + d_backing_inode(old_dentry)->i_uid, + d_backing_inode(old_dentry)->i_mode + }; + char *buffer = NULL, *buffer2 = NULL; + struct aa_profile *profile; + int error; + + /* buffer freed below, lname is pointer in buffer */ + buffer = aa_get_buffer(false); + buffer2 = aa_get_buffer(false); + error = -ENOMEM; + if (!buffer || !buffer2) + goto out; + + error = fn_for_each_confined(label, profile, + profile_path_link(profile, &link, buffer, &target, + buffer2, &cond)); +out: + aa_put_buffer(buffer); + aa_put_buffer(buffer2); + return error; +} + +static void update_file_ctx(struct aa_file_ctx *fctx, struct aa_label *label, + u32 request) +{ + struct aa_label *l, *old; + + /* update caching of label on file_ctx */ + spin_lock(&fctx->lock); + old = rcu_dereference_protected(fctx->label, + lockdep_is_held(&fctx->lock)); + l = aa_label_merge(old, label, GFP_ATOMIC); + if (l) { + if (l != old) { + rcu_assign_pointer(fctx->label, l); + aa_put_label(old); + } else + aa_put_label(l); + fctx->allow |= request; + } + spin_unlock(&fctx->lock); +} + +static int __file_path_perm(const char *op, struct aa_label *label, + struct aa_label *flabel, struct file *file, + u32 request, u32 denied, bool in_atomic) +{ + struct aa_profile *profile; + struct aa_perms perms = {}; + struct path_cond cond = { + .uid = i_uid_into_mnt(file_mnt_user_ns(file), file_inode(file)), + .mode = file_inode(file)->i_mode + }; + char *buffer; + int flags, error; + + /* revalidation due to label out of date. No revocation at this time */ + if (!denied && aa_label_is_subset(flabel, label)) + /* TODO: check for revocation on stale profiles */ + return 0; + + flags = PATH_DELEGATE_DELETED | (S_ISDIR(cond.mode) ? PATH_IS_DIR : 0); + buffer = aa_get_buffer(in_atomic); + if (!buffer) + return -ENOMEM; + + /* check every profile in task label not in current cache */ + error = fn_for_each_not_in_set(flabel, label, profile, + profile_path_perm(op, profile, &file->f_path, buffer, + request, &cond, flags, &perms)); + if (denied && !error) { + /* + * check every profile in file label that was not tested + * in the initial check above. + * + * TODO: cache full perms so this only happens because of + * conditionals + * TODO: don't audit here + */ + if (label == flabel) + error = fn_for_each(label, profile, + profile_path_perm(op, profile, &file->f_path, + buffer, request, &cond, flags, + &perms)); + else + error = fn_for_each_not_in_set(label, flabel, profile, + profile_path_perm(op, profile, &file->f_path, + buffer, request, &cond, flags, + &perms)); + } + if (!error) + update_file_ctx(file_ctx(file), label, request); + + aa_put_buffer(buffer); + + return error; +} + +static int __file_sock_perm(const char *op, struct aa_label *label, + struct aa_label *flabel, struct file *file, + u32 request, u32 denied) +{ + struct socket *sock = (struct socket *) file->private_data; + int error; + + AA_BUG(!sock); + + /* revalidation due to label out of date. No revocation at this time */ + if (!denied && aa_label_is_subset(flabel, label)) + return 0; + + /* TODO: improve to skip profiles cached in flabel */ + error = aa_sock_file_perm(label, op, request, sock); + if (denied) { + /* TODO: improve to skip profiles checked above */ + /* check every profile in file label to is cached */ + last_error(error, aa_sock_file_perm(flabel, op, request, sock)); + } + if (!error) + update_file_ctx(file_ctx(file), label, request); + + return error; +} + +/** + * aa_file_perm - do permission revalidation check & audit for @file + * @op: operation being checked + * @label: label being enforced (NOT NULL) + * @file: file to revalidate access permissions on (NOT NULL) + * @request: requested permissions + * @in_atomic: whether allocations need to be done in atomic context + * + * Returns: %0 if access allowed else error + */ +int aa_file_perm(const char *op, struct aa_label *label, struct file *file, + u32 request, bool in_atomic) +{ + struct aa_file_ctx *fctx; + struct aa_label *flabel; + u32 denied; + int error = 0; + + AA_BUG(!label); + AA_BUG(!file); + + fctx = file_ctx(file); + + rcu_read_lock(); + flabel = rcu_dereference(fctx->label); + AA_BUG(!flabel); + + /* revalidate access, if task is unconfined, or the cached cred + * doesn't match or if the request is for more permissions than + * was granted. + * + * Note: the test for !unconfined(flabel) is to handle file + * delegation from unconfined tasks + */ + denied = request & ~fctx->allow; + if (unconfined(label) || unconfined(flabel) || + (!denied && aa_label_is_subset(flabel, label))) { + rcu_read_unlock(); + goto done; + } + + flabel = aa_get_newest_label(flabel); + rcu_read_unlock(); + /* TODO: label cross check */ + + if (file->f_path.mnt && path_mediated_fs(file->f_path.dentry)) + error = __file_path_perm(op, label, flabel, file, request, + denied, in_atomic); + + else if (S_ISSOCK(file_inode(file)->i_mode)) + error = __file_sock_perm(op, label, flabel, file, request, + denied); + aa_put_label(flabel); + +done: + return error; +} + +static void revalidate_tty(struct aa_label *label) +{ + struct tty_struct *tty; + int drop_tty = 0; + + tty = get_current_tty(); + if (!tty) + return; + + spin_lock(&tty->files_lock); + if (!list_empty(&tty->tty_files)) { + struct tty_file_private *file_priv; + struct file *file; + /* TODO: Revalidate access to controlling tty. */ + file_priv = list_first_entry(&tty->tty_files, + struct tty_file_private, list); + file = file_priv->file; + + if (aa_file_perm(OP_INHERIT, label, file, MAY_READ | MAY_WRITE, + IN_ATOMIC)) + drop_tty = 1; + } + spin_unlock(&tty->files_lock); + tty_kref_put(tty); + + if (drop_tty) + no_tty(); +} + +static int match_file(const void *p, struct file *file, unsigned int fd) +{ + struct aa_label *label = (struct aa_label *)p; + + if (aa_file_perm(OP_INHERIT, label, file, aa_map_file_to_perms(file), + IN_ATOMIC)) + return fd + 1; + return 0; +} + + +/* based on selinux's flush_unauthorized_files */ +void aa_inherit_files(const struct cred *cred, struct files_struct *files) +{ + struct aa_label *label = aa_get_newest_cred_label(cred); + struct file *devnull = NULL; + unsigned int n; + + revalidate_tty(label); + + /* Revalidate access to inherited open files. */ + n = iterate_fd(files, 0, match_file, label); + if (!n) /* none found? */ + goto out; + + devnull = dentry_open(&aa_null, O_RDWR, cred); + if (IS_ERR(devnull)) + devnull = NULL; + /* replace all the matching ones with this */ + do { + replace_fd(n - 1, devnull, 0); + } while ((n = iterate_fd(files, n, match_file, label)) != 0); + if (devnull) + fput(devnull); +out: + aa_put_label(label); +} diff --git a/security/apparmor/include/apparmor.h b/security/apparmor/include/apparmor.h new file mode 100644 index 000000000..9c3fc36a0 --- /dev/null +++ b/security/apparmor/include/apparmor.h @@ -0,0 +1,46 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * AppArmor security module + * + * This file contains AppArmor basic global + * + * Copyright (C) 1998-2008 Novell/SUSE + * Copyright 2009-2017 Canonical Ltd. + */ + +#ifndef __APPARMOR_H +#define __APPARMOR_H + +#include <linux/types.h> + +/* + * Class of mediation types in the AppArmor policy db + */ +#define AA_CLASS_ENTRY 0 +#define AA_CLASS_UNKNOWN 1 +#define AA_CLASS_FILE 2 +#define AA_CLASS_CAP 3 +#define AA_CLASS_DEPRECATED 4 +#define AA_CLASS_RLIMITS 5 +#define AA_CLASS_DOMAIN 6 +#define AA_CLASS_MOUNT 7 +#define AA_CLASS_PTRACE 9 +#define AA_CLASS_SIGNAL 10 +#define AA_CLASS_NET 14 +#define AA_CLASS_LABEL 16 + +#define AA_CLASS_LAST AA_CLASS_LABEL + +/* Control parameters settable through module/boot flags */ +extern enum audit_mode aa_g_audit; +extern bool aa_g_audit_header; +extern bool aa_g_debug; +extern bool aa_g_hash_policy; +extern bool aa_g_export_binary; +extern int aa_g_rawdata_compression_level; +extern bool aa_g_lock_policy; +extern bool aa_g_logsyscall; +extern bool aa_g_paranoid_load; +extern unsigned int aa_g_path_max; + +#endif /* __APPARMOR_H */ diff --git a/security/apparmor/include/apparmorfs.h b/security/apparmor/include/apparmorfs.h new file mode 100644 index 000000000..1e94904f6 --- /dev/null +++ b/security/apparmor/include/apparmorfs.h @@ -0,0 +1,134 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * AppArmor security module + * + * This file contains AppArmor filesystem definitions. + * + * Copyright (C) 1998-2008 Novell/SUSE + * Copyright 2009-2010 Canonical Ltd. + */ + +#ifndef __AA_APPARMORFS_H +#define __AA_APPARMORFS_H + +extern struct path aa_null; + +enum aa_sfs_type { + AA_SFS_TYPE_BOOLEAN, + AA_SFS_TYPE_STRING, + AA_SFS_TYPE_U64, + AA_SFS_TYPE_FOPS, + AA_SFS_TYPE_DIR, +}; + +struct aa_sfs_entry; + +struct aa_sfs_entry { + const char *name; + struct dentry *dentry; + umode_t mode; + enum aa_sfs_type v_type; + union { + bool boolean; + char *string; + unsigned long u64; + struct aa_sfs_entry *files; + } v; + const struct file_operations *file_ops; +}; + +extern const struct file_operations aa_sfs_seq_file_ops; + +#define AA_SFS_FILE_BOOLEAN(_name, _value) \ + { .name = (_name), .mode = 0444, \ + .v_type = AA_SFS_TYPE_BOOLEAN, .v.boolean = (_value), \ + .file_ops = &aa_sfs_seq_file_ops } +#define AA_SFS_FILE_STRING(_name, _value) \ + { .name = (_name), .mode = 0444, \ + .v_type = AA_SFS_TYPE_STRING, .v.string = (_value), \ + .file_ops = &aa_sfs_seq_file_ops } +#define AA_SFS_FILE_U64(_name, _value) \ + { .name = (_name), .mode = 0444, \ + .v_type = AA_SFS_TYPE_U64, .v.u64 = (_value), \ + .file_ops = &aa_sfs_seq_file_ops } +#define AA_SFS_FILE_FOPS(_name, _mode, _fops) \ + { .name = (_name), .v_type = AA_SFS_TYPE_FOPS, \ + .mode = (_mode), .file_ops = (_fops) } +#define AA_SFS_DIR(_name, _value) \ + { .name = (_name), .v_type = AA_SFS_TYPE_DIR, .v.files = (_value) } + +extern void __init aa_destroy_aafs(void); + +struct aa_profile; +struct aa_ns; + +enum aafs_ns_type { + AAFS_NS_DIR, + AAFS_NS_PROFS, + AAFS_NS_NS, + AAFS_NS_RAW_DATA, + AAFS_NS_LOAD, + AAFS_NS_REPLACE, + AAFS_NS_REMOVE, + AAFS_NS_REVISION, + AAFS_NS_COUNT, + AAFS_NS_MAX_COUNT, + AAFS_NS_SIZE, + AAFS_NS_MAX_SIZE, + AAFS_NS_OWNER, + AAFS_NS_SIZEOF, +}; + +enum aafs_prof_type { + AAFS_PROF_DIR, + AAFS_PROF_PROFS, + AAFS_PROF_NAME, + AAFS_PROF_MODE, + AAFS_PROF_ATTACH, + AAFS_PROF_HASH, + AAFS_PROF_RAW_DATA, + AAFS_PROF_RAW_HASH, + AAFS_PROF_RAW_ABI, + AAFS_PROF_SIZEOF, +}; + +#define ns_dir(X) ((X)->dents[AAFS_NS_DIR]) +#define ns_subns_dir(X) ((X)->dents[AAFS_NS_NS]) +#define ns_subprofs_dir(X) ((X)->dents[AAFS_NS_PROFS]) +#define ns_subdata_dir(X) ((X)->dents[AAFS_NS_RAW_DATA]) +#define ns_subload(X) ((X)->dents[AAFS_NS_LOAD]) +#define ns_subreplace(X) ((X)->dents[AAFS_NS_REPLACE]) +#define ns_subremove(X) ((X)->dents[AAFS_NS_REMOVE]) +#define ns_subrevision(X) ((X)->dents[AAFS_NS_REVISION]) + +#define prof_dir(X) ((X)->dents[AAFS_PROF_DIR]) +#define prof_child_dir(X) ((X)->dents[AAFS_PROF_PROFS]) + +void __aa_bump_ns_revision(struct aa_ns *ns); +void __aafs_profile_rmdir(struct aa_profile *profile); +void __aafs_profile_migrate_dents(struct aa_profile *old, + struct aa_profile *new); +int __aafs_profile_mkdir(struct aa_profile *profile, struct dentry *parent); +void __aafs_ns_rmdir(struct aa_ns *ns); +int __aafs_ns_mkdir(struct aa_ns *ns, struct dentry *parent, const char *name, + struct dentry *dent); + +struct aa_loaddata; + +#ifdef CONFIG_SECURITY_APPARMOR_EXPORT_BINARY +void __aa_fs_remove_rawdata(struct aa_loaddata *rawdata); +int __aa_fs_create_rawdata(struct aa_ns *ns, struct aa_loaddata *rawdata); +#else +static inline void __aa_fs_remove_rawdata(struct aa_loaddata *rawdata) +{ + /* empty stub */ +} + +static inline int __aa_fs_create_rawdata(struct aa_ns *ns, + struct aa_loaddata *rawdata) +{ + return 0; +} +#endif /* CONFIG_SECURITY_APPARMOR_EXPORT_BINARY */ + +#endif /* __AA_APPARMORFS_H */ diff --git a/security/apparmor/include/audit.h b/security/apparmor/include/audit.h new file mode 100644 index 000000000..18519a4eb --- /dev/null +++ b/security/apparmor/include/audit.h @@ -0,0 +1,193 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * AppArmor security module + * + * This file contains AppArmor auditing function definitions. + * + * Copyright (C) 1998-2008 Novell/SUSE + * Copyright 2009-2010 Canonical Ltd. + */ + +#ifndef __AA_AUDIT_H +#define __AA_AUDIT_H + +#include <linux/audit.h> +#include <linux/fs.h> +#include <linux/lsm_audit.h> +#include <linux/sched.h> +#include <linux/slab.h> + +#include "file.h" +#include "label.h" + +extern const char *const audit_mode_names[]; +#define AUDIT_MAX_INDEX 5 +enum audit_mode { + AUDIT_NORMAL, /* follow normal auditing of accesses */ + AUDIT_QUIET_DENIED, /* quiet all denied access messages */ + AUDIT_QUIET, /* quiet all messages */ + AUDIT_NOQUIET, /* do not quiet audit messages */ + AUDIT_ALL /* audit all accesses */ +}; + +enum audit_type { + AUDIT_APPARMOR_AUDIT, + AUDIT_APPARMOR_ALLOWED, + AUDIT_APPARMOR_DENIED, + AUDIT_APPARMOR_HINT, + AUDIT_APPARMOR_STATUS, + AUDIT_APPARMOR_ERROR, + AUDIT_APPARMOR_KILL, + AUDIT_APPARMOR_AUTO +}; + +#define OP_NULL NULL + +#define OP_SYSCTL "sysctl" +#define OP_CAPABLE "capable" + +#define OP_UNLINK "unlink" +#define OP_MKDIR "mkdir" +#define OP_RMDIR "rmdir" +#define OP_MKNOD "mknod" +#define OP_TRUNC "truncate" +#define OP_LINK "link" +#define OP_SYMLINK "symlink" +#define OP_RENAME_SRC "rename_src" +#define OP_RENAME_DEST "rename_dest" +#define OP_CHMOD "chmod" +#define OP_CHOWN "chown" +#define OP_GETATTR "getattr" +#define OP_OPEN "open" + +#define OP_FRECEIVE "file_receive" +#define OP_FPERM "file_perm" +#define OP_FLOCK "file_lock" +#define OP_FMMAP "file_mmap" +#define OP_FMPROT "file_mprotect" +#define OP_INHERIT "file_inherit" + +#define OP_PIVOTROOT "pivotroot" +#define OP_MOUNT "mount" +#define OP_UMOUNT "umount" + +#define OP_CREATE "create" +#define OP_POST_CREATE "post_create" +#define OP_BIND "bind" +#define OP_CONNECT "connect" +#define OP_LISTEN "listen" +#define OP_ACCEPT "accept" +#define OP_SENDMSG "sendmsg" +#define OP_RECVMSG "recvmsg" +#define OP_GETSOCKNAME "getsockname" +#define OP_GETPEERNAME "getpeername" +#define OP_GETSOCKOPT "getsockopt" +#define OP_SETSOCKOPT "setsockopt" +#define OP_SHUTDOWN "socket_shutdown" + +#define OP_PTRACE "ptrace" +#define OP_SIGNAL "signal" + +#define OP_EXEC "exec" + +#define OP_CHANGE_HAT "change_hat" +#define OP_CHANGE_PROFILE "change_profile" +#define OP_CHANGE_ONEXEC "change_onexec" +#define OP_STACK "stack" +#define OP_STACK_ONEXEC "stack_onexec" + +#define OP_SETPROCATTR "setprocattr" +#define OP_SETRLIMIT "setrlimit" + +#define OP_PROF_REPL "profile_replace" +#define OP_PROF_LOAD "profile_load" +#define OP_PROF_RM "profile_remove" + + +struct apparmor_audit_data { + int error; + int type; + const char *op; + struct aa_label *label; + const char *name; + const char *info; + u32 request; + u32 denied; + union { + /* these entries require a custom callback fn */ + struct { + struct aa_label *peer; + union { + struct { + const char *target; + kuid_t ouid; + } fs; + struct { + int rlim; + unsigned long max; + } rlim; + struct { + int signal; + int unmappedsig; + }; + struct { + int type, protocol; + struct sock *peer_sk; + void *addr; + int addrlen; + } net; + }; + }; + struct { + struct aa_profile *profile; + const char *ns; + long pos; + } iface; + struct { + const char *src_name; + const char *type; + const char *trans; + const char *data; + unsigned long flags; + } mnt; + }; +}; + +/* macros for dealing with apparmor_audit_data structure */ +#define aad(SA) ((SA)->apparmor_audit_data) +#define DEFINE_AUDIT_DATA(NAME, T, X) \ + /* TODO: cleanup audit init so we don't need _aad = {0,} */ \ + struct apparmor_audit_data NAME ## _aad = { .op = (X), }; \ + struct common_audit_data NAME = \ + { \ + .type = (T), \ + .u.tsk = NULL, \ + }; \ + NAME.apparmor_audit_data = &(NAME ## _aad) + +void aa_audit_msg(int type, struct common_audit_data *sa, + void (*cb) (struct audit_buffer *, void *)); +int aa_audit(int type, struct aa_profile *profile, struct common_audit_data *sa, + void (*cb) (struct audit_buffer *, void *)); + +#define aa_audit_error(ERROR, SA, CB) \ +({ \ + aad((SA))->error = (ERROR); \ + aa_audit_msg(AUDIT_APPARMOR_ERROR, (SA), (CB)); \ + aad((SA))->error; \ +}) + + +static inline int complain_error(int error) +{ + if (error == -EPERM || error == -EACCES) + return 0; + return error; +} + +void aa_audit_rule_free(void *vrule); +int aa_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule); +int aa_audit_rule_known(struct audit_krule *rule); +int aa_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule); + +#endif /* __AA_AUDIT_H */ diff --git a/security/apparmor/include/capability.h b/security/apparmor/include/capability.h new file mode 100644 index 000000000..d420e2d10 --- /dev/null +++ b/security/apparmor/include/capability.h @@ -0,0 +1,46 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * AppArmor security module + * + * This file contains AppArmor capability mediation definitions. + * + * Copyright (C) 1998-2008 Novell/SUSE + * Copyright 2009-2013 Canonical Ltd. + */ + +#ifndef __AA_CAPABILITY_H +#define __AA_CAPABILITY_H + +#include <linux/sched.h> + +#include "apparmorfs.h" + +struct aa_label; + +/* aa_caps - confinement data for capabilities + * @allowed: capabilities mask + * @audit: caps that are to be audited + * @denied: caps that are explicitly denied + * @quiet: caps that should not be audited + * @kill: caps that when requested will result in the task being killed + * @extended: caps that are subject finer grained mediation + */ +struct aa_caps { + kernel_cap_t allow; + kernel_cap_t audit; + kernel_cap_t denied; + kernel_cap_t quiet; + kernel_cap_t kill; + kernel_cap_t extended; +}; + +extern struct aa_sfs_entry aa_sfs_entry_caps[]; + +int aa_capable(struct aa_label *label, int cap, unsigned int opts); + +static inline void aa_free_cap_rules(struct aa_caps *caps) +{ + /* NOP */ +} + +#endif /* __AA_CAPBILITY_H */ diff --git a/security/apparmor/include/cred.h b/security/apparmor/include/cred.h new file mode 100644 index 000000000..0b9ae4804 --- /dev/null +++ b/security/apparmor/include/cred.h @@ -0,0 +1,188 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * AppArmor security module + * + * This file contains AppArmor contexts used to associate "labels" to objects. + * + * Copyright (C) 1998-2008 Novell/SUSE + * Copyright 2009-2010 Canonical Ltd. + */ + +#ifndef __AA_CONTEXT_H +#define __AA_CONTEXT_H + +#include <linux/cred.h> +#include <linux/slab.h> +#include <linux/sched.h> + +#include "label.h" +#include "policy_ns.h" +#include "task.h" + +static inline struct aa_label *cred_label(const struct cred *cred) +{ + struct aa_label **blob = cred->security + apparmor_blob_sizes.lbs_cred; + + AA_BUG(!blob); + return *blob; +} + +static inline void set_cred_label(const struct cred *cred, + struct aa_label *label) +{ + struct aa_label **blob = cred->security + apparmor_blob_sizes.lbs_cred; + + AA_BUG(!blob); + *blob = label; +} + +/** + * aa_cred_raw_label - obtain cred's label + * @cred: cred to obtain label from (NOT NULL) + * + * Returns: confining label + * + * does NOT increment reference count + */ +static inline struct aa_label *aa_cred_raw_label(const struct cred *cred) +{ + struct aa_label *label = cred_label(cred); + + AA_BUG(!label); + return label; +} + +/** + * aa_get_newest_cred_label - obtain the newest label on a cred + * @cred: cred to obtain label from (NOT NULL) + * + * Returns: newest version of confining label + */ +static inline struct aa_label *aa_get_newest_cred_label(const struct cred *cred) +{ + return aa_get_newest_label(aa_cred_raw_label(cred)); +} + +/** + * __aa_task_raw_label - retrieve another task's label + * @task: task to query (NOT NULL) + * + * Returns: @task's label without incrementing its ref count + * + * If @task != current needs to be called in RCU safe critical section + */ +static inline struct aa_label *__aa_task_raw_label(struct task_struct *task) +{ + return aa_cred_raw_label(__task_cred(task)); +} + +/** + * aa_current_raw_label - find the current tasks confining label + * + * Returns: up to date confining label or the ns unconfined label (NOT NULL) + * + * This fn will not update the tasks cred to the most up to date version + * of the label so it is safe to call when inside of locks. + */ +static inline struct aa_label *aa_current_raw_label(void) +{ + return aa_cred_raw_label(current_cred()); +} + +/** + * aa_get_current_label - get the newest version of the current tasks label + * + * Returns: newest version of confining label (NOT NULL) + * + * This fn will not update the tasks cred, so it is safe inside of locks + * + * The returned reference must be put with aa_put_label() + */ +static inline struct aa_label *aa_get_current_label(void) +{ + struct aa_label *l = aa_current_raw_label(); + + if (label_is_stale(l)) + return aa_get_newest_label(l); + return aa_get_label(l); +} + +#define __end_current_label_crit_section(X) end_current_label_crit_section(X) + +/** + * end_label_crit_section - put a reference found with begin_current_label.. + * @label: label reference to put + * + * Should only be used with a reference obtained with + * begin_current_label_crit_section and never used in situations where the + * task cred may be updated + */ +static inline void end_current_label_crit_section(struct aa_label *label) +{ + if (label != aa_current_raw_label()) + aa_put_label(label); +} + +/** + * __begin_current_label_crit_section - current's confining label + * + * Returns: up to date confining label or the ns unconfined label (NOT NULL) + * + * safe to call inside locks + * + * The returned reference must be put with __end_current_label_crit_section() + * This must NOT be used if the task cred could be updated within the + * critical section between __begin_current_label_crit_section() .. + * __end_current_label_crit_section() + */ +static inline struct aa_label *__begin_current_label_crit_section(void) +{ + struct aa_label *label = aa_current_raw_label(); + + if (label_is_stale(label)) + label = aa_get_newest_label(label); + + return label; +} + +/** + * begin_current_label_crit_section - current's confining label and update it + * + * Returns: up to date confining label or the ns unconfined label (NOT NULL) + * + * Not safe to call inside locks + * + * The returned reference must be put with end_current_label_crit_section() + * This must NOT be used if the task cred could be updated within the + * critical section between begin_current_label_crit_section() .. + * end_current_label_crit_section() + */ +static inline struct aa_label *begin_current_label_crit_section(void) +{ + struct aa_label *label = aa_current_raw_label(); + + might_sleep(); + + if (label_is_stale(label)) { + label = aa_get_newest_label(label); + if (aa_replace_current_label(label) == 0) + /* task cred will keep the reference */ + aa_put_label(label); + } + + return label; +} + +static inline struct aa_ns *aa_get_current_ns(void) +{ + struct aa_label *label; + struct aa_ns *ns; + + label = __begin_current_label_crit_section(); + ns = aa_get_ns(labels_ns(label)); + __end_current_label_crit_section(label); + + return ns; +} + +#endif /* __AA_CONTEXT_H */ diff --git a/security/apparmor/include/crypto.h b/security/apparmor/include/crypto.h new file mode 100644 index 000000000..636a04e20 --- /dev/null +++ b/security/apparmor/include/crypto.h @@ -0,0 +1,37 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * AppArmor security module + * + * This file contains AppArmor policy loading interface function definitions. + * + * Copyright 2013 Canonical Ltd. + */ + +#ifndef __APPARMOR_CRYPTO_H +#define __APPARMOR_CRYPTO_H + +#include "policy.h" + +#ifdef CONFIG_SECURITY_APPARMOR_HASH +unsigned int aa_hash_size(void); +char *aa_calc_hash(void *data, size_t len); +int aa_calc_profile_hash(struct aa_profile *profile, u32 version, void *start, + size_t len); +#else +static inline char *aa_calc_hash(void *data, size_t len) +{ + return NULL; +} +static inline int aa_calc_profile_hash(struct aa_profile *profile, u32 version, + void *start, size_t len) +{ + return 0; +} + +static inline unsigned int aa_hash_size(void) +{ + return 0; +} +#endif + +#endif /* __APPARMOR_CRYPTO_H */ diff --git a/security/apparmor/include/domain.h b/security/apparmor/include/domain.h new file mode 100644 index 000000000..d14928fe1 --- /dev/null +++ b/security/apparmor/include/domain.h @@ -0,0 +1,39 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * AppArmor security module + * + * This file contains AppArmor security domain transition function definitions. + * + * Copyright (C) 1998-2008 Novell/SUSE + * Copyright 2009-2010 Canonical Ltd. + */ + +#include <linux/binfmts.h> +#include <linux/types.h> + +#include "label.h" + +#ifndef __AA_DOMAIN_H +#define __AA_DOMAIN_H + +struct aa_domain { + int size; + char **table; +}; + +#define AA_CHANGE_NOFLAGS 0 +#define AA_CHANGE_TEST 1 +#define AA_CHANGE_CHILD 2 +#define AA_CHANGE_ONEXEC 4 +#define AA_CHANGE_STACK 8 + +struct aa_label *x_table_lookup(struct aa_profile *profile, u32 xindex, + const char **name); + +int apparmor_bprm_creds_for_exec(struct linux_binprm *bprm); + +void aa_free_domain_entries(struct aa_domain *domain); +int aa_change_hat(const char *hats[], int count, u64 token, int flags); +int aa_change_profile(const char *fqname, int flags); + +#endif /* __AA_DOMAIN_H */ diff --git a/security/apparmor/include/file.h b/security/apparmor/include/file.h new file mode 100644 index 000000000..029cb20e3 --- /dev/null +++ b/security/apparmor/include/file.h @@ -0,0 +1,240 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * AppArmor security module + * + * This file contains AppArmor file mediation function definitions. + * + * Copyright (C) 1998-2008 Novell/SUSE + * Copyright 2009-2010 Canonical Ltd. + */ + +#ifndef __AA_FILE_H +#define __AA_FILE_H + +#include <linux/spinlock.h> + +#include "domain.h" +#include "match.h" +#include "perms.h" + +struct aa_profile; +struct path; + +#define mask_mode_t(X) (X & (MAY_EXEC | MAY_WRITE | MAY_READ | MAY_APPEND)) + +#define AA_AUDIT_FILE_MASK (MAY_READ | MAY_WRITE | MAY_EXEC | MAY_APPEND |\ + AA_MAY_CREATE | AA_MAY_DELETE | \ + AA_MAY_GETATTR | AA_MAY_SETATTR | \ + AA_MAY_CHMOD | AA_MAY_CHOWN | AA_MAY_LOCK | \ + AA_EXEC_MMAP | AA_MAY_LINK) + +static inline struct aa_file_ctx *file_ctx(struct file *file) +{ + return file->f_security + apparmor_blob_sizes.lbs_file; +} + +/* struct aa_file_ctx - the AppArmor context the file was opened in + * @lock: lock to update the ctx + * @label: label currently cached on the ctx + * @perms: the permission the file was opened with + */ +struct aa_file_ctx { + spinlock_t lock; + struct aa_label __rcu *label; + u32 allow; +}; + +/** + * aa_alloc_file_ctx - allocate file_ctx + * @label: initial label of task creating the file + * @gfp: gfp flags for allocation + * + * Returns: file_ctx or NULL on failure + */ +static inline struct aa_file_ctx *aa_alloc_file_ctx(struct aa_label *label, + gfp_t gfp) +{ + struct aa_file_ctx *ctx; + + ctx = kzalloc(sizeof(struct aa_file_ctx), gfp); + if (ctx) { + spin_lock_init(&ctx->lock); + rcu_assign_pointer(ctx->label, aa_get_label(label)); + } + return ctx; +} + +/** + * aa_free_file_ctx - free a file_ctx + * @ctx: file_ctx to free (MAYBE_NULL) + */ +static inline void aa_free_file_ctx(struct aa_file_ctx *ctx) +{ + if (ctx) { + aa_put_label(rcu_access_pointer(ctx->label)); + kfree_sensitive(ctx); + } +} + +static inline struct aa_label *aa_get_file_label(struct aa_file_ctx *ctx) +{ + return aa_get_label_rcu(&ctx->label); +} + +/* + * The xindex is broken into 3 parts + * - index - an index into either the exec name table or the variable table + * - exec type - which determines how the executable name and index are used + * - flags - which modify how the destination name is applied + */ +#define AA_X_INDEX_MASK 0x03ff + +#define AA_X_TYPE_MASK 0x0c00 +#define AA_X_TYPE_SHIFT 10 +#define AA_X_NONE 0x0000 +#define AA_X_NAME 0x0400 /* use executable name px */ +#define AA_X_TABLE 0x0800 /* use a specified name ->n# */ + +#define AA_X_UNSAFE 0x1000 +#define AA_X_CHILD 0x2000 /* make >AA_X_NONE apply to children */ +#define AA_X_INHERIT 0x4000 +#define AA_X_UNCONFINED 0x8000 + +/* need to make conditional which ones are being set */ +struct path_cond { + kuid_t uid; + umode_t mode; +}; + +#define COMBINED_PERM_MASK(X) ((X).allow | (X).audit | (X).quiet | (X).kill) + +/* FIXME: split perms from dfa and match this to description + * also add delegation info. + */ +static inline u16 dfa_map_xindex(u16 mask) +{ + u16 old_index = (mask >> 10) & 0xf; + u16 index = 0; + + if (mask & 0x100) + index |= AA_X_UNSAFE; + if (mask & 0x200) + index |= AA_X_INHERIT; + if (mask & 0x80) + index |= AA_X_UNCONFINED; + + if (old_index == 1) { + index |= AA_X_UNCONFINED; + } else if (old_index == 2) { + index |= AA_X_NAME; + } else if (old_index == 3) { + index |= AA_X_NAME | AA_X_CHILD; + } else if (old_index) { + index |= AA_X_TABLE; + index |= old_index - 4; + } + + return index; +} + +/* + * map old dfa inline permissions to new format + */ +#define dfa_user_allow(dfa, state) (((ACCEPT_TABLE(dfa)[state]) & 0x7f) | \ + ((ACCEPT_TABLE(dfa)[state]) & 0x80000000)) +#define dfa_user_xbits(dfa, state) (((ACCEPT_TABLE(dfa)[state]) >> 7) & 0x7f) +#define dfa_user_audit(dfa, state) ((ACCEPT_TABLE2(dfa)[state]) & 0x7f) +#define dfa_user_quiet(dfa, state) (((ACCEPT_TABLE2(dfa)[state]) >> 7) & 0x7f) +#define dfa_user_xindex(dfa, state) \ + (dfa_map_xindex(ACCEPT_TABLE(dfa)[state] & 0x3fff)) + +#define dfa_other_allow(dfa, state) ((((ACCEPT_TABLE(dfa)[state]) >> 14) & \ + 0x7f) | \ + ((ACCEPT_TABLE(dfa)[state]) & 0x80000000)) +#define dfa_other_xbits(dfa, state) \ + ((((ACCEPT_TABLE(dfa)[state]) >> 7) >> 14) & 0x7f) +#define dfa_other_audit(dfa, state) (((ACCEPT_TABLE2(dfa)[state]) >> 14) & 0x7f) +#define dfa_other_quiet(dfa, state) \ + ((((ACCEPT_TABLE2(dfa)[state]) >> 7) >> 14) & 0x7f) +#define dfa_other_xindex(dfa, state) \ + dfa_map_xindex((ACCEPT_TABLE(dfa)[state] >> 14) & 0x3fff) + +int aa_audit_file(struct aa_profile *profile, struct aa_perms *perms, + const char *op, u32 request, const char *name, + const char *target, struct aa_label *tlabel, kuid_t ouid, + const char *info, int error); + +/** + * struct aa_file_rules - components used for file rule permissions + * @dfa: dfa to match path names and conditionals against + * @perms: permission table indexed by the matched state accept entry of @dfa + * @trans: transition table for indexed by named x transitions + * + * File permission are determined by matching a path against @dfa and + * then using the value of the accept entry for the matching state as + * an index into @perms. If a named exec transition is required it is + * looked up in the transition table. + */ +struct aa_file_rules { + unsigned int start; + struct aa_dfa *dfa; + /* struct perms perms; */ + struct aa_domain trans; + /* TODO: add delegate table */ +}; + +struct aa_perms aa_compute_fperms(struct aa_dfa *dfa, unsigned int state, + struct path_cond *cond); +unsigned int aa_str_perms(struct aa_dfa *dfa, unsigned int start, + const char *name, struct path_cond *cond, + struct aa_perms *perms); + +int __aa_path_perm(const char *op, struct aa_profile *profile, + const char *name, u32 request, struct path_cond *cond, + int flags, struct aa_perms *perms); +int aa_path_perm(const char *op, struct aa_label *label, + const struct path *path, int flags, u32 request, + struct path_cond *cond); + +int aa_path_link(struct aa_label *label, struct dentry *old_dentry, + const struct path *new_dir, struct dentry *new_dentry); + +int aa_file_perm(const char *op, struct aa_label *label, struct file *file, + u32 request, bool in_atomic); + +void aa_inherit_files(const struct cred *cred, struct files_struct *files); + +static inline void aa_free_file_rules(struct aa_file_rules *rules) +{ + aa_put_dfa(rules->dfa); + aa_free_domain_entries(&rules->trans); +} + +/** + * aa_map_file_perms - map file flags to AppArmor permissions + * @file: open file to map flags to AppArmor permissions + * + * Returns: apparmor permission set for the file + */ +static inline u32 aa_map_file_to_perms(struct file *file) +{ + int flags = file->f_flags; + u32 perms = 0; + + if (file->f_mode & FMODE_WRITE) + perms |= MAY_WRITE; + if (file->f_mode & FMODE_READ) + perms |= MAY_READ; + + if ((flags & O_APPEND) && (perms & MAY_WRITE)) + perms = (perms & ~MAY_WRITE) | MAY_APPEND; + /* trunc implies write permission */ + if (flags & O_TRUNC) + perms |= MAY_WRITE; + if (flags & O_CREAT) + perms |= AA_MAY_CREATE; + + return perms; +} + +#endif /* __AA_FILE_H */ diff --git a/security/apparmor/include/ipc.h b/security/apparmor/include/ipc.h new file mode 100644 index 000000000..a1ac6ffb9 --- /dev/null +++ b/security/apparmor/include/ipc.h @@ -0,0 +1,18 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * AppArmor security module + * + * This file contains AppArmor ipc mediation function definitions. + * + * Copyright (C) 1998-2008 Novell/SUSE + * Copyright 2009-2017 Canonical Ltd. + */ + +#ifndef __AA_IPC_H +#define __AA_IPC_H + +#include <linux/sched.h> + +int aa_may_signal(struct aa_label *sender, struct aa_label *target, int sig); + +#endif /* __AA_IPC_H */ diff --git a/security/apparmor/include/label.h b/security/apparmor/include/label.h new file mode 100644 index 000000000..860484c6f --- /dev/null +++ b/security/apparmor/include/label.h @@ -0,0 +1,467 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * AppArmor security module + * + * This file contains AppArmor label definitions + * + * Copyright 2017 Canonical Ltd. + */ + +#ifndef __AA_LABEL_H +#define __AA_LABEL_H + +#include <linux/atomic.h> +#include <linux/audit.h> +#include <linux/rbtree.h> +#include <linux/rcupdate.h> + +#include "apparmor.h" +#include "lib.h" + +struct aa_ns; + +#define LOCAL_VEC_ENTRIES 8 +#define DEFINE_VEC(T, V) \ + struct aa_ ## T *(_ ## V ## _localtmp)[LOCAL_VEC_ENTRIES]; \ + struct aa_ ## T **(V) + +#define vec_setup(T, V, N, GFP) \ +({ \ + if ((N) <= LOCAL_VEC_ENTRIES) { \ + typeof(N) i; \ + (V) = (_ ## V ## _localtmp); \ + for (i = 0; i < (N); i++) \ + (V)[i] = NULL; \ + } else \ + (V) = kzalloc(sizeof(struct aa_ ## T *) * (N), (GFP)); \ + (V) ? 0 : -ENOMEM; \ +}) + +#define vec_cleanup(T, V, N) \ +do { \ + int i; \ + for (i = 0; i < (N); i++) { \ + if (!IS_ERR_OR_NULL((V)[i])) \ + aa_put_ ## T((V)[i]); \ + } \ + if ((V) != _ ## V ## _localtmp) \ + kfree(V); \ +} while (0) + +#define vec_last(VEC, SIZE) ((VEC)[(SIZE) - 1]) +#define vec_ns(VEC, SIZE) (vec_last((VEC), (SIZE))->ns) +#define vec_labelset(VEC, SIZE) (&vec_ns((VEC), (SIZE))->labels) +#define cleanup_domain_vec(V, L) cleanup_label_vec((V), (L)->size) + +struct aa_profile; +#define VEC_FLAG_TERMINATE 1 +int aa_vec_unique(struct aa_profile **vec, int n, int flags); +struct aa_label *aa_vec_find_or_create_label(struct aa_profile **vec, int len, + gfp_t gfp); +#define aa_sort_and_merge_vec(N, V) \ + aa_sort_and_merge_profiles((N), (struct aa_profile **)(V)) + + +/* struct aa_labelset - set of labels for a namespace + * + * Labels are reference counted; aa_labelset does not contribute to label + * reference counts. Once a label's last refcount is put it is removed from + * the set. + */ +struct aa_labelset { + rwlock_t lock; + + struct rb_root root; +}; + +#define __labelset_for_each(LS, N) \ + for ((N) = rb_first(&(LS)->root); (N); (N) = rb_next(N)) + +enum label_flags { + FLAG_HAT = 1, /* profile is a hat */ + FLAG_UNCONFINED = 2, /* label unconfined only if all */ + FLAG_NULL = 4, /* profile is null learning profile */ + FLAG_IX_ON_NAME_ERROR = 8, /* fallback to ix on name lookup fail */ + FLAG_IMMUTIBLE = 0x10, /* don't allow changes/replacement */ + FLAG_USER_DEFINED = 0x20, /* user based profile - lower privs */ + FLAG_NO_LIST_REF = 0x40, /* list doesn't keep profile ref */ + FLAG_NS_COUNT = 0x80, /* carries NS ref count */ + FLAG_IN_TREE = 0x100, /* label is in tree */ + FLAG_PROFILE = 0x200, /* label is a profile */ + FLAG_EXPLICIT = 0x400, /* explicit static label */ + FLAG_STALE = 0x800, /* replaced/removed */ + FLAG_RENAMED = 0x1000, /* label has renaming in it */ + FLAG_REVOKED = 0x2000, /* label has revocation in it */ + FLAG_DEBUG1 = 0x4000, + FLAG_DEBUG2 = 0x8000, + + /* These flags must correspond with PATH_flags */ + /* TODO: add new path flags */ +}; + +struct aa_label; +struct aa_proxy { + struct kref count; + struct aa_label __rcu *label; +}; + +struct label_it { + int i, j; +}; + +/* struct aa_label - lazy labeling struct + * @count: ref count of active users + * @node: rbtree position + * @rcu: rcu callback struct + * @proxy: is set to the label that replaced this label + * @hname: text representation of the label (MAYBE_NULL) + * @flags: stale and other flags - values may change under label set lock + * @secid: secid that references this label + * @size: number of entries in @ent[] + * @ent: set of profiles for label, actual size determined by @size + */ +struct aa_label { + struct kref count; + struct rb_node node; + struct rcu_head rcu; + struct aa_proxy *proxy; + __counted char *hname; + long flags; + u32 secid; + int size; + struct aa_profile *vec[]; +}; + +#define last_error(E, FN) \ +do { \ + int __subE = (FN); \ + if (__subE) \ + (E) = __subE; \ +} while (0) + +#define label_isprofile(X) ((X)->flags & FLAG_PROFILE) +#define label_unconfined(X) ((X)->flags & FLAG_UNCONFINED) +#define unconfined(X) label_unconfined(X) +#define label_is_stale(X) ((X)->flags & FLAG_STALE) +#define __label_make_stale(X) ((X)->flags |= FLAG_STALE) +#define labels_ns(X) (vec_ns(&((X)->vec[0]), (X)->size)) +#define labels_set(X) (&labels_ns(X)->labels) +#define labels_view(X) labels_ns(X) +#define labels_profile(X) ((X)->vec[(X)->size - 1]) + + +int aa_label_next_confined(struct aa_label *l, int i); + +/* for each profile in a label */ +#define label_for_each(I, L, P) \ + for ((I).i = 0; ((P) = (L)->vec[(I).i]); ++((I).i)) + +/* assumes break/goto ended label_for_each */ +#define label_for_each_cont(I, L, P) \ + for (++((I).i); ((P) = (L)->vec[(I).i]); ++((I).i)) + +#define next_comb(I, L1, L2) \ +do { \ + (I).j++; \ + if ((I).j >= (L2)->size) { \ + (I).i++; \ + (I).j = 0; \ + } \ +} while (0) + + +/* for each combination of P1 in L1, and P2 in L2 */ +#define label_for_each_comb(I, L1, L2, P1, P2) \ +for ((I).i = (I).j = 0; \ + ((P1) = (L1)->vec[(I).i]) && ((P2) = (L2)->vec[(I).j]); \ + (I) = next_comb(I, L1, L2)) + +#define fn_for_each_comb(L1, L2, P1, P2, FN) \ +({ \ + struct label_it i; \ + int __E = 0; \ + label_for_each_comb(i, (L1), (L2), (P1), (P2)) { \ + last_error(__E, (FN)); \ + } \ + __E; \ +}) + +/* for each profile that is enforcing confinement in a label */ +#define label_for_each_confined(I, L, P) \ + for ((I).i = aa_label_next_confined((L), 0); \ + ((P) = (L)->vec[(I).i]); \ + (I).i = aa_label_next_confined((L), (I).i + 1)) + +#define label_for_each_in_merge(I, A, B, P) \ + for ((I).i = (I).j = 0; \ + ((P) = aa_label_next_in_merge(&(I), (A), (B))); \ + ) + +#define label_for_each_not_in_set(I, SET, SUB, P) \ + for ((I).i = (I).j = 0; \ + ((P) = __aa_label_next_not_in_set(&(I), (SET), (SUB))); \ + ) + +#define next_in_ns(i, NS, L) \ +({ \ + typeof(i) ___i = (i); \ + while ((L)->vec[___i] && (L)->vec[___i]->ns != (NS)) \ + (___i)++; \ + (___i); \ +}) + +#define label_for_each_in_ns(I, NS, L, P) \ + for ((I).i = next_in_ns(0, (NS), (L)); \ + ((P) = (L)->vec[(I).i]); \ + (I).i = next_in_ns((I).i + 1, (NS), (L))) + +#define fn_for_each_in_ns(L, P, FN) \ +({ \ + struct label_it __i; \ + struct aa_ns *__ns = labels_ns(L); \ + int __E = 0; \ + label_for_each_in_ns(__i, __ns, (L), (P)) { \ + last_error(__E, (FN)); \ + } \ + __E; \ +}) + + +#define fn_for_each_XXX(L, P, FN, ...) \ +({ \ + struct label_it i; \ + int __E = 0; \ + label_for_each ## __VA_ARGS__(i, (L), (P)) { \ + last_error(__E, (FN)); \ + } \ + __E; \ +}) + +#define fn_for_each(L, P, FN) fn_for_each_XXX(L, P, FN) +#define fn_for_each_confined(L, P, FN) fn_for_each_XXX(L, P, FN, _confined) + +#define fn_for_each2_XXX(L1, L2, P, FN, ...) \ +({ \ + struct label_it i; \ + int __E = 0; \ + label_for_each ## __VA_ARGS__(i, (L1), (L2), (P)) { \ + last_error(__E, (FN)); \ + } \ + __E; \ +}) + +#define fn_for_each_in_merge(L1, L2, P, FN) \ + fn_for_each2_XXX((L1), (L2), P, FN, _in_merge) +#define fn_for_each_not_in_set(L1, L2, P, FN) \ + fn_for_each2_XXX((L1), (L2), P, FN, _not_in_set) + +#define LABEL_MEDIATES(L, C) \ +({ \ + struct aa_profile *profile; \ + struct label_it i; \ + int ret = 0; \ + label_for_each(i, (L), profile) { \ + if (PROFILE_MEDIATES(profile, (C))) { \ + ret = 1; \ + break; \ + } \ + } \ + ret; \ +}) + + +void aa_labelset_destroy(struct aa_labelset *ls); +void aa_labelset_init(struct aa_labelset *ls); +void __aa_labelset_update_subtree(struct aa_ns *ns); + +void aa_label_destroy(struct aa_label *label); +void aa_label_free(struct aa_label *label); +void aa_label_kref(struct kref *kref); +bool aa_label_init(struct aa_label *label, int size, gfp_t gfp); +struct aa_label *aa_label_alloc(int size, struct aa_proxy *proxy, gfp_t gfp); + +bool aa_label_is_subset(struct aa_label *set, struct aa_label *sub); +bool aa_label_is_unconfined_subset(struct aa_label *set, struct aa_label *sub); +struct aa_profile *__aa_label_next_not_in_set(struct label_it *I, + struct aa_label *set, + struct aa_label *sub); +bool aa_label_remove(struct aa_label *label); +struct aa_label *aa_label_insert(struct aa_labelset *ls, struct aa_label *l); +bool aa_label_replace(struct aa_label *old, struct aa_label *new); +bool aa_label_make_newest(struct aa_labelset *ls, struct aa_label *old, + struct aa_label *new); + +struct aa_label *aa_label_find(struct aa_label *l); + +struct aa_profile *aa_label_next_in_merge(struct label_it *I, + struct aa_label *a, + struct aa_label *b); +struct aa_label *aa_label_find_merge(struct aa_label *a, struct aa_label *b); +struct aa_label *aa_label_merge(struct aa_label *a, struct aa_label *b, + gfp_t gfp); + + +bool aa_update_label_name(struct aa_ns *ns, struct aa_label *label, gfp_t gfp); + +#define FLAGS_NONE 0 +#define FLAG_SHOW_MODE 1 +#define FLAG_VIEW_SUBNS 2 +#define FLAG_HIDDEN_UNCONFINED 4 +#define FLAG_ABS_ROOT 8 +int aa_label_snxprint(char *str, size_t size, struct aa_ns *view, + struct aa_label *label, int flags); +int aa_label_asxprint(char **strp, struct aa_ns *ns, struct aa_label *label, + int flags, gfp_t gfp); +int aa_label_acntsxprint(char __counted **strp, struct aa_ns *ns, + struct aa_label *label, int flags, gfp_t gfp); +void aa_label_xaudit(struct audit_buffer *ab, struct aa_ns *ns, + struct aa_label *label, int flags, gfp_t gfp); +void aa_label_seq_xprint(struct seq_file *f, struct aa_ns *ns, + struct aa_label *label, int flags, gfp_t gfp); +void aa_label_xprintk(struct aa_ns *ns, struct aa_label *label, int flags, + gfp_t gfp); +void aa_label_audit(struct audit_buffer *ab, struct aa_label *label, gfp_t gfp); +void aa_label_seq_print(struct seq_file *f, struct aa_label *label, gfp_t gfp); +void aa_label_printk(struct aa_label *label, gfp_t gfp); + +struct aa_label *aa_label_strn_parse(struct aa_label *base, const char *str, + size_t n, gfp_t gfp, bool create, + bool force_stack); +struct aa_label *aa_label_parse(struct aa_label *base, const char *str, + gfp_t gfp, bool create, bool force_stack); + +static inline const char *aa_label_strn_split(const char *str, int n) +{ + const char *pos; + unsigned int state; + + state = aa_dfa_matchn_until(stacksplitdfa, DFA_START, str, n, &pos); + if (!ACCEPT_TABLE(stacksplitdfa)[state]) + return NULL; + + return pos - 3; +} + +static inline const char *aa_label_str_split(const char *str) +{ + const char *pos; + unsigned int state; + + state = aa_dfa_match_until(stacksplitdfa, DFA_START, str, &pos); + if (!ACCEPT_TABLE(stacksplitdfa)[state]) + return NULL; + + return pos - 3; +} + + + +struct aa_perms; +int aa_label_match(struct aa_profile *profile, struct aa_label *label, + unsigned int state, bool subns, u32 request, + struct aa_perms *perms); + + +/** + * __aa_get_label - get a reference count to uncounted label reference + * @l: reference to get a count on + * + * Returns: pointer to reference OR NULL if race is lost and reference is + * being repeated. + * Requires: lock held, and the return code MUST be checked + */ +static inline struct aa_label *__aa_get_label(struct aa_label *l) +{ + if (l && kref_get_unless_zero(&l->count)) + return l; + + return NULL; +} + +static inline struct aa_label *aa_get_label(struct aa_label *l) +{ + if (l) + kref_get(&(l->count)); + + return l; +} + + +/** + * aa_get_label_rcu - increment refcount on a label that can be replaced + * @l: pointer to label that can be replaced (NOT NULL) + * + * Returns: pointer to a refcounted label. + * else NULL if no label + */ +static inline struct aa_label *aa_get_label_rcu(struct aa_label __rcu **l) +{ + struct aa_label *c; + + rcu_read_lock(); + do { + c = rcu_dereference(*l); + } while (c && !kref_get_unless_zero(&c->count)); + rcu_read_unlock(); + + return c; +} + +/** + * aa_get_newest_label - find the newest version of @l + * @l: the label to check for newer versions of + * + * Returns: refcounted newest version of @l taking into account + * replacement, renames and removals + * return @l. + */ +static inline struct aa_label *aa_get_newest_label(struct aa_label *l) +{ + if (!l) + return NULL; + + if (label_is_stale(l)) { + struct aa_label *tmp; + + AA_BUG(!l->proxy); + AA_BUG(!l->proxy->label); + /* BUG: only way this can happen is @l ref count and its + * replacement count have gone to 0 and are on their way + * to destruction. ie. we have a refcounting error + */ + tmp = aa_get_label_rcu(&l->proxy->label); + AA_BUG(!tmp); + + return tmp; + } + + return aa_get_label(l); +} + +static inline void aa_put_label(struct aa_label *l) +{ + if (l) + kref_put(&l->count, aa_label_kref); +} + + +struct aa_proxy *aa_alloc_proxy(struct aa_label *l, gfp_t gfp); +void aa_proxy_kref(struct kref *kref); + +static inline struct aa_proxy *aa_get_proxy(struct aa_proxy *proxy) +{ + if (proxy) + kref_get(&(proxy->count)); + + return proxy; +} + +static inline void aa_put_proxy(struct aa_proxy *proxy) +{ + if (proxy) + kref_put(&proxy->count, aa_proxy_kref); +} + +void __aa_proxy_redirect(struct aa_label *orig, struct aa_label *new); + +#endif /* __AA_LABEL_H */ diff --git a/security/apparmor/include/lib.h b/security/apparmor/include/lib.h new file mode 100644 index 000000000..f42359f58 --- /dev/null +++ b/security/apparmor/include/lib.h @@ -0,0 +1,298 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * AppArmor security module + * + * This file contains AppArmor lib definitions + * + * 2017 Canonical Ltd. + */ + +#ifndef __AA_LIB_H +#define __AA_LIB_H + +#include <linux/slab.h> +#include <linux/fs.h> +#include <linux/lsm_hooks.h> + +#include "match.h" + +/* + * DEBUG remains global (no per profile flag) since it is mostly used in sysctl + * which is not related to profile accesses. + */ + +#define DEBUG_ON (aa_g_debug) +/* + * split individual debug cases out in preparation for finer grained + * debug controls in the future. + */ +#define AA_DEBUG_LABEL DEBUG_ON +#define dbg_printk(__fmt, __args...) pr_debug(__fmt, ##__args) +#define AA_DEBUG(fmt, args...) \ + do { \ + if (DEBUG_ON) \ + pr_debug_ratelimited("AppArmor: " fmt, ##args); \ + } while (0) + +#define AA_WARN(X) WARN((X), "APPARMOR WARN %s: %s\n", __func__, #X) + +#define AA_BUG(X, args...) \ + do { \ + _Pragma("GCC diagnostic ignored \"-Wformat-zero-length\""); \ + AA_BUG_FMT((X), "" args); \ + _Pragma("GCC diagnostic warning \"-Wformat-zero-length\""); \ + } while (0) +#ifdef CONFIG_SECURITY_APPARMOR_DEBUG_ASSERTS +#define AA_BUG_FMT(X, fmt, args...) \ + WARN((X), "AppArmor WARN %s: (" #X "): " fmt, __func__, ##args) +#else +#define AA_BUG_FMT(X, fmt, args...) no_printk(fmt, ##args) +#endif + +#define AA_ERROR(fmt, args...) \ + pr_err_ratelimited("AppArmor: " fmt, ##args) + +/* Flag indicating whether initialization completed */ +extern int apparmor_initialized; + +/* fn's in lib */ +const char *skipn_spaces(const char *str, size_t n); +char *aa_split_fqname(char *args, char **ns_name); +const char *aa_splitn_fqname(const char *fqname, size_t n, const char **ns_name, + size_t *ns_len); +void aa_info_message(const char *str); + +/* Security blob offsets */ +extern struct lsm_blob_sizes apparmor_blob_sizes; + +/** + * aa_strneq - compare null terminated @str to a non null terminated substring + * @str: a null terminated string + * @sub: a substring, not necessarily null terminated + * @len: length of @sub to compare + * + * The @str string must be full consumed for this to be considered a match + */ +static inline bool aa_strneq(const char *str, const char *sub, int len) +{ + return !strncmp(str, sub, len) && !str[len]; +} + +/** + * aa_dfa_null_transition - step to next state after null character + * @dfa: the dfa to match against + * @start: the state of the dfa to start matching in + * + * aa_dfa_null_transition transitions to the next state after a null + * character which is not used in standard matching and is only + * used to separate pairs. + */ +static inline unsigned int aa_dfa_null_transition(struct aa_dfa *dfa, + unsigned int start) +{ + /* the null transition only needs the string's null terminator byte */ + return aa_dfa_next(dfa, start, 0); +} + +static inline bool path_mediated_fs(struct dentry *dentry) +{ + return !(dentry->d_sb->s_flags & SB_NOUSER); +} + + +struct counted_str { + struct kref count; + char name[]; +}; + +#define str_to_counted(str) \ + ((struct counted_str *)(str - offsetof(struct counted_str, name))) + +#define __counted /* atm just a notation */ + +void aa_str_kref(struct kref *kref); +char *aa_str_alloc(int size, gfp_t gfp); + + +static inline __counted char *aa_get_str(__counted char *str) +{ + if (str) + kref_get(&(str_to_counted(str)->count)); + + return str; +} + +static inline void aa_put_str(__counted char *str) +{ + if (str) + kref_put(&str_to_counted(str)->count, aa_str_kref); +} + + +/* struct aa_policy - common part of both namespaces and profiles + * @name: name of the object + * @hname - The hierarchical name + * @list: list policy object is on + * @profiles: head of the profiles list contained in the object + */ +struct aa_policy { + const char *name; + __counted char *hname; + struct list_head list; + struct list_head profiles; +}; + +/** + * basename - find the last component of an hname + * @name: hname to find the base profile name component of (NOT NULL) + * + * Returns: the tail (base profile name) name component of an hname + */ +static inline const char *basename(const char *hname) +{ + char *split; + + hname = strim((char *)hname); + for (split = strstr(hname, "//"); split; split = strstr(hname, "//")) + hname = split + 2; + + return hname; +} + +/** + * __policy_find - find a policy by @name on a policy list + * @head: list to search (NOT NULL) + * @name: name to search for (NOT NULL) + * + * Requires: rcu_read_lock be held + * + * Returns: unrefcounted policy that match @name or NULL if not found + */ +static inline struct aa_policy *__policy_find(struct list_head *head, + const char *name) +{ + struct aa_policy *policy; + + list_for_each_entry_rcu(policy, head, list) { + if (!strcmp(policy->name, name)) + return policy; + } + return NULL; +} + +/** + * __policy_strn_find - find a policy that's name matches @len chars of @str + * @head: list to search (NOT NULL) + * @str: string to search for (NOT NULL) + * @len: length of match required + * + * Requires: rcu_read_lock be held + * + * Returns: unrefcounted policy that match @str or NULL if not found + * + * if @len == strlen(@strlen) then this is equiv to __policy_find + * other wise it allows searching for policy by a partial match of name + */ +static inline struct aa_policy *__policy_strn_find(struct list_head *head, + const char *str, int len) +{ + struct aa_policy *policy; + + list_for_each_entry_rcu(policy, head, list) { + if (aa_strneq(policy->name, str, len)) + return policy; + } + + return NULL; +} + +bool aa_policy_init(struct aa_policy *policy, const char *prefix, + const char *name, gfp_t gfp); +void aa_policy_destroy(struct aa_policy *policy); + + +/* + * fn_label_build - abstract out the build of a label transition + * @L: label the transition is being computed for + * @P: profile parameter derived from L by this macro, can be passed to FN + * @GFP: memory allocation type to use + * @FN: fn to call for each profile transition. @P is set to the profile + * + * Returns: new label on success + * ERR_PTR if build @FN fails + * NULL if label_build fails due to low memory conditions + * + * @FN must return a label or ERR_PTR on failure. NULL is not allowed + */ +#define fn_label_build(L, P, GFP, FN) \ +({ \ + __label__ __cleanup, __done; \ + struct aa_label *__new_; \ + \ + if ((L)->size > 1) { \ + /* TODO: add cache of transitions already done */ \ + struct label_it __i; \ + int __j, __k, __count; \ + DEFINE_VEC(label, __lvec); \ + DEFINE_VEC(profile, __pvec); \ + if (vec_setup(label, __lvec, (L)->size, (GFP))) { \ + __new_ = NULL; \ + goto __done; \ + } \ + __j = 0; \ + label_for_each(__i, (L), (P)) { \ + __new_ = (FN); \ + AA_BUG(!__new_); \ + if (IS_ERR(__new_)) \ + goto __cleanup; \ + __lvec[__j++] = __new_; \ + } \ + for (__j = __count = 0; __j < (L)->size; __j++) \ + __count += __lvec[__j]->size; \ + if (!vec_setup(profile, __pvec, __count, (GFP))) { \ + for (__j = __k = 0; __j < (L)->size; __j++) { \ + label_for_each(__i, __lvec[__j], (P)) \ + __pvec[__k++] = aa_get_profile(P); \ + } \ + __count -= aa_vec_unique(__pvec, __count, 0); \ + if (__count > 1) { \ + __new_ = aa_vec_find_or_create_label(__pvec,\ + __count, (GFP)); \ + /* only fails if out of Mem */ \ + if (!__new_) \ + __new_ = NULL; \ + } else \ + __new_ = aa_get_label(&__pvec[0]->label); \ + vec_cleanup(profile, __pvec, __count); \ + } else \ + __new_ = NULL; \ +__cleanup: \ + vec_cleanup(label, __lvec, (L)->size); \ + } else { \ + (P) = labels_profile(L); \ + __new_ = (FN); \ + } \ +__done: \ + if (!__new_) \ + AA_DEBUG("label build failed\n"); \ + (__new_); \ +}) + + +#define __fn_build_in_ns(NS, P, NS_FN, OTHER_FN) \ +({ \ + struct aa_label *__new; \ + if ((P)->ns != (NS)) \ + __new = (OTHER_FN); \ + else \ + __new = (NS_FN); \ + (__new); \ +}) + +#define fn_label_build_in_ns(L, P, GFP, NS_FN, OTHER_FN) \ +({ \ + fn_label_build((L), (P), (GFP), \ + __fn_build_in_ns(labels_ns(L), (P), (NS_FN), (OTHER_FN))); \ +}) + +#endif /* __AA_LIB_H */ diff --git a/security/apparmor/include/match.h b/security/apparmor/include/match.h new file mode 100644 index 000000000..884489590 --- /dev/null +++ b/security/apparmor/include/match.h @@ -0,0 +1,196 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * AppArmor security module + * + * This file contains AppArmor policy dfa matching engine definitions. + * + * Copyright (C) 1998-2008 Novell/SUSE + * Copyright 2009-2012 Canonical Ltd. + */ + +#ifndef __AA_MATCH_H +#define __AA_MATCH_H + +#include <linux/kref.h> + +#define DFA_NOMATCH 0 +#define DFA_START 1 + + +/** + * The format used for transition tables is based on the GNU flex table + * file format (--tables-file option; see Table File Format in the flex + * info pages and the flex sources for documentation). The magic number + * used in the header is 0x1B5E783D instead of 0xF13C57B1 though, because + * new tables have been defined and others YY_ID_CHK (check) and YY_ID_DEF + * (default) tables are used slightly differently (see the apparmor-parser + * package). + * + * + * The data in the packed dfa is stored in network byte order, and the tables + * are arranged for flexibility. We convert the table data to host native + * byte order. + * + * The dfa begins with a table set header, and is followed by the actual + * tables. + */ + +#define YYTH_MAGIC 0x1B5E783D +#define YYTH_FLAG_DIFF_ENCODE 1 +#define YYTH_FLAG_OOB_TRANS 2 +#define YYTH_FLAGS (YYTH_FLAG_DIFF_ENCODE | YYTH_FLAG_OOB_TRANS) + +#define MAX_OOB_SUPPORTED 1 + +struct table_set_header { + u32 th_magic; /* YYTH_MAGIC */ + u32 th_hsize; + u32 th_ssize; + u16 th_flags; + char th_version[]; +}; + +/* The YYTD_ID are one less than flex table mappings. The flex id + * has 1 subtracted at table load time, this allows us to directly use the + * ID's as indexes. + */ +#define YYTD_ID_ACCEPT 0 +#define YYTD_ID_BASE 1 +#define YYTD_ID_CHK 2 +#define YYTD_ID_DEF 3 +#define YYTD_ID_EC 4 +#define YYTD_ID_META 5 +#define YYTD_ID_ACCEPT2 6 +#define YYTD_ID_NXT 7 +#define YYTD_ID_TSIZE 8 +#define YYTD_ID_MAX 8 + +#define YYTD_DATA8 1 +#define YYTD_DATA16 2 +#define YYTD_DATA32 4 +#define YYTD_DATA64 8 + +/* ACCEPT & ACCEPT2 tables gets 6 dedicated flags, YYTD_DATAX define the + * first flags + */ +#define ACCEPT1_FLAGS(X) ((X) & 0x3f) +#define ACCEPT2_FLAGS(X) ACCEPT1_FLAGS((X) >> YYTD_ID_ACCEPT2) +#define TO_ACCEPT1_FLAG(X) ACCEPT1_FLAGS(X) +#define TO_ACCEPT2_FLAG(X) (ACCEPT1_FLAGS(X) << YYTD_ID_ACCEPT2) +#define DFA_FLAG_VERIFY_STATES 0x1000 + +struct table_header { + u16 td_id; + u16 td_flags; + u32 td_hilen; + u32 td_lolen; + char td_data[]; +}; + +#define DEFAULT_TABLE(DFA) ((u16 *)((DFA)->tables[YYTD_ID_DEF]->td_data)) +#define BASE_TABLE(DFA) ((u32 *)((DFA)->tables[YYTD_ID_BASE]->td_data)) +#define NEXT_TABLE(DFA) ((u16 *)((DFA)->tables[YYTD_ID_NXT]->td_data)) +#define CHECK_TABLE(DFA) ((u16 *)((DFA)->tables[YYTD_ID_CHK]->td_data)) +#define EQUIV_TABLE(DFA) ((u8 *)((DFA)->tables[YYTD_ID_EC]->td_data)) +#define ACCEPT_TABLE(DFA) ((u32 *)((DFA)->tables[YYTD_ID_ACCEPT]->td_data)) +#define ACCEPT_TABLE2(DFA) ((u32 *)((DFA)->tables[YYTD_ID_ACCEPT2]->td_data)) + +struct aa_dfa { + struct kref count; + u16 flags; + u32 max_oob; + struct table_header *tables[YYTD_ID_TSIZE]; +}; + +extern struct aa_dfa *nulldfa; +extern struct aa_dfa *stacksplitdfa; + +#define byte_to_byte(X) (X) + +#define UNPACK_ARRAY(TABLE, BLOB, LEN, TTYPE, BTYPE, NTOHX) \ + do { \ + typeof(LEN) __i; \ + TTYPE *__t = (TTYPE *) TABLE; \ + BTYPE *__b = (BTYPE *) BLOB; \ + for (__i = 0; __i < LEN; __i++) { \ + __t[__i] = NTOHX(__b[__i]); \ + } \ + } while (0) + +static inline size_t table_size(size_t len, size_t el_size) +{ + return ALIGN(sizeof(struct table_header) + len * el_size, 8); +} + +int aa_setup_dfa_engine(void); +void aa_teardown_dfa_engine(void); + +struct aa_dfa *aa_dfa_unpack(void *blob, size_t size, int flags); +unsigned int aa_dfa_match_len(struct aa_dfa *dfa, unsigned int start, + const char *str, int len); +unsigned int aa_dfa_match(struct aa_dfa *dfa, unsigned int start, + const char *str); +unsigned int aa_dfa_next(struct aa_dfa *dfa, unsigned int state, + const char c); +unsigned int aa_dfa_outofband_transition(struct aa_dfa *dfa, + unsigned int state); +unsigned int aa_dfa_match_until(struct aa_dfa *dfa, unsigned int start, + const char *str, const char **retpos); +unsigned int aa_dfa_matchn_until(struct aa_dfa *dfa, unsigned int start, + const char *str, int n, const char **retpos); + +void aa_dfa_free_kref(struct kref *kref); + +#define WB_HISTORY_SIZE 24 +struct match_workbuf { + unsigned int count; + unsigned int pos; + unsigned int len; + unsigned int size; /* power of 2, same as history size */ + unsigned int history[WB_HISTORY_SIZE]; +}; +#define DEFINE_MATCH_WB(N) \ +struct match_workbuf N = { \ + .count = 0, \ + .pos = 0, \ + .len = 0, \ +} + +unsigned int aa_dfa_leftmatch(struct aa_dfa *dfa, unsigned int start, + const char *str, unsigned int *count); + +/** + * aa_get_dfa - increment refcount on dfa @p + * @dfa: dfa (MAYBE NULL) + * + * Returns: pointer to @dfa if @dfa is NULL will return NULL + * Requires: @dfa must be held with valid refcount when called + */ +static inline struct aa_dfa *aa_get_dfa(struct aa_dfa *dfa) +{ + if (dfa) + kref_get(&(dfa->count)); + + return dfa; +} + +/** + * aa_put_dfa - put a dfa refcount + * @dfa: dfa to put refcount (MAYBE NULL) + * + * Requires: if @dfa != NULL that a valid refcount be held + */ +static inline void aa_put_dfa(struct aa_dfa *dfa) +{ + if (dfa) + kref_put(&dfa->count, aa_dfa_free_kref); +} + +#define MATCH_FLAG_DIFF_ENCODE 0x80000000 +#define MARK_DIFF_ENCODE 0x40000000 +#define MATCH_FLAG_OOB_TRANSITION 0x20000000 +#define MATCH_FLAGS_MASK 0xff000000 +#define MATCH_FLAGS_VALID (MATCH_FLAG_DIFF_ENCODE | MATCH_FLAG_OOB_TRANSITION) +#define MATCH_FLAGS_INVALID (MATCH_FLAGS_MASK & ~MATCH_FLAGS_VALID) + +#endif /* __AA_MATCH_H */ diff --git a/security/apparmor/include/mount.h b/security/apparmor/include/mount.h new file mode 100644 index 000000000..a710683b2 --- /dev/null +++ b/security/apparmor/include/mount.h @@ -0,0 +1,50 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * AppArmor security module + * + * This file contains AppArmor file mediation function definitions. + * + * Copyright 2017 Canonical Ltd. + */ + +#ifndef __AA_MOUNT_H +#define __AA_MOUNT_H + +#include <linux/fs.h> +#include <linux/path.h> + +#include "domain.h" +#include "policy.h" + +/* mount perms */ +#define AA_MAY_PIVOTROOT 0x01 +#define AA_MAY_MOUNT 0x02 +#define AA_MAY_UMOUNT 0x04 +#define AA_AUDIT_DATA 0x40 +#define AA_MNT_CONT_MATCH 0x40 + +#define AA_MS_IGNORE_MASK (MS_KERNMOUNT | MS_NOSEC | MS_ACTIVE | MS_BORN) + +int aa_remount(struct aa_label *label, const struct path *path, + unsigned long flags, void *data); + +int aa_bind_mount(struct aa_label *label, const struct path *path, + const char *old_name, unsigned long flags); + + +int aa_mount_change_type(struct aa_label *label, const struct path *path, + unsigned long flags); + +int aa_move_mount(struct aa_label *label, const struct path *path, + const char *old_name); + +int aa_new_mount(struct aa_label *label, const char *dev_name, + const struct path *path, const char *type, unsigned long flags, + void *data); + +int aa_umount(struct aa_label *label, struct vfsmount *mnt, int flags); + +int aa_pivotroot(struct aa_label *label, const struct path *old_path, + const struct path *new_path); + +#endif /* __AA_MOUNT_H */ diff --git a/security/apparmor/include/net.h b/security/apparmor/include/net.h new file mode 100644 index 000000000..aadb4b29f --- /dev/null +++ b/security/apparmor/include/net.h @@ -0,0 +1,112 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * AppArmor security module + * + * This file contains AppArmor network mediation definitions. + * + * Copyright (C) 1998-2008 Novell/SUSE + * Copyright 2009-2017 Canonical Ltd. + */ + +#ifndef __AA_NET_H +#define __AA_NET_H + +#include <net/sock.h> +#include <linux/path.h> + +#include "apparmorfs.h" +#include "label.h" +#include "perms.h" +#include "policy.h" + +#define AA_MAY_SEND AA_MAY_WRITE +#define AA_MAY_RECEIVE AA_MAY_READ + +#define AA_MAY_SHUTDOWN AA_MAY_DELETE + +#define AA_MAY_CONNECT AA_MAY_OPEN +#define AA_MAY_ACCEPT 0x00100000 + +#define AA_MAY_BIND 0x00200000 +#define AA_MAY_LISTEN 0x00400000 + +#define AA_MAY_SETOPT 0x01000000 +#define AA_MAY_GETOPT 0x02000000 + +#define NET_PERMS_MASK (AA_MAY_SEND | AA_MAY_RECEIVE | AA_MAY_CREATE | \ + AA_MAY_SHUTDOWN | AA_MAY_BIND | AA_MAY_LISTEN | \ + AA_MAY_CONNECT | AA_MAY_ACCEPT | AA_MAY_SETATTR | \ + AA_MAY_GETATTR | AA_MAY_SETOPT | AA_MAY_GETOPT) + +#define NET_FS_PERMS (AA_MAY_SEND | AA_MAY_RECEIVE | AA_MAY_CREATE | \ + AA_MAY_SHUTDOWN | AA_MAY_CONNECT | AA_MAY_RENAME |\ + AA_MAY_SETATTR | AA_MAY_GETATTR | AA_MAY_CHMOD | \ + AA_MAY_CHOWN | AA_MAY_CHGRP | AA_MAY_LOCK | \ + AA_MAY_MPROT) + +#define NET_PEER_MASK (AA_MAY_SEND | AA_MAY_RECEIVE | AA_MAY_CONNECT | \ + AA_MAY_ACCEPT) +struct aa_sk_ctx { + struct aa_label *label; + struct aa_label *peer; +}; + +#define SK_CTX(X) ((X)->sk_security) +#define SOCK_ctx(X) SOCK_INODE(X)->i_security +#define DEFINE_AUDIT_NET(NAME, OP, SK, F, T, P) \ + struct lsm_network_audit NAME ## _net = { .sk = (SK), \ + .family = (F)}; \ + DEFINE_AUDIT_DATA(NAME, \ + ((SK) && (F) != AF_UNIX) ? LSM_AUDIT_DATA_NET : \ + LSM_AUDIT_DATA_NONE, \ + OP); \ + NAME.u.net = &(NAME ## _net); \ + aad(&NAME)->net.type = (T); \ + aad(&NAME)->net.protocol = (P) + +#define DEFINE_AUDIT_SK(NAME, OP, SK) \ + DEFINE_AUDIT_NET(NAME, OP, SK, (SK)->sk_family, (SK)->sk_type, \ + (SK)->sk_protocol) + + +#define af_select(FAMILY, FN, DEF_FN) \ +({ \ + int __e; \ + switch ((FAMILY)) { \ + default: \ + __e = DEF_FN; \ + } \ + __e; \ +}) + +struct aa_secmark { + u8 audit; + u8 deny; + u32 secid; + char *label; +}; + +extern struct aa_sfs_entry aa_sfs_entry_network[]; + +void audit_net_cb(struct audit_buffer *ab, void *va); +int aa_profile_af_perm(struct aa_profile *profile, struct common_audit_data *sa, + u32 request, u16 family, int type); +int aa_af_perm(struct aa_label *label, const char *op, u32 request, u16 family, + int type, int protocol); +static inline int aa_profile_af_sk_perm(struct aa_profile *profile, + struct common_audit_data *sa, + u32 request, + struct sock *sk) +{ + return aa_profile_af_perm(profile, sa, request, sk->sk_family, + sk->sk_type); +} +int aa_sk_perm(const char *op, u32 request, struct sock *sk); + +int aa_sock_file_perm(struct aa_label *label, const char *op, u32 request, + struct socket *sock); + +int apparmor_secmark_check(struct aa_label *label, char *op, u32 request, + u32 secid, const struct sock *sk); + +#endif /* __AA_NET_H */ diff --git a/security/apparmor/include/path.h b/security/apparmor/include/path.h new file mode 100644 index 000000000..343189903 --- /dev/null +++ b/security/apparmor/include/path.h @@ -0,0 +1,32 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * AppArmor security module + * + * This file contains AppArmor basic path manipulation function definitions. + * + * Copyright (C) 1998-2008 Novell/SUSE + * Copyright 2009-2010 Canonical Ltd. + */ + +#ifndef __AA_PATH_H +#define __AA_PATH_H + +enum path_flags { + PATH_IS_DIR = 0x1, /* path is a directory */ + PATH_CONNECT_PATH = 0x4, /* connect disconnected paths to / */ + PATH_CHROOT_REL = 0x8, /* do path lookup relative to chroot */ + PATH_CHROOT_NSCONNECT = 0x10, /* connect paths that are at ns root */ + + PATH_DELEGATE_DELETED = 0x10000, /* delegate deleted files */ + PATH_MEDIATE_DELETED = 0x20000, /* mediate deleted paths */ +}; + +int aa_path_name(const struct path *path, int flags, char *buffer, + const char **name, const char **info, + const char *disconnected); + +#define IN_ATOMIC true +char *aa_get_buffer(bool in_atomic); +void aa_put_buffer(char *buf); + +#endif /* __AA_PATH_H */ diff --git a/security/apparmor/include/perms.h b/security/apparmor/include/perms.h new file mode 100644 index 000000000..13f20c598 --- /dev/null +++ b/security/apparmor/include/perms.h @@ -0,0 +1,156 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * AppArmor security module + * + * This file contains AppArmor basic permission sets definitions. + * + * Copyright 2017 Canonical Ltd. + */ + +#ifndef __AA_PERM_H +#define __AA_PERM_H + +#include <linux/fs.h> +#include "label.h" + +#define AA_MAY_EXEC MAY_EXEC +#define AA_MAY_WRITE MAY_WRITE +#define AA_MAY_READ MAY_READ +#define AA_MAY_APPEND MAY_APPEND + +#define AA_MAY_CREATE 0x0010 +#define AA_MAY_DELETE 0x0020 +#define AA_MAY_OPEN 0x0040 +#define AA_MAY_RENAME 0x0080 /* pair */ + +#define AA_MAY_SETATTR 0x0100 /* meta write */ +#define AA_MAY_GETATTR 0x0200 /* meta read */ +#define AA_MAY_SETCRED 0x0400 /* security cred/attr */ +#define AA_MAY_GETCRED 0x0800 + +#define AA_MAY_CHMOD 0x1000 /* pair */ +#define AA_MAY_CHOWN 0x2000 /* pair */ +#define AA_MAY_CHGRP 0x4000 /* pair */ +#define AA_MAY_LOCK 0x8000 /* LINK_SUBSET overlaid */ + +#define AA_EXEC_MMAP 0x00010000 +#define AA_MAY_MPROT 0x00020000 /* extend conditions */ +#define AA_MAY_LINK 0x00040000 /* pair */ +#define AA_MAY_SNAPSHOT 0x00080000 /* pair */ + +#define AA_MAY_DELEGATE +#define AA_CONT_MATCH 0x08000000 + +#define AA_MAY_STACK 0x10000000 +#define AA_MAY_ONEXEC 0x20000000 /* either stack or change_profile */ +#define AA_MAY_CHANGE_PROFILE 0x40000000 +#define AA_MAY_CHANGEHAT 0x80000000 + +#define AA_LINK_SUBSET AA_MAY_LOCK /* overlaid */ + + +#define PERMS_CHRS_MASK (MAY_READ | MAY_WRITE | AA_MAY_CREATE | \ + AA_MAY_DELETE | AA_MAY_LINK | AA_MAY_LOCK | \ + AA_MAY_EXEC | AA_EXEC_MMAP | AA_MAY_APPEND) + +#define PERMS_NAMES_MASK (PERMS_CHRS_MASK | AA_MAY_OPEN | AA_MAY_RENAME | \ + AA_MAY_SETATTR | AA_MAY_GETATTR | AA_MAY_SETCRED | \ + AA_MAY_GETCRED | AA_MAY_CHMOD | AA_MAY_CHOWN | \ + AA_MAY_CHGRP | AA_MAY_MPROT | AA_MAY_SNAPSHOT | \ + AA_MAY_STACK | AA_MAY_ONEXEC | \ + AA_MAY_CHANGE_PROFILE | AA_MAY_CHANGEHAT) + +extern const char aa_file_perm_chrs[]; +extern const char *aa_file_perm_names[]; + +struct aa_perms { + u32 allow; + u32 audit; /* set only when allow is set */ + + u32 deny; /* explicit deny, or conflict if allow also set */ + u32 quiet; /* set only when ~allow | deny */ + u32 kill; /* set only when ~allow | deny */ + u32 stop; /* set only when ~allow | deny */ + + u32 complain; /* accumulates only used when ~allow & ~deny */ + u32 cond; /* set only when ~allow and ~deny */ + + u32 hide; /* set only when ~allow | deny */ + u32 prompt; /* accumulates only used when ~allow & ~deny */ + + /* Reserved: + * u32 subtree; / * set only when allow is set * / + */ + u16 xindex; +}; + +#define ALL_PERMS_MASK 0xffffffff +extern struct aa_perms nullperms; +extern struct aa_perms allperms; + + +#define xcheck(FN1, FN2) \ +({ \ + int e, error = FN1; \ + e = FN2; \ + if (e) \ + error = e; \ + error; \ +}) + + +/* + * TODO: update for labels pointing to labels instead of profiles + * TODO: optimize the walk, currently does subwalk of L2 for each P in L1 + * gah this doesn't allow for label compound check!!!! + */ +#define xcheck_ns_profile_profile(P1, P2, FN, args...) \ +({ \ + int ____e = 0; \ + if (P1->ns == P2->ns) \ + ____e = FN((P1), (P2), args); \ + (____e); \ +}) + +#define xcheck_ns_profile_label(P, L, FN, args...) \ +({ \ + struct aa_profile *__p2; \ + fn_for_each((L), __p2, \ + xcheck_ns_profile_profile((P), __p2, (FN), args)); \ +}) + +#define xcheck_ns_labels(L1, L2, FN, args...) \ +({ \ + struct aa_profile *__p1; \ + fn_for_each((L1), __p1, FN(__p1, (L2), args)); \ +}) + +/* Do the cross check but applying FN at the profiles level */ +#define xcheck_labels_profiles(L1, L2, FN, args...) \ + xcheck_ns_labels((L1), (L2), xcheck_ns_profile_label, (FN), args) + +#define xcheck_labels(L1, L2, P, FN1, FN2) \ + xcheck(fn_for_each((L1), (P), (FN1)), fn_for_each((L2), (P), (FN2))) + + +void aa_perm_mask_to_str(char *str, size_t str_size, const char *chrs, + u32 mask); +void aa_audit_perm_names(struct audit_buffer *ab, const char * const *names, + u32 mask); +void aa_audit_perm_mask(struct audit_buffer *ab, u32 mask, const char *chrs, + u32 chrsmask, const char * const *names, u32 namesmask); +void aa_apply_modes_to_perms(struct aa_profile *profile, + struct aa_perms *perms); +void aa_compute_perms(struct aa_dfa *dfa, unsigned int state, + struct aa_perms *perms); +void aa_perms_accum(struct aa_perms *accum, struct aa_perms *addend); +void aa_perms_accum_raw(struct aa_perms *accum, struct aa_perms *addend); +void aa_profile_match_label(struct aa_profile *profile, struct aa_label *label, + int type, u32 request, struct aa_perms *perms); +int aa_profile_label_perm(struct aa_profile *profile, struct aa_profile *target, + u32 request, int type, u32 *deny, + struct common_audit_data *sa); +int aa_check_perms(struct aa_profile *profile, struct aa_perms *perms, + u32 request, struct common_audit_data *sa, + void (*cb)(struct audit_buffer *, void *)); +#endif /* __AA_PERM_H */ diff --git a/security/apparmor/include/policy.h b/security/apparmor/include/policy.h new file mode 100644 index 000000000..639b5b248 --- /dev/null +++ b/security/apparmor/include/policy.h @@ -0,0 +1,315 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * AppArmor security module + * + * This file contains AppArmor policy definitions. + * + * Copyright (C) 1998-2008 Novell/SUSE + * Copyright 2009-2010 Canonical Ltd. + */ + +#ifndef __AA_POLICY_H +#define __AA_POLICY_H + +#include <linux/capability.h> +#include <linux/cred.h> +#include <linux/kref.h> +#include <linux/rhashtable.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/socket.h> + +#include "apparmor.h" +#include "audit.h" +#include "capability.h" +#include "domain.h" +#include "file.h" +#include "lib.h" +#include "label.h" +#include "net.h" +#include "perms.h" +#include "resource.h" + + +struct aa_ns; + +extern int unprivileged_userns_apparmor_policy; + +extern const char *const aa_profile_mode_names[]; +#define APPARMOR_MODE_NAMES_MAX_INDEX 4 + +#define PROFILE_MODE(_profile, _mode) \ + ((aa_g_profile_mode == (_mode)) || \ + ((_profile)->mode == (_mode))) + +#define COMPLAIN_MODE(_profile) PROFILE_MODE((_profile), APPARMOR_COMPLAIN) + +#define KILL_MODE(_profile) PROFILE_MODE((_profile), APPARMOR_KILL) + +#define PROFILE_IS_HAT(_profile) ((_profile)->label.flags & FLAG_HAT) + +#define CHECK_DEBUG1(_profile) ((_profile)->label.flags & FLAG_DEBUG1) + +#define CHECK_DEBUG2(_profile) ((_profile)->label.flags & FLAG_DEBUG2) + +#define profile_is_stale(_profile) (label_is_stale(&(_profile)->label)) + +#define on_list_rcu(X) (!list_empty(X) && (X)->prev != LIST_POISON2) + +/* + * FIXME: currently need a clean way to replace and remove profiles as a + * set. It should be done at the namespace level. + * Either, with a set of profiles loaded at the namespace level or via + * a mark and remove marked interface. + */ +enum profile_mode { + APPARMOR_ENFORCE, /* enforce access rules */ + APPARMOR_COMPLAIN, /* allow and log access violations */ + APPARMOR_KILL, /* kill task on access violation */ + APPARMOR_UNCONFINED, /* profile set to unconfined */ +}; + + +/* struct aa_policydb - match engine for a policy + * dfa: dfa pattern match + * start: set of start states for the different classes of data + */ +struct aa_policydb { + /* Generic policy DFA specific rule types will be subsections of it */ + struct aa_dfa *dfa; + unsigned int start[AA_CLASS_LAST + 1]; + +}; + +/* struct aa_data - generic data structure + * key: name for retrieving this data + * size: size of data in bytes + * data: binary data + * head: reserved for rhashtable + */ +struct aa_data { + char *key; + u32 size; + char *data; + struct rhash_head head; +}; + + +/* struct aa_profile - basic confinement data + * @base - base components of the profile (name, refcount, lists, lock ...) + * @label - label this profile is an extension of + * @parent: parent of profile + * @ns: namespace the profile is in + * @rename: optional profile name that this profile renamed + * @attach: human readable attachment string + * @xmatch: optional extended matching for unconfined executables names + * @xmatch_len: xmatch prefix len, used to determine xmatch priority + * @audit: the auditing mode of the profile + * @mode: the enforcement mode of the profile + * @path_flags: flags controlling path generation behavior + * @disconnected: what to prepend if attach_disconnected is specified + * @size: the memory consumed by this profiles rules + * @policy: general match rules governing policy + * @file: The set of rules governing basic file access and domain transitions + * @caps: capabilities for the profile + * @rlimits: rlimits for the profile + * + * @dents: dentries for the profiles file entries in apparmorfs + * @dirname: name of the profile dir in apparmorfs + * @data: hashtable for free-form policy aa_data + * + * The AppArmor profile contains the basic confinement data. Each profile + * has a name, and exists in a namespace. The @name and @exec_match are + * used to determine profile attachment against unconfined tasks. All other + * attachments are determined by profile X transition rules. + * + * Profiles have a hierarchy where hats and children profiles keep + * a reference to their parent. + * + * Profile names can not begin with a : and can not contain the \0 + * character. If a profile name begins with / it will be considered when + * determining profile attachment on "unconfined" tasks. + */ +struct aa_profile { + struct aa_policy base; + struct aa_profile __rcu *parent; + + struct aa_ns *ns; + const char *rename; + + const char *attach; + struct aa_dfa *xmatch; + unsigned int xmatch_len; + enum audit_mode audit; + long mode; + u32 path_flags; + const char *disconnected; + int size; + + struct aa_policydb policy; + struct aa_file_rules file; + struct aa_caps caps; + + int xattr_count; + char **xattrs; + + struct aa_rlimit rlimits; + + int secmark_count; + struct aa_secmark *secmark; + + struct aa_loaddata *rawdata; + unsigned char *hash; + char *dirname; + struct dentry *dents[AAFS_PROF_SIZEOF]; + struct rhashtable *data; + struct aa_label label; +}; + +extern enum profile_mode aa_g_profile_mode; + +#define AA_MAY_LOAD_POLICY AA_MAY_APPEND +#define AA_MAY_REPLACE_POLICY AA_MAY_WRITE +#define AA_MAY_REMOVE_POLICY AA_MAY_DELETE + +#define profiles_ns(P) ((P)->ns) +#define name_is_shared(A, B) ((A)->hname && (A)->hname == (B)->hname) + +void aa_add_profile(struct aa_policy *common, struct aa_profile *profile); + + +void aa_free_proxy_kref(struct kref *kref); +struct aa_profile *aa_alloc_profile(const char *name, struct aa_proxy *proxy, + gfp_t gfp); +struct aa_profile *aa_new_null_profile(struct aa_profile *parent, bool hat, + const char *base, gfp_t gfp); +void aa_free_profile(struct aa_profile *profile); +void aa_free_profile_kref(struct kref *kref); +struct aa_profile *aa_find_child(struct aa_profile *parent, const char *name); +struct aa_profile *aa_lookupn_profile(struct aa_ns *ns, const char *hname, + size_t n); +struct aa_profile *aa_lookup_profile(struct aa_ns *ns, const char *name); +struct aa_profile *aa_fqlookupn_profile(struct aa_label *base, + const char *fqname, size_t n); +struct aa_profile *aa_match_profile(struct aa_ns *ns, const char *name); + +ssize_t aa_replace_profiles(struct aa_ns *view, struct aa_label *label, + u32 mask, struct aa_loaddata *udata); +ssize_t aa_remove_profiles(struct aa_ns *view, struct aa_label *label, + char *name, size_t size); +void __aa_profile_list_release(struct list_head *head); + +#define PROF_ADD 1 +#define PROF_REPLACE 0 + +#define profile_unconfined(X) ((X)->mode == APPARMOR_UNCONFINED) + +/** + * aa_get_newest_profile - simple wrapper fn to wrap the label version + * @p: profile (NOT NULL) + * + * Returns refcount to newest version of the profile (maybe @p) + * + * Requires: @p must be held with a valid refcount + */ +static inline struct aa_profile *aa_get_newest_profile(struct aa_profile *p) +{ + return labels_profile(aa_get_newest_label(&p->label)); +} + +static inline unsigned int PROFILE_MEDIATES(struct aa_profile *profile, + unsigned char class) +{ + if (class <= AA_CLASS_LAST) + return profile->policy.start[class]; + else + return aa_dfa_match_len(profile->policy.dfa, + profile->policy.start[0], &class, 1); +} + +static inline unsigned int PROFILE_MEDIATES_AF(struct aa_profile *profile, + u16 AF) { + unsigned int state = PROFILE_MEDIATES(profile, AA_CLASS_NET); + __be16 be_af = cpu_to_be16(AF); + + if (!state) + return 0; + return aa_dfa_match_len(profile->policy.dfa, state, (char *) &be_af, 2); +} + +/** + * aa_get_profile - increment refcount on profile @p + * @p: profile (MAYBE NULL) + * + * Returns: pointer to @p if @p is NULL will return NULL + * Requires: @p must be held with valid refcount when called + */ +static inline struct aa_profile *aa_get_profile(struct aa_profile *p) +{ + if (p) + kref_get(&(p->label.count)); + + return p; +} + +/** + * aa_get_profile_not0 - increment refcount on profile @p found via lookup + * @p: profile (MAYBE NULL) + * + * Returns: pointer to @p if @p is NULL will return NULL + * Requires: @p must be held with valid refcount when called + */ +static inline struct aa_profile *aa_get_profile_not0(struct aa_profile *p) +{ + if (p && kref_get_unless_zero(&p->label.count)) + return p; + + return NULL; +} + +/** + * aa_get_profile_rcu - increment a refcount profile that can be replaced + * @p: pointer to profile that can be replaced (NOT NULL) + * + * Returns: pointer to a refcounted profile. + * else NULL if no profile + */ +static inline struct aa_profile *aa_get_profile_rcu(struct aa_profile __rcu **p) +{ + struct aa_profile *c; + + rcu_read_lock(); + do { + c = rcu_dereference(*p); + } while (c && !kref_get_unless_zero(&c->label.count)); + rcu_read_unlock(); + + return c; +} + +/** + * aa_put_profile - decrement refcount on profile @p + * @p: profile (MAYBE NULL) + */ +static inline void aa_put_profile(struct aa_profile *p) +{ + if (p) + kref_put(&p->label.count, aa_label_kref); +} + +static inline int AUDIT_MODE(struct aa_profile *profile) +{ + if (aa_g_audit != AUDIT_NORMAL) + return aa_g_audit; + + return profile->audit; +} + +bool aa_policy_view_capable(struct aa_label *label, struct aa_ns *ns); +bool aa_policy_admin_capable(struct aa_label *label, struct aa_ns *ns); +int aa_may_manage_policy(struct aa_label *label, struct aa_ns *ns, + u32 mask); +bool aa_current_policy_view_capable(struct aa_ns *ns); +bool aa_current_policy_admin_capable(struct aa_ns *ns); + +#endif /* __AA_POLICY_H */ diff --git a/security/apparmor/include/policy_ns.h b/security/apparmor/include/policy_ns.h new file mode 100644 index 000000000..33d665516 --- /dev/null +++ b/security/apparmor/include/policy_ns.h @@ -0,0 +1,165 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * AppArmor security module + * + * This file contains AppArmor policy definitions. + * + * Copyright (C) 1998-2008 Novell/SUSE + * Copyright 2009-2017 Canonical Ltd. + */ + +#ifndef __AA_NAMESPACE_H +#define __AA_NAMESPACE_H + +#include <linux/kref.h> + +#include "apparmor.h" +#include "apparmorfs.h" +#include "label.h" +#include "policy.h" + + +/* struct aa_ns_acct - accounting of profiles in namespace + * @max_size: maximum space allowed for all profiles in namespace + * @max_count: maximum number of profiles that can be in this namespace + * @size: current size of profiles + * @count: current count of profiles (includes null profiles) + */ +struct aa_ns_acct { + int max_size; + int max_count; + int size; + int count; +}; + +/* struct aa_ns - namespace for a set of profiles + * @base: common policy + * @parent: parent of namespace + * @lock: lock for modifying the object + * @acct: accounting for the namespace + * @unconfined: special unconfined profile for the namespace + * @sub_ns: list of namespaces under the current namespace. + * @uniq_null: uniq value used for null learning profiles + * @uniq_id: a unique id count for the profiles in the namespace + * @level: level of ns within the tree hierarchy + * @dents: dentries for the namespaces file entries in apparmorfs + * + * An aa_ns defines the set profiles that are searched to determine which + * profile to attach to a task. Profiles can not be shared between aa_ns + * and profile names within a namespace are guaranteed to be unique. When + * profiles in separate namespaces have the same name they are NOT considered + * to be equivalent. + * + * Namespaces are hierarchical and only namespaces and profiles below the + * current namespace are visible. + * + * Namespace names must be unique and can not contain the characters :/\0 + */ +struct aa_ns { + struct aa_policy base; + struct aa_ns *parent; + struct mutex lock; + struct aa_ns_acct acct; + struct aa_profile *unconfined; + struct list_head sub_ns; + atomic_t uniq_null; + long uniq_id; + int level; + long revision; + wait_queue_head_t wait; + + struct aa_labelset labels; + struct list_head rawdata_list; + + struct dentry *dents[AAFS_NS_SIZEOF]; +}; + +extern struct aa_label *kernel_t; +extern struct aa_ns *root_ns; + +extern const char *aa_hidden_ns_name; + +#define ns_unconfined(NS) (&(NS)->unconfined->label) + +bool aa_ns_visible(struct aa_ns *curr, struct aa_ns *view, bool subns); +const char *aa_ns_name(struct aa_ns *parent, struct aa_ns *child, bool subns); +void aa_free_ns(struct aa_ns *ns); +int aa_alloc_root_ns(void); +void aa_free_root_ns(void); +void aa_free_ns_kref(struct kref *kref); + +struct aa_ns *aa_find_ns(struct aa_ns *root, const char *name); +struct aa_ns *aa_findn_ns(struct aa_ns *root, const char *name, size_t n); +struct aa_ns *__aa_lookupn_ns(struct aa_ns *view, const char *hname, size_t n); +struct aa_ns *aa_lookupn_ns(struct aa_ns *view, const char *name, size_t n); +struct aa_ns *__aa_find_or_create_ns(struct aa_ns *parent, const char *name, + struct dentry *dir); +struct aa_ns *aa_prepare_ns(struct aa_ns *root, const char *name); +void __aa_remove_ns(struct aa_ns *ns); + +static inline struct aa_profile *aa_deref_parent(struct aa_profile *p) +{ + return rcu_dereference_protected(p->parent, + mutex_is_locked(&p->ns->lock)); +} + +/** + * aa_get_ns - increment references count on @ns + * @ns: namespace to increment reference count of (MAYBE NULL) + * + * Returns: pointer to @ns, if @ns is NULL returns NULL + * Requires: @ns must be held with valid refcount when called + */ +static inline struct aa_ns *aa_get_ns(struct aa_ns *ns) +{ + if (ns) + aa_get_profile(ns->unconfined); + + return ns; +} + +/** + * aa_put_ns - decrement refcount on @ns + * @ns: namespace to put reference of + * + * Decrement reference count of @ns and if no longer in use free it + */ +static inline void aa_put_ns(struct aa_ns *ns) +{ + if (ns) + aa_put_profile(ns->unconfined); +} + +/** + * __aa_findn_ns - find a namespace on a list by @name + * @head: list to search for namespace on (NOT NULL) + * @name: name of namespace to look for (NOT NULL) + * @n: length of @name + * Returns: unrefcounted namespace + * + * Requires: rcu_read_lock be held + */ +static inline struct aa_ns *__aa_findn_ns(struct list_head *head, + const char *name, size_t n) +{ + return (struct aa_ns *)__policy_strn_find(head, name, n); +} + +static inline struct aa_ns *__aa_find_ns(struct list_head *head, + const char *name) +{ + return __aa_findn_ns(head, name, strlen(name)); +} + +static inline struct aa_ns *__aa_lookup_ns(struct aa_ns *base, + const char *hname) +{ + return __aa_lookupn_ns(base, hname, strlen(hname)); +} + +static inline struct aa_ns *aa_lookup_ns(struct aa_ns *view, const char *name) +{ + return aa_lookupn_ns(view, name, strlen(name)); +} + +#endif /* AA_NAMESPACE_H */ diff --git a/security/apparmor/include/policy_unpack.h b/security/apparmor/include/policy_unpack.h new file mode 100644 index 000000000..e89b70144 --- /dev/null +++ b/security/apparmor/include/policy_unpack.h @@ -0,0 +1,179 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * AppArmor security module + * + * This file contains AppArmor policy loading interface function definitions. + * + * Copyright (C) 1998-2008 Novell/SUSE + * Copyright 2009-2010 Canonical Ltd. + */ + +#ifndef __POLICY_INTERFACE_H +#define __POLICY_INTERFACE_H + +#include <linux/list.h> +#include <linux/kref.h> +#include <linux/dcache.h> +#include <linux/workqueue.h> + +struct aa_load_ent { + struct list_head list; + struct aa_profile *new; + struct aa_profile *old; + struct aa_profile *rename; + const char *ns_name; +}; + +void aa_load_ent_free(struct aa_load_ent *ent); +struct aa_load_ent *aa_load_ent_alloc(void); + +#define PACKED_FLAG_HAT 1 +#define PACKED_FLAG_DEBUG1 2 +#define PACKED_FLAG_DEBUG2 4 + +#define PACKED_MODE_ENFORCE 0 +#define PACKED_MODE_COMPLAIN 1 +#define PACKED_MODE_KILL 2 +#define PACKED_MODE_UNCONFINED 3 + +struct aa_ns; + +enum { + AAFS_LOADDATA_ABI = 0, + AAFS_LOADDATA_REVISION, + AAFS_LOADDATA_HASH, + AAFS_LOADDATA_DATA, + AAFS_LOADDATA_COMPRESSED_SIZE, + AAFS_LOADDATA_DIR, /* must be last actual entry */ + AAFS_LOADDATA_NDENTS /* count of entries */ +}; + +/* + * The AppArmor interface treats data as a type byte followed by the + * actual data. The interface has the notion of a named entry + * which has a name (AA_NAME typecode followed by name string) followed by + * the entries typecode and data. Named types allow for optional + * elements and extensions to be added and tested for without breaking + * backwards compatibility. + */ + +enum aa_code { + AA_U8, + AA_U16, + AA_U32, + AA_U64, + AA_NAME, /* same as string except it is items name */ + AA_STRING, + AA_BLOB, + AA_STRUCT, + AA_STRUCTEND, + AA_LIST, + AA_LISTEND, + AA_ARRAY, + AA_ARRAYEND, +}; + +/* + * aa_ext is the read of the buffer containing the serialized profile. The + * data is copied into a kernel buffer in apparmorfs and then handed off to + * the unpack routines. + */ +struct aa_ext { + void *start; + void *end; + void *pos; /* pointer to current position in the buffer */ + u32 version; +}; + +/* + * struct aa_loaddata - buffer of policy raw_data set + * + * there is no loaddata ref for being on ns list, nor a ref from + * d_inode(@dentry) when grab a ref from these, @ns->lock must be held + * && __aa_get_loaddata() needs to be used, and the return value + * checked, if NULL the loaddata is already being reaped and should be + * considered dead. + */ +struct aa_loaddata { + struct kref count; + struct list_head list; + struct work_struct work; + struct dentry *dents[AAFS_LOADDATA_NDENTS]; + struct aa_ns *ns; + char *name; + size_t size; /* the original size of the payload */ + size_t compressed_size; /* the compressed size of the payload */ + long revision; /* the ns policy revision this caused */ + int abi; + unsigned char *hash; + + /* Pointer to payload. If @compressed_size > 0, then this is the + * compressed version of the payload, else it is the uncompressed + * version (with the size indicated by @size). + */ + char *data; +}; + +int aa_unpack(struct aa_loaddata *udata, struct list_head *lh, const char **ns); + +/** + * __aa_get_loaddata - get a reference count to uncounted data reference + * @data: reference to get a count on + * + * Returns: pointer to reference OR NULL if race is lost and reference is + * being repeated. + * Requires: @data->ns->lock held, and the return code MUST be checked + * + * Use only from inode->i_private and @data->list found references + */ +static inline struct aa_loaddata * +__aa_get_loaddata(struct aa_loaddata *data) +{ + if (data && kref_get_unless_zero(&(data->count))) + return data; + + return NULL; +} + +/** + * aa_get_loaddata - get a reference count from a counted data reference + * @data: reference to get a count on + * + * Returns: point to reference + * Requires: @data to have a valid reference count on it. It is a bug + * if the race to reap can be encountered when it is used. + */ +static inline struct aa_loaddata * +aa_get_loaddata(struct aa_loaddata *data) +{ + struct aa_loaddata *tmp = __aa_get_loaddata(data); + + AA_BUG(data && !tmp); + + return tmp; +} + +void __aa_loaddata_update(struct aa_loaddata *data, long revision); +bool aa_rawdata_eq(struct aa_loaddata *l, struct aa_loaddata *r); +void aa_loaddata_kref(struct kref *kref); +struct aa_loaddata *aa_loaddata_alloc(size_t size); +static inline void aa_put_loaddata(struct aa_loaddata *data) +{ + if (data) + kref_put(&data->count, aa_loaddata_kref); +} + +#if IS_ENABLED(CONFIG_KUNIT) +bool aa_inbounds(struct aa_ext *e, size_t size); +size_t aa_unpack_u16_chunk(struct aa_ext *e, char **chunk); +bool aa_unpack_X(struct aa_ext *e, enum aa_code code); +bool aa_unpack_nameX(struct aa_ext *e, enum aa_code code, const char *name); +bool aa_unpack_u32(struct aa_ext *e, u32 *data, const char *name); +bool aa_unpack_u64(struct aa_ext *e, u64 *data, const char *name); +size_t aa_unpack_array(struct aa_ext *e, const char *name); +size_t aa_unpack_blob(struct aa_ext *e, char **blob, const char *name); +int aa_unpack_str(struct aa_ext *e, const char **string, const char *name); +int aa_unpack_strdup(struct aa_ext *e, char **string, const char *name); +#endif + +#endif /* __POLICY_INTERFACE_H */ diff --git a/security/apparmor/include/procattr.h b/security/apparmor/include/procattr.h new file mode 100644 index 000000000..31689437e --- /dev/null +++ b/security/apparmor/include/procattr.h @@ -0,0 +1,17 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * AppArmor security module + * + * This file contains AppArmor /proc/<pid>/attr/ interface function definitions. + * + * Copyright (C) 1998-2008 Novell/SUSE + * Copyright 2009-2010 Canonical Ltd. + */ + +#ifndef __AA_PROCATTR_H +#define __AA_PROCATTR_H + +int aa_getprocattr(struct aa_label *label, char **string); +int aa_setprocattr_changehat(char *args, size_t size, int flags); + +#endif /* __AA_PROCATTR_H */ diff --git a/security/apparmor/include/resource.h b/security/apparmor/include/resource.h new file mode 100644 index 000000000..961d85d32 --- /dev/null +++ b/security/apparmor/include/resource.h @@ -0,0 +1,46 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * AppArmor security module + * + * This file contains AppArmor resource limits function definitions. + * + * Copyright (C) 1998-2008 Novell/SUSE + * Copyright 2009-2010 Canonical Ltd. + */ + +#ifndef __AA_RESOURCE_H +#define __AA_RESOURCE_H + +#include <linux/resource.h> +#include <linux/sched.h> + +#include "apparmorfs.h" + +struct aa_profile; + +/* struct aa_rlimit - rlimit settings for the profile + * @mask: which hard limits to set + * @limits: rlimit values that override task limits + * + * AppArmor rlimits are used to set confined task rlimits. Only the + * limits specified in @mask will be controlled by apparmor. + */ +struct aa_rlimit { + unsigned int mask; + struct rlimit limits[RLIM_NLIMITS]; +}; + +extern struct aa_sfs_entry aa_sfs_entry_rlimit[]; + +int aa_map_resource(int resource); +int aa_task_setrlimit(struct aa_label *label, struct task_struct *task, + unsigned int resource, struct rlimit *new_rlim); + +void __aa_transition_rlimits(struct aa_label *old, struct aa_label *new); + +static inline void aa_free_rlimit_rules(struct aa_rlimit *rlims) +{ + /* NOP */ +} + +#endif /* __AA_RESOURCE_H */ diff --git a/security/apparmor/include/secid.h b/security/apparmor/include/secid.h new file mode 100644 index 000000000..a912a5d5d --- /dev/null +++ b/security/apparmor/include/secid.h @@ -0,0 +1,37 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * AppArmor security module + * + * This file contains AppArmor security identifier (secid) definitions + * + * Copyright 2009-2018 Canonical Ltd. + */ + +#ifndef __AA_SECID_H +#define __AA_SECID_H + +#include <linux/slab.h> +#include <linux/types.h> + +struct aa_label; + +/* secid value that will not be allocated */ +#define AA_SECID_INVALID 0 + +/* secid value that matches any other secid */ +#define AA_SECID_WILDCARD 1 + +/* sysctl to enable displaying mode when converting secid to secctx */ +extern int apparmor_display_secid_mode; + +struct aa_label *aa_secid_to_label(u32 secid); +int apparmor_secid_to_secctx(u32 secid, char **secdata, u32 *seclen); +int apparmor_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid); +void apparmor_release_secctx(char *secdata, u32 seclen); + + +int aa_alloc_secid(struct aa_label *label, gfp_t gfp); +void aa_free_secid(u32 secid); +void aa_secid_update(u32 secid, struct aa_label *label); + +#endif /* __AA_SECID_H */ diff --git a/security/apparmor/include/sig_names.h b/security/apparmor/include/sig_names.h new file mode 100644 index 000000000..cbf7a997e --- /dev/null +++ b/security/apparmor/include/sig_names.h @@ -0,0 +1,101 @@ +#include <linux/signal.h> + +#define SIGUNKNOWN 0 +#define MAXMAPPED_SIG 35 +#define MAXMAPPED_SIGNAME (MAXMAPPED_SIG + 1) +#define SIGRT_BASE 128 + +/* provide a mapping of arch signal to internal signal # for mediation + * those that are always an alias SIGCLD for SIGCLHD and SIGPOLL for SIGIO + * map to the same entry those that may/or may not get a separate entry + */ +static const int sig_map[MAXMAPPED_SIG] = { + [0] = MAXMAPPED_SIG, /* existence test */ + [SIGHUP] = 1, + [SIGINT] = 2, + [SIGQUIT] = 3, + [SIGILL] = 4, + [SIGTRAP] = 5, /* -, 5, - */ + [SIGABRT] = 6, /* SIGIOT: -, 6, - */ + [SIGBUS] = 7, /* 10, 7, 10 */ + [SIGFPE] = 8, + [SIGKILL] = 9, + [SIGUSR1] = 10, /* 30, 10, 16 */ + [SIGSEGV] = 11, + [SIGUSR2] = 12, /* 31, 12, 17 */ + [SIGPIPE] = 13, + [SIGALRM] = 14, + [SIGTERM] = 15, +#ifdef SIGSTKFLT + [SIGSTKFLT] = 16, /* -, 16, - */ +#endif + [SIGCHLD] = 17, /* 20, 17, 18. SIGCHLD -, -, 18 */ + [SIGCONT] = 18, /* 19, 18, 25 */ + [SIGSTOP] = 19, /* 17, 19, 23 */ + [SIGTSTP] = 20, /* 18, 20, 24 */ + [SIGTTIN] = 21, /* 21, 21, 26 */ + [SIGTTOU] = 22, /* 22, 22, 27 */ + [SIGURG] = 23, /* 16, 23, 21 */ + [SIGXCPU] = 24, /* 24, 24, 30 */ + [SIGXFSZ] = 25, /* 25, 25, 31 */ + [SIGVTALRM] = 26, /* 26, 26, 28 */ + [SIGPROF] = 27, /* 27, 27, 29 */ + [SIGWINCH] = 28, /* 28, 28, 20 */ + [SIGIO] = 29, /* SIGPOLL: 23, 29, 22 */ + [SIGPWR] = 30, /* 29, 30, 19. SIGINFO 29, -, - */ +#ifdef SIGSYS + [SIGSYS] = 31, /* 12, 31, 12. often SIG LOST/UNUSED */ +#endif +#ifdef SIGEMT + [SIGEMT] = 32, /* 7, - , 7 */ +#endif +#if defined(SIGLOST) && SIGPWR != SIGLOST /* sparc */ + [SIGLOST] = 33, /* unused on Linux */ +#endif +#if defined(SIGUNUSED) && \ + defined(SIGLOST) && defined(SIGSYS) && SIGLOST != SIGSYS + [SIGUNUSED] = 34, /* -, 31, - */ +#endif +}; + +/* this table is ordered post sig_map[sig] mapping */ +static const char *const sig_names[MAXMAPPED_SIGNAME] = { + "unknown", + "hup", + "int", + "quit", + "ill", + "trap", + "abrt", + "bus", + "fpe", + "kill", + "usr1", + "segv", + "usr2", + "pipe", + "alrm", + "term", + "stkflt", + "chld", + "cont", + "stop", + "stp", + "ttin", + "ttou", + "urg", + "xcpu", + "xfsz", + "vtalrm", + "prof", + "winch", + "io", + "pwr", + "sys", + "emt", + "lost", + "unused", + + "exists", /* always last existence test mapped to MAXMAPPED_SIG */ +}; + diff --git a/security/apparmor/include/task.h b/security/apparmor/include/task.h new file mode 100644 index 000000000..13437d62c --- /dev/null +++ b/security/apparmor/include/task.h @@ -0,0 +1,98 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * AppArmor security module + * + * This file contains AppArmor task related definitions and mediation + * + * Copyright 2017 Canonical Ltd. + */ + +#ifndef __AA_TASK_H +#define __AA_TASK_H + +static inline struct aa_task_ctx *task_ctx(struct task_struct *task) +{ + return task->security + apparmor_blob_sizes.lbs_task; +} + +/* + * struct aa_task_ctx - information for current task label change + * @nnp: snapshot of label at time of no_new_privs + * @onexec: profile to transition to on next exec (MAY BE NULL) + * @previous: profile the task may return to (MAY BE NULL) + * @token: magic value the task must know for returning to @previous_profile + */ +struct aa_task_ctx { + struct aa_label *nnp; + struct aa_label *onexec; + struct aa_label *previous; + u64 token; +}; + +int aa_replace_current_label(struct aa_label *label); +int aa_set_current_onexec(struct aa_label *label, bool stack); +int aa_set_current_hat(struct aa_label *label, u64 token); +int aa_restore_previous_label(u64 cookie); +struct aa_label *aa_get_task_label(struct task_struct *task); + +/** + * aa_free_task_ctx - free a task_ctx + * @ctx: task_ctx to free (MAYBE NULL) + */ +static inline void aa_free_task_ctx(struct aa_task_ctx *ctx) +{ + if (ctx) { + aa_put_label(ctx->nnp); + aa_put_label(ctx->previous); + aa_put_label(ctx->onexec); + } +} + +/** + * aa_dup_task_ctx - duplicate a task context, incrementing reference counts + * @new: a blank task context (NOT NULL) + * @old: the task context to copy (NOT NULL) + */ +static inline void aa_dup_task_ctx(struct aa_task_ctx *new, + const struct aa_task_ctx *old) +{ + *new = *old; + aa_get_label(new->nnp); + aa_get_label(new->previous); + aa_get_label(new->onexec); +} + +/** + * aa_clear_task_ctx_trans - clear transition tracking info from the ctx + * @ctx: task context to clear (NOT NULL) + */ +static inline void aa_clear_task_ctx_trans(struct aa_task_ctx *ctx) +{ + AA_BUG(!ctx); + + aa_put_label(ctx->previous); + aa_put_label(ctx->onexec); + ctx->previous = NULL; + ctx->onexec = NULL; + ctx->token = 0; +} + +#define AA_PTRACE_TRACE MAY_WRITE +#define AA_PTRACE_READ MAY_READ +#define AA_MAY_BE_TRACED AA_MAY_APPEND +#define AA_MAY_BE_READ AA_MAY_CREATE +#define PTRACE_PERM_SHIFT 2 + +#define AA_PTRACE_PERM_MASK (AA_PTRACE_READ | AA_PTRACE_TRACE | \ + AA_MAY_BE_READ | AA_MAY_BE_TRACED) +#define AA_SIGNAL_PERM_MASK (MAY_READ | MAY_WRITE) + +#define AA_SFS_SIG_MASK "hup int quit ill trap abrt bus fpe kill usr1 " \ + "segv usr2 pipe alrm term stkflt chld cont stop stp ttin ttou urg " \ + "xcpu xfsz vtalrm prof winch io pwr sys emt lost" + +int aa_may_ptrace(struct aa_label *tracer, struct aa_label *tracee, + u32 request); + + +#endif /* __AA_TASK_H */ diff --git a/security/apparmor/ipc.c b/security/apparmor/ipc.c new file mode 100644 index 000000000..3dbbc59d4 --- /dev/null +++ b/security/apparmor/ipc.c @@ -0,0 +1,108 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * AppArmor security module + * + * This file contains AppArmor ipc mediation + * + * Copyright (C) 1998-2008 Novell/SUSE + * Copyright 2009-2017 Canonical Ltd. + */ + +#include <linux/gfp.h> + +#include "include/audit.h" +#include "include/capability.h" +#include "include/cred.h" +#include "include/policy.h" +#include "include/ipc.h" +#include "include/sig_names.h" + + +static inline int map_signal_num(int sig) +{ + if (sig > SIGRTMAX) + return SIGUNKNOWN; + else if (sig >= SIGRTMIN) + return sig - SIGRTMIN + SIGRT_BASE; + else if (sig < MAXMAPPED_SIG) + return sig_map[sig]; + return SIGUNKNOWN; +} + +/** + * audit_signal_mask - convert mask to permission string + * @mask: permission mask to convert + * + * Returns: pointer to static string + */ +static const char *audit_signal_mask(u32 mask) +{ + if (mask & MAY_READ) + return "receive"; + if (mask & MAY_WRITE) + return "send"; + return ""; +} + +/** + * audit_cb - call back for signal specific audit fields + * @ab: audit_buffer (NOT NULL) + * @va: audit struct to audit values of (NOT NULL) + */ +static void audit_signal_cb(struct audit_buffer *ab, void *va) +{ + struct common_audit_data *sa = va; + + if (aad(sa)->request & AA_SIGNAL_PERM_MASK) { + audit_log_format(ab, " requested_mask=\"%s\"", + audit_signal_mask(aad(sa)->request)); + if (aad(sa)->denied & AA_SIGNAL_PERM_MASK) { + audit_log_format(ab, " denied_mask=\"%s\"", + audit_signal_mask(aad(sa)->denied)); + } + } + if (aad(sa)->signal == SIGUNKNOWN) + audit_log_format(ab, "signal=unknown(%d)", + aad(sa)->unmappedsig); + else if (aad(sa)->signal < MAXMAPPED_SIGNAME) + audit_log_format(ab, " signal=%s", sig_names[aad(sa)->signal]); + else + audit_log_format(ab, " signal=rtmin+%d", + aad(sa)->signal - SIGRT_BASE); + audit_log_format(ab, " peer="); + aa_label_xaudit(ab, labels_ns(aad(sa)->label), aad(sa)->peer, + FLAGS_NONE, GFP_ATOMIC); +} + +static int profile_signal_perm(struct aa_profile *profile, + struct aa_label *peer, u32 request, + struct common_audit_data *sa) +{ + struct aa_perms perms; + unsigned int state; + + if (profile_unconfined(profile) || + !PROFILE_MEDIATES(profile, AA_CLASS_SIGNAL)) + return 0; + + aad(sa)->peer = peer; + /* TODO: secondary cache check <profile, profile, perm> */ + state = aa_dfa_next(profile->policy.dfa, + profile->policy.start[AA_CLASS_SIGNAL], + aad(sa)->signal); + aa_label_match(profile, peer, state, false, request, &perms); + aa_apply_modes_to_perms(profile, &perms); + return aa_check_perms(profile, &perms, request, sa, audit_signal_cb); +} + +int aa_may_signal(struct aa_label *sender, struct aa_label *target, int sig) +{ + struct aa_profile *profile; + DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, OP_SIGNAL); + + aad(&sa)->signal = map_signal_num(sig); + aad(&sa)->unmappedsig = sig; + return xcheck_labels(sender, target, profile, + profile_signal_perm(profile, target, MAY_WRITE, &sa), + profile_signal_perm(profile, sender, MAY_READ, &sa)); +} diff --git a/security/apparmor/label.c b/security/apparmor/label.c new file mode 100644 index 000000000..a67c5897e --- /dev/null +++ b/security/apparmor/label.c @@ -0,0 +1,2163 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * AppArmor security module + * + * This file contains AppArmor label definitions + * + * Copyright 2017 Canonical Ltd. + */ + +#include <linux/audit.h> +#include <linux/seq_file.h> +#include <linux/sort.h> + +#include "include/apparmor.h" +#include "include/cred.h" +#include "include/label.h" +#include "include/policy.h" +#include "include/secid.h" + + +/* + * the aa_label represents the set of profiles confining an object + * + * Labels maintain a reference count to the set of pointers they reference + * Labels are ref counted by + * tasks and object via the security field/security context off the field + * code - will take a ref count on a label if it needs the label + * beyond what is possible with an rcu_read_lock. + * profiles - each profile is a label + * secids - a pinned secid will keep a refcount of the label it is + * referencing + * objects - inode, files, sockets, ... + * + * Labels are not ref counted by the label set, so they maybe removed and + * freed when no longer in use. + * + */ + +#define PROXY_POISON 97 +#define LABEL_POISON 100 + +static void free_proxy(struct aa_proxy *proxy) +{ + if (proxy) { + /* p->label will not updated any more as p is dead */ + aa_put_label(rcu_dereference_protected(proxy->label, true)); + memset(proxy, 0, sizeof(*proxy)); + RCU_INIT_POINTER(proxy->label, (struct aa_label *)PROXY_POISON); + kfree(proxy); + } +} + +void aa_proxy_kref(struct kref *kref) +{ + struct aa_proxy *proxy = container_of(kref, struct aa_proxy, count); + + free_proxy(proxy); +} + +struct aa_proxy *aa_alloc_proxy(struct aa_label *label, gfp_t gfp) +{ + struct aa_proxy *new; + + new = kzalloc(sizeof(struct aa_proxy), gfp); + if (new) { + kref_init(&new->count); + rcu_assign_pointer(new->label, aa_get_label(label)); + } + return new; +} + +/* requires profile list write lock held */ +void __aa_proxy_redirect(struct aa_label *orig, struct aa_label *new) +{ + struct aa_label *tmp; + + AA_BUG(!orig); + AA_BUG(!new); + lockdep_assert_held_write(&labels_set(orig)->lock); + + tmp = rcu_dereference_protected(orig->proxy->label, + &labels_ns(orig)->lock); + rcu_assign_pointer(orig->proxy->label, aa_get_label(new)); + orig->flags |= FLAG_STALE; + aa_put_label(tmp); +} + +static void __proxy_share(struct aa_label *old, struct aa_label *new) +{ + struct aa_proxy *proxy = new->proxy; + + new->proxy = aa_get_proxy(old->proxy); + __aa_proxy_redirect(old, new); + aa_put_proxy(proxy); +} + + +/** + * ns_cmp - compare ns for label set ordering + * @a: ns to compare (NOT NULL) + * @b: ns to compare (NOT NULL) + * + * Returns: <0 if a < b + * ==0 if a == b + * >0 if a > b + */ +static int ns_cmp(struct aa_ns *a, struct aa_ns *b) +{ + int res; + + AA_BUG(!a); + AA_BUG(!b); + AA_BUG(!a->base.hname); + AA_BUG(!b->base.hname); + + if (a == b) + return 0; + + res = a->level - b->level; + if (res) + return res; + + return strcmp(a->base.hname, b->base.hname); +} + +/** + * profile_cmp - profile comparison for set ordering + * @a: profile to compare (NOT NULL) + * @b: profile to compare (NOT NULL) + * + * Returns: <0 if a < b + * ==0 if a == b + * >0 if a > b + */ +static int profile_cmp(struct aa_profile *a, struct aa_profile *b) +{ + int res; + + AA_BUG(!a); + AA_BUG(!b); + AA_BUG(!a->ns); + AA_BUG(!b->ns); + AA_BUG(!a->base.hname); + AA_BUG(!b->base.hname); + + if (a == b || a->base.hname == b->base.hname) + return 0; + res = ns_cmp(a->ns, b->ns); + if (res) + return res; + + return strcmp(a->base.hname, b->base.hname); +} + +/** + * vec_cmp - label comparison for set ordering + * @a: label to compare (NOT NULL) + * @vec: vector of profiles to compare (NOT NULL) + * @n: length of @vec + * + * Returns: <0 if a < vec + * ==0 if a == vec + * >0 if a > vec + */ +static int vec_cmp(struct aa_profile **a, int an, struct aa_profile **b, int bn) +{ + int i; + + AA_BUG(!a); + AA_BUG(!*a); + AA_BUG(!b); + AA_BUG(!*b); + AA_BUG(an <= 0); + AA_BUG(bn <= 0); + + for (i = 0; i < an && i < bn; i++) { + int res = profile_cmp(a[i], b[i]); + + if (res != 0) + return res; + } + + return an - bn; +} + +static bool vec_is_stale(struct aa_profile **vec, int n) +{ + int i; + + AA_BUG(!vec); + + for (i = 0; i < n; i++) { + if (profile_is_stale(vec[i])) + return true; + } + + return false; +} + +static long accum_vec_flags(struct aa_profile **vec, int n) +{ + long u = FLAG_UNCONFINED; + int i; + + AA_BUG(!vec); + + for (i = 0; i < n; i++) { + u |= vec[i]->label.flags & (FLAG_DEBUG1 | FLAG_DEBUG2 | + FLAG_STALE); + if (!(u & vec[i]->label.flags & FLAG_UNCONFINED)) + u &= ~FLAG_UNCONFINED; + } + + return u; +} + +static int sort_cmp(const void *a, const void *b) +{ + return profile_cmp(*(struct aa_profile **)a, *(struct aa_profile **)b); +} + +/* + * assumes vec is sorted + * Assumes @vec has null terminator at vec[n], and will null terminate + * vec[n - dups] + */ +static inline int unique(struct aa_profile **vec, int n) +{ + int i, pos, dups = 0; + + AA_BUG(n < 1); + AA_BUG(!vec); + + pos = 0; + for (i = 1; i < n; i++) { + int res = profile_cmp(vec[pos], vec[i]); + + AA_BUG(res > 0, "vec not sorted"); + if (res == 0) { + /* drop duplicate */ + aa_put_profile(vec[i]); + dups++; + continue; + } + pos++; + if (dups) + vec[pos] = vec[i]; + } + + AA_BUG(dups < 0); + + return dups; +} + +/** + * aa_vec_unique - canonical sort and unique a list of profiles + * @n: number of refcounted profiles in the list (@n > 0) + * @vec: list of profiles to sort and merge + * + * Returns: the number of duplicates eliminated == references put + * + * If @flags & VEC_FLAG_TERMINATE @vec has null terminator at vec[n], and will + * null terminate vec[n - dups] + */ +int aa_vec_unique(struct aa_profile **vec, int n, int flags) +{ + int i, dups = 0; + + AA_BUG(n < 1); + AA_BUG(!vec); + + /* vecs are usually small and inorder, have a fallback for larger */ + if (n > 8) { + sort(vec, n, sizeof(struct aa_profile *), sort_cmp, NULL); + dups = unique(vec, n); + goto out; + } + + /* insertion sort + unique in one */ + for (i = 1; i < n; i++) { + struct aa_profile *tmp = vec[i]; + int pos, j; + + for (pos = i - 1 - dups; pos >= 0; pos--) { + int res = profile_cmp(vec[pos], tmp); + + if (res == 0) { + /* drop duplicate entry */ + aa_put_profile(tmp); + dups++; + goto continue_outer; + } else if (res < 0) + break; + } + /* pos is at entry < tmp, or index -1. Set to insert pos */ + pos++; + + for (j = i - dups; j > pos; j--) + vec[j] = vec[j - 1]; + vec[pos] = tmp; +continue_outer: + ; + } + + AA_BUG(dups < 0); + +out: + if (flags & VEC_FLAG_TERMINATE) + vec[n - dups] = NULL; + + return dups; +} + + +void aa_label_destroy(struct aa_label *label) +{ + AA_BUG(!label); + + if (!label_isprofile(label)) { + struct aa_profile *profile; + struct label_it i; + + aa_put_str(label->hname); + + label_for_each(i, label, profile) { + aa_put_profile(profile); + label->vec[i.i] = (struct aa_profile *) + (LABEL_POISON + (long) i.i); + } + } + + if (label->proxy) { + if (rcu_dereference_protected(label->proxy->label, true) == label) + rcu_assign_pointer(label->proxy->label, NULL); + aa_put_proxy(label->proxy); + } + aa_free_secid(label->secid); + + label->proxy = (struct aa_proxy *) PROXY_POISON + 1; +} + +void aa_label_free(struct aa_label *label) +{ + if (!label) + return; + + aa_label_destroy(label); + kfree(label); +} + +static void label_free_switch(struct aa_label *label) +{ + if (label->flags & FLAG_NS_COUNT) + aa_free_ns(labels_ns(label)); + else if (label_isprofile(label)) + aa_free_profile(labels_profile(label)); + else + aa_label_free(label); +} + +static void label_free_rcu(struct rcu_head *head) +{ + struct aa_label *label = container_of(head, struct aa_label, rcu); + + if (label->flags & FLAG_IN_TREE) + (void) aa_label_remove(label); + label_free_switch(label); +} + +void aa_label_kref(struct kref *kref) +{ + struct aa_label *label = container_of(kref, struct aa_label, count); + struct aa_ns *ns = labels_ns(label); + + if (!ns) { + /* never live, no rcu callback needed, just using the fn */ + label_free_switch(label); + return; + } + /* TODO: update labels_profile macro so it works here */ + AA_BUG(label_isprofile(label) && + on_list_rcu(&label->vec[0]->base.profiles)); + AA_BUG(label_isprofile(label) && + on_list_rcu(&label->vec[0]->base.list)); + + /* TODO: if compound label and not stale add to reclaim cache */ + call_rcu(&label->rcu, label_free_rcu); +} + +static void label_free_or_put_new(struct aa_label *label, struct aa_label *new) +{ + if (label != new) + /* need to free directly to break circular ref with proxy */ + aa_label_free(new); + else + aa_put_label(new); +} + +bool aa_label_init(struct aa_label *label, int size, gfp_t gfp) +{ + AA_BUG(!label); + AA_BUG(size < 1); + + if (aa_alloc_secid(label, gfp) < 0) + return false; + + label->size = size; /* doesn't include null */ + label->vec[size] = NULL; /* null terminate */ + kref_init(&label->count); + RB_CLEAR_NODE(&label->node); + + return true; +} + +/** + * aa_label_alloc - allocate a label with a profile vector of @size length + * @size: size of profile vector in the label + * @proxy: proxy to use OR null if to allocate a new one + * @gfp: memory allocation type + * + * Returns: new label + * else NULL if failed + */ +struct aa_label *aa_label_alloc(int size, struct aa_proxy *proxy, gfp_t gfp) +{ + struct aa_label *new; + + AA_BUG(size < 1); + + /* + 1 for null terminator entry on vec */ + new = kzalloc(struct_size(new, vec, size + 1), gfp); + AA_DEBUG("%s (%p)\n", __func__, new); + if (!new) + goto fail; + + if (!aa_label_init(new, size, gfp)) + goto fail; + + if (!proxy) { + proxy = aa_alloc_proxy(new, gfp); + if (!proxy) + goto fail; + } else + aa_get_proxy(proxy); + /* just set new's proxy, don't redirect proxy here if it was passed in*/ + new->proxy = proxy; + + return new; + +fail: + kfree(new); + + return NULL; +} + + +/** + * label_cmp - label comparison for set ordering + * @a: label to compare (NOT NULL) + * @b: label to compare (NOT NULL) + * + * Returns: <0 if a < b + * ==0 if a == b + * >0 if a > b + */ +static int label_cmp(struct aa_label *a, struct aa_label *b) +{ + AA_BUG(!b); + + if (a == b) + return 0; + + return vec_cmp(a->vec, a->size, b->vec, b->size); +} + +/* helper fn for label_for_each_confined */ +int aa_label_next_confined(struct aa_label *label, int i) +{ + AA_BUG(!label); + AA_BUG(i < 0); + + for (; i < label->size; i++) { + if (!profile_unconfined(label->vec[i])) + return i; + } + + return i; +} + +/** + * __aa_label_next_not_in_set - return the next profile of @sub not in @set + * @I: label iterator + * @set: label to test against + * @sub: label to if is subset of @set + * + * Returns: profile in @sub that is not in @set, with iterator set pos after + * else NULL if @sub is a subset of @set + */ +struct aa_profile *__aa_label_next_not_in_set(struct label_it *I, + struct aa_label *set, + struct aa_label *sub) +{ + AA_BUG(!set); + AA_BUG(!I); + AA_BUG(I->i < 0); + AA_BUG(I->i > set->size); + AA_BUG(!sub); + AA_BUG(I->j < 0); + AA_BUG(I->j > sub->size); + + while (I->j < sub->size && I->i < set->size) { + int res = profile_cmp(sub->vec[I->j], set->vec[I->i]); + + if (res == 0) { + (I->j)++; + (I->i)++; + } else if (res > 0) + (I->i)++; + else + return sub->vec[(I->j)++]; + } + + if (I->j < sub->size) + return sub->vec[(I->j)++]; + + return NULL; +} + +/** + * aa_label_is_subset - test if @sub is a subset of @set + * @set: label to test against + * @sub: label to test if is subset of @set + * + * Returns: true if @sub is subset of @set + * else false + */ +bool aa_label_is_subset(struct aa_label *set, struct aa_label *sub) +{ + struct label_it i = { }; + + AA_BUG(!set); + AA_BUG(!sub); + + if (sub == set) + return true; + + return __aa_label_next_not_in_set(&i, set, sub) == NULL; +} + +/** + * aa_label_is_unconfined_subset - test if @sub is a subset of @set + * @set: label to test against + * @sub: label to test if is subset of @set + * + * This checks for subset but taking into account unconfined. IF + * @sub contains an unconfined profile that does not have a matching + * unconfined in @set then this will not cause the test to fail. + * Conversely we don't care about an unconfined in @set that is not in + * @sub + * + * Returns: true if @sub is special_subset of @set + * else false + */ +bool aa_label_is_unconfined_subset(struct aa_label *set, struct aa_label *sub) +{ + struct label_it i = { }; + struct aa_profile *p; + + AA_BUG(!set); + AA_BUG(!sub); + + if (sub == set) + return true; + + do { + p = __aa_label_next_not_in_set(&i, set, sub); + if (p && !profile_unconfined(p)) + break; + } while (p); + + return p == NULL; +} + + +/** + * __label_remove - remove @label from the label set + * @l: label to remove + * @new: label to redirect to + * + * Requires: labels_set(@label)->lock write_lock + * Returns: true if the label was in the tree and removed + */ +static bool __label_remove(struct aa_label *label, struct aa_label *new) +{ + struct aa_labelset *ls = labels_set(label); + + AA_BUG(!ls); + AA_BUG(!label); + lockdep_assert_held_write(&ls->lock); + + if (new) + __aa_proxy_redirect(label, new); + + if (!label_is_stale(label)) + __label_make_stale(label); + + if (label->flags & FLAG_IN_TREE) { + rb_erase(&label->node, &ls->root); + label->flags &= ~FLAG_IN_TREE; + return true; + } + + return false; +} + +/** + * __label_replace - replace @old with @new in label set + * @old: label to remove from label set + * @new: label to replace @old with + * + * Requires: labels_set(@old)->lock write_lock + * valid ref count be held on @new + * Returns: true if @old was in set and replaced by @new + * + * Note: current implementation requires label set be order in such a way + * that @new directly replaces @old position in the set (ie. + * using pointer comparison of the label address would not work) + */ +static bool __label_replace(struct aa_label *old, struct aa_label *new) +{ + struct aa_labelset *ls = labels_set(old); + + AA_BUG(!ls); + AA_BUG(!old); + AA_BUG(!new); + lockdep_assert_held_write(&ls->lock); + AA_BUG(new->flags & FLAG_IN_TREE); + + if (!label_is_stale(old)) + __label_make_stale(old); + + if (old->flags & FLAG_IN_TREE) { + rb_replace_node(&old->node, &new->node, &ls->root); + old->flags &= ~FLAG_IN_TREE; + new->flags |= FLAG_IN_TREE; + return true; + } + + return false; +} + +/** + * __label_insert - attempt to insert @l into a label set + * @ls: set of labels to insert @l into (NOT NULL) + * @label: new label to insert (NOT NULL) + * @replace: whether insertion should replace existing entry that is not stale + * + * Requires: @ls->lock + * caller to hold a valid ref on l + * if @replace is true l has a preallocated proxy associated + * Returns: @l if successful in inserting @l - with additional refcount + * else ref counted equivalent label that is already in the set, + * the else condition only happens if @replace is false + */ +static struct aa_label *__label_insert(struct aa_labelset *ls, + struct aa_label *label, bool replace) +{ + struct rb_node **new, *parent = NULL; + + AA_BUG(!ls); + AA_BUG(!label); + AA_BUG(labels_set(label) != ls); + lockdep_assert_held_write(&ls->lock); + AA_BUG(label->flags & FLAG_IN_TREE); + + /* Figure out where to put new node */ + new = &ls->root.rb_node; + while (*new) { + struct aa_label *this = rb_entry(*new, struct aa_label, node); + int result = label_cmp(label, this); + + parent = *new; + if (result == 0) { + /* !__aa_get_label means queued for destruction, + * so replace in place, however the label has + * died before the replacement so do not share + * the proxy + */ + if (!replace && !label_is_stale(this)) { + if (__aa_get_label(this)) + return this; + } else + __proxy_share(this, label); + AA_BUG(!__label_replace(this, label)); + return aa_get_label(label); + } else if (result < 0) + new = &((*new)->rb_left); + else /* (result > 0) */ + new = &((*new)->rb_right); + } + + /* Add new node and rebalance tree. */ + rb_link_node(&label->node, parent, new); + rb_insert_color(&label->node, &ls->root); + label->flags |= FLAG_IN_TREE; + + return aa_get_label(label); +} + +/** + * __vec_find - find label that matches @vec in label set + * @vec: vec of profiles to find matching label for (NOT NULL) + * @n: length of @vec + * + * Requires: @vec_labelset(vec) lock held + * caller to hold a valid ref on l + * + * Returns: ref counted @label if matching label is in tree + * ref counted label that is equiv to @l in tree + * else NULL if @vec equiv is not in tree + */ +static struct aa_label *__vec_find(struct aa_profile **vec, int n) +{ + struct rb_node *node; + + AA_BUG(!vec); + AA_BUG(!*vec); + AA_BUG(n <= 0); + + node = vec_labelset(vec, n)->root.rb_node; + while (node) { + struct aa_label *this = rb_entry(node, struct aa_label, node); + int result = vec_cmp(this->vec, this->size, vec, n); + + if (result > 0) + node = node->rb_left; + else if (result < 0) + node = node->rb_right; + else + return __aa_get_label(this); + } + + return NULL; +} + +/** + * __label_find - find label @label in label set + * @label: label to find (NOT NULL) + * + * Requires: labels_set(@label)->lock held + * caller to hold a valid ref on l + * + * Returns: ref counted @label if @label is in tree OR + * ref counted label that is equiv to @label in tree + * else NULL if @label or equiv is not in tree + */ +static struct aa_label *__label_find(struct aa_label *label) +{ + AA_BUG(!label); + + return __vec_find(label->vec, label->size); +} + + +/** + * aa_label_remove - remove a label from the labelset + * @label: label to remove + * + * Returns: true if @label was removed from the tree + * else @label was not in tree so it could not be removed + */ +bool aa_label_remove(struct aa_label *label) +{ + struct aa_labelset *ls = labels_set(label); + unsigned long flags; + bool res; + + AA_BUG(!ls); + + write_lock_irqsave(&ls->lock, flags); + res = __label_remove(label, ns_unconfined(labels_ns(label))); + write_unlock_irqrestore(&ls->lock, flags); + + return res; +} + +/** + * aa_label_replace - replace a label @old with a new version @new + * @old: label to replace + * @new: label replacing @old + * + * Returns: true if @old was in tree and replaced + * else @old was not in tree, and @new was not inserted + */ +bool aa_label_replace(struct aa_label *old, struct aa_label *new) +{ + unsigned long flags; + bool res; + + if (name_is_shared(old, new) && labels_ns(old) == labels_ns(new)) { + write_lock_irqsave(&labels_set(old)->lock, flags); + if (old->proxy != new->proxy) + __proxy_share(old, new); + else + __aa_proxy_redirect(old, new); + res = __label_replace(old, new); + write_unlock_irqrestore(&labels_set(old)->lock, flags); + } else { + struct aa_label *l; + struct aa_labelset *ls = labels_set(old); + + write_lock_irqsave(&ls->lock, flags); + res = __label_remove(old, new); + if (labels_ns(old) != labels_ns(new)) { + write_unlock_irqrestore(&ls->lock, flags); + ls = labels_set(new); + write_lock_irqsave(&ls->lock, flags); + } + l = __label_insert(ls, new, true); + res = (l == new); + write_unlock_irqrestore(&ls->lock, flags); + aa_put_label(l); + } + + return res; +} + +/** + * vec_find - find label @l in label set + * @vec: array of profiles to find equiv label for (NOT NULL) + * @n: length of @vec + * + * Returns: refcounted label if @vec equiv is in tree + * else NULL if @vec equiv is not in tree + */ +static struct aa_label *vec_find(struct aa_profile **vec, int n) +{ + struct aa_labelset *ls; + struct aa_label *label; + unsigned long flags; + + AA_BUG(!vec); + AA_BUG(!*vec); + AA_BUG(n <= 0); + + ls = vec_labelset(vec, n); + read_lock_irqsave(&ls->lock, flags); + label = __vec_find(vec, n); + read_unlock_irqrestore(&ls->lock, flags); + + return label; +} + +/* requires sort and merge done first */ +static struct aa_label *vec_create_and_insert_label(struct aa_profile **vec, + int len, gfp_t gfp) +{ + struct aa_label *label = NULL; + struct aa_labelset *ls; + unsigned long flags; + struct aa_label *new; + int i; + + AA_BUG(!vec); + + if (len == 1) + return aa_get_label(&vec[0]->label); + + ls = labels_set(&vec[len - 1]->label); + + /* TODO: enable when read side is lockless + * check if label exists before taking locks + */ + new = aa_label_alloc(len, NULL, gfp); + if (!new) + return NULL; + + for (i = 0; i < len; i++) + new->vec[i] = aa_get_profile(vec[i]); + + write_lock_irqsave(&ls->lock, flags); + label = __label_insert(ls, new, false); + write_unlock_irqrestore(&ls->lock, flags); + label_free_or_put_new(label, new); + + return label; +} + +struct aa_label *aa_vec_find_or_create_label(struct aa_profile **vec, int len, + gfp_t gfp) +{ + struct aa_label *label = vec_find(vec, len); + + if (label) + return label; + + return vec_create_and_insert_label(vec, len, gfp); +} + +/** + * aa_label_find - find label @label in label set + * @label: label to find (NOT NULL) + * + * Requires: caller to hold a valid ref on l + * + * Returns: refcounted @label if @label is in tree + * refcounted label that is equiv to @label in tree + * else NULL if @label or equiv is not in tree + */ +struct aa_label *aa_label_find(struct aa_label *label) +{ + AA_BUG(!label); + + return vec_find(label->vec, label->size); +} + + +/** + * aa_label_insert - insert label @label into @ls or return existing label + * @ls - labelset to insert @label into + * @label - label to insert + * + * Requires: caller to hold a valid ref on @label + * + * Returns: ref counted @label if successful in inserting @label + * else ref counted equivalent label that is already in the set + */ +struct aa_label *aa_label_insert(struct aa_labelset *ls, struct aa_label *label) +{ + struct aa_label *l; + unsigned long flags; + + AA_BUG(!ls); + AA_BUG(!label); + + /* check if label exists before taking lock */ + if (!label_is_stale(label)) { + read_lock_irqsave(&ls->lock, flags); + l = __label_find(label); + read_unlock_irqrestore(&ls->lock, flags); + if (l) + return l; + } + + write_lock_irqsave(&ls->lock, flags); + l = __label_insert(ls, label, false); + write_unlock_irqrestore(&ls->lock, flags); + + return l; +} + + +/** + * aa_label_next_in_merge - find the next profile when merging @a and @b + * @I: label iterator + * @a: label to merge + * @b: label to merge + * + * Returns: next profile + * else null if no more profiles + */ +struct aa_profile *aa_label_next_in_merge(struct label_it *I, + struct aa_label *a, + struct aa_label *b) +{ + AA_BUG(!a); + AA_BUG(!b); + AA_BUG(!I); + AA_BUG(I->i < 0); + AA_BUG(I->i > a->size); + AA_BUG(I->j < 0); + AA_BUG(I->j > b->size); + + if (I->i < a->size) { + if (I->j < b->size) { + int res = profile_cmp(a->vec[I->i], b->vec[I->j]); + + if (res > 0) + return b->vec[(I->j)++]; + if (res == 0) + (I->j)++; + } + + return a->vec[(I->i)++]; + } + + if (I->j < b->size) + return b->vec[(I->j)++]; + + return NULL; +} + +/** + * label_merge_cmp - cmp of @a merging with @b against @z for set ordering + * @a: label to merge then compare (NOT NULL) + * @b: label to merge then compare (NOT NULL) + * @z: label to compare merge against (NOT NULL) + * + * Assumes: using the most recent versions of @a, @b, and @z + * + * Returns: <0 if a < b + * ==0 if a == b + * >0 if a > b + */ +static int label_merge_cmp(struct aa_label *a, struct aa_label *b, + struct aa_label *z) +{ + struct aa_profile *p = NULL; + struct label_it i = { }; + int k; + + AA_BUG(!a); + AA_BUG(!b); + AA_BUG(!z); + + for (k = 0; + k < z->size && (p = aa_label_next_in_merge(&i, a, b)); + k++) { + int res = profile_cmp(p, z->vec[k]); + + if (res != 0) + return res; + } + + if (p) + return 1; + else if (k < z->size) + return -1; + return 0; +} + +/** + * label_merge_insert - create a new label by merging @a and @b + * @new: preallocated label to merge into (NOT NULL) + * @a: label to merge with @b (NOT NULL) + * @b: label to merge with @a (NOT NULL) + * + * Requires: preallocated proxy + * + * Returns: ref counted label either @new if merge is unique + * @a if @b is a subset of @a + * @b if @a is a subset of @b + * + * NOTE: will not use @new if the merge results in @new == @a or @b + * + * Must be used within labelset write lock to avoid racing with + * setting labels stale. + */ +static struct aa_label *label_merge_insert(struct aa_label *new, + struct aa_label *a, + struct aa_label *b) +{ + struct aa_label *label; + struct aa_labelset *ls; + struct aa_profile *next; + struct label_it i; + unsigned long flags; + int k = 0, invcount = 0; + bool stale = false; + + AA_BUG(!a); + AA_BUG(a->size < 0); + AA_BUG(!b); + AA_BUG(b->size < 0); + AA_BUG(!new); + AA_BUG(new->size < a->size + b->size); + + label_for_each_in_merge(i, a, b, next) { + AA_BUG(!next); + if (profile_is_stale(next)) { + new->vec[k] = aa_get_newest_profile(next); + AA_BUG(!new->vec[k]->label.proxy); + AA_BUG(!new->vec[k]->label.proxy->label); + if (next->label.proxy != new->vec[k]->label.proxy) + invcount++; + k++; + stale = true; + } else + new->vec[k++] = aa_get_profile(next); + } + /* set to actual size which is <= allocated len */ + new->size = k; + new->vec[k] = NULL; + + if (invcount) { + new->size -= aa_vec_unique(&new->vec[0], new->size, + VEC_FLAG_TERMINATE); + /* TODO: deal with reference labels */ + if (new->size == 1) { + label = aa_get_label(&new->vec[0]->label); + return label; + } + } else if (!stale) { + /* + * merge could be same as a || b, note: it is not possible + * for new->size == a->size == b->size unless a == b + */ + if (k == a->size) + return aa_get_label(a); + else if (k == b->size) + return aa_get_label(b); + } + new->flags |= accum_vec_flags(new->vec, new->size); + ls = labels_set(new); + write_lock_irqsave(&ls->lock, flags); + label = __label_insert(labels_set(new), new, false); + write_unlock_irqrestore(&ls->lock, flags); + + return label; +} + +/** + * labelset_of_merge - find which labelset a merged label should be inserted + * @a: label to merge and insert + * @b: label to merge and insert + * + * Returns: labelset that the merged label should be inserted into + */ +static struct aa_labelset *labelset_of_merge(struct aa_label *a, + struct aa_label *b) +{ + struct aa_ns *nsa = labels_ns(a); + struct aa_ns *nsb = labels_ns(b); + + if (ns_cmp(nsa, nsb) <= 0) + return &nsa->labels; + return &nsb->labels; +} + +/** + * __label_find_merge - find label that is equiv to merge of @a and @b + * @ls: set of labels to search (NOT NULL) + * @a: label to merge with @b (NOT NULL) + * @b: label to merge with @a (NOT NULL) + * + * Requires: ls->lock read_lock held + * + * Returns: ref counted label that is equiv to merge of @a and @b + * else NULL if merge of @a and @b is not in set + */ +static struct aa_label *__label_find_merge(struct aa_labelset *ls, + struct aa_label *a, + struct aa_label *b) +{ + struct rb_node *node; + + AA_BUG(!ls); + AA_BUG(!a); + AA_BUG(!b); + + if (a == b) + return __label_find(a); + + node = ls->root.rb_node; + while (node) { + struct aa_label *this = container_of(node, struct aa_label, + node); + int result = label_merge_cmp(a, b, this); + + if (result < 0) + node = node->rb_left; + else if (result > 0) + node = node->rb_right; + else + return __aa_get_label(this); + } + + return NULL; +} + + +/** + * aa_label_find_merge - find label that is equiv to merge of @a and @b + * @a: label to merge with @b (NOT NULL) + * @b: label to merge with @a (NOT NULL) + * + * Requires: labels be fully constructed with a valid ns + * + * Returns: ref counted label that is equiv to merge of @a and @b + * else NULL if merge of @a and @b is not in set + */ +struct aa_label *aa_label_find_merge(struct aa_label *a, struct aa_label *b) +{ + struct aa_labelset *ls; + struct aa_label *label, *ar = NULL, *br = NULL; + unsigned long flags; + + AA_BUG(!a); + AA_BUG(!b); + + if (label_is_stale(a)) + a = ar = aa_get_newest_label(a); + if (label_is_stale(b)) + b = br = aa_get_newest_label(b); + ls = labelset_of_merge(a, b); + read_lock_irqsave(&ls->lock, flags); + label = __label_find_merge(ls, a, b); + read_unlock_irqrestore(&ls->lock, flags); + aa_put_label(ar); + aa_put_label(br); + + return label; +} + +/** + * aa_label_merge - attempt to insert new merged label of @a and @b + * @ls: set of labels to insert label into (NOT NULL) + * @a: label to merge with @b (NOT NULL) + * @b: label to merge with @a (NOT NULL) + * @gfp: memory allocation type + * + * Requires: caller to hold valid refs on @a and @b + * labels be fully constructed with a valid ns + * + * Returns: ref counted new label if successful in inserting merge of a & b + * else ref counted equivalent label that is already in the set. + * else NULL if could not create label (-ENOMEM) + */ +struct aa_label *aa_label_merge(struct aa_label *a, struct aa_label *b, + gfp_t gfp) +{ + struct aa_label *label = NULL; + + AA_BUG(!a); + AA_BUG(!b); + + if (a == b) + return aa_get_newest_label(a); + + /* TODO: enable when read side is lockless + * check if label exists before taking locks + if (!label_is_stale(a) && !label_is_stale(b)) + label = aa_label_find_merge(a, b); + */ + + if (!label) { + struct aa_label *new; + + a = aa_get_newest_label(a); + b = aa_get_newest_label(b); + + /* could use label_merge_len(a, b), but requires double + * comparison for small savings + */ + new = aa_label_alloc(a->size + b->size, NULL, gfp); + if (!new) + goto out; + + label = label_merge_insert(new, a, b); + label_free_or_put_new(label, new); +out: + aa_put_label(a); + aa_put_label(b); + } + + return label; +} + +static inline bool label_is_visible(struct aa_profile *profile, + struct aa_label *label) +{ + return aa_ns_visible(profile->ns, labels_ns(label), true); +} + +/* match a profile and its associated ns component if needed + * Assumes visibility test has already been done. + * If a subns profile is not to be matched should be prescreened with + * visibility test. + */ +static inline unsigned int match_component(struct aa_profile *profile, + struct aa_profile *tp, + unsigned int state) +{ + const char *ns_name; + + if (profile->ns == tp->ns) + return aa_dfa_match(profile->policy.dfa, state, tp->base.hname); + + /* try matching with namespace name and then profile */ + ns_name = aa_ns_name(profile->ns, tp->ns, true); + state = aa_dfa_match_len(profile->policy.dfa, state, ":", 1); + state = aa_dfa_match(profile->policy.dfa, state, ns_name); + state = aa_dfa_match_len(profile->policy.dfa, state, ":", 1); + return aa_dfa_match(profile->policy.dfa, state, tp->base.hname); +} + +/** + * label_compound_match - find perms for full compound label + * @profile: profile to find perms for + * @label: label to check access permissions for + * @start: state to start match in + * @subns: whether to do permission checks on components in a subns + * @request: permissions to request + * @perms: perms struct to set + * + * Returns: 0 on success else ERROR + * + * For the label A//&B//&C this does the perm match for A//&B//&C + * @perms should be preinitialized with allperms OR a previous permission + * check to be stacked. + */ +static int label_compound_match(struct aa_profile *profile, + struct aa_label *label, + unsigned int state, bool subns, u32 request, + struct aa_perms *perms) +{ + struct aa_profile *tp; + struct label_it i; + + /* find first subcomponent that is visible */ + label_for_each(i, label, tp) { + if (!aa_ns_visible(profile->ns, tp->ns, subns)) + continue; + state = match_component(profile, tp, state); + if (!state) + goto fail; + goto next; + } + + /* no component visible */ + *perms = allperms; + return 0; + +next: + label_for_each_cont(i, label, tp) { + if (!aa_ns_visible(profile->ns, tp->ns, subns)) + continue; + state = aa_dfa_match(profile->policy.dfa, state, "//&"); + state = match_component(profile, tp, state); + if (!state) + goto fail; + } + aa_compute_perms(profile->policy.dfa, state, perms); + aa_apply_modes_to_perms(profile, perms); + if ((perms->allow & request) != request) + return -EACCES; + + return 0; + +fail: + *perms = nullperms; + return state; +} + +/** + * label_components_match - find perms for all subcomponents of a label + * @profile: profile to find perms for + * @label: label to check access permissions for + * @start: state to start match in + * @subns: whether to do permission checks on components in a subns + * @request: permissions to request + * @perms: an initialized perms struct to add accumulation to + * + * Returns: 0 on success else ERROR + * + * For the label A//&B//&C this does the perm match for each of A and B and C + * @perms should be preinitialized with allperms OR a previous permission + * check to be stacked. + */ +static int label_components_match(struct aa_profile *profile, + struct aa_label *label, unsigned int start, + bool subns, u32 request, + struct aa_perms *perms) +{ + struct aa_profile *tp; + struct label_it i; + struct aa_perms tmp; + unsigned int state = 0; + + /* find first subcomponent to test */ + label_for_each(i, label, tp) { + if (!aa_ns_visible(profile->ns, tp->ns, subns)) + continue; + state = match_component(profile, tp, start); + if (!state) + goto fail; + goto next; + } + + /* no subcomponents visible - no change in perms */ + return 0; + +next: + aa_compute_perms(profile->policy.dfa, state, &tmp); + aa_apply_modes_to_perms(profile, &tmp); + aa_perms_accum(perms, &tmp); + label_for_each_cont(i, label, tp) { + if (!aa_ns_visible(profile->ns, tp->ns, subns)) + continue; + state = match_component(profile, tp, start); + if (!state) + goto fail; + aa_compute_perms(profile->policy.dfa, state, &tmp); + aa_apply_modes_to_perms(profile, &tmp); + aa_perms_accum(perms, &tmp); + } + + if ((perms->allow & request) != request) + return -EACCES; + + return 0; + +fail: + *perms = nullperms; + return -EACCES; +} + +/** + * aa_label_match - do a multi-component label match + * @profile: profile to match against (NOT NULL) + * @label: label to match (NOT NULL) + * @state: state to start in + * @subns: whether to match subns components + * @request: permission request + * @perms: Returns computed perms (NOT NULL) + * + * Returns: the state the match finished in, may be the none matching state + */ +int aa_label_match(struct aa_profile *profile, struct aa_label *label, + unsigned int state, bool subns, u32 request, + struct aa_perms *perms) +{ + int error = label_compound_match(profile, label, state, subns, request, + perms); + if (!error) + return error; + + *perms = allperms; + return label_components_match(profile, label, state, subns, request, + perms); +} + + +/** + * aa_update_label_name - update a label to have a stored name + * @ns: ns being viewed from (NOT NULL) + * @label: label to update (NOT NULL) + * @gfp: type of memory allocation + * + * Requires: labels_set(label) not locked in caller + * + * note: only updates the label name if it does not have a name already + * and if it is in the labelset + */ +bool aa_update_label_name(struct aa_ns *ns, struct aa_label *label, gfp_t gfp) +{ + struct aa_labelset *ls; + unsigned long flags; + char __counted *name; + bool res = false; + + AA_BUG(!ns); + AA_BUG(!label); + + if (label->hname || labels_ns(label) != ns) + return res; + + if (aa_label_acntsxprint(&name, ns, label, FLAGS_NONE, gfp) < 0) + return res; + + ls = labels_set(label); + write_lock_irqsave(&ls->lock, flags); + if (!label->hname && label->flags & FLAG_IN_TREE) { + label->hname = name; + res = true; + } else + aa_put_str(name); + write_unlock_irqrestore(&ls->lock, flags); + + return res; +} + +/* + * cached label name is present and visible + * @label->hname only exists if label is namespace hierachical + */ +static inline bool use_label_hname(struct aa_ns *ns, struct aa_label *label, + int flags) +{ + if (label->hname && (!ns || labels_ns(label) == ns) && + !(flags & ~FLAG_SHOW_MODE)) + return true; + + return false; +} + +/* helper macro for snprint routines */ +#define update_for_len(total, len, size, str) \ +do { \ + size_t ulen = len; \ + \ + AA_BUG(len < 0); \ + total += ulen; \ + ulen = min(ulen, size); \ + size -= ulen; \ + str += ulen; \ +} while (0) + +/** + * aa_profile_snxprint - print a profile name to a buffer + * @str: buffer to write to. (MAY BE NULL if @size == 0) + * @size: size of buffer + * @view: namespace profile is being viewed from + * @profile: profile to view (NOT NULL) + * @flags: whether to include the mode string + * @prev_ns: last ns printed when used in compound print + * + * Returns: size of name written or would be written if larger than + * available buffer + * + * Note: will not print anything if the profile is not visible + */ +static int aa_profile_snxprint(char *str, size_t size, struct aa_ns *view, + struct aa_profile *profile, int flags, + struct aa_ns **prev_ns) +{ + const char *ns_name = NULL; + + AA_BUG(!str && size != 0); + AA_BUG(!profile); + + if (!view) + view = profiles_ns(profile); + + if (view != profile->ns && + (!prev_ns || (*prev_ns != profile->ns))) { + if (prev_ns) + *prev_ns = profile->ns; + ns_name = aa_ns_name(view, profile->ns, + flags & FLAG_VIEW_SUBNS); + if (ns_name == aa_hidden_ns_name) { + if (flags & FLAG_HIDDEN_UNCONFINED) + return snprintf(str, size, "%s", "unconfined"); + return snprintf(str, size, "%s", ns_name); + } + } + + if ((flags & FLAG_SHOW_MODE) && profile != profile->ns->unconfined) { + const char *modestr = aa_profile_mode_names[profile->mode]; + + if (ns_name) + return snprintf(str, size, ":%s:%s (%s)", ns_name, + profile->base.hname, modestr); + return snprintf(str, size, "%s (%s)", profile->base.hname, + modestr); + } + + if (ns_name) + return snprintf(str, size, ":%s:%s", ns_name, + profile->base.hname); + return snprintf(str, size, "%s", profile->base.hname); +} + +static const char *label_modename(struct aa_ns *ns, struct aa_label *label, + int flags) +{ + struct aa_profile *profile; + struct label_it i; + int mode = -1, count = 0; + + label_for_each(i, label, profile) { + if (aa_ns_visible(ns, profile->ns, flags & FLAG_VIEW_SUBNS)) { + count++; + if (profile == profile->ns->unconfined) + /* special case unconfined so stacks with + * unconfined don't report as mixed. ie. + * profile_foo//&:ns1:unconfined (mixed) + */ + continue; + if (mode == -1) + mode = profile->mode; + else if (mode != profile->mode) + return "mixed"; + } + } + + if (count == 0) + return "-"; + if (mode == -1) + /* everything was unconfined */ + mode = APPARMOR_UNCONFINED; + + return aa_profile_mode_names[mode]; +} + +/* if any visible label is not unconfined the display_mode returns true */ +static inline bool display_mode(struct aa_ns *ns, struct aa_label *label, + int flags) +{ + if ((flags & FLAG_SHOW_MODE)) { + struct aa_profile *profile; + struct label_it i; + + label_for_each(i, label, profile) { + if (aa_ns_visible(ns, profile->ns, + flags & FLAG_VIEW_SUBNS) && + profile != profile->ns->unconfined) + return true; + } + /* only ns->unconfined in set of profiles in ns */ + return false; + } + + return false; +} + +/** + * aa_label_snxprint - print a label name to a string buffer + * @str: buffer to write to. (MAY BE NULL if @size == 0) + * @size: size of buffer + * @ns: namespace profile is being viewed from + * @label: label to view (NOT NULL) + * @flags: whether to include the mode string + * + * Returns: size of name written or would be written if larger than + * available buffer + * + * Note: labels do not have to be strictly hierarchical to the ns as + * objects may be shared across different namespaces and thus + * pickup labeling from each ns. If a particular part of the + * label is not visible it will just be excluded. And if none + * of the label is visible "---" will be used. + */ +int aa_label_snxprint(char *str, size_t size, struct aa_ns *ns, + struct aa_label *label, int flags) +{ + struct aa_profile *profile; + struct aa_ns *prev_ns = NULL; + struct label_it i; + int count = 0, total = 0; + ssize_t len; + + AA_BUG(!str && size != 0); + AA_BUG(!label); + + if (AA_DEBUG_LABEL && (flags & FLAG_ABS_ROOT)) { + ns = root_ns; + len = snprintf(str, size, "_"); + update_for_len(total, len, size, str); + } else if (!ns) { + ns = labels_ns(label); + } + + label_for_each(i, label, profile) { + if (aa_ns_visible(ns, profile->ns, flags & FLAG_VIEW_SUBNS)) { + if (count > 0) { + len = snprintf(str, size, "//&"); + update_for_len(total, len, size, str); + } + len = aa_profile_snxprint(str, size, ns, profile, + flags & FLAG_VIEW_SUBNS, + &prev_ns); + update_for_len(total, len, size, str); + count++; + } + } + + if (count == 0) { + if (flags & FLAG_HIDDEN_UNCONFINED) + return snprintf(str, size, "%s", "unconfined"); + return snprintf(str, size, "%s", aa_hidden_ns_name); + } + + /* count == 1 && ... is for backwards compat where the mode + * is not displayed for 'unconfined' in the current ns + */ + if (display_mode(ns, label, flags)) { + len = snprintf(str, size, " (%s)", + label_modename(ns, label, flags)); + update_for_len(total, len, size, str); + } + + return total; +} +#undef update_for_len + +/** + * aa_label_asxprint - allocate a string buffer and print label into it + * @strp: Returns - the allocated buffer with the label name. (NOT NULL) + * @ns: namespace profile is being viewed from + * @label: label to view (NOT NULL) + * @flags: flags controlling what label info is printed + * @gfp: kernel memory allocation type + * + * Returns: size of name written or would be written if larger than + * available buffer + */ +int aa_label_asxprint(char **strp, struct aa_ns *ns, struct aa_label *label, + int flags, gfp_t gfp) +{ + int size; + + AA_BUG(!strp); + AA_BUG(!label); + + size = aa_label_snxprint(NULL, 0, ns, label, flags); + if (size < 0) + return size; + + *strp = kmalloc(size + 1, gfp); + if (!*strp) + return -ENOMEM; + return aa_label_snxprint(*strp, size + 1, ns, label, flags); +} + +/** + * aa_label_acntsxprint - allocate a __counted string buffer and print label + * @strp: buffer to write to. + * @ns: namespace profile is being viewed from + * @label: label to view (NOT NULL) + * @flags: flags controlling what label info is printed + * @gfp: kernel memory allocation type + * + * Returns: size of name written or would be written if larger than + * available buffer + */ +int aa_label_acntsxprint(char __counted **strp, struct aa_ns *ns, + struct aa_label *label, int flags, gfp_t gfp) +{ + int size; + + AA_BUG(!strp); + AA_BUG(!label); + + size = aa_label_snxprint(NULL, 0, ns, label, flags); + if (size < 0) + return size; + + *strp = aa_str_alloc(size + 1, gfp); + if (!*strp) + return -ENOMEM; + return aa_label_snxprint(*strp, size + 1, ns, label, flags); +} + + +void aa_label_xaudit(struct audit_buffer *ab, struct aa_ns *ns, + struct aa_label *label, int flags, gfp_t gfp) +{ + const char *str; + char *name = NULL; + int len; + + AA_BUG(!ab); + AA_BUG(!label); + + if (!use_label_hname(ns, label, flags) || + display_mode(ns, label, flags)) { + len = aa_label_asxprint(&name, ns, label, flags, gfp); + if (len < 0) { + AA_DEBUG("label print error"); + return; + } + str = name; + } else { + str = (char *) label->hname; + len = strlen(str); + } + if (audit_string_contains_control(str, len)) + audit_log_n_hex(ab, str, len); + else + audit_log_n_string(ab, str, len); + + kfree(name); +} + +void aa_label_seq_xprint(struct seq_file *f, struct aa_ns *ns, + struct aa_label *label, int flags, gfp_t gfp) +{ + AA_BUG(!f); + AA_BUG(!label); + + if (!use_label_hname(ns, label, flags)) { + char *str; + int len; + + len = aa_label_asxprint(&str, ns, label, flags, gfp); + if (len < 0) { + AA_DEBUG("label print error"); + return; + } + seq_puts(f, str); + kfree(str); + } else if (display_mode(ns, label, flags)) + seq_printf(f, "%s (%s)", label->hname, + label_modename(ns, label, flags)); + else + seq_puts(f, label->hname); +} + +void aa_label_xprintk(struct aa_ns *ns, struct aa_label *label, int flags, + gfp_t gfp) +{ + AA_BUG(!label); + + if (!use_label_hname(ns, label, flags)) { + char *str; + int len; + + len = aa_label_asxprint(&str, ns, label, flags, gfp); + if (len < 0) { + AA_DEBUG("label print error"); + return; + } + pr_info("%s", str); + kfree(str); + } else if (display_mode(ns, label, flags)) + pr_info("%s (%s)", label->hname, + label_modename(ns, label, flags)); + else + pr_info("%s", label->hname); +} + +void aa_label_audit(struct audit_buffer *ab, struct aa_label *label, gfp_t gfp) +{ + struct aa_ns *ns = aa_get_current_ns(); + + aa_label_xaudit(ab, ns, label, FLAG_VIEW_SUBNS, gfp); + aa_put_ns(ns); +} + +void aa_label_seq_print(struct seq_file *f, struct aa_label *label, gfp_t gfp) +{ + struct aa_ns *ns = aa_get_current_ns(); + + aa_label_seq_xprint(f, ns, label, FLAG_VIEW_SUBNS, gfp); + aa_put_ns(ns); +} + +void aa_label_printk(struct aa_label *label, gfp_t gfp) +{ + struct aa_ns *ns = aa_get_current_ns(); + + aa_label_xprintk(ns, label, FLAG_VIEW_SUBNS, gfp); + aa_put_ns(ns); +} + +static int label_count_strn_entries(const char *str, size_t n) +{ + const char *end = str + n; + const char *split; + int count = 1; + + AA_BUG(!str); + + for (split = aa_label_strn_split(str, end - str); + split; + split = aa_label_strn_split(str, end - str)) { + count++; + str = split + 3; + } + + return count; +} + +/* + * ensure stacks with components like + * :ns:A//&B + * have :ns: applied to both 'A' and 'B' by making the lookup relative + * to the base if the lookup specifies an ns, else making the stacked lookup + * relative to the last embedded ns in the string. + */ +static struct aa_profile *fqlookupn_profile(struct aa_label *base, + struct aa_label *currentbase, + const char *str, size_t n) +{ + const char *first = skipn_spaces(str, n); + + if (first && *first == ':') + return aa_fqlookupn_profile(base, str, n); + + return aa_fqlookupn_profile(currentbase, str, n); +} + +/** + * aa_label_strn_parse - parse, validate and convert a text string to a label + * @base: base label to use for lookups (NOT NULL) + * @str: null terminated text string (NOT NULL) + * @n: length of str to parse, will stop at \0 if encountered before n + * @gfp: allocation type + * @create: true if should create compound labels if they don't exist + * @force_stack: true if should stack even if no leading & + * + * Returns: the matching refcounted label if present + * else ERRPTR + */ +struct aa_label *aa_label_strn_parse(struct aa_label *base, const char *str, + size_t n, gfp_t gfp, bool create, + bool force_stack) +{ + DEFINE_VEC(profile, vec); + struct aa_label *label, *currbase = base; + int i, len, stack = 0, error; + const char *end = str + n; + const char *split; + + AA_BUG(!base); + AA_BUG(!str); + + str = skipn_spaces(str, n); + if (str == NULL || (AA_DEBUG_LABEL && *str == '_' && + base != &root_ns->unconfined->label)) + return ERR_PTR(-EINVAL); + + len = label_count_strn_entries(str, end - str); + if (*str == '&' || force_stack) { + /* stack on top of base */ + stack = base->size; + len += stack; + if (*str == '&') + str++; + } + + error = vec_setup(profile, vec, len, gfp); + if (error) + return ERR_PTR(error); + + for (i = 0; i < stack; i++) + vec[i] = aa_get_profile(base->vec[i]); + + for (split = aa_label_strn_split(str, end - str), i = stack; + split && i < len; i++) { + vec[i] = fqlookupn_profile(base, currbase, str, split - str); + if (!vec[i]) + goto fail; + /* + * if component specified a new ns it becomes the new base + * so that subsequent lookups are relative to it + */ + if (vec[i]->ns != labels_ns(currbase)) + currbase = &vec[i]->label; + str = split + 3; + split = aa_label_strn_split(str, end - str); + } + /* last element doesn't have a split */ + if (i < len) { + vec[i] = fqlookupn_profile(base, currbase, str, end - str); + if (!vec[i]) + goto fail; + } + if (len == 1) + /* no need to free vec as len < LOCAL_VEC_ENTRIES */ + return &vec[0]->label; + + len -= aa_vec_unique(vec, len, VEC_FLAG_TERMINATE); + /* TODO: deal with reference labels */ + if (len == 1) { + label = aa_get_label(&vec[0]->label); + goto out; + } + + if (create) + label = aa_vec_find_or_create_label(vec, len, gfp); + else + label = vec_find(vec, len); + if (!label) + goto fail; + +out: + /* use adjusted len from after vec_unique, not original */ + vec_cleanup(profile, vec, len); + return label; + +fail: + label = ERR_PTR(-ENOENT); + goto out; +} + +struct aa_label *aa_label_parse(struct aa_label *base, const char *str, + gfp_t gfp, bool create, bool force_stack) +{ + return aa_label_strn_parse(base, str, strlen(str), gfp, create, + force_stack); +} + +/** + * aa_labelset_destroy - remove all labels from the label set + * @ls: label set to cleanup (NOT NULL) + * + * Labels that are removed from the set may still exist beyond the set + * being destroyed depending on their reference counting + */ +void aa_labelset_destroy(struct aa_labelset *ls) +{ + struct rb_node *node; + unsigned long flags; + + AA_BUG(!ls); + + write_lock_irqsave(&ls->lock, flags); + for (node = rb_first(&ls->root); node; node = rb_first(&ls->root)) { + struct aa_label *this = rb_entry(node, struct aa_label, node); + + if (labels_ns(this) != root_ns) + __label_remove(this, + ns_unconfined(labels_ns(this)->parent)); + else + __label_remove(this, NULL); + } + write_unlock_irqrestore(&ls->lock, flags); +} + +/* + * @ls: labelset to init (NOT NULL) + */ +void aa_labelset_init(struct aa_labelset *ls) +{ + AA_BUG(!ls); + + rwlock_init(&ls->lock); + ls->root = RB_ROOT; +} + +static struct aa_label *labelset_next_stale(struct aa_labelset *ls) +{ + struct aa_label *label; + struct rb_node *node; + unsigned long flags; + + AA_BUG(!ls); + + read_lock_irqsave(&ls->lock, flags); + + __labelset_for_each(ls, node) { + label = rb_entry(node, struct aa_label, node); + if ((label_is_stale(label) || + vec_is_stale(label->vec, label->size)) && + __aa_get_label(label)) + goto out; + + } + label = NULL; + +out: + read_unlock_irqrestore(&ls->lock, flags); + + return label; +} + +/** + * __label_update - insert updated version of @label into labelset + * @label - the label to update/replace + * + * Returns: new label that is up to date + * else NULL on failure + * + * Requires: @ns lock be held + * + * Note: worst case is the stale @label does not get updated and has + * to be updated at a later time. + */ +static struct aa_label *__label_update(struct aa_label *label) +{ + struct aa_label *new, *tmp; + struct aa_labelset *ls; + unsigned long flags; + int i, invcount = 0; + + AA_BUG(!label); + AA_BUG(!mutex_is_locked(&labels_ns(label)->lock)); + + new = aa_label_alloc(label->size, label->proxy, GFP_KERNEL); + if (!new) + return NULL; + + /* + * while holding the ns_lock will stop profile replacement, removal, + * and label updates, label merging and removal can be occurring + */ + ls = labels_set(label); + write_lock_irqsave(&ls->lock, flags); + for (i = 0; i < label->size; i++) { + AA_BUG(!label->vec[i]); + new->vec[i] = aa_get_newest_profile(label->vec[i]); + AA_BUG(!new->vec[i]); + AA_BUG(!new->vec[i]->label.proxy); + AA_BUG(!new->vec[i]->label.proxy->label); + if (new->vec[i]->label.proxy != label->vec[i]->label.proxy) + invcount++; + } + + /* updated stale label by being removed/renamed from labelset */ + if (invcount) { + new->size -= aa_vec_unique(&new->vec[0], new->size, + VEC_FLAG_TERMINATE); + /* TODO: deal with reference labels */ + if (new->size == 1) { + tmp = aa_get_label(&new->vec[0]->label); + AA_BUG(tmp == label); + goto remove; + } + if (labels_set(label) != labels_set(new)) { + write_unlock_irqrestore(&ls->lock, flags); + tmp = aa_label_insert(labels_set(new), new); + write_lock_irqsave(&ls->lock, flags); + goto remove; + } + } else + AA_BUG(labels_ns(label) != labels_ns(new)); + + tmp = __label_insert(labels_set(label), new, true); +remove: + /* ensure label is removed, and redirected correctly */ + __label_remove(label, tmp); + write_unlock_irqrestore(&ls->lock, flags); + label_free_or_put_new(tmp, new); + + return tmp; +} + +/** + * __labelset_update - update labels in @ns + * @ns: namespace to update labels in (NOT NULL) + * + * Requires: @ns lock be held + * + * Walk the labelset ensuring that all labels are up to date and valid + * Any label that has a stale component is marked stale and replaced and + * by an updated version. + * + * If failures happen due to memory pressures then stale labels will + * be left in place until the next pass. + */ +static void __labelset_update(struct aa_ns *ns) +{ + struct aa_label *label; + + AA_BUG(!ns); + AA_BUG(!mutex_is_locked(&ns->lock)); + + do { + label = labelset_next_stale(&ns->labels); + if (label) { + struct aa_label *l = __label_update(label); + + aa_put_label(l); + aa_put_label(label); + } + } while (label); +} + +/** + * __aa_labelset_update_subtree - update all labels with a stale component + * @ns: ns to start update at (NOT NULL) + * + * Requires: @ns lock be held + * + * Invalidates labels based on @p in @ns and any children namespaces. + */ +void __aa_labelset_update_subtree(struct aa_ns *ns) +{ + struct aa_ns *child; + + AA_BUG(!ns); + AA_BUG(!mutex_is_locked(&ns->lock)); + + __labelset_update(ns); + + list_for_each_entry(child, &ns->sub_ns, base.list) { + mutex_lock_nested(&child->lock, child->level); + __aa_labelset_update_subtree(child); + mutex_unlock(&child->lock); + } +} diff --git a/security/apparmor/lib.c b/security/apparmor/lib.c new file mode 100644 index 000000000..1c72a6110 --- /dev/null +++ b/security/apparmor/lib.c @@ -0,0 +1,542 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * AppArmor security module + * + * This file contains basic common functions used in AppArmor + * + * Copyright (C) 1998-2008 Novell/SUSE + * Copyright 2009-2010 Canonical Ltd. + */ + +#include <linux/ctype.h> +#include <linux/mm.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/vmalloc.h> + +#include "include/audit.h" +#include "include/apparmor.h" +#include "include/lib.h" +#include "include/perms.h" +#include "include/policy.h" + +struct aa_perms nullperms; +struct aa_perms allperms = { .allow = ALL_PERMS_MASK, + .quiet = ALL_PERMS_MASK, + .hide = ALL_PERMS_MASK }; + +/** + * aa_split_fqname - split a fqname into a profile and namespace name + * @fqname: a full qualified name in namespace profile format (NOT NULL) + * @ns_name: pointer to portion of the string containing the ns name (NOT NULL) + * + * Returns: profile name or NULL if one is not specified + * + * Split a namespace name from a profile name (see policy.c for naming + * description). If a portion of the name is missing it returns NULL for + * that portion. + * + * NOTE: may modify the @fqname string. The pointers returned point + * into the @fqname string. + */ +char *aa_split_fqname(char *fqname, char **ns_name) +{ + char *name = strim(fqname); + + *ns_name = NULL; + if (name[0] == ':') { + char *split = strchr(&name[1], ':'); + *ns_name = skip_spaces(&name[1]); + if (split) { + /* overwrite ':' with \0 */ + *split++ = 0; + if (strncmp(split, "//", 2) == 0) + split += 2; + name = skip_spaces(split); + } else + /* a ns name without a following profile is allowed */ + name = NULL; + } + if (name && *name == 0) + name = NULL; + + return name; +} + +/** + * skipn_spaces - Removes leading whitespace from @str. + * @str: The string to be stripped. + * + * Returns a pointer to the first non-whitespace character in @str. + * if all whitespace will return NULL + */ + +const char *skipn_spaces(const char *str, size_t n) +{ + for (; n && isspace(*str); --n) + ++str; + if (n) + return (char *)str; + return NULL; +} + +const char *aa_splitn_fqname(const char *fqname, size_t n, const char **ns_name, + size_t *ns_len) +{ + const char *end = fqname + n; + const char *name = skipn_spaces(fqname, n); + + *ns_name = NULL; + *ns_len = 0; + + if (!name) + return NULL; + + if (name[0] == ':') { + char *split = strnchr(&name[1], end - &name[1], ':'); + *ns_name = skipn_spaces(&name[1], end - &name[1]); + if (!*ns_name) + return NULL; + if (split) { + *ns_len = split - *ns_name; + if (*ns_len == 0) + *ns_name = NULL; + split++; + if (end - split > 1 && strncmp(split, "//", 2) == 0) + split += 2; + name = skipn_spaces(split, end - split); + } else { + /* a ns name without a following profile is allowed */ + name = NULL; + *ns_len = end - *ns_name; + } + } + if (name && *name == 0) + name = NULL; + + return name; +} + +/** + * aa_info_message - log a none profile related status message + * @str: message to log + */ +void aa_info_message(const char *str) +{ + if (audit_enabled) { + DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, NULL); + + aad(&sa)->info = str; + aa_audit_msg(AUDIT_APPARMOR_STATUS, &sa, NULL); + } + printk(KERN_INFO "AppArmor: %s\n", str); +} + +__counted char *aa_str_alloc(int size, gfp_t gfp) +{ + struct counted_str *str; + + str = kmalloc(struct_size(str, name, size), gfp); + if (!str) + return NULL; + + kref_init(&str->count); + return str->name; +} + +void aa_str_kref(struct kref *kref) +{ + kfree(container_of(kref, struct counted_str, count)); +} + + +const char aa_file_perm_chrs[] = "xwracd km l "; +const char *aa_file_perm_names[] = { + "exec", + "write", + "read", + "append", + + "create", + "delete", + "open", + "rename", + + "setattr", + "getattr", + "setcred", + "getcred", + + "chmod", + "chown", + "chgrp", + "lock", + + "mmap", + "mprot", + "link", + "snapshot", + + "unknown", + "unknown", + "unknown", + "unknown", + + "unknown", + "unknown", + "unknown", + "unknown", + + "stack", + "change_onexec", + "change_profile", + "change_hat", +}; + +/** + * aa_perm_mask_to_str - convert a perm mask to its short string + * @str: character buffer to store string in (at least 10 characters) + * @str_size: size of the @str buffer + * @chrs: NUL-terminated character buffer of permission characters + * @mask: permission mask to convert + */ +void aa_perm_mask_to_str(char *str, size_t str_size, const char *chrs, u32 mask) +{ + unsigned int i, perm = 1; + size_t num_chrs = strlen(chrs); + + for (i = 0; i < num_chrs; perm <<= 1, i++) { + if (mask & perm) { + /* Ensure that one byte is left for NUL-termination */ + if (WARN_ON_ONCE(str_size <= 1)) + break; + + *str++ = chrs[i]; + str_size--; + } + } + *str = '\0'; +} + +void aa_audit_perm_names(struct audit_buffer *ab, const char * const *names, + u32 mask) +{ + const char *fmt = "%s"; + unsigned int i, perm = 1; + bool prev = false; + + for (i = 0; i < 32; perm <<= 1, i++) { + if (mask & perm) { + audit_log_format(ab, fmt, names[i]); + if (!prev) { + prev = true; + fmt = " %s"; + } + } + } +} + +void aa_audit_perm_mask(struct audit_buffer *ab, u32 mask, const char *chrs, + u32 chrsmask, const char * const *names, u32 namesmask) +{ + char str[33]; + + audit_log_format(ab, "\""); + if ((mask & chrsmask) && chrs) { + aa_perm_mask_to_str(str, sizeof(str), chrs, mask & chrsmask); + mask &= ~chrsmask; + audit_log_format(ab, "%s", str); + if (mask & namesmask) + audit_log_format(ab, " "); + } + if ((mask & namesmask) && names) + aa_audit_perm_names(ab, names, mask & namesmask); + audit_log_format(ab, "\""); +} + +/** + * aa_audit_perms_cb - generic callback fn for auditing perms + * @ab: audit buffer (NOT NULL) + * @va: audit struct to audit values of (NOT NULL) + */ +static void aa_audit_perms_cb(struct audit_buffer *ab, void *va) +{ + struct common_audit_data *sa = va; + + if (aad(sa)->request) { + audit_log_format(ab, " requested_mask="); + aa_audit_perm_mask(ab, aad(sa)->request, aa_file_perm_chrs, + PERMS_CHRS_MASK, aa_file_perm_names, + PERMS_NAMES_MASK); + } + if (aad(sa)->denied) { + audit_log_format(ab, "denied_mask="); + aa_audit_perm_mask(ab, aad(sa)->denied, aa_file_perm_chrs, + PERMS_CHRS_MASK, aa_file_perm_names, + PERMS_NAMES_MASK); + } + audit_log_format(ab, " peer="); + aa_label_xaudit(ab, labels_ns(aad(sa)->label), aad(sa)->peer, + FLAGS_NONE, GFP_ATOMIC); +} + +/** + * aa_apply_modes_to_perms - apply namespace and profile flags to perms + * @profile: that perms where computed from + * @perms: perms to apply mode modifiers to + * + * TODO: split into profile and ns based flags for when accumulating perms + */ +void aa_apply_modes_to_perms(struct aa_profile *profile, struct aa_perms *perms) +{ + switch (AUDIT_MODE(profile)) { + case AUDIT_ALL: + perms->audit = ALL_PERMS_MASK; + fallthrough; + case AUDIT_NOQUIET: + perms->quiet = 0; + break; + case AUDIT_QUIET: + perms->audit = 0; + fallthrough; + case AUDIT_QUIET_DENIED: + perms->quiet = ALL_PERMS_MASK; + break; + } + + if (KILL_MODE(profile)) + perms->kill = ALL_PERMS_MASK; + else if (COMPLAIN_MODE(profile)) + perms->complain = ALL_PERMS_MASK; +/* + * TODO: + * else if (PROMPT_MODE(profile)) + * perms->prompt = ALL_PERMS_MASK; + */ +} + +static u32 map_other(u32 x) +{ + return ((x & 0x3) << 8) | /* SETATTR/GETATTR */ + ((x & 0x1c) << 18) | /* ACCEPT/BIND/LISTEN */ + ((x & 0x60) << 19); /* SETOPT/GETOPT */ +} + +static u32 map_xbits(u32 x) +{ + return ((x & 0x1) << 7) | + ((x & 0x7e) << 9); +} + +void aa_compute_perms(struct aa_dfa *dfa, unsigned int state, + struct aa_perms *perms) +{ + /* This mapping is convulated due to history. + * v1-v4: only file perms + * v5: added policydb which dropped in perm user conditional to + * gain new perm bits, but had to map around the xbits because + * the userspace compiler was still munging them. + * v9: adds using the xbits in policydb because the compiler now + * supports treating policydb permission bits different. + * Unfortunately there is not way to force auditing on the + * perms represented by the xbits + */ + *perms = (struct aa_perms) { + .allow = dfa_user_allow(dfa, state) | + map_xbits(dfa_user_xbits(dfa, state)), + .audit = dfa_user_audit(dfa, state), + .quiet = dfa_user_quiet(dfa, state) | + map_xbits(dfa_other_xbits(dfa, state)), + }; + + /* for v5-v9 perm mapping in the policydb, the other set is used + * to extend the general perm set + */ + perms->allow |= map_other(dfa_other_allow(dfa, state)); + perms->audit |= map_other(dfa_other_audit(dfa, state)); + perms->quiet |= map_other(dfa_other_quiet(dfa, state)); +} + +/** + * aa_perms_accum_raw - accumulate perms with out masking off overlapping perms + * @accum - perms struct to accumulate into + * @addend - perms struct to add to @accum + */ +void aa_perms_accum_raw(struct aa_perms *accum, struct aa_perms *addend) +{ + accum->deny |= addend->deny; + accum->allow &= addend->allow & ~addend->deny; + accum->audit |= addend->audit & addend->allow; + accum->quiet &= addend->quiet & ~addend->allow; + accum->kill |= addend->kill & ~addend->allow; + accum->stop |= addend->stop & ~addend->allow; + accum->complain |= addend->complain & ~addend->allow & ~addend->deny; + accum->cond |= addend->cond & ~addend->allow & ~addend->deny; + accum->hide &= addend->hide & ~addend->allow; + accum->prompt |= addend->prompt & ~addend->allow & ~addend->deny; +} + +/** + * aa_perms_accum - accumulate perms, masking off overlapping perms + * @accum - perms struct to accumulate into + * @addend - perms struct to add to @accum + */ +void aa_perms_accum(struct aa_perms *accum, struct aa_perms *addend) +{ + accum->deny |= addend->deny; + accum->allow &= addend->allow & ~accum->deny; + accum->audit |= addend->audit & accum->allow; + accum->quiet &= addend->quiet & ~accum->allow; + accum->kill |= addend->kill & ~accum->allow; + accum->stop |= addend->stop & ~accum->allow; + accum->complain |= addend->complain & ~accum->allow & ~accum->deny; + accum->cond |= addend->cond & ~accum->allow & ~accum->deny; + accum->hide &= addend->hide & ~accum->allow; + accum->prompt |= addend->prompt & ~accum->allow & ~accum->deny; +} + +void aa_profile_match_label(struct aa_profile *profile, struct aa_label *label, + int type, u32 request, struct aa_perms *perms) +{ + /* TODO: doesn't yet handle extended types */ + unsigned int state; + + state = aa_dfa_next(profile->policy.dfa, + profile->policy.start[AA_CLASS_LABEL], + type); + aa_label_match(profile, label, state, false, request, perms); +} + + +/* currently unused */ +int aa_profile_label_perm(struct aa_profile *profile, struct aa_profile *target, + u32 request, int type, u32 *deny, + struct common_audit_data *sa) +{ + struct aa_perms perms; + + aad(sa)->label = &profile->label; + aad(sa)->peer = &target->label; + aad(sa)->request = request; + + aa_profile_match_label(profile, &target->label, type, request, &perms); + aa_apply_modes_to_perms(profile, &perms); + *deny |= request & perms.deny; + return aa_check_perms(profile, &perms, request, sa, aa_audit_perms_cb); +} + +/** + * aa_check_perms - do audit mode selection based on perms set + * @profile: profile being checked + * @perms: perms computed for the request + * @request: requested perms + * @deny: Returns: explicit deny set + * @sa: initialized audit structure (MAY BE NULL if not auditing) + * @cb: callback fn for type specific fields (MAY BE NULL) + * + * Returns: 0 if permission else error code + * + * Note: profile audit modes need to be set before calling by setting the + * perm masks appropriately. + * + * If not auditing then complain mode is not enabled and the + * error code will indicate whether there was an explicit deny + * with a positive value. + */ +int aa_check_perms(struct aa_profile *profile, struct aa_perms *perms, + u32 request, struct common_audit_data *sa, + void (*cb)(struct audit_buffer *, void *)) +{ + int type, error; + u32 denied = request & (~perms->allow | perms->deny); + + if (likely(!denied)) { + /* mask off perms that are not being force audited */ + request &= perms->audit; + if (!request || !sa) + return 0; + + type = AUDIT_APPARMOR_AUDIT; + error = 0; + } else { + error = -EACCES; + + if (denied & perms->kill) + type = AUDIT_APPARMOR_KILL; + else if (denied == (denied & perms->complain)) + type = AUDIT_APPARMOR_ALLOWED; + else + type = AUDIT_APPARMOR_DENIED; + + if (denied == (denied & perms->hide)) + error = -ENOENT; + + denied &= ~perms->quiet; + if (!sa || !denied) + return error; + } + + if (sa) { + aad(sa)->label = &profile->label; + aad(sa)->request = request; + aad(sa)->denied = denied; + aad(sa)->error = error; + aa_audit_msg(type, sa, cb); + } + + if (type == AUDIT_APPARMOR_ALLOWED) + error = 0; + + return error; +} + + +/** + * aa_policy_init - initialize a policy structure + * @policy: policy to initialize (NOT NULL) + * @prefix: prefix name if any is required. (MAYBE NULL) + * @name: name of the policy, init will make a copy of it (NOT NULL) + * @gfp: allocation mode + * + * Note: this fn creates a copy of strings passed in + * + * Returns: true if policy init successful + */ +bool aa_policy_init(struct aa_policy *policy, const char *prefix, + const char *name, gfp_t gfp) +{ + char *hname; + + /* freed by policy_free */ + if (prefix) { + hname = aa_str_alloc(strlen(prefix) + strlen(name) + 3, gfp); + if (hname) + sprintf(hname, "%s//%s", prefix, name); + } else { + hname = aa_str_alloc(strlen(name) + 1, gfp); + if (hname) + strcpy(hname, name); + } + if (!hname) + return false; + policy->hname = hname; + /* base.name is a substring of fqname */ + policy->name = basename(policy->hname); + INIT_LIST_HEAD(&policy->list); + INIT_LIST_HEAD(&policy->profiles); + + return true; +} + +/** + * aa_policy_destroy - free the elements referenced by @policy + * @policy: policy that is to have its elements freed (NOT NULL) + */ +void aa_policy_destroy(struct aa_policy *policy) +{ + AA_BUG(on_list_rcu(&policy->profiles)); + AA_BUG(on_list_rcu(&policy->list)); + + /* don't free name as its a subset of hname */ + aa_put_str(policy->hname); +} diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c new file mode 100644 index 000000000..1e2f40db1 --- /dev/null +++ b/security/apparmor/lsm.c @@ -0,0 +1,1929 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * AppArmor security module + * + * This file contains AppArmor LSM hooks. + * + * Copyright (C) 1998-2008 Novell/SUSE + * Copyright 2009-2010 Canonical Ltd. + */ + +#include <linux/lsm_hooks.h> +#include <linux/moduleparam.h> +#include <linux/mm.h> +#include <linux/mman.h> +#include <linux/mount.h> +#include <linux/namei.h> +#include <linux/ptrace.h> +#include <linux/ctype.h> +#include <linux/sysctl.h> +#include <linux/audit.h> +#include <linux/user_namespace.h> +#include <linux/netfilter_ipv4.h> +#include <linux/netfilter_ipv6.h> +#include <linux/zlib.h> +#include <net/sock.h> +#include <uapi/linux/mount.h> + +#include "include/apparmor.h" +#include "include/apparmorfs.h" +#include "include/audit.h" +#include "include/capability.h" +#include "include/cred.h" +#include "include/file.h" +#include "include/ipc.h" +#include "include/net.h" +#include "include/path.h" +#include "include/label.h" +#include "include/policy.h" +#include "include/policy_ns.h" +#include "include/procattr.h" +#include "include/mount.h" +#include "include/secid.h" + +/* Flag indicating whether initialization completed */ +int apparmor_initialized; + +union aa_buffer { + struct list_head list; + char buffer[1]; +}; + +#define RESERVE_COUNT 2 +static int reserve_count = RESERVE_COUNT; +static int buffer_count; + +static LIST_HEAD(aa_global_buffers); +static DEFINE_SPINLOCK(aa_buffers_lock); + +/* + * LSM hook functions + */ + +/* + * put the associated labels + */ +static void apparmor_cred_free(struct cred *cred) +{ + aa_put_label(cred_label(cred)); + set_cred_label(cred, NULL); +} + +/* + * allocate the apparmor part of blank credentials + */ +static int apparmor_cred_alloc_blank(struct cred *cred, gfp_t gfp) +{ + set_cred_label(cred, NULL); + return 0; +} + +/* + * prepare new cred label for modification by prepare_cred block + */ +static int apparmor_cred_prepare(struct cred *new, const struct cred *old, + gfp_t gfp) +{ + set_cred_label(new, aa_get_newest_label(cred_label(old))); + return 0; +} + +/* + * transfer the apparmor data to a blank set of creds + */ +static void apparmor_cred_transfer(struct cred *new, const struct cred *old) +{ + set_cred_label(new, aa_get_newest_label(cred_label(old))); +} + +static void apparmor_task_free(struct task_struct *task) +{ + + aa_free_task_ctx(task_ctx(task)); +} + +static int apparmor_task_alloc(struct task_struct *task, + unsigned long clone_flags) +{ + struct aa_task_ctx *new = task_ctx(task); + + aa_dup_task_ctx(new, task_ctx(current)); + + return 0; +} + +static int apparmor_ptrace_access_check(struct task_struct *child, + unsigned int mode) +{ + struct aa_label *tracer, *tracee; + int error; + + tracer = __begin_current_label_crit_section(); + tracee = aa_get_task_label(child); + error = aa_may_ptrace(tracer, tracee, + (mode & PTRACE_MODE_READ) ? AA_PTRACE_READ + : AA_PTRACE_TRACE); + aa_put_label(tracee); + __end_current_label_crit_section(tracer); + + return error; +} + +static int apparmor_ptrace_traceme(struct task_struct *parent) +{ + struct aa_label *tracer, *tracee; + int error; + + tracee = __begin_current_label_crit_section(); + tracer = aa_get_task_label(parent); + error = aa_may_ptrace(tracer, tracee, AA_PTRACE_TRACE); + aa_put_label(tracer); + __end_current_label_crit_section(tracee); + + return error; +} + +/* Derived from security/commoncap.c:cap_capget */ +static int apparmor_capget(struct task_struct *target, kernel_cap_t *effective, + kernel_cap_t *inheritable, kernel_cap_t *permitted) +{ + struct aa_label *label; + const struct cred *cred; + + rcu_read_lock(); + cred = __task_cred(target); + label = aa_get_newest_cred_label(cred); + + /* + * cap_capget is stacked ahead of this and will + * initialize effective and permitted. + */ + if (!unconfined(label)) { + struct aa_profile *profile; + struct label_it i; + + label_for_each_confined(i, label, profile) { + if (COMPLAIN_MODE(profile)) + continue; + *effective = cap_intersect(*effective, + profile->caps.allow); + *permitted = cap_intersect(*permitted, + profile->caps.allow); + } + } + rcu_read_unlock(); + aa_put_label(label); + + return 0; +} + +static int apparmor_capable(const struct cred *cred, struct user_namespace *ns, + int cap, unsigned int opts) +{ + struct aa_label *label; + int error = 0; + + label = aa_get_newest_cred_label(cred); + if (!unconfined(label)) + error = aa_capable(label, cap, opts); + aa_put_label(label); + + return error; +} + +/** + * common_perm - basic common permission check wrapper fn for paths + * @op: operation being checked + * @path: path to check permission of (NOT NULL) + * @mask: requested permissions mask + * @cond: conditional info for the permission request (NOT NULL) + * + * Returns: %0 else error code if error or permission denied + */ +static int common_perm(const char *op, const struct path *path, u32 mask, + struct path_cond *cond) +{ + struct aa_label *label; + int error = 0; + + label = __begin_current_label_crit_section(); + if (!unconfined(label)) + error = aa_path_perm(op, label, path, 0, mask, cond); + __end_current_label_crit_section(label); + + return error; +} + +/** + * common_perm_cond - common permission wrapper around inode cond + * @op: operation being checked + * @path: location to check (NOT NULL) + * @mask: requested permissions mask + * + * Returns: %0 else error code if error or permission denied + */ +static int common_perm_cond(const char *op, const struct path *path, u32 mask) +{ + struct user_namespace *mnt_userns = mnt_user_ns(path->mnt); + struct path_cond cond = { + i_uid_into_mnt(mnt_userns, d_backing_inode(path->dentry)), + d_backing_inode(path->dentry)->i_mode + }; + + if (!path_mediated_fs(path->dentry)) + return 0; + + return common_perm(op, path, mask, &cond); +} + +/** + * common_perm_dir_dentry - common permission wrapper when path is dir, dentry + * @op: operation being checked + * @dir: directory of the dentry (NOT NULL) + * @dentry: dentry to check (NOT NULL) + * @mask: requested permissions mask + * @cond: conditional info for the permission request (NOT NULL) + * + * Returns: %0 else error code if error or permission denied + */ +static int common_perm_dir_dentry(const char *op, const struct path *dir, + struct dentry *dentry, u32 mask, + struct path_cond *cond) +{ + struct path path = { .mnt = dir->mnt, .dentry = dentry }; + + return common_perm(op, &path, mask, cond); +} + +/** + * common_perm_rm - common permission wrapper for operations doing rm + * @op: operation being checked + * @dir: directory that the dentry is in (NOT NULL) + * @dentry: dentry being rm'd (NOT NULL) + * @mask: requested permission mask + * + * Returns: %0 else error code if error or permission denied + */ +static int common_perm_rm(const char *op, const struct path *dir, + struct dentry *dentry, u32 mask) +{ + struct inode *inode = d_backing_inode(dentry); + struct user_namespace *mnt_userns = mnt_user_ns(dir->mnt); + struct path_cond cond = { }; + + if (!inode || !path_mediated_fs(dentry)) + return 0; + + cond.uid = i_uid_into_mnt(mnt_userns, inode); + cond.mode = inode->i_mode; + + return common_perm_dir_dentry(op, dir, dentry, mask, &cond); +} + +/** + * common_perm_create - common permission wrapper for operations doing create + * @op: operation being checked + * @dir: directory that dentry will be created in (NOT NULL) + * @dentry: dentry to create (NOT NULL) + * @mask: request permission mask + * @mode: created file mode + * + * Returns: %0 else error code if error or permission denied + */ +static int common_perm_create(const char *op, const struct path *dir, + struct dentry *dentry, u32 mask, umode_t mode) +{ + struct path_cond cond = { current_fsuid(), mode }; + + if (!path_mediated_fs(dir->dentry)) + return 0; + + return common_perm_dir_dentry(op, dir, dentry, mask, &cond); +} + +static int apparmor_path_unlink(const struct path *dir, struct dentry *dentry) +{ + return common_perm_rm(OP_UNLINK, dir, dentry, AA_MAY_DELETE); +} + +static int apparmor_path_mkdir(const struct path *dir, struct dentry *dentry, + umode_t mode) +{ + return common_perm_create(OP_MKDIR, dir, dentry, AA_MAY_CREATE, + S_IFDIR); +} + +static int apparmor_path_rmdir(const struct path *dir, struct dentry *dentry) +{ + return common_perm_rm(OP_RMDIR, dir, dentry, AA_MAY_DELETE); +} + +static int apparmor_path_mknod(const struct path *dir, struct dentry *dentry, + umode_t mode, unsigned int dev) +{ + return common_perm_create(OP_MKNOD, dir, dentry, AA_MAY_CREATE, mode); +} + +static int apparmor_path_truncate(const struct path *path) +{ + return common_perm_cond(OP_TRUNC, path, MAY_WRITE | AA_MAY_SETATTR); +} + +static int apparmor_path_symlink(const struct path *dir, struct dentry *dentry, + const char *old_name) +{ + return common_perm_create(OP_SYMLINK, dir, dentry, AA_MAY_CREATE, + S_IFLNK); +} + +static int apparmor_path_link(struct dentry *old_dentry, const struct path *new_dir, + struct dentry *new_dentry) +{ + struct aa_label *label; + int error = 0; + + if (!path_mediated_fs(old_dentry)) + return 0; + + label = begin_current_label_crit_section(); + if (!unconfined(label)) + error = aa_path_link(label, old_dentry, new_dir, new_dentry); + end_current_label_crit_section(label); + + return error; +} + +static int apparmor_path_rename(const struct path *old_dir, struct dentry *old_dentry, + const struct path *new_dir, struct dentry *new_dentry, + const unsigned int flags) +{ + struct aa_label *label; + int error = 0; + + if (!path_mediated_fs(old_dentry)) + return 0; + if ((flags & RENAME_EXCHANGE) && !path_mediated_fs(new_dentry)) + return 0; + + label = begin_current_label_crit_section(); + if (!unconfined(label)) { + struct user_namespace *mnt_userns = mnt_user_ns(old_dir->mnt); + struct path old_path = { .mnt = old_dir->mnt, + .dentry = old_dentry }; + struct path new_path = { .mnt = new_dir->mnt, + .dentry = new_dentry }; + struct path_cond cond = { + i_uid_into_mnt(mnt_userns, d_backing_inode(old_dentry)), + d_backing_inode(old_dentry)->i_mode + }; + + if (flags & RENAME_EXCHANGE) { + struct path_cond cond_exchange = { + i_uid_into_mnt(mnt_userns, d_backing_inode(new_dentry)), + d_backing_inode(new_dentry)->i_mode + }; + + error = aa_path_perm(OP_RENAME_SRC, label, &new_path, 0, + MAY_READ | AA_MAY_GETATTR | MAY_WRITE | + AA_MAY_SETATTR | AA_MAY_DELETE, + &cond_exchange); + if (!error) + error = aa_path_perm(OP_RENAME_DEST, label, &old_path, + 0, MAY_WRITE | AA_MAY_SETATTR | + AA_MAY_CREATE, &cond_exchange); + } + + if (!error) + error = aa_path_perm(OP_RENAME_SRC, label, &old_path, 0, + MAY_READ | AA_MAY_GETATTR | MAY_WRITE | + AA_MAY_SETATTR | AA_MAY_DELETE, + &cond); + if (!error) + error = aa_path_perm(OP_RENAME_DEST, label, &new_path, + 0, MAY_WRITE | AA_MAY_SETATTR | + AA_MAY_CREATE, &cond); + + } + end_current_label_crit_section(label); + + return error; +} + +static int apparmor_path_chmod(const struct path *path, umode_t mode) +{ + return common_perm_cond(OP_CHMOD, path, AA_MAY_CHMOD); +} + +static int apparmor_path_chown(const struct path *path, kuid_t uid, kgid_t gid) +{ + return common_perm_cond(OP_CHOWN, path, AA_MAY_CHOWN); +} + +static int apparmor_inode_getattr(const struct path *path) +{ + return common_perm_cond(OP_GETATTR, path, AA_MAY_GETATTR); +} + +static int apparmor_file_open(struct file *file) +{ + struct aa_file_ctx *fctx = file_ctx(file); + struct aa_label *label; + int error = 0; + + if (!path_mediated_fs(file->f_path.dentry)) + return 0; + + /* If in exec, permission is handled by bprm hooks. + * Cache permissions granted by the previous exec check, with + * implicit read and executable mmap which are required to + * actually execute the image. + */ + if (current->in_execve) { + fctx->allow = MAY_EXEC | MAY_READ | AA_EXEC_MMAP; + return 0; + } + + label = aa_get_newest_cred_label(file->f_cred); + if (!unconfined(label)) { + struct user_namespace *mnt_userns = file_mnt_user_ns(file); + struct inode *inode = file_inode(file); + struct path_cond cond = { + i_uid_into_mnt(mnt_userns, inode), + inode->i_mode + }; + + error = aa_path_perm(OP_OPEN, label, &file->f_path, 0, + aa_map_file_to_perms(file), &cond); + /* todo cache full allowed permissions set and state */ + fctx->allow = aa_map_file_to_perms(file); + } + aa_put_label(label); + + return error; +} + +static int apparmor_file_alloc_security(struct file *file) +{ + struct aa_file_ctx *ctx = file_ctx(file); + struct aa_label *label = begin_current_label_crit_section(); + + spin_lock_init(&ctx->lock); + rcu_assign_pointer(ctx->label, aa_get_label(label)); + end_current_label_crit_section(label); + return 0; +} + +static void apparmor_file_free_security(struct file *file) +{ + struct aa_file_ctx *ctx = file_ctx(file); + + if (ctx) + aa_put_label(rcu_access_pointer(ctx->label)); +} + +static int common_file_perm(const char *op, struct file *file, u32 mask, + bool in_atomic) +{ + struct aa_label *label; + int error = 0; + + /* don't reaudit files closed during inheritance */ + if (file->f_path.dentry == aa_null.dentry) + return -EACCES; + + label = __begin_current_label_crit_section(); + error = aa_file_perm(op, label, file, mask, in_atomic); + __end_current_label_crit_section(label); + + return error; +} + +static int apparmor_file_receive(struct file *file) +{ + return common_file_perm(OP_FRECEIVE, file, aa_map_file_to_perms(file), + false); +} + +static int apparmor_file_permission(struct file *file, int mask) +{ + return common_file_perm(OP_FPERM, file, mask, false); +} + +static int apparmor_file_lock(struct file *file, unsigned int cmd) +{ + u32 mask = AA_MAY_LOCK; + + if (cmd == F_WRLCK) + mask |= MAY_WRITE; + + return common_file_perm(OP_FLOCK, file, mask, false); +} + +static int common_mmap(const char *op, struct file *file, unsigned long prot, + unsigned long flags, bool in_atomic) +{ + int mask = 0; + + if (!file || !file_ctx(file)) + return 0; + + if (prot & PROT_READ) + mask |= MAY_READ; + /* + * Private mappings don't require write perms since they don't + * write back to the files + */ + if ((prot & PROT_WRITE) && !(flags & MAP_PRIVATE)) + mask |= MAY_WRITE; + if (prot & PROT_EXEC) + mask |= AA_EXEC_MMAP; + + return common_file_perm(op, file, mask, in_atomic); +} + +static int apparmor_mmap_file(struct file *file, unsigned long reqprot, + unsigned long prot, unsigned long flags) +{ + return common_mmap(OP_FMMAP, file, prot, flags, GFP_ATOMIC); +} + +static int apparmor_file_mprotect(struct vm_area_struct *vma, + unsigned long reqprot, unsigned long prot) +{ + return common_mmap(OP_FMPROT, vma->vm_file, prot, + !(vma->vm_flags & VM_SHARED) ? MAP_PRIVATE : 0, + false); +} + +static int apparmor_sb_mount(const char *dev_name, const struct path *path, + const char *type, unsigned long flags, void *data) +{ + struct aa_label *label; + int error = 0; + + /* Discard magic */ + if ((flags & MS_MGC_MSK) == MS_MGC_VAL) + flags &= ~MS_MGC_MSK; + + flags &= ~AA_MS_IGNORE_MASK; + + label = __begin_current_label_crit_section(); + if (!unconfined(label)) { + if (flags & MS_REMOUNT) + error = aa_remount(label, path, flags, data); + else if (flags & MS_BIND) + error = aa_bind_mount(label, path, dev_name, flags); + else if (flags & (MS_SHARED | MS_PRIVATE | MS_SLAVE | + MS_UNBINDABLE)) + error = aa_mount_change_type(label, path, flags); + else if (flags & MS_MOVE) + error = aa_move_mount(label, path, dev_name); + else + error = aa_new_mount(label, dev_name, path, type, + flags, data); + } + __end_current_label_crit_section(label); + + return error; +} + +static int apparmor_sb_umount(struct vfsmount *mnt, int flags) +{ + struct aa_label *label; + int error = 0; + + label = __begin_current_label_crit_section(); + if (!unconfined(label)) + error = aa_umount(label, mnt, flags); + __end_current_label_crit_section(label); + + return error; +} + +static int apparmor_sb_pivotroot(const struct path *old_path, + const struct path *new_path) +{ + struct aa_label *label; + int error = 0; + + label = aa_get_current_label(); + if (!unconfined(label)) + error = aa_pivotroot(label, old_path, new_path); + aa_put_label(label); + + return error; +} + +static int apparmor_getprocattr(struct task_struct *task, const char *name, + char **value) +{ + int error = -ENOENT; + /* released below */ + const struct cred *cred = get_task_cred(task); + struct aa_task_ctx *ctx = task_ctx(current); + struct aa_label *label = NULL; + + if (strcmp(name, "current") == 0) + label = aa_get_newest_label(cred_label(cred)); + else if (strcmp(name, "prev") == 0 && ctx->previous) + label = aa_get_newest_label(ctx->previous); + else if (strcmp(name, "exec") == 0 && ctx->onexec) + label = aa_get_newest_label(ctx->onexec); + else + error = -EINVAL; + + if (label) + error = aa_getprocattr(label, value); + + aa_put_label(label); + put_cred(cred); + + return error; +} + +static int apparmor_setprocattr(const char *name, void *value, + size_t size) +{ + char *command, *largs = NULL, *args = value; + size_t arg_size; + int error; + DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, OP_SETPROCATTR); + + if (size == 0) + return -EINVAL; + + /* AppArmor requires that the buffer must be null terminated atm */ + if (args[size - 1] != '\0') { + /* null terminate */ + largs = args = kmalloc(size + 1, GFP_KERNEL); + if (!args) + return -ENOMEM; + memcpy(args, value, size); + args[size] = '\0'; + } + + error = -EINVAL; + args = strim(args); + command = strsep(&args, " "); + if (!args) + goto out; + args = skip_spaces(args); + if (!*args) + goto out; + + arg_size = size - (args - (largs ? largs : (char *) value)); + if (strcmp(name, "current") == 0) { + if (strcmp(command, "changehat") == 0) { + error = aa_setprocattr_changehat(args, arg_size, + AA_CHANGE_NOFLAGS); + } else if (strcmp(command, "permhat") == 0) { + error = aa_setprocattr_changehat(args, arg_size, + AA_CHANGE_TEST); + } else if (strcmp(command, "changeprofile") == 0) { + error = aa_change_profile(args, AA_CHANGE_NOFLAGS); + } else if (strcmp(command, "permprofile") == 0) { + error = aa_change_profile(args, AA_CHANGE_TEST); + } else if (strcmp(command, "stack") == 0) { + error = aa_change_profile(args, AA_CHANGE_STACK); + } else + goto fail; + } else if (strcmp(name, "exec") == 0) { + if (strcmp(command, "exec") == 0) + error = aa_change_profile(args, AA_CHANGE_ONEXEC); + else if (strcmp(command, "stack") == 0) + error = aa_change_profile(args, (AA_CHANGE_ONEXEC | + AA_CHANGE_STACK)); + else + goto fail; + } else + /* only support the "current" and "exec" process attributes */ + goto fail; + + if (!error) + error = size; +out: + kfree(largs); + return error; + +fail: + aad(&sa)->label = begin_current_label_crit_section(); + aad(&sa)->info = name; + aad(&sa)->error = error = -EINVAL; + aa_audit_msg(AUDIT_APPARMOR_DENIED, &sa, NULL); + end_current_label_crit_section(aad(&sa)->label); + goto out; +} + +/** + * apparmor_bprm_committing_creds - do task cleanup on committing new creds + * @bprm: binprm for the exec (NOT NULL) + */ +static void apparmor_bprm_committing_creds(struct linux_binprm *bprm) +{ + struct aa_label *label = aa_current_raw_label(); + struct aa_label *new_label = cred_label(bprm->cred); + + /* bail out if unconfined or not changing profile */ + if ((new_label->proxy == label->proxy) || + (unconfined(new_label))) + return; + + aa_inherit_files(bprm->cred, current->files); + + current->pdeath_signal = 0; + + /* reset soft limits and set hard limits for the new label */ + __aa_transition_rlimits(label, new_label); +} + +/** + * apparmor_bprm_committed_cred - do cleanup after new creds committed + * @bprm: binprm for the exec (NOT NULL) + */ +static void apparmor_bprm_committed_creds(struct linux_binprm *bprm) +{ + /* clear out temporary/transitional state from the context */ + aa_clear_task_ctx_trans(task_ctx(current)); + + return; +} + +static void apparmor_current_getsecid_subj(u32 *secid) +{ + struct aa_label *label = aa_get_current_label(); + *secid = label->secid; + aa_put_label(label); +} + +static void apparmor_task_getsecid_obj(struct task_struct *p, u32 *secid) +{ + struct aa_label *label = aa_get_task_label(p); + *secid = label->secid; + aa_put_label(label); +} + +static int apparmor_task_setrlimit(struct task_struct *task, + unsigned int resource, struct rlimit *new_rlim) +{ + struct aa_label *label = __begin_current_label_crit_section(); + int error = 0; + + if (!unconfined(label)) + error = aa_task_setrlimit(label, task, resource, new_rlim); + __end_current_label_crit_section(label); + + return error; +} + +static int apparmor_task_kill(struct task_struct *target, struct kernel_siginfo *info, + int sig, const struct cred *cred) +{ + struct aa_label *cl, *tl; + int error; + + if (cred) { + /* + * Dealing with USB IO specific behavior + */ + cl = aa_get_newest_cred_label(cred); + tl = aa_get_task_label(target); + error = aa_may_signal(cl, tl, sig); + aa_put_label(cl); + aa_put_label(tl); + return error; + } + + cl = __begin_current_label_crit_section(); + tl = aa_get_task_label(target); + error = aa_may_signal(cl, tl, sig); + aa_put_label(tl); + __end_current_label_crit_section(cl); + + return error; +} + +/** + * apparmor_sk_alloc_security - allocate and attach the sk_security field + */ +static int apparmor_sk_alloc_security(struct sock *sk, int family, gfp_t flags) +{ + struct aa_sk_ctx *ctx; + + ctx = kzalloc(sizeof(*ctx), flags); + if (!ctx) + return -ENOMEM; + + SK_CTX(sk) = ctx; + + return 0; +} + +/** + * apparmor_sk_free_security - free the sk_security field + */ +static void apparmor_sk_free_security(struct sock *sk) +{ + struct aa_sk_ctx *ctx = SK_CTX(sk); + + SK_CTX(sk) = NULL; + aa_put_label(ctx->label); + aa_put_label(ctx->peer); + kfree(ctx); +} + +/** + * apparmor_sk_clone_security - clone the sk_security field + */ +static void apparmor_sk_clone_security(const struct sock *sk, + struct sock *newsk) +{ + struct aa_sk_ctx *ctx = SK_CTX(sk); + struct aa_sk_ctx *new = SK_CTX(newsk); + + if (new->label) + aa_put_label(new->label); + new->label = aa_get_label(ctx->label); + + if (new->peer) + aa_put_label(new->peer); + new->peer = aa_get_label(ctx->peer); +} + +/** + * apparmor_socket_create - check perms before creating a new socket + */ +static int apparmor_socket_create(int family, int type, int protocol, int kern) +{ + struct aa_label *label; + int error = 0; + + AA_BUG(in_interrupt()); + + label = begin_current_label_crit_section(); + if (!(kern || unconfined(label))) + error = af_select(family, + create_perm(label, family, type, protocol), + aa_af_perm(label, OP_CREATE, AA_MAY_CREATE, + family, type, protocol)); + end_current_label_crit_section(label); + + return error; +} + +/** + * apparmor_socket_post_create - setup the per-socket security struct + * + * Note: + * - kernel sockets currently labeled unconfined but we may want to + * move to a special kernel label + * - socket may not have sk here if created with sock_create_lite or + * sock_alloc. These should be accept cases which will be handled in + * sock_graft. + */ +static int apparmor_socket_post_create(struct socket *sock, int family, + int type, int protocol, int kern) +{ + struct aa_label *label; + + if (kern) { + label = aa_get_label(kernel_t); + } else + label = aa_get_current_label(); + + if (sock->sk) { + struct aa_sk_ctx *ctx = SK_CTX(sock->sk); + + aa_put_label(ctx->label); + ctx->label = aa_get_label(label); + } + aa_put_label(label); + + return 0; +} + +/** + * apparmor_socket_bind - check perms before bind addr to socket + */ +static int apparmor_socket_bind(struct socket *sock, + struct sockaddr *address, int addrlen) +{ + AA_BUG(!sock); + AA_BUG(!sock->sk); + AA_BUG(!address); + AA_BUG(in_interrupt()); + + return af_select(sock->sk->sk_family, + bind_perm(sock, address, addrlen), + aa_sk_perm(OP_BIND, AA_MAY_BIND, sock->sk)); +} + +/** + * apparmor_socket_connect - check perms before connecting @sock to @address + */ +static int apparmor_socket_connect(struct socket *sock, + struct sockaddr *address, int addrlen) +{ + AA_BUG(!sock); + AA_BUG(!sock->sk); + AA_BUG(!address); + AA_BUG(in_interrupt()); + + return af_select(sock->sk->sk_family, + connect_perm(sock, address, addrlen), + aa_sk_perm(OP_CONNECT, AA_MAY_CONNECT, sock->sk)); +} + +/** + * apparmor_socket_listen - check perms before allowing listen + */ +static int apparmor_socket_listen(struct socket *sock, int backlog) +{ + AA_BUG(!sock); + AA_BUG(!sock->sk); + AA_BUG(in_interrupt()); + + return af_select(sock->sk->sk_family, + listen_perm(sock, backlog), + aa_sk_perm(OP_LISTEN, AA_MAY_LISTEN, sock->sk)); +} + +/** + * apparmor_socket_accept - check perms before accepting a new connection. + * + * Note: while @newsock is created and has some information, the accept + * has not been done. + */ +static int apparmor_socket_accept(struct socket *sock, struct socket *newsock) +{ + AA_BUG(!sock); + AA_BUG(!sock->sk); + AA_BUG(!newsock); + AA_BUG(in_interrupt()); + + return af_select(sock->sk->sk_family, + accept_perm(sock, newsock), + aa_sk_perm(OP_ACCEPT, AA_MAY_ACCEPT, sock->sk)); +} + +static int aa_sock_msg_perm(const char *op, u32 request, struct socket *sock, + struct msghdr *msg, int size) +{ + AA_BUG(!sock); + AA_BUG(!sock->sk); + AA_BUG(!msg); + AA_BUG(in_interrupt()); + + return af_select(sock->sk->sk_family, + msg_perm(op, request, sock, msg, size), + aa_sk_perm(op, request, sock->sk)); +} + +/** + * apparmor_socket_sendmsg - check perms before sending msg to another socket + */ +static int apparmor_socket_sendmsg(struct socket *sock, + struct msghdr *msg, int size) +{ + return aa_sock_msg_perm(OP_SENDMSG, AA_MAY_SEND, sock, msg, size); +} + +/** + * apparmor_socket_recvmsg - check perms before receiving a message + */ +static int apparmor_socket_recvmsg(struct socket *sock, + struct msghdr *msg, int size, int flags) +{ + return aa_sock_msg_perm(OP_RECVMSG, AA_MAY_RECEIVE, sock, msg, size); +} + +/* revaliation, get/set attr, shutdown */ +static int aa_sock_perm(const char *op, u32 request, struct socket *sock) +{ + AA_BUG(!sock); + AA_BUG(!sock->sk); + AA_BUG(in_interrupt()); + + return af_select(sock->sk->sk_family, + sock_perm(op, request, sock), + aa_sk_perm(op, request, sock->sk)); +} + +/** + * apparmor_socket_getsockname - check perms before getting the local address + */ +static int apparmor_socket_getsockname(struct socket *sock) +{ + return aa_sock_perm(OP_GETSOCKNAME, AA_MAY_GETATTR, sock); +} + +/** + * apparmor_socket_getpeername - check perms before getting remote address + */ +static int apparmor_socket_getpeername(struct socket *sock) +{ + return aa_sock_perm(OP_GETPEERNAME, AA_MAY_GETATTR, sock); +} + +/* revaliation, get/set attr, opt */ +static int aa_sock_opt_perm(const char *op, u32 request, struct socket *sock, + int level, int optname) +{ + AA_BUG(!sock); + AA_BUG(!sock->sk); + AA_BUG(in_interrupt()); + + return af_select(sock->sk->sk_family, + opt_perm(op, request, sock, level, optname), + aa_sk_perm(op, request, sock->sk)); +} + +/** + * apparmor_socket_getsockopt - check perms before getting socket options + */ +static int apparmor_socket_getsockopt(struct socket *sock, int level, + int optname) +{ + return aa_sock_opt_perm(OP_GETSOCKOPT, AA_MAY_GETOPT, sock, + level, optname); +} + +/** + * apparmor_socket_setsockopt - check perms before setting socket options + */ +static int apparmor_socket_setsockopt(struct socket *sock, int level, + int optname) +{ + return aa_sock_opt_perm(OP_SETSOCKOPT, AA_MAY_SETOPT, sock, + level, optname); +} + +/** + * apparmor_socket_shutdown - check perms before shutting down @sock conn + */ +static int apparmor_socket_shutdown(struct socket *sock, int how) +{ + return aa_sock_perm(OP_SHUTDOWN, AA_MAY_SHUTDOWN, sock); +} + +#ifdef CONFIG_NETWORK_SECMARK +/** + * apparmor_socket_sock_rcv_skb - check perms before associating skb to sk + * + * Note: can not sleep may be called with locks held + * + * dont want protocol specific in __skb_recv_datagram() + * to deny an incoming connection socket_sock_rcv_skb() + */ +static int apparmor_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) +{ + struct aa_sk_ctx *ctx = SK_CTX(sk); + + if (!skb->secmark) + return 0; + + return apparmor_secmark_check(ctx->label, OP_RECVMSG, AA_MAY_RECEIVE, + skb->secmark, sk); +} +#endif + + +static struct aa_label *sk_peer_label(struct sock *sk) +{ + struct aa_sk_ctx *ctx = SK_CTX(sk); + + if (ctx->peer) + return ctx->peer; + + return ERR_PTR(-ENOPROTOOPT); +} + +/** + * apparmor_socket_getpeersec_stream - get security context of peer + * + * Note: for tcp only valid if using ipsec or cipso on lan + */ +static int apparmor_socket_getpeersec_stream(struct socket *sock, + char __user *optval, + int __user *optlen, + unsigned int len) +{ + char *name; + int slen, error = 0; + struct aa_label *label; + struct aa_label *peer; + + label = begin_current_label_crit_section(); + peer = sk_peer_label(sock->sk); + if (IS_ERR(peer)) { + error = PTR_ERR(peer); + goto done; + } + slen = aa_label_asxprint(&name, labels_ns(label), peer, + FLAG_SHOW_MODE | FLAG_VIEW_SUBNS | + FLAG_HIDDEN_UNCONFINED, GFP_KERNEL); + /* don't include terminating \0 in slen, it breaks some apps */ + if (slen < 0) { + error = -ENOMEM; + } else { + if (slen > len) { + error = -ERANGE; + } else if (copy_to_user(optval, name, slen)) { + error = -EFAULT; + goto out; + } + if (put_user(slen, optlen)) + error = -EFAULT; +out: + kfree(name); + + } + +done: + end_current_label_crit_section(label); + + return error; +} + +/** + * apparmor_socket_getpeersec_dgram - get security label of packet + * @sock: the peer socket + * @skb: packet data + * @secid: pointer to where to put the secid of the packet + * + * Sets the netlabel socket state on sk from parent + */ +static int apparmor_socket_getpeersec_dgram(struct socket *sock, + struct sk_buff *skb, u32 *secid) + +{ + /* TODO: requires secid support */ + return -ENOPROTOOPT; +} + +/** + * apparmor_sock_graft - Initialize newly created socket + * @sk: child sock + * @parent: parent socket + * + * Note: could set off of SOCK_CTX(parent) but need to track inode and we can + * just set sk security information off of current creating process label + * Labeling of sk for accept case - probably should be sock based + * instead of task, because of the case where an implicitly labeled + * socket is shared by different tasks. + */ +static void apparmor_sock_graft(struct sock *sk, struct socket *parent) +{ + struct aa_sk_ctx *ctx = SK_CTX(sk); + + if (!ctx->label) + ctx->label = aa_get_current_label(); +} + +#ifdef CONFIG_NETWORK_SECMARK +static int apparmor_inet_conn_request(const struct sock *sk, struct sk_buff *skb, + struct request_sock *req) +{ + struct aa_sk_ctx *ctx = SK_CTX(sk); + + if (!skb->secmark) + return 0; + + return apparmor_secmark_check(ctx->label, OP_CONNECT, AA_MAY_CONNECT, + skb->secmark, sk); +} +#endif + +/* + * The cred blob is a pointer to, not an instance of, an aa_label. + */ +struct lsm_blob_sizes apparmor_blob_sizes __lsm_ro_after_init = { + .lbs_cred = sizeof(struct aa_label *), + .lbs_file = sizeof(struct aa_file_ctx), + .lbs_task = sizeof(struct aa_task_ctx), +}; + +static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = { + LSM_HOOK_INIT(ptrace_access_check, apparmor_ptrace_access_check), + LSM_HOOK_INIT(ptrace_traceme, apparmor_ptrace_traceme), + LSM_HOOK_INIT(capget, apparmor_capget), + LSM_HOOK_INIT(capable, apparmor_capable), + + LSM_HOOK_INIT(sb_mount, apparmor_sb_mount), + LSM_HOOK_INIT(sb_umount, apparmor_sb_umount), + LSM_HOOK_INIT(sb_pivotroot, apparmor_sb_pivotroot), + + LSM_HOOK_INIT(path_link, apparmor_path_link), + LSM_HOOK_INIT(path_unlink, apparmor_path_unlink), + LSM_HOOK_INIT(path_symlink, apparmor_path_symlink), + LSM_HOOK_INIT(path_mkdir, apparmor_path_mkdir), + LSM_HOOK_INIT(path_rmdir, apparmor_path_rmdir), + LSM_HOOK_INIT(path_mknod, apparmor_path_mknod), + LSM_HOOK_INIT(path_rename, apparmor_path_rename), + LSM_HOOK_INIT(path_chmod, apparmor_path_chmod), + LSM_HOOK_INIT(path_chown, apparmor_path_chown), + LSM_HOOK_INIT(path_truncate, apparmor_path_truncate), + LSM_HOOK_INIT(inode_getattr, apparmor_inode_getattr), + + LSM_HOOK_INIT(file_open, apparmor_file_open), + LSM_HOOK_INIT(file_receive, apparmor_file_receive), + LSM_HOOK_INIT(file_permission, apparmor_file_permission), + LSM_HOOK_INIT(file_alloc_security, apparmor_file_alloc_security), + LSM_HOOK_INIT(file_free_security, apparmor_file_free_security), + LSM_HOOK_INIT(mmap_file, apparmor_mmap_file), + LSM_HOOK_INIT(file_mprotect, apparmor_file_mprotect), + LSM_HOOK_INIT(file_lock, apparmor_file_lock), + + LSM_HOOK_INIT(getprocattr, apparmor_getprocattr), + LSM_HOOK_INIT(setprocattr, apparmor_setprocattr), + + LSM_HOOK_INIT(sk_alloc_security, apparmor_sk_alloc_security), + LSM_HOOK_INIT(sk_free_security, apparmor_sk_free_security), + LSM_HOOK_INIT(sk_clone_security, apparmor_sk_clone_security), + + LSM_HOOK_INIT(socket_create, apparmor_socket_create), + LSM_HOOK_INIT(socket_post_create, apparmor_socket_post_create), + LSM_HOOK_INIT(socket_bind, apparmor_socket_bind), + LSM_HOOK_INIT(socket_connect, apparmor_socket_connect), + LSM_HOOK_INIT(socket_listen, apparmor_socket_listen), + LSM_HOOK_INIT(socket_accept, apparmor_socket_accept), + LSM_HOOK_INIT(socket_sendmsg, apparmor_socket_sendmsg), + LSM_HOOK_INIT(socket_recvmsg, apparmor_socket_recvmsg), + LSM_HOOK_INIT(socket_getsockname, apparmor_socket_getsockname), + LSM_HOOK_INIT(socket_getpeername, apparmor_socket_getpeername), + LSM_HOOK_INIT(socket_getsockopt, apparmor_socket_getsockopt), + LSM_HOOK_INIT(socket_setsockopt, apparmor_socket_setsockopt), + LSM_HOOK_INIT(socket_shutdown, apparmor_socket_shutdown), +#ifdef CONFIG_NETWORK_SECMARK + LSM_HOOK_INIT(socket_sock_rcv_skb, apparmor_socket_sock_rcv_skb), +#endif + LSM_HOOK_INIT(socket_getpeersec_stream, + apparmor_socket_getpeersec_stream), + LSM_HOOK_INIT(socket_getpeersec_dgram, + apparmor_socket_getpeersec_dgram), + LSM_HOOK_INIT(sock_graft, apparmor_sock_graft), +#ifdef CONFIG_NETWORK_SECMARK + LSM_HOOK_INIT(inet_conn_request, apparmor_inet_conn_request), +#endif + + LSM_HOOK_INIT(cred_alloc_blank, apparmor_cred_alloc_blank), + LSM_HOOK_INIT(cred_free, apparmor_cred_free), + LSM_HOOK_INIT(cred_prepare, apparmor_cred_prepare), + LSM_HOOK_INIT(cred_transfer, apparmor_cred_transfer), + + LSM_HOOK_INIT(bprm_creds_for_exec, apparmor_bprm_creds_for_exec), + LSM_HOOK_INIT(bprm_committing_creds, apparmor_bprm_committing_creds), + LSM_HOOK_INIT(bprm_committed_creds, apparmor_bprm_committed_creds), + + LSM_HOOK_INIT(task_free, apparmor_task_free), + LSM_HOOK_INIT(task_alloc, apparmor_task_alloc), + LSM_HOOK_INIT(current_getsecid_subj, apparmor_current_getsecid_subj), + LSM_HOOK_INIT(task_getsecid_obj, apparmor_task_getsecid_obj), + LSM_HOOK_INIT(task_setrlimit, apparmor_task_setrlimit), + LSM_HOOK_INIT(task_kill, apparmor_task_kill), + +#ifdef CONFIG_AUDIT + LSM_HOOK_INIT(audit_rule_init, aa_audit_rule_init), + LSM_HOOK_INIT(audit_rule_known, aa_audit_rule_known), + LSM_HOOK_INIT(audit_rule_match, aa_audit_rule_match), + LSM_HOOK_INIT(audit_rule_free, aa_audit_rule_free), +#endif + + LSM_HOOK_INIT(secid_to_secctx, apparmor_secid_to_secctx), + LSM_HOOK_INIT(secctx_to_secid, apparmor_secctx_to_secid), + LSM_HOOK_INIT(release_secctx, apparmor_release_secctx), +}; + +/* + * AppArmor sysfs module parameters + */ + +static int param_set_aabool(const char *val, const struct kernel_param *kp); +static int param_get_aabool(char *buffer, const struct kernel_param *kp); +#define param_check_aabool param_check_bool +static const struct kernel_param_ops param_ops_aabool = { + .flags = KERNEL_PARAM_OPS_FL_NOARG, + .set = param_set_aabool, + .get = param_get_aabool +}; + +static int param_set_aauint(const char *val, const struct kernel_param *kp); +static int param_get_aauint(char *buffer, const struct kernel_param *kp); +#define param_check_aauint param_check_uint +static const struct kernel_param_ops param_ops_aauint = { + .set = param_set_aauint, + .get = param_get_aauint +}; + +static int param_set_aacompressionlevel(const char *val, + const struct kernel_param *kp); +static int param_get_aacompressionlevel(char *buffer, + const struct kernel_param *kp); +#define param_check_aacompressionlevel param_check_int +static const struct kernel_param_ops param_ops_aacompressionlevel = { + .set = param_set_aacompressionlevel, + .get = param_get_aacompressionlevel +}; + +static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp); +static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp); +#define param_check_aalockpolicy param_check_bool +static const struct kernel_param_ops param_ops_aalockpolicy = { + .flags = KERNEL_PARAM_OPS_FL_NOARG, + .set = param_set_aalockpolicy, + .get = param_get_aalockpolicy +}; + +static int param_set_audit(const char *val, const struct kernel_param *kp); +static int param_get_audit(char *buffer, const struct kernel_param *kp); + +static int param_set_mode(const char *val, const struct kernel_param *kp); +static int param_get_mode(char *buffer, const struct kernel_param *kp); + +/* Flag values, also controllable via /sys/module/apparmor/parameters + * We define special types as we want to do additional mediation. + */ + +/* AppArmor global enforcement switch - complain, enforce, kill */ +enum profile_mode aa_g_profile_mode = APPARMOR_ENFORCE; +module_param_call(mode, param_set_mode, param_get_mode, + &aa_g_profile_mode, S_IRUSR | S_IWUSR); + +/* whether policy verification hashing is enabled */ +bool aa_g_hash_policy = IS_ENABLED(CONFIG_SECURITY_APPARMOR_HASH_DEFAULT); +#ifdef CONFIG_SECURITY_APPARMOR_HASH +module_param_named(hash_policy, aa_g_hash_policy, aabool, S_IRUSR | S_IWUSR); +#endif + +/* whether policy exactly as loaded is retained for debug and checkpointing */ +bool aa_g_export_binary = IS_ENABLED(CONFIG_SECURITY_APPARMOR_EXPORT_BINARY); +#ifdef CONFIG_SECURITY_APPARMOR_EXPORT_BINARY +module_param_named(export_binary, aa_g_export_binary, aabool, 0600); +#endif + +/* policy loaddata compression level */ +int aa_g_rawdata_compression_level = Z_DEFAULT_COMPRESSION; +module_param_named(rawdata_compression_level, aa_g_rawdata_compression_level, + aacompressionlevel, 0400); + +/* Debug mode */ +bool aa_g_debug = IS_ENABLED(CONFIG_SECURITY_APPARMOR_DEBUG_MESSAGES); +module_param_named(debug, aa_g_debug, aabool, S_IRUSR | S_IWUSR); + +/* Audit mode */ +enum audit_mode aa_g_audit; +module_param_call(audit, param_set_audit, param_get_audit, + &aa_g_audit, S_IRUSR | S_IWUSR); + +/* Determines if audit header is included in audited messages. This + * provides more context if the audit daemon is not running + */ +bool aa_g_audit_header = true; +module_param_named(audit_header, aa_g_audit_header, aabool, + S_IRUSR | S_IWUSR); + +/* lock out loading/removal of policy + * TODO: add in at boot loading of policy, which is the only way to + * load policy, if lock_policy is set + */ +bool aa_g_lock_policy; +module_param_named(lock_policy, aa_g_lock_policy, aalockpolicy, + S_IRUSR | S_IWUSR); + +/* Syscall logging mode */ +bool aa_g_logsyscall; +module_param_named(logsyscall, aa_g_logsyscall, aabool, S_IRUSR | S_IWUSR); + +/* Maximum pathname length before accesses will start getting rejected */ +unsigned int aa_g_path_max = 2 * PATH_MAX; +module_param_named(path_max, aa_g_path_max, aauint, S_IRUSR); + +/* Determines how paranoid loading of policy is and how much verification + * on the loaded policy is done. + * DEPRECATED: read only as strict checking of load is always done now + * that none root users (user namespaces) can load policy. + */ +bool aa_g_paranoid_load = IS_ENABLED(CONFIG_SECURITY_APPARMOR_PARANOID_LOAD); +module_param_named(paranoid_load, aa_g_paranoid_load, aabool, S_IRUGO); + +static int param_get_aaintbool(char *buffer, const struct kernel_param *kp); +static int param_set_aaintbool(const char *val, const struct kernel_param *kp); +#define param_check_aaintbool param_check_int +static const struct kernel_param_ops param_ops_aaintbool = { + .set = param_set_aaintbool, + .get = param_get_aaintbool +}; +/* Boot time disable flag */ +static int apparmor_enabled __lsm_ro_after_init = 1; +module_param_named(enabled, apparmor_enabled, aaintbool, 0444); + +static int __init apparmor_enabled_setup(char *str) +{ + unsigned long enabled; + int error = kstrtoul(str, 0, &enabled); + if (!error) + apparmor_enabled = enabled ? 1 : 0; + return 1; +} + +__setup("apparmor=", apparmor_enabled_setup); + +/* set global flag turning off the ability to load policy */ +static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp) +{ + if (!apparmor_enabled) + return -EINVAL; + if (apparmor_initialized && !aa_current_policy_admin_capable(NULL)) + return -EPERM; + return param_set_bool(val, kp); +} + +static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp) +{ + if (!apparmor_enabled) + return -EINVAL; + if (apparmor_initialized && !aa_current_policy_view_capable(NULL)) + return -EPERM; + return param_get_bool(buffer, kp); +} + +static int param_set_aabool(const char *val, const struct kernel_param *kp) +{ + if (!apparmor_enabled) + return -EINVAL; + if (apparmor_initialized && !aa_current_policy_admin_capable(NULL)) + return -EPERM; + return param_set_bool(val, kp); +} + +static int param_get_aabool(char *buffer, const struct kernel_param *kp) +{ + if (!apparmor_enabled) + return -EINVAL; + if (apparmor_initialized && !aa_current_policy_view_capable(NULL)) + return -EPERM; + return param_get_bool(buffer, kp); +} + +static int param_set_aauint(const char *val, const struct kernel_param *kp) +{ + int error; + + if (!apparmor_enabled) + return -EINVAL; + /* file is ro but enforce 2nd line check */ + if (apparmor_initialized) + return -EPERM; + + error = param_set_uint(val, kp); + aa_g_path_max = max_t(uint32_t, aa_g_path_max, sizeof(union aa_buffer)); + pr_info("AppArmor: buffer size set to %d bytes\n", aa_g_path_max); + + return error; +} + +static int param_get_aauint(char *buffer, const struct kernel_param *kp) +{ + if (!apparmor_enabled) + return -EINVAL; + if (apparmor_initialized && !aa_current_policy_view_capable(NULL)) + return -EPERM; + return param_get_uint(buffer, kp); +} + +/* Can only be set before AppArmor is initialized (i.e. on boot cmdline). */ +static int param_set_aaintbool(const char *val, const struct kernel_param *kp) +{ + struct kernel_param kp_local; + bool value; + int error; + + if (apparmor_initialized) + return -EPERM; + + /* Create local copy, with arg pointing to bool type. */ + value = !!*((int *)kp->arg); + memcpy(&kp_local, kp, sizeof(kp_local)); + kp_local.arg = &value; + + error = param_set_bool(val, &kp_local); + if (!error) + *((int *)kp->arg) = *((bool *)kp_local.arg); + return error; +} + +/* + * To avoid changing /sys/module/apparmor/parameters/enabled from Y/N to + * 1/0, this converts the "int that is actually bool" back to bool for + * display in the /sys filesystem, while keeping it "int" for the LSM + * infrastructure. + */ +static int param_get_aaintbool(char *buffer, const struct kernel_param *kp) +{ + struct kernel_param kp_local; + bool value; + + /* Create local copy, with arg pointing to bool type. */ + value = !!*((int *)kp->arg); + memcpy(&kp_local, kp, sizeof(kp_local)); + kp_local.arg = &value; + + return param_get_bool(buffer, &kp_local); +} + +static int param_set_aacompressionlevel(const char *val, + const struct kernel_param *kp) +{ + int error; + + if (!apparmor_enabled) + return -EINVAL; + if (apparmor_initialized) + return -EPERM; + + error = param_set_int(val, kp); + + aa_g_rawdata_compression_level = clamp(aa_g_rawdata_compression_level, + Z_NO_COMPRESSION, + Z_BEST_COMPRESSION); + pr_info("AppArmor: policy rawdata compression level set to %u\n", + aa_g_rawdata_compression_level); + + return error; +} + +static int param_get_aacompressionlevel(char *buffer, + const struct kernel_param *kp) +{ + if (!apparmor_enabled) + return -EINVAL; + if (apparmor_initialized && !aa_current_policy_view_capable(NULL)) + return -EPERM; + return param_get_int(buffer, kp); +} + +static int param_get_audit(char *buffer, const struct kernel_param *kp) +{ + if (!apparmor_enabled) + return -EINVAL; + if (apparmor_initialized && !aa_current_policy_view_capable(NULL)) + return -EPERM; + return sprintf(buffer, "%s", audit_mode_names[aa_g_audit]); +} + +static int param_set_audit(const char *val, const struct kernel_param *kp) +{ + int i; + + if (!apparmor_enabled) + return -EINVAL; + if (!val) + return -EINVAL; + if (apparmor_initialized && !aa_current_policy_admin_capable(NULL)) + return -EPERM; + + i = match_string(audit_mode_names, AUDIT_MAX_INDEX, val); + if (i < 0) + return -EINVAL; + + aa_g_audit = i; + return 0; +} + +static int param_get_mode(char *buffer, const struct kernel_param *kp) +{ + if (!apparmor_enabled) + return -EINVAL; + if (apparmor_initialized && !aa_current_policy_view_capable(NULL)) + return -EPERM; + + return sprintf(buffer, "%s", aa_profile_mode_names[aa_g_profile_mode]); +} + +static int param_set_mode(const char *val, const struct kernel_param *kp) +{ + int i; + + if (!apparmor_enabled) + return -EINVAL; + if (!val) + return -EINVAL; + if (apparmor_initialized && !aa_current_policy_admin_capable(NULL)) + return -EPERM; + + i = match_string(aa_profile_mode_names, APPARMOR_MODE_NAMES_MAX_INDEX, + val); + if (i < 0) + return -EINVAL; + + aa_g_profile_mode = i; + return 0; +} + +char *aa_get_buffer(bool in_atomic) +{ + union aa_buffer *aa_buf; + bool try_again = true; + gfp_t flags = (GFP_KERNEL | __GFP_RETRY_MAYFAIL | __GFP_NOWARN); + +retry: + spin_lock(&aa_buffers_lock); + if (buffer_count > reserve_count || + (in_atomic && !list_empty(&aa_global_buffers))) { + aa_buf = list_first_entry(&aa_global_buffers, union aa_buffer, + list); + list_del(&aa_buf->list); + buffer_count--; + spin_unlock(&aa_buffers_lock); + return &aa_buf->buffer[0]; + } + if (in_atomic) { + /* + * out of reserve buffers and in atomic context so increase + * how many buffers to keep in reserve + */ + reserve_count++; + flags = GFP_ATOMIC; + } + spin_unlock(&aa_buffers_lock); + + if (!in_atomic) + might_sleep(); + aa_buf = kmalloc(aa_g_path_max, flags); + if (!aa_buf) { + if (try_again) { + try_again = false; + goto retry; + } + pr_warn_once("AppArmor: Failed to allocate a memory buffer.\n"); + return NULL; + } + return &aa_buf->buffer[0]; +} + +void aa_put_buffer(char *buf) +{ + union aa_buffer *aa_buf; + + if (!buf) + return; + aa_buf = container_of(buf, union aa_buffer, buffer[0]); + + spin_lock(&aa_buffers_lock); + list_add(&aa_buf->list, &aa_global_buffers); + buffer_count++; + spin_unlock(&aa_buffers_lock); +} + +/* + * AppArmor init functions + */ + +/** + * set_init_ctx - set a task context and profile on the first task. + * + * TODO: allow setting an alternate profile than unconfined + */ +static int __init set_init_ctx(void) +{ + struct cred *cred = (__force struct cred *)current->real_cred; + + set_cred_label(cred, aa_get_label(ns_unconfined(root_ns))); + + return 0; +} + +static void destroy_buffers(void) +{ + union aa_buffer *aa_buf; + + spin_lock(&aa_buffers_lock); + while (!list_empty(&aa_global_buffers)) { + aa_buf = list_first_entry(&aa_global_buffers, union aa_buffer, + list); + list_del(&aa_buf->list); + spin_unlock(&aa_buffers_lock); + kfree(aa_buf); + spin_lock(&aa_buffers_lock); + } + spin_unlock(&aa_buffers_lock); +} + +static int __init alloc_buffers(void) +{ + union aa_buffer *aa_buf; + int i, num; + + /* + * A function may require two buffers at once. Usually the buffers are + * used for a short period of time and are shared. On UP kernel buffers + * two should be enough, with more CPUs it is possible that more + * buffers will be used simultaneously. The preallocated pool may grow. + * This preallocation has also the side-effect that AppArmor will be + * disabled early at boot if aa_g_path_max is extremly high. + */ + if (num_online_cpus() > 1) + num = 4 + RESERVE_COUNT; + else + num = 2 + RESERVE_COUNT; + + for (i = 0; i < num; i++) { + + aa_buf = kmalloc(aa_g_path_max, GFP_KERNEL | + __GFP_RETRY_MAYFAIL | __GFP_NOWARN); + if (!aa_buf) { + destroy_buffers(); + return -ENOMEM; + } + aa_put_buffer(&aa_buf->buffer[0]); + } + return 0; +} + +#ifdef CONFIG_SYSCTL +static int apparmor_dointvec(struct ctl_table *table, int write, + void *buffer, size_t *lenp, loff_t *ppos) +{ + if (!aa_current_policy_admin_capable(NULL)) + return -EPERM; + if (!apparmor_enabled) + return -EINVAL; + + return proc_dointvec(table, write, buffer, lenp, ppos); +} + +static struct ctl_path apparmor_sysctl_path[] = { + { .procname = "kernel", }, + { } +}; + +static struct ctl_table apparmor_sysctl_table[] = { + { + .procname = "unprivileged_userns_apparmor_policy", + .data = &unprivileged_userns_apparmor_policy, + .maxlen = sizeof(int), + .mode = 0600, + .proc_handler = apparmor_dointvec, + }, + { + .procname = "apparmor_display_secid_mode", + .data = &apparmor_display_secid_mode, + .maxlen = sizeof(int), + .mode = 0600, + .proc_handler = apparmor_dointvec, + }, + + { } +}; + +static int __init apparmor_init_sysctl(void) +{ + return register_sysctl_paths(apparmor_sysctl_path, + apparmor_sysctl_table) ? 0 : -ENOMEM; +} +#else +static inline int apparmor_init_sysctl(void) +{ + return 0; +} +#endif /* CONFIG_SYSCTL */ + +#if defined(CONFIG_NETFILTER) && defined(CONFIG_NETWORK_SECMARK) +static unsigned int apparmor_ip_postroute(void *priv, + struct sk_buff *skb, + const struct nf_hook_state *state) +{ + struct aa_sk_ctx *ctx; + struct sock *sk; + + if (!skb->secmark) + return NF_ACCEPT; + + sk = skb_to_full_sk(skb); + if (sk == NULL) + return NF_ACCEPT; + + ctx = SK_CTX(sk); + if (!apparmor_secmark_check(ctx->label, OP_SENDMSG, AA_MAY_SEND, + skb->secmark, sk)) + return NF_ACCEPT; + + return NF_DROP_ERR(-ECONNREFUSED); + +} + +static const struct nf_hook_ops apparmor_nf_ops[] = { + { + .hook = apparmor_ip_postroute, + .pf = NFPROTO_IPV4, + .hooknum = NF_INET_POST_ROUTING, + .priority = NF_IP_PRI_SELINUX_FIRST, + }, +#if IS_ENABLED(CONFIG_IPV6) + { + .hook = apparmor_ip_postroute, + .pf = NFPROTO_IPV6, + .hooknum = NF_INET_POST_ROUTING, + .priority = NF_IP6_PRI_SELINUX_FIRST, + }, +#endif +}; + +static int __net_init apparmor_nf_register(struct net *net) +{ + return nf_register_net_hooks(net, apparmor_nf_ops, + ARRAY_SIZE(apparmor_nf_ops)); +} + +static void __net_exit apparmor_nf_unregister(struct net *net) +{ + nf_unregister_net_hooks(net, apparmor_nf_ops, + ARRAY_SIZE(apparmor_nf_ops)); +} + +static struct pernet_operations apparmor_net_ops = { + .init = apparmor_nf_register, + .exit = apparmor_nf_unregister, +}; + +static int __init apparmor_nf_ip_init(void) +{ + int err; + + if (!apparmor_enabled) + return 0; + + err = register_pernet_subsys(&apparmor_net_ops); + if (err) + panic("Apparmor: register_pernet_subsys: error %d\n", err); + + return 0; +} +__initcall(apparmor_nf_ip_init); +#endif + +static int __init apparmor_init(void) +{ + int error; + + error = aa_setup_dfa_engine(); + if (error) { + AA_ERROR("Unable to setup dfa engine\n"); + goto alloc_out; + } + + error = aa_alloc_root_ns(); + if (error) { + AA_ERROR("Unable to allocate default profile namespace\n"); + goto alloc_out; + } + + error = apparmor_init_sysctl(); + if (error) { + AA_ERROR("Unable to register sysctls\n"); + goto alloc_out; + + } + + error = alloc_buffers(); + if (error) { + AA_ERROR("Unable to allocate work buffers\n"); + goto alloc_out; + } + + error = set_init_ctx(); + if (error) { + AA_ERROR("Failed to set context on init task\n"); + aa_free_root_ns(); + goto buffers_out; + } + security_add_hooks(apparmor_hooks, ARRAY_SIZE(apparmor_hooks), + "apparmor"); + + /* Report that AppArmor successfully initialized */ + apparmor_initialized = 1; + if (aa_g_profile_mode == APPARMOR_COMPLAIN) + aa_info_message("AppArmor initialized: complain mode enabled"); + else if (aa_g_profile_mode == APPARMOR_KILL) + aa_info_message("AppArmor initialized: kill mode enabled"); + else + aa_info_message("AppArmor initialized"); + + return error; + +buffers_out: + destroy_buffers(); +alloc_out: + aa_destroy_aafs(); + aa_teardown_dfa_engine(); + + apparmor_enabled = false; + return error; +} + +DEFINE_LSM(apparmor) = { + .name = "apparmor", + .flags = LSM_FLAG_LEGACY_MAJOR | LSM_FLAG_EXCLUSIVE, + .enabled = &apparmor_enabled, + .blobs = &apparmor_blob_sizes, + .init = apparmor_init, +}; diff --git a/security/apparmor/match.c b/security/apparmor/match.c new file mode 100644 index 000000000..3e9e1eaf9 --- /dev/null +++ b/security/apparmor/match.c @@ -0,0 +1,792 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * AppArmor security module + * + * This file contains AppArmor dfa based regular expression matching engine + * + * Copyright (C) 1998-2008 Novell/SUSE + * Copyright 2009-2012 Canonical Ltd. + */ + +#include <linux/errno.h> +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/slab.h> +#include <linux/vmalloc.h> +#include <linux/err.h> +#include <linux/kref.h> + +#include "include/lib.h" +#include "include/match.h" + +#define base_idx(X) ((X) & 0xffffff) + +static char nulldfa_src[] = { + #include "nulldfa.in" +}; +struct aa_dfa *nulldfa; + +static char stacksplitdfa_src[] = { + #include "stacksplitdfa.in" +}; +struct aa_dfa *stacksplitdfa; + +int aa_setup_dfa_engine(void) +{ + int error; + + nulldfa = aa_dfa_unpack(nulldfa_src, sizeof(nulldfa_src), + TO_ACCEPT1_FLAG(YYTD_DATA32) | + TO_ACCEPT2_FLAG(YYTD_DATA32)); + if (IS_ERR(nulldfa)) { + error = PTR_ERR(nulldfa); + nulldfa = NULL; + return error; + } + + stacksplitdfa = aa_dfa_unpack(stacksplitdfa_src, + sizeof(stacksplitdfa_src), + TO_ACCEPT1_FLAG(YYTD_DATA32) | + TO_ACCEPT2_FLAG(YYTD_DATA32)); + if (IS_ERR(stacksplitdfa)) { + aa_put_dfa(nulldfa); + nulldfa = NULL; + error = PTR_ERR(stacksplitdfa); + stacksplitdfa = NULL; + return error; + } + + return 0; +} + +void aa_teardown_dfa_engine(void) +{ + aa_put_dfa(stacksplitdfa); + aa_put_dfa(nulldfa); +} + +/** + * unpack_table - unpack a dfa table (one of accept, default, base, next check) + * @blob: data to unpack (NOT NULL) + * @bsize: size of blob + * + * Returns: pointer to table else NULL on failure + * + * NOTE: must be freed by kvfree (not kfree) + */ +static struct table_header *unpack_table(char *blob, size_t bsize) +{ + struct table_header *table = NULL; + struct table_header th; + size_t tsize; + + if (bsize < sizeof(struct table_header)) + goto out; + + /* loaded td_id's start at 1, subtract 1 now to avoid doing + * it every time we use td_id as an index + */ + th.td_id = be16_to_cpu(*(__be16 *) (blob)) - 1; + if (th.td_id > YYTD_ID_MAX) + goto out; + th.td_flags = be16_to_cpu(*(__be16 *) (blob + 2)); + th.td_lolen = be32_to_cpu(*(__be32 *) (blob + 8)); + blob += sizeof(struct table_header); + + if (!(th.td_flags == YYTD_DATA16 || th.td_flags == YYTD_DATA32 || + th.td_flags == YYTD_DATA8)) + goto out; + + /* if we have a table it must have some entries */ + if (th.td_lolen == 0) + goto out; + tsize = table_size(th.td_lolen, th.td_flags); + if (bsize < tsize) + goto out; + + table = kvzalloc(tsize, GFP_KERNEL); + if (table) { + table->td_id = th.td_id; + table->td_flags = th.td_flags; + table->td_lolen = th.td_lolen; + if (th.td_flags == YYTD_DATA8) + UNPACK_ARRAY(table->td_data, blob, th.td_lolen, + u8, u8, byte_to_byte); + else if (th.td_flags == YYTD_DATA16) + UNPACK_ARRAY(table->td_data, blob, th.td_lolen, + u16, __be16, be16_to_cpu); + else if (th.td_flags == YYTD_DATA32) + UNPACK_ARRAY(table->td_data, blob, th.td_lolen, + u32, __be32, be32_to_cpu); + else + goto fail; + /* if table was vmalloced make sure the page tables are synced + * before it is used, as it goes live to all cpus. + */ + if (is_vmalloc_addr(table)) + vm_unmap_aliases(); + } + +out: + return table; +fail: + kvfree(table); + return NULL; +} + +/** + * verify_table_headers - verify that the tables headers are as expected + * @tables - array of dfa tables to check (NOT NULL) + * @flags: flags controlling what type of accept table are acceptable + * + * Assumes dfa has gone through the first pass verification done by unpacking + * NOTE: this does not valid accept table values + * + * Returns: %0 else error code on failure to verify + */ +static int verify_table_headers(struct table_header **tables, int flags) +{ + size_t state_count, trans_count; + int error = -EPROTO; + + /* check that required tables exist */ + if (!(tables[YYTD_ID_DEF] && tables[YYTD_ID_BASE] && + tables[YYTD_ID_NXT] && tables[YYTD_ID_CHK])) + goto out; + + /* accept.size == default.size == base.size */ + state_count = tables[YYTD_ID_BASE]->td_lolen; + if (ACCEPT1_FLAGS(flags)) { + if (!tables[YYTD_ID_ACCEPT]) + goto out; + if (state_count != tables[YYTD_ID_ACCEPT]->td_lolen) + goto out; + } + if (ACCEPT2_FLAGS(flags)) { + if (!tables[YYTD_ID_ACCEPT2]) + goto out; + if (state_count != tables[YYTD_ID_ACCEPT2]->td_lolen) + goto out; + } + if (state_count != tables[YYTD_ID_DEF]->td_lolen) + goto out; + + /* next.size == chk.size */ + trans_count = tables[YYTD_ID_NXT]->td_lolen; + if (trans_count != tables[YYTD_ID_CHK]->td_lolen) + goto out; + + /* if equivalence classes then its table size must be 256 */ + if (tables[YYTD_ID_EC] && tables[YYTD_ID_EC]->td_lolen != 256) + goto out; + + error = 0; +out: + return error; +} + +/** + * verify_dfa - verify that transitions and states in the tables are in bounds. + * @dfa: dfa to test (NOT NULL) + * + * Assumes dfa has gone through the first pass verification done by unpacking + * NOTE: this does not valid accept table values + * + * Returns: %0 else error code on failure to verify + */ +static int verify_dfa(struct aa_dfa *dfa) +{ + size_t i, state_count, trans_count; + int error = -EPROTO; + + state_count = dfa->tables[YYTD_ID_BASE]->td_lolen; + trans_count = dfa->tables[YYTD_ID_NXT]->td_lolen; + if (state_count == 0) + goto out; + for (i = 0; i < state_count; i++) { + if (!(BASE_TABLE(dfa)[i] & MATCH_FLAG_DIFF_ENCODE) && + (DEFAULT_TABLE(dfa)[i] >= state_count)) + goto out; + if (BASE_TABLE(dfa)[i] & MATCH_FLAGS_INVALID) { + pr_err("AppArmor DFA state with invalid match flags"); + goto out; + } + if ((BASE_TABLE(dfa)[i] & MATCH_FLAG_DIFF_ENCODE)) { + if (!(dfa->flags & YYTH_FLAG_DIFF_ENCODE)) { + pr_err("AppArmor DFA diff encoded transition state without header flag"); + goto out; + } + } + if ((BASE_TABLE(dfa)[i] & MATCH_FLAG_OOB_TRANSITION)) { + if (base_idx(BASE_TABLE(dfa)[i]) < dfa->max_oob) { + pr_err("AppArmor DFA out of bad transition out of range"); + goto out; + } + if (!(dfa->flags & YYTH_FLAG_OOB_TRANS)) { + pr_err("AppArmor DFA out of bad transition state without header flag"); + goto out; + } + } + if (base_idx(BASE_TABLE(dfa)[i]) + 255 >= trans_count) { + pr_err("AppArmor DFA next/check upper bounds error\n"); + goto out; + } + } + + for (i = 0; i < trans_count; i++) { + if (NEXT_TABLE(dfa)[i] >= state_count) + goto out; + if (CHECK_TABLE(dfa)[i] >= state_count) + goto out; + } + + /* Now that all the other tables are verified, verify diffencoding */ + for (i = 0; i < state_count; i++) { + size_t j, k; + + for (j = i; + (BASE_TABLE(dfa)[j] & MATCH_FLAG_DIFF_ENCODE) && + !(BASE_TABLE(dfa)[j] & MARK_DIFF_ENCODE); + j = k) { + k = DEFAULT_TABLE(dfa)[j]; + if (j == k) + goto out; + if (k < j) + break; /* already verified */ + BASE_TABLE(dfa)[j] |= MARK_DIFF_ENCODE; + } + } + error = 0; + +out: + return error; +} + +/** + * dfa_free - free a dfa allocated by aa_dfa_unpack + * @dfa: the dfa to free (MAYBE NULL) + * + * Requires: reference count to dfa == 0 + */ +static void dfa_free(struct aa_dfa *dfa) +{ + if (dfa) { + int i; + + for (i = 0; i < ARRAY_SIZE(dfa->tables); i++) { + kvfree(dfa->tables[i]); + dfa->tables[i] = NULL; + } + kfree(dfa); + } +} + +/** + * aa_dfa_free_kref - free aa_dfa by kref (called by aa_put_dfa) + * @kr: kref callback for freeing of a dfa (NOT NULL) + */ +void aa_dfa_free_kref(struct kref *kref) +{ + struct aa_dfa *dfa = container_of(kref, struct aa_dfa, count); + dfa_free(dfa); +} + +/** + * aa_dfa_unpack - unpack the binary tables of a serialized dfa + * @blob: aligned serialized stream of data to unpack (NOT NULL) + * @size: size of data to unpack + * @flags: flags controlling what type of accept tables are acceptable + * + * Unpack a dfa that has been serialized. To find information on the dfa + * format look in Documentation/admin-guide/LSM/apparmor.rst + * Assumes the dfa @blob stream has been aligned on a 8 byte boundary + * + * Returns: an unpacked dfa ready for matching or ERR_PTR on failure + */ +struct aa_dfa *aa_dfa_unpack(void *blob, size_t size, int flags) +{ + int hsize; + int error = -ENOMEM; + char *data = blob; + struct table_header *table = NULL; + struct aa_dfa *dfa = kzalloc(sizeof(struct aa_dfa), GFP_KERNEL); + if (!dfa) + goto fail; + + kref_init(&dfa->count); + + error = -EPROTO; + + /* get dfa table set header */ + if (size < sizeof(struct table_set_header)) + goto fail; + + if (ntohl(*(__be32 *) data) != YYTH_MAGIC) + goto fail; + + hsize = ntohl(*(__be32 *) (data + 4)); + if (size < hsize) + goto fail; + + dfa->flags = ntohs(*(__be16 *) (data + 12)); + if (dfa->flags & ~(YYTH_FLAGS)) + goto fail; + + /* + * TODO: needed for dfa to support more than 1 oob + * if (dfa->flags & YYTH_FLAGS_OOB_TRANS) { + * if (hsize < 16 + 4) + * goto fail; + * dfa->max_oob = ntol(*(__be32 *) (data + 16)); + * if (dfa->max <= MAX_OOB_SUPPORTED) { + * pr_err("AppArmor DFA OOB greater than supported\n"); + * goto fail; + * } + * } + */ + dfa->max_oob = 1; + + data += hsize; + size -= hsize; + + while (size > 0) { + table = unpack_table(data, size); + if (!table) + goto fail; + + switch (table->td_id) { + case YYTD_ID_ACCEPT: + if (!(table->td_flags & ACCEPT1_FLAGS(flags))) + goto fail; + break; + case YYTD_ID_ACCEPT2: + if (!(table->td_flags & ACCEPT2_FLAGS(flags))) + goto fail; + break; + case YYTD_ID_BASE: + if (table->td_flags != YYTD_DATA32) + goto fail; + break; + case YYTD_ID_DEF: + case YYTD_ID_NXT: + case YYTD_ID_CHK: + if (table->td_flags != YYTD_DATA16) + goto fail; + break; + case YYTD_ID_EC: + if (table->td_flags != YYTD_DATA8) + goto fail; + break; + default: + goto fail; + } + /* check for duplicate table entry */ + if (dfa->tables[table->td_id]) + goto fail; + dfa->tables[table->td_id] = table; + data += table_size(table->td_lolen, table->td_flags); + size -= table_size(table->td_lolen, table->td_flags); + table = NULL; + } + error = verify_table_headers(dfa->tables, flags); + if (error) + goto fail; + + if (flags & DFA_FLAG_VERIFY_STATES) { + error = verify_dfa(dfa); + if (error) + goto fail; + } + + return dfa; + +fail: + kvfree(table); + dfa_free(dfa); + return ERR_PTR(error); +} + +#define match_char(state, def, base, next, check, C) \ +do { \ + u32 b = (base)[(state)]; \ + unsigned int pos = base_idx(b) + (C); \ + if ((check)[pos] != (state)) { \ + (state) = (def)[(state)]; \ + if (b & MATCH_FLAG_DIFF_ENCODE) \ + continue; \ + break; \ + } \ + (state) = (next)[pos]; \ + break; \ +} while (1) + +/** + * aa_dfa_match_len - traverse @dfa to find state @str stops at + * @dfa: the dfa to match @str against (NOT NULL) + * @start: the state of the dfa to start matching in + * @str: the string of bytes to match against the dfa (NOT NULL) + * @len: length of the string of bytes to match + * + * aa_dfa_match_len will match @str against the dfa and return the state it + * finished matching in. The final state can be used to look up the accepting + * label, or as the start state of a continuing match. + * + * This function will happily match again the 0 byte and only finishes + * when @len input is consumed. + * + * Returns: final state reached after input is consumed + */ +unsigned int aa_dfa_match_len(struct aa_dfa *dfa, unsigned int start, + const char *str, int len) +{ + u16 *def = DEFAULT_TABLE(dfa); + u32 *base = BASE_TABLE(dfa); + u16 *next = NEXT_TABLE(dfa); + u16 *check = CHECK_TABLE(dfa); + unsigned int state = start; + + if (state == 0) + return 0; + + /* current state is <state>, matching character *str */ + if (dfa->tables[YYTD_ID_EC]) { + /* Equivalence class table defined */ + u8 *equiv = EQUIV_TABLE(dfa); + for (; len; len--) + match_char(state, def, base, next, check, + equiv[(u8) *str++]); + } else { + /* default is direct to next state */ + for (; len; len--) + match_char(state, def, base, next, check, (u8) *str++); + } + + return state; +} + +/** + * aa_dfa_match - traverse @dfa to find state @str stops at + * @dfa: the dfa to match @str against (NOT NULL) + * @start: the state of the dfa to start matching in + * @str: the null terminated string of bytes to match against the dfa (NOT NULL) + * + * aa_dfa_match will match @str against the dfa and return the state it + * finished matching in. The final state can be used to look up the accepting + * label, or as the start state of a continuing match. + * + * Returns: final state reached after input is consumed + */ +unsigned int aa_dfa_match(struct aa_dfa *dfa, unsigned int start, + const char *str) +{ + u16 *def = DEFAULT_TABLE(dfa); + u32 *base = BASE_TABLE(dfa); + u16 *next = NEXT_TABLE(dfa); + u16 *check = CHECK_TABLE(dfa); + unsigned int state = start; + + if (state == 0) + return 0; + + /* current state is <state>, matching character *str */ + if (dfa->tables[YYTD_ID_EC]) { + /* Equivalence class table defined */ + u8 *equiv = EQUIV_TABLE(dfa); + /* default is direct to next state */ + while (*str) + match_char(state, def, base, next, check, + equiv[(u8) *str++]); + } else { + /* default is direct to next state */ + while (*str) + match_char(state, def, base, next, check, (u8) *str++); + } + + return state; +} + +/** + * aa_dfa_next - step one character to the next state in the dfa + * @dfa: the dfa to traverse (NOT NULL) + * @state: the state to start in + * @c: the input character to transition on + * + * aa_dfa_match will step through the dfa by one input character @c + * + * Returns: state reach after input @c + */ +unsigned int aa_dfa_next(struct aa_dfa *dfa, unsigned int state, + const char c) +{ + u16 *def = DEFAULT_TABLE(dfa); + u32 *base = BASE_TABLE(dfa); + u16 *next = NEXT_TABLE(dfa); + u16 *check = CHECK_TABLE(dfa); + + /* current state is <state>, matching character *str */ + if (dfa->tables[YYTD_ID_EC]) { + /* Equivalence class table defined */ + u8 *equiv = EQUIV_TABLE(dfa); + match_char(state, def, base, next, check, equiv[(u8) c]); + } else + match_char(state, def, base, next, check, (u8) c); + + return state; +} + +unsigned int aa_dfa_outofband_transition(struct aa_dfa *dfa, unsigned int state) +{ + u16 *def = DEFAULT_TABLE(dfa); + u32 *base = BASE_TABLE(dfa); + u16 *next = NEXT_TABLE(dfa); + u16 *check = CHECK_TABLE(dfa); + u32 b = (base)[(state)]; + + if (!(b & MATCH_FLAG_OOB_TRANSITION)) + return DFA_NOMATCH; + + /* No Equivalence class remapping for outofband transitions */ + match_char(state, def, base, next, check, -1); + + return state; +} + +/** + * aa_dfa_match_until - traverse @dfa until accept state or end of input + * @dfa: the dfa to match @str against (NOT NULL) + * @start: the state of the dfa to start matching in + * @str: the null terminated string of bytes to match against the dfa (NOT NULL) + * @retpos: first character in str after match OR end of string + * + * aa_dfa_match will match @str against the dfa and return the state it + * finished matching in. The final state can be used to look up the accepting + * label, or as the start state of a continuing match. + * + * Returns: final state reached after input is consumed + */ +unsigned int aa_dfa_match_until(struct aa_dfa *dfa, unsigned int start, + const char *str, const char **retpos) +{ + u16 *def = DEFAULT_TABLE(dfa); + u32 *base = BASE_TABLE(dfa); + u16 *next = NEXT_TABLE(dfa); + u16 *check = CHECK_TABLE(dfa); + u32 *accept = ACCEPT_TABLE(dfa); + unsigned int state = start, pos; + + if (state == 0) + return 0; + + /* current state is <state>, matching character *str */ + if (dfa->tables[YYTD_ID_EC]) { + /* Equivalence class table defined */ + u8 *equiv = EQUIV_TABLE(dfa); + /* default is direct to next state */ + while (*str) { + pos = base_idx(base[state]) + equiv[(u8) *str++]; + if (check[pos] == state) + state = next[pos]; + else + state = def[state]; + if (accept[state]) + break; + } + } else { + /* default is direct to next state */ + while (*str) { + pos = base_idx(base[state]) + (u8) *str++; + if (check[pos] == state) + state = next[pos]; + else + state = def[state]; + if (accept[state]) + break; + } + } + + *retpos = str; + return state; +} + +/** + * aa_dfa_matchn_until - traverse @dfa until accept or @n bytes consumed + * @dfa: the dfa to match @str against (NOT NULL) + * @start: the state of the dfa to start matching in + * @str: the string of bytes to match against the dfa (NOT NULL) + * @n: length of the string of bytes to match + * @retpos: first character in str after match OR str + n + * + * aa_dfa_match_len will match @str against the dfa and return the state it + * finished matching in. The final state can be used to look up the accepting + * label, or as the start state of a continuing match. + * + * This function will happily match again the 0 byte and only finishes + * when @n input is consumed. + * + * Returns: final state reached after input is consumed + */ +unsigned int aa_dfa_matchn_until(struct aa_dfa *dfa, unsigned int start, + const char *str, int n, const char **retpos) +{ + u16 *def = DEFAULT_TABLE(dfa); + u32 *base = BASE_TABLE(dfa); + u16 *next = NEXT_TABLE(dfa); + u16 *check = CHECK_TABLE(dfa); + u32 *accept = ACCEPT_TABLE(dfa); + unsigned int state = start, pos; + + *retpos = NULL; + if (state == 0) + return 0; + + /* current state is <state>, matching character *str */ + if (dfa->tables[YYTD_ID_EC]) { + /* Equivalence class table defined */ + u8 *equiv = EQUIV_TABLE(dfa); + /* default is direct to next state */ + for (; n; n--) { + pos = base_idx(base[state]) + equiv[(u8) *str++]; + if (check[pos] == state) + state = next[pos]; + else + state = def[state]; + if (accept[state]) + break; + } + } else { + /* default is direct to next state */ + for (; n; n--) { + pos = base_idx(base[state]) + (u8) *str++; + if (check[pos] == state) + state = next[pos]; + else + state = def[state]; + if (accept[state]) + break; + } + } + + *retpos = str; + return state; +} + +#define inc_wb_pos(wb) \ +do { \ + wb->pos = (wb->pos + 1) & (WB_HISTORY_SIZE - 1); \ + wb->len = (wb->len + 1) & (WB_HISTORY_SIZE - 1); \ +} while (0) + +/* For DFAs that don't support extended tagging of states */ +static bool is_loop(struct match_workbuf *wb, unsigned int state, + unsigned int *adjust) +{ + unsigned int pos = wb->pos; + unsigned int i; + + if (wb->history[pos] < state) + return false; + + for (i = 0; i <= wb->len; i++) { + if (wb->history[pos] == state) { + *adjust = i; + return true; + } + if (pos == 0) + pos = WB_HISTORY_SIZE; + pos--; + } + + *adjust = i; + return true; +} + +static unsigned int leftmatch_fb(struct aa_dfa *dfa, unsigned int start, + const char *str, struct match_workbuf *wb, + unsigned int *count) +{ + u16 *def = DEFAULT_TABLE(dfa); + u32 *base = BASE_TABLE(dfa); + u16 *next = NEXT_TABLE(dfa); + u16 *check = CHECK_TABLE(dfa); + unsigned int state = start, pos; + + AA_BUG(!dfa); + AA_BUG(!str); + AA_BUG(!wb); + AA_BUG(!count); + + *count = 0; + if (state == 0) + return 0; + + /* current state is <state>, matching character *str */ + if (dfa->tables[YYTD_ID_EC]) { + /* Equivalence class table defined */ + u8 *equiv = EQUIV_TABLE(dfa); + /* default is direct to next state */ + while (*str) { + unsigned int adjust; + + wb->history[wb->pos] = state; + pos = base_idx(base[state]) + equiv[(u8) *str++]; + if (check[pos] == state) + state = next[pos]; + else + state = def[state]; + if (is_loop(wb, state, &adjust)) { + state = aa_dfa_match(dfa, state, str); + *count -= adjust; + goto out; + } + inc_wb_pos(wb); + (*count)++; + } + } else { + /* default is direct to next state */ + while (*str) { + unsigned int adjust; + + wb->history[wb->pos] = state; + pos = base_idx(base[state]) + (u8) *str++; + if (check[pos] == state) + state = next[pos]; + else + state = def[state]; + if (is_loop(wb, state, &adjust)) { + state = aa_dfa_match(dfa, state, str); + *count -= adjust; + goto out; + } + inc_wb_pos(wb); + (*count)++; + } + } + +out: + if (!state) + *count = 0; + return state; +} + +/** + * aa_dfa_leftmatch - traverse @dfa to find state @str stops at + * @dfa: the dfa to match @str against (NOT NULL) + * @start: the state of the dfa to start matching in + * @str: the null terminated string of bytes to match against the dfa (NOT NULL) + * @count: current count of longest left. + * + * aa_dfa_match will match @str against the dfa and return the state it + * finished matching in. The final state can be used to look up the accepting + * label, or as the start state of a continuing match. + * + * Returns: final state reached after input is consumed + */ +unsigned int aa_dfa_leftmatch(struct aa_dfa *dfa, unsigned int start, + const char *str, unsigned int *count) +{ + DEFINE_MATCH_WB(wb); + + /* TODO: match for extended state dfas */ + + return leftmatch_fb(dfa, start, str, &wb, count); +} diff --git a/security/apparmor/mount.c b/security/apparmor/mount.c new file mode 100644 index 000000000..f61247241 --- /dev/null +++ b/security/apparmor/mount.c @@ -0,0 +1,740 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * AppArmor security module + * + * This file contains AppArmor mediation of files + * + * Copyright (C) 1998-2008 Novell/SUSE + * Copyright 2009-2017 Canonical Ltd. + */ + +#include <linux/fs.h> +#include <linux/mount.h> +#include <linux/namei.h> +#include <uapi/linux/mount.h> + +#include "include/apparmor.h" +#include "include/audit.h" +#include "include/cred.h" +#include "include/domain.h" +#include "include/file.h" +#include "include/match.h" +#include "include/mount.h" +#include "include/path.h" +#include "include/policy.h" + + +static void audit_mnt_flags(struct audit_buffer *ab, unsigned long flags) +{ + if (flags & MS_RDONLY) + audit_log_format(ab, "ro"); + else + audit_log_format(ab, "rw"); + if (flags & MS_NOSUID) + audit_log_format(ab, ", nosuid"); + if (flags & MS_NODEV) + audit_log_format(ab, ", nodev"); + if (flags & MS_NOEXEC) + audit_log_format(ab, ", noexec"); + if (flags & MS_SYNCHRONOUS) + audit_log_format(ab, ", sync"); + if (flags & MS_REMOUNT) + audit_log_format(ab, ", remount"); + if (flags & MS_MANDLOCK) + audit_log_format(ab, ", mand"); + if (flags & MS_DIRSYNC) + audit_log_format(ab, ", dirsync"); + if (flags & MS_NOATIME) + audit_log_format(ab, ", noatime"); + if (flags & MS_NODIRATIME) + audit_log_format(ab, ", nodiratime"); + if (flags & MS_BIND) + audit_log_format(ab, flags & MS_REC ? ", rbind" : ", bind"); + if (flags & MS_MOVE) + audit_log_format(ab, ", move"); + if (flags & MS_SILENT) + audit_log_format(ab, ", silent"); + if (flags & MS_POSIXACL) + audit_log_format(ab, ", acl"); + if (flags & MS_UNBINDABLE) + audit_log_format(ab, flags & MS_REC ? ", runbindable" : + ", unbindable"); + if (flags & MS_PRIVATE) + audit_log_format(ab, flags & MS_REC ? ", rprivate" : + ", private"); + if (flags & MS_SLAVE) + audit_log_format(ab, flags & MS_REC ? ", rslave" : + ", slave"); + if (flags & MS_SHARED) + audit_log_format(ab, flags & MS_REC ? ", rshared" : + ", shared"); + if (flags & MS_RELATIME) + audit_log_format(ab, ", relatime"); + if (flags & MS_I_VERSION) + audit_log_format(ab, ", iversion"); + if (flags & MS_STRICTATIME) + audit_log_format(ab, ", strictatime"); + if (flags & MS_NOUSER) + audit_log_format(ab, ", nouser"); +} + +/** + * audit_cb - call back for mount specific audit fields + * @ab: audit_buffer (NOT NULL) + * @va: audit struct to audit values of (NOT NULL) + */ +static void audit_cb(struct audit_buffer *ab, void *va) +{ + struct common_audit_data *sa = va; + + if (aad(sa)->mnt.type) { + audit_log_format(ab, " fstype="); + audit_log_untrustedstring(ab, aad(sa)->mnt.type); + } + if (aad(sa)->mnt.src_name) { + audit_log_format(ab, " srcname="); + audit_log_untrustedstring(ab, aad(sa)->mnt.src_name); + } + if (aad(sa)->mnt.trans) { + audit_log_format(ab, " trans="); + audit_log_untrustedstring(ab, aad(sa)->mnt.trans); + } + if (aad(sa)->mnt.flags) { + audit_log_format(ab, " flags=\""); + audit_mnt_flags(ab, aad(sa)->mnt.flags); + audit_log_format(ab, "\""); + } + if (aad(sa)->mnt.data) { + audit_log_format(ab, " options="); + audit_log_untrustedstring(ab, aad(sa)->mnt.data); + } +} + +/** + * audit_mount - handle the auditing of mount operations + * @profile: the profile being enforced (NOT NULL) + * @op: operation being mediated (NOT NULL) + * @name: name of object being mediated (MAYBE NULL) + * @src_name: src_name of object being mediated (MAYBE_NULL) + * @type: type of filesystem (MAYBE_NULL) + * @trans: name of trans (MAYBE NULL) + * @flags: filesystem independent mount flags + * @data: filesystem mount flags + * @request: permissions requested + * @perms: the permissions computed for the request (NOT NULL) + * @info: extra information message (MAYBE NULL) + * @error: 0 if operation allowed else failure error code + * + * Returns: %0 or error on failure + */ +static int audit_mount(struct aa_profile *profile, const char *op, + const char *name, const char *src_name, + const char *type, const char *trans, + unsigned long flags, const void *data, u32 request, + struct aa_perms *perms, const char *info, int error) +{ + int audit_type = AUDIT_APPARMOR_AUTO; + DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, op); + + if (likely(!error)) { + u32 mask = perms->audit; + + if (unlikely(AUDIT_MODE(profile) == AUDIT_ALL)) + mask = 0xffff; + + /* mask off perms that are not being force audited */ + request &= mask; + + if (likely(!request)) + return 0; + audit_type = AUDIT_APPARMOR_AUDIT; + } else { + /* only report permissions that were denied */ + request = request & ~perms->allow; + + if (request & perms->kill) + audit_type = AUDIT_APPARMOR_KILL; + + /* quiet known rejects, assumes quiet and kill do not overlap */ + if ((request & perms->quiet) && + AUDIT_MODE(profile) != AUDIT_NOQUIET && + AUDIT_MODE(profile) != AUDIT_ALL) + request &= ~perms->quiet; + + if (!request) + return error; + } + + aad(&sa)->name = name; + aad(&sa)->mnt.src_name = src_name; + aad(&sa)->mnt.type = type; + aad(&sa)->mnt.trans = trans; + aad(&sa)->mnt.flags = flags; + if (data && (perms->audit & AA_AUDIT_DATA)) + aad(&sa)->mnt.data = data; + aad(&sa)->info = info; + aad(&sa)->error = error; + + return aa_audit(audit_type, profile, &sa, audit_cb); +} + +/** + * match_mnt_flags - Do an ordered match on mount flags + * @dfa: dfa to match against + * @state: state to start in + * @flags: mount flags to match against + * + * Mount flags are encoded as an ordered match. This is done instead of + * checking against a simple bitmask, to allow for logical operations + * on the flags. + * + * Returns: next state after flags match + */ +static unsigned int match_mnt_flags(struct aa_dfa *dfa, unsigned int state, + unsigned long flags) +{ + unsigned int i; + + for (i = 0; i <= 31 ; ++i) { + if ((1 << i) & flags) + state = aa_dfa_next(dfa, state, i + 1); + } + + return state; +} + +/** + * compute_mnt_perms - compute mount permission associated with @state + * @dfa: dfa to match against (NOT NULL) + * @state: state match finished in + * + * Returns: mount permissions + */ +static struct aa_perms compute_mnt_perms(struct aa_dfa *dfa, + unsigned int state) +{ + struct aa_perms perms = { + .allow = dfa_user_allow(dfa, state), + .audit = dfa_user_audit(dfa, state), + .quiet = dfa_user_quiet(dfa, state), + }; + + return perms; +} + +static const char * const mnt_info_table[] = { + "match succeeded", + "failed mntpnt match", + "failed srcname match", + "failed type match", + "failed flags match", + "failed data match", + "failed perms check" +}; + +/* + * Returns 0 on success else element that match failed in, this is the + * index into the mnt_info_table above + */ +static int do_match_mnt(struct aa_dfa *dfa, unsigned int start, + const char *mntpnt, const char *devname, + const char *type, unsigned long flags, + void *data, bool binary, struct aa_perms *perms) +{ + unsigned int state; + + AA_BUG(!dfa); + AA_BUG(!perms); + + state = aa_dfa_match(dfa, start, mntpnt); + state = aa_dfa_null_transition(dfa, state); + if (!state) + return 1; + + if (devname) + state = aa_dfa_match(dfa, state, devname); + state = aa_dfa_null_transition(dfa, state); + if (!state) + return 2; + + if (type) + state = aa_dfa_match(dfa, state, type); + state = aa_dfa_null_transition(dfa, state); + if (!state) + return 3; + + state = match_mnt_flags(dfa, state, flags); + if (!state) + return 4; + *perms = compute_mnt_perms(dfa, state); + if (perms->allow & AA_MAY_MOUNT) + return 0; + + /* only match data if not binary and the DFA flags data is expected */ + if (data && !binary && (perms->allow & AA_MNT_CONT_MATCH)) { + state = aa_dfa_null_transition(dfa, state); + if (!state) + return 4; + + state = aa_dfa_match(dfa, state, data); + if (!state) + return 5; + *perms = compute_mnt_perms(dfa, state); + if (perms->allow & AA_MAY_MOUNT) + return 0; + } + + /* failed at perms check, don't confuse with flags match */ + return 6; +} + + +static int path_flags(struct aa_profile *profile, const struct path *path) +{ + AA_BUG(!profile); + AA_BUG(!path); + + return profile->path_flags | + (S_ISDIR(path->dentry->d_inode->i_mode) ? PATH_IS_DIR : 0); +} + +/** + * match_mnt_path_str - handle path matching for mount + * @profile: the confining profile + * @mntpath: for the mntpnt (NOT NULL) + * @buffer: buffer to be used to lookup mntpath + * @devname: string for the devname/src_name (MAY BE NULL OR ERRPTR) + * @type: string for the dev type (MAYBE NULL) + * @flags: mount flags to match + * @data: fs mount data (MAYBE NULL) + * @binary: whether @data is binary + * @devinfo: error str if (IS_ERR(@devname)) + * + * Returns: 0 on success else error + */ +static int match_mnt_path_str(struct aa_profile *profile, + const struct path *mntpath, char *buffer, + const char *devname, const char *type, + unsigned long flags, void *data, bool binary, + const char *devinfo) +{ + struct aa_perms perms = { }; + const char *mntpnt = NULL, *info = NULL; + int pos, error; + + AA_BUG(!profile); + AA_BUG(!mntpath); + AA_BUG(!buffer); + + if (!PROFILE_MEDIATES(profile, AA_CLASS_MOUNT)) + return 0; + + error = aa_path_name(mntpath, path_flags(profile, mntpath), buffer, + &mntpnt, &info, profile->disconnected); + if (error) + goto audit; + if (IS_ERR(devname)) { + error = PTR_ERR(devname); + devname = NULL; + info = devinfo; + goto audit; + } + + error = -EACCES; + pos = do_match_mnt(profile->policy.dfa, + profile->policy.start[AA_CLASS_MOUNT], + mntpnt, devname, type, flags, data, binary, &perms); + if (pos) { + info = mnt_info_table[pos]; + goto audit; + } + error = 0; + +audit: + return audit_mount(profile, OP_MOUNT, mntpnt, devname, type, NULL, + flags, data, AA_MAY_MOUNT, &perms, info, error); +} + +/** + * match_mnt - handle path matching for mount + * @profile: the confining profile + * @path: for the mntpnt (NOT NULL) + * @buffer: buffer to be used to lookup mntpath + * @devpath: path devname/src_name (MAYBE NULL) + * @devbuffer: buffer to be used to lookup devname/src_name + * @type: string for the dev type (MAYBE NULL) + * @flags: mount flags to match + * @data: fs mount data (MAYBE NULL) + * @binary: whether @data is binary + * + * Returns: 0 on success else error + */ +static int match_mnt(struct aa_profile *profile, const struct path *path, + char *buffer, const struct path *devpath, char *devbuffer, + const char *type, unsigned long flags, void *data, + bool binary) +{ + const char *devname = NULL, *info = NULL; + int error = -EACCES; + + AA_BUG(!profile); + AA_BUG(devpath && !devbuffer); + + if (!PROFILE_MEDIATES(profile, AA_CLASS_MOUNT)) + return 0; + + if (devpath) { + error = aa_path_name(devpath, path_flags(profile, devpath), + devbuffer, &devname, &info, + profile->disconnected); + if (error) + devname = ERR_PTR(error); + } + + return match_mnt_path_str(profile, path, buffer, devname, type, flags, + data, binary, info); +} + +int aa_remount(struct aa_label *label, const struct path *path, + unsigned long flags, void *data) +{ + struct aa_profile *profile; + char *buffer = NULL; + bool binary; + int error; + + AA_BUG(!label); + AA_BUG(!path); + + binary = path->dentry->d_sb->s_type->fs_flags & FS_BINARY_MOUNTDATA; + + buffer = aa_get_buffer(false); + if (!buffer) + return -ENOMEM; + error = fn_for_each_confined(label, profile, + match_mnt(profile, path, buffer, NULL, NULL, NULL, + flags, data, binary)); + aa_put_buffer(buffer); + + return error; +} + +int aa_bind_mount(struct aa_label *label, const struct path *path, + const char *dev_name, unsigned long flags) +{ + struct aa_profile *profile; + char *buffer = NULL, *old_buffer = NULL; + struct path old_path; + int error; + + AA_BUG(!label); + AA_BUG(!path); + + if (!dev_name || !*dev_name) + return -EINVAL; + + flags &= MS_REC | MS_BIND; + + error = kern_path(dev_name, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &old_path); + if (error) + return error; + + buffer = aa_get_buffer(false); + old_buffer = aa_get_buffer(false); + error = -ENOMEM; + if (!buffer || !old_buffer) + goto out; + + error = fn_for_each_confined(label, profile, + match_mnt(profile, path, buffer, &old_path, old_buffer, + NULL, flags, NULL, false)); +out: + aa_put_buffer(buffer); + aa_put_buffer(old_buffer); + path_put(&old_path); + + return error; +} + +int aa_mount_change_type(struct aa_label *label, const struct path *path, + unsigned long flags) +{ + struct aa_profile *profile; + char *buffer = NULL; + int error; + + AA_BUG(!label); + AA_BUG(!path); + + /* These are the flags allowed by do_change_type() */ + flags &= (MS_REC | MS_SILENT | MS_SHARED | MS_PRIVATE | MS_SLAVE | + MS_UNBINDABLE); + + buffer = aa_get_buffer(false); + if (!buffer) + return -ENOMEM; + error = fn_for_each_confined(label, profile, + match_mnt(profile, path, buffer, NULL, NULL, NULL, + flags, NULL, false)); + aa_put_buffer(buffer); + + return error; +} + +int aa_move_mount(struct aa_label *label, const struct path *path, + const char *orig_name) +{ + struct aa_profile *profile; + char *buffer = NULL, *old_buffer = NULL; + struct path old_path; + int error; + + AA_BUG(!label); + AA_BUG(!path); + + if (!orig_name || !*orig_name) + return -EINVAL; + + error = kern_path(orig_name, LOOKUP_FOLLOW, &old_path); + if (error) + return error; + + buffer = aa_get_buffer(false); + old_buffer = aa_get_buffer(false); + error = -ENOMEM; + if (!buffer || !old_buffer) + goto out; + error = fn_for_each_confined(label, profile, + match_mnt(profile, path, buffer, &old_path, old_buffer, + NULL, MS_MOVE, NULL, false)); +out: + aa_put_buffer(buffer); + aa_put_buffer(old_buffer); + path_put(&old_path); + + return error; +} + +int aa_new_mount(struct aa_label *label, const char *dev_name, + const struct path *path, const char *type, unsigned long flags, + void *data) +{ + struct aa_profile *profile; + char *buffer = NULL, *dev_buffer = NULL; + bool binary = true; + int error; + int requires_dev = 0; + struct path tmp_path, *dev_path = NULL; + + AA_BUG(!label); + AA_BUG(!path); + + if (type) { + struct file_system_type *fstype; + + fstype = get_fs_type(type); + if (!fstype) + return -ENODEV; + binary = fstype->fs_flags & FS_BINARY_MOUNTDATA; + requires_dev = fstype->fs_flags & FS_REQUIRES_DEV; + put_filesystem(fstype); + + if (requires_dev) { + if (!dev_name || !*dev_name) + return -ENOENT; + + error = kern_path(dev_name, LOOKUP_FOLLOW, &tmp_path); + if (error) + return error; + dev_path = &tmp_path; + } + } + + buffer = aa_get_buffer(false); + if (!buffer) { + error = -ENOMEM; + goto out; + } + if (dev_path) { + dev_buffer = aa_get_buffer(false); + if (!dev_buffer) { + error = -ENOMEM; + goto out; + } + error = fn_for_each_confined(label, profile, + match_mnt(profile, path, buffer, dev_path, dev_buffer, + type, flags, data, binary)); + } else { + error = fn_for_each_confined(label, profile, + match_mnt_path_str(profile, path, buffer, dev_name, + type, flags, data, binary, NULL)); + } + +out: + aa_put_buffer(buffer); + aa_put_buffer(dev_buffer); + if (dev_path) + path_put(dev_path); + + return error; +} + +static int profile_umount(struct aa_profile *profile, const struct path *path, + char *buffer) +{ + struct aa_perms perms = { }; + const char *name = NULL, *info = NULL; + unsigned int state; + int error; + + AA_BUG(!profile); + AA_BUG(!path); + + if (!PROFILE_MEDIATES(profile, AA_CLASS_MOUNT)) + return 0; + + error = aa_path_name(path, path_flags(profile, path), buffer, &name, + &info, profile->disconnected); + if (error) + goto audit; + + state = aa_dfa_match(profile->policy.dfa, + profile->policy.start[AA_CLASS_MOUNT], + name); + perms = compute_mnt_perms(profile->policy.dfa, state); + if (AA_MAY_UMOUNT & ~perms.allow) + error = -EACCES; + +audit: + return audit_mount(profile, OP_UMOUNT, name, NULL, NULL, NULL, 0, NULL, + AA_MAY_UMOUNT, &perms, info, error); +} + +int aa_umount(struct aa_label *label, struct vfsmount *mnt, int flags) +{ + struct aa_profile *profile; + char *buffer = NULL; + int error; + struct path path = { .mnt = mnt, .dentry = mnt->mnt_root }; + + AA_BUG(!label); + AA_BUG(!mnt); + + buffer = aa_get_buffer(false); + if (!buffer) + return -ENOMEM; + + error = fn_for_each_confined(label, profile, + profile_umount(profile, &path, buffer)); + aa_put_buffer(buffer); + + return error; +} + +/* helper fn for transition on pivotroot + * + * Returns: label for transition or ERR_PTR. Does not return NULL + */ +static struct aa_label *build_pivotroot(struct aa_profile *profile, + const struct path *new_path, + char *new_buffer, + const struct path *old_path, + char *old_buffer) +{ + const char *old_name, *new_name = NULL, *info = NULL; + const char *trans_name = NULL; + struct aa_perms perms = { }; + unsigned int state; + int error; + + AA_BUG(!profile); + AA_BUG(!new_path); + AA_BUG(!old_path); + + if (profile_unconfined(profile) || + !PROFILE_MEDIATES(profile, AA_CLASS_MOUNT)) + return aa_get_newest_label(&profile->label); + + error = aa_path_name(old_path, path_flags(profile, old_path), + old_buffer, &old_name, &info, + profile->disconnected); + if (error) + goto audit; + error = aa_path_name(new_path, path_flags(profile, new_path), + new_buffer, &new_name, &info, + profile->disconnected); + if (error) + goto audit; + + error = -EACCES; + state = aa_dfa_match(profile->policy.dfa, + profile->policy.start[AA_CLASS_MOUNT], + new_name); + state = aa_dfa_null_transition(profile->policy.dfa, state); + state = aa_dfa_match(profile->policy.dfa, state, old_name); + perms = compute_mnt_perms(profile->policy.dfa, state); + + if (AA_MAY_PIVOTROOT & perms.allow) + error = 0; + +audit: + error = audit_mount(profile, OP_PIVOTROOT, new_name, old_name, + NULL, trans_name, 0, NULL, AA_MAY_PIVOTROOT, + &perms, info, error); + if (error) + return ERR_PTR(error); + + return aa_get_newest_label(&profile->label); +} + +int aa_pivotroot(struct aa_label *label, const struct path *old_path, + const struct path *new_path) +{ + struct aa_profile *profile; + struct aa_label *target = NULL; + char *old_buffer = NULL, *new_buffer = NULL, *info = NULL; + int error; + + AA_BUG(!label); + AA_BUG(!old_path); + AA_BUG(!new_path); + + old_buffer = aa_get_buffer(false); + new_buffer = aa_get_buffer(false); + error = -ENOMEM; + if (!old_buffer || !new_buffer) + goto out; + target = fn_label_build(label, profile, GFP_KERNEL, + build_pivotroot(profile, new_path, new_buffer, + old_path, old_buffer)); + if (!target) { + info = "label build failed"; + error = -ENOMEM; + goto fail; + } else if (!IS_ERR(target)) { + error = aa_replace_current_label(target); + if (error) { + /* TODO: audit target */ + aa_put_label(target); + goto out; + } + aa_put_label(target); + } else + /* already audited error */ + error = PTR_ERR(target); +out: + aa_put_buffer(old_buffer); + aa_put_buffer(new_buffer); + + return error; + +fail: + /* TODO: add back in auditing of new_name and old_name */ + error = fn_for_each(label, profile, + audit_mount(profile, OP_PIVOTROOT, NULL /*new_name */, + NULL /* old_name */, + NULL, NULL, + 0, NULL, AA_MAY_PIVOTROOT, &nullperms, info, + error)); + goto out; +} diff --git a/security/apparmor/net.c b/security/apparmor/net.c new file mode 100644 index 000000000..7efe4d172 --- /dev/null +++ b/security/apparmor/net.c @@ -0,0 +1,257 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * AppArmor security module + * + * This file contains AppArmor network mediation + * + * Copyright (C) 1998-2008 Novell/SUSE + * Copyright 2009-2017 Canonical Ltd. + */ + +#include "include/apparmor.h" +#include "include/audit.h" +#include "include/cred.h" +#include "include/label.h" +#include "include/net.h" +#include "include/policy.h" +#include "include/secid.h" + +#include "net_names.h" + + +struct aa_sfs_entry aa_sfs_entry_network[] = { + AA_SFS_FILE_STRING("af_mask", AA_SFS_AF_MASK), + { } +}; + +static const char * const net_mask_names[] = { + "unknown", + "send", + "receive", + "unknown", + + "create", + "shutdown", + "connect", + "unknown", + + "setattr", + "getattr", + "setcred", + "getcred", + + "chmod", + "chown", + "chgrp", + "lock", + + "mmap", + "mprot", + "unknown", + "unknown", + + "accept", + "bind", + "listen", + "unknown", + + "setopt", + "getopt", + "unknown", + "unknown", + + "unknown", + "unknown", + "unknown", + "unknown", +}; + + +/* audit callback for net specific fields */ +void audit_net_cb(struct audit_buffer *ab, void *va) +{ + struct common_audit_data *sa = va; + + if (address_family_names[sa->u.net->family]) + audit_log_format(ab, " family=\"%s\"", + address_family_names[sa->u.net->family]); + else + audit_log_format(ab, " family=\"unknown(%d)\"", + sa->u.net->family); + if (sock_type_names[aad(sa)->net.type]) + audit_log_format(ab, " sock_type=\"%s\"", + sock_type_names[aad(sa)->net.type]); + else + audit_log_format(ab, " sock_type=\"unknown(%d)\"", + aad(sa)->net.type); + audit_log_format(ab, " protocol=%d", aad(sa)->net.protocol); + + if (aad(sa)->request & NET_PERMS_MASK) { + audit_log_format(ab, " requested_mask="); + aa_audit_perm_mask(ab, aad(sa)->request, NULL, 0, + net_mask_names, NET_PERMS_MASK); + + if (aad(sa)->denied & NET_PERMS_MASK) { + audit_log_format(ab, " denied_mask="); + aa_audit_perm_mask(ab, aad(sa)->denied, NULL, 0, + net_mask_names, NET_PERMS_MASK); + } + } + if (aad(sa)->peer) { + audit_log_format(ab, " peer="); + aa_label_xaudit(ab, labels_ns(aad(sa)->label), aad(sa)->peer, + FLAGS_NONE, GFP_ATOMIC); + } +} + +/* Generic af perm */ +int aa_profile_af_perm(struct aa_profile *profile, struct common_audit_data *sa, + u32 request, u16 family, int type) +{ + struct aa_perms perms = { }; + unsigned int state; + __be16 buffer[2]; + + AA_BUG(family >= AF_MAX); + AA_BUG(type < 0 || type >= SOCK_MAX); + + if (profile_unconfined(profile)) + return 0; + state = PROFILE_MEDIATES(profile, AA_CLASS_NET); + if (!state) + return 0; + + buffer[0] = cpu_to_be16(family); + buffer[1] = cpu_to_be16((u16) type); + state = aa_dfa_match_len(profile->policy.dfa, state, (char *) &buffer, + 4); + aa_compute_perms(profile->policy.dfa, state, &perms); + aa_apply_modes_to_perms(profile, &perms); + + return aa_check_perms(profile, &perms, request, sa, audit_net_cb); +} + +int aa_af_perm(struct aa_label *label, const char *op, u32 request, u16 family, + int type, int protocol) +{ + struct aa_profile *profile; + DEFINE_AUDIT_NET(sa, op, NULL, family, type, protocol); + + return fn_for_each_confined(label, profile, + aa_profile_af_perm(profile, &sa, request, family, + type)); +} + +static int aa_label_sk_perm(struct aa_label *label, const char *op, u32 request, + struct sock *sk) +{ + struct aa_sk_ctx *ctx = SK_CTX(sk); + int error = 0; + + AA_BUG(!label); + AA_BUG(!sk); + + if (ctx->label != kernel_t && !unconfined(label)) { + struct aa_profile *profile; + DEFINE_AUDIT_SK(sa, op, sk); + + error = fn_for_each_confined(label, profile, + aa_profile_af_sk_perm(profile, &sa, request, sk)); + } + + return error; +} + +int aa_sk_perm(const char *op, u32 request, struct sock *sk) +{ + struct aa_label *label; + int error; + + AA_BUG(!sk); + AA_BUG(in_interrupt()); + + /* TODO: switch to begin_current_label ???? */ + label = begin_current_label_crit_section(); + error = aa_label_sk_perm(label, op, request, sk); + end_current_label_crit_section(label); + + return error; +} + + +int aa_sock_file_perm(struct aa_label *label, const char *op, u32 request, + struct socket *sock) +{ + AA_BUG(!label); + AA_BUG(!sock); + AA_BUG(!sock->sk); + + return aa_label_sk_perm(label, op, request, sock->sk); +} + +#ifdef CONFIG_NETWORK_SECMARK +static int apparmor_secmark_init(struct aa_secmark *secmark) +{ + struct aa_label *label; + + if (secmark->label[0] == '*') { + secmark->secid = AA_SECID_WILDCARD; + return 0; + } + + label = aa_label_strn_parse(&root_ns->unconfined->label, + secmark->label, strlen(secmark->label), + GFP_ATOMIC, false, false); + + if (IS_ERR(label)) + return PTR_ERR(label); + + secmark->secid = label->secid; + + return 0; +} + +static int aa_secmark_perm(struct aa_profile *profile, u32 request, u32 secid, + struct common_audit_data *sa) +{ + int i, ret; + struct aa_perms perms = { }; + + if (profile->secmark_count == 0) + return 0; + + for (i = 0; i < profile->secmark_count; i++) { + if (!profile->secmark[i].secid) { + ret = apparmor_secmark_init(&profile->secmark[i]); + if (ret) + return ret; + } + + if (profile->secmark[i].secid == secid || + profile->secmark[i].secid == AA_SECID_WILDCARD) { + if (profile->secmark[i].deny) + perms.deny = ALL_PERMS_MASK; + else + perms.allow = ALL_PERMS_MASK; + + if (profile->secmark[i].audit) + perms.audit = ALL_PERMS_MASK; + } + } + + aa_apply_modes_to_perms(profile, &perms); + + return aa_check_perms(profile, &perms, request, sa, audit_net_cb); +} + +int apparmor_secmark_check(struct aa_label *label, char *op, u32 request, + u32 secid, const struct sock *sk) +{ + struct aa_profile *profile; + DEFINE_AUDIT_SK(sa, op, sk); + + return fn_for_each_confined(label, profile, + aa_secmark_perm(profile, request, secid, + &sa)); +} +#endif diff --git a/security/apparmor/nulldfa.in b/security/apparmor/nulldfa.in new file mode 100644 index 000000000..095f42a24 --- /dev/null +++ b/security/apparmor/nulldfa.in @@ -0,0 +1,107 @@ +0x1B, 0x5E, 0x78, 0x3D, 0x00, 0x00, 0x00, 0x18, 0x00, 0x00, 0x04, +0x90, 0x00, 0x00, 0x6E, 0x6F, 0x74, 0x66, 0x6C, 0x65, 0x78, 0x00, +0x00, 0x00, 0x00, 0x01, 0x00, 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b/security/apparmor/path.c new file mode 100644 index 000000000..45ec994b5 --- /dev/null +++ b/security/apparmor/path.c @@ -0,0 +1,217 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * AppArmor security module + * + * This file contains AppArmor function for pathnames + * + * Copyright (C) 1998-2008 Novell/SUSE + * Copyright 2009-2010 Canonical Ltd. + */ + +#include <linux/magic.h> +#include <linux/mount.h> +#include <linux/namei.h> +#include <linux/nsproxy.h> +#include <linux/path.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/fs_struct.h> + +#include "include/apparmor.h" +#include "include/path.h" +#include "include/policy.h" + +/* modified from dcache.c */ +static int prepend(char **buffer, int buflen, const char *str, int namelen) +{ + buflen -= namelen; + if (buflen < 0) + return -ENAMETOOLONG; + *buffer -= namelen; + memcpy(*buffer, str, namelen); + return 0; +} + +#define CHROOT_NSCONNECT (PATH_CHROOT_REL | PATH_CHROOT_NSCONNECT) + +/* If the path is not connected to the expected root, + * check if it is a sysctl and handle specially else remove any + * leading / that __d_path may have returned. + * Unless + * specifically directed to connect the path, + * OR + * if in a chroot and doing chroot relative paths and the path + * resolves to the namespace root (would be connected outside + * of chroot) and specifically directed to connect paths to + * namespace root. + */ +static int disconnect(const struct path *path, char *buf, char **name, + int flags, const char *disconnected) +{ + int error = 0; + + if (!(flags & PATH_CONNECT_PATH) && + !(((flags & CHROOT_NSCONNECT) == CHROOT_NSCONNECT) && + our_mnt(path->mnt))) { + /* disconnected path, don't return pathname starting + * with '/' + */ + error = -EACCES; + if (**name == '/') + *name = *name + 1; + } else { + if (**name != '/') + /* CONNECT_PATH with missing root */ + error = prepend(name, *name - buf, "/", 1); + if (!error && disconnected) + error = prepend(name, *name - buf, disconnected, + strlen(disconnected)); + } + + return error; +} + +/** + * d_namespace_path - lookup a name associated with a given path + * @path: path to lookup (NOT NULL) + * @buf: buffer to store path to (NOT NULL) + * @name: Returns - pointer for start of path name with in @buf (NOT NULL) + * @flags: flags controlling path lookup + * @disconnected: string to prefix to disconnected paths + * + * Handle path name lookup. + * + * Returns: %0 else error code if path lookup fails + * When no error the path name is returned in @name which points to + * a position in @buf + */ +static int d_namespace_path(const struct path *path, char *buf, char **name, + int flags, const char *disconnected) +{ + char *res; + int error = 0; + int connected = 1; + int isdir = (flags & PATH_IS_DIR) ? 1 : 0; + int buflen = aa_g_path_max - isdir; + + if (path->mnt->mnt_flags & MNT_INTERNAL) { + /* it's not mounted anywhere */ + res = dentry_path(path->dentry, buf, buflen); + *name = res; + if (IS_ERR(res)) { + *name = buf; + return PTR_ERR(res); + } + if (path->dentry->d_sb->s_magic == PROC_SUPER_MAGIC && + strncmp(*name, "/sys/", 5) == 0) { + /* TODO: convert over to using a per namespace + * control instead of hard coded /proc + */ + error = prepend(name, *name - buf, "/proc", 5); + goto out; + } else + error = disconnect(path, buf, name, flags, + disconnected); + goto out; + } + + /* resolve paths relative to chroot?*/ + if (flags & PATH_CHROOT_REL) { + struct path root; + get_fs_root(current->fs, &root); + res = __d_path(path, &root, buf, buflen); + path_put(&root); + } else { + res = d_absolute_path(path, buf, buflen); + if (!our_mnt(path->mnt)) + connected = 0; + } + + /* handle error conditions - and still allow a partial path to + * be returned. + */ + if (!res || IS_ERR(res)) { + if (PTR_ERR(res) == -ENAMETOOLONG) { + error = -ENAMETOOLONG; + *name = buf; + goto out; + } + connected = 0; + res = dentry_path_raw(path->dentry, buf, buflen); + if (IS_ERR(res)) { + error = PTR_ERR(res); + *name = buf; + goto out; + } + } else if (!our_mnt(path->mnt)) + connected = 0; + + *name = res; + + if (!connected) + error = disconnect(path, buf, name, flags, disconnected); + + /* Handle two cases: + * 1. A deleted dentry && profile is not allowing mediation of deleted + * 2. On some filesystems, newly allocated dentries appear to the + * security_path hooks as a deleted dentry except without an inode + * allocated. + */ + if (d_unlinked(path->dentry) && d_is_positive(path->dentry) && + !(flags & (PATH_MEDIATE_DELETED | PATH_DELEGATE_DELETED))) { + error = -ENOENT; + goto out; + } + +out: + /* + * Append "/" to the pathname. The root directory is a special + * case; it already ends in slash. + */ + if (!error && isdir && ((*name)[1] != '\0' || (*name)[0] != '/')) + strcpy(&buf[aa_g_path_max - 2], "/"); + + return error; +} + +/** + * aa_path_name - get the pathname to a buffer ensure dir / is appended + * @path: path the file (NOT NULL) + * @flags: flags controlling path name generation + * @buffer: buffer to put name in (NOT NULL) + * @name: Returns - the generated path name if !error (NOT NULL) + * @info: Returns - information on why the path lookup failed (MAYBE NULL) + * @disconnected: string to prepend to disconnected paths + * + * @name is a pointer to the beginning of the pathname (which usually differs + * from the beginning of the buffer), or NULL. If there is an error @name + * may contain a partial or invalid name that can be used for audit purposes, + * but it can not be used for mediation. + * + * We need PATH_IS_DIR to indicate whether the file is a directory or not + * because the file may not yet exist, and so we cannot check the inode's + * file type. + * + * Returns: %0 else error code if could retrieve name + */ +int aa_path_name(const struct path *path, int flags, char *buffer, + const char **name, const char **info, const char *disconnected) +{ + char *str = NULL; + int error = d_namespace_path(path, buffer, &str, flags, disconnected); + + if (info && error) { + if (error == -ENOENT) + *info = "Failed name lookup - deleted entry"; + else if (error == -EACCES) + *info = "Failed name lookup - disconnected path"; + else if (error == -ENAMETOOLONG) + *info = "Failed name lookup - name too long"; + else + *info = "Failed name lookup"; + } + + *name = str; + + return error; +} diff --git a/security/apparmor/policy.c b/security/apparmor/policy.c new file mode 100644 index 000000000..c7b84fb56 --- /dev/null +++ b/security/apparmor/policy.c @@ -0,0 +1,1209 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * AppArmor security module + * + * This file contains AppArmor policy manipulation functions + * + * Copyright (C) 1998-2008 Novell/SUSE + * Copyright 2009-2010 Canonical Ltd. + * + * AppArmor policy is based around profiles, which contain the rules a + * task is confined by. Every task in the system has a profile attached + * to it determined either by matching "unconfined" tasks against the + * visible set of profiles or by following a profiles attachment rules. + * + * Each profile exists in a profile namespace which is a container of + * visible profiles. Each namespace contains a special "unconfined" profile, + * which doesn't enforce any confinement on a task beyond DAC. + * + * Namespace and profile names can be written together in either + * of two syntaxes. + * :namespace:profile - used by kernel interfaces for easy detection + * namespace://profile - used by policy + * + * Profile names can not start with : or @ or ^ and may not contain \0 + * + * Reserved profile names + * unconfined - special automatically generated unconfined profile + * inherit - special name to indicate profile inheritance + * null-XXXX-YYYY - special automatically generated learning profiles + * + * Namespace names may not start with / or @ and may not contain \0 or : + * Reserved namespace names + * user-XXXX - user defined profiles + * + * a // in a profile or namespace name indicates a hierarchical name with the + * name before the // being the parent and the name after the child. + * + * Profile and namespace hierarchies serve two different but similar purposes. + * The namespace contains the set of visible profiles that are considered + * for attachment. The hierarchy of namespaces allows for virtualizing + * the namespace so that for example a chroot can have its own set of profiles + * which may define some local user namespaces. + * The profile hierarchy severs two distinct purposes, + * - it allows for sub profiles or hats, which allows an application to run + * subprograms under its own profile with different restriction than it + * self, and not have it use the system profile. + * eg. if a mail program starts an editor, the policy might make the + * restrictions tighter on the editor tighter than the mail program, + * and definitely different than general editor restrictions + * - it allows for binary hierarchy of profiles, so that execution history + * is preserved. This feature isn't exploited by AppArmor reference policy + * but is allowed. NOTE: this is currently suboptimal because profile + * aliasing is not currently implemented so that a profile for each + * level must be defined. + * eg. /bin/bash///bin/ls as a name would indicate /bin/ls was started + * from /bin/bash + * + * A profile or namespace name that can contain one or more // separators + * is referred to as an hname (hierarchical). + * eg. /bin/bash//bin/ls + * + * An fqname is a name that may contain both namespace and profile hnames. + * eg. :ns:/bin/bash//bin/ls + * + * NOTES: + * - locking of profile lists is currently fairly coarse. All profile + * lists within a namespace use the namespace lock. + * FIXME: move profile lists to using rcu_lists + */ + +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/string.h> +#include <linux/cred.h> +#include <linux/rculist.h> +#include <linux/user_namespace.h> + +#include "include/apparmor.h" +#include "include/capability.h" +#include "include/cred.h" +#include "include/file.h" +#include "include/ipc.h" +#include "include/match.h" +#include "include/path.h" +#include "include/policy.h" +#include "include/policy_ns.h" +#include "include/policy_unpack.h" +#include "include/resource.h" + +int unprivileged_userns_apparmor_policy = 1; + +const char *const aa_profile_mode_names[] = { + "enforce", + "complain", + "kill", + "unconfined", +}; + + +/** + * __add_profile - add a profiles to list and label tree + * @list: list to add it to (NOT NULL) + * @profile: the profile to add (NOT NULL) + * + * refcount @profile, should be put by __list_remove_profile + * + * Requires: namespace lock be held, or list not be shared + */ +static void __add_profile(struct list_head *list, struct aa_profile *profile) +{ + struct aa_label *l; + + AA_BUG(!list); + AA_BUG(!profile); + AA_BUG(!profile->ns); + AA_BUG(!mutex_is_locked(&profile->ns->lock)); + + list_add_rcu(&profile->base.list, list); + /* get list reference */ + aa_get_profile(profile); + l = aa_label_insert(&profile->ns->labels, &profile->label); + AA_BUG(l != &profile->label); + aa_put_label(l); +} + +/** + * __list_remove_profile - remove a profile from the list it is on + * @profile: the profile to remove (NOT NULL) + * + * remove a profile from the list, warning generally removal should + * be done with __replace_profile as most profile removals are + * replacements to the unconfined profile. + * + * put @profile list refcount + * + * Requires: namespace lock be held, or list not have been live + */ +static void __list_remove_profile(struct aa_profile *profile) +{ + AA_BUG(!profile); + AA_BUG(!profile->ns); + AA_BUG(!mutex_is_locked(&profile->ns->lock)); + + list_del_rcu(&profile->base.list); + aa_put_profile(profile); +} + +/** + * __remove_profile - remove old profile, and children + * @profile: profile to be replaced (NOT NULL) + * + * Requires: namespace list lock be held, or list not be shared + */ +static void __remove_profile(struct aa_profile *profile) +{ + AA_BUG(!profile); + AA_BUG(!profile->ns); + AA_BUG(!mutex_is_locked(&profile->ns->lock)); + + /* release any children lists first */ + __aa_profile_list_release(&profile->base.profiles); + /* released by free_profile */ + aa_label_remove(&profile->label); + __aafs_profile_rmdir(profile); + __list_remove_profile(profile); +} + +/** + * __aa_profile_list_release - remove all profiles on the list and put refs + * @head: list of profiles (NOT NULL) + * + * Requires: namespace lock be held + */ +void __aa_profile_list_release(struct list_head *head) +{ + struct aa_profile *profile, *tmp; + list_for_each_entry_safe(profile, tmp, head, base.list) + __remove_profile(profile); +} + +/** + * aa_free_data - free a data blob + * @ptr: data to free + * @arg: unused + */ +static void aa_free_data(void *ptr, void *arg) +{ + struct aa_data *data = ptr; + + kfree_sensitive(data->data); + kfree_sensitive(data->key); + kfree_sensitive(data); +} + +/** + * aa_free_profile - free a profile + * @profile: the profile to free (MAYBE NULL) + * + * Free a profile, its hats and null_profile. All references to the profile, + * its hats and null_profile must have been put. + * + * If the profile was referenced from a task context, free_profile() will + * be called from an rcu callback routine, so we must not sleep here. + */ +void aa_free_profile(struct aa_profile *profile) +{ + struct rhashtable *rht; + int i; + + AA_DEBUG("%s(%p)\n", __func__, profile); + + if (!profile) + return; + + /* free children profiles */ + aa_policy_destroy(&profile->base); + aa_put_profile(rcu_access_pointer(profile->parent)); + + aa_put_ns(profile->ns); + kfree_sensitive(profile->rename); + kfree_sensitive(profile->disconnected); + + aa_free_file_rules(&profile->file); + aa_free_cap_rules(&profile->caps); + aa_free_rlimit_rules(&profile->rlimits); + + for (i = 0; i < profile->xattr_count; i++) + kfree_sensitive(profile->xattrs[i]); + kfree_sensitive(profile->xattrs); + for (i = 0; i < profile->secmark_count; i++) + kfree_sensitive(profile->secmark[i].label); + kfree_sensitive(profile->secmark); + kfree_sensitive(profile->dirname); + aa_put_dfa(profile->xmatch); + aa_put_dfa(profile->policy.dfa); + + if (profile->data) { + rht = profile->data; + profile->data = NULL; + rhashtable_free_and_destroy(rht, aa_free_data, NULL); + kfree_sensitive(rht); + } + + kfree_sensitive(profile->hash); + aa_put_loaddata(profile->rawdata); + aa_label_destroy(&profile->label); + + kfree_sensitive(profile); +} + +/** + * aa_alloc_profile - allocate, initialize and return a new profile + * @hname: name of the profile (NOT NULL) + * @gfp: allocation type + * + * Returns: refcount profile or NULL on failure + */ +struct aa_profile *aa_alloc_profile(const char *hname, struct aa_proxy *proxy, + gfp_t gfp) +{ + struct aa_profile *profile; + + /* freed by free_profile - usually through aa_put_profile */ + profile = kzalloc(struct_size(profile, label.vec, 2), gfp); + if (!profile) + return NULL; + + if (!aa_policy_init(&profile->base, NULL, hname, gfp)) + goto fail; + if (!aa_label_init(&profile->label, 1, gfp)) + goto fail; + + /* update being set needed by fs interface */ + if (!proxy) { + proxy = aa_alloc_proxy(&profile->label, gfp); + if (!proxy) + goto fail; + } else + aa_get_proxy(proxy); + profile->label.proxy = proxy; + + profile->label.hname = profile->base.hname; + profile->label.flags |= FLAG_PROFILE; + profile->label.vec[0] = profile; + + /* refcount released by caller */ + return profile; + +fail: + aa_free_profile(profile); + + return NULL; +} + +/* TODO: profile accounting - setup in remove */ + +/** + * __strn_find_child - find a profile on @head list using substring of @name + * @head: list to search (NOT NULL) + * @name: name of profile (NOT NULL) + * @len: length of @name substring to match + * + * Requires: rcu_read_lock be held + * + * Returns: unrefcounted profile ptr, or NULL if not found + */ +static struct aa_profile *__strn_find_child(struct list_head *head, + const char *name, int len) +{ + return (struct aa_profile *)__policy_strn_find(head, name, len); +} + +/** + * __find_child - find a profile on @head list with a name matching @name + * @head: list to search (NOT NULL) + * @name: name of profile (NOT NULL) + * + * Requires: rcu_read_lock be held + * + * Returns: unrefcounted profile ptr, or NULL if not found + */ +static struct aa_profile *__find_child(struct list_head *head, const char *name) +{ + return __strn_find_child(head, name, strlen(name)); +} + +/** + * aa_find_child - find a profile by @name in @parent + * @parent: profile to search (NOT NULL) + * @name: profile name to search for (NOT NULL) + * + * Returns: a refcounted profile or NULL if not found + */ +struct aa_profile *aa_find_child(struct aa_profile *parent, const char *name) +{ + struct aa_profile *profile; + + rcu_read_lock(); + do { + profile = __find_child(&parent->base.profiles, name); + } while (profile && !aa_get_profile_not0(profile)); + rcu_read_unlock(); + + /* refcount released by caller */ + return profile; +} + +/** + * __lookup_parent - lookup the parent of a profile of name @hname + * @ns: namespace to lookup profile in (NOT NULL) + * @hname: hierarchical profile name to find parent of (NOT NULL) + * + * Lookups up the parent of a fully qualified profile name, the profile + * that matches hname does not need to exist, in general this + * is used to load a new profile. + * + * Requires: rcu_read_lock be held + * + * Returns: unrefcounted policy or NULL if not found + */ +static struct aa_policy *__lookup_parent(struct aa_ns *ns, + const char *hname) +{ + struct aa_policy *policy; + struct aa_profile *profile = NULL; + char *split; + + policy = &ns->base; + + for (split = strstr(hname, "//"); split;) { + profile = __strn_find_child(&policy->profiles, hname, + split - hname); + if (!profile) + return NULL; + policy = &profile->base; + hname = split + 2; + split = strstr(hname, "//"); + } + if (!profile) + return &ns->base; + return &profile->base; +} + +/** + * __lookupn_profile - lookup the profile matching @hname + * @base: base list to start looking up profile name from (NOT NULL) + * @hname: hierarchical profile name (NOT NULL) + * @n: length of @hname + * + * Requires: rcu_read_lock be held + * + * Returns: unrefcounted profile pointer or NULL if not found + * + * Do a relative name lookup, recursing through profile tree. + */ +static struct aa_profile *__lookupn_profile(struct aa_policy *base, + const char *hname, size_t n) +{ + struct aa_profile *profile = NULL; + const char *split; + + for (split = strnstr(hname, "//", n); split; + split = strnstr(hname, "//", n)) { + profile = __strn_find_child(&base->profiles, hname, + split - hname); + if (!profile) + return NULL; + + base = &profile->base; + n -= split + 2 - hname; + hname = split + 2; + } + + if (n) + return __strn_find_child(&base->profiles, hname, n); + return NULL; +} + +static struct aa_profile *__lookup_profile(struct aa_policy *base, + const char *hname) +{ + return __lookupn_profile(base, hname, strlen(hname)); +} + +/** + * aa_lookupn_profile - find a profile by its full or partial name + * @ns: the namespace to start from (NOT NULL) + * @hname: name to do lookup on. Does not contain namespace prefix (NOT NULL) + * @n: size of @hname + * + * Returns: refcounted profile or NULL if not found + */ +struct aa_profile *aa_lookupn_profile(struct aa_ns *ns, const char *hname, + size_t n) +{ + struct aa_profile *profile; + + rcu_read_lock(); + do { + profile = __lookupn_profile(&ns->base, hname, n); + } while (profile && !aa_get_profile_not0(profile)); + rcu_read_unlock(); + + /* the unconfined profile is not in the regular profile list */ + if (!profile && strncmp(hname, "unconfined", n) == 0) + profile = aa_get_newest_profile(ns->unconfined); + + /* refcount released by caller */ + return profile; +} + +struct aa_profile *aa_lookup_profile(struct aa_ns *ns, const char *hname) +{ + return aa_lookupn_profile(ns, hname, strlen(hname)); +} + +struct aa_profile *aa_fqlookupn_profile(struct aa_label *base, + const char *fqname, size_t n) +{ + struct aa_profile *profile; + struct aa_ns *ns; + const char *name, *ns_name; + size_t ns_len; + + name = aa_splitn_fqname(fqname, n, &ns_name, &ns_len); + if (ns_name) { + ns = aa_lookupn_ns(labels_ns(base), ns_name, ns_len); + if (!ns) + return NULL; + } else + ns = aa_get_ns(labels_ns(base)); + + if (name) + profile = aa_lookupn_profile(ns, name, n - (name - fqname)); + else if (ns) + /* default profile for ns, currently unconfined */ + profile = aa_get_newest_profile(ns->unconfined); + else + profile = NULL; + aa_put_ns(ns); + + return profile; +} + +/** + * aa_new_null_profile - create or find a null-X learning profile + * @parent: profile that caused this profile to be created (NOT NULL) + * @hat: true if the null- learning profile is a hat + * @base: name to base the null profile off of + * @gfp: type of allocation + * + * Find/Create a null- complain mode profile used in learning mode. The + * name of the profile is unique and follows the format of parent//null-XXX. + * where XXX is based on the @name or if that fails or is not supplied + * a unique number + * + * null profiles are added to the profile list but the list does not + * hold a count on them so that they are automatically released when + * not in use. + * + * Returns: new refcounted profile else NULL on failure + */ +struct aa_profile *aa_new_null_profile(struct aa_profile *parent, bool hat, + const char *base, gfp_t gfp) +{ + struct aa_profile *p, *profile; + const char *bname; + char *name = NULL; + + AA_BUG(!parent); + + if (base) { + name = kmalloc(strlen(parent->base.hname) + 8 + strlen(base), + gfp); + if (name) { + sprintf(name, "%s//null-%s", parent->base.hname, base); + goto name; + } + /* fall through to try shorter uniq */ + } + + name = kmalloc(strlen(parent->base.hname) + 2 + 7 + 8, gfp); + if (!name) + return NULL; + sprintf(name, "%s//null-%x", parent->base.hname, + atomic_inc_return(&parent->ns->uniq_null)); + +name: + /* lookup to see if this is a dup creation */ + bname = basename(name); + profile = aa_find_child(parent, bname); + if (profile) + goto out; + + profile = aa_alloc_profile(name, NULL, gfp); + if (!profile) + goto fail; + + profile->mode = APPARMOR_COMPLAIN; + profile->label.flags |= FLAG_NULL; + if (hat) + profile->label.flags |= FLAG_HAT; + profile->path_flags = parent->path_flags; + + /* released on free_profile */ + rcu_assign_pointer(profile->parent, aa_get_profile(parent)); + profile->ns = aa_get_ns(parent->ns); + profile->file.dfa = aa_get_dfa(nulldfa); + profile->policy.dfa = aa_get_dfa(nulldfa); + + mutex_lock_nested(&profile->ns->lock, profile->ns->level); + p = __find_child(&parent->base.profiles, bname); + if (p) { + aa_free_profile(profile); + profile = aa_get_profile(p); + } else { + __add_profile(&parent->base.profiles, profile); + } + mutex_unlock(&profile->ns->lock); + + /* refcount released by caller */ +out: + kfree(name); + + return profile; + +fail: + kfree(name); + aa_free_profile(profile); + return NULL; +} + +/** + * replacement_allowed - test to see if replacement is allowed + * @profile: profile to test if it can be replaced (MAYBE NULL) + * @noreplace: true if replacement shouldn't be allowed but addition is okay + * @info: Returns - info about why replacement failed (NOT NULL) + * + * Returns: %0 if replacement allowed else error code + */ +static int replacement_allowed(struct aa_profile *profile, int noreplace, + const char **info) +{ + if (profile) { + if (profile->label.flags & FLAG_IMMUTIBLE) { + *info = "cannot replace immutable profile"; + return -EPERM; + } else if (noreplace) { + *info = "profile already exists"; + return -EEXIST; + } + } + return 0; +} + +/* audit callback for net specific fields */ +static void audit_cb(struct audit_buffer *ab, void *va) +{ + struct common_audit_data *sa = va; + + if (aad(sa)->iface.ns) { + audit_log_format(ab, " ns="); + audit_log_untrustedstring(ab, aad(sa)->iface.ns); + } +} + +/** + * audit_policy - Do auditing of policy changes + * @label: label to check if it can manage policy + * @op: policy operation being performed + * @ns_name: name of namespace being manipulated + * @name: name of profile being manipulated (NOT NULL) + * @info: any extra information to be audited (MAYBE NULL) + * @error: error code + * + * Returns: the error to be returned after audit is done + */ +static int audit_policy(struct aa_label *label, const char *op, + const char *ns_name, const char *name, + const char *info, int error) +{ + DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, op); + + aad(&sa)->iface.ns = ns_name; + aad(&sa)->name = name; + aad(&sa)->info = info; + aad(&sa)->error = error; + aad(&sa)->label = label; + + aa_audit_msg(AUDIT_APPARMOR_STATUS, &sa, audit_cb); + + return error; +} + +/* don't call out to other LSMs in the stack for apparmor policy admin + * permissions + */ +static int policy_ns_capable(struct aa_label *label, + struct user_namespace *userns, int cap) +{ + int err; + + /* check for MAC_ADMIN cap in cred */ + err = cap_capable(current_cred(), userns, cap, CAP_OPT_NONE); + if (!err) + err = aa_capable(label, cap, CAP_OPT_NONE); + + return err; +} + +/** + * aa_policy_view_capable - check if viewing policy in at @ns is allowed + * label: label that is trying to view policy in ns + * ns: namespace being viewed by @label (may be NULL if @label's ns) + * Returns: true if viewing policy is allowed + * + * If @ns is NULL then the namespace being viewed is assumed to be the + * tasks current namespace. + */ +bool aa_policy_view_capable(struct aa_label *label, struct aa_ns *ns) +{ + struct user_namespace *user_ns = current_user_ns(); + struct aa_ns *view_ns = labels_view(label); + bool root_in_user_ns = uid_eq(current_euid(), make_kuid(user_ns, 0)) || + in_egroup_p(make_kgid(user_ns, 0)); + bool response = false; + if (!ns) + ns = view_ns; + + if (root_in_user_ns && aa_ns_visible(view_ns, ns, true) && + (user_ns == &init_user_ns || + (unprivileged_userns_apparmor_policy != 0 && + user_ns->level == view_ns->level))) + response = true; + + return response; +} + +bool aa_policy_admin_capable(struct aa_label *label, struct aa_ns *ns) +{ + struct user_namespace *user_ns = current_user_ns(); + bool capable = policy_ns_capable(label, user_ns, CAP_MAC_ADMIN) == 0; + + AA_DEBUG("cap_mac_admin? %d\n", capable); + AA_DEBUG("policy locked? %d\n", aa_g_lock_policy); + + return aa_policy_view_capable(label, ns) && capable && + !aa_g_lock_policy; +} + +bool aa_current_policy_view_capable(struct aa_ns *ns) +{ + struct aa_label *label; + bool res; + + label = __begin_current_label_crit_section(); + res = aa_policy_view_capable(label, ns); + __end_current_label_crit_section(label); + + return res; +} + +bool aa_current_policy_admin_capable(struct aa_ns *ns) +{ + struct aa_label *label; + bool res; + + label = __begin_current_label_crit_section(); + res = aa_policy_admin_capable(label, ns); + __end_current_label_crit_section(label); + + return res; +} + +/** + * aa_may_manage_policy - can the current task manage policy + * @label: label to check if it can manage policy + * @op: the policy manipulation operation being done + * + * Returns: 0 if the task is allowed to manipulate policy else error + */ +int aa_may_manage_policy(struct aa_label *label, struct aa_ns *ns, u32 mask) +{ + const char *op; + + if (mask & AA_MAY_REMOVE_POLICY) + op = OP_PROF_RM; + else if (mask & AA_MAY_REPLACE_POLICY) + op = OP_PROF_REPL; + else + op = OP_PROF_LOAD; + + /* check if loading policy is locked out */ + if (aa_g_lock_policy) + return audit_policy(label, op, NULL, NULL, "policy_locked", + -EACCES); + + if (!aa_policy_admin_capable(label, ns)) + return audit_policy(label, op, NULL, NULL, "not policy admin", + -EACCES); + + /* TODO: add fine grained mediation of policy loads */ + return 0; +} + +static struct aa_profile *__list_lookup_parent(struct list_head *lh, + struct aa_profile *profile) +{ + const char *base = basename(profile->base.hname); + long len = base - profile->base.hname; + struct aa_load_ent *ent; + + /* parent won't have trailing // so remove from len */ + if (len <= 2) + return NULL; + len -= 2; + + list_for_each_entry(ent, lh, list) { + if (ent->new == profile) + continue; + if (strncmp(ent->new->base.hname, profile->base.hname, len) == + 0 && ent->new->base.hname[len] == 0) + return ent->new; + } + + return NULL; +} + +/** + * __replace_profile - replace @old with @new on a list + * @old: profile to be replaced (NOT NULL) + * @new: profile to replace @old with (NOT NULL) + * @share_proxy: transfer @old->proxy to @new + * + * Will duplicate and refcount elements that @new inherits from @old + * and will inherit @old children. + * + * refcount @new for list, put @old list refcount + * + * Requires: namespace list lock be held, or list not be shared + */ +static void __replace_profile(struct aa_profile *old, struct aa_profile *new) +{ + struct aa_profile *child, *tmp; + + if (!list_empty(&old->base.profiles)) { + LIST_HEAD(lh); + list_splice_init_rcu(&old->base.profiles, &lh, synchronize_rcu); + + list_for_each_entry_safe(child, tmp, &lh, base.list) { + struct aa_profile *p; + + list_del_init(&child->base.list); + p = __find_child(&new->base.profiles, child->base.name); + if (p) { + /* @p replaces @child */ + __replace_profile(child, p); + continue; + } + + /* inherit @child and its children */ + /* TODO: update hname of inherited children */ + /* list refcount transferred to @new */ + p = aa_deref_parent(child); + rcu_assign_pointer(child->parent, aa_get_profile(new)); + list_add_rcu(&child->base.list, &new->base.profiles); + aa_put_profile(p); + } + } + + if (!rcu_access_pointer(new->parent)) { + struct aa_profile *parent = aa_deref_parent(old); + rcu_assign_pointer(new->parent, aa_get_profile(parent)); + } + aa_label_replace(&old->label, &new->label); + /* migrate dents must come after label replacement b/c update */ + __aafs_profile_migrate_dents(old, new); + + if (list_empty(&new->base.list)) { + /* new is not on a list already */ + list_replace_rcu(&old->base.list, &new->base.list); + aa_get_profile(new); + aa_put_profile(old); + } else + __list_remove_profile(old); +} + +/** + * __lookup_replace - lookup replacement information for a profile + * @ns - namespace the lookup occurs in + * @hname - name of profile to lookup + * @noreplace - true if not replacing an existing profile + * @p - Returns: profile to be replaced + * @info - Returns: info string on why lookup failed + * + * Returns: profile to replace (no ref) on success else ptr error + */ +static int __lookup_replace(struct aa_ns *ns, const char *hname, + bool noreplace, struct aa_profile **p, + const char **info) +{ + *p = aa_get_profile(__lookup_profile(&ns->base, hname)); + if (*p) { + int error = replacement_allowed(*p, noreplace, info); + if (error) { + *info = "profile can not be replaced"; + return error; + } + } + + return 0; +} + +static void share_name(struct aa_profile *old, struct aa_profile *new) +{ + aa_put_str(new->base.hname); + aa_get_str(old->base.hname); + new->base.hname = old->base.hname; + new->base.name = old->base.name; + new->label.hname = old->label.hname; +} + +/* Update to newest version of parent after previous replacements + * Returns: unrefcount newest version of parent + */ +static struct aa_profile *update_to_newest_parent(struct aa_profile *new) +{ + struct aa_profile *parent, *newest; + + parent = rcu_dereference_protected(new->parent, + mutex_is_locked(&new->ns->lock)); + newest = aa_get_newest_profile(parent); + + /* parent replaced in this atomic set? */ + if (newest != parent) { + aa_put_profile(parent); + rcu_assign_pointer(new->parent, newest); + } else + aa_put_profile(newest); + + return newest; +} + +/** + * aa_replace_profiles - replace profile(s) on the profile list + * @policy_ns: namespace load is occurring on + * @label: label that is attempting to load/replace policy + * @mask: permission mask + * @udata: serialized data stream (NOT NULL) + * + * unpack and replace a profile on the profile list and uses of that profile + * by any task creds via invalidating the old version of the profile, which + * tasks will notice to update their own cred. If the profile does not exist + * on the profile list it is added. + * + * Returns: size of data consumed else error code on failure. + */ +ssize_t aa_replace_profiles(struct aa_ns *policy_ns, struct aa_label *label, + u32 mask, struct aa_loaddata *udata) +{ + const char *ns_name = NULL, *info = NULL; + struct aa_ns *ns = NULL; + struct aa_load_ent *ent, *tmp; + struct aa_loaddata *rawdata_ent; + const char *op; + ssize_t count, error; + LIST_HEAD(lh); + + op = mask & AA_MAY_REPLACE_POLICY ? OP_PROF_REPL : OP_PROF_LOAD; + aa_get_loaddata(udata); + /* released below */ + error = aa_unpack(udata, &lh, &ns_name); + if (error) + goto out; + + /* ensure that profiles are all for the same ns + * TODO: update locking to remove this constaint. All profiles in + * the load set must succeed as a set or the load will + * fail. Sort ent list and take ns locks in hierarchy order + */ + count = 0; + list_for_each_entry(ent, &lh, list) { + if (ns_name) { + if (ent->ns_name && + strcmp(ent->ns_name, ns_name) != 0) { + info = "policy load has mixed namespaces"; + error = -EACCES; + goto fail; + } + } else if (ent->ns_name) { + if (count) { + info = "policy load has mixed namespaces"; + error = -EACCES; + goto fail; + } + ns_name = ent->ns_name; + } else + count++; + } + if (ns_name) { + ns = aa_prepare_ns(policy_ns ? policy_ns : labels_ns(label), + ns_name); + if (IS_ERR(ns)) { + op = OP_PROF_LOAD; + info = "failed to prepare namespace"; + error = PTR_ERR(ns); + ns = NULL; + ent = NULL; + goto fail; + } + } else + ns = aa_get_ns(policy_ns ? policy_ns : labels_ns(label)); + + mutex_lock_nested(&ns->lock, ns->level); + /* check for duplicate rawdata blobs: space and file dedup */ + if (!list_empty(&ns->rawdata_list)) { + list_for_each_entry(rawdata_ent, &ns->rawdata_list, list) { + if (aa_rawdata_eq(rawdata_ent, udata)) { + struct aa_loaddata *tmp; + + tmp = __aa_get_loaddata(rawdata_ent); + /* check we didn't fail the race */ + if (tmp) { + aa_put_loaddata(udata); + udata = tmp; + break; + } + } + } + } + /* setup parent and ns info */ + list_for_each_entry(ent, &lh, list) { + struct aa_policy *policy; + + if (aa_g_export_binary) + ent->new->rawdata = aa_get_loaddata(udata); + error = __lookup_replace(ns, ent->new->base.hname, + !(mask & AA_MAY_REPLACE_POLICY), + &ent->old, &info); + if (error) + goto fail_lock; + + if (ent->new->rename) { + error = __lookup_replace(ns, ent->new->rename, + !(mask & AA_MAY_REPLACE_POLICY), + &ent->rename, &info); + if (error) + goto fail_lock; + } + + /* released when @new is freed */ + ent->new->ns = aa_get_ns(ns); + + if (ent->old || ent->rename) + continue; + + /* no ref on policy only use inside lock */ + policy = __lookup_parent(ns, ent->new->base.hname); + if (!policy) { + struct aa_profile *p; + p = __list_lookup_parent(&lh, ent->new); + if (!p) { + error = -ENOENT; + info = "parent does not exist"; + goto fail_lock; + } + rcu_assign_pointer(ent->new->parent, aa_get_profile(p)); + } else if (policy != &ns->base) { + /* released on profile replacement or free_profile */ + struct aa_profile *p = (struct aa_profile *) policy; + rcu_assign_pointer(ent->new->parent, aa_get_profile(p)); + } + } + + /* create new fs entries for introspection if needed */ + if (!udata->dents[AAFS_LOADDATA_DIR] && aa_g_export_binary) { + error = __aa_fs_create_rawdata(ns, udata); + if (error) { + info = "failed to create raw_data dir and files"; + ent = NULL; + goto fail_lock; + } + } + list_for_each_entry(ent, &lh, list) { + if (!ent->old) { + struct dentry *parent; + if (rcu_access_pointer(ent->new->parent)) { + struct aa_profile *p; + p = aa_deref_parent(ent->new); + parent = prof_child_dir(p); + } else + parent = ns_subprofs_dir(ent->new->ns); + error = __aafs_profile_mkdir(ent->new, parent); + } + + if (error) { + info = "failed to create"; + goto fail_lock; + } + } + + /* Done with checks that may fail - do actual replacement */ + __aa_bump_ns_revision(ns); + if (aa_g_export_binary) + __aa_loaddata_update(udata, ns->revision); + list_for_each_entry_safe(ent, tmp, &lh, list) { + list_del_init(&ent->list); + op = (!ent->old && !ent->rename) ? OP_PROF_LOAD : OP_PROF_REPL; + + if (ent->old && ent->old->rawdata == ent->new->rawdata && + ent->new->rawdata) { + /* dedup actual profile replacement */ + audit_policy(label, op, ns_name, ent->new->base.hname, + "same as current profile, skipping", + error); + /* break refcount cycle with proxy. */ + aa_put_proxy(ent->new->label.proxy); + ent->new->label.proxy = NULL; + goto skip; + } + + /* + * TODO: finer dedup based on profile range in data. Load set + * can differ but profile may remain unchanged + */ + audit_policy(label, op, ns_name, ent->new->base.hname, NULL, + error); + + if (ent->old) { + share_name(ent->old, ent->new); + __replace_profile(ent->old, ent->new); + } else { + struct list_head *lh; + + if (rcu_access_pointer(ent->new->parent)) { + struct aa_profile *parent; + + parent = update_to_newest_parent(ent->new); + lh = &parent->base.profiles; + } else + lh = &ns->base.profiles; + __add_profile(lh, ent->new); + } + skip: + aa_load_ent_free(ent); + } + __aa_labelset_update_subtree(ns); + mutex_unlock(&ns->lock); + +out: + aa_put_ns(ns); + aa_put_loaddata(udata); + kfree(ns_name); + + if (error) + return error; + return udata->size; + +fail_lock: + mutex_unlock(&ns->lock); + + /* audit cause of failure */ + op = (ent && !ent->old) ? OP_PROF_LOAD : OP_PROF_REPL; +fail: + audit_policy(label, op, ns_name, ent ? ent->new->base.hname : NULL, + info, error); + /* audit status that rest of profiles in the atomic set failed too */ + info = "valid profile in failed atomic policy load"; + list_for_each_entry(tmp, &lh, list) { + if (tmp == ent) { + info = "unchecked profile in failed atomic policy load"; + /* skip entry that caused failure */ + continue; + } + op = (!tmp->old) ? OP_PROF_LOAD : OP_PROF_REPL; + audit_policy(label, op, ns_name, tmp->new->base.hname, info, + error); + } + list_for_each_entry_safe(ent, tmp, &lh, list) { + list_del_init(&ent->list); + aa_load_ent_free(ent); + } + + goto out; +} + +/** + * aa_remove_profiles - remove profile(s) from the system + * @policy_ns: namespace the remove is being done from + * @subj: label attempting to remove policy + * @fqname: name of the profile or namespace to remove (NOT NULL) + * @size: size of the name + * + * Remove a profile or sub namespace from the current namespace, so that + * they can not be found anymore and mark them as replaced by unconfined + * + * NOTE: removing confinement does not restore rlimits to preconfinement values + * + * Returns: size of data consume else error code if fails + */ +ssize_t aa_remove_profiles(struct aa_ns *policy_ns, struct aa_label *subj, + char *fqname, size_t size) +{ + struct aa_ns *ns = NULL; + struct aa_profile *profile = NULL; + const char *name = fqname, *info = NULL; + const char *ns_name = NULL; + ssize_t error = 0; + + if (*fqname == 0) { + info = "no profile specified"; + error = -ENOENT; + goto fail; + } + + if (fqname[0] == ':') { + size_t ns_len; + + name = aa_splitn_fqname(fqname, size, &ns_name, &ns_len); + /* released below */ + ns = aa_lookupn_ns(policy_ns ? policy_ns : labels_ns(subj), + ns_name, ns_len); + if (!ns) { + info = "namespace does not exist"; + error = -ENOENT; + goto fail; + } + } else + /* released below */ + ns = aa_get_ns(policy_ns ? policy_ns : labels_ns(subj)); + + if (!name) { + /* remove namespace - can only happen if fqname[0] == ':' */ + mutex_lock_nested(&ns->parent->lock, ns->parent->level); + __aa_bump_ns_revision(ns); + __aa_remove_ns(ns); + mutex_unlock(&ns->parent->lock); + } else { + /* remove profile */ + mutex_lock_nested(&ns->lock, ns->level); + profile = aa_get_profile(__lookup_profile(&ns->base, name)); + if (!profile) { + error = -ENOENT; + info = "profile does not exist"; + goto fail_ns_lock; + } + name = profile->base.hname; + __aa_bump_ns_revision(ns); + __remove_profile(profile); + __aa_labelset_update_subtree(ns); + mutex_unlock(&ns->lock); + } + + /* don't fail removal if audit fails */ + (void) audit_policy(subj, OP_PROF_RM, ns_name, name, info, + error); + aa_put_ns(ns); + aa_put_profile(profile); + return size; + +fail_ns_lock: + mutex_unlock(&ns->lock); + aa_put_ns(ns); + +fail: + (void) audit_policy(subj, OP_PROF_RM, ns_name, name, info, + error); + return error; +} diff --git a/security/apparmor/policy_ns.c b/security/apparmor/policy_ns.c new file mode 100644 index 000000000..78700d94b --- /dev/null +++ b/security/apparmor/policy_ns.c @@ -0,0 +1,435 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * AppArmor security module + * + * This file contains AppArmor policy manipulation functions + * + * Copyright (C) 1998-2008 Novell/SUSE + * Copyright 2009-2017 Canonical Ltd. + * + * AppArmor policy namespaces, allow for different sets of policies + * to be loaded for tasks within the namespace. + */ + +#include <linux/list.h> +#include <linux/mutex.h> +#include <linux/slab.h> +#include <linux/string.h> + +#include "include/apparmor.h" +#include "include/cred.h" +#include "include/policy_ns.h" +#include "include/label.h" +#include "include/policy.h" + +/* kernel label */ +struct aa_label *kernel_t; + +/* root profile namespace */ +struct aa_ns *root_ns; +const char *aa_hidden_ns_name = "---"; + +/** + * aa_ns_visible - test if @view is visible from @curr + * @curr: namespace to treat as the parent (NOT NULL) + * @view: namespace to test if visible from @curr (NOT NULL) + * @subns: whether view of a subns is allowed + * + * Returns: true if @view is visible from @curr else false + */ +bool aa_ns_visible(struct aa_ns *curr, struct aa_ns *view, bool subns) +{ + if (curr == view) + return true; + + if (!subns) + return false; + + for ( ; view; view = view->parent) { + if (view->parent == curr) + return true; + } + + return false; +} + +/** + * aa_ns_name - Find the ns name to display for @view from @curr + * @curr: current namespace (NOT NULL) + * @view: namespace attempting to view (NOT NULL) + * @subns: are subns visible + * + * Returns: name of @view visible from @curr + */ +const char *aa_ns_name(struct aa_ns *curr, struct aa_ns *view, bool subns) +{ + /* if view == curr then the namespace name isn't displayed */ + if (curr == view) + return ""; + + if (aa_ns_visible(curr, view, subns)) { + /* at this point if a ns is visible it is in a view ns + * thus the curr ns.hname is a prefix of its name. + * Only output the virtualized portion of the name + * Add + 2 to skip over // separating curr hname prefix + * from the visible tail of the views hname + */ + return view->base.hname + strlen(curr->base.hname) + 2; + } + + return aa_hidden_ns_name; +} + +static struct aa_profile *alloc_unconfined(const char *name) +{ + struct aa_profile *profile; + + profile = aa_alloc_profile(name, NULL, GFP_KERNEL); + if (!profile) + return NULL; + + profile->label.flags |= FLAG_IX_ON_NAME_ERROR | + FLAG_IMMUTIBLE | FLAG_NS_COUNT | FLAG_UNCONFINED; + profile->mode = APPARMOR_UNCONFINED; + profile->file.dfa = aa_get_dfa(nulldfa); + profile->policy.dfa = aa_get_dfa(nulldfa); + + return profile; +} + +/** + * alloc_ns - allocate, initialize and return a new namespace + * @prefix: parent namespace name (MAYBE NULL) + * @name: a preallocated name (NOT NULL) + * + * Returns: refcounted namespace or NULL on failure. + */ +static struct aa_ns *alloc_ns(const char *prefix, const char *name) +{ + struct aa_ns *ns; + + ns = kzalloc(sizeof(*ns), GFP_KERNEL); + AA_DEBUG("%s(%p)\n", __func__, ns); + if (!ns) + return NULL; + if (!aa_policy_init(&ns->base, prefix, name, GFP_KERNEL)) + goto fail_ns; + + INIT_LIST_HEAD(&ns->sub_ns); + INIT_LIST_HEAD(&ns->rawdata_list); + mutex_init(&ns->lock); + init_waitqueue_head(&ns->wait); + + /* released by aa_free_ns() */ + ns->unconfined = alloc_unconfined("unconfined"); + if (!ns->unconfined) + goto fail_unconfined; + /* ns and ns->unconfined share ns->unconfined refcount */ + ns->unconfined->ns = ns; + + atomic_set(&ns->uniq_null, 0); + + aa_labelset_init(&ns->labels); + + return ns; + +fail_unconfined: + aa_policy_destroy(&ns->base); +fail_ns: + kfree_sensitive(ns); + return NULL; +} + +/** + * aa_free_ns - free a profile namespace + * @ns: the namespace to free (MAYBE NULL) + * + * Requires: All references to the namespace must have been put, if the + * namespace was referenced by a profile confining a task, + */ +void aa_free_ns(struct aa_ns *ns) +{ + if (!ns) + return; + + aa_policy_destroy(&ns->base); + aa_labelset_destroy(&ns->labels); + aa_put_ns(ns->parent); + + ns->unconfined->ns = NULL; + aa_free_profile(ns->unconfined); + kfree_sensitive(ns); +} + +/** + * aa_findn_ns - look up a profile namespace on the namespace list + * @root: namespace to search in (NOT NULL) + * @name: name of namespace to find (NOT NULL) + * @n: length of @name + * + * Returns: a refcounted namespace on the list, or NULL if no namespace + * called @name exists. + * + * refcount released by caller + */ +struct aa_ns *aa_findn_ns(struct aa_ns *root, const char *name, size_t n) +{ + struct aa_ns *ns = NULL; + + rcu_read_lock(); + ns = aa_get_ns(__aa_findn_ns(&root->sub_ns, name, n)); + rcu_read_unlock(); + + return ns; +} + +/** + * aa_find_ns - look up a profile namespace on the namespace list + * @root: namespace to search in (NOT NULL) + * @name: name of namespace to find (NOT NULL) + * + * Returns: a refcounted namespace on the list, or NULL if no namespace + * called @name exists. + * + * refcount released by caller + */ +struct aa_ns *aa_find_ns(struct aa_ns *root, const char *name) +{ + return aa_findn_ns(root, name, strlen(name)); +} + +/** + * __aa_lookupn_ns - lookup the namespace matching @hname + * @view: namespace to search in (NOT NULL) + * @hname: hierarchical ns name (NOT NULL) + * @n: length of @hname + * + * Requires: rcu_read_lock be held + * + * Returns: unrefcounted ns pointer or NULL if not found + * + * Do a relative name lookup, recursing through profile tree. + */ +struct aa_ns *__aa_lookupn_ns(struct aa_ns *view, const char *hname, size_t n) +{ + struct aa_ns *ns = view; + const char *split; + + for (split = strnstr(hname, "//", n); split; + split = strnstr(hname, "//", n)) { + ns = __aa_findn_ns(&ns->sub_ns, hname, split - hname); + if (!ns) + return NULL; + + n -= split + 2 - hname; + hname = split + 2; + } + + if (n) + return __aa_findn_ns(&ns->sub_ns, hname, n); + return NULL; +} + +/** + * aa_lookupn_ns - look up a policy namespace relative to @view + * @view: namespace to search in (NOT NULL) + * @name: name of namespace to find (NOT NULL) + * @n: length of @name + * + * Returns: a refcounted namespace on the list, or NULL if no namespace + * called @name exists. + * + * refcount released by caller + */ +struct aa_ns *aa_lookupn_ns(struct aa_ns *view, const char *name, size_t n) +{ + struct aa_ns *ns = NULL; + + rcu_read_lock(); + ns = aa_get_ns(__aa_lookupn_ns(view, name, n)); + rcu_read_unlock(); + + return ns; +} + +static struct aa_ns *__aa_create_ns(struct aa_ns *parent, const char *name, + struct dentry *dir) +{ + struct aa_ns *ns; + int error; + + AA_BUG(!parent); + AA_BUG(!name); + AA_BUG(!mutex_is_locked(&parent->lock)); + + ns = alloc_ns(parent->base.hname, name); + if (!ns) + return ERR_PTR(-ENOMEM); + ns->level = parent->level + 1; + mutex_lock_nested(&ns->lock, ns->level); + error = __aafs_ns_mkdir(ns, ns_subns_dir(parent), name, dir); + if (error) { + AA_ERROR("Failed to create interface for ns %s\n", + ns->base.name); + mutex_unlock(&ns->lock); + aa_free_ns(ns); + return ERR_PTR(error); + } + ns->parent = aa_get_ns(parent); + list_add_rcu(&ns->base.list, &parent->sub_ns); + /* add list ref */ + aa_get_ns(ns); + mutex_unlock(&ns->lock); + + return ns; +} + +/** + * __aa_find_or_create_ns - create an ns, fail if it already exists + * @parent: the parent of the namespace being created + * @name: the name of the namespace + * @dir: if not null the dir to put the ns entries in + * + * Returns: the a refcounted ns that has been add or an ERR_PTR + */ +struct aa_ns *__aa_find_or_create_ns(struct aa_ns *parent, const char *name, + struct dentry *dir) +{ + struct aa_ns *ns; + + AA_BUG(!mutex_is_locked(&parent->lock)); + + /* try and find the specified ns */ + /* released by caller */ + ns = aa_get_ns(__aa_find_ns(&parent->sub_ns, name)); + if (!ns) + ns = __aa_create_ns(parent, name, dir); + else + ns = ERR_PTR(-EEXIST); + + /* return ref */ + return ns; +} + +/** + * aa_prepare_ns - find an existing or create a new namespace of @name + * @parent: ns to treat as parent + * @name: the namespace to find or add (NOT NULL) + * + * Returns: refcounted namespace or PTR_ERR if failed to create one + */ +struct aa_ns *aa_prepare_ns(struct aa_ns *parent, const char *name) +{ + struct aa_ns *ns; + + mutex_lock_nested(&parent->lock, parent->level); + /* try and find the specified ns and if it doesn't exist create it */ + /* released by caller */ + ns = aa_get_ns(__aa_find_ns(&parent->sub_ns, name)); + if (!ns) + ns = __aa_create_ns(parent, name, NULL); + mutex_unlock(&parent->lock); + + /* return ref */ + return ns; +} + +static void __ns_list_release(struct list_head *head); + +/** + * destroy_ns - remove everything contained by @ns + * @ns: namespace to have it contents removed (NOT NULL) + */ +static void destroy_ns(struct aa_ns *ns) +{ + if (!ns) + return; + + mutex_lock_nested(&ns->lock, ns->level); + /* release all profiles in this namespace */ + __aa_profile_list_release(&ns->base.profiles); + + /* release all sub namespaces */ + __ns_list_release(&ns->sub_ns); + + if (ns->parent) { + unsigned long flags; + + write_lock_irqsave(&ns->labels.lock, flags); + __aa_proxy_redirect(ns_unconfined(ns), + ns_unconfined(ns->parent)); + write_unlock_irqrestore(&ns->labels.lock, flags); + } + __aafs_ns_rmdir(ns); + mutex_unlock(&ns->lock); +} + +/** + * __aa_remove_ns - remove a namespace and all its children + * @ns: namespace to be removed (NOT NULL) + * + * Requires: ns->parent->lock be held and ns removed from parent. + */ +void __aa_remove_ns(struct aa_ns *ns) +{ + /* remove ns from namespace list */ + list_del_rcu(&ns->base.list); + destroy_ns(ns); + aa_put_ns(ns); +} + +/** + * __ns_list_release - remove all profile namespaces on the list put refs + * @head: list of profile namespaces (NOT NULL) + * + * Requires: namespace lock be held + */ +static void __ns_list_release(struct list_head *head) +{ + struct aa_ns *ns, *tmp; + + list_for_each_entry_safe(ns, tmp, head, base.list) + __aa_remove_ns(ns); + +} + +/** + * aa_alloc_root_ns - allocate the root profile namespace + * + * Returns: %0 on success else error + * + */ +int __init aa_alloc_root_ns(void) +{ + struct aa_profile *kernel_p; + + /* released by aa_free_root_ns - used as list ref*/ + root_ns = alloc_ns(NULL, "root"); + if (!root_ns) + return -ENOMEM; + + kernel_p = alloc_unconfined("kernel_t"); + if (!kernel_p) { + destroy_ns(root_ns); + aa_free_ns(root_ns); + return -ENOMEM; + } + kernel_t = &kernel_p->label; + root_ns->unconfined->ns = aa_get_ns(root_ns); + + return 0; +} + + /** + * aa_free_root_ns - free the root profile namespace + */ +void __init aa_free_root_ns(void) +{ + struct aa_ns *ns = root_ns; + + root_ns = NULL; + + aa_label_free(kernel_t); + destroy_ns(ns); + aa_put_ns(ns); +} diff --git a/security/apparmor/policy_unpack.c b/security/apparmor/policy_unpack.c new file mode 100644 index 000000000..633e778ec --- /dev/null +++ b/security/apparmor/policy_unpack.c @@ -0,0 +1,1237 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * AppArmor security module + * + * This file contains AppArmor functions for unpacking policy loaded from + * userspace. + * + * Copyright (C) 1998-2008 Novell/SUSE + * Copyright 2009-2010 Canonical Ltd. + * + * AppArmor uses a serialized binary format for loading policy. To find + * policy format documentation see Documentation/admin-guide/LSM/apparmor.rst + * All policy is validated before it is used. + */ + +#include <asm/unaligned.h> +#include <kunit/visibility.h> +#include <linux/ctype.h> +#include <linux/errno.h> +#include <linux/zlib.h> + +#include "include/apparmor.h" +#include "include/audit.h" +#include "include/cred.h" +#include "include/crypto.h" +#include "include/match.h" +#include "include/path.h" +#include "include/policy.h" +#include "include/policy_unpack.h" + +#define K_ABI_MASK 0x3ff +#define FORCE_COMPLAIN_FLAG 0x800 +#define VERSION_LT(X, Y) (((X) & K_ABI_MASK) < ((Y) & K_ABI_MASK)) +#define VERSION_GT(X, Y) (((X) & K_ABI_MASK) > ((Y) & K_ABI_MASK)) + +#define v5 5 /* base version */ +#define v6 6 /* per entry policydb mediation check */ +#define v7 7 +#define v8 8 /* full network masking */ + +/* audit callback for unpack fields */ +static void audit_cb(struct audit_buffer *ab, void *va) +{ + struct common_audit_data *sa = va; + + if (aad(sa)->iface.ns) { + audit_log_format(ab, " ns="); + audit_log_untrustedstring(ab, aad(sa)->iface.ns); + } + if (aad(sa)->name) { + audit_log_format(ab, " name="); + audit_log_untrustedstring(ab, aad(sa)->name); + } + if (aad(sa)->iface.pos) + audit_log_format(ab, " offset=%ld", aad(sa)->iface.pos); +} + +/** + * audit_iface - do audit message for policy unpacking/load/replace/remove + * @new: profile if it has been allocated (MAYBE NULL) + * @ns_name: name of the ns the profile is to be loaded to (MAY BE NULL) + * @name: name of the profile being manipulated (MAYBE NULL) + * @info: any extra info about the failure (MAYBE NULL) + * @e: buffer position info + * @error: error code + * + * Returns: %0 or error + */ +static int audit_iface(struct aa_profile *new, const char *ns_name, + const char *name, const char *info, struct aa_ext *e, + int error) +{ + struct aa_profile *profile = labels_profile(aa_current_raw_label()); + DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, NULL); + if (e) + aad(&sa)->iface.pos = e->pos - e->start; + aad(&sa)->iface.ns = ns_name; + if (new) + aad(&sa)->name = new->base.hname; + else + aad(&sa)->name = name; + aad(&sa)->info = info; + aad(&sa)->error = error; + + return aa_audit(AUDIT_APPARMOR_STATUS, profile, &sa, audit_cb); +} + +void __aa_loaddata_update(struct aa_loaddata *data, long revision) +{ + AA_BUG(!data); + AA_BUG(!data->ns); + AA_BUG(!mutex_is_locked(&data->ns->lock)); + AA_BUG(data->revision > revision); + + data->revision = revision; + if ((data->dents[AAFS_LOADDATA_REVISION])) { + d_inode(data->dents[AAFS_LOADDATA_DIR])->i_mtime = + current_time(d_inode(data->dents[AAFS_LOADDATA_DIR])); + d_inode(data->dents[AAFS_LOADDATA_REVISION])->i_mtime = + current_time(d_inode(data->dents[AAFS_LOADDATA_REVISION])); + } +} + +bool aa_rawdata_eq(struct aa_loaddata *l, struct aa_loaddata *r) +{ + if (l->size != r->size) + return false; + if (l->compressed_size != r->compressed_size) + return false; + if (aa_g_hash_policy && memcmp(l->hash, r->hash, aa_hash_size()) != 0) + return false; + return memcmp(l->data, r->data, r->compressed_size ?: r->size) == 0; +} + +/* + * need to take the ns mutex lock which is NOT safe most places that + * put_loaddata is called, so we have to delay freeing it + */ +static void do_loaddata_free(struct work_struct *work) +{ + struct aa_loaddata *d = container_of(work, struct aa_loaddata, work); + struct aa_ns *ns = aa_get_ns(d->ns); + + if (ns) { + mutex_lock_nested(&ns->lock, ns->level); + __aa_fs_remove_rawdata(d); + mutex_unlock(&ns->lock); + aa_put_ns(ns); + } + + kfree_sensitive(d->hash); + kfree_sensitive(d->name); + kvfree(d->data); + kfree_sensitive(d); +} + +void aa_loaddata_kref(struct kref *kref) +{ + struct aa_loaddata *d = container_of(kref, struct aa_loaddata, count); + + if (d) { + INIT_WORK(&d->work, do_loaddata_free); + schedule_work(&d->work); + } +} + +struct aa_loaddata *aa_loaddata_alloc(size_t size) +{ + struct aa_loaddata *d; + + d = kzalloc(sizeof(*d), GFP_KERNEL); + if (d == NULL) + return ERR_PTR(-ENOMEM); + d->data = kvzalloc(size, GFP_KERNEL); + if (!d->data) { + kfree(d); + return ERR_PTR(-ENOMEM); + } + kref_init(&d->count); + INIT_LIST_HEAD(&d->list); + + return d; +} + +/* test if read will be in packed data bounds */ +VISIBLE_IF_KUNIT bool aa_inbounds(struct aa_ext *e, size_t size) +{ + return (size <= e->end - e->pos); +} +EXPORT_SYMBOL_IF_KUNIT(aa_inbounds); + +static void *kvmemdup(const void *src, size_t len) +{ + void *p = kvmalloc(len, GFP_KERNEL); + + if (p) + memcpy(p, src, len); + return p; +} + +/** + * aa_unpack_u16_chunk - test and do bounds checking for a u16 size based chunk + * @e: serialized data read head (NOT NULL) + * @chunk: start address for chunk of data (NOT NULL) + * + * Returns: the size of chunk found with the read head at the end of the chunk. + */ +VISIBLE_IF_KUNIT size_t aa_unpack_u16_chunk(struct aa_ext *e, char **chunk) +{ + size_t size = 0; + void *pos = e->pos; + + if (!aa_inbounds(e, sizeof(u16))) + goto fail; + size = le16_to_cpu(get_unaligned((__le16 *) e->pos)); + e->pos += sizeof(__le16); + if (!aa_inbounds(e, size)) + goto fail; + *chunk = e->pos; + e->pos += size; + return size; + +fail: + e->pos = pos; + return 0; +} +EXPORT_SYMBOL_IF_KUNIT(aa_unpack_u16_chunk); + +/* unpack control byte */ +VISIBLE_IF_KUNIT bool aa_unpack_X(struct aa_ext *e, enum aa_code code) +{ + if (!aa_inbounds(e, 1)) + return false; + if (*(u8 *) e->pos != code) + return false; + e->pos++; + return true; +} +EXPORT_SYMBOL_IF_KUNIT(aa_unpack_X); + +/** + * aa_unpack_nameX - check is the next element is of type X with a name of @name + * @e: serialized data extent information (NOT NULL) + * @code: type code + * @name: name to match to the serialized element. (MAYBE NULL) + * + * check that the next serialized data element is of type X and has a tag + * name @name. If @name is specified then there must be a matching + * name element in the stream. If @name is NULL any name element will be + * skipped and only the typecode will be tested. + * + * Returns true on success (both type code and name tests match) and the read + * head is advanced past the headers + * + * Returns: false if either match fails, the read head does not move + */ +VISIBLE_IF_KUNIT bool aa_unpack_nameX(struct aa_ext *e, enum aa_code code, const char *name) +{ + /* + * May need to reset pos if name or type doesn't match + */ + void *pos = e->pos; + /* + * Check for presence of a tagname, and if present name size + * AA_NAME tag value is a u16. + */ + if (aa_unpack_X(e, AA_NAME)) { + char *tag = NULL; + size_t size = aa_unpack_u16_chunk(e, &tag); + /* if a name is specified it must match. otherwise skip tag */ + if (name && (!size || tag[size-1] != '\0' || strcmp(name, tag))) + goto fail; + } else if (name) { + /* if a name is specified and there is no name tag fail */ + goto fail; + } + + /* now check if type code matches */ + if (aa_unpack_X(e, code)) + return true; + +fail: + e->pos = pos; + return false; +} +EXPORT_SYMBOL_IF_KUNIT(aa_unpack_nameX); + +static bool unpack_u8(struct aa_ext *e, u8 *data, const char *name) +{ + void *pos = e->pos; + + if (aa_unpack_nameX(e, AA_U8, name)) { + if (!aa_inbounds(e, sizeof(u8))) + goto fail; + if (data) + *data = *((u8 *)e->pos); + e->pos += sizeof(u8); + return true; + } + +fail: + e->pos = pos; + return false; +} + +VISIBLE_IF_KUNIT bool aa_unpack_u32(struct aa_ext *e, u32 *data, const char *name) +{ + void *pos = e->pos; + + if (aa_unpack_nameX(e, AA_U32, name)) { + if (!aa_inbounds(e, sizeof(u32))) + goto fail; + if (data) + *data = le32_to_cpu(get_unaligned((__le32 *) e->pos)); + e->pos += sizeof(u32); + return true; + } + +fail: + e->pos = pos; + return false; +} +EXPORT_SYMBOL_IF_KUNIT(aa_unpack_u32); + +VISIBLE_IF_KUNIT bool aa_unpack_u64(struct aa_ext *e, u64 *data, const char *name) +{ + void *pos = e->pos; + + if (aa_unpack_nameX(e, AA_U64, name)) { + if (!aa_inbounds(e, sizeof(u64))) + goto fail; + if (data) + *data = le64_to_cpu(get_unaligned((__le64 *) e->pos)); + e->pos += sizeof(u64); + return true; + } + +fail: + e->pos = pos; + return false; +} +EXPORT_SYMBOL_IF_KUNIT(aa_unpack_u64); + +VISIBLE_IF_KUNIT size_t aa_unpack_array(struct aa_ext *e, const char *name) +{ + void *pos = e->pos; + + if (aa_unpack_nameX(e, AA_ARRAY, name)) { + int size; + if (!aa_inbounds(e, sizeof(u16))) + goto fail; + size = (int)le16_to_cpu(get_unaligned((__le16 *) e->pos)); + e->pos += sizeof(u16); + return size; + } + +fail: + e->pos = pos; + return 0; +} +EXPORT_SYMBOL_IF_KUNIT(aa_unpack_array); + +VISIBLE_IF_KUNIT size_t aa_unpack_blob(struct aa_ext *e, char **blob, const char *name) +{ + void *pos = e->pos; + + if (aa_unpack_nameX(e, AA_BLOB, name)) { + u32 size; + if (!aa_inbounds(e, sizeof(u32))) + goto fail; + size = le32_to_cpu(get_unaligned((__le32 *) e->pos)); + e->pos += sizeof(u32); + if (aa_inbounds(e, (size_t) size)) { + *blob = e->pos; + e->pos += size; + return size; + } + } + +fail: + e->pos = pos; + return 0; +} +EXPORT_SYMBOL_IF_KUNIT(aa_unpack_blob); + +VISIBLE_IF_KUNIT int aa_unpack_str(struct aa_ext *e, const char **string, const char *name) +{ + char *src_str; + size_t size = 0; + void *pos = e->pos; + *string = NULL; + if (aa_unpack_nameX(e, AA_STRING, name)) { + size = aa_unpack_u16_chunk(e, &src_str); + if (size) { + /* strings are null terminated, length is size - 1 */ + if (src_str[size - 1] != 0) + goto fail; + *string = src_str; + + return size; + } + } + +fail: + e->pos = pos; + return 0; +} +EXPORT_SYMBOL_IF_KUNIT(aa_unpack_str); + +VISIBLE_IF_KUNIT int aa_unpack_strdup(struct aa_ext *e, char **string, const char *name) +{ + const char *tmp; + void *pos = e->pos; + int res = aa_unpack_str(e, &tmp, name); + *string = NULL; + + if (!res) + return 0; + + *string = kmemdup(tmp, res, GFP_KERNEL); + if (!*string) { + e->pos = pos; + return 0; + } + + return res; +} +EXPORT_SYMBOL_IF_KUNIT(aa_unpack_strdup); + + +/** + * unpack_dfa - unpack a file rule dfa + * @e: serialized data extent information (NOT NULL) + * + * returns dfa or ERR_PTR or NULL if no dfa + */ +static struct aa_dfa *unpack_dfa(struct aa_ext *e) +{ + char *blob = NULL; + size_t size; + struct aa_dfa *dfa = NULL; + + size = aa_unpack_blob(e, &blob, "aadfa"); + if (size) { + /* + * The dfa is aligned with in the blob to 8 bytes + * from the beginning of the stream. + * alignment adjust needed by dfa unpack + */ + size_t sz = blob - (char *) e->start - + ((e->pos - e->start) & 7); + size_t pad = ALIGN(sz, 8) - sz; + int flags = TO_ACCEPT1_FLAG(YYTD_DATA32) | + TO_ACCEPT2_FLAG(YYTD_DATA32); + if (aa_g_paranoid_load) + flags |= DFA_FLAG_VERIFY_STATES; + dfa = aa_dfa_unpack(blob + pad, size - pad, flags); + + if (IS_ERR(dfa)) + return dfa; + + } + + return dfa; +} + +/** + * unpack_trans_table - unpack a profile transition table + * @e: serialized data extent information (NOT NULL) + * @profile: profile to add the accept table to (NOT NULL) + * + * Returns: true if table successfully unpacked + */ +static bool unpack_trans_table(struct aa_ext *e, struct aa_profile *profile) +{ + void *saved_pos = e->pos; + + /* exec table is optional */ + if (aa_unpack_nameX(e, AA_STRUCT, "xtable")) { + int i, size; + + size = aa_unpack_array(e, NULL); + /* currently 4 exec bits and entries 0-3 are reserved iupcx */ + if (size > 16 - 4) + goto fail; + profile->file.trans.table = kcalloc(size, sizeof(char *), + GFP_KERNEL); + if (!profile->file.trans.table) + goto fail; + + profile->file.trans.size = size; + for (i = 0; i < size; i++) { + char *str; + int c, j, pos, size2 = aa_unpack_strdup(e, &str, NULL); + /* aa_unpack_strdup verifies that the last character is + * null termination byte. + */ + if (!size2) + goto fail; + profile->file.trans.table[i] = str; + /* verify that name doesn't start with space */ + if (isspace(*str)) + goto fail; + + /* count internal # of internal \0 */ + for (c = j = 0; j < size2 - 1; j++) { + if (!str[j]) { + pos = j; + c++; + } + } + if (*str == ':') { + /* first character after : must be valid */ + if (!str[1]) + goto fail; + /* beginning with : requires an embedded \0, + * verify that exactly 1 internal \0 exists + * trailing \0 already verified by aa_unpack_strdup + * + * convert \0 back to : for label_parse + */ + if (c == 1) + str[pos] = ':'; + else if (c > 1) + goto fail; + } else if (c) + /* fail - all other cases with embedded \0 */ + goto fail; + } + if (!aa_unpack_nameX(e, AA_ARRAYEND, NULL)) + goto fail; + if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL)) + goto fail; + } + return true; + +fail: + aa_free_domain_entries(&profile->file.trans); + e->pos = saved_pos; + return false; +} + +static bool unpack_xattrs(struct aa_ext *e, struct aa_profile *profile) +{ + void *pos = e->pos; + + if (aa_unpack_nameX(e, AA_STRUCT, "xattrs")) { + int i, size; + + size = aa_unpack_array(e, NULL); + profile->xattr_count = size; + profile->xattrs = kcalloc(size, sizeof(char *), GFP_KERNEL); + if (!profile->xattrs) + goto fail; + for (i = 0; i < size; i++) { + if (!aa_unpack_strdup(e, &profile->xattrs[i], NULL)) + goto fail; + } + if (!aa_unpack_nameX(e, AA_ARRAYEND, NULL)) + goto fail; + if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL)) + goto fail; + } + + return true; + +fail: + e->pos = pos; + return false; +} + +static bool unpack_secmark(struct aa_ext *e, struct aa_profile *profile) +{ + void *pos = e->pos; + int i, size; + + if (aa_unpack_nameX(e, AA_STRUCT, "secmark")) { + size = aa_unpack_array(e, NULL); + + profile->secmark = kcalloc(size, sizeof(struct aa_secmark), + GFP_KERNEL); + if (!profile->secmark) + goto fail; + + profile->secmark_count = size; + + for (i = 0; i < size; i++) { + if (!unpack_u8(e, &profile->secmark[i].audit, NULL)) + goto fail; + if (!unpack_u8(e, &profile->secmark[i].deny, NULL)) + goto fail; + if (!aa_unpack_strdup(e, &profile->secmark[i].label, NULL)) + goto fail; + } + if (!aa_unpack_nameX(e, AA_ARRAYEND, NULL)) + goto fail; + if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL)) + goto fail; + } + + return true; + +fail: + if (profile->secmark) { + for (i = 0; i < size; i++) + kfree(profile->secmark[i].label); + kfree(profile->secmark); + profile->secmark_count = 0; + profile->secmark = NULL; + } + + e->pos = pos; + return false; +} + +static bool unpack_rlimits(struct aa_ext *e, struct aa_profile *profile) +{ + void *pos = e->pos; + + /* rlimits are optional */ + if (aa_unpack_nameX(e, AA_STRUCT, "rlimits")) { + int i, size; + u32 tmp = 0; + if (!aa_unpack_u32(e, &tmp, NULL)) + goto fail; + profile->rlimits.mask = tmp; + + size = aa_unpack_array(e, NULL); + if (size > RLIM_NLIMITS) + goto fail; + for (i = 0; i < size; i++) { + u64 tmp2 = 0; + int a = aa_map_resource(i); + if (!aa_unpack_u64(e, &tmp2, NULL)) + goto fail; + profile->rlimits.limits[a].rlim_max = tmp2; + } + if (!aa_unpack_nameX(e, AA_ARRAYEND, NULL)) + goto fail; + if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL)) + goto fail; + } + return true; + +fail: + e->pos = pos; + return false; +} + +static u32 strhash(const void *data, u32 len, u32 seed) +{ + const char * const *key = data; + + return jhash(*key, strlen(*key), seed); +} + +static int datacmp(struct rhashtable_compare_arg *arg, const void *obj) +{ + const struct aa_data *data = obj; + const char * const *key = arg->key; + + return strcmp(data->key, *key); +} + +/** + * unpack_profile - unpack a serialized profile + * @e: serialized data extent information (NOT NULL) + * @ns_name: pointer of newly allocated copy of %NULL in case of error + * + * NOTE: unpack profile sets audit struct if there is a failure + */ +static struct aa_profile *unpack_profile(struct aa_ext *e, char **ns_name) +{ + struct aa_profile *profile = NULL; + const char *tmpname, *tmpns = NULL, *name = NULL; + const char *info = "failed to unpack profile"; + size_t ns_len; + struct rhashtable_params params = { 0 }; + char *key = NULL, *disconnected = NULL; + struct aa_data *data; + int i, error = -EPROTO; + kernel_cap_t tmpcap; + u32 tmp; + + *ns_name = NULL; + + /* check that we have the right struct being passed */ + if (!aa_unpack_nameX(e, AA_STRUCT, "profile")) + goto fail; + if (!aa_unpack_str(e, &name, NULL)) + goto fail; + if (*name == '\0') + goto fail; + + tmpname = aa_splitn_fqname(name, strlen(name), &tmpns, &ns_len); + if (tmpns) { + if (!tmpname) { + info = "empty profile name"; + goto fail; + } + *ns_name = kstrndup(tmpns, ns_len, GFP_KERNEL); + if (!*ns_name) { + info = "out of memory"; + goto fail; + } + name = tmpname; + } + + profile = aa_alloc_profile(name, NULL, GFP_KERNEL); + if (!profile) + return ERR_PTR(-ENOMEM); + + /* profile renaming is optional */ + (void) aa_unpack_str(e, &profile->rename, "rename"); + + /* attachment string is optional */ + (void) aa_unpack_str(e, &profile->attach, "attach"); + + /* xmatch is optional and may be NULL */ + profile->xmatch = unpack_dfa(e); + if (IS_ERR(profile->xmatch)) { + error = PTR_ERR(profile->xmatch); + profile->xmatch = NULL; + info = "bad xmatch"; + goto fail; + } + /* xmatch_len is not optional if xmatch is set */ + if (profile->xmatch) { + if (!aa_unpack_u32(e, &tmp, NULL)) { + info = "missing xmatch len"; + goto fail; + } + profile->xmatch_len = tmp; + } + + /* disconnected attachment string is optional */ + (void) aa_unpack_strdup(e, &disconnected, "disconnected"); + profile->disconnected = disconnected; + + /* per profile debug flags (complain, audit) */ + if (!aa_unpack_nameX(e, AA_STRUCT, "flags")) { + info = "profile missing flags"; + goto fail; + } + info = "failed to unpack profile flags"; + if (!aa_unpack_u32(e, &tmp, NULL)) + goto fail; + if (tmp & PACKED_FLAG_HAT) + profile->label.flags |= FLAG_HAT; + if (tmp & PACKED_FLAG_DEBUG1) + profile->label.flags |= FLAG_DEBUG1; + if (tmp & PACKED_FLAG_DEBUG2) + profile->label.flags |= FLAG_DEBUG2; + if (!aa_unpack_u32(e, &tmp, NULL)) + goto fail; + if (tmp == PACKED_MODE_COMPLAIN || (e->version & FORCE_COMPLAIN_FLAG)) { + profile->mode = APPARMOR_COMPLAIN; + } else if (tmp == PACKED_MODE_ENFORCE) { + profile->mode = APPARMOR_ENFORCE; + } else if (tmp == PACKED_MODE_KILL) { + profile->mode = APPARMOR_KILL; + } else if (tmp == PACKED_MODE_UNCONFINED) { + profile->mode = APPARMOR_UNCONFINED; + profile->label.flags |= FLAG_UNCONFINED; + } else { + goto fail; + } + if (!aa_unpack_u32(e, &tmp, NULL)) + goto fail; + if (tmp) + profile->audit = AUDIT_ALL; + + if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL)) + goto fail; + + /* path_flags is optional */ + if (aa_unpack_u32(e, &profile->path_flags, "path_flags")) + profile->path_flags |= profile->label.flags & + PATH_MEDIATE_DELETED; + else + /* set a default value if path_flags field is not present */ + profile->path_flags = PATH_MEDIATE_DELETED; + + info = "failed to unpack profile capabilities"; + if (!aa_unpack_u32(e, &(profile->caps.allow.cap[0]), NULL)) + goto fail; + if (!aa_unpack_u32(e, &(profile->caps.audit.cap[0]), NULL)) + goto fail; + if (!aa_unpack_u32(e, &(profile->caps.quiet.cap[0]), NULL)) + goto fail; + if (!aa_unpack_u32(e, &tmpcap.cap[0], NULL)) + goto fail; + + info = "failed to unpack upper profile capabilities"; + if (aa_unpack_nameX(e, AA_STRUCT, "caps64")) { + /* optional upper half of 64 bit caps */ + if (!aa_unpack_u32(e, &(profile->caps.allow.cap[1]), NULL)) + goto fail; + if (!aa_unpack_u32(e, &(profile->caps.audit.cap[1]), NULL)) + goto fail; + if (!aa_unpack_u32(e, &(profile->caps.quiet.cap[1]), NULL)) + goto fail; + if (!aa_unpack_u32(e, &(tmpcap.cap[1]), NULL)) + goto fail; + if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL)) + goto fail; + } + + info = "failed to unpack extended profile capabilities"; + if (aa_unpack_nameX(e, AA_STRUCT, "capsx")) { + /* optional extended caps mediation mask */ + if (!aa_unpack_u32(e, &(profile->caps.extended.cap[0]), NULL)) + goto fail; + if (!aa_unpack_u32(e, &(profile->caps.extended.cap[1]), NULL)) + goto fail; + if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL)) + goto fail; + } + + if (!unpack_xattrs(e, profile)) { + info = "failed to unpack profile xattrs"; + goto fail; + } + + if (!unpack_rlimits(e, profile)) { + info = "failed to unpack profile rlimits"; + goto fail; + } + + if (!unpack_secmark(e, profile)) { + info = "failed to unpack profile secmark rules"; + goto fail; + } + + if (aa_unpack_nameX(e, AA_STRUCT, "policydb")) { + /* generic policy dfa - optional and may be NULL */ + info = "failed to unpack policydb"; + profile->policy.dfa = unpack_dfa(e); + if (IS_ERR(profile->policy.dfa)) { + error = PTR_ERR(profile->policy.dfa); + profile->policy.dfa = NULL; + goto fail; + } else if (!profile->policy.dfa) { + error = -EPROTO; + goto fail; + } + if (!aa_unpack_u32(e, &profile->policy.start[0], "start")) + /* default start state */ + profile->policy.start[0] = DFA_START; + /* setup class index */ + for (i = AA_CLASS_FILE; i <= AA_CLASS_LAST; i++) { + profile->policy.start[i] = + aa_dfa_next(profile->policy.dfa, + profile->policy.start[0], + i); + } + if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL)) + goto fail; + } else + profile->policy.dfa = aa_get_dfa(nulldfa); + + /* get file rules */ + profile->file.dfa = unpack_dfa(e); + if (IS_ERR(profile->file.dfa)) { + error = PTR_ERR(profile->file.dfa); + profile->file.dfa = NULL; + info = "failed to unpack profile file rules"; + goto fail; + } else if (profile->file.dfa) { + if (!aa_unpack_u32(e, &profile->file.start, "dfa_start")) + /* default start state */ + profile->file.start = DFA_START; + } else if (profile->policy.dfa && + profile->policy.start[AA_CLASS_FILE]) { + profile->file.dfa = aa_get_dfa(profile->policy.dfa); + profile->file.start = profile->policy.start[AA_CLASS_FILE]; + } else + profile->file.dfa = aa_get_dfa(nulldfa); + + if (!unpack_trans_table(e, profile)) { + info = "failed to unpack profile transition table"; + goto fail; + } + + if (aa_unpack_nameX(e, AA_STRUCT, "data")) { + info = "out of memory"; + profile->data = kzalloc(sizeof(*profile->data), GFP_KERNEL); + if (!profile->data) + goto fail; + + params.nelem_hint = 3; + params.key_len = sizeof(void *); + params.key_offset = offsetof(struct aa_data, key); + params.head_offset = offsetof(struct aa_data, head); + params.hashfn = strhash; + params.obj_cmpfn = datacmp; + + if (rhashtable_init(profile->data, ¶ms)) { + info = "failed to init key, value hash table"; + goto fail; + } + + while (aa_unpack_strdup(e, &key, NULL)) { + data = kzalloc(sizeof(*data), GFP_KERNEL); + if (!data) { + kfree_sensitive(key); + goto fail; + } + + data->key = key; + data->size = aa_unpack_blob(e, &data->data, NULL); + data->data = kvmemdup(data->data, data->size); + if (data->size && !data->data) { + kfree_sensitive(data->key); + kfree_sensitive(data); + goto fail; + } + + if (rhashtable_insert_fast(profile->data, &data->head, + profile->data->p)) { + kfree_sensitive(data->key); + kfree_sensitive(data); + info = "failed to insert data to table"; + goto fail; + } + } + + if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL)) { + info = "failed to unpack end of key, value data table"; + goto fail; + } + } + + if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL)) { + info = "failed to unpack end of profile"; + goto fail; + } + + return profile; + +fail: + if (profile) + name = NULL; + else if (!name) + name = "unknown"; + audit_iface(profile, NULL, name, info, e, error); + aa_free_profile(profile); + + return ERR_PTR(error); +} + +/** + * verify_header - unpack serialized stream header + * @e: serialized data read head (NOT NULL) + * @required: whether the header is required or optional + * @ns: Returns - namespace if one is specified else NULL (NOT NULL) + * + * Returns: error or 0 if header is good + */ +static int verify_header(struct aa_ext *e, int required, const char **ns) +{ + int error = -EPROTONOSUPPORT; + const char *name = NULL; + *ns = NULL; + + /* get the interface version */ + if (!aa_unpack_u32(e, &e->version, "version")) { + if (required) { + audit_iface(NULL, NULL, NULL, "invalid profile format", + e, error); + return error; + } + } + + /* Check that the interface version is currently supported. + * if not specified use previous version + * Mask off everything that is not kernel abi version + */ + if (VERSION_LT(e->version, v5) || VERSION_GT(e->version, v8)) { + audit_iface(NULL, NULL, NULL, "unsupported interface version", + e, error); + return error; + } + + /* read the namespace if present */ + if (aa_unpack_str(e, &name, "namespace")) { + if (*name == '\0') { + audit_iface(NULL, NULL, NULL, "invalid namespace name", + e, error); + return error; + } + if (*ns && strcmp(*ns, name)) { + audit_iface(NULL, NULL, NULL, "invalid ns change", e, + error); + } else if (!*ns) { + *ns = kstrdup(name, GFP_KERNEL); + if (!*ns) + return -ENOMEM; + } + } + + return 0; +} + +static bool verify_xindex(int xindex, int table_size) +{ + int index, xtype; + xtype = xindex & AA_X_TYPE_MASK; + index = xindex & AA_X_INDEX_MASK; + if (xtype == AA_X_TABLE && index >= table_size) + return false; + return true; +} + +/* verify dfa xindexes are in range of transition tables */ +static bool verify_dfa_xindex(struct aa_dfa *dfa, int table_size) +{ + int i; + for (i = 0; i < dfa->tables[YYTD_ID_ACCEPT]->td_lolen; i++) { + if (!verify_xindex(dfa_user_xindex(dfa, i), table_size)) + return false; + if (!verify_xindex(dfa_other_xindex(dfa, i), table_size)) + return false; + } + return true; +} + +/** + * verify_profile - Do post unpack analysis to verify profile consistency + * @profile: profile to verify (NOT NULL) + * + * Returns: 0 if passes verification else error + */ +static int verify_profile(struct aa_profile *profile) +{ + if (profile->file.dfa && + !verify_dfa_xindex(profile->file.dfa, + profile->file.trans.size)) { + audit_iface(profile, NULL, NULL, "Invalid named transition", + NULL, -EPROTO); + return -EPROTO; + } + + return 0; +} + +void aa_load_ent_free(struct aa_load_ent *ent) +{ + if (ent) { + aa_put_profile(ent->rename); + aa_put_profile(ent->old); + aa_put_profile(ent->new); + kfree(ent->ns_name); + kfree_sensitive(ent); + } +} + +struct aa_load_ent *aa_load_ent_alloc(void) +{ + struct aa_load_ent *ent = kzalloc(sizeof(*ent), GFP_KERNEL); + if (ent) + INIT_LIST_HEAD(&ent->list); + return ent; +} + +static int deflate_compress(const char *src, size_t slen, char **dst, + size_t *dlen) +{ +#ifdef CONFIG_SECURITY_APPARMOR_EXPORT_BINARY + int error; + struct z_stream_s strm; + void *stgbuf, *dstbuf; + size_t stglen = deflateBound(slen); + + memset(&strm, 0, sizeof(strm)); + + if (stglen < slen) + return -EFBIG; + + strm.workspace = kvzalloc(zlib_deflate_workspacesize(MAX_WBITS, + MAX_MEM_LEVEL), + GFP_KERNEL); + if (!strm.workspace) + return -ENOMEM; + + error = zlib_deflateInit(&strm, aa_g_rawdata_compression_level); + if (error != Z_OK) { + error = -ENOMEM; + goto fail_deflate_init; + } + + stgbuf = kvzalloc(stglen, GFP_KERNEL); + if (!stgbuf) { + error = -ENOMEM; + goto fail_stg_alloc; + } + + strm.next_in = src; + strm.avail_in = slen; + strm.next_out = stgbuf; + strm.avail_out = stglen; + + error = zlib_deflate(&strm, Z_FINISH); + if (error != Z_STREAM_END) { + error = -EINVAL; + goto fail_deflate; + } + error = 0; + + if (is_vmalloc_addr(stgbuf)) { + dstbuf = kvzalloc(strm.total_out, GFP_KERNEL); + if (dstbuf) { + memcpy(dstbuf, stgbuf, strm.total_out); + kvfree(stgbuf); + } + } else + /* + * If the staging buffer was kmalloc'd, then using krealloc is + * probably going to be faster. The destination buffer will + * always be smaller, so it's just shrunk, avoiding a memcpy + */ + dstbuf = krealloc(stgbuf, strm.total_out, GFP_KERNEL); + + if (!dstbuf) { + error = -ENOMEM; + goto fail_deflate; + } + + *dst = dstbuf; + *dlen = strm.total_out; + +fail_stg_alloc: + zlib_deflateEnd(&strm); +fail_deflate_init: + kvfree(strm.workspace); + return error; + +fail_deflate: + kvfree(stgbuf); + goto fail_stg_alloc; +#else + *dlen = slen; + return 0; +#endif +} + +static int compress_loaddata(struct aa_loaddata *data) +{ + + AA_BUG(data->compressed_size > 0); + + /* + * Shortcut the no compression case, else we increase the amount of + * storage required by a small amount + */ + if (aa_g_rawdata_compression_level != 0) { + void *udata = data->data; + int error = deflate_compress(udata, data->size, &data->data, + &data->compressed_size); + if (error) + return error; + + if (udata != data->data) + kvfree(udata); + } else + data->compressed_size = data->size; + + return 0; +} + +/** + * aa_unpack - unpack packed binary profile(s) data loaded from user space + * @udata: user data copied to kmem (NOT NULL) + * @lh: list to place unpacked profiles in a aa_repl_ws + * @ns: Returns namespace profile is in if specified else NULL (NOT NULL) + * + * Unpack user data and return refcounted allocated profile(s) stored in + * @lh in order of discovery, with the list chain stored in base.list + * or error + * + * Returns: profile(s) on @lh else error pointer if fails to unpack + */ +int aa_unpack(struct aa_loaddata *udata, struct list_head *lh, + const char **ns) +{ + struct aa_load_ent *tmp, *ent; + struct aa_profile *profile = NULL; + int error; + struct aa_ext e = { + .start = udata->data, + .end = udata->data + udata->size, + .pos = udata->data, + }; + + *ns = NULL; + while (e.pos < e.end) { + char *ns_name = NULL; + void *start; + error = verify_header(&e, e.pos == e.start, ns); + if (error) + goto fail; + + start = e.pos; + profile = unpack_profile(&e, &ns_name); + if (IS_ERR(profile)) { + error = PTR_ERR(profile); + goto fail; + } + + error = verify_profile(profile); + if (error) + goto fail_profile; + + if (aa_g_hash_policy) + error = aa_calc_profile_hash(profile, e.version, start, + e.pos - start); + if (error) + goto fail_profile; + + ent = aa_load_ent_alloc(); + if (!ent) { + error = -ENOMEM; + goto fail_profile; + } + + ent->new = profile; + ent->ns_name = ns_name; + list_add_tail(&ent->list, lh); + } + udata->abi = e.version & K_ABI_MASK; + if (aa_g_hash_policy) { + udata->hash = aa_calc_hash(udata->data, udata->size); + if (IS_ERR(udata->hash)) { + error = PTR_ERR(udata->hash); + udata->hash = NULL; + goto fail; + } + } + + if (aa_g_export_binary) { + error = compress_loaddata(udata); + if (error) + goto fail; + } + return 0; + +fail_profile: + aa_put_profile(profile); + +fail: + list_for_each_entry_safe(ent, tmp, lh, list) { + list_del_init(&ent->list); + aa_load_ent_free(ent); + } + + return error; +} diff --git a/security/apparmor/policy_unpack_test.c b/security/apparmor/policy_unpack_test.c new file mode 100644 index 000000000..f25cf2a02 --- /dev/null +++ b/security/apparmor/policy_unpack_test.c @@ -0,0 +1,612 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * KUnit tests for AppArmor's policy unpack. + */ + +#include <kunit/test.h> +#include <kunit/visibility.h> + +#include "include/policy.h" +#include "include/policy_unpack.h" + +#define TEST_STRING_NAME "TEST_STRING" +#define TEST_STRING_DATA "testing" +#define TEST_STRING_BUF_OFFSET \ + (3 + strlen(TEST_STRING_NAME) + 1) + +#define TEST_U32_NAME "U32_TEST" +#define TEST_U32_DATA ((u32)0x01020304) +#define TEST_NAMED_U32_BUF_OFFSET \ + (TEST_STRING_BUF_OFFSET + 3 + strlen(TEST_STRING_DATA) + 1) +#define TEST_U32_BUF_OFFSET \ + (TEST_NAMED_U32_BUF_OFFSET + 3 + strlen(TEST_U32_NAME) + 1) + +#define TEST_U16_OFFSET (TEST_U32_BUF_OFFSET + 3) +#define TEST_U16_DATA ((u16)(TEST_U32_DATA >> 16)) + +#define TEST_U64_NAME "U64_TEST" +#define TEST_U64_DATA ((u64)0x0102030405060708) +#define TEST_NAMED_U64_BUF_OFFSET (TEST_U32_BUF_OFFSET + sizeof(u32) + 1) +#define TEST_U64_BUF_OFFSET \ + (TEST_NAMED_U64_BUF_OFFSET + 3 + strlen(TEST_U64_NAME) + 1) + +#define TEST_BLOB_NAME "BLOB_TEST" +#define TEST_BLOB_DATA "\xde\xad\x00\xbe\xef" +#define TEST_BLOB_DATA_SIZE (ARRAY_SIZE(TEST_BLOB_DATA)) +#define TEST_NAMED_BLOB_BUF_OFFSET (TEST_U64_BUF_OFFSET + sizeof(u64) + 1) +#define TEST_BLOB_BUF_OFFSET \ + (TEST_NAMED_BLOB_BUF_OFFSET + 3 + strlen(TEST_BLOB_NAME) + 1) + +#define TEST_ARRAY_NAME "ARRAY_TEST" +#define TEST_ARRAY_SIZE 16 +#define TEST_NAMED_ARRAY_BUF_OFFSET \ + (TEST_BLOB_BUF_OFFSET + 5 + TEST_BLOB_DATA_SIZE) +#define TEST_ARRAY_BUF_OFFSET \ + (TEST_NAMED_ARRAY_BUF_OFFSET + 3 + strlen(TEST_ARRAY_NAME) + 1) + +MODULE_IMPORT_NS(EXPORTED_FOR_KUNIT_TESTING); + +struct policy_unpack_fixture { + struct aa_ext *e; + size_t e_size; +}; + +static struct aa_ext *build_aa_ext_struct(struct policy_unpack_fixture *puf, + struct kunit *test, size_t buf_size) +{ + char *buf; + struct aa_ext *e; + + buf = kunit_kzalloc(test, buf_size, GFP_USER); + KUNIT_EXPECT_NOT_ERR_OR_NULL(test, buf); + + e = kunit_kmalloc(test, sizeof(*e), GFP_USER); + KUNIT_EXPECT_NOT_ERR_OR_NULL(test, e); + + e->start = buf; + e->end = e->start + buf_size; + e->pos = e->start; + + *buf = AA_NAME; + *(buf + 1) = strlen(TEST_STRING_NAME) + 1; + strcpy(buf + 3, TEST_STRING_NAME); + + buf = e->start + TEST_STRING_BUF_OFFSET; + *buf = AA_STRING; + *(buf + 1) = strlen(TEST_STRING_DATA) + 1; + strcpy(buf + 3, TEST_STRING_DATA); + + buf = e->start + TEST_NAMED_U32_BUF_OFFSET; + *buf = AA_NAME; + *(buf + 1) = strlen(TEST_U32_NAME) + 1; + strcpy(buf + 3, TEST_U32_NAME); + *(buf + 3 + strlen(TEST_U32_NAME) + 1) = AA_U32; + *((u32 *)(buf + 3 + strlen(TEST_U32_NAME) + 2)) = TEST_U32_DATA; + + buf = e->start + TEST_NAMED_U64_BUF_OFFSET; + *buf = AA_NAME; + *(buf + 1) = strlen(TEST_U64_NAME) + 1; + strcpy(buf + 3, TEST_U64_NAME); + *(buf + 3 + strlen(TEST_U64_NAME) + 1) = AA_U64; + *((u64 *)(buf + 3 + strlen(TEST_U64_NAME) + 2)) = TEST_U64_DATA; + + buf = e->start + TEST_NAMED_BLOB_BUF_OFFSET; + *buf = AA_NAME; + *(buf + 1) = strlen(TEST_BLOB_NAME) + 1; + strcpy(buf + 3, TEST_BLOB_NAME); + *(buf + 3 + strlen(TEST_BLOB_NAME) + 1) = AA_BLOB; + *(buf + 3 + strlen(TEST_BLOB_NAME) + 2) = TEST_BLOB_DATA_SIZE; + memcpy(buf + 3 + strlen(TEST_BLOB_NAME) + 6, + TEST_BLOB_DATA, TEST_BLOB_DATA_SIZE); + + buf = e->start + TEST_NAMED_ARRAY_BUF_OFFSET; + *buf = AA_NAME; + *(buf + 1) = strlen(TEST_ARRAY_NAME) + 1; + strcpy(buf + 3, TEST_ARRAY_NAME); + *(buf + 3 + strlen(TEST_ARRAY_NAME) + 1) = AA_ARRAY; + *((u16 *)(buf + 3 + strlen(TEST_ARRAY_NAME) + 2)) = TEST_ARRAY_SIZE; + + return e; +} + +static int policy_unpack_test_init(struct kunit *test) +{ + size_t e_size = TEST_ARRAY_BUF_OFFSET + sizeof(u16) + 1; + struct policy_unpack_fixture *puf; + + puf = kunit_kmalloc(test, sizeof(*puf), GFP_USER); + KUNIT_EXPECT_NOT_ERR_OR_NULL(test, puf); + + puf->e_size = e_size; + puf->e = build_aa_ext_struct(puf, test, e_size); + + test->priv = puf; + return 0; +} + +static void policy_unpack_test_inbounds_when_inbounds(struct kunit *test) +{ + struct policy_unpack_fixture *puf = test->priv; + + KUNIT_EXPECT_TRUE(test, aa_inbounds(puf->e, 0)); + KUNIT_EXPECT_TRUE(test, aa_inbounds(puf->e, puf->e_size / 2)); + KUNIT_EXPECT_TRUE(test, aa_inbounds(puf->e, puf->e_size)); +} + +static void policy_unpack_test_inbounds_when_out_of_bounds(struct kunit *test) +{ + struct policy_unpack_fixture *puf = test->priv; + + KUNIT_EXPECT_FALSE(test, aa_inbounds(puf->e, puf->e_size + 1)); +} + +static void policy_unpack_test_unpack_array_with_null_name(struct kunit *test) +{ + struct policy_unpack_fixture *puf = test->priv; + u16 array_size; + + puf->e->pos += TEST_ARRAY_BUF_OFFSET; + + array_size = aa_unpack_array(puf->e, NULL); + + KUNIT_EXPECT_EQ(test, array_size, (u16)TEST_ARRAY_SIZE); + KUNIT_EXPECT_PTR_EQ(test, puf->e->pos, + puf->e->start + TEST_ARRAY_BUF_OFFSET + sizeof(u16) + 1); +} + +static void policy_unpack_test_unpack_array_with_name(struct kunit *test) +{ + struct policy_unpack_fixture *puf = test->priv; + const char name[] = TEST_ARRAY_NAME; + u16 array_size; + + puf->e->pos += TEST_NAMED_ARRAY_BUF_OFFSET; + + array_size = aa_unpack_array(puf->e, name); + + KUNIT_EXPECT_EQ(test, array_size, (u16)TEST_ARRAY_SIZE); + KUNIT_EXPECT_PTR_EQ(test, puf->e->pos, + puf->e->start + TEST_ARRAY_BUF_OFFSET + sizeof(u16) + 1); +} + +static void policy_unpack_test_unpack_array_out_of_bounds(struct kunit *test) +{ + struct policy_unpack_fixture *puf = test->priv; + const char name[] = TEST_ARRAY_NAME; + u16 array_size; + + puf->e->pos += TEST_NAMED_ARRAY_BUF_OFFSET; + puf->e->end = puf->e->start + TEST_ARRAY_BUF_OFFSET + sizeof(u16); + + array_size = aa_unpack_array(puf->e, name); + + KUNIT_EXPECT_EQ(test, array_size, 0); + KUNIT_EXPECT_PTR_EQ(test, puf->e->pos, + puf->e->start + TEST_NAMED_ARRAY_BUF_OFFSET); +} + +static void policy_unpack_test_unpack_blob_with_null_name(struct kunit *test) +{ + struct policy_unpack_fixture *puf = test->priv; + char *blob = NULL; + size_t size; + + puf->e->pos += TEST_BLOB_BUF_OFFSET; + size = aa_unpack_blob(puf->e, &blob, NULL); + + KUNIT_ASSERT_EQ(test, size, TEST_BLOB_DATA_SIZE); + KUNIT_EXPECT_TRUE(test, + memcmp(blob, TEST_BLOB_DATA, TEST_BLOB_DATA_SIZE) == 0); +} + +static void policy_unpack_test_unpack_blob_with_name(struct kunit *test) +{ + struct policy_unpack_fixture *puf = test->priv; + char *blob = NULL; + size_t size; + + puf->e->pos += TEST_NAMED_BLOB_BUF_OFFSET; + size = aa_unpack_blob(puf->e, &blob, TEST_BLOB_NAME); + + KUNIT_ASSERT_EQ(test, size, TEST_BLOB_DATA_SIZE); + KUNIT_EXPECT_TRUE(test, + memcmp(blob, TEST_BLOB_DATA, TEST_BLOB_DATA_SIZE) == 0); +} + +static void policy_unpack_test_unpack_blob_out_of_bounds(struct kunit *test) +{ + struct policy_unpack_fixture *puf = test->priv; + char *blob = NULL; + void *start; + int size; + + puf->e->pos += TEST_NAMED_BLOB_BUF_OFFSET; + start = puf->e->pos; + puf->e->end = puf->e->start + TEST_BLOB_BUF_OFFSET + + TEST_BLOB_DATA_SIZE - 1; + + size = aa_unpack_blob(puf->e, &blob, TEST_BLOB_NAME); + + KUNIT_EXPECT_EQ(test, size, 0); + KUNIT_EXPECT_PTR_EQ(test, puf->e->pos, start); +} + +static void policy_unpack_test_unpack_str_with_null_name(struct kunit *test) +{ + struct policy_unpack_fixture *puf = test->priv; + const char *string = NULL; + size_t size; + + puf->e->pos += TEST_STRING_BUF_OFFSET; + size = aa_unpack_str(puf->e, &string, NULL); + + KUNIT_EXPECT_EQ(test, size, strlen(TEST_STRING_DATA) + 1); + KUNIT_EXPECT_STREQ(test, string, TEST_STRING_DATA); +} + +static void policy_unpack_test_unpack_str_with_name(struct kunit *test) +{ + struct policy_unpack_fixture *puf = test->priv; + const char *string = NULL; + size_t size; + + size = aa_unpack_str(puf->e, &string, TEST_STRING_NAME); + + KUNIT_EXPECT_EQ(test, size, strlen(TEST_STRING_DATA) + 1); + KUNIT_EXPECT_STREQ(test, string, TEST_STRING_DATA); +} + +static void policy_unpack_test_unpack_str_out_of_bounds(struct kunit *test) +{ + struct policy_unpack_fixture *puf = test->priv; + const char *string = NULL; + void *start = puf->e->pos; + int size; + + puf->e->end = puf->e->pos + TEST_STRING_BUF_OFFSET + + strlen(TEST_STRING_DATA) - 1; + + size = aa_unpack_str(puf->e, &string, TEST_STRING_NAME); + + KUNIT_EXPECT_EQ(test, size, 0); + KUNIT_EXPECT_PTR_EQ(test, puf->e->pos, start); +} + +static void policy_unpack_test_unpack_strdup_with_null_name(struct kunit *test) +{ + struct policy_unpack_fixture *puf = test->priv; + char *string = NULL; + size_t size; + + puf->e->pos += TEST_STRING_BUF_OFFSET; + size = aa_unpack_strdup(puf->e, &string, NULL); + + KUNIT_EXPECT_EQ(test, size, strlen(TEST_STRING_DATA) + 1); + KUNIT_EXPECT_FALSE(test, + ((uintptr_t)puf->e->start <= (uintptr_t)string) + && ((uintptr_t)string <= (uintptr_t)puf->e->end)); + KUNIT_EXPECT_STREQ(test, string, TEST_STRING_DATA); +} + +static void policy_unpack_test_unpack_strdup_with_name(struct kunit *test) +{ + struct policy_unpack_fixture *puf = test->priv; + char *string = NULL; + size_t size; + + size = aa_unpack_strdup(puf->e, &string, TEST_STRING_NAME); + + KUNIT_EXPECT_EQ(test, size, strlen(TEST_STRING_DATA) + 1); + KUNIT_EXPECT_FALSE(test, + ((uintptr_t)puf->e->start <= (uintptr_t)string) + && ((uintptr_t)string <= (uintptr_t)puf->e->end)); + KUNIT_EXPECT_STREQ(test, string, TEST_STRING_DATA); +} + +static void policy_unpack_test_unpack_strdup_out_of_bounds(struct kunit *test) +{ + struct policy_unpack_fixture *puf = test->priv; + void *start = puf->e->pos; + char *string = NULL; + int size; + + puf->e->end = puf->e->pos + TEST_STRING_BUF_OFFSET + + strlen(TEST_STRING_DATA) - 1; + + size = aa_unpack_strdup(puf->e, &string, TEST_STRING_NAME); + + KUNIT_EXPECT_EQ(test, size, 0); + KUNIT_EXPECT_NULL(test, string); + KUNIT_EXPECT_PTR_EQ(test, puf->e->pos, start); +} + +static void policy_unpack_test_unpack_nameX_with_null_name(struct kunit *test) +{ + struct policy_unpack_fixture *puf = test->priv; + bool success; + + puf->e->pos += TEST_U32_BUF_OFFSET; + + success = aa_unpack_nameX(puf->e, AA_U32, NULL); + + KUNIT_EXPECT_TRUE(test, success); + KUNIT_EXPECT_PTR_EQ(test, puf->e->pos, + puf->e->start + TEST_U32_BUF_OFFSET + 1); +} + +static void policy_unpack_test_unpack_nameX_with_wrong_code(struct kunit *test) +{ + struct policy_unpack_fixture *puf = test->priv; + bool success; + + puf->e->pos += TEST_U32_BUF_OFFSET; + + success = aa_unpack_nameX(puf->e, AA_BLOB, NULL); + + KUNIT_EXPECT_FALSE(test, success); + KUNIT_EXPECT_PTR_EQ(test, puf->e->pos, + puf->e->start + TEST_U32_BUF_OFFSET); +} + +static void policy_unpack_test_unpack_nameX_with_name(struct kunit *test) +{ + struct policy_unpack_fixture *puf = test->priv; + const char name[] = TEST_U32_NAME; + bool success; + + puf->e->pos += TEST_NAMED_U32_BUF_OFFSET; + + success = aa_unpack_nameX(puf->e, AA_U32, name); + + KUNIT_EXPECT_TRUE(test, success); + KUNIT_EXPECT_PTR_EQ(test, puf->e->pos, + puf->e->start + TEST_U32_BUF_OFFSET + 1); +} + +static void policy_unpack_test_unpack_nameX_with_wrong_name(struct kunit *test) +{ + struct policy_unpack_fixture *puf = test->priv; + static const char name[] = "12345678"; + bool success; + + puf->e->pos += TEST_NAMED_U32_BUF_OFFSET; + + success = aa_unpack_nameX(puf->e, AA_U32, name); + + KUNIT_EXPECT_FALSE(test, success); + KUNIT_EXPECT_PTR_EQ(test, puf->e->pos, + puf->e->start + TEST_NAMED_U32_BUF_OFFSET); +} + +static void policy_unpack_test_unpack_u16_chunk_basic(struct kunit *test) +{ + struct policy_unpack_fixture *puf = test->priv; + char *chunk = NULL; + size_t size; + + puf->e->pos += TEST_U16_OFFSET; + /* + * WARNING: For unit testing purposes, we're pushing puf->e->end past + * the end of the allocated memory. Doing anything other than comparing + * memory addresses is dangerous. + */ + puf->e->end += TEST_U16_DATA; + + size = aa_unpack_u16_chunk(puf->e, &chunk); + + KUNIT_EXPECT_PTR_EQ(test, chunk, + puf->e->start + TEST_U16_OFFSET + 2); + KUNIT_EXPECT_EQ(test, size, TEST_U16_DATA); + KUNIT_EXPECT_PTR_EQ(test, puf->e->pos, (chunk + TEST_U16_DATA)); +} + +static void policy_unpack_test_unpack_u16_chunk_out_of_bounds_1( + struct kunit *test) +{ + struct policy_unpack_fixture *puf = test->priv; + char *chunk = NULL; + size_t size; + + puf->e->pos = puf->e->end - 1; + + size = aa_unpack_u16_chunk(puf->e, &chunk); + + KUNIT_EXPECT_EQ(test, size, 0); + KUNIT_EXPECT_NULL(test, chunk); + KUNIT_EXPECT_PTR_EQ(test, puf->e->pos, puf->e->end - 1); +} + +static void policy_unpack_test_unpack_u16_chunk_out_of_bounds_2( + struct kunit *test) +{ + struct policy_unpack_fixture *puf = test->priv; + char *chunk = NULL; + size_t size; + + puf->e->pos += TEST_U16_OFFSET; + /* + * WARNING: For unit testing purposes, we're pushing puf->e->end past + * the end of the allocated memory. Doing anything other than comparing + * memory addresses is dangerous. + */ + puf->e->end = puf->e->pos + TEST_U16_DATA - 1; + + size = aa_unpack_u16_chunk(puf->e, &chunk); + + KUNIT_EXPECT_EQ(test, size, 0); + KUNIT_EXPECT_NULL(test, chunk); + KUNIT_EXPECT_PTR_EQ(test, puf->e->pos, puf->e->start + TEST_U16_OFFSET); +} + +static void policy_unpack_test_unpack_u32_with_null_name(struct kunit *test) +{ + struct policy_unpack_fixture *puf = test->priv; + bool success; + u32 data = 0; + + puf->e->pos += TEST_U32_BUF_OFFSET; + + success = aa_unpack_u32(puf->e, &data, NULL); + + KUNIT_EXPECT_TRUE(test, success); + KUNIT_EXPECT_EQ(test, data, TEST_U32_DATA); + KUNIT_EXPECT_PTR_EQ(test, puf->e->pos, + puf->e->start + TEST_U32_BUF_OFFSET + sizeof(u32) + 1); +} + +static void policy_unpack_test_unpack_u32_with_name(struct kunit *test) +{ + struct policy_unpack_fixture *puf = test->priv; + const char name[] = TEST_U32_NAME; + bool success; + u32 data = 0; + + puf->e->pos += TEST_NAMED_U32_BUF_OFFSET; + + success = aa_unpack_u32(puf->e, &data, name); + + KUNIT_EXPECT_TRUE(test, success); + KUNIT_EXPECT_EQ(test, data, TEST_U32_DATA); + KUNIT_EXPECT_PTR_EQ(test, puf->e->pos, + puf->e->start + TEST_U32_BUF_OFFSET + sizeof(u32) + 1); +} + +static void policy_unpack_test_unpack_u32_out_of_bounds(struct kunit *test) +{ + struct policy_unpack_fixture *puf = test->priv; + const char name[] = TEST_U32_NAME; + bool success; + u32 data = 0; + + puf->e->pos += TEST_NAMED_U32_BUF_OFFSET; + puf->e->end = puf->e->start + TEST_U32_BUF_OFFSET + sizeof(u32); + + success = aa_unpack_u32(puf->e, &data, name); + + KUNIT_EXPECT_FALSE(test, success); + KUNIT_EXPECT_PTR_EQ(test, puf->e->pos, + puf->e->start + TEST_NAMED_U32_BUF_OFFSET); +} + +static void policy_unpack_test_unpack_u64_with_null_name(struct kunit *test) +{ + struct policy_unpack_fixture *puf = test->priv; + bool success; + u64 data = 0; + + puf->e->pos += TEST_U64_BUF_OFFSET; + + success = aa_unpack_u64(puf->e, &data, NULL); + + KUNIT_EXPECT_TRUE(test, success); + KUNIT_EXPECT_EQ(test, data, TEST_U64_DATA); + KUNIT_EXPECT_PTR_EQ(test, puf->e->pos, + puf->e->start + TEST_U64_BUF_OFFSET + sizeof(u64) + 1); +} + +static void policy_unpack_test_unpack_u64_with_name(struct kunit *test) +{ + struct policy_unpack_fixture *puf = test->priv; + const char name[] = TEST_U64_NAME; + bool success; + u64 data = 0; + + puf->e->pos += TEST_NAMED_U64_BUF_OFFSET; + + success = aa_unpack_u64(puf->e, &data, name); + + KUNIT_EXPECT_TRUE(test, success); + KUNIT_EXPECT_EQ(test, data, TEST_U64_DATA); + KUNIT_EXPECT_PTR_EQ(test, puf->e->pos, + puf->e->start + TEST_U64_BUF_OFFSET + sizeof(u64) + 1); +} + +static void policy_unpack_test_unpack_u64_out_of_bounds(struct kunit *test) +{ + struct policy_unpack_fixture *puf = test->priv; + const char name[] = TEST_U64_NAME; + bool success; + u64 data = 0; + + puf->e->pos += TEST_NAMED_U64_BUF_OFFSET; + puf->e->end = puf->e->start + TEST_U64_BUF_OFFSET + sizeof(u64); + + success = aa_unpack_u64(puf->e, &data, name); + + KUNIT_EXPECT_FALSE(test, success); + KUNIT_EXPECT_PTR_EQ(test, puf->e->pos, + puf->e->start + TEST_NAMED_U64_BUF_OFFSET); +} + +static void policy_unpack_test_unpack_X_code_match(struct kunit *test) +{ + struct policy_unpack_fixture *puf = test->priv; + bool success = aa_unpack_X(puf->e, AA_NAME); + + KUNIT_EXPECT_TRUE(test, success); + KUNIT_EXPECT_TRUE(test, puf->e->pos == puf->e->start + 1); +} + +static void policy_unpack_test_unpack_X_code_mismatch(struct kunit *test) +{ + struct policy_unpack_fixture *puf = test->priv; + bool success = aa_unpack_X(puf->e, AA_STRING); + + KUNIT_EXPECT_FALSE(test, success); + KUNIT_EXPECT_TRUE(test, puf->e->pos == puf->e->start); +} + +static void policy_unpack_test_unpack_X_out_of_bounds(struct kunit *test) +{ + struct policy_unpack_fixture *puf = test->priv; + bool success; + + puf->e->pos = puf->e->end; + success = aa_unpack_X(puf->e, AA_NAME); + + KUNIT_EXPECT_FALSE(test, success); +} + +static struct kunit_case apparmor_policy_unpack_test_cases[] = { + KUNIT_CASE(policy_unpack_test_inbounds_when_inbounds), + KUNIT_CASE(policy_unpack_test_inbounds_when_out_of_bounds), + KUNIT_CASE(policy_unpack_test_unpack_array_with_null_name), + KUNIT_CASE(policy_unpack_test_unpack_array_with_name), + KUNIT_CASE(policy_unpack_test_unpack_array_out_of_bounds), + KUNIT_CASE(policy_unpack_test_unpack_blob_with_null_name), + KUNIT_CASE(policy_unpack_test_unpack_blob_with_name), + KUNIT_CASE(policy_unpack_test_unpack_blob_out_of_bounds), + KUNIT_CASE(policy_unpack_test_unpack_nameX_with_null_name), + KUNIT_CASE(policy_unpack_test_unpack_nameX_with_wrong_code), + KUNIT_CASE(policy_unpack_test_unpack_nameX_with_name), + KUNIT_CASE(policy_unpack_test_unpack_nameX_with_wrong_name), + KUNIT_CASE(policy_unpack_test_unpack_str_with_null_name), + KUNIT_CASE(policy_unpack_test_unpack_str_with_name), + KUNIT_CASE(policy_unpack_test_unpack_str_out_of_bounds), + KUNIT_CASE(policy_unpack_test_unpack_strdup_with_null_name), + KUNIT_CASE(policy_unpack_test_unpack_strdup_with_name), + KUNIT_CASE(policy_unpack_test_unpack_strdup_out_of_bounds), + KUNIT_CASE(policy_unpack_test_unpack_u16_chunk_basic), + KUNIT_CASE(policy_unpack_test_unpack_u16_chunk_out_of_bounds_1), + KUNIT_CASE(policy_unpack_test_unpack_u16_chunk_out_of_bounds_2), + KUNIT_CASE(policy_unpack_test_unpack_u32_with_null_name), + KUNIT_CASE(policy_unpack_test_unpack_u32_with_name), + KUNIT_CASE(policy_unpack_test_unpack_u32_out_of_bounds), + KUNIT_CASE(policy_unpack_test_unpack_u64_with_null_name), + KUNIT_CASE(policy_unpack_test_unpack_u64_with_name), + KUNIT_CASE(policy_unpack_test_unpack_u64_out_of_bounds), + KUNIT_CASE(policy_unpack_test_unpack_X_code_match), + KUNIT_CASE(policy_unpack_test_unpack_X_code_mismatch), + KUNIT_CASE(policy_unpack_test_unpack_X_out_of_bounds), + {}, +}; + +static struct kunit_suite apparmor_policy_unpack_test_module = { + .name = "apparmor_policy_unpack", + .init = policy_unpack_test_init, + .test_cases = apparmor_policy_unpack_test_cases, +}; + +kunit_test_suite(apparmor_policy_unpack_test_module); + +MODULE_LICENSE("GPL"); diff --git a/security/apparmor/procattr.c b/security/apparmor/procattr.c new file mode 100644 index 000000000..86ad26ef7 --- /dev/null +++ b/security/apparmor/procattr.c @@ -0,0 +1,136 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * AppArmor security module + * + * This file contains AppArmor /proc/<pid>/attr/ interface functions + * + * Copyright (C) 1998-2008 Novell/SUSE + * Copyright 2009-2010 Canonical Ltd. + */ + +#include "include/apparmor.h" +#include "include/cred.h" +#include "include/policy.h" +#include "include/policy_ns.h" +#include "include/domain.h" +#include "include/procattr.h" + + +/** + * aa_getprocattr - Return the profile information for @profile + * @profile: the profile to print profile info about (NOT NULL) + * @string: Returns - string containing the profile info (NOT NULL) + * + * Requires: profile != NULL + * + * Creates a string containing the namespace_name://profile_name for + * @profile. + * + * Returns: size of string placed in @string else error code on failure + */ +int aa_getprocattr(struct aa_label *label, char **string) +{ + struct aa_ns *ns = labels_ns(label); + struct aa_ns *current_ns = aa_get_current_ns(); + int len; + + if (!aa_ns_visible(current_ns, ns, true)) { + aa_put_ns(current_ns); + return -EACCES; + } + + len = aa_label_snxprint(NULL, 0, current_ns, label, + FLAG_SHOW_MODE | FLAG_VIEW_SUBNS | + FLAG_HIDDEN_UNCONFINED); + AA_BUG(len < 0); + + *string = kmalloc(len + 2, GFP_KERNEL); + if (!*string) { + aa_put_ns(current_ns); + return -ENOMEM; + } + + len = aa_label_snxprint(*string, len + 2, current_ns, label, + FLAG_SHOW_MODE | FLAG_VIEW_SUBNS | + FLAG_HIDDEN_UNCONFINED); + if (len < 0) { + aa_put_ns(current_ns); + return len; + } + + (*string)[len] = '\n'; + (*string)[len + 1] = 0; + + aa_put_ns(current_ns); + return len + 1; +} + +/** + * split_token_from_name - separate a string of form <token>^<name> + * @op: operation being checked + * @args: string to parse (NOT NULL) + * @token: stores returned parsed token value (NOT NULL) + * + * Returns: start position of name after token else NULL on failure + */ +static char *split_token_from_name(const char *op, char *args, u64 *token) +{ + char *name; + + *token = simple_strtoull(args, &name, 16); + if ((name == args) || *name != '^') { + AA_ERROR("%s: Invalid input '%s'", op, args); + return ERR_PTR(-EINVAL); + } + + name++; /* skip ^ */ + if (!*name) + name = NULL; + return name; +} + +/** + * aa_setprocattr_changehat - handle procattr interface to change_hat + * @args: args received from writing to /proc/<pid>/attr/current (NOT NULL) + * @size: size of the args + * @flags: set of flags governing behavior + * + * Returns: %0 or error code if change_hat fails + */ +int aa_setprocattr_changehat(char *args, size_t size, int flags) +{ + char *hat; + u64 token; + const char *hats[16]; /* current hard limit on # of names */ + int count = 0; + + hat = split_token_from_name(OP_CHANGE_HAT, args, &token); + if (IS_ERR(hat)) + return PTR_ERR(hat); + + if (!hat && !token) { + AA_ERROR("change_hat: Invalid input, NULL hat and NULL magic"); + return -EINVAL; + } + + if (hat) { + /* set up hat name vector, args guaranteed null terminated + * at args[size] by setprocattr. + * + * If there are multiple hat names in the buffer each is + * separated by a \0. Ie. userspace writes them pre tokenized + */ + char *end = args + size; + for (count = 0; (hat < end) && count < 16; ++count) { + char *next = hat + strlen(hat) + 1; + hats[count] = hat; + AA_DEBUG("%s: (pid %d) Magic 0x%llx count %d hat '%s'\n" + , __func__, current->pid, token, count, hat); + hat = next; + } + } else + AA_DEBUG("%s: (pid %d) Magic 0x%llx count %d Hat '%s'\n", + __func__, current->pid, token, count, "<NULL>"); + + return aa_change_hat(hats, count, token, flags); +} diff --git a/security/apparmor/resource.c b/security/apparmor/resource.c new file mode 100644 index 000000000..1ae487425 --- /dev/null +++ b/security/apparmor/resource.c @@ -0,0 +1,187 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * AppArmor security module + * + * This file contains AppArmor resource mediation and attachment + * + * Copyright (C) 1998-2008 Novell/SUSE + * Copyright 2009-2010 Canonical Ltd. + */ + +#include <linux/audit.h> +#include <linux/security.h> + +#include "include/audit.h" +#include "include/cred.h" +#include "include/resource.h" +#include "include/policy.h" + +/* + * Table of rlimit names: we generate it from resource.h. + */ +#include "rlim_names.h" + +struct aa_sfs_entry aa_sfs_entry_rlimit[] = { + AA_SFS_FILE_STRING("mask", AA_SFS_RLIMIT_MASK), + { } +}; + +/* audit callback for resource specific fields */ +static void audit_cb(struct audit_buffer *ab, void *va) +{ + struct common_audit_data *sa = va; + + audit_log_format(ab, " rlimit=%s value=%lu", + rlim_names[aad(sa)->rlim.rlim], aad(sa)->rlim.max); + if (aad(sa)->peer) { + audit_log_format(ab, " peer="); + aa_label_xaudit(ab, labels_ns(aad(sa)->label), aad(sa)->peer, + FLAGS_NONE, GFP_ATOMIC); + } +} + +/** + * audit_resource - audit setting resource limit + * @profile: profile being enforced (NOT NULL) + * @resource: rlimit being auditing + * @value: value being set + * @error: error value + * + * Returns: 0 or sa->error else other error code on failure + */ +static int audit_resource(struct aa_profile *profile, unsigned int resource, + unsigned long value, struct aa_label *peer, + const char *info, int error) +{ + DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, OP_SETRLIMIT); + + aad(&sa)->rlim.rlim = resource; + aad(&sa)->rlim.max = value; + aad(&sa)->peer = peer; + aad(&sa)->info = info; + aad(&sa)->error = error; + + return aa_audit(AUDIT_APPARMOR_AUTO, profile, &sa, audit_cb); +} + +/** + * aa_map_resouce - map compiled policy resource to internal # + * @resource: flattened policy resource number + * + * Returns: resource # for the current architecture. + * + * rlimit resource can vary based on architecture, map the compiled policy + * resource # to the internal representation for the architecture. + */ +int aa_map_resource(int resource) +{ + return rlim_map[resource]; +} + +static int profile_setrlimit(struct aa_profile *profile, unsigned int resource, + struct rlimit *new_rlim) +{ + int e = 0; + + if (profile->rlimits.mask & (1 << resource) && new_rlim->rlim_max > + profile->rlimits.limits[resource].rlim_max) + e = -EACCES; + return audit_resource(profile, resource, new_rlim->rlim_max, NULL, NULL, + e); +} + +/** + * aa_task_setrlimit - test permission to set an rlimit + * @label - label confining the task (NOT NULL) + * @task - task the resource is being set on + * @resource - the resource being set + * @new_rlim - the new resource limit (NOT NULL) + * + * Control raising the processes hard limit. + * + * Returns: 0 or error code if setting resource failed + */ +int aa_task_setrlimit(struct aa_label *label, struct task_struct *task, + unsigned int resource, struct rlimit *new_rlim) +{ + struct aa_profile *profile; + struct aa_label *peer; + int error = 0; + + rcu_read_lock(); + peer = aa_get_newest_cred_label(__task_cred(task)); + rcu_read_unlock(); + + /* TODO: extend resource control to handle other (non current) + * profiles. AppArmor rules currently have the implicit assumption + * that the task is setting the resource of a task confined with + * the same profile or that the task setting the resource of another + * task has CAP_SYS_RESOURCE. + */ + + if (label != peer && + aa_capable(label, CAP_SYS_RESOURCE, CAP_OPT_NOAUDIT) != 0) + error = fn_for_each(label, profile, + audit_resource(profile, resource, + new_rlim->rlim_max, peer, + "cap_sys_resource", -EACCES)); + else + error = fn_for_each_confined(label, profile, + profile_setrlimit(profile, resource, new_rlim)); + aa_put_label(peer); + + return error; +} + +/** + * __aa_transition_rlimits - apply new profile rlimits + * @old_l: old label on task (NOT NULL) + * @new_l: new label with rlimits to apply (NOT NULL) + */ +void __aa_transition_rlimits(struct aa_label *old_l, struct aa_label *new_l) +{ + unsigned int mask = 0; + struct rlimit *rlim, *initrlim; + struct aa_profile *old, *new; + struct label_it i; + + old = labels_profile(old_l); + new = labels_profile(new_l); + + /* for any rlimits the profile controlled, reset the soft limit + * to the lesser of the tasks hard limit and the init tasks soft limit + */ + label_for_each_confined(i, old_l, old) { + if (old->rlimits.mask) { + int j; + + for (j = 0, mask = 1; j < RLIM_NLIMITS; j++, + mask <<= 1) { + if (old->rlimits.mask & mask) { + rlim = current->signal->rlim + j; + initrlim = init_task.signal->rlim + j; + rlim->rlim_cur = min(rlim->rlim_max, + initrlim->rlim_cur); + } + } + } + } + + /* set any new hard limits as dictated by the new profile */ + label_for_each_confined(i, new_l, new) { + int j; + + if (!new->rlimits.mask) + continue; + for (j = 0, mask = 1; j < RLIM_NLIMITS; j++, mask <<= 1) { + if (!(new->rlimits.mask & mask)) + continue; + + rlim = current->signal->rlim + j; + rlim->rlim_max = min(rlim->rlim_max, + new->rlimits.limits[j].rlim_max); + /* soft limit should not exceed hard limit */ + rlim->rlim_cur = min(rlim->rlim_cur, rlim->rlim_max); + } + } +} diff --git a/security/apparmor/secid.c b/security/apparmor/secid.c new file mode 100644 index 000000000..24a0e23f1 --- /dev/null +++ b/security/apparmor/secid.c @@ -0,0 +1,149 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * AppArmor security module + * + * This file contains AppArmor security identifier (secid) manipulation fns + * + * Copyright 2009-2017 Canonical Ltd. + * + * AppArmor allocates a unique secid for every label used. If a label + * is replaced it receives the secid of the label it is replacing. + */ + +#include <linux/errno.h> +#include <linux/err.h> +#include <linux/gfp.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/xarray.h> + +#include "include/cred.h" +#include "include/lib.h" +#include "include/secid.h" +#include "include/label.h" +#include "include/policy_ns.h" + +/* + * secids - do not pin labels with a refcount. They rely on the label + * properly updating/freeing them + */ +#define AA_FIRST_SECID 2 + +static DEFINE_XARRAY_FLAGS(aa_secids, XA_FLAGS_LOCK_IRQ | XA_FLAGS_TRACK_FREE); + +int apparmor_display_secid_mode; + +/* + * TODO: allow policy to reserve a secid range? + * TODO: add secid pinning + * TODO: use secid_update in label replace + */ + +/** + * aa_secid_update - update a secid mapping to a new label + * @secid: secid to update + * @label: label the secid will now map to + */ +void aa_secid_update(u32 secid, struct aa_label *label) +{ + unsigned long flags; + + xa_lock_irqsave(&aa_secids, flags); + __xa_store(&aa_secids, secid, label, 0); + xa_unlock_irqrestore(&aa_secids, flags); +} + +/** + * + * see label for inverse aa_label_to_secid + */ +struct aa_label *aa_secid_to_label(u32 secid) +{ + return xa_load(&aa_secids, secid); +} + +int apparmor_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) +{ + /* TODO: cache secctx and ref count so we don't have to recreate */ + struct aa_label *label = aa_secid_to_label(secid); + int flags = FLAG_VIEW_SUBNS | FLAG_HIDDEN_UNCONFINED | FLAG_ABS_ROOT; + int len; + + AA_BUG(!seclen); + + if (!label) + return -EINVAL; + + if (apparmor_display_secid_mode) + flags |= FLAG_SHOW_MODE; + + if (secdata) + len = aa_label_asxprint(secdata, root_ns, label, + flags, GFP_ATOMIC); + else + len = aa_label_snxprint(NULL, 0, root_ns, label, flags); + + if (len < 0) + return -ENOMEM; + + *seclen = len; + + return 0; +} + +int apparmor_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid) +{ + struct aa_label *label; + + label = aa_label_strn_parse(&root_ns->unconfined->label, secdata, + seclen, GFP_KERNEL, false, false); + if (IS_ERR(label)) + return PTR_ERR(label); + *secid = label->secid; + + return 0; +} + +void apparmor_release_secctx(char *secdata, u32 seclen) +{ + kfree(secdata); +} + +/** + * aa_alloc_secid - allocate a new secid for a profile + * @label: the label to allocate a secid for + * @gfp: memory allocation flags + * + * Returns: 0 with @label->secid initialized + * <0 returns error with @label->secid set to AA_SECID_INVALID + */ +int aa_alloc_secid(struct aa_label *label, gfp_t gfp) +{ + unsigned long flags; + int ret; + + xa_lock_irqsave(&aa_secids, flags); + ret = __xa_alloc(&aa_secids, &label->secid, label, + XA_LIMIT(AA_FIRST_SECID, INT_MAX), gfp); + xa_unlock_irqrestore(&aa_secids, flags); + + if (ret < 0) { + label->secid = AA_SECID_INVALID; + return ret; + } + + return 0; +} + +/** + * aa_free_secid - free a secid + * @secid: secid to free + */ +void aa_free_secid(u32 secid) +{ + unsigned long flags; + + xa_lock_irqsave(&aa_secids, flags); + __xa_erase(&aa_secids, secid); + xa_unlock_irqrestore(&aa_secids, flags); +} diff --git a/security/apparmor/stacksplitdfa.in b/security/apparmor/stacksplitdfa.in new file mode 100644 index 000000000..4bddd10b6 --- /dev/null +++ b/security/apparmor/stacksplitdfa.in @@ -0,0 +1,114 @@ +/* 0x1 [^\000]*[^/\000]//& */ 0x1B, 0x5E, 0x78, 0x3D, 0x00, 0x00, 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instead creates a new one. Ideally the task + * should return to the previous cred if it has not been modified. + */ + +#include <linux/gfp.h> +#include <linux/ptrace.h> + +#include "include/audit.h" +#include "include/cred.h" +#include "include/policy.h" +#include "include/task.h" + +/** + * aa_get_task_label - Get another task's label + * @task: task to query (NOT NULL) + * + * Returns: counted reference to @task's label + */ +struct aa_label *aa_get_task_label(struct task_struct *task) +{ + struct aa_label *p; + + rcu_read_lock(); + p = aa_get_newest_label(__aa_task_raw_label(task)); + rcu_read_unlock(); + + return p; +} + +/** + * aa_replace_current_label - replace the current tasks label + * @label: new label (NOT NULL) + * + * Returns: 0 or error on failure + */ +int aa_replace_current_label(struct aa_label *label) +{ + struct aa_label *old = aa_current_raw_label(); + struct aa_task_ctx *ctx = task_ctx(current); + struct cred *new; + + AA_BUG(!label); + + if (old == label) + return 0; + + if (current_cred() != current_real_cred()) + return -EBUSY; + + new = prepare_creds(); + if (!new) + return -ENOMEM; + + if (ctx->nnp && label_is_stale(ctx->nnp)) { + struct aa_label *tmp = ctx->nnp; + + ctx->nnp = aa_get_newest_label(tmp); + aa_put_label(tmp); + } + if (unconfined(label) || (labels_ns(old) != labels_ns(label))) + /* + * if switching to unconfined or a different label namespace + * clear out context state + */ + aa_clear_task_ctx_trans(task_ctx(current)); + + /* + * be careful switching cred label, when racing replacement it + * is possible that the cred labels's->proxy->label is the reference + * keeping @label valid, so make sure to get its reference before + * dropping the reference on the cred's label + */ + aa_get_label(label); + aa_put_label(cred_label(new)); + set_cred_label(new, label); + + commit_creds(new); + return 0; +} + + +/** + * aa_set_current_onexec - set the tasks change_profile to happen onexec + * @label: system label to set at exec (MAYBE NULL to clear value) + * @stack: whether stacking should be done + * Returns: 0 or error on failure + */ +int aa_set_current_onexec(struct aa_label *label, bool stack) +{ + struct aa_task_ctx *ctx = task_ctx(current); + + aa_get_label(label); + aa_put_label(ctx->onexec); + ctx->onexec = label; + ctx->token = stack; + + return 0; +} + +/** + * aa_set_current_hat - set the current tasks hat + * @label: label to set as the current hat (NOT NULL) + * @token: token value that must be specified to change from the hat + * + * Do switch of tasks hat. If the task is currently in a hat + * validate the token to match. + * + * Returns: 0 or error on failure + */ +int aa_set_current_hat(struct aa_label *label, u64 token) +{ + struct aa_task_ctx *ctx = task_ctx(current); + struct cred *new; + + new = prepare_creds(); + if (!new) + return -ENOMEM; + AA_BUG(!label); + + if (!ctx->previous) { + /* transfer refcount */ + ctx->previous = cred_label(new); + ctx->token = token; + } else if (ctx->token == token) { + aa_put_label(cred_label(new)); + } else { + /* previous_profile && ctx->token != token */ + abort_creds(new); + return -EACCES; + } + + set_cred_label(new, aa_get_newest_label(label)); + /* clear exec on switching context */ + aa_put_label(ctx->onexec); + ctx->onexec = NULL; + + commit_creds(new); + return 0; +} + +/** + * aa_restore_previous_label - exit from hat context restoring previous label + * @token: the token that must be matched to exit hat context + * + * Attempt to return out of a hat to the previous label. The token + * must match the stored token value. + * + * Returns: 0 or error of failure + */ +int aa_restore_previous_label(u64 token) +{ + struct aa_task_ctx *ctx = task_ctx(current); + struct cred *new; + + if (ctx->token != token) + return -EACCES; + /* ignore restores when there is no saved label */ + if (!ctx->previous) + return 0; + + new = prepare_creds(); + if (!new) + return -ENOMEM; + + aa_put_label(cred_label(new)); + set_cred_label(new, aa_get_newest_label(ctx->previous)); + AA_BUG(!cred_label(new)); + /* clear exec && prev information when restoring to previous context */ + aa_clear_task_ctx_trans(ctx); + + commit_creds(new); + + return 0; +} + +/** + * audit_ptrace_mask - convert mask to permission string + * @mask: permission mask to convert + * + * Returns: pointer to static string + */ +static const char *audit_ptrace_mask(u32 mask) +{ + switch (mask) { + case MAY_READ: + return "read"; + case MAY_WRITE: + return "trace"; + case AA_MAY_BE_READ: + return "readby"; + case AA_MAY_BE_TRACED: + return "tracedby"; + } + return ""; +} + +/* call back to audit ptrace fields */ +static void audit_ptrace_cb(struct audit_buffer *ab, void *va) +{ + struct common_audit_data *sa = va; + + if (aad(sa)->request & AA_PTRACE_PERM_MASK) { + audit_log_format(ab, " requested_mask=\"%s\"", + audit_ptrace_mask(aad(sa)->request)); + + if (aad(sa)->denied & AA_PTRACE_PERM_MASK) { + audit_log_format(ab, " denied_mask=\"%s\"", + audit_ptrace_mask(aad(sa)->denied)); + } + } + audit_log_format(ab, " peer="); + aa_label_xaudit(ab, labels_ns(aad(sa)->label), aad(sa)->peer, + FLAGS_NONE, GFP_ATOMIC); +} + +/* assumes check for PROFILE_MEDIATES is already done */ +/* TODO: conditionals */ +static int profile_ptrace_perm(struct aa_profile *profile, + struct aa_label *peer, u32 request, + struct common_audit_data *sa) +{ + struct aa_perms perms = { }; + + aad(sa)->peer = peer; + aa_profile_match_label(profile, peer, AA_CLASS_PTRACE, request, + &perms); + aa_apply_modes_to_perms(profile, &perms); + return aa_check_perms(profile, &perms, request, sa, audit_ptrace_cb); +} + +static int profile_tracee_perm(struct aa_profile *tracee, + struct aa_label *tracer, u32 request, + struct common_audit_data *sa) +{ + if (profile_unconfined(tracee) || unconfined(tracer) || + !PROFILE_MEDIATES(tracee, AA_CLASS_PTRACE)) + return 0; + + return profile_ptrace_perm(tracee, tracer, request, sa); +} + +static int profile_tracer_perm(struct aa_profile *tracer, + struct aa_label *tracee, u32 request, + struct common_audit_data *sa) +{ + if (profile_unconfined(tracer)) + return 0; + + if (PROFILE_MEDIATES(tracer, AA_CLASS_PTRACE)) + return profile_ptrace_perm(tracer, tracee, request, sa); + + /* profile uses the old style capability check for ptrace */ + if (&tracer->label == tracee) + return 0; + + aad(sa)->label = &tracer->label; + aad(sa)->peer = tracee; + aad(sa)->request = 0; + aad(sa)->error = aa_capable(&tracer->label, CAP_SYS_PTRACE, + CAP_OPT_NONE); + + return aa_audit(AUDIT_APPARMOR_AUTO, tracer, sa, audit_ptrace_cb); +} + +/** + * aa_may_ptrace - test if tracer task can trace the tracee + * @tracer: label of the task doing the tracing (NOT NULL) + * @tracee: task label to be traced + * @request: permission request + * + * Returns: %0 else error code if permission denied or error + */ +int aa_may_ptrace(struct aa_label *tracer, struct aa_label *tracee, + u32 request) +{ + struct aa_profile *profile; + u32 xrequest = request << PTRACE_PERM_SHIFT; + DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, OP_PTRACE); + + return xcheck_labels(tracer, tracee, profile, + profile_tracer_perm(profile, tracee, request, &sa), + profile_tracee_perm(profile, tracer, xrequest, &sa)); +} diff --git a/security/bpf/Makefile b/security/bpf/Makefile new file mode 100644 index 000000000..c7a89a962 --- /dev/null +++ b/security/bpf/Makefile @@ -0,0 +1,5 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Copyright (C) 2020 Google LLC. + +obj-$(CONFIG_BPF_LSM) := hooks.o diff --git a/security/bpf/hooks.c b/security/bpf/hooks.c new file mode 100644 index 000000000..e5971fa74 --- /dev/null +++ b/security/bpf/hooks.c @@ -0,0 +1,34 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* + * Copyright (C) 2020 Google LLC. + */ +#include <linux/lsm_hooks.h> +#include <linux/bpf_lsm.h> + +static struct security_hook_list bpf_lsm_hooks[] __lsm_ro_after_init = { + #define LSM_HOOK(RET, DEFAULT, NAME, ...) \ + LSM_HOOK_INIT(NAME, bpf_lsm_##NAME), + #include <linux/lsm_hook_defs.h> + #undef LSM_HOOK + LSM_HOOK_INIT(inode_free_security, bpf_inode_storage_free), + LSM_HOOK_INIT(task_free, bpf_task_storage_free), +}; + +static int __init bpf_lsm_init(void) +{ + security_add_hooks(bpf_lsm_hooks, ARRAY_SIZE(bpf_lsm_hooks), "bpf"); + pr_info("LSM support for eBPF active\n"); + return 0; +} + +struct lsm_blob_sizes bpf_lsm_blob_sizes __lsm_ro_after_init = { + .lbs_inode = sizeof(struct bpf_storage_blob), + .lbs_task = sizeof(struct bpf_storage_blob), +}; + +DEFINE_LSM(bpf) = { + .name = "bpf", + .init = bpf_lsm_init, + .blobs = &bpf_lsm_blob_sizes +}; diff --git a/security/commoncap.c b/security/commoncap.c new file mode 100644 index 000000000..bc751fa5a --- /dev/null +++ b/security/commoncap.c @@ -0,0 +1,1485 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* Common capabilities, needed by capability.o. + */ + +#include <linux/capability.h> +#include <linux/audit.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/lsm_hooks.h> +#include <linux/file.h> +#include <linux/mm.h> +#include <linux/mman.h> +#include <linux/pagemap.h> +#include <linux/swap.h> +#include <linux/skbuff.h> +#include <linux/netlink.h> +#include <linux/ptrace.h> +#include <linux/xattr.h> +#include <linux/hugetlb.h> +#include <linux/mount.h> +#include <linux/sched.h> +#include <linux/prctl.h> +#include <linux/securebits.h> +#include <linux/user_namespace.h> +#include <linux/binfmts.h> +#include <linux/personality.h> +#include <linux/mnt_idmapping.h> + +/* + * If a non-root user executes a setuid-root binary in + * !secure(SECURE_NOROOT) mode, then we raise capabilities. + * However if fE is also set, then the intent is for only + * the file capabilities to be applied, and the setuid-root + * bit is left on either to change the uid (plausible) or + * to get full privilege on a kernel without file capabilities + * support. So in that case we do not raise capabilities. + * + * Warn if that happens, once per boot. + */ +static void warn_setuid_and_fcaps_mixed(const char *fname) +{ + static int warned; + if (!warned) { + printk(KERN_INFO "warning: `%s' has both setuid-root and" + " effective capabilities. Therefore not raising all" + " capabilities.\n", fname); + warned = 1; + } +} + +/** + * cap_capable - Determine whether a task has a particular effective capability + * @cred: The credentials to use + * @targ_ns: The user namespace in which we need the capability + * @cap: The capability to check for + * @opts: Bitmask of options defined in include/linux/security.h + * + * Determine whether the nominated task has the specified capability amongst + * its effective set, returning 0 if it does, -ve if it does not. + * + * NOTE WELL: cap_has_capability() cannot be used like the kernel's capable() + * and has_capability() functions. That is, it has the reverse semantics: + * cap_has_capability() returns 0 when a task has a capability, but the + * kernel's capable() and has_capability() returns 1 for this case. + */ +int cap_capable(const struct cred *cred, struct user_namespace *targ_ns, + int cap, unsigned int opts) +{ + struct user_namespace *ns = targ_ns; + + /* See if cred has the capability in the target user namespace + * by examining the target user namespace and all of the target + * user namespace's parents. + */ + for (;;) { + /* Do we have the necessary capabilities? */ + if (ns == cred->user_ns) + return cap_raised(cred->cap_effective, cap) ? 0 : -EPERM; + + /* + * If we're already at a lower level than we're looking for, + * we're done searching. + */ + if (ns->level <= cred->user_ns->level) + return -EPERM; + + /* + * The owner of the user namespace in the parent of the + * user namespace has all caps. + */ + if ((ns->parent == cred->user_ns) && uid_eq(ns->owner, cred->euid)) + return 0; + + /* + * If you have a capability in a parent user ns, then you have + * it over all children user namespaces as well. + */ + ns = ns->parent; + } + + /* We never get here */ +} + +/** + * cap_settime - Determine whether the current process may set the system clock + * @ts: The time to set + * @tz: The timezone to set + * + * Determine whether the current process may set the system clock and timezone + * information, returning 0 if permission granted, -ve if denied. + */ +int cap_settime(const struct timespec64 *ts, const struct timezone *tz) +{ + if (!capable(CAP_SYS_TIME)) + return -EPERM; + return 0; +} + +/** + * cap_ptrace_access_check - Determine whether the current process may access + * another + * @child: The process to be accessed + * @mode: The mode of attachment. + * + * If we are in the same or an ancestor user_ns and have all the target + * task's capabilities, then ptrace access is allowed. + * If we have the ptrace capability to the target user_ns, then ptrace + * access is allowed. + * Else denied. + * + * Determine whether a process may access another, returning 0 if permission + * granted, -ve if denied. + */ +int cap_ptrace_access_check(struct task_struct *child, unsigned int mode) +{ + int ret = 0; + const struct cred *cred, *child_cred; + const kernel_cap_t *caller_caps; + + rcu_read_lock(); + cred = current_cred(); + child_cred = __task_cred(child); + if (mode & PTRACE_MODE_FSCREDS) + caller_caps = &cred->cap_effective; + else + caller_caps = &cred->cap_permitted; + if (cred->user_ns == child_cred->user_ns && + cap_issubset(child_cred->cap_permitted, *caller_caps)) + goto out; + if (ns_capable(child_cred->user_ns, CAP_SYS_PTRACE)) + goto out; + ret = -EPERM; +out: + rcu_read_unlock(); + return ret; +} + +/** + * cap_ptrace_traceme - Determine whether another process may trace the current + * @parent: The task proposed to be the tracer + * + * If parent is in the same or an ancestor user_ns and has all current's + * capabilities, then ptrace access is allowed. + * If parent has the ptrace capability to current's user_ns, then ptrace + * access is allowed. + * Else denied. + * + * Determine whether the nominated task is permitted to trace the current + * process, returning 0 if permission is granted, -ve if denied. + */ +int cap_ptrace_traceme(struct task_struct *parent) +{ + int ret = 0; + const struct cred *cred, *child_cred; + + rcu_read_lock(); + cred = __task_cred(parent); + child_cred = current_cred(); + if (cred->user_ns == child_cred->user_ns && + cap_issubset(child_cred->cap_permitted, cred->cap_permitted)) + goto out; + if (has_ns_capability(parent, child_cred->user_ns, CAP_SYS_PTRACE)) + goto out; + ret = -EPERM; +out: + rcu_read_unlock(); + return ret; +} + +/** + * cap_capget - Retrieve a task's capability sets + * @target: The task from which to retrieve the capability sets + * @effective: The place to record the effective set + * @inheritable: The place to record the inheritable set + * @permitted: The place to record the permitted set + * + * This function retrieves the capabilities of the nominated task and returns + * them to the caller. + */ +int cap_capget(struct task_struct *target, kernel_cap_t *effective, + kernel_cap_t *inheritable, kernel_cap_t *permitted) +{ + const struct cred *cred; + + /* Derived from kernel/capability.c:sys_capget. */ + rcu_read_lock(); + cred = __task_cred(target); + *effective = cred->cap_effective; + *inheritable = cred->cap_inheritable; + *permitted = cred->cap_permitted; + rcu_read_unlock(); + return 0; +} + +/* + * Determine whether the inheritable capabilities are limited to the old + * permitted set. Returns 1 if they are limited, 0 if they are not. + */ +static inline int cap_inh_is_capped(void) +{ + /* they are so limited unless the current task has the CAP_SETPCAP + * capability + */ + if (cap_capable(current_cred(), current_cred()->user_ns, + CAP_SETPCAP, CAP_OPT_NONE) == 0) + return 0; + return 1; +} + +/** + * cap_capset - Validate and apply proposed changes to current's capabilities + * @new: The proposed new credentials; alterations should be made here + * @old: The current task's current credentials + * @effective: A pointer to the proposed new effective capabilities set + * @inheritable: A pointer to the proposed new inheritable capabilities set + * @permitted: A pointer to the proposed new permitted capabilities set + * + * This function validates and applies a proposed mass change to the current + * process's capability sets. The changes are made to the proposed new + * credentials, and assuming no error, will be committed by the caller of LSM. + */ +int cap_capset(struct cred *new, + const struct cred *old, + const kernel_cap_t *effective, + const kernel_cap_t *inheritable, + const kernel_cap_t *permitted) +{ + if (cap_inh_is_capped() && + !cap_issubset(*inheritable, + cap_combine(old->cap_inheritable, + old->cap_permitted))) + /* incapable of using this inheritable set */ + return -EPERM; + + if (!cap_issubset(*inheritable, + cap_combine(old->cap_inheritable, + old->cap_bset))) + /* no new pI capabilities outside bounding set */ + return -EPERM; + + /* verify restrictions on target's new Permitted set */ + if (!cap_issubset(*permitted, old->cap_permitted)) + return -EPERM; + + /* verify the _new_Effective_ is a subset of the _new_Permitted_ */ + if (!cap_issubset(*effective, *permitted)) + return -EPERM; + + new->cap_effective = *effective; + new->cap_inheritable = *inheritable; + new->cap_permitted = *permitted; + + /* + * Mask off ambient bits that are no longer both permitted and + * inheritable. + */ + new->cap_ambient = cap_intersect(new->cap_ambient, + cap_intersect(*permitted, + *inheritable)); + if (WARN_ON(!cap_ambient_invariant_ok(new))) + return -EINVAL; + return 0; +} + +/** + * cap_inode_need_killpriv - Determine if inode change affects privileges + * @dentry: The inode/dentry in being changed with change marked ATTR_KILL_PRIV + * + * Determine if an inode having a change applied that's marked ATTR_KILL_PRIV + * affects the security markings on that inode, and if it is, should + * inode_killpriv() be invoked or the change rejected. + * + * Return: 1 if security.capability has a value, meaning inode_killpriv() + * is required, 0 otherwise, meaning inode_killpriv() is not required. + */ +int cap_inode_need_killpriv(struct dentry *dentry) +{ + struct inode *inode = d_backing_inode(dentry); + int error; + + error = __vfs_getxattr(dentry, inode, XATTR_NAME_CAPS, NULL, 0); + return error > 0; +} + +/** + * cap_inode_killpriv - Erase the security markings on an inode + * + * @mnt_userns: user namespace of the mount the inode was found from + * @dentry: The inode/dentry to alter + * + * Erase the privilege-enhancing security markings on an inode. + * + * If the inode has been found through an idmapped mount the user namespace of + * the vfsmount must be passed through @mnt_userns. This function will then + * take care to map the inode according to @mnt_userns before checking + * permissions. On non-idmapped mounts or if permission checking is to be + * performed on the raw inode simply passs init_user_ns. + * + * Return: 0 if successful, -ve on error. + */ +int cap_inode_killpriv(struct user_namespace *mnt_userns, struct dentry *dentry) +{ + int error; + + error = __vfs_removexattr(mnt_userns, dentry, XATTR_NAME_CAPS); + if (error == -EOPNOTSUPP) + error = 0; + return error; +} + +static bool rootid_owns_currentns(kuid_t kroot) +{ + struct user_namespace *ns; + + if (!uid_valid(kroot)) + return false; + + for (ns = current_user_ns(); ; ns = ns->parent) { + if (from_kuid(ns, kroot) == 0) + return true; + if (ns == &init_user_ns) + break; + } + + return false; +} + +static __u32 sansflags(__u32 m) +{ + return m & ~VFS_CAP_FLAGS_EFFECTIVE; +} + +static bool is_v2header(size_t size, const struct vfs_cap_data *cap) +{ + if (size != XATTR_CAPS_SZ_2) + return false; + return sansflags(le32_to_cpu(cap->magic_etc)) == VFS_CAP_REVISION_2; +} + +static bool is_v3header(size_t size, const struct vfs_cap_data *cap) +{ + if (size != XATTR_CAPS_SZ_3) + return false; + return sansflags(le32_to_cpu(cap->magic_etc)) == VFS_CAP_REVISION_3; +} + +/* + * getsecurity: We are called for security.* before any attempt to read the + * xattr from the inode itself. + * + * This gives us a chance to read the on-disk value and convert it. If we + * return -EOPNOTSUPP, then vfs_getxattr() will call the i_op handler. + * + * Note we are not called by vfs_getxattr_alloc(), but that is only called + * by the integrity subsystem, which really wants the unconverted values - + * so that's good. + */ +int cap_inode_getsecurity(struct user_namespace *mnt_userns, + struct inode *inode, const char *name, void **buffer, + bool alloc) +{ + int size, ret; + kuid_t kroot; + u32 nsmagic, magic; + uid_t root, mappedroot; + char *tmpbuf = NULL; + struct vfs_cap_data *cap; + struct vfs_ns_cap_data *nscap = NULL; + struct dentry *dentry; + struct user_namespace *fs_ns; + + if (strcmp(name, "capability") != 0) + return -EOPNOTSUPP; + + dentry = d_find_any_alias(inode); + if (!dentry) + return -EINVAL; + + size = sizeof(struct vfs_ns_cap_data); + ret = (int)vfs_getxattr_alloc(mnt_userns, dentry, XATTR_NAME_CAPS, + &tmpbuf, size, GFP_NOFS); + dput(dentry); + + if (ret < 0 || !tmpbuf) { + size = ret; + goto out_free; + } + + fs_ns = inode->i_sb->s_user_ns; + cap = (struct vfs_cap_data *) tmpbuf; + if (is_v2header((size_t) ret, cap)) { + root = 0; + } else if (is_v3header((size_t) ret, cap)) { + nscap = (struct vfs_ns_cap_data *) tmpbuf; + root = le32_to_cpu(nscap->rootid); + } else { + size = -EINVAL; + goto out_free; + } + + kroot = make_kuid(fs_ns, root); + + /* If this is an idmapped mount shift the kuid. */ + kroot = mapped_kuid_fs(mnt_userns, fs_ns, kroot); + + /* If the root kuid maps to a valid uid in current ns, then return + * this as a nscap. */ + mappedroot = from_kuid(current_user_ns(), kroot); + if (mappedroot != (uid_t)-1 && mappedroot != (uid_t)0) { + size = sizeof(struct vfs_ns_cap_data); + if (alloc) { + if (!nscap) { + /* v2 -> v3 conversion */ + nscap = kzalloc(size, GFP_ATOMIC); + if (!nscap) { + size = -ENOMEM; + goto out_free; + } + nsmagic = VFS_CAP_REVISION_3; + magic = le32_to_cpu(cap->magic_etc); + if (magic & VFS_CAP_FLAGS_EFFECTIVE) + nsmagic |= VFS_CAP_FLAGS_EFFECTIVE; + memcpy(&nscap->data, &cap->data, sizeof(__le32) * 2 * VFS_CAP_U32); + nscap->magic_etc = cpu_to_le32(nsmagic); + } else { + /* use allocated v3 buffer */ + tmpbuf = NULL; + } + nscap->rootid = cpu_to_le32(mappedroot); + *buffer = nscap; + } + goto out_free; + } + + if (!rootid_owns_currentns(kroot)) { + size = -EOVERFLOW; + goto out_free; + } + + /* This comes from a parent namespace. Return as a v2 capability */ + size = sizeof(struct vfs_cap_data); + if (alloc) { + if (nscap) { + /* v3 -> v2 conversion */ + cap = kzalloc(size, GFP_ATOMIC); + if (!cap) { + size = -ENOMEM; + goto out_free; + } + magic = VFS_CAP_REVISION_2; + nsmagic = le32_to_cpu(nscap->magic_etc); + if (nsmagic & VFS_CAP_FLAGS_EFFECTIVE) + magic |= VFS_CAP_FLAGS_EFFECTIVE; + memcpy(&cap->data, &nscap->data, sizeof(__le32) * 2 * VFS_CAP_U32); + cap->magic_etc = cpu_to_le32(magic); + } else { + /* use unconverted v2 */ + tmpbuf = NULL; + } + *buffer = cap; + } +out_free: + kfree(tmpbuf); + return size; +} + +/** + * rootid_from_xattr - translate root uid of vfs caps + * + * @value: vfs caps value which may be modified by this function + * @size: size of @ivalue + * @task_ns: user namespace of the caller + * @mnt_userns: user namespace of the mount the inode was found from + * @fs_userns: user namespace of the filesystem + * + * If the inode has been found through an idmapped mount the user namespace of + * the vfsmount must be passed through @mnt_userns. This function will then + * take care to map the inode according to @mnt_userns before checking + * permissions. On non-idmapped mounts or if permission checking is to be + * performed on the raw inode simply passs init_user_ns. + */ +static kuid_t rootid_from_xattr(const void *value, size_t size, + struct user_namespace *task_ns, + struct user_namespace *mnt_userns, + struct user_namespace *fs_userns) +{ + const struct vfs_ns_cap_data *nscap = value; + kuid_t rootkid; + uid_t rootid = 0; + + if (size == XATTR_CAPS_SZ_3) + rootid = le32_to_cpu(nscap->rootid); + + rootkid = make_kuid(task_ns, rootid); + return mapped_kuid_user(mnt_userns, fs_userns, rootkid); +} + +static bool validheader(size_t size, const struct vfs_cap_data *cap) +{ + return is_v2header(size, cap) || is_v3header(size, cap); +} + +/** + * cap_convert_nscap - check vfs caps + * + * @mnt_userns: user namespace of the mount the inode was found from + * @dentry: used to retrieve inode to check permissions on + * @ivalue: vfs caps value which may be modified by this function + * @size: size of @ivalue + * + * User requested a write of security.capability. If needed, update the + * xattr to change from v2 to v3, or to fixup the v3 rootid. + * + * If the inode has been found through an idmapped mount the user namespace of + * the vfsmount must be passed through @mnt_userns. This function will then + * take care to map the inode according to @mnt_userns before checking + * permissions. On non-idmapped mounts or if permission checking is to be + * performed on the raw inode simply passs init_user_ns. + * + * Return: On success, return the new size; on error, return < 0. + */ +int cap_convert_nscap(struct user_namespace *mnt_userns, struct dentry *dentry, + const void **ivalue, size_t size) +{ + struct vfs_ns_cap_data *nscap; + uid_t nsrootid; + const struct vfs_cap_data *cap = *ivalue; + __u32 magic, nsmagic; + struct inode *inode = d_backing_inode(dentry); + struct user_namespace *task_ns = current_user_ns(), + *fs_ns = inode->i_sb->s_user_ns; + kuid_t rootid; + size_t newsize; + + if (!*ivalue) + return -EINVAL; + if (!validheader(size, cap)) + return -EINVAL; + if (!capable_wrt_inode_uidgid(mnt_userns, inode, CAP_SETFCAP)) + return -EPERM; + if (size == XATTR_CAPS_SZ_2 && (mnt_userns == fs_ns)) + if (ns_capable(inode->i_sb->s_user_ns, CAP_SETFCAP)) + /* user is privileged, just write the v2 */ + return size; + + rootid = rootid_from_xattr(*ivalue, size, task_ns, mnt_userns, fs_ns); + if (!uid_valid(rootid)) + return -EINVAL; + + nsrootid = from_kuid(fs_ns, rootid); + if (nsrootid == -1) + return -EINVAL; + + newsize = sizeof(struct vfs_ns_cap_data); + nscap = kmalloc(newsize, GFP_ATOMIC); + if (!nscap) + return -ENOMEM; + nscap->rootid = cpu_to_le32(nsrootid); + nsmagic = VFS_CAP_REVISION_3; + magic = le32_to_cpu(cap->magic_etc); + if (magic & VFS_CAP_FLAGS_EFFECTIVE) + nsmagic |= VFS_CAP_FLAGS_EFFECTIVE; + nscap->magic_etc = cpu_to_le32(nsmagic); + memcpy(&nscap->data, &cap->data, sizeof(__le32) * 2 * VFS_CAP_U32); + + *ivalue = nscap; + return newsize; +} + +/* + * Calculate the new process capability sets from the capability sets attached + * to a file. + */ +static inline int bprm_caps_from_vfs_caps(struct cpu_vfs_cap_data *caps, + struct linux_binprm *bprm, + bool *effective, + bool *has_fcap) +{ + struct cred *new = bprm->cred; + unsigned i; + int ret = 0; + + if (caps->magic_etc & VFS_CAP_FLAGS_EFFECTIVE) + *effective = true; + + if (caps->magic_etc & VFS_CAP_REVISION_MASK) + *has_fcap = true; + + CAP_FOR_EACH_U32(i) { + __u32 permitted = caps->permitted.cap[i]; + __u32 inheritable = caps->inheritable.cap[i]; + + /* + * pP' = (X & fP) | (pI & fI) + * The addition of pA' is handled later. + */ + new->cap_permitted.cap[i] = + (new->cap_bset.cap[i] & permitted) | + (new->cap_inheritable.cap[i] & inheritable); + + if (permitted & ~new->cap_permitted.cap[i]) + /* insufficient to execute correctly */ + ret = -EPERM; + } + + /* + * For legacy apps, with no internal support for recognizing they + * do not have enough capabilities, we return an error if they are + * missing some "forced" (aka file-permitted) capabilities. + */ + return *effective ? ret : 0; +} + +/** + * get_vfs_caps_from_disk - retrieve vfs caps from disk + * + * @mnt_userns: user namespace of the mount the inode was found from + * @dentry: dentry from which @inode is retrieved + * @cpu_caps: vfs capabilities + * + * Extract the on-exec-apply capability sets for an executable file. + * + * If the inode has been found through an idmapped mount the user namespace of + * the vfsmount must be passed through @mnt_userns. This function will then + * take care to map the inode according to @mnt_userns before checking + * permissions. On non-idmapped mounts or if permission checking is to be + * performed on the raw inode simply passs init_user_ns. + */ +int get_vfs_caps_from_disk(struct user_namespace *mnt_userns, + const struct dentry *dentry, + struct cpu_vfs_cap_data *cpu_caps) +{ + struct inode *inode = d_backing_inode(dentry); + __u32 magic_etc; + unsigned tocopy, i; + int size; + struct vfs_ns_cap_data data, *nscaps = &data; + struct vfs_cap_data *caps = (struct vfs_cap_data *) &data; + kuid_t rootkuid; + struct user_namespace *fs_ns; + + memset(cpu_caps, 0, sizeof(struct cpu_vfs_cap_data)); + + if (!inode) + return -ENODATA; + + fs_ns = inode->i_sb->s_user_ns; + size = __vfs_getxattr((struct dentry *)dentry, inode, + XATTR_NAME_CAPS, &data, XATTR_CAPS_SZ); + if (size == -ENODATA || size == -EOPNOTSUPP) + /* no data, that's ok */ + return -ENODATA; + + if (size < 0) + return size; + + if (size < sizeof(magic_etc)) + return -EINVAL; + + cpu_caps->magic_etc = magic_etc = le32_to_cpu(caps->magic_etc); + + rootkuid = make_kuid(fs_ns, 0); + switch (magic_etc & VFS_CAP_REVISION_MASK) { + case VFS_CAP_REVISION_1: + if (size != XATTR_CAPS_SZ_1) + return -EINVAL; + tocopy = VFS_CAP_U32_1; + break; + case VFS_CAP_REVISION_2: + if (size != XATTR_CAPS_SZ_2) + return -EINVAL; + tocopy = VFS_CAP_U32_2; + break; + case VFS_CAP_REVISION_3: + if (size != XATTR_CAPS_SZ_3) + return -EINVAL; + tocopy = VFS_CAP_U32_3; + rootkuid = make_kuid(fs_ns, le32_to_cpu(nscaps->rootid)); + break; + + default: + return -EINVAL; + } + /* Limit the caps to the mounter of the filesystem + * or the more limited uid specified in the xattr. + */ + rootkuid = mapped_kuid_fs(mnt_userns, fs_ns, rootkuid); + if (!rootid_owns_currentns(rootkuid)) + return -ENODATA; + + CAP_FOR_EACH_U32(i) { + if (i >= tocopy) + break; + cpu_caps->permitted.cap[i] = le32_to_cpu(caps->data[i].permitted); + cpu_caps->inheritable.cap[i] = le32_to_cpu(caps->data[i].inheritable); + } + + cpu_caps->permitted.cap[CAP_LAST_U32] &= CAP_LAST_U32_VALID_MASK; + cpu_caps->inheritable.cap[CAP_LAST_U32] &= CAP_LAST_U32_VALID_MASK; + + cpu_caps->rootid = rootkuid; + + return 0; +} + +/* + * Attempt to get the on-exec apply capability sets for an executable file from + * its xattrs and, if present, apply them to the proposed credentials being + * constructed by execve(). + */ +static int get_file_caps(struct linux_binprm *bprm, struct file *file, + bool *effective, bool *has_fcap) +{ + int rc = 0; + struct cpu_vfs_cap_data vcaps; + + cap_clear(bprm->cred->cap_permitted); + + if (!file_caps_enabled) + return 0; + + if (!mnt_may_suid(file->f_path.mnt)) + return 0; + + /* + * This check is redundant with mnt_may_suid() but is kept to make + * explicit that capability bits are limited to s_user_ns and its + * descendants. + */ + if (!current_in_userns(file->f_path.mnt->mnt_sb->s_user_ns)) + return 0; + + rc = get_vfs_caps_from_disk(file_mnt_user_ns(file), + file->f_path.dentry, &vcaps); + if (rc < 0) { + if (rc == -EINVAL) + printk(KERN_NOTICE "Invalid argument reading file caps for %s\n", + bprm->filename); + else if (rc == -ENODATA) + rc = 0; + goto out; + } + + rc = bprm_caps_from_vfs_caps(&vcaps, bprm, effective, has_fcap); + +out: + if (rc) + cap_clear(bprm->cred->cap_permitted); + + return rc; +} + +static inline bool root_privileged(void) { return !issecure(SECURE_NOROOT); } + +static inline bool __is_real(kuid_t uid, struct cred *cred) +{ return uid_eq(cred->uid, uid); } + +static inline bool __is_eff(kuid_t uid, struct cred *cred) +{ return uid_eq(cred->euid, uid); } + +static inline bool __is_suid(kuid_t uid, struct cred *cred) +{ return !__is_real(uid, cred) && __is_eff(uid, cred); } + +/* + * handle_privileged_root - Handle case of privileged root + * @bprm: The execution parameters, including the proposed creds + * @has_fcap: Are any file capabilities set? + * @effective: Do we have effective root privilege? + * @root_uid: This namespace' root UID WRT initial USER namespace + * + * Handle the case where root is privileged and hasn't been neutered by + * SECURE_NOROOT. If file capabilities are set, they won't be combined with + * set UID root and nothing is changed. If we are root, cap_permitted is + * updated. If we have become set UID root, the effective bit is set. + */ +static void handle_privileged_root(struct linux_binprm *bprm, bool has_fcap, + bool *effective, kuid_t root_uid) +{ + const struct cred *old = current_cred(); + struct cred *new = bprm->cred; + + if (!root_privileged()) + return; + /* + * If the legacy file capability is set, then don't set privs + * for a setuid root binary run by a non-root user. Do set it + * for a root user just to cause least surprise to an admin. + */ + if (has_fcap && __is_suid(root_uid, new)) { + warn_setuid_and_fcaps_mixed(bprm->filename); + return; + } + /* + * To support inheritance of root-permissions and suid-root + * executables under compatibility mode, we override the + * capability sets for the file. + */ + if (__is_eff(root_uid, new) || __is_real(root_uid, new)) { + /* pP' = (cap_bset & ~0) | (pI & ~0) */ + new->cap_permitted = cap_combine(old->cap_bset, + old->cap_inheritable); + } + /* + * If only the real uid is 0, we do not set the effective bit. + */ + if (__is_eff(root_uid, new)) + *effective = true; +} + +#define __cap_gained(field, target, source) \ + !cap_issubset(target->cap_##field, source->cap_##field) +#define __cap_grew(target, source, cred) \ + !cap_issubset(cred->cap_##target, cred->cap_##source) +#define __cap_full(field, cred) \ + cap_issubset(CAP_FULL_SET, cred->cap_##field) + +static inline bool __is_setuid(struct cred *new, const struct cred *old) +{ return !uid_eq(new->euid, old->uid); } + +static inline bool __is_setgid(struct cred *new, const struct cred *old) +{ return !gid_eq(new->egid, old->gid); } + +/* + * 1) Audit candidate if current->cap_effective is set + * + * We do not bother to audit if 3 things are true: + * 1) cap_effective has all caps + * 2) we became root *OR* are were already root + * 3) root is supposed to have all caps (SECURE_NOROOT) + * Since this is just a normal root execing a process. + * + * Number 1 above might fail if you don't have a full bset, but I think + * that is interesting information to audit. + * + * A number of other conditions require logging: + * 2) something prevented setuid root getting all caps + * 3) non-setuid root gets fcaps + * 4) non-setuid root gets ambient + */ +static inline bool nonroot_raised_pE(struct cred *new, const struct cred *old, + kuid_t root, bool has_fcap) +{ + bool ret = false; + + if ((__cap_grew(effective, ambient, new) && + !(__cap_full(effective, new) && + (__is_eff(root, new) || __is_real(root, new)) && + root_privileged())) || + (root_privileged() && + __is_suid(root, new) && + !__cap_full(effective, new)) || + (!__is_setuid(new, old) && + ((has_fcap && + __cap_gained(permitted, new, old)) || + __cap_gained(ambient, new, old)))) + + ret = true; + + return ret; +} + +/** + * cap_bprm_creds_from_file - Set up the proposed credentials for execve(). + * @bprm: The execution parameters, including the proposed creds + * @file: The file to pull the credentials from + * + * Set up the proposed credentials for a new execution context being + * constructed by execve(). The proposed creds in @bprm->cred is altered, + * which won't take effect immediately. + * + * Return: 0 if successful, -ve on error. + */ +int cap_bprm_creds_from_file(struct linux_binprm *bprm, struct file *file) +{ + /* Process setpcap binaries and capabilities for uid 0 */ + const struct cred *old = current_cred(); + struct cred *new = bprm->cred; + bool effective = false, has_fcap = false, is_setid; + int ret; + kuid_t root_uid; + + if (WARN_ON(!cap_ambient_invariant_ok(old))) + return -EPERM; + + ret = get_file_caps(bprm, file, &effective, &has_fcap); + if (ret < 0) + return ret; + + root_uid = make_kuid(new->user_ns, 0); + + handle_privileged_root(bprm, has_fcap, &effective, root_uid); + + /* if we have fs caps, clear dangerous personality flags */ + if (__cap_gained(permitted, new, old)) + bprm->per_clear |= PER_CLEAR_ON_SETID; + + /* Don't let someone trace a set[ug]id/setpcap binary with the revised + * credentials unless they have the appropriate permit. + * + * In addition, if NO_NEW_PRIVS, then ensure we get no new privs. + */ + is_setid = __is_setuid(new, old) || __is_setgid(new, old); + + if ((is_setid || __cap_gained(permitted, new, old)) && + ((bprm->unsafe & ~LSM_UNSAFE_PTRACE) || + !ptracer_capable(current, new->user_ns))) { + /* downgrade; they get no more than they had, and maybe less */ + if (!ns_capable(new->user_ns, CAP_SETUID) || + (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS)) { + new->euid = new->uid; + new->egid = new->gid; + } + new->cap_permitted = cap_intersect(new->cap_permitted, + old->cap_permitted); + } + + new->suid = new->fsuid = new->euid; + new->sgid = new->fsgid = new->egid; + + /* File caps or setid cancels ambient. */ + if (has_fcap || is_setid) + cap_clear(new->cap_ambient); + + /* + * Now that we've computed pA', update pP' to give: + * pP' = (X & fP) | (pI & fI) | pA' + */ + new->cap_permitted = cap_combine(new->cap_permitted, new->cap_ambient); + + /* + * Set pE' = (fE ? pP' : pA'). Because pA' is zero if fE is set, + * this is the same as pE' = (fE ? pP' : 0) | pA'. + */ + if (effective) + new->cap_effective = new->cap_permitted; + else + new->cap_effective = new->cap_ambient; + + if (WARN_ON(!cap_ambient_invariant_ok(new))) + return -EPERM; + + if (nonroot_raised_pE(new, old, root_uid, has_fcap)) { + ret = audit_log_bprm_fcaps(bprm, new, old); + if (ret < 0) + return ret; + } + + new->securebits &= ~issecure_mask(SECURE_KEEP_CAPS); + + if (WARN_ON(!cap_ambient_invariant_ok(new))) + return -EPERM; + + /* Check for privilege-elevated exec. */ + if (is_setid || + (!__is_real(root_uid, new) && + (effective || + __cap_grew(permitted, ambient, new)))) + bprm->secureexec = 1; + + return 0; +} + +/** + * cap_inode_setxattr - Determine whether an xattr may be altered + * @dentry: The inode/dentry being altered + * @name: The name of the xattr to be changed + * @value: The value that the xattr will be changed to + * @size: The size of value + * @flags: The replacement flag + * + * Determine whether an xattr may be altered or set on an inode, returning 0 if + * permission is granted, -ve if denied. + * + * This is used to make sure security xattrs don't get updated or set by those + * who aren't privileged to do so. + */ +int cap_inode_setxattr(struct dentry *dentry, const char *name, + const void *value, size_t size, int flags) +{ + struct user_namespace *user_ns = dentry->d_sb->s_user_ns; + + /* Ignore non-security xattrs */ + if (strncmp(name, XATTR_SECURITY_PREFIX, + XATTR_SECURITY_PREFIX_LEN) != 0) + return 0; + + /* + * For XATTR_NAME_CAPS the check will be done in + * cap_convert_nscap(), called by setxattr() + */ + if (strcmp(name, XATTR_NAME_CAPS) == 0) + return 0; + + if (!ns_capable(user_ns, CAP_SYS_ADMIN)) + return -EPERM; + return 0; +} + +/** + * cap_inode_removexattr - Determine whether an xattr may be removed + * + * @mnt_userns: User namespace of the mount the inode was found from + * @dentry: The inode/dentry being altered + * @name: The name of the xattr to be changed + * + * Determine whether an xattr may be removed from an inode, returning 0 if + * permission is granted, -ve if denied. + * + * If the inode has been found through an idmapped mount the user namespace of + * the vfsmount must be passed through @mnt_userns. This function will then + * take care to map the inode according to @mnt_userns before checking + * permissions. On non-idmapped mounts or if permission checking is to be + * performed on the raw inode simply passs init_user_ns. + * + * This is used to make sure security xattrs don't get removed by those who + * aren't privileged to remove them. + */ +int cap_inode_removexattr(struct user_namespace *mnt_userns, + struct dentry *dentry, const char *name) +{ + struct user_namespace *user_ns = dentry->d_sb->s_user_ns; + + /* Ignore non-security xattrs */ + if (strncmp(name, XATTR_SECURITY_PREFIX, + XATTR_SECURITY_PREFIX_LEN) != 0) + return 0; + + if (strcmp(name, XATTR_NAME_CAPS) == 0) { + /* security.capability gets namespaced */ + struct inode *inode = d_backing_inode(dentry); + if (!inode) + return -EINVAL; + if (!capable_wrt_inode_uidgid(mnt_userns, inode, CAP_SETFCAP)) + return -EPERM; + return 0; + } + + if (!ns_capable(user_ns, CAP_SYS_ADMIN)) + return -EPERM; + return 0; +} + +/* + * cap_emulate_setxuid() fixes the effective / permitted capabilities of + * a process after a call to setuid, setreuid, or setresuid. + * + * 1) When set*uiding _from_ one of {r,e,s}uid == 0 _to_ all of + * {r,e,s}uid != 0, the permitted and effective capabilities are + * cleared. + * + * 2) When set*uiding _from_ euid == 0 _to_ euid != 0, the effective + * capabilities of the process are cleared. + * + * 3) When set*uiding _from_ euid != 0 _to_ euid == 0, the effective + * capabilities are set to the permitted capabilities. + * + * fsuid is handled elsewhere. fsuid == 0 and {r,e,s}uid!= 0 should + * never happen. + * + * -astor + * + * cevans - New behaviour, Oct '99 + * A process may, via prctl(), elect to keep its capabilities when it + * calls setuid() and switches away from uid==0. Both permitted and + * effective sets will be retained. + * Without this change, it was impossible for a daemon to drop only some + * of its privilege. The call to setuid(!=0) would drop all privileges! + * Keeping uid 0 is not an option because uid 0 owns too many vital + * files.. + * Thanks to Olaf Kirch and Peter Benie for spotting this. + */ +static inline void cap_emulate_setxuid(struct cred *new, const struct cred *old) +{ + kuid_t root_uid = make_kuid(old->user_ns, 0); + + if ((uid_eq(old->uid, root_uid) || + uid_eq(old->euid, root_uid) || + uid_eq(old->suid, root_uid)) && + (!uid_eq(new->uid, root_uid) && + !uid_eq(new->euid, root_uid) && + !uid_eq(new->suid, root_uid))) { + if (!issecure(SECURE_KEEP_CAPS)) { + cap_clear(new->cap_permitted); + cap_clear(new->cap_effective); + } + + /* + * Pre-ambient programs expect setresuid to nonroot followed + * by exec to drop capabilities. We should make sure that + * this remains the case. + */ + cap_clear(new->cap_ambient); + } + if (uid_eq(old->euid, root_uid) && !uid_eq(new->euid, root_uid)) + cap_clear(new->cap_effective); + if (!uid_eq(old->euid, root_uid) && uid_eq(new->euid, root_uid)) + new->cap_effective = new->cap_permitted; +} + +/** + * cap_task_fix_setuid - Fix up the results of setuid() call + * @new: The proposed credentials + * @old: The current task's current credentials + * @flags: Indications of what has changed + * + * Fix up the results of setuid() call before the credential changes are + * actually applied. + * + * Return: 0 to grant the changes, -ve to deny them. + */ +int cap_task_fix_setuid(struct cred *new, const struct cred *old, int flags) +{ + switch (flags) { + case LSM_SETID_RE: + case LSM_SETID_ID: + case LSM_SETID_RES: + /* juggle the capabilities to follow [RES]UID changes unless + * otherwise suppressed */ + if (!issecure(SECURE_NO_SETUID_FIXUP)) + cap_emulate_setxuid(new, old); + break; + + case LSM_SETID_FS: + /* juggle the capabilties to follow FSUID changes, unless + * otherwise suppressed + * + * FIXME - is fsuser used for all CAP_FS_MASK capabilities? + * if not, we might be a bit too harsh here. + */ + if (!issecure(SECURE_NO_SETUID_FIXUP)) { + kuid_t root_uid = make_kuid(old->user_ns, 0); + if (uid_eq(old->fsuid, root_uid) && !uid_eq(new->fsuid, root_uid)) + new->cap_effective = + cap_drop_fs_set(new->cap_effective); + + if (!uid_eq(old->fsuid, root_uid) && uid_eq(new->fsuid, root_uid)) + new->cap_effective = + cap_raise_fs_set(new->cap_effective, + new->cap_permitted); + } + break; + + default: + return -EINVAL; + } + + return 0; +} + +/* + * Rationale: code calling task_setscheduler, task_setioprio, and + * task_setnice, assumes that + * . if capable(cap_sys_nice), then those actions should be allowed + * . if not capable(cap_sys_nice), but acting on your own processes, + * then those actions should be allowed + * This is insufficient now since you can call code without suid, but + * yet with increased caps. + * So we check for increased caps on the target process. + */ +static int cap_safe_nice(struct task_struct *p) +{ + int is_subset, ret = 0; + + rcu_read_lock(); + is_subset = cap_issubset(__task_cred(p)->cap_permitted, + current_cred()->cap_permitted); + if (!is_subset && !ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) + ret = -EPERM; + rcu_read_unlock(); + + return ret; +} + +/** + * cap_task_setscheduler - Detemine if scheduler policy change is permitted + * @p: The task to affect + * + * Detemine if the requested scheduler policy change is permitted for the + * specified task. + * + * Return: 0 if permission is granted, -ve if denied. + */ +int cap_task_setscheduler(struct task_struct *p) +{ + return cap_safe_nice(p); +} + +/** + * cap_task_setioprio - Detemine if I/O priority change is permitted + * @p: The task to affect + * @ioprio: The I/O priority to set + * + * Detemine if the requested I/O priority change is permitted for the specified + * task. + * + * Return: 0 if permission is granted, -ve if denied. + */ +int cap_task_setioprio(struct task_struct *p, int ioprio) +{ + return cap_safe_nice(p); +} + +/** + * cap_task_setnice - Detemine if task priority change is permitted + * @p: The task to affect + * @nice: The nice value to set + * + * Detemine if the requested task priority change is permitted for the + * specified task. + * + * Return: 0 if permission is granted, -ve if denied. + */ +int cap_task_setnice(struct task_struct *p, int nice) +{ + return cap_safe_nice(p); +} + +/* + * Implement PR_CAPBSET_DROP. Attempt to remove the specified capability from + * the current task's bounding set. Returns 0 on success, -ve on error. + */ +static int cap_prctl_drop(unsigned long cap) +{ + struct cred *new; + + if (!ns_capable(current_user_ns(), CAP_SETPCAP)) + return -EPERM; + if (!cap_valid(cap)) + return -EINVAL; + + new = prepare_creds(); + if (!new) + return -ENOMEM; + cap_lower(new->cap_bset, cap); + return commit_creds(new); +} + +/** + * cap_task_prctl - Implement process control functions for this security module + * @option: The process control function requested + * @arg2: The argument data for this function + * @arg3: The argument data for this function + * @arg4: The argument data for this function + * @arg5: The argument data for this function + * + * Allow process control functions (sys_prctl()) to alter capabilities; may + * also deny access to other functions not otherwise implemented here. + * + * Return: 0 or +ve on success, -ENOSYS if this function is not implemented + * here, other -ve on error. If -ENOSYS is returned, sys_prctl() and other LSM + * modules will consider performing the function. + */ +int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3, + unsigned long arg4, unsigned long arg5) +{ + const struct cred *old = current_cred(); + struct cred *new; + + switch (option) { + case PR_CAPBSET_READ: + if (!cap_valid(arg2)) + return -EINVAL; + return !!cap_raised(old->cap_bset, arg2); + + case PR_CAPBSET_DROP: + return cap_prctl_drop(arg2); + + /* + * The next four prctl's remain to assist with transitioning a + * system from legacy UID=0 based privilege (when filesystem + * capabilities are not in use) to a system using filesystem + * capabilities only - as the POSIX.1e draft intended. + * + * Note: + * + * PR_SET_SECUREBITS = + * issecure_mask(SECURE_KEEP_CAPS_LOCKED) + * | issecure_mask(SECURE_NOROOT) + * | issecure_mask(SECURE_NOROOT_LOCKED) + * | issecure_mask(SECURE_NO_SETUID_FIXUP) + * | issecure_mask(SECURE_NO_SETUID_FIXUP_LOCKED) + * + * will ensure that the current process and all of its + * children will be locked into a pure + * capability-based-privilege environment. + */ + case PR_SET_SECUREBITS: + if ((((old->securebits & SECURE_ALL_LOCKS) >> 1) + & (old->securebits ^ arg2)) /*[1]*/ + || ((old->securebits & SECURE_ALL_LOCKS & ~arg2)) /*[2]*/ + || (arg2 & ~(SECURE_ALL_LOCKS | SECURE_ALL_BITS)) /*[3]*/ + || (cap_capable(current_cred(), + current_cred()->user_ns, + CAP_SETPCAP, + CAP_OPT_NONE) != 0) /*[4]*/ + /* + * [1] no changing of bits that are locked + * [2] no unlocking of locks + * [3] no setting of unsupported bits + * [4] doing anything requires privilege (go read about + * the "sendmail capabilities bug") + */ + ) + /* cannot change a locked bit */ + return -EPERM; + + new = prepare_creds(); + if (!new) + return -ENOMEM; + new->securebits = arg2; + return commit_creds(new); + + case PR_GET_SECUREBITS: + return old->securebits; + + case PR_GET_KEEPCAPS: + return !!issecure(SECURE_KEEP_CAPS); + + case PR_SET_KEEPCAPS: + if (arg2 > 1) /* Note, we rely on arg2 being unsigned here */ + return -EINVAL; + if (issecure(SECURE_KEEP_CAPS_LOCKED)) + return -EPERM; + + new = prepare_creds(); + if (!new) + return -ENOMEM; + if (arg2) + new->securebits |= issecure_mask(SECURE_KEEP_CAPS); + else + new->securebits &= ~issecure_mask(SECURE_KEEP_CAPS); + return commit_creds(new); + + case PR_CAP_AMBIENT: + if (arg2 == PR_CAP_AMBIENT_CLEAR_ALL) { + if (arg3 | arg4 | arg5) + return -EINVAL; + + new = prepare_creds(); + if (!new) + return -ENOMEM; + cap_clear(new->cap_ambient); + return commit_creds(new); + } + + if (((!cap_valid(arg3)) | arg4 | arg5)) + return -EINVAL; + + if (arg2 == PR_CAP_AMBIENT_IS_SET) { + return !!cap_raised(current_cred()->cap_ambient, arg3); + } else if (arg2 != PR_CAP_AMBIENT_RAISE && + arg2 != PR_CAP_AMBIENT_LOWER) { + return -EINVAL; + } else { + if (arg2 == PR_CAP_AMBIENT_RAISE && + (!cap_raised(current_cred()->cap_permitted, arg3) || + !cap_raised(current_cred()->cap_inheritable, + arg3) || + issecure(SECURE_NO_CAP_AMBIENT_RAISE))) + return -EPERM; + + new = prepare_creds(); + if (!new) + return -ENOMEM; + if (arg2 == PR_CAP_AMBIENT_RAISE) + cap_raise(new->cap_ambient, arg3); + else + cap_lower(new->cap_ambient, arg3); + return commit_creds(new); + } + + default: + /* No functionality available - continue with default */ + return -ENOSYS; + } +} + +/** + * cap_vm_enough_memory - Determine whether a new virtual mapping is permitted + * @mm: The VM space in which the new mapping is to be made + * @pages: The size of the mapping + * + * Determine whether the allocation of a new virtual mapping by the current + * task is permitted. + * + * Return: 1 if permission is granted, 0 if not. + */ +int cap_vm_enough_memory(struct mm_struct *mm, long pages) +{ + int cap_sys_admin = 0; + + if (cap_capable(current_cred(), &init_user_ns, + CAP_SYS_ADMIN, CAP_OPT_NOAUDIT) == 0) + cap_sys_admin = 1; + + return cap_sys_admin; +} + +/** + * cap_mmap_addr - check if able to map given addr + * @addr: address attempting to be mapped + * + * If the process is attempting to map memory below dac_mmap_min_addr they need + * CAP_SYS_RAWIO. The other parameters to this function are unused by the + * capability security module. + * + * Return: 0 if this mapping should be allowed or -EPERM if not. + */ +int cap_mmap_addr(unsigned long addr) +{ + int ret = 0; + + if (addr < dac_mmap_min_addr) { + ret = cap_capable(current_cred(), &init_user_ns, CAP_SYS_RAWIO, + CAP_OPT_NONE); + /* set PF_SUPERPRIV if it turns out we allow the low mmap */ + if (ret == 0) + current->flags |= PF_SUPERPRIV; + } + return ret; +} + +int cap_mmap_file(struct file *file, unsigned long reqprot, + unsigned long prot, unsigned long flags) +{ + return 0; +} + +#ifdef CONFIG_SECURITY + +static struct security_hook_list capability_hooks[] __lsm_ro_after_init = { + LSM_HOOK_INIT(capable, cap_capable), + LSM_HOOK_INIT(settime, cap_settime), + LSM_HOOK_INIT(ptrace_access_check, cap_ptrace_access_check), + LSM_HOOK_INIT(ptrace_traceme, cap_ptrace_traceme), + LSM_HOOK_INIT(capget, cap_capget), + LSM_HOOK_INIT(capset, cap_capset), + LSM_HOOK_INIT(bprm_creds_from_file, cap_bprm_creds_from_file), + LSM_HOOK_INIT(inode_need_killpriv, cap_inode_need_killpriv), + LSM_HOOK_INIT(inode_killpriv, cap_inode_killpriv), + LSM_HOOK_INIT(inode_getsecurity, cap_inode_getsecurity), + LSM_HOOK_INIT(mmap_addr, cap_mmap_addr), + LSM_HOOK_INIT(mmap_file, cap_mmap_file), + LSM_HOOK_INIT(task_fix_setuid, cap_task_fix_setuid), + LSM_HOOK_INIT(task_prctl, cap_task_prctl), + LSM_HOOK_INIT(task_setscheduler, cap_task_setscheduler), + LSM_HOOK_INIT(task_setioprio, cap_task_setioprio), + LSM_HOOK_INIT(task_setnice, cap_task_setnice), + LSM_HOOK_INIT(vm_enough_memory, cap_vm_enough_memory), +}; + +static int __init capability_init(void) +{ + security_add_hooks(capability_hooks, ARRAY_SIZE(capability_hooks), + "capability"); + return 0; +} + +DEFINE_LSM(capability) = { + .name = "capability", + .order = LSM_ORDER_FIRST, + .init = capability_init, +}; + +#endif /* CONFIG_SECURITY */ diff --git a/security/device_cgroup.c b/security/device_cgroup.c new file mode 100644 index 000000000..bef2b9285 --- /dev/null +++ b/security/device_cgroup.c @@ -0,0 +1,877 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * device_cgroup.c - device cgroup subsystem + * + * Copyright 2007 IBM Corp + */ + +#include <linux/bpf-cgroup.h> +#include <linux/device_cgroup.h> +#include <linux/cgroup.h> +#include <linux/ctype.h> +#include <linux/list.h> +#include <linux/uaccess.h> +#include <linux/seq_file.h> +#include <linux/slab.h> +#include <linux/rcupdate.h> +#include <linux/mutex.h> + +#ifdef CONFIG_CGROUP_DEVICE + +static DEFINE_MUTEX(devcgroup_mutex); + +enum devcg_behavior { + DEVCG_DEFAULT_NONE, + DEVCG_DEFAULT_ALLOW, + DEVCG_DEFAULT_DENY, +}; + +/* + * exception list locking rules: + * hold devcgroup_mutex for update/read. + * hold rcu_read_lock() for read. + */ + +struct dev_exception_item { + u32 major, minor; + short type; + short access; + struct list_head list; + struct rcu_head rcu; +}; + +struct dev_cgroup { + struct cgroup_subsys_state css; + struct list_head exceptions; + enum devcg_behavior behavior; +}; + +static inline struct dev_cgroup *css_to_devcgroup(struct cgroup_subsys_state *s) +{ + return s ? container_of(s, struct dev_cgroup, css) : NULL; +} + +static inline struct dev_cgroup *task_devcgroup(struct task_struct *task) +{ + return css_to_devcgroup(task_css(task, devices_cgrp_id)); +} + +/* + * called under devcgroup_mutex + */ +static int dev_exceptions_copy(struct list_head *dest, struct list_head *orig) +{ + struct dev_exception_item *ex, *tmp, *new; + + lockdep_assert_held(&devcgroup_mutex); + + list_for_each_entry(ex, orig, list) { + new = kmemdup(ex, sizeof(*ex), GFP_KERNEL); + if (!new) + goto free_and_exit; + list_add_tail(&new->list, dest); + } + + return 0; + +free_and_exit: + list_for_each_entry_safe(ex, tmp, dest, list) { + list_del(&ex->list); + kfree(ex); + } + return -ENOMEM; +} + +static void dev_exceptions_move(struct list_head *dest, struct list_head *orig) +{ + struct dev_exception_item *ex, *tmp; + + lockdep_assert_held(&devcgroup_mutex); + + list_for_each_entry_safe(ex, tmp, orig, list) { + list_move_tail(&ex->list, dest); + } +} + +/* + * called under devcgroup_mutex + */ +static int dev_exception_add(struct dev_cgroup *dev_cgroup, + struct dev_exception_item *ex) +{ + struct dev_exception_item *excopy, *walk; + + lockdep_assert_held(&devcgroup_mutex); + + excopy = kmemdup(ex, sizeof(*ex), GFP_KERNEL); + if (!excopy) + return -ENOMEM; + + list_for_each_entry(walk, &dev_cgroup->exceptions, list) { + if (walk->type != ex->type) + continue; + if (walk->major != ex->major) + continue; + if (walk->minor != ex->minor) + continue; + + walk->access |= ex->access; + kfree(excopy); + excopy = NULL; + } + + if (excopy != NULL) + list_add_tail_rcu(&excopy->list, &dev_cgroup->exceptions); + return 0; +} + +/* + * called under devcgroup_mutex + */ +static void dev_exception_rm(struct dev_cgroup *dev_cgroup, + struct dev_exception_item *ex) +{ + struct dev_exception_item *walk, *tmp; + + lockdep_assert_held(&devcgroup_mutex); + + list_for_each_entry_safe(walk, tmp, &dev_cgroup->exceptions, list) { + if (walk->type != ex->type) + continue; + if (walk->major != ex->major) + continue; + if (walk->minor != ex->minor) + continue; + + walk->access &= ~ex->access; + if (!walk->access) { + list_del_rcu(&walk->list); + kfree_rcu(walk, rcu); + } + } +} + +static void __dev_exception_clean(struct dev_cgroup *dev_cgroup) +{ + struct dev_exception_item *ex, *tmp; + + list_for_each_entry_safe(ex, tmp, &dev_cgroup->exceptions, list) { + list_del_rcu(&ex->list); + kfree_rcu(ex, rcu); + } +} + +/** + * dev_exception_clean - frees all entries of the exception list + * @dev_cgroup: dev_cgroup with the exception list to be cleaned + * + * called under devcgroup_mutex + */ +static void dev_exception_clean(struct dev_cgroup *dev_cgroup) +{ + lockdep_assert_held(&devcgroup_mutex); + + __dev_exception_clean(dev_cgroup); +} + +static inline bool is_devcg_online(const struct dev_cgroup *devcg) +{ + return (devcg->behavior != DEVCG_DEFAULT_NONE); +} + +/** + * devcgroup_online - initializes devcgroup's behavior and exceptions based on + * parent's + * @css: css getting online + * returns 0 in case of success, error code otherwise + */ +static int devcgroup_online(struct cgroup_subsys_state *css) +{ + struct dev_cgroup *dev_cgroup = css_to_devcgroup(css); + struct dev_cgroup *parent_dev_cgroup = css_to_devcgroup(css->parent); + int ret = 0; + + mutex_lock(&devcgroup_mutex); + + if (parent_dev_cgroup == NULL) + dev_cgroup->behavior = DEVCG_DEFAULT_ALLOW; + else { + ret = dev_exceptions_copy(&dev_cgroup->exceptions, + &parent_dev_cgroup->exceptions); + if (!ret) + dev_cgroup->behavior = parent_dev_cgroup->behavior; + } + mutex_unlock(&devcgroup_mutex); + + return ret; +} + +static void devcgroup_offline(struct cgroup_subsys_state *css) +{ + struct dev_cgroup *dev_cgroup = css_to_devcgroup(css); + + mutex_lock(&devcgroup_mutex); + dev_cgroup->behavior = DEVCG_DEFAULT_NONE; + mutex_unlock(&devcgroup_mutex); +} + +/* + * called from kernel/cgroup.c with cgroup_lock() held. + */ +static struct cgroup_subsys_state * +devcgroup_css_alloc(struct cgroup_subsys_state *parent_css) +{ + struct dev_cgroup *dev_cgroup; + + dev_cgroup = kzalloc(sizeof(*dev_cgroup), GFP_KERNEL); + if (!dev_cgroup) + return ERR_PTR(-ENOMEM); + INIT_LIST_HEAD(&dev_cgroup->exceptions); + dev_cgroup->behavior = DEVCG_DEFAULT_NONE; + + return &dev_cgroup->css; +} + +static void devcgroup_css_free(struct cgroup_subsys_state *css) +{ + struct dev_cgroup *dev_cgroup = css_to_devcgroup(css); + + __dev_exception_clean(dev_cgroup); + kfree(dev_cgroup); +} + +#define DEVCG_ALLOW 1 +#define DEVCG_DENY 2 +#define DEVCG_LIST 3 + +#define MAJMINLEN 13 +#define ACCLEN 4 + +static void set_access(char *acc, short access) +{ + int idx = 0; + memset(acc, 0, ACCLEN); + if (access & DEVCG_ACC_READ) + acc[idx++] = 'r'; + if (access & DEVCG_ACC_WRITE) + acc[idx++] = 'w'; + if (access & DEVCG_ACC_MKNOD) + acc[idx++] = 'm'; +} + +static char type_to_char(short type) +{ + if (type == DEVCG_DEV_ALL) + return 'a'; + if (type == DEVCG_DEV_CHAR) + return 'c'; + if (type == DEVCG_DEV_BLOCK) + return 'b'; + return 'X'; +} + +static void set_majmin(char *str, unsigned m) +{ + if (m == ~0) + strcpy(str, "*"); + else + sprintf(str, "%u", m); +} + +static int devcgroup_seq_show(struct seq_file *m, void *v) +{ + struct dev_cgroup *devcgroup = css_to_devcgroup(seq_css(m)); + struct dev_exception_item *ex; + char maj[MAJMINLEN], min[MAJMINLEN], acc[ACCLEN]; + + rcu_read_lock(); + /* + * To preserve the compatibility: + * - Only show the "all devices" when the default policy is to allow + * - List the exceptions in case the default policy is to deny + * This way, the file remains as a "whitelist of devices" + */ + if (devcgroup->behavior == DEVCG_DEFAULT_ALLOW) { + set_access(acc, DEVCG_ACC_MASK); + set_majmin(maj, ~0); + set_majmin(min, ~0); + seq_printf(m, "%c %s:%s %s\n", type_to_char(DEVCG_DEV_ALL), + maj, min, acc); + } else { + list_for_each_entry_rcu(ex, &devcgroup->exceptions, list) { + set_access(acc, ex->access); + set_majmin(maj, ex->major); + set_majmin(min, ex->minor); + seq_printf(m, "%c %s:%s %s\n", type_to_char(ex->type), + maj, min, acc); + } + } + rcu_read_unlock(); + + return 0; +} + +/** + * match_exception - iterates the exception list trying to find a complete match + * @exceptions: list of exceptions + * @type: device type (DEVCG_DEV_BLOCK or DEVCG_DEV_CHAR) + * @major: device file major number, ~0 to match all + * @minor: device file minor number, ~0 to match all + * @access: permission mask (DEVCG_ACC_READ, DEVCG_ACC_WRITE, DEVCG_ACC_MKNOD) + * + * It is considered a complete match if an exception is found that will + * contain the entire range of provided parameters. + * + * Return: true in case it matches an exception completely + */ +static bool match_exception(struct list_head *exceptions, short type, + u32 major, u32 minor, short access) +{ + struct dev_exception_item *ex; + + list_for_each_entry_rcu(ex, exceptions, list) { + if ((type & DEVCG_DEV_BLOCK) && !(ex->type & DEVCG_DEV_BLOCK)) + continue; + if ((type & DEVCG_DEV_CHAR) && !(ex->type & DEVCG_DEV_CHAR)) + continue; + if (ex->major != ~0 && ex->major != major) + continue; + if (ex->minor != ~0 && ex->minor != minor) + continue; + /* provided access cannot have more than the exception rule */ + if (access & (~ex->access)) + continue; + return true; + } + return false; +} + +/** + * match_exception_partial - iterates the exception list trying to find a partial match + * @exceptions: list of exceptions + * @type: device type (DEVCG_DEV_BLOCK or DEVCG_DEV_CHAR) + * @major: device file major number, ~0 to match all + * @minor: device file minor number, ~0 to match all + * @access: permission mask (DEVCG_ACC_READ, DEVCG_ACC_WRITE, DEVCG_ACC_MKNOD) + * + * It is considered a partial match if an exception's range is found to + * contain *any* of the devices specified by provided parameters. This is + * used to make sure no extra access is being granted that is forbidden by + * any of the exception list. + * + * Return: true in case the provided range mat matches an exception completely + */ +static bool match_exception_partial(struct list_head *exceptions, short type, + u32 major, u32 minor, short access) +{ + struct dev_exception_item *ex; + + list_for_each_entry_rcu(ex, exceptions, list, + lockdep_is_held(&devcgroup_mutex)) { + if ((type & DEVCG_DEV_BLOCK) && !(ex->type & DEVCG_DEV_BLOCK)) + continue; + if ((type & DEVCG_DEV_CHAR) && !(ex->type & DEVCG_DEV_CHAR)) + continue; + /* + * We must be sure that both the exception and the provided + * range aren't masking all devices + */ + if (ex->major != ~0 && major != ~0 && ex->major != major) + continue; + if (ex->minor != ~0 && minor != ~0 && ex->minor != minor) + continue; + /* + * In order to make sure the provided range isn't matching + * an exception, all its access bits shouldn't match the + * exception's access bits + */ + if (!(access & ex->access)) + continue; + return true; + } + return false; +} + +/** + * verify_new_ex - verifies if a new exception is allowed by parent cgroup's permissions + * @dev_cgroup: dev cgroup to be tested against + * @refex: new exception + * @behavior: behavior of the exception's dev_cgroup + * + * This is used to make sure a child cgroup won't have more privileges + * than its parent + */ +static bool verify_new_ex(struct dev_cgroup *dev_cgroup, + struct dev_exception_item *refex, + enum devcg_behavior behavior) +{ + bool match = false; + + RCU_LOCKDEP_WARN(!rcu_read_lock_held() && + !lockdep_is_held(&devcgroup_mutex), + "device_cgroup:verify_new_ex called without proper synchronization"); + + if (dev_cgroup->behavior == DEVCG_DEFAULT_ALLOW) { + if (behavior == DEVCG_DEFAULT_ALLOW) { + /* + * new exception in the child doesn't matter, only + * adding extra restrictions + */ + return true; + } else { + /* + * new exception in the child will add more devices + * that can be acessed, so it can't match any of + * parent's exceptions, even slightly + */ + match = match_exception_partial(&dev_cgroup->exceptions, + refex->type, + refex->major, + refex->minor, + refex->access); + + if (match) + return false; + return true; + } + } else { + /* + * Only behavior == DEVCG_DEFAULT_DENY allowed here, therefore + * the new exception will add access to more devices and must + * be contained completely in an parent's exception to be + * allowed + */ + match = match_exception(&dev_cgroup->exceptions, refex->type, + refex->major, refex->minor, + refex->access); + + if (match) + /* parent has an exception that matches the proposed */ + return true; + else + return false; + } + return false; +} + +/* + * parent_has_perm: + * when adding a new allow rule to a device exception list, the rule + * must be allowed in the parent device + */ +static int parent_has_perm(struct dev_cgroup *childcg, + struct dev_exception_item *ex) +{ + struct dev_cgroup *parent = css_to_devcgroup(childcg->css.parent); + + if (!parent) + return 1; + return verify_new_ex(parent, ex, childcg->behavior); +} + +/** + * parent_allows_removal - verify if it's ok to remove an exception + * @childcg: child cgroup from where the exception will be removed + * @ex: exception being removed + * + * When removing an exception in cgroups with default ALLOW policy, it must + * be checked if removing it will give the child cgroup more access than the + * parent. + * + * Return: true if it's ok to remove exception, false otherwise + */ +static bool parent_allows_removal(struct dev_cgroup *childcg, + struct dev_exception_item *ex) +{ + struct dev_cgroup *parent = css_to_devcgroup(childcg->css.parent); + + if (!parent) + return true; + + /* It's always allowed to remove access to devices */ + if (childcg->behavior == DEVCG_DEFAULT_DENY) + return true; + + /* + * Make sure you're not removing part or a whole exception existing in + * the parent cgroup + */ + return !match_exception_partial(&parent->exceptions, ex->type, + ex->major, ex->minor, ex->access); +} + +/** + * may_allow_all - checks if it's possible to change the behavior to + * allow based on parent's rules. + * @parent: device cgroup's parent + * returns: != 0 in case it's allowed, 0 otherwise + */ +static inline int may_allow_all(struct dev_cgroup *parent) +{ + if (!parent) + return 1; + return parent->behavior == DEVCG_DEFAULT_ALLOW; +} + +/** + * revalidate_active_exceptions - walks through the active exception list and + * revalidates the exceptions based on parent's + * behavior and exceptions. The exceptions that + * are no longer valid will be removed. + * Called with devcgroup_mutex held. + * @devcg: cgroup which exceptions will be checked + * + * This is one of the three key functions for hierarchy implementation. + * This function is responsible for re-evaluating all the cgroup's active + * exceptions due to a parent's exception change. + * Refer to Documentation/admin-guide/cgroup-v1/devices.rst for more details. + */ +static void revalidate_active_exceptions(struct dev_cgroup *devcg) +{ + struct dev_exception_item *ex; + struct list_head *this, *tmp; + + list_for_each_safe(this, tmp, &devcg->exceptions) { + ex = container_of(this, struct dev_exception_item, list); + if (!parent_has_perm(devcg, ex)) + dev_exception_rm(devcg, ex); + } +} + +/** + * propagate_exception - propagates a new exception to the children + * @devcg_root: device cgroup that added a new exception + * @ex: new exception to be propagated + * + * returns: 0 in case of success, != 0 in case of error + */ +static int propagate_exception(struct dev_cgroup *devcg_root, + struct dev_exception_item *ex) +{ + struct cgroup_subsys_state *pos; + int rc = 0; + + rcu_read_lock(); + + css_for_each_descendant_pre(pos, &devcg_root->css) { + struct dev_cgroup *devcg = css_to_devcgroup(pos); + + /* + * Because devcgroup_mutex is held, no devcg will become + * online or offline during the tree walk (see on/offline + * methods), and online ones are safe to access outside RCU + * read lock without bumping refcnt. + */ + if (pos == &devcg_root->css || !is_devcg_online(devcg)) + continue; + + rcu_read_unlock(); + + /* + * in case both root's behavior and devcg is allow, a new + * restriction means adding to the exception list + */ + if (devcg_root->behavior == DEVCG_DEFAULT_ALLOW && + devcg->behavior == DEVCG_DEFAULT_ALLOW) { + rc = dev_exception_add(devcg, ex); + if (rc) + return rc; + } else { + /* + * in the other possible cases: + * root's behavior: allow, devcg's: deny + * root's behavior: deny, devcg's: deny + * the exception will be removed + */ + dev_exception_rm(devcg, ex); + } + revalidate_active_exceptions(devcg); + + rcu_read_lock(); + } + + rcu_read_unlock(); + return rc; +} + +/* + * Modify the exception list using allow/deny rules. + * CAP_SYS_ADMIN is needed for this. It's at least separate from CAP_MKNOD + * so we can give a container CAP_MKNOD to let it create devices but not + * modify the exception list. + * It seems likely we'll want to add a CAP_CONTAINER capability to allow + * us to also grant CAP_SYS_ADMIN to containers without giving away the + * device exception list controls, but for now we'll stick with CAP_SYS_ADMIN + * + * Taking rules away is always allowed (given CAP_SYS_ADMIN). Granting + * new access is only allowed if you're in the top-level cgroup, or your + * parent cgroup has the access you're asking for. + */ +static int devcgroup_update_access(struct dev_cgroup *devcgroup, + int filetype, char *buffer) +{ + const char *b; + char temp[12]; /* 11 + 1 characters needed for a u32 */ + int count, rc = 0; + struct dev_exception_item ex; + struct dev_cgroup *parent = css_to_devcgroup(devcgroup->css.parent); + struct dev_cgroup tmp_devcgrp; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + memset(&ex, 0, sizeof(ex)); + memset(&tmp_devcgrp, 0, sizeof(tmp_devcgrp)); + b = buffer; + + switch (*b) { + case 'a': + switch (filetype) { + case DEVCG_ALLOW: + if (css_has_online_children(&devcgroup->css)) + return -EINVAL; + + if (!may_allow_all(parent)) + return -EPERM; + if (!parent) { + devcgroup->behavior = DEVCG_DEFAULT_ALLOW; + dev_exception_clean(devcgroup); + break; + } + + INIT_LIST_HEAD(&tmp_devcgrp.exceptions); + rc = dev_exceptions_copy(&tmp_devcgrp.exceptions, + &devcgroup->exceptions); + if (rc) + return rc; + dev_exception_clean(devcgroup); + rc = dev_exceptions_copy(&devcgroup->exceptions, + &parent->exceptions); + if (rc) { + dev_exceptions_move(&devcgroup->exceptions, + &tmp_devcgrp.exceptions); + return rc; + } + devcgroup->behavior = DEVCG_DEFAULT_ALLOW; + dev_exception_clean(&tmp_devcgrp); + break; + case DEVCG_DENY: + if (css_has_online_children(&devcgroup->css)) + return -EINVAL; + + dev_exception_clean(devcgroup); + devcgroup->behavior = DEVCG_DEFAULT_DENY; + break; + default: + return -EINVAL; + } + return 0; + case 'b': + ex.type = DEVCG_DEV_BLOCK; + break; + case 'c': + ex.type = DEVCG_DEV_CHAR; + break; + default: + return -EINVAL; + } + b++; + if (!isspace(*b)) + return -EINVAL; + b++; + if (*b == '*') { + ex.major = ~0; + b++; + } else if (isdigit(*b)) { + memset(temp, 0, sizeof(temp)); + for (count = 0; count < sizeof(temp) - 1; count++) { + temp[count] = *b; + b++; + if (!isdigit(*b)) + break; + } + rc = kstrtou32(temp, 10, &ex.major); + if (rc) + return -EINVAL; + } else { + return -EINVAL; + } + if (*b != ':') + return -EINVAL; + b++; + + /* read minor */ + if (*b == '*') { + ex.minor = ~0; + b++; + } else if (isdigit(*b)) { + memset(temp, 0, sizeof(temp)); + for (count = 0; count < sizeof(temp) - 1; count++) { + temp[count] = *b; + b++; + if (!isdigit(*b)) + break; + } + rc = kstrtou32(temp, 10, &ex.minor); + if (rc) + return -EINVAL; + } else { + return -EINVAL; + } + if (!isspace(*b)) + return -EINVAL; + for (b++, count = 0; count < 3; count++, b++) { + switch (*b) { + case 'r': + ex.access |= DEVCG_ACC_READ; + break; + case 'w': + ex.access |= DEVCG_ACC_WRITE; + break; + case 'm': + ex.access |= DEVCG_ACC_MKNOD; + break; + case '\n': + case '\0': + count = 3; + break; + default: + return -EINVAL; + } + } + + switch (filetype) { + case DEVCG_ALLOW: + /* + * If the default policy is to allow by default, try to remove + * an matching exception instead. And be silent about it: we + * don't want to break compatibility + */ + if (devcgroup->behavior == DEVCG_DEFAULT_ALLOW) { + /* Check if the parent allows removing it first */ + if (!parent_allows_removal(devcgroup, &ex)) + return -EPERM; + dev_exception_rm(devcgroup, &ex); + break; + } + + if (!parent_has_perm(devcgroup, &ex)) + return -EPERM; + rc = dev_exception_add(devcgroup, &ex); + break; + case DEVCG_DENY: + /* + * If the default policy is to deny by default, try to remove + * an matching exception instead. And be silent about it: we + * don't want to break compatibility + */ + if (devcgroup->behavior == DEVCG_DEFAULT_DENY) + dev_exception_rm(devcgroup, &ex); + else + rc = dev_exception_add(devcgroup, &ex); + + if (rc) + break; + /* we only propagate new restrictions */ + rc = propagate_exception(devcgroup, &ex); + break; + default: + rc = -EINVAL; + } + return rc; +} + +static ssize_t devcgroup_access_write(struct kernfs_open_file *of, + char *buf, size_t nbytes, loff_t off) +{ + int retval; + + mutex_lock(&devcgroup_mutex); + retval = devcgroup_update_access(css_to_devcgroup(of_css(of)), + of_cft(of)->private, strstrip(buf)); + mutex_unlock(&devcgroup_mutex); + return retval ?: nbytes; +} + +static struct cftype dev_cgroup_files[] = { + { + .name = "allow", + .write = devcgroup_access_write, + .private = DEVCG_ALLOW, + }, + { + .name = "deny", + .write = devcgroup_access_write, + .private = DEVCG_DENY, + }, + { + .name = "list", + .seq_show = devcgroup_seq_show, + .private = DEVCG_LIST, + }, + { } /* terminate */ +}; + +struct cgroup_subsys devices_cgrp_subsys = { + .css_alloc = devcgroup_css_alloc, + .css_free = devcgroup_css_free, + .css_online = devcgroup_online, + .css_offline = devcgroup_offline, + .legacy_cftypes = dev_cgroup_files, +}; + +/** + * devcgroup_legacy_check_permission - checks if an inode operation is permitted + * @dev_cgroup: the dev cgroup to be tested against + * @type: device type + * @major: device major number + * @minor: device minor number + * @access: combination of DEVCG_ACC_WRITE, DEVCG_ACC_READ and DEVCG_ACC_MKNOD + * + * returns 0 on success, -EPERM case the operation is not permitted + */ +static int devcgroup_legacy_check_permission(short type, u32 major, u32 minor, + short access) +{ + struct dev_cgroup *dev_cgroup; + bool rc; + + rcu_read_lock(); + dev_cgroup = task_devcgroup(current); + if (dev_cgroup->behavior == DEVCG_DEFAULT_ALLOW) + /* Can't match any of the exceptions, even partially */ + rc = !match_exception_partial(&dev_cgroup->exceptions, + type, major, minor, access); + else + /* Need to match completely one exception to be allowed */ + rc = match_exception(&dev_cgroup->exceptions, type, major, + minor, access); + rcu_read_unlock(); + + if (!rc) + return -EPERM; + + return 0; +} + +#endif /* CONFIG_CGROUP_DEVICE */ + +#if defined(CONFIG_CGROUP_DEVICE) || defined(CONFIG_CGROUP_BPF) + +int devcgroup_check_permission(short type, u32 major, u32 minor, short access) +{ + int rc = BPF_CGROUP_RUN_PROG_DEVICE_CGROUP(type, major, minor, access); + + if (rc) + return rc; + + #ifdef CONFIG_CGROUP_DEVICE + return devcgroup_legacy_check_permission(type, major, minor, access); + + #else /* CONFIG_CGROUP_DEVICE */ + return 0; + + #endif /* CONFIG_CGROUP_DEVICE */ +} +EXPORT_SYMBOL(devcgroup_check_permission); +#endif /* defined(CONFIG_CGROUP_DEVICE) || defined(CONFIG_CGROUP_BPF) */ diff --git a/security/inode.c b/security/inode.c new file mode 100644 index 000000000..6c3269397 --- /dev/null +++ b/security/inode.c @@ -0,0 +1,350 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * inode.c - securityfs + * + * Copyright (C) 2005 Greg Kroah-Hartman <gregkh@suse.de> + * + * Based on fs/debugfs/inode.c which had the following copyright notice: + * Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com> + * Copyright (C) 2004 IBM Inc. + */ + +/* #define DEBUG */ +#include <linux/sysfs.h> +#include <linux/kobject.h> +#include <linux/fs.h> +#include <linux/fs_context.h> +#include <linux/mount.h> +#include <linux/pagemap.h> +#include <linux/init.h> +#include <linux/namei.h> +#include <linux/security.h> +#include <linux/lsm_hooks.h> +#include <linux/magic.h> + +static struct vfsmount *mount; +static int mount_count; + +static void securityfs_free_inode(struct inode *inode) +{ + if (S_ISLNK(inode->i_mode)) + kfree(inode->i_link); + free_inode_nonrcu(inode); +} + +static const struct super_operations securityfs_super_operations = { + .statfs = simple_statfs, + .free_inode = securityfs_free_inode, +}; + +static int securityfs_fill_super(struct super_block *sb, struct fs_context *fc) +{ + static const struct tree_descr files[] = {{""}}; + int error; + + error = simple_fill_super(sb, SECURITYFS_MAGIC, files); + if (error) + return error; + + sb->s_op = &securityfs_super_operations; + + return 0; +} + +static int securityfs_get_tree(struct fs_context *fc) +{ + return get_tree_single(fc, securityfs_fill_super); +} + +static const struct fs_context_operations securityfs_context_ops = { + .get_tree = securityfs_get_tree, +}; + +static int securityfs_init_fs_context(struct fs_context *fc) +{ + fc->ops = &securityfs_context_ops; + return 0; +} + +static struct file_system_type fs_type = { + .owner = THIS_MODULE, + .name = "securityfs", + .init_fs_context = securityfs_init_fs_context, + .kill_sb = kill_litter_super, +}; + +/** + * securityfs_create_dentry - create a dentry in the securityfs filesystem + * + * @name: a pointer to a string containing the name of the file to create. + * @mode: the permission that the file should have + * @parent: a pointer to the parent dentry for this file. This should be a + * directory dentry if set. If this parameter is %NULL, then the + * file will be created in the root of the securityfs filesystem. + * @data: a pointer to something that the caller will want to get to later + * on. The inode.i_private pointer will point to this value on + * the open() call. + * @fops: a pointer to a struct file_operations that should be used for + * this file. + * @iops: a point to a struct of inode_operations that should be used for + * this file/dir + * + * This is the basic "create a file/dir/symlink" function for + * securityfs. It allows for a wide range of flexibility in creating + * a file, or a directory (if you want to create a directory, the + * securityfs_create_dir() function is recommended to be used + * instead). + * + * This function returns a pointer to a dentry if it succeeds. This + * pointer must be passed to the securityfs_remove() function when the + * file is to be removed (no automatic cleanup happens if your module + * is unloaded, you are responsible here). If an error occurs, the + * function will return the error value (via ERR_PTR). + * + * If securityfs is not enabled in the kernel, the value %-ENODEV is + * returned. + */ +static struct dentry *securityfs_create_dentry(const char *name, umode_t mode, + struct dentry *parent, void *data, + const struct file_operations *fops, + const struct inode_operations *iops) +{ + struct dentry *dentry; + struct inode *dir, *inode; + int error; + + if (!(mode & S_IFMT)) + mode = (mode & S_IALLUGO) | S_IFREG; + + pr_debug("securityfs: creating file '%s'\n",name); + + error = simple_pin_fs(&fs_type, &mount, &mount_count); + if (error) + return ERR_PTR(error); + + if (!parent) + parent = mount->mnt_root; + + dir = d_inode(parent); + + inode_lock(dir); + dentry = lookup_one_len(name, parent, strlen(name)); + if (IS_ERR(dentry)) + goto out; + + if (d_really_is_positive(dentry)) { + error = -EEXIST; + goto out1; + } + + inode = new_inode(dir->i_sb); + if (!inode) { + error = -ENOMEM; + goto out1; + } + + inode->i_ino = get_next_ino(); + inode->i_mode = mode; + inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode); + inode->i_private = data; + if (S_ISDIR(mode)) { + inode->i_op = &simple_dir_inode_operations; + inode->i_fop = &simple_dir_operations; + inc_nlink(inode); + inc_nlink(dir); + } else if (S_ISLNK(mode)) { + inode->i_op = iops ? iops : &simple_symlink_inode_operations; + inode->i_link = data; + } else { + inode->i_fop = fops; + } + d_instantiate(dentry, inode); + dget(dentry); + inode_unlock(dir); + return dentry; + +out1: + dput(dentry); + dentry = ERR_PTR(error); +out: + inode_unlock(dir); + simple_release_fs(&mount, &mount_count); + return dentry; +} + +/** + * securityfs_create_file - create a file in the securityfs filesystem + * + * @name: a pointer to a string containing the name of the file to create. + * @mode: the permission that the file should have + * @parent: a pointer to the parent dentry for this file. This should be a + * directory dentry if set. If this parameter is %NULL, then the + * file will be created in the root of the securityfs filesystem. + * @data: a pointer to something that the caller will want to get to later + * on. The inode.i_private pointer will point to this value on + * the open() call. + * @fops: a pointer to a struct file_operations that should be used for + * this file. + * + * This function creates a file in securityfs with the given @name. + * + * This function returns a pointer to a dentry if it succeeds. This + * pointer must be passed to the securityfs_remove() function when the file is + * to be removed (no automatic cleanup happens if your module is unloaded, + * you are responsible here). If an error occurs, the function will return + * the error value (via ERR_PTR). + * + * If securityfs is not enabled in the kernel, the value %-ENODEV is + * returned. + */ +struct dentry *securityfs_create_file(const char *name, umode_t mode, + struct dentry *parent, void *data, + const struct file_operations *fops) +{ + return securityfs_create_dentry(name, mode, parent, data, fops, NULL); +} +EXPORT_SYMBOL_GPL(securityfs_create_file); + +/** + * securityfs_create_dir - create a directory in the securityfs filesystem + * + * @name: a pointer to a string containing the name of the directory to + * create. + * @parent: a pointer to the parent dentry for this file. This should be a + * directory dentry if set. If this parameter is %NULL, then the + * directory will be created in the root of the securityfs filesystem. + * + * This function creates a directory in securityfs with the given @name. + * + * This function returns a pointer to a dentry if it succeeds. This + * pointer must be passed to the securityfs_remove() function when the file is + * to be removed (no automatic cleanup happens if your module is unloaded, + * you are responsible here). If an error occurs, the function will return + * the error value (via ERR_PTR). + * + * If securityfs is not enabled in the kernel, the value %-ENODEV is + * returned. + */ +struct dentry *securityfs_create_dir(const char *name, struct dentry *parent) +{ + return securityfs_create_file(name, S_IFDIR | 0755, parent, NULL, NULL); +} +EXPORT_SYMBOL_GPL(securityfs_create_dir); + +/** + * securityfs_create_symlink - create a symlink in the securityfs filesystem + * + * @name: a pointer to a string containing the name of the symlink to + * create. + * @parent: a pointer to the parent dentry for the symlink. This should be a + * directory dentry if set. If this parameter is %NULL, then the + * directory will be created in the root of the securityfs filesystem. + * @target: a pointer to a string containing the name of the symlink's target. + * If this parameter is %NULL, then the @iops parameter needs to be + * setup to handle .readlink and .get_link inode_operations. + * @iops: a pointer to the struct inode_operations to use for the symlink. If + * this parameter is %NULL, then the default simple_symlink_inode + * operations will be used. + * + * This function creates a symlink in securityfs with the given @name. + * + * This function returns a pointer to a dentry if it succeeds. This + * pointer must be passed to the securityfs_remove() function when the file is + * to be removed (no automatic cleanup happens if your module is unloaded, + * you are responsible here). If an error occurs, the function will return + * the error value (via ERR_PTR). + * + * If securityfs is not enabled in the kernel, the value %-ENODEV is + * returned. + */ +struct dentry *securityfs_create_symlink(const char *name, + struct dentry *parent, + const char *target, + const struct inode_operations *iops) +{ + struct dentry *dent; + char *link = NULL; + + if (target) { + link = kstrdup(target, GFP_KERNEL); + if (!link) + return ERR_PTR(-ENOMEM); + } + dent = securityfs_create_dentry(name, S_IFLNK | 0444, parent, + link, NULL, iops); + if (IS_ERR(dent)) + kfree(link); + + return dent; +} +EXPORT_SYMBOL_GPL(securityfs_create_symlink); + +/** + * securityfs_remove - removes a file or directory from the securityfs filesystem + * + * @dentry: a pointer to a the dentry of the file or directory to be removed. + * + * This function removes a file or directory in securityfs that was previously + * created with a call to another securityfs function (like + * securityfs_create_file() or variants thereof.) + * + * This function is required to be called in order for the file to be + * removed. No automatic cleanup of files will happen when a module is + * removed; you are responsible here. + */ +void securityfs_remove(struct dentry *dentry) +{ + struct inode *dir; + + if (!dentry || IS_ERR(dentry)) + return; + + dir = d_inode(dentry->d_parent); + inode_lock(dir); + if (simple_positive(dentry)) { + if (d_is_dir(dentry)) + simple_rmdir(dir, dentry); + else + simple_unlink(dir, dentry); + dput(dentry); + } + inode_unlock(dir); + simple_release_fs(&mount, &mount_count); +} +EXPORT_SYMBOL_GPL(securityfs_remove); + +#ifdef CONFIG_SECURITY +static struct dentry *lsm_dentry; +static ssize_t lsm_read(struct file *filp, char __user *buf, size_t count, + loff_t *ppos) +{ + return simple_read_from_buffer(buf, count, ppos, lsm_names, + strlen(lsm_names)); +} + +static const struct file_operations lsm_ops = { + .read = lsm_read, + .llseek = generic_file_llseek, +}; +#endif + +static int __init securityfs_init(void) +{ + int retval; + + retval = sysfs_create_mount_point(kernel_kobj, "security"); + if (retval) + return retval; + + retval = register_filesystem(&fs_type); + if (retval) { + sysfs_remove_mount_point(kernel_kobj, "security"); + return retval; + } +#ifdef CONFIG_SECURITY + lsm_dentry = securityfs_create_file("lsm", 0444, NULL, NULL, + &lsm_ops); +#endif + return 0; +} +core_initcall(securityfs_init); diff --git a/security/integrity/Kconfig b/security/integrity/Kconfig new file mode 100644 index 000000000..599429f99 --- /dev/null +++ b/security/integrity/Kconfig @@ -0,0 +1,115 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +config INTEGRITY + bool "Integrity subsystem" + depends on SECURITY + default y + help + This option enables the integrity subsystem, which is comprised + of a number of different components including the Integrity + Measurement Architecture (IMA), Extended Verification Module + (EVM), IMA-appraisal extension, digital signature verification + extension and audit measurement log support. + + Each of these components can be enabled/disabled separately. + Refer to the individual components for additional details. + +if INTEGRITY + +config INTEGRITY_SIGNATURE + bool "Digital signature verification using multiple keyrings" + default n + select KEYS + select SIGNATURE + help + This option enables digital signature verification support + using multiple keyrings. It defines separate keyrings for each + of the different use cases - evm, ima, and modules. + Different keyrings improves search performance, but also allow + to "lock" certain keyring to prevent adding new keys. + This is useful for evm and module keyrings, when keys are + usually only added from initramfs. + +config INTEGRITY_ASYMMETRIC_KEYS + bool "Enable asymmetric keys support" + depends on INTEGRITY_SIGNATURE + default n + select ASYMMETRIC_KEY_TYPE + select ASYMMETRIC_PUBLIC_KEY_SUBTYPE + select CRYPTO_RSA + select X509_CERTIFICATE_PARSER + help + This option enables digital signature verification using + asymmetric keys. + +config INTEGRITY_TRUSTED_KEYRING + bool "Require all keys on the integrity keyrings be signed" + depends on SYSTEM_TRUSTED_KEYRING + depends on INTEGRITY_ASYMMETRIC_KEYS + default y + help + This option requires that all keys added to the .ima and + .evm keyrings be signed by a key on the system trusted + keyring. + +config INTEGRITY_PLATFORM_KEYRING + bool "Provide keyring for platform/firmware trusted keys" + depends on INTEGRITY_ASYMMETRIC_KEYS + depends on SYSTEM_BLACKLIST_KEYRING + help + Provide a separate, distinct keyring for platform trusted keys, which + the kernel automatically populates during initialization from values + provided by the platform for verifying the kexec'ed kerned image + and, possibly, the initramfs signature. + +config INTEGRITY_MACHINE_KEYRING + bool "Provide a keyring to which Machine Owner Keys may be added" + depends on SECONDARY_TRUSTED_KEYRING + depends on INTEGRITY_ASYMMETRIC_KEYS + depends on SYSTEM_BLACKLIST_KEYRING + depends on LOAD_UEFI_KEYS + depends on !IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY + help + If set, provide a keyring to which Machine Owner Keys (MOK) may + be added. This keyring shall contain just MOK keys. Unlike keys + in the platform keyring, keys contained in the .machine keyring will + be trusted within the kernel. + +config LOAD_UEFI_KEYS + depends on INTEGRITY_PLATFORM_KEYRING + depends on EFI + def_bool y + +config LOAD_IPL_KEYS + depends on INTEGRITY_PLATFORM_KEYRING + depends on S390 + def_bool y + +config LOAD_PPC_KEYS + bool "Enable loading of platform and blacklisted keys for POWER" + depends on INTEGRITY_PLATFORM_KEYRING + depends on PPC_SECURE_BOOT + default y + help + Enable loading of keys to the .platform keyring and blacklisted + hashes to the .blacklist keyring for powerpc based platforms. + +config INTEGRITY_AUDIT + bool "Enables integrity auditing support " + depends on AUDIT + default y + help + In addition to enabling integrity auditing support, this + option adds a kernel parameter 'integrity_audit', which + controls the level of integrity auditing messages. + 0 - basic integrity auditing messages (default) + 1 - additional integrity auditing messages + + Additional informational integrity auditing messages would + be enabled by specifying 'integrity_audit=1' on the kernel + command line. + +source "security/integrity/ima/Kconfig" +source "security/integrity/evm/Kconfig" + +endif # if INTEGRITY diff --git a/security/integrity/Makefile b/security/integrity/Makefile new file mode 100644 index 000000000..d0ffe37dc --- /dev/null +++ b/security/integrity/Makefile @@ -0,0 +1,22 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Makefile for caching inode integrity data (iint) +# + +obj-$(CONFIG_INTEGRITY) += integrity.o + +integrity-y := iint.o +integrity-$(CONFIG_INTEGRITY_AUDIT) += integrity_audit.o +integrity-$(CONFIG_INTEGRITY_SIGNATURE) += digsig.o +integrity-$(CONFIG_INTEGRITY_ASYMMETRIC_KEYS) += digsig_asymmetric.o +integrity-$(CONFIG_INTEGRITY_PLATFORM_KEYRING) += platform_certs/platform_keyring.o +integrity-$(CONFIG_INTEGRITY_MACHINE_KEYRING) += platform_certs/machine_keyring.o +integrity-$(CONFIG_LOAD_UEFI_KEYS) += platform_certs/efi_parser.o \ + platform_certs/load_uefi.o \ + platform_certs/keyring_handler.o +integrity-$(CONFIG_LOAD_IPL_KEYS) += platform_certs/load_ipl_s390.o +integrity-$(CONFIG_LOAD_PPC_KEYS) += platform_certs/efi_parser.o \ + platform_certs/load_powerpc.o \ + platform_certs/keyring_handler.o +obj-$(CONFIG_IMA) += ima/ +obj-$(CONFIG_EVM) += evm/ diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c new file mode 100644 index 000000000..f2193c531 --- /dev/null +++ b/security/integrity/digsig.c @@ -0,0 +1,221 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2011 Intel Corporation + * + * Author: + * Dmitry Kasatkin <dmitry.kasatkin@intel.com> + */ + +#include <linux/err.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/cred.h> +#include <linux/kernel_read_file.h> +#include <linux/key-type.h> +#include <linux/digsig.h> +#include <linux/vmalloc.h> +#include <crypto/public_key.h> +#include <keys/system_keyring.h> + +#include "integrity.h" + +static struct key *keyring[INTEGRITY_KEYRING_MAX]; + +static const char * const keyring_name[INTEGRITY_KEYRING_MAX] = { +#ifndef CONFIG_INTEGRITY_TRUSTED_KEYRING + "_evm", + "_ima", +#else + ".evm", + ".ima", +#endif + ".platform", + ".machine", +}; + +#ifdef CONFIG_IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY +#define restrict_link_to_ima restrict_link_by_builtin_and_secondary_trusted +#else +#define restrict_link_to_ima restrict_link_by_builtin_trusted +#endif + +static struct key *integrity_keyring_from_id(const unsigned int id) +{ + if (id >= INTEGRITY_KEYRING_MAX) + return ERR_PTR(-EINVAL); + + if (!keyring[id]) { + keyring[id] = + request_key(&key_type_keyring, keyring_name[id], NULL); + if (IS_ERR(keyring[id])) { + int err = PTR_ERR(keyring[id]); + pr_err("no %s keyring: %d\n", keyring_name[id], err); + keyring[id] = NULL; + return ERR_PTR(err); + } + } + + return keyring[id]; +} + +int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen, + const char *digest, int digestlen) +{ + struct key *keyring; + + if (siglen < 2) + return -EINVAL; + + keyring = integrity_keyring_from_id(id); + if (IS_ERR(keyring)) + return PTR_ERR(keyring); + + switch (sig[1]) { + case 1: + /* v1 API expect signature without xattr type */ + return digsig_verify(keyring, sig + 1, siglen - 1, digest, + digestlen); + case 2: /* regular file data hash based signature */ + case 3: /* struct ima_file_id data based signature */ + return asymmetric_verify(keyring, sig, siglen, digest, + digestlen); + } + + return -EOPNOTSUPP; +} + +int integrity_modsig_verify(const unsigned int id, const struct modsig *modsig) +{ + struct key *keyring; + + keyring = integrity_keyring_from_id(id); + if (IS_ERR(keyring)) + return PTR_ERR(keyring); + + return ima_modsig_verify(keyring, modsig); +} + +static int __init __integrity_init_keyring(const unsigned int id, + key_perm_t perm, + struct key_restriction *restriction) +{ + const struct cred *cred = current_cred(); + int err = 0; + + keyring[id] = keyring_alloc(keyring_name[id], KUIDT_INIT(0), + KGIDT_INIT(0), cred, perm, + KEY_ALLOC_NOT_IN_QUOTA, restriction, NULL); + if (IS_ERR(keyring[id])) { + err = PTR_ERR(keyring[id]); + pr_info("Can't allocate %s keyring (%d)\n", + keyring_name[id], err); + keyring[id] = NULL; + } else { + if (id == INTEGRITY_KEYRING_PLATFORM) + set_platform_trusted_keys(keyring[id]); + if (id == INTEGRITY_KEYRING_MACHINE && trust_moklist()) + set_machine_trusted_keys(keyring[id]); + if (id == INTEGRITY_KEYRING_IMA) + load_module_cert(keyring[id]); + } + + return err; +} + +int __init integrity_init_keyring(const unsigned int id) +{ + struct key_restriction *restriction; + key_perm_t perm; + int ret; + + perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW + | KEY_USR_READ | KEY_USR_SEARCH; + + if (id == INTEGRITY_KEYRING_PLATFORM || + id == INTEGRITY_KEYRING_MACHINE) { + restriction = NULL; + goto out; + } + + if (!IS_ENABLED(CONFIG_INTEGRITY_TRUSTED_KEYRING)) + return 0; + + restriction = kzalloc(sizeof(struct key_restriction), GFP_KERNEL); + if (!restriction) + return -ENOMEM; + + restriction->check = restrict_link_to_ima; + + /* + * MOK keys can only be added through a read-only runtime services + * UEFI variable during boot. No additional keys shall be allowed to + * load into the machine keyring following init from userspace. + */ + if (id != INTEGRITY_KEYRING_MACHINE) + perm |= KEY_USR_WRITE; + +out: + ret = __integrity_init_keyring(id, perm, restriction); + if (ret) + kfree(restriction); + return ret; +} + +static int __init integrity_add_key(const unsigned int id, const void *data, + off_t size, key_perm_t perm) +{ + key_ref_t key; + int rc = 0; + + if (!keyring[id]) + return -EINVAL; + + key = key_create_or_update(make_key_ref(keyring[id], 1), "asymmetric", + NULL, data, size, perm, + KEY_ALLOC_NOT_IN_QUOTA); + if (IS_ERR(key)) { + rc = PTR_ERR(key); + pr_err("Problem loading X.509 certificate %d\n", rc); + } else { + pr_notice("Loaded X.509 cert '%s'\n", + key_ref_to_ptr(key)->description); + key_ref_put(key); + } + + return rc; + +} + +int __init integrity_load_x509(const unsigned int id, const char *path) +{ + void *data = NULL; + size_t size; + int rc; + key_perm_t perm; + + rc = kernel_read_file_from_path(path, 0, &data, INT_MAX, NULL, + READING_X509_CERTIFICATE); + if (rc < 0) { + pr_err("Unable to open file: %s (%d)", path, rc); + return rc; + } + size = rc; + + perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW | KEY_USR_READ; + + pr_info("Loading X.509 certificate: %s\n", path); + rc = integrity_add_key(id, (const void *)data, size, perm); + + vfree(data); + return rc; +} + +int __init integrity_load_cert(const unsigned int id, const char *source, + const void *data, size_t len, key_perm_t perm) +{ + if (!data) + return -EINVAL; + + pr_info("Loading X.509 certificate: %s\n", source); + return integrity_add_key(id, data, len, perm); +} diff --git a/security/integrity/digsig_asymmetric.c b/security/integrity/digsig_asymmetric.c new file mode 100644 index 000000000..895f4b9ce --- /dev/null +++ b/security/integrity/digsig_asymmetric.c @@ -0,0 +1,157 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2013 Intel Corporation + * + * Author: + * Dmitry Kasatkin <dmitry.kasatkin@intel.com> + */ + +#include <linux/err.h> +#include <linux/ratelimit.h> +#include <linux/key-type.h> +#include <crypto/public_key.h> +#include <crypto/hash_info.h> +#include <keys/asymmetric-type.h> +#include <keys/system_keyring.h> + +#include "integrity.h" + +/* + * Request an asymmetric key. + */ +static struct key *request_asymmetric_key(struct key *keyring, uint32_t keyid) +{ + struct key *key; + char name[12]; + + sprintf(name, "id:%08x", keyid); + + pr_debug("key search: \"%s\"\n", name); + + key = get_ima_blacklist_keyring(); + if (key) { + key_ref_t kref; + + kref = keyring_search(make_key_ref(key, 1), + &key_type_asymmetric, name, true); + if (!IS_ERR(kref)) { + pr_err("Key '%s' is in ima_blacklist_keyring\n", name); + return ERR_PTR(-EKEYREJECTED); + } + } + + if (keyring) { + /* search in specific keyring */ + key_ref_t kref; + + kref = keyring_search(make_key_ref(keyring, 1), + &key_type_asymmetric, name, true); + if (IS_ERR(kref)) + key = ERR_CAST(kref); + else + key = key_ref_to_ptr(kref); + } else { + key = request_key(&key_type_asymmetric, name, NULL); + } + + if (IS_ERR(key)) { + if (keyring) + pr_err_ratelimited("Request for unknown key '%s' in '%s' keyring. err %ld\n", + name, keyring->description, + PTR_ERR(key)); + else + pr_err_ratelimited("Request for unknown key '%s' err %ld\n", + name, PTR_ERR(key)); + + switch (PTR_ERR(key)) { + /* Hide some search errors */ + case -EACCES: + case -ENOTDIR: + case -EAGAIN: + return ERR_PTR(-ENOKEY); + default: + return key; + } + } + + pr_debug("%s() = 0 [%x]\n", __func__, key_serial(key)); + + return key; +} + +int asymmetric_verify(struct key *keyring, const char *sig, + int siglen, const char *data, int datalen) +{ + struct public_key_signature pks; + struct signature_v2_hdr *hdr = (struct signature_v2_hdr *)sig; + const struct public_key *pk; + struct key *key; + int ret; + + if (siglen <= sizeof(*hdr)) + return -EBADMSG; + + siglen -= sizeof(*hdr); + + if (siglen != be16_to_cpu(hdr->sig_size)) + return -EBADMSG; + + if (hdr->hash_algo >= HASH_ALGO__LAST) + return -ENOPKG; + + key = request_asymmetric_key(keyring, be32_to_cpu(hdr->keyid)); + if (IS_ERR(key)) + return PTR_ERR(key); + + memset(&pks, 0, sizeof(pks)); + + pks.hash_algo = hash_algo_name[hdr->hash_algo]; + + pk = asymmetric_key_public_key(key); + pks.pkey_algo = pk->pkey_algo; + if (!strcmp(pk->pkey_algo, "rsa")) { + pks.encoding = "pkcs1"; + } else if (!strncmp(pk->pkey_algo, "ecdsa-", 6)) { + /* edcsa-nist-p192 etc. */ + pks.encoding = "x962"; + } else if (!strcmp(pk->pkey_algo, "ecrdsa") || + !strcmp(pk->pkey_algo, "sm2")) { + pks.encoding = "raw"; + } else { + ret = -ENOPKG; + goto out; + } + + pks.digest = (u8 *)data; + pks.digest_size = datalen; + pks.s = hdr->sig; + pks.s_size = siglen; + ret = verify_signature(key, &pks); +out: + key_put(key); + pr_debug("%s() = %d\n", __func__, ret); + return ret; +} + +/** + * integrity_kernel_module_request - prevent crypto-pkcs1pad(rsa,*) requests + * @kmod_name: kernel module name + * + * We have situation, when public_key_verify_signature() in case of RSA + * algorithm use alg_name to store internal information in order to + * construct an algorithm on the fly, but crypto_larval_lookup() will try + * to use alg_name in order to load kernel module with same name. + * Since we don't have any real "crypto-pkcs1pad(rsa,*)" kernel modules, + * we are safe to fail such module request from crypto_larval_lookup(). + * + * In this way we prevent modprobe execution during digsig verification + * and avoid possible deadlock if modprobe and/or it's dependencies + * also signed with digsig. + */ +int integrity_kernel_module_request(char *kmod_name) +{ + if (strncmp(kmod_name, "crypto-pkcs1pad(rsa,", 20) == 0) + return -EINVAL; + + return 0; +} diff --git a/security/integrity/evm/Kconfig b/security/integrity/evm/Kconfig new file mode 100644 index 000000000..a6e19d23e --- /dev/null +++ b/security/integrity/evm/Kconfig @@ -0,0 +1,74 @@ +# SPDX-License-Identifier: GPL-2.0-only +config EVM + bool "EVM support" + select KEYS + select ENCRYPTED_KEYS + select CRYPTO_HMAC + select CRYPTO_SHA1 + select CRYPTO_HASH_INFO + default n + help + EVM protects a file's security extended attributes against + integrity attacks. + + If you are unsure how to answer this question, answer N. + +config EVM_ATTR_FSUUID + bool "FSUUID (version 2)" + default y + depends on EVM + help + Include filesystem UUID for HMAC calculation. + + Default value is 'selected', which is former version 2. + if 'not selected', it is former version 1 + + WARNING: changing the HMAC calculation method or adding + additional info to the calculation, requires existing EVM + labeled file systems to be relabeled. + +config EVM_EXTRA_SMACK_XATTRS + bool "Additional SMACK xattrs" + depends on EVM && SECURITY_SMACK + default n + help + Include additional SMACK xattrs for HMAC calculation. + + In addition to the original security xattrs (eg. security.selinux, + security.SMACK64, security.capability, and security.ima) included + in the HMAC calculation, enabling this option includes newly defined + Smack xattrs: security.SMACK64EXEC, security.SMACK64TRANSMUTE and + security.SMACK64MMAP. + + WARNING: changing the HMAC calculation method or adding + additional info to the calculation, requires existing EVM + labeled file systems to be relabeled. + +config EVM_ADD_XATTRS + bool "Add additional EVM extended attributes at runtime" + depends on EVM + default n + help + Allow userland to provide additional xattrs for HMAC calculation. + + When this option is enabled, root can add additional xattrs to the + list used by EVM by writing them into + /sys/kernel/security/integrity/evm/evm_xattrs. + +config EVM_LOAD_X509 + bool "Load an X509 certificate onto the '.evm' trusted keyring" + depends on EVM && INTEGRITY_TRUSTED_KEYRING + default n + help + Load an X509 certificate onto the '.evm' trusted keyring. + + This option enables X509 certificate loading from the kernel + onto the '.evm' trusted keyring. A public key can be used to + verify EVM integrity starting from the 'init' process. + +config EVM_X509_PATH + string "EVM X509 certificate path" + depends on EVM_LOAD_X509 + default "/etc/keys/x509_evm.der" + help + This option defines X509 certificate path. diff --git a/security/integrity/evm/Makefile b/security/integrity/evm/Makefile new file mode 100644 index 000000000..a56f5613b --- /dev/null +++ b/security/integrity/evm/Makefile @@ -0,0 +1,8 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +# Makefile for building the Extended Verification Module(EVM) +# +obj-$(CONFIG_EVM) += evm.o + +evm-y := evm_main.o evm_crypto.o evm_secfs.o +evm-$(CONFIG_FS_POSIX_ACL) += evm_posix_acl.o diff --git a/security/integrity/evm/evm.h b/security/integrity/evm/evm.h new file mode 100644 index 000000000..f8b8c5004 --- /dev/null +++ b/security/integrity/evm/evm.h @@ -0,0 +1,65 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2005-2010 IBM Corporation + * + * Authors: + * Mimi Zohar <zohar@us.ibm.com> + * Kylene Hall <kjhall@us.ibm.com> + * + * File: evm.h + */ + +#ifndef __INTEGRITY_EVM_H +#define __INTEGRITY_EVM_H + +#include <linux/xattr.h> +#include <linux/security.h> + +#include "../integrity.h" + +#define EVM_INIT_HMAC 0x0001 +#define EVM_INIT_X509 0x0002 +#define EVM_ALLOW_METADATA_WRITES 0x0004 +#define EVM_SETUP_COMPLETE 0x80000000 /* userland has signaled key load */ + +#define EVM_KEY_MASK (EVM_INIT_HMAC | EVM_INIT_X509) +#define EVM_INIT_MASK (EVM_INIT_HMAC | EVM_INIT_X509 | EVM_SETUP_COMPLETE | \ + EVM_ALLOW_METADATA_WRITES) + +struct xattr_list { + struct list_head list; + char *name; + bool enabled; +}; + +extern int evm_initialized; + +#define EVM_ATTR_FSUUID 0x0001 + +extern int evm_hmac_attrs; + +/* List of EVM protected security xattrs */ +extern struct list_head evm_config_xattrnames; + +struct evm_digest { + struct ima_digest_data hdr; + char digest[IMA_MAX_DIGEST_SIZE]; +} __packed; + +int evm_init_key(void); +int evm_update_evmxattr(struct dentry *dentry, + const char *req_xattr_name, + const char *req_xattr_value, + size_t req_xattr_value_len); +int evm_calc_hmac(struct dentry *dentry, const char *req_xattr_name, + const char *req_xattr_value, + size_t req_xattr_value_len, struct evm_digest *data); +int evm_calc_hash(struct dentry *dentry, const char *req_xattr_name, + const char *req_xattr_value, + size_t req_xattr_value_len, char type, + struct evm_digest *data); +int evm_init_hmac(struct inode *inode, const struct xattr *xattr, + char *hmac_val); +int evm_init_secfs(void); + +#endif diff --git a/security/integrity/evm/evm_crypto.c b/security/integrity/evm/evm_crypto.c new file mode 100644 index 000000000..b9395f8ef --- /dev/null +++ b/security/integrity/evm/evm_crypto.c @@ -0,0 +1,428 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2005-2010 IBM Corporation + * + * Authors: + * Mimi Zohar <zohar@us.ibm.com> + * Kylene Hall <kjhall@us.ibm.com> + * + * File: evm_crypto.c + * Using root's kernel master key (kmk), calculate the HMAC + */ + +#define pr_fmt(fmt) "EVM: "fmt + +#include <linux/export.h> +#include <linux/crypto.h> +#include <linux/xattr.h> +#include <linux/evm.h> +#include <keys/encrypted-type.h> +#include <crypto/hash.h> +#include <crypto/hash_info.h> +#include "evm.h" + +#define EVMKEY "evm-key" +#define MAX_KEY_SIZE 128 +static unsigned char evmkey[MAX_KEY_SIZE]; +static const int evmkey_len = MAX_KEY_SIZE; + +static struct crypto_shash *hmac_tfm; +static struct crypto_shash *evm_tfm[HASH_ALGO__LAST]; + +static DEFINE_MUTEX(mutex); + +#define EVM_SET_KEY_BUSY 0 + +static unsigned long evm_set_key_flags; + +static const char evm_hmac[] = "hmac(sha1)"; + +/** + * evm_set_key() - set EVM HMAC key from the kernel + * @key: pointer to a buffer with the key data + * @keylen: length of the key data + * + * This function allows setting the EVM HMAC key from the kernel + * without using the "encrypted" key subsystem keys. It can be used + * by the crypto HW kernel module which has its own way of managing + * keys. + * + * key length should be between 32 and 128 bytes long + */ +int evm_set_key(void *key, size_t keylen) +{ + int rc; + + rc = -EBUSY; + if (test_and_set_bit(EVM_SET_KEY_BUSY, &evm_set_key_flags)) + goto busy; + rc = -EINVAL; + if (keylen > MAX_KEY_SIZE) + goto inval; + memcpy(evmkey, key, keylen); + evm_initialized |= EVM_INIT_HMAC; + pr_info("key initialized\n"); + return 0; +inval: + clear_bit(EVM_SET_KEY_BUSY, &evm_set_key_flags); +busy: + pr_err("key initialization failed\n"); + return rc; +} +EXPORT_SYMBOL_GPL(evm_set_key); + +static struct shash_desc *init_desc(char type, uint8_t hash_algo) +{ + long rc; + const char *algo; + struct crypto_shash **tfm, *tmp_tfm; + struct shash_desc *desc; + + if (type == EVM_XATTR_HMAC) { + if (!(evm_initialized & EVM_INIT_HMAC)) { + pr_err_once("HMAC key is not set\n"); + return ERR_PTR(-ENOKEY); + } + tfm = &hmac_tfm; + algo = evm_hmac; + } else { + if (hash_algo >= HASH_ALGO__LAST) + return ERR_PTR(-EINVAL); + + tfm = &evm_tfm[hash_algo]; + algo = hash_algo_name[hash_algo]; + } + + if (*tfm) + goto alloc; + mutex_lock(&mutex); + if (*tfm) + goto unlock; + + tmp_tfm = crypto_alloc_shash(algo, 0, CRYPTO_NOLOAD); + if (IS_ERR(tmp_tfm)) { + pr_err("Can not allocate %s (reason: %ld)\n", algo, + PTR_ERR(tmp_tfm)); + mutex_unlock(&mutex); + return ERR_CAST(tmp_tfm); + } + if (type == EVM_XATTR_HMAC) { + rc = crypto_shash_setkey(tmp_tfm, evmkey, evmkey_len); + if (rc) { + crypto_free_shash(tmp_tfm); + mutex_unlock(&mutex); + return ERR_PTR(rc); + } + } + *tfm = tmp_tfm; +unlock: + mutex_unlock(&mutex); +alloc: + desc = kmalloc(sizeof(*desc) + crypto_shash_descsize(*tfm), + GFP_KERNEL); + if (!desc) + return ERR_PTR(-ENOMEM); + + desc->tfm = *tfm; + + rc = crypto_shash_init(desc); + if (rc) { + kfree(desc); + return ERR_PTR(rc); + } + return desc; +} + +/* Protect against 'cutting & pasting' security.evm xattr, include inode + * specific info. + * + * (Additional directory/file metadata needs to be added for more complete + * protection.) + */ +static void hmac_add_misc(struct shash_desc *desc, struct inode *inode, + char type, char *digest) +{ + struct h_misc { + unsigned long ino; + __u32 generation; + uid_t uid; + gid_t gid; + umode_t mode; + } hmac_misc; + + memset(&hmac_misc, 0, sizeof(hmac_misc)); + /* Don't include the inode or generation number in portable + * signatures + */ + if (type != EVM_XATTR_PORTABLE_DIGSIG) { + hmac_misc.ino = inode->i_ino; + hmac_misc.generation = inode->i_generation; + } + /* The hmac uid and gid must be encoded in the initial user + * namespace (not the filesystems user namespace) as encoding + * them in the filesystems user namespace allows an attack + * where first they are written in an unprivileged fuse mount + * of a filesystem and then the system is tricked to mount the + * filesystem for real on next boot and trust it because + * everything is signed. + */ + hmac_misc.uid = from_kuid(&init_user_ns, inode->i_uid); + hmac_misc.gid = from_kgid(&init_user_ns, inode->i_gid); + hmac_misc.mode = inode->i_mode; + crypto_shash_update(desc, (const u8 *)&hmac_misc, sizeof(hmac_misc)); + if ((evm_hmac_attrs & EVM_ATTR_FSUUID) && + type != EVM_XATTR_PORTABLE_DIGSIG) + crypto_shash_update(desc, (u8 *)&inode->i_sb->s_uuid, UUID_SIZE); + crypto_shash_final(desc, digest); + + pr_debug("hmac_misc: (%zu) [%*phN]\n", sizeof(struct h_misc), + (int)sizeof(struct h_misc), &hmac_misc); +} + +/* + * Dump large security xattr values as a continuous ascii hexademical string. + * (pr_debug is limited to 64 bytes.) + */ +static void dump_security_xattr(const char *prefix, const void *src, + size_t count) +{ +#if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG) + char *asciihex, *p; + + p = asciihex = kmalloc(count * 2 + 1, GFP_KERNEL); + if (!asciihex) + return; + + p = bin2hex(p, src, count); + *p = 0; + pr_debug("%s: (%zu) %.*s\n", prefix, count, (int)count * 2, asciihex); + kfree(asciihex); +#endif +} + +/* + * Calculate the HMAC value across the set of protected security xattrs. + * + * Instead of retrieving the requested xattr, for performance, calculate + * the hmac using the requested xattr value. Don't alloc/free memory for + * each xattr, but attempt to re-use the previously allocated memory. + */ +static int evm_calc_hmac_or_hash(struct dentry *dentry, + const char *req_xattr_name, + const char *req_xattr_value, + size_t req_xattr_value_len, + uint8_t type, struct evm_digest *data) +{ + struct inode *inode = d_backing_inode(dentry); + struct xattr_list *xattr; + struct shash_desc *desc; + size_t xattr_size = 0; + char *xattr_value = NULL; + int error; + int size, user_space_size; + bool ima_present = false; + + if (!(inode->i_opflags & IOP_XATTR) || + inode->i_sb->s_user_ns != &init_user_ns) + return -EOPNOTSUPP; + + desc = init_desc(type, data->hdr.algo); + if (IS_ERR(desc)) + return PTR_ERR(desc); + + data->hdr.length = crypto_shash_digestsize(desc->tfm); + + error = -ENODATA; + list_for_each_entry_lockless(xattr, &evm_config_xattrnames, list) { + bool is_ima = false; + + if (strcmp(xattr->name, XATTR_NAME_IMA) == 0) + is_ima = true; + + /* + * Skip non-enabled xattrs for locally calculated + * signatures/HMACs. + */ + if (type != EVM_XATTR_PORTABLE_DIGSIG && !xattr->enabled) + continue; + + if ((req_xattr_name && req_xattr_value) + && !strcmp(xattr->name, req_xattr_name)) { + error = 0; + crypto_shash_update(desc, (const u8 *)req_xattr_value, + req_xattr_value_len); + if (is_ima) + ima_present = true; + + if (req_xattr_value_len < 64) + pr_debug("%s: (%zu) [%*phN]\n", req_xattr_name, + req_xattr_value_len, + (int)req_xattr_value_len, + req_xattr_value); + else + dump_security_xattr(req_xattr_name, + req_xattr_value, + req_xattr_value_len); + continue; + } + size = vfs_getxattr_alloc(&init_user_ns, dentry, xattr->name, + &xattr_value, xattr_size, GFP_NOFS); + if (size == -ENOMEM) { + error = -ENOMEM; + goto out; + } + if (size < 0) + continue; + + user_space_size = vfs_getxattr(&init_user_ns, dentry, + xattr->name, NULL, 0); + if (user_space_size != size) + pr_debug("file %s: xattr %s size mismatch (kernel: %d, user: %d)\n", + dentry->d_name.name, xattr->name, size, + user_space_size); + error = 0; + xattr_size = size; + crypto_shash_update(desc, (const u8 *)xattr_value, xattr_size); + if (is_ima) + ima_present = true; + + if (xattr_size < 64) + pr_debug("%s: (%zu) [%*phN]", xattr->name, xattr_size, + (int)xattr_size, xattr_value); + else + dump_security_xattr(xattr->name, xattr_value, + xattr_size); + } + hmac_add_misc(desc, inode, type, data->digest); + + /* Portable EVM signatures must include an IMA hash */ + if (type == EVM_XATTR_PORTABLE_DIGSIG && !ima_present) + error = -EPERM; +out: + kfree(xattr_value); + kfree(desc); + return error; +} + +int evm_calc_hmac(struct dentry *dentry, const char *req_xattr_name, + const char *req_xattr_value, size_t req_xattr_value_len, + struct evm_digest *data) +{ + return evm_calc_hmac_or_hash(dentry, req_xattr_name, req_xattr_value, + req_xattr_value_len, EVM_XATTR_HMAC, data); +} + +int evm_calc_hash(struct dentry *dentry, const char *req_xattr_name, + const char *req_xattr_value, size_t req_xattr_value_len, + char type, struct evm_digest *data) +{ + return evm_calc_hmac_or_hash(dentry, req_xattr_name, req_xattr_value, + req_xattr_value_len, type, data); +} + +static int evm_is_immutable(struct dentry *dentry, struct inode *inode) +{ + const struct evm_ima_xattr_data *xattr_data = NULL; + struct integrity_iint_cache *iint; + int rc = 0; + + iint = integrity_iint_find(inode); + if (iint && (iint->flags & EVM_IMMUTABLE_DIGSIG)) + return 1; + + /* Do this the hard way */ + rc = vfs_getxattr_alloc(&init_user_ns, dentry, XATTR_NAME_EVM, + (char **)&xattr_data, 0, GFP_NOFS); + if (rc <= 0) { + if (rc == -ENODATA) + return 0; + return rc; + } + if (xattr_data->type == EVM_XATTR_PORTABLE_DIGSIG) + rc = 1; + else + rc = 0; + + kfree(xattr_data); + return rc; +} + + +/* + * Calculate the hmac and update security.evm xattr + * + * Expects to be called with i_mutex locked. + */ +int evm_update_evmxattr(struct dentry *dentry, const char *xattr_name, + const char *xattr_value, size_t xattr_value_len) +{ + struct inode *inode = d_backing_inode(dentry); + struct evm_digest data; + int rc = 0; + + /* + * Don't permit any transformation of the EVM xattr if the signature + * is of an immutable type + */ + rc = evm_is_immutable(dentry, inode); + if (rc < 0) + return rc; + if (rc) + return -EPERM; + + data.hdr.algo = HASH_ALGO_SHA1; + rc = evm_calc_hmac(dentry, xattr_name, xattr_value, + xattr_value_len, &data); + if (rc == 0) { + data.hdr.xattr.sha1.type = EVM_XATTR_HMAC; + rc = __vfs_setxattr_noperm(&init_user_ns, dentry, + XATTR_NAME_EVM, + &data.hdr.xattr.data[1], + SHA1_DIGEST_SIZE + 1, 0); + } else if (rc == -ENODATA && (inode->i_opflags & IOP_XATTR)) { + rc = __vfs_removexattr(&init_user_ns, dentry, XATTR_NAME_EVM); + } + return rc; +} + +int evm_init_hmac(struct inode *inode, const struct xattr *lsm_xattr, + char *hmac_val) +{ + struct shash_desc *desc; + + desc = init_desc(EVM_XATTR_HMAC, HASH_ALGO_SHA1); + if (IS_ERR(desc)) { + pr_info("init_desc failed\n"); + return PTR_ERR(desc); + } + + crypto_shash_update(desc, lsm_xattr->value, lsm_xattr->value_len); + hmac_add_misc(desc, inode, EVM_XATTR_HMAC, hmac_val); + kfree(desc); + return 0; +} + +/* + * Get the key from the TPM for the SHA1-HMAC + */ +int evm_init_key(void) +{ + struct key *evm_key; + struct encrypted_key_payload *ekp; + int rc; + + evm_key = request_key(&key_type_encrypted, EVMKEY, NULL); + if (IS_ERR(evm_key)) + return -ENOENT; + + down_read(&evm_key->sem); + ekp = evm_key->payload.data[0]; + + rc = evm_set_key(ekp->decrypted_data, ekp->decrypted_datalen); + + /* burn the original key contents */ + memset(ekp->decrypted_data, 0, ekp->decrypted_datalen); + up_read(&evm_key->sem); + key_put(evm_key); + return rc; +} diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c new file mode 100644 index 000000000..a338f1944 --- /dev/null +++ b/security/integrity/evm/evm_main.c @@ -0,0 +1,919 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2005-2010 IBM Corporation + * + * Author: + * Mimi Zohar <zohar@us.ibm.com> + * Kylene Hall <kjhall@us.ibm.com> + * + * File: evm_main.c + * implements evm_inode_setxattr, evm_inode_post_setxattr, + * evm_inode_removexattr, and evm_verifyxattr + */ + +#define pr_fmt(fmt) "EVM: "fmt + +#include <linux/init.h> +#include <linux/crypto.h> +#include <linux/audit.h> +#include <linux/xattr.h> +#include <linux/integrity.h> +#include <linux/evm.h> +#include <linux/magic.h> +#include <linux/posix_acl_xattr.h> + +#include <crypto/hash.h> +#include <crypto/hash_info.h> +#include <crypto/algapi.h> +#include "evm.h" + +int evm_initialized; + +static const char * const integrity_status_msg[] = { + "pass", "pass_immutable", "fail", "fail_immutable", "no_label", + "no_xattrs", "unknown" +}; +int evm_hmac_attrs; + +static struct xattr_list evm_config_default_xattrnames[] = { + { + .name = XATTR_NAME_SELINUX, + .enabled = IS_ENABLED(CONFIG_SECURITY_SELINUX) + }, + { + .name = XATTR_NAME_SMACK, + .enabled = IS_ENABLED(CONFIG_SECURITY_SMACK) + }, + { + .name = XATTR_NAME_SMACKEXEC, + .enabled = IS_ENABLED(CONFIG_EVM_EXTRA_SMACK_XATTRS) + }, + { + .name = XATTR_NAME_SMACKTRANSMUTE, + .enabled = IS_ENABLED(CONFIG_EVM_EXTRA_SMACK_XATTRS) + }, + { + .name = XATTR_NAME_SMACKMMAP, + .enabled = IS_ENABLED(CONFIG_EVM_EXTRA_SMACK_XATTRS) + }, + { + .name = XATTR_NAME_APPARMOR, + .enabled = IS_ENABLED(CONFIG_SECURITY_APPARMOR) + }, + { + .name = XATTR_NAME_IMA, + .enabled = IS_ENABLED(CONFIG_IMA_APPRAISE) + }, + { + .name = XATTR_NAME_CAPS, + .enabled = true + }, +}; + +LIST_HEAD(evm_config_xattrnames); + +static int evm_fixmode __ro_after_init; +static int __init evm_set_fixmode(char *str) +{ + if (strncmp(str, "fix", 3) == 0) + evm_fixmode = 1; + else + pr_err("invalid \"%s\" mode", str); + + return 1; +} +__setup("evm=", evm_set_fixmode); + +static void __init evm_init_config(void) +{ + int i, xattrs; + + xattrs = ARRAY_SIZE(evm_config_default_xattrnames); + + pr_info("Initialising EVM extended attributes:\n"); + for (i = 0; i < xattrs; i++) { + pr_info("%s%s\n", evm_config_default_xattrnames[i].name, + !evm_config_default_xattrnames[i].enabled ? + " (disabled)" : ""); + list_add_tail(&evm_config_default_xattrnames[i].list, + &evm_config_xattrnames); + } + +#ifdef CONFIG_EVM_ATTR_FSUUID + evm_hmac_attrs |= EVM_ATTR_FSUUID; +#endif + pr_info("HMAC attrs: 0x%x\n", evm_hmac_attrs); +} + +static bool evm_key_loaded(void) +{ + return (bool)(evm_initialized & EVM_KEY_MASK); +} + +/* + * This function determines whether or not it is safe to ignore verification + * errors, based on the ability of EVM to calculate HMACs. If the HMAC key + * is not loaded, and it cannot be loaded in the future due to the + * EVM_SETUP_COMPLETE initialization flag, allowing an operation despite the + * attrs/xattrs being found invalid will not make them valid. + */ +static bool evm_hmac_disabled(void) +{ + if (evm_initialized & EVM_INIT_HMAC) + return false; + + if (!(evm_initialized & EVM_SETUP_COMPLETE)) + return false; + + return true; +} + +static int evm_find_protected_xattrs(struct dentry *dentry) +{ + struct inode *inode = d_backing_inode(dentry); + struct xattr_list *xattr; + int error; + int count = 0; + + if (!(inode->i_opflags & IOP_XATTR)) + return -EOPNOTSUPP; + + list_for_each_entry_lockless(xattr, &evm_config_xattrnames, list) { + error = __vfs_getxattr(dentry, inode, xattr->name, NULL, 0); + if (error < 0) { + if (error == -ENODATA) + continue; + return error; + } + count++; + } + + return count; +} + +/* + * evm_verify_hmac - calculate and compare the HMAC with the EVM xattr + * + * Compute the HMAC on the dentry's protected set of extended attributes + * and compare it against the stored security.evm xattr. + * + * For performance: + * - use the previoulsy retrieved xattr value and length to calculate the + * HMAC.) + * - cache the verification result in the iint, when available. + * + * Returns integrity status + */ +static enum integrity_status evm_verify_hmac(struct dentry *dentry, + const char *xattr_name, + char *xattr_value, + size_t xattr_value_len, + struct integrity_iint_cache *iint) +{ + struct evm_ima_xattr_data *xattr_data = NULL; + struct signature_v2_hdr *hdr; + enum integrity_status evm_status = INTEGRITY_PASS; + struct evm_digest digest; + struct inode *inode; + int rc, xattr_len, evm_immutable = 0; + + if (iint && (iint->evm_status == INTEGRITY_PASS || + iint->evm_status == INTEGRITY_PASS_IMMUTABLE)) + return iint->evm_status; + + /* if status is not PASS, try to check again - against -ENOMEM */ + + /* first need to know the sig type */ + rc = vfs_getxattr_alloc(&init_user_ns, dentry, XATTR_NAME_EVM, + (char **)&xattr_data, 0, GFP_NOFS); + if (rc <= 0) { + evm_status = INTEGRITY_FAIL; + if (rc == -ENODATA) { + rc = evm_find_protected_xattrs(dentry); + if (rc > 0) + evm_status = INTEGRITY_NOLABEL; + else if (rc == 0) + evm_status = INTEGRITY_NOXATTRS; /* new file */ + } else if (rc == -EOPNOTSUPP) { + evm_status = INTEGRITY_UNKNOWN; + } + goto out; + } + + xattr_len = rc; + + /* check value type */ + switch (xattr_data->type) { + case EVM_XATTR_HMAC: + if (xattr_len != sizeof(struct evm_xattr)) { + evm_status = INTEGRITY_FAIL; + goto out; + } + + digest.hdr.algo = HASH_ALGO_SHA1; + rc = evm_calc_hmac(dentry, xattr_name, xattr_value, + xattr_value_len, &digest); + if (rc) + break; + rc = crypto_memneq(xattr_data->data, digest.digest, + SHA1_DIGEST_SIZE); + if (rc) + rc = -EINVAL; + break; + case EVM_XATTR_PORTABLE_DIGSIG: + evm_immutable = 1; + fallthrough; + case EVM_IMA_XATTR_DIGSIG: + /* accept xattr with non-empty signature field */ + if (xattr_len <= sizeof(struct signature_v2_hdr)) { + evm_status = INTEGRITY_FAIL; + goto out; + } + + hdr = (struct signature_v2_hdr *)xattr_data; + digest.hdr.algo = hdr->hash_algo; + rc = evm_calc_hash(dentry, xattr_name, xattr_value, + xattr_value_len, xattr_data->type, &digest); + if (rc) + break; + rc = integrity_digsig_verify(INTEGRITY_KEYRING_EVM, + (const char *)xattr_data, xattr_len, + digest.digest, digest.hdr.length); + if (!rc) { + inode = d_backing_inode(dentry); + + if (xattr_data->type == EVM_XATTR_PORTABLE_DIGSIG) { + if (iint) + iint->flags |= EVM_IMMUTABLE_DIGSIG; + evm_status = INTEGRITY_PASS_IMMUTABLE; + } else if (!IS_RDONLY(inode) && + !(inode->i_sb->s_readonly_remount) && + !IS_IMMUTABLE(inode)) { + evm_update_evmxattr(dentry, xattr_name, + xattr_value, + xattr_value_len); + } + } + break; + default: + rc = -EINVAL; + break; + } + + if (rc) { + if (rc == -ENODATA) + evm_status = INTEGRITY_NOXATTRS; + else if (evm_immutable) + evm_status = INTEGRITY_FAIL_IMMUTABLE; + else + evm_status = INTEGRITY_FAIL; + } + pr_debug("digest: (%d) [%*phN]\n", digest.hdr.length, digest.hdr.length, + digest.digest); +out: + if (iint) + iint->evm_status = evm_status; + kfree(xattr_data); + return evm_status; +} + +static int evm_protected_xattr_common(const char *req_xattr_name, + bool all_xattrs) +{ + int namelen; + int found = 0; + struct xattr_list *xattr; + + namelen = strlen(req_xattr_name); + list_for_each_entry_lockless(xattr, &evm_config_xattrnames, list) { + if (!all_xattrs && !xattr->enabled) + continue; + + if ((strlen(xattr->name) == namelen) + && (strncmp(req_xattr_name, xattr->name, namelen) == 0)) { + found = 1; + break; + } + if (strncmp(req_xattr_name, + xattr->name + XATTR_SECURITY_PREFIX_LEN, + strlen(req_xattr_name)) == 0) { + found = 1; + break; + } + } + + return found; +} + +static int evm_protected_xattr(const char *req_xattr_name) +{ + return evm_protected_xattr_common(req_xattr_name, false); +} + +int evm_protected_xattr_if_enabled(const char *req_xattr_name) +{ + return evm_protected_xattr_common(req_xattr_name, true); +} + +/** + * evm_read_protected_xattrs - read EVM protected xattr names, lengths, values + * @dentry: dentry of the read xattrs + * @buffer: buffer xattr names, lengths or values are copied to + * @buffer_size: size of buffer + * @type: n: names, l: lengths, v: values + * @canonical_fmt: data format (true: little endian, false: native format) + * + * Read protected xattr names (separated by |), lengths (u32) or values for a + * given dentry and return the total size of copied data. If buffer is NULL, + * just return the total size. + * + * Returns the total size on success, a negative value on error. + */ +int evm_read_protected_xattrs(struct dentry *dentry, u8 *buffer, + int buffer_size, char type, bool canonical_fmt) +{ + struct xattr_list *xattr; + int rc, size, total_size = 0; + + list_for_each_entry_lockless(xattr, &evm_config_xattrnames, list) { + rc = __vfs_getxattr(dentry, d_backing_inode(dentry), + xattr->name, NULL, 0); + if (rc < 0 && rc == -ENODATA) + continue; + else if (rc < 0) + return rc; + + switch (type) { + case 'n': + size = strlen(xattr->name) + 1; + if (buffer) { + if (total_size) + *(buffer + total_size - 1) = '|'; + + memcpy(buffer + total_size, xattr->name, size); + } + break; + case 'l': + size = sizeof(u32); + if (buffer) { + if (canonical_fmt) + rc = (__force int)cpu_to_le32(rc); + + *(u32 *)(buffer + total_size) = rc; + } + break; + case 'v': + size = rc; + if (buffer) { + rc = __vfs_getxattr(dentry, + d_backing_inode(dentry), xattr->name, + buffer + total_size, + buffer_size - total_size); + if (rc < 0) + return rc; + } + break; + default: + return -EINVAL; + } + + total_size += size; + } + + return total_size; +} + +/** + * evm_verifyxattr - verify the integrity of the requested xattr + * @dentry: object of the verify xattr + * @xattr_name: requested xattr + * @xattr_value: requested xattr value + * @xattr_value_len: requested xattr value length + * @iint: inode integrity metadata + * + * Calculate the HMAC for the given dentry and verify it against the stored + * security.evm xattr. For performance, use the xattr value and length + * previously retrieved to calculate the HMAC. + * + * Returns the xattr integrity status. + * + * This function requires the caller to lock the inode's i_mutex before it + * is executed. + */ +enum integrity_status evm_verifyxattr(struct dentry *dentry, + const char *xattr_name, + void *xattr_value, size_t xattr_value_len, + struct integrity_iint_cache *iint) +{ + if (!evm_key_loaded() || !evm_protected_xattr(xattr_name)) + return INTEGRITY_UNKNOWN; + + if (!iint) { + iint = integrity_iint_find(d_backing_inode(dentry)); + if (!iint) + return INTEGRITY_UNKNOWN; + } + return evm_verify_hmac(dentry, xattr_name, xattr_value, + xattr_value_len, iint); +} +EXPORT_SYMBOL_GPL(evm_verifyxattr); + +/* + * evm_verify_current_integrity - verify the dentry's metadata integrity + * @dentry: pointer to the affected dentry + * + * Verify and return the dentry's metadata integrity. The exceptions are + * before EVM is initialized or in 'fix' mode. + */ +static enum integrity_status evm_verify_current_integrity(struct dentry *dentry) +{ + struct inode *inode = d_backing_inode(dentry); + + if (!evm_key_loaded() || !S_ISREG(inode->i_mode) || evm_fixmode) + return INTEGRITY_PASS; + return evm_verify_hmac(dentry, NULL, NULL, 0, NULL); +} + +/* + * evm_xattr_acl_change - check if passed ACL changes the inode mode + * @mnt_userns: user namespace of the idmapped mount + * @dentry: pointer to the affected dentry + * @xattr_name: requested xattr + * @xattr_value: requested xattr value + * @xattr_value_len: requested xattr value length + * + * Check if passed ACL changes the inode mode, which is protected by EVM. + * + * Returns 1 if passed ACL causes inode mode change, 0 otherwise. + */ +static int evm_xattr_acl_change(struct user_namespace *mnt_userns, + struct dentry *dentry, const char *xattr_name, + const void *xattr_value, size_t xattr_value_len) +{ +#ifdef CONFIG_FS_POSIX_ACL + umode_t mode; + struct posix_acl *acl = NULL, *acl_res; + struct inode *inode = d_backing_inode(dentry); + int rc; + + /* + * An earlier comment here mentioned that the idmappings for + * ACL_{GROUP,USER} don't matter since EVM is only interested in the + * mode stored as part of POSIX ACLs. Nonetheless, if it must translate + * from the uapi POSIX ACL representation to the VFS internal POSIX ACL + * representation it should do so correctly. There's no guarantee that + * we won't change POSIX ACLs in a way that ACL_{GROUP,USER} matters + * for the mode at some point and it's difficult to keep track of all + * the LSM and integrity modules and what they do to POSIX ACLs. + * + * Frankly, EVM shouldn't try to interpret the uapi struct for POSIX + * ACLs it received. It requires knowledge that only the VFS is + * guaranteed to have. + */ + acl = vfs_set_acl_prepare(mnt_userns, i_user_ns(inode), + xattr_value, xattr_value_len); + if (IS_ERR_OR_NULL(acl)) + return 1; + + acl_res = acl; + /* + * Passing mnt_userns is necessary to correctly determine the GID in + * an idmapped mount, as the GID is used to clear the setgid bit in + * the inode mode. + */ + rc = posix_acl_update_mode(mnt_userns, inode, &mode, &acl_res); + + posix_acl_release(acl); + + if (rc) + return 1; + + if (inode->i_mode != mode) + return 1; +#endif + return 0; +} + +/* + * evm_xattr_change - check if passed xattr value differs from current value + * @mnt_userns: user namespace of the idmapped mount + * @dentry: pointer to the affected dentry + * @xattr_name: requested xattr + * @xattr_value: requested xattr value + * @xattr_value_len: requested xattr value length + * + * Check if passed xattr value differs from current value. + * + * Returns 1 if passed xattr value differs from current value, 0 otherwise. + */ +static int evm_xattr_change(struct user_namespace *mnt_userns, + struct dentry *dentry, const char *xattr_name, + const void *xattr_value, size_t xattr_value_len) +{ + char *xattr_data = NULL; + int rc = 0; + + if (posix_xattr_acl(xattr_name)) + return evm_xattr_acl_change(mnt_userns, dentry, xattr_name, + xattr_value, xattr_value_len); + + rc = vfs_getxattr_alloc(&init_user_ns, dentry, xattr_name, &xattr_data, + 0, GFP_NOFS); + if (rc < 0) + return 1; + + if (rc == xattr_value_len) + rc = !!memcmp(xattr_value, xattr_data, rc); + else + rc = 1; + + kfree(xattr_data); + return rc; +} + +/* + * evm_protect_xattr - protect the EVM extended attribute + * + * Prevent security.evm from being modified or removed without the + * necessary permissions or when the existing value is invalid. + * + * The posix xattr acls are 'system' prefixed, which normally would not + * affect security.evm. An interesting side affect of writing posix xattr + * acls is their modifying of the i_mode, which is included in security.evm. + * For posix xattr acls only, permit security.evm, even if it currently + * doesn't exist, to be updated unless the EVM signature is immutable. + */ +static int evm_protect_xattr(struct user_namespace *mnt_userns, + struct dentry *dentry, const char *xattr_name, + const void *xattr_value, size_t xattr_value_len) +{ + enum integrity_status evm_status; + + if (strcmp(xattr_name, XATTR_NAME_EVM) == 0) { + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + } else if (!evm_protected_xattr(xattr_name)) { + if (!posix_xattr_acl(xattr_name)) + return 0; + evm_status = evm_verify_current_integrity(dentry); + if ((evm_status == INTEGRITY_PASS) || + (evm_status == INTEGRITY_NOXATTRS)) + return 0; + goto out; + } + + evm_status = evm_verify_current_integrity(dentry); + if (evm_status == INTEGRITY_NOXATTRS) { + struct integrity_iint_cache *iint; + + /* Exception if the HMAC is not going to be calculated. */ + if (evm_hmac_disabled()) + return 0; + + iint = integrity_iint_find(d_backing_inode(dentry)); + if (iint && (iint->flags & IMA_NEW_FILE)) + return 0; + + /* exception for pseudo filesystems */ + if (dentry->d_sb->s_magic == TMPFS_MAGIC + || dentry->d_sb->s_magic == SYSFS_MAGIC) + return 0; + + integrity_audit_msg(AUDIT_INTEGRITY_METADATA, + dentry->d_inode, dentry->d_name.name, + "update_metadata", + integrity_status_msg[evm_status], + -EPERM, 0); + } +out: + /* Exception if the HMAC is not going to be calculated. */ + if (evm_hmac_disabled() && (evm_status == INTEGRITY_NOLABEL || + evm_status == INTEGRITY_UNKNOWN)) + return 0; + + /* + * Writing other xattrs is safe for portable signatures, as portable + * signatures are immutable and can never be updated. + */ + if (evm_status == INTEGRITY_FAIL_IMMUTABLE) + return 0; + + if (evm_status == INTEGRITY_PASS_IMMUTABLE && + !evm_xattr_change(mnt_userns, dentry, xattr_name, xattr_value, + xattr_value_len)) + return 0; + + if (evm_status != INTEGRITY_PASS && + evm_status != INTEGRITY_PASS_IMMUTABLE) + integrity_audit_msg(AUDIT_INTEGRITY_METADATA, d_backing_inode(dentry), + dentry->d_name.name, "appraise_metadata", + integrity_status_msg[evm_status], + -EPERM, 0); + return evm_status == INTEGRITY_PASS ? 0 : -EPERM; +} + +/** + * evm_inode_setxattr - protect the EVM extended attribute + * @mnt_userns: user namespace of the idmapped mount + * @dentry: pointer to the affected dentry + * @xattr_name: pointer to the affected extended attribute name + * @xattr_value: pointer to the new extended attribute value + * @xattr_value_len: pointer to the new extended attribute value length + * + * Before allowing the 'security.evm' protected xattr to be updated, + * verify the existing value is valid. As only the kernel should have + * access to the EVM encrypted key needed to calculate the HMAC, prevent + * userspace from writing HMAC value. Writing 'security.evm' requires + * requires CAP_SYS_ADMIN privileges. + */ +int evm_inode_setxattr(struct user_namespace *mnt_userns, struct dentry *dentry, + const char *xattr_name, const void *xattr_value, + size_t xattr_value_len) +{ + const struct evm_ima_xattr_data *xattr_data = xattr_value; + + /* Policy permits modification of the protected xattrs even though + * there's no HMAC key loaded + */ + if (evm_initialized & EVM_ALLOW_METADATA_WRITES) + return 0; + + if (strcmp(xattr_name, XATTR_NAME_EVM) == 0) { + if (!xattr_value_len) + return -EINVAL; + if (xattr_data->type != EVM_IMA_XATTR_DIGSIG && + xattr_data->type != EVM_XATTR_PORTABLE_DIGSIG) + return -EPERM; + } + return evm_protect_xattr(mnt_userns, dentry, xattr_name, xattr_value, + xattr_value_len); +} + +/** + * evm_inode_removexattr - protect the EVM extended attribute + * @mnt_userns: user namespace of the idmapped mount + * @dentry: pointer to the affected dentry + * @xattr_name: pointer to the affected extended attribute name + * + * Removing 'security.evm' requires CAP_SYS_ADMIN privileges and that + * the current value is valid. + */ +int evm_inode_removexattr(struct user_namespace *mnt_userns, + struct dentry *dentry, const char *xattr_name) +{ + /* Policy permits modification of the protected xattrs even though + * there's no HMAC key loaded + */ + if (evm_initialized & EVM_ALLOW_METADATA_WRITES) + return 0; + + return evm_protect_xattr(mnt_userns, dentry, xattr_name, NULL, 0); +} + +static void evm_reset_status(struct inode *inode) +{ + struct integrity_iint_cache *iint; + + iint = integrity_iint_find(inode); + if (iint) + iint->evm_status = INTEGRITY_UNKNOWN; +} + +/** + * evm_revalidate_status - report whether EVM status re-validation is necessary + * @xattr_name: pointer to the affected extended attribute name + * + * Report whether callers of evm_verifyxattr() should re-validate the + * EVM status. + * + * Return true if re-validation is necessary, false otherwise. + */ +bool evm_revalidate_status(const char *xattr_name) +{ + if (!evm_key_loaded()) + return false; + + /* evm_inode_post_setattr() passes NULL */ + if (!xattr_name) + return true; + + if (!evm_protected_xattr(xattr_name) && !posix_xattr_acl(xattr_name) && + strcmp(xattr_name, XATTR_NAME_EVM)) + return false; + + return true; +} + +/** + * evm_inode_post_setxattr - update 'security.evm' to reflect the changes + * @dentry: pointer to the affected dentry + * @xattr_name: pointer to the affected extended attribute name + * @xattr_value: pointer to the new extended attribute value + * @xattr_value_len: pointer to the new extended attribute value length + * + * Update the HMAC stored in 'security.evm' to reflect the change. + * + * No need to take the i_mutex lock here, as this function is called from + * __vfs_setxattr_noperm(). The caller of which has taken the inode's + * i_mutex lock. + */ +void evm_inode_post_setxattr(struct dentry *dentry, const char *xattr_name, + const void *xattr_value, size_t xattr_value_len) +{ + if (!evm_revalidate_status(xattr_name)) + return; + + evm_reset_status(dentry->d_inode); + + if (!strcmp(xattr_name, XATTR_NAME_EVM)) + return; + + if (!(evm_initialized & EVM_INIT_HMAC)) + return; + + evm_update_evmxattr(dentry, xattr_name, xattr_value, xattr_value_len); +} + +/** + * evm_inode_post_removexattr - update 'security.evm' after removing the xattr + * @dentry: pointer to the affected dentry + * @xattr_name: pointer to the affected extended attribute name + * + * Update the HMAC stored in 'security.evm' to reflect removal of the xattr. + * + * No need to take the i_mutex lock here, as this function is called from + * vfs_removexattr() which takes the i_mutex. + */ +void evm_inode_post_removexattr(struct dentry *dentry, const char *xattr_name) +{ + if (!evm_revalidate_status(xattr_name)) + return; + + evm_reset_status(dentry->d_inode); + + if (!strcmp(xattr_name, XATTR_NAME_EVM)) + return; + + if (!(evm_initialized & EVM_INIT_HMAC)) + return; + + evm_update_evmxattr(dentry, xattr_name, NULL, 0); +} + +static int evm_attr_change(struct user_namespace *mnt_userns, + struct dentry *dentry, struct iattr *attr) +{ + struct inode *inode = d_backing_inode(dentry); + unsigned int ia_valid = attr->ia_valid; + + if (!i_uid_needs_update(mnt_userns, attr, inode) && + !i_gid_needs_update(mnt_userns, attr, inode) && + (!(ia_valid & ATTR_MODE) || attr->ia_mode == inode->i_mode)) + return 0; + + return 1; +} + +/** + * evm_inode_setattr - prevent updating an invalid EVM extended attribute + * @idmap: idmap of the mount + * @dentry: pointer to the affected dentry + * @attr: iattr structure containing the new file attributes + * + * Permit update of file attributes when files have a valid EVM signature, + * except in the case of them having an immutable portable signature. + */ +int evm_inode_setattr(struct user_namespace *mnt_userns, struct dentry *dentry, + struct iattr *attr) +{ + unsigned int ia_valid = attr->ia_valid; + enum integrity_status evm_status; + + /* Policy permits modification of the protected attrs even though + * there's no HMAC key loaded + */ + if (evm_initialized & EVM_ALLOW_METADATA_WRITES) + return 0; + + if (!(ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID))) + return 0; + evm_status = evm_verify_current_integrity(dentry); + /* + * Writing attrs is safe for portable signatures, as portable signatures + * are immutable and can never be updated. + */ + if ((evm_status == INTEGRITY_PASS) || + (evm_status == INTEGRITY_NOXATTRS) || + (evm_status == INTEGRITY_FAIL_IMMUTABLE) || + (evm_hmac_disabled() && (evm_status == INTEGRITY_NOLABEL || + evm_status == INTEGRITY_UNKNOWN))) + return 0; + + if (evm_status == INTEGRITY_PASS_IMMUTABLE && + !evm_attr_change(mnt_userns, dentry, attr)) + return 0; + + integrity_audit_msg(AUDIT_INTEGRITY_METADATA, d_backing_inode(dentry), + dentry->d_name.name, "appraise_metadata", + integrity_status_msg[evm_status], -EPERM, 0); + return -EPERM; +} + +/** + * evm_inode_post_setattr - update 'security.evm' after modifying metadata + * @dentry: pointer to the affected dentry + * @ia_valid: for the UID and GID status + * + * For now, update the HMAC stored in 'security.evm' to reflect UID/GID + * changes. + * + * This function is called from notify_change(), which expects the caller + * to lock the inode's i_mutex. + */ +void evm_inode_post_setattr(struct dentry *dentry, int ia_valid) +{ + if (!evm_revalidate_status(NULL)) + return; + + evm_reset_status(dentry->d_inode); + + if (!(evm_initialized & EVM_INIT_HMAC)) + return; + + if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID)) + evm_update_evmxattr(dentry, NULL, NULL, 0); +} + +/* + * evm_inode_init_security - initializes security.evm HMAC value + */ +int evm_inode_init_security(struct inode *inode, + const struct xattr *lsm_xattr, + struct xattr *evm_xattr) +{ + struct evm_xattr *xattr_data; + int rc; + + if (!(evm_initialized & EVM_INIT_HMAC) || + !evm_protected_xattr(lsm_xattr->name)) + return 0; + + xattr_data = kzalloc(sizeof(*xattr_data), GFP_NOFS); + if (!xattr_data) + return -ENOMEM; + + xattr_data->data.type = EVM_XATTR_HMAC; + rc = evm_init_hmac(inode, lsm_xattr, xattr_data->digest); + if (rc < 0) + goto out; + + evm_xattr->value = xattr_data; + evm_xattr->value_len = sizeof(*xattr_data); + evm_xattr->name = XATTR_EVM_SUFFIX; + return 0; +out: + kfree(xattr_data); + return rc; +} +EXPORT_SYMBOL_GPL(evm_inode_init_security); + +#ifdef CONFIG_EVM_LOAD_X509 +void __init evm_load_x509(void) +{ + int rc; + + rc = integrity_load_x509(INTEGRITY_KEYRING_EVM, CONFIG_EVM_X509_PATH); + if (!rc) + evm_initialized |= EVM_INIT_X509; +} +#endif + +static int __init init_evm(void) +{ + int error; + struct list_head *pos, *q; + + evm_init_config(); + + error = integrity_init_keyring(INTEGRITY_KEYRING_EVM); + if (error) + goto error; + + error = evm_init_secfs(); + if (error < 0) { + pr_info("Error registering secfs\n"); + goto error; + } + +error: + if (error != 0) { + if (!list_empty(&evm_config_xattrnames)) { + list_for_each_safe(pos, q, &evm_config_xattrnames) + list_del(pos); + } + } + + return error; +} + +late_initcall(init_evm); diff --git a/security/integrity/evm/evm_posix_acl.c b/security/integrity/evm/evm_posix_acl.c new file mode 100644 index 000000000..37275800c --- /dev/null +++ b/security/integrity/evm/evm_posix_acl.c @@ -0,0 +1,23 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2011 IBM Corporation + * + * Author: + * Mimi Zohar <zohar@us.ibm.com> + */ + +#include <linux/xattr.h> +#include <linux/evm.h> + +int posix_xattr_acl(const char *xattr) +{ + int xattr_len = strlen(xattr); + + if ((strlen(XATTR_NAME_POSIX_ACL_ACCESS) == xattr_len) + && (strncmp(XATTR_NAME_POSIX_ACL_ACCESS, xattr, xattr_len) == 0)) + return 1; + if ((strlen(XATTR_NAME_POSIX_ACL_DEFAULT) == xattr_len) + && (strncmp(XATTR_NAME_POSIX_ACL_DEFAULT, xattr, xattr_len) == 0)) + return 1; + return 0; +} diff --git a/security/integrity/evm/evm_secfs.c b/security/integrity/evm/evm_secfs.c new file mode 100644 index 000000000..8a9db7dfc --- /dev/null +++ b/security/integrity/evm/evm_secfs.c @@ -0,0 +1,334 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2010 IBM Corporation + * + * Authors: + * Mimi Zohar <zohar@us.ibm.com> + * + * File: evm_secfs.c + * - Used to signal when key is on keyring + * - Get the key and enable EVM + */ + +#include <linux/audit.h> +#include <linux/uaccess.h> +#include <linux/init.h> +#include <linux/mutex.h> +#include "evm.h" + +static struct dentry *evm_dir; +static struct dentry *evm_init_tpm; +static struct dentry *evm_symlink; + +#ifdef CONFIG_EVM_ADD_XATTRS +static struct dentry *evm_xattrs; +static DEFINE_MUTEX(xattr_list_mutex); +static int evm_xattrs_locked; +#endif + +/** + * evm_read_key - read() for <securityfs>/evm + * + * @filp: file pointer, not actually used + * @buf: where to put the result + * @count: maximum to send along + * @ppos: where to start + * + * Returns number of bytes read or error code, as appropriate + */ +static ssize_t evm_read_key(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + char temp[80]; + ssize_t rc; + + if (*ppos != 0) + return 0; + + sprintf(temp, "%d", (evm_initialized & ~EVM_SETUP_COMPLETE)); + rc = simple_read_from_buffer(buf, count, ppos, temp, strlen(temp)); + + return rc; +} + +/** + * evm_write_key - write() for <securityfs>/evm + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start + * + * Used to signal that key is on the kernel key ring. + * - get the integrity hmac key from the kernel key ring + * - create list of hmac protected extended attributes + * Returns number of bytes written or error code, as appropriate + */ +static ssize_t evm_write_key(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + unsigned int i; + int ret; + + if (!capable(CAP_SYS_ADMIN) || (evm_initialized & EVM_SETUP_COMPLETE)) + return -EPERM; + + ret = kstrtouint_from_user(buf, count, 0, &i); + + if (ret) + return ret; + + /* Reject invalid values */ + if (!i || (i & ~EVM_INIT_MASK) != 0) + return -EINVAL; + + /* + * Don't allow a request to enable metadata writes if + * an HMAC key is loaded. + */ + if ((i & EVM_ALLOW_METADATA_WRITES) && + (evm_initialized & EVM_INIT_HMAC) != 0) + return -EPERM; + + if (i & EVM_INIT_HMAC) { + ret = evm_init_key(); + if (ret != 0) + return ret; + /* Forbid further writes after the symmetric key is loaded */ + i |= EVM_SETUP_COMPLETE; + } + + evm_initialized |= i; + + /* Don't allow protected metadata modification if a symmetric key + * is loaded + */ + if (evm_initialized & EVM_INIT_HMAC) + evm_initialized &= ~(EVM_ALLOW_METADATA_WRITES); + + return count; +} + +static const struct file_operations evm_key_ops = { + .read = evm_read_key, + .write = evm_write_key, +}; + +#ifdef CONFIG_EVM_ADD_XATTRS +/** + * evm_read_xattrs - read() for <securityfs>/evm_xattrs + * + * @filp: file pointer, not actually used + * @buf: where to put the result + * @count: maximum to send along + * @ppos: where to start + * + * Returns number of bytes read or error code, as appropriate + */ +static ssize_t evm_read_xattrs(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + char *temp; + int offset = 0; + ssize_t rc, size = 0; + struct xattr_list *xattr; + + if (*ppos != 0) + return 0; + + rc = mutex_lock_interruptible(&xattr_list_mutex); + if (rc) + return -ERESTARTSYS; + + list_for_each_entry(xattr, &evm_config_xattrnames, list) { + if (!xattr->enabled) + continue; + + size += strlen(xattr->name) + 1; + } + + temp = kmalloc(size + 1, GFP_KERNEL); + if (!temp) { + mutex_unlock(&xattr_list_mutex); + return -ENOMEM; + } + + list_for_each_entry(xattr, &evm_config_xattrnames, list) { + if (!xattr->enabled) + continue; + + sprintf(temp + offset, "%s\n", xattr->name); + offset += strlen(xattr->name) + 1; + } + + mutex_unlock(&xattr_list_mutex); + rc = simple_read_from_buffer(buf, count, ppos, temp, strlen(temp)); + + kfree(temp); + + return rc; +} + +/** + * evm_write_xattrs - write() for <securityfs>/evm_xattrs + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start + * + * Returns number of bytes written or error code, as appropriate + */ +static ssize_t evm_write_xattrs(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + int len, err; + struct xattr_list *xattr, *tmp; + struct audit_buffer *ab; + struct iattr newattrs; + struct inode *inode; + + if (!capable(CAP_SYS_ADMIN) || evm_xattrs_locked) + return -EPERM; + + if (*ppos != 0) + return -EINVAL; + + if (count > XATTR_NAME_MAX) + return -E2BIG; + + ab = audit_log_start(audit_context(), GFP_KERNEL, + AUDIT_INTEGRITY_EVM_XATTR); + if (!ab && IS_ENABLED(CONFIG_AUDIT)) + return -ENOMEM; + + xattr = kmalloc(sizeof(struct xattr_list), GFP_KERNEL); + if (!xattr) { + err = -ENOMEM; + goto out; + } + + xattr->enabled = true; + xattr->name = memdup_user_nul(buf, count); + if (IS_ERR(xattr->name)) { + err = PTR_ERR(xattr->name); + xattr->name = NULL; + goto out; + } + + /* Remove any trailing newline */ + len = strlen(xattr->name); + if (len && xattr->name[len-1] == '\n') + xattr->name[len-1] = '\0'; + + audit_log_format(ab, "xattr="); + audit_log_untrustedstring(ab, xattr->name); + + if (strcmp(xattr->name, ".") == 0) { + evm_xattrs_locked = 1; + newattrs.ia_mode = S_IFREG | 0440; + newattrs.ia_valid = ATTR_MODE; + inode = evm_xattrs->d_inode; + inode_lock(inode); + err = simple_setattr(&init_user_ns, evm_xattrs, &newattrs); + inode_unlock(inode); + if (!err) + err = count; + goto out; + } + + if (strncmp(xattr->name, XATTR_SECURITY_PREFIX, + XATTR_SECURITY_PREFIX_LEN) != 0) { + err = -EINVAL; + goto out; + } + + /* + * xattr_list_mutex guards against races in evm_read_xattrs(). + * Entries are only added to the evm_config_xattrnames list + * and never deleted. Therefore, the list is traversed + * using list_for_each_entry_lockless() without holding + * the mutex in evm_calc_hmac_or_hash(), evm_find_protected_xattrs() + * and evm_protected_xattr(). + */ + mutex_lock(&xattr_list_mutex); + list_for_each_entry(tmp, &evm_config_xattrnames, list) { + if (strcmp(xattr->name, tmp->name) == 0) { + err = -EEXIST; + if (!tmp->enabled) { + tmp->enabled = true; + err = count; + } + mutex_unlock(&xattr_list_mutex); + goto out; + } + } + list_add_tail_rcu(&xattr->list, &evm_config_xattrnames); + mutex_unlock(&xattr_list_mutex); + + audit_log_format(ab, " res=0"); + audit_log_end(ab); + return count; +out: + audit_log_format(ab, " res=%d", (err < 0) ? err : 0); + audit_log_end(ab); + if (xattr) { + kfree(xattr->name); + kfree(xattr); + } + return err; +} + +static const struct file_operations evm_xattr_ops = { + .read = evm_read_xattrs, + .write = evm_write_xattrs, +}; + +static int evm_init_xattrs(void) +{ + evm_xattrs = securityfs_create_file("evm_xattrs", 0660, evm_dir, NULL, + &evm_xattr_ops); + if (!evm_xattrs || IS_ERR(evm_xattrs)) + return -EFAULT; + + return 0; +} +#else +static int evm_init_xattrs(void) +{ + return 0; +} +#endif + +int __init evm_init_secfs(void) +{ + int error = 0; + + evm_dir = securityfs_create_dir("evm", integrity_dir); + if (!evm_dir || IS_ERR(evm_dir)) + return -EFAULT; + + evm_init_tpm = securityfs_create_file("evm", 0660, + evm_dir, NULL, &evm_key_ops); + if (!evm_init_tpm || IS_ERR(evm_init_tpm)) { + error = -EFAULT; + goto out; + } + + evm_symlink = securityfs_create_symlink("evm", NULL, + "integrity/evm/evm", NULL); + if (!evm_symlink || IS_ERR(evm_symlink)) { + error = -EFAULT; + goto out; + } + + if (evm_init_xattrs() != 0) { + error = -EFAULT; + goto out; + } + + return 0; +out: + securityfs_remove(evm_symlink); + securityfs_remove(evm_init_tpm); + securityfs_remove(evm_dir); + return error; +} diff --git a/security/integrity/iint.c b/security/integrity/iint.c new file mode 100644 index 000000000..cb251ab0e --- /dev/null +++ b/security/integrity/iint.c @@ -0,0 +1,261 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2008 IBM Corporation + * + * Authors: + * Mimi Zohar <zohar@us.ibm.com> + * + * File: integrity_iint.c + * - implements the integrity hooks: integrity_inode_alloc, + * integrity_inode_free + * - cache integrity information associated with an inode + * using a rbtree tree. + */ +#include <linux/slab.h> +#include <linux/init.h> +#include <linux/spinlock.h> +#include <linux/rbtree.h> +#include <linux/file.h> +#include <linux/uaccess.h> +#include <linux/security.h> +#include <linux/lsm_hooks.h> +#include "integrity.h" + +static struct rb_root integrity_iint_tree = RB_ROOT; +static DEFINE_RWLOCK(integrity_iint_lock); +static struct kmem_cache *iint_cache __read_mostly; + +struct dentry *integrity_dir; + +/* + * __integrity_iint_find - return the iint associated with an inode + */ +static struct integrity_iint_cache *__integrity_iint_find(struct inode *inode) +{ + struct integrity_iint_cache *iint; + struct rb_node *n = integrity_iint_tree.rb_node; + + while (n) { + iint = rb_entry(n, struct integrity_iint_cache, rb_node); + + if (inode < iint->inode) + n = n->rb_left; + else if (inode > iint->inode) + n = n->rb_right; + else + return iint; + } + + return NULL; +} + +/* + * integrity_iint_find - return the iint associated with an inode + */ +struct integrity_iint_cache *integrity_iint_find(struct inode *inode) +{ + struct integrity_iint_cache *iint; + + if (!IS_IMA(inode)) + return NULL; + + read_lock(&integrity_iint_lock); + iint = __integrity_iint_find(inode); + read_unlock(&integrity_iint_lock); + + return iint; +} + +#define IMA_MAX_NESTING (FILESYSTEM_MAX_STACK_DEPTH+1) + +/* + * It is not clear that IMA should be nested at all, but as long is it measures + * files both on overlayfs and on underlying fs, we need to annotate the iint + * mutex to avoid lockdep false positives related to IMA + overlayfs. + * See ovl_lockdep_annotate_inode_mutex_key() for more details. + */ +static inline void iint_lockdep_annotate(struct integrity_iint_cache *iint, + struct inode *inode) +{ +#ifdef CONFIG_LOCKDEP + static struct lock_class_key iint_mutex_key[IMA_MAX_NESTING]; + + int depth = inode->i_sb->s_stack_depth; + + if (WARN_ON_ONCE(depth < 0 || depth >= IMA_MAX_NESTING)) + depth = 0; + + lockdep_set_class(&iint->mutex, &iint_mutex_key[depth]); +#endif +} + +static void iint_init_always(struct integrity_iint_cache *iint, + struct inode *inode) +{ + iint->ima_hash = NULL; + iint->version = 0; + iint->flags = 0UL; + iint->atomic_flags = 0UL; + iint->ima_file_status = INTEGRITY_UNKNOWN; + iint->ima_mmap_status = INTEGRITY_UNKNOWN; + iint->ima_bprm_status = INTEGRITY_UNKNOWN; + iint->ima_read_status = INTEGRITY_UNKNOWN; + iint->ima_creds_status = INTEGRITY_UNKNOWN; + iint->evm_status = INTEGRITY_UNKNOWN; + iint->measured_pcrs = 0; + mutex_init(&iint->mutex); + iint_lockdep_annotate(iint, inode); +} + +static void iint_free(struct integrity_iint_cache *iint) +{ + kfree(iint->ima_hash); + mutex_destroy(&iint->mutex); + kmem_cache_free(iint_cache, iint); +} + +/** + * integrity_inode_get - find or allocate an iint associated with an inode + * @inode: pointer to the inode + * @return: allocated iint + * + * Caller must lock i_mutex + */ +struct integrity_iint_cache *integrity_inode_get(struct inode *inode) +{ + struct rb_node **p; + struct rb_node *node, *parent = NULL; + struct integrity_iint_cache *iint, *test_iint; + + /* + * The integrity's "iint_cache" is initialized at security_init(), + * unless it is not included in the ordered list of LSMs enabled + * on the boot command line. + */ + if (!iint_cache) + panic("%s: lsm=integrity required.\n", __func__); + + iint = integrity_iint_find(inode); + if (iint) + return iint; + + iint = kmem_cache_alloc(iint_cache, GFP_NOFS); + if (!iint) + return NULL; + + iint_init_always(iint, inode); + + write_lock(&integrity_iint_lock); + + p = &integrity_iint_tree.rb_node; + while (*p) { + parent = *p; + test_iint = rb_entry(parent, struct integrity_iint_cache, + rb_node); + if (inode < test_iint->inode) { + p = &(*p)->rb_left; + } else if (inode > test_iint->inode) { + p = &(*p)->rb_right; + } else { + write_unlock(&integrity_iint_lock); + kmem_cache_free(iint_cache, iint); + return test_iint; + } + } + + iint->inode = inode; + node = &iint->rb_node; + inode->i_flags |= S_IMA; + rb_link_node(node, parent, p); + rb_insert_color(node, &integrity_iint_tree); + + write_unlock(&integrity_iint_lock); + return iint; +} + +/** + * integrity_inode_free - called on security_inode_free + * @inode: pointer to the inode + * + * Free the integrity information(iint) associated with an inode. + */ +void integrity_inode_free(struct inode *inode) +{ + struct integrity_iint_cache *iint; + + if (!IS_IMA(inode)) + return; + + write_lock(&integrity_iint_lock); + iint = __integrity_iint_find(inode); + rb_erase(&iint->rb_node, &integrity_iint_tree); + write_unlock(&integrity_iint_lock); + + iint_free(iint); +} + +static void iint_init_once(void *foo) +{ + struct integrity_iint_cache *iint = (struct integrity_iint_cache *) foo; + + memset(iint, 0, sizeof(*iint)); +} + +static int __init integrity_iintcache_init(void) +{ + iint_cache = + kmem_cache_create("iint_cache", sizeof(struct integrity_iint_cache), + 0, SLAB_PANIC, iint_init_once); + return 0; +} +DEFINE_LSM(integrity) = { + .name = "integrity", + .init = integrity_iintcache_init, +}; + + +/* + * integrity_kernel_read - read data from the file + * + * This is a function for reading file content instead of kernel_read(). + * It does not perform locking checks to ensure it cannot be blocked. + * It does not perform security checks because it is irrelevant for IMA. + * + */ +int integrity_kernel_read(struct file *file, loff_t offset, + void *addr, unsigned long count) +{ + return __kernel_read(file, addr, count, &offset); +} + +/* + * integrity_load_keys - load integrity keys hook + * + * Hooks is called from init/main.c:kernel_init_freeable() + * when rootfs is ready + */ +void __init integrity_load_keys(void) +{ + ima_load_x509(); + + if (!IS_ENABLED(CONFIG_IMA_LOAD_X509)) + evm_load_x509(); +} + +static int __init integrity_fs_init(void) +{ + integrity_dir = securityfs_create_dir("integrity", NULL); + if (IS_ERR(integrity_dir)) { + int ret = PTR_ERR(integrity_dir); + + if (ret != -ENODEV) + pr_err("Unable to create integrity sysfs dir: %d\n", + ret); + integrity_dir = NULL; + return ret; + } + + return 0; +} + +late_initcall(integrity_fs_init) diff --git a/security/integrity/ima/Kconfig b/security/integrity/ima/Kconfig new file mode 100644 index 000000000..6ef7bde55 --- /dev/null +++ b/security/integrity/ima/Kconfig @@ -0,0 +1,322 @@ +# SPDX-License-Identifier: GPL-2.0-only +# IBM Integrity Measurement Architecture +# +config IMA + bool "Integrity Measurement Architecture(IMA)" + select SECURITYFS + select CRYPTO + select CRYPTO_HMAC + select CRYPTO_SHA1 + select CRYPTO_HASH_INFO + select TCG_TPM if HAS_IOMEM + select TCG_TIS if TCG_TPM && X86 + select TCG_CRB if TCG_TPM && ACPI + select TCG_IBMVTPM if TCG_TPM && PPC_PSERIES + select INTEGRITY_AUDIT if AUDIT + help + The Trusted Computing Group(TCG) runtime Integrity + Measurement Architecture(IMA) maintains a list of hash + values of executables and other sensitive system files, + as they are read or executed. If an attacker manages + to change the contents of an important system file + being measured, we can tell. + + If your system has a TPM chip, then IMA also maintains + an aggregate integrity value over this list inside the + TPM hardware, so that the TPM can prove to a third party + whether or not critical system files have been modified. + Read <https://www.usenix.org/events/sec04/tech/sailer.html> + to learn more about IMA. + If unsure, say N. + +if IMA + +config IMA_KEXEC + bool "Enable carrying the IMA measurement list across a soft boot" + depends on TCG_TPM && HAVE_IMA_KEXEC + default n + help + TPM PCRs are only reset on a hard reboot. In order to validate + a TPM's quote after a soft boot, the IMA measurement list of the + running kernel must be saved and restored on boot. + + Depending on the IMA policy, the measurement list can grow to + be very large. + +config IMA_MEASURE_PCR_IDX + int + range 8 14 + default 10 + help + IMA_MEASURE_PCR_IDX determines the TPM PCR register index + that IMA uses to maintain the integrity aggregate of the + measurement list. If unsure, use the default 10. + +config IMA_LSM_RULES + bool + depends on AUDIT && (SECURITY_SELINUX || SECURITY_SMACK || SECURITY_APPARMOR) + default y + help + Disabling this option will disregard LSM based policy rules. + +choice + prompt "Default template" + default IMA_NG_TEMPLATE + help + Select the default IMA measurement template. + + The original 'ima' measurement list template contains a + hash, defined as 20 bytes, and a null terminated pathname, + limited to 255 characters. The 'ima-ng' measurement list + template permits both larger hash digests and longer + pathnames. The configured default template can be replaced + by specifying "ima_template=" on the boot command line. + + config IMA_NG_TEMPLATE + bool "ima-ng (default)" + config IMA_SIG_TEMPLATE + bool "ima-sig" +endchoice + +config IMA_DEFAULT_TEMPLATE + string + default "ima-ng" if IMA_NG_TEMPLATE + default "ima-sig" if IMA_SIG_TEMPLATE + +choice + prompt "Default integrity hash algorithm" + default IMA_DEFAULT_HASH_SHA1 + help + Select the default hash algorithm used for the measurement + list, integrity appraisal and audit log. The compiled default + hash algorithm can be overwritten using the kernel command + line 'ima_hash=' option. + + config IMA_DEFAULT_HASH_SHA1 + bool "SHA1 (default)" + depends on CRYPTO_SHA1=y + + config IMA_DEFAULT_HASH_SHA256 + bool "SHA256" + depends on CRYPTO_SHA256=y + + config IMA_DEFAULT_HASH_SHA512 + bool "SHA512" + depends on CRYPTO_SHA512=y + + config IMA_DEFAULT_HASH_WP512 + bool "WP512" + depends on CRYPTO_WP512=y + + config IMA_DEFAULT_HASH_SM3 + bool "SM3" + depends on CRYPTO_SM3_GENERIC=y +endchoice + +config IMA_DEFAULT_HASH + string + default "sha1" if IMA_DEFAULT_HASH_SHA1 + default "sha256" if IMA_DEFAULT_HASH_SHA256 + default "sha512" if IMA_DEFAULT_HASH_SHA512 + default "wp512" if IMA_DEFAULT_HASH_WP512 + default "sm3" if IMA_DEFAULT_HASH_SM3 + +config IMA_WRITE_POLICY + bool "Enable multiple writes to the IMA policy" + default n + help + IMA policy can now be updated multiple times. The new rules get + appended to the original policy. Have in mind that the rules are + scanned in FIFO order so be careful when you design and add new ones. + + If unsure, say N. + +config IMA_READ_POLICY + bool "Enable reading back the current IMA policy" + default y if IMA_WRITE_POLICY + default n if !IMA_WRITE_POLICY + help + It is often useful to be able to read back the IMA policy. It is + even more important after introducing CONFIG_IMA_WRITE_POLICY. + This option allows the root user to see the current policy rules. + +config IMA_APPRAISE + bool "Appraise integrity measurements" + default n + help + This option enables local measurement integrity appraisal. + It requires the system to be labeled with a security extended + attribute containing the file hash measurement. To protect + the security extended attributes from offline attack, enable + and configure EVM. + + For more information on integrity appraisal refer to: + <http://linux-ima.sourceforge.net> + If unsure, say N. + +config IMA_ARCH_POLICY + bool "Enable loading an IMA architecture specific policy" + depends on (KEXEC_SIG && IMA) || IMA_APPRAISE \ + && INTEGRITY_ASYMMETRIC_KEYS + default n + help + This option enables loading an IMA architecture specific policy + based on run time secure boot flags. + +config IMA_APPRAISE_BUILD_POLICY + bool "IMA build time configured policy rules" + depends on IMA_APPRAISE && INTEGRITY_ASYMMETRIC_KEYS + default n + help + This option defines an IMA appraisal policy at build time, which + is enforced at run time without having to specify a builtin + policy name on the boot command line. The build time appraisal + policy rules persist after loading a custom policy. + + Depending on the rules configured, this policy may require kernel + modules, firmware, the kexec kernel image, and/or the IMA policy + to be signed. Unsigned files might prevent the system from + booting or applications from working properly. + +config IMA_APPRAISE_REQUIRE_FIRMWARE_SIGS + bool "Appraise firmware signatures" + depends on IMA_APPRAISE_BUILD_POLICY + default n + help + This option defines a policy requiring all firmware to be signed, + including the regulatory.db. If both this option and + CFG80211_REQUIRE_SIGNED_REGDB are enabled, then both signature + verification methods are necessary. + +config IMA_APPRAISE_REQUIRE_KEXEC_SIGS + bool "Appraise kexec kernel image signatures" + depends on IMA_APPRAISE_BUILD_POLICY + default n + help + Enabling this rule will require all kexec'ed kernel images to + be signed and verified by a public key on the trusted IMA + keyring. + + Kernel image signatures can not be verified by the original + kexec_load syscall. Enabling this rule will prevent its + usage. + +config IMA_APPRAISE_REQUIRE_MODULE_SIGS + bool "Appraise kernel modules signatures" + depends on IMA_APPRAISE_BUILD_POLICY + default n + help + Enabling this rule will require all kernel modules to be signed + and verified by a public key on the trusted IMA keyring. + + Kernel module signatures can only be verified by IMA-appraisal, + via the finit_module syscall. Enabling this rule will prevent + the usage of the init_module syscall. + +config IMA_APPRAISE_REQUIRE_POLICY_SIGS + bool "Appraise IMA policy signature" + depends on IMA_APPRAISE_BUILD_POLICY + default n + help + Enabling this rule will require the IMA policy to be signed and + and verified by a key on the trusted IMA keyring. + +config IMA_APPRAISE_BOOTPARAM + bool "ima_appraise boot parameter" + depends on IMA_APPRAISE + default y + help + This option enables the different "ima_appraise=" modes + (eg. fix, log) from the boot command line. + +config IMA_APPRAISE_MODSIG + bool "Support module-style signatures for appraisal" + depends on IMA_APPRAISE + depends on INTEGRITY_ASYMMETRIC_KEYS + select PKCS7_MESSAGE_PARSER + select MODULE_SIG_FORMAT + default n + help + Adds support for signatures appended to files. The format of the + appended signature is the same used for signed kernel modules. + The modsig keyword can be used in the IMA policy to allow a hook + to accept such signatures. + +config IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY + bool "Permit keys validly signed by a built-in or secondary CA cert (EXPERIMENTAL)" + depends on SYSTEM_TRUSTED_KEYRING + depends on SECONDARY_TRUSTED_KEYRING + depends on INTEGRITY_ASYMMETRIC_KEYS + select INTEGRITY_TRUSTED_KEYRING + default n + help + Keys may be added to the IMA or IMA blacklist keyrings, if the + key is validly signed by a CA cert in the system built-in or + secondary trusted keyrings. + + Intermediate keys between those the kernel has compiled in and the + IMA keys to be added may be added to the system secondary keyring, + provided they are validly signed by a key already resident in the + built-in or secondary trusted keyrings. + +config IMA_BLACKLIST_KEYRING + bool "Create IMA machine owner blacklist keyrings (EXPERIMENTAL)" + depends on SYSTEM_TRUSTED_KEYRING + depends on INTEGRITY_TRUSTED_KEYRING + default n + help + This option creates an IMA blacklist keyring, which contains all + revoked IMA keys. It is consulted before any other keyring. If + the search is successful the requested operation is rejected and + an error is returned to the caller. + +config IMA_LOAD_X509 + bool "Load X509 certificate onto the '.ima' trusted keyring" + depends on INTEGRITY_TRUSTED_KEYRING + default n + help + File signature verification is based on the public keys + loaded on the .ima trusted keyring. These public keys are + X509 certificates signed by a trusted key on the + .system keyring. This option enables X509 certificate + loading from the kernel onto the '.ima' trusted keyring. + +config IMA_X509_PATH + string "IMA X509 certificate path" + depends on IMA_LOAD_X509 + default "/etc/keys/x509_ima.der" + help + This option defines IMA X509 certificate path. + +config IMA_APPRAISE_SIGNED_INIT + bool "Require signed user-space initialization" + depends on IMA_LOAD_X509 + default n + help + This option requires user-space init to be signed. + +config IMA_MEASURE_ASYMMETRIC_KEYS + bool + depends on ASYMMETRIC_PUBLIC_KEY_SUBTYPE=y + default y + +config IMA_QUEUE_EARLY_BOOT_KEYS + bool + depends on IMA_MEASURE_ASYMMETRIC_KEYS + depends on SYSTEM_TRUSTED_KEYRING + default y + +config IMA_SECURE_AND_OR_TRUSTED_BOOT + bool + depends on IMA_ARCH_POLICY + help + This option is selected by architectures to enable secure and/or + trusted boot based on IMA runtime policies. + +config IMA_DISABLE_HTABLE + bool "Disable htable to allow measurement of duplicate records" + default n + help + This option disables htable to allow measurement of duplicate records. + +endif diff --git a/security/integrity/ima/Makefile b/security/integrity/ima/Makefile new file mode 100644 index 000000000..2499f2485 --- /dev/null +++ b/security/integrity/ima/Makefile @@ -0,0 +1,20 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Makefile for building Trusted Computing Group's(TCG) runtime Integrity +# Measurement Architecture(IMA). +# + +obj-$(CONFIG_IMA) += ima.o + +ima-y := ima_fs.o ima_queue.o ima_init.o ima_main.o ima_crypto.o ima_api.o \ + ima_policy.o ima_template.o ima_template_lib.o +ima-$(CONFIG_IMA_APPRAISE) += ima_appraise.o +ima-$(CONFIG_IMA_APPRAISE_MODSIG) += ima_modsig.o +ima-$(CONFIG_HAVE_IMA_KEXEC) += ima_kexec.o +ima-$(CONFIG_IMA_BLACKLIST_KEYRING) += ima_mok.o +ima-$(CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS) += ima_asymmetric_keys.o +ima-$(CONFIG_IMA_QUEUE_EARLY_BOOT_KEYS) += ima_queue_keys.o + +ifeq ($(CONFIG_EFI),y) +ima-$(CONFIG_IMA_SECURE_AND_OR_TRUSTED_BOOT) += ima_efi.o +endif diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h new file mode 100644 index 000000000..be965a871 --- /dev/null +++ b/security/integrity/ima/ima.h @@ -0,0 +1,453 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2005,2006,2007,2008 IBM Corporation + * + * Authors: + * Reiner Sailer <sailer@watson.ibm.com> + * Mimi Zohar <zohar@us.ibm.com> + * + * File: ima.h + * internal Integrity Measurement Architecture (IMA) definitions + */ + +#ifndef __LINUX_IMA_H +#define __LINUX_IMA_H + +#include <linux/types.h> +#include <linux/crypto.h> +#include <linux/fs.h> +#include <linux/security.h> +#include <linux/hash.h> +#include <linux/tpm.h> +#include <linux/audit.h> +#include <crypto/hash_info.h> + +#include "../integrity.h" + +enum ima_show_type { IMA_SHOW_BINARY, IMA_SHOW_BINARY_NO_FIELD_LEN, + IMA_SHOW_BINARY_OLD_STRING_FMT, IMA_SHOW_ASCII }; +enum tpm_pcrs { TPM_PCR0 = 0, TPM_PCR8 = 8, TPM_PCR10 = 10 }; + +/* digest size for IMA, fits SHA1 or MD5 */ +#define IMA_DIGEST_SIZE SHA1_DIGEST_SIZE +#define IMA_EVENT_NAME_LEN_MAX 255 + +#define IMA_HASH_BITS 10 +#define IMA_MEASURE_HTABLE_SIZE (1 << IMA_HASH_BITS) + +#define IMA_TEMPLATE_FIELD_ID_MAX_LEN 16 +#define IMA_TEMPLATE_NUM_FIELDS_MAX 15 + +#define IMA_TEMPLATE_IMA_NAME "ima" +#define IMA_TEMPLATE_IMA_FMT "d|n" + +#define NR_BANKS(chip) ((chip != NULL) ? chip->nr_allocated_banks : 0) + +/* current content of the policy */ +extern int ima_policy_flag; + +/* bitset of digests algorithms allowed in the setxattr hook */ +extern atomic_t ima_setxattr_allowed_hash_algorithms; + +/* set during initialization */ +extern int ima_hash_algo __ro_after_init; +extern int ima_sha1_idx __ro_after_init; +extern int ima_hash_algo_idx __ro_after_init; +extern int ima_extra_slots __ro_after_init; +extern int ima_appraise; +extern struct tpm_chip *ima_tpm_chip; +extern const char boot_aggregate_name[]; + +/* IMA event related data */ +struct ima_event_data { + struct integrity_iint_cache *iint; + struct file *file; + const unsigned char *filename; + struct evm_ima_xattr_data *xattr_value; + int xattr_len; + const struct modsig *modsig; + const char *violation; + const void *buf; + int buf_len; +}; + +/* IMA template field data definition */ +struct ima_field_data { + u8 *data; + u32 len; +}; + +/* IMA template field definition */ +struct ima_template_field { + const char field_id[IMA_TEMPLATE_FIELD_ID_MAX_LEN]; + int (*field_init)(struct ima_event_data *event_data, + struct ima_field_data *field_data); + void (*field_show)(struct seq_file *m, enum ima_show_type show, + struct ima_field_data *field_data); +}; + +/* IMA template descriptor definition */ +struct ima_template_desc { + struct list_head list; + char *name; + char *fmt; + int num_fields; + const struct ima_template_field **fields; +}; + +struct ima_template_entry { + int pcr; + struct tpm_digest *digests; + struct ima_template_desc *template_desc; /* template descriptor */ + u32 template_data_len; + struct ima_field_data template_data[]; /* template related data */ +}; + +struct ima_queue_entry { + struct hlist_node hnext; /* place in hash collision list */ + struct list_head later; /* place in ima_measurements list */ + struct ima_template_entry *entry; +}; +extern struct list_head ima_measurements; /* list of all measurements */ + +/* Some details preceding the binary serialized measurement list */ +struct ima_kexec_hdr { + u16 version; + u16 _reserved0; + u32 _reserved1; + u64 buffer_size; + u64 count; +}; + +extern const int read_idmap[]; + +#ifdef CONFIG_HAVE_IMA_KEXEC +void ima_load_kexec_buffer(void); +#else +static inline void ima_load_kexec_buffer(void) {} +#endif /* CONFIG_HAVE_IMA_KEXEC */ + +/* + * The default binary_runtime_measurements list format is defined as the + * platform native format. The canonical format is defined as little-endian. + */ +extern bool ima_canonical_fmt; + +/* Internal IMA function definitions */ +int ima_init(void); +int ima_fs_init(void); +int ima_add_template_entry(struct ima_template_entry *entry, int violation, + const char *op, struct inode *inode, + const unsigned char *filename); +int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash); +int ima_calc_buffer_hash(const void *buf, loff_t len, + struct ima_digest_data *hash); +int ima_calc_field_array_hash(struct ima_field_data *field_data, + struct ima_template_entry *entry); +int ima_calc_boot_aggregate(struct ima_digest_data *hash); +void ima_add_violation(struct file *file, const unsigned char *filename, + struct integrity_iint_cache *iint, + const char *op, const char *cause); +int ima_init_crypto(void); +void ima_putc(struct seq_file *m, void *data, int datalen); +void ima_print_digest(struct seq_file *m, u8 *digest, u32 size); +int template_desc_init_fields(const char *template_fmt, + const struct ima_template_field ***fields, + int *num_fields); +struct ima_template_desc *ima_template_desc_current(void); +struct ima_template_desc *ima_template_desc_buf(void); +struct ima_template_desc *lookup_template_desc(const char *name); +bool ima_template_has_modsig(const struct ima_template_desc *ima_template); +int ima_restore_measurement_entry(struct ima_template_entry *entry); +int ima_restore_measurement_list(loff_t bufsize, void *buf); +int ima_measurements_show(struct seq_file *m, void *v); +unsigned long ima_get_binary_runtime_size(void); +int ima_init_template(void); +void ima_init_template_list(void); +int __init ima_init_digests(void); +int ima_lsm_policy_change(struct notifier_block *nb, unsigned long event, + void *lsm_data); + +/* + * used to protect h_table and sha_table + */ +extern spinlock_t ima_queue_lock; + +struct ima_h_table { + atomic_long_t len; /* number of stored measurements in the list */ + atomic_long_t violations; + struct hlist_head queue[IMA_MEASURE_HTABLE_SIZE]; +}; +extern struct ima_h_table ima_htable; + +static inline unsigned int ima_hash_key(u8 *digest) +{ + /* there is no point in taking a hash of part of a digest */ + return (digest[0] | digest[1] << 8) % IMA_MEASURE_HTABLE_SIZE; +} + +#define __ima_hooks(hook) \ + hook(NONE, none) \ + hook(FILE_CHECK, file) \ + hook(MMAP_CHECK, mmap) \ + hook(BPRM_CHECK, bprm) \ + hook(CREDS_CHECK, creds) \ + hook(POST_SETATTR, post_setattr) \ + hook(MODULE_CHECK, module) \ + hook(FIRMWARE_CHECK, firmware) \ + hook(KEXEC_KERNEL_CHECK, kexec_kernel) \ + hook(KEXEC_INITRAMFS_CHECK, kexec_initramfs) \ + hook(POLICY_CHECK, policy) \ + hook(KEXEC_CMDLINE, kexec_cmdline) \ + hook(KEY_CHECK, key) \ + hook(CRITICAL_DATA, critical_data) \ + hook(SETXATTR_CHECK, setxattr_check) \ + hook(MAX_CHECK, none) + +#define __ima_hook_enumify(ENUM, str) ENUM, +#define __ima_stringify(arg) (#arg) +#define __ima_hook_measuring_stringify(ENUM, str) \ + (__ima_stringify(measuring_ ##str)), + +enum ima_hooks { + __ima_hooks(__ima_hook_enumify) +}; + +static const char * const ima_hooks_measure_str[] = { + __ima_hooks(__ima_hook_measuring_stringify) +}; + +static inline const char *func_measure_str(enum ima_hooks func) +{ + if (func >= MAX_CHECK) + return ima_hooks_measure_str[NONE]; + + return ima_hooks_measure_str[func]; +} + +extern const char *const func_tokens[]; + +struct modsig; + +#ifdef CONFIG_IMA_QUEUE_EARLY_BOOT_KEYS +/* + * To track keys that need to be measured. + */ +struct ima_key_entry { + struct list_head list; + void *payload; + size_t payload_len; + char *keyring_name; +}; +void ima_init_key_queue(void); +bool ima_should_queue_key(void); +bool ima_queue_key(struct key *keyring, const void *payload, + size_t payload_len); +void ima_process_queued_keys(void); +#else +static inline void ima_init_key_queue(void) {} +static inline bool ima_should_queue_key(void) { return false; } +static inline bool ima_queue_key(struct key *keyring, + const void *payload, + size_t payload_len) { return false; } +static inline void ima_process_queued_keys(void) {} +#endif /* CONFIG_IMA_QUEUE_EARLY_BOOT_KEYS */ + +/* LIM API function definitions */ +int ima_get_action(struct user_namespace *mnt_userns, struct inode *inode, + const struct cred *cred, u32 secid, int mask, + enum ima_hooks func, int *pcr, + struct ima_template_desc **template_desc, + const char *func_data, unsigned int *allowed_algos); +int ima_must_measure(struct inode *inode, int mask, enum ima_hooks func); +int ima_collect_measurement(struct integrity_iint_cache *iint, + struct file *file, void *buf, loff_t size, + enum hash_algo algo, struct modsig *modsig); +void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file, + const unsigned char *filename, + struct evm_ima_xattr_data *xattr_value, + int xattr_len, const struct modsig *modsig, int pcr, + struct ima_template_desc *template_desc); +int process_buffer_measurement(struct user_namespace *mnt_userns, + struct inode *inode, const void *buf, int size, + const char *eventname, enum ima_hooks func, + int pcr, const char *func_data, + bool buf_hash, u8 *digest, size_t digest_len); +void ima_audit_measurement(struct integrity_iint_cache *iint, + const unsigned char *filename); +int ima_alloc_init_template(struct ima_event_data *event_data, + struct ima_template_entry **entry, + struct ima_template_desc *template_desc); +int ima_store_template(struct ima_template_entry *entry, int violation, + struct inode *inode, + const unsigned char *filename, int pcr); +void ima_free_template_entry(struct ima_template_entry *entry); +const char *ima_d_path(const struct path *path, char **pathbuf, char *filename); + +/* IMA policy related functions */ +int ima_match_policy(struct user_namespace *mnt_userns, struct inode *inode, + const struct cred *cred, u32 secid, enum ima_hooks func, + int mask, int flags, int *pcr, + struct ima_template_desc **template_desc, + const char *func_data, unsigned int *allowed_algos); +void ima_init_policy(void); +void ima_update_policy(void); +void ima_update_policy_flags(void); +ssize_t ima_parse_add_rule(char *); +void ima_delete_rules(void); +int ima_check_policy(void); +void *ima_policy_start(struct seq_file *m, loff_t *pos); +void *ima_policy_next(struct seq_file *m, void *v, loff_t *pos); +void ima_policy_stop(struct seq_file *m, void *v); +int ima_policy_show(struct seq_file *m, void *v); + +/* Appraise integrity measurements */ +#define IMA_APPRAISE_ENFORCE 0x01 +#define IMA_APPRAISE_FIX 0x02 +#define IMA_APPRAISE_LOG 0x04 +#define IMA_APPRAISE_MODULES 0x08 +#define IMA_APPRAISE_FIRMWARE 0x10 +#define IMA_APPRAISE_POLICY 0x20 +#define IMA_APPRAISE_KEXEC 0x40 + +#ifdef CONFIG_IMA_APPRAISE +int ima_check_blacklist(struct integrity_iint_cache *iint, + const struct modsig *modsig, int pcr); +int ima_appraise_measurement(enum ima_hooks func, + struct integrity_iint_cache *iint, + struct file *file, const unsigned char *filename, + struct evm_ima_xattr_data *xattr_value, + int xattr_len, const struct modsig *modsig); +int ima_must_appraise(struct user_namespace *mnt_userns, struct inode *inode, + int mask, enum ima_hooks func); +void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file); +enum integrity_status ima_get_cache_status(struct integrity_iint_cache *iint, + enum ima_hooks func); +enum hash_algo ima_get_hash_algo(const struct evm_ima_xattr_data *xattr_value, + int xattr_len); +int ima_read_xattr(struct dentry *dentry, + struct evm_ima_xattr_data **xattr_value); + +#else +static inline int ima_check_blacklist(struct integrity_iint_cache *iint, + const struct modsig *modsig, int pcr) +{ + return 0; +} + +static inline int ima_appraise_measurement(enum ima_hooks func, + struct integrity_iint_cache *iint, + struct file *file, + const unsigned char *filename, + struct evm_ima_xattr_data *xattr_value, + int xattr_len, + const struct modsig *modsig) +{ + return INTEGRITY_UNKNOWN; +} + +static inline int ima_must_appraise(struct user_namespace *mnt_userns, + struct inode *inode, int mask, + enum ima_hooks func) +{ + return 0; +} + +static inline void ima_update_xattr(struct integrity_iint_cache *iint, + struct file *file) +{ +} + +static inline enum integrity_status ima_get_cache_status(struct integrity_iint_cache + *iint, + enum ima_hooks func) +{ + return INTEGRITY_UNKNOWN; +} + +static inline enum hash_algo +ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value, int xattr_len) +{ + return ima_hash_algo; +} + +static inline int ima_read_xattr(struct dentry *dentry, + struct evm_ima_xattr_data **xattr_value) +{ + return 0; +} + +#endif /* CONFIG_IMA_APPRAISE */ + +#ifdef CONFIG_IMA_APPRAISE_MODSIG +int ima_read_modsig(enum ima_hooks func, const void *buf, loff_t buf_len, + struct modsig **modsig); +void ima_collect_modsig(struct modsig *modsig, const void *buf, loff_t size); +int ima_get_modsig_digest(const struct modsig *modsig, enum hash_algo *algo, + const u8 **digest, u32 *digest_size); +int ima_get_raw_modsig(const struct modsig *modsig, const void **data, + u32 *data_len); +void ima_free_modsig(struct modsig *modsig); +#else +static inline int ima_read_modsig(enum ima_hooks func, const void *buf, + loff_t buf_len, struct modsig **modsig) +{ + return -EOPNOTSUPP; +} + +static inline void ima_collect_modsig(struct modsig *modsig, const void *buf, + loff_t size) +{ +} + +static inline int ima_get_modsig_digest(const struct modsig *modsig, + enum hash_algo *algo, const u8 **digest, + u32 *digest_size) +{ + return -EOPNOTSUPP; +} + +static inline int ima_get_raw_modsig(const struct modsig *modsig, + const void **data, u32 *data_len) +{ + return -EOPNOTSUPP; +} + +static inline void ima_free_modsig(struct modsig *modsig) +{ +} +#endif /* CONFIG_IMA_APPRAISE_MODSIG */ + +/* LSM based policy rules require audit */ +#ifdef CONFIG_IMA_LSM_RULES + +#define ima_filter_rule_init security_audit_rule_init +#define ima_filter_rule_free security_audit_rule_free +#define ima_filter_rule_match security_audit_rule_match + +#else + +static inline int ima_filter_rule_init(u32 field, u32 op, char *rulestr, + void **lsmrule) +{ + return -EINVAL; +} + +static inline void ima_filter_rule_free(void *lsmrule) +{ +} + +static inline int ima_filter_rule_match(u32 secid, u32 field, u32 op, + void *lsmrule) +{ + return -EINVAL; +} +#endif /* CONFIG_IMA_LSM_RULES */ + +#ifdef CONFIG_IMA_READ_POLICY +#define POLICY_FILE_FLAGS (S_IWUSR | S_IRUSR) +#else +#define POLICY_FILE_FLAGS S_IWUSR +#endif /* CONFIG_IMA_READ_POLICY */ + +#endif /* __LINUX_IMA_H */ diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c new file mode 100644 index 000000000..026c8c9db --- /dev/null +++ b/security/integrity/ima/ima_api.c @@ -0,0 +1,455 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2008 IBM Corporation + * + * Author: Mimi Zohar <zohar@us.ibm.com> + * + * File: ima_api.c + * Implements must_appraise_or_measure, collect_measurement, + * appraise_measurement, store_measurement and store_template. + */ +#include <linux/slab.h> +#include <linux/file.h> +#include <linux/fs.h> +#include <linux/xattr.h> +#include <linux/evm.h> +#include <linux/iversion.h> +#include <linux/fsverity.h> + +#include "ima.h" + +/* + * ima_free_template_entry - free an existing template entry + */ +void ima_free_template_entry(struct ima_template_entry *entry) +{ + int i; + + for (i = 0; i < entry->template_desc->num_fields; i++) + kfree(entry->template_data[i].data); + + kfree(entry->digests); + kfree(entry); +} + +/* + * ima_alloc_init_template - create and initialize a new template entry + */ +int ima_alloc_init_template(struct ima_event_data *event_data, + struct ima_template_entry **entry, + struct ima_template_desc *desc) +{ + struct ima_template_desc *template_desc; + struct tpm_digest *digests; + int i, result = 0; + + if (desc) + template_desc = desc; + else + template_desc = ima_template_desc_current(); + + *entry = kzalloc(struct_size(*entry, template_data, + template_desc->num_fields), GFP_NOFS); + if (!*entry) + return -ENOMEM; + + digests = kcalloc(NR_BANKS(ima_tpm_chip) + ima_extra_slots, + sizeof(*digests), GFP_NOFS); + if (!digests) { + kfree(*entry); + *entry = NULL; + return -ENOMEM; + } + + (*entry)->digests = digests; + (*entry)->template_desc = template_desc; + for (i = 0; i < template_desc->num_fields; i++) { + const struct ima_template_field *field = + template_desc->fields[i]; + u32 len; + + result = field->field_init(event_data, + &((*entry)->template_data[i])); + if (result != 0) + goto out; + + len = (*entry)->template_data[i].len; + (*entry)->template_data_len += sizeof(len); + (*entry)->template_data_len += len; + } + return 0; +out: + ima_free_template_entry(*entry); + *entry = NULL; + return result; +} + +/* + * ima_store_template - store ima template measurements + * + * Calculate the hash of a template entry, add the template entry + * to an ordered list of measurement entries maintained inside the kernel, + * and also update the aggregate integrity value (maintained inside the + * configured TPM PCR) over the hashes of the current list of measurement + * entries. + * + * Applications retrieve the current kernel-held measurement list through + * the securityfs entries in /sys/kernel/security/ima. The signed aggregate + * TPM PCR (called quote) can be retrieved using a TPM user space library + * and is used to validate the measurement list. + * + * Returns 0 on success, error code otherwise + */ +int ima_store_template(struct ima_template_entry *entry, + int violation, struct inode *inode, + const unsigned char *filename, int pcr) +{ + static const char op[] = "add_template_measure"; + static const char audit_cause[] = "hashing_error"; + char *template_name = entry->template_desc->name; + int result; + + if (!violation) { + result = ima_calc_field_array_hash(&entry->template_data[0], + entry); + if (result < 0) { + integrity_audit_msg(AUDIT_INTEGRITY_PCR, inode, + template_name, op, + audit_cause, result, 0); + return result; + } + } + entry->pcr = pcr; + result = ima_add_template_entry(entry, violation, op, inode, filename); + return result; +} + +/* + * ima_add_violation - add violation to measurement list. + * + * Violations are flagged in the measurement list with zero hash values. + * By extending the PCR with 0xFF's instead of with zeroes, the PCR + * value is invalidated. + */ +void ima_add_violation(struct file *file, const unsigned char *filename, + struct integrity_iint_cache *iint, + const char *op, const char *cause) +{ + struct ima_template_entry *entry; + struct inode *inode = file_inode(file); + struct ima_event_data event_data = { .iint = iint, + .file = file, + .filename = filename, + .violation = cause }; + int violation = 1; + int result; + + /* can overflow, only indicator */ + atomic_long_inc(&ima_htable.violations); + + result = ima_alloc_init_template(&event_data, &entry, NULL); + if (result < 0) { + result = -ENOMEM; + goto err_out; + } + result = ima_store_template(entry, violation, inode, + filename, CONFIG_IMA_MEASURE_PCR_IDX); + if (result < 0) + ima_free_template_entry(entry); +err_out: + integrity_audit_msg(AUDIT_INTEGRITY_PCR, inode, filename, + op, cause, result, 0); +} + +/** + * ima_get_action - appraise & measure decision based on policy. + * @mnt_userns: user namespace of the mount the inode was found from + * @inode: pointer to the inode associated with the object being validated + * @cred: pointer to credentials structure to validate + * @secid: secid of the task being validated + * @mask: contains the permission mask (MAY_READ, MAY_WRITE, MAY_EXEC, + * MAY_APPEND) + * @func: caller identifier + * @pcr: pointer filled in if matched measure policy sets pcr= + * @template_desc: pointer filled in if matched measure policy sets template= + * @func_data: func specific data, may be NULL + * @allowed_algos: allowlist of hash algorithms for the IMA xattr + * + * The policy is defined in terms of keypairs: + * subj=, obj=, type=, func=, mask=, fsmagic= + * subj,obj, and type: are LSM specific. + * func: FILE_CHECK | BPRM_CHECK | CREDS_CHECK | MMAP_CHECK | MODULE_CHECK + * | KEXEC_CMDLINE | KEY_CHECK | CRITICAL_DATA + * mask: contains the permission mask + * fsmagic: hex value + * + * Returns IMA_MEASURE, IMA_APPRAISE mask. + * + */ +int ima_get_action(struct user_namespace *mnt_userns, struct inode *inode, + const struct cred *cred, u32 secid, int mask, + enum ima_hooks func, int *pcr, + struct ima_template_desc **template_desc, + const char *func_data, unsigned int *allowed_algos) +{ + int flags = IMA_MEASURE | IMA_AUDIT | IMA_APPRAISE | IMA_HASH; + + flags &= ima_policy_flag; + + return ima_match_policy(mnt_userns, inode, cred, secid, func, mask, + flags, pcr, template_desc, func_data, + allowed_algos); +} + +static int ima_get_verity_digest(struct integrity_iint_cache *iint, + struct ima_max_digest_data *hash) +{ + enum hash_algo verity_alg; + int ret; + + /* + * On failure, 'measure' policy rules will result in a file data + * hash containing 0's. + */ + ret = fsverity_get_digest(iint->inode, hash->digest, &verity_alg); + if (ret) + return ret; + + /* + * Unlike in the case of actually calculating the file hash, in + * the fsverity case regardless of the hash algorithm, return + * the verity digest to be included in the measurement list. A + * mismatch between the verity algorithm and the xattr signature + * algorithm, if one exists, will be detected later. + */ + hash->hdr.algo = verity_alg; + hash->hdr.length = hash_digest_size[verity_alg]; + return 0; +} + +/* + * ima_collect_measurement - collect file measurement + * + * Calculate the file hash, if it doesn't already exist, + * storing the measurement and i_version in the iint. + * + * Must be called with iint->mutex held. + * + * Return 0 on success, error code otherwise + */ +int ima_collect_measurement(struct integrity_iint_cache *iint, + struct file *file, void *buf, loff_t size, + enum hash_algo algo, struct modsig *modsig) +{ + const char *audit_cause = "failed"; + struct inode *inode = file_inode(file); + struct inode *real_inode = d_real_inode(file_dentry(file)); + const char *filename = file->f_path.dentry->d_name.name; + struct ima_max_digest_data hash; + int result = 0; + int length; + void *tmpbuf; + u64 i_version; + + /* + * Always collect the modsig, because IMA might have already collected + * the file digest without collecting the modsig in a previous + * measurement rule. + */ + if (modsig) + ima_collect_modsig(modsig, buf, size); + + if (iint->flags & IMA_COLLECTED) + goto out; + + /* + * Detecting file change is based on i_version. On filesystems + * which do not support i_version, support was originally limited + * to an initial measurement/appraisal/audit, but was modified to + * assume the file changed. + */ + i_version = inode_query_iversion(inode); + hash.hdr.algo = algo; + hash.hdr.length = hash_digest_size[algo]; + + /* Initialize hash digest to 0's in case of failure */ + memset(&hash.digest, 0, sizeof(hash.digest)); + + if (iint->flags & IMA_VERITY_REQUIRED) { + result = ima_get_verity_digest(iint, &hash); + switch (result) { + case 0: + break; + case -ENODATA: + audit_cause = "no-verity-digest"; + break; + default: + audit_cause = "invalid-verity-digest"; + break; + } + } else if (buf) { + result = ima_calc_buffer_hash(buf, size, &hash.hdr); + } else { + result = ima_calc_file_hash(file, &hash.hdr); + } + + if (result && result != -EBADF && result != -EINVAL) + goto out; + + length = sizeof(hash.hdr) + hash.hdr.length; + tmpbuf = krealloc(iint->ima_hash, length, GFP_NOFS); + if (!tmpbuf) { + result = -ENOMEM; + goto out; + } + + iint->ima_hash = tmpbuf; + memcpy(iint->ima_hash, &hash, length); + iint->version = i_version; + if (real_inode != inode) { + iint->real_ino = real_inode->i_ino; + iint->real_dev = real_inode->i_sb->s_dev; + } + + /* Possibly temporary failure due to type of read (eg. O_DIRECT) */ + if (!result) + iint->flags |= IMA_COLLECTED; +out: + if (result) { + if (file->f_flags & O_DIRECT) + audit_cause = "failed(directio)"; + + integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, + filename, "collect_data", audit_cause, + result, 0); + } + return result; +} + +/* + * ima_store_measurement - store file measurement + * + * Create an "ima" template and then store the template by calling + * ima_store_template. + * + * We only get here if the inode has not already been measured, + * but the measurement could already exist: + * - multiple copies of the same file on either the same or + * different filesystems. + * - the inode was previously flushed as well as the iint info, + * containing the hashing info. + * + * Must be called with iint->mutex held. + */ +void ima_store_measurement(struct integrity_iint_cache *iint, + struct file *file, const unsigned char *filename, + struct evm_ima_xattr_data *xattr_value, + int xattr_len, const struct modsig *modsig, int pcr, + struct ima_template_desc *template_desc) +{ + static const char op[] = "add_template_measure"; + static const char audit_cause[] = "ENOMEM"; + int result = -ENOMEM; + struct inode *inode = file_inode(file); + struct ima_template_entry *entry; + struct ima_event_data event_data = { .iint = iint, + .file = file, + .filename = filename, + .xattr_value = xattr_value, + .xattr_len = xattr_len, + .modsig = modsig }; + int violation = 0; + + /* + * We still need to store the measurement in the case of MODSIG because + * we only have its contents to put in the list at the time of + * appraisal, but a file measurement from earlier might already exist in + * the measurement list. + */ + if (iint->measured_pcrs & (0x1 << pcr) && !modsig) + return; + + result = ima_alloc_init_template(&event_data, &entry, template_desc); + if (result < 0) { + integrity_audit_msg(AUDIT_INTEGRITY_PCR, inode, filename, + op, audit_cause, result, 0); + return; + } + + result = ima_store_template(entry, violation, inode, filename, pcr); + if ((!result || result == -EEXIST) && !(file->f_flags & O_DIRECT)) { + iint->flags |= IMA_MEASURED; + iint->measured_pcrs |= (0x1 << pcr); + } + if (result < 0) + ima_free_template_entry(entry); +} + +void ima_audit_measurement(struct integrity_iint_cache *iint, + const unsigned char *filename) +{ + struct audit_buffer *ab; + char *hash; + const char *algo_name = hash_algo_name[iint->ima_hash->algo]; + int i; + + if (iint->flags & IMA_AUDITED) + return; + + hash = kzalloc((iint->ima_hash->length * 2) + 1, GFP_KERNEL); + if (!hash) + return; + + for (i = 0; i < iint->ima_hash->length; i++) + hex_byte_pack(hash + (i * 2), iint->ima_hash->digest[i]); + hash[i * 2] = '\0'; + + ab = audit_log_start(audit_context(), GFP_KERNEL, + AUDIT_INTEGRITY_RULE); + if (!ab) + goto out; + + audit_log_format(ab, "file="); + audit_log_untrustedstring(ab, filename); + audit_log_format(ab, " hash=\"%s:%s\"", algo_name, hash); + + audit_log_task_info(ab); + audit_log_end(ab); + + iint->flags |= IMA_AUDITED; +out: + kfree(hash); + return; +} + +/* + * ima_d_path - return a pointer to the full pathname + * + * Attempt to return a pointer to the full pathname for use in the + * IMA measurement list, IMA audit records, and auditing logs. + * + * On failure, return a pointer to a copy of the filename, not dname. + * Returning a pointer to dname, could result in using the pointer + * after the memory has been freed. + */ +const char *ima_d_path(const struct path *path, char **pathbuf, char *namebuf) +{ + char *pathname = NULL; + + *pathbuf = __getname(); + if (*pathbuf) { + pathname = d_absolute_path(path, *pathbuf, PATH_MAX); + if (IS_ERR(pathname)) { + __putname(*pathbuf); + *pathbuf = NULL; + pathname = NULL; + } + } + + if (!pathname) { + strscpy(namebuf, path->dentry->d_name.name, NAME_MAX); + pathname = namebuf; + } + + return pathname; +} diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c new file mode 100644 index 000000000..3e0fbbd99 --- /dev/null +++ b/security/integrity/ima/ima_appraise.c @@ -0,0 +1,788 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2011 IBM Corporation + * + * Author: + * Mimi Zohar <zohar@us.ibm.com> + */ +#include <linux/module.h> +#include <linux/init.h> +#include <linux/file.h> +#include <linux/fs.h> +#include <linux/xattr.h> +#include <linux/magic.h> +#include <linux/ima.h> +#include <linux/evm.h> +#include <linux/fsverity.h> +#include <keys/system_keyring.h> +#include <uapi/linux/fsverity.h> + +#include "ima.h" + +#ifdef CONFIG_IMA_APPRAISE_BOOTPARAM +static char *ima_appraise_cmdline_default __initdata; +core_param(ima_appraise, ima_appraise_cmdline_default, charp, 0); + +void __init ima_appraise_parse_cmdline(void) +{ + const char *str = ima_appraise_cmdline_default; + bool sb_state = arch_ima_get_secureboot(); + int appraisal_state = ima_appraise; + + if (!str) + return; + + if (strncmp(str, "off", 3) == 0) + appraisal_state = 0; + else if (strncmp(str, "log", 3) == 0) + appraisal_state = IMA_APPRAISE_LOG; + else if (strncmp(str, "fix", 3) == 0) + appraisal_state = IMA_APPRAISE_FIX; + else if (strncmp(str, "enforce", 7) == 0) + appraisal_state = IMA_APPRAISE_ENFORCE; + else + pr_err("invalid \"%s\" appraise option", str); + + /* If appraisal state was changed, but secure boot is enabled, + * keep its default */ + if (sb_state) { + if (!(appraisal_state & IMA_APPRAISE_ENFORCE)) + pr_info("Secure boot enabled: ignoring ima_appraise=%s option", + str); + } else { + ima_appraise = appraisal_state; + } +} +#endif + +/* + * is_ima_appraise_enabled - return appraise status + * + * Only return enabled, if not in ima_appraise="fix" or "log" modes. + */ +bool is_ima_appraise_enabled(void) +{ + return ima_appraise & IMA_APPRAISE_ENFORCE; +} + +/* + * ima_must_appraise - set appraise flag + * + * Return 1 to appraise or hash + */ +int ima_must_appraise(struct user_namespace *mnt_userns, struct inode *inode, + int mask, enum ima_hooks func) +{ + u32 secid; + + if (!ima_appraise) + return 0; + + security_current_getsecid_subj(&secid); + return ima_match_policy(mnt_userns, inode, current_cred(), secid, + func, mask, IMA_APPRAISE | IMA_HASH, NULL, + NULL, NULL, NULL); +} + +static int ima_fix_xattr(struct dentry *dentry, + struct integrity_iint_cache *iint) +{ + int rc, offset; + u8 algo = iint->ima_hash->algo; + + if (algo <= HASH_ALGO_SHA1) { + offset = 1; + iint->ima_hash->xattr.sha1.type = IMA_XATTR_DIGEST; + } else { + offset = 0; + iint->ima_hash->xattr.ng.type = IMA_XATTR_DIGEST_NG; + iint->ima_hash->xattr.ng.algo = algo; + } + rc = __vfs_setxattr_noperm(&init_user_ns, dentry, XATTR_NAME_IMA, + &iint->ima_hash->xattr.data[offset], + (sizeof(iint->ima_hash->xattr) - offset) + + iint->ima_hash->length, 0); + return rc; +} + +/* Return specific func appraised cached result */ +enum integrity_status ima_get_cache_status(struct integrity_iint_cache *iint, + enum ima_hooks func) +{ + switch (func) { + case MMAP_CHECK: + return iint->ima_mmap_status; + case BPRM_CHECK: + return iint->ima_bprm_status; + case CREDS_CHECK: + return iint->ima_creds_status; + case FILE_CHECK: + case POST_SETATTR: + return iint->ima_file_status; + case MODULE_CHECK ... MAX_CHECK - 1: + default: + return iint->ima_read_status; + } +} + +static void ima_set_cache_status(struct integrity_iint_cache *iint, + enum ima_hooks func, + enum integrity_status status) +{ + switch (func) { + case MMAP_CHECK: + iint->ima_mmap_status = status; + break; + case BPRM_CHECK: + iint->ima_bprm_status = status; + break; + case CREDS_CHECK: + iint->ima_creds_status = status; + break; + case FILE_CHECK: + case POST_SETATTR: + iint->ima_file_status = status; + break; + case MODULE_CHECK ... MAX_CHECK - 1: + default: + iint->ima_read_status = status; + break; + } +} + +static void ima_cache_flags(struct integrity_iint_cache *iint, + enum ima_hooks func) +{ + switch (func) { + case MMAP_CHECK: + iint->flags |= (IMA_MMAP_APPRAISED | IMA_APPRAISED); + break; + case BPRM_CHECK: + iint->flags |= (IMA_BPRM_APPRAISED | IMA_APPRAISED); + break; + case CREDS_CHECK: + iint->flags |= (IMA_CREDS_APPRAISED | IMA_APPRAISED); + break; + case FILE_CHECK: + case POST_SETATTR: + iint->flags |= (IMA_FILE_APPRAISED | IMA_APPRAISED); + break; + case MODULE_CHECK ... MAX_CHECK - 1: + default: + iint->flags |= (IMA_READ_APPRAISED | IMA_APPRAISED); + break; + } +} + +enum hash_algo ima_get_hash_algo(const struct evm_ima_xattr_data *xattr_value, + int xattr_len) +{ + struct signature_v2_hdr *sig; + enum hash_algo ret; + + if (!xattr_value || xattr_len < 2) + /* return default hash algo */ + return ima_hash_algo; + + switch (xattr_value->type) { + case IMA_VERITY_DIGSIG: + sig = (typeof(sig))xattr_value; + if (sig->version != 3 || xattr_len <= sizeof(*sig) || + sig->hash_algo >= HASH_ALGO__LAST) + return ima_hash_algo; + return sig->hash_algo; + case EVM_IMA_XATTR_DIGSIG: + sig = (typeof(sig))xattr_value; + if (sig->version != 2 || xattr_len <= sizeof(*sig) + || sig->hash_algo >= HASH_ALGO__LAST) + return ima_hash_algo; + return sig->hash_algo; + case IMA_XATTR_DIGEST_NG: + /* first byte contains algorithm id */ + ret = xattr_value->data[0]; + if (ret < HASH_ALGO__LAST) + return ret; + break; + case IMA_XATTR_DIGEST: + /* this is for backward compatibility */ + if (xattr_len == 21) { + unsigned int zero = 0; + if (!memcmp(&xattr_value->data[16], &zero, 4)) + return HASH_ALGO_MD5; + else + return HASH_ALGO_SHA1; + } else if (xattr_len == 17) + return HASH_ALGO_MD5; + break; + } + + /* return default hash algo */ + return ima_hash_algo; +} + +int ima_read_xattr(struct dentry *dentry, + struct evm_ima_xattr_data **xattr_value) +{ + ssize_t ret; + + ret = vfs_getxattr_alloc(&init_user_ns, dentry, XATTR_NAME_IMA, + (char **)xattr_value, 0, GFP_NOFS); + if (ret == -EOPNOTSUPP) + ret = 0; + return ret; +} + +/* + * calc_file_id_hash - calculate the hash of the ima_file_id struct data + * @type: xattr type [enum evm_ima_xattr_type] + * @algo: hash algorithm [enum hash_algo] + * @digest: pointer to the digest to be hashed + * @hash: (out) pointer to the hash + * + * IMA signature version 3 disambiguates the data that is signed by + * indirectly signing the hash of the ima_file_id structure data. + * + * Signing the ima_file_id struct is currently only supported for + * IMA_VERITY_DIGSIG type xattrs. + * + * Return 0 on success, error code otherwise. + */ +static int calc_file_id_hash(enum evm_ima_xattr_type type, + enum hash_algo algo, const u8 *digest, + struct ima_digest_data *hash) +{ + struct ima_file_id file_id = { + .hash_type = IMA_VERITY_DIGSIG, .hash_algorithm = algo}; + unsigned int unused = HASH_MAX_DIGESTSIZE - hash_digest_size[algo]; + + if (type != IMA_VERITY_DIGSIG) + return -EINVAL; + + memcpy(file_id.hash, digest, hash_digest_size[algo]); + + hash->algo = algo; + hash->length = hash_digest_size[algo]; + + return ima_calc_buffer_hash(&file_id, sizeof(file_id) - unused, hash); +} + +/* + * xattr_verify - verify xattr digest or signature + * + * Verify whether the hash or signature matches the file contents. + * + * Return 0 on success, error code otherwise. + */ +static int xattr_verify(enum ima_hooks func, struct integrity_iint_cache *iint, + struct evm_ima_xattr_data *xattr_value, int xattr_len, + enum integrity_status *status, const char **cause) +{ + struct ima_max_digest_data hash; + struct signature_v2_hdr *sig; + int rc = -EINVAL, hash_start = 0; + int mask; + + switch (xattr_value->type) { + case IMA_XATTR_DIGEST_NG: + /* first byte contains algorithm id */ + hash_start = 1; + fallthrough; + case IMA_XATTR_DIGEST: + if (*status != INTEGRITY_PASS_IMMUTABLE) { + if (iint->flags & IMA_DIGSIG_REQUIRED) { + if (iint->flags & IMA_VERITY_REQUIRED) + *cause = "verity-signature-required"; + else + *cause = "IMA-signature-required"; + *status = INTEGRITY_FAIL; + break; + } + clear_bit(IMA_DIGSIG, &iint->atomic_flags); + } else { + set_bit(IMA_DIGSIG, &iint->atomic_flags); + } + if (xattr_len - sizeof(xattr_value->type) - hash_start >= + iint->ima_hash->length) + /* + * xattr length may be longer. md5 hash in previous + * version occupied 20 bytes in xattr, instead of 16 + */ + rc = memcmp(&xattr_value->data[hash_start], + iint->ima_hash->digest, + iint->ima_hash->length); + else + rc = -EINVAL; + if (rc) { + *cause = "invalid-hash"; + *status = INTEGRITY_FAIL; + break; + } + *status = INTEGRITY_PASS; + break; + case EVM_IMA_XATTR_DIGSIG: + set_bit(IMA_DIGSIG, &iint->atomic_flags); + + mask = IMA_DIGSIG_REQUIRED | IMA_VERITY_REQUIRED; + if ((iint->flags & mask) == mask) { + *cause = "verity-signature-required"; + *status = INTEGRITY_FAIL; + break; + } + + sig = (typeof(sig))xattr_value; + if (sig->version >= 3) { + *cause = "invalid-signature-version"; + *status = INTEGRITY_FAIL; + break; + } + rc = integrity_digsig_verify(INTEGRITY_KEYRING_IMA, + (const char *)xattr_value, + xattr_len, + iint->ima_hash->digest, + iint->ima_hash->length); + if (rc == -EOPNOTSUPP) { + *status = INTEGRITY_UNKNOWN; + break; + } + if (IS_ENABLED(CONFIG_INTEGRITY_PLATFORM_KEYRING) && rc && + func == KEXEC_KERNEL_CHECK) + rc = integrity_digsig_verify(INTEGRITY_KEYRING_PLATFORM, + (const char *)xattr_value, + xattr_len, + iint->ima_hash->digest, + iint->ima_hash->length); + if (rc) { + *cause = "invalid-signature"; + *status = INTEGRITY_FAIL; + } else { + *status = INTEGRITY_PASS; + } + break; + case IMA_VERITY_DIGSIG: + set_bit(IMA_DIGSIG, &iint->atomic_flags); + + if (iint->flags & IMA_DIGSIG_REQUIRED) { + if (!(iint->flags & IMA_VERITY_REQUIRED)) { + *cause = "IMA-signature-required"; + *status = INTEGRITY_FAIL; + break; + } + } + + sig = (typeof(sig))xattr_value; + if (sig->version != 3) { + *cause = "invalid-signature-version"; + *status = INTEGRITY_FAIL; + break; + } + + rc = calc_file_id_hash(IMA_VERITY_DIGSIG, iint->ima_hash->algo, + iint->ima_hash->digest, &hash.hdr); + if (rc) { + *cause = "sigv3-hashing-error"; + *status = INTEGRITY_FAIL; + break; + } + + rc = integrity_digsig_verify(INTEGRITY_KEYRING_IMA, + (const char *)xattr_value, + xattr_len, hash.digest, + hash.hdr.length); + if (rc) { + *cause = "invalid-verity-signature"; + *status = INTEGRITY_FAIL; + } else { + *status = INTEGRITY_PASS; + } + + break; + default: + *status = INTEGRITY_UNKNOWN; + *cause = "unknown-ima-data"; + break; + } + + return rc; +} + +/* + * modsig_verify - verify modsig signature + * + * Verify whether the signature matches the file contents. + * + * Return 0 on success, error code otherwise. + */ +static int modsig_verify(enum ima_hooks func, const struct modsig *modsig, + enum integrity_status *status, const char **cause) +{ + int rc; + + rc = integrity_modsig_verify(INTEGRITY_KEYRING_IMA, modsig); + if (IS_ENABLED(CONFIG_INTEGRITY_PLATFORM_KEYRING) && rc && + func == KEXEC_KERNEL_CHECK) + rc = integrity_modsig_verify(INTEGRITY_KEYRING_PLATFORM, + modsig); + if (rc) { + *cause = "invalid-signature"; + *status = INTEGRITY_FAIL; + } else { + *status = INTEGRITY_PASS; + } + + return rc; +} + +/* + * ima_check_blacklist - determine if the binary is blacklisted. + * + * Add the hash of the blacklisted binary to the measurement list, based + * on policy. + * + * Returns -EPERM if the hash is blacklisted. + */ +int ima_check_blacklist(struct integrity_iint_cache *iint, + const struct modsig *modsig, int pcr) +{ + enum hash_algo hash_algo; + const u8 *digest = NULL; + u32 digestsize = 0; + int rc = 0; + + if (!(iint->flags & IMA_CHECK_BLACKLIST)) + return 0; + + if (iint->flags & IMA_MODSIG_ALLOWED && modsig) { + ima_get_modsig_digest(modsig, &hash_algo, &digest, &digestsize); + + rc = is_binary_blacklisted(digest, digestsize); + if ((rc == -EPERM) && (iint->flags & IMA_MEASURE)) + process_buffer_measurement(&init_user_ns, NULL, digest, digestsize, + "blacklisted-hash", NONE, + pcr, NULL, false, NULL, 0); + } + + return rc; +} + +/* + * ima_appraise_measurement - appraise file measurement + * + * Call evm_verifyxattr() to verify the integrity of 'security.ima'. + * Assuming success, compare the xattr hash with the collected measurement. + * + * Return 0 on success, error code otherwise + */ +int ima_appraise_measurement(enum ima_hooks func, + struct integrity_iint_cache *iint, + struct file *file, const unsigned char *filename, + struct evm_ima_xattr_data *xattr_value, + int xattr_len, const struct modsig *modsig) +{ + static const char op[] = "appraise_data"; + const char *cause = "unknown"; + struct dentry *dentry = file_dentry(file); + struct inode *inode = d_backing_inode(dentry); + enum integrity_status status = INTEGRITY_UNKNOWN; + int rc = xattr_len; + bool try_modsig = iint->flags & IMA_MODSIG_ALLOWED && modsig; + + /* If not appraising a modsig, we need an xattr. */ + if (!(inode->i_opflags & IOP_XATTR) && !try_modsig) + return INTEGRITY_UNKNOWN; + + /* If reading the xattr failed and there's no modsig, error out. */ + if (rc <= 0 && !try_modsig) { + if (rc && rc != -ENODATA) + goto out; + + if (iint->flags & IMA_DIGSIG_REQUIRED) { + if (iint->flags & IMA_VERITY_REQUIRED) + cause = "verity-signature-required"; + else + cause = "IMA-signature-required"; + } else { + cause = "missing-hash"; + } + + status = INTEGRITY_NOLABEL; + if (file->f_mode & FMODE_CREATED) + iint->flags |= IMA_NEW_FILE; + if ((iint->flags & IMA_NEW_FILE) && + (!(iint->flags & IMA_DIGSIG_REQUIRED) || + (inode->i_size == 0))) + status = INTEGRITY_PASS; + goto out; + } + + status = evm_verifyxattr(dentry, XATTR_NAME_IMA, xattr_value, + rc < 0 ? 0 : rc, iint); + switch (status) { + case INTEGRITY_PASS: + case INTEGRITY_PASS_IMMUTABLE: + case INTEGRITY_UNKNOWN: + break; + case INTEGRITY_NOXATTRS: /* No EVM protected xattrs. */ + /* It's fine not to have xattrs when using a modsig. */ + if (try_modsig) + break; + fallthrough; + case INTEGRITY_NOLABEL: /* No security.evm xattr. */ + cause = "missing-HMAC"; + goto out; + case INTEGRITY_FAIL_IMMUTABLE: + set_bit(IMA_DIGSIG, &iint->atomic_flags); + cause = "invalid-fail-immutable"; + goto out; + case INTEGRITY_FAIL: /* Invalid HMAC/signature. */ + cause = "invalid-HMAC"; + goto out; + default: + WARN_ONCE(true, "Unexpected integrity status %d\n", status); + } + + if (xattr_value) + rc = xattr_verify(func, iint, xattr_value, xattr_len, &status, + &cause); + + /* + * If we have a modsig and either no imasig or the imasig's key isn't + * known, then try verifying the modsig. + */ + if (try_modsig && + (!xattr_value || xattr_value->type == IMA_XATTR_DIGEST_NG || + rc == -ENOKEY)) + rc = modsig_verify(func, modsig, &status, &cause); + +out: + /* + * File signatures on some filesystems can not be properly verified. + * When such filesystems are mounted by an untrusted mounter or on a + * system not willing to accept such a risk, fail the file signature + * verification. + */ + if ((inode->i_sb->s_iflags & SB_I_IMA_UNVERIFIABLE_SIGNATURE) && + ((inode->i_sb->s_iflags & SB_I_UNTRUSTED_MOUNTER) || + (iint->flags & IMA_FAIL_UNVERIFIABLE_SIGS))) { + status = INTEGRITY_FAIL; + cause = "unverifiable-signature"; + integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, filename, + op, cause, rc, 0); + } else if (status != INTEGRITY_PASS) { + /* Fix mode, but don't replace file signatures. */ + if ((ima_appraise & IMA_APPRAISE_FIX) && !try_modsig && + (!xattr_value || + xattr_value->type != EVM_IMA_XATTR_DIGSIG)) { + if (!ima_fix_xattr(dentry, iint)) + status = INTEGRITY_PASS; + } + + /* + * Permit new files with file/EVM portable signatures, but + * without data. + */ + if (inode->i_size == 0 && iint->flags & IMA_NEW_FILE && + test_bit(IMA_DIGSIG, &iint->atomic_flags)) { + status = INTEGRITY_PASS; + } + + integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, filename, + op, cause, rc, 0); + } else { + ima_cache_flags(iint, func); + } + + ima_set_cache_status(iint, func, status); + return status; +} + +/* + * ima_update_xattr - update 'security.ima' hash value + */ +void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file) +{ + struct dentry *dentry = file_dentry(file); + int rc = 0; + + /* do not collect and update hash for digital signatures */ + if (test_bit(IMA_DIGSIG, &iint->atomic_flags)) + return; + + if ((iint->ima_file_status != INTEGRITY_PASS) && + !(iint->flags & IMA_HASH)) + return; + + rc = ima_collect_measurement(iint, file, NULL, 0, ima_hash_algo, NULL); + if (rc < 0) + return; + + inode_lock(file_inode(file)); + ima_fix_xattr(dentry, iint); + inode_unlock(file_inode(file)); +} + +/** + * ima_inode_post_setattr - reflect file metadata changes + * @mnt_userns: user namespace of the mount the inode was found from + * @dentry: pointer to the affected dentry + * + * Changes to a dentry's metadata might result in needing to appraise. + * + * This function is called from notify_change(), which expects the caller + * to lock the inode's i_mutex. + */ +void ima_inode_post_setattr(struct user_namespace *mnt_userns, + struct dentry *dentry) +{ + struct inode *inode = d_backing_inode(dentry); + struct integrity_iint_cache *iint; + int action; + + if (!(ima_policy_flag & IMA_APPRAISE) || !S_ISREG(inode->i_mode) + || !(inode->i_opflags & IOP_XATTR)) + return; + + action = ima_must_appraise(mnt_userns, inode, MAY_ACCESS, POST_SETATTR); + iint = integrity_iint_find(inode); + if (iint) { + set_bit(IMA_CHANGE_ATTR, &iint->atomic_flags); + if (!action) + clear_bit(IMA_UPDATE_XATTR, &iint->atomic_flags); + } +} + +/* + * ima_protect_xattr - protect 'security.ima' + * + * Ensure that not just anyone can modify or remove 'security.ima'. + */ +static int ima_protect_xattr(struct dentry *dentry, const char *xattr_name, + const void *xattr_value, size_t xattr_value_len) +{ + if (strcmp(xattr_name, XATTR_NAME_IMA) == 0) { + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + return 1; + } + return 0; +} + +static void ima_reset_appraise_flags(struct inode *inode, int digsig) +{ + struct integrity_iint_cache *iint; + + if (!(ima_policy_flag & IMA_APPRAISE) || !S_ISREG(inode->i_mode)) + return; + + iint = integrity_iint_find(inode); + if (!iint) + return; + iint->measured_pcrs = 0; + set_bit(IMA_CHANGE_XATTR, &iint->atomic_flags); + if (digsig) + set_bit(IMA_DIGSIG, &iint->atomic_flags); + else + clear_bit(IMA_DIGSIG, &iint->atomic_flags); +} + +/** + * validate_hash_algo() - Block setxattr with unsupported hash algorithms + * @dentry: object of the setxattr() + * @xattr_value: userland supplied xattr value + * @xattr_value_len: length of xattr_value + * + * The xattr value is mapped to its hash algorithm, and this algorithm + * must be built in the kernel for the setxattr to be allowed. + * + * Emit an audit message when the algorithm is invalid. + * + * Return: 0 on success, else an error. + */ +static int validate_hash_algo(struct dentry *dentry, + const struct evm_ima_xattr_data *xattr_value, + size_t xattr_value_len) +{ + char *path = NULL, *pathbuf = NULL; + enum hash_algo xattr_hash_algo; + const char *errmsg = "unavailable-hash-algorithm"; + unsigned int allowed_hashes; + + xattr_hash_algo = ima_get_hash_algo(xattr_value, xattr_value_len); + + allowed_hashes = atomic_read(&ima_setxattr_allowed_hash_algorithms); + + if (allowed_hashes) { + /* success if the algorithm is allowed in the ima policy */ + if (allowed_hashes & (1U << xattr_hash_algo)) + return 0; + + /* + * We use a different audit message when the hash algorithm + * is denied by a policy rule, instead of not being built + * in the kernel image + */ + errmsg = "denied-hash-algorithm"; + } else { + if (likely(xattr_hash_algo == ima_hash_algo)) + return 0; + + /* allow any xattr using an algorithm built in the kernel */ + if (crypto_has_alg(hash_algo_name[xattr_hash_algo], 0, 0)) + return 0; + } + + pathbuf = kmalloc(PATH_MAX, GFP_KERNEL); + if (!pathbuf) + return -EACCES; + + path = dentry_path(dentry, pathbuf, PATH_MAX); + + integrity_audit_msg(AUDIT_INTEGRITY_DATA, d_inode(dentry), path, + "set_data", errmsg, -EACCES, 0); + + kfree(pathbuf); + + return -EACCES; +} + +int ima_inode_setxattr(struct dentry *dentry, const char *xattr_name, + const void *xattr_value, size_t xattr_value_len) +{ + const struct evm_ima_xattr_data *xvalue = xattr_value; + int digsig = 0; + int result; + int err; + + result = ima_protect_xattr(dentry, xattr_name, xattr_value, + xattr_value_len); + if (result == 1) { + if (!xattr_value_len || (xvalue->type >= IMA_XATTR_LAST)) + return -EINVAL; + + err = validate_hash_algo(dentry, xvalue, xattr_value_len); + if (err) + return err; + + digsig = (xvalue->type == EVM_IMA_XATTR_DIGSIG); + } else if (!strcmp(xattr_name, XATTR_NAME_EVM) && xattr_value_len > 0) { + digsig = (xvalue->type == EVM_XATTR_PORTABLE_DIGSIG); + } + if (result == 1 || evm_revalidate_status(xattr_name)) { + ima_reset_appraise_flags(d_backing_inode(dentry), digsig); + if (result == 1) + result = 0; + } + return result; +} + +int ima_inode_removexattr(struct dentry *dentry, const char *xattr_name) +{ + int result; + + result = ima_protect_xattr(dentry, xattr_name, NULL, 0); + if (result == 1 || evm_revalidate_status(xattr_name)) { + ima_reset_appraise_flags(d_backing_inode(dentry), 0); + if (result == 1) + result = 0; + } + return result; +} diff --git a/security/integrity/ima/ima_asymmetric_keys.c b/security/integrity/ima/ima_asymmetric_keys.c new file mode 100644 index 000000000..f6aa0b47a --- /dev/null +++ b/security/integrity/ima/ima_asymmetric_keys.c @@ -0,0 +1,66 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2019 Microsoft Corporation + * + * Author: Lakshmi Ramasubramanian (nramas@linux.microsoft.com) + * + * File: ima_asymmetric_keys.c + * Defines an IMA hook to measure asymmetric keys on key + * create or update. + */ + +#include <keys/asymmetric-type.h> +#include <linux/user_namespace.h> +#include <linux/ima.h> +#include "ima.h" + +/** + * ima_post_key_create_or_update - measure asymmetric keys + * @keyring: keyring to which the key is linked to + * @key: created or updated key + * @payload: The data used to instantiate or update the key. + * @payload_len: The length of @payload. + * @flags: key flags + * @create: flag indicating whether the key was created or updated + * + * Keys can only be measured, not appraised. + * The payload data used to instantiate or update the key is measured. + */ +void ima_post_key_create_or_update(struct key *keyring, struct key *key, + const void *payload, size_t payload_len, + unsigned long flags, bool create) +{ + bool queued = false; + + /* Only asymmetric keys are handled by this hook. */ + if (key->type != &key_type_asymmetric) + return; + + if (!payload || (payload_len == 0)) + return; + + if (ima_should_queue_key()) + queued = ima_queue_key(keyring, payload, payload_len); + + if (queued) + return; + + /* + * keyring->description points to the name of the keyring + * (such as ".builtin_trusted_keys", ".ima", etc.) to + * which the given key is linked to. + * + * The name of the keyring is passed in the "eventname" + * parameter to process_buffer_measurement() and is set + * in the "eventname" field in ima_event_data for + * the key measurement IMA event. + * + * The name of the keyring is also passed in the "keyring" + * parameter to process_buffer_measurement() to check + * if the IMA policy is configured to measure a key linked + * to the given keyring. + */ + process_buffer_measurement(&init_user_ns, NULL, payload, payload_len, + keyring->description, KEY_CHECK, 0, + keyring->description, false, NULL, 0); +} diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c new file mode 100644 index 000000000..644990566 --- /dev/null +++ b/security/integrity/ima/ima_crypto.c @@ -0,0 +1,882 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2005,2006,2007,2008 IBM Corporation + * + * Authors: + * Mimi Zohar <zohar@us.ibm.com> + * Kylene Hall <kjhall@us.ibm.com> + * + * File: ima_crypto.c + * Calculates md5/sha1 file hash, template hash, boot-aggreate hash + */ + +#include <linux/kernel.h> +#include <linux/moduleparam.h> +#include <linux/ratelimit.h> +#include <linux/file.h> +#include <linux/crypto.h> +#include <linux/scatterlist.h> +#include <linux/err.h> +#include <linux/slab.h> +#include <crypto/hash.h> + +#include "ima.h" + +/* minimum file size for ahash use */ +static unsigned long ima_ahash_minsize; +module_param_named(ahash_minsize, ima_ahash_minsize, ulong, 0644); +MODULE_PARM_DESC(ahash_minsize, "Minimum file size for ahash use"); + +/* default is 0 - 1 page. */ +static int ima_maxorder; +static unsigned int ima_bufsize = PAGE_SIZE; + +static int param_set_bufsize(const char *val, const struct kernel_param *kp) +{ + unsigned long long size; + int order; + + size = memparse(val, NULL); + order = get_order(size); + if (order >= MAX_ORDER) + return -EINVAL; + ima_maxorder = order; + ima_bufsize = PAGE_SIZE << order; + return 0; +} + +static const struct kernel_param_ops param_ops_bufsize = { + .set = param_set_bufsize, + .get = param_get_uint, +}; +#define param_check_bufsize(name, p) __param_check(name, p, unsigned int) + +module_param_named(ahash_bufsize, ima_bufsize, bufsize, 0644); +MODULE_PARM_DESC(ahash_bufsize, "Maximum ahash buffer size"); + +static struct crypto_shash *ima_shash_tfm; +static struct crypto_ahash *ima_ahash_tfm; + +struct ima_algo_desc { + struct crypto_shash *tfm; + enum hash_algo algo; +}; + +int ima_sha1_idx __ro_after_init; +int ima_hash_algo_idx __ro_after_init; +/* + * Additional number of slots reserved, as needed, for SHA1 + * and IMA default algo. + */ +int ima_extra_slots __ro_after_init; + +static struct ima_algo_desc *ima_algo_array; + +static int __init ima_init_ima_crypto(void) +{ + long rc; + + ima_shash_tfm = crypto_alloc_shash(hash_algo_name[ima_hash_algo], 0, 0); + if (IS_ERR(ima_shash_tfm)) { + rc = PTR_ERR(ima_shash_tfm); + pr_err("Can not allocate %s (reason: %ld)\n", + hash_algo_name[ima_hash_algo], rc); + return rc; + } + pr_info("Allocated hash algorithm: %s\n", + hash_algo_name[ima_hash_algo]); + return 0; +} + +static struct crypto_shash *ima_alloc_tfm(enum hash_algo algo) +{ + struct crypto_shash *tfm = ima_shash_tfm; + int rc, i; + + if (algo < 0 || algo >= HASH_ALGO__LAST) + algo = ima_hash_algo; + + if (algo == ima_hash_algo) + return tfm; + + for (i = 0; i < NR_BANKS(ima_tpm_chip) + ima_extra_slots; i++) + if (ima_algo_array[i].tfm && ima_algo_array[i].algo == algo) + return ima_algo_array[i].tfm; + + tfm = crypto_alloc_shash(hash_algo_name[algo], 0, 0); + if (IS_ERR(tfm)) { + rc = PTR_ERR(tfm); + pr_err("Can not allocate %s (reason: %d)\n", + hash_algo_name[algo], rc); + } + return tfm; +} + +int __init ima_init_crypto(void) +{ + enum hash_algo algo; + long rc; + int i; + + rc = ima_init_ima_crypto(); + if (rc) + return rc; + + ima_sha1_idx = -1; + ima_hash_algo_idx = -1; + + for (i = 0; i < NR_BANKS(ima_tpm_chip); i++) { + algo = ima_tpm_chip->allocated_banks[i].crypto_id; + if (algo == HASH_ALGO_SHA1) + ima_sha1_idx = i; + + if (algo == ima_hash_algo) + ima_hash_algo_idx = i; + } + + if (ima_sha1_idx < 0) { + ima_sha1_idx = NR_BANKS(ima_tpm_chip) + ima_extra_slots++; + if (ima_hash_algo == HASH_ALGO_SHA1) + ima_hash_algo_idx = ima_sha1_idx; + } + + if (ima_hash_algo_idx < 0) + ima_hash_algo_idx = NR_BANKS(ima_tpm_chip) + ima_extra_slots++; + + ima_algo_array = kcalloc(NR_BANKS(ima_tpm_chip) + ima_extra_slots, + sizeof(*ima_algo_array), GFP_KERNEL); + if (!ima_algo_array) { + rc = -ENOMEM; + goto out; + } + + for (i = 0; i < NR_BANKS(ima_tpm_chip); i++) { + algo = ima_tpm_chip->allocated_banks[i].crypto_id; + ima_algo_array[i].algo = algo; + + /* unknown TPM algorithm */ + if (algo == HASH_ALGO__LAST) + continue; + + if (algo == ima_hash_algo) { + ima_algo_array[i].tfm = ima_shash_tfm; + continue; + } + + ima_algo_array[i].tfm = ima_alloc_tfm(algo); + if (IS_ERR(ima_algo_array[i].tfm)) { + if (algo == HASH_ALGO_SHA1) { + rc = PTR_ERR(ima_algo_array[i].tfm); + ima_algo_array[i].tfm = NULL; + goto out_array; + } + + ima_algo_array[i].tfm = NULL; + } + } + + if (ima_sha1_idx >= NR_BANKS(ima_tpm_chip)) { + if (ima_hash_algo == HASH_ALGO_SHA1) { + ima_algo_array[ima_sha1_idx].tfm = ima_shash_tfm; + } else { + ima_algo_array[ima_sha1_idx].tfm = + ima_alloc_tfm(HASH_ALGO_SHA1); + if (IS_ERR(ima_algo_array[ima_sha1_idx].tfm)) { + rc = PTR_ERR(ima_algo_array[ima_sha1_idx].tfm); + goto out_array; + } + } + + ima_algo_array[ima_sha1_idx].algo = HASH_ALGO_SHA1; + } + + if (ima_hash_algo_idx >= NR_BANKS(ima_tpm_chip) && + ima_hash_algo_idx != ima_sha1_idx) { + ima_algo_array[ima_hash_algo_idx].tfm = ima_shash_tfm; + ima_algo_array[ima_hash_algo_idx].algo = ima_hash_algo; + } + + return 0; +out_array: + for (i = 0; i < NR_BANKS(ima_tpm_chip) + ima_extra_slots; i++) { + if (!ima_algo_array[i].tfm || + ima_algo_array[i].tfm == ima_shash_tfm) + continue; + + crypto_free_shash(ima_algo_array[i].tfm); + } + kfree(ima_algo_array); +out: + crypto_free_shash(ima_shash_tfm); + return rc; +} + +static void ima_free_tfm(struct crypto_shash *tfm) +{ + int i; + + if (tfm == ima_shash_tfm) + return; + + for (i = 0; i < NR_BANKS(ima_tpm_chip) + ima_extra_slots; i++) + if (ima_algo_array[i].tfm == tfm) + return; + + crypto_free_shash(tfm); +} + +/** + * ima_alloc_pages() - Allocate contiguous pages. + * @max_size: Maximum amount of memory to allocate. + * @allocated_size: Returned size of actual allocation. + * @last_warn: Should the min_size allocation warn or not. + * + * Tries to do opportunistic allocation for memory first trying to allocate + * max_size amount of memory and then splitting that until zero order is + * reached. Allocation is tried without generating allocation warnings unless + * last_warn is set. Last_warn set affects only last allocation of zero order. + * + * By default, ima_maxorder is 0 and it is equivalent to kmalloc(GFP_KERNEL) + * + * Return pointer to allocated memory, or NULL on failure. + */ +static void *ima_alloc_pages(loff_t max_size, size_t *allocated_size, + int last_warn) +{ + void *ptr; + int order = ima_maxorder; + gfp_t gfp_mask = __GFP_RECLAIM | __GFP_NOWARN | __GFP_NORETRY; + + if (order) + order = min(get_order(max_size), order); + + for (; order; order--) { + ptr = (void *)__get_free_pages(gfp_mask, order); + if (ptr) { + *allocated_size = PAGE_SIZE << order; + return ptr; + } + } + + /* order is zero - one page */ + + gfp_mask = GFP_KERNEL; + + if (!last_warn) + gfp_mask |= __GFP_NOWARN; + + ptr = (void *)__get_free_pages(gfp_mask, 0); + if (ptr) { + *allocated_size = PAGE_SIZE; + return ptr; + } + + *allocated_size = 0; + return NULL; +} + +/** + * ima_free_pages() - Free pages allocated by ima_alloc_pages(). + * @ptr: Pointer to allocated pages. + * @size: Size of allocated buffer. + */ +static void ima_free_pages(void *ptr, size_t size) +{ + if (!ptr) + return; + free_pages((unsigned long)ptr, get_order(size)); +} + +static struct crypto_ahash *ima_alloc_atfm(enum hash_algo algo) +{ + struct crypto_ahash *tfm = ima_ahash_tfm; + int rc; + + if (algo < 0 || algo >= HASH_ALGO__LAST) + algo = ima_hash_algo; + + if (algo != ima_hash_algo || !tfm) { + tfm = crypto_alloc_ahash(hash_algo_name[algo], 0, 0); + if (!IS_ERR(tfm)) { + if (algo == ima_hash_algo) + ima_ahash_tfm = tfm; + } else { + rc = PTR_ERR(tfm); + pr_err("Can not allocate %s (reason: %d)\n", + hash_algo_name[algo], rc); + } + } + return tfm; +} + +static void ima_free_atfm(struct crypto_ahash *tfm) +{ + if (tfm != ima_ahash_tfm) + crypto_free_ahash(tfm); +} + +static inline int ahash_wait(int err, struct crypto_wait *wait) +{ + + err = crypto_wait_req(err, wait); + + if (err) + pr_crit_ratelimited("ahash calculation failed: err: %d\n", err); + + return err; +} + +static int ima_calc_file_hash_atfm(struct file *file, + struct ima_digest_data *hash, + struct crypto_ahash *tfm) +{ + loff_t i_size, offset; + char *rbuf[2] = { NULL, }; + int rc, rbuf_len, active = 0, ahash_rc = 0; + struct ahash_request *req; + struct scatterlist sg[1]; + struct crypto_wait wait; + size_t rbuf_size[2]; + + hash->length = crypto_ahash_digestsize(tfm); + + req = ahash_request_alloc(tfm, GFP_KERNEL); + if (!req) + return -ENOMEM; + + crypto_init_wait(&wait); + ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG | + CRYPTO_TFM_REQ_MAY_SLEEP, + crypto_req_done, &wait); + + rc = ahash_wait(crypto_ahash_init(req), &wait); + if (rc) + goto out1; + + i_size = i_size_read(file_inode(file)); + + if (i_size == 0) + goto out2; + + /* + * Try to allocate maximum size of memory. + * Fail if even a single page cannot be allocated. + */ + rbuf[0] = ima_alloc_pages(i_size, &rbuf_size[0], 1); + if (!rbuf[0]) { + rc = -ENOMEM; + goto out1; + } + + /* Only allocate one buffer if that is enough. */ + if (i_size > rbuf_size[0]) { + /* + * Try to allocate secondary buffer. If that fails fallback to + * using single buffering. Use previous memory allocation size + * as baseline for possible allocation size. + */ + rbuf[1] = ima_alloc_pages(i_size - rbuf_size[0], + &rbuf_size[1], 0); + } + + for (offset = 0; offset < i_size; offset += rbuf_len) { + if (!rbuf[1] && offset) { + /* Not using two buffers, and it is not the first + * read/request, wait for the completion of the + * previous ahash_update() request. + */ + rc = ahash_wait(ahash_rc, &wait); + if (rc) + goto out3; + } + /* read buffer */ + rbuf_len = min_t(loff_t, i_size - offset, rbuf_size[active]); + rc = integrity_kernel_read(file, offset, rbuf[active], + rbuf_len); + if (rc != rbuf_len) { + if (rc >= 0) + rc = -EINVAL; + /* + * Forward current rc, do not overwrite with return value + * from ahash_wait() + */ + ahash_wait(ahash_rc, &wait); + goto out3; + } + + if (rbuf[1] && offset) { + /* Using two buffers, and it is not the first + * read/request, wait for the completion of the + * previous ahash_update() request. + */ + rc = ahash_wait(ahash_rc, &wait); + if (rc) + goto out3; + } + + sg_init_one(&sg[0], rbuf[active], rbuf_len); + ahash_request_set_crypt(req, sg, NULL, rbuf_len); + + ahash_rc = crypto_ahash_update(req); + + if (rbuf[1]) + active = !active; /* swap buffers, if we use two */ + } + /* wait for the last update request to complete */ + rc = ahash_wait(ahash_rc, &wait); +out3: + ima_free_pages(rbuf[0], rbuf_size[0]); + ima_free_pages(rbuf[1], rbuf_size[1]); +out2: + if (!rc) { + ahash_request_set_crypt(req, NULL, hash->digest, 0); + rc = ahash_wait(crypto_ahash_final(req), &wait); + } +out1: + ahash_request_free(req); + return rc; +} + +static int ima_calc_file_ahash(struct file *file, struct ima_digest_data *hash) +{ + struct crypto_ahash *tfm; + int rc; + + tfm = ima_alloc_atfm(hash->algo); + if (IS_ERR(tfm)) + return PTR_ERR(tfm); + + rc = ima_calc_file_hash_atfm(file, hash, tfm); + + ima_free_atfm(tfm); + + return rc; +} + +static int ima_calc_file_hash_tfm(struct file *file, + struct ima_digest_data *hash, + struct crypto_shash *tfm) +{ + loff_t i_size, offset = 0; + char *rbuf; + int rc; + SHASH_DESC_ON_STACK(shash, tfm); + + shash->tfm = tfm; + + hash->length = crypto_shash_digestsize(tfm); + + rc = crypto_shash_init(shash); + if (rc != 0) + return rc; + + i_size = i_size_read(file_inode(file)); + + if (i_size == 0) + goto out; + + rbuf = kzalloc(PAGE_SIZE, GFP_KERNEL); + if (!rbuf) + return -ENOMEM; + + while (offset < i_size) { + int rbuf_len; + + rbuf_len = integrity_kernel_read(file, offset, rbuf, PAGE_SIZE); + if (rbuf_len < 0) { + rc = rbuf_len; + break; + } + if (rbuf_len == 0) { /* unexpected EOF */ + rc = -EINVAL; + break; + } + offset += rbuf_len; + + rc = crypto_shash_update(shash, rbuf, rbuf_len); + if (rc) + break; + } + kfree(rbuf); +out: + if (!rc) + rc = crypto_shash_final(shash, hash->digest); + return rc; +} + +static int ima_calc_file_shash(struct file *file, struct ima_digest_data *hash) +{ + struct crypto_shash *tfm; + int rc; + + tfm = ima_alloc_tfm(hash->algo); + if (IS_ERR(tfm)) + return PTR_ERR(tfm); + + rc = ima_calc_file_hash_tfm(file, hash, tfm); + + ima_free_tfm(tfm); + + return rc; +} + +/* + * ima_calc_file_hash - calculate file hash + * + * Asynchronous hash (ahash) allows using HW acceleration for calculating + * a hash. ahash performance varies for different data sizes on different + * crypto accelerators. shash performance might be better for smaller files. + * The 'ima.ahash_minsize' module parameter allows specifying the best + * minimum file size for using ahash on the system. + * + * If the ima.ahash_minsize parameter is not specified, this function uses + * shash for the hash calculation. If ahash fails, it falls back to using + * shash. + */ +int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash) +{ + loff_t i_size; + int rc; + struct file *f = file; + bool new_file_instance = false; + + /* + * For consistency, fail file's opened with the O_DIRECT flag on + * filesystems mounted with/without DAX option. + */ + if (file->f_flags & O_DIRECT) { + hash->length = hash_digest_size[ima_hash_algo]; + hash->algo = ima_hash_algo; + return -EINVAL; + } + + /* Open a new file instance in O_RDONLY if we cannot read */ + if (!(file->f_mode & FMODE_READ)) { + int flags = file->f_flags & ~(O_WRONLY | O_APPEND | + O_TRUNC | O_CREAT | O_NOCTTY | O_EXCL); + flags |= O_RDONLY; + f = dentry_open(&file->f_path, flags, file->f_cred); + if (IS_ERR(f)) + return PTR_ERR(f); + + new_file_instance = true; + } + + i_size = i_size_read(file_inode(f)); + + if (ima_ahash_minsize && i_size >= ima_ahash_minsize) { + rc = ima_calc_file_ahash(f, hash); + if (!rc) + goto out; + } + + rc = ima_calc_file_shash(f, hash); +out: + if (new_file_instance) + fput(f); + return rc; +} + +/* + * Calculate the hash of template data + */ +static int ima_calc_field_array_hash_tfm(struct ima_field_data *field_data, + struct ima_template_entry *entry, + int tfm_idx) +{ + SHASH_DESC_ON_STACK(shash, ima_algo_array[tfm_idx].tfm); + struct ima_template_desc *td = entry->template_desc; + int num_fields = entry->template_desc->num_fields; + int rc, i; + + shash->tfm = ima_algo_array[tfm_idx].tfm; + + rc = crypto_shash_init(shash); + if (rc != 0) + return rc; + + for (i = 0; i < num_fields; i++) { + u8 buffer[IMA_EVENT_NAME_LEN_MAX + 1] = { 0 }; + u8 *data_to_hash = field_data[i].data; + u32 datalen = field_data[i].len; + u32 datalen_to_hash = !ima_canonical_fmt ? + datalen : (__force u32)cpu_to_le32(datalen); + + if (strcmp(td->name, IMA_TEMPLATE_IMA_NAME) != 0) { + rc = crypto_shash_update(shash, + (const u8 *) &datalen_to_hash, + sizeof(datalen_to_hash)); + if (rc) + break; + } else if (strcmp(td->fields[i]->field_id, "n") == 0) { + memcpy(buffer, data_to_hash, datalen); + data_to_hash = buffer; + datalen = IMA_EVENT_NAME_LEN_MAX + 1; + } + rc = crypto_shash_update(shash, data_to_hash, datalen); + if (rc) + break; + } + + if (!rc) + rc = crypto_shash_final(shash, entry->digests[tfm_idx].digest); + + return rc; +} + +int ima_calc_field_array_hash(struct ima_field_data *field_data, + struct ima_template_entry *entry) +{ + u16 alg_id; + int rc, i; + + rc = ima_calc_field_array_hash_tfm(field_data, entry, ima_sha1_idx); + if (rc) + return rc; + + entry->digests[ima_sha1_idx].alg_id = TPM_ALG_SHA1; + + for (i = 0; i < NR_BANKS(ima_tpm_chip) + ima_extra_slots; i++) { + if (i == ima_sha1_idx) + continue; + + if (i < NR_BANKS(ima_tpm_chip)) { + alg_id = ima_tpm_chip->allocated_banks[i].alg_id; + entry->digests[i].alg_id = alg_id; + } + + /* for unmapped TPM algorithms digest is still a padded SHA1 */ + if (!ima_algo_array[i].tfm) { + memcpy(entry->digests[i].digest, + entry->digests[ima_sha1_idx].digest, + TPM_DIGEST_SIZE); + continue; + } + + rc = ima_calc_field_array_hash_tfm(field_data, entry, i); + if (rc) + return rc; + } + return rc; +} + +static int calc_buffer_ahash_atfm(const void *buf, loff_t len, + struct ima_digest_data *hash, + struct crypto_ahash *tfm) +{ + struct ahash_request *req; + struct scatterlist sg; + struct crypto_wait wait; + int rc, ahash_rc = 0; + + hash->length = crypto_ahash_digestsize(tfm); + + req = ahash_request_alloc(tfm, GFP_KERNEL); + if (!req) + return -ENOMEM; + + crypto_init_wait(&wait); + ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG | + CRYPTO_TFM_REQ_MAY_SLEEP, + crypto_req_done, &wait); + + rc = ahash_wait(crypto_ahash_init(req), &wait); + if (rc) + goto out; + + sg_init_one(&sg, buf, len); + ahash_request_set_crypt(req, &sg, NULL, len); + + ahash_rc = crypto_ahash_update(req); + + /* wait for the update request to complete */ + rc = ahash_wait(ahash_rc, &wait); + if (!rc) { + ahash_request_set_crypt(req, NULL, hash->digest, 0); + rc = ahash_wait(crypto_ahash_final(req), &wait); + } +out: + ahash_request_free(req); + return rc; +} + +static int calc_buffer_ahash(const void *buf, loff_t len, + struct ima_digest_data *hash) +{ + struct crypto_ahash *tfm; + int rc; + + tfm = ima_alloc_atfm(hash->algo); + if (IS_ERR(tfm)) + return PTR_ERR(tfm); + + rc = calc_buffer_ahash_atfm(buf, len, hash, tfm); + + ima_free_atfm(tfm); + + return rc; +} + +static int calc_buffer_shash_tfm(const void *buf, loff_t size, + struct ima_digest_data *hash, + struct crypto_shash *tfm) +{ + SHASH_DESC_ON_STACK(shash, tfm); + unsigned int len; + int rc; + + shash->tfm = tfm; + + hash->length = crypto_shash_digestsize(tfm); + + rc = crypto_shash_init(shash); + if (rc != 0) + return rc; + + while (size) { + len = size < PAGE_SIZE ? size : PAGE_SIZE; + rc = crypto_shash_update(shash, buf, len); + if (rc) + break; + buf += len; + size -= len; + } + + if (!rc) + rc = crypto_shash_final(shash, hash->digest); + return rc; +} + +static int calc_buffer_shash(const void *buf, loff_t len, + struct ima_digest_data *hash) +{ + struct crypto_shash *tfm; + int rc; + + tfm = ima_alloc_tfm(hash->algo); + if (IS_ERR(tfm)) + return PTR_ERR(tfm); + + rc = calc_buffer_shash_tfm(buf, len, hash, tfm); + + ima_free_tfm(tfm); + return rc; +} + +int ima_calc_buffer_hash(const void *buf, loff_t len, + struct ima_digest_data *hash) +{ + int rc; + + if (ima_ahash_minsize && len >= ima_ahash_minsize) { + rc = calc_buffer_ahash(buf, len, hash); + if (!rc) + return 0; + } + + return calc_buffer_shash(buf, len, hash); +} + +static void ima_pcrread(u32 idx, struct tpm_digest *d) +{ + if (!ima_tpm_chip) + return; + + if (tpm_pcr_read(ima_tpm_chip, idx, d) != 0) + pr_err("Error Communicating to TPM chip\n"); +} + +/* + * The boot_aggregate is a cumulative hash over TPM registers 0 - 7. With + * TPM 1.2 the boot_aggregate was based on reading the SHA1 PCRs, but with + * TPM 2.0 hash agility, TPM chips could support multiple TPM PCR banks, + * allowing firmware to configure and enable different banks. + * + * Knowing which TPM bank is read to calculate the boot_aggregate digest + * needs to be conveyed to a verifier. For this reason, use the same + * hash algorithm for reading the TPM PCRs as for calculating the boot + * aggregate digest as stored in the measurement list. + */ +static int ima_calc_boot_aggregate_tfm(char *digest, u16 alg_id, + struct crypto_shash *tfm) +{ + struct tpm_digest d = { .alg_id = alg_id, .digest = {0} }; + int rc; + u32 i; + SHASH_DESC_ON_STACK(shash, tfm); + + shash->tfm = tfm; + + pr_devel("calculating the boot-aggregate based on TPM bank: %04x\n", + d.alg_id); + + rc = crypto_shash_init(shash); + if (rc != 0) + return rc; + + /* cumulative digest over TPM registers 0-7 */ + for (i = TPM_PCR0; i < TPM_PCR8; i++) { + ima_pcrread(i, &d); + /* now accumulate with current aggregate */ + rc = crypto_shash_update(shash, d.digest, + crypto_shash_digestsize(tfm)); + if (rc != 0) + return rc; + } + /* + * Extend cumulative digest over TPM registers 8-9, which contain + * measurement for the kernel command line (reg. 8) and image (reg. 9) + * in a typical PCR allocation. Registers 8-9 are only included in + * non-SHA1 boot_aggregate digests to avoid ambiguity. + */ + if (alg_id != TPM_ALG_SHA1) { + for (i = TPM_PCR8; i < TPM_PCR10; i++) { + ima_pcrread(i, &d); + rc = crypto_shash_update(shash, d.digest, + crypto_shash_digestsize(tfm)); + } + } + if (!rc) + crypto_shash_final(shash, digest); + return rc; +} + +int ima_calc_boot_aggregate(struct ima_digest_data *hash) +{ + struct crypto_shash *tfm; + u16 crypto_id, alg_id; + int rc, i, bank_idx = -1; + + for (i = 0; i < ima_tpm_chip->nr_allocated_banks; i++) { + crypto_id = ima_tpm_chip->allocated_banks[i].crypto_id; + if (crypto_id == hash->algo) { + bank_idx = i; + break; + } + + if (crypto_id == HASH_ALGO_SHA256) + bank_idx = i; + + if (bank_idx == -1 && crypto_id == HASH_ALGO_SHA1) + bank_idx = i; + } + + if (bank_idx == -1) { + pr_err("No suitable TPM algorithm for boot aggregate\n"); + return 0; + } + + hash->algo = ima_tpm_chip->allocated_banks[bank_idx].crypto_id; + + tfm = ima_alloc_tfm(hash->algo); + if (IS_ERR(tfm)) + return PTR_ERR(tfm); + + hash->length = crypto_shash_digestsize(tfm); + alg_id = ima_tpm_chip->allocated_banks[bank_idx].alg_id; + rc = ima_calc_boot_aggregate_tfm(hash->digest, alg_id, tfm); + + ima_free_tfm(tfm); + + return rc; +} diff --git a/security/integrity/ima/ima_efi.c b/security/integrity/ima/ima_efi.c new file mode 100644 index 000000000..9db66fe31 --- /dev/null +++ b/security/integrity/ima/ima_efi.c @@ -0,0 +1,75 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Copyright (C) 2018 IBM Corporation + */ +#include <linux/efi.h> +#include <linux/module.h> +#include <linux/ima.h> +#include <asm/efi.h> + +#ifndef arch_ima_efi_boot_mode +#define arch_ima_efi_boot_mode efi_secureboot_mode_unset +#endif + +static enum efi_secureboot_mode get_sb_mode(void) +{ + enum efi_secureboot_mode mode; + + if (!efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE)) { + pr_info("ima: secureboot mode unknown, no efi\n"); + return efi_secureboot_mode_unknown; + } + + mode = efi_get_secureboot_mode(efi.get_variable); + if (mode == efi_secureboot_mode_disabled) + pr_info("ima: secureboot mode disabled\n"); + else if (mode == efi_secureboot_mode_unknown) + pr_info("ima: secureboot mode unknown\n"); + else + pr_info("ima: secureboot mode enabled\n"); + return mode; +} + +bool arch_ima_get_secureboot(void) +{ + static enum efi_secureboot_mode sb_mode; + static bool initialized; + + if (!initialized && efi_enabled(EFI_BOOT)) { + sb_mode = arch_ima_efi_boot_mode; + + if (sb_mode == efi_secureboot_mode_unset) + sb_mode = get_sb_mode(); + initialized = true; + } + + if (sb_mode == efi_secureboot_mode_enabled) + return true; + else + return false; +} + +/* secureboot arch rules */ +static const char * const sb_arch_rules[] = { +#if !IS_ENABLED(CONFIG_KEXEC_SIG) + "appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig", +#endif /* CONFIG_KEXEC_SIG */ + "measure func=KEXEC_KERNEL_CHECK", +#if !IS_ENABLED(CONFIG_MODULE_SIG) + "appraise func=MODULE_CHECK appraise_type=imasig", +#endif + "measure func=MODULE_CHECK", + NULL +}; + +const char * const *arch_get_ima_policy(void) +{ + if (IS_ENABLED(CONFIG_IMA_ARCH_POLICY) && arch_ima_get_secureboot()) { + if (IS_ENABLED(CONFIG_MODULE_SIG)) + set_module_sig_enforced(); + if (IS_ENABLED(CONFIG_KEXEC_SIG)) + set_kexec_sig_enforced(); + return sb_arch_rules; + } + return NULL; +} diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c new file mode 100644 index 000000000..cd1683dad --- /dev/null +++ b/security/integrity/ima/ima_fs.c @@ -0,0 +1,522 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2005,2006,2007,2008 IBM Corporation + * + * Authors: + * Kylene Hall <kjhall@us.ibm.com> + * Reiner Sailer <sailer@us.ibm.com> + * Mimi Zohar <zohar@us.ibm.com> + * + * File: ima_fs.c + * implemenents security file system for reporting + * current measurement list and IMA statistics + */ + +#include <linux/fcntl.h> +#include <linux/kernel_read_file.h> +#include <linux/slab.h> +#include <linux/init.h> +#include <linux/seq_file.h> +#include <linux/rculist.h> +#include <linux/rcupdate.h> +#include <linux/parser.h> +#include <linux/vmalloc.h> + +#include "ima.h" + +static DEFINE_MUTEX(ima_write_mutex); + +bool ima_canonical_fmt; +static int __init default_canonical_fmt_setup(char *str) +{ +#ifdef __BIG_ENDIAN + ima_canonical_fmt = true; +#endif + return 1; +} +__setup("ima_canonical_fmt", default_canonical_fmt_setup); + +static int valid_policy = 1; + +static ssize_t ima_show_htable_value(char __user *buf, size_t count, + loff_t *ppos, atomic_long_t *val) +{ + char tmpbuf[32]; /* greater than largest 'long' string value */ + ssize_t len; + + len = scnprintf(tmpbuf, sizeof(tmpbuf), "%li\n", atomic_long_read(val)); + return simple_read_from_buffer(buf, count, ppos, tmpbuf, len); +} + +static ssize_t ima_show_htable_violations(struct file *filp, + char __user *buf, + size_t count, loff_t *ppos) +{ + return ima_show_htable_value(buf, count, ppos, &ima_htable.violations); +} + +static const struct file_operations ima_htable_violations_ops = { + .read = ima_show_htable_violations, + .llseek = generic_file_llseek, +}; + +static ssize_t ima_show_measurements_count(struct file *filp, + char __user *buf, + size_t count, loff_t *ppos) +{ + return ima_show_htable_value(buf, count, ppos, &ima_htable.len); + +} + +static const struct file_operations ima_measurements_count_ops = { + .read = ima_show_measurements_count, + .llseek = generic_file_llseek, +}; + +/* returns pointer to hlist_node */ +static void *ima_measurements_start(struct seq_file *m, loff_t *pos) +{ + loff_t l = *pos; + struct ima_queue_entry *qe; + + /* we need a lock since pos could point beyond last element */ + rcu_read_lock(); + list_for_each_entry_rcu(qe, &ima_measurements, later) { + if (!l--) { + rcu_read_unlock(); + return qe; + } + } + rcu_read_unlock(); + return NULL; +} + +static void *ima_measurements_next(struct seq_file *m, void *v, loff_t *pos) +{ + struct ima_queue_entry *qe = v; + + /* lock protects when reading beyond last element + * against concurrent list-extension + */ + rcu_read_lock(); + qe = list_entry_rcu(qe->later.next, struct ima_queue_entry, later); + rcu_read_unlock(); + (*pos)++; + + return (&qe->later == &ima_measurements) ? NULL : qe; +} + +static void ima_measurements_stop(struct seq_file *m, void *v) +{ +} + +void ima_putc(struct seq_file *m, void *data, int datalen) +{ + while (datalen--) + seq_putc(m, *(char *)data++); +} + +/* print format: + * 32bit-le=pcr# + * char[20]=template digest + * 32bit-le=template name size + * char[n]=template name + * [eventdata length] + * eventdata[n]=template specific data + */ +int ima_measurements_show(struct seq_file *m, void *v) +{ + /* the list never shrinks, so we don't need a lock here */ + struct ima_queue_entry *qe = v; + struct ima_template_entry *e; + char *template_name; + u32 pcr, namelen, template_data_len; /* temporary fields */ + bool is_ima_template = false; + int i; + + /* get entry */ + e = qe->entry; + if (e == NULL) + return -1; + + template_name = (e->template_desc->name[0] != '\0') ? + e->template_desc->name : e->template_desc->fmt; + + /* + * 1st: PCRIndex + * PCR used defaults to the same (config option) in + * little-endian format, unless set in policy + */ + pcr = !ima_canonical_fmt ? e->pcr : (__force u32)cpu_to_le32(e->pcr); + ima_putc(m, &pcr, sizeof(e->pcr)); + + /* 2nd: template digest */ + ima_putc(m, e->digests[ima_sha1_idx].digest, TPM_DIGEST_SIZE); + + /* 3rd: template name size */ + namelen = !ima_canonical_fmt ? strlen(template_name) : + (__force u32)cpu_to_le32(strlen(template_name)); + ima_putc(m, &namelen, sizeof(namelen)); + + /* 4th: template name */ + ima_putc(m, template_name, strlen(template_name)); + + /* 5th: template length (except for 'ima' template) */ + if (strcmp(template_name, IMA_TEMPLATE_IMA_NAME) == 0) + is_ima_template = true; + + if (!is_ima_template) { + template_data_len = !ima_canonical_fmt ? e->template_data_len : + (__force u32)cpu_to_le32(e->template_data_len); + ima_putc(m, &template_data_len, sizeof(e->template_data_len)); + } + + /* 6th: template specific data */ + for (i = 0; i < e->template_desc->num_fields; i++) { + enum ima_show_type show = IMA_SHOW_BINARY; + const struct ima_template_field *field = + e->template_desc->fields[i]; + + if (is_ima_template && strcmp(field->field_id, "d") == 0) + show = IMA_SHOW_BINARY_NO_FIELD_LEN; + if (is_ima_template && strcmp(field->field_id, "n") == 0) + show = IMA_SHOW_BINARY_OLD_STRING_FMT; + field->field_show(m, show, &e->template_data[i]); + } + return 0; +} + +static const struct seq_operations ima_measurments_seqops = { + .start = ima_measurements_start, + .next = ima_measurements_next, + .stop = ima_measurements_stop, + .show = ima_measurements_show +}; + +static int ima_measurements_open(struct inode *inode, struct file *file) +{ + return seq_open(file, &ima_measurments_seqops); +} + +static const struct file_operations ima_measurements_ops = { + .open = ima_measurements_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; + +void ima_print_digest(struct seq_file *m, u8 *digest, u32 size) +{ + u32 i; + + for (i = 0; i < size; i++) + seq_printf(m, "%02x", *(digest + i)); +} + +/* print in ascii */ +static int ima_ascii_measurements_show(struct seq_file *m, void *v) +{ + /* the list never shrinks, so we don't need a lock here */ + struct ima_queue_entry *qe = v; + struct ima_template_entry *e; + char *template_name; + int i; + + /* get entry */ + e = qe->entry; + if (e == NULL) + return -1; + + template_name = (e->template_desc->name[0] != '\0') ? + e->template_desc->name : e->template_desc->fmt; + + /* 1st: PCR used (config option) */ + seq_printf(m, "%2d ", e->pcr); + + /* 2nd: SHA1 template hash */ + ima_print_digest(m, e->digests[ima_sha1_idx].digest, TPM_DIGEST_SIZE); + + /* 3th: template name */ + seq_printf(m, " %s", template_name); + + /* 4th: template specific data */ + for (i = 0; i < e->template_desc->num_fields; i++) { + seq_puts(m, " "); + if (e->template_data[i].len == 0) + continue; + + e->template_desc->fields[i]->field_show(m, IMA_SHOW_ASCII, + &e->template_data[i]); + } + seq_puts(m, "\n"); + return 0; +} + +static const struct seq_operations ima_ascii_measurements_seqops = { + .start = ima_measurements_start, + .next = ima_measurements_next, + .stop = ima_measurements_stop, + .show = ima_ascii_measurements_show +}; + +static int ima_ascii_measurements_open(struct inode *inode, struct file *file) +{ + return seq_open(file, &ima_ascii_measurements_seqops); +} + +static const struct file_operations ima_ascii_measurements_ops = { + .open = ima_ascii_measurements_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; + +static ssize_t ima_read_policy(char *path) +{ + void *data = NULL; + char *datap; + size_t size; + int rc, pathlen = strlen(path); + + char *p; + + /* remove \n */ + datap = path; + strsep(&datap, "\n"); + + rc = kernel_read_file_from_path(path, 0, &data, INT_MAX, NULL, + READING_POLICY); + if (rc < 0) { + pr_err("Unable to open file: %s (%d)", path, rc); + return rc; + } + size = rc; + rc = 0; + + datap = data; + while (size > 0 && (p = strsep(&datap, "\n"))) { + pr_debug("rule: %s\n", p); + rc = ima_parse_add_rule(p); + if (rc < 0) + break; + size -= rc; + } + + vfree(data); + if (rc < 0) + return rc; + else if (size) + return -EINVAL; + else + return pathlen; +} + +static ssize_t ima_write_policy(struct file *file, const char __user *buf, + size_t datalen, loff_t *ppos) +{ + char *data; + ssize_t result; + + if (datalen >= PAGE_SIZE) + datalen = PAGE_SIZE - 1; + + /* No partial writes. */ + result = -EINVAL; + if (*ppos != 0) + goto out; + + data = memdup_user_nul(buf, datalen); + if (IS_ERR(data)) { + result = PTR_ERR(data); + goto out; + } + + result = mutex_lock_interruptible(&ima_write_mutex); + if (result < 0) + goto out_free; + + if (data[0] == '/') { + result = ima_read_policy(data); + } else if (ima_appraise & IMA_APPRAISE_POLICY) { + pr_err("signed policy file (specified as an absolute pathname) required\n"); + integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL, NULL, + "policy_update", "signed policy required", + 1, 0); + result = -EACCES; + } else { + result = ima_parse_add_rule(data); + } + mutex_unlock(&ima_write_mutex); +out_free: + kfree(data); +out: + if (result < 0) + valid_policy = 0; + + return result; +} + +static struct dentry *ima_dir; +static struct dentry *ima_symlink; +static struct dentry *binary_runtime_measurements; +static struct dentry *ascii_runtime_measurements; +static struct dentry *runtime_measurements_count; +static struct dentry *violations; +static struct dentry *ima_policy; + +enum ima_fs_flags { + IMA_FS_BUSY, +}; + +static unsigned long ima_fs_flags; + +#ifdef CONFIG_IMA_READ_POLICY +static const struct seq_operations ima_policy_seqops = { + .start = ima_policy_start, + .next = ima_policy_next, + .stop = ima_policy_stop, + .show = ima_policy_show, +}; +#endif + +/* + * ima_open_policy: sequentialize access to the policy file + */ +static int ima_open_policy(struct inode *inode, struct file *filp) +{ + if (!(filp->f_flags & O_WRONLY)) { +#ifndef CONFIG_IMA_READ_POLICY + return -EACCES; +#else + if ((filp->f_flags & O_ACCMODE) != O_RDONLY) + return -EACCES; + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + return seq_open(filp, &ima_policy_seqops); +#endif + } + if (test_and_set_bit(IMA_FS_BUSY, &ima_fs_flags)) + return -EBUSY; + return 0; +} + +/* + * ima_release_policy - start using the new measure policy rules. + * + * Initially, ima_measure points to the default policy rules, now + * point to the new policy rules, and remove the securityfs policy file, + * assuming a valid policy. + */ +static int ima_release_policy(struct inode *inode, struct file *file) +{ + const char *cause = valid_policy ? "completed" : "failed"; + + if ((file->f_flags & O_ACCMODE) == O_RDONLY) + return seq_release(inode, file); + + if (valid_policy && ima_check_policy() < 0) { + cause = "failed"; + valid_policy = 0; + } + + pr_info("policy update %s\n", cause); + integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL, NULL, + "policy_update", cause, !valid_policy, 0); + + if (!valid_policy) { + ima_delete_rules(); + valid_policy = 1; + clear_bit(IMA_FS_BUSY, &ima_fs_flags); + return 0; + } + + ima_update_policy(); +#if !defined(CONFIG_IMA_WRITE_POLICY) && !defined(CONFIG_IMA_READ_POLICY) + securityfs_remove(ima_policy); + ima_policy = NULL; +#elif defined(CONFIG_IMA_WRITE_POLICY) + clear_bit(IMA_FS_BUSY, &ima_fs_flags); +#elif defined(CONFIG_IMA_READ_POLICY) + inode->i_mode &= ~S_IWUSR; +#endif + return 0; +} + +static const struct file_operations ima_measure_policy_ops = { + .open = ima_open_policy, + .write = ima_write_policy, + .read = seq_read, + .release = ima_release_policy, + .llseek = generic_file_llseek, +}; + +int __init ima_fs_init(void) +{ + int ret; + + ima_dir = securityfs_create_dir("ima", integrity_dir); + if (IS_ERR(ima_dir)) + return PTR_ERR(ima_dir); + + ima_symlink = securityfs_create_symlink("ima", NULL, "integrity/ima", + NULL); + if (IS_ERR(ima_symlink)) { + ret = PTR_ERR(ima_symlink); + goto out; + } + + binary_runtime_measurements = + securityfs_create_file("binary_runtime_measurements", + S_IRUSR | S_IRGRP, ima_dir, NULL, + &ima_measurements_ops); + if (IS_ERR(binary_runtime_measurements)) { + ret = PTR_ERR(binary_runtime_measurements); + goto out; + } + + ascii_runtime_measurements = + securityfs_create_file("ascii_runtime_measurements", + S_IRUSR | S_IRGRP, ima_dir, NULL, + &ima_ascii_measurements_ops); + if (IS_ERR(ascii_runtime_measurements)) { + ret = PTR_ERR(ascii_runtime_measurements); + goto out; + } + + runtime_measurements_count = + securityfs_create_file("runtime_measurements_count", + S_IRUSR | S_IRGRP, ima_dir, NULL, + &ima_measurements_count_ops); + if (IS_ERR(runtime_measurements_count)) { + ret = PTR_ERR(runtime_measurements_count); + goto out; + } + + violations = + securityfs_create_file("violations", S_IRUSR | S_IRGRP, + ima_dir, NULL, &ima_htable_violations_ops); + if (IS_ERR(violations)) { + ret = PTR_ERR(violations); + goto out; + } + + ima_policy = securityfs_create_file("policy", POLICY_FILE_FLAGS, + ima_dir, NULL, + &ima_measure_policy_ops); + if (IS_ERR(ima_policy)) { + ret = PTR_ERR(ima_policy); + goto out; + } + + return 0; +out: + securityfs_remove(ima_policy); + securityfs_remove(violations); + securityfs_remove(runtime_measurements_count); + securityfs_remove(ascii_runtime_measurements); + securityfs_remove(binary_runtime_measurements); + securityfs_remove(ima_symlink); + securityfs_remove(ima_dir); + + return ret; +} diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c new file mode 100644 index 000000000..63979aefc --- /dev/null +++ b/security/integrity/ima/ima_init.c @@ -0,0 +1,158 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2005,2006,2007,2008 IBM Corporation + * + * Authors: + * Reiner Sailer <sailer@watson.ibm.com> + * Leendert van Doorn <leendert@watson.ibm.com> + * Mimi Zohar <zohar@us.ibm.com> + * + * File: ima_init.c + * initialization and cleanup functions + */ + +#include <linux/init.h> +#include <linux/scatterlist.h> +#include <linux/slab.h> +#include <linux/err.h> +#include <linux/ima.h> +#include <generated/utsrelease.h> + +#include "ima.h" + +/* name for boot aggregate entry */ +const char boot_aggregate_name[] = "boot_aggregate"; +struct tpm_chip *ima_tpm_chip; + +/* Add the boot aggregate to the IMA measurement list and extend + * the PCR register. + * + * Calculate the boot aggregate, a hash over tpm registers 0-7, + * assuming a TPM chip exists, and zeroes if the TPM chip does not + * exist. Add the boot aggregate measurement to the measurement + * list and extend the PCR register. + * + * If a tpm chip does not exist, indicate the core root of trust is + * not hardware based by invalidating the aggregate PCR value. + * (The aggregate PCR value is invalidated by adding one value to + * the measurement list and extending the aggregate PCR value with + * a different value.) Violations add a zero entry to the measurement + * list and extend the aggregate PCR value with ff...ff's. + */ +static int __init ima_add_boot_aggregate(void) +{ + static const char op[] = "add_boot_aggregate"; + const char *audit_cause = "ENOMEM"; + struct ima_template_entry *entry; + struct integrity_iint_cache tmp_iint, *iint = &tmp_iint; + struct ima_event_data event_data = { .iint = iint, + .filename = boot_aggregate_name }; + struct ima_max_digest_data hash; + int result = -ENOMEM; + int violation = 0; + + memset(iint, 0, sizeof(*iint)); + memset(&hash, 0, sizeof(hash)); + iint->ima_hash = &hash.hdr; + iint->ima_hash->algo = ima_hash_algo; + iint->ima_hash->length = hash_digest_size[ima_hash_algo]; + + /* + * With TPM 2.0 hash agility, TPM chips could support multiple TPM + * PCR banks, allowing firmware to configure and enable different + * banks. The SHA1 bank is not necessarily enabled. + * + * Use the same hash algorithm for reading the TPM PCRs as for + * calculating the boot aggregate digest. Preference is given to + * the configured IMA default hash algorithm. Otherwise, use the + * TCG required banks - SHA256 for TPM 2.0, SHA1 for TPM 1.2. + * Ultimately select SHA1 also for TPM 2.0 if the SHA256 PCR bank + * is not found. + */ + if (ima_tpm_chip) { + result = ima_calc_boot_aggregate(&hash.hdr); + if (result < 0) { + audit_cause = "hashing_error"; + goto err_out; + } + } + + result = ima_alloc_init_template(&event_data, &entry, NULL); + if (result < 0) { + audit_cause = "alloc_entry"; + goto err_out; + } + + result = ima_store_template(entry, violation, NULL, + boot_aggregate_name, + CONFIG_IMA_MEASURE_PCR_IDX); + if (result < 0) { + ima_free_template_entry(entry); + audit_cause = "store_entry"; + goto err_out; + } + return 0; +err_out: + integrity_audit_msg(AUDIT_INTEGRITY_PCR, NULL, boot_aggregate_name, op, + audit_cause, result, 0); + return result; +} + +#ifdef CONFIG_IMA_LOAD_X509 +void __init ima_load_x509(void) +{ + int unset_flags = ima_policy_flag & IMA_APPRAISE; + + ima_policy_flag &= ~unset_flags; + integrity_load_x509(INTEGRITY_KEYRING_IMA, CONFIG_IMA_X509_PATH); + + /* load also EVM key to avoid appraisal */ + evm_load_x509(); + + ima_policy_flag |= unset_flags; +} +#endif + +int __init ima_init(void) +{ + int rc; + + ima_tpm_chip = tpm_default_chip(); + if (!ima_tpm_chip) + pr_info("No TPM chip found, activating TPM-bypass!\n"); + + rc = integrity_init_keyring(INTEGRITY_KEYRING_IMA); + if (rc) + return rc; + + rc = ima_init_crypto(); + if (rc) + return rc; + rc = ima_init_template(); + if (rc != 0) + return rc; + + /* It can be called before ima_init_digests(), it does not use TPM. */ + ima_load_kexec_buffer(); + + rc = ima_init_digests(); + if (rc != 0) + return rc; + rc = ima_add_boot_aggregate(); /* boot aggregate must be first entry */ + if (rc != 0) + return rc; + + ima_init_policy(); + + rc = ima_fs_init(); + if (rc != 0) + return rc; + + ima_init_key_queue(); + + ima_measure_critical_data("kernel_info", "kernel_version", + UTS_RELEASE, strlen(UTS_RELEASE), false, + NULL, 0); + + return rc; +} diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c new file mode 100644 index 000000000..419dc405c --- /dev/null +++ b/security/integrity/ima/ima_kexec.c @@ -0,0 +1,166 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2016 IBM Corporation + * + * Authors: + * Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com> + * Mimi Zohar <zohar@linux.vnet.ibm.com> + */ + +#include <linux/seq_file.h> +#include <linux/vmalloc.h> +#include <linux/kexec.h> +#include <linux/of.h> +#include <linux/ima.h> +#include "ima.h" + +#ifdef CONFIG_IMA_KEXEC +static int ima_dump_measurement_list(unsigned long *buffer_size, void **buffer, + unsigned long segment_size) +{ + struct ima_queue_entry *qe; + struct seq_file file; + struct ima_kexec_hdr khdr; + int ret = 0; + + /* segment size can't change between kexec load and execute */ + file.buf = vmalloc(segment_size); + if (!file.buf) { + ret = -ENOMEM; + goto out; + } + + file.size = segment_size; + file.read_pos = 0; + file.count = sizeof(khdr); /* reserved space */ + + memset(&khdr, 0, sizeof(khdr)); + khdr.version = 1; + list_for_each_entry_rcu(qe, &ima_measurements, later) { + if (file.count < file.size) { + khdr.count++; + ima_measurements_show(&file, qe); + } else { + ret = -EINVAL; + break; + } + } + + if (ret < 0) + goto out; + + /* + * fill in reserved space with some buffer details + * (eg. version, buffer size, number of measurements) + */ + khdr.buffer_size = file.count; + if (ima_canonical_fmt) { + khdr.version = cpu_to_le16(khdr.version); + khdr.count = cpu_to_le64(khdr.count); + khdr.buffer_size = cpu_to_le64(khdr.buffer_size); + } + memcpy(file.buf, &khdr, sizeof(khdr)); + + print_hex_dump_debug("ima dump: ", DUMP_PREFIX_NONE, 16, 1, + file.buf, file.count < 100 ? file.count : 100, + true); + + *buffer_size = file.count; + *buffer = file.buf; +out: + if (ret == -EINVAL) + vfree(file.buf); + return ret; +} + +/* + * Called during kexec_file_load so that IMA can add a segment to the kexec + * image for the measurement list for the next kernel. + * + * This function assumes that kexec_mutex is held. + */ +void ima_add_kexec_buffer(struct kimage *image) +{ + struct kexec_buf kbuf = { .image = image, .buf_align = PAGE_SIZE, + .buf_min = 0, .buf_max = ULONG_MAX, + .top_down = true }; + unsigned long binary_runtime_size; + + /* use more understandable variable names than defined in kbuf */ + void *kexec_buffer = NULL; + size_t kexec_buffer_size; + size_t kexec_segment_size; + int ret; + + /* + * Reserve an extra half page of memory for additional measurements + * added during the kexec load. + */ + binary_runtime_size = ima_get_binary_runtime_size(); + if (binary_runtime_size >= ULONG_MAX - PAGE_SIZE) + kexec_segment_size = ULONG_MAX; + else + kexec_segment_size = ALIGN(ima_get_binary_runtime_size() + + PAGE_SIZE / 2, PAGE_SIZE); + if ((kexec_segment_size == ULONG_MAX) || + ((kexec_segment_size >> PAGE_SHIFT) > totalram_pages() / 2)) { + pr_err("Binary measurement list too large.\n"); + return; + } + + ima_dump_measurement_list(&kexec_buffer_size, &kexec_buffer, + kexec_segment_size); + if (!kexec_buffer) { + pr_err("Not enough memory for the kexec measurement buffer.\n"); + return; + } + + kbuf.buffer = kexec_buffer; + kbuf.bufsz = kexec_buffer_size; + kbuf.memsz = kexec_segment_size; + ret = kexec_add_buffer(&kbuf); + if (ret) { + pr_err("Error passing over kexec measurement buffer.\n"); + vfree(kexec_buffer); + return; + } + + image->ima_buffer_addr = kbuf.mem; + image->ima_buffer_size = kexec_segment_size; + image->ima_buffer = kexec_buffer; + + pr_debug("kexec measurement buffer for the loaded kernel at 0x%lx.\n", + kbuf.mem); +} +#endif /* IMA_KEXEC */ + +/* + * Restore the measurement list from the previous kernel. + */ +void __init ima_load_kexec_buffer(void) +{ + void *kexec_buffer = NULL; + size_t kexec_buffer_size = 0; + int rc; + + rc = ima_get_kexec_buffer(&kexec_buffer, &kexec_buffer_size); + switch (rc) { + case 0: + rc = ima_restore_measurement_list(kexec_buffer_size, + kexec_buffer); + if (rc != 0) + pr_err("Failed to restore the measurement list: %d\n", + rc); + + ima_free_kexec_buffer(); + break; + case -ENOTSUPP: + pr_debug("Restoring the measurement list not supported\n"); + break; + case -ENOENT: + pr_debug("No measurement list to restore\n"); + break; + default: + pr_debug("Error restoring the measurement list: %d\n", rc); + } +} diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c new file mode 100644 index 000000000..185666d90 --- /dev/null +++ b/security/integrity/ima/ima_main.c @@ -0,0 +1,1100 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Integrity Measurement Architecture + * + * Copyright (C) 2005,2006,2007,2008 IBM Corporation + * + * Authors: + * Reiner Sailer <sailer@watson.ibm.com> + * Serge Hallyn <serue@us.ibm.com> + * Kylene Hall <kylene@us.ibm.com> + * Mimi Zohar <zohar@us.ibm.com> + * + * File: ima_main.c + * implements the IMA hooks: ima_bprm_check, ima_file_mmap, + * and ima_file_check. + */ + +#include <linux/module.h> +#include <linux/file.h> +#include <linux/binfmts.h> +#include <linux/kernel_read_file.h> +#include <linux/mount.h> +#include <linux/mman.h> +#include <linux/slab.h> +#include <linux/xattr.h> +#include <linux/ima.h> +#include <linux/iversion.h> +#include <linux/fs.h> +#include <linux/iversion.h> + +#include "ima.h" + +#ifdef CONFIG_IMA_APPRAISE +int ima_appraise = IMA_APPRAISE_ENFORCE; +#else +int ima_appraise; +#endif + +int __ro_after_init ima_hash_algo = HASH_ALGO_SHA1; +static int hash_setup_done; + +static struct notifier_block ima_lsm_policy_notifier = { + .notifier_call = ima_lsm_policy_change, +}; + +static int __init hash_setup(char *str) +{ + struct ima_template_desc *template_desc = ima_template_desc_current(); + int i; + + if (hash_setup_done) + return 1; + + if (strcmp(template_desc->name, IMA_TEMPLATE_IMA_NAME) == 0) { + if (strncmp(str, "sha1", 4) == 0) { + ima_hash_algo = HASH_ALGO_SHA1; + } else if (strncmp(str, "md5", 3) == 0) { + ima_hash_algo = HASH_ALGO_MD5; + } else { + pr_err("invalid hash algorithm \"%s\" for template \"%s\"", + str, IMA_TEMPLATE_IMA_NAME); + return 1; + } + goto out; + } + + i = match_string(hash_algo_name, HASH_ALGO__LAST, str); + if (i < 0) { + pr_err("invalid hash algorithm \"%s\"", str); + return 1; + } + + ima_hash_algo = i; +out: + hash_setup_done = 1; + return 1; +} +__setup("ima_hash=", hash_setup); + +enum hash_algo ima_get_current_hash_algo(void) +{ + return ima_hash_algo; +} + +/* Prevent mmap'ing a file execute that is already mmap'ed write */ +static int mmap_violation_check(enum ima_hooks func, struct file *file, + char **pathbuf, const char **pathname, + char *filename) +{ + struct inode *inode; + int rc = 0; + + if ((func == MMAP_CHECK) && mapping_writably_mapped(file->f_mapping)) { + rc = -ETXTBSY; + inode = file_inode(file); + + if (!*pathbuf) /* ima_rdwr_violation possibly pre-fetched */ + *pathname = ima_d_path(&file->f_path, pathbuf, + filename); + integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, *pathname, + "mmap_file", "mmapped_writers", rc, 0); + } + return rc; +} + +/* + * ima_rdwr_violation_check + * + * Only invalidate the PCR for measured files: + * - Opening a file for write when already open for read, + * results in a time of measure, time of use (ToMToU) error. + * - Opening a file for read when already open for write, + * could result in a file measurement error. + * + */ +static void ima_rdwr_violation_check(struct file *file, + struct integrity_iint_cache *iint, + int must_measure, + char **pathbuf, + const char **pathname, + char *filename) +{ + struct inode *inode = file_inode(file); + fmode_t mode = file->f_mode; + bool send_tomtou = false, send_writers = false; + + if (mode & FMODE_WRITE) { + if (atomic_read(&inode->i_readcount) && IS_IMA(inode)) { + if (!iint) + iint = integrity_iint_find(inode); + /* IMA_MEASURE is set from reader side */ + if (iint && test_bit(IMA_MUST_MEASURE, + &iint->atomic_flags)) + send_tomtou = true; + } + } else { + if (must_measure) + set_bit(IMA_MUST_MEASURE, &iint->atomic_flags); + if (inode_is_open_for_write(inode) && must_measure) + send_writers = true; + } + + if (!send_tomtou && !send_writers) + return; + + *pathname = ima_d_path(&file->f_path, pathbuf, filename); + + if (send_tomtou) + ima_add_violation(file, *pathname, iint, + "invalid_pcr", "ToMToU"); + if (send_writers) + ima_add_violation(file, *pathname, iint, + "invalid_pcr", "open_writers"); +} + +static void ima_check_last_writer(struct integrity_iint_cache *iint, + struct inode *inode, struct file *file) +{ + fmode_t mode = file->f_mode; + bool update; + + if (!(mode & FMODE_WRITE)) + return; + + mutex_lock(&iint->mutex); + if (atomic_read(&inode->i_writecount) == 1) { + update = test_and_clear_bit(IMA_UPDATE_XATTR, + &iint->atomic_flags); + if (!IS_I_VERSION(inode) || + !inode_eq_iversion(inode, iint->version) || + (iint->flags & IMA_NEW_FILE)) { + iint->flags &= ~(IMA_DONE_MASK | IMA_NEW_FILE); + iint->measured_pcrs = 0; + if (update) + ima_update_xattr(iint, file); + } + } + mutex_unlock(&iint->mutex); +} + +/** + * ima_file_free - called on __fput() + * @file: pointer to file structure being freed + * + * Flag files that changed, based on i_version + */ +void ima_file_free(struct file *file) +{ + struct inode *inode = file_inode(file); + struct integrity_iint_cache *iint; + + if (!ima_policy_flag || !S_ISREG(inode->i_mode)) + return; + + iint = integrity_iint_find(inode); + if (!iint) + return; + + ima_check_last_writer(iint, inode, file); +} + +static int process_measurement(struct file *file, const struct cred *cred, + u32 secid, char *buf, loff_t size, int mask, + enum ima_hooks func) +{ + struct inode *backing_inode, *inode = file_inode(file); + struct integrity_iint_cache *iint = NULL; + struct ima_template_desc *template_desc = NULL; + char *pathbuf = NULL; + char filename[NAME_MAX]; + const char *pathname = NULL; + int rc = 0, action, must_appraise = 0; + int pcr = CONFIG_IMA_MEASURE_PCR_IDX; + struct evm_ima_xattr_data *xattr_value = NULL; + struct modsig *modsig = NULL; + int xattr_len = 0; + bool violation_check; + enum hash_algo hash_algo; + unsigned int allowed_algos = 0; + + if (!ima_policy_flag || !S_ISREG(inode->i_mode)) + return 0; + + /* Return an IMA_MEASURE, IMA_APPRAISE, IMA_AUDIT action + * bitmask based on the appraise/audit/measurement policy. + * Included is the appraise submask. + */ + action = ima_get_action(file_mnt_user_ns(file), inode, cred, secid, + mask, func, &pcr, &template_desc, NULL, + &allowed_algos); + violation_check = ((func == FILE_CHECK || func == MMAP_CHECK) && + (ima_policy_flag & IMA_MEASURE)); + if (!action && !violation_check) + return 0; + + must_appraise = action & IMA_APPRAISE; + + /* Is the appraise rule hook specific? */ + if (action & IMA_FILE_APPRAISE) + func = FILE_CHECK; + + inode_lock(inode); + + if (action) { + iint = integrity_inode_get(inode); + if (!iint) + rc = -ENOMEM; + } + + if (!rc && violation_check) + ima_rdwr_violation_check(file, iint, action & IMA_MEASURE, + &pathbuf, &pathname, filename); + + inode_unlock(inode); + + if (rc) + goto out; + if (!action) + goto out; + + mutex_lock(&iint->mutex); + + if (test_and_clear_bit(IMA_CHANGE_ATTR, &iint->atomic_flags)) + /* reset appraisal flags if ima_inode_post_setattr was called */ + iint->flags &= ~(IMA_APPRAISE | IMA_APPRAISED | + IMA_APPRAISE_SUBMASK | IMA_APPRAISED_SUBMASK | + IMA_NONACTION_FLAGS); + + /* + * Re-evaulate the file if either the xattr has changed or the + * kernel has no way of detecting file change on the filesystem. + * (Limited to privileged mounted filesystems.) + */ + if (test_and_clear_bit(IMA_CHANGE_XATTR, &iint->atomic_flags) || + ((inode->i_sb->s_iflags & SB_I_IMA_UNVERIFIABLE_SIGNATURE) && + !(inode->i_sb->s_iflags & SB_I_UNTRUSTED_MOUNTER) && + !(action & IMA_FAIL_UNVERIFIABLE_SIGS))) { + iint->flags &= ~IMA_DONE_MASK; + iint->measured_pcrs = 0; + } + + /* Detect and re-evaluate changes made to the backing file. */ + backing_inode = d_real_inode(file_dentry(file)); + if (backing_inode != inode && + (action & IMA_DO_MASK) && (iint->flags & IMA_DONE_MASK)) { + if (!IS_I_VERSION(backing_inode) || + backing_inode->i_sb->s_dev != iint->real_dev || + backing_inode->i_ino != iint->real_ino || + !inode_eq_iversion(backing_inode, iint->version)) { + iint->flags &= ~IMA_DONE_MASK; + iint->measured_pcrs = 0; + } + } + + /* Determine if already appraised/measured based on bitmask + * (IMA_MEASURE, IMA_MEASURED, IMA_XXXX_APPRAISE, IMA_XXXX_APPRAISED, + * IMA_AUDIT, IMA_AUDITED) + */ + iint->flags |= action; + action &= IMA_DO_MASK; + action &= ~((iint->flags & (IMA_DONE_MASK ^ IMA_MEASURED)) >> 1); + + /* If target pcr is already measured, unset IMA_MEASURE action */ + if ((action & IMA_MEASURE) && (iint->measured_pcrs & (0x1 << pcr))) + action ^= IMA_MEASURE; + + /* HASH sets the digital signature and update flags, nothing else */ + if ((action & IMA_HASH) && + !(test_bit(IMA_DIGSIG, &iint->atomic_flags))) { + xattr_len = ima_read_xattr(file_dentry(file), &xattr_value); + if ((xattr_value && xattr_len > 2) && + (xattr_value->type == EVM_IMA_XATTR_DIGSIG)) + set_bit(IMA_DIGSIG, &iint->atomic_flags); + iint->flags |= IMA_HASHED; + action ^= IMA_HASH; + set_bit(IMA_UPDATE_XATTR, &iint->atomic_flags); + } + + /* Nothing to do, just return existing appraised status */ + if (!action) { + if (must_appraise) { + rc = mmap_violation_check(func, file, &pathbuf, + &pathname, filename); + if (!rc) + rc = ima_get_cache_status(iint, func); + } + goto out_locked; + } + + if ((action & IMA_APPRAISE_SUBMASK) || + strcmp(template_desc->name, IMA_TEMPLATE_IMA_NAME) != 0) { + /* read 'security.ima' */ + xattr_len = ima_read_xattr(file_dentry(file), &xattr_value); + + /* + * Read the appended modsig if allowed by the policy, and allow + * an additional measurement list entry, if needed, based on the + * template format and whether the file was already measured. + */ + if (iint->flags & IMA_MODSIG_ALLOWED) { + rc = ima_read_modsig(func, buf, size, &modsig); + + if (!rc && ima_template_has_modsig(template_desc) && + iint->flags & IMA_MEASURED) + action |= IMA_MEASURE; + } + } + + hash_algo = ima_get_hash_algo(xattr_value, xattr_len); + + rc = ima_collect_measurement(iint, file, buf, size, hash_algo, modsig); + if (rc != 0 && rc != -EBADF && rc != -EINVAL) + goto out_locked; + + if (!pathbuf) /* ima_rdwr_violation possibly pre-fetched */ + pathname = ima_d_path(&file->f_path, &pathbuf, filename); + + if (action & IMA_MEASURE) + ima_store_measurement(iint, file, pathname, + xattr_value, xattr_len, modsig, pcr, + template_desc); + if (rc == 0 && (action & IMA_APPRAISE_SUBMASK)) { + rc = ima_check_blacklist(iint, modsig, pcr); + if (rc != -EPERM) { + inode_lock(inode); + rc = ima_appraise_measurement(func, iint, file, + pathname, xattr_value, + xattr_len, modsig); + inode_unlock(inode); + } + if (!rc) + rc = mmap_violation_check(func, file, &pathbuf, + &pathname, filename); + } + if (action & IMA_AUDIT) + ima_audit_measurement(iint, pathname); + + if ((file->f_flags & O_DIRECT) && (iint->flags & IMA_PERMIT_DIRECTIO)) + rc = 0; + + /* Ensure the digest was generated using an allowed algorithm */ + if (rc == 0 && must_appraise && allowed_algos != 0 && + (allowed_algos & (1U << hash_algo)) == 0) { + rc = -EACCES; + + integrity_audit_msg(AUDIT_INTEGRITY_DATA, file_inode(file), + pathname, "collect_data", + "denied-hash-algorithm", rc, 0); + } +out_locked: + if ((mask & MAY_WRITE) && test_bit(IMA_DIGSIG, &iint->atomic_flags) && + !(iint->flags & IMA_NEW_FILE)) + rc = -EACCES; + mutex_unlock(&iint->mutex); + kfree(xattr_value); + ima_free_modsig(modsig); +out: + if (pathbuf) + __putname(pathbuf); + if (must_appraise) { + if (rc && (ima_appraise & IMA_APPRAISE_ENFORCE)) + return -EACCES; + if (file->f_mode & FMODE_WRITE) + set_bit(IMA_UPDATE_XATTR, &iint->atomic_flags); + } + return 0; +} + +/** + * ima_file_mmap - based on policy, collect/store measurement. + * @file: pointer to the file to be measured (May be NULL) + * @reqprot: protection requested by the application + * @prot: protection that will be applied by the kernel + * @flags: operational flags + * + * Measure files being mmapped executable based on the ima_must_measure() + * policy decision. + * + * On success return 0. On integrity appraisal error, assuming the file + * is in policy and IMA-appraisal is in enforcing mode, return -EACCES. + */ +int ima_file_mmap(struct file *file, unsigned long reqprot, + unsigned long prot, unsigned long flags) +{ + u32 secid; + + if (file && (prot & PROT_EXEC)) { + security_current_getsecid_subj(&secid); + return process_measurement(file, current_cred(), secid, NULL, + 0, MAY_EXEC, MMAP_CHECK); + } + + return 0; +} + +/** + * ima_file_mprotect - based on policy, limit mprotect change + * @vma: vm_area_struct protection is set to + * @prot: contains the protection that will be applied by the kernel. + * + * Files can be mmap'ed read/write and later changed to execute to circumvent + * IMA's mmap appraisal policy rules. Due to locking issues (mmap semaphore + * would be taken before i_mutex), files can not be measured or appraised at + * this point. Eliminate this integrity gap by denying the mprotect + * PROT_EXECUTE change, if an mmap appraise policy rule exists. + * + * On mprotect change success, return 0. On failure, return -EACESS. + */ +int ima_file_mprotect(struct vm_area_struct *vma, unsigned long prot) +{ + struct ima_template_desc *template = NULL; + struct file *file; + char filename[NAME_MAX]; + char *pathbuf = NULL; + const char *pathname = NULL; + struct inode *inode; + int result = 0; + int action; + u32 secid; + int pcr; + + /* Is mprotect making an mmap'ed file executable? */ + if (!(ima_policy_flag & IMA_APPRAISE) || !vma->vm_file || + !(prot & PROT_EXEC) || (vma->vm_flags & VM_EXEC)) + return 0; + + security_current_getsecid_subj(&secid); + inode = file_inode(vma->vm_file); + action = ima_get_action(file_mnt_user_ns(vma->vm_file), inode, + current_cred(), secid, MAY_EXEC, MMAP_CHECK, + &pcr, &template, NULL, NULL); + + /* Is the mmap'ed file in policy? */ + if (!(action & (IMA_MEASURE | IMA_APPRAISE_SUBMASK))) + return 0; + + if (action & IMA_APPRAISE_SUBMASK) + result = -EPERM; + + file = vma->vm_file; + pathname = ima_d_path(&file->f_path, &pathbuf, filename); + integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, pathname, + "collect_data", "failed-mprotect", result, 0); + if (pathbuf) + __putname(pathbuf); + + return result; +} + +/** + * ima_bprm_check - based on policy, collect/store measurement. + * @bprm: contains the linux_binprm structure + * + * The OS protects against an executable file, already open for write, + * from being executed in deny_write_access() and an executable file, + * already open for execute, from being modified in get_write_access(). + * So we can be certain that what we verify and measure here is actually + * what is being executed. + * + * On success return 0. On integrity appraisal error, assuming the file + * is in policy and IMA-appraisal is in enforcing mode, return -EACCES. + */ +int ima_bprm_check(struct linux_binprm *bprm) +{ + int ret; + u32 secid; + + security_current_getsecid_subj(&secid); + ret = process_measurement(bprm->file, current_cred(), secid, NULL, 0, + MAY_EXEC, BPRM_CHECK); + if (ret) + return ret; + + security_cred_getsecid(bprm->cred, &secid); + return process_measurement(bprm->file, bprm->cred, secid, NULL, 0, + MAY_EXEC, CREDS_CHECK); +} + +/** + * ima_file_check - based on policy, collect/store measurement. + * @file: pointer to the file to be measured + * @mask: contains MAY_READ, MAY_WRITE, MAY_EXEC or MAY_APPEND + * + * Measure files based on the ima_must_measure() policy decision. + * + * On success return 0. On integrity appraisal error, assuming the file + * is in policy and IMA-appraisal is in enforcing mode, return -EACCES. + */ +int ima_file_check(struct file *file, int mask) +{ + u32 secid; + + security_current_getsecid_subj(&secid); + return process_measurement(file, current_cred(), secid, NULL, 0, + mask & (MAY_READ | MAY_WRITE | MAY_EXEC | + MAY_APPEND), FILE_CHECK); +} +EXPORT_SYMBOL_GPL(ima_file_check); + +static int __ima_inode_hash(struct inode *inode, struct file *file, char *buf, + size_t buf_size) +{ + struct integrity_iint_cache *iint = NULL, tmp_iint; + int rc, hash_algo; + + if (ima_policy_flag) { + iint = integrity_iint_find(inode); + if (iint) + mutex_lock(&iint->mutex); + } + + if ((!iint || !(iint->flags & IMA_COLLECTED)) && file) { + if (iint) + mutex_unlock(&iint->mutex); + + memset(&tmp_iint, 0, sizeof(tmp_iint)); + tmp_iint.inode = inode; + mutex_init(&tmp_iint.mutex); + + rc = ima_collect_measurement(&tmp_iint, file, NULL, 0, + ima_hash_algo, NULL); + if (rc < 0) { + /* ima_hash could be allocated in case of failure. */ + if (rc != -ENOMEM) + kfree(tmp_iint.ima_hash); + + return -EOPNOTSUPP; + } + + iint = &tmp_iint; + mutex_lock(&iint->mutex); + } + + if (!iint) + return -EOPNOTSUPP; + + /* + * ima_file_hash can be called when ima_collect_measurement has still + * not been called, we might not always have a hash. + */ + if (!iint->ima_hash) { + mutex_unlock(&iint->mutex); + return -EOPNOTSUPP; + } + + if (buf) { + size_t copied_size; + + copied_size = min_t(size_t, iint->ima_hash->length, buf_size); + memcpy(buf, iint->ima_hash->digest, copied_size); + } + hash_algo = iint->ima_hash->algo; + mutex_unlock(&iint->mutex); + + if (iint == &tmp_iint) + kfree(iint->ima_hash); + + return hash_algo; +} + +/** + * ima_file_hash - return a measurement of the file + * @file: pointer to the file + * @buf: buffer in which to store the hash + * @buf_size: length of the buffer + * + * On success, return the hash algorithm (as defined in the enum hash_algo). + * If buf is not NULL, this function also outputs the hash into buf. + * If the hash is larger than buf_size, then only buf_size bytes will be copied. + * It generally just makes sense to pass a buffer capable of holding the largest + * possible hash: IMA_MAX_DIGEST_SIZE. + * The file hash returned is based on the entire file, including the appended + * signature. + * + * If the measurement cannot be performed, return -EOPNOTSUPP. + * If the parameters are incorrect, return -EINVAL. + */ +int ima_file_hash(struct file *file, char *buf, size_t buf_size) +{ + if (!file) + return -EINVAL; + + return __ima_inode_hash(file_inode(file), file, buf, buf_size); +} +EXPORT_SYMBOL_GPL(ima_file_hash); + +/** + * ima_inode_hash - return the stored measurement if the inode has been hashed + * and is in the iint cache. + * @inode: pointer to the inode + * @buf: buffer in which to store the hash + * @buf_size: length of the buffer + * + * On success, return the hash algorithm (as defined in the enum hash_algo). + * If buf is not NULL, this function also outputs the hash into buf. + * If the hash is larger than buf_size, then only buf_size bytes will be copied. + * It generally just makes sense to pass a buffer capable of holding the largest + * possible hash: IMA_MAX_DIGEST_SIZE. + * The hash returned is based on the entire contents, including the appended + * signature. + * + * If IMA is disabled or if no measurement is available, return -EOPNOTSUPP. + * If the parameters are incorrect, return -EINVAL. + */ +int ima_inode_hash(struct inode *inode, char *buf, size_t buf_size) +{ + if (!inode) + return -EINVAL; + + return __ima_inode_hash(inode, NULL, buf, buf_size); +} +EXPORT_SYMBOL_GPL(ima_inode_hash); + +/** + * ima_post_create_tmpfile - mark newly created tmpfile as new + * @mnt_userns: user namespace of the mount the inode was found from + * @inode: inode of the newly created tmpfile + * + * No measuring, appraising or auditing of newly created tmpfiles is needed. + * Skip calling process_measurement(), but indicate which newly, created + * tmpfiles are in policy. + */ +void ima_post_create_tmpfile(struct user_namespace *mnt_userns, + struct inode *inode) +{ + struct integrity_iint_cache *iint; + int must_appraise; + + if (!ima_policy_flag || !S_ISREG(inode->i_mode)) + return; + + must_appraise = ima_must_appraise(mnt_userns, inode, MAY_ACCESS, + FILE_CHECK); + if (!must_appraise) + return; + + /* Nothing to do if we can't allocate memory */ + iint = integrity_inode_get(inode); + if (!iint) + return; + + /* needed for writing the security xattrs */ + set_bit(IMA_UPDATE_XATTR, &iint->atomic_flags); + iint->ima_file_status = INTEGRITY_PASS; +} + +/** + * ima_post_path_mknod - mark as a new inode + * @mnt_userns: user namespace of the mount the inode was found from + * @dentry: newly created dentry + * + * Mark files created via the mknodat syscall as new, so that the + * file data can be written later. + */ +void ima_post_path_mknod(struct user_namespace *mnt_userns, + struct dentry *dentry) +{ + struct integrity_iint_cache *iint; + struct inode *inode = dentry->d_inode; + int must_appraise; + + if (!ima_policy_flag || !S_ISREG(inode->i_mode)) + return; + + must_appraise = ima_must_appraise(mnt_userns, inode, MAY_ACCESS, + FILE_CHECK); + if (!must_appraise) + return; + + /* Nothing to do if we can't allocate memory */ + iint = integrity_inode_get(inode); + if (!iint) + return; + + /* needed for re-opening empty files */ + iint->flags |= IMA_NEW_FILE; +} + +/** + * ima_read_file - pre-measure/appraise hook decision based on policy + * @file: pointer to the file to be measured/appraised/audit + * @read_id: caller identifier + * @contents: whether a subsequent call will be made to ima_post_read_file() + * + * Permit reading a file based on policy. The policy rules are written + * in terms of the policy identifier. Appraising the integrity of + * a file requires a file descriptor. + * + * For permission return 0, otherwise return -EACCES. + */ +int ima_read_file(struct file *file, enum kernel_read_file_id read_id, + bool contents) +{ + enum ima_hooks func; + u32 secid; + + /* + * Do devices using pre-allocated memory run the risk of the + * firmware being accessible to the device prior to the completion + * of IMA's signature verification any more than when using two + * buffers? It may be desirable to include the buffer address + * in this API and walk all the dma_map_single() mappings to check. + */ + + /* + * There will be a call made to ima_post_read_file() with + * a filled buffer, so we don't need to perform an extra + * read early here. + */ + if (contents) + return 0; + + /* Read entire file for all partial reads. */ + func = read_idmap[read_id] ?: FILE_CHECK; + security_current_getsecid_subj(&secid); + return process_measurement(file, current_cred(), secid, NULL, + 0, MAY_READ, func); +} + +const int read_idmap[READING_MAX_ID] = { + [READING_FIRMWARE] = FIRMWARE_CHECK, + [READING_MODULE] = MODULE_CHECK, + [READING_KEXEC_IMAGE] = KEXEC_KERNEL_CHECK, + [READING_KEXEC_INITRAMFS] = KEXEC_INITRAMFS_CHECK, + [READING_POLICY] = POLICY_CHECK +}; + +/** + * ima_post_read_file - in memory collect/appraise/audit measurement + * @file: pointer to the file to be measured/appraised/audit + * @buf: pointer to in memory file contents + * @size: size of in memory file contents + * @read_id: caller identifier + * + * Measure/appraise/audit in memory file based on policy. Policy rules + * are written in terms of a policy identifier. + * + * On success return 0. On integrity appraisal error, assuming the file + * is in policy and IMA-appraisal is in enforcing mode, return -EACCES. + */ +int ima_post_read_file(struct file *file, void *buf, loff_t size, + enum kernel_read_file_id read_id) +{ + enum ima_hooks func; + u32 secid; + + /* permit signed certs */ + if (!file && read_id == READING_X509_CERTIFICATE) + return 0; + + if (!file || !buf || size == 0) { /* should never happen */ + if (ima_appraise & IMA_APPRAISE_ENFORCE) + return -EACCES; + return 0; + } + + func = read_idmap[read_id] ?: FILE_CHECK; + security_current_getsecid_subj(&secid); + return process_measurement(file, current_cred(), secid, buf, size, + MAY_READ, func); +} + +/** + * ima_load_data - appraise decision based on policy + * @id: kernel load data caller identifier + * @contents: whether the full contents will be available in a later + * call to ima_post_load_data(). + * + * Callers of this LSM hook can not measure, appraise, or audit the + * data provided by userspace. Enforce policy rules requiring a file + * signature (eg. kexec'ed kernel image). + * + * For permission return 0, otherwise return -EACCES. + */ +int ima_load_data(enum kernel_load_data_id id, bool contents) +{ + bool ima_enforce, sig_enforce; + + ima_enforce = + (ima_appraise & IMA_APPRAISE_ENFORCE) == IMA_APPRAISE_ENFORCE; + + switch (id) { + case LOADING_KEXEC_IMAGE: + if (IS_ENABLED(CONFIG_KEXEC_SIG) + && arch_ima_get_secureboot()) { + pr_err("impossible to appraise a kernel image without a file descriptor; try using kexec_file_load syscall.\n"); + return -EACCES; + } + + if (ima_enforce && (ima_appraise & IMA_APPRAISE_KEXEC)) { + pr_err("impossible to appraise a kernel image without a file descriptor; try using kexec_file_load syscall.\n"); + return -EACCES; /* INTEGRITY_UNKNOWN */ + } + break; + case LOADING_FIRMWARE: + if (ima_enforce && (ima_appraise & IMA_APPRAISE_FIRMWARE) && !contents) { + pr_err("Prevent firmware sysfs fallback loading.\n"); + return -EACCES; /* INTEGRITY_UNKNOWN */ + } + break; + case LOADING_MODULE: + sig_enforce = is_module_sig_enforced(); + + if (ima_enforce && (!sig_enforce + && (ima_appraise & IMA_APPRAISE_MODULES))) { + pr_err("impossible to appraise a module without a file descriptor. sig_enforce kernel parameter might help\n"); + return -EACCES; /* INTEGRITY_UNKNOWN */ + } + break; + default: + break; + } + return 0; +} + +/** + * ima_post_load_data - appraise decision based on policy + * @buf: pointer to in memory file contents + * @size: size of in memory file contents + * @load_id: kernel load data caller identifier + * @description: @load_id-specific description of contents + * + * Measure/appraise/audit in memory buffer based on policy. Policy rules + * are written in terms of a policy identifier. + * + * On success return 0. On integrity appraisal error, assuming the file + * is in policy and IMA-appraisal is in enforcing mode, return -EACCES. + */ +int ima_post_load_data(char *buf, loff_t size, + enum kernel_load_data_id load_id, + char *description) +{ + if (load_id == LOADING_FIRMWARE) { + if ((ima_appraise & IMA_APPRAISE_FIRMWARE) && + (ima_appraise & IMA_APPRAISE_ENFORCE)) { + pr_err("Prevent firmware loading_store.\n"); + return -EACCES; /* INTEGRITY_UNKNOWN */ + } + return 0; + } + + return 0; +} + +/** + * process_buffer_measurement - Measure the buffer or the buffer data hash + * @mnt_userns: user namespace of the mount the inode was found from + * @inode: inode associated with the object being measured (NULL for KEY_CHECK) + * @buf: pointer to the buffer that needs to be added to the log. + * @size: size of buffer(in bytes). + * @eventname: event name to be used for the buffer entry. + * @func: IMA hook + * @pcr: pcr to extend the measurement + * @func_data: func specific data, may be NULL + * @buf_hash: measure buffer data hash + * @digest: buffer digest will be written to + * @digest_len: buffer length + * + * Based on policy, either the buffer data or buffer data hash is measured + * + * Return: 0 if the buffer has been successfully measured, 1 if the digest + * has been written to the passed location but not added to a measurement entry, + * a negative value otherwise. + */ +int process_buffer_measurement(struct user_namespace *mnt_userns, + struct inode *inode, const void *buf, int size, + const char *eventname, enum ima_hooks func, + int pcr, const char *func_data, + bool buf_hash, u8 *digest, size_t digest_len) +{ + int ret = 0; + const char *audit_cause = "ENOMEM"; + struct ima_template_entry *entry = NULL; + struct integrity_iint_cache iint = {}; + struct ima_event_data event_data = {.iint = &iint, + .filename = eventname, + .buf = buf, + .buf_len = size}; + struct ima_template_desc *template; + struct ima_max_digest_data hash; + char digest_hash[IMA_MAX_DIGEST_SIZE]; + int digest_hash_len = hash_digest_size[ima_hash_algo]; + int violation = 0; + int action = 0; + u32 secid; + + if (digest && digest_len < digest_hash_len) + return -EINVAL; + + if (!ima_policy_flag && !digest) + return -ENOENT; + + template = ima_template_desc_buf(); + if (!template) { + ret = -EINVAL; + audit_cause = "ima_template_desc_buf"; + goto out; + } + + /* + * Both LSM hooks and auxilary based buffer measurements are + * based on policy. To avoid code duplication, differentiate + * between the LSM hooks and auxilary buffer measurements, + * retrieving the policy rule information only for the LSM hook + * buffer measurements. + */ + if (func) { + security_current_getsecid_subj(&secid); + action = ima_get_action(mnt_userns, inode, current_cred(), + secid, 0, func, &pcr, &template, + func_data, NULL); + if (!(action & IMA_MEASURE) && !digest) + return -ENOENT; + } + + if (!pcr) + pcr = CONFIG_IMA_MEASURE_PCR_IDX; + + iint.ima_hash = &hash.hdr; + iint.ima_hash->algo = ima_hash_algo; + iint.ima_hash->length = hash_digest_size[ima_hash_algo]; + + ret = ima_calc_buffer_hash(buf, size, iint.ima_hash); + if (ret < 0) { + audit_cause = "hashing_error"; + goto out; + } + + if (buf_hash) { + memcpy(digest_hash, hash.hdr.digest, digest_hash_len); + + ret = ima_calc_buffer_hash(digest_hash, digest_hash_len, + iint.ima_hash); + if (ret < 0) { + audit_cause = "hashing_error"; + goto out; + } + + event_data.buf = digest_hash; + event_data.buf_len = digest_hash_len; + } + + if (digest) + memcpy(digest, iint.ima_hash->digest, digest_hash_len); + + if (!ima_policy_flag || (func && !(action & IMA_MEASURE))) + return 1; + + ret = ima_alloc_init_template(&event_data, &entry, template); + if (ret < 0) { + audit_cause = "alloc_entry"; + goto out; + } + + ret = ima_store_template(entry, violation, NULL, event_data.buf, pcr); + if (ret < 0) { + audit_cause = "store_entry"; + ima_free_template_entry(entry); + } + +out: + if (ret < 0) + integrity_audit_message(AUDIT_INTEGRITY_PCR, NULL, eventname, + func_measure_str(func), + audit_cause, ret, 0, ret); + + return ret; +} + +/** + * ima_kexec_cmdline - measure kexec cmdline boot args + * @kernel_fd: file descriptor of the kexec kernel being loaded + * @buf: pointer to buffer + * @size: size of buffer + * + * Buffers can only be measured, not appraised. + */ +void ima_kexec_cmdline(int kernel_fd, const void *buf, int size) +{ + struct fd f; + + if (!buf || !size) + return; + + f = fdget(kernel_fd); + if (!f.file) + return; + + process_buffer_measurement(file_mnt_user_ns(f.file), file_inode(f.file), + buf, size, "kexec-cmdline", KEXEC_CMDLINE, 0, + NULL, false, NULL, 0); + fdput(f); +} + +/** + * ima_measure_critical_data - measure kernel integrity critical data + * @event_label: unique event label for grouping and limiting critical data + * @event_name: event name for the record in the IMA measurement list + * @buf: pointer to buffer data + * @buf_len: length of buffer data (in bytes) + * @hash: measure buffer data hash + * @digest: buffer digest will be written to + * @digest_len: buffer length + * + * Measure data critical to the integrity of the kernel into the IMA log + * and extend the pcr. Examples of critical data could be various data + * structures, policies, and states stored in kernel memory that can + * impact the integrity of the system. + * + * Return: 0 if the buffer has been successfully measured, 1 if the digest + * has been written to the passed location but not added to a measurement entry, + * a negative value otherwise. + */ +int ima_measure_critical_data(const char *event_label, + const char *event_name, + const void *buf, size_t buf_len, + bool hash, u8 *digest, size_t digest_len) +{ + if (!event_name || !event_label || !buf || !buf_len) + return -ENOPARAM; + + return process_buffer_measurement(&init_user_ns, NULL, buf, buf_len, + event_name, CRITICAL_DATA, 0, + event_label, hash, digest, + digest_len); +} +EXPORT_SYMBOL_GPL(ima_measure_critical_data); + +static int __init init_ima(void) +{ + int error; + + ima_appraise_parse_cmdline(); + ima_init_template_list(); + hash_setup(CONFIG_IMA_DEFAULT_HASH); + error = ima_init(); + + if (error && strcmp(hash_algo_name[ima_hash_algo], + CONFIG_IMA_DEFAULT_HASH) != 0) { + pr_info("Allocating %s failed, going to use default hash algorithm %s\n", + hash_algo_name[ima_hash_algo], CONFIG_IMA_DEFAULT_HASH); + hash_setup_done = 0; + hash_setup(CONFIG_IMA_DEFAULT_HASH); + error = ima_init(); + } + + if (error) + return error; + + error = register_blocking_lsm_notifier(&ima_lsm_policy_notifier); + if (error) + pr_warn("Couldn't register LSM notifier, error %d\n", error); + + if (!error) + ima_update_policy_flags(); + + return error; +} + +late_initcall(init_ima); /* Start IMA after the TPM is available */ diff --git a/security/integrity/ima/ima_modsig.c b/security/integrity/ima/ima_modsig.c new file mode 100644 index 000000000..3e7bee300 --- /dev/null +++ b/security/integrity/ima/ima_modsig.c @@ -0,0 +1,151 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * IMA support for appraising module-style appended signatures. + * + * Copyright (C) 2019 IBM Corporation + * + * Author: + * Thiago Jung Bauermann <bauerman@linux.ibm.com> + */ + +#include <linux/types.h> +#include <linux/module_signature.h> +#include <keys/asymmetric-type.h> +#include <crypto/pkcs7.h> + +#include "ima.h" + +struct modsig { + struct pkcs7_message *pkcs7_msg; + + enum hash_algo hash_algo; + + /* This digest will go in the 'd-modsig' field of the IMA template. */ + const u8 *digest; + u32 digest_size; + + /* + * This is what will go to the measurement list if the template requires + * storing the signature. + */ + int raw_pkcs7_len; + u8 raw_pkcs7[]; +}; + +/* + * ima_read_modsig - Read modsig from buf. + * + * Return: 0 on success, error code otherwise. + */ +int ima_read_modsig(enum ima_hooks func, const void *buf, loff_t buf_len, + struct modsig **modsig) +{ + const size_t marker_len = strlen(MODULE_SIG_STRING); + const struct module_signature *sig; + struct modsig *hdr; + size_t sig_len; + const void *p; + int rc; + + if (buf_len <= marker_len + sizeof(*sig)) + return -ENOENT; + + p = buf + buf_len - marker_len; + if (memcmp(p, MODULE_SIG_STRING, marker_len)) + return -ENOENT; + + buf_len -= marker_len; + sig = (const struct module_signature *)(p - sizeof(*sig)); + + rc = mod_check_sig(sig, buf_len, func_tokens[func]); + if (rc) + return rc; + + sig_len = be32_to_cpu(sig->sig_len); + buf_len -= sig_len + sizeof(*sig); + + /* Allocate sig_len additional bytes to hold the raw PKCS#7 data. */ + hdr = kzalloc(sizeof(*hdr) + sig_len, GFP_KERNEL); + if (!hdr) + return -ENOMEM; + + hdr->pkcs7_msg = pkcs7_parse_message(buf + buf_len, sig_len); + if (IS_ERR(hdr->pkcs7_msg)) { + rc = PTR_ERR(hdr->pkcs7_msg); + kfree(hdr); + return rc; + } + + memcpy(hdr->raw_pkcs7, buf + buf_len, sig_len); + hdr->raw_pkcs7_len = sig_len; + + /* We don't know the hash algorithm yet. */ + hdr->hash_algo = HASH_ALGO__LAST; + + *modsig = hdr; + + return 0; +} + +/** + * ima_collect_modsig - Calculate the file hash without the appended signature. + * @modsig: parsed module signature + * @buf: data to verify the signature on + * @size: data size + * + * Since the modsig is part of the file contents, the hash used in its signature + * isn't the same one ordinarily calculated by IMA. Therefore PKCS7 code + * calculates a separate one for signature verification. + */ +void ima_collect_modsig(struct modsig *modsig, const void *buf, loff_t size) +{ + int rc; + + /* + * Provide the file contents (minus the appended sig) so that the PKCS7 + * code can calculate the file hash. + */ + size -= modsig->raw_pkcs7_len + strlen(MODULE_SIG_STRING) + + sizeof(struct module_signature); + rc = pkcs7_supply_detached_data(modsig->pkcs7_msg, buf, size); + if (rc) + return; + + /* Ask the PKCS7 code to calculate the file hash. */ + rc = pkcs7_get_digest(modsig->pkcs7_msg, &modsig->digest, + &modsig->digest_size, &modsig->hash_algo); +} + +int ima_modsig_verify(struct key *keyring, const struct modsig *modsig) +{ + return verify_pkcs7_message_sig(NULL, 0, modsig->pkcs7_msg, keyring, + VERIFYING_MODULE_SIGNATURE, NULL, NULL); +} + +int ima_get_modsig_digest(const struct modsig *modsig, enum hash_algo *algo, + const u8 **digest, u32 *digest_size) +{ + *algo = modsig->hash_algo; + *digest = modsig->digest; + *digest_size = modsig->digest_size; + + return 0; +} + +int ima_get_raw_modsig(const struct modsig *modsig, const void **data, + u32 *data_len) +{ + *data = &modsig->raw_pkcs7; + *data_len = modsig->raw_pkcs7_len; + + return 0; +} + +void ima_free_modsig(struct modsig *modsig) +{ + if (!modsig) + return; + + pkcs7_free_message(modsig->pkcs7_msg); + kfree(modsig); +} diff --git a/security/integrity/ima/ima_mok.c b/security/integrity/ima/ima_mok.c new file mode 100644 index 000000000..95cc31525 --- /dev/null +++ b/security/integrity/ima/ima_mok.c @@ -0,0 +1,49 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2015 Juniper Networks, Inc. + * + * Author: + * Petko Manolov <petko.manolov@konsulko.com> + */ + +#include <linux/export.h> +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/cred.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/slab.h> +#include <keys/system_keyring.h> + + +struct key *ima_blacklist_keyring; + +/* + * Allocate the IMA blacklist keyring + */ +static __init int ima_mok_init(void) +{ + struct key_restriction *restriction; + + pr_notice("Allocating IMA blacklist keyring.\n"); + + restriction = kzalloc(sizeof(struct key_restriction), GFP_KERNEL); + if (!restriction) + panic("Can't allocate IMA blacklist restriction."); + + restriction->check = restrict_link_by_builtin_trusted; + + ima_blacklist_keyring = keyring_alloc(".ima_blacklist", + KUIDT_INIT(0), KGIDT_INIT(0), current_cred(), + (KEY_POS_ALL & ~KEY_POS_SETATTR) | + KEY_USR_VIEW | KEY_USR_READ | + KEY_USR_WRITE | KEY_USR_SEARCH, + KEY_ALLOC_NOT_IN_QUOTA | + KEY_ALLOC_SET_KEEP, + restriction, NULL); + + if (IS_ERR(ima_blacklist_keyring)) + panic("Can't allocate IMA blacklist keyring."); + return 0; +} +device_initcall(ima_mok_init); diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c new file mode 100644 index 000000000..bdc40535f --- /dev/null +++ b/security/integrity/ima/ima_policy.c @@ -0,0 +1,2307 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2008 IBM Corporation + * Author: Mimi Zohar <zohar@us.ibm.com> + * + * ima_policy.c + * - initialize default measure policy rules + */ + +#include <linux/init.h> +#include <linux/list.h> +#include <linux/kernel_read_file.h> +#include <linux/fs.h> +#include <linux/security.h> +#include <linux/magic.h> +#include <linux/parser.h> +#include <linux/slab.h> +#include <linux/rculist.h> +#include <linux/seq_file.h> +#include <linux/ima.h> + +#include "ima.h" + +/* flags definitions */ +#define IMA_FUNC 0x0001 +#define IMA_MASK 0x0002 +#define IMA_FSMAGIC 0x0004 +#define IMA_UID 0x0008 +#define IMA_FOWNER 0x0010 +#define IMA_FSUUID 0x0020 +#define IMA_INMASK 0x0040 +#define IMA_EUID 0x0080 +#define IMA_PCR 0x0100 +#define IMA_FSNAME 0x0200 +#define IMA_KEYRINGS 0x0400 +#define IMA_LABEL 0x0800 +#define IMA_VALIDATE_ALGOS 0x1000 +#define IMA_GID 0x2000 +#define IMA_EGID 0x4000 +#define IMA_FGROUP 0x8000 + +#define UNKNOWN 0 +#define MEASURE 0x0001 /* same as IMA_MEASURE */ +#define DONT_MEASURE 0x0002 +#define APPRAISE 0x0004 /* same as IMA_APPRAISE */ +#define DONT_APPRAISE 0x0008 +#define AUDIT 0x0040 +#define HASH 0x0100 +#define DONT_HASH 0x0200 + +#define INVALID_PCR(a) (((a) < 0) || \ + (a) >= (sizeof_field(struct integrity_iint_cache, measured_pcrs) * 8)) + +int ima_policy_flag; +static int temp_ima_appraise; +static int build_ima_appraise __ro_after_init; + +atomic_t ima_setxattr_allowed_hash_algorithms; + +#define MAX_LSM_RULES 6 +enum lsm_rule_types { LSM_OBJ_USER, LSM_OBJ_ROLE, LSM_OBJ_TYPE, + LSM_SUBJ_USER, LSM_SUBJ_ROLE, LSM_SUBJ_TYPE +}; + +enum policy_types { ORIGINAL_TCB = 1, DEFAULT_TCB }; + +enum policy_rule_list { IMA_DEFAULT_POLICY = 1, IMA_CUSTOM_POLICY }; + +struct ima_rule_opt_list { + size_t count; + char *items[]; +}; + +struct ima_rule_entry { + struct list_head list; + int action; + unsigned int flags; + enum ima_hooks func; + int mask; + unsigned long fsmagic; + uuid_t fsuuid; + kuid_t uid; + kgid_t gid; + kuid_t fowner; + kgid_t fgroup; + bool (*uid_op)(kuid_t cred_uid, kuid_t rule_uid); /* Handlers for operators */ + bool (*gid_op)(kgid_t cred_gid, kgid_t rule_gid); + bool (*fowner_op)(kuid_t cred_uid, kuid_t rule_uid); /* uid_eq(), uid_gt(), uid_lt() */ + bool (*fgroup_op)(kgid_t cred_gid, kgid_t rule_gid); /* gid_eq(), gid_gt(), gid_lt() */ + int pcr; + unsigned int allowed_algos; /* bitfield of allowed hash algorithms */ + struct { + void *rule; /* LSM file metadata specific */ + char *args_p; /* audit value */ + int type; /* audit type */ + } lsm[MAX_LSM_RULES]; + char *fsname; + struct ima_rule_opt_list *keyrings; /* Measure keys added to these keyrings */ + struct ima_rule_opt_list *label; /* Measure data grouped under this label */ + struct ima_template_desc *template; +}; + +/* + * sanity check in case the kernels gains more hash algorithms that can + * fit in an unsigned int + */ +static_assert( + 8 * sizeof(unsigned int) >= HASH_ALGO__LAST, + "The bitfield allowed_algos in ima_rule_entry is too small to contain all the supported hash algorithms, consider using a bigger type"); + +/* + * Without LSM specific knowledge, the default policy can only be + * written in terms of .action, .func, .mask, .fsmagic, .uid, .gid, + * .fowner, and .fgroup + */ + +/* + * The minimum rule set to allow for full TCB coverage. Measures all files + * opened or mmap for exec and everything read by root. Dangerous because + * normal users can easily run the machine out of memory simply building + * and running executables. + */ +static struct ima_rule_entry dont_measure_rules[] __ro_after_init = { + {.action = DONT_MEASURE, .fsmagic = PROC_SUPER_MAGIC, .flags = IMA_FSMAGIC}, + {.action = DONT_MEASURE, .fsmagic = SYSFS_MAGIC, .flags = IMA_FSMAGIC}, + {.action = DONT_MEASURE, .fsmagic = DEBUGFS_MAGIC, .flags = IMA_FSMAGIC}, + {.action = DONT_MEASURE, .fsmagic = TMPFS_MAGIC, .flags = IMA_FSMAGIC}, + {.action = DONT_MEASURE, .fsmagic = DEVPTS_SUPER_MAGIC, .flags = IMA_FSMAGIC}, + {.action = DONT_MEASURE, .fsmagic = BINFMTFS_MAGIC, .flags = IMA_FSMAGIC}, + {.action = DONT_MEASURE, .fsmagic = SECURITYFS_MAGIC, .flags = IMA_FSMAGIC}, + {.action = DONT_MEASURE, .fsmagic = SELINUX_MAGIC, .flags = IMA_FSMAGIC}, + {.action = DONT_MEASURE, .fsmagic = SMACK_MAGIC, .flags = IMA_FSMAGIC}, + {.action = DONT_MEASURE, .fsmagic = CGROUP_SUPER_MAGIC, + .flags = IMA_FSMAGIC}, + {.action = DONT_MEASURE, .fsmagic = CGROUP2_SUPER_MAGIC, + .flags = IMA_FSMAGIC}, + {.action = DONT_MEASURE, .fsmagic = NSFS_MAGIC, .flags = IMA_FSMAGIC}, + {.action = DONT_MEASURE, .fsmagic = EFIVARFS_MAGIC, .flags = IMA_FSMAGIC} +}; + +static struct ima_rule_entry original_measurement_rules[] __ro_after_init = { + {.action = MEASURE, .func = MMAP_CHECK, .mask = MAY_EXEC, + .flags = IMA_FUNC | IMA_MASK}, + {.action = MEASURE, .func = BPRM_CHECK, .mask = MAY_EXEC, + .flags = IMA_FUNC | IMA_MASK}, + {.action = MEASURE, .func = FILE_CHECK, .mask = MAY_READ, + .uid = GLOBAL_ROOT_UID, .uid_op = &uid_eq, + .flags = IMA_FUNC | IMA_MASK | IMA_UID}, + {.action = MEASURE, .func = MODULE_CHECK, .flags = IMA_FUNC}, + {.action = MEASURE, .func = FIRMWARE_CHECK, .flags = IMA_FUNC}, +}; + +static struct ima_rule_entry default_measurement_rules[] __ro_after_init = { + {.action = MEASURE, .func = MMAP_CHECK, .mask = MAY_EXEC, + .flags = IMA_FUNC | IMA_MASK}, + {.action = MEASURE, .func = BPRM_CHECK, .mask = MAY_EXEC, + .flags = IMA_FUNC | IMA_MASK}, + {.action = MEASURE, .func = FILE_CHECK, .mask = MAY_READ, + .uid = GLOBAL_ROOT_UID, .uid_op = &uid_eq, + .flags = IMA_FUNC | IMA_INMASK | IMA_EUID}, + {.action = MEASURE, .func = FILE_CHECK, .mask = MAY_READ, + .uid = GLOBAL_ROOT_UID, .uid_op = &uid_eq, + .flags = IMA_FUNC | IMA_INMASK | IMA_UID}, + {.action = MEASURE, .func = MODULE_CHECK, .flags = IMA_FUNC}, + {.action = MEASURE, .func = FIRMWARE_CHECK, .flags = IMA_FUNC}, + {.action = MEASURE, .func = POLICY_CHECK, .flags = IMA_FUNC}, +}; + +static struct ima_rule_entry default_appraise_rules[] __ro_after_init = { + {.action = DONT_APPRAISE, .fsmagic = PROC_SUPER_MAGIC, .flags = IMA_FSMAGIC}, + {.action = DONT_APPRAISE, .fsmagic = SYSFS_MAGIC, .flags = IMA_FSMAGIC}, + {.action = DONT_APPRAISE, .fsmagic = DEBUGFS_MAGIC, .flags = IMA_FSMAGIC}, + {.action = DONT_APPRAISE, .fsmagic = TMPFS_MAGIC, .flags = IMA_FSMAGIC}, + {.action = DONT_APPRAISE, .fsmagic = RAMFS_MAGIC, .flags = IMA_FSMAGIC}, + {.action = DONT_APPRAISE, .fsmagic = DEVPTS_SUPER_MAGIC, .flags = IMA_FSMAGIC}, + {.action = DONT_APPRAISE, .fsmagic = BINFMTFS_MAGIC, .flags = IMA_FSMAGIC}, + {.action = DONT_APPRAISE, .fsmagic = SECURITYFS_MAGIC, .flags = IMA_FSMAGIC}, + {.action = DONT_APPRAISE, .fsmagic = SELINUX_MAGIC, .flags = IMA_FSMAGIC}, + {.action = DONT_APPRAISE, .fsmagic = SMACK_MAGIC, .flags = IMA_FSMAGIC}, + {.action = DONT_APPRAISE, .fsmagic = NSFS_MAGIC, .flags = IMA_FSMAGIC}, + {.action = DONT_APPRAISE, .fsmagic = EFIVARFS_MAGIC, .flags = IMA_FSMAGIC}, + {.action = DONT_APPRAISE, .fsmagic = CGROUP_SUPER_MAGIC, .flags = IMA_FSMAGIC}, + {.action = DONT_APPRAISE, .fsmagic = CGROUP2_SUPER_MAGIC, .flags = IMA_FSMAGIC}, +#ifdef CONFIG_IMA_WRITE_POLICY + {.action = APPRAISE, .func = POLICY_CHECK, + .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED}, +#endif +#ifndef CONFIG_IMA_APPRAISE_SIGNED_INIT + {.action = APPRAISE, .fowner = GLOBAL_ROOT_UID, .fowner_op = &uid_eq, + .flags = IMA_FOWNER}, +#else + /* force signature */ + {.action = APPRAISE, .fowner = GLOBAL_ROOT_UID, .fowner_op = &uid_eq, + .flags = IMA_FOWNER | IMA_DIGSIG_REQUIRED}, +#endif +}; + +static struct ima_rule_entry build_appraise_rules[] __ro_after_init = { +#ifdef CONFIG_IMA_APPRAISE_REQUIRE_MODULE_SIGS + {.action = APPRAISE, .func = MODULE_CHECK, + .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED}, +#endif +#ifdef CONFIG_IMA_APPRAISE_REQUIRE_FIRMWARE_SIGS + {.action = APPRAISE, .func = FIRMWARE_CHECK, + .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED}, +#endif +#ifdef CONFIG_IMA_APPRAISE_REQUIRE_KEXEC_SIGS + {.action = APPRAISE, .func = KEXEC_KERNEL_CHECK, + .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED}, +#endif +#ifdef CONFIG_IMA_APPRAISE_REQUIRE_POLICY_SIGS + {.action = APPRAISE, .func = POLICY_CHECK, + .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED}, +#endif +}; + +static struct ima_rule_entry secure_boot_rules[] __ro_after_init = { + {.action = APPRAISE, .func = MODULE_CHECK, + .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED}, + {.action = APPRAISE, .func = FIRMWARE_CHECK, + .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED}, + {.action = APPRAISE, .func = KEXEC_KERNEL_CHECK, + .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED}, + {.action = APPRAISE, .func = POLICY_CHECK, + .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED}, +}; + +static struct ima_rule_entry critical_data_rules[] __ro_after_init = { + {.action = MEASURE, .func = CRITICAL_DATA, .flags = IMA_FUNC}, +}; + +/* An array of architecture specific rules */ +static struct ima_rule_entry *arch_policy_entry __ro_after_init; + +static LIST_HEAD(ima_default_rules); +static LIST_HEAD(ima_policy_rules); +static LIST_HEAD(ima_temp_rules); +static struct list_head __rcu *ima_rules = (struct list_head __rcu *)(&ima_default_rules); + +static int ima_policy __initdata; + +static int __init default_measure_policy_setup(char *str) +{ + if (ima_policy) + return 1; + + ima_policy = ORIGINAL_TCB; + return 1; +} +__setup("ima_tcb", default_measure_policy_setup); + +static bool ima_use_appraise_tcb __initdata; +static bool ima_use_secure_boot __initdata; +static bool ima_use_critical_data __initdata; +static bool ima_fail_unverifiable_sigs __ro_after_init; +static int __init policy_setup(char *str) +{ + char *p; + + while ((p = strsep(&str, " |\n")) != NULL) { + if (*p == ' ') + continue; + if ((strcmp(p, "tcb") == 0) && !ima_policy) + ima_policy = DEFAULT_TCB; + else if (strcmp(p, "appraise_tcb") == 0) + ima_use_appraise_tcb = true; + else if (strcmp(p, "secure_boot") == 0) + ima_use_secure_boot = true; + else if (strcmp(p, "critical_data") == 0) + ima_use_critical_data = true; + else if (strcmp(p, "fail_securely") == 0) + ima_fail_unverifiable_sigs = true; + else + pr_err("policy \"%s\" not found", p); + } + + return 1; +} +__setup("ima_policy=", policy_setup); + +static int __init default_appraise_policy_setup(char *str) +{ + ima_use_appraise_tcb = true; + return 1; +} +__setup("ima_appraise_tcb", default_appraise_policy_setup); + +static struct ima_rule_opt_list *ima_alloc_rule_opt_list(const substring_t *src) +{ + struct ima_rule_opt_list *opt_list; + size_t count = 0; + char *src_copy; + char *cur, *next; + size_t i; + + src_copy = match_strdup(src); + if (!src_copy) + return ERR_PTR(-ENOMEM); + + next = src_copy; + while ((cur = strsep(&next, "|"))) { + /* Don't accept an empty list item */ + if (!(*cur)) { + kfree(src_copy); + return ERR_PTR(-EINVAL); + } + count++; + } + + /* Don't accept an empty list */ + if (!count) { + kfree(src_copy); + return ERR_PTR(-EINVAL); + } + + opt_list = kzalloc(struct_size(opt_list, items, count), GFP_KERNEL); + if (!opt_list) { + kfree(src_copy); + return ERR_PTR(-ENOMEM); + } + + /* + * strsep() has already replaced all instances of '|' with '\0', + * leaving a byte sequence of NUL-terminated strings. Reference each + * string with the array of items. + * + * IMPORTANT: Ownership of the allocated buffer is transferred from + * src_copy to the first element in the items array. To free the + * buffer, kfree() must only be called on the first element of the + * array. + */ + for (i = 0, cur = src_copy; i < count; i++) { + opt_list->items[i] = cur; + cur = strchr(cur, '\0') + 1; + } + opt_list->count = count; + + return opt_list; +} + +static void ima_free_rule_opt_list(struct ima_rule_opt_list *opt_list) +{ + if (!opt_list) + return; + + if (opt_list->count) { + kfree(opt_list->items[0]); + opt_list->count = 0; + } + + kfree(opt_list); +} + +static void ima_lsm_free_rule(struct ima_rule_entry *entry) +{ + int i; + + for (i = 0; i < MAX_LSM_RULES; i++) { + ima_filter_rule_free(entry->lsm[i].rule); + kfree(entry->lsm[i].args_p); + } +} + +static void ima_free_rule(struct ima_rule_entry *entry) +{ + if (!entry) + return; + + /* + * entry->template->fields may be allocated in ima_parse_rule() but that + * reference is owned by the corresponding ima_template_desc element in + * the defined_templates list and cannot be freed here + */ + kfree(entry->fsname); + ima_free_rule_opt_list(entry->keyrings); + ima_lsm_free_rule(entry); + kfree(entry); +} + +static struct ima_rule_entry *ima_lsm_copy_rule(struct ima_rule_entry *entry) +{ + struct ima_rule_entry *nentry; + int i; + + /* + * Immutable elements are copied over as pointers and data; only + * lsm rules can change + */ + nentry = kmemdup(entry, sizeof(*nentry), GFP_KERNEL); + if (!nentry) + return NULL; + + memset(nentry->lsm, 0, sizeof_field(struct ima_rule_entry, lsm)); + + for (i = 0; i < MAX_LSM_RULES; i++) { + if (!entry->lsm[i].args_p) + continue; + + nentry->lsm[i].type = entry->lsm[i].type; + nentry->lsm[i].args_p = entry->lsm[i].args_p; + + ima_filter_rule_init(nentry->lsm[i].type, Audit_equal, + nentry->lsm[i].args_p, + &nentry->lsm[i].rule); + if (!nentry->lsm[i].rule) + pr_warn("rule for LSM \'%s\' is undefined\n", + nentry->lsm[i].args_p); + } + return nentry; +} + +static int ima_lsm_update_rule(struct ima_rule_entry *entry) +{ + int i; + struct ima_rule_entry *nentry; + + nentry = ima_lsm_copy_rule(entry); + if (!nentry) + return -ENOMEM; + + list_replace_rcu(&entry->list, &nentry->list); + synchronize_rcu(); + /* + * ima_lsm_copy_rule() shallow copied all references, except for the + * LSM references, from entry to nentry so we only want to free the LSM + * references and the entry itself. All other memory references will now + * be owned by nentry. + */ + for (i = 0; i < MAX_LSM_RULES; i++) + ima_filter_rule_free(entry->lsm[i].rule); + kfree(entry); + + return 0; +} + +static bool ima_rule_contains_lsm_cond(struct ima_rule_entry *entry) +{ + int i; + + for (i = 0; i < MAX_LSM_RULES; i++) + if (entry->lsm[i].args_p) + return true; + + return false; +} + +/* + * The LSM policy can be reloaded, leaving the IMA LSM based rules referring + * to the old, stale LSM policy. Update the IMA LSM based rules to reflect + * the reloaded LSM policy. + */ +static void ima_lsm_update_rules(void) +{ + struct ima_rule_entry *entry, *e; + int result; + + list_for_each_entry_safe(entry, e, &ima_policy_rules, list) { + if (!ima_rule_contains_lsm_cond(entry)) + continue; + + result = ima_lsm_update_rule(entry); + if (result) { + pr_err("lsm rule update error %d\n", result); + return; + } + } +} + +int ima_lsm_policy_change(struct notifier_block *nb, unsigned long event, + void *lsm_data) +{ + if (event != LSM_POLICY_CHANGE) + return NOTIFY_DONE; + + ima_lsm_update_rules(); + return NOTIFY_OK; +} + +/** + * ima_match_rule_data - determine whether func_data matches the policy rule + * @rule: a pointer to a rule + * @func_data: data to match against the measure rule data + * @cred: a pointer to a credentials structure for user validation + * + * Returns true if func_data matches one in the rule, false otherwise. + */ +static bool ima_match_rule_data(struct ima_rule_entry *rule, + const char *func_data, + const struct cred *cred) +{ + const struct ima_rule_opt_list *opt_list = NULL; + bool matched = false; + size_t i; + + if ((rule->flags & IMA_UID) && !rule->uid_op(cred->uid, rule->uid)) + return false; + + switch (rule->func) { + case KEY_CHECK: + if (!rule->keyrings) + return true; + + opt_list = rule->keyrings; + break; + case CRITICAL_DATA: + if (!rule->label) + return true; + + opt_list = rule->label; + break; + default: + return false; + } + + if (!func_data) + return false; + + for (i = 0; i < opt_list->count; i++) { + if (!strcmp(opt_list->items[i], func_data)) { + matched = true; + break; + } + } + + return matched; +} + +/** + * ima_match_rules - determine whether an inode matches the policy rule. + * @rule: a pointer to a rule + * @mnt_userns: user namespace of the mount the inode was found from + * @inode: a pointer to an inode + * @cred: a pointer to a credentials structure for user validation + * @secid: the secid of the task to be validated + * @func: LIM hook identifier + * @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC) + * @func_data: func specific data, may be NULL + * + * Returns true on rule match, false on failure. + */ +static bool ima_match_rules(struct ima_rule_entry *rule, + struct user_namespace *mnt_userns, + struct inode *inode, const struct cred *cred, + u32 secid, enum ima_hooks func, int mask, + const char *func_data) +{ + int i; + bool result = false; + struct ima_rule_entry *lsm_rule = rule; + bool rule_reinitialized = false; + + if ((rule->flags & IMA_FUNC) && + (rule->func != func && func != POST_SETATTR)) + return false; + + switch (func) { + case KEY_CHECK: + case CRITICAL_DATA: + return ((rule->func == func) && + ima_match_rule_data(rule, func_data, cred)); + default: + break; + } + + if ((rule->flags & IMA_MASK) && + (rule->mask != mask && func != POST_SETATTR)) + return false; + if ((rule->flags & IMA_INMASK) && + (!(rule->mask & mask) && func != POST_SETATTR)) + return false; + if ((rule->flags & IMA_FSMAGIC) + && rule->fsmagic != inode->i_sb->s_magic) + return false; + if ((rule->flags & IMA_FSNAME) + && strcmp(rule->fsname, inode->i_sb->s_type->name)) + return false; + if ((rule->flags & IMA_FSUUID) && + !uuid_equal(&rule->fsuuid, &inode->i_sb->s_uuid)) + return false; + if ((rule->flags & IMA_UID) && !rule->uid_op(cred->uid, rule->uid)) + return false; + if (rule->flags & IMA_EUID) { + if (has_capability_noaudit(current, CAP_SETUID)) { + if (!rule->uid_op(cred->euid, rule->uid) + && !rule->uid_op(cred->suid, rule->uid) + && !rule->uid_op(cred->uid, rule->uid)) + return false; + } else if (!rule->uid_op(cred->euid, rule->uid)) + return false; + } + if ((rule->flags & IMA_GID) && !rule->gid_op(cred->gid, rule->gid)) + return false; + if (rule->flags & IMA_EGID) { + if (has_capability_noaudit(current, CAP_SETGID)) { + if (!rule->gid_op(cred->egid, rule->gid) + && !rule->gid_op(cred->sgid, rule->gid) + && !rule->gid_op(cred->gid, rule->gid)) + return false; + } else if (!rule->gid_op(cred->egid, rule->gid)) + return false; + } + if ((rule->flags & IMA_FOWNER) && + !rule->fowner_op(i_uid_into_mnt(mnt_userns, inode), rule->fowner)) + return false; + if ((rule->flags & IMA_FGROUP) && + !rule->fgroup_op(i_gid_into_mnt(mnt_userns, inode), rule->fgroup)) + return false; + for (i = 0; i < MAX_LSM_RULES; i++) { + int rc = 0; + u32 osid; + + if (!lsm_rule->lsm[i].rule) { + if (!lsm_rule->lsm[i].args_p) + continue; + else + return false; + } + +retry: + switch (i) { + case LSM_OBJ_USER: + case LSM_OBJ_ROLE: + case LSM_OBJ_TYPE: + security_inode_getsecid(inode, &osid); + rc = ima_filter_rule_match(osid, lsm_rule->lsm[i].type, + Audit_equal, + lsm_rule->lsm[i].rule); + break; + case LSM_SUBJ_USER: + case LSM_SUBJ_ROLE: + case LSM_SUBJ_TYPE: + rc = ima_filter_rule_match(secid, lsm_rule->lsm[i].type, + Audit_equal, + lsm_rule->lsm[i].rule); + break; + default: + break; + } + + if (rc == -ESTALE && !rule_reinitialized) { + lsm_rule = ima_lsm_copy_rule(rule); + if (lsm_rule) { + rule_reinitialized = true; + goto retry; + } + } + if (!rc) { + result = false; + goto out; + } + } + result = true; + +out: + if (rule_reinitialized) { + for (i = 0; i < MAX_LSM_RULES; i++) + ima_filter_rule_free(lsm_rule->lsm[i].rule); + kfree(lsm_rule); + } + return result; +} + +/* + * In addition to knowing that we need to appraise the file in general, + * we need to differentiate between calling hooks, for hook specific rules. + */ +static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func) +{ + if (!(rule->flags & IMA_FUNC)) + return IMA_FILE_APPRAISE; + + switch (func) { + case MMAP_CHECK: + return IMA_MMAP_APPRAISE; + case BPRM_CHECK: + return IMA_BPRM_APPRAISE; + case CREDS_CHECK: + return IMA_CREDS_APPRAISE; + case FILE_CHECK: + case POST_SETATTR: + return IMA_FILE_APPRAISE; + case MODULE_CHECK ... MAX_CHECK - 1: + default: + return IMA_READ_APPRAISE; + } +} + +/** + * ima_match_policy - decision based on LSM and other conditions + * @mnt_userns: user namespace of the mount the inode was found from + * @inode: pointer to an inode for which the policy decision is being made + * @cred: pointer to a credentials structure for which the policy decision is + * being made + * @secid: LSM secid of the task to be validated + * @func: IMA hook identifier + * @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC) + * @flags: IMA actions to consider (e.g. IMA_MEASURE | IMA_APPRAISE) + * @pcr: set the pcr to extend + * @template_desc: the template that should be used for this rule + * @func_data: func specific data, may be NULL + * @allowed_algos: allowlist of hash algorithms for the IMA xattr + * + * Measure decision based on func/mask/fsmagic and LSM(subj/obj/type) + * conditions. + * + * Since the IMA policy may be updated multiple times we need to lock the + * list when walking it. Reads are many orders of magnitude more numerous + * than writes so ima_match_policy() is classical RCU candidate. + */ +int ima_match_policy(struct user_namespace *mnt_userns, struct inode *inode, + const struct cred *cred, u32 secid, enum ima_hooks func, + int mask, int flags, int *pcr, + struct ima_template_desc **template_desc, + const char *func_data, unsigned int *allowed_algos) +{ + struct ima_rule_entry *entry; + int action = 0, actmask = flags | (flags << 1); + struct list_head *ima_rules_tmp; + + if (template_desc && !*template_desc) + *template_desc = ima_template_desc_current(); + + rcu_read_lock(); + ima_rules_tmp = rcu_dereference(ima_rules); + list_for_each_entry_rcu(entry, ima_rules_tmp, list) { + + if (!(entry->action & actmask)) + continue; + + if (!ima_match_rules(entry, mnt_userns, inode, cred, secid, + func, mask, func_data)) + continue; + + action |= entry->flags & IMA_NONACTION_FLAGS; + + action |= entry->action & IMA_DO_MASK; + if (entry->action & IMA_APPRAISE) { + action |= get_subaction(entry, func); + action &= ~IMA_HASH; + if (ima_fail_unverifiable_sigs) + action |= IMA_FAIL_UNVERIFIABLE_SIGS; + + if (allowed_algos && + entry->flags & IMA_VALIDATE_ALGOS) + *allowed_algos = entry->allowed_algos; + } + + if (entry->action & IMA_DO_MASK) + actmask &= ~(entry->action | entry->action << 1); + else + actmask &= ~(entry->action | entry->action >> 1); + + if ((pcr) && (entry->flags & IMA_PCR)) + *pcr = entry->pcr; + + if (template_desc && entry->template) + *template_desc = entry->template; + + if (!actmask) + break; + } + rcu_read_unlock(); + + return action; +} + +/** + * ima_update_policy_flags() - Update global IMA variables + * + * Update ima_policy_flag and ima_setxattr_allowed_hash_algorithms + * based on the currently loaded policy. + * + * With ima_policy_flag, the decision to short circuit out of a function + * or not call the function in the first place can be made earlier. + * + * With ima_setxattr_allowed_hash_algorithms, the policy can restrict the + * set of hash algorithms accepted when updating the security.ima xattr of + * a file. + * + * Context: called after a policy update and at system initialization. + */ +void ima_update_policy_flags(void) +{ + struct ima_rule_entry *entry; + int new_policy_flag = 0; + struct list_head *ima_rules_tmp; + + rcu_read_lock(); + ima_rules_tmp = rcu_dereference(ima_rules); + list_for_each_entry_rcu(entry, ima_rules_tmp, list) { + /* + * SETXATTR_CHECK rules do not implement a full policy check + * because rule checking would probably have an important + * performance impact on setxattr(). As a consequence, only one + * SETXATTR_CHECK can be active at a given time. + * Because we want to preserve that property, we set out to use + * atomic_cmpxchg. Either: + * - the atomic was non-zero: a setxattr hash policy is + * already enforced, we do nothing + * - the atomic was zero: no setxattr policy was set, enable + * the setxattr hash policy + */ + if (entry->func == SETXATTR_CHECK) { + atomic_cmpxchg(&ima_setxattr_allowed_hash_algorithms, + 0, entry->allowed_algos); + /* SETXATTR_CHECK doesn't impact ima_policy_flag */ + continue; + } + + if (entry->action & IMA_DO_MASK) + new_policy_flag |= entry->action; + } + rcu_read_unlock(); + + ima_appraise |= (build_ima_appraise | temp_ima_appraise); + if (!ima_appraise) + new_policy_flag &= ~IMA_APPRAISE; + + ima_policy_flag = new_policy_flag; +} + +static int ima_appraise_flag(enum ima_hooks func) +{ + if (func == MODULE_CHECK) + return IMA_APPRAISE_MODULES; + else if (func == FIRMWARE_CHECK) + return IMA_APPRAISE_FIRMWARE; + else if (func == POLICY_CHECK) + return IMA_APPRAISE_POLICY; + else if (func == KEXEC_KERNEL_CHECK) + return IMA_APPRAISE_KEXEC; + return 0; +} + +static void add_rules(struct ima_rule_entry *entries, int count, + enum policy_rule_list policy_rule) +{ + int i = 0; + + for (i = 0; i < count; i++) { + struct ima_rule_entry *entry; + + if (policy_rule & IMA_DEFAULT_POLICY) + list_add_tail(&entries[i].list, &ima_default_rules); + + if (policy_rule & IMA_CUSTOM_POLICY) { + entry = kmemdup(&entries[i], sizeof(*entry), + GFP_KERNEL); + if (!entry) + continue; + + list_add_tail(&entry->list, &ima_policy_rules); + } + if (entries[i].action == APPRAISE) { + if (entries != build_appraise_rules) + temp_ima_appraise |= + ima_appraise_flag(entries[i].func); + else + build_ima_appraise |= + ima_appraise_flag(entries[i].func); + } + } +} + +static int ima_parse_rule(char *rule, struct ima_rule_entry *entry); + +static int __init ima_init_arch_policy(void) +{ + const char * const *arch_rules; + const char * const *rules; + int arch_entries = 0; + int i = 0; + + arch_rules = arch_get_ima_policy(); + if (!arch_rules) + return arch_entries; + + /* Get number of rules */ + for (rules = arch_rules; *rules != NULL; rules++) + arch_entries++; + + arch_policy_entry = kcalloc(arch_entries + 1, + sizeof(*arch_policy_entry), GFP_KERNEL); + if (!arch_policy_entry) + return 0; + + /* Convert each policy string rules to struct ima_rule_entry format */ + for (rules = arch_rules, i = 0; *rules != NULL; rules++) { + char rule[255]; + int result; + + result = strscpy(rule, *rules, sizeof(rule)); + + INIT_LIST_HEAD(&arch_policy_entry[i].list); + result = ima_parse_rule(rule, &arch_policy_entry[i]); + if (result) { + pr_warn("Skipping unknown architecture policy rule: %s\n", + rule); + memset(&arch_policy_entry[i], 0, + sizeof(*arch_policy_entry)); + continue; + } + i++; + } + return i; +} + +/** + * ima_init_policy - initialize the default measure rules. + * + * ima_rules points to either the ima_default_rules or the new ima_policy_rules. + */ +void __init ima_init_policy(void) +{ + int build_appraise_entries, arch_entries; + + /* if !ima_policy, we load NO default rules */ + if (ima_policy) + add_rules(dont_measure_rules, ARRAY_SIZE(dont_measure_rules), + IMA_DEFAULT_POLICY); + + switch (ima_policy) { + case ORIGINAL_TCB: + add_rules(original_measurement_rules, + ARRAY_SIZE(original_measurement_rules), + IMA_DEFAULT_POLICY); + break; + case DEFAULT_TCB: + add_rules(default_measurement_rules, + ARRAY_SIZE(default_measurement_rules), + IMA_DEFAULT_POLICY); + break; + default: + break; + } + + /* + * Based on runtime secure boot flags, insert arch specific measurement + * and appraise rules requiring file signatures for both the initial + * and custom policies, prior to other appraise rules. + * (Highest priority) + */ + arch_entries = ima_init_arch_policy(); + if (!arch_entries) + pr_info("No architecture policies found\n"); + else + add_rules(arch_policy_entry, arch_entries, + IMA_DEFAULT_POLICY | IMA_CUSTOM_POLICY); + + /* + * Insert the builtin "secure_boot" policy rules requiring file + * signatures, prior to other appraise rules. + */ + if (ima_use_secure_boot) + add_rules(secure_boot_rules, ARRAY_SIZE(secure_boot_rules), + IMA_DEFAULT_POLICY); + + /* + * Insert the build time appraise rules requiring file signatures + * for both the initial and custom policies, prior to other appraise + * rules. As the secure boot rules includes all of the build time + * rules, include either one or the other set of rules, but not both. + */ + build_appraise_entries = ARRAY_SIZE(build_appraise_rules); + if (build_appraise_entries) { + if (ima_use_secure_boot) + add_rules(build_appraise_rules, build_appraise_entries, + IMA_CUSTOM_POLICY); + else + add_rules(build_appraise_rules, build_appraise_entries, + IMA_DEFAULT_POLICY | IMA_CUSTOM_POLICY); + } + + if (ima_use_appraise_tcb) + add_rules(default_appraise_rules, + ARRAY_SIZE(default_appraise_rules), + IMA_DEFAULT_POLICY); + + if (ima_use_critical_data) + add_rules(critical_data_rules, + ARRAY_SIZE(critical_data_rules), + IMA_DEFAULT_POLICY); + + atomic_set(&ima_setxattr_allowed_hash_algorithms, 0); + + ima_update_policy_flags(); +} + +/* Make sure we have a valid policy, at least containing some rules. */ +int ima_check_policy(void) +{ + if (list_empty(&ima_temp_rules)) + return -EINVAL; + return 0; +} + +/** + * ima_update_policy - update default_rules with new measure rules + * + * Called on file .release to update the default rules with a complete new + * policy. What we do here is to splice ima_policy_rules and ima_temp_rules so + * they make a queue. The policy may be updated multiple times and this is the + * RCU updater. + * + * Policy rules are never deleted so ima_policy_flag gets zeroed only once when + * we switch from the default policy to user defined. + */ +void ima_update_policy(void) +{ + struct list_head *policy = &ima_policy_rules; + + list_splice_tail_init_rcu(&ima_temp_rules, policy, synchronize_rcu); + + if (ima_rules != (struct list_head __rcu *)policy) { + ima_policy_flag = 0; + + rcu_assign_pointer(ima_rules, policy); + /* + * IMA architecture specific policy rules are specified + * as strings and converted to an array of ima_entry_rules + * on boot. After loading a custom policy, free the + * architecture specific rules stored as an array. + */ + kfree(arch_policy_entry); + } + ima_update_policy_flags(); + + /* Custom IMA policy has been loaded */ + ima_process_queued_keys(); +} + +/* Keep the enumeration in sync with the policy_tokens! */ +enum policy_opt { + Opt_measure, Opt_dont_measure, + Opt_appraise, Opt_dont_appraise, + Opt_audit, Opt_hash, Opt_dont_hash, + Opt_obj_user, Opt_obj_role, Opt_obj_type, + Opt_subj_user, Opt_subj_role, Opt_subj_type, + Opt_func, Opt_mask, Opt_fsmagic, Opt_fsname, Opt_fsuuid, + Opt_uid_eq, Opt_euid_eq, Opt_gid_eq, Opt_egid_eq, + Opt_fowner_eq, Opt_fgroup_eq, + Opt_uid_gt, Opt_euid_gt, Opt_gid_gt, Opt_egid_gt, + Opt_fowner_gt, Opt_fgroup_gt, + Opt_uid_lt, Opt_euid_lt, Opt_gid_lt, Opt_egid_lt, + Opt_fowner_lt, Opt_fgroup_lt, + Opt_digest_type, + Opt_appraise_type, Opt_appraise_flag, Opt_appraise_algos, + Opt_permit_directio, Opt_pcr, Opt_template, Opt_keyrings, + Opt_label, Opt_err +}; + +static const match_table_t policy_tokens = { + {Opt_measure, "measure"}, + {Opt_dont_measure, "dont_measure"}, + {Opt_appraise, "appraise"}, + {Opt_dont_appraise, "dont_appraise"}, + {Opt_audit, "audit"}, + {Opt_hash, "hash"}, + {Opt_dont_hash, "dont_hash"}, + {Opt_obj_user, "obj_user=%s"}, + {Opt_obj_role, "obj_role=%s"}, + {Opt_obj_type, "obj_type=%s"}, + {Opt_subj_user, "subj_user=%s"}, + {Opt_subj_role, "subj_role=%s"}, + {Opt_subj_type, "subj_type=%s"}, + {Opt_func, "func=%s"}, + {Opt_mask, "mask=%s"}, + {Opt_fsmagic, "fsmagic=%s"}, + {Opt_fsname, "fsname=%s"}, + {Opt_fsuuid, "fsuuid=%s"}, + {Opt_uid_eq, "uid=%s"}, + {Opt_euid_eq, "euid=%s"}, + {Opt_gid_eq, "gid=%s"}, + {Opt_egid_eq, "egid=%s"}, + {Opt_fowner_eq, "fowner=%s"}, + {Opt_fgroup_eq, "fgroup=%s"}, + {Opt_uid_gt, "uid>%s"}, + {Opt_euid_gt, "euid>%s"}, + {Opt_gid_gt, "gid>%s"}, + {Opt_egid_gt, "egid>%s"}, + {Opt_fowner_gt, "fowner>%s"}, + {Opt_fgroup_gt, "fgroup>%s"}, + {Opt_uid_lt, "uid<%s"}, + {Opt_euid_lt, "euid<%s"}, + {Opt_gid_lt, "gid<%s"}, + {Opt_egid_lt, "egid<%s"}, + {Opt_fowner_lt, "fowner<%s"}, + {Opt_fgroup_lt, "fgroup<%s"}, + {Opt_digest_type, "digest_type=%s"}, + {Opt_appraise_type, "appraise_type=%s"}, + {Opt_appraise_flag, "appraise_flag=%s"}, + {Opt_appraise_algos, "appraise_algos=%s"}, + {Opt_permit_directio, "permit_directio"}, + {Opt_pcr, "pcr=%s"}, + {Opt_template, "template=%s"}, + {Opt_keyrings, "keyrings=%s"}, + {Opt_label, "label=%s"}, + {Opt_err, NULL} +}; + +static int ima_lsm_rule_init(struct ima_rule_entry *entry, + substring_t *args, int lsm_rule, int audit_type) +{ + int result; + + if (entry->lsm[lsm_rule].rule) + return -EINVAL; + + entry->lsm[lsm_rule].args_p = match_strdup(args); + if (!entry->lsm[lsm_rule].args_p) + return -ENOMEM; + + entry->lsm[lsm_rule].type = audit_type; + result = ima_filter_rule_init(entry->lsm[lsm_rule].type, Audit_equal, + entry->lsm[lsm_rule].args_p, + &entry->lsm[lsm_rule].rule); + if (!entry->lsm[lsm_rule].rule) { + pr_warn("rule for LSM \'%s\' is undefined\n", + entry->lsm[lsm_rule].args_p); + + if (ima_rules == (struct list_head __rcu *)(&ima_default_rules)) { + kfree(entry->lsm[lsm_rule].args_p); + entry->lsm[lsm_rule].args_p = NULL; + result = -EINVAL; + } else + result = 0; + } + + return result; +} + +static void ima_log_string_op(struct audit_buffer *ab, char *key, char *value, + enum policy_opt rule_operator) +{ + if (!ab) + return; + + switch (rule_operator) { + case Opt_uid_gt: + case Opt_euid_gt: + case Opt_gid_gt: + case Opt_egid_gt: + case Opt_fowner_gt: + case Opt_fgroup_gt: + audit_log_format(ab, "%s>", key); + break; + case Opt_uid_lt: + case Opt_euid_lt: + case Opt_gid_lt: + case Opt_egid_lt: + case Opt_fowner_lt: + case Opt_fgroup_lt: + audit_log_format(ab, "%s<", key); + break; + default: + audit_log_format(ab, "%s=", key); + } + audit_log_format(ab, "%s ", value); +} +static void ima_log_string(struct audit_buffer *ab, char *key, char *value) +{ + ima_log_string_op(ab, key, value, Opt_err); +} + +/* + * Validating the appended signature included in the measurement list requires + * the file hash calculated without the appended signature (i.e., the 'd-modsig' + * field). Therefore, notify the user if they have the 'modsig' field but not + * the 'd-modsig' field in the template. + */ +static void check_template_modsig(const struct ima_template_desc *template) +{ +#define MSG "template with 'modsig' field also needs 'd-modsig' field\n" + bool has_modsig, has_dmodsig; + static bool checked; + int i; + + /* We only need to notify the user once. */ + if (checked) + return; + + has_modsig = has_dmodsig = false; + for (i = 0; i < template->num_fields; i++) { + if (!strcmp(template->fields[i]->field_id, "modsig")) + has_modsig = true; + else if (!strcmp(template->fields[i]->field_id, "d-modsig")) + has_dmodsig = true; + } + + if (has_modsig && !has_dmodsig) + pr_notice(MSG); + + checked = true; +#undef MSG +} + +/* + * Warn if the template does not contain the given field. + */ +static void check_template_field(const struct ima_template_desc *template, + const char *field, const char *msg) +{ + int i; + + for (i = 0; i < template->num_fields; i++) + if (!strcmp(template->fields[i]->field_id, field)) + return; + + pr_notice_once("%s", msg); +} + +static bool ima_validate_rule(struct ima_rule_entry *entry) +{ + /* Ensure that the action is set and is compatible with the flags */ + if (entry->action == UNKNOWN) + return false; + + if (entry->action != MEASURE && entry->flags & IMA_PCR) + return false; + + if (entry->action != APPRAISE && + entry->flags & (IMA_DIGSIG_REQUIRED | IMA_MODSIG_ALLOWED | + IMA_CHECK_BLACKLIST | IMA_VALIDATE_ALGOS)) + return false; + + /* + * The IMA_FUNC bit must be set if and only if there's a valid hook + * function specified, and vice versa. Enforcing this property allows + * for the NONE case below to validate a rule without an explicit hook + * function. + */ + if (((entry->flags & IMA_FUNC) && entry->func == NONE) || + (!(entry->flags & IMA_FUNC) && entry->func != NONE)) + return false; + + /* + * Ensure that the hook function is compatible with the other + * components of the rule + */ + switch (entry->func) { + case NONE: + case FILE_CHECK: + case MMAP_CHECK: + case BPRM_CHECK: + case CREDS_CHECK: + case POST_SETATTR: + case FIRMWARE_CHECK: + case POLICY_CHECK: + if (entry->flags & ~(IMA_FUNC | IMA_MASK | IMA_FSMAGIC | + IMA_UID | IMA_FOWNER | IMA_FSUUID | + IMA_INMASK | IMA_EUID | IMA_PCR | + IMA_FSNAME | IMA_GID | IMA_EGID | + IMA_FGROUP | IMA_DIGSIG_REQUIRED | + IMA_PERMIT_DIRECTIO | IMA_VALIDATE_ALGOS | + IMA_VERITY_REQUIRED)) + return false; + + break; + case MODULE_CHECK: + case KEXEC_KERNEL_CHECK: + case KEXEC_INITRAMFS_CHECK: + if (entry->flags & ~(IMA_FUNC | IMA_MASK | IMA_FSMAGIC | + IMA_UID | IMA_FOWNER | IMA_FSUUID | + IMA_INMASK | IMA_EUID | IMA_PCR | + IMA_FSNAME | IMA_GID | IMA_EGID | + IMA_FGROUP | IMA_DIGSIG_REQUIRED | + IMA_PERMIT_DIRECTIO | IMA_MODSIG_ALLOWED | + IMA_CHECK_BLACKLIST | IMA_VALIDATE_ALGOS)) + return false; + + break; + case KEXEC_CMDLINE: + if (entry->action & ~(MEASURE | DONT_MEASURE)) + return false; + + if (entry->flags & ~(IMA_FUNC | IMA_FSMAGIC | IMA_UID | + IMA_FOWNER | IMA_FSUUID | IMA_EUID | + IMA_PCR | IMA_FSNAME | IMA_GID | IMA_EGID | + IMA_FGROUP)) + return false; + + break; + case KEY_CHECK: + if (entry->action & ~(MEASURE | DONT_MEASURE)) + return false; + + if (entry->flags & ~(IMA_FUNC | IMA_UID | IMA_GID | IMA_PCR | + IMA_KEYRINGS)) + return false; + + if (ima_rule_contains_lsm_cond(entry)) + return false; + + break; + case CRITICAL_DATA: + if (entry->action & ~(MEASURE | DONT_MEASURE)) + return false; + + if (entry->flags & ~(IMA_FUNC | IMA_UID | IMA_GID | IMA_PCR | + IMA_LABEL)) + return false; + + if (ima_rule_contains_lsm_cond(entry)) + return false; + + break; + case SETXATTR_CHECK: + /* any action other than APPRAISE is unsupported */ + if (entry->action != APPRAISE) + return false; + + /* SETXATTR_CHECK requires an appraise_algos parameter */ + if (!(entry->flags & IMA_VALIDATE_ALGOS)) + return false; + + /* + * full policies are not supported, they would have too + * much of a performance impact + */ + if (entry->flags & ~(IMA_FUNC | IMA_VALIDATE_ALGOS)) + return false; + + break; + default: + return false; + } + + /* Ensure that combinations of flags are compatible with each other */ + if (entry->flags & IMA_CHECK_BLACKLIST && + !(entry->flags & IMA_MODSIG_ALLOWED)) + return false; + + /* + * Unlike for regular IMA 'appraise' policy rules where security.ima + * xattr may contain either a file hash or signature, the security.ima + * xattr for fsverity must contain a file signature (sigv3). Ensure + * that 'appraise' rules for fsverity require file signatures by + * checking the IMA_DIGSIG_REQUIRED flag is set. + */ + if (entry->action == APPRAISE && + (entry->flags & IMA_VERITY_REQUIRED) && + !(entry->flags & IMA_DIGSIG_REQUIRED)) + return false; + + return true; +} + +static unsigned int ima_parse_appraise_algos(char *arg) +{ + unsigned int res = 0; + int idx; + char *token; + + while ((token = strsep(&arg, ",")) != NULL) { + idx = match_string(hash_algo_name, HASH_ALGO__LAST, token); + + if (idx < 0) { + pr_err("unknown hash algorithm \"%s\"", + token); + return 0; + } + + if (!crypto_has_alg(hash_algo_name[idx], 0, 0)) { + pr_err("unavailable hash algorithm \"%s\", check your kernel configuration", + token); + return 0; + } + + /* Add the hash algorithm to the 'allowed' bitfield */ + res |= (1U << idx); + } + + return res; +} + +static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) +{ + struct audit_buffer *ab; + char *from; + char *p; + bool eid_token; /* either euid or egid */ + struct ima_template_desc *template_desc; + int result = 0; + + ab = integrity_audit_log_start(audit_context(), GFP_KERNEL, + AUDIT_INTEGRITY_POLICY_RULE); + + entry->uid = INVALID_UID; + entry->gid = INVALID_GID; + entry->fowner = INVALID_UID; + entry->fgroup = INVALID_GID; + entry->uid_op = &uid_eq; + entry->gid_op = &gid_eq; + entry->fowner_op = &uid_eq; + entry->fgroup_op = &gid_eq; + entry->action = UNKNOWN; + while ((p = strsep(&rule, " \t")) != NULL) { + substring_t args[MAX_OPT_ARGS]; + int token; + unsigned long lnum; + + if (result < 0) + break; + if ((*p == '\0') || (*p == ' ') || (*p == '\t')) + continue; + token = match_token(p, policy_tokens, args); + switch (token) { + case Opt_measure: + ima_log_string(ab, "action", "measure"); + + if (entry->action != UNKNOWN) + result = -EINVAL; + + entry->action = MEASURE; + break; + case Opt_dont_measure: + ima_log_string(ab, "action", "dont_measure"); + + if (entry->action != UNKNOWN) + result = -EINVAL; + + entry->action = DONT_MEASURE; + break; + case Opt_appraise: + ima_log_string(ab, "action", "appraise"); + + if (entry->action != UNKNOWN) + result = -EINVAL; + + entry->action = APPRAISE; + break; + case Opt_dont_appraise: + ima_log_string(ab, "action", "dont_appraise"); + + if (entry->action != UNKNOWN) + result = -EINVAL; + + entry->action = DONT_APPRAISE; + break; + case Opt_audit: + ima_log_string(ab, "action", "audit"); + + if (entry->action != UNKNOWN) + result = -EINVAL; + + entry->action = AUDIT; + break; + case Opt_hash: + ima_log_string(ab, "action", "hash"); + + if (entry->action != UNKNOWN) + result = -EINVAL; + + entry->action = HASH; + break; + case Opt_dont_hash: + ima_log_string(ab, "action", "dont_hash"); + + if (entry->action != UNKNOWN) + result = -EINVAL; + + entry->action = DONT_HASH; + break; + case Opt_func: + ima_log_string(ab, "func", args[0].from); + + if (entry->func) + result = -EINVAL; + + if (strcmp(args[0].from, "FILE_CHECK") == 0) + entry->func = FILE_CHECK; + /* PATH_CHECK is for backwards compat */ + else if (strcmp(args[0].from, "PATH_CHECK") == 0) + entry->func = FILE_CHECK; + else if (strcmp(args[0].from, "MODULE_CHECK") == 0) + entry->func = MODULE_CHECK; + else if (strcmp(args[0].from, "FIRMWARE_CHECK") == 0) + entry->func = FIRMWARE_CHECK; + else if ((strcmp(args[0].from, "FILE_MMAP") == 0) + || (strcmp(args[0].from, "MMAP_CHECK") == 0)) + entry->func = MMAP_CHECK; + else if (strcmp(args[0].from, "BPRM_CHECK") == 0) + entry->func = BPRM_CHECK; + else if (strcmp(args[0].from, "CREDS_CHECK") == 0) + entry->func = CREDS_CHECK; + else if (strcmp(args[0].from, "KEXEC_KERNEL_CHECK") == + 0) + entry->func = KEXEC_KERNEL_CHECK; + else if (strcmp(args[0].from, "KEXEC_INITRAMFS_CHECK") + == 0) + entry->func = KEXEC_INITRAMFS_CHECK; + else if (strcmp(args[0].from, "POLICY_CHECK") == 0) + entry->func = POLICY_CHECK; + else if (strcmp(args[0].from, "KEXEC_CMDLINE") == 0) + entry->func = KEXEC_CMDLINE; + else if (IS_ENABLED(CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS) && + strcmp(args[0].from, "KEY_CHECK") == 0) + entry->func = KEY_CHECK; + else if (strcmp(args[0].from, "CRITICAL_DATA") == 0) + entry->func = CRITICAL_DATA; + else if (strcmp(args[0].from, "SETXATTR_CHECK") == 0) + entry->func = SETXATTR_CHECK; + else + result = -EINVAL; + if (!result) + entry->flags |= IMA_FUNC; + break; + case Opt_mask: + ima_log_string(ab, "mask", args[0].from); + + if (entry->mask) + result = -EINVAL; + + from = args[0].from; + if (*from == '^') + from++; + + if ((strcmp(from, "MAY_EXEC")) == 0) + entry->mask = MAY_EXEC; + else if (strcmp(from, "MAY_WRITE") == 0) + entry->mask = MAY_WRITE; + else if (strcmp(from, "MAY_READ") == 0) + entry->mask = MAY_READ; + else if (strcmp(from, "MAY_APPEND") == 0) + entry->mask = MAY_APPEND; + else + result = -EINVAL; + if (!result) + entry->flags |= (*args[0].from == '^') + ? IMA_INMASK : IMA_MASK; + break; + case Opt_fsmagic: + ima_log_string(ab, "fsmagic", args[0].from); + + if (entry->fsmagic) { + result = -EINVAL; + break; + } + + result = kstrtoul(args[0].from, 16, &entry->fsmagic); + if (!result) + entry->flags |= IMA_FSMAGIC; + break; + case Opt_fsname: + ima_log_string(ab, "fsname", args[0].from); + + entry->fsname = kstrdup(args[0].from, GFP_KERNEL); + if (!entry->fsname) { + result = -ENOMEM; + break; + } + result = 0; + entry->flags |= IMA_FSNAME; + break; + case Opt_keyrings: + ima_log_string(ab, "keyrings", args[0].from); + + if (!IS_ENABLED(CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS) || + entry->keyrings) { + result = -EINVAL; + break; + } + + entry->keyrings = ima_alloc_rule_opt_list(args); + if (IS_ERR(entry->keyrings)) { + result = PTR_ERR(entry->keyrings); + entry->keyrings = NULL; + break; + } + + entry->flags |= IMA_KEYRINGS; + break; + case Opt_label: + ima_log_string(ab, "label", args[0].from); + + if (entry->label) { + result = -EINVAL; + break; + } + + entry->label = ima_alloc_rule_opt_list(args); + if (IS_ERR(entry->label)) { + result = PTR_ERR(entry->label); + entry->label = NULL; + break; + } + + entry->flags |= IMA_LABEL; + break; + case Opt_fsuuid: + ima_log_string(ab, "fsuuid", args[0].from); + + if (!uuid_is_null(&entry->fsuuid)) { + result = -EINVAL; + break; + } + + result = uuid_parse(args[0].from, &entry->fsuuid); + if (!result) + entry->flags |= IMA_FSUUID; + break; + case Opt_uid_gt: + case Opt_euid_gt: + entry->uid_op = &uid_gt; + fallthrough; + case Opt_uid_lt: + case Opt_euid_lt: + if ((token == Opt_uid_lt) || (token == Opt_euid_lt)) + entry->uid_op = &uid_lt; + fallthrough; + case Opt_uid_eq: + case Opt_euid_eq: + eid_token = (token == Opt_euid_eq) || + (token == Opt_euid_gt) || + (token == Opt_euid_lt); + + ima_log_string_op(ab, eid_token ? "euid" : "uid", + args[0].from, token); + + if (uid_valid(entry->uid)) { + result = -EINVAL; + break; + } + + result = kstrtoul(args[0].from, 10, &lnum); + if (!result) { + entry->uid = make_kuid(current_user_ns(), + (uid_t) lnum); + if (!uid_valid(entry->uid) || + (uid_t)lnum != lnum) + result = -EINVAL; + else + entry->flags |= eid_token + ? IMA_EUID : IMA_UID; + } + break; + case Opt_gid_gt: + case Opt_egid_gt: + entry->gid_op = &gid_gt; + fallthrough; + case Opt_gid_lt: + case Opt_egid_lt: + if ((token == Opt_gid_lt) || (token == Opt_egid_lt)) + entry->gid_op = &gid_lt; + fallthrough; + case Opt_gid_eq: + case Opt_egid_eq: + eid_token = (token == Opt_egid_eq) || + (token == Opt_egid_gt) || + (token == Opt_egid_lt); + + ima_log_string_op(ab, eid_token ? "egid" : "gid", + args[0].from, token); + + if (gid_valid(entry->gid)) { + result = -EINVAL; + break; + } + + result = kstrtoul(args[0].from, 10, &lnum); + if (!result) { + entry->gid = make_kgid(current_user_ns(), + (gid_t)lnum); + if (!gid_valid(entry->gid) || + (((gid_t)lnum) != lnum)) + result = -EINVAL; + else + entry->flags |= eid_token + ? IMA_EGID : IMA_GID; + } + break; + case Opt_fowner_gt: + entry->fowner_op = &uid_gt; + fallthrough; + case Opt_fowner_lt: + if (token == Opt_fowner_lt) + entry->fowner_op = &uid_lt; + fallthrough; + case Opt_fowner_eq: + ima_log_string_op(ab, "fowner", args[0].from, token); + + if (uid_valid(entry->fowner)) { + result = -EINVAL; + break; + } + + result = kstrtoul(args[0].from, 10, &lnum); + if (!result) { + entry->fowner = make_kuid(current_user_ns(), + (uid_t)lnum); + if (!uid_valid(entry->fowner) || + (((uid_t)lnum) != lnum)) + result = -EINVAL; + else + entry->flags |= IMA_FOWNER; + } + break; + case Opt_fgroup_gt: + entry->fgroup_op = &gid_gt; + fallthrough; + case Opt_fgroup_lt: + if (token == Opt_fgroup_lt) + entry->fgroup_op = &gid_lt; + fallthrough; + case Opt_fgroup_eq: + ima_log_string_op(ab, "fgroup", args[0].from, token); + + if (gid_valid(entry->fgroup)) { + result = -EINVAL; + break; + } + + result = kstrtoul(args[0].from, 10, &lnum); + if (!result) { + entry->fgroup = make_kgid(current_user_ns(), + (gid_t)lnum); + if (!gid_valid(entry->fgroup) || + (((gid_t)lnum) != lnum)) + result = -EINVAL; + else + entry->flags |= IMA_FGROUP; + } + break; + case Opt_obj_user: + ima_log_string(ab, "obj_user", args[0].from); + result = ima_lsm_rule_init(entry, args, + LSM_OBJ_USER, + AUDIT_OBJ_USER); + break; + case Opt_obj_role: + ima_log_string(ab, "obj_role", args[0].from); + result = ima_lsm_rule_init(entry, args, + LSM_OBJ_ROLE, + AUDIT_OBJ_ROLE); + break; + case Opt_obj_type: + ima_log_string(ab, "obj_type", args[0].from); + result = ima_lsm_rule_init(entry, args, + LSM_OBJ_TYPE, + AUDIT_OBJ_TYPE); + break; + case Opt_subj_user: + ima_log_string(ab, "subj_user", args[0].from); + result = ima_lsm_rule_init(entry, args, + LSM_SUBJ_USER, + AUDIT_SUBJ_USER); + break; + case Opt_subj_role: + ima_log_string(ab, "subj_role", args[0].from); + result = ima_lsm_rule_init(entry, args, + LSM_SUBJ_ROLE, + AUDIT_SUBJ_ROLE); + break; + case Opt_subj_type: + ima_log_string(ab, "subj_type", args[0].from); + result = ima_lsm_rule_init(entry, args, + LSM_SUBJ_TYPE, + AUDIT_SUBJ_TYPE); + break; + case Opt_digest_type: + ima_log_string(ab, "digest_type", args[0].from); + if (entry->flags & IMA_DIGSIG_REQUIRED) + result = -EINVAL; + else if ((strcmp(args[0].from, "verity")) == 0) + entry->flags |= IMA_VERITY_REQUIRED; + else + result = -EINVAL; + break; + case Opt_appraise_type: + ima_log_string(ab, "appraise_type", args[0].from); + + if ((strcmp(args[0].from, "imasig")) == 0) { + if (entry->flags & IMA_VERITY_REQUIRED) + result = -EINVAL; + else + entry->flags |= IMA_DIGSIG_REQUIRED; + } else if (strcmp(args[0].from, "sigv3") == 0) { + /* Only fsverity supports sigv3 for now */ + if (entry->flags & IMA_VERITY_REQUIRED) + entry->flags |= IMA_DIGSIG_REQUIRED; + else + result = -EINVAL; + } else if (IS_ENABLED(CONFIG_IMA_APPRAISE_MODSIG) && + strcmp(args[0].from, "imasig|modsig") == 0) { + if (entry->flags & IMA_VERITY_REQUIRED) + result = -EINVAL; + else + entry->flags |= IMA_DIGSIG_REQUIRED | + IMA_MODSIG_ALLOWED; + } else { + result = -EINVAL; + } + break; + case Opt_appraise_flag: + ima_log_string(ab, "appraise_flag", args[0].from); + if (IS_ENABLED(CONFIG_IMA_APPRAISE_MODSIG) && + strstr(args[0].from, "blacklist")) + entry->flags |= IMA_CHECK_BLACKLIST; + else + result = -EINVAL; + break; + case Opt_appraise_algos: + ima_log_string(ab, "appraise_algos", args[0].from); + + if (entry->allowed_algos) { + result = -EINVAL; + break; + } + + entry->allowed_algos = + ima_parse_appraise_algos(args[0].from); + /* invalid or empty list of algorithms */ + if (!entry->allowed_algos) { + result = -EINVAL; + break; + } + + entry->flags |= IMA_VALIDATE_ALGOS; + + break; + case Opt_permit_directio: + entry->flags |= IMA_PERMIT_DIRECTIO; + break; + case Opt_pcr: + ima_log_string(ab, "pcr", args[0].from); + + result = kstrtoint(args[0].from, 10, &entry->pcr); + if (result || INVALID_PCR(entry->pcr)) + result = -EINVAL; + else + entry->flags |= IMA_PCR; + + break; + case Opt_template: + ima_log_string(ab, "template", args[0].from); + if (entry->action != MEASURE) { + result = -EINVAL; + break; + } + template_desc = lookup_template_desc(args[0].from); + if (!template_desc || entry->template) { + result = -EINVAL; + break; + } + + /* + * template_desc_init_fields() does nothing if + * the template is already initialised, so + * it's safe to do this unconditionally + */ + template_desc_init_fields(template_desc->fmt, + &(template_desc->fields), + &(template_desc->num_fields)); + entry->template = template_desc; + break; + case Opt_err: + ima_log_string(ab, "UNKNOWN", p); + result = -EINVAL; + break; + } + } + if (!result && !ima_validate_rule(entry)) + result = -EINVAL; + else if (entry->action == APPRAISE) + temp_ima_appraise |= ima_appraise_flag(entry->func); + + if (!result && entry->flags & IMA_MODSIG_ALLOWED) { + template_desc = entry->template ? entry->template : + ima_template_desc_current(); + check_template_modsig(template_desc); + } + + /* d-ngv2 template field recommended for unsigned fs-verity digests */ + if (!result && entry->action == MEASURE && + entry->flags & IMA_VERITY_REQUIRED) { + template_desc = entry->template ? entry->template : + ima_template_desc_current(); + check_template_field(template_desc, "d-ngv2", + "verity rules should include d-ngv2"); + } + + audit_log_format(ab, "res=%d", !result); + audit_log_end(ab); + return result; +} + +/** + * ima_parse_add_rule - add a rule to ima_policy_rules + * @rule: ima measurement policy rule + * + * Avoid locking by allowing just one writer at a time in ima_write_policy() + * Returns the length of the rule parsed, an error code on failure + */ +ssize_t ima_parse_add_rule(char *rule) +{ + static const char op[] = "update_policy"; + char *p; + struct ima_rule_entry *entry; + ssize_t result, len; + int audit_info = 0; + + p = strsep(&rule, "\n"); + len = strlen(p) + 1; + p += strspn(p, " \t"); + + if (*p == '#' || *p == '\0') + return len; + + entry = kzalloc(sizeof(*entry), GFP_KERNEL); + if (!entry) { + integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL, + NULL, op, "-ENOMEM", -ENOMEM, audit_info); + return -ENOMEM; + } + + INIT_LIST_HEAD(&entry->list); + + result = ima_parse_rule(p, entry); + if (result) { + ima_free_rule(entry); + integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL, + NULL, op, "invalid-policy", result, + audit_info); + return result; + } + + list_add_tail(&entry->list, &ima_temp_rules); + + return len; +} + +/** + * ima_delete_rules() called to cleanup invalid in-flight policy. + * We don't need locking as we operate on the temp list, which is + * different from the active one. There is also only one user of + * ima_delete_rules() at a time. + */ +void ima_delete_rules(void) +{ + struct ima_rule_entry *entry, *tmp; + + temp_ima_appraise = 0; + list_for_each_entry_safe(entry, tmp, &ima_temp_rules, list) { + list_del(&entry->list); + ima_free_rule(entry); + } +} + +#define __ima_hook_stringify(func, str) (#func), + +const char *const func_tokens[] = { + __ima_hooks(__ima_hook_stringify) +}; + +#ifdef CONFIG_IMA_READ_POLICY +enum { + mask_exec = 0, mask_write, mask_read, mask_append +}; + +static const char *const mask_tokens[] = { + "^MAY_EXEC", + "^MAY_WRITE", + "^MAY_READ", + "^MAY_APPEND" +}; + +void *ima_policy_start(struct seq_file *m, loff_t *pos) +{ + loff_t l = *pos; + struct ima_rule_entry *entry; + struct list_head *ima_rules_tmp; + + rcu_read_lock(); + ima_rules_tmp = rcu_dereference(ima_rules); + list_for_each_entry_rcu(entry, ima_rules_tmp, list) { + if (!l--) { + rcu_read_unlock(); + return entry; + } + } + rcu_read_unlock(); + return NULL; +} + +void *ima_policy_next(struct seq_file *m, void *v, loff_t *pos) +{ + struct ima_rule_entry *entry = v; + + rcu_read_lock(); + entry = list_entry_rcu(entry->list.next, struct ima_rule_entry, list); + rcu_read_unlock(); + (*pos)++; + + return (&entry->list == &ima_default_rules || + &entry->list == &ima_policy_rules) ? NULL : entry; +} + +void ima_policy_stop(struct seq_file *m, void *v) +{ +} + +#define pt(token) policy_tokens[token].pattern +#define mt(token) mask_tokens[token] + +/* + * policy_func_show - display the ima_hooks policy rule + */ +static void policy_func_show(struct seq_file *m, enum ima_hooks func) +{ + if (func > 0 && func < MAX_CHECK) + seq_printf(m, "func=%s ", func_tokens[func]); + else + seq_printf(m, "func=%d ", func); +} + +static void ima_show_rule_opt_list(struct seq_file *m, + const struct ima_rule_opt_list *opt_list) +{ + size_t i; + + for (i = 0; i < opt_list->count; i++) + seq_printf(m, "%s%s", i ? "|" : "", opt_list->items[i]); +} + +static void ima_policy_show_appraise_algos(struct seq_file *m, + unsigned int allowed_hashes) +{ + int idx, list_size = 0; + + for (idx = 0; idx < HASH_ALGO__LAST; idx++) { + if (!(allowed_hashes & (1U << idx))) + continue; + + /* only add commas if the list contains multiple entries */ + if (list_size++) + seq_puts(m, ","); + + seq_puts(m, hash_algo_name[idx]); + } +} + +int ima_policy_show(struct seq_file *m, void *v) +{ + struct ima_rule_entry *entry = v; + int i; + char tbuf[64] = {0,}; + int offset = 0; + + rcu_read_lock(); + + /* Do not print rules with inactive LSM labels */ + for (i = 0; i < MAX_LSM_RULES; i++) { + if (entry->lsm[i].args_p && !entry->lsm[i].rule) { + rcu_read_unlock(); + return 0; + } + } + + if (entry->action & MEASURE) + seq_puts(m, pt(Opt_measure)); + if (entry->action & DONT_MEASURE) + seq_puts(m, pt(Opt_dont_measure)); + if (entry->action & APPRAISE) + seq_puts(m, pt(Opt_appraise)); + if (entry->action & DONT_APPRAISE) + seq_puts(m, pt(Opt_dont_appraise)); + if (entry->action & AUDIT) + seq_puts(m, pt(Opt_audit)); + if (entry->action & HASH) + seq_puts(m, pt(Opt_hash)); + if (entry->action & DONT_HASH) + seq_puts(m, pt(Opt_dont_hash)); + + seq_puts(m, " "); + + if (entry->flags & IMA_FUNC) + policy_func_show(m, entry->func); + + if ((entry->flags & IMA_MASK) || (entry->flags & IMA_INMASK)) { + if (entry->flags & IMA_MASK) + offset = 1; + if (entry->mask & MAY_EXEC) + seq_printf(m, pt(Opt_mask), mt(mask_exec) + offset); + if (entry->mask & MAY_WRITE) + seq_printf(m, pt(Opt_mask), mt(mask_write) + offset); + if (entry->mask & MAY_READ) + seq_printf(m, pt(Opt_mask), mt(mask_read) + offset); + if (entry->mask & MAY_APPEND) + seq_printf(m, pt(Opt_mask), mt(mask_append) + offset); + seq_puts(m, " "); + } + + if (entry->flags & IMA_FSMAGIC) { + snprintf(tbuf, sizeof(tbuf), "0x%lx", entry->fsmagic); + seq_printf(m, pt(Opt_fsmagic), tbuf); + seq_puts(m, " "); + } + + if (entry->flags & IMA_FSNAME) { + snprintf(tbuf, sizeof(tbuf), "%s", entry->fsname); + seq_printf(m, pt(Opt_fsname), tbuf); + seq_puts(m, " "); + } + + if (entry->flags & IMA_KEYRINGS) { + seq_puts(m, "keyrings="); + ima_show_rule_opt_list(m, entry->keyrings); + seq_puts(m, " "); + } + + if (entry->flags & IMA_LABEL) { + seq_puts(m, "label="); + ima_show_rule_opt_list(m, entry->label); + seq_puts(m, " "); + } + + if (entry->flags & IMA_PCR) { + snprintf(tbuf, sizeof(tbuf), "%d", entry->pcr); + seq_printf(m, pt(Opt_pcr), tbuf); + seq_puts(m, " "); + } + + if (entry->flags & IMA_FSUUID) { + seq_printf(m, "fsuuid=%pU", &entry->fsuuid); + seq_puts(m, " "); + } + + if (entry->flags & IMA_UID) { + snprintf(tbuf, sizeof(tbuf), "%d", __kuid_val(entry->uid)); + if (entry->uid_op == &uid_gt) + seq_printf(m, pt(Opt_uid_gt), tbuf); + else if (entry->uid_op == &uid_lt) + seq_printf(m, pt(Opt_uid_lt), tbuf); + else + seq_printf(m, pt(Opt_uid_eq), tbuf); + seq_puts(m, " "); + } + + if (entry->flags & IMA_EUID) { + snprintf(tbuf, sizeof(tbuf), "%d", __kuid_val(entry->uid)); + if (entry->uid_op == &uid_gt) + seq_printf(m, pt(Opt_euid_gt), tbuf); + else if (entry->uid_op == &uid_lt) + seq_printf(m, pt(Opt_euid_lt), tbuf); + else + seq_printf(m, pt(Opt_euid_eq), tbuf); + seq_puts(m, " "); + } + + if (entry->flags & IMA_GID) { + snprintf(tbuf, sizeof(tbuf), "%d", __kgid_val(entry->gid)); + if (entry->gid_op == &gid_gt) + seq_printf(m, pt(Opt_gid_gt), tbuf); + else if (entry->gid_op == &gid_lt) + seq_printf(m, pt(Opt_gid_lt), tbuf); + else + seq_printf(m, pt(Opt_gid_eq), tbuf); + seq_puts(m, " "); + } + + if (entry->flags & IMA_EGID) { + snprintf(tbuf, sizeof(tbuf), "%d", __kgid_val(entry->gid)); + if (entry->gid_op == &gid_gt) + seq_printf(m, pt(Opt_egid_gt), tbuf); + else if (entry->gid_op == &gid_lt) + seq_printf(m, pt(Opt_egid_lt), tbuf); + else + seq_printf(m, pt(Opt_egid_eq), tbuf); + seq_puts(m, " "); + } + + if (entry->flags & IMA_FOWNER) { + snprintf(tbuf, sizeof(tbuf), "%d", __kuid_val(entry->fowner)); + if (entry->fowner_op == &uid_gt) + seq_printf(m, pt(Opt_fowner_gt), tbuf); + else if (entry->fowner_op == &uid_lt) + seq_printf(m, pt(Opt_fowner_lt), tbuf); + else + seq_printf(m, pt(Opt_fowner_eq), tbuf); + seq_puts(m, " "); + } + + if (entry->flags & IMA_FGROUP) { + snprintf(tbuf, sizeof(tbuf), "%d", __kgid_val(entry->fgroup)); + if (entry->fgroup_op == &gid_gt) + seq_printf(m, pt(Opt_fgroup_gt), tbuf); + else if (entry->fgroup_op == &gid_lt) + seq_printf(m, pt(Opt_fgroup_lt), tbuf); + else + seq_printf(m, pt(Opt_fgroup_eq), tbuf); + seq_puts(m, " "); + } + + if (entry->flags & IMA_VALIDATE_ALGOS) { + seq_puts(m, "appraise_algos="); + ima_policy_show_appraise_algos(m, entry->allowed_algos); + seq_puts(m, " "); + } + + for (i = 0; i < MAX_LSM_RULES; i++) { + if (entry->lsm[i].rule) { + switch (i) { + case LSM_OBJ_USER: + seq_printf(m, pt(Opt_obj_user), + entry->lsm[i].args_p); + break; + case LSM_OBJ_ROLE: + seq_printf(m, pt(Opt_obj_role), + entry->lsm[i].args_p); + break; + case LSM_OBJ_TYPE: + seq_printf(m, pt(Opt_obj_type), + entry->lsm[i].args_p); + break; + case LSM_SUBJ_USER: + seq_printf(m, pt(Opt_subj_user), + entry->lsm[i].args_p); + break; + case LSM_SUBJ_ROLE: + seq_printf(m, pt(Opt_subj_role), + entry->lsm[i].args_p); + break; + case LSM_SUBJ_TYPE: + seq_printf(m, pt(Opt_subj_type), + entry->lsm[i].args_p); + break; + } + seq_puts(m, " "); + } + } + if (entry->template) + seq_printf(m, "template=%s ", entry->template->name); + if (entry->flags & IMA_DIGSIG_REQUIRED) { + if (entry->flags & IMA_VERITY_REQUIRED) + seq_puts(m, "appraise_type=sigv3 "); + else if (entry->flags & IMA_MODSIG_ALLOWED) + seq_puts(m, "appraise_type=imasig|modsig "); + else + seq_puts(m, "appraise_type=imasig "); + } + if (entry->flags & IMA_VERITY_REQUIRED) + seq_puts(m, "digest_type=verity "); + if (entry->flags & IMA_CHECK_BLACKLIST) + seq_puts(m, "appraise_flag=check_blacklist "); + if (entry->flags & IMA_PERMIT_DIRECTIO) + seq_puts(m, "permit_directio "); + rcu_read_unlock(); + seq_puts(m, "\n"); + return 0; +} +#endif /* CONFIG_IMA_READ_POLICY */ + +#if defined(CONFIG_IMA_APPRAISE) && defined(CONFIG_INTEGRITY_TRUSTED_KEYRING) +/* + * ima_appraise_signature: whether IMA will appraise a given function using + * an IMA digital signature. This is restricted to cases where the kernel + * has a set of built-in trusted keys in order to avoid an attacker simply + * loading additional keys. + */ +bool ima_appraise_signature(enum kernel_read_file_id id) +{ + struct ima_rule_entry *entry; + bool found = false; + enum ima_hooks func; + struct list_head *ima_rules_tmp; + + if (id >= READING_MAX_ID) + return false; + + if (id == READING_KEXEC_IMAGE && !(ima_appraise & IMA_APPRAISE_ENFORCE) + && security_locked_down(LOCKDOWN_KEXEC)) + return false; + + func = read_idmap[id] ?: FILE_CHECK; + + rcu_read_lock(); + ima_rules_tmp = rcu_dereference(ima_rules); + list_for_each_entry_rcu(entry, ima_rules_tmp, list) { + if (entry->action != APPRAISE) + continue; + + /* + * A generic entry will match, but otherwise require that it + * match the func we're looking for + */ + if (entry->func && entry->func != func) + continue; + + /* + * We require this to be a digital signature, not a raw IMA + * hash. + */ + if (entry->flags & IMA_DIGSIG_REQUIRED) + found = true; + + /* + * We've found a rule that matches, so break now even if it + * didn't require a digital signature - a later rule that does + * won't override it, so would be a false positive. + */ + break; + } + + rcu_read_unlock(); + return found; +} +#endif /* CONFIG_IMA_APPRAISE && CONFIG_INTEGRITY_TRUSTED_KEYRING */ diff --git a/security/integrity/ima/ima_queue.c b/security/integrity/ima/ima_queue.c new file mode 100644 index 000000000..532da87ce --- /dev/null +++ b/security/integrity/ima/ima_queue.c @@ -0,0 +1,241 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2005,2006,2007,2008 IBM Corporation + * + * Authors: + * Serge Hallyn <serue@us.ibm.com> + * Reiner Sailer <sailer@watson.ibm.com> + * Mimi Zohar <zohar@us.ibm.com> + * + * File: ima_queue.c + * Implements queues that store template measurements and + * maintains aggregate over the stored measurements + * in the pre-configured TPM PCR (if available). + * The measurement list is append-only. No entry is + * ever removed or changed during the boot-cycle. + */ + +#include <linux/rculist.h> +#include <linux/slab.h> +#include "ima.h" + +#define AUDIT_CAUSE_LEN_MAX 32 + +/* pre-allocated array of tpm_digest structures to extend a PCR */ +static struct tpm_digest *digests; + +LIST_HEAD(ima_measurements); /* list of all measurements */ +#ifdef CONFIG_IMA_KEXEC +static unsigned long binary_runtime_size; +#else +static unsigned long binary_runtime_size = ULONG_MAX; +#endif + +/* key: inode (before secure-hashing a file) */ +struct ima_h_table ima_htable = { + .len = ATOMIC_LONG_INIT(0), + .violations = ATOMIC_LONG_INIT(0), + .queue[0 ... IMA_MEASURE_HTABLE_SIZE - 1] = HLIST_HEAD_INIT +}; + +/* mutex protects atomicity of extending measurement list + * and extending the TPM PCR aggregate. Since tpm_extend can take + * long (and the tpm driver uses a mutex), we can't use the spinlock. + */ +static DEFINE_MUTEX(ima_extend_list_mutex); + +/* lookup up the digest value in the hash table, and return the entry */ +static struct ima_queue_entry *ima_lookup_digest_entry(u8 *digest_value, + int pcr) +{ + struct ima_queue_entry *qe, *ret = NULL; + unsigned int key; + int rc; + + key = ima_hash_key(digest_value); + rcu_read_lock(); + hlist_for_each_entry_rcu(qe, &ima_htable.queue[key], hnext) { + rc = memcmp(qe->entry->digests[ima_hash_algo_idx].digest, + digest_value, hash_digest_size[ima_hash_algo]); + if ((rc == 0) && (qe->entry->pcr == pcr)) { + ret = qe; + break; + } + } + rcu_read_unlock(); + return ret; +} + +/* + * Calculate the memory required for serializing a single + * binary_runtime_measurement list entry, which contains a + * couple of variable length fields (e.g template name and data). + */ +static int get_binary_runtime_size(struct ima_template_entry *entry) +{ + int size = 0; + + size += sizeof(u32); /* pcr */ + size += TPM_DIGEST_SIZE; + size += sizeof(int); /* template name size field */ + size += strlen(entry->template_desc->name); + size += sizeof(entry->template_data_len); + size += entry->template_data_len; + return size; +} + +/* ima_add_template_entry helper function: + * - Add template entry to the measurement list and hash table, for + * all entries except those carried across kexec. + * + * (Called with ima_extend_list_mutex held.) + */ +static int ima_add_digest_entry(struct ima_template_entry *entry, + bool update_htable) +{ + struct ima_queue_entry *qe; + unsigned int key; + + qe = kmalloc(sizeof(*qe), GFP_KERNEL); + if (qe == NULL) { + pr_err("OUT OF MEMORY ERROR creating queue entry\n"); + return -ENOMEM; + } + qe->entry = entry; + + INIT_LIST_HEAD(&qe->later); + list_add_tail_rcu(&qe->later, &ima_measurements); + + atomic_long_inc(&ima_htable.len); + if (update_htable) { + key = ima_hash_key(entry->digests[ima_hash_algo_idx].digest); + hlist_add_head_rcu(&qe->hnext, &ima_htable.queue[key]); + } + + if (binary_runtime_size != ULONG_MAX) { + int size; + + size = get_binary_runtime_size(entry); + binary_runtime_size = (binary_runtime_size < ULONG_MAX - size) ? + binary_runtime_size + size : ULONG_MAX; + } + return 0; +} + +/* + * Return the amount of memory required for serializing the + * entire binary_runtime_measurement list, including the ima_kexec_hdr + * structure. + */ +unsigned long ima_get_binary_runtime_size(void) +{ + if (binary_runtime_size >= (ULONG_MAX - sizeof(struct ima_kexec_hdr))) + return ULONG_MAX; + else + return binary_runtime_size + sizeof(struct ima_kexec_hdr); +} + +static int ima_pcr_extend(struct tpm_digest *digests_arg, int pcr) +{ + int result = 0; + + if (!ima_tpm_chip) + return result; + + result = tpm_pcr_extend(ima_tpm_chip, pcr, digests_arg); + if (result != 0) + pr_err("Error Communicating to TPM chip, result: %d\n", result); + return result; +} + +/* + * Add template entry to the measurement list and hash table, and + * extend the pcr. + * + * On systems which support carrying the IMA measurement list across + * kexec, maintain the total memory size required for serializing the + * binary_runtime_measurements. + */ +int ima_add_template_entry(struct ima_template_entry *entry, int violation, + const char *op, struct inode *inode, + const unsigned char *filename) +{ + u8 *digest = entry->digests[ima_hash_algo_idx].digest; + struct tpm_digest *digests_arg = entry->digests; + const char *audit_cause = "hash_added"; + char tpm_audit_cause[AUDIT_CAUSE_LEN_MAX]; + int audit_info = 1; + int result = 0, tpmresult = 0; + + mutex_lock(&ima_extend_list_mutex); + if (!violation && !IS_ENABLED(CONFIG_IMA_DISABLE_HTABLE)) { + if (ima_lookup_digest_entry(digest, entry->pcr)) { + audit_cause = "hash_exists"; + result = -EEXIST; + goto out; + } + } + + result = ima_add_digest_entry(entry, + !IS_ENABLED(CONFIG_IMA_DISABLE_HTABLE)); + if (result < 0) { + audit_cause = "ENOMEM"; + audit_info = 0; + goto out; + } + + if (violation) /* invalidate pcr */ + digests_arg = digests; + + tpmresult = ima_pcr_extend(digests_arg, entry->pcr); + if (tpmresult != 0) { + snprintf(tpm_audit_cause, AUDIT_CAUSE_LEN_MAX, "TPM_error(%d)", + tpmresult); + audit_cause = tpm_audit_cause; + audit_info = 0; + } +out: + mutex_unlock(&ima_extend_list_mutex); + integrity_audit_msg(AUDIT_INTEGRITY_PCR, inode, filename, + op, audit_cause, result, audit_info); + return result; +} + +int ima_restore_measurement_entry(struct ima_template_entry *entry) +{ + int result = 0; + + mutex_lock(&ima_extend_list_mutex); + result = ima_add_digest_entry(entry, 0); + mutex_unlock(&ima_extend_list_mutex); + return result; +} + +int __init ima_init_digests(void) +{ + u16 digest_size; + u16 crypto_id; + int i; + + if (!ima_tpm_chip) + return 0; + + digests = kcalloc(ima_tpm_chip->nr_allocated_banks, sizeof(*digests), + GFP_NOFS); + if (!digests) + return -ENOMEM; + + for (i = 0; i < ima_tpm_chip->nr_allocated_banks; i++) { + digests[i].alg_id = ima_tpm_chip->allocated_banks[i].alg_id; + digest_size = ima_tpm_chip->allocated_banks[i].digest_size; + crypto_id = ima_tpm_chip->allocated_banks[i].crypto_id; + + /* for unmapped TPM algorithms digest is still a padded SHA1 */ + if (crypto_id == HASH_ALGO__LAST) + digest_size = SHA1_DIGEST_SIZE; + + memset(digests[i].digest, 0xff, digest_size); + } + + return 0; +} diff --git a/security/integrity/ima/ima_queue_keys.c b/security/integrity/ima/ima_queue_keys.c new file mode 100644 index 000000000..93056c03b --- /dev/null +++ b/security/integrity/ima/ima_queue_keys.c @@ -0,0 +1,177 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2019 Microsoft Corporation + * + * Author: Lakshmi Ramasubramanian (nramas@linux.microsoft.com) + * + * File: ima_queue_keys.c + * Enables deferred processing of keys + */ + +#include <linux/user_namespace.h> +#include <linux/workqueue.h> +#include <keys/asymmetric-type.h> +#include "ima.h" + +/* + * Flag to indicate whether a key can be processed + * right away or should be queued for processing later. + */ +static bool ima_process_keys; + +/* + * To synchronize access to the list of keys that need to be measured + */ +static DEFINE_MUTEX(ima_keys_lock); +static LIST_HEAD(ima_keys); + +/* + * If custom IMA policy is not loaded then keys queued up + * for measurement should be freed. This worker is used + * for handling this scenario. + */ +static long ima_key_queue_timeout = 300000; /* 5 Minutes */ +static void ima_keys_handler(struct work_struct *work); +static DECLARE_DELAYED_WORK(ima_keys_delayed_work, ima_keys_handler); +static bool timer_expired; + +/* + * This worker function frees keys that may still be + * queued up in case custom IMA policy was not loaded. + */ +static void ima_keys_handler(struct work_struct *work) +{ + timer_expired = true; + ima_process_queued_keys(); +} + +/* + * This function sets up a worker to free queued keys in case + * custom IMA policy was never loaded. + */ +void ima_init_key_queue(void) +{ + schedule_delayed_work(&ima_keys_delayed_work, + msecs_to_jiffies(ima_key_queue_timeout)); +} + +static void ima_free_key_entry(struct ima_key_entry *entry) +{ + if (entry) { + kfree(entry->payload); + kfree(entry->keyring_name); + kfree(entry); + } +} + +static struct ima_key_entry *ima_alloc_key_entry(struct key *keyring, + const void *payload, + size_t payload_len) +{ + int rc = 0; + const char *audit_cause = "ENOMEM"; + struct ima_key_entry *entry; + + entry = kzalloc(sizeof(*entry), GFP_KERNEL); + if (entry) { + entry->payload = kmemdup(payload, payload_len, GFP_KERNEL); + entry->keyring_name = kstrdup(keyring->description, + GFP_KERNEL); + entry->payload_len = payload_len; + } + + if ((entry == NULL) || (entry->payload == NULL) || + (entry->keyring_name == NULL)) { + rc = -ENOMEM; + goto out; + } + + INIT_LIST_HEAD(&entry->list); + +out: + if (rc) { + integrity_audit_message(AUDIT_INTEGRITY_PCR, NULL, + keyring->description, + func_measure_str(KEY_CHECK), + audit_cause, rc, 0, rc); + ima_free_key_entry(entry); + entry = NULL; + } + + return entry; +} + +bool ima_queue_key(struct key *keyring, const void *payload, + size_t payload_len) +{ + bool queued = false; + struct ima_key_entry *entry; + + entry = ima_alloc_key_entry(keyring, payload, payload_len); + if (!entry) + return false; + + mutex_lock(&ima_keys_lock); + if (!ima_process_keys) { + list_add_tail(&entry->list, &ima_keys); + queued = true; + } + mutex_unlock(&ima_keys_lock); + + if (!queued) + ima_free_key_entry(entry); + + return queued; +} + +/* + * ima_process_queued_keys() - process keys queued for measurement + * + * This function sets ima_process_keys to true and processes queued keys. + * From here on keys will be processed right away (not queued). + */ +void ima_process_queued_keys(void) +{ + struct ima_key_entry *entry, *tmp; + bool process = false; + + if (ima_process_keys) + return; + + /* + * Since ima_process_keys is set to true, any new key will be + * processed immediately and not be queued to ima_keys list. + * First one setting the ima_process_keys flag to true will + * process the queued keys. + */ + mutex_lock(&ima_keys_lock); + if (!ima_process_keys) { + ima_process_keys = true; + process = true; + } + mutex_unlock(&ima_keys_lock); + + if (!process) + return; + + if (!timer_expired) + cancel_delayed_work_sync(&ima_keys_delayed_work); + + list_for_each_entry_safe(entry, tmp, &ima_keys, list) { + if (!timer_expired) + process_buffer_measurement(&init_user_ns, NULL, + entry->payload, + entry->payload_len, + entry->keyring_name, + KEY_CHECK, 0, + entry->keyring_name, + false, NULL, 0); + list_del(&entry->list); + ima_free_key_entry(entry); + } +} + +inline bool ima_should_queue_key(void) +{ + return !ima_process_keys; +} diff --git a/security/integrity/ima/ima_template.c b/security/integrity/ima/ima_template.c new file mode 100644 index 000000000..04c49f05c --- /dev/null +++ b/security/integrity/ima/ima_template.c @@ -0,0 +1,536 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2013 Politecnico di Torino, Italy + * TORSEC group -- https://security.polito.it + * + * Author: Roberto Sassu <roberto.sassu@polito.it> + * + * File: ima_template.c + * Helpers to manage template descriptors. + */ + +#include <linux/rculist.h> +#include "ima.h" +#include "ima_template_lib.h" + +enum header_fields { HDR_PCR, HDR_DIGEST, HDR_TEMPLATE_NAME, + HDR_TEMPLATE_DATA, HDR__LAST }; + +static struct ima_template_desc builtin_templates[] = { + {.name = IMA_TEMPLATE_IMA_NAME, .fmt = IMA_TEMPLATE_IMA_FMT}, + {.name = "ima-ng", .fmt = "d-ng|n-ng"}, + {.name = "ima-sig", .fmt = "d-ng|n-ng|sig"}, + {.name = "ima-ngv2", .fmt = "d-ngv2|n-ng"}, + {.name = "ima-sigv2", .fmt = "d-ngv2|n-ng|sig"}, + {.name = "ima-buf", .fmt = "d-ng|n-ng|buf"}, + {.name = "ima-modsig", .fmt = "d-ng|n-ng|sig|d-modsig|modsig"}, + {.name = "evm-sig", + .fmt = "d-ng|n-ng|evmsig|xattrnames|xattrlengths|xattrvalues|iuid|igid|imode"}, + {.name = "", .fmt = ""}, /* placeholder for a custom format */ +}; + +static LIST_HEAD(defined_templates); +static DEFINE_SPINLOCK(template_list); +static int template_setup_done; + +static const struct ima_template_field supported_fields[] = { + {.field_id = "d", .field_init = ima_eventdigest_init, + .field_show = ima_show_template_digest}, + {.field_id = "n", .field_init = ima_eventname_init, + .field_show = ima_show_template_string}, + {.field_id = "d-ng", .field_init = ima_eventdigest_ng_init, + .field_show = ima_show_template_digest_ng}, + {.field_id = "d-ngv2", .field_init = ima_eventdigest_ngv2_init, + .field_show = ima_show_template_digest_ngv2}, + {.field_id = "n-ng", .field_init = ima_eventname_ng_init, + .field_show = ima_show_template_string}, + {.field_id = "sig", .field_init = ima_eventsig_init, + .field_show = ima_show_template_sig}, + {.field_id = "buf", .field_init = ima_eventbuf_init, + .field_show = ima_show_template_buf}, + {.field_id = "d-modsig", .field_init = ima_eventdigest_modsig_init, + .field_show = ima_show_template_digest_ng}, + {.field_id = "modsig", .field_init = ima_eventmodsig_init, + .field_show = ima_show_template_sig}, + {.field_id = "evmsig", .field_init = ima_eventevmsig_init, + .field_show = ima_show_template_sig}, + {.field_id = "iuid", .field_init = ima_eventinodeuid_init, + .field_show = ima_show_template_uint}, + {.field_id = "igid", .field_init = ima_eventinodegid_init, + .field_show = ima_show_template_uint}, + {.field_id = "imode", .field_init = ima_eventinodemode_init, + .field_show = ima_show_template_uint}, + {.field_id = "xattrnames", + .field_init = ima_eventinodexattrnames_init, + .field_show = ima_show_template_string}, + {.field_id = "xattrlengths", + .field_init = ima_eventinodexattrlengths_init, + .field_show = ima_show_template_sig}, + {.field_id = "xattrvalues", + .field_init = ima_eventinodexattrvalues_init, + .field_show = ima_show_template_sig}, +}; + +/* + * Used when restoring measurements carried over from a kexec. 'd' and 'n' don't + * need to be accounted for since they shouldn't be defined in the same template + * description as 'd-ng' and 'n-ng' respectively. + */ +#define MAX_TEMPLATE_NAME_LEN \ + sizeof("d-ng|n-ng|evmsig|xattrnames|xattrlengths|xattrvalues|iuid|igid|imode") + +static struct ima_template_desc *ima_template; +static struct ima_template_desc *ima_buf_template; + +/** + * ima_template_has_modsig - Check whether template has modsig-related fields. + * @ima_template: IMA template to check. + * + * Tells whether the given template has fields referencing a file's appended + * signature. + */ +bool ima_template_has_modsig(const struct ima_template_desc *ima_template) +{ + int i; + + for (i = 0; i < ima_template->num_fields; i++) + if (!strcmp(ima_template->fields[i]->field_id, "modsig") || + !strcmp(ima_template->fields[i]->field_id, "d-modsig")) + return true; + + return false; +} + +static int __init ima_template_setup(char *str) +{ + struct ima_template_desc *template_desc; + int template_len = strlen(str); + + if (template_setup_done) + return 1; + + if (!ima_template) + ima_init_template_list(); + + /* + * Verify that a template with the supplied name exists. + * If not, use CONFIG_IMA_DEFAULT_TEMPLATE. + */ + template_desc = lookup_template_desc(str); + if (!template_desc) { + pr_err("template %s not found, using %s\n", + str, CONFIG_IMA_DEFAULT_TEMPLATE); + return 1; + } + + /* + * Verify whether the current hash algorithm is supported + * by the 'ima' template. + */ + if (template_len == 3 && strcmp(str, IMA_TEMPLATE_IMA_NAME) == 0 && + ima_hash_algo != HASH_ALGO_SHA1 && ima_hash_algo != HASH_ALGO_MD5) { + pr_err("template does not support hash alg\n"); + return 1; + } + + ima_template = template_desc; + template_setup_done = 1; + return 1; +} +__setup("ima_template=", ima_template_setup); + +static int __init ima_template_fmt_setup(char *str) +{ + int num_templates = ARRAY_SIZE(builtin_templates); + + if (template_setup_done) + return 1; + + if (template_desc_init_fields(str, NULL, NULL) < 0) { + pr_err("format string '%s' not valid, using template %s\n", + str, CONFIG_IMA_DEFAULT_TEMPLATE); + return 1; + } + + builtin_templates[num_templates - 1].fmt = str; + ima_template = builtin_templates + num_templates - 1; + template_setup_done = 1; + + return 1; +} +__setup("ima_template_fmt=", ima_template_fmt_setup); + +struct ima_template_desc *lookup_template_desc(const char *name) +{ + struct ima_template_desc *template_desc; + int found = 0; + + rcu_read_lock(); + list_for_each_entry_rcu(template_desc, &defined_templates, list) { + if ((strcmp(template_desc->name, name) == 0) || + (strcmp(template_desc->fmt, name) == 0)) { + found = 1; + break; + } + } + rcu_read_unlock(); + return found ? template_desc : NULL; +} + +static const struct ima_template_field * +lookup_template_field(const char *field_id) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(supported_fields); i++) + if (strncmp(supported_fields[i].field_id, field_id, + IMA_TEMPLATE_FIELD_ID_MAX_LEN) == 0) + return &supported_fields[i]; + return NULL; +} + +static int template_fmt_size(const char *template_fmt) +{ + char c; + int template_fmt_len = strlen(template_fmt); + int i = 0, j = 0; + + while (i < template_fmt_len) { + c = template_fmt[i]; + if (c == '|') + j++; + i++; + } + + return j + 1; +} + +int template_desc_init_fields(const char *template_fmt, + const struct ima_template_field ***fields, + int *num_fields) +{ + const char *template_fmt_ptr; + const struct ima_template_field *found_fields[IMA_TEMPLATE_NUM_FIELDS_MAX]; + int template_num_fields; + int i, len; + + if (num_fields && *num_fields > 0) /* already initialized? */ + return 0; + + template_num_fields = template_fmt_size(template_fmt); + + if (template_num_fields > IMA_TEMPLATE_NUM_FIELDS_MAX) { + pr_err("format string '%s' contains too many fields\n", + template_fmt); + return -EINVAL; + } + + for (i = 0, template_fmt_ptr = template_fmt; i < template_num_fields; + i++, template_fmt_ptr += len + 1) { + char tmp_field_id[IMA_TEMPLATE_FIELD_ID_MAX_LEN + 1]; + + len = strchrnul(template_fmt_ptr, '|') - template_fmt_ptr; + if (len == 0 || len > IMA_TEMPLATE_FIELD_ID_MAX_LEN) { + pr_err("Invalid field with length %d\n", len); + return -EINVAL; + } + + memcpy(tmp_field_id, template_fmt_ptr, len); + tmp_field_id[len] = '\0'; + found_fields[i] = lookup_template_field(tmp_field_id); + if (!found_fields[i]) { + pr_err("field '%s' not found\n", tmp_field_id); + return -ENOENT; + } + } + + if (fields && num_fields) { + *fields = kmalloc_array(i, sizeof(**fields), GFP_KERNEL); + if (*fields == NULL) + return -ENOMEM; + + memcpy(*fields, found_fields, i * sizeof(**fields)); + *num_fields = i; + } + + return 0; +} + +void ima_init_template_list(void) +{ + int i; + + if (!list_empty(&defined_templates)) + return; + + spin_lock(&template_list); + for (i = 0; i < ARRAY_SIZE(builtin_templates); i++) { + list_add_tail_rcu(&builtin_templates[i].list, + &defined_templates); + } + spin_unlock(&template_list); +} + +struct ima_template_desc *ima_template_desc_current(void) +{ + if (!ima_template) { + ima_init_template_list(); + ima_template = + lookup_template_desc(CONFIG_IMA_DEFAULT_TEMPLATE); + } + return ima_template; +} + +struct ima_template_desc *ima_template_desc_buf(void) +{ + if (!ima_buf_template) { + ima_init_template_list(); + ima_buf_template = lookup_template_desc("ima-buf"); + } + return ima_buf_template; +} + +int __init ima_init_template(void) +{ + struct ima_template_desc *template = ima_template_desc_current(); + int result; + + result = template_desc_init_fields(template->fmt, + &(template->fields), + &(template->num_fields)); + if (result < 0) { + pr_err("template %s init failed, result: %d\n", + (strlen(template->name) ? + template->name : template->fmt), result); + return result; + } + + template = ima_template_desc_buf(); + if (!template) { + pr_err("Failed to get ima-buf template\n"); + return -EINVAL; + } + + result = template_desc_init_fields(template->fmt, + &(template->fields), + &(template->num_fields)); + if (result < 0) + pr_err("template %s init failed, result: %d\n", + (strlen(template->name) ? + template->name : template->fmt), result); + + return result; +} + +static struct ima_template_desc *restore_template_fmt(char *template_name) +{ + struct ima_template_desc *template_desc = NULL; + int ret; + + ret = template_desc_init_fields(template_name, NULL, NULL); + if (ret < 0) { + pr_err("attempting to initialize the template \"%s\" failed\n", + template_name); + goto out; + } + + template_desc = kzalloc(sizeof(*template_desc), GFP_KERNEL); + if (!template_desc) + goto out; + + template_desc->name = ""; + template_desc->fmt = kstrdup(template_name, GFP_KERNEL); + if (!template_desc->fmt) { + kfree(template_desc); + template_desc = NULL; + goto out; + } + + spin_lock(&template_list); + list_add_tail_rcu(&template_desc->list, &defined_templates); + spin_unlock(&template_list); +out: + return template_desc; +} + +static int ima_restore_template_data(struct ima_template_desc *template_desc, + void *template_data, + int template_data_size, + struct ima_template_entry **entry) +{ + struct tpm_digest *digests; + int ret = 0; + int i; + + *entry = kzalloc(struct_size(*entry, template_data, + template_desc->num_fields), GFP_NOFS); + if (!*entry) + return -ENOMEM; + + digests = kcalloc(NR_BANKS(ima_tpm_chip) + ima_extra_slots, + sizeof(*digests), GFP_NOFS); + if (!digests) { + kfree(*entry); + return -ENOMEM; + } + + (*entry)->digests = digests; + + ret = ima_parse_buf(template_data, template_data + template_data_size, + NULL, template_desc->num_fields, + (*entry)->template_data, NULL, NULL, + ENFORCE_FIELDS | ENFORCE_BUFEND, "template data"); + if (ret < 0) { + kfree((*entry)->digests); + kfree(*entry); + return ret; + } + + (*entry)->template_desc = template_desc; + for (i = 0; i < template_desc->num_fields; i++) { + struct ima_field_data *field_data = &(*entry)->template_data[i]; + u8 *data = field_data->data; + + (*entry)->template_data[i].data = + kzalloc(field_data->len + 1, GFP_KERNEL); + if (!(*entry)->template_data[i].data) { + ret = -ENOMEM; + break; + } + memcpy((*entry)->template_data[i].data, data, field_data->len); + (*entry)->template_data_len += sizeof(field_data->len); + (*entry)->template_data_len += field_data->len; + } + + if (ret < 0) { + ima_free_template_entry(*entry); + *entry = NULL; + } + + return ret; +} + +/* Restore the serialized binary measurement list without extending PCRs. */ +int ima_restore_measurement_list(loff_t size, void *buf) +{ + char template_name[MAX_TEMPLATE_NAME_LEN]; + unsigned char zero[TPM_DIGEST_SIZE] = { 0 }; + + struct ima_kexec_hdr *khdr = buf; + struct ima_field_data hdr[HDR__LAST] = { + [HDR_PCR] = {.len = sizeof(u32)}, + [HDR_DIGEST] = {.len = TPM_DIGEST_SIZE}, + }; + + void *bufp = buf + sizeof(*khdr); + void *bufendp; + struct ima_template_entry *entry; + struct ima_template_desc *template_desc; + DECLARE_BITMAP(hdr_mask, HDR__LAST); + unsigned long count = 0; + int ret = 0; + + if (!buf || size < sizeof(*khdr)) + return 0; + + if (ima_canonical_fmt) { + khdr->version = le16_to_cpu((__force __le16)khdr->version); + khdr->count = le64_to_cpu((__force __le64)khdr->count); + khdr->buffer_size = le64_to_cpu((__force __le64)khdr->buffer_size); + } + + if (khdr->version != 1) { + pr_err("attempting to restore a incompatible measurement list"); + return -EINVAL; + } + + if (khdr->count > ULONG_MAX - 1) { + pr_err("attempting to restore too many measurements"); + return -EINVAL; + } + + bitmap_zero(hdr_mask, HDR__LAST); + bitmap_set(hdr_mask, HDR_PCR, 1); + bitmap_set(hdr_mask, HDR_DIGEST, 1); + + /* + * ima kexec buffer prefix: version, buffer size, count + * v1 format: pcr, digest, template-name-len, template-name, + * template-data-size, template-data + */ + bufendp = buf + khdr->buffer_size; + while ((bufp < bufendp) && (count++ < khdr->count)) { + int enforce_mask = ENFORCE_FIELDS; + + enforce_mask |= (count == khdr->count) ? ENFORCE_BUFEND : 0; + ret = ima_parse_buf(bufp, bufendp, &bufp, HDR__LAST, hdr, NULL, + hdr_mask, enforce_mask, "entry header"); + if (ret < 0) + break; + + if (hdr[HDR_TEMPLATE_NAME].len >= MAX_TEMPLATE_NAME_LEN) { + pr_err("attempting to restore a template name that is too long\n"); + ret = -EINVAL; + break; + } + + /* template name is not null terminated */ + memcpy(template_name, hdr[HDR_TEMPLATE_NAME].data, + hdr[HDR_TEMPLATE_NAME].len); + template_name[hdr[HDR_TEMPLATE_NAME].len] = 0; + + if (strcmp(template_name, "ima") == 0) { + pr_err("attempting to restore an unsupported template \"%s\" failed\n", + template_name); + ret = -EINVAL; + break; + } + + template_desc = lookup_template_desc(template_name); + if (!template_desc) { + template_desc = restore_template_fmt(template_name); + if (!template_desc) + break; + } + + /* + * Only the running system's template format is initialized + * on boot. As needed, initialize the other template formats. + */ + ret = template_desc_init_fields(template_desc->fmt, + &(template_desc->fields), + &(template_desc->num_fields)); + if (ret < 0) { + pr_err("attempting to restore the template fmt \"%s\" failed\n", + template_desc->fmt); + ret = -EINVAL; + break; + } + + ret = ima_restore_template_data(template_desc, + hdr[HDR_TEMPLATE_DATA].data, + hdr[HDR_TEMPLATE_DATA].len, + &entry); + if (ret < 0) + break; + + if (memcmp(hdr[HDR_DIGEST].data, zero, sizeof(zero))) { + ret = ima_calc_field_array_hash( + &entry->template_data[0], + entry); + if (ret < 0) { + pr_err("cannot calculate template digest\n"); + ret = -EINVAL; + break; + } + } + + entry->pcr = !ima_canonical_fmt ? *(u32 *)(hdr[HDR_PCR].data) : + le32_to_cpu(*(__le32 *)(hdr[HDR_PCR].data)); + ret = ima_restore_measurement_entry(entry); + if (ret < 0) + break; + + } + return ret; +} diff --git a/security/integrity/ima/ima_template_lib.c b/security/integrity/ima/ima_template_lib.c new file mode 100644 index 000000000..7bf9b1507 --- /dev/null +++ b/security/integrity/ima/ima_template_lib.c @@ -0,0 +1,746 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2013 Politecnico di Torino, Italy + * TORSEC group -- https://security.polito.it + * + * Author: Roberto Sassu <roberto.sassu@polito.it> + * + * File: ima_template_lib.c + * Library of supported template fields. + */ + +#include "ima_template_lib.h" +#include <linux/xattr.h> +#include <linux/evm.h> + +static bool ima_template_hash_algo_allowed(u8 algo) +{ + if (algo == HASH_ALGO_SHA1 || algo == HASH_ALGO_MD5) + return true; + + return false; +} + +enum data_formats { + DATA_FMT_DIGEST = 0, + DATA_FMT_DIGEST_WITH_ALGO, + DATA_FMT_DIGEST_WITH_TYPE_AND_ALGO, + DATA_FMT_STRING, + DATA_FMT_HEX, + DATA_FMT_UINT +}; + +enum digest_type { + DIGEST_TYPE_IMA, + DIGEST_TYPE_VERITY, + DIGEST_TYPE__LAST +}; + +#define DIGEST_TYPE_NAME_LEN_MAX 7 /* including NUL */ +static const char * const digest_type_name[DIGEST_TYPE__LAST] = { + [DIGEST_TYPE_IMA] = "ima", + [DIGEST_TYPE_VERITY] = "verity" +}; + +static int ima_write_template_field_data(const void *data, const u32 datalen, + enum data_formats datafmt, + struct ima_field_data *field_data) +{ + u8 *buf, *buf_ptr; + u32 buflen = datalen; + + if (datafmt == DATA_FMT_STRING) + buflen = datalen + 1; + + buf = kzalloc(buflen, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + memcpy(buf, data, datalen); + + /* + * Replace all space characters with underscore for event names and + * strings. This avoid that, during the parsing of a measurements list, + * filenames with spaces or that end with the suffix ' (deleted)' are + * split into multiple template fields (the space is the delimitator + * character for measurements lists in ASCII format). + */ + if (datafmt == DATA_FMT_STRING) { + for (buf_ptr = buf; buf_ptr - buf < datalen; buf_ptr++) + if (*buf_ptr == ' ') + *buf_ptr = '_'; + } + + field_data->data = buf; + field_data->len = buflen; + return 0; +} + +static void ima_show_template_data_ascii(struct seq_file *m, + enum ima_show_type show, + enum data_formats datafmt, + struct ima_field_data *field_data) +{ + u8 *buf_ptr = field_data->data; + u32 buflen = field_data->len; + + switch (datafmt) { + case DATA_FMT_DIGEST_WITH_TYPE_AND_ALGO: + case DATA_FMT_DIGEST_WITH_ALGO: + buf_ptr = strrchr(field_data->data, ':'); + if (buf_ptr != field_data->data) + seq_printf(m, "%s", field_data->data); + + /* skip ':' and '\0' */ + buf_ptr += 2; + buflen -= buf_ptr - field_data->data; + fallthrough; + case DATA_FMT_DIGEST: + case DATA_FMT_HEX: + if (!buflen) + break; + ima_print_digest(m, buf_ptr, buflen); + break; + case DATA_FMT_STRING: + seq_printf(m, "%s", buf_ptr); + break; + case DATA_FMT_UINT: + switch (field_data->len) { + case sizeof(u8): + seq_printf(m, "%u", *(u8 *)buf_ptr); + break; + case sizeof(u16): + if (ima_canonical_fmt) + seq_printf(m, "%u", + le16_to_cpu(*(__le16 *)buf_ptr)); + else + seq_printf(m, "%u", *(u16 *)buf_ptr); + break; + case sizeof(u32): + if (ima_canonical_fmt) + seq_printf(m, "%u", + le32_to_cpu(*(__le32 *)buf_ptr)); + else + seq_printf(m, "%u", *(u32 *)buf_ptr); + break; + case sizeof(u64): + if (ima_canonical_fmt) + seq_printf(m, "%llu", + le64_to_cpu(*(__le64 *)buf_ptr)); + else + seq_printf(m, "%llu", *(u64 *)buf_ptr); + break; + default: + break; + } + break; + default: + break; + } +} + +static void ima_show_template_data_binary(struct seq_file *m, + enum ima_show_type show, + enum data_formats datafmt, + struct ima_field_data *field_data) +{ + u32 len = (show == IMA_SHOW_BINARY_OLD_STRING_FMT) ? + strlen(field_data->data) : field_data->len; + + if (show != IMA_SHOW_BINARY_NO_FIELD_LEN) { + u32 field_len = !ima_canonical_fmt ? + len : (__force u32)cpu_to_le32(len); + + ima_putc(m, &field_len, sizeof(field_len)); + } + + if (!len) + return; + + ima_putc(m, field_data->data, len); +} + +static void ima_show_template_field_data(struct seq_file *m, + enum ima_show_type show, + enum data_formats datafmt, + struct ima_field_data *field_data) +{ + switch (show) { + case IMA_SHOW_ASCII: + ima_show_template_data_ascii(m, show, datafmt, field_data); + break; + case IMA_SHOW_BINARY: + case IMA_SHOW_BINARY_NO_FIELD_LEN: + case IMA_SHOW_BINARY_OLD_STRING_FMT: + ima_show_template_data_binary(m, show, datafmt, field_data); + break; + default: + break; + } +} + +void ima_show_template_digest(struct seq_file *m, enum ima_show_type show, + struct ima_field_data *field_data) +{ + ima_show_template_field_data(m, show, DATA_FMT_DIGEST, field_data); +} + +void ima_show_template_digest_ng(struct seq_file *m, enum ima_show_type show, + struct ima_field_data *field_data) +{ + ima_show_template_field_data(m, show, DATA_FMT_DIGEST_WITH_ALGO, + field_data); +} + +void ima_show_template_digest_ngv2(struct seq_file *m, enum ima_show_type show, + struct ima_field_data *field_data) +{ + ima_show_template_field_data(m, show, + DATA_FMT_DIGEST_WITH_TYPE_AND_ALGO, + field_data); +} + +void ima_show_template_string(struct seq_file *m, enum ima_show_type show, + struct ima_field_data *field_data) +{ + ima_show_template_field_data(m, show, DATA_FMT_STRING, field_data); +} + +void ima_show_template_sig(struct seq_file *m, enum ima_show_type show, + struct ima_field_data *field_data) +{ + ima_show_template_field_data(m, show, DATA_FMT_HEX, field_data); +} + +void ima_show_template_buf(struct seq_file *m, enum ima_show_type show, + struct ima_field_data *field_data) +{ + ima_show_template_field_data(m, show, DATA_FMT_HEX, field_data); +} + +void ima_show_template_uint(struct seq_file *m, enum ima_show_type show, + struct ima_field_data *field_data) +{ + ima_show_template_field_data(m, show, DATA_FMT_UINT, field_data); +} + +/** + * ima_parse_buf() - Parses lengths and data from an input buffer + * @bufstartp: Buffer start address. + * @bufendp: Buffer end address. + * @bufcurp: Pointer to remaining (non-parsed) data. + * @maxfields: Length of fields array. + * @fields: Array containing lengths and pointers of parsed data. + * @curfields: Number of array items containing parsed data. + * @len_mask: Bitmap (if bit is set, data length should not be parsed). + * @enforce_mask: Check if curfields == maxfields and/or bufcurp == bufendp. + * @bufname: String identifier of the input buffer. + * + * Return: 0 on success, -EINVAL on error. + */ +int ima_parse_buf(void *bufstartp, void *bufendp, void **bufcurp, + int maxfields, struct ima_field_data *fields, int *curfields, + unsigned long *len_mask, int enforce_mask, char *bufname) +{ + void *bufp = bufstartp; + int i; + + for (i = 0; i < maxfields; i++) { + if (len_mask == NULL || !test_bit(i, len_mask)) { + if (bufp > (bufendp - sizeof(u32))) + break; + + if (ima_canonical_fmt) + fields[i].len = le32_to_cpu(*(__le32 *)bufp); + else + fields[i].len = *(u32 *)bufp; + + bufp += sizeof(u32); + } + + if (bufp > (bufendp - fields[i].len)) + break; + + fields[i].data = bufp; + bufp += fields[i].len; + } + + if ((enforce_mask & ENFORCE_FIELDS) && i != maxfields) { + pr_err("%s: nr of fields mismatch: expected: %d, current: %d\n", + bufname, maxfields, i); + return -EINVAL; + } + + if ((enforce_mask & ENFORCE_BUFEND) && bufp != bufendp) { + pr_err("%s: buf end mismatch: expected: %p, current: %p\n", + bufname, bufendp, bufp); + return -EINVAL; + } + + if (curfields) + *curfields = i; + + if (bufcurp) + *bufcurp = bufp; + + return 0; +} + +static int ima_eventdigest_init_common(const u8 *digest, u32 digestsize, + u8 digest_type, u8 hash_algo, + struct ima_field_data *field_data) +{ + /* + * digest formats: + * - DATA_FMT_DIGEST: digest + * - DATA_FMT_DIGEST_WITH_ALGO: <hash algo> + ':' + '\0' + digest, + * - DATA_FMT_DIGEST_WITH_TYPE_AND_ALGO: + * <digest type> + ':' + <hash algo> + ':' + '\0' + digest, + * + * where 'DATA_FMT_DIGEST' is the original digest format ('d') + * with a hash size limitation of 20 bytes, + * where <digest type> is either "ima" or "verity", + * where <hash algo> is the hash_algo_name[] string. + */ + u8 buffer[DIGEST_TYPE_NAME_LEN_MAX + CRYPTO_MAX_ALG_NAME + 2 + + IMA_MAX_DIGEST_SIZE] = { 0 }; + enum data_formats fmt = DATA_FMT_DIGEST; + u32 offset = 0; + + if (digest_type < DIGEST_TYPE__LAST && hash_algo < HASH_ALGO__LAST) { + fmt = DATA_FMT_DIGEST_WITH_TYPE_AND_ALGO; + offset += 1 + sprintf(buffer, "%s:%s:", + digest_type_name[digest_type], + hash_algo_name[hash_algo]); + } else if (hash_algo < HASH_ALGO__LAST) { + fmt = DATA_FMT_DIGEST_WITH_ALGO; + offset += 1 + sprintf(buffer, "%s:", + hash_algo_name[hash_algo]); + } + + if (digest) + memcpy(buffer + offset, digest, digestsize); + else + /* + * If digest is NULL, the event being recorded is a violation. + * Make room for the digest by increasing the offset by the + * hash algorithm digest size. + */ + offset += hash_digest_size[hash_algo]; + + return ima_write_template_field_data(buffer, offset + digestsize, + fmt, field_data); +} + +/* + * This function writes the digest of an event (with size limit). + */ +int ima_eventdigest_init(struct ima_event_data *event_data, + struct ima_field_data *field_data) +{ + struct ima_max_digest_data hash; + u8 *cur_digest = NULL; + u32 cur_digestsize = 0; + struct inode *inode; + int result; + + memset(&hash, 0, sizeof(hash)); + + if (event_data->violation) /* recording a violation. */ + goto out; + + if (ima_template_hash_algo_allowed(event_data->iint->ima_hash->algo)) { + cur_digest = event_data->iint->ima_hash->digest; + cur_digestsize = event_data->iint->ima_hash->length; + goto out; + } + + if ((const char *)event_data->filename == boot_aggregate_name) { + if (ima_tpm_chip) { + hash.hdr.algo = HASH_ALGO_SHA1; + result = ima_calc_boot_aggregate(&hash.hdr); + + /* algo can change depending on available PCR banks */ + if (!result && hash.hdr.algo != HASH_ALGO_SHA1) + result = -EINVAL; + + if (result < 0) + memset(&hash, 0, sizeof(hash)); + } + + cur_digest = hash.hdr.digest; + cur_digestsize = hash_digest_size[HASH_ALGO_SHA1]; + goto out; + } + + if (!event_data->file) /* missing info to re-calculate the digest */ + return -EINVAL; + + inode = file_inode(event_data->file); + hash.hdr.algo = ima_template_hash_algo_allowed(ima_hash_algo) ? + ima_hash_algo : HASH_ALGO_SHA1; + result = ima_calc_file_hash(event_data->file, &hash.hdr); + if (result) { + integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, + event_data->filename, "collect_data", + "failed", result, 0); + return result; + } + cur_digest = hash.hdr.digest; + cur_digestsize = hash.hdr.length; +out: + return ima_eventdigest_init_common(cur_digest, cur_digestsize, + DIGEST_TYPE__LAST, HASH_ALGO__LAST, + field_data); +} + +/* + * This function writes the digest of an event (without size limit). + */ +int ima_eventdigest_ng_init(struct ima_event_data *event_data, + struct ima_field_data *field_data) +{ + u8 *cur_digest = NULL, hash_algo = ima_hash_algo; + u32 cur_digestsize = 0; + + if (event_data->violation) /* recording a violation. */ + goto out; + + cur_digest = event_data->iint->ima_hash->digest; + cur_digestsize = event_data->iint->ima_hash->length; + + hash_algo = event_data->iint->ima_hash->algo; +out: + return ima_eventdigest_init_common(cur_digest, cur_digestsize, + DIGEST_TYPE__LAST, hash_algo, + field_data); +} + +/* + * This function writes the digest of an event (without size limit), + * prefixed with both the digest type and hash algorithm. + */ +int ima_eventdigest_ngv2_init(struct ima_event_data *event_data, + struct ima_field_data *field_data) +{ + u8 *cur_digest = NULL, hash_algo = ima_hash_algo; + u32 cur_digestsize = 0; + u8 digest_type = DIGEST_TYPE_IMA; + + if (event_data->violation) /* recording a violation. */ + goto out; + + cur_digest = event_data->iint->ima_hash->digest; + cur_digestsize = event_data->iint->ima_hash->length; + + hash_algo = event_data->iint->ima_hash->algo; + if (event_data->iint->flags & IMA_VERITY_REQUIRED) + digest_type = DIGEST_TYPE_VERITY; +out: + return ima_eventdigest_init_common(cur_digest, cur_digestsize, + digest_type, hash_algo, + field_data); +} + +/* + * This function writes the digest of the file which is expected to match the + * digest contained in the file's appended signature. + */ +int ima_eventdigest_modsig_init(struct ima_event_data *event_data, + struct ima_field_data *field_data) +{ + enum hash_algo hash_algo; + const u8 *cur_digest; + u32 cur_digestsize; + + if (!event_data->modsig) + return 0; + + if (event_data->violation) { + /* Recording a violation. */ + hash_algo = HASH_ALGO_SHA1; + cur_digest = NULL; + cur_digestsize = 0; + } else { + int rc; + + rc = ima_get_modsig_digest(event_data->modsig, &hash_algo, + &cur_digest, &cur_digestsize); + if (rc) + return rc; + else if (hash_algo == HASH_ALGO__LAST || cur_digestsize == 0) + /* There was some error collecting the digest. */ + return -EINVAL; + } + + return ima_eventdigest_init_common(cur_digest, cur_digestsize, + DIGEST_TYPE__LAST, hash_algo, + field_data); +} + +static int ima_eventname_init_common(struct ima_event_data *event_data, + struct ima_field_data *field_data, + bool size_limit) +{ + const char *cur_filename = NULL; + u32 cur_filename_len = 0; + + BUG_ON(event_data->filename == NULL && event_data->file == NULL); + + if (event_data->filename) { + cur_filename = event_data->filename; + cur_filename_len = strlen(event_data->filename); + + if (!size_limit || cur_filename_len <= IMA_EVENT_NAME_LEN_MAX) + goto out; + } + + if (event_data->file) { + cur_filename = event_data->file->f_path.dentry->d_name.name; + cur_filename_len = strlen(cur_filename); + } else + /* + * Truncate filename if the latter is too long and + * the file descriptor is not available. + */ + cur_filename_len = IMA_EVENT_NAME_LEN_MAX; +out: + return ima_write_template_field_data(cur_filename, cur_filename_len, + DATA_FMT_STRING, field_data); +} + +/* + * This function writes the name of an event (with size limit). + */ +int ima_eventname_init(struct ima_event_data *event_data, + struct ima_field_data *field_data) +{ + return ima_eventname_init_common(event_data, field_data, true); +} + +/* + * This function writes the name of an event (without size limit). + */ +int ima_eventname_ng_init(struct ima_event_data *event_data, + struct ima_field_data *field_data) +{ + return ima_eventname_init_common(event_data, field_data, false); +} + +/* + * ima_eventsig_init - include the file signature as part of the template data + */ +int ima_eventsig_init(struct ima_event_data *event_data, + struct ima_field_data *field_data) +{ + struct evm_ima_xattr_data *xattr_value = event_data->xattr_value; + + if (!xattr_value || + (xattr_value->type != EVM_IMA_XATTR_DIGSIG && + xattr_value->type != IMA_VERITY_DIGSIG)) + return ima_eventevmsig_init(event_data, field_data); + + return ima_write_template_field_data(xattr_value, event_data->xattr_len, + DATA_FMT_HEX, field_data); +} + +/* + * ima_eventbuf_init - include the buffer(kexec-cmldine) as part of the + * template data. + */ +int ima_eventbuf_init(struct ima_event_data *event_data, + struct ima_field_data *field_data) +{ + if ((!event_data->buf) || (event_data->buf_len == 0)) + return 0; + + return ima_write_template_field_data(event_data->buf, + event_data->buf_len, DATA_FMT_HEX, + field_data); +} + +/* + * ima_eventmodsig_init - include the appended file signature as part of the + * template data + */ +int ima_eventmodsig_init(struct ima_event_data *event_data, + struct ima_field_data *field_data) +{ + const void *data; + u32 data_len; + int rc; + + if (!event_data->modsig) + return 0; + + /* + * modsig is a runtime structure containing pointers. Get its raw data + * instead. + */ + rc = ima_get_raw_modsig(event_data->modsig, &data, &data_len); + if (rc) + return rc; + + return ima_write_template_field_data(data, data_len, DATA_FMT_HEX, + field_data); +} + +/* + * ima_eventevmsig_init - include the EVM portable signature as part of the + * template data + */ +int ima_eventevmsig_init(struct ima_event_data *event_data, + struct ima_field_data *field_data) +{ + struct evm_ima_xattr_data *xattr_data = NULL; + int rc = 0; + + if (!event_data->file) + return 0; + + rc = vfs_getxattr_alloc(&init_user_ns, file_dentry(event_data->file), + XATTR_NAME_EVM, (char **)&xattr_data, 0, + GFP_NOFS); + if (rc <= 0) + return 0; + + if (xattr_data->type != EVM_XATTR_PORTABLE_DIGSIG) { + kfree(xattr_data); + return 0; + } + + rc = ima_write_template_field_data((char *)xattr_data, rc, DATA_FMT_HEX, + field_data); + kfree(xattr_data); + return rc; +} + +static int ima_eventinodedac_init_common(struct ima_event_data *event_data, + struct ima_field_data *field_data, + bool get_uid) +{ + unsigned int id; + + if (!event_data->file) + return 0; + + if (get_uid) + id = i_uid_read(file_inode(event_data->file)); + else + id = i_gid_read(file_inode(event_data->file)); + + if (ima_canonical_fmt) { + if (sizeof(id) == sizeof(u16)) + id = (__force u16)cpu_to_le16(id); + else + id = (__force u32)cpu_to_le32(id); + } + + return ima_write_template_field_data((void *)&id, sizeof(id), + DATA_FMT_UINT, field_data); +} + +/* + * ima_eventinodeuid_init - include the inode UID as part of the template + * data + */ +int ima_eventinodeuid_init(struct ima_event_data *event_data, + struct ima_field_data *field_data) +{ + return ima_eventinodedac_init_common(event_data, field_data, true); +} + +/* + * ima_eventinodegid_init - include the inode GID as part of the template + * data + */ +int ima_eventinodegid_init(struct ima_event_data *event_data, + struct ima_field_data *field_data) +{ + return ima_eventinodedac_init_common(event_data, field_data, false); +} + +/* + * ima_eventinodemode_init - include the inode mode as part of the template + * data + */ +int ima_eventinodemode_init(struct ima_event_data *event_data, + struct ima_field_data *field_data) +{ + struct inode *inode; + u16 mode; + + if (!event_data->file) + return 0; + + inode = file_inode(event_data->file); + mode = inode->i_mode; + if (ima_canonical_fmt) + mode = (__force u16)cpu_to_le16(mode); + + return ima_write_template_field_data((char *)&mode, sizeof(mode), + DATA_FMT_UINT, field_data); +} + +static int ima_eventinodexattrs_init_common(struct ima_event_data *event_data, + struct ima_field_data *field_data, + char type) +{ + u8 *buffer = NULL; + int rc; + + if (!event_data->file) + return 0; + + rc = evm_read_protected_xattrs(file_dentry(event_data->file), NULL, 0, + type, ima_canonical_fmt); + if (rc < 0) + return 0; + + buffer = kmalloc(rc, GFP_KERNEL); + if (!buffer) + return 0; + + rc = evm_read_protected_xattrs(file_dentry(event_data->file), buffer, + rc, type, ima_canonical_fmt); + if (rc < 0) { + rc = 0; + goto out; + } + + rc = ima_write_template_field_data((char *)buffer, rc, DATA_FMT_HEX, + field_data); +out: + kfree(buffer); + return rc; +} + +/* + * ima_eventinodexattrnames_init - include a list of xattr names as part of the + * template data + */ +int ima_eventinodexattrnames_init(struct ima_event_data *event_data, + struct ima_field_data *field_data) +{ + return ima_eventinodexattrs_init_common(event_data, field_data, 'n'); +} + +/* + * ima_eventinodexattrlengths_init - include a list of xattr lengths as part of + * the template data + */ +int ima_eventinodexattrlengths_init(struct ima_event_data *event_data, + struct ima_field_data *field_data) +{ + return ima_eventinodexattrs_init_common(event_data, field_data, 'l'); +} + +/* + * ima_eventinodexattrvalues_init - include a list of xattr values as part of + * the template data + */ +int ima_eventinodexattrvalues_init(struct ima_event_data *event_data, + struct ima_field_data *field_data) +{ + return ima_eventinodexattrs_init_common(event_data, field_data, 'v'); +} diff --git a/security/integrity/ima/ima_template_lib.h b/security/integrity/ima/ima_template_lib.h new file mode 100644 index 000000000..9f7c335f3 --- /dev/null +++ b/security/integrity/ima/ima_template_lib.h @@ -0,0 +1,69 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2013 Politecnico di Torino, Italy + * TORSEC group -- https://security.polito.it + * + * Author: Roberto Sassu <roberto.sassu@polito.it> + * + * File: ima_template_lib.h + * Header for the library of supported template fields. + */ +#ifndef __LINUX_IMA_TEMPLATE_LIB_H +#define __LINUX_IMA_TEMPLATE_LIB_H + +#include <linux/seq_file.h> +#include "ima.h" + +#define ENFORCE_FIELDS 0x00000001 +#define ENFORCE_BUFEND 0x00000002 + +void ima_show_template_digest(struct seq_file *m, enum ima_show_type show, + struct ima_field_data *field_data); +void ima_show_template_digest_ng(struct seq_file *m, enum ima_show_type show, + struct ima_field_data *field_data); +void ima_show_template_digest_ngv2(struct seq_file *m, enum ima_show_type show, + struct ima_field_data *field_data); +void ima_show_template_string(struct seq_file *m, enum ima_show_type show, + struct ima_field_data *field_data); +void ima_show_template_sig(struct seq_file *m, enum ima_show_type show, + struct ima_field_data *field_data); +void ima_show_template_buf(struct seq_file *m, enum ima_show_type show, + struct ima_field_data *field_data); +void ima_show_template_uint(struct seq_file *m, enum ima_show_type show, + struct ima_field_data *field_data); +int ima_parse_buf(void *bufstartp, void *bufendp, void **bufcurp, + int maxfields, struct ima_field_data *fields, int *curfields, + unsigned long *len_mask, int enforce_mask, char *bufname); +int ima_eventdigest_init(struct ima_event_data *event_data, + struct ima_field_data *field_data); +int ima_eventname_init(struct ima_event_data *event_data, + struct ima_field_data *field_data); +int ima_eventdigest_ng_init(struct ima_event_data *event_data, + struct ima_field_data *field_data); +int ima_eventdigest_ngv2_init(struct ima_event_data *event_data, + struct ima_field_data *field_data); +int ima_eventdigest_modsig_init(struct ima_event_data *event_data, + struct ima_field_data *field_data); +int ima_eventname_ng_init(struct ima_event_data *event_data, + struct ima_field_data *field_data); +int ima_eventsig_init(struct ima_event_data *event_data, + struct ima_field_data *field_data); +int ima_eventbuf_init(struct ima_event_data *event_data, + struct ima_field_data *field_data); +int ima_eventmodsig_init(struct ima_event_data *event_data, + struct ima_field_data *field_data); +int ima_eventevmsig_init(struct ima_event_data *event_data, + struct ima_field_data *field_data); +int ima_eventinodeuid_init(struct ima_event_data *event_data, + struct ima_field_data *field_data); +int ima_eventinodegid_init(struct ima_event_data *event_data, + struct ima_field_data *field_data); +int ima_eventinodemode_init(struct ima_event_data *event_data, + struct ima_field_data *field_data); +int ima_eventinodexattrnames_init(struct ima_event_data *event_data, + struct ima_field_data *field_data); +int ima_eventinodexattrlengths_init(struct ima_event_data *event_data, + struct ima_field_data *field_data); +int ima_eventinodexattrvalues_init(struct ima_event_data *event_data, + struct ima_field_data *field_data); +#endif /* __LINUX_IMA_TEMPLATE_LIB_H */ diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h new file mode 100644 index 000000000..52c3c806b --- /dev/null +++ b/security/integrity/integrity.h @@ -0,0 +1,335 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2009-2010 IBM Corporation + * + * Authors: + * Mimi Zohar <zohar@us.ibm.com> + */ + +#ifdef pr_fmt +#undef pr_fmt +#endif + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/types.h> +#include <linux/integrity.h> +#include <crypto/sha1.h> +#include <crypto/hash.h> +#include <linux/key.h> +#include <linux/audit.h> + +/* iint action cache flags */ +#define IMA_MEASURE 0x00000001 +#define IMA_MEASURED 0x00000002 +#define IMA_APPRAISE 0x00000004 +#define IMA_APPRAISED 0x00000008 +/*#define IMA_COLLECT 0x00000010 do not use this flag */ +#define IMA_COLLECTED 0x00000020 +#define IMA_AUDIT 0x00000040 +#define IMA_AUDITED 0x00000080 +#define IMA_HASH 0x00000100 +#define IMA_HASHED 0x00000200 + +/* iint policy rule cache flags */ +#define IMA_NONACTION_FLAGS 0xff000000 +#define IMA_DIGSIG_REQUIRED 0x01000000 +#define IMA_PERMIT_DIRECTIO 0x02000000 +#define IMA_NEW_FILE 0x04000000 +#define EVM_IMMUTABLE_DIGSIG 0x08000000 +#define IMA_FAIL_UNVERIFIABLE_SIGS 0x10000000 +#define IMA_MODSIG_ALLOWED 0x20000000 +#define IMA_CHECK_BLACKLIST 0x40000000 +#define IMA_VERITY_REQUIRED 0x80000000 + +#define IMA_DO_MASK (IMA_MEASURE | IMA_APPRAISE | IMA_AUDIT | \ + IMA_HASH | IMA_APPRAISE_SUBMASK) +#define IMA_DONE_MASK (IMA_MEASURED | IMA_APPRAISED | IMA_AUDITED | \ + IMA_HASHED | IMA_COLLECTED | \ + IMA_APPRAISED_SUBMASK) + +/* iint subaction appraise cache flags */ +#define IMA_FILE_APPRAISE 0x00001000 +#define IMA_FILE_APPRAISED 0x00002000 +#define IMA_MMAP_APPRAISE 0x00004000 +#define IMA_MMAP_APPRAISED 0x00008000 +#define IMA_BPRM_APPRAISE 0x00010000 +#define IMA_BPRM_APPRAISED 0x00020000 +#define IMA_READ_APPRAISE 0x00040000 +#define IMA_READ_APPRAISED 0x00080000 +#define IMA_CREDS_APPRAISE 0x00100000 +#define IMA_CREDS_APPRAISED 0x00200000 +#define IMA_APPRAISE_SUBMASK (IMA_FILE_APPRAISE | IMA_MMAP_APPRAISE | \ + IMA_BPRM_APPRAISE | IMA_READ_APPRAISE | \ + IMA_CREDS_APPRAISE) +#define IMA_APPRAISED_SUBMASK (IMA_FILE_APPRAISED | IMA_MMAP_APPRAISED | \ + IMA_BPRM_APPRAISED | IMA_READ_APPRAISED | \ + IMA_CREDS_APPRAISED) + +/* iint cache atomic_flags */ +#define IMA_CHANGE_XATTR 0 +#define IMA_UPDATE_XATTR 1 +#define IMA_CHANGE_ATTR 2 +#define IMA_DIGSIG 3 +#define IMA_MUST_MEASURE 4 + +enum evm_ima_xattr_type { + IMA_XATTR_DIGEST = 0x01, + EVM_XATTR_HMAC, + EVM_IMA_XATTR_DIGSIG, + IMA_XATTR_DIGEST_NG, + EVM_XATTR_PORTABLE_DIGSIG, + IMA_VERITY_DIGSIG, + IMA_XATTR_LAST +}; + +struct evm_ima_xattr_data { + u8 type; + u8 data[]; +} __packed; + +/* Only used in the EVM HMAC code. */ +struct evm_xattr { + struct evm_ima_xattr_data data; + u8 digest[SHA1_DIGEST_SIZE]; +} __packed; + +#define IMA_MAX_DIGEST_SIZE HASH_MAX_DIGESTSIZE + +struct ima_digest_data { + u8 algo; + u8 length; + union { + struct { + u8 unused; + u8 type; + } sha1; + struct { + u8 type; + u8 algo; + } ng; + u8 data[2]; + } xattr; + u8 digest[]; +} __packed; + +/* + * Instead of wrapping the ima_digest_data struct inside a local structure + * with the maximum hash size, define ima_max_digest_data struct. + */ +struct ima_max_digest_data { + struct ima_digest_data hdr; + u8 digest[HASH_MAX_DIGESTSIZE]; +} __packed; + +/* + * signature header format v2 - for using with asymmetric keys + * + * The signature_v2_hdr struct includes a signature format version + * to simplify defining new signature formats. + * + * signature format: + * version 2: regular file data hash based signature + * version 3: struct ima_file_id data based signature + */ +struct signature_v2_hdr { + uint8_t type; /* xattr type */ + uint8_t version; /* signature format version */ + uint8_t hash_algo; /* Digest algorithm [enum hash_algo] */ + __be32 keyid; /* IMA key identifier - not X509/PGP specific */ + __be16 sig_size; /* signature size */ + uint8_t sig[]; /* signature payload */ +} __packed; + +/* + * IMA signature version 3 disambiguates the data that is signed, by + * indirectly signing the hash of the ima_file_id structure data, + * containing either the fsverity_descriptor struct digest or, in the + * future, the regular IMA file hash. + * + * (The hash of the ima_file_id structure is only of the portion used.) + */ +struct ima_file_id { + __u8 hash_type; /* xattr type [enum evm_ima_xattr_type] */ + __u8 hash_algorithm; /* Digest algorithm [enum hash_algo] */ + __u8 hash[HASH_MAX_DIGESTSIZE]; +} __packed; + +/* integrity data associated with an inode */ +struct integrity_iint_cache { + struct rb_node rb_node; /* rooted in integrity_iint_tree */ + struct mutex mutex; /* protects: version, flags, digest */ + struct inode *inode; /* back pointer to inode in question */ + u64 version; /* track inode changes */ + unsigned long flags; + unsigned long measured_pcrs; + unsigned long atomic_flags; + unsigned long real_ino; + dev_t real_dev; + enum integrity_status ima_file_status:4; + enum integrity_status ima_mmap_status:4; + enum integrity_status ima_bprm_status:4; + enum integrity_status ima_read_status:4; + enum integrity_status ima_creds_status:4; + enum integrity_status evm_status:4; + struct ima_digest_data *ima_hash; +}; + +/* rbtree tree calls to lookup, insert, delete + * integrity data associated with an inode. + */ +struct integrity_iint_cache *integrity_iint_find(struct inode *inode); + +int integrity_kernel_read(struct file *file, loff_t offset, + void *addr, unsigned long count); + +#define INTEGRITY_KEYRING_EVM 0 +#define INTEGRITY_KEYRING_IMA 1 +#define INTEGRITY_KEYRING_PLATFORM 2 +#define INTEGRITY_KEYRING_MACHINE 3 +#define INTEGRITY_KEYRING_MAX 4 + +extern struct dentry *integrity_dir; + +struct modsig; + +#ifdef CONFIG_INTEGRITY_SIGNATURE + +int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen, + const char *digest, int digestlen); +int integrity_modsig_verify(unsigned int id, const struct modsig *modsig); + +int __init integrity_init_keyring(const unsigned int id); +int __init integrity_load_x509(const unsigned int id, const char *path); +int __init integrity_load_cert(const unsigned int id, const char *source, + const void *data, size_t len, key_perm_t perm); +#else + +static inline int integrity_digsig_verify(const unsigned int id, + const char *sig, int siglen, + const char *digest, int digestlen) +{ + return -EOPNOTSUPP; +} + +static inline int integrity_modsig_verify(unsigned int id, + const struct modsig *modsig) +{ + return -EOPNOTSUPP; +} + +static inline int integrity_init_keyring(const unsigned int id) +{ + return 0; +} + +static inline int __init integrity_load_cert(const unsigned int id, + const char *source, + const void *data, size_t len, + key_perm_t perm) +{ + return 0; +} +#endif /* CONFIG_INTEGRITY_SIGNATURE */ + +#ifdef CONFIG_INTEGRITY_ASYMMETRIC_KEYS +int asymmetric_verify(struct key *keyring, const char *sig, + int siglen, const char *data, int datalen); +#else +static inline int asymmetric_verify(struct key *keyring, const char *sig, + int siglen, const char *data, int datalen) +{ + return -EOPNOTSUPP; +} +#endif + +#ifdef CONFIG_IMA_APPRAISE_MODSIG +int ima_modsig_verify(struct key *keyring, const struct modsig *modsig); +#else +static inline int ima_modsig_verify(struct key *keyring, + const struct modsig *modsig) +{ + return -EOPNOTSUPP; +} +#endif + +#ifdef CONFIG_IMA_LOAD_X509 +void __init ima_load_x509(void); +#else +static inline void ima_load_x509(void) +{ +} +#endif + +#ifdef CONFIG_EVM_LOAD_X509 +void __init evm_load_x509(void); +#else +static inline void evm_load_x509(void) +{ +} +#endif + +#ifdef CONFIG_INTEGRITY_AUDIT +/* declarations */ +void integrity_audit_msg(int audit_msgno, struct inode *inode, + const unsigned char *fname, const char *op, + const char *cause, int result, int info); + +void integrity_audit_message(int audit_msgno, struct inode *inode, + const unsigned char *fname, const char *op, + const char *cause, int result, int info, + int errno); + +static inline struct audit_buffer * +integrity_audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, int type) +{ + return audit_log_start(ctx, gfp_mask, type); +} + +#else +static inline void integrity_audit_msg(int audit_msgno, struct inode *inode, + const unsigned char *fname, + const char *op, const char *cause, + int result, int info) +{ +} + +static inline void integrity_audit_message(int audit_msgno, + struct inode *inode, + const unsigned char *fname, + const char *op, const char *cause, + int result, int info, int errno) +{ +} + +static inline struct audit_buffer * +integrity_audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, int type) +{ + return NULL; +} + +#endif + +#ifdef CONFIG_INTEGRITY_PLATFORM_KEYRING +void __init add_to_platform_keyring(const char *source, const void *data, + size_t len); +#else +static inline void __init add_to_platform_keyring(const char *source, + const void *data, size_t len) +{ +} +#endif + +#ifdef CONFIG_INTEGRITY_MACHINE_KEYRING +void __init add_to_machine_keyring(const char *source, const void *data, size_t len); +bool __init trust_moklist(void); +#else +static inline void __init add_to_machine_keyring(const char *source, + const void *data, size_t len) +{ +} +static inline bool __init trust_moklist(void) +{ + return false; +} +#endif diff --git a/security/integrity/integrity_audit.c b/security/integrity/integrity_audit.c new file mode 100644 index 000000000..0ec5e4c22 --- /dev/null +++ b/security/integrity/integrity_audit.c @@ -0,0 +1,69 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2008 IBM Corporation + * Author: Mimi Zohar <zohar@us.ibm.com> + * + * File: integrity_audit.c + * Audit calls for the integrity subsystem + */ + +#include <linux/fs.h> +#include <linux/gfp.h> +#include <linux/audit.h> +#include "integrity.h" + +static int integrity_audit_info; + +/* ima_audit_setup - enable informational auditing messages */ +static int __init integrity_audit_setup(char *str) +{ + unsigned long audit; + + if (!kstrtoul(str, 0, &audit)) + integrity_audit_info = audit ? 1 : 0; + return 1; +} +__setup("integrity_audit=", integrity_audit_setup); + +void integrity_audit_msg(int audit_msgno, struct inode *inode, + const unsigned char *fname, const char *op, + const char *cause, int result, int audit_info) +{ + integrity_audit_message(audit_msgno, inode, fname, op, cause, + result, audit_info, 0); +} + +void integrity_audit_message(int audit_msgno, struct inode *inode, + const unsigned char *fname, const char *op, + const char *cause, int result, int audit_info, + int errno) +{ + struct audit_buffer *ab; + char name[TASK_COMM_LEN]; + + if (!integrity_audit_info && audit_info == 1) /* Skip info messages */ + return; + + ab = audit_log_start(audit_context(), GFP_KERNEL, audit_msgno); + if (!ab) + return; + audit_log_format(ab, "pid=%d uid=%u auid=%u ses=%u", + task_pid_nr(current), + from_kuid(&init_user_ns, current_uid()), + from_kuid(&init_user_ns, audit_get_loginuid(current)), + audit_get_sessionid(current)); + audit_log_task_context(ab); + audit_log_format(ab, " op=%s cause=%s comm=", op, cause); + audit_log_untrustedstring(ab, get_task_comm(name, current)); + if (fname) { + audit_log_format(ab, " name="); + audit_log_untrustedstring(ab, fname); + } + if (inode) { + audit_log_format(ab, " dev="); + audit_log_untrustedstring(ab, inode->i_sb->s_id); + audit_log_format(ab, " ino=%lu", inode->i_ino); + } + audit_log_format(ab, " res=%d errno=%d", !result, errno); + audit_log_end(ab); +} diff --git a/security/integrity/platform_certs/efi_parser.c b/security/integrity/platform_certs/efi_parser.c new file mode 100644 index 000000000..d98260f84 --- /dev/null +++ b/security/integrity/platform_certs/efi_parser.c @@ -0,0 +1,108 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* EFI signature/key/certificate list parser + * + * Copyright (C) 2012, 2016 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#define pr_fmt(fmt) "EFI: "fmt +#include <linux/module.h> +#include <linux/printk.h> +#include <linux/err.h> +#include <linux/efi.h> + +/** + * parse_efi_signature_list - Parse an EFI signature list for certificates + * @source: The source of the key + * @data: The data blob to parse + * @size: The size of the data blob + * @get_handler_for_guid: Get the handler func for the sig type (or NULL) + * + * Parse an EFI signature list looking for elements of interest. A list is + * made up of a series of sublists, where all the elements in a sublist are of + * the same type, but sublists can be of different types. + * + * For each sublist encountered, the @get_handler_for_guid function is called + * with the type specifier GUID and returns either a pointer to a function to + * handle elements of that type or NULL if the type is not of interest. + * + * If the sublist is of interest, each element is passed to the handler + * function in turn. + * + * Error EBADMSG is returned if the list doesn't parse correctly and 0 is + * returned if the list was parsed correctly. No error can be returned from + * the @get_handler_for_guid function or the element handler function it + * returns. + */ +int __init parse_efi_signature_list( + const char *source, + const void *data, size_t size, + efi_element_handler_t (*get_handler_for_guid)(const efi_guid_t *)) +{ + efi_element_handler_t handler; + unsigned int offs = 0; + + pr_devel("-->%s(,%zu)\n", __func__, size); + + while (size > 0) { + const efi_signature_data_t *elem; + efi_signature_list_t list; + size_t lsize, esize, hsize, elsize; + + if (size < sizeof(list)) + return -EBADMSG; + + memcpy(&list, data, sizeof(list)); + pr_devel("LIST[%04x] guid=%pUl ls=%x hs=%x ss=%x\n", + offs, + &list.signature_type, list.signature_list_size, + list.signature_header_size, list.signature_size); + + lsize = list.signature_list_size; + hsize = list.signature_header_size; + esize = list.signature_size; + elsize = lsize - sizeof(list) - hsize; + + if (lsize > size) { + pr_devel("<--%s() = -EBADMSG [overrun @%x]\n", + __func__, offs); + return -EBADMSG; + } + + if (lsize < sizeof(list) || + lsize - sizeof(list) < hsize || + esize < sizeof(*elem) || + elsize < esize || + elsize % esize != 0) { + pr_devel("- bad size combo @%x\n", offs); + return -EBADMSG; + } + + handler = get_handler_for_guid(&list.signature_type); + if (!handler) { + data += lsize; + size -= lsize; + offs += lsize; + continue; + } + + data += sizeof(list) + hsize; + size -= sizeof(list) + hsize; + offs += sizeof(list) + hsize; + + for (; elsize > 0; elsize -= esize) { + elem = data; + + pr_devel("ELEM[%04x]\n", offs); + handler(source, + &elem->signature_data, + esize - sizeof(*elem)); + + data += esize; + size -= esize; + offs += esize; + } + } + + return 0; +} diff --git a/security/integrity/platform_certs/keyring_handler.c b/security/integrity/platform_certs/keyring_handler.c new file mode 100644 index 000000000..8a1124e4d --- /dev/null +++ b/security/integrity/platform_certs/keyring_handler.c @@ -0,0 +1,85 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/cred.h> +#include <linux/err.h> +#include <linux/efi.h> +#include <linux/slab.h> +#include <keys/asymmetric-type.h> +#include <keys/system_keyring.h> +#include "../integrity.h" +#include "keyring_handler.h" + +static efi_guid_t efi_cert_x509_guid __initdata = EFI_CERT_X509_GUID; +static efi_guid_t efi_cert_x509_sha256_guid __initdata = + EFI_CERT_X509_SHA256_GUID; +static efi_guid_t efi_cert_sha256_guid __initdata = EFI_CERT_SHA256_GUID; + +/* + * Blacklist an X509 TBS hash. + */ +static __init void uefi_blacklist_x509_tbs(const char *source, + const void *data, size_t len) +{ + mark_hash_blacklisted(data, len, BLACKLIST_HASH_X509_TBS); +} + +/* + * Blacklist the hash of an executable. + */ +static __init void uefi_blacklist_binary(const char *source, + const void *data, size_t len) +{ + mark_hash_blacklisted(data, len, BLACKLIST_HASH_BINARY); +} + +/* + * Add an X509 cert to the revocation list. + */ +static __init void uefi_revocation_list_x509(const char *source, + const void *data, size_t len) +{ + add_key_to_revocation_list(data, len); +} + +/* + * Return the appropriate handler for particular signature list types found in + * the UEFI db tables. + */ +__init efi_element_handler_t get_handler_for_db(const efi_guid_t *sig_type) +{ + if (efi_guidcmp(*sig_type, efi_cert_x509_guid) == 0) + return add_to_platform_keyring; + return NULL; +} + +/* + * Return the appropriate handler for particular signature list types found in + * the MokListRT tables. + */ +__init efi_element_handler_t get_handler_for_mok(const efi_guid_t *sig_type) +{ + if (efi_guidcmp(*sig_type, efi_cert_x509_guid) == 0) { + if (IS_ENABLED(CONFIG_INTEGRITY_MACHINE_KEYRING) && trust_moklist()) + return add_to_machine_keyring; + else + return add_to_platform_keyring; + } + return NULL; +} + +/* + * Return the appropriate handler for particular signature list types found in + * the UEFI dbx and MokListXRT tables. + */ +__init efi_element_handler_t get_handler_for_dbx(const efi_guid_t *sig_type) +{ + if (efi_guidcmp(*sig_type, efi_cert_x509_sha256_guid) == 0) + return uefi_blacklist_x509_tbs; + if (efi_guidcmp(*sig_type, efi_cert_sha256_guid) == 0) + return uefi_blacklist_binary; + if (efi_guidcmp(*sig_type, efi_cert_x509_guid) == 0) + return uefi_revocation_list_x509; + return NULL; +} diff --git a/security/integrity/platform_certs/keyring_handler.h b/security/integrity/platform_certs/keyring_handler.h new file mode 100644 index 000000000..212d894a8 --- /dev/null +++ b/security/integrity/platform_certs/keyring_handler.h @@ -0,0 +1,45 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef PLATFORM_CERTS_INTERNAL_H +#define PLATFORM_CERTS_INTERNAL_H + +#include <linux/efi.h> + +void blacklist_hash(const char *source, const void *data, + size_t len, const char *type, + size_t type_len); + +/* + * Blacklist an X509 TBS hash. + */ +void blacklist_x509_tbs(const char *source, const void *data, size_t len); + +/* + * Blacklist the hash of an executable. + */ +void blacklist_binary(const char *source, const void *data, size_t len); + +/* + * Return the handler for particular signature list types found in the db. + */ +efi_element_handler_t get_handler_for_db(const efi_guid_t *sig_type); + +/* + * Return the handler for particular signature list types found in the mok. + */ +efi_element_handler_t get_handler_for_mok(const efi_guid_t *sig_type); + +/* + * Return the handler for particular signature list types found in the dbx. + */ +efi_element_handler_t get_handler_for_dbx(const efi_guid_t *sig_type); + +#endif + +#ifndef UEFI_QUIRK_SKIP_CERT +#define UEFI_QUIRK_SKIP_CERT(vendor, product) \ + .matches = { \ + DMI_MATCH(DMI_BOARD_VENDOR, vendor), \ + DMI_MATCH(DMI_PRODUCT_NAME, product), \ + }, +#endif diff --git a/security/integrity/platform_certs/load_ipl_s390.c b/security/integrity/platform_certs/load_ipl_s390.c new file mode 100644 index 000000000..e769dcb7e --- /dev/null +++ b/security/integrity/platform_certs/load_ipl_s390.c @@ -0,0 +1,36 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/cred.h> +#include <linux/err.h> +#include <linux/efi.h> +#include <linux/slab.h> +#include <keys/asymmetric-type.h> +#include <keys/system_keyring.h> +#include <asm/boot_data.h> +#include "../integrity.h" + +/* + * Load the certs contained in the IPL report created by the machine loader + * into the platform trusted keyring. + */ +static int __init load_ipl_certs(void) +{ + void *ptr, *end; + unsigned int len; + + if (!ipl_cert_list_addr) + return 0; + /* Copy the certificates to the system keyring */ + ptr = (void *) ipl_cert_list_addr; + end = ptr + ipl_cert_list_size; + while ((void *) ptr < end) { + len = *(unsigned int *) ptr; + ptr += sizeof(unsigned int); + add_to_platform_keyring("IPL:db", ptr, len); + ptr += len; + } + return 0; +} +late_initcall(load_ipl_certs); diff --git a/security/integrity/platform_certs/load_powerpc.c b/security/integrity/platform_certs/load_powerpc.c new file mode 100644 index 000000000..a2900cb85 --- /dev/null +++ b/security/integrity/platform_certs/load_powerpc.c @@ -0,0 +1,96 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2019 IBM Corporation + * Author: Nayna Jain + * + * - loads keys and hashes stored and controlled by the firmware. + */ +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/cred.h> +#include <linux/err.h> +#include <linux/slab.h> +#include <linux/of.h> +#include <asm/secure_boot.h> +#include <asm/secvar.h> +#include "keyring_handler.h" + +/* + * Get a certificate list blob from the named secure variable. + */ +static __init void *get_cert_list(u8 *key, unsigned long keylen, uint64_t *size) +{ + int rc; + void *db; + + rc = secvar_ops->get(key, keylen, NULL, size); + if (rc) { + pr_err("Couldn't get size: %d\n", rc); + return NULL; + } + + db = kmalloc(*size, GFP_KERNEL); + if (!db) + return NULL; + + rc = secvar_ops->get(key, keylen, db, size); + if (rc) { + kfree(db); + pr_err("Error reading %s var: %d\n", key, rc); + return NULL; + } + + return db; +} + +/* + * Load the certs contained in the keys databases into the platform trusted + * keyring and the blacklisted X.509 cert SHA256 hashes into the blacklist + * keyring. + */ +static int __init load_powerpc_certs(void) +{ + void *db = NULL, *dbx = NULL; + uint64_t dbsize = 0, dbxsize = 0; + int rc = 0; + struct device_node *node; + + if (!secvar_ops) + return -ENODEV; + + /* The following only applies for the edk2-compat backend. */ + node = of_find_compatible_node(NULL, NULL, "ibm,edk2-compat-v1"); + if (!node) + return -ENODEV; + + /* + * Get db, and dbx. They might not exist, so it isn't an error if we + * can't get them. + */ + db = get_cert_list("db", 3, &dbsize); + if (!db) { + pr_err("Couldn't get db list from firmware\n"); + } else { + rc = parse_efi_signature_list("powerpc:db", db, dbsize, + get_handler_for_db); + if (rc) + pr_err("Couldn't parse db signatures: %d\n", rc); + kfree(db); + } + + dbx = get_cert_list("dbx", 4, &dbxsize); + if (!dbx) { + pr_info("Couldn't get dbx list from firmware\n"); + } else { + rc = parse_efi_signature_list("powerpc:dbx", dbx, dbxsize, + get_handler_for_dbx); + if (rc) + pr_err("Couldn't parse dbx signatures: %d\n", rc); + kfree(dbx); + } + + of_node_put(node); + + return rc; +} +late_initcall(load_powerpc_certs); diff --git a/security/integrity/platform_certs/load_uefi.c b/security/integrity/platform_certs/load_uefi.c new file mode 100644 index 000000000..d1fdd1134 --- /dev/null +++ b/security/integrity/platform_certs/load_uefi.c @@ -0,0 +1,238 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/cred.h> +#include <linux/dmi.h> +#include <linux/err.h> +#include <linux/efi.h> +#include <linux/slab.h> +#include <linux/ima.h> +#include <keys/asymmetric-type.h> +#include <keys/system_keyring.h> +#include "../integrity.h" +#include "keyring_handler.h" + +/* + * On T2 Macs reading the db and dbx efi variables to load UEFI Secure Boot + * certificates causes occurrence of a page fault in Apple's firmware and + * a crash disabling EFI runtime services. The following quirk skips reading + * these variables. + */ +static const struct dmi_system_id uefi_skip_cert[] = { + { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookPro15,1") }, + { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookPro15,2") }, + { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookPro15,3") }, + { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookPro15,4") }, + { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookPro16,1") }, + { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookPro16,2") }, + { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookPro16,3") }, + { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookPro16,4") }, + { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookAir8,1") }, + { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookAir8,2") }, + { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookAir9,1") }, + { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "Macmini8,1") }, + { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacPro7,1") }, + { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "iMac20,1") }, + { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "iMac20,2") }, + { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "iMacPro1,1") }, + { } +}; + +/* + * Look to see if a UEFI variable called MokIgnoreDB exists and return true if + * it does. + * + * This UEFI variable is set by the shim if a user tells the shim to not use + * the certs/hashes in the UEFI db variable for verification purposes. If it + * is set, we should ignore the db variable also and the true return indicates + * this. + */ +static __init bool uefi_check_ignore_db(void) +{ + efi_status_t status; + unsigned int db = 0; + unsigned long size = sizeof(db); + efi_guid_t guid = EFI_SHIM_LOCK_GUID; + + status = efi.get_variable(L"MokIgnoreDB", &guid, NULL, &size, &db); + return status == EFI_SUCCESS; +} + +/* + * Get a certificate list blob from the named EFI variable. + */ +static __init void *get_cert_list(efi_char16_t *name, efi_guid_t *guid, + unsigned long *size, efi_status_t *status) +{ + unsigned long lsize = 4; + unsigned long tmpdb[4]; + void *db; + + *status = efi.get_variable(name, guid, NULL, &lsize, &tmpdb); + if (*status == EFI_NOT_FOUND) + return NULL; + + if (*status != EFI_BUFFER_TOO_SMALL) { + pr_err("Couldn't get size: 0x%lx\n", *status); + return NULL; + } + + db = kmalloc(lsize, GFP_KERNEL); + if (!db) + return NULL; + + *status = efi.get_variable(name, guid, NULL, &lsize, db); + if (*status != EFI_SUCCESS) { + kfree(db); + pr_err("Error reading db var: 0x%lx\n", *status); + return NULL; + } + + *size = lsize; + return db; +} + +/* + * load_moklist_certs() - Load MokList certs + * + * Load the certs contained in the UEFI MokListRT database into the + * platform trusted keyring. + * + * This routine checks the EFI MOK config table first. If and only if + * that fails, this routine uses the MokListRT ordinary UEFI variable. + * + * Return: Status + */ +static int __init load_moklist_certs(void) +{ + struct efi_mokvar_table_entry *mokvar_entry; + efi_guid_t mok_var = EFI_SHIM_LOCK_GUID; + void *mok; + unsigned long moksize; + efi_status_t status; + int rc; + + /* First try to load certs from the EFI MOKvar config table. + * It's not an error if the MOKvar config table doesn't exist + * or the MokListRT entry is not found in it. + */ + mokvar_entry = efi_mokvar_entry_find("MokListRT"); + if (mokvar_entry) { + rc = parse_efi_signature_list("UEFI:MokListRT (MOKvar table)", + mokvar_entry->data, + mokvar_entry->data_size, + get_handler_for_mok); + /* All done if that worked. */ + if (!rc) + return rc; + + pr_err("Couldn't parse MokListRT signatures from EFI MOKvar config table: %d\n", + rc); + } + + /* Get MokListRT. It might not exist, so it isn't an error + * if we can't get it. + */ + mok = get_cert_list(L"MokListRT", &mok_var, &moksize, &status); + if (mok) { + rc = parse_efi_signature_list("UEFI:MokListRT", + mok, moksize, get_handler_for_mok); + kfree(mok); + if (rc) + pr_err("Couldn't parse MokListRT signatures: %d\n", rc); + return rc; + } + if (status == EFI_NOT_FOUND) + pr_debug("MokListRT variable wasn't found\n"); + else + pr_info("Couldn't get UEFI MokListRT\n"); + return 0; +} + +/* + * load_uefi_certs() - Load certs from UEFI sources + * + * Load the certs contained in the UEFI databases into the platform trusted + * keyring and the UEFI blacklisted X.509 cert SHA256 hashes into the blacklist + * keyring. + */ +static int __init load_uefi_certs(void) +{ + efi_guid_t secure_var = EFI_IMAGE_SECURITY_DATABASE_GUID; + efi_guid_t mok_var = EFI_SHIM_LOCK_GUID; + void *db = NULL, *dbx = NULL, *mokx = NULL; + unsigned long dbsize = 0, dbxsize = 0, mokxsize = 0; + efi_status_t status; + int rc = 0; + const struct dmi_system_id *dmi_id; + + dmi_id = dmi_first_match(uefi_skip_cert); + if (dmi_id) { + pr_err("Reading UEFI Secure Boot Certs is not supported on T2 Macs.\n"); + return false; + } + + if (!efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE)) + return false; + + /* Get db and dbx. They might not exist, so it isn't an error + * if we can't get them. + */ + if (!uefi_check_ignore_db()) { + db = get_cert_list(L"db", &secure_var, &dbsize, &status); + if (!db) { + if (status == EFI_NOT_FOUND) + pr_debug("MODSIGN: db variable wasn't found\n"); + else + pr_err("MODSIGN: Couldn't get UEFI db list\n"); + } else { + rc = parse_efi_signature_list("UEFI:db", + db, dbsize, get_handler_for_db); + if (rc) + pr_err("Couldn't parse db signatures: %d\n", + rc); + kfree(db); + } + } + + dbx = get_cert_list(L"dbx", &secure_var, &dbxsize, &status); + if (!dbx) { + if (status == EFI_NOT_FOUND) + pr_debug("dbx variable wasn't found\n"); + else + pr_info("Couldn't get UEFI dbx list\n"); + } else { + rc = parse_efi_signature_list("UEFI:dbx", + dbx, dbxsize, + get_handler_for_dbx); + if (rc) + pr_err("Couldn't parse dbx signatures: %d\n", rc); + kfree(dbx); + } + + /* the MOK/MOKx can not be trusted when secure boot is disabled */ + if (!arch_ima_get_secureboot()) + return 0; + + mokx = get_cert_list(L"MokListXRT", &mok_var, &mokxsize, &status); + if (!mokx) { + if (status == EFI_NOT_FOUND) + pr_debug("mokx variable wasn't found\n"); + else + pr_info("Couldn't get mokx list\n"); + } else { + rc = parse_efi_signature_list("UEFI:MokListXRT", + mokx, mokxsize, + get_handler_for_dbx); + if (rc) + pr_err("Couldn't parse mokx signatures %d\n", rc); + kfree(mokx); + } + + /* Load the MokListRT certs */ + rc = load_moklist_certs(); + + return rc; +} +late_initcall(load_uefi_certs); diff --git a/security/integrity/platform_certs/machine_keyring.c b/security/integrity/platform_certs/machine_keyring.c new file mode 100644 index 000000000..7aaed7950 --- /dev/null +++ b/security/integrity/platform_certs/machine_keyring.c @@ -0,0 +1,77 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Machine keyring routines. + * + * Copyright (c) 2021, Oracle and/or its affiliates. + */ + +#include <linux/efi.h> +#include "../integrity.h" + +static bool trust_mok; + +static __init int machine_keyring_init(void) +{ + int rc; + + rc = integrity_init_keyring(INTEGRITY_KEYRING_MACHINE); + if (rc) + return rc; + + pr_notice("Machine keyring initialized\n"); + return 0; +} +device_initcall(machine_keyring_init); + +void __init add_to_machine_keyring(const char *source, const void *data, size_t len) +{ + key_perm_t perm; + int rc; + + perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW; + rc = integrity_load_cert(INTEGRITY_KEYRING_MACHINE, source, data, len, perm); + + /* + * Some MOKList keys may not pass the machine keyring restrictions. + * If the restriction check does not pass and the platform keyring + * is configured, try to add it into that keyring instead. + */ + if (rc && IS_ENABLED(CONFIG_INTEGRITY_PLATFORM_KEYRING)) + rc = integrity_load_cert(INTEGRITY_KEYRING_PLATFORM, source, + data, len, perm); + + if (rc) + pr_info("Error adding keys to machine keyring %s\n", source); +} + +/* + * Try to load the MokListTrustedRT MOK variable to see if we should trust + * the MOK keys within the kernel. It is not an error if this variable + * does not exist. If it does not exist, MOK keys should not be trusted + * within the machine keyring. + */ +static __init bool uefi_check_trust_mok_keys(void) +{ + struct efi_mokvar_table_entry *mokvar_entry; + + mokvar_entry = efi_mokvar_entry_find("MokListTrustedRT"); + + if (mokvar_entry) + return true; + + return false; +} + +bool __init trust_moklist(void) +{ + static bool initialized; + + if (!initialized) { + initialized = true; + + if (uefi_check_trust_mok_keys()) + trust_mok = true; + } + + return trust_mok; +} diff --git a/security/integrity/platform_certs/platform_keyring.c b/security/integrity/platform_certs/platform_keyring.c new file mode 100644 index 000000000..bcafd7387 --- /dev/null +++ b/security/integrity/platform_certs/platform_keyring.c @@ -0,0 +1,58 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Platform keyring for firmware/platform keys + * + * Copyright IBM Corporation, 2018 + * Author(s): Nayna Jain <nayna@linux.ibm.com> + */ + +#include <linux/export.h> +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/cred.h> +#include <linux/err.h> +#include <linux/slab.h> +#include "../integrity.h" + +/** + * add_to_platform_keyring - Add to platform keyring without validation. + * @source: Source of key + * @data: The blob holding the key + * @len: The length of the data blob + * + * Add a key to the platform keyring without checking its trust chain. This + * is available only during kernel initialisation. + */ +void __init add_to_platform_keyring(const char *source, const void *data, + size_t len) +{ + key_perm_t perm; + int rc; + + perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW; + + rc = integrity_load_cert(INTEGRITY_KEYRING_PLATFORM, source, data, len, + perm); + if (rc) + pr_info("Error adding keys to platform keyring %s\n", source); +} + +/* + * Create the trusted keyrings. + */ +static __init int platform_keyring_init(void) +{ + int rc; + + rc = integrity_init_keyring(INTEGRITY_KEYRING_PLATFORM); + if (rc) + return rc; + + pr_notice("Platform Keyring initialized\n"); + return 0; +} + +/* + * Must be initialised before we try and load the keys into the keyring. + */ +device_initcall(platform_keyring_init); diff --git a/security/keys/Kconfig b/security/keys/Kconfig new file mode 100644 index 000000000..abb03a1b2 --- /dev/null +++ b/security/keys/Kconfig @@ -0,0 +1,135 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +# Key management configuration +# + +config KEYS + bool "Enable access key retention support" + select ASSOCIATIVE_ARRAY + help + This option provides support for retaining authentication tokens and + access keys in the kernel. + + It also includes provision of methods by which such keys might be + associated with a process so that network filesystems, encryption + support and the like can find them. + + Furthermore, a special type of key is available that acts as keyring: + a searchable sequence of keys. Each process is equipped with access + to five standard keyrings: UID-specific, GID-specific, session, + process and thread. + + If you are unsure as to whether this is required, answer N. + +config KEYS_REQUEST_CACHE + bool "Enable temporary caching of the last request_key() result" + depends on KEYS + help + This option causes the result of the last successful request_key() + call that didn't upcall to the kernel to be cached temporarily in the + task_struct. The cache is cleared by exit and just prior to the + resumption of userspace. + + This allows the key used for multiple step processes where each step + wants to request a key that is likely the same as the one requested + by the last step to save on the searching. + + An example of such a process is a pathwalk through a network + filesystem in which each method needs to request an authentication + key. Pathwalk will call multiple methods for each dentry traversed + (permission, d_revalidate, lookup, getxattr, getacl, ...). + +config PERSISTENT_KEYRINGS + bool "Enable register of persistent per-UID keyrings" + depends on KEYS + help + This option provides a register of persistent per-UID keyrings, + primarily aimed at Kerberos key storage. The keyrings are persistent + in the sense that they stay around after all processes of that UID + have exited, not that they survive the machine being rebooted. + + A particular keyring may be accessed by either the user whose keyring + it is or by a process with administrative privileges. The active + LSMs gets to rule on which admin-level processes get to access the + cache. + + Keyrings are created and added into the register upon demand and get + removed if they expire (a default timeout is set upon creation). + +config BIG_KEYS + bool "Large payload keys" + depends on KEYS + depends on TMPFS + depends on CRYPTO_LIB_CHACHA20POLY1305 = y + help + This option provides support for holding large keys within the kernel + (for example Kerberos ticket caches). The data may be stored out to + swapspace by tmpfs. + + If you are unsure as to whether this is required, answer N. + +config TRUSTED_KEYS + tristate "TRUSTED KEYS" + depends on KEYS + help + This option provides support for creating, sealing, and unsealing + keys in the kernel. Trusted keys are random number symmetric keys, + generated and sealed by a trust source selected at kernel boot-time. + Userspace will only ever see encrypted blobs. + + If you are unsure as to whether this is required, answer N. + +if TRUSTED_KEYS +source "security/keys/trusted-keys/Kconfig" +endif + +config ENCRYPTED_KEYS + tristate "ENCRYPTED KEYS" + depends on KEYS + select CRYPTO + select CRYPTO_HMAC + select CRYPTO_AES + select CRYPTO_CBC + select CRYPTO_SHA256 + select CRYPTO_RNG + help + This option provides support for create/encrypting/decrypting keys + in the kernel. Encrypted keys are instantiated using kernel + generated random numbers or provided decrypted data, and are + encrypted/decrypted with a 'master' symmetric key. The 'master' + key can be either a trusted-key or user-key type. Only encrypted + blobs are ever output to Userspace. + + If you are unsure as to whether this is required, answer N. + +config USER_DECRYPTED_DATA + bool "Allow encrypted keys with user decrypted data" + depends on ENCRYPTED_KEYS + help + This option provides support for instantiating encrypted keys using + user-provided decrypted data. The decrypted data must be hex-ascii + encoded. + + If you are unsure as to whether this is required, answer N. + +config KEY_DH_OPERATIONS + bool "Diffie-Hellman operations on retained keys" + depends on KEYS + select CRYPTO + select CRYPTO_KDF800108_CTR + select CRYPTO_DH + help + This option provides support for calculating Diffie-Hellman + public keys and shared secrets using values stored as keys + in the kernel. + + If you are unsure as to whether this is required, answer N. + +config KEY_NOTIFICATIONS + bool "Provide key/keyring change notifications" + depends on KEYS && WATCH_QUEUE + help + This option provides support for getting change notifications + on keys and keyrings on which the caller has View permission. + This makes use of pipes to handle the notification buffer and + provides KEYCTL_WATCH_KEY to enable/disable watches. diff --git a/security/keys/Makefile b/security/keys/Makefile new file mode 100644 index 000000000..5f40807f0 --- /dev/null +++ b/security/keys/Makefile @@ -0,0 +1,32 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Makefile for key management +# + +# +# Core +# +obj-y := \ + gc.o \ + key.o \ + keyring.o \ + keyctl.o \ + permission.o \ + process_keys.o \ + request_key.o \ + request_key_auth.o \ + user_defined.o +compat-obj-$(CONFIG_KEY_DH_OPERATIONS) += compat_dh.o +obj-$(CONFIG_COMPAT) += compat.o $(compat-obj-y) +obj-$(CONFIG_PROC_FS) += proc.o +obj-$(CONFIG_SYSCTL) += sysctl.o +obj-$(CONFIG_PERSISTENT_KEYRINGS) += persistent.o +obj-$(CONFIG_KEY_DH_OPERATIONS) += dh.o +obj-$(CONFIG_ASYMMETRIC_KEY_TYPE) += keyctl_pkey.o + +# +# Key types +# +obj-$(CONFIG_BIG_KEYS) += big_key.o +obj-$(CONFIG_TRUSTED_KEYS) += trusted-keys/ +obj-$(CONFIG_ENCRYPTED_KEYS) += encrypted-keys/ diff --git a/security/keys/big_key.c b/security/keys/big_key.c new file mode 100644 index 000000000..c3367622c --- /dev/null +++ b/security/keys/big_key.c @@ -0,0 +1,290 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* Large capacity key type + * + * Copyright (C) 2017-2020 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. + * Copyright (C) 2013 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#define pr_fmt(fmt) "big_key: "fmt +#include <linux/init.h> +#include <linux/seq_file.h> +#include <linux/file.h> +#include <linux/shmem_fs.h> +#include <linux/err.h> +#include <linux/random.h> +#include <keys/user-type.h> +#include <keys/big_key-type.h> +#include <crypto/chacha20poly1305.h> + +/* + * Layout of key payload words. + */ +struct big_key_payload { + u8 *data; + struct path path; + size_t length; +}; +#define to_big_key_payload(payload) \ + (struct big_key_payload *)((payload).data) + +/* + * If the data is under this limit, there's no point creating a shm file to + * hold it as the permanently resident metadata for the shmem fs will be at + * least as large as the data. + */ +#define BIG_KEY_FILE_THRESHOLD (sizeof(struct inode) + sizeof(struct dentry)) + +/* + * big_key defined keys take an arbitrary string as the description and an + * arbitrary blob of data as the payload + */ +struct key_type key_type_big_key = { + .name = "big_key", + .preparse = big_key_preparse, + .free_preparse = big_key_free_preparse, + .instantiate = generic_key_instantiate, + .revoke = big_key_revoke, + .destroy = big_key_destroy, + .describe = big_key_describe, + .read = big_key_read, + .update = big_key_update, +}; + +/* + * Preparse a big key + */ +int big_key_preparse(struct key_preparsed_payload *prep) +{ + struct big_key_payload *payload = to_big_key_payload(prep->payload); + struct file *file; + u8 *buf, *enckey; + ssize_t written; + size_t datalen = prep->datalen; + size_t enclen = datalen + CHACHA20POLY1305_AUTHTAG_SIZE; + int ret; + + BUILD_BUG_ON(sizeof(*payload) != sizeof(prep->payload.data)); + + if (datalen <= 0 || datalen > 1024 * 1024 || !prep->data) + return -EINVAL; + + /* Set an arbitrary quota */ + prep->quotalen = 16; + + payload->length = datalen; + + if (datalen > BIG_KEY_FILE_THRESHOLD) { + /* Create a shmem file to store the data in. This will permit the data + * to be swapped out if needed. + * + * File content is stored encrypted with randomly generated key. + * Since the key is random for each file, we can set the nonce + * to zero, provided we never define a ->update() call. + */ + loff_t pos = 0; + + buf = kvmalloc(enclen, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + /* generate random key */ + enckey = kmalloc(CHACHA20POLY1305_KEY_SIZE, GFP_KERNEL); + if (!enckey) { + ret = -ENOMEM; + goto error; + } + ret = get_random_bytes_wait(enckey, CHACHA20POLY1305_KEY_SIZE); + if (unlikely(ret)) + goto err_enckey; + + /* encrypt data */ + chacha20poly1305_encrypt(buf, prep->data, datalen, NULL, 0, + 0, enckey); + + /* save aligned data to file */ + file = shmem_kernel_file_setup("", enclen, 0); + if (IS_ERR(file)) { + ret = PTR_ERR(file); + goto err_enckey; + } + + written = kernel_write(file, buf, enclen, &pos); + if (written != enclen) { + ret = written; + if (written >= 0) + ret = -EIO; + goto err_fput; + } + + /* Pin the mount and dentry to the key so that we can open it again + * later + */ + payload->data = enckey; + payload->path = file->f_path; + path_get(&payload->path); + fput(file); + kvfree_sensitive(buf, enclen); + } else { + /* Just store the data in a buffer */ + void *data = kmalloc(datalen, GFP_KERNEL); + + if (!data) + return -ENOMEM; + + payload->data = data; + memcpy(data, prep->data, prep->datalen); + } + return 0; + +err_fput: + fput(file); +err_enckey: + kfree_sensitive(enckey); +error: + kvfree_sensitive(buf, enclen); + return ret; +} + +/* + * Clear preparsement. + */ +void big_key_free_preparse(struct key_preparsed_payload *prep) +{ + struct big_key_payload *payload = to_big_key_payload(prep->payload); + + if (prep->datalen > BIG_KEY_FILE_THRESHOLD) + path_put(&payload->path); + kfree_sensitive(payload->data); +} + +/* + * dispose of the links from a revoked keyring + * - called with the key sem write-locked + */ +void big_key_revoke(struct key *key) +{ + struct big_key_payload *payload = to_big_key_payload(key->payload); + + /* clear the quota */ + key_payload_reserve(key, 0); + if (key_is_positive(key) && payload->length > BIG_KEY_FILE_THRESHOLD) + vfs_truncate(&payload->path, 0); +} + +/* + * dispose of the data dangling from the corpse of a big_key key + */ +void big_key_destroy(struct key *key) +{ + struct big_key_payload *payload = to_big_key_payload(key->payload); + + if (payload->length > BIG_KEY_FILE_THRESHOLD) { + path_put(&payload->path); + payload->path.mnt = NULL; + payload->path.dentry = NULL; + } + kfree_sensitive(payload->data); + payload->data = NULL; +} + +/* + * Update a big key + */ +int big_key_update(struct key *key, struct key_preparsed_payload *prep) +{ + int ret; + + ret = key_payload_reserve(key, prep->datalen); + if (ret < 0) + return ret; + + if (key_is_positive(key)) + big_key_destroy(key); + + return generic_key_instantiate(key, prep); +} + +/* + * describe the big_key key + */ +void big_key_describe(const struct key *key, struct seq_file *m) +{ + struct big_key_payload *payload = to_big_key_payload(key->payload); + + seq_puts(m, key->description); + + if (key_is_positive(key)) + seq_printf(m, ": %zu [%s]", + payload->length, + payload->length > BIG_KEY_FILE_THRESHOLD ? "file" : "buff"); +} + +/* + * read the key data + * - the key's semaphore is read-locked + */ +long big_key_read(const struct key *key, char *buffer, size_t buflen) +{ + struct big_key_payload *payload = to_big_key_payload(key->payload); + size_t datalen = payload->length; + long ret; + + if (!buffer || buflen < datalen) + return datalen; + + if (datalen > BIG_KEY_FILE_THRESHOLD) { + struct file *file; + u8 *buf, *enckey = payload->data; + size_t enclen = datalen + CHACHA20POLY1305_AUTHTAG_SIZE; + loff_t pos = 0; + + buf = kvmalloc(enclen, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + file = dentry_open(&payload->path, O_RDONLY, current_cred()); + if (IS_ERR(file)) { + ret = PTR_ERR(file); + goto error; + } + + /* read file to kernel and decrypt */ + ret = kernel_read(file, buf, enclen, &pos); + if (ret != enclen) { + if (ret >= 0) + ret = -EIO; + goto err_fput; + } + + ret = chacha20poly1305_decrypt(buf, buf, enclen, NULL, 0, 0, + enckey) ? 0 : -EBADMSG; + if (unlikely(ret)) + goto err_fput; + + ret = datalen; + + /* copy out decrypted data */ + memcpy(buffer, buf, datalen); + +err_fput: + fput(file); +error: + kvfree_sensitive(buf, enclen); + } else { + ret = datalen; + memcpy(buffer, payload->data, datalen); + } + + return ret; +} + +/* + * Register key type + */ +static int __init big_key_init(void) +{ + return register_key_type(&key_type_big_key); +} + +late_initcall(big_key_init); diff --git a/security/keys/compat.c b/security/keys/compat.c new file mode 100644 index 000000000..1545efdca --- /dev/null +++ b/security/keys/compat.c @@ -0,0 +1,132 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* 32-bit compatibility syscall for 64-bit systems + * + * Copyright (C) 2004-5 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#include <linux/syscalls.h> +#include <linux/keyctl.h> +#include <linux/compat.h> +#include <linux/slab.h> +#include "internal.h" + +/* + * The key control system call, 32-bit compatibility version for 64-bit archs + */ +COMPAT_SYSCALL_DEFINE5(keyctl, u32, option, + u32, arg2, u32, arg3, u32, arg4, u32, arg5) +{ + switch (option) { + case KEYCTL_GET_KEYRING_ID: + return keyctl_get_keyring_ID(arg2, arg3); + + case KEYCTL_JOIN_SESSION_KEYRING: + return keyctl_join_session_keyring(compat_ptr(arg2)); + + case KEYCTL_UPDATE: + return keyctl_update_key(arg2, compat_ptr(arg3), arg4); + + case KEYCTL_REVOKE: + return keyctl_revoke_key(arg2); + + case KEYCTL_DESCRIBE: + return keyctl_describe_key(arg2, compat_ptr(arg3), arg4); + + case KEYCTL_CLEAR: + return keyctl_keyring_clear(arg2); + + case KEYCTL_LINK: + return keyctl_keyring_link(arg2, arg3); + + case KEYCTL_UNLINK: + return keyctl_keyring_unlink(arg2, arg3); + + case KEYCTL_SEARCH: + return keyctl_keyring_search(arg2, compat_ptr(arg3), + compat_ptr(arg4), arg5); + + case KEYCTL_READ: + return keyctl_read_key(arg2, compat_ptr(arg3), arg4); + + case KEYCTL_CHOWN: + return keyctl_chown_key(arg2, arg3, arg4); + + case KEYCTL_SETPERM: + return keyctl_setperm_key(arg2, arg3); + + case KEYCTL_INSTANTIATE: + return keyctl_instantiate_key(arg2, compat_ptr(arg3), arg4, + arg5); + + case KEYCTL_NEGATE: + return keyctl_negate_key(arg2, arg3, arg4); + + case KEYCTL_SET_REQKEY_KEYRING: + return keyctl_set_reqkey_keyring(arg2); + + case KEYCTL_SET_TIMEOUT: + return keyctl_set_timeout(arg2, arg3); + + case KEYCTL_ASSUME_AUTHORITY: + return keyctl_assume_authority(arg2); + + case KEYCTL_GET_SECURITY: + return keyctl_get_security(arg2, compat_ptr(arg3), arg4); + + case KEYCTL_SESSION_TO_PARENT: + return keyctl_session_to_parent(); + + case KEYCTL_REJECT: + return keyctl_reject_key(arg2, arg3, arg4, arg5); + + case KEYCTL_INSTANTIATE_IOV: + return keyctl_instantiate_key_iov(arg2, compat_ptr(arg3), arg4, + arg5); + + case KEYCTL_INVALIDATE: + return keyctl_invalidate_key(arg2); + + case KEYCTL_GET_PERSISTENT: + return keyctl_get_persistent(arg2, arg3); + + case KEYCTL_DH_COMPUTE: + return compat_keyctl_dh_compute(compat_ptr(arg2), + compat_ptr(arg3), + arg4, compat_ptr(arg5)); + + case KEYCTL_RESTRICT_KEYRING: + return keyctl_restrict_keyring(arg2, compat_ptr(arg3), + compat_ptr(arg4)); + + case KEYCTL_PKEY_QUERY: + if (arg3 != 0) + return -EINVAL; + return keyctl_pkey_query(arg2, + compat_ptr(arg4), + compat_ptr(arg5)); + + case KEYCTL_PKEY_ENCRYPT: + case KEYCTL_PKEY_DECRYPT: + case KEYCTL_PKEY_SIGN: + return keyctl_pkey_e_d_s(option, + compat_ptr(arg2), compat_ptr(arg3), + compat_ptr(arg4), compat_ptr(arg5)); + + case KEYCTL_PKEY_VERIFY: + return keyctl_pkey_verify(compat_ptr(arg2), compat_ptr(arg3), + compat_ptr(arg4), compat_ptr(arg5)); + + case KEYCTL_MOVE: + return keyctl_keyring_move(arg2, arg3, arg4, arg5); + + case KEYCTL_CAPABILITIES: + return keyctl_capabilities(compat_ptr(arg2), arg3); + + case KEYCTL_WATCH_KEY: + return keyctl_watch_key(arg2, arg3, arg4); + + default: + return -EOPNOTSUPP; + } +} diff --git a/security/keys/compat_dh.c b/security/keys/compat_dh.c new file mode 100644 index 000000000..19384e7e9 --- /dev/null +++ b/security/keys/compat_dh.c @@ -0,0 +1,36 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* 32-bit compatibility syscall for 64-bit systems for DH operations + * + * Copyright (C) 2016 Stephan Mueller <smueller@chronox.de> + */ + +#include <linux/uaccess.h> + +#include "internal.h" + +/* + * Perform the DH computation or DH based key derivation. + * + * If successful, 0 will be returned. + */ +long compat_keyctl_dh_compute(struct keyctl_dh_params __user *params, + char __user *buffer, size_t buflen, + struct compat_keyctl_kdf_params __user *kdf) +{ + struct keyctl_kdf_params kdfcopy; + struct compat_keyctl_kdf_params compat_kdfcopy; + + if (!kdf) + return __keyctl_dh_compute(params, buffer, buflen, NULL); + + if (copy_from_user(&compat_kdfcopy, kdf, sizeof(compat_kdfcopy)) != 0) + return -EFAULT; + + kdfcopy.hashname = compat_ptr(compat_kdfcopy.hashname); + kdfcopy.otherinfo = compat_ptr(compat_kdfcopy.otherinfo); + kdfcopy.otherinfolen = compat_kdfcopy.otherinfolen; + memcpy(kdfcopy.__spare, compat_kdfcopy.__spare, + sizeof(kdfcopy.__spare)); + + return __keyctl_dh_compute(params, buffer, buflen, &kdfcopy); +} diff --git a/security/keys/dh.c b/security/keys/dh.c new file mode 100644 index 000000000..b339760a3 --- /dev/null +++ b/security/keys/dh.c @@ -0,0 +1,333 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* Crypto operations using stored keys + * + * Copyright (c) 2016, Intel Corporation + */ + +#include <linux/slab.h> +#include <linux/uaccess.h> +#include <linux/scatterlist.h> +#include <linux/crypto.h> +#include <crypto/hash.h> +#include <crypto/kpp.h> +#include <crypto/dh.h> +#include <crypto/kdf_sp800108.h> +#include <keys/user-type.h> +#include "internal.h" + +static ssize_t dh_data_from_key(key_serial_t keyid, const void **data) +{ + struct key *key; + key_ref_t key_ref; + long status; + ssize_t ret; + + key_ref = lookup_user_key(keyid, 0, KEY_NEED_READ); + if (IS_ERR(key_ref)) { + ret = -ENOKEY; + goto error; + } + + key = key_ref_to_ptr(key_ref); + + ret = -EOPNOTSUPP; + if (key->type == &key_type_user) { + down_read(&key->sem); + status = key_validate(key); + if (status == 0) { + const struct user_key_payload *payload; + uint8_t *duplicate; + + payload = user_key_payload_locked(key); + + duplicate = kmemdup(payload->data, payload->datalen, + GFP_KERNEL); + if (duplicate) { + *data = duplicate; + ret = payload->datalen; + } else { + ret = -ENOMEM; + } + } + up_read(&key->sem); + } + + key_put(key); +error: + return ret; +} + +static void dh_free_data(struct dh *dh) +{ + kfree_sensitive(dh->key); + kfree_sensitive(dh->p); + kfree_sensitive(dh->g); +} + +struct dh_completion { + struct completion completion; + int err; +}; + +static void dh_crypto_done(struct crypto_async_request *req, int err) +{ + struct dh_completion *compl = req->data; + + if (err == -EINPROGRESS) + return; + + compl->err = err; + complete(&compl->completion); +} + +static int kdf_alloc(struct crypto_shash **hash, char *hashname) +{ + struct crypto_shash *tfm; + + /* allocate synchronous hash */ + tfm = crypto_alloc_shash(hashname, 0, 0); + if (IS_ERR(tfm)) { + pr_info("could not allocate digest TFM handle %s\n", hashname); + return PTR_ERR(tfm); + } + + if (crypto_shash_digestsize(tfm) == 0) { + crypto_free_shash(tfm); + return -EINVAL; + } + + *hash = tfm; + + return 0; +} + +static void kdf_dealloc(struct crypto_shash *hash) +{ + if (hash) + crypto_free_shash(hash); +} + +static int keyctl_dh_compute_kdf(struct crypto_shash *hash, + char __user *buffer, size_t buflen, + uint8_t *kbuf, size_t kbuflen) +{ + struct kvec kbuf_iov = { .iov_base = kbuf, .iov_len = kbuflen }; + uint8_t *outbuf = NULL; + int ret; + size_t outbuf_len = roundup(buflen, crypto_shash_digestsize(hash)); + + outbuf = kmalloc(outbuf_len, GFP_KERNEL); + if (!outbuf) { + ret = -ENOMEM; + goto err; + } + + ret = crypto_kdf108_ctr_generate(hash, &kbuf_iov, 1, outbuf, outbuf_len); + if (ret) + goto err; + + ret = buflen; + if (copy_to_user(buffer, outbuf, buflen) != 0) + ret = -EFAULT; + +err: + kfree_sensitive(outbuf); + return ret; +} + +long __keyctl_dh_compute(struct keyctl_dh_params __user *params, + char __user *buffer, size_t buflen, + struct keyctl_kdf_params *kdfcopy) +{ + long ret; + ssize_t dlen; + int secretlen; + int outlen; + struct keyctl_dh_params pcopy; + struct dh dh_inputs; + struct scatterlist outsg; + struct dh_completion compl; + struct crypto_kpp *tfm; + struct kpp_request *req; + uint8_t *secret; + uint8_t *outbuf; + struct crypto_shash *hash = NULL; + + if (!params || (!buffer && buflen)) { + ret = -EINVAL; + goto out1; + } + if (copy_from_user(&pcopy, params, sizeof(pcopy)) != 0) { + ret = -EFAULT; + goto out1; + } + + if (kdfcopy) { + char *hashname; + + if (memchr_inv(kdfcopy->__spare, 0, sizeof(kdfcopy->__spare))) { + ret = -EINVAL; + goto out1; + } + + if (buflen > KEYCTL_KDF_MAX_OUTPUT_LEN || + kdfcopy->otherinfolen > KEYCTL_KDF_MAX_OI_LEN) { + ret = -EMSGSIZE; + goto out1; + } + + /* get KDF name string */ + hashname = strndup_user(kdfcopy->hashname, CRYPTO_MAX_ALG_NAME); + if (IS_ERR(hashname)) { + ret = PTR_ERR(hashname); + goto out1; + } + + /* allocate KDF from the kernel crypto API */ + ret = kdf_alloc(&hash, hashname); + kfree(hashname); + if (ret) + goto out1; + } + + memset(&dh_inputs, 0, sizeof(dh_inputs)); + + dlen = dh_data_from_key(pcopy.prime, &dh_inputs.p); + if (dlen < 0) { + ret = dlen; + goto out1; + } + dh_inputs.p_size = dlen; + + dlen = dh_data_from_key(pcopy.base, &dh_inputs.g); + if (dlen < 0) { + ret = dlen; + goto out2; + } + dh_inputs.g_size = dlen; + + dlen = dh_data_from_key(pcopy.private, &dh_inputs.key); + if (dlen < 0) { + ret = dlen; + goto out2; + } + dh_inputs.key_size = dlen; + + secretlen = crypto_dh_key_len(&dh_inputs); + secret = kmalloc(secretlen, GFP_KERNEL); + if (!secret) { + ret = -ENOMEM; + goto out2; + } + ret = crypto_dh_encode_key(secret, secretlen, &dh_inputs); + if (ret) + goto out3; + + tfm = crypto_alloc_kpp("dh", 0, 0); + if (IS_ERR(tfm)) { + ret = PTR_ERR(tfm); + goto out3; + } + + ret = crypto_kpp_set_secret(tfm, secret, secretlen); + if (ret) + goto out4; + + outlen = crypto_kpp_maxsize(tfm); + + if (!kdfcopy) { + /* + * When not using a KDF, buflen 0 is used to read the + * required buffer length + */ + if (buflen == 0) { + ret = outlen; + goto out4; + } else if (outlen > buflen) { + ret = -EOVERFLOW; + goto out4; + } + } + + outbuf = kzalloc(kdfcopy ? (outlen + kdfcopy->otherinfolen) : outlen, + GFP_KERNEL); + if (!outbuf) { + ret = -ENOMEM; + goto out4; + } + + sg_init_one(&outsg, outbuf, outlen); + + req = kpp_request_alloc(tfm, GFP_KERNEL); + if (!req) { + ret = -ENOMEM; + goto out5; + } + + kpp_request_set_input(req, NULL, 0); + kpp_request_set_output(req, &outsg, outlen); + init_completion(&compl.completion); + kpp_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG | + CRYPTO_TFM_REQ_MAY_SLEEP, + dh_crypto_done, &compl); + + /* + * For DH, generate_public_key and generate_shared_secret are + * the same calculation + */ + ret = crypto_kpp_generate_public_key(req); + if (ret == -EINPROGRESS) { + wait_for_completion(&compl.completion); + ret = compl.err; + if (ret) + goto out6; + } + + if (kdfcopy) { + /* + * Concatenate SP800-56A otherinfo past DH shared secret -- the + * input to the KDF is (DH shared secret || otherinfo) + */ + if (copy_from_user(outbuf + req->dst_len, kdfcopy->otherinfo, + kdfcopy->otherinfolen) != 0) { + ret = -EFAULT; + goto out6; + } + + ret = keyctl_dh_compute_kdf(hash, buffer, buflen, outbuf, + req->dst_len + kdfcopy->otherinfolen); + } else if (copy_to_user(buffer, outbuf, req->dst_len) == 0) { + ret = req->dst_len; + } else { + ret = -EFAULT; + } + +out6: + kpp_request_free(req); +out5: + kfree_sensitive(outbuf); +out4: + crypto_free_kpp(tfm); +out3: + kfree_sensitive(secret); +out2: + dh_free_data(&dh_inputs); +out1: + kdf_dealloc(hash); + return ret; +} + +long keyctl_dh_compute(struct keyctl_dh_params __user *params, + char __user *buffer, size_t buflen, + struct keyctl_kdf_params __user *kdf) +{ + struct keyctl_kdf_params kdfcopy; + + if (!kdf) + return __keyctl_dh_compute(params, buffer, buflen, NULL); + + if (copy_from_user(&kdfcopy, kdf, sizeof(kdfcopy)) != 0) + return -EFAULT; + + return __keyctl_dh_compute(params, buffer, buflen, &kdfcopy); +} diff --git a/security/keys/encrypted-keys/Makefile b/security/keys/encrypted-keys/Makefile new file mode 100644 index 000000000..7a44dce6f --- /dev/null +++ b/security/keys/encrypted-keys/Makefile @@ -0,0 +1,11 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Makefile for encrypted keys +# + +obj-$(CONFIG_ENCRYPTED_KEYS) += encrypted-keys.o + +encrypted-keys-y := encrypted.o ecryptfs_format.o +masterkey-$(CONFIG_TRUSTED_KEYS) := masterkey_trusted.o +masterkey-$(CONFIG_TRUSTED_KEYS)-$(CONFIG_ENCRYPTED_KEYS) := masterkey_trusted.o +encrypted-keys-y += $(masterkey-y) $(masterkey-m-m) diff --git a/security/keys/encrypted-keys/ecryptfs_format.c b/security/keys/encrypted-keys/ecryptfs_format.c new file mode 100644 index 000000000..8fdd76105 --- /dev/null +++ b/security/keys/encrypted-keys/ecryptfs_format.c @@ -0,0 +1,77 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * ecryptfs_format.c: helper functions for the encrypted key type + * + * Copyright (C) 2006 International Business Machines Corp. + * Copyright (C) 2010 Politecnico di Torino, Italy + * TORSEC group -- https://security.polito.it + * + * Authors: + * Michael A. Halcrow <mahalcro@us.ibm.com> + * Tyler Hicks <tyhicks@ou.edu> + * Roberto Sassu <roberto.sassu@polito.it> + */ + +#include <linux/export.h> +#include <linux/string.h> +#include "ecryptfs_format.h" + +u8 *ecryptfs_get_auth_tok_key(struct ecryptfs_auth_tok *auth_tok) +{ + return auth_tok->token.password.session_key_encryption_key; +} +EXPORT_SYMBOL(ecryptfs_get_auth_tok_key); + +/* + * ecryptfs_get_versions() + * + * Source code taken from the software 'ecryptfs-utils' version 83. + * + */ +void ecryptfs_get_versions(int *major, int *minor, int *file_version) +{ + *major = ECRYPTFS_VERSION_MAJOR; + *minor = ECRYPTFS_VERSION_MINOR; + if (file_version) + *file_version = ECRYPTFS_SUPPORTED_FILE_VERSION; +} +EXPORT_SYMBOL(ecryptfs_get_versions); + +/* + * ecryptfs_fill_auth_tok - fill the ecryptfs_auth_tok structure + * + * Fill the ecryptfs_auth_tok structure with required ecryptfs data. + * The source code is inspired to the original function generate_payload() + * shipped with the software 'ecryptfs-utils' version 83. + * + */ +int ecryptfs_fill_auth_tok(struct ecryptfs_auth_tok *auth_tok, + const char *key_desc) +{ + int major, minor; + + ecryptfs_get_versions(&major, &minor, NULL); + auth_tok->version = (((uint16_t)(major << 8) & 0xFF00) + | ((uint16_t)minor & 0x00FF)); + auth_tok->token_type = ECRYPTFS_PASSWORD; + strncpy((char *)auth_tok->token.password.signature, key_desc, + ECRYPTFS_PASSWORD_SIG_SIZE); + auth_tok->token.password.session_key_encryption_key_bytes = + ECRYPTFS_MAX_KEY_BYTES; + /* + * Removed auth_tok->token.password.salt and + * auth_tok->token.password.session_key_encryption_key + * initialization from the original code + */ + /* TODO: Make the hash parameterizable via policy */ + auth_tok->token.password.flags |= + ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET; + /* The kernel code will encrypt the session key. */ + auth_tok->session_key.encrypted_key[0] = 0; + auth_tok->session_key.encrypted_key_size = 0; + /* Default; subject to change by kernel eCryptfs */ + auth_tok->token.password.hash_algo = PGP_DIGEST_ALGO_SHA512; + auth_tok->token.password.flags &= ~(ECRYPTFS_PERSISTENT_PASSWORD); + return 0; +} +EXPORT_SYMBOL(ecryptfs_fill_auth_tok); diff --git a/security/keys/encrypted-keys/ecryptfs_format.h b/security/keys/encrypted-keys/ecryptfs_format.h new file mode 100644 index 000000000..ed8466578 --- /dev/null +++ b/security/keys/encrypted-keys/ecryptfs_format.h @@ -0,0 +1,27 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * ecryptfs_format.h: helper functions for the encrypted key type + * + * Copyright (C) 2006 International Business Machines Corp. + * Copyright (C) 2010 Politecnico di Torino, Italy + * TORSEC group -- https://security.polito.it + * + * Authors: + * Michael A. Halcrow <mahalcro@us.ibm.com> + * Tyler Hicks <tyhicks@ou.edu> + * Roberto Sassu <roberto.sassu@polito.it> + */ + +#ifndef __KEYS_ECRYPTFS_H +#define __KEYS_ECRYPTFS_H + +#include <linux/ecryptfs.h> + +#define PGP_DIGEST_ALGO_SHA512 10 + +u8 *ecryptfs_get_auth_tok_key(struct ecryptfs_auth_tok *auth_tok); +void ecryptfs_get_versions(int *major, int *minor, int *file_version); +int ecryptfs_fill_auth_tok(struct ecryptfs_auth_tok *auth_tok, + const char *key_desc); + +#endif /* __KEYS_ECRYPTFS_H */ diff --git a/security/keys/encrypted-keys/encrypted.c b/security/keys/encrypted-keys/encrypted.c new file mode 100644 index 000000000..1e313982a --- /dev/null +++ b/security/keys/encrypted-keys/encrypted.c @@ -0,0 +1,1043 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2010 IBM Corporation + * Copyright (C) 2010 Politecnico di Torino, Italy + * TORSEC group -- https://security.polito.it + * + * Authors: + * Mimi Zohar <zohar@us.ibm.com> + * Roberto Sassu <roberto.sassu@polito.it> + * + * See Documentation/security/keys/trusted-encrypted.rst + */ + +#include <linux/uaccess.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/slab.h> +#include <linux/parser.h> +#include <linux/string.h> +#include <linux/err.h> +#include <keys/user-type.h> +#include <keys/trusted-type.h> +#include <keys/encrypted-type.h> +#include <linux/key-type.h> +#include <linux/random.h> +#include <linux/rcupdate.h> +#include <linux/scatterlist.h> +#include <linux/ctype.h> +#include <crypto/aes.h> +#include <crypto/algapi.h> +#include <crypto/hash.h> +#include <crypto/sha2.h> +#include <crypto/skcipher.h> + +#include "encrypted.h" +#include "ecryptfs_format.h" + +static const char KEY_TRUSTED_PREFIX[] = "trusted:"; +static const char KEY_USER_PREFIX[] = "user:"; +static const char hash_alg[] = "sha256"; +static const char hmac_alg[] = "hmac(sha256)"; +static const char blkcipher_alg[] = "cbc(aes)"; +static const char key_format_default[] = "default"; +static const char key_format_ecryptfs[] = "ecryptfs"; +static const char key_format_enc32[] = "enc32"; +static unsigned int ivsize; +static int blksize; + +#define KEY_TRUSTED_PREFIX_LEN (sizeof (KEY_TRUSTED_PREFIX) - 1) +#define KEY_USER_PREFIX_LEN (sizeof (KEY_USER_PREFIX) - 1) +#define KEY_ECRYPTFS_DESC_LEN 16 +#define HASH_SIZE SHA256_DIGEST_SIZE +#define MAX_DATA_SIZE 4096 +#define MIN_DATA_SIZE 20 +#define KEY_ENC32_PAYLOAD_LEN 32 + +static struct crypto_shash *hash_tfm; + +enum { + Opt_new, Opt_load, Opt_update, Opt_err +}; + +enum { + Opt_default, Opt_ecryptfs, Opt_enc32, Opt_error +}; + +static const match_table_t key_format_tokens = { + {Opt_default, "default"}, + {Opt_ecryptfs, "ecryptfs"}, + {Opt_enc32, "enc32"}, + {Opt_error, NULL} +}; + +static const match_table_t key_tokens = { + {Opt_new, "new"}, + {Opt_load, "load"}, + {Opt_update, "update"}, + {Opt_err, NULL} +}; + +static bool user_decrypted_data = IS_ENABLED(CONFIG_USER_DECRYPTED_DATA); +module_param(user_decrypted_data, bool, 0); +MODULE_PARM_DESC(user_decrypted_data, + "Allow instantiation of encrypted keys using provided decrypted data"); + +static int aes_get_sizes(void) +{ + struct crypto_skcipher *tfm; + + tfm = crypto_alloc_skcipher(blkcipher_alg, 0, CRYPTO_ALG_ASYNC); + if (IS_ERR(tfm)) { + pr_err("encrypted_key: failed to alloc_cipher (%ld)\n", + PTR_ERR(tfm)); + return PTR_ERR(tfm); + } + ivsize = crypto_skcipher_ivsize(tfm); + blksize = crypto_skcipher_blocksize(tfm); + crypto_free_skcipher(tfm); + return 0; +} + +/* + * valid_ecryptfs_desc - verify the description of a new/loaded encrypted key + * + * The description of a encrypted key with format 'ecryptfs' must contain + * exactly 16 hexadecimal characters. + * + */ +static int valid_ecryptfs_desc(const char *ecryptfs_desc) +{ + int i; + + if (strlen(ecryptfs_desc) != KEY_ECRYPTFS_DESC_LEN) { + pr_err("encrypted_key: key description must be %d hexadecimal " + "characters long\n", KEY_ECRYPTFS_DESC_LEN); + return -EINVAL; + } + + for (i = 0; i < KEY_ECRYPTFS_DESC_LEN; i++) { + if (!isxdigit(ecryptfs_desc[i])) { + pr_err("encrypted_key: key description must contain " + "only hexadecimal characters\n"); + return -EINVAL; + } + } + + return 0; +} + +/* + * valid_master_desc - verify the 'key-type:desc' of a new/updated master-key + * + * key-type:= "trusted:" | "user:" + * desc:= master-key description + * + * Verify that 'key-type' is valid and that 'desc' exists. On key update, + * only the master key description is permitted to change, not the key-type. + * The key-type remains constant. + * + * On success returns 0, otherwise -EINVAL. + */ +static int valid_master_desc(const char *new_desc, const char *orig_desc) +{ + int prefix_len; + + if (!strncmp(new_desc, KEY_TRUSTED_PREFIX, KEY_TRUSTED_PREFIX_LEN)) + prefix_len = KEY_TRUSTED_PREFIX_LEN; + else if (!strncmp(new_desc, KEY_USER_PREFIX, KEY_USER_PREFIX_LEN)) + prefix_len = KEY_USER_PREFIX_LEN; + else + return -EINVAL; + + if (!new_desc[prefix_len]) + return -EINVAL; + + if (orig_desc && strncmp(new_desc, orig_desc, prefix_len)) + return -EINVAL; + + return 0; +} + +/* + * datablob_parse - parse the keyctl data + * + * datablob format: + * new [<format>] <master-key name> <decrypted data length> [<decrypted data>] + * load [<format>] <master-key name> <decrypted data length> + * <encrypted iv + data> + * update <new-master-key name> + * + * Tokenizes a copy of the keyctl data, returning a pointer to each token, + * which is null terminated. + * + * On success returns 0, otherwise -EINVAL. + */ +static int datablob_parse(char *datablob, const char **format, + char **master_desc, char **decrypted_datalen, + char **hex_encoded_iv, char **decrypted_data) +{ + substring_t args[MAX_OPT_ARGS]; + int ret = -EINVAL; + int key_cmd; + int key_format; + char *p, *keyword; + + keyword = strsep(&datablob, " \t"); + if (!keyword) { + pr_info("encrypted_key: insufficient parameters specified\n"); + return ret; + } + key_cmd = match_token(keyword, key_tokens, args); + + /* Get optional format: default | ecryptfs */ + p = strsep(&datablob, " \t"); + if (!p) { + pr_err("encrypted_key: insufficient parameters specified\n"); + return ret; + } + + key_format = match_token(p, key_format_tokens, args); + switch (key_format) { + case Opt_ecryptfs: + case Opt_enc32: + case Opt_default: + *format = p; + *master_desc = strsep(&datablob, " \t"); + break; + case Opt_error: + *master_desc = p; + break; + } + + if (!*master_desc) { + pr_info("encrypted_key: master key parameter is missing\n"); + goto out; + } + + if (valid_master_desc(*master_desc, NULL) < 0) { + pr_info("encrypted_key: master key parameter \'%s\' " + "is invalid\n", *master_desc); + goto out; + } + + if (decrypted_datalen) { + *decrypted_datalen = strsep(&datablob, " \t"); + if (!*decrypted_datalen) { + pr_info("encrypted_key: keylen parameter is missing\n"); + goto out; + } + } + + switch (key_cmd) { + case Opt_new: + if (!decrypted_datalen) { + pr_info("encrypted_key: keyword \'%s\' not allowed " + "when called from .update method\n", keyword); + break; + } + *decrypted_data = strsep(&datablob, " \t"); + ret = 0; + break; + case Opt_load: + if (!decrypted_datalen) { + pr_info("encrypted_key: keyword \'%s\' not allowed " + "when called from .update method\n", keyword); + break; + } + *hex_encoded_iv = strsep(&datablob, " \t"); + if (!*hex_encoded_iv) { + pr_info("encrypted_key: hex blob is missing\n"); + break; + } + ret = 0; + break; + case Opt_update: + if (decrypted_datalen) { + pr_info("encrypted_key: keyword \'%s\' not allowed " + "when called from .instantiate method\n", + keyword); + break; + } + ret = 0; + break; + case Opt_err: + pr_info("encrypted_key: keyword \'%s\' not recognized\n", + keyword); + break; + } +out: + return ret; +} + +/* + * datablob_format - format as an ascii string, before copying to userspace + */ +static char *datablob_format(struct encrypted_key_payload *epayload, + size_t asciiblob_len) +{ + char *ascii_buf, *bufp; + u8 *iv = epayload->iv; + int len; + int i; + + ascii_buf = kmalloc(asciiblob_len + 1, GFP_KERNEL); + if (!ascii_buf) + goto out; + + ascii_buf[asciiblob_len] = '\0'; + + /* copy datablob master_desc and datalen strings */ + len = sprintf(ascii_buf, "%s %s %s ", epayload->format, + epayload->master_desc, epayload->datalen); + + /* convert the hex encoded iv, encrypted-data and HMAC to ascii */ + bufp = &ascii_buf[len]; + for (i = 0; i < (asciiblob_len - len) / 2; i++) + bufp = hex_byte_pack(bufp, iv[i]); +out: + return ascii_buf; +} + +/* + * request_user_key - request the user key + * + * Use a user provided key to encrypt/decrypt an encrypted-key. + */ +static struct key *request_user_key(const char *master_desc, const u8 **master_key, + size_t *master_keylen) +{ + const struct user_key_payload *upayload; + struct key *ukey; + + ukey = request_key(&key_type_user, master_desc, NULL); + if (IS_ERR(ukey)) + goto error; + + down_read(&ukey->sem); + upayload = user_key_payload_locked(ukey); + if (!upayload) { + /* key was revoked before we acquired its semaphore */ + up_read(&ukey->sem); + key_put(ukey); + ukey = ERR_PTR(-EKEYREVOKED); + goto error; + } + *master_key = upayload->data; + *master_keylen = upayload->datalen; +error: + return ukey; +} + +static int calc_hmac(u8 *digest, const u8 *key, unsigned int keylen, + const u8 *buf, unsigned int buflen) +{ + struct crypto_shash *tfm; + int err; + + tfm = crypto_alloc_shash(hmac_alg, 0, 0); + if (IS_ERR(tfm)) { + pr_err("encrypted_key: can't alloc %s transform: %ld\n", + hmac_alg, PTR_ERR(tfm)); + return PTR_ERR(tfm); + } + + err = crypto_shash_setkey(tfm, key, keylen); + if (!err) + err = crypto_shash_tfm_digest(tfm, buf, buflen, digest); + crypto_free_shash(tfm); + return err; +} + +enum derived_key_type { ENC_KEY, AUTH_KEY }; + +/* Derive authentication/encryption key from trusted key */ +static int get_derived_key(u8 *derived_key, enum derived_key_type key_type, + const u8 *master_key, size_t master_keylen) +{ + u8 *derived_buf; + unsigned int derived_buf_len; + int ret; + + derived_buf_len = strlen("AUTH_KEY") + 1 + master_keylen; + if (derived_buf_len < HASH_SIZE) + derived_buf_len = HASH_SIZE; + + derived_buf = kzalloc(derived_buf_len, GFP_KERNEL); + if (!derived_buf) + return -ENOMEM; + + if (key_type) + strcpy(derived_buf, "AUTH_KEY"); + else + strcpy(derived_buf, "ENC_KEY"); + + memcpy(derived_buf + strlen(derived_buf) + 1, master_key, + master_keylen); + ret = crypto_shash_tfm_digest(hash_tfm, derived_buf, derived_buf_len, + derived_key); + kfree_sensitive(derived_buf); + return ret; +} + +static struct skcipher_request *init_skcipher_req(const u8 *key, + unsigned int key_len) +{ + struct skcipher_request *req; + struct crypto_skcipher *tfm; + int ret; + + tfm = crypto_alloc_skcipher(blkcipher_alg, 0, CRYPTO_ALG_ASYNC); + if (IS_ERR(tfm)) { + pr_err("encrypted_key: failed to load %s transform (%ld)\n", + blkcipher_alg, PTR_ERR(tfm)); + return ERR_CAST(tfm); + } + + ret = crypto_skcipher_setkey(tfm, key, key_len); + if (ret < 0) { + pr_err("encrypted_key: failed to setkey (%d)\n", ret); + crypto_free_skcipher(tfm); + return ERR_PTR(ret); + } + + req = skcipher_request_alloc(tfm, GFP_KERNEL); + if (!req) { + pr_err("encrypted_key: failed to allocate request for %s\n", + blkcipher_alg); + crypto_free_skcipher(tfm); + return ERR_PTR(-ENOMEM); + } + + skcipher_request_set_callback(req, 0, NULL, NULL); + return req; +} + +static struct key *request_master_key(struct encrypted_key_payload *epayload, + const u8 **master_key, size_t *master_keylen) +{ + struct key *mkey = ERR_PTR(-EINVAL); + + if (!strncmp(epayload->master_desc, KEY_TRUSTED_PREFIX, + KEY_TRUSTED_PREFIX_LEN)) { + mkey = request_trusted_key(epayload->master_desc + + KEY_TRUSTED_PREFIX_LEN, + master_key, master_keylen); + } else if (!strncmp(epayload->master_desc, KEY_USER_PREFIX, + KEY_USER_PREFIX_LEN)) { + mkey = request_user_key(epayload->master_desc + + KEY_USER_PREFIX_LEN, + master_key, master_keylen); + } else + goto out; + + if (IS_ERR(mkey)) { + int ret = PTR_ERR(mkey); + + if (ret == -ENOTSUPP) + pr_info("encrypted_key: key %s not supported", + epayload->master_desc); + else + pr_info("encrypted_key: key %s not found", + epayload->master_desc); + goto out; + } + + dump_master_key(*master_key, *master_keylen); +out: + return mkey; +} + +/* Before returning data to userspace, encrypt decrypted data. */ +static int derived_key_encrypt(struct encrypted_key_payload *epayload, + const u8 *derived_key, + unsigned int derived_keylen) +{ + struct scatterlist sg_in[2]; + struct scatterlist sg_out[1]; + struct crypto_skcipher *tfm; + struct skcipher_request *req; + unsigned int encrypted_datalen; + u8 iv[AES_BLOCK_SIZE]; + int ret; + + encrypted_datalen = roundup(epayload->decrypted_datalen, blksize); + + req = init_skcipher_req(derived_key, derived_keylen); + ret = PTR_ERR(req); + if (IS_ERR(req)) + goto out; + dump_decrypted_data(epayload); + + sg_init_table(sg_in, 2); + sg_set_buf(&sg_in[0], epayload->decrypted_data, + epayload->decrypted_datalen); + sg_set_page(&sg_in[1], ZERO_PAGE(0), AES_BLOCK_SIZE, 0); + + sg_init_table(sg_out, 1); + sg_set_buf(sg_out, epayload->encrypted_data, encrypted_datalen); + + memcpy(iv, epayload->iv, sizeof(iv)); + skcipher_request_set_crypt(req, sg_in, sg_out, encrypted_datalen, iv); + ret = crypto_skcipher_encrypt(req); + tfm = crypto_skcipher_reqtfm(req); + skcipher_request_free(req); + crypto_free_skcipher(tfm); + if (ret < 0) + pr_err("encrypted_key: failed to encrypt (%d)\n", ret); + else + dump_encrypted_data(epayload, encrypted_datalen); +out: + return ret; +} + +static int datablob_hmac_append(struct encrypted_key_payload *epayload, + const u8 *master_key, size_t master_keylen) +{ + u8 derived_key[HASH_SIZE]; + u8 *digest; + int ret; + + ret = get_derived_key(derived_key, AUTH_KEY, master_key, master_keylen); + if (ret < 0) + goto out; + + digest = epayload->format + epayload->datablob_len; + ret = calc_hmac(digest, derived_key, sizeof derived_key, + epayload->format, epayload->datablob_len); + if (!ret) + dump_hmac(NULL, digest, HASH_SIZE); +out: + memzero_explicit(derived_key, sizeof(derived_key)); + return ret; +} + +/* verify HMAC before decrypting encrypted key */ +static int datablob_hmac_verify(struct encrypted_key_payload *epayload, + const u8 *format, const u8 *master_key, + size_t master_keylen) +{ + u8 derived_key[HASH_SIZE]; + u8 digest[HASH_SIZE]; + int ret; + char *p; + unsigned short len; + + ret = get_derived_key(derived_key, AUTH_KEY, master_key, master_keylen); + if (ret < 0) + goto out; + + len = epayload->datablob_len; + if (!format) { + p = epayload->master_desc; + len -= strlen(epayload->format) + 1; + } else + p = epayload->format; + + ret = calc_hmac(digest, derived_key, sizeof derived_key, p, len); + if (ret < 0) + goto out; + ret = crypto_memneq(digest, epayload->format + epayload->datablob_len, + sizeof(digest)); + if (ret) { + ret = -EINVAL; + dump_hmac("datablob", + epayload->format + epayload->datablob_len, + HASH_SIZE); + dump_hmac("calc", digest, HASH_SIZE); + } +out: + memzero_explicit(derived_key, sizeof(derived_key)); + return ret; +} + +static int derived_key_decrypt(struct encrypted_key_payload *epayload, + const u8 *derived_key, + unsigned int derived_keylen) +{ + struct scatterlist sg_in[1]; + struct scatterlist sg_out[2]; + struct crypto_skcipher *tfm; + struct skcipher_request *req; + unsigned int encrypted_datalen; + u8 iv[AES_BLOCK_SIZE]; + u8 *pad; + int ret; + + /* Throwaway buffer to hold the unused zero padding at the end */ + pad = kmalloc(AES_BLOCK_SIZE, GFP_KERNEL); + if (!pad) + return -ENOMEM; + + encrypted_datalen = roundup(epayload->decrypted_datalen, blksize); + req = init_skcipher_req(derived_key, derived_keylen); + ret = PTR_ERR(req); + if (IS_ERR(req)) + goto out; + dump_encrypted_data(epayload, encrypted_datalen); + + sg_init_table(sg_in, 1); + sg_init_table(sg_out, 2); + sg_set_buf(sg_in, epayload->encrypted_data, encrypted_datalen); + sg_set_buf(&sg_out[0], epayload->decrypted_data, + epayload->decrypted_datalen); + sg_set_buf(&sg_out[1], pad, AES_BLOCK_SIZE); + + memcpy(iv, epayload->iv, sizeof(iv)); + skcipher_request_set_crypt(req, sg_in, sg_out, encrypted_datalen, iv); + ret = crypto_skcipher_decrypt(req); + tfm = crypto_skcipher_reqtfm(req); + skcipher_request_free(req); + crypto_free_skcipher(tfm); + if (ret < 0) + goto out; + dump_decrypted_data(epayload); +out: + kfree(pad); + return ret; +} + +/* Allocate memory for decrypted key and datablob. */ +static struct encrypted_key_payload *encrypted_key_alloc(struct key *key, + const char *format, + const char *master_desc, + const char *datalen, + const char *decrypted_data) +{ + struct encrypted_key_payload *epayload = NULL; + unsigned short datablob_len; + unsigned short decrypted_datalen; + unsigned short payload_datalen; + unsigned int encrypted_datalen; + unsigned int format_len; + long dlen; + int i; + int ret; + + ret = kstrtol(datalen, 10, &dlen); + if (ret < 0 || dlen < MIN_DATA_SIZE || dlen > MAX_DATA_SIZE) + return ERR_PTR(-EINVAL); + + format_len = (!format) ? strlen(key_format_default) : strlen(format); + decrypted_datalen = dlen; + payload_datalen = decrypted_datalen; + + if (decrypted_data) { + if (!user_decrypted_data) { + pr_err("encrypted key: instantiation of keys using provided decrypted data is disabled since CONFIG_USER_DECRYPTED_DATA is set to false\n"); + return ERR_PTR(-EINVAL); + } + if (strlen(decrypted_data) != decrypted_datalen * 2) { + pr_err("encrypted key: decrypted data provided does not match decrypted data length provided\n"); + return ERR_PTR(-EINVAL); + } + for (i = 0; i < strlen(decrypted_data); i++) { + if (!isxdigit(decrypted_data[i])) { + pr_err("encrypted key: decrypted data provided must contain only hexadecimal characters\n"); + return ERR_PTR(-EINVAL); + } + } + } + + if (format) { + if (!strcmp(format, key_format_ecryptfs)) { + if (dlen != ECRYPTFS_MAX_KEY_BYTES) { + pr_err("encrypted_key: keylen for the ecryptfs format must be equal to %d bytes\n", + ECRYPTFS_MAX_KEY_BYTES); + return ERR_PTR(-EINVAL); + } + decrypted_datalen = ECRYPTFS_MAX_KEY_BYTES; + payload_datalen = sizeof(struct ecryptfs_auth_tok); + } else if (!strcmp(format, key_format_enc32)) { + if (decrypted_datalen != KEY_ENC32_PAYLOAD_LEN) { + pr_err("encrypted_key: enc32 key payload incorrect length: %d\n", + decrypted_datalen); + return ERR_PTR(-EINVAL); + } + } + } + + encrypted_datalen = roundup(decrypted_datalen, blksize); + + datablob_len = format_len + 1 + strlen(master_desc) + 1 + + strlen(datalen) + 1 + ivsize + 1 + encrypted_datalen; + + ret = key_payload_reserve(key, payload_datalen + datablob_len + + HASH_SIZE + 1); + if (ret < 0) + return ERR_PTR(ret); + + epayload = kzalloc(sizeof(*epayload) + payload_datalen + + datablob_len + HASH_SIZE + 1, GFP_KERNEL); + if (!epayload) + return ERR_PTR(-ENOMEM); + + epayload->payload_datalen = payload_datalen; + epayload->decrypted_datalen = decrypted_datalen; + epayload->datablob_len = datablob_len; + return epayload; +} + +static int encrypted_key_decrypt(struct encrypted_key_payload *epayload, + const char *format, const char *hex_encoded_iv) +{ + struct key *mkey; + u8 derived_key[HASH_SIZE]; + const u8 *master_key; + u8 *hmac; + const char *hex_encoded_data; + unsigned int encrypted_datalen; + size_t master_keylen; + size_t asciilen; + int ret; + + encrypted_datalen = roundup(epayload->decrypted_datalen, blksize); + asciilen = (ivsize + 1 + encrypted_datalen + HASH_SIZE) * 2; + if (strlen(hex_encoded_iv) != asciilen) + return -EINVAL; + + hex_encoded_data = hex_encoded_iv + (2 * ivsize) + 2; + ret = hex2bin(epayload->iv, hex_encoded_iv, ivsize); + if (ret < 0) + return -EINVAL; + ret = hex2bin(epayload->encrypted_data, hex_encoded_data, + encrypted_datalen); + if (ret < 0) + return -EINVAL; + + hmac = epayload->format + epayload->datablob_len; + ret = hex2bin(hmac, hex_encoded_data + (encrypted_datalen * 2), + HASH_SIZE); + if (ret < 0) + return -EINVAL; + + mkey = request_master_key(epayload, &master_key, &master_keylen); + if (IS_ERR(mkey)) + return PTR_ERR(mkey); + + ret = datablob_hmac_verify(epayload, format, master_key, master_keylen); + if (ret < 0) { + pr_err("encrypted_key: bad hmac (%d)\n", ret); + goto out; + } + + ret = get_derived_key(derived_key, ENC_KEY, master_key, master_keylen); + if (ret < 0) + goto out; + + ret = derived_key_decrypt(epayload, derived_key, sizeof derived_key); + if (ret < 0) + pr_err("encrypted_key: failed to decrypt key (%d)\n", ret); +out: + up_read(&mkey->sem); + key_put(mkey); + memzero_explicit(derived_key, sizeof(derived_key)); + return ret; +} + +static void __ekey_init(struct encrypted_key_payload *epayload, + const char *format, const char *master_desc, + const char *datalen) +{ + unsigned int format_len; + + format_len = (!format) ? strlen(key_format_default) : strlen(format); + epayload->format = epayload->payload_data + epayload->payload_datalen; + epayload->master_desc = epayload->format + format_len + 1; + epayload->datalen = epayload->master_desc + strlen(master_desc) + 1; + epayload->iv = epayload->datalen + strlen(datalen) + 1; + epayload->encrypted_data = epayload->iv + ivsize + 1; + epayload->decrypted_data = epayload->payload_data; + + if (!format) + memcpy(epayload->format, key_format_default, format_len); + else { + if (!strcmp(format, key_format_ecryptfs)) + epayload->decrypted_data = + ecryptfs_get_auth_tok_key((struct ecryptfs_auth_tok *)epayload->payload_data); + + memcpy(epayload->format, format, format_len); + } + + memcpy(epayload->master_desc, master_desc, strlen(master_desc)); + memcpy(epayload->datalen, datalen, strlen(datalen)); +} + +/* + * encrypted_init - initialize an encrypted key + * + * For a new key, use either a random number or user-provided decrypted data in + * case it is provided. A random number is used for the iv in both cases. For + * an old key, decrypt the hex encoded data. + */ +static int encrypted_init(struct encrypted_key_payload *epayload, + const char *key_desc, const char *format, + const char *master_desc, const char *datalen, + const char *hex_encoded_iv, const char *decrypted_data) +{ + int ret = 0; + + if (format && !strcmp(format, key_format_ecryptfs)) { + ret = valid_ecryptfs_desc(key_desc); + if (ret < 0) + return ret; + + ecryptfs_fill_auth_tok((struct ecryptfs_auth_tok *)epayload->payload_data, + key_desc); + } + + __ekey_init(epayload, format, master_desc, datalen); + if (hex_encoded_iv) { + ret = encrypted_key_decrypt(epayload, format, hex_encoded_iv); + } else if (decrypted_data) { + get_random_bytes(epayload->iv, ivsize); + ret = hex2bin(epayload->decrypted_data, decrypted_data, + epayload->decrypted_datalen); + } else { + get_random_bytes(epayload->iv, ivsize); + get_random_bytes(epayload->decrypted_data, epayload->decrypted_datalen); + } + return ret; +} + +/* + * encrypted_instantiate - instantiate an encrypted key + * + * Instantiates the key: + * - by decrypting an existing encrypted datablob, or + * - by creating a new encrypted key based on a kernel random number, or + * - using provided decrypted data. + * + * On success, return 0. Otherwise return errno. + */ +static int encrypted_instantiate(struct key *key, + struct key_preparsed_payload *prep) +{ + struct encrypted_key_payload *epayload = NULL; + char *datablob = NULL; + const char *format = NULL; + char *master_desc = NULL; + char *decrypted_datalen = NULL; + char *hex_encoded_iv = NULL; + char *decrypted_data = NULL; + size_t datalen = prep->datalen; + int ret; + + if (datalen <= 0 || datalen > 32767 || !prep->data) + return -EINVAL; + + datablob = kmalloc(datalen + 1, GFP_KERNEL); + if (!datablob) + return -ENOMEM; + datablob[datalen] = 0; + memcpy(datablob, prep->data, datalen); + ret = datablob_parse(datablob, &format, &master_desc, + &decrypted_datalen, &hex_encoded_iv, &decrypted_data); + if (ret < 0) + goto out; + + epayload = encrypted_key_alloc(key, format, master_desc, + decrypted_datalen, decrypted_data); + if (IS_ERR(epayload)) { + ret = PTR_ERR(epayload); + goto out; + } + ret = encrypted_init(epayload, key->description, format, master_desc, + decrypted_datalen, hex_encoded_iv, decrypted_data); + if (ret < 0) { + kfree_sensitive(epayload); + goto out; + } + + rcu_assign_keypointer(key, epayload); +out: + kfree_sensitive(datablob); + return ret; +} + +static void encrypted_rcu_free(struct rcu_head *rcu) +{ + struct encrypted_key_payload *epayload; + + epayload = container_of(rcu, struct encrypted_key_payload, rcu); + kfree_sensitive(epayload); +} + +/* + * encrypted_update - update the master key description + * + * Change the master key description for an existing encrypted key. + * The next read will return an encrypted datablob using the new + * master key description. + * + * On success, return 0. Otherwise return errno. + */ +static int encrypted_update(struct key *key, struct key_preparsed_payload *prep) +{ + struct encrypted_key_payload *epayload = key->payload.data[0]; + struct encrypted_key_payload *new_epayload; + char *buf; + char *new_master_desc = NULL; + const char *format = NULL; + size_t datalen = prep->datalen; + int ret = 0; + + if (key_is_negative(key)) + return -ENOKEY; + if (datalen <= 0 || datalen > 32767 || !prep->data) + return -EINVAL; + + buf = kmalloc(datalen + 1, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + buf[datalen] = 0; + memcpy(buf, prep->data, datalen); + ret = datablob_parse(buf, &format, &new_master_desc, NULL, NULL, NULL); + if (ret < 0) + goto out; + + ret = valid_master_desc(new_master_desc, epayload->master_desc); + if (ret < 0) + goto out; + + new_epayload = encrypted_key_alloc(key, epayload->format, + new_master_desc, epayload->datalen, NULL); + if (IS_ERR(new_epayload)) { + ret = PTR_ERR(new_epayload); + goto out; + } + + __ekey_init(new_epayload, epayload->format, new_master_desc, + epayload->datalen); + + memcpy(new_epayload->iv, epayload->iv, ivsize); + memcpy(new_epayload->payload_data, epayload->payload_data, + epayload->payload_datalen); + + rcu_assign_keypointer(key, new_epayload); + call_rcu(&epayload->rcu, encrypted_rcu_free); +out: + kfree_sensitive(buf); + return ret; +} + +/* + * encrypted_read - format and copy out the encrypted data + * + * The resulting datablob format is: + * <master-key name> <decrypted data length> <encrypted iv> <encrypted data> + * + * On success, return to userspace the encrypted key datablob size. + */ +static long encrypted_read(const struct key *key, char *buffer, + size_t buflen) +{ + struct encrypted_key_payload *epayload; + struct key *mkey; + const u8 *master_key; + size_t master_keylen; + char derived_key[HASH_SIZE]; + char *ascii_buf; + size_t asciiblob_len; + int ret; + + epayload = dereference_key_locked(key); + + /* returns the hex encoded iv, encrypted-data, and hmac as ascii */ + asciiblob_len = epayload->datablob_len + ivsize + 1 + + roundup(epayload->decrypted_datalen, blksize) + + (HASH_SIZE * 2); + + if (!buffer || buflen < asciiblob_len) + return asciiblob_len; + + mkey = request_master_key(epayload, &master_key, &master_keylen); + if (IS_ERR(mkey)) + return PTR_ERR(mkey); + + ret = get_derived_key(derived_key, ENC_KEY, master_key, master_keylen); + if (ret < 0) + goto out; + + ret = derived_key_encrypt(epayload, derived_key, sizeof derived_key); + if (ret < 0) + goto out; + + ret = datablob_hmac_append(epayload, master_key, master_keylen); + if (ret < 0) + goto out; + + ascii_buf = datablob_format(epayload, asciiblob_len); + if (!ascii_buf) { + ret = -ENOMEM; + goto out; + } + + up_read(&mkey->sem); + key_put(mkey); + memzero_explicit(derived_key, sizeof(derived_key)); + + memcpy(buffer, ascii_buf, asciiblob_len); + kfree_sensitive(ascii_buf); + + return asciiblob_len; +out: + up_read(&mkey->sem); + key_put(mkey); + memzero_explicit(derived_key, sizeof(derived_key)); + return ret; +} + +/* + * encrypted_destroy - clear and free the key's payload + */ +static void encrypted_destroy(struct key *key) +{ + kfree_sensitive(key->payload.data[0]); +} + +struct key_type key_type_encrypted = { + .name = "encrypted", + .instantiate = encrypted_instantiate, + .update = encrypted_update, + .destroy = encrypted_destroy, + .describe = user_describe, + .read = encrypted_read, +}; +EXPORT_SYMBOL_GPL(key_type_encrypted); + +static int __init init_encrypted(void) +{ + int ret; + + hash_tfm = crypto_alloc_shash(hash_alg, 0, 0); + if (IS_ERR(hash_tfm)) { + pr_err("encrypted_key: can't allocate %s transform: %ld\n", + hash_alg, PTR_ERR(hash_tfm)); + return PTR_ERR(hash_tfm); + } + + ret = aes_get_sizes(); + if (ret < 0) + goto out; + ret = register_key_type(&key_type_encrypted); + if (ret < 0) + goto out; + return 0; +out: + crypto_free_shash(hash_tfm); + return ret; + +} + +static void __exit cleanup_encrypted(void) +{ + crypto_free_shash(hash_tfm); + unregister_key_type(&key_type_encrypted); +} + +late_initcall(init_encrypted); +module_exit(cleanup_encrypted); + +MODULE_LICENSE("GPL"); diff --git a/security/keys/encrypted-keys/encrypted.h b/security/keys/encrypted-keys/encrypted.h new file mode 100644 index 000000000..1809995db --- /dev/null +++ b/security/keys/encrypted-keys/encrypted.h @@ -0,0 +1,67 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __ENCRYPTED_KEY_H +#define __ENCRYPTED_KEY_H + +#define ENCRYPTED_DEBUG 0 +#if defined(CONFIG_TRUSTED_KEYS) || \ + (defined(CONFIG_TRUSTED_KEYS_MODULE) && defined(CONFIG_ENCRYPTED_KEYS_MODULE)) +extern struct key *request_trusted_key(const char *trusted_desc, + const u8 **master_key, size_t *master_keylen); +#else +static inline struct key *request_trusted_key(const char *trusted_desc, + const u8 **master_key, + size_t *master_keylen) +{ + return ERR_PTR(-EOPNOTSUPP); +} +#endif + +#if ENCRYPTED_DEBUG +static inline void dump_master_key(const u8 *master_key, size_t master_keylen) +{ + print_hex_dump(KERN_ERR, "master key: ", DUMP_PREFIX_NONE, 32, 1, + master_key, master_keylen, 0); +} + +static inline void dump_decrypted_data(struct encrypted_key_payload *epayload) +{ + print_hex_dump(KERN_ERR, "decrypted data: ", DUMP_PREFIX_NONE, 32, 1, + epayload->decrypted_data, + epayload->decrypted_datalen, 0); +} + +static inline void dump_encrypted_data(struct encrypted_key_payload *epayload, + unsigned int encrypted_datalen) +{ + print_hex_dump(KERN_ERR, "encrypted data: ", DUMP_PREFIX_NONE, 32, 1, + epayload->encrypted_data, encrypted_datalen, 0); +} + +static inline void dump_hmac(const char *str, const u8 *digest, + unsigned int hmac_size) +{ + if (str) + pr_info("encrypted_key: %s", str); + print_hex_dump(KERN_ERR, "hmac: ", DUMP_PREFIX_NONE, 32, 1, digest, + hmac_size, 0); +} +#else +static inline void dump_master_key(const u8 *master_key, size_t master_keylen) +{ +} + +static inline void dump_decrypted_data(struct encrypted_key_payload *epayload) +{ +} + +static inline void dump_encrypted_data(struct encrypted_key_payload *epayload, + unsigned int encrypted_datalen) +{ +} + +static inline void dump_hmac(const char *str, const u8 *digest, + unsigned int hmac_size) +{ +} +#endif +#endif diff --git a/security/keys/encrypted-keys/masterkey_trusted.c b/security/keys/encrypted-keys/masterkey_trusted.c new file mode 100644 index 000000000..e6d22ce77 --- /dev/null +++ b/security/keys/encrypted-keys/masterkey_trusted.c @@ -0,0 +1,43 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2010 IBM Corporation + * Copyright (C) 2010 Politecnico di Torino, Italy + * TORSEC group -- https://security.polito.it + * + * Authors: + * Mimi Zohar <zohar@us.ibm.com> + * Roberto Sassu <roberto.sassu@polito.it> + * + * See Documentation/security/keys/trusted-encrypted.rst + */ + +#include <linux/uaccess.h> +#include <linux/err.h> +#include <keys/trusted-type.h> +#include <keys/encrypted-type.h> +#include "encrypted.h" + +/* + * request_trusted_key - request the trusted key + * + * Trusted keys are sealed to PCRs and other metadata. Although userspace + * manages both trusted/encrypted key-types, like the encrypted key type + * data, trusted key type data is not visible decrypted from userspace. + */ +struct key *request_trusted_key(const char *trusted_desc, + const u8 **master_key, size_t *master_keylen) +{ + struct trusted_key_payload *tpayload; + struct key *tkey; + + tkey = request_key(&key_type_trusted, trusted_desc, NULL); + if (IS_ERR(tkey)) + goto error; + + down_read(&tkey->sem); + tpayload = tkey->payload.data[0]; + *master_key = tpayload->key; + *master_keylen = tpayload->key_len; +error: + return tkey; +} diff --git a/security/keys/gc.c b/security/keys/gc.c new file mode 100644 index 000000000..eaddaceda --- /dev/null +++ b/security/keys/gc.c @@ -0,0 +1,380 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* Key garbage collector + * + * Copyright (C) 2009-2011 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#include <linux/slab.h> +#include <linux/security.h> +#include <keys/keyring-type.h> +#include "internal.h" + +/* + * Delay between key revocation/expiry in seconds + */ +unsigned key_gc_delay = 5 * 60; + +/* + * Reaper for unused keys. + */ +static void key_garbage_collector(struct work_struct *work); +DECLARE_WORK(key_gc_work, key_garbage_collector); + +/* + * Reaper for links from keyrings to dead keys. + */ +static void key_gc_timer_func(struct timer_list *); +static DEFINE_TIMER(key_gc_timer, key_gc_timer_func); + +static time64_t key_gc_next_run = TIME64_MAX; +static struct key_type *key_gc_dead_keytype; + +static unsigned long key_gc_flags; +#define KEY_GC_KEY_EXPIRED 0 /* A key expired and needs unlinking */ +#define KEY_GC_REAP_KEYTYPE 1 /* A keytype is being unregistered */ +#define KEY_GC_REAPING_KEYTYPE 2 /* Cleared when keytype reaped */ + + +/* + * Any key whose type gets unregistered will be re-typed to this if it can't be + * immediately unlinked. + */ +struct key_type key_type_dead = { + .name = ".dead", +}; + +/* + * Schedule a garbage collection run. + * - time precision isn't particularly important + */ +void key_schedule_gc(time64_t gc_at) +{ + unsigned long expires; + time64_t now = ktime_get_real_seconds(); + + kenter("%lld", gc_at - now); + + if (gc_at <= now || test_bit(KEY_GC_REAP_KEYTYPE, &key_gc_flags)) { + kdebug("IMMEDIATE"); + schedule_work(&key_gc_work); + } else if (gc_at < key_gc_next_run) { + kdebug("DEFERRED"); + key_gc_next_run = gc_at; + expires = jiffies + (gc_at - now) * HZ; + mod_timer(&key_gc_timer, expires); + } +} + +/* + * Set the expiration time on a key. + */ +void key_set_expiry(struct key *key, time64_t expiry) +{ + key->expiry = expiry; + if (expiry != TIME64_MAX) { + if (!(key->type->flags & KEY_TYPE_INSTANT_REAP)) + expiry += key_gc_delay; + key_schedule_gc(expiry); + } +} + +/* + * Schedule a dead links collection run. + */ +void key_schedule_gc_links(void) +{ + set_bit(KEY_GC_KEY_EXPIRED, &key_gc_flags); + schedule_work(&key_gc_work); +} + +/* + * Some key's cleanup time was met after it expired, so we need to get the + * reaper to go through a cycle finding expired keys. + */ +static void key_gc_timer_func(struct timer_list *unused) +{ + kenter(""); + key_gc_next_run = TIME64_MAX; + key_schedule_gc_links(); +} + +/* + * Reap keys of dead type. + * + * We use three flags to make sure we see three complete cycles of the garbage + * collector: the first to mark keys of that type as being dead, the second to + * collect dead links and the third to clean up the dead keys. We have to be + * careful as there may already be a cycle in progress. + * + * The caller must be holding key_types_sem. + */ +void key_gc_keytype(struct key_type *ktype) +{ + kenter("%s", ktype->name); + + key_gc_dead_keytype = ktype; + set_bit(KEY_GC_REAPING_KEYTYPE, &key_gc_flags); + smp_mb(); + set_bit(KEY_GC_REAP_KEYTYPE, &key_gc_flags); + + kdebug("schedule"); + schedule_work(&key_gc_work); + + kdebug("sleep"); + wait_on_bit(&key_gc_flags, KEY_GC_REAPING_KEYTYPE, + TASK_UNINTERRUPTIBLE); + + key_gc_dead_keytype = NULL; + kleave(""); +} + +/* + * Garbage collect a list of unreferenced, detached keys + */ +static noinline void key_gc_unused_keys(struct list_head *keys) +{ + while (!list_empty(keys)) { + struct key *key = + list_entry(keys->next, struct key, graveyard_link); + short state = key->state; + + list_del(&key->graveyard_link); + + kdebug("- %u", key->serial); + key_check(key); + +#ifdef CONFIG_KEY_NOTIFICATIONS + remove_watch_list(key->watchers, key->serial); + key->watchers = NULL; +#endif + + /* Throw away the key data if the key is instantiated */ + if (state == KEY_IS_POSITIVE && key->type->destroy) + key->type->destroy(key); + + security_key_free(key); + + /* deal with the user's key tracking and quota */ + if (test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { + spin_lock(&key->user->lock); + key->user->qnkeys--; + key->user->qnbytes -= key->quotalen; + spin_unlock(&key->user->lock); + } + + atomic_dec(&key->user->nkeys); + if (state != KEY_IS_UNINSTANTIATED) + atomic_dec(&key->user->nikeys); + + key_user_put(key->user); + key_put_tag(key->domain_tag); + kfree(key->description); + + memzero_explicit(key, sizeof(*key)); + kmem_cache_free(key_jar, key); + } +} + +/* + * Garbage collector for unused keys. + * + * This is done in process context so that we don't have to disable interrupts + * all over the place. key_put() schedules this rather than trying to do the + * cleanup itself, which means key_put() doesn't have to sleep. + */ +static void key_garbage_collector(struct work_struct *work) +{ + static LIST_HEAD(graveyard); + static u8 gc_state; /* Internal persistent state */ +#define KEY_GC_REAP_AGAIN 0x01 /* - Need another cycle */ +#define KEY_GC_REAPING_LINKS 0x02 /* - We need to reap links */ +#define KEY_GC_REAPING_DEAD_1 0x10 /* - We need to mark dead keys */ +#define KEY_GC_REAPING_DEAD_2 0x20 /* - We need to reap dead key links */ +#define KEY_GC_REAPING_DEAD_3 0x40 /* - We need to reap dead keys */ +#define KEY_GC_FOUND_DEAD_KEY 0x80 /* - We found at least one dead key */ + + struct rb_node *cursor; + struct key *key; + time64_t new_timer, limit, expiry; + + kenter("[%lx,%x]", key_gc_flags, gc_state); + + limit = ktime_get_real_seconds(); + + /* Work out what we're going to be doing in this pass */ + gc_state &= KEY_GC_REAPING_DEAD_1 | KEY_GC_REAPING_DEAD_2; + gc_state <<= 1; + if (test_and_clear_bit(KEY_GC_KEY_EXPIRED, &key_gc_flags)) + gc_state |= KEY_GC_REAPING_LINKS; + + if (test_and_clear_bit(KEY_GC_REAP_KEYTYPE, &key_gc_flags)) + gc_state |= KEY_GC_REAPING_DEAD_1; + kdebug("new pass %x", gc_state); + + new_timer = TIME64_MAX; + + /* As only this function is permitted to remove things from the key + * serial tree, if cursor is non-NULL then it will always point to a + * valid node in the tree - even if lock got dropped. + */ + spin_lock(&key_serial_lock); + cursor = rb_first(&key_serial_tree); + +continue_scanning: + while (cursor) { + key = rb_entry(cursor, struct key, serial_node); + cursor = rb_next(cursor); + + if (refcount_read(&key->usage) == 0) + goto found_unreferenced_key; + + if (unlikely(gc_state & KEY_GC_REAPING_DEAD_1)) { + if (key->type == key_gc_dead_keytype) { + gc_state |= KEY_GC_FOUND_DEAD_KEY; + set_bit(KEY_FLAG_DEAD, &key->flags); + key->perm = 0; + goto skip_dead_key; + } else if (key->type == &key_type_keyring && + key->restrict_link) { + goto found_restricted_keyring; + } + } + + expiry = key->expiry; + if (expiry != TIME64_MAX) { + if (!(key->type->flags & KEY_TYPE_INSTANT_REAP)) + expiry += key_gc_delay; + if (expiry > limit && expiry < new_timer) { + kdebug("will expire %x in %lld", + key_serial(key), key->expiry - limit); + new_timer = key->expiry; + } + } + + if (unlikely(gc_state & KEY_GC_REAPING_DEAD_2)) + if (key->type == key_gc_dead_keytype) + gc_state |= KEY_GC_FOUND_DEAD_KEY; + + if ((gc_state & KEY_GC_REAPING_LINKS) || + unlikely(gc_state & KEY_GC_REAPING_DEAD_2)) { + if (key->type == &key_type_keyring) + goto found_keyring; + } + + if (unlikely(gc_state & KEY_GC_REAPING_DEAD_3)) + if (key->type == key_gc_dead_keytype) + goto destroy_dead_key; + + skip_dead_key: + if (spin_is_contended(&key_serial_lock) || need_resched()) + goto contended; + } + +contended: + spin_unlock(&key_serial_lock); + +maybe_resched: + if (cursor) { + cond_resched(); + spin_lock(&key_serial_lock); + goto continue_scanning; + } + + /* We've completed the pass. Set the timer if we need to and queue a + * new cycle if necessary. We keep executing cycles until we find one + * where we didn't reap any keys. + */ + kdebug("pass complete"); + + if (new_timer != TIME64_MAX) { + new_timer += key_gc_delay; + key_schedule_gc(new_timer); + } + + if (unlikely(gc_state & KEY_GC_REAPING_DEAD_2) || + !list_empty(&graveyard)) { + /* Make sure that all pending keyring payload destructions are + * fulfilled and that people aren't now looking at dead or + * dying keys that they don't have a reference upon or a link + * to. + */ + kdebug("gc sync"); + synchronize_rcu(); + } + + if (!list_empty(&graveyard)) { + kdebug("gc keys"); + key_gc_unused_keys(&graveyard); + } + + if (unlikely(gc_state & (KEY_GC_REAPING_DEAD_1 | + KEY_GC_REAPING_DEAD_2))) { + if (!(gc_state & KEY_GC_FOUND_DEAD_KEY)) { + /* No remaining dead keys: short circuit the remaining + * keytype reap cycles. + */ + kdebug("dead short"); + gc_state &= ~(KEY_GC_REAPING_DEAD_1 | KEY_GC_REAPING_DEAD_2); + gc_state |= KEY_GC_REAPING_DEAD_3; + } else { + gc_state |= KEY_GC_REAP_AGAIN; + } + } + + if (unlikely(gc_state & KEY_GC_REAPING_DEAD_3)) { + kdebug("dead wake"); + smp_mb(); + clear_bit(KEY_GC_REAPING_KEYTYPE, &key_gc_flags); + wake_up_bit(&key_gc_flags, KEY_GC_REAPING_KEYTYPE); + } + + if (gc_state & KEY_GC_REAP_AGAIN) + schedule_work(&key_gc_work); + kleave(" [end %x]", gc_state); + return; + + /* We found an unreferenced key - once we've removed it from the tree, + * we can safely drop the lock. + */ +found_unreferenced_key: + kdebug("unrefd key %d", key->serial); + rb_erase(&key->serial_node, &key_serial_tree); + spin_unlock(&key_serial_lock); + + list_add_tail(&key->graveyard_link, &graveyard); + gc_state |= KEY_GC_REAP_AGAIN; + goto maybe_resched; + + /* We found a restricted keyring and need to update the restriction if + * it is associated with the dead key type. + */ +found_restricted_keyring: + spin_unlock(&key_serial_lock); + keyring_restriction_gc(key, key_gc_dead_keytype); + goto maybe_resched; + + /* We found a keyring and we need to check the payload for links to + * dead or expired keys. We don't flag another reap immediately as we + * have to wait for the old payload to be destroyed by RCU before we + * can reap the keys to which it refers. + */ +found_keyring: + spin_unlock(&key_serial_lock); + keyring_gc(key, limit); + goto maybe_resched; + + /* We found a dead key that is still referenced. Reset its type and + * destroy its payload with its semaphore held. + */ +destroy_dead_key: + spin_unlock(&key_serial_lock); + kdebug("destroy key %d", key->serial); + down_write(&key->sem); + key->type = &key_type_dead; + if (key_gc_dead_keytype->destroy) + key_gc_dead_keytype->destroy(key); + memset(&key->payload, KEY_DESTROY, sizeof(key->payload)); + up_write(&key->sem); + goto maybe_resched; +} diff --git a/security/keys/internal.h b/security/keys/internal.h new file mode 100644 index 000000000..ec2ec335b --- /dev/null +++ b/security/keys/internal.h @@ -0,0 +1,383 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* Authentication token and access key management internal defs + * + * Copyright (C) 2003-5, 2007 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#ifndef _INTERNAL_H +#define _INTERNAL_H + +#include <linux/sched.h> +#include <linux/wait_bit.h> +#include <linux/cred.h> +#include <linux/key-type.h> +#include <linux/task_work.h> +#include <linux/keyctl.h> +#include <linux/refcount.h> +#include <linux/watch_queue.h> +#include <linux/compat.h> +#include <linux/mm.h> +#include <linux/vmalloc.h> + +struct iovec; + +#ifdef __KDEBUG +#define kenter(FMT, ...) \ + printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__) +#define kleave(FMT, ...) \ + printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__) +#define kdebug(FMT, ...) \ + printk(KERN_DEBUG " "FMT"\n", ##__VA_ARGS__) +#else +#define kenter(FMT, ...) \ + no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__) +#define kleave(FMT, ...) \ + no_printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__) +#define kdebug(FMT, ...) \ + no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__) +#endif + +extern struct key_type key_type_dead; +extern struct key_type key_type_user; +extern struct key_type key_type_logon; + +/*****************************************************************************/ +/* + * Keep track of keys for a user. + * + * This needs to be separate to user_struct to avoid a refcount-loop + * (user_struct pins some keyrings which pin this struct). + * + * We also keep track of keys under request from userspace for this UID here. + */ +struct key_user { + struct rb_node node; + struct mutex cons_lock; /* construction initiation lock */ + spinlock_t lock; + refcount_t usage; /* for accessing qnkeys & qnbytes */ + atomic_t nkeys; /* number of keys */ + atomic_t nikeys; /* number of instantiated keys */ + kuid_t uid; + int qnkeys; /* number of keys allocated to this user */ + int qnbytes; /* number of bytes allocated to this user */ +}; + +extern struct rb_root key_user_tree; +extern spinlock_t key_user_lock; +extern struct key_user root_key_user; + +extern struct key_user *key_user_lookup(kuid_t uid); +extern void key_user_put(struct key_user *user); + +/* + * Key quota limits. + * - root has its own separate limits to everyone else + */ +extern unsigned key_quota_root_maxkeys; +extern unsigned key_quota_root_maxbytes; +extern unsigned key_quota_maxkeys; +extern unsigned key_quota_maxbytes; + +#define KEYQUOTA_LINK_BYTES 4 /* a link in a keyring is worth 4 bytes */ + + +extern struct kmem_cache *key_jar; +extern struct rb_root key_serial_tree; +extern spinlock_t key_serial_lock; +extern struct mutex key_construction_mutex; +extern wait_queue_head_t request_key_conswq; + +extern void key_set_index_key(struct keyring_index_key *index_key); +extern struct key_type *key_type_lookup(const char *type); +extern void key_type_put(struct key_type *ktype); + +extern int __key_link_lock(struct key *keyring, + const struct keyring_index_key *index_key); +extern int __key_move_lock(struct key *l_keyring, struct key *u_keyring, + const struct keyring_index_key *index_key); +extern int __key_link_begin(struct key *keyring, + const struct keyring_index_key *index_key, + struct assoc_array_edit **_edit); +extern int __key_link_check_live_key(struct key *keyring, struct key *key); +extern void __key_link(struct key *keyring, struct key *key, + struct assoc_array_edit **_edit); +extern void __key_link_end(struct key *keyring, + const struct keyring_index_key *index_key, + struct assoc_array_edit *edit); + +extern key_ref_t find_key_to_update(key_ref_t keyring_ref, + const struct keyring_index_key *index_key); + +extern struct key *keyring_search_instkey(struct key *keyring, + key_serial_t target_id); + +extern int iterate_over_keyring(const struct key *keyring, + int (*func)(const struct key *key, void *data), + void *data); + +struct keyring_search_context { + struct keyring_index_key index_key; + const struct cred *cred; + struct key_match_data match_data; + unsigned flags; +#define KEYRING_SEARCH_NO_STATE_CHECK 0x0001 /* Skip state checks */ +#define KEYRING_SEARCH_DO_STATE_CHECK 0x0002 /* Override NO_STATE_CHECK */ +#define KEYRING_SEARCH_NO_UPDATE_TIME 0x0004 /* Don't update times */ +#define KEYRING_SEARCH_NO_CHECK_PERM 0x0008 /* Don't check permissions */ +#define KEYRING_SEARCH_DETECT_TOO_DEEP 0x0010 /* Give an error on excessive depth */ +#define KEYRING_SEARCH_SKIP_EXPIRED 0x0020 /* Ignore expired keys (intention to replace) */ +#define KEYRING_SEARCH_RECURSE 0x0040 /* Search child keyrings also */ + + int (*iterator)(const void *object, void *iterator_data); + + /* Internal stuff */ + int skipped_ret; + bool possessed; + key_ref_t result; + time64_t now; +}; + +extern bool key_default_cmp(const struct key *key, + const struct key_match_data *match_data); +extern key_ref_t keyring_search_rcu(key_ref_t keyring_ref, + struct keyring_search_context *ctx); + +extern key_ref_t search_cred_keyrings_rcu(struct keyring_search_context *ctx); +extern key_ref_t search_process_keyrings_rcu(struct keyring_search_context *ctx); + +extern struct key *find_keyring_by_name(const char *name, bool uid_keyring); + +extern int look_up_user_keyrings(struct key **, struct key **); +extern struct key *get_user_session_keyring_rcu(const struct cred *); +extern int install_thread_keyring_to_cred(struct cred *); +extern int install_process_keyring_to_cred(struct cred *); +extern int install_session_keyring_to_cred(struct cred *, struct key *); + +extern struct key *request_key_and_link(struct key_type *type, + const char *description, + struct key_tag *domain_tag, + const void *callout_info, + size_t callout_len, + void *aux, + struct key *dest_keyring, + unsigned long flags); + +extern bool lookup_user_key_possessed(const struct key *key, + const struct key_match_data *match_data); + +extern long join_session_keyring(const char *name); +extern void key_change_session_keyring(struct callback_head *twork); + +extern struct work_struct key_gc_work; +extern unsigned key_gc_delay; +extern void keyring_gc(struct key *keyring, time64_t limit); +extern void keyring_restriction_gc(struct key *keyring, + struct key_type *dead_type); +void key_set_expiry(struct key *key, time64_t expiry); +extern void key_schedule_gc(time64_t gc_at); +extern void key_schedule_gc_links(void); +extern void key_gc_keytype(struct key_type *ktype); + +extern int key_task_permission(const key_ref_t key_ref, + const struct cred *cred, + enum key_need_perm need_perm); + +static inline void notify_key(struct key *key, + enum key_notification_subtype subtype, u32 aux) +{ +#ifdef CONFIG_KEY_NOTIFICATIONS + struct key_notification n = { + .watch.type = WATCH_TYPE_KEY_NOTIFY, + .watch.subtype = subtype, + .watch.info = watch_sizeof(n), + .key_id = key_serial(key), + .aux = aux, + }; + + post_watch_notification(key->watchers, &n.watch, current_cred(), + n.key_id); +#endif +} + +/* + * Check to see whether permission is granted to use a key in the desired way. + */ +static inline int key_permission(const key_ref_t key_ref, + enum key_need_perm need_perm) +{ + return key_task_permission(key_ref, current_cred(), need_perm); +} + +extern struct key_type key_type_request_key_auth; +extern struct key *request_key_auth_new(struct key *target, + const char *op, + const void *callout_info, + size_t callout_len, + struct key *dest_keyring); + +extern struct key *key_get_instantiation_authkey(key_serial_t target_id); + +/* + * Determine whether a key is dead. + */ +static inline bool key_is_dead(const struct key *key, time64_t limit) +{ + time64_t expiry = key->expiry; + + if (expiry != TIME64_MAX) { + if (!(key->type->flags & KEY_TYPE_INSTANT_REAP)) + expiry += key_gc_delay; + if (expiry <= limit) + return true; + } + + return + key->flags & ((1 << KEY_FLAG_DEAD) | + (1 << KEY_FLAG_INVALIDATED)) || + key->domain_tag->removed; +} + +/* + * keyctl() functions + */ +extern long keyctl_get_keyring_ID(key_serial_t, int); +extern long keyctl_join_session_keyring(const char __user *); +extern long keyctl_update_key(key_serial_t, const void __user *, size_t); +extern long keyctl_revoke_key(key_serial_t); +extern long keyctl_keyring_clear(key_serial_t); +extern long keyctl_keyring_link(key_serial_t, key_serial_t); +extern long keyctl_keyring_move(key_serial_t, key_serial_t, key_serial_t, unsigned int); +extern long keyctl_keyring_unlink(key_serial_t, key_serial_t); +extern long keyctl_describe_key(key_serial_t, char __user *, size_t); +extern long keyctl_keyring_search(key_serial_t, const char __user *, + const char __user *, key_serial_t); +extern long keyctl_read_key(key_serial_t, char __user *, size_t); +extern long keyctl_chown_key(key_serial_t, uid_t, gid_t); +extern long keyctl_setperm_key(key_serial_t, key_perm_t); +extern long keyctl_instantiate_key(key_serial_t, const void __user *, + size_t, key_serial_t); +extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t); +extern long keyctl_set_reqkey_keyring(int); +extern long keyctl_set_timeout(key_serial_t, unsigned); +extern long keyctl_assume_authority(key_serial_t); +extern long keyctl_get_security(key_serial_t keyid, char __user *buffer, + size_t buflen); +extern long keyctl_session_to_parent(void); +extern long keyctl_reject_key(key_serial_t, unsigned, unsigned, key_serial_t); +extern long keyctl_instantiate_key_iov(key_serial_t, + const struct iovec __user *, + unsigned, key_serial_t); +extern long keyctl_invalidate_key(key_serial_t); +extern long keyctl_restrict_keyring(key_serial_t id, + const char __user *_type, + const char __user *_restriction); +#ifdef CONFIG_PERSISTENT_KEYRINGS +extern long keyctl_get_persistent(uid_t, key_serial_t); +extern unsigned persistent_keyring_expiry; +#else +static inline long keyctl_get_persistent(uid_t uid, key_serial_t destring) +{ + return -EOPNOTSUPP; +} +#endif + +#ifdef CONFIG_KEY_DH_OPERATIONS +extern long keyctl_dh_compute(struct keyctl_dh_params __user *, char __user *, + size_t, struct keyctl_kdf_params __user *); +extern long __keyctl_dh_compute(struct keyctl_dh_params __user *, char __user *, + size_t, struct keyctl_kdf_params *); +#ifdef CONFIG_COMPAT +extern long compat_keyctl_dh_compute(struct keyctl_dh_params __user *params, + char __user *buffer, size_t buflen, + struct compat_keyctl_kdf_params __user *kdf); +#endif +#define KEYCTL_KDF_MAX_OUTPUT_LEN 1024 /* max length of KDF output */ +#define KEYCTL_KDF_MAX_OI_LEN 64 /* max length of otherinfo */ +#else +static inline long keyctl_dh_compute(struct keyctl_dh_params __user *params, + char __user *buffer, size_t buflen, + struct keyctl_kdf_params __user *kdf) +{ + return -EOPNOTSUPP; +} + +#ifdef CONFIG_COMPAT +static inline long compat_keyctl_dh_compute( + struct keyctl_dh_params __user *params, + char __user *buffer, size_t buflen, + struct keyctl_kdf_params __user *kdf) +{ + return -EOPNOTSUPP; +} +#endif +#endif + +#ifdef CONFIG_ASYMMETRIC_KEY_TYPE +extern long keyctl_pkey_query(key_serial_t, + const char __user *, + struct keyctl_pkey_query __user *); + +extern long keyctl_pkey_verify(const struct keyctl_pkey_params __user *, + const char __user *, + const void __user *, const void __user *); + +extern long keyctl_pkey_e_d_s(int, + const struct keyctl_pkey_params __user *, + const char __user *, + const void __user *, void __user *); +#else +static inline long keyctl_pkey_query(key_serial_t id, + const char __user *_info, + struct keyctl_pkey_query __user *_res) +{ + return -EOPNOTSUPP; +} + +static inline long keyctl_pkey_verify(const struct keyctl_pkey_params __user *params, + const char __user *_info, + const void __user *_in, + const void __user *_in2) +{ + return -EOPNOTSUPP; +} + +static inline long keyctl_pkey_e_d_s(int op, + const struct keyctl_pkey_params __user *params, + const char __user *_info, + const void __user *_in, + void __user *_out) +{ + return -EOPNOTSUPP; +} +#endif + +extern long keyctl_capabilities(unsigned char __user *_buffer, size_t buflen); + +#ifdef CONFIG_KEY_NOTIFICATIONS +extern long keyctl_watch_key(key_serial_t, int, int); +#else +static inline long keyctl_watch_key(key_serial_t key_id, int watch_fd, int watch_id) +{ + return -EOPNOTSUPP; +} +#endif + +/* + * Debugging key validation + */ +#ifdef KEY_DEBUGGING +extern void __key_check(const struct key *); + +static inline void key_check(const struct key *key) +{ + if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC)) + __key_check(key); +} + +#else + +#define key_check(key) do {} while(0) + +#endif +#endif /* _INTERNAL_H */ diff --git a/security/keys/key.c b/security/keys/key.c new file mode 100644 index 000000000..e65240641 --- /dev/null +++ b/security/keys/key.c @@ -0,0 +1,1215 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* Basic authentication token and access key management + * + * Copyright (C) 2004-2008 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#include <linux/export.h> +#include <linux/init.h> +#include <linux/poison.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/security.h> +#include <linux/workqueue.h> +#include <linux/random.h> +#include <linux/ima.h> +#include <linux/err.h> +#include "internal.h" + +struct kmem_cache *key_jar; +struct rb_root key_serial_tree; /* tree of keys indexed by serial */ +DEFINE_SPINLOCK(key_serial_lock); + +struct rb_root key_user_tree; /* tree of quota records indexed by UID */ +DEFINE_SPINLOCK(key_user_lock); + +unsigned int key_quota_root_maxkeys = 1000000; /* root's key count quota */ +unsigned int key_quota_root_maxbytes = 25000000; /* root's key space quota */ +unsigned int key_quota_maxkeys = 200; /* general key count quota */ +unsigned int key_quota_maxbytes = 20000; /* general key space quota */ + +static LIST_HEAD(key_types_list); +static DECLARE_RWSEM(key_types_sem); + +/* We serialise key instantiation and link */ +DEFINE_MUTEX(key_construction_mutex); + +#ifdef KEY_DEBUGGING +void __key_check(const struct key *key) +{ + printk("__key_check: key %p {%08x} should be {%08x}\n", + key, key->magic, KEY_DEBUG_MAGIC); + BUG(); +} +#endif + +/* + * Get the key quota record for a user, allocating a new record if one doesn't + * already exist. + */ +struct key_user *key_user_lookup(kuid_t uid) +{ + struct key_user *candidate = NULL, *user; + struct rb_node *parent, **p; + +try_again: + parent = NULL; + p = &key_user_tree.rb_node; + spin_lock(&key_user_lock); + + /* search the tree for a user record with a matching UID */ + while (*p) { + parent = *p; + user = rb_entry(parent, struct key_user, node); + + if (uid_lt(uid, user->uid)) + p = &(*p)->rb_left; + else if (uid_gt(uid, user->uid)) + p = &(*p)->rb_right; + else + goto found; + } + + /* if we get here, we failed to find a match in the tree */ + if (!candidate) { + /* allocate a candidate user record if we don't already have + * one */ + spin_unlock(&key_user_lock); + + user = NULL; + candidate = kmalloc(sizeof(struct key_user), GFP_KERNEL); + if (unlikely(!candidate)) + goto out; + + /* the allocation may have scheduled, so we need to repeat the + * search lest someone else added the record whilst we were + * asleep */ + goto try_again; + } + + /* if we get here, then the user record still hadn't appeared on the + * second pass - so we use the candidate record */ + refcount_set(&candidate->usage, 1); + atomic_set(&candidate->nkeys, 0); + atomic_set(&candidate->nikeys, 0); + candidate->uid = uid; + candidate->qnkeys = 0; + candidate->qnbytes = 0; + spin_lock_init(&candidate->lock); + mutex_init(&candidate->cons_lock); + + rb_link_node(&candidate->node, parent, p); + rb_insert_color(&candidate->node, &key_user_tree); + spin_unlock(&key_user_lock); + user = candidate; + goto out; + + /* okay - we found a user record for this UID */ +found: + refcount_inc(&user->usage); + spin_unlock(&key_user_lock); + kfree(candidate); +out: + return user; +} + +/* + * Dispose of a user structure + */ +void key_user_put(struct key_user *user) +{ + if (refcount_dec_and_lock(&user->usage, &key_user_lock)) { + rb_erase(&user->node, &key_user_tree); + spin_unlock(&key_user_lock); + + kfree(user); + } +} + +/* + * Allocate a serial number for a key. These are assigned randomly to avoid + * security issues through covert channel problems. + */ +static inline void key_alloc_serial(struct key *key) +{ + struct rb_node *parent, **p; + struct key *xkey; + + /* propose a random serial number and look for a hole for it in the + * serial number tree */ + do { + get_random_bytes(&key->serial, sizeof(key->serial)); + + key->serial >>= 1; /* negative numbers are not permitted */ + } while (key->serial < 3); + + spin_lock(&key_serial_lock); + +attempt_insertion: + parent = NULL; + p = &key_serial_tree.rb_node; + + while (*p) { + parent = *p; + xkey = rb_entry(parent, struct key, serial_node); + + if (key->serial < xkey->serial) + p = &(*p)->rb_left; + else if (key->serial > xkey->serial) + p = &(*p)->rb_right; + else + goto serial_exists; + } + + /* we've found a suitable hole - arrange for this key to occupy it */ + rb_link_node(&key->serial_node, parent, p); + rb_insert_color(&key->serial_node, &key_serial_tree); + + spin_unlock(&key_serial_lock); + return; + + /* we found a key with the proposed serial number - walk the tree from + * that point looking for the next unused serial number */ +serial_exists: + for (;;) { + key->serial++; + if (key->serial < 3) { + key->serial = 3; + goto attempt_insertion; + } + + parent = rb_next(parent); + if (!parent) + goto attempt_insertion; + + xkey = rb_entry(parent, struct key, serial_node); + if (key->serial < xkey->serial) + goto attempt_insertion; + } +} + +/** + * key_alloc - Allocate a key of the specified type. + * @type: The type of key to allocate. + * @desc: The key description to allow the key to be searched out. + * @uid: The owner of the new key. + * @gid: The group ID for the new key's group permissions. + * @cred: The credentials specifying UID namespace. + * @perm: The permissions mask of the new key. + * @flags: Flags specifying quota properties. + * @restrict_link: Optional link restriction for new keyrings. + * + * Allocate a key of the specified type with the attributes given. The key is + * returned in an uninstantiated state and the caller needs to instantiate the + * key before returning. + * + * The restrict_link structure (if not NULL) will be freed when the + * keyring is destroyed, so it must be dynamically allocated. + * + * The user's key count quota is updated to reflect the creation of the key and + * the user's key data quota has the default for the key type reserved. The + * instantiation function should amend this as necessary. If insufficient + * quota is available, -EDQUOT will be returned. + * + * The LSM security modules can prevent a key being created, in which case + * -EACCES will be returned. + * + * Returns a pointer to the new key if successful and an error code otherwise. + * + * Note that the caller needs to ensure the key type isn't uninstantiated. + * Internally this can be done by locking key_types_sem. Externally, this can + * be done by either never unregistering the key type, or making sure + * key_alloc() calls don't race with module unloading. + */ +struct key *key_alloc(struct key_type *type, const char *desc, + kuid_t uid, kgid_t gid, const struct cred *cred, + key_perm_t perm, unsigned long flags, + struct key_restriction *restrict_link) +{ + struct key_user *user = NULL; + struct key *key; + size_t desclen, quotalen; + int ret; + + key = ERR_PTR(-EINVAL); + if (!desc || !*desc) + goto error; + + if (type->vet_description) { + ret = type->vet_description(desc); + if (ret < 0) { + key = ERR_PTR(ret); + goto error; + } + } + + desclen = strlen(desc); + quotalen = desclen + 1 + type->def_datalen; + + /* get hold of the key tracking for this user */ + user = key_user_lookup(uid); + if (!user) + goto no_memory_1; + + /* check that the user's quota permits allocation of another key and + * its description */ + if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) { + unsigned maxkeys = uid_eq(uid, GLOBAL_ROOT_UID) ? + key_quota_root_maxkeys : key_quota_maxkeys; + unsigned maxbytes = uid_eq(uid, GLOBAL_ROOT_UID) ? + key_quota_root_maxbytes : key_quota_maxbytes; + + spin_lock(&user->lock); + if (!(flags & KEY_ALLOC_QUOTA_OVERRUN)) { + if (user->qnkeys + 1 > maxkeys || + user->qnbytes + quotalen > maxbytes || + user->qnbytes + quotalen < user->qnbytes) + goto no_quota; + } + + user->qnkeys++; + user->qnbytes += quotalen; + spin_unlock(&user->lock); + } + + /* allocate and initialise the key and its description */ + key = kmem_cache_zalloc(key_jar, GFP_KERNEL); + if (!key) + goto no_memory_2; + + key->index_key.desc_len = desclen; + key->index_key.description = kmemdup(desc, desclen + 1, GFP_KERNEL); + if (!key->index_key.description) + goto no_memory_3; + key->index_key.type = type; + key_set_index_key(&key->index_key); + + refcount_set(&key->usage, 1); + init_rwsem(&key->sem); + lockdep_set_class(&key->sem, &type->lock_class); + key->user = user; + key->quotalen = quotalen; + key->datalen = type->def_datalen; + key->uid = uid; + key->gid = gid; + key->perm = perm; + key->expiry = TIME64_MAX; + key->restrict_link = restrict_link; + key->last_used_at = ktime_get_real_seconds(); + + if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) + key->flags |= 1 << KEY_FLAG_IN_QUOTA; + if (flags & KEY_ALLOC_BUILT_IN) + key->flags |= 1 << KEY_FLAG_BUILTIN; + if (flags & KEY_ALLOC_UID_KEYRING) + key->flags |= 1 << KEY_FLAG_UID_KEYRING; + if (flags & KEY_ALLOC_SET_KEEP) + key->flags |= 1 << KEY_FLAG_KEEP; + +#ifdef KEY_DEBUGGING + key->magic = KEY_DEBUG_MAGIC; +#endif + + /* let the security module know about the key */ + ret = security_key_alloc(key, cred, flags); + if (ret < 0) + goto security_error; + + /* publish the key by giving it a serial number */ + refcount_inc(&key->domain_tag->usage); + atomic_inc(&user->nkeys); + key_alloc_serial(key); + +error: + return key; + +security_error: + kfree(key->description); + kmem_cache_free(key_jar, key); + if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) { + spin_lock(&user->lock); + user->qnkeys--; + user->qnbytes -= quotalen; + spin_unlock(&user->lock); + } + key_user_put(user); + key = ERR_PTR(ret); + goto error; + +no_memory_3: + kmem_cache_free(key_jar, key); +no_memory_2: + if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) { + spin_lock(&user->lock); + user->qnkeys--; + user->qnbytes -= quotalen; + spin_unlock(&user->lock); + } + key_user_put(user); +no_memory_1: + key = ERR_PTR(-ENOMEM); + goto error; + +no_quota: + spin_unlock(&user->lock); + key_user_put(user); + key = ERR_PTR(-EDQUOT); + goto error; +} +EXPORT_SYMBOL(key_alloc); + +/** + * key_payload_reserve - Adjust data quota reservation for the key's payload + * @key: The key to make the reservation for. + * @datalen: The amount of data payload the caller now wants. + * + * Adjust the amount of the owning user's key data quota that a key reserves. + * If the amount is increased, then -EDQUOT may be returned if there isn't + * enough free quota available. + * + * If successful, 0 is returned. + */ +int key_payload_reserve(struct key *key, size_t datalen) +{ + int delta = (int)datalen - key->datalen; + int ret = 0; + + key_check(key); + + /* contemplate the quota adjustment */ + if (delta != 0 && test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { + unsigned maxbytes = uid_eq(key->user->uid, GLOBAL_ROOT_UID) ? + key_quota_root_maxbytes : key_quota_maxbytes; + + spin_lock(&key->user->lock); + + if (delta > 0 && + (key->user->qnbytes + delta > maxbytes || + key->user->qnbytes + delta < key->user->qnbytes)) { + ret = -EDQUOT; + } + else { + key->user->qnbytes += delta; + key->quotalen += delta; + } + spin_unlock(&key->user->lock); + } + + /* change the recorded data length if that didn't generate an error */ + if (ret == 0) + key->datalen = datalen; + + return ret; +} +EXPORT_SYMBOL(key_payload_reserve); + +/* + * Change the key state to being instantiated. + */ +static void mark_key_instantiated(struct key *key, int reject_error) +{ + /* Commit the payload before setting the state; barrier versus + * key_read_state(). + */ + smp_store_release(&key->state, + (reject_error < 0) ? reject_error : KEY_IS_POSITIVE); +} + +/* + * Instantiate a key and link it into the target keyring atomically. Must be + * called with the target keyring's semaphore writelocked. The target key's + * semaphore need not be locked as instantiation is serialised by + * key_construction_mutex. + */ +static int __key_instantiate_and_link(struct key *key, + struct key_preparsed_payload *prep, + struct key *keyring, + struct key *authkey, + struct assoc_array_edit **_edit) +{ + int ret, awaken; + + key_check(key); + key_check(keyring); + + awaken = 0; + ret = -EBUSY; + + mutex_lock(&key_construction_mutex); + + /* can't instantiate twice */ + if (key->state == KEY_IS_UNINSTANTIATED) { + /* instantiate the key */ + ret = key->type->instantiate(key, prep); + + if (ret == 0) { + /* mark the key as being instantiated */ + atomic_inc(&key->user->nikeys); + mark_key_instantiated(key, 0); + notify_key(key, NOTIFY_KEY_INSTANTIATED, 0); + + if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags)) + awaken = 1; + + /* and link it into the destination keyring */ + if (keyring) { + if (test_bit(KEY_FLAG_KEEP, &keyring->flags)) + set_bit(KEY_FLAG_KEEP, &key->flags); + + __key_link(keyring, key, _edit); + } + + /* disable the authorisation key */ + if (authkey) + key_invalidate(authkey); + + key_set_expiry(key, prep->expiry); + } + } + + mutex_unlock(&key_construction_mutex); + + /* wake up anyone waiting for a key to be constructed */ + if (awaken) + wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT); + + return ret; +} + +/** + * key_instantiate_and_link - Instantiate a key and link it into the keyring. + * @key: The key to instantiate. + * @data: The data to use to instantiate the keyring. + * @datalen: The length of @data. + * @keyring: Keyring to create a link in on success (or NULL). + * @authkey: The authorisation token permitting instantiation. + * + * Instantiate a key that's in the uninstantiated state using the provided data + * and, if successful, link it in to the destination keyring if one is + * supplied. + * + * If successful, 0 is returned, the authorisation token is revoked and anyone + * waiting for the key is woken up. If the key was already instantiated, + * -EBUSY will be returned. + */ +int key_instantiate_and_link(struct key *key, + const void *data, + size_t datalen, + struct key *keyring, + struct key *authkey) +{ + struct key_preparsed_payload prep; + struct assoc_array_edit *edit = NULL; + int ret; + + memset(&prep, 0, sizeof(prep)); + prep.orig_description = key->description; + prep.data = data; + prep.datalen = datalen; + prep.quotalen = key->type->def_datalen; + prep.expiry = TIME64_MAX; + if (key->type->preparse) { + ret = key->type->preparse(&prep); + if (ret < 0) + goto error; + } + + if (keyring) { + ret = __key_link_lock(keyring, &key->index_key); + if (ret < 0) + goto error; + + ret = __key_link_begin(keyring, &key->index_key, &edit); + if (ret < 0) + goto error_link_end; + + if (keyring->restrict_link && keyring->restrict_link->check) { + struct key_restriction *keyres = keyring->restrict_link; + + ret = keyres->check(keyring, key->type, &prep.payload, + keyres->key); + if (ret < 0) + goto error_link_end; + } + } + + ret = __key_instantiate_and_link(key, &prep, keyring, authkey, &edit); + +error_link_end: + if (keyring) + __key_link_end(keyring, &key->index_key, edit); + +error: + if (key->type->preparse) + key->type->free_preparse(&prep); + return ret; +} + +EXPORT_SYMBOL(key_instantiate_and_link); + +/** + * key_reject_and_link - Negatively instantiate a key and link it into the keyring. + * @key: The key to instantiate. + * @timeout: The timeout on the negative key. + * @error: The error to return when the key is hit. + * @keyring: Keyring to create a link in on success (or NULL). + * @authkey: The authorisation token permitting instantiation. + * + * Negatively instantiate a key that's in the uninstantiated state and, if + * successful, set its timeout and stored error and link it in to the + * destination keyring if one is supplied. The key and any links to the key + * will be automatically garbage collected after the timeout expires. + * + * Negative keys are used to rate limit repeated request_key() calls by causing + * them to return the stored error code (typically ENOKEY) until the negative + * key expires. + * + * If successful, 0 is returned, the authorisation token is revoked and anyone + * waiting for the key is woken up. If the key was already instantiated, + * -EBUSY will be returned. + */ +int key_reject_and_link(struct key *key, + unsigned timeout, + unsigned error, + struct key *keyring, + struct key *authkey) +{ + struct assoc_array_edit *edit = NULL; + int ret, awaken, link_ret = 0; + + key_check(key); + key_check(keyring); + + awaken = 0; + ret = -EBUSY; + + if (keyring) { + if (keyring->restrict_link) + return -EPERM; + + link_ret = __key_link_lock(keyring, &key->index_key); + if (link_ret == 0) { + link_ret = __key_link_begin(keyring, &key->index_key, &edit); + if (link_ret < 0) + __key_link_end(keyring, &key->index_key, edit); + } + } + + mutex_lock(&key_construction_mutex); + + /* can't instantiate twice */ + if (key->state == KEY_IS_UNINSTANTIATED) { + /* mark the key as being negatively instantiated */ + atomic_inc(&key->user->nikeys); + mark_key_instantiated(key, -error); + notify_key(key, NOTIFY_KEY_INSTANTIATED, -error); + key_set_expiry(key, ktime_get_real_seconds() + timeout); + + if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags)) + awaken = 1; + + ret = 0; + + /* and link it into the destination keyring */ + if (keyring && link_ret == 0) + __key_link(keyring, key, &edit); + + /* disable the authorisation key */ + if (authkey) + key_invalidate(authkey); + } + + mutex_unlock(&key_construction_mutex); + + if (keyring && link_ret == 0) + __key_link_end(keyring, &key->index_key, edit); + + /* wake up anyone waiting for a key to be constructed */ + if (awaken) + wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT); + + return ret == 0 ? link_ret : ret; +} +EXPORT_SYMBOL(key_reject_and_link); + +/** + * key_put - Discard a reference to a key. + * @key: The key to discard a reference from. + * + * Discard a reference to a key, and when all the references are gone, we + * schedule the cleanup task to come and pull it out of the tree in process + * context at some later time. + */ +void key_put(struct key *key) +{ + if (key) { + key_check(key); + + if (refcount_dec_and_test(&key->usage)) + schedule_work(&key_gc_work); + } +} +EXPORT_SYMBOL(key_put); + +/* + * Find a key by its serial number. + */ +struct key *key_lookup(key_serial_t id) +{ + struct rb_node *n; + struct key *key; + + spin_lock(&key_serial_lock); + + /* search the tree for the specified key */ + n = key_serial_tree.rb_node; + while (n) { + key = rb_entry(n, struct key, serial_node); + + if (id < key->serial) + n = n->rb_left; + else if (id > key->serial) + n = n->rb_right; + else + goto found; + } + +not_found: + key = ERR_PTR(-ENOKEY); + goto error; + +found: + /* A key is allowed to be looked up only if someone still owns a + * reference to it - otherwise it's awaiting the gc. + */ + if (!refcount_inc_not_zero(&key->usage)) + goto not_found; + +error: + spin_unlock(&key_serial_lock); + return key; +} + +/* + * Find and lock the specified key type against removal. + * + * We return with the sem read-locked if successful. If the type wasn't + * available -ENOKEY is returned instead. + */ +struct key_type *key_type_lookup(const char *type) +{ + struct key_type *ktype; + + down_read(&key_types_sem); + + /* look up the key type to see if it's one of the registered kernel + * types */ + list_for_each_entry(ktype, &key_types_list, link) { + if (strcmp(ktype->name, type) == 0) + goto found_kernel_type; + } + + up_read(&key_types_sem); + ktype = ERR_PTR(-ENOKEY); + +found_kernel_type: + return ktype; +} + +void key_set_timeout(struct key *key, unsigned timeout) +{ + time64_t expiry = TIME64_MAX; + + /* make the changes with the locks held to prevent races */ + down_write(&key->sem); + + if (timeout > 0) + expiry = ktime_get_real_seconds() + timeout; + key_set_expiry(key, expiry); + + up_write(&key->sem); +} +EXPORT_SYMBOL_GPL(key_set_timeout); + +/* + * Unlock a key type locked by key_type_lookup(). + */ +void key_type_put(struct key_type *ktype) +{ + up_read(&key_types_sem); +} + +/* + * Attempt to update an existing key. + * + * The key is given to us with an incremented refcount that we need to discard + * if we get an error. + */ +static inline key_ref_t __key_update(key_ref_t key_ref, + struct key_preparsed_payload *prep) +{ + struct key *key = key_ref_to_ptr(key_ref); + int ret; + + /* need write permission on the key to update it */ + ret = key_permission(key_ref, KEY_NEED_WRITE); + if (ret < 0) + goto error; + + ret = -EEXIST; + if (!key->type->update) + goto error; + + down_write(&key->sem); + + ret = key->type->update(key, prep); + if (ret == 0) { + /* Updating a negative key positively instantiates it */ + mark_key_instantiated(key, 0); + notify_key(key, NOTIFY_KEY_UPDATED, 0); + } + + up_write(&key->sem); + + if (ret < 0) + goto error; +out: + return key_ref; + +error: + key_put(key); + key_ref = ERR_PTR(ret); + goto out; +} + +/** + * key_create_or_update - Update or create and instantiate a key. + * @keyring_ref: A pointer to the destination keyring with possession flag. + * @type: The type of key. + * @description: The searchable description for the key. + * @payload: The data to use to instantiate or update the key. + * @plen: The length of @payload. + * @perm: The permissions mask for a new key. + * @flags: The quota flags for a new key. + * + * Search the destination keyring for a key of the same description and if one + * is found, update it, otherwise create and instantiate a new one and create a + * link to it from that keyring. + * + * If perm is KEY_PERM_UNDEF then an appropriate key permissions mask will be + * concocted. + * + * Returns a pointer to the new key if successful, -ENODEV if the key type + * wasn't available, -ENOTDIR if the keyring wasn't a keyring, -EACCES if the + * caller isn't permitted to modify the keyring or the LSM did not permit + * creation of the key. + * + * On success, the possession flag from the keyring ref will be tacked on to + * the key ref before it is returned. + */ +key_ref_t key_create_or_update(key_ref_t keyring_ref, + const char *type, + const char *description, + const void *payload, + size_t plen, + key_perm_t perm, + unsigned long flags) +{ + struct keyring_index_key index_key = { + .description = description, + }; + struct key_preparsed_payload prep; + struct assoc_array_edit *edit = NULL; + const struct cred *cred = current_cred(); + struct key *keyring, *key = NULL; + key_ref_t key_ref; + int ret; + struct key_restriction *restrict_link = NULL; + + /* look up the key type to see if it's one of the registered kernel + * types */ + index_key.type = key_type_lookup(type); + if (IS_ERR(index_key.type)) { + key_ref = ERR_PTR(-ENODEV); + goto error; + } + + key_ref = ERR_PTR(-EINVAL); + if (!index_key.type->instantiate || + (!index_key.description && !index_key.type->preparse)) + goto error_put_type; + + keyring = key_ref_to_ptr(keyring_ref); + + key_check(keyring); + + if (!(flags & KEY_ALLOC_BYPASS_RESTRICTION)) + restrict_link = keyring->restrict_link; + + key_ref = ERR_PTR(-ENOTDIR); + if (keyring->type != &key_type_keyring) + goto error_put_type; + + memset(&prep, 0, sizeof(prep)); + prep.orig_description = description; + prep.data = payload; + prep.datalen = plen; + prep.quotalen = index_key.type->def_datalen; + prep.expiry = TIME64_MAX; + if (index_key.type->preparse) { + ret = index_key.type->preparse(&prep); + if (ret < 0) { + key_ref = ERR_PTR(ret); + goto error_free_prep; + } + if (!index_key.description) + index_key.description = prep.description; + key_ref = ERR_PTR(-EINVAL); + if (!index_key.description) + goto error_free_prep; + } + index_key.desc_len = strlen(index_key.description); + key_set_index_key(&index_key); + + ret = __key_link_lock(keyring, &index_key); + if (ret < 0) { + key_ref = ERR_PTR(ret); + goto error_free_prep; + } + + ret = __key_link_begin(keyring, &index_key, &edit); + if (ret < 0) { + key_ref = ERR_PTR(ret); + goto error_link_end; + } + + if (restrict_link && restrict_link->check) { + ret = restrict_link->check(keyring, index_key.type, + &prep.payload, restrict_link->key); + if (ret < 0) { + key_ref = ERR_PTR(ret); + goto error_link_end; + } + } + + /* if we're going to allocate a new key, we're going to have + * to modify the keyring */ + ret = key_permission(keyring_ref, KEY_NEED_WRITE); + if (ret < 0) { + key_ref = ERR_PTR(ret); + goto error_link_end; + } + + /* if it's possible to update this type of key, search for an existing + * key of the same type and description in the destination keyring and + * update that instead if possible + */ + if (index_key.type->update) { + key_ref = find_key_to_update(keyring_ref, &index_key); + if (key_ref) + goto found_matching_key; + } + + /* if the client doesn't provide, decide on the permissions we want */ + if (perm == KEY_PERM_UNDEF) { + perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR; + perm |= KEY_USR_VIEW; + + if (index_key.type->read) + perm |= KEY_POS_READ; + + if (index_key.type == &key_type_keyring || + index_key.type->update) + perm |= KEY_POS_WRITE; + } + + /* allocate a new key */ + key = key_alloc(index_key.type, index_key.description, + cred->fsuid, cred->fsgid, cred, perm, flags, NULL); + if (IS_ERR(key)) { + key_ref = ERR_CAST(key); + goto error_link_end; + } + + /* instantiate it and link it into the target keyring */ + ret = __key_instantiate_and_link(key, &prep, keyring, NULL, &edit); + if (ret < 0) { + key_put(key); + key_ref = ERR_PTR(ret); + goto error_link_end; + } + + ima_post_key_create_or_update(keyring, key, payload, plen, + flags, true); + + key_ref = make_key_ref(key, is_key_possessed(keyring_ref)); + +error_link_end: + __key_link_end(keyring, &index_key, edit); +error_free_prep: + if (index_key.type->preparse) + index_key.type->free_preparse(&prep); +error_put_type: + key_type_put(index_key.type); +error: + return key_ref; + + found_matching_key: + /* we found a matching key, so we're going to try to update it + * - we can drop the locks first as we have the key pinned + */ + __key_link_end(keyring, &index_key, edit); + + key = key_ref_to_ptr(key_ref); + if (test_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags)) { + ret = wait_for_key_construction(key, true); + if (ret < 0) { + key_ref_put(key_ref); + key_ref = ERR_PTR(ret); + goto error_free_prep; + } + } + + key_ref = __key_update(key_ref, &prep); + + if (!IS_ERR(key_ref)) + ima_post_key_create_or_update(keyring, key, + payload, plen, + flags, false); + + goto error_free_prep; +} +EXPORT_SYMBOL(key_create_or_update); + +/** + * key_update - Update a key's contents. + * @key_ref: The pointer (plus possession flag) to the key. + * @payload: The data to be used to update the key. + * @plen: The length of @payload. + * + * Attempt to update the contents of a key with the given payload data. The + * caller must be granted Write permission on the key. Negative keys can be + * instantiated by this method. + * + * Returns 0 on success, -EACCES if not permitted and -EOPNOTSUPP if the key + * type does not support updating. The key type may return other errors. + */ +int key_update(key_ref_t key_ref, const void *payload, size_t plen) +{ + struct key_preparsed_payload prep; + struct key *key = key_ref_to_ptr(key_ref); + int ret; + + key_check(key); + + /* the key must be writable */ + ret = key_permission(key_ref, KEY_NEED_WRITE); + if (ret < 0) + return ret; + + /* attempt to update it if supported */ + if (!key->type->update) + return -EOPNOTSUPP; + + memset(&prep, 0, sizeof(prep)); + prep.data = payload; + prep.datalen = plen; + prep.quotalen = key->type->def_datalen; + prep.expiry = TIME64_MAX; + if (key->type->preparse) { + ret = key->type->preparse(&prep); + if (ret < 0) + goto error; + } + + down_write(&key->sem); + + ret = key->type->update(key, &prep); + if (ret == 0) { + /* Updating a negative key positively instantiates it */ + mark_key_instantiated(key, 0); + notify_key(key, NOTIFY_KEY_UPDATED, 0); + } + + up_write(&key->sem); + +error: + if (key->type->preparse) + key->type->free_preparse(&prep); + return ret; +} +EXPORT_SYMBOL(key_update); + +/** + * key_revoke - Revoke a key. + * @key: The key to be revoked. + * + * Mark a key as being revoked and ask the type to free up its resources. The + * revocation timeout is set and the key and all its links will be + * automatically garbage collected after key_gc_delay amount of time if they + * are not manually dealt with first. + */ +void key_revoke(struct key *key) +{ + time64_t time; + + key_check(key); + + /* make sure no one's trying to change or use the key when we mark it + * - we tell lockdep that we might nest because we might be revoking an + * authorisation key whilst holding the sem on a key we've just + * instantiated + */ + down_write_nested(&key->sem, 1); + if (!test_and_set_bit(KEY_FLAG_REVOKED, &key->flags)) { + notify_key(key, NOTIFY_KEY_REVOKED, 0); + if (key->type->revoke) + key->type->revoke(key); + + /* set the death time to no more than the expiry time */ + time = ktime_get_real_seconds(); + if (key->revoked_at == 0 || key->revoked_at > time) { + key->revoked_at = time; + key_schedule_gc(key->revoked_at + key_gc_delay); + } + } + + up_write(&key->sem); +} +EXPORT_SYMBOL(key_revoke); + +/** + * key_invalidate - Invalidate a key. + * @key: The key to be invalidated. + * + * Mark a key as being invalidated and have it cleaned up immediately. The key + * is ignored by all searches and other operations from this point. + */ +void key_invalidate(struct key *key) +{ + kenter("%d", key_serial(key)); + + key_check(key); + + if (!test_bit(KEY_FLAG_INVALIDATED, &key->flags)) { + down_write_nested(&key->sem, 1); + if (!test_and_set_bit(KEY_FLAG_INVALIDATED, &key->flags)) { + notify_key(key, NOTIFY_KEY_INVALIDATED, 0); + key_schedule_gc_links(); + } + up_write(&key->sem); + } +} +EXPORT_SYMBOL(key_invalidate); + +/** + * generic_key_instantiate - Simple instantiation of a key from preparsed data + * @key: The key to be instantiated + * @prep: The preparsed data to load. + * + * Instantiate a key from preparsed data. We assume we can just copy the data + * in directly and clear the old pointers. + * + * This can be pointed to directly by the key type instantiate op pointer. + */ +int generic_key_instantiate(struct key *key, struct key_preparsed_payload *prep) +{ + int ret; + + pr_devel("==>%s()\n", __func__); + + ret = key_payload_reserve(key, prep->quotalen); + if (ret == 0) { + rcu_assign_keypointer(key, prep->payload.data[0]); + key->payload.data[1] = prep->payload.data[1]; + key->payload.data[2] = prep->payload.data[2]; + key->payload.data[3] = prep->payload.data[3]; + prep->payload.data[0] = NULL; + prep->payload.data[1] = NULL; + prep->payload.data[2] = NULL; + prep->payload.data[3] = NULL; + } + pr_devel("<==%s() = %d\n", __func__, ret); + return ret; +} +EXPORT_SYMBOL(generic_key_instantiate); + +/** + * register_key_type - Register a type of key. + * @ktype: The new key type. + * + * Register a new key type. + * + * Returns 0 on success or -EEXIST if a type of this name already exists. + */ +int register_key_type(struct key_type *ktype) +{ + struct key_type *p; + int ret; + + memset(&ktype->lock_class, 0, sizeof(ktype->lock_class)); + + ret = -EEXIST; + down_write(&key_types_sem); + + /* disallow key types with the same name */ + list_for_each_entry(p, &key_types_list, link) { + if (strcmp(p->name, ktype->name) == 0) + goto out; + } + + /* store the type */ + list_add(&ktype->link, &key_types_list); + + pr_notice("Key type %s registered\n", ktype->name); + ret = 0; + +out: + up_write(&key_types_sem); + return ret; +} +EXPORT_SYMBOL(register_key_type); + +/** + * unregister_key_type - Unregister a type of key. + * @ktype: The key type. + * + * Unregister a key type and mark all the extant keys of this type as dead. + * Those keys of this type are then destroyed to get rid of their payloads and + * they and their links will be garbage collected as soon as possible. + */ +void unregister_key_type(struct key_type *ktype) +{ + down_write(&key_types_sem); + list_del_init(&ktype->link); + downgrade_write(&key_types_sem); + key_gc_keytype(ktype); + pr_notice("Key type %s unregistered\n", ktype->name); + up_read(&key_types_sem); +} +EXPORT_SYMBOL(unregister_key_type); + +/* + * Initialise the key management state. + */ +void __init key_init(void) +{ + /* allocate a slab in which we can store keys */ + key_jar = kmem_cache_create("key_jar", sizeof(struct key), + 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); + + /* add the special key types */ + list_add_tail(&key_type_keyring.link, &key_types_list); + list_add_tail(&key_type_dead.link, &key_types_list); + list_add_tail(&key_type_user.link, &key_types_list); + list_add_tail(&key_type_logon.link, &key_types_list); + + /* record the root user tracking */ + rb_link_node(&root_key_user.node, + NULL, + &key_user_tree.rb_node); + + rb_insert_color(&root_key_user.node, + &key_user_tree); +} diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c new file mode 100644 index 000000000..19be69fa4 --- /dev/null +++ b/security/keys/keyctl.c @@ -0,0 +1,2026 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* Userspace key control operations + * + * Copyright (C) 2004-5 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#include <linux/init.h> +#include <linux/sched.h> +#include <linux/sched/task.h> +#include <linux/slab.h> +#include <linux/syscalls.h> +#include <linux/key.h> +#include <linux/keyctl.h> +#include <linux/fs.h> +#include <linux/capability.h> +#include <linux/cred.h> +#include <linux/string.h> +#include <linux/err.h> +#include <linux/vmalloc.h> +#include <linux/security.h> +#include <linux/uio.h> +#include <linux/uaccess.h> +#include <keys/request_key_auth-type.h> +#include "internal.h" + +#define KEY_MAX_DESC_SIZE 4096 + +static const unsigned char keyrings_capabilities[2] = { + [0] = (KEYCTL_CAPS0_CAPABILITIES | + (IS_ENABLED(CONFIG_PERSISTENT_KEYRINGS) ? KEYCTL_CAPS0_PERSISTENT_KEYRINGS : 0) | + (IS_ENABLED(CONFIG_KEY_DH_OPERATIONS) ? KEYCTL_CAPS0_DIFFIE_HELLMAN : 0) | + (IS_ENABLED(CONFIG_ASYMMETRIC_KEY_TYPE) ? KEYCTL_CAPS0_PUBLIC_KEY : 0) | + (IS_ENABLED(CONFIG_BIG_KEYS) ? KEYCTL_CAPS0_BIG_KEY : 0) | + KEYCTL_CAPS0_INVALIDATE | + KEYCTL_CAPS0_RESTRICT_KEYRING | + KEYCTL_CAPS0_MOVE + ), + [1] = (KEYCTL_CAPS1_NS_KEYRING_NAME | + KEYCTL_CAPS1_NS_KEY_TAG | + (IS_ENABLED(CONFIG_KEY_NOTIFICATIONS) ? KEYCTL_CAPS1_NOTIFICATIONS : 0) + ), +}; + +static int key_get_type_from_user(char *type, + const char __user *_type, + unsigned len) +{ + int ret; + + ret = strncpy_from_user(type, _type, len); + if (ret < 0) + return ret; + if (ret == 0 || ret >= len) + return -EINVAL; + if (type[0] == '.') + return -EPERM; + type[len - 1] = '\0'; + return 0; +} + +/* + * Extract the description of a new key from userspace and either add it as a + * new key to the specified keyring or update a matching key in that keyring. + * + * If the description is NULL or an empty string, the key type is asked to + * generate one from the payload. + * + * The keyring must be writable so that we can attach the key to it. + * + * If successful, the new key's serial number is returned, otherwise an error + * code is returned. + */ +SYSCALL_DEFINE5(add_key, const char __user *, _type, + const char __user *, _description, + const void __user *, _payload, + size_t, plen, + key_serial_t, ringid) +{ + key_ref_t keyring_ref, key_ref; + char type[32], *description; + void *payload; + long ret; + + ret = -EINVAL; + if (plen > 1024 * 1024 - 1) + goto error; + + /* draw all the data into kernel space */ + ret = key_get_type_from_user(type, _type, sizeof(type)); + if (ret < 0) + goto error; + + description = NULL; + if (_description) { + description = strndup_user(_description, KEY_MAX_DESC_SIZE); + if (IS_ERR(description)) { + ret = PTR_ERR(description); + goto error; + } + if (!*description) { + kfree(description); + description = NULL; + } else if ((description[0] == '.') && + (strncmp(type, "keyring", 7) == 0)) { + ret = -EPERM; + goto error2; + } + } + + /* pull the payload in if one was supplied */ + payload = NULL; + + if (plen) { + ret = -ENOMEM; + payload = kvmalloc(plen, GFP_KERNEL); + if (!payload) + goto error2; + + ret = -EFAULT; + if (copy_from_user(payload, _payload, plen) != 0) + goto error3; + } + + /* find the target keyring (which must be writable) */ + keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE); + if (IS_ERR(keyring_ref)) { + ret = PTR_ERR(keyring_ref); + goto error3; + } + + /* create or update the requested key and add it to the target + * keyring */ + key_ref = key_create_or_update(keyring_ref, type, description, + payload, plen, KEY_PERM_UNDEF, + KEY_ALLOC_IN_QUOTA); + if (!IS_ERR(key_ref)) { + ret = key_ref_to_ptr(key_ref)->serial; + key_ref_put(key_ref); + } + else { + ret = PTR_ERR(key_ref); + } + + key_ref_put(keyring_ref); + error3: + kvfree_sensitive(payload, plen); + error2: + kfree(description); + error: + return ret; +} + +/* + * Search the process keyrings and keyring trees linked from those for a + * matching key. Keyrings must have appropriate Search permission to be + * searched. + * + * If a key is found, it will be attached to the destination keyring if there's + * one specified and the serial number of the key will be returned. + * + * If no key is found, /sbin/request-key will be invoked if _callout_info is + * non-NULL in an attempt to create a key. The _callout_info string will be + * passed to /sbin/request-key to aid with completing the request. If the + * _callout_info string is "" then it will be changed to "-". + */ +SYSCALL_DEFINE4(request_key, const char __user *, _type, + const char __user *, _description, + const char __user *, _callout_info, + key_serial_t, destringid) +{ + struct key_type *ktype; + struct key *key; + key_ref_t dest_ref; + size_t callout_len; + char type[32], *description, *callout_info; + long ret; + + /* pull the type into kernel space */ + ret = key_get_type_from_user(type, _type, sizeof(type)); + if (ret < 0) + goto error; + + /* pull the description into kernel space */ + description = strndup_user(_description, KEY_MAX_DESC_SIZE); + if (IS_ERR(description)) { + ret = PTR_ERR(description); + goto error; + } + + /* pull the callout info into kernel space */ + callout_info = NULL; + callout_len = 0; + if (_callout_info) { + callout_info = strndup_user(_callout_info, PAGE_SIZE); + if (IS_ERR(callout_info)) { + ret = PTR_ERR(callout_info); + goto error2; + } + callout_len = strlen(callout_info); + } + + /* get the destination keyring if specified */ + dest_ref = NULL; + if (destringid) { + dest_ref = lookup_user_key(destringid, KEY_LOOKUP_CREATE, + KEY_NEED_WRITE); + if (IS_ERR(dest_ref)) { + ret = PTR_ERR(dest_ref); + goto error3; + } + } + + /* find the key type */ + ktype = key_type_lookup(type); + if (IS_ERR(ktype)) { + ret = PTR_ERR(ktype); + goto error4; + } + + /* do the search */ + key = request_key_and_link(ktype, description, NULL, callout_info, + callout_len, NULL, key_ref_to_ptr(dest_ref), + KEY_ALLOC_IN_QUOTA); + if (IS_ERR(key)) { + ret = PTR_ERR(key); + goto error5; + } + + /* wait for the key to finish being constructed */ + ret = wait_for_key_construction(key, 1); + if (ret < 0) + goto error6; + + ret = key->serial; + +error6: + key_put(key); +error5: + key_type_put(ktype); +error4: + key_ref_put(dest_ref); +error3: + kfree(callout_info); +error2: + kfree(description); +error: + return ret; +} + +/* + * Get the ID of the specified process keyring. + * + * The requested keyring must have search permission to be found. + * + * If successful, the ID of the requested keyring will be returned. + */ +long keyctl_get_keyring_ID(key_serial_t id, int create) +{ + key_ref_t key_ref; + unsigned long lflags; + long ret; + + lflags = create ? KEY_LOOKUP_CREATE : 0; + key_ref = lookup_user_key(id, lflags, KEY_NEED_SEARCH); + if (IS_ERR(key_ref)) { + ret = PTR_ERR(key_ref); + goto error; + } + + ret = key_ref_to_ptr(key_ref)->serial; + key_ref_put(key_ref); +error: + return ret; +} + +/* + * Join a (named) session keyring. + * + * Create and join an anonymous session keyring or join a named session + * keyring, creating it if necessary. A named session keyring must have Search + * permission for it to be joined. Session keyrings without this permit will + * be skipped over. It is not permitted for userspace to create or join + * keyrings whose name begin with a dot. + * + * If successful, the ID of the joined session keyring will be returned. + */ +long keyctl_join_session_keyring(const char __user *_name) +{ + char *name; + long ret; + + /* fetch the name from userspace */ + name = NULL; + if (_name) { + name = strndup_user(_name, KEY_MAX_DESC_SIZE); + if (IS_ERR(name)) { + ret = PTR_ERR(name); + goto error; + } + + ret = -EPERM; + if (name[0] == '.') + goto error_name; + } + + /* join the session */ + ret = join_session_keyring(name); +error_name: + kfree(name); +error: + return ret; +} + +/* + * Update a key's data payload from the given data. + * + * The key must grant the caller Write permission and the key type must support + * updating for this to work. A negative key can be positively instantiated + * with this call. + * + * If successful, 0 will be returned. If the key type does not support + * updating, then -EOPNOTSUPP will be returned. + */ +long keyctl_update_key(key_serial_t id, + const void __user *_payload, + size_t plen) +{ + key_ref_t key_ref; + void *payload; + long ret; + + ret = -EINVAL; + if (plen > PAGE_SIZE) + goto error; + + /* pull the payload in if one was supplied */ + payload = NULL; + if (plen) { + ret = -ENOMEM; + payload = kvmalloc(plen, GFP_KERNEL); + if (!payload) + goto error; + + ret = -EFAULT; + if (copy_from_user(payload, _payload, plen) != 0) + goto error2; + } + + /* find the target key (which must be writable) */ + key_ref = lookup_user_key(id, 0, KEY_NEED_WRITE); + if (IS_ERR(key_ref)) { + ret = PTR_ERR(key_ref); + goto error2; + } + + /* update the key */ + ret = key_update(key_ref, payload, plen); + + key_ref_put(key_ref); +error2: + kvfree_sensitive(payload, plen); +error: + return ret; +} + +/* + * Revoke a key. + * + * The key must be grant the caller Write or Setattr permission for this to + * work. The key type should give up its quota claim when revoked. The key + * and any links to the key will be automatically garbage collected after a + * certain amount of time (/proc/sys/kernel/keys/gc_delay). + * + * Keys with KEY_FLAG_KEEP set should not be revoked. + * + * If successful, 0 is returned. + */ +long keyctl_revoke_key(key_serial_t id) +{ + key_ref_t key_ref; + struct key *key; + long ret; + + key_ref = lookup_user_key(id, 0, KEY_NEED_WRITE); + if (IS_ERR(key_ref)) { + ret = PTR_ERR(key_ref); + if (ret != -EACCES) + goto error; + key_ref = lookup_user_key(id, 0, KEY_NEED_SETATTR); + if (IS_ERR(key_ref)) { + ret = PTR_ERR(key_ref); + goto error; + } + } + + key = key_ref_to_ptr(key_ref); + ret = 0; + if (test_bit(KEY_FLAG_KEEP, &key->flags)) + ret = -EPERM; + else + key_revoke(key); + + key_ref_put(key_ref); +error: + return ret; +} + +/* + * Invalidate a key. + * + * The key must be grant the caller Invalidate permission for this to work. + * The key and any links to the key will be automatically garbage collected + * immediately. + * + * Keys with KEY_FLAG_KEEP set should not be invalidated. + * + * If successful, 0 is returned. + */ +long keyctl_invalidate_key(key_serial_t id) +{ + key_ref_t key_ref; + struct key *key; + long ret; + + kenter("%d", id); + + key_ref = lookup_user_key(id, 0, KEY_NEED_SEARCH); + if (IS_ERR(key_ref)) { + ret = PTR_ERR(key_ref); + + /* Root is permitted to invalidate certain special keys */ + if (capable(CAP_SYS_ADMIN)) { + key_ref = lookup_user_key(id, 0, KEY_SYSADMIN_OVERRIDE); + if (IS_ERR(key_ref)) + goto error; + if (test_bit(KEY_FLAG_ROOT_CAN_INVAL, + &key_ref_to_ptr(key_ref)->flags)) + goto invalidate; + goto error_put; + } + + goto error; + } + +invalidate: + key = key_ref_to_ptr(key_ref); + ret = 0; + if (test_bit(KEY_FLAG_KEEP, &key->flags)) + ret = -EPERM; + else + key_invalidate(key); +error_put: + key_ref_put(key_ref); +error: + kleave(" = %ld", ret); + return ret; +} + +/* + * Clear the specified keyring, creating an empty process keyring if one of the + * special keyring IDs is used. + * + * The keyring must grant the caller Write permission and not have + * KEY_FLAG_KEEP set for this to work. If successful, 0 will be returned. + */ +long keyctl_keyring_clear(key_serial_t ringid) +{ + key_ref_t keyring_ref; + struct key *keyring; + long ret; + + keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE); + if (IS_ERR(keyring_ref)) { + ret = PTR_ERR(keyring_ref); + + /* Root is permitted to invalidate certain special keyrings */ + if (capable(CAP_SYS_ADMIN)) { + keyring_ref = lookup_user_key(ringid, 0, + KEY_SYSADMIN_OVERRIDE); + if (IS_ERR(keyring_ref)) + goto error; + if (test_bit(KEY_FLAG_ROOT_CAN_CLEAR, + &key_ref_to_ptr(keyring_ref)->flags)) + goto clear; + goto error_put; + } + + goto error; + } + +clear: + keyring = key_ref_to_ptr(keyring_ref); + if (test_bit(KEY_FLAG_KEEP, &keyring->flags)) + ret = -EPERM; + else + ret = keyring_clear(keyring); +error_put: + key_ref_put(keyring_ref); +error: + return ret; +} + +/* + * Create a link from a keyring to a key if there's no matching key in the + * keyring, otherwise replace the link to the matching key with a link to the + * new key. + * + * The key must grant the caller Link permission and the keyring must grant + * the caller Write permission. Furthermore, if an additional link is created, + * the keyring's quota will be extended. + * + * If successful, 0 will be returned. + */ +long keyctl_keyring_link(key_serial_t id, key_serial_t ringid) +{ + key_ref_t keyring_ref, key_ref; + long ret; + + keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE); + if (IS_ERR(keyring_ref)) { + ret = PTR_ERR(keyring_ref); + goto error; + } + + key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE, KEY_NEED_LINK); + if (IS_ERR(key_ref)) { + ret = PTR_ERR(key_ref); + goto error2; + } + + ret = key_link(key_ref_to_ptr(keyring_ref), key_ref_to_ptr(key_ref)); + + key_ref_put(key_ref); +error2: + key_ref_put(keyring_ref); +error: + return ret; +} + +/* + * Unlink a key from a keyring. + * + * The keyring must grant the caller Write permission for this to work; the key + * itself need not grant the caller anything. If the last link to a key is + * removed then that key will be scheduled for destruction. + * + * Keys or keyrings with KEY_FLAG_KEEP set should not be unlinked. + * + * If successful, 0 will be returned. + */ +long keyctl_keyring_unlink(key_serial_t id, key_serial_t ringid) +{ + key_ref_t keyring_ref, key_ref; + struct key *keyring, *key; + long ret; + + keyring_ref = lookup_user_key(ringid, 0, KEY_NEED_WRITE); + if (IS_ERR(keyring_ref)) { + ret = PTR_ERR(keyring_ref); + goto error; + } + + key_ref = lookup_user_key(id, KEY_LOOKUP_PARTIAL, KEY_NEED_UNLINK); + if (IS_ERR(key_ref)) { + ret = PTR_ERR(key_ref); + goto error2; + } + + keyring = key_ref_to_ptr(keyring_ref); + key = key_ref_to_ptr(key_ref); + if (test_bit(KEY_FLAG_KEEP, &keyring->flags) && + test_bit(KEY_FLAG_KEEP, &key->flags)) + ret = -EPERM; + else + ret = key_unlink(keyring, key); + + key_ref_put(key_ref); +error2: + key_ref_put(keyring_ref); +error: + return ret; +} + +/* + * Move a link to a key from one keyring to another, displacing any matching + * key from the destination keyring. + * + * The key must grant the caller Link permission and both keyrings must grant + * the caller Write permission. There must also be a link in the from keyring + * to the key. If both keyrings are the same, nothing is done. + * + * If successful, 0 will be returned. + */ +long keyctl_keyring_move(key_serial_t id, key_serial_t from_ringid, + key_serial_t to_ringid, unsigned int flags) +{ + key_ref_t key_ref, from_ref, to_ref; + long ret; + + if (flags & ~KEYCTL_MOVE_EXCL) + return -EINVAL; + + key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE, KEY_NEED_LINK); + if (IS_ERR(key_ref)) + return PTR_ERR(key_ref); + + from_ref = lookup_user_key(from_ringid, 0, KEY_NEED_WRITE); + if (IS_ERR(from_ref)) { + ret = PTR_ERR(from_ref); + goto error2; + } + + to_ref = lookup_user_key(to_ringid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE); + if (IS_ERR(to_ref)) { + ret = PTR_ERR(to_ref); + goto error3; + } + + ret = key_move(key_ref_to_ptr(key_ref), key_ref_to_ptr(from_ref), + key_ref_to_ptr(to_ref), flags); + + key_ref_put(to_ref); +error3: + key_ref_put(from_ref); +error2: + key_ref_put(key_ref); + return ret; +} + +/* + * Return a description of a key to userspace. + * + * The key must grant the caller View permission for this to work. + * + * If there's a buffer, we place up to buflen bytes of data into it formatted + * in the following way: + * + * type;uid;gid;perm;description<NUL> + * + * If successful, we return the amount of description available, irrespective + * of how much we may have copied into the buffer. + */ +long keyctl_describe_key(key_serial_t keyid, + char __user *buffer, + size_t buflen) +{ + struct key *key, *instkey; + key_ref_t key_ref; + char *infobuf; + long ret; + int desclen, infolen; + + key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, KEY_NEED_VIEW); + if (IS_ERR(key_ref)) { + /* viewing a key under construction is permitted if we have the + * authorisation token handy */ + if (PTR_ERR(key_ref) == -EACCES) { + instkey = key_get_instantiation_authkey(keyid); + if (!IS_ERR(instkey)) { + key_put(instkey); + key_ref = lookup_user_key(keyid, + KEY_LOOKUP_PARTIAL, + KEY_AUTHTOKEN_OVERRIDE); + if (!IS_ERR(key_ref)) + goto okay; + } + } + + ret = PTR_ERR(key_ref); + goto error; + } + +okay: + key = key_ref_to_ptr(key_ref); + desclen = strlen(key->description); + + /* calculate how much information we're going to return */ + ret = -ENOMEM; + infobuf = kasprintf(GFP_KERNEL, + "%s;%d;%d;%08x;", + key->type->name, + from_kuid_munged(current_user_ns(), key->uid), + from_kgid_munged(current_user_ns(), key->gid), + key->perm); + if (!infobuf) + goto error2; + infolen = strlen(infobuf); + ret = infolen + desclen + 1; + + /* consider returning the data */ + if (buffer && buflen >= ret) { + if (copy_to_user(buffer, infobuf, infolen) != 0 || + copy_to_user(buffer + infolen, key->description, + desclen + 1) != 0) + ret = -EFAULT; + } + + kfree(infobuf); +error2: + key_ref_put(key_ref); +error: + return ret; +} + +/* + * Search the specified keyring and any keyrings it links to for a matching + * key. Only keyrings that grant the caller Search permission will be searched + * (this includes the starting keyring). Only keys with Search permission can + * be found. + * + * If successful, the found key will be linked to the destination keyring if + * supplied and the key has Link permission, and the found key ID will be + * returned. + */ +long keyctl_keyring_search(key_serial_t ringid, + const char __user *_type, + const char __user *_description, + key_serial_t destringid) +{ + struct key_type *ktype; + key_ref_t keyring_ref, key_ref, dest_ref; + char type[32], *description; + long ret; + + /* pull the type and description into kernel space */ + ret = key_get_type_from_user(type, _type, sizeof(type)); + if (ret < 0) + goto error; + + description = strndup_user(_description, KEY_MAX_DESC_SIZE); + if (IS_ERR(description)) { + ret = PTR_ERR(description); + goto error; + } + + /* get the keyring at which to begin the search */ + keyring_ref = lookup_user_key(ringid, 0, KEY_NEED_SEARCH); + if (IS_ERR(keyring_ref)) { + ret = PTR_ERR(keyring_ref); + goto error2; + } + + /* get the destination keyring if specified */ + dest_ref = NULL; + if (destringid) { + dest_ref = lookup_user_key(destringid, KEY_LOOKUP_CREATE, + KEY_NEED_WRITE); + if (IS_ERR(dest_ref)) { + ret = PTR_ERR(dest_ref); + goto error3; + } + } + + /* find the key type */ + ktype = key_type_lookup(type); + if (IS_ERR(ktype)) { + ret = PTR_ERR(ktype); + goto error4; + } + + /* do the search */ + key_ref = keyring_search(keyring_ref, ktype, description, true); + if (IS_ERR(key_ref)) { + ret = PTR_ERR(key_ref); + + /* treat lack or presence of a negative key the same */ + if (ret == -EAGAIN) + ret = -ENOKEY; + goto error5; + } + + /* link the resulting key to the destination keyring if we can */ + if (dest_ref) { + ret = key_permission(key_ref, KEY_NEED_LINK); + if (ret < 0) + goto error6; + + ret = key_link(key_ref_to_ptr(dest_ref), key_ref_to_ptr(key_ref)); + if (ret < 0) + goto error6; + } + + ret = key_ref_to_ptr(key_ref)->serial; + +error6: + key_ref_put(key_ref); +error5: + key_type_put(ktype); +error4: + key_ref_put(dest_ref); +error3: + key_ref_put(keyring_ref); +error2: + kfree(description); +error: + return ret; +} + +/* + * Call the read method + */ +static long __keyctl_read_key(struct key *key, char *buffer, size_t buflen) +{ + long ret; + + down_read(&key->sem); + ret = key_validate(key); + if (ret == 0) + ret = key->type->read(key, buffer, buflen); + up_read(&key->sem); + return ret; +} + +/* + * Read a key's payload. + * + * The key must either grant the caller Read permission, or it must grant the + * caller Search permission when searched for from the process keyrings. + * + * If successful, we place up to buflen bytes of data into the buffer, if one + * is provided, and return the amount of data that is available in the key, + * irrespective of how much we copied into the buffer. + */ +long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen) +{ + struct key *key; + key_ref_t key_ref; + long ret; + char *key_data = NULL; + size_t key_data_len; + + /* find the key first */ + key_ref = lookup_user_key(keyid, 0, KEY_DEFER_PERM_CHECK); + if (IS_ERR(key_ref)) { + ret = -ENOKEY; + goto out; + } + + key = key_ref_to_ptr(key_ref); + + ret = key_read_state(key); + if (ret < 0) + goto key_put_out; /* Negatively instantiated */ + + /* see if we can read it directly */ + ret = key_permission(key_ref, KEY_NEED_READ); + if (ret == 0) + goto can_read_key; + if (ret != -EACCES) + goto key_put_out; + + /* we can't; see if it's searchable from this process's keyrings + * - we automatically take account of the fact that it may be + * dangling off an instantiation key + */ + if (!is_key_possessed(key_ref)) { + ret = -EACCES; + goto key_put_out; + } + + /* the key is probably readable - now try to read it */ +can_read_key: + if (!key->type->read) { + ret = -EOPNOTSUPP; + goto key_put_out; + } + + if (!buffer || !buflen) { + /* Get the key length from the read method */ + ret = __keyctl_read_key(key, NULL, 0); + goto key_put_out; + } + + /* + * Read the data with the semaphore held (since we might sleep) + * to protect against the key being updated or revoked. + * + * Allocating a temporary buffer to hold the keys before + * transferring them to user buffer to avoid potential + * deadlock involving page fault and mmap_lock. + * + * key_data_len = (buflen <= PAGE_SIZE) + * ? buflen : actual length of key data + * + * This prevents allocating arbitrary large buffer which can + * be much larger than the actual key length. In the latter case, + * at least 2 passes of this loop is required. + */ + key_data_len = (buflen <= PAGE_SIZE) ? buflen : 0; + for (;;) { + if (key_data_len) { + key_data = kvmalloc(key_data_len, GFP_KERNEL); + if (!key_data) { + ret = -ENOMEM; + goto key_put_out; + } + } + + ret = __keyctl_read_key(key, key_data, key_data_len); + + /* + * Read methods will just return the required length without + * any copying if the provided length isn't large enough. + */ + if (ret <= 0 || ret > buflen) + break; + + /* + * The key may change (unlikely) in between 2 consecutive + * __keyctl_read_key() calls. In this case, we reallocate + * a larger buffer and redo the key read when + * key_data_len < ret <= buflen. + */ + if (ret > key_data_len) { + if (unlikely(key_data)) + kvfree_sensitive(key_data, key_data_len); + key_data_len = ret; + continue; /* Allocate buffer */ + } + + if (copy_to_user(buffer, key_data, ret)) + ret = -EFAULT; + break; + } + kvfree_sensitive(key_data, key_data_len); + +key_put_out: + key_put(key); +out: + return ret; +} + +/* + * Change the ownership of a key + * + * The key must grant the caller Setattr permission for this to work, though + * the key need not be fully instantiated yet. For the UID to be changed, or + * for the GID to be changed to a group the caller is not a member of, the + * caller must have sysadmin capability. If either uid or gid is -1 then that + * attribute is not changed. + * + * If the UID is to be changed, the new user must have sufficient quota to + * accept the key. The quota deduction will be removed from the old user to + * the new user should the attribute be changed. + * + * If successful, 0 will be returned. + */ +long keyctl_chown_key(key_serial_t id, uid_t user, gid_t group) +{ + struct key_user *newowner, *zapowner = NULL; + struct key *key; + key_ref_t key_ref; + long ret; + kuid_t uid; + kgid_t gid; + + uid = make_kuid(current_user_ns(), user); + gid = make_kgid(current_user_ns(), group); + ret = -EINVAL; + if ((user != (uid_t) -1) && !uid_valid(uid)) + goto error; + if ((group != (gid_t) -1) && !gid_valid(gid)) + goto error; + + ret = 0; + if (user == (uid_t) -1 && group == (gid_t) -1) + goto error; + + key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL, + KEY_NEED_SETATTR); + if (IS_ERR(key_ref)) { + ret = PTR_ERR(key_ref); + goto error; + } + + key = key_ref_to_ptr(key_ref); + + /* make the changes with the locks held to prevent chown/chown races */ + ret = -EACCES; + down_write(&key->sem); + + { + bool is_privileged_op = false; + + /* only the sysadmin can chown a key to some other UID */ + if (user != (uid_t) -1 && !uid_eq(key->uid, uid)) + is_privileged_op = true; + + /* only the sysadmin can set the key's GID to a group other + * than one of those that the current process subscribes to */ + if (group != (gid_t) -1 && !gid_eq(gid, key->gid) && !in_group_p(gid)) + is_privileged_op = true; + + if (is_privileged_op && !capable(CAP_SYS_ADMIN)) + goto error_put; + } + + /* change the UID */ + if (user != (uid_t) -1 && !uid_eq(uid, key->uid)) { + ret = -ENOMEM; + newowner = key_user_lookup(uid); + if (!newowner) + goto error_put; + + /* transfer the quota burden to the new user */ + if (test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { + unsigned maxkeys = uid_eq(uid, GLOBAL_ROOT_UID) ? + key_quota_root_maxkeys : key_quota_maxkeys; + unsigned maxbytes = uid_eq(uid, GLOBAL_ROOT_UID) ? + key_quota_root_maxbytes : key_quota_maxbytes; + + spin_lock(&newowner->lock); + if (newowner->qnkeys + 1 > maxkeys || + newowner->qnbytes + key->quotalen > maxbytes || + newowner->qnbytes + key->quotalen < + newowner->qnbytes) + goto quota_overrun; + + newowner->qnkeys++; + newowner->qnbytes += key->quotalen; + spin_unlock(&newowner->lock); + + spin_lock(&key->user->lock); + key->user->qnkeys--; + key->user->qnbytes -= key->quotalen; + spin_unlock(&key->user->lock); + } + + atomic_dec(&key->user->nkeys); + atomic_inc(&newowner->nkeys); + + if (key->state != KEY_IS_UNINSTANTIATED) { + atomic_dec(&key->user->nikeys); + atomic_inc(&newowner->nikeys); + } + + zapowner = key->user; + key->user = newowner; + key->uid = uid; + } + + /* change the GID */ + if (group != (gid_t) -1) + key->gid = gid; + + notify_key(key, NOTIFY_KEY_SETATTR, 0); + ret = 0; + +error_put: + up_write(&key->sem); + key_put(key); + if (zapowner) + key_user_put(zapowner); +error: + return ret; + +quota_overrun: + spin_unlock(&newowner->lock); + zapowner = newowner; + ret = -EDQUOT; + goto error_put; +} + +/* + * Change the permission mask on a key. + * + * The key must grant the caller Setattr permission for this to work, though + * the key need not be fully instantiated yet. If the caller does not have + * sysadmin capability, it may only change the permission on keys that it owns. + */ +long keyctl_setperm_key(key_serial_t id, key_perm_t perm) +{ + struct key *key; + key_ref_t key_ref; + long ret; + + ret = -EINVAL; + if (perm & ~(KEY_POS_ALL | KEY_USR_ALL | KEY_GRP_ALL | KEY_OTH_ALL)) + goto error; + + key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL, + KEY_NEED_SETATTR); + if (IS_ERR(key_ref)) { + ret = PTR_ERR(key_ref); + goto error; + } + + key = key_ref_to_ptr(key_ref); + + /* make the changes with the locks held to prevent chown/chmod races */ + ret = -EACCES; + down_write(&key->sem); + + /* if we're not the sysadmin, we can only change a key that we own */ + if (uid_eq(key->uid, current_fsuid()) || capable(CAP_SYS_ADMIN)) { + key->perm = perm; + notify_key(key, NOTIFY_KEY_SETATTR, 0); + ret = 0; + } + + up_write(&key->sem); + key_put(key); +error: + return ret; +} + +/* + * Get the destination keyring for instantiation and check that the caller has + * Write permission on it. + */ +static long get_instantiation_keyring(key_serial_t ringid, + struct request_key_auth *rka, + struct key **_dest_keyring) +{ + key_ref_t dkref; + + *_dest_keyring = NULL; + + /* just return a NULL pointer if we weren't asked to make a link */ + if (ringid == 0) + return 0; + + /* if a specific keyring is nominated by ID, then use that */ + if (ringid > 0) { + dkref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE); + if (IS_ERR(dkref)) + return PTR_ERR(dkref); + *_dest_keyring = key_ref_to_ptr(dkref); + return 0; + } + + if (ringid == KEY_SPEC_REQKEY_AUTH_KEY) + return -EINVAL; + + /* otherwise specify the destination keyring recorded in the + * authorisation key (any KEY_SPEC_*_KEYRING) */ + if (ringid >= KEY_SPEC_REQUESTOR_KEYRING) { + *_dest_keyring = key_get(rka->dest_keyring); + return 0; + } + + return -ENOKEY; +} + +/* + * Change the request_key authorisation key on the current process. + */ +static int keyctl_change_reqkey_auth(struct key *key) +{ + struct cred *new; + + new = prepare_creds(); + if (!new) + return -ENOMEM; + + key_put(new->request_key_auth); + new->request_key_auth = key_get(key); + + return commit_creds(new); +} + +/* + * Instantiate a key with the specified payload and link the key into the + * destination keyring if one is given. + * + * The caller must have the appropriate instantiation permit set for this to + * work (see keyctl_assume_authority). No other permissions are required. + * + * If successful, 0 will be returned. + */ +static long keyctl_instantiate_key_common(key_serial_t id, + struct iov_iter *from, + key_serial_t ringid) +{ + const struct cred *cred = current_cred(); + struct request_key_auth *rka; + struct key *instkey, *dest_keyring; + size_t plen = from ? iov_iter_count(from) : 0; + void *payload; + long ret; + + kenter("%d,,%zu,%d", id, plen, ringid); + + if (!plen) + from = NULL; + + ret = -EINVAL; + if (plen > 1024 * 1024 - 1) + goto error; + + /* the appropriate instantiation authorisation key must have been + * assumed before calling this */ + ret = -EPERM; + instkey = cred->request_key_auth; + if (!instkey) + goto error; + + rka = instkey->payload.data[0]; + if (rka->target_key->serial != id) + goto error; + + /* pull the payload in if one was supplied */ + payload = NULL; + + if (from) { + ret = -ENOMEM; + payload = kvmalloc(plen, GFP_KERNEL); + if (!payload) + goto error; + + ret = -EFAULT; + if (!copy_from_iter_full(payload, plen, from)) + goto error2; + } + + /* find the destination keyring amongst those belonging to the + * requesting task */ + ret = get_instantiation_keyring(ringid, rka, &dest_keyring); + if (ret < 0) + goto error2; + + /* instantiate the key and link it into a keyring */ + ret = key_instantiate_and_link(rka->target_key, payload, plen, + dest_keyring, instkey); + + key_put(dest_keyring); + + /* discard the assumed authority if it's just been disabled by + * instantiation of the key */ + if (ret == 0) + keyctl_change_reqkey_auth(NULL); + +error2: + kvfree_sensitive(payload, plen); +error: + return ret; +} + +/* + * Instantiate a key with the specified payload and link the key into the + * destination keyring if one is given. + * + * The caller must have the appropriate instantiation permit set for this to + * work (see keyctl_assume_authority). No other permissions are required. + * + * If successful, 0 will be returned. + */ +long keyctl_instantiate_key(key_serial_t id, + const void __user *_payload, + size_t plen, + key_serial_t ringid) +{ + if (_payload && plen) { + struct iovec iov; + struct iov_iter from; + int ret; + + ret = import_single_range(ITER_SOURCE, (void __user *)_payload, plen, + &iov, &from); + if (unlikely(ret)) + return ret; + + return keyctl_instantiate_key_common(id, &from, ringid); + } + + return keyctl_instantiate_key_common(id, NULL, ringid); +} + +/* + * Instantiate a key with the specified multipart payload and link the key into + * the destination keyring if one is given. + * + * The caller must have the appropriate instantiation permit set for this to + * work (see keyctl_assume_authority). No other permissions are required. + * + * If successful, 0 will be returned. + */ +long keyctl_instantiate_key_iov(key_serial_t id, + const struct iovec __user *_payload_iov, + unsigned ioc, + key_serial_t ringid) +{ + struct iovec iovstack[UIO_FASTIOV], *iov = iovstack; + struct iov_iter from; + long ret; + + if (!_payload_iov) + ioc = 0; + + ret = import_iovec(ITER_SOURCE, _payload_iov, ioc, + ARRAY_SIZE(iovstack), &iov, &from); + if (ret < 0) + return ret; + ret = keyctl_instantiate_key_common(id, &from, ringid); + kfree(iov); + return ret; +} + +/* + * Negatively instantiate the key with the given timeout (in seconds) and link + * the key into the destination keyring if one is given. + * + * The caller must have the appropriate instantiation permit set for this to + * work (see keyctl_assume_authority). No other permissions are required. + * + * The key and any links to the key will be automatically garbage collected + * after the timeout expires. + * + * Negative keys are used to rate limit repeated request_key() calls by causing + * them to return -ENOKEY until the negative key expires. + * + * If successful, 0 will be returned. + */ +long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid) +{ + return keyctl_reject_key(id, timeout, ENOKEY, ringid); +} + +/* + * Negatively instantiate the key with the given timeout (in seconds) and error + * code and link the key into the destination keyring if one is given. + * + * The caller must have the appropriate instantiation permit set for this to + * work (see keyctl_assume_authority). No other permissions are required. + * + * The key and any links to the key will be automatically garbage collected + * after the timeout expires. + * + * Negative keys are used to rate limit repeated request_key() calls by causing + * them to return the specified error code until the negative key expires. + * + * If successful, 0 will be returned. + */ +long keyctl_reject_key(key_serial_t id, unsigned timeout, unsigned error, + key_serial_t ringid) +{ + const struct cred *cred = current_cred(); + struct request_key_auth *rka; + struct key *instkey, *dest_keyring; + long ret; + + kenter("%d,%u,%u,%d", id, timeout, error, ringid); + + /* must be a valid error code and mustn't be a kernel special */ + if (error <= 0 || + error >= MAX_ERRNO || + error == ERESTARTSYS || + error == ERESTARTNOINTR || + error == ERESTARTNOHAND || + error == ERESTART_RESTARTBLOCK) + return -EINVAL; + + /* the appropriate instantiation authorisation key must have been + * assumed before calling this */ + ret = -EPERM; + instkey = cred->request_key_auth; + if (!instkey) + goto error; + + rka = instkey->payload.data[0]; + if (rka->target_key->serial != id) + goto error; + + /* find the destination keyring if present (which must also be + * writable) */ + ret = get_instantiation_keyring(ringid, rka, &dest_keyring); + if (ret < 0) + goto error; + + /* instantiate the key and link it into a keyring */ + ret = key_reject_and_link(rka->target_key, timeout, error, + dest_keyring, instkey); + + key_put(dest_keyring); + + /* discard the assumed authority if it's just been disabled by + * instantiation of the key */ + if (ret == 0) + keyctl_change_reqkey_auth(NULL); + +error: + return ret; +} + +/* + * Read or set the default keyring in which request_key() will cache keys and + * return the old setting. + * + * If a thread or process keyring is specified then it will be created if it + * doesn't yet exist. The old setting will be returned if successful. + */ +long keyctl_set_reqkey_keyring(int reqkey_defl) +{ + struct cred *new; + int ret, old_setting; + + old_setting = current_cred_xxx(jit_keyring); + + if (reqkey_defl == KEY_REQKEY_DEFL_NO_CHANGE) + return old_setting; + + new = prepare_creds(); + if (!new) + return -ENOMEM; + + switch (reqkey_defl) { + case KEY_REQKEY_DEFL_THREAD_KEYRING: + ret = install_thread_keyring_to_cred(new); + if (ret < 0) + goto error; + goto set; + + case KEY_REQKEY_DEFL_PROCESS_KEYRING: + ret = install_process_keyring_to_cred(new); + if (ret < 0) + goto error; + goto set; + + case KEY_REQKEY_DEFL_DEFAULT: + case KEY_REQKEY_DEFL_SESSION_KEYRING: + case KEY_REQKEY_DEFL_USER_KEYRING: + case KEY_REQKEY_DEFL_USER_SESSION_KEYRING: + case KEY_REQKEY_DEFL_REQUESTOR_KEYRING: + goto set; + + case KEY_REQKEY_DEFL_NO_CHANGE: + case KEY_REQKEY_DEFL_GROUP_KEYRING: + default: + ret = -EINVAL; + goto error; + } + +set: + new->jit_keyring = reqkey_defl; + commit_creds(new); + return old_setting; +error: + abort_creds(new); + return ret; +} + +/* + * Set or clear the timeout on a key. + * + * Either the key must grant the caller Setattr permission or else the caller + * must hold an instantiation authorisation token for the key. + * + * The timeout is either 0 to clear the timeout, or a number of seconds from + * the current time. The key and any links to the key will be automatically + * garbage collected after the timeout expires. + * + * Keys with KEY_FLAG_KEEP set should not be timed out. + * + * If successful, 0 is returned. + */ +long keyctl_set_timeout(key_serial_t id, unsigned timeout) +{ + struct key *key, *instkey; + key_ref_t key_ref; + long ret; + + key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL, + KEY_NEED_SETATTR); + if (IS_ERR(key_ref)) { + /* setting the timeout on a key under construction is permitted + * if we have the authorisation token handy */ + if (PTR_ERR(key_ref) == -EACCES) { + instkey = key_get_instantiation_authkey(id); + if (!IS_ERR(instkey)) { + key_put(instkey); + key_ref = lookup_user_key(id, + KEY_LOOKUP_PARTIAL, + KEY_AUTHTOKEN_OVERRIDE); + if (!IS_ERR(key_ref)) + goto okay; + } + } + + ret = PTR_ERR(key_ref); + goto error; + } + +okay: + key = key_ref_to_ptr(key_ref); + ret = 0; + if (test_bit(KEY_FLAG_KEEP, &key->flags)) { + ret = -EPERM; + } else { + key_set_timeout(key, timeout); + notify_key(key, NOTIFY_KEY_SETATTR, 0); + } + key_put(key); + +error: + return ret; +} + +/* + * Assume (or clear) the authority to instantiate the specified key. + * + * This sets the authoritative token currently in force for key instantiation. + * This must be done for a key to be instantiated. It has the effect of making + * available all the keys from the caller of the request_key() that created a + * key to request_key() calls made by the caller of this function. + * + * The caller must have the instantiation key in their process keyrings with a + * Search permission grant available to the caller. + * + * If the ID given is 0, then the setting will be cleared and 0 returned. + * + * If the ID given has a matching an authorisation key, then that key will be + * set and its ID will be returned. The authorisation key can be read to get + * the callout information passed to request_key(). + */ +long keyctl_assume_authority(key_serial_t id) +{ + struct key *authkey; + long ret; + + /* special key IDs aren't permitted */ + ret = -EINVAL; + if (id < 0) + goto error; + + /* we divest ourselves of authority if given an ID of 0 */ + if (id == 0) { + ret = keyctl_change_reqkey_auth(NULL); + goto error; + } + + /* attempt to assume the authority temporarily granted to us whilst we + * instantiate the specified key + * - the authorisation key must be in the current task's keyrings + * somewhere + */ + authkey = key_get_instantiation_authkey(id); + if (IS_ERR(authkey)) { + ret = PTR_ERR(authkey); + goto error; + } + + ret = keyctl_change_reqkey_auth(authkey); + if (ret == 0) + ret = authkey->serial; + key_put(authkey); +error: + return ret; +} + +/* + * Get a key's the LSM security label. + * + * The key must grant the caller View permission for this to work. + * + * If there's a buffer, then up to buflen bytes of data will be placed into it. + * + * If successful, the amount of information available will be returned, + * irrespective of how much was copied (including the terminal NUL). + */ +long keyctl_get_security(key_serial_t keyid, + char __user *buffer, + size_t buflen) +{ + struct key *key, *instkey; + key_ref_t key_ref; + char *context; + long ret; + + key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, KEY_NEED_VIEW); + if (IS_ERR(key_ref)) { + if (PTR_ERR(key_ref) != -EACCES) + return PTR_ERR(key_ref); + + /* viewing a key under construction is also permitted if we + * have the authorisation token handy */ + instkey = key_get_instantiation_authkey(keyid); + if (IS_ERR(instkey)) + return PTR_ERR(instkey); + key_put(instkey); + + key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, + KEY_AUTHTOKEN_OVERRIDE); + if (IS_ERR(key_ref)) + return PTR_ERR(key_ref); + } + + key = key_ref_to_ptr(key_ref); + ret = security_key_getsecurity(key, &context); + if (ret == 0) { + /* if no information was returned, give userspace an empty + * string */ + ret = 1; + if (buffer && buflen > 0 && + copy_to_user(buffer, "", 1) != 0) + ret = -EFAULT; + } else if (ret > 0) { + /* return as much data as there's room for */ + if (buffer && buflen > 0) { + if (buflen > ret) + buflen = ret; + + if (copy_to_user(buffer, context, buflen) != 0) + ret = -EFAULT; + } + + kfree(context); + } + + key_ref_put(key_ref); + return ret; +} + +/* + * Attempt to install the calling process's session keyring on the process's + * parent process. + * + * The keyring must exist and must grant the caller LINK permission, and the + * parent process must be single-threaded and must have the same effective + * ownership as this process and mustn't be SUID/SGID. + * + * The keyring will be emplaced on the parent when it next resumes userspace. + * + * If successful, 0 will be returned. + */ +long keyctl_session_to_parent(void) +{ + struct task_struct *me, *parent; + const struct cred *mycred, *pcred; + struct callback_head *newwork, *oldwork; + key_ref_t keyring_r; + struct cred *cred; + int ret; + + keyring_r = lookup_user_key(KEY_SPEC_SESSION_KEYRING, 0, KEY_NEED_LINK); + if (IS_ERR(keyring_r)) + return PTR_ERR(keyring_r); + + ret = -ENOMEM; + + /* our parent is going to need a new cred struct, a new tgcred struct + * and new security data, so we allocate them here to prevent ENOMEM in + * our parent */ + cred = cred_alloc_blank(); + if (!cred) + goto error_keyring; + newwork = &cred->rcu; + + cred->session_keyring = key_ref_to_ptr(keyring_r); + keyring_r = NULL; + init_task_work(newwork, key_change_session_keyring); + + me = current; + rcu_read_lock(); + write_lock_irq(&tasklist_lock); + + ret = -EPERM; + oldwork = NULL; + parent = rcu_dereference_protected(me->real_parent, + lockdep_is_held(&tasklist_lock)); + + /* the parent mustn't be init and mustn't be a kernel thread */ + if (parent->pid <= 1 || !parent->mm) + goto unlock; + + /* the parent must be single threaded */ + if (!thread_group_empty(parent)) + goto unlock; + + /* the parent and the child must have different session keyrings or + * there's no point */ + mycred = current_cred(); + pcred = __task_cred(parent); + if (mycred == pcred || + mycred->session_keyring == pcred->session_keyring) { + ret = 0; + goto unlock; + } + + /* the parent must have the same effective ownership and mustn't be + * SUID/SGID */ + if (!uid_eq(pcred->uid, mycred->euid) || + !uid_eq(pcred->euid, mycred->euid) || + !uid_eq(pcred->suid, mycred->euid) || + !gid_eq(pcred->gid, mycred->egid) || + !gid_eq(pcred->egid, mycred->egid) || + !gid_eq(pcred->sgid, mycred->egid)) + goto unlock; + + /* the keyrings must have the same UID */ + if ((pcred->session_keyring && + !uid_eq(pcred->session_keyring->uid, mycred->euid)) || + !uid_eq(mycred->session_keyring->uid, mycred->euid)) + goto unlock; + + /* cancel an already pending keyring replacement */ + oldwork = task_work_cancel(parent, key_change_session_keyring); + + /* the replacement session keyring is applied just prior to userspace + * restarting */ + ret = task_work_add(parent, newwork, TWA_RESUME); + if (!ret) + newwork = NULL; +unlock: + write_unlock_irq(&tasklist_lock); + rcu_read_unlock(); + if (oldwork) + put_cred(container_of(oldwork, struct cred, rcu)); + if (newwork) + put_cred(cred); + return ret; + +error_keyring: + key_ref_put(keyring_r); + return ret; +} + +/* + * Apply a restriction to a given keyring. + * + * The caller must have Setattr permission to change keyring restrictions. + * + * The requested type name may be a NULL pointer to reject all attempts + * to link to the keyring. In this case, _restriction must also be NULL. + * Otherwise, both _type and _restriction must be non-NULL. + * + * Returns 0 if successful. + */ +long keyctl_restrict_keyring(key_serial_t id, const char __user *_type, + const char __user *_restriction) +{ + key_ref_t key_ref; + char type[32]; + char *restriction = NULL; + long ret; + + key_ref = lookup_user_key(id, 0, KEY_NEED_SETATTR); + if (IS_ERR(key_ref)) + return PTR_ERR(key_ref); + + ret = -EINVAL; + if (_type) { + if (!_restriction) + goto error; + + ret = key_get_type_from_user(type, _type, sizeof(type)); + if (ret < 0) + goto error; + + restriction = strndup_user(_restriction, PAGE_SIZE); + if (IS_ERR(restriction)) { + ret = PTR_ERR(restriction); + goto error; + } + } else { + if (_restriction) + goto error; + } + + ret = keyring_restrict(key_ref, _type ? type : NULL, restriction); + kfree(restriction); +error: + key_ref_put(key_ref); + return ret; +} + +#ifdef CONFIG_KEY_NOTIFICATIONS +/* + * Watch for changes to a key. + * + * The caller must have View permission to watch a key or keyring. + */ +long keyctl_watch_key(key_serial_t id, int watch_queue_fd, int watch_id) +{ + struct watch_queue *wqueue; + struct watch_list *wlist = NULL; + struct watch *watch = NULL; + struct key *key; + key_ref_t key_ref; + long ret; + + if (watch_id < -1 || watch_id > 0xff) + return -EINVAL; + + key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE, KEY_NEED_VIEW); + if (IS_ERR(key_ref)) + return PTR_ERR(key_ref); + key = key_ref_to_ptr(key_ref); + + wqueue = get_watch_queue(watch_queue_fd); + if (IS_ERR(wqueue)) { + ret = PTR_ERR(wqueue); + goto err_key; + } + + if (watch_id >= 0) { + ret = -ENOMEM; + if (!key->watchers) { + wlist = kzalloc(sizeof(*wlist), GFP_KERNEL); + if (!wlist) + goto err_wqueue; + init_watch_list(wlist, NULL); + } + + watch = kzalloc(sizeof(*watch), GFP_KERNEL); + if (!watch) + goto err_wlist; + + init_watch(watch, wqueue); + watch->id = key->serial; + watch->info_id = (u32)watch_id << WATCH_INFO_ID__SHIFT; + + ret = security_watch_key(key); + if (ret < 0) + goto err_watch; + + down_write(&key->sem); + if (!key->watchers) { + key->watchers = wlist; + wlist = NULL; + } + + ret = add_watch_to_object(watch, key->watchers); + up_write(&key->sem); + + if (ret == 0) + watch = NULL; + } else { + ret = -EBADSLT; + if (key->watchers) { + down_write(&key->sem); + ret = remove_watch_from_object(key->watchers, + wqueue, key_serial(key), + false); + up_write(&key->sem); + } + } + +err_watch: + kfree(watch); +err_wlist: + kfree(wlist); +err_wqueue: + put_watch_queue(wqueue); +err_key: + key_put(key); + return ret; +} +#endif /* CONFIG_KEY_NOTIFICATIONS */ + +/* + * Get keyrings subsystem capabilities. + */ +long keyctl_capabilities(unsigned char __user *_buffer, size_t buflen) +{ + size_t size = buflen; + + if (size > 0) { + if (size > sizeof(keyrings_capabilities)) + size = sizeof(keyrings_capabilities); + if (copy_to_user(_buffer, keyrings_capabilities, size) != 0) + return -EFAULT; + if (size < buflen && + clear_user(_buffer + size, buflen - size) != 0) + return -EFAULT; + } + + return sizeof(keyrings_capabilities); +} + +/* + * The key control system call + */ +SYSCALL_DEFINE5(keyctl, int, option, unsigned long, arg2, unsigned long, arg3, + unsigned long, arg4, unsigned long, arg5) +{ + switch (option) { + case KEYCTL_GET_KEYRING_ID: + return keyctl_get_keyring_ID((key_serial_t) arg2, + (int) arg3); + + case KEYCTL_JOIN_SESSION_KEYRING: + return keyctl_join_session_keyring((const char __user *) arg2); + + case KEYCTL_UPDATE: + return keyctl_update_key((key_serial_t) arg2, + (const void __user *) arg3, + (size_t) arg4); + + case KEYCTL_REVOKE: + return keyctl_revoke_key((key_serial_t) arg2); + + case KEYCTL_DESCRIBE: + return keyctl_describe_key((key_serial_t) arg2, + (char __user *) arg3, + (unsigned) arg4); + + case KEYCTL_CLEAR: + return keyctl_keyring_clear((key_serial_t) arg2); + + case KEYCTL_LINK: + return keyctl_keyring_link((key_serial_t) arg2, + (key_serial_t) arg3); + + case KEYCTL_UNLINK: + return keyctl_keyring_unlink((key_serial_t) arg2, + (key_serial_t) arg3); + + case KEYCTL_SEARCH: + return keyctl_keyring_search((key_serial_t) arg2, + (const char __user *) arg3, + (const char __user *) arg4, + (key_serial_t) arg5); + + case KEYCTL_READ: + return keyctl_read_key((key_serial_t) arg2, + (char __user *) arg3, + (size_t) arg4); + + case KEYCTL_CHOWN: + return keyctl_chown_key((key_serial_t) arg2, + (uid_t) arg3, + (gid_t) arg4); + + case KEYCTL_SETPERM: + return keyctl_setperm_key((key_serial_t) arg2, + (key_perm_t) arg3); + + case KEYCTL_INSTANTIATE: + return keyctl_instantiate_key((key_serial_t) arg2, + (const void __user *) arg3, + (size_t) arg4, + (key_serial_t) arg5); + + case KEYCTL_NEGATE: + return keyctl_negate_key((key_serial_t) arg2, + (unsigned) arg3, + (key_serial_t) arg4); + + case KEYCTL_SET_REQKEY_KEYRING: + return keyctl_set_reqkey_keyring(arg2); + + case KEYCTL_SET_TIMEOUT: + return keyctl_set_timeout((key_serial_t) arg2, + (unsigned) arg3); + + case KEYCTL_ASSUME_AUTHORITY: + return keyctl_assume_authority((key_serial_t) arg2); + + case KEYCTL_GET_SECURITY: + return keyctl_get_security((key_serial_t) arg2, + (char __user *) arg3, + (size_t) arg4); + + case KEYCTL_SESSION_TO_PARENT: + return keyctl_session_to_parent(); + + case KEYCTL_REJECT: + return keyctl_reject_key((key_serial_t) arg2, + (unsigned) arg3, + (unsigned) arg4, + (key_serial_t) arg5); + + case KEYCTL_INSTANTIATE_IOV: + return keyctl_instantiate_key_iov( + (key_serial_t) arg2, + (const struct iovec __user *) arg3, + (unsigned) arg4, + (key_serial_t) arg5); + + case KEYCTL_INVALIDATE: + return keyctl_invalidate_key((key_serial_t) arg2); + + case KEYCTL_GET_PERSISTENT: + return keyctl_get_persistent((uid_t)arg2, (key_serial_t)arg3); + + case KEYCTL_DH_COMPUTE: + return keyctl_dh_compute((struct keyctl_dh_params __user *) arg2, + (char __user *) arg3, (size_t) arg4, + (struct keyctl_kdf_params __user *) arg5); + + case KEYCTL_RESTRICT_KEYRING: + return keyctl_restrict_keyring((key_serial_t) arg2, + (const char __user *) arg3, + (const char __user *) arg4); + + case KEYCTL_PKEY_QUERY: + if (arg3 != 0) + return -EINVAL; + return keyctl_pkey_query((key_serial_t)arg2, + (const char __user *)arg4, + (struct keyctl_pkey_query __user *)arg5); + + case KEYCTL_PKEY_ENCRYPT: + case KEYCTL_PKEY_DECRYPT: + case KEYCTL_PKEY_SIGN: + return keyctl_pkey_e_d_s( + option, + (const struct keyctl_pkey_params __user *)arg2, + (const char __user *)arg3, + (const void __user *)arg4, + (void __user *)arg5); + + case KEYCTL_PKEY_VERIFY: + return keyctl_pkey_verify( + (const struct keyctl_pkey_params __user *)arg2, + (const char __user *)arg3, + (const void __user *)arg4, + (const void __user *)arg5); + + case KEYCTL_MOVE: + return keyctl_keyring_move((key_serial_t)arg2, + (key_serial_t)arg3, + (key_serial_t)arg4, + (unsigned int)arg5); + + case KEYCTL_CAPABILITIES: + return keyctl_capabilities((unsigned char __user *)arg2, (size_t)arg3); + + case KEYCTL_WATCH_KEY: + return keyctl_watch_key((key_serial_t)arg2, (int)arg3, (int)arg4); + + default: + return -EOPNOTSUPP; + } +} diff --git a/security/keys/keyctl_pkey.c b/security/keys/keyctl_pkey.c new file mode 100644 index 000000000..97bc27bbf --- /dev/null +++ b/security/keys/keyctl_pkey.c @@ -0,0 +1,327 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* Public-key operation keyctls + * + * Copyright (C) 2016 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#include <linux/slab.h> +#include <linux/err.h> +#include <linux/key.h> +#include <linux/keyctl.h> +#include <linux/parser.h> +#include <linux/uaccess.h> +#include <keys/user-type.h> +#include "internal.h" + +static void keyctl_pkey_params_free(struct kernel_pkey_params *params) +{ + kfree(params->info); + key_put(params->key); +} + +enum { + Opt_err, + Opt_enc, /* "enc=<encoding>" eg. "enc=oaep" */ + Opt_hash, /* "hash=<digest-name>" eg. "hash=sha1" */ +}; + +static const match_table_t param_keys = { + { Opt_enc, "enc=%s" }, + { Opt_hash, "hash=%s" }, + { Opt_err, NULL } +}; + +/* + * Parse the information string which consists of key=val pairs. + */ +static int keyctl_pkey_params_parse(struct kernel_pkey_params *params) +{ + unsigned long token_mask = 0; + substring_t args[MAX_OPT_ARGS]; + char *c = params->info, *p, *q; + int token; + + while ((p = strsep(&c, " \t"))) { + if (*p == '\0' || *p == ' ' || *p == '\t') + continue; + token = match_token(p, param_keys, args); + if (token == Opt_err) + return -EINVAL; + if (__test_and_set_bit(token, &token_mask)) + return -EINVAL; + q = args[0].from; + if (!q[0]) + return -EINVAL; + + switch (token) { + case Opt_enc: + params->encoding = q; + break; + + case Opt_hash: + params->hash_algo = q; + break; + + default: + return -EINVAL; + } + } + + return 0; +} + +/* + * Interpret parameters. Callers must always call the free function + * on params, even if an error is returned. + */ +static int keyctl_pkey_params_get(key_serial_t id, + const char __user *_info, + struct kernel_pkey_params *params) +{ + key_ref_t key_ref; + void *p; + int ret; + + memset(params, 0, sizeof(*params)); + params->encoding = "raw"; + + p = strndup_user(_info, PAGE_SIZE); + if (IS_ERR(p)) + return PTR_ERR(p); + params->info = p; + + ret = keyctl_pkey_params_parse(params); + if (ret < 0) + return ret; + + key_ref = lookup_user_key(id, 0, KEY_NEED_SEARCH); + if (IS_ERR(key_ref)) + return PTR_ERR(key_ref); + params->key = key_ref_to_ptr(key_ref); + + if (!params->key->type->asym_query) + return -EOPNOTSUPP; + + return 0; +} + +/* + * Get parameters from userspace. Callers must always call the free function + * on params, even if an error is returned. + */ +static int keyctl_pkey_params_get_2(const struct keyctl_pkey_params __user *_params, + const char __user *_info, + int op, + struct kernel_pkey_params *params) +{ + struct keyctl_pkey_params uparams; + struct kernel_pkey_query info; + int ret; + + memset(params, 0, sizeof(*params)); + params->encoding = "raw"; + + if (copy_from_user(&uparams, _params, sizeof(uparams)) != 0) + return -EFAULT; + + ret = keyctl_pkey_params_get(uparams.key_id, _info, params); + if (ret < 0) + return ret; + + ret = params->key->type->asym_query(params, &info); + if (ret < 0) + return ret; + + switch (op) { + case KEYCTL_PKEY_ENCRYPT: + if (uparams.in_len > info.max_dec_size || + uparams.out_len > info.max_enc_size) + return -EINVAL; + break; + case KEYCTL_PKEY_DECRYPT: + if (uparams.in_len > info.max_enc_size || + uparams.out_len > info.max_dec_size) + return -EINVAL; + break; + case KEYCTL_PKEY_SIGN: + if (uparams.in_len > info.max_data_size || + uparams.out_len > info.max_sig_size) + return -EINVAL; + break; + case KEYCTL_PKEY_VERIFY: + if (uparams.in_len > info.max_data_size || + uparams.in2_len > info.max_sig_size) + return -EINVAL; + break; + default: + BUG(); + } + + params->in_len = uparams.in_len; + params->out_len = uparams.out_len; /* Note: same as in2_len */ + return 0; +} + +/* + * Query information about an asymmetric key. + */ +long keyctl_pkey_query(key_serial_t id, + const char __user *_info, + struct keyctl_pkey_query __user *_res) +{ + struct kernel_pkey_params params; + struct kernel_pkey_query res; + long ret; + + ret = keyctl_pkey_params_get(id, _info, ¶ms); + if (ret < 0) + goto error; + + ret = params.key->type->asym_query(¶ms, &res); + if (ret < 0) + goto error; + + ret = -EFAULT; + if (copy_to_user(_res, &res, sizeof(res)) == 0 && + clear_user(_res->__spare, sizeof(_res->__spare)) == 0) + ret = 0; + +error: + keyctl_pkey_params_free(¶ms); + return ret; +} + +/* + * Encrypt/decrypt/sign + * + * Encrypt data, decrypt data or sign data using a public key. + * + * _info is a string of supplementary information in key=val format. For + * instance, it might contain: + * + * "enc=pkcs1 hash=sha256" + * + * where enc= specifies the encoding and hash= selects the OID to go in that + * particular encoding if required. If enc= isn't supplied, it's assumed that + * the caller is supplying raw values. + * + * If successful, the amount of data written into the output buffer is + * returned. + */ +long keyctl_pkey_e_d_s(int op, + const struct keyctl_pkey_params __user *_params, + const char __user *_info, + const void __user *_in, + void __user *_out) +{ + struct kernel_pkey_params params; + void *in, *out; + long ret; + + ret = keyctl_pkey_params_get_2(_params, _info, op, ¶ms); + if (ret < 0) + goto error_params; + + ret = -EOPNOTSUPP; + if (!params.key->type->asym_eds_op) + goto error_params; + + switch (op) { + case KEYCTL_PKEY_ENCRYPT: + params.op = kernel_pkey_encrypt; + break; + case KEYCTL_PKEY_DECRYPT: + params.op = kernel_pkey_decrypt; + break; + case KEYCTL_PKEY_SIGN: + params.op = kernel_pkey_sign; + break; + default: + BUG(); + } + + in = memdup_user(_in, params.in_len); + if (IS_ERR(in)) { + ret = PTR_ERR(in); + goto error_params; + } + + ret = -ENOMEM; + out = kmalloc(params.out_len, GFP_KERNEL); + if (!out) + goto error_in; + + ret = params.key->type->asym_eds_op(¶ms, in, out); + if (ret < 0) + goto error_out; + + if (copy_to_user(_out, out, ret) != 0) + ret = -EFAULT; + +error_out: + kfree(out); +error_in: + kfree(in); +error_params: + keyctl_pkey_params_free(¶ms); + return ret; +} + +/* + * Verify a signature. + * + * Verify a public key signature using the given key, or if not given, search + * for a matching key. + * + * _info is a string of supplementary information in key=val format. For + * instance, it might contain: + * + * "enc=pkcs1 hash=sha256" + * + * where enc= specifies the signature blob encoding and hash= selects the OID + * to go in that particular encoding. If enc= isn't supplied, it's assumed + * that the caller is supplying raw values. + * + * If successful, 0 is returned. + */ +long keyctl_pkey_verify(const struct keyctl_pkey_params __user *_params, + const char __user *_info, + const void __user *_in, + const void __user *_in2) +{ + struct kernel_pkey_params params; + void *in, *in2; + long ret; + + ret = keyctl_pkey_params_get_2(_params, _info, KEYCTL_PKEY_VERIFY, + ¶ms); + if (ret < 0) + goto error_params; + + ret = -EOPNOTSUPP; + if (!params.key->type->asym_verify_signature) + goto error_params; + + in = memdup_user(_in, params.in_len); + if (IS_ERR(in)) { + ret = PTR_ERR(in); + goto error_params; + } + + in2 = memdup_user(_in2, params.in2_len); + if (IS_ERR(in2)) { + ret = PTR_ERR(in2); + goto error_in; + } + + params.op = kernel_pkey_verify; + ret = params.key->type->asym_verify_signature(¶ms, in, in2); + + kfree(in2); +error_in: + kfree(in); +error_params: + keyctl_pkey_params_free(¶ms); + return ret; +} diff --git a/security/keys/keyring.c b/security/keys/keyring.c new file mode 100644 index 000000000..4448758f6 --- /dev/null +++ b/security/keys/keyring.c @@ -0,0 +1,1794 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* Keyring handling + * + * Copyright (C) 2004-2005, 2008, 2013 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#include <linux/export.h> +#include <linux/init.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/security.h> +#include <linux/seq_file.h> +#include <linux/err.h> +#include <linux/user_namespace.h> +#include <linux/nsproxy.h> +#include <keys/keyring-type.h> +#include <keys/user-type.h> +#include <linux/assoc_array_priv.h> +#include <linux/uaccess.h> +#include <net/net_namespace.h> +#include "internal.h" + +/* + * When plumbing the depths of the key tree, this sets a hard limit + * set on how deep we're willing to go. + */ +#define KEYRING_SEARCH_MAX_DEPTH 6 + +/* + * We mark pointers we pass to the associative array with bit 1 set if + * they're keyrings and clear otherwise. + */ +#define KEYRING_PTR_SUBTYPE 0x2UL + +static inline bool keyring_ptr_is_keyring(const struct assoc_array_ptr *x) +{ + return (unsigned long)x & KEYRING_PTR_SUBTYPE; +} +static inline struct key *keyring_ptr_to_key(const struct assoc_array_ptr *x) +{ + void *object = assoc_array_ptr_to_leaf(x); + return (struct key *)((unsigned long)object & ~KEYRING_PTR_SUBTYPE); +} +static inline void *keyring_key_to_ptr(struct key *key) +{ + if (key->type == &key_type_keyring) + return (void *)((unsigned long)key | KEYRING_PTR_SUBTYPE); + return key; +} + +static DEFINE_RWLOCK(keyring_name_lock); + +/* + * Clean up the bits of user_namespace that belong to us. + */ +void key_free_user_ns(struct user_namespace *ns) +{ + write_lock(&keyring_name_lock); + list_del_init(&ns->keyring_name_list); + write_unlock(&keyring_name_lock); + + key_put(ns->user_keyring_register); +#ifdef CONFIG_PERSISTENT_KEYRINGS + key_put(ns->persistent_keyring_register); +#endif +} + +/* + * The keyring key type definition. Keyrings are simply keys of this type and + * can be treated as ordinary keys in addition to having their own special + * operations. + */ +static int keyring_preparse(struct key_preparsed_payload *prep); +static void keyring_free_preparse(struct key_preparsed_payload *prep); +static int keyring_instantiate(struct key *keyring, + struct key_preparsed_payload *prep); +static void keyring_revoke(struct key *keyring); +static void keyring_destroy(struct key *keyring); +static void keyring_describe(const struct key *keyring, struct seq_file *m); +static long keyring_read(const struct key *keyring, + char *buffer, size_t buflen); + +struct key_type key_type_keyring = { + .name = "keyring", + .def_datalen = 0, + .preparse = keyring_preparse, + .free_preparse = keyring_free_preparse, + .instantiate = keyring_instantiate, + .revoke = keyring_revoke, + .destroy = keyring_destroy, + .describe = keyring_describe, + .read = keyring_read, +}; +EXPORT_SYMBOL(key_type_keyring); + +/* + * Semaphore to serialise link/link calls to prevent two link calls in parallel + * introducing a cycle. + */ +static DEFINE_MUTEX(keyring_serialise_link_lock); + +/* + * Publish the name of a keyring so that it can be found by name (if it has + * one and it doesn't begin with a dot). + */ +static void keyring_publish_name(struct key *keyring) +{ + struct user_namespace *ns = current_user_ns(); + + if (keyring->description && + keyring->description[0] && + keyring->description[0] != '.') { + write_lock(&keyring_name_lock); + list_add_tail(&keyring->name_link, &ns->keyring_name_list); + write_unlock(&keyring_name_lock); + } +} + +/* + * Preparse a keyring payload + */ +static int keyring_preparse(struct key_preparsed_payload *prep) +{ + return prep->datalen != 0 ? -EINVAL : 0; +} + +/* + * Free a preparse of a user defined key payload + */ +static void keyring_free_preparse(struct key_preparsed_payload *prep) +{ +} + +/* + * Initialise a keyring. + * + * Returns 0 on success, -EINVAL if given any data. + */ +static int keyring_instantiate(struct key *keyring, + struct key_preparsed_payload *prep) +{ + assoc_array_init(&keyring->keys); + /* make the keyring available by name if it has one */ + keyring_publish_name(keyring); + return 0; +} + +/* + * Multiply 64-bits by 32-bits to 96-bits and fold back to 64-bit. Ideally we'd + * fold the carry back too, but that requires inline asm. + */ +static u64 mult_64x32_and_fold(u64 x, u32 y) +{ + u64 hi = (u64)(u32)(x >> 32) * y; + u64 lo = (u64)(u32)(x) * y; + return lo + ((u64)(u32)hi << 32) + (u32)(hi >> 32); +} + +/* + * Hash a key type and description. + */ +static void hash_key_type_and_desc(struct keyring_index_key *index_key) +{ + const unsigned level_shift = ASSOC_ARRAY_LEVEL_STEP; + const unsigned long fan_mask = ASSOC_ARRAY_FAN_MASK; + const char *description = index_key->description; + unsigned long hash, type; + u32 piece; + u64 acc; + int n, desc_len = index_key->desc_len; + + type = (unsigned long)index_key->type; + acc = mult_64x32_and_fold(type, desc_len + 13); + acc = mult_64x32_and_fold(acc, 9207); + piece = (unsigned long)index_key->domain_tag; + acc = mult_64x32_and_fold(acc, piece); + acc = mult_64x32_and_fold(acc, 9207); + + for (;;) { + n = desc_len; + if (n <= 0) + break; + if (n > 4) + n = 4; + piece = 0; + memcpy(&piece, description, n); + description += n; + desc_len -= n; + acc = mult_64x32_and_fold(acc, piece); + acc = mult_64x32_and_fold(acc, 9207); + } + + /* Fold the hash down to 32 bits if need be. */ + hash = acc; + if (ASSOC_ARRAY_KEY_CHUNK_SIZE == 32) + hash ^= acc >> 32; + + /* Squidge all the keyrings into a separate part of the tree to + * ordinary keys by making sure the lowest level segment in the hash is + * zero for keyrings and non-zero otherwise. + */ + if (index_key->type != &key_type_keyring && (hash & fan_mask) == 0) + hash |= (hash >> (ASSOC_ARRAY_KEY_CHUNK_SIZE - level_shift)) | 1; + else if (index_key->type == &key_type_keyring && (hash & fan_mask) != 0) + hash = (hash + (hash << level_shift)) & ~fan_mask; + index_key->hash = hash; +} + +/* + * Finalise an index key to include a part of the description actually in the + * index key, to set the domain tag and to calculate the hash. + */ +void key_set_index_key(struct keyring_index_key *index_key) +{ + static struct key_tag default_domain_tag = { .usage = REFCOUNT_INIT(1), }; + size_t n = min_t(size_t, index_key->desc_len, sizeof(index_key->desc)); + + memcpy(index_key->desc, index_key->description, n); + + if (!index_key->domain_tag) { + if (index_key->type->flags & KEY_TYPE_NET_DOMAIN) + index_key->domain_tag = current->nsproxy->net_ns->key_domain; + else + index_key->domain_tag = &default_domain_tag; + } + + hash_key_type_and_desc(index_key); +} + +/** + * key_put_tag - Release a ref on a tag. + * @tag: The tag to release. + * + * This releases a reference the given tag and returns true if that ref was the + * last one. + */ +bool key_put_tag(struct key_tag *tag) +{ + if (refcount_dec_and_test(&tag->usage)) { + kfree_rcu(tag, rcu); + return true; + } + + return false; +} + +/** + * key_remove_domain - Kill off a key domain and gc its keys + * @domain_tag: The domain tag to release. + * + * This marks a domain tag as being dead and releases a ref on it. If that + * wasn't the last reference, the garbage collector is poked to try and delete + * all keys that were in the domain. + */ +void key_remove_domain(struct key_tag *domain_tag) +{ + domain_tag->removed = true; + if (!key_put_tag(domain_tag)) + key_schedule_gc_links(); +} + +/* + * Build the next index key chunk. + * + * We return it one word-sized chunk at a time. + */ +static unsigned long keyring_get_key_chunk(const void *data, int level) +{ + const struct keyring_index_key *index_key = data; + unsigned long chunk = 0; + const u8 *d; + int desc_len = index_key->desc_len, n = sizeof(chunk); + + level /= ASSOC_ARRAY_KEY_CHUNK_SIZE; + switch (level) { + case 0: + return index_key->hash; + case 1: + return index_key->x; + case 2: + return (unsigned long)index_key->type; + case 3: + return (unsigned long)index_key->domain_tag; + default: + level -= 4; + if (desc_len <= sizeof(index_key->desc)) + return 0; + + d = index_key->description + sizeof(index_key->desc); + d += level * sizeof(long); + desc_len -= sizeof(index_key->desc); + if (desc_len > n) + desc_len = n; + do { + chunk <<= 8; + chunk |= *d++; + } while (--desc_len > 0); + return chunk; + } +} + +static unsigned long keyring_get_object_key_chunk(const void *object, int level) +{ + const struct key *key = keyring_ptr_to_key(object); + return keyring_get_key_chunk(&key->index_key, level); +} + +static bool keyring_compare_object(const void *object, const void *data) +{ + const struct keyring_index_key *index_key = data; + const struct key *key = keyring_ptr_to_key(object); + + return key->index_key.type == index_key->type && + key->index_key.domain_tag == index_key->domain_tag && + key->index_key.desc_len == index_key->desc_len && + memcmp(key->index_key.description, index_key->description, + index_key->desc_len) == 0; +} + +/* + * Compare the index keys of a pair of objects and determine the bit position + * at which they differ - if they differ. + */ +static int keyring_diff_objects(const void *object, const void *data) +{ + const struct key *key_a = keyring_ptr_to_key(object); + const struct keyring_index_key *a = &key_a->index_key; + const struct keyring_index_key *b = data; + unsigned long seg_a, seg_b; + int level, i; + + level = 0; + seg_a = a->hash; + seg_b = b->hash; + if ((seg_a ^ seg_b) != 0) + goto differ; + level += ASSOC_ARRAY_KEY_CHUNK_SIZE / 8; + + /* The number of bits contributed by the hash is controlled by a + * constant in the assoc_array headers. Everything else thereafter we + * can deal with as being machine word-size dependent. + */ + seg_a = a->x; + seg_b = b->x; + if ((seg_a ^ seg_b) != 0) + goto differ; + level += sizeof(unsigned long); + + /* The next bit may not work on big endian */ + seg_a = (unsigned long)a->type; + seg_b = (unsigned long)b->type; + if ((seg_a ^ seg_b) != 0) + goto differ; + level += sizeof(unsigned long); + + seg_a = (unsigned long)a->domain_tag; + seg_b = (unsigned long)b->domain_tag; + if ((seg_a ^ seg_b) != 0) + goto differ; + level += sizeof(unsigned long); + + i = sizeof(a->desc); + if (a->desc_len <= i) + goto same; + + for (; i < a->desc_len; i++) { + seg_a = *(unsigned char *)(a->description + i); + seg_b = *(unsigned char *)(b->description + i); + if ((seg_a ^ seg_b) != 0) + goto differ_plus_i; + } + +same: + return -1; + +differ_plus_i: + level += i; +differ: + i = level * 8 + __ffs(seg_a ^ seg_b); + return i; +} + +/* + * Free an object after stripping the keyring flag off of the pointer. + */ +static void keyring_free_object(void *object) +{ + key_put(keyring_ptr_to_key(object)); +} + +/* + * Operations for keyring management by the index-tree routines. + */ +static const struct assoc_array_ops keyring_assoc_array_ops = { + .get_key_chunk = keyring_get_key_chunk, + .get_object_key_chunk = keyring_get_object_key_chunk, + .compare_object = keyring_compare_object, + .diff_objects = keyring_diff_objects, + .free_object = keyring_free_object, +}; + +/* + * Clean up a keyring when it is destroyed. Unpublish its name if it had one + * and dispose of its data. + * + * The garbage collector detects the final key_put(), removes the keyring from + * the serial number tree and then does RCU synchronisation before coming here, + * so we shouldn't need to worry about code poking around here with the RCU + * readlock held by this time. + */ +static void keyring_destroy(struct key *keyring) +{ + if (keyring->description) { + write_lock(&keyring_name_lock); + + if (keyring->name_link.next != NULL && + !list_empty(&keyring->name_link)) + list_del(&keyring->name_link); + + write_unlock(&keyring_name_lock); + } + + if (keyring->restrict_link) { + struct key_restriction *keyres = keyring->restrict_link; + + key_put(keyres->key); + kfree(keyres); + } + + assoc_array_destroy(&keyring->keys, &keyring_assoc_array_ops); +} + +/* + * Describe a keyring for /proc. + */ +static void keyring_describe(const struct key *keyring, struct seq_file *m) +{ + if (keyring->description) + seq_puts(m, keyring->description); + else + seq_puts(m, "[anon]"); + + if (key_is_positive(keyring)) { + if (keyring->keys.nr_leaves_on_tree != 0) + seq_printf(m, ": %lu", keyring->keys.nr_leaves_on_tree); + else + seq_puts(m, ": empty"); + } +} + +struct keyring_read_iterator_context { + size_t buflen; + size_t count; + key_serial_t *buffer; +}; + +static int keyring_read_iterator(const void *object, void *data) +{ + struct keyring_read_iterator_context *ctx = data; + const struct key *key = keyring_ptr_to_key(object); + + kenter("{%s,%d},,{%zu/%zu}", + key->type->name, key->serial, ctx->count, ctx->buflen); + + if (ctx->count >= ctx->buflen) + return 1; + + *ctx->buffer++ = key->serial; + ctx->count += sizeof(key->serial); + return 0; +} + +/* + * Read a list of key IDs from the keyring's contents in binary form + * + * The keyring's semaphore is read-locked by the caller. This prevents someone + * from modifying it under us - which could cause us to read key IDs multiple + * times. + */ +static long keyring_read(const struct key *keyring, + char *buffer, size_t buflen) +{ + struct keyring_read_iterator_context ctx; + long ret; + + kenter("{%d},,%zu", key_serial(keyring), buflen); + + if (buflen & (sizeof(key_serial_t) - 1)) + return -EINVAL; + + /* Copy as many key IDs as fit into the buffer */ + if (buffer && buflen) { + ctx.buffer = (key_serial_t *)buffer; + ctx.buflen = buflen; + ctx.count = 0; + ret = assoc_array_iterate(&keyring->keys, + keyring_read_iterator, &ctx); + if (ret < 0) { + kleave(" = %ld [iterate]", ret); + return ret; + } + } + + /* Return the size of the buffer needed */ + ret = keyring->keys.nr_leaves_on_tree * sizeof(key_serial_t); + if (ret <= buflen) + kleave("= %ld [ok]", ret); + else + kleave("= %ld [buffer too small]", ret); + return ret; +} + +/* + * Allocate a keyring and link into the destination keyring. + */ +struct key *keyring_alloc(const char *description, kuid_t uid, kgid_t gid, + const struct cred *cred, key_perm_t perm, + unsigned long flags, + struct key_restriction *restrict_link, + struct key *dest) +{ + struct key *keyring; + int ret; + + keyring = key_alloc(&key_type_keyring, description, + uid, gid, cred, perm, flags, restrict_link); + if (!IS_ERR(keyring)) { + ret = key_instantiate_and_link(keyring, NULL, 0, dest, NULL); + if (ret < 0) { + key_put(keyring); + keyring = ERR_PTR(ret); + } + } + + return keyring; +} +EXPORT_SYMBOL(keyring_alloc); + +/** + * restrict_link_reject - Give -EPERM to restrict link + * @keyring: The keyring being added to. + * @type: The type of key being added. + * @payload: The payload of the key intended to be added. + * @restriction_key: Keys providing additional data for evaluating restriction. + * + * Reject the addition of any links to a keyring. It can be overridden by + * passing KEY_ALLOC_BYPASS_RESTRICTION to key_instantiate_and_link() when + * adding a key to a keyring. + * + * This is meant to be stored in a key_restriction structure which is passed + * in the restrict_link parameter to keyring_alloc(). + */ +int restrict_link_reject(struct key *keyring, + const struct key_type *type, + const union key_payload *payload, + struct key *restriction_key) +{ + return -EPERM; +} + +/* + * By default, we keys found by getting an exact match on their descriptions. + */ +bool key_default_cmp(const struct key *key, + const struct key_match_data *match_data) +{ + return strcmp(key->description, match_data->raw_data) == 0; +} + +/* + * Iteration function to consider each key found. + */ +static int keyring_search_iterator(const void *object, void *iterator_data) +{ + struct keyring_search_context *ctx = iterator_data; + const struct key *key = keyring_ptr_to_key(object); + unsigned long kflags = READ_ONCE(key->flags); + short state = READ_ONCE(key->state); + + kenter("{%d}", key->serial); + + /* ignore keys not of this type */ + if (key->type != ctx->index_key.type) { + kleave(" = 0 [!type]"); + return 0; + } + + /* skip invalidated, revoked and expired keys */ + if (ctx->flags & KEYRING_SEARCH_DO_STATE_CHECK) { + time64_t expiry = READ_ONCE(key->expiry); + + if (kflags & ((1 << KEY_FLAG_INVALIDATED) | + (1 << KEY_FLAG_REVOKED))) { + ctx->result = ERR_PTR(-EKEYREVOKED); + kleave(" = %d [invrev]", ctx->skipped_ret); + goto skipped; + } + + if (expiry && ctx->now >= expiry) { + if (!(ctx->flags & KEYRING_SEARCH_SKIP_EXPIRED)) + ctx->result = ERR_PTR(-EKEYEXPIRED); + kleave(" = %d [expire]", ctx->skipped_ret); + goto skipped; + } + } + + /* keys that don't match */ + if (!ctx->match_data.cmp(key, &ctx->match_data)) { + kleave(" = 0 [!match]"); + return 0; + } + + /* key must have search permissions */ + if (!(ctx->flags & KEYRING_SEARCH_NO_CHECK_PERM) && + key_task_permission(make_key_ref(key, ctx->possessed), + ctx->cred, KEY_NEED_SEARCH) < 0) { + ctx->result = ERR_PTR(-EACCES); + kleave(" = %d [!perm]", ctx->skipped_ret); + goto skipped; + } + + if (ctx->flags & KEYRING_SEARCH_DO_STATE_CHECK) { + /* we set a different error code if we pass a negative key */ + if (state < 0) { + ctx->result = ERR_PTR(state); + kleave(" = %d [neg]", ctx->skipped_ret); + goto skipped; + } + } + + /* Found */ + ctx->result = make_key_ref(key, ctx->possessed); + kleave(" = 1 [found]"); + return 1; + +skipped: + return ctx->skipped_ret; +} + +/* + * Search inside a keyring for a key. We can search by walking to it + * directly based on its index-key or we can iterate over the entire + * tree looking for it, based on the match function. + */ +static int search_keyring(struct key *keyring, struct keyring_search_context *ctx) +{ + if (ctx->match_data.lookup_type == KEYRING_SEARCH_LOOKUP_DIRECT) { + const void *object; + + object = assoc_array_find(&keyring->keys, + &keyring_assoc_array_ops, + &ctx->index_key); + return object ? ctx->iterator(object, ctx) : 0; + } + return assoc_array_iterate(&keyring->keys, ctx->iterator, ctx); +} + +/* + * Search a tree of keyrings that point to other keyrings up to the maximum + * depth. + */ +static bool search_nested_keyrings(struct key *keyring, + struct keyring_search_context *ctx) +{ + struct { + struct key *keyring; + struct assoc_array_node *node; + int slot; + } stack[KEYRING_SEARCH_MAX_DEPTH]; + + struct assoc_array_shortcut *shortcut; + struct assoc_array_node *node; + struct assoc_array_ptr *ptr; + struct key *key; + int sp = 0, slot; + + kenter("{%d},{%s,%s}", + keyring->serial, + ctx->index_key.type->name, + ctx->index_key.description); + +#define STATE_CHECKS (KEYRING_SEARCH_NO_STATE_CHECK | KEYRING_SEARCH_DO_STATE_CHECK) + BUG_ON((ctx->flags & STATE_CHECKS) == 0 || + (ctx->flags & STATE_CHECKS) == STATE_CHECKS); + + if (ctx->index_key.description) + key_set_index_key(&ctx->index_key); + + /* Check to see if this top-level keyring is what we are looking for + * and whether it is valid or not. + */ + if (ctx->match_data.lookup_type == KEYRING_SEARCH_LOOKUP_ITERATE || + keyring_compare_object(keyring, &ctx->index_key)) { + ctx->skipped_ret = 2; + switch (ctx->iterator(keyring_key_to_ptr(keyring), ctx)) { + case 1: + goto found; + case 2: + return false; + default: + break; + } + } + + ctx->skipped_ret = 0; + + /* Start processing a new keyring */ +descend_to_keyring: + kdebug("descend to %d", keyring->serial); + if (keyring->flags & ((1 << KEY_FLAG_INVALIDATED) | + (1 << KEY_FLAG_REVOKED))) + goto not_this_keyring; + + /* Search through the keys in this keyring before its searching its + * subtrees. + */ + if (search_keyring(keyring, ctx)) + goto found; + + /* Then manually iterate through the keyrings nested in this one. + * + * Start from the root node of the index tree. Because of the way the + * hash function has been set up, keyrings cluster on the leftmost + * branch of the root node (root slot 0) or in the root node itself. + * Non-keyrings avoid the leftmost branch of the root entirely (root + * slots 1-15). + */ + if (!(ctx->flags & KEYRING_SEARCH_RECURSE)) + goto not_this_keyring; + + ptr = READ_ONCE(keyring->keys.root); + if (!ptr) + goto not_this_keyring; + + if (assoc_array_ptr_is_shortcut(ptr)) { + /* If the root is a shortcut, either the keyring only contains + * keyring pointers (everything clusters behind root slot 0) or + * doesn't contain any keyring pointers. + */ + shortcut = assoc_array_ptr_to_shortcut(ptr); + if ((shortcut->index_key[0] & ASSOC_ARRAY_FAN_MASK) != 0) + goto not_this_keyring; + + ptr = READ_ONCE(shortcut->next_node); + node = assoc_array_ptr_to_node(ptr); + goto begin_node; + } + + node = assoc_array_ptr_to_node(ptr); + ptr = node->slots[0]; + if (!assoc_array_ptr_is_meta(ptr)) + goto begin_node; + +descend_to_node: + /* Descend to a more distal node in this keyring's content tree and go + * through that. + */ + kdebug("descend"); + if (assoc_array_ptr_is_shortcut(ptr)) { + shortcut = assoc_array_ptr_to_shortcut(ptr); + ptr = READ_ONCE(shortcut->next_node); + BUG_ON(!assoc_array_ptr_is_node(ptr)); + } + node = assoc_array_ptr_to_node(ptr); + +begin_node: + kdebug("begin_node"); + slot = 0; +ascend_to_node: + /* Go through the slots in a node */ + for (; slot < ASSOC_ARRAY_FAN_OUT; slot++) { + ptr = READ_ONCE(node->slots[slot]); + + if (assoc_array_ptr_is_meta(ptr) && node->back_pointer) + goto descend_to_node; + + if (!keyring_ptr_is_keyring(ptr)) + continue; + + key = keyring_ptr_to_key(ptr); + + if (sp >= KEYRING_SEARCH_MAX_DEPTH) { + if (ctx->flags & KEYRING_SEARCH_DETECT_TOO_DEEP) { + ctx->result = ERR_PTR(-ELOOP); + return false; + } + goto not_this_keyring; + } + + /* Search a nested keyring */ + if (!(ctx->flags & KEYRING_SEARCH_NO_CHECK_PERM) && + key_task_permission(make_key_ref(key, ctx->possessed), + ctx->cred, KEY_NEED_SEARCH) < 0) + continue; + + /* stack the current position */ + stack[sp].keyring = keyring; + stack[sp].node = node; + stack[sp].slot = slot; + sp++; + + /* begin again with the new keyring */ + keyring = key; + goto descend_to_keyring; + } + + /* We've dealt with all the slots in the current node, so now we need + * to ascend to the parent and continue processing there. + */ + ptr = READ_ONCE(node->back_pointer); + slot = node->parent_slot; + + if (ptr && assoc_array_ptr_is_shortcut(ptr)) { + shortcut = assoc_array_ptr_to_shortcut(ptr); + ptr = READ_ONCE(shortcut->back_pointer); + slot = shortcut->parent_slot; + } + if (!ptr) + goto not_this_keyring; + node = assoc_array_ptr_to_node(ptr); + slot++; + + /* If we've ascended to the root (zero backpointer), we must have just + * finished processing the leftmost branch rather than the root slots - + * so there can't be any more keyrings for us to find. + */ + if (node->back_pointer) { + kdebug("ascend %d", slot); + goto ascend_to_node; + } + + /* The keyring we're looking at was disqualified or didn't contain a + * matching key. + */ +not_this_keyring: + kdebug("not_this_keyring %d", sp); + if (sp <= 0) { + kleave(" = false"); + return false; + } + + /* Resume the processing of a keyring higher up in the tree */ + sp--; + keyring = stack[sp].keyring; + node = stack[sp].node; + slot = stack[sp].slot + 1; + kdebug("ascend to %d [%d]", keyring->serial, slot); + goto ascend_to_node; + + /* We found a viable match */ +found: + key = key_ref_to_ptr(ctx->result); + key_check(key); + if (!(ctx->flags & KEYRING_SEARCH_NO_UPDATE_TIME)) { + key->last_used_at = ctx->now; + keyring->last_used_at = ctx->now; + while (sp > 0) + stack[--sp].keyring->last_used_at = ctx->now; + } + kleave(" = true"); + return true; +} + +/** + * keyring_search_rcu - Search a keyring tree for a matching key under RCU + * @keyring_ref: A pointer to the keyring with possession indicator. + * @ctx: The keyring search context. + * + * Search the supplied keyring tree for a key that matches the criteria given. + * The root keyring and any linked keyrings must grant Search permission to the + * caller to be searchable and keys can only be found if they too grant Search + * to the caller. The possession flag on the root keyring pointer controls use + * of the possessor bits in permissions checking of the entire tree. In + * addition, the LSM gets to forbid keyring searches and key matches. + * + * The search is performed as a breadth-then-depth search up to the prescribed + * limit (KEYRING_SEARCH_MAX_DEPTH). The caller must hold the RCU read lock to + * prevent keyrings from being destroyed or rearranged whilst they are being + * searched. + * + * Keys are matched to the type provided and are then filtered by the match + * function, which is given the description to use in any way it sees fit. The + * match function may use any attributes of a key that it wishes to + * determine the match. Normally the match function from the key type would be + * used. + * + * RCU can be used to prevent the keyring key lists from disappearing without + * the need to take lots of locks. + * + * Returns a pointer to the found key and increments the key usage count if + * successful; -EAGAIN if no matching keys were found, or if expired or revoked + * keys were found; -ENOKEY if only negative keys were found; -ENOTDIR if the + * specified keyring wasn't a keyring. + * + * In the case of a successful return, the possession attribute from + * @keyring_ref is propagated to the returned key reference. + */ +key_ref_t keyring_search_rcu(key_ref_t keyring_ref, + struct keyring_search_context *ctx) +{ + struct key *keyring; + long err; + + ctx->iterator = keyring_search_iterator; + ctx->possessed = is_key_possessed(keyring_ref); + ctx->result = ERR_PTR(-EAGAIN); + + keyring = key_ref_to_ptr(keyring_ref); + key_check(keyring); + + if (keyring->type != &key_type_keyring) + return ERR_PTR(-ENOTDIR); + + if (!(ctx->flags & KEYRING_SEARCH_NO_CHECK_PERM)) { + err = key_task_permission(keyring_ref, ctx->cred, KEY_NEED_SEARCH); + if (err < 0) + return ERR_PTR(err); + } + + ctx->now = ktime_get_real_seconds(); + if (search_nested_keyrings(keyring, ctx)) + __key_get(key_ref_to_ptr(ctx->result)); + return ctx->result; +} + +/** + * keyring_search - Search the supplied keyring tree for a matching key + * @keyring: The root of the keyring tree to be searched. + * @type: The type of keyring we want to find. + * @description: The name of the keyring we want to find. + * @recurse: True to search the children of @keyring also + * + * As keyring_search_rcu() above, but using the current task's credentials and + * type's default matching function and preferred search method. + */ +key_ref_t keyring_search(key_ref_t keyring, + struct key_type *type, + const char *description, + bool recurse) +{ + struct keyring_search_context ctx = { + .index_key.type = type, + .index_key.description = description, + .index_key.desc_len = strlen(description), + .cred = current_cred(), + .match_data.cmp = key_default_cmp, + .match_data.raw_data = description, + .match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT, + .flags = KEYRING_SEARCH_DO_STATE_CHECK, + }; + key_ref_t key; + int ret; + + if (recurse) + ctx.flags |= KEYRING_SEARCH_RECURSE; + if (type->match_preparse) { + ret = type->match_preparse(&ctx.match_data); + if (ret < 0) + return ERR_PTR(ret); + } + + rcu_read_lock(); + key = keyring_search_rcu(keyring, &ctx); + rcu_read_unlock(); + + if (type->match_free) + type->match_free(&ctx.match_data); + return key; +} +EXPORT_SYMBOL(keyring_search); + +static struct key_restriction *keyring_restriction_alloc( + key_restrict_link_func_t check) +{ + struct key_restriction *keyres = + kzalloc(sizeof(struct key_restriction), GFP_KERNEL); + + if (!keyres) + return ERR_PTR(-ENOMEM); + + keyres->check = check; + + return keyres; +} + +/* + * Semaphore to serialise restriction setup to prevent reference count + * cycles through restriction key pointers. + */ +static DECLARE_RWSEM(keyring_serialise_restrict_sem); + +/* + * Check for restriction cycles that would prevent keyring garbage collection. + * keyring_serialise_restrict_sem must be held. + */ +static bool keyring_detect_restriction_cycle(const struct key *dest_keyring, + struct key_restriction *keyres) +{ + while (keyres && keyres->key && + keyres->key->type == &key_type_keyring) { + if (keyres->key == dest_keyring) + return true; + + keyres = keyres->key->restrict_link; + } + + return false; +} + +/** + * keyring_restrict - Look up and apply a restriction to a keyring + * @keyring_ref: The keyring to be restricted + * @type: The key type that will provide the restriction checker. + * @restriction: The restriction options to apply to the keyring + * + * Look up a keyring and apply a restriction to it. The restriction is managed + * by the specific key type, but can be configured by the options specified in + * the restriction string. + */ +int keyring_restrict(key_ref_t keyring_ref, const char *type, + const char *restriction) +{ + struct key *keyring; + struct key_type *restrict_type = NULL; + struct key_restriction *restrict_link; + int ret = 0; + + keyring = key_ref_to_ptr(keyring_ref); + key_check(keyring); + + if (keyring->type != &key_type_keyring) + return -ENOTDIR; + + if (!type) { + restrict_link = keyring_restriction_alloc(restrict_link_reject); + } else { + restrict_type = key_type_lookup(type); + + if (IS_ERR(restrict_type)) + return PTR_ERR(restrict_type); + + if (!restrict_type->lookup_restriction) { + ret = -ENOENT; + goto error; + } + + restrict_link = restrict_type->lookup_restriction(restriction); + } + + if (IS_ERR(restrict_link)) { + ret = PTR_ERR(restrict_link); + goto error; + } + + down_write(&keyring->sem); + down_write(&keyring_serialise_restrict_sem); + + if (keyring->restrict_link) { + ret = -EEXIST; + } else if (keyring_detect_restriction_cycle(keyring, restrict_link)) { + ret = -EDEADLK; + } else { + keyring->restrict_link = restrict_link; + notify_key(keyring, NOTIFY_KEY_SETATTR, 0); + } + + up_write(&keyring_serialise_restrict_sem); + up_write(&keyring->sem); + + if (ret < 0) { + key_put(restrict_link->key); + kfree(restrict_link); + } + +error: + if (restrict_type) + key_type_put(restrict_type); + + return ret; +} +EXPORT_SYMBOL(keyring_restrict); + +/* + * Search the given keyring for a key that might be updated. + * + * The caller must guarantee that the keyring is a keyring and that the + * permission is granted to modify the keyring as no check is made here. The + * caller must also hold a lock on the keyring semaphore. + * + * Returns a pointer to the found key with usage count incremented if + * successful and returns NULL if not found. Revoked and invalidated keys are + * skipped over. + * + * If successful, the possession indicator is propagated from the keyring ref + * to the returned key reference. + */ +key_ref_t find_key_to_update(key_ref_t keyring_ref, + const struct keyring_index_key *index_key) +{ + struct key *keyring, *key; + const void *object; + + keyring = key_ref_to_ptr(keyring_ref); + + kenter("{%d},{%s,%s}", + keyring->serial, index_key->type->name, index_key->description); + + object = assoc_array_find(&keyring->keys, &keyring_assoc_array_ops, + index_key); + + if (object) + goto found; + + kleave(" = NULL"); + return NULL; + +found: + key = keyring_ptr_to_key(object); + if (key->flags & ((1 << KEY_FLAG_INVALIDATED) | + (1 << KEY_FLAG_REVOKED))) { + kleave(" = NULL [x]"); + return NULL; + } + __key_get(key); + kleave(" = {%d}", key->serial); + return make_key_ref(key, is_key_possessed(keyring_ref)); +} + +/* + * Find a keyring with the specified name. + * + * Only keyrings that have nonzero refcount, are not revoked, and are owned by a + * user in the current user namespace are considered. If @uid_keyring is %true, + * the keyring additionally must have been allocated as a user or user session + * keyring; otherwise, it must grant Search permission directly to the caller. + * + * Returns a pointer to the keyring with the keyring's refcount having being + * incremented on success. -ENOKEY is returned if a key could not be found. + */ +struct key *find_keyring_by_name(const char *name, bool uid_keyring) +{ + struct user_namespace *ns = current_user_ns(); + struct key *keyring; + + if (!name) + return ERR_PTR(-EINVAL); + + read_lock(&keyring_name_lock); + + /* Search this hash bucket for a keyring with a matching name that + * grants Search permission and that hasn't been revoked + */ + list_for_each_entry(keyring, &ns->keyring_name_list, name_link) { + if (!kuid_has_mapping(ns, keyring->user->uid)) + continue; + + if (test_bit(KEY_FLAG_REVOKED, &keyring->flags)) + continue; + + if (strcmp(keyring->description, name) != 0) + continue; + + if (uid_keyring) { + if (!test_bit(KEY_FLAG_UID_KEYRING, + &keyring->flags)) + continue; + } else { + if (key_permission(make_key_ref(keyring, 0), + KEY_NEED_SEARCH) < 0) + continue; + } + + /* we've got a match but we might end up racing with + * key_cleanup() if the keyring is currently 'dead' + * (ie. it has a zero usage count) */ + if (!refcount_inc_not_zero(&keyring->usage)) + continue; + keyring->last_used_at = ktime_get_real_seconds(); + goto out; + } + + keyring = ERR_PTR(-ENOKEY); +out: + read_unlock(&keyring_name_lock); + return keyring; +} + +static int keyring_detect_cycle_iterator(const void *object, + void *iterator_data) +{ + struct keyring_search_context *ctx = iterator_data; + const struct key *key = keyring_ptr_to_key(object); + + kenter("{%d}", key->serial); + + /* We might get a keyring with matching index-key that is nonetheless a + * different keyring. */ + if (key != ctx->match_data.raw_data) + return 0; + + ctx->result = ERR_PTR(-EDEADLK); + return 1; +} + +/* + * See if a cycle will be created by inserting acyclic tree B in acyclic + * tree A at the topmost level (ie: as a direct child of A). + * + * Since we are adding B to A at the top level, checking for cycles should just + * be a matter of seeing if node A is somewhere in tree B. + */ +static int keyring_detect_cycle(struct key *A, struct key *B) +{ + struct keyring_search_context ctx = { + .index_key = A->index_key, + .match_data.raw_data = A, + .match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT, + .iterator = keyring_detect_cycle_iterator, + .flags = (KEYRING_SEARCH_NO_STATE_CHECK | + KEYRING_SEARCH_NO_UPDATE_TIME | + KEYRING_SEARCH_NO_CHECK_PERM | + KEYRING_SEARCH_DETECT_TOO_DEEP | + KEYRING_SEARCH_RECURSE), + }; + + rcu_read_lock(); + search_nested_keyrings(B, &ctx); + rcu_read_unlock(); + return PTR_ERR(ctx.result) == -EAGAIN ? 0 : PTR_ERR(ctx.result); +} + +/* + * Lock keyring for link. + */ +int __key_link_lock(struct key *keyring, + const struct keyring_index_key *index_key) + __acquires(&keyring->sem) + __acquires(&keyring_serialise_link_lock) +{ + if (keyring->type != &key_type_keyring) + return -ENOTDIR; + + down_write(&keyring->sem); + + /* Serialise link/link calls to prevent parallel calls causing a cycle + * when linking two keyring in opposite orders. + */ + if (index_key->type == &key_type_keyring) + mutex_lock(&keyring_serialise_link_lock); + + return 0; +} + +/* + * Lock keyrings for move (link/unlink combination). + */ +int __key_move_lock(struct key *l_keyring, struct key *u_keyring, + const struct keyring_index_key *index_key) + __acquires(&l_keyring->sem) + __acquires(&u_keyring->sem) + __acquires(&keyring_serialise_link_lock) +{ + if (l_keyring->type != &key_type_keyring || + u_keyring->type != &key_type_keyring) + return -ENOTDIR; + + /* We have to be very careful here to take the keyring locks in the + * right order, lest we open ourselves to deadlocking against another + * move operation. + */ + if (l_keyring < u_keyring) { + down_write(&l_keyring->sem); + down_write_nested(&u_keyring->sem, 1); + } else { + down_write(&u_keyring->sem); + down_write_nested(&l_keyring->sem, 1); + } + + /* Serialise link/link calls to prevent parallel calls causing a cycle + * when linking two keyring in opposite orders. + */ + if (index_key->type == &key_type_keyring) + mutex_lock(&keyring_serialise_link_lock); + + return 0; +} + +/* + * Preallocate memory so that a key can be linked into to a keyring. + */ +int __key_link_begin(struct key *keyring, + const struct keyring_index_key *index_key, + struct assoc_array_edit **_edit) +{ + struct assoc_array_edit *edit; + int ret; + + kenter("%d,%s,%s,", + keyring->serial, index_key->type->name, index_key->description); + + BUG_ON(index_key->desc_len == 0); + BUG_ON(*_edit != NULL); + + *_edit = NULL; + + ret = -EKEYREVOKED; + if (test_bit(KEY_FLAG_REVOKED, &keyring->flags)) + goto error; + + /* Create an edit script that will insert/replace the key in the + * keyring tree. + */ + edit = assoc_array_insert(&keyring->keys, + &keyring_assoc_array_ops, + index_key, + NULL); + if (IS_ERR(edit)) { + ret = PTR_ERR(edit); + goto error; + } + + /* If we're not replacing a link in-place then we're going to need some + * extra quota. + */ + if (!edit->dead_leaf) { + ret = key_payload_reserve(keyring, + keyring->datalen + KEYQUOTA_LINK_BYTES); + if (ret < 0) + goto error_cancel; + } + + *_edit = edit; + kleave(" = 0"); + return 0; + +error_cancel: + assoc_array_cancel_edit(edit); +error: + kleave(" = %d", ret); + return ret; +} + +/* + * Check already instantiated keys aren't going to be a problem. + * + * The caller must have called __key_link_begin(). Don't need to call this for + * keys that were created since __key_link_begin() was called. + */ +int __key_link_check_live_key(struct key *keyring, struct key *key) +{ + if (key->type == &key_type_keyring) + /* check that we aren't going to create a cycle by linking one + * keyring to another */ + return keyring_detect_cycle(keyring, key); + return 0; +} + +/* + * Link a key into to a keyring. + * + * Must be called with __key_link_begin() having being called. Discards any + * already extant link to matching key if there is one, so that each keyring + * holds at most one link to any given key of a particular type+description + * combination. + */ +void __key_link(struct key *keyring, struct key *key, + struct assoc_array_edit **_edit) +{ + __key_get(key); + assoc_array_insert_set_object(*_edit, keyring_key_to_ptr(key)); + assoc_array_apply_edit(*_edit); + *_edit = NULL; + notify_key(keyring, NOTIFY_KEY_LINKED, key_serial(key)); +} + +/* + * Finish linking a key into to a keyring. + * + * Must be called with __key_link_begin() having being called. + */ +void __key_link_end(struct key *keyring, + const struct keyring_index_key *index_key, + struct assoc_array_edit *edit) + __releases(&keyring->sem) + __releases(&keyring_serialise_link_lock) +{ + BUG_ON(index_key->type == NULL); + kenter("%d,%s,", keyring->serial, index_key->type->name); + + if (edit) { + if (!edit->dead_leaf) { + key_payload_reserve(keyring, + keyring->datalen - KEYQUOTA_LINK_BYTES); + } + assoc_array_cancel_edit(edit); + } + up_write(&keyring->sem); + + if (index_key->type == &key_type_keyring) + mutex_unlock(&keyring_serialise_link_lock); +} + +/* + * Check addition of keys to restricted keyrings. + */ +static int __key_link_check_restriction(struct key *keyring, struct key *key) +{ + if (!keyring->restrict_link || !keyring->restrict_link->check) + return 0; + return keyring->restrict_link->check(keyring, key->type, &key->payload, + keyring->restrict_link->key); +} + +/** + * key_link - Link a key to a keyring + * @keyring: The keyring to make the link in. + * @key: The key to link to. + * + * Make a link in a keyring to a key, such that the keyring holds a reference + * on that key and the key can potentially be found by searching that keyring. + * + * This function will write-lock the keyring's semaphore and will consume some + * of the user's key data quota to hold the link. + * + * Returns 0 if successful, -ENOTDIR if the keyring isn't a keyring, + * -EKEYREVOKED if the keyring has been revoked, -ENFILE if the keyring is + * full, -EDQUOT if there is insufficient key data quota remaining to add + * another link or -ENOMEM if there's insufficient memory. + * + * It is assumed that the caller has checked that it is permitted for a link to + * be made (the keyring should have Write permission and the key Link + * permission). + */ +int key_link(struct key *keyring, struct key *key) +{ + struct assoc_array_edit *edit = NULL; + int ret; + + kenter("{%d,%d}", keyring->serial, refcount_read(&keyring->usage)); + + key_check(keyring); + key_check(key); + + ret = __key_link_lock(keyring, &key->index_key); + if (ret < 0) + goto error; + + ret = __key_link_begin(keyring, &key->index_key, &edit); + if (ret < 0) + goto error_end; + + kdebug("begun {%d,%d}", keyring->serial, refcount_read(&keyring->usage)); + ret = __key_link_check_restriction(keyring, key); + if (ret == 0) + ret = __key_link_check_live_key(keyring, key); + if (ret == 0) + __key_link(keyring, key, &edit); + +error_end: + __key_link_end(keyring, &key->index_key, edit); +error: + kleave(" = %d {%d,%d}", ret, keyring->serial, refcount_read(&keyring->usage)); + return ret; +} +EXPORT_SYMBOL(key_link); + +/* + * Lock a keyring for unlink. + */ +static int __key_unlink_lock(struct key *keyring) + __acquires(&keyring->sem) +{ + if (keyring->type != &key_type_keyring) + return -ENOTDIR; + + down_write(&keyring->sem); + return 0; +} + +/* + * Begin the process of unlinking a key from a keyring. + */ +static int __key_unlink_begin(struct key *keyring, struct key *key, + struct assoc_array_edit **_edit) +{ + struct assoc_array_edit *edit; + + BUG_ON(*_edit != NULL); + + edit = assoc_array_delete(&keyring->keys, &keyring_assoc_array_ops, + &key->index_key); + if (IS_ERR(edit)) + return PTR_ERR(edit); + + if (!edit) + return -ENOENT; + + *_edit = edit; + return 0; +} + +/* + * Apply an unlink change. + */ +static void __key_unlink(struct key *keyring, struct key *key, + struct assoc_array_edit **_edit) +{ + assoc_array_apply_edit(*_edit); + notify_key(keyring, NOTIFY_KEY_UNLINKED, key_serial(key)); + *_edit = NULL; + key_payload_reserve(keyring, keyring->datalen - KEYQUOTA_LINK_BYTES); +} + +/* + * Finish unlinking a key from to a keyring. + */ +static void __key_unlink_end(struct key *keyring, + struct key *key, + struct assoc_array_edit *edit) + __releases(&keyring->sem) +{ + if (edit) + assoc_array_cancel_edit(edit); + up_write(&keyring->sem); +} + +/** + * key_unlink - Unlink the first link to a key from a keyring. + * @keyring: The keyring to remove the link from. + * @key: The key the link is to. + * + * Remove a link from a keyring to a key. + * + * This function will write-lock the keyring's semaphore. + * + * Returns 0 if successful, -ENOTDIR if the keyring isn't a keyring, -ENOENT if + * the key isn't linked to by the keyring or -ENOMEM if there's insufficient + * memory. + * + * It is assumed that the caller has checked that it is permitted for a link to + * be removed (the keyring should have Write permission; no permissions are + * required on the key). + */ +int key_unlink(struct key *keyring, struct key *key) +{ + struct assoc_array_edit *edit = NULL; + int ret; + + key_check(keyring); + key_check(key); + + ret = __key_unlink_lock(keyring); + if (ret < 0) + return ret; + + ret = __key_unlink_begin(keyring, key, &edit); + if (ret == 0) + __key_unlink(keyring, key, &edit); + __key_unlink_end(keyring, key, edit); + return ret; +} +EXPORT_SYMBOL(key_unlink); + +/** + * key_move - Move a key from one keyring to another + * @key: The key to move + * @from_keyring: The keyring to remove the link from. + * @to_keyring: The keyring to make the link in. + * @flags: Qualifying flags, such as KEYCTL_MOVE_EXCL. + * + * Make a link in @to_keyring to a key, such that the keyring holds a reference + * on that key and the key can potentially be found by searching that keyring + * whilst simultaneously removing a link to the key from @from_keyring. + * + * This function will write-lock both keyring's semaphores and will consume + * some of the user's key data quota to hold the link on @to_keyring. + * + * Returns 0 if successful, -ENOTDIR if either keyring isn't a keyring, + * -EKEYREVOKED if either keyring has been revoked, -ENFILE if the second + * keyring is full, -EDQUOT if there is insufficient key data quota remaining + * to add another link or -ENOMEM if there's insufficient memory. If + * KEYCTL_MOVE_EXCL is set, then -EEXIST will be returned if there's already a + * matching key in @to_keyring. + * + * It is assumed that the caller has checked that it is permitted for a link to + * be made (the keyring should have Write permission and the key Link + * permission). + */ +int key_move(struct key *key, + struct key *from_keyring, + struct key *to_keyring, + unsigned int flags) +{ + struct assoc_array_edit *from_edit = NULL, *to_edit = NULL; + int ret; + + kenter("%d,%d,%d", key->serial, from_keyring->serial, to_keyring->serial); + + if (from_keyring == to_keyring) + return 0; + + key_check(key); + key_check(from_keyring); + key_check(to_keyring); + + ret = __key_move_lock(from_keyring, to_keyring, &key->index_key); + if (ret < 0) + goto out; + ret = __key_unlink_begin(from_keyring, key, &from_edit); + if (ret < 0) + goto error; + ret = __key_link_begin(to_keyring, &key->index_key, &to_edit); + if (ret < 0) + goto error; + + ret = -EEXIST; + if (to_edit->dead_leaf && (flags & KEYCTL_MOVE_EXCL)) + goto error; + + ret = __key_link_check_restriction(to_keyring, key); + if (ret < 0) + goto error; + ret = __key_link_check_live_key(to_keyring, key); + if (ret < 0) + goto error; + + __key_unlink(from_keyring, key, &from_edit); + __key_link(to_keyring, key, &to_edit); +error: + __key_link_end(to_keyring, &key->index_key, to_edit); + __key_unlink_end(from_keyring, key, from_edit); +out: + kleave(" = %d", ret); + return ret; +} +EXPORT_SYMBOL(key_move); + +/** + * keyring_clear - Clear a keyring + * @keyring: The keyring to clear. + * + * Clear the contents of the specified keyring. + * + * Returns 0 if successful or -ENOTDIR if the keyring isn't a keyring. + */ +int keyring_clear(struct key *keyring) +{ + struct assoc_array_edit *edit; + int ret; + + if (keyring->type != &key_type_keyring) + return -ENOTDIR; + + down_write(&keyring->sem); + + edit = assoc_array_clear(&keyring->keys, &keyring_assoc_array_ops); + if (IS_ERR(edit)) { + ret = PTR_ERR(edit); + } else { + if (edit) + assoc_array_apply_edit(edit); + notify_key(keyring, NOTIFY_KEY_CLEARED, 0); + key_payload_reserve(keyring, 0); + ret = 0; + } + + up_write(&keyring->sem); + return ret; +} +EXPORT_SYMBOL(keyring_clear); + +/* + * Dispose of the links from a revoked keyring. + * + * This is called with the key sem write-locked. + */ +static void keyring_revoke(struct key *keyring) +{ + struct assoc_array_edit *edit; + + edit = assoc_array_clear(&keyring->keys, &keyring_assoc_array_ops); + if (!IS_ERR(edit)) { + if (edit) + assoc_array_apply_edit(edit); + key_payload_reserve(keyring, 0); + } +} + +static bool keyring_gc_select_iterator(void *object, void *iterator_data) +{ + struct key *key = keyring_ptr_to_key(object); + time64_t *limit = iterator_data; + + if (key_is_dead(key, *limit)) + return false; + key_get(key); + return true; +} + +static int keyring_gc_check_iterator(const void *object, void *iterator_data) +{ + const struct key *key = keyring_ptr_to_key(object); + time64_t *limit = iterator_data; + + key_check(key); + return key_is_dead(key, *limit); +} + +/* + * Garbage collect pointers from a keyring. + * + * Not called with any locks held. The keyring's key struct will not be + * deallocated under us as only our caller may deallocate it. + */ +void keyring_gc(struct key *keyring, time64_t limit) +{ + int result; + + kenter("%x{%s}", keyring->serial, keyring->description ?: ""); + + if (keyring->flags & ((1 << KEY_FLAG_INVALIDATED) | + (1 << KEY_FLAG_REVOKED))) + goto dont_gc; + + /* scan the keyring looking for dead keys */ + rcu_read_lock(); + result = assoc_array_iterate(&keyring->keys, + keyring_gc_check_iterator, &limit); + rcu_read_unlock(); + if (result == true) + goto do_gc; + +dont_gc: + kleave(" [no gc]"); + return; + +do_gc: + down_write(&keyring->sem); + assoc_array_gc(&keyring->keys, &keyring_assoc_array_ops, + keyring_gc_select_iterator, &limit); + up_write(&keyring->sem); + kleave(" [gc]"); +} + +/* + * Garbage collect restriction pointers from a keyring. + * + * Keyring restrictions are associated with a key type, and must be cleaned + * up if the key type is unregistered. The restriction is altered to always + * reject additional keys so a keyring cannot be opened up by unregistering + * a key type. + * + * Not called with any keyring locks held. The keyring's key struct will not + * be deallocated under us as only our caller may deallocate it. + * + * The caller is required to hold key_types_sem and dead_type->sem. This is + * fulfilled by key_gc_keytype() holding the locks on behalf of + * key_garbage_collector(), which it invokes on a workqueue. + */ +void keyring_restriction_gc(struct key *keyring, struct key_type *dead_type) +{ + struct key_restriction *keyres; + + kenter("%x{%s}", keyring->serial, keyring->description ?: ""); + + /* + * keyring->restrict_link is only assigned at key allocation time + * or with the key type locked, so the only values that could be + * concurrently assigned to keyring->restrict_link are for key + * types other than dead_type. Given this, it's ok to check + * the key type before acquiring keyring->sem. + */ + if (!dead_type || !keyring->restrict_link || + keyring->restrict_link->keytype != dead_type) { + kleave(" [no restriction gc]"); + return; + } + + /* Lock the keyring to ensure that a link is not in progress */ + down_write(&keyring->sem); + + keyres = keyring->restrict_link; + + keyres->check = restrict_link_reject; + + key_put(keyres->key); + keyres->key = NULL; + keyres->keytype = NULL; + + up_write(&keyring->sem); + + kleave(" [restriction gc]"); +} diff --git a/security/keys/permission.c b/security/keys/permission.c new file mode 100644 index 000000000..4a61f804e --- /dev/null +++ b/security/keys/permission.c @@ -0,0 +1,123 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* Key permission checking + * + * Copyright (C) 2005 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#include <linux/export.h> +#include <linux/security.h> +#include "internal.h" + +/** + * key_task_permission - Check a key can be used + * @key_ref: The key to check. + * @cred: The credentials to use. + * @need_perm: The permission required. + * + * Check to see whether permission is granted to use a key in the desired way, + * but permit the security modules to override. + * + * The caller must hold either a ref on cred or must hold the RCU readlock. + * + * Returns 0 if successful, -EACCES if access is denied based on the + * permissions bits or the LSM check. + */ +int key_task_permission(const key_ref_t key_ref, const struct cred *cred, + enum key_need_perm need_perm) +{ + struct key *key; + key_perm_t kperm, mask; + int ret; + + switch (need_perm) { + default: + WARN_ON(1); + return -EACCES; + case KEY_NEED_UNLINK: + case KEY_SYSADMIN_OVERRIDE: + case KEY_AUTHTOKEN_OVERRIDE: + case KEY_DEFER_PERM_CHECK: + goto lsm; + + case KEY_NEED_VIEW: mask = KEY_OTH_VIEW; break; + case KEY_NEED_READ: mask = KEY_OTH_READ; break; + case KEY_NEED_WRITE: mask = KEY_OTH_WRITE; break; + case KEY_NEED_SEARCH: mask = KEY_OTH_SEARCH; break; + case KEY_NEED_LINK: mask = KEY_OTH_LINK; break; + case KEY_NEED_SETATTR: mask = KEY_OTH_SETATTR; break; + } + + key = key_ref_to_ptr(key_ref); + + /* use the second 8-bits of permissions for keys the caller owns */ + if (uid_eq(key->uid, cred->fsuid)) { + kperm = key->perm >> 16; + goto use_these_perms; + } + + /* use the third 8-bits of permissions for keys the caller has a group + * membership in common with */ + if (gid_valid(key->gid) && key->perm & KEY_GRP_ALL) { + if (gid_eq(key->gid, cred->fsgid)) { + kperm = key->perm >> 8; + goto use_these_perms; + } + + ret = groups_search(cred->group_info, key->gid); + if (ret) { + kperm = key->perm >> 8; + goto use_these_perms; + } + } + + /* otherwise use the least-significant 8-bits */ + kperm = key->perm; + +use_these_perms: + + /* use the top 8-bits of permissions for keys the caller possesses + * - possessor permissions are additive with other permissions + */ + if (is_key_possessed(key_ref)) + kperm |= key->perm >> 24; + + if ((kperm & mask) != mask) + return -EACCES; + + /* let LSM be the final arbiter */ +lsm: + return security_key_permission(key_ref, cred, need_perm); +} +EXPORT_SYMBOL(key_task_permission); + +/** + * key_validate - Validate a key. + * @key: The key to be validated. + * + * Check that a key is valid, returning 0 if the key is okay, -ENOKEY if the + * key is invalidated, -EKEYREVOKED if the key's type has been removed or if + * the key has been revoked or -EKEYEXPIRED if the key has expired. + */ +int key_validate(const struct key *key) +{ + unsigned long flags = READ_ONCE(key->flags); + time64_t expiry = READ_ONCE(key->expiry); + + if (flags & (1 << KEY_FLAG_INVALIDATED)) + return -ENOKEY; + + /* check it's still accessible */ + if (flags & ((1 << KEY_FLAG_REVOKED) | + (1 << KEY_FLAG_DEAD))) + return -EKEYREVOKED; + + /* check it hasn't expired */ + if (expiry) { + if (ktime_get_real_seconds() >= expiry) + return -EKEYEXPIRED; + } + + return 0; +} +EXPORT_SYMBOL(key_validate); diff --git a/security/keys/persistent.c b/security/keys/persistent.c new file mode 100644 index 000000000..97af230aa --- /dev/null +++ b/security/keys/persistent.c @@ -0,0 +1,167 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* General persistent per-UID keyrings register + * + * Copyright (C) 2013 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#include <linux/user_namespace.h> +#include <linux/cred.h> + +#include "internal.h" + +unsigned persistent_keyring_expiry = 3 * 24 * 3600; /* Expire after 3 days of non-use */ + +/* + * Create the persistent keyring register for the current user namespace. + * + * Called with the namespace's sem locked for writing. + */ +static int key_create_persistent_register(struct user_namespace *ns) +{ + struct key *reg = keyring_alloc(".persistent_register", + KUIDT_INIT(0), KGIDT_INIT(0), + current_cred(), + ((KEY_POS_ALL & ~KEY_POS_SETATTR) | + KEY_USR_VIEW | KEY_USR_READ), + KEY_ALLOC_NOT_IN_QUOTA, NULL, NULL); + if (IS_ERR(reg)) + return PTR_ERR(reg); + + ns->persistent_keyring_register = reg; + return 0; +} + +/* + * Create the persistent keyring for the specified user. + * + * Called with the namespace's sem locked for writing. + */ +static key_ref_t key_create_persistent(struct user_namespace *ns, kuid_t uid, + struct keyring_index_key *index_key) +{ + struct key *persistent; + key_ref_t reg_ref, persistent_ref; + + if (!ns->persistent_keyring_register) { + long err = key_create_persistent_register(ns); + if (err < 0) + return ERR_PTR(err); + } else { + reg_ref = make_key_ref(ns->persistent_keyring_register, true); + persistent_ref = find_key_to_update(reg_ref, index_key); + if (persistent_ref) + return persistent_ref; + } + + persistent = keyring_alloc(index_key->description, + uid, INVALID_GID, current_cred(), + ((KEY_POS_ALL & ~KEY_POS_SETATTR) | + KEY_USR_VIEW | KEY_USR_READ), + KEY_ALLOC_NOT_IN_QUOTA, NULL, + ns->persistent_keyring_register); + if (IS_ERR(persistent)) + return ERR_CAST(persistent); + + return make_key_ref(persistent, true); +} + +/* + * Get the persistent keyring for a specific UID and link it to the nominated + * keyring. + */ +static long key_get_persistent(struct user_namespace *ns, kuid_t uid, + key_ref_t dest_ref) +{ + struct keyring_index_key index_key; + struct key *persistent; + key_ref_t reg_ref, persistent_ref; + char buf[32]; + long ret; + + /* Look in the register if it exists */ + memset(&index_key, 0, sizeof(index_key)); + index_key.type = &key_type_keyring; + index_key.description = buf; + index_key.desc_len = sprintf(buf, "_persistent.%u", from_kuid(ns, uid)); + key_set_index_key(&index_key); + + if (ns->persistent_keyring_register) { + reg_ref = make_key_ref(ns->persistent_keyring_register, true); + down_read(&ns->keyring_sem); + persistent_ref = find_key_to_update(reg_ref, &index_key); + up_read(&ns->keyring_sem); + + if (persistent_ref) + goto found; + } + + /* It wasn't in the register, so we'll need to create it. We might + * also need to create the register. + */ + down_write(&ns->keyring_sem); + persistent_ref = key_create_persistent(ns, uid, &index_key); + up_write(&ns->keyring_sem); + if (!IS_ERR(persistent_ref)) + goto found; + + return PTR_ERR(persistent_ref); + +found: + ret = key_task_permission(persistent_ref, current_cred(), KEY_NEED_LINK); + if (ret == 0) { + persistent = key_ref_to_ptr(persistent_ref); + ret = key_link(key_ref_to_ptr(dest_ref), persistent); + if (ret == 0) { + key_set_timeout(persistent, persistent_keyring_expiry); + ret = persistent->serial; + } + } + + key_ref_put(persistent_ref); + return ret; +} + +/* + * Get the persistent keyring for a specific UID and link it to the nominated + * keyring. + */ +long keyctl_get_persistent(uid_t _uid, key_serial_t destid) +{ + struct user_namespace *ns = current_user_ns(); + key_ref_t dest_ref; + kuid_t uid; + long ret; + + /* -1 indicates the current user */ + if (_uid == (uid_t)-1) { + uid = current_uid(); + } else { + uid = make_kuid(ns, _uid); + if (!uid_valid(uid)) + return -EINVAL; + + /* You can only see your own persistent cache if you're not + * sufficiently privileged. + */ + if (!uid_eq(uid, current_uid()) && + !uid_eq(uid, current_euid()) && + !ns_capable(ns, CAP_SETUID)) + return -EPERM; + } + + /* There must be a destination keyring */ + dest_ref = lookup_user_key(destid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE); + if (IS_ERR(dest_ref)) + return PTR_ERR(dest_ref); + if (key_ref_to_ptr(dest_ref)->type != &key_type_keyring) { + ret = -ENOTDIR; + goto out_put_dest; + } + + ret = key_get_persistent(ns, uid, dest_ref); + +out_put_dest: + key_ref_put(dest_ref); + return ret; +} diff --git a/security/keys/proc.c b/security/keys/proc.c new file mode 100644 index 000000000..4f4e2c182 --- /dev/null +++ b/security/keys/proc.c @@ -0,0 +1,323 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* procfs files for key database enumeration + * + * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#include <linux/init.h> +#include <linux/sched.h> +#include <linux/fs.h> +#include <linux/proc_fs.h> +#include <linux/seq_file.h> +#include <asm/errno.h> +#include "internal.h" + +static void *proc_keys_start(struct seq_file *p, loff_t *_pos); +static void *proc_keys_next(struct seq_file *p, void *v, loff_t *_pos); +static void proc_keys_stop(struct seq_file *p, void *v); +static int proc_keys_show(struct seq_file *m, void *v); + +static const struct seq_operations proc_keys_ops = { + .start = proc_keys_start, + .next = proc_keys_next, + .stop = proc_keys_stop, + .show = proc_keys_show, +}; + +static void *proc_key_users_start(struct seq_file *p, loff_t *_pos); +static void *proc_key_users_next(struct seq_file *p, void *v, loff_t *_pos); +static void proc_key_users_stop(struct seq_file *p, void *v); +static int proc_key_users_show(struct seq_file *m, void *v); + +static const struct seq_operations proc_key_users_ops = { + .start = proc_key_users_start, + .next = proc_key_users_next, + .stop = proc_key_users_stop, + .show = proc_key_users_show, +}; + +/* + * Declare the /proc files. + */ +static int __init key_proc_init(void) +{ + struct proc_dir_entry *p; + + p = proc_create_seq("keys", 0, NULL, &proc_keys_ops); + if (!p) + panic("Cannot create /proc/keys\n"); + + p = proc_create_seq("key-users", 0, NULL, &proc_key_users_ops); + if (!p) + panic("Cannot create /proc/key-users\n"); + + return 0; +} + +__initcall(key_proc_init); + +/* + * Implement "/proc/keys" to provide a list of the keys on the system that + * grant View permission to the caller. + */ +static struct rb_node *key_serial_next(struct seq_file *p, struct rb_node *n) +{ + struct user_namespace *user_ns = seq_user_ns(p); + + n = rb_next(n); + while (n) { + struct key *key = rb_entry(n, struct key, serial_node); + if (kuid_has_mapping(user_ns, key->user->uid)) + break; + n = rb_next(n); + } + return n; +} + +static struct key *find_ge_key(struct seq_file *p, key_serial_t id) +{ + struct user_namespace *user_ns = seq_user_ns(p); + struct rb_node *n = key_serial_tree.rb_node; + struct key *minkey = NULL; + + while (n) { + struct key *key = rb_entry(n, struct key, serial_node); + if (id < key->serial) { + if (!minkey || minkey->serial > key->serial) + minkey = key; + n = n->rb_left; + } else if (id > key->serial) { + n = n->rb_right; + } else { + minkey = key; + break; + } + key = NULL; + } + + if (!minkey) + return NULL; + + for (;;) { + if (kuid_has_mapping(user_ns, minkey->user->uid)) + return minkey; + n = rb_next(&minkey->serial_node); + if (!n) + return NULL; + minkey = rb_entry(n, struct key, serial_node); + } +} + +static void *proc_keys_start(struct seq_file *p, loff_t *_pos) + __acquires(key_serial_lock) +{ + key_serial_t pos = *_pos; + struct key *key; + + spin_lock(&key_serial_lock); + + if (*_pos > INT_MAX) + return NULL; + key = find_ge_key(p, pos); + if (!key) + return NULL; + *_pos = key->serial; + return &key->serial_node; +} + +static inline key_serial_t key_node_serial(struct rb_node *n) +{ + struct key *key = rb_entry(n, struct key, serial_node); + return key->serial; +} + +static void *proc_keys_next(struct seq_file *p, void *v, loff_t *_pos) +{ + struct rb_node *n; + + n = key_serial_next(p, v); + if (n) + *_pos = key_node_serial(n); + else + (*_pos)++; + return n; +} + +static void proc_keys_stop(struct seq_file *p, void *v) + __releases(key_serial_lock) +{ + spin_unlock(&key_serial_lock); +} + +static int proc_keys_show(struct seq_file *m, void *v) +{ + struct rb_node *_p = v; + struct key *key = rb_entry(_p, struct key, serial_node); + unsigned long flags; + key_ref_t key_ref, skey_ref; + time64_t now, expiry; + char xbuf[16]; + short state; + u64 timo; + int rc; + + struct keyring_search_context ctx = { + .index_key = key->index_key, + .cred = m->file->f_cred, + .match_data.cmp = lookup_user_key_possessed, + .match_data.raw_data = key, + .match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT, + .flags = (KEYRING_SEARCH_NO_STATE_CHECK | + KEYRING_SEARCH_RECURSE), + }; + + key_ref = make_key_ref(key, 0); + + /* determine if the key is possessed by this process (a test we can + * skip if the key does not indicate the possessor can view it + */ + if (key->perm & KEY_POS_VIEW) { + rcu_read_lock(); + skey_ref = search_cred_keyrings_rcu(&ctx); + rcu_read_unlock(); + if (!IS_ERR(skey_ref)) { + key_ref_put(skey_ref); + key_ref = make_key_ref(key, 1); + } + } + + /* check whether the current task is allowed to view the key */ + rc = key_task_permission(key_ref, ctx.cred, KEY_NEED_VIEW); + if (rc < 0) + return 0; + + now = ktime_get_real_seconds(); + + rcu_read_lock(); + + /* come up with a suitable timeout value */ + expiry = READ_ONCE(key->expiry); + if (expiry == TIME64_MAX) { + memcpy(xbuf, "perm", 5); + } else if (now >= expiry) { + memcpy(xbuf, "expd", 5); + } else { + timo = expiry - now; + + if (timo < 60) + sprintf(xbuf, "%llus", timo); + else if (timo < 60*60) + sprintf(xbuf, "%llum", div_u64(timo, 60)); + else if (timo < 60*60*24) + sprintf(xbuf, "%lluh", div_u64(timo, 60 * 60)); + else if (timo < 60*60*24*7) + sprintf(xbuf, "%llud", div_u64(timo, 60 * 60 * 24)); + else + sprintf(xbuf, "%lluw", div_u64(timo, 60 * 60 * 24 * 7)); + } + + state = key_read_state(key); + +#define showflag(FLAGS, LETTER, FLAG) \ + ((FLAGS & (1 << FLAG)) ? LETTER : '-') + + flags = READ_ONCE(key->flags); + seq_printf(m, "%08x %c%c%c%c%c%c%c %5d %4s %08x %5d %5d %-9.9s ", + key->serial, + state != KEY_IS_UNINSTANTIATED ? 'I' : '-', + showflag(flags, 'R', KEY_FLAG_REVOKED), + showflag(flags, 'D', KEY_FLAG_DEAD), + showflag(flags, 'Q', KEY_FLAG_IN_QUOTA), + showflag(flags, 'U', KEY_FLAG_USER_CONSTRUCT), + state < 0 ? 'N' : '-', + showflag(flags, 'i', KEY_FLAG_INVALIDATED), + refcount_read(&key->usage), + xbuf, + key->perm, + from_kuid_munged(seq_user_ns(m), key->uid), + from_kgid_munged(seq_user_ns(m), key->gid), + key->type->name); + +#undef showflag + + if (key->type->describe) + key->type->describe(key, m); + seq_putc(m, '\n'); + + rcu_read_unlock(); + return 0; +} + +static struct rb_node *__key_user_next(struct user_namespace *user_ns, struct rb_node *n) +{ + while (n) { + struct key_user *user = rb_entry(n, struct key_user, node); + if (kuid_has_mapping(user_ns, user->uid)) + break; + n = rb_next(n); + } + return n; +} + +static struct rb_node *key_user_next(struct user_namespace *user_ns, struct rb_node *n) +{ + return __key_user_next(user_ns, rb_next(n)); +} + +static struct rb_node *key_user_first(struct user_namespace *user_ns, struct rb_root *r) +{ + struct rb_node *n = rb_first(r); + return __key_user_next(user_ns, n); +} + +static void *proc_key_users_start(struct seq_file *p, loff_t *_pos) + __acquires(key_user_lock) +{ + struct rb_node *_p; + loff_t pos = *_pos; + + spin_lock(&key_user_lock); + + _p = key_user_first(seq_user_ns(p), &key_user_tree); + while (pos > 0 && _p) { + pos--; + _p = key_user_next(seq_user_ns(p), _p); + } + + return _p; +} + +static void *proc_key_users_next(struct seq_file *p, void *v, loff_t *_pos) +{ + (*_pos)++; + return key_user_next(seq_user_ns(p), (struct rb_node *)v); +} + +static void proc_key_users_stop(struct seq_file *p, void *v) + __releases(key_user_lock) +{ + spin_unlock(&key_user_lock); +} + +static int proc_key_users_show(struct seq_file *m, void *v) +{ + struct rb_node *_p = v; + struct key_user *user = rb_entry(_p, struct key_user, node); + unsigned maxkeys = uid_eq(user->uid, GLOBAL_ROOT_UID) ? + key_quota_root_maxkeys : key_quota_maxkeys; + unsigned maxbytes = uid_eq(user->uid, GLOBAL_ROOT_UID) ? + key_quota_root_maxbytes : key_quota_maxbytes; + + seq_printf(m, "%5u: %5d %d/%d %d/%d %d/%d\n", + from_kuid_munged(seq_user_ns(m), user->uid), + refcount_read(&user->usage), + atomic_read(&user->nkeys), + atomic_read(&user->nikeys), + user->qnkeys, + maxkeys, + user->qnbytes, + maxbytes); + + return 0; +} diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c new file mode 100644 index 000000000..b5d5333ab --- /dev/null +++ b/security/keys/process_keys.c @@ -0,0 +1,965 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* Manage a process's keyrings + * + * Copyright (C) 2004-2005, 2008 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#include <linux/init.h> +#include <linux/sched.h> +#include <linux/sched/user.h> +#include <linux/keyctl.h> +#include <linux/fs.h> +#include <linux/err.h> +#include <linux/mutex.h> +#include <linux/security.h> +#include <linux/user_namespace.h> +#include <linux/uaccess.h> +#include <linux/init_task.h> +#include <keys/request_key_auth-type.h> +#include "internal.h" + +/* Session keyring create vs join semaphore */ +static DEFINE_MUTEX(key_session_mutex); + +/* The root user's tracking struct */ +struct key_user root_key_user = { + .usage = REFCOUNT_INIT(3), + .cons_lock = __MUTEX_INITIALIZER(root_key_user.cons_lock), + .lock = __SPIN_LOCK_UNLOCKED(root_key_user.lock), + .nkeys = ATOMIC_INIT(2), + .nikeys = ATOMIC_INIT(2), + .uid = GLOBAL_ROOT_UID, +}; + +/* + * Get or create a user register keyring. + */ +static struct key *get_user_register(struct user_namespace *user_ns) +{ + struct key *reg_keyring = READ_ONCE(user_ns->user_keyring_register); + + if (reg_keyring) + return reg_keyring; + + down_write(&user_ns->keyring_sem); + + /* Make sure there's a register keyring. It gets owned by the + * user_namespace's owner. + */ + reg_keyring = user_ns->user_keyring_register; + if (!reg_keyring) { + reg_keyring = keyring_alloc(".user_reg", + user_ns->owner, INVALID_GID, + &init_cred, + KEY_POS_WRITE | KEY_POS_SEARCH | + KEY_USR_VIEW | KEY_USR_READ, + 0, + NULL, NULL); + if (!IS_ERR(reg_keyring)) + smp_store_release(&user_ns->user_keyring_register, + reg_keyring); + } + + up_write(&user_ns->keyring_sem); + + /* We don't return a ref since the keyring is pinned by the user_ns */ + return reg_keyring; +} + +/* + * Look up the user and user session keyrings for the current process's UID, + * creating them if they don't exist. + */ +int look_up_user_keyrings(struct key **_user_keyring, + struct key **_user_session_keyring) +{ + const struct cred *cred = current_cred(); + struct user_namespace *user_ns = current_user_ns(); + struct key *reg_keyring, *uid_keyring, *session_keyring; + key_perm_t user_keyring_perm; + key_ref_t uid_keyring_r, session_keyring_r; + uid_t uid = from_kuid(user_ns, cred->user->uid); + char buf[20]; + int ret; + + user_keyring_perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_ALL; + + kenter("%u", uid); + + reg_keyring = get_user_register(user_ns); + if (IS_ERR(reg_keyring)) + return PTR_ERR(reg_keyring); + + down_write(&user_ns->keyring_sem); + ret = 0; + + /* Get the user keyring. Note that there may be one in existence + * already as it may have been pinned by a session, but the user_struct + * pointing to it may have been destroyed by setuid. + */ + snprintf(buf, sizeof(buf), "_uid.%u", uid); + uid_keyring_r = keyring_search(make_key_ref(reg_keyring, true), + &key_type_keyring, buf, false); + kdebug("_uid %p", uid_keyring_r); + if (uid_keyring_r == ERR_PTR(-EAGAIN)) { + uid_keyring = keyring_alloc(buf, cred->user->uid, INVALID_GID, + cred, user_keyring_perm, + KEY_ALLOC_UID_KEYRING | + KEY_ALLOC_IN_QUOTA, + NULL, reg_keyring); + if (IS_ERR(uid_keyring)) { + ret = PTR_ERR(uid_keyring); + goto error; + } + } else if (IS_ERR(uid_keyring_r)) { + ret = PTR_ERR(uid_keyring_r); + goto error; + } else { + uid_keyring = key_ref_to_ptr(uid_keyring_r); + } + + /* Get a default session keyring (which might also exist already) */ + snprintf(buf, sizeof(buf), "_uid_ses.%u", uid); + session_keyring_r = keyring_search(make_key_ref(reg_keyring, true), + &key_type_keyring, buf, false); + kdebug("_uid_ses %p", session_keyring_r); + if (session_keyring_r == ERR_PTR(-EAGAIN)) { + session_keyring = keyring_alloc(buf, cred->user->uid, INVALID_GID, + cred, user_keyring_perm, + KEY_ALLOC_UID_KEYRING | + KEY_ALLOC_IN_QUOTA, + NULL, NULL); + if (IS_ERR(session_keyring)) { + ret = PTR_ERR(session_keyring); + goto error_release; + } + + /* We install a link from the user session keyring to + * the user keyring. + */ + ret = key_link(session_keyring, uid_keyring); + if (ret < 0) + goto error_release_session; + + /* And only then link the user-session keyring to the + * register. + */ + ret = key_link(reg_keyring, session_keyring); + if (ret < 0) + goto error_release_session; + } else if (IS_ERR(session_keyring_r)) { + ret = PTR_ERR(session_keyring_r); + goto error_release; + } else { + session_keyring = key_ref_to_ptr(session_keyring_r); + } + + up_write(&user_ns->keyring_sem); + + if (_user_session_keyring) + *_user_session_keyring = session_keyring; + else + key_put(session_keyring); + if (_user_keyring) + *_user_keyring = uid_keyring; + else + key_put(uid_keyring); + kleave(" = 0"); + return 0; + +error_release_session: + key_put(session_keyring); +error_release: + key_put(uid_keyring); +error: + up_write(&user_ns->keyring_sem); + kleave(" = %d", ret); + return ret; +} + +/* + * Get the user session keyring if it exists, but don't create it if it + * doesn't. + */ +struct key *get_user_session_keyring_rcu(const struct cred *cred) +{ + struct key *reg_keyring = READ_ONCE(cred->user_ns->user_keyring_register); + key_ref_t session_keyring_r; + char buf[20]; + + struct keyring_search_context ctx = { + .index_key.type = &key_type_keyring, + .index_key.description = buf, + .cred = cred, + .match_data.cmp = key_default_cmp, + .match_data.raw_data = buf, + .match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT, + .flags = KEYRING_SEARCH_DO_STATE_CHECK, + }; + + if (!reg_keyring) + return NULL; + + ctx.index_key.desc_len = snprintf(buf, sizeof(buf), "_uid_ses.%u", + from_kuid(cred->user_ns, + cred->user->uid)); + + session_keyring_r = keyring_search_rcu(make_key_ref(reg_keyring, true), + &ctx); + if (IS_ERR(session_keyring_r)) + return NULL; + return key_ref_to_ptr(session_keyring_r); +} + +/* + * Install a thread keyring to the given credentials struct if it didn't have + * one already. This is allowed to overrun the quota. + * + * Return: 0 if a thread keyring is now present; -errno on failure. + */ +int install_thread_keyring_to_cred(struct cred *new) +{ + struct key *keyring; + + if (new->thread_keyring) + return 0; + + keyring = keyring_alloc("_tid", new->uid, new->gid, new, + KEY_POS_ALL | KEY_USR_VIEW, + KEY_ALLOC_QUOTA_OVERRUN, + NULL, NULL); + if (IS_ERR(keyring)) + return PTR_ERR(keyring); + + new->thread_keyring = keyring; + return 0; +} + +/* + * Install a thread keyring to the current task if it didn't have one already. + * + * Return: 0 if a thread keyring is now present; -errno on failure. + */ +static int install_thread_keyring(void) +{ + struct cred *new; + int ret; + + new = prepare_creds(); + if (!new) + return -ENOMEM; + + ret = install_thread_keyring_to_cred(new); + if (ret < 0) { + abort_creds(new); + return ret; + } + + return commit_creds(new); +} + +/* + * Install a process keyring to the given credentials struct if it didn't have + * one already. This is allowed to overrun the quota. + * + * Return: 0 if a process keyring is now present; -errno on failure. + */ +int install_process_keyring_to_cred(struct cred *new) +{ + struct key *keyring; + + if (new->process_keyring) + return 0; + + keyring = keyring_alloc("_pid", new->uid, new->gid, new, + KEY_POS_ALL | KEY_USR_VIEW, + KEY_ALLOC_QUOTA_OVERRUN, + NULL, NULL); + if (IS_ERR(keyring)) + return PTR_ERR(keyring); + + new->process_keyring = keyring; + return 0; +} + +/* + * Install a process keyring to the current task if it didn't have one already. + * + * Return: 0 if a process keyring is now present; -errno on failure. + */ +static int install_process_keyring(void) +{ + struct cred *new; + int ret; + + new = prepare_creds(); + if (!new) + return -ENOMEM; + + ret = install_process_keyring_to_cred(new); + if (ret < 0) { + abort_creds(new); + return ret; + } + + return commit_creds(new); +} + +/* + * Install the given keyring as the session keyring of the given credentials + * struct, replacing the existing one if any. If the given keyring is NULL, + * then install a new anonymous session keyring. + * @cred can not be in use by any task yet. + * + * Return: 0 on success; -errno on failure. + */ +int install_session_keyring_to_cred(struct cred *cred, struct key *keyring) +{ + unsigned long flags; + struct key *old; + + might_sleep(); + + /* create an empty session keyring */ + if (!keyring) { + flags = KEY_ALLOC_QUOTA_OVERRUN; + if (cred->session_keyring) + flags = KEY_ALLOC_IN_QUOTA; + + keyring = keyring_alloc("_ses", cred->uid, cred->gid, cred, + KEY_POS_ALL | KEY_USR_VIEW | KEY_USR_READ, + flags, NULL, NULL); + if (IS_ERR(keyring)) + return PTR_ERR(keyring); + } else { + __key_get(keyring); + } + + /* install the keyring */ + old = cred->session_keyring; + cred->session_keyring = keyring; + + if (old) + key_put(old); + + return 0; +} + +/* + * Install the given keyring as the session keyring of the current task, + * replacing the existing one if any. If the given keyring is NULL, then + * install a new anonymous session keyring. + * + * Return: 0 on success; -errno on failure. + */ +static int install_session_keyring(struct key *keyring) +{ + struct cred *new; + int ret; + + new = prepare_creds(); + if (!new) + return -ENOMEM; + + ret = install_session_keyring_to_cred(new, keyring); + if (ret < 0) { + abort_creds(new); + return ret; + } + + return commit_creds(new); +} + +/* + * Handle the fsuid changing. + */ +void key_fsuid_changed(struct cred *new_cred) +{ + /* update the ownership of the thread keyring */ + if (new_cred->thread_keyring) { + down_write(&new_cred->thread_keyring->sem); + new_cred->thread_keyring->uid = new_cred->fsuid; + up_write(&new_cred->thread_keyring->sem); + } +} + +/* + * Handle the fsgid changing. + */ +void key_fsgid_changed(struct cred *new_cred) +{ + /* update the ownership of the thread keyring */ + if (new_cred->thread_keyring) { + down_write(&new_cred->thread_keyring->sem); + new_cred->thread_keyring->gid = new_cred->fsgid; + up_write(&new_cred->thread_keyring->sem); + } +} + +/* + * Search the process keyrings attached to the supplied cred for the first + * matching key under RCU conditions (the caller must be holding the RCU read + * lock). + * + * The search criteria are the type and the match function. The description is + * given to the match function as a parameter, but doesn't otherwise influence + * the search. Typically the match function will compare the description + * parameter to the key's description. + * + * This can only search keyrings that grant Search permission to the supplied + * credentials. Keyrings linked to searched keyrings will also be searched if + * they grant Search permission too. Keys can only be found if they grant + * Search permission to the credentials. + * + * Returns a pointer to the key with the key usage count incremented if + * successful, -EAGAIN if we didn't find any matching key or -ENOKEY if we only + * matched negative keys. + * + * In the case of a successful return, the possession attribute is set on the + * returned key reference. + */ +key_ref_t search_cred_keyrings_rcu(struct keyring_search_context *ctx) +{ + struct key *user_session; + key_ref_t key_ref, ret, err; + const struct cred *cred = ctx->cred; + + /* we want to return -EAGAIN or -ENOKEY if any of the keyrings were + * searchable, but we failed to find a key or we found a negative key; + * otherwise we want to return a sample error (probably -EACCES) if + * none of the keyrings were searchable + * + * in terms of priority: success > -ENOKEY > -EAGAIN > other error + */ + key_ref = NULL; + ret = NULL; + err = ERR_PTR(-EAGAIN); + + /* search the thread keyring first */ + if (cred->thread_keyring) { + key_ref = keyring_search_rcu( + make_key_ref(cred->thread_keyring, 1), ctx); + if (!IS_ERR(key_ref)) + goto found; + + switch (PTR_ERR(key_ref)) { + case -EAGAIN: /* no key */ + case -ENOKEY: /* negative key */ + ret = key_ref; + break; + default: + err = key_ref; + break; + } + } + + /* search the process keyring second */ + if (cred->process_keyring) { + key_ref = keyring_search_rcu( + make_key_ref(cred->process_keyring, 1), ctx); + if (!IS_ERR(key_ref)) + goto found; + + switch (PTR_ERR(key_ref)) { + case -EAGAIN: /* no key */ + if (ret) + break; + fallthrough; + case -ENOKEY: /* negative key */ + ret = key_ref; + break; + default: + err = key_ref; + break; + } + } + + /* search the session keyring */ + if (cred->session_keyring) { + key_ref = keyring_search_rcu( + make_key_ref(cred->session_keyring, 1), ctx); + + if (!IS_ERR(key_ref)) + goto found; + + switch (PTR_ERR(key_ref)) { + case -EAGAIN: /* no key */ + if (ret) + break; + fallthrough; + case -ENOKEY: /* negative key */ + ret = key_ref; + break; + default: + err = key_ref; + break; + } + } + /* or search the user-session keyring */ + else if ((user_session = get_user_session_keyring_rcu(cred))) { + key_ref = keyring_search_rcu(make_key_ref(user_session, 1), + ctx); + key_put(user_session); + + if (!IS_ERR(key_ref)) + goto found; + + switch (PTR_ERR(key_ref)) { + case -EAGAIN: /* no key */ + if (ret) + break; + fallthrough; + case -ENOKEY: /* negative key */ + ret = key_ref; + break; + default: + err = key_ref; + break; + } + } + + /* no key - decide on the error we're going to go for */ + key_ref = ret ? ret : err; + +found: + return key_ref; +} + +/* + * Search the process keyrings attached to the supplied cred for the first + * matching key in the manner of search_my_process_keyrings(), but also search + * the keys attached to the assumed authorisation key using its credentials if + * one is available. + * + * The caller must be holding the RCU read lock. + * + * Return same as search_cred_keyrings_rcu(). + */ +key_ref_t search_process_keyrings_rcu(struct keyring_search_context *ctx) +{ + struct request_key_auth *rka; + key_ref_t key_ref, ret = ERR_PTR(-EACCES), err; + + key_ref = search_cred_keyrings_rcu(ctx); + if (!IS_ERR(key_ref)) + goto found; + err = key_ref; + + /* if this process has an instantiation authorisation key, then we also + * search the keyrings of the process mentioned there + * - we don't permit access to request_key auth keys via this method + */ + if (ctx->cred->request_key_auth && + ctx->cred == current_cred() && + ctx->index_key.type != &key_type_request_key_auth + ) { + const struct cred *cred = ctx->cred; + + if (key_validate(cred->request_key_auth) == 0) { + rka = ctx->cred->request_key_auth->payload.data[0]; + + //// was search_process_keyrings() [ie. recursive] + ctx->cred = rka->cred; + key_ref = search_cred_keyrings_rcu(ctx); + ctx->cred = cred; + + if (!IS_ERR(key_ref)) + goto found; + ret = key_ref; + } + } + + /* no key - decide on the error we're going to go for */ + if (err == ERR_PTR(-ENOKEY) || ret == ERR_PTR(-ENOKEY)) + key_ref = ERR_PTR(-ENOKEY); + else if (err == ERR_PTR(-EACCES)) + key_ref = ret; + else + key_ref = err; + +found: + return key_ref; +} +/* + * See if the key we're looking at is the target key. + */ +bool lookup_user_key_possessed(const struct key *key, + const struct key_match_data *match_data) +{ + return key == match_data->raw_data; +} + +/* + * Look up a key ID given us by userspace with a given permissions mask to get + * the key it refers to. + * + * Flags can be passed to request that special keyrings be created if referred + * to directly, to permit partially constructed keys to be found and to skip + * validity and permission checks on the found key. + * + * Returns a pointer to the key with an incremented usage count if successful; + * -EINVAL if the key ID is invalid; -ENOKEY if the key ID does not correspond + * to a key or the best found key was a negative key; -EKEYREVOKED or + * -EKEYEXPIRED if the best found key was revoked or expired; -EACCES if the + * found key doesn't grant the requested permit or the LSM denied access to it; + * or -ENOMEM if a special keyring couldn't be created. + * + * In the case of a successful return, the possession attribute is set on the + * returned key reference. + */ +key_ref_t lookup_user_key(key_serial_t id, unsigned long lflags, + enum key_need_perm need_perm) +{ + struct keyring_search_context ctx = { + .match_data.cmp = lookup_user_key_possessed, + .match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT, + .flags = (KEYRING_SEARCH_NO_STATE_CHECK | + KEYRING_SEARCH_RECURSE), + }; + struct request_key_auth *rka; + struct key *key, *user_session; + key_ref_t key_ref, skey_ref; + int ret; + +try_again: + ctx.cred = get_current_cred(); + key_ref = ERR_PTR(-ENOKEY); + + switch (id) { + case KEY_SPEC_THREAD_KEYRING: + if (!ctx.cred->thread_keyring) { + if (!(lflags & KEY_LOOKUP_CREATE)) + goto error; + + ret = install_thread_keyring(); + if (ret < 0) { + key_ref = ERR_PTR(ret); + goto error; + } + goto reget_creds; + } + + key = ctx.cred->thread_keyring; + __key_get(key); + key_ref = make_key_ref(key, 1); + break; + + case KEY_SPEC_PROCESS_KEYRING: + if (!ctx.cred->process_keyring) { + if (!(lflags & KEY_LOOKUP_CREATE)) + goto error; + + ret = install_process_keyring(); + if (ret < 0) { + key_ref = ERR_PTR(ret); + goto error; + } + goto reget_creds; + } + + key = ctx.cred->process_keyring; + __key_get(key); + key_ref = make_key_ref(key, 1); + break; + + case KEY_SPEC_SESSION_KEYRING: + if (!ctx.cred->session_keyring) { + /* always install a session keyring upon access if one + * doesn't exist yet */ + ret = look_up_user_keyrings(NULL, &user_session); + if (ret < 0) + goto error; + if (lflags & KEY_LOOKUP_CREATE) + ret = join_session_keyring(NULL); + else + ret = install_session_keyring(user_session); + + key_put(user_session); + if (ret < 0) + goto error; + goto reget_creds; + } else if (test_bit(KEY_FLAG_UID_KEYRING, + &ctx.cred->session_keyring->flags) && + lflags & KEY_LOOKUP_CREATE) { + ret = join_session_keyring(NULL); + if (ret < 0) + goto error; + goto reget_creds; + } + + key = ctx.cred->session_keyring; + __key_get(key); + key_ref = make_key_ref(key, 1); + break; + + case KEY_SPEC_USER_KEYRING: + ret = look_up_user_keyrings(&key, NULL); + if (ret < 0) + goto error; + key_ref = make_key_ref(key, 1); + break; + + case KEY_SPEC_USER_SESSION_KEYRING: + ret = look_up_user_keyrings(NULL, &key); + if (ret < 0) + goto error; + key_ref = make_key_ref(key, 1); + break; + + case KEY_SPEC_GROUP_KEYRING: + /* group keyrings are not yet supported */ + key_ref = ERR_PTR(-EINVAL); + goto error; + + case KEY_SPEC_REQKEY_AUTH_KEY: + key = ctx.cred->request_key_auth; + if (!key) + goto error; + + __key_get(key); + key_ref = make_key_ref(key, 1); + break; + + case KEY_SPEC_REQUESTOR_KEYRING: + if (!ctx.cred->request_key_auth) + goto error; + + down_read(&ctx.cred->request_key_auth->sem); + if (test_bit(KEY_FLAG_REVOKED, + &ctx.cred->request_key_auth->flags)) { + key_ref = ERR_PTR(-EKEYREVOKED); + key = NULL; + } else { + rka = ctx.cred->request_key_auth->payload.data[0]; + key = rka->dest_keyring; + __key_get(key); + } + up_read(&ctx.cred->request_key_auth->sem); + if (!key) + goto error; + key_ref = make_key_ref(key, 1); + break; + + default: + key_ref = ERR_PTR(-EINVAL); + if (id < 1) + goto error; + + key = key_lookup(id); + if (IS_ERR(key)) { + key_ref = ERR_CAST(key); + goto error; + } + + key_ref = make_key_ref(key, 0); + + /* check to see if we possess the key */ + ctx.index_key = key->index_key; + ctx.match_data.raw_data = key; + kdebug("check possessed"); + rcu_read_lock(); + skey_ref = search_process_keyrings_rcu(&ctx); + rcu_read_unlock(); + kdebug("possessed=%p", skey_ref); + + if (!IS_ERR(skey_ref)) { + key_put(key); + key_ref = skey_ref; + } + + break; + } + + /* unlink does not use the nominated key in any way, so can skip all + * the permission checks as it is only concerned with the keyring */ + if (need_perm != KEY_NEED_UNLINK) { + if (!(lflags & KEY_LOOKUP_PARTIAL)) { + ret = wait_for_key_construction(key, true); + switch (ret) { + case -ERESTARTSYS: + goto invalid_key; + default: + if (need_perm != KEY_AUTHTOKEN_OVERRIDE && + need_perm != KEY_DEFER_PERM_CHECK) + goto invalid_key; + break; + case 0: + break; + } + } else if (need_perm != KEY_DEFER_PERM_CHECK) { + ret = key_validate(key); + if (ret < 0) + goto invalid_key; + } + + ret = -EIO; + if (!(lflags & KEY_LOOKUP_PARTIAL) && + key_read_state(key) == KEY_IS_UNINSTANTIATED) + goto invalid_key; + } + + /* check the permissions */ + ret = key_task_permission(key_ref, ctx.cred, need_perm); + if (ret < 0) + goto invalid_key; + + key->last_used_at = ktime_get_real_seconds(); + +error: + put_cred(ctx.cred); + return key_ref; + +invalid_key: + key_ref_put(key_ref); + key_ref = ERR_PTR(ret); + goto error; + + /* if we attempted to install a keyring, then it may have caused new + * creds to be installed */ +reget_creds: + put_cred(ctx.cred); + goto try_again; +} +EXPORT_SYMBOL(lookup_user_key); + +/* + * Join the named keyring as the session keyring if possible else attempt to + * create a new one of that name and join that. + * + * If the name is NULL, an empty anonymous keyring will be installed as the + * session keyring. + * + * Named session keyrings are joined with a semaphore held to prevent the + * keyrings from going away whilst the attempt is made to going them and also + * to prevent a race in creating compatible session keyrings. + */ +long join_session_keyring(const char *name) +{ + const struct cred *old; + struct cred *new; + struct key *keyring; + long ret, serial; + + new = prepare_creds(); + if (!new) + return -ENOMEM; + old = current_cred(); + + /* if no name is provided, install an anonymous keyring */ + if (!name) { + ret = install_session_keyring_to_cred(new, NULL); + if (ret < 0) + goto error; + + serial = new->session_keyring->serial; + ret = commit_creds(new); + if (ret == 0) + ret = serial; + goto okay; + } + + /* allow the user to join or create a named keyring */ + mutex_lock(&key_session_mutex); + + /* look for an existing keyring of this name */ + keyring = find_keyring_by_name(name, false); + if (PTR_ERR(keyring) == -ENOKEY) { + /* not found - try and create a new one */ + keyring = keyring_alloc( + name, old->uid, old->gid, old, + KEY_POS_ALL | KEY_USR_VIEW | KEY_USR_READ | KEY_USR_LINK, + KEY_ALLOC_IN_QUOTA, NULL, NULL); + if (IS_ERR(keyring)) { + ret = PTR_ERR(keyring); + goto error2; + } + } else if (IS_ERR(keyring)) { + ret = PTR_ERR(keyring); + goto error2; + } else if (keyring == new->session_keyring) { + ret = 0; + goto error3; + } + + /* we've got a keyring - now to install it */ + ret = install_session_keyring_to_cred(new, keyring); + if (ret < 0) + goto error3; + + commit_creds(new); + mutex_unlock(&key_session_mutex); + + ret = keyring->serial; + key_put(keyring); +okay: + return ret; + +error3: + key_put(keyring); +error2: + mutex_unlock(&key_session_mutex); +error: + abort_creds(new); + return ret; +} + +/* + * Replace a process's session keyring on behalf of one of its children when + * the target process is about to resume userspace execution. + */ +void key_change_session_keyring(struct callback_head *twork) +{ + const struct cred *old = current_cred(); + struct cred *new = container_of(twork, struct cred, rcu); + + if (unlikely(current->flags & PF_EXITING)) { + put_cred(new); + return; + } + + /* If get_ucounts fails more bits are needed in the refcount */ + if (unlikely(!get_ucounts(old->ucounts))) { + WARN_ONCE(1, "In %s get_ucounts failed\n", __func__); + put_cred(new); + return; + } + + new-> uid = old-> uid; + new-> euid = old-> euid; + new-> suid = old-> suid; + new->fsuid = old->fsuid; + new-> gid = old-> gid; + new-> egid = old-> egid; + new-> sgid = old-> sgid; + new->fsgid = old->fsgid; + new->user = get_uid(old->user); + new->ucounts = old->ucounts; + new->user_ns = get_user_ns(old->user_ns); + new->group_info = get_group_info(old->group_info); + + new->securebits = old->securebits; + new->cap_inheritable = old->cap_inheritable; + new->cap_permitted = old->cap_permitted; + new->cap_effective = old->cap_effective; + new->cap_ambient = old->cap_ambient; + new->cap_bset = old->cap_bset; + + new->jit_keyring = old->jit_keyring; + new->thread_keyring = key_get(old->thread_keyring); + new->process_keyring = key_get(old->process_keyring); + + security_transfer_creds(new, old); + + commit_creds(new); +} + +/* + * Make sure that root's user and user-session keyrings exist. + */ +static int __init init_root_keyring(void) +{ + return look_up_user_keyrings(NULL, NULL); +} + +late_initcall(init_root_keyring); diff --git a/security/keys/request_key.c b/security/keys/request_key.c new file mode 100644 index 000000000..a7673ad86 --- /dev/null +++ b/security/keys/request_key.c @@ -0,0 +1,821 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* Request a key from userspace + * + * Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * See Documentation/security/keys/request-key.rst + */ + +#include <linux/export.h> +#include <linux/sched.h> +#include <linux/kmod.h> +#include <linux/err.h> +#include <linux/keyctl.h> +#include <linux/slab.h> +#include <net/net_namespace.h> +#include "internal.h" +#include <keys/request_key_auth-type.h> + +#define key_negative_timeout 60 /* default timeout on a negative key's existence */ + +static struct key *check_cached_key(struct keyring_search_context *ctx) +{ +#ifdef CONFIG_KEYS_REQUEST_CACHE + struct key *key = current->cached_requested_key; + + if (key && + ctx->match_data.cmp(key, &ctx->match_data) && + !(key->flags & ((1 << KEY_FLAG_INVALIDATED) | + (1 << KEY_FLAG_REVOKED)))) + return key_get(key); +#endif + return NULL; +} + +static void cache_requested_key(struct key *key) +{ +#ifdef CONFIG_KEYS_REQUEST_CACHE + struct task_struct *t = current; + + /* Do not cache key if it is a kernel thread */ + if (!(t->flags & PF_KTHREAD)) { + key_put(t->cached_requested_key); + t->cached_requested_key = key_get(key); + set_tsk_thread_flag(t, TIF_NOTIFY_RESUME); + } +#endif +} + +/** + * complete_request_key - Complete the construction of a key. + * @authkey: The authorisation key. + * @error: The success or failute of the construction. + * + * Complete the attempt to construct a key. The key will be negated + * if an error is indicated. The authorisation key will be revoked + * unconditionally. + */ +void complete_request_key(struct key *authkey, int error) +{ + struct request_key_auth *rka = get_request_key_auth(authkey); + struct key *key = rka->target_key; + + kenter("%d{%d},%d", authkey->serial, key->serial, error); + + if (error < 0) + key_negate_and_link(key, key_negative_timeout, NULL, authkey); + else + key_revoke(authkey); +} +EXPORT_SYMBOL(complete_request_key); + +/* + * Initialise a usermode helper that is going to have a specific session + * keyring. + * + * This is called in context of freshly forked kthread before kernel_execve(), + * so we can simply install the desired session_keyring at this point. + */ +static int umh_keys_init(struct subprocess_info *info, struct cred *cred) +{ + struct key *keyring = info->data; + + return install_session_keyring_to_cred(cred, keyring); +} + +/* + * Clean up a usermode helper with session keyring. + */ +static void umh_keys_cleanup(struct subprocess_info *info) +{ + struct key *keyring = info->data; + key_put(keyring); +} + +/* + * Call a usermode helper with a specific session keyring. + */ +static int call_usermodehelper_keys(const char *path, char **argv, char **envp, + struct key *session_keyring, int wait) +{ + struct subprocess_info *info; + + info = call_usermodehelper_setup(path, argv, envp, GFP_KERNEL, + umh_keys_init, umh_keys_cleanup, + session_keyring); + if (!info) + return -ENOMEM; + + key_get(session_keyring); + return call_usermodehelper_exec(info, wait); +} + +/* + * Request userspace finish the construction of a key + * - execute "/sbin/request-key <op> <key> <uid> <gid> <keyring> <keyring> <keyring>" + */ +static int call_sbin_request_key(struct key *authkey, void *aux) +{ + static char const request_key[] = "/sbin/request-key"; + struct request_key_auth *rka = get_request_key_auth(authkey); + const struct cred *cred = current_cred(); + key_serial_t prkey, sskey; + struct key *key = rka->target_key, *keyring, *session, *user_session; + char *argv[9], *envp[3], uid_str[12], gid_str[12]; + char key_str[12], keyring_str[3][12]; + char desc[20]; + int ret, i; + + kenter("{%d},{%d},%s", key->serial, authkey->serial, rka->op); + + ret = look_up_user_keyrings(NULL, &user_session); + if (ret < 0) + goto error_us; + + /* allocate a new session keyring */ + sprintf(desc, "_req.%u", key->serial); + + cred = get_current_cred(); + keyring = keyring_alloc(desc, cred->fsuid, cred->fsgid, cred, + KEY_POS_ALL | KEY_USR_VIEW | KEY_USR_READ, + KEY_ALLOC_QUOTA_OVERRUN, NULL, NULL); + put_cred(cred); + if (IS_ERR(keyring)) { + ret = PTR_ERR(keyring); + goto error_alloc; + } + + /* attach the auth key to the session keyring */ + ret = key_link(keyring, authkey); + if (ret < 0) + goto error_link; + + /* record the UID and GID */ + sprintf(uid_str, "%d", from_kuid(&init_user_ns, cred->fsuid)); + sprintf(gid_str, "%d", from_kgid(&init_user_ns, cred->fsgid)); + + /* we say which key is under construction */ + sprintf(key_str, "%d", key->serial); + + /* we specify the process's default keyrings */ + sprintf(keyring_str[0], "%d", + cred->thread_keyring ? cred->thread_keyring->serial : 0); + + prkey = 0; + if (cred->process_keyring) + prkey = cred->process_keyring->serial; + sprintf(keyring_str[1], "%d", prkey); + + session = cred->session_keyring; + if (!session) + session = user_session; + sskey = session->serial; + + sprintf(keyring_str[2], "%d", sskey); + + /* set up a minimal environment */ + i = 0; + envp[i++] = "HOME=/"; + envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin"; + envp[i] = NULL; + + /* set up the argument list */ + i = 0; + argv[i++] = (char *)request_key; + argv[i++] = (char *)rka->op; + argv[i++] = key_str; + argv[i++] = uid_str; + argv[i++] = gid_str; + argv[i++] = keyring_str[0]; + argv[i++] = keyring_str[1]; + argv[i++] = keyring_str[2]; + argv[i] = NULL; + + /* do it */ + ret = call_usermodehelper_keys(request_key, argv, envp, keyring, + UMH_WAIT_PROC); + kdebug("usermode -> 0x%x", ret); + if (ret >= 0) { + /* ret is the exit/wait code */ + if (test_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags) || + key_validate(key) < 0) + ret = -ENOKEY; + else + /* ignore any errors from userspace if the key was + * instantiated */ + ret = 0; + } + +error_link: + key_put(keyring); + +error_alloc: + key_put(user_session); +error_us: + complete_request_key(authkey, ret); + kleave(" = %d", ret); + return ret; +} + +/* + * Call out to userspace for key construction. + * + * Program failure is ignored in favour of key status. + */ +static int construct_key(struct key *key, const void *callout_info, + size_t callout_len, void *aux, + struct key *dest_keyring) +{ + request_key_actor_t actor; + struct key *authkey; + int ret; + + kenter("%d,%p,%zu,%p", key->serial, callout_info, callout_len, aux); + + /* allocate an authorisation key */ + authkey = request_key_auth_new(key, "create", callout_info, callout_len, + dest_keyring); + if (IS_ERR(authkey)) + return PTR_ERR(authkey); + + /* Make the call */ + actor = call_sbin_request_key; + if (key->type->request_key) + actor = key->type->request_key; + + ret = actor(authkey, aux); + + /* check that the actor called complete_request_key() prior to + * returning an error */ + WARN_ON(ret < 0 && + !test_bit(KEY_FLAG_INVALIDATED, &authkey->flags)); + + key_put(authkey); + kleave(" = %d", ret); + return ret; +} + +/* + * Get the appropriate destination keyring for the request. + * + * The keyring selected is returned with an extra reference upon it which the + * caller must release. + */ +static int construct_get_dest_keyring(struct key **_dest_keyring) +{ + struct request_key_auth *rka; + const struct cred *cred = current_cred(); + struct key *dest_keyring = *_dest_keyring, *authkey; + int ret; + + kenter("%p", dest_keyring); + + /* find the appropriate keyring */ + if (dest_keyring) { + /* the caller supplied one */ + key_get(dest_keyring); + } else { + bool do_perm_check = true; + + /* use a default keyring; falling through the cases until we + * find one that we actually have */ + switch (cred->jit_keyring) { + case KEY_REQKEY_DEFL_DEFAULT: + case KEY_REQKEY_DEFL_REQUESTOR_KEYRING: + if (cred->request_key_auth) { + authkey = cred->request_key_auth; + down_read(&authkey->sem); + rka = get_request_key_auth(authkey); + if (!test_bit(KEY_FLAG_REVOKED, + &authkey->flags)) + dest_keyring = + key_get(rka->dest_keyring); + up_read(&authkey->sem); + if (dest_keyring) { + do_perm_check = false; + break; + } + } + + fallthrough; + case KEY_REQKEY_DEFL_THREAD_KEYRING: + dest_keyring = key_get(cred->thread_keyring); + if (dest_keyring) + break; + + fallthrough; + case KEY_REQKEY_DEFL_PROCESS_KEYRING: + dest_keyring = key_get(cred->process_keyring); + if (dest_keyring) + break; + + fallthrough; + case KEY_REQKEY_DEFL_SESSION_KEYRING: + dest_keyring = key_get(cred->session_keyring); + + if (dest_keyring) + break; + + fallthrough; + case KEY_REQKEY_DEFL_USER_SESSION_KEYRING: + ret = look_up_user_keyrings(NULL, &dest_keyring); + if (ret < 0) + return ret; + break; + + case KEY_REQKEY_DEFL_USER_KEYRING: + ret = look_up_user_keyrings(&dest_keyring, NULL); + if (ret < 0) + return ret; + break; + + case KEY_REQKEY_DEFL_GROUP_KEYRING: + default: + BUG(); + } + + /* + * Require Write permission on the keyring. This is essential + * because the default keyring may be the session keyring, and + * joining a keyring only requires Search permission. + * + * However, this check is skipped for the "requestor keyring" so + * that /sbin/request-key can itself use request_key() to add + * keys to the original requestor's destination keyring. + */ + if (dest_keyring && do_perm_check) { + ret = key_permission(make_key_ref(dest_keyring, 1), + KEY_NEED_WRITE); + if (ret) { + key_put(dest_keyring); + return ret; + } + } + } + + *_dest_keyring = dest_keyring; + kleave(" [dk %d]", key_serial(dest_keyring)); + return 0; +} + +/* + * Allocate a new key in under-construction state and attempt to link it in to + * the requested keyring. + * + * May return a key that's already under construction instead if there was a + * race between two thread calling request_key(). + */ +static int construct_alloc_key(struct keyring_search_context *ctx, + struct key *dest_keyring, + unsigned long flags, + struct key_user *user, + struct key **_key) +{ + struct assoc_array_edit *edit = NULL; + struct key *key; + key_perm_t perm; + key_ref_t key_ref; + int ret; + + kenter("%s,%s,,,", + ctx->index_key.type->name, ctx->index_key.description); + + *_key = NULL; + mutex_lock(&user->cons_lock); + + perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR; + perm |= KEY_USR_VIEW; + if (ctx->index_key.type->read) + perm |= KEY_POS_READ; + if (ctx->index_key.type == &key_type_keyring || + ctx->index_key.type->update) + perm |= KEY_POS_WRITE; + + key = key_alloc(ctx->index_key.type, ctx->index_key.description, + ctx->cred->fsuid, ctx->cred->fsgid, ctx->cred, + perm, flags, NULL); + if (IS_ERR(key)) + goto alloc_failed; + + set_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags); + + if (dest_keyring) { + ret = __key_link_lock(dest_keyring, &key->index_key); + if (ret < 0) + goto link_lock_failed; + } + + /* + * Attach the key to the destination keyring under lock, but we do need + * to do another check just in case someone beat us to it whilst we + * waited for locks. + * + * The caller might specify a comparison function which looks for keys + * that do not exactly match but are still equivalent from the caller's + * perspective. The __key_link_begin() operation must be done only after + * an actual key is determined. + */ + mutex_lock(&key_construction_mutex); + + rcu_read_lock(); + key_ref = search_process_keyrings_rcu(ctx); + rcu_read_unlock(); + if (!IS_ERR(key_ref)) + goto key_already_present; + + if (dest_keyring) { + ret = __key_link_begin(dest_keyring, &key->index_key, &edit); + if (ret < 0) + goto link_alloc_failed; + __key_link(dest_keyring, key, &edit); + } + + mutex_unlock(&key_construction_mutex); + if (dest_keyring) + __key_link_end(dest_keyring, &key->index_key, edit); + mutex_unlock(&user->cons_lock); + *_key = key; + kleave(" = 0 [%d]", key_serial(key)); + return 0; + + /* the key is now present - we tell the caller that we found it by + * returning -EINPROGRESS */ +key_already_present: + key_put(key); + mutex_unlock(&key_construction_mutex); + key = key_ref_to_ptr(key_ref); + if (dest_keyring) { + ret = __key_link_begin(dest_keyring, &key->index_key, &edit); + if (ret < 0) + goto link_alloc_failed_unlocked; + ret = __key_link_check_live_key(dest_keyring, key); + if (ret == 0) + __key_link(dest_keyring, key, &edit); + __key_link_end(dest_keyring, &key->index_key, edit); + if (ret < 0) + goto link_check_failed; + } + mutex_unlock(&user->cons_lock); + *_key = key; + kleave(" = -EINPROGRESS [%d]", key_serial(key)); + return -EINPROGRESS; + +link_check_failed: + mutex_unlock(&user->cons_lock); + key_put(key); + kleave(" = %d [linkcheck]", ret); + return ret; + +link_alloc_failed: + mutex_unlock(&key_construction_mutex); +link_alloc_failed_unlocked: + __key_link_end(dest_keyring, &key->index_key, edit); +link_lock_failed: + mutex_unlock(&user->cons_lock); + key_put(key); + kleave(" = %d [prelink]", ret); + return ret; + +alloc_failed: + mutex_unlock(&user->cons_lock); + kleave(" = %ld", PTR_ERR(key)); + return PTR_ERR(key); +} + +/* + * Commence key construction. + */ +static struct key *construct_key_and_link(struct keyring_search_context *ctx, + const char *callout_info, + size_t callout_len, + void *aux, + struct key *dest_keyring, + unsigned long flags) +{ + struct key_user *user; + struct key *key; + int ret; + + kenter(""); + + if (ctx->index_key.type == &key_type_keyring) + return ERR_PTR(-EPERM); + + ret = construct_get_dest_keyring(&dest_keyring); + if (ret) + goto error; + + user = key_user_lookup(current_fsuid()); + if (!user) { + ret = -ENOMEM; + goto error_put_dest_keyring; + } + + ret = construct_alloc_key(ctx, dest_keyring, flags, user, &key); + key_user_put(user); + + if (ret == 0) { + ret = construct_key(key, callout_info, callout_len, aux, + dest_keyring); + if (ret < 0) { + kdebug("cons failed"); + goto construction_failed; + } + } else if (ret == -EINPROGRESS) { + ret = 0; + } else { + goto error_put_dest_keyring; + } + + key_put(dest_keyring); + kleave(" = key %d", key_serial(key)); + return key; + +construction_failed: + key_negate_and_link(key, key_negative_timeout, NULL, NULL); + key_put(key); +error_put_dest_keyring: + key_put(dest_keyring); +error: + kleave(" = %d", ret); + return ERR_PTR(ret); +} + +/** + * request_key_and_link - Request a key and cache it in a keyring. + * @type: The type of key we want. + * @description: The searchable description of the key. + * @domain_tag: The domain in which the key operates. + * @callout_info: The data to pass to the instantiation upcall (or NULL). + * @callout_len: The length of callout_info. + * @aux: Auxiliary data for the upcall. + * @dest_keyring: Where to cache the key. + * @flags: Flags to key_alloc(). + * + * A key matching the specified criteria (type, description, domain_tag) is + * searched for in the process's keyrings and returned with its usage count + * incremented if found. Otherwise, if callout_info is not NULL, a key will be + * allocated and some service (probably in userspace) will be asked to + * instantiate it. + * + * If successfully found or created, the key will be linked to the destination + * keyring if one is provided. + * + * Returns a pointer to the key if successful; -EACCES, -ENOKEY, -EKEYREVOKED + * or -EKEYEXPIRED if an inaccessible, negative, revoked or expired key was + * found; -ENOKEY if no key was found and no @callout_info was given; -EDQUOT + * if insufficient key quota was available to create a new key; or -ENOMEM if + * insufficient memory was available. + * + * If the returned key was created, then it may still be under construction, + * and wait_for_key_construction() should be used to wait for that to complete. + */ +struct key *request_key_and_link(struct key_type *type, + const char *description, + struct key_tag *domain_tag, + const void *callout_info, + size_t callout_len, + void *aux, + struct key *dest_keyring, + unsigned long flags) +{ + struct keyring_search_context ctx = { + .index_key.type = type, + .index_key.domain_tag = domain_tag, + .index_key.description = description, + .index_key.desc_len = strlen(description), + .cred = current_cred(), + .match_data.cmp = key_default_cmp, + .match_data.raw_data = description, + .match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT, + .flags = (KEYRING_SEARCH_DO_STATE_CHECK | + KEYRING_SEARCH_SKIP_EXPIRED | + KEYRING_SEARCH_RECURSE), + }; + struct key *key; + key_ref_t key_ref; + int ret; + + kenter("%s,%s,%p,%zu,%p,%p,%lx", + ctx.index_key.type->name, ctx.index_key.description, + callout_info, callout_len, aux, dest_keyring, flags); + + if (type->match_preparse) { + ret = type->match_preparse(&ctx.match_data); + if (ret < 0) { + key = ERR_PTR(ret); + goto error; + } + } + + key = check_cached_key(&ctx); + if (key) + goto error_free; + + /* search all the process keyrings for a key */ + rcu_read_lock(); + key_ref = search_process_keyrings_rcu(&ctx); + rcu_read_unlock(); + + if (!IS_ERR(key_ref)) { + if (dest_keyring) { + ret = key_task_permission(key_ref, current_cred(), + KEY_NEED_LINK); + if (ret < 0) { + key_ref_put(key_ref); + key = ERR_PTR(ret); + goto error_free; + } + } + + key = key_ref_to_ptr(key_ref); + if (dest_keyring) { + ret = key_link(dest_keyring, key); + if (ret < 0) { + key_put(key); + key = ERR_PTR(ret); + goto error_free; + } + } + + /* Only cache the key on immediate success */ + cache_requested_key(key); + } else if (PTR_ERR(key_ref) != -EAGAIN) { + key = ERR_CAST(key_ref); + } else { + /* the search failed, but the keyrings were searchable, so we + * should consult userspace if we can */ + key = ERR_PTR(-ENOKEY); + if (!callout_info) + goto error_free; + + key = construct_key_and_link(&ctx, callout_info, callout_len, + aux, dest_keyring, flags); + } + +error_free: + if (type->match_free) + type->match_free(&ctx.match_data); +error: + kleave(" = %p", key); + return key; +} + +/** + * wait_for_key_construction - Wait for construction of a key to complete + * @key: The key being waited for. + * @intr: Whether to wait interruptibly. + * + * Wait for a key to finish being constructed. + * + * Returns 0 if successful; -ERESTARTSYS if the wait was interrupted; -ENOKEY + * if the key was negated; or -EKEYREVOKED or -EKEYEXPIRED if the key was + * revoked or expired. + */ +int wait_for_key_construction(struct key *key, bool intr) +{ + int ret; + + ret = wait_on_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT, + intr ? TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE); + if (ret) + return -ERESTARTSYS; + ret = key_read_state(key); + if (ret < 0) + return ret; + return key_validate(key); +} +EXPORT_SYMBOL(wait_for_key_construction); + +/** + * request_key_tag - Request a key and wait for construction + * @type: Type of key. + * @description: The searchable description of the key. + * @domain_tag: The domain in which the key operates. + * @callout_info: The data to pass to the instantiation upcall (or NULL). + * + * As for request_key_and_link() except that it does not add the returned key + * to a keyring if found, new keys are always allocated in the user's quota, + * the callout_info must be a NUL-terminated string and no auxiliary data can + * be passed. + * + * Furthermore, it then works as wait_for_key_construction() to wait for the + * completion of keys undergoing construction with a non-interruptible wait. + */ +struct key *request_key_tag(struct key_type *type, + const char *description, + struct key_tag *domain_tag, + const char *callout_info) +{ + struct key *key; + size_t callout_len = 0; + int ret; + + if (callout_info) + callout_len = strlen(callout_info); + key = request_key_and_link(type, description, domain_tag, + callout_info, callout_len, + NULL, NULL, KEY_ALLOC_IN_QUOTA); + if (!IS_ERR(key)) { + ret = wait_for_key_construction(key, false); + if (ret < 0) { + key_put(key); + return ERR_PTR(ret); + } + } + return key; +} +EXPORT_SYMBOL(request_key_tag); + +/** + * request_key_with_auxdata - Request a key with auxiliary data for the upcaller + * @type: The type of key we want. + * @description: The searchable description of the key. + * @domain_tag: The domain in which the key operates. + * @callout_info: The data to pass to the instantiation upcall (or NULL). + * @callout_len: The length of callout_info. + * @aux: Auxiliary data for the upcall. + * + * As for request_key_and_link() except that it does not add the returned key + * to a keyring if found and new keys are always allocated in the user's quota. + * + * Furthermore, it then works as wait_for_key_construction() to wait for the + * completion of keys undergoing construction with a non-interruptible wait. + */ +struct key *request_key_with_auxdata(struct key_type *type, + const char *description, + struct key_tag *domain_tag, + const void *callout_info, + size_t callout_len, + void *aux) +{ + struct key *key; + int ret; + + key = request_key_and_link(type, description, domain_tag, + callout_info, callout_len, + aux, NULL, KEY_ALLOC_IN_QUOTA); + if (!IS_ERR(key)) { + ret = wait_for_key_construction(key, false); + if (ret < 0) { + key_put(key); + return ERR_PTR(ret); + } + } + return key; +} +EXPORT_SYMBOL(request_key_with_auxdata); + +/** + * request_key_rcu - Request key from RCU-read-locked context + * @type: The type of key we want. + * @description: The name of the key we want. + * @domain_tag: The domain in which the key operates. + * + * Request a key from a context that we may not sleep in (such as RCU-mode + * pathwalk). Keys under construction are ignored. + * + * Return a pointer to the found key if successful, -ENOKEY if we couldn't find + * a key or some other error if the key found was unsuitable or inaccessible. + */ +struct key *request_key_rcu(struct key_type *type, + const char *description, + struct key_tag *domain_tag) +{ + struct keyring_search_context ctx = { + .index_key.type = type, + .index_key.domain_tag = domain_tag, + .index_key.description = description, + .index_key.desc_len = strlen(description), + .cred = current_cred(), + .match_data.cmp = key_default_cmp, + .match_data.raw_data = description, + .match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT, + .flags = (KEYRING_SEARCH_DO_STATE_CHECK | + KEYRING_SEARCH_SKIP_EXPIRED), + }; + struct key *key; + key_ref_t key_ref; + + kenter("%s,%s", type->name, description); + + key = check_cached_key(&ctx); + if (key) + return key; + + /* search all the process keyrings for a key */ + key_ref = search_process_keyrings_rcu(&ctx); + if (IS_ERR(key_ref)) { + key = ERR_CAST(key_ref); + if (PTR_ERR(key_ref) == -EAGAIN) + key = ERR_PTR(-ENOKEY); + } else { + key = key_ref_to_ptr(key_ref); + cache_requested_key(key); + } + + kleave(" = %p", key); + return key; +} +EXPORT_SYMBOL(request_key_rcu); diff --git a/security/keys/request_key_auth.c b/security/keys/request_key_auth.c new file mode 100644 index 000000000..41e973500 --- /dev/null +++ b/security/keys/request_key_auth.c @@ -0,0 +1,283 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* Request key authorisation token key definition. + * + * Copyright (C) 2005 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * See Documentation/security/keys/request-key.rst + */ + +#include <linux/sched.h> +#include <linux/err.h> +#include <linux/seq_file.h> +#include <linux/slab.h> +#include <linux/uaccess.h> +#include "internal.h" +#include <keys/request_key_auth-type.h> + +static int request_key_auth_preparse(struct key_preparsed_payload *); +static void request_key_auth_free_preparse(struct key_preparsed_payload *); +static int request_key_auth_instantiate(struct key *, + struct key_preparsed_payload *); +static void request_key_auth_describe(const struct key *, struct seq_file *); +static void request_key_auth_revoke(struct key *); +static void request_key_auth_destroy(struct key *); +static long request_key_auth_read(const struct key *, char *, size_t); + +/* + * The request-key authorisation key type definition. + */ +struct key_type key_type_request_key_auth = { + .name = ".request_key_auth", + .def_datalen = sizeof(struct request_key_auth), + .preparse = request_key_auth_preparse, + .free_preparse = request_key_auth_free_preparse, + .instantiate = request_key_auth_instantiate, + .describe = request_key_auth_describe, + .revoke = request_key_auth_revoke, + .destroy = request_key_auth_destroy, + .read = request_key_auth_read, +}; + +static int request_key_auth_preparse(struct key_preparsed_payload *prep) +{ + return 0; +} + +static void request_key_auth_free_preparse(struct key_preparsed_payload *prep) +{ +} + +/* + * Instantiate a request-key authorisation key. + */ +static int request_key_auth_instantiate(struct key *key, + struct key_preparsed_payload *prep) +{ + rcu_assign_keypointer(key, (struct request_key_auth *)prep->data); + return 0; +} + +/* + * Describe an authorisation token. + */ +static void request_key_auth_describe(const struct key *key, + struct seq_file *m) +{ + struct request_key_auth *rka = dereference_key_rcu(key); + + if (!rka) + return; + + seq_puts(m, "key:"); + seq_puts(m, key->description); + if (key_is_positive(key)) + seq_printf(m, " pid:%d ci:%zu", rka->pid, rka->callout_len); +} + +/* + * Read the callout_info data (retrieves the callout information). + * - the key's semaphore is read-locked + */ +static long request_key_auth_read(const struct key *key, + char *buffer, size_t buflen) +{ + struct request_key_auth *rka = dereference_key_locked(key); + size_t datalen; + long ret; + + if (!rka) + return -EKEYREVOKED; + + datalen = rka->callout_len; + ret = datalen; + + /* we can return the data as is */ + if (buffer && buflen > 0) { + if (buflen > datalen) + buflen = datalen; + + memcpy(buffer, rka->callout_info, buflen); + } + + return ret; +} + +static void free_request_key_auth(struct request_key_auth *rka) +{ + if (!rka) + return; + key_put(rka->target_key); + key_put(rka->dest_keyring); + if (rka->cred) + put_cred(rka->cred); + kfree(rka->callout_info); + kfree(rka); +} + +/* + * Dispose of the request_key_auth record under RCU conditions + */ +static void request_key_auth_rcu_disposal(struct rcu_head *rcu) +{ + struct request_key_auth *rka = + container_of(rcu, struct request_key_auth, rcu); + + free_request_key_auth(rka); +} + +/* + * Handle revocation of an authorisation token key. + * + * Called with the key sem write-locked. + */ +static void request_key_auth_revoke(struct key *key) +{ + struct request_key_auth *rka = dereference_key_locked(key); + + kenter("{%d}", key->serial); + rcu_assign_keypointer(key, NULL); + call_rcu(&rka->rcu, request_key_auth_rcu_disposal); +} + +/* + * Destroy an instantiation authorisation token key. + */ +static void request_key_auth_destroy(struct key *key) +{ + struct request_key_auth *rka = rcu_access_pointer(key->payload.rcu_data0); + + kenter("{%d}", key->serial); + if (rka) { + rcu_assign_keypointer(key, NULL); + call_rcu(&rka->rcu, request_key_auth_rcu_disposal); + } +} + +/* + * Create an authorisation token for /sbin/request-key or whoever to gain + * access to the caller's security data. + */ +struct key *request_key_auth_new(struct key *target, const char *op, + const void *callout_info, size_t callout_len, + struct key *dest_keyring) +{ + struct request_key_auth *rka, *irka; + const struct cred *cred = current_cred(); + struct key *authkey = NULL; + char desc[20]; + int ret = -ENOMEM; + + kenter("%d,", target->serial); + + /* allocate a auth record */ + rka = kzalloc(sizeof(*rka), GFP_KERNEL); + if (!rka) + goto error; + rka->callout_info = kmemdup(callout_info, callout_len, GFP_KERNEL); + if (!rka->callout_info) + goto error_free_rka; + rka->callout_len = callout_len; + strlcpy(rka->op, op, sizeof(rka->op)); + + /* see if the calling process is already servicing the key request of + * another process */ + if (cred->request_key_auth) { + /* it is - use that instantiation context here too */ + down_read(&cred->request_key_auth->sem); + + /* if the auth key has been revoked, then the key we're + * servicing is already instantiated */ + if (test_bit(KEY_FLAG_REVOKED, + &cred->request_key_auth->flags)) { + up_read(&cred->request_key_auth->sem); + ret = -EKEYREVOKED; + goto error_free_rka; + } + + irka = cred->request_key_auth->payload.data[0]; + rka->cred = get_cred(irka->cred); + rka->pid = irka->pid; + + up_read(&cred->request_key_auth->sem); + } + else { + /* it isn't - use this process as the context */ + rka->cred = get_cred(cred); + rka->pid = current->pid; + } + + rka->target_key = key_get(target); + rka->dest_keyring = key_get(dest_keyring); + + /* allocate the auth key */ + sprintf(desc, "%x", target->serial); + + authkey = key_alloc(&key_type_request_key_auth, desc, + cred->fsuid, cred->fsgid, cred, + KEY_POS_VIEW | KEY_POS_READ | KEY_POS_SEARCH | KEY_POS_LINK | + KEY_USR_VIEW, KEY_ALLOC_NOT_IN_QUOTA, NULL); + if (IS_ERR(authkey)) { + ret = PTR_ERR(authkey); + goto error_free_rka; + } + + /* construct the auth key */ + ret = key_instantiate_and_link(authkey, rka, 0, NULL, NULL); + if (ret < 0) + goto error_put_authkey; + + kleave(" = {%d,%d}", authkey->serial, refcount_read(&authkey->usage)); + return authkey; + +error_put_authkey: + key_put(authkey); +error_free_rka: + free_request_key_auth(rka); +error: + kleave("= %d", ret); + return ERR_PTR(ret); +} + +/* + * Search the current process's keyrings for the authorisation key for + * instantiation of a key. + */ +struct key *key_get_instantiation_authkey(key_serial_t target_id) +{ + char description[16]; + struct keyring_search_context ctx = { + .index_key.type = &key_type_request_key_auth, + .index_key.description = description, + .cred = current_cred(), + .match_data.cmp = key_default_cmp, + .match_data.raw_data = description, + .match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT, + .flags = (KEYRING_SEARCH_DO_STATE_CHECK | + KEYRING_SEARCH_RECURSE), + }; + struct key *authkey; + key_ref_t authkey_ref; + + ctx.index_key.desc_len = sprintf(description, "%x", target_id); + + rcu_read_lock(); + authkey_ref = search_process_keyrings_rcu(&ctx); + rcu_read_unlock(); + + if (IS_ERR(authkey_ref)) { + authkey = ERR_CAST(authkey_ref); + if (authkey == ERR_PTR(-EAGAIN)) + authkey = ERR_PTR(-ENOKEY); + goto error; + } + + authkey = key_ref_to_ptr(authkey_ref); + if (test_bit(KEY_FLAG_REVOKED, &authkey->flags)) { + key_put(authkey); + authkey = ERR_PTR(-EKEYREVOKED); + } + +error: + return authkey; +} diff --git a/security/keys/sysctl.c b/security/keys/sysctl.c new file mode 100644 index 000000000..b46b651b3 --- /dev/null +++ b/security/keys/sysctl.c @@ -0,0 +1,70 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* Key management controls + * + * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#include <linux/key.h> +#include <linux/sysctl.h> +#include "internal.h" + +struct ctl_table key_sysctls[] = { + { + .procname = "maxkeys", + .data = &key_quota_maxkeys, + .maxlen = sizeof(unsigned), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = (void *) SYSCTL_ONE, + .extra2 = (void *) SYSCTL_INT_MAX, + }, + { + .procname = "maxbytes", + .data = &key_quota_maxbytes, + .maxlen = sizeof(unsigned), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = (void *) SYSCTL_ONE, + .extra2 = (void *) SYSCTL_INT_MAX, + }, + { + .procname = "root_maxkeys", + .data = &key_quota_root_maxkeys, + .maxlen = sizeof(unsigned), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = (void *) SYSCTL_ONE, + .extra2 = (void *) SYSCTL_INT_MAX, + }, + { + .procname = "root_maxbytes", + .data = &key_quota_root_maxbytes, + .maxlen = sizeof(unsigned), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = (void *) SYSCTL_ONE, + .extra2 = (void *) SYSCTL_INT_MAX, + }, + { + .procname = "gc_delay", + .data = &key_gc_delay, + .maxlen = sizeof(unsigned), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = (void *) SYSCTL_ZERO, + .extra2 = (void *) SYSCTL_INT_MAX, + }, +#ifdef CONFIG_PERSISTENT_KEYRINGS + { + .procname = "persistent_keyring_expiry", + .data = &persistent_keyring_expiry, + .maxlen = sizeof(unsigned), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = (void *) SYSCTL_ZERO, + .extra2 = (void *) SYSCTL_INT_MAX, + }, +#endif + { } +}; diff --git a/security/keys/trusted-keys/Kconfig b/security/keys/trusted-keys/Kconfig new file mode 100644 index 000000000..dbfdd8536 --- /dev/null +++ b/security/keys/trusted-keys/Kconfig @@ -0,0 +1,38 @@ +config TRUSTED_KEYS_TPM + bool "TPM-based trusted keys" + depends on TCG_TPM >= TRUSTED_KEYS + default y + select CRYPTO + select CRYPTO_HMAC + select CRYPTO_SHA1 + select CRYPTO_HASH_INFO + select ASN1_ENCODER + select OID_REGISTRY + select ASN1 + help + Enable use of the Trusted Platform Module (TPM) as trusted key + backend. Trusted keys are random number symmetric keys, + which will be generated and RSA-sealed by the TPM. + The TPM only unseals the keys, if the boot PCRs and other + criteria match. + +config TRUSTED_KEYS_TEE + bool "TEE-based trusted keys" + depends on TEE >= TRUSTED_KEYS + default y + help + Enable use of the Trusted Execution Environment (TEE) as trusted + key backend. + +config TRUSTED_KEYS_CAAM + bool "CAAM-based trusted keys" + depends on CRYPTO_DEV_FSL_CAAM_JR >= TRUSTED_KEYS + select CRYPTO_DEV_FSL_CAAM_BLOB_GEN + default y + help + Enable use of NXP's Cryptographic Accelerator and Assurance Module + (CAAM) as trusted key backend. + +if !TRUSTED_KEYS_TPM && !TRUSTED_KEYS_TEE && !TRUSTED_KEYS_CAAM +comment "No trust source selected!" +endif diff --git a/security/keys/trusted-keys/Makefile b/security/keys/trusted-keys/Makefile new file mode 100644 index 000000000..735aa0bc0 --- /dev/null +++ b/security/keys/trusted-keys/Makefile @@ -0,0 +1,16 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Makefile for trusted keys +# + +obj-$(CONFIG_TRUSTED_KEYS) += trusted.o +trusted-y += trusted_core.o +trusted-$(CONFIG_TRUSTED_KEYS_TPM) += trusted_tpm1.o + +$(obj)/trusted_tpm2.o: $(obj)/tpm2key.asn1.h +trusted-$(CONFIG_TRUSTED_KEYS_TPM) += trusted_tpm2.o +trusted-$(CONFIG_TRUSTED_KEYS_TPM) += tpm2key.asn1.o + +trusted-$(CONFIG_TRUSTED_KEYS_TEE) += trusted_tee.o + +trusted-$(CONFIG_TRUSTED_KEYS_CAAM) += trusted_caam.o diff --git a/security/keys/trusted-keys/tpm2key.asn1 b/security/keys/trusted-keys/tpm2key.asn1 new file mode 100644 index 000000000..f57f869ad --- /dev/null +++ b/security/keys/trusted-keys/tpm2key.asn1 @@ -0,0 +1,11 @@ +--- +--- ASN.1 for TPM 2.0 keys +--- + +TPMKey ::= SEQUENCE { + type OBJECT IDENTIFIER ({tpm2_key_type}), + emptyAuth [0] EXPLICIT BOOLEAN OPTIONAL, + parent INTEGER ({tpm2_key_parent}), + pubkey OCTET STRING ({tpm2_key_pub}), + privkey OCTET STRING ({tpm2_key_priv}) + } diff --git a/security/keys/trusted-keys/trusted_caam.c b/security/keys/trusted-keys/trusted_caam.c new file mode 100644 index 000000000..e3415c520 --- /dev/null +++ b/security/keys/trusted-keys/trusted_caam.c @@ -0,0 +1,80 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2021 Pengutronix, Ahmad Fatoum <kernel@pengutronix.de> + */ + +#include <keys/trusted_caam.h> +#include <keys/trusted-type.h> +#include <linux/build_bug.h> +#include <linux/key-type.h> +#include <soc/fsl/caam-blob.h> + +static struct caam_blob_priv *blobifier; + +#define KEYMOD "SECURE_KEY" + +static_assert(MAX_KEY_SIZE + CAAM_BLOB_OVERHEAD <= CAAM_BLOB_MAX_LEN); +static_assert(MAX_BLOB_SIZE <= CAAM_BLOB_MAX_LEN); + +static int trusted_caam_seal(struct trusted_key_payload *p, char *datablob) +{ + int ret; + struct caam_blob_info info = { + .input = p->key, .input_len = p->key_len, + .output = p->blob, .output_len = MAX_BLOB_SIZE, + .key_mod = KEYMOD, .key_mod_len = sizeof(KEYMOD) - 1, + }; + + ret = caam_encap_blob(blobifier, &info); + if (ret) + return ret; + + p->blob_len = info.output_len; + return 0; +} + +static int trusted_caam_unseal(struct trusted_key_payload *p, char *datablob) +{ + int ret; + struct caam_blob_info info = { + .input = p->blob, .input_len = p->blob_len, + .output = p->key, .output_len = MAX_KEY_SIZE, + .key_mod = KEYMOD, .key_mod_len = sizeof(KEYMOD) - 1, + }; + + ret = caam_decap_blob(blobifier, &info); + if (ret) + return ret; + + p->key_len = info.output_len; + return 0; +} + +static int trusted_caam_init(void) +{ + int ret; + + blobifier = caam_blob_gen_init(); + if (IS_ERR(blobifier)) + return PTR_ERR(blobifier); + + ret = register_key_type(&key_type_trusted); + if (ret) + caam_blob_gen_exit(blobifier); + + return ret; +} + +static void trusted_caam_exit(void) +{ + unregister_key_type(&key_type_trusted); + caam_blob_gen_exit(blobifier); +} + +struct trusted_key_ops trusted_key_caam_ops = { + .migratable = 0, /* non-migratable */ + .init = trusted_caam_init, + .seal = trusted_caam_seal, + .unseal = trusted_caam_unseal, + .exit = trusted_caam_exit, +}; diff --git a/security/keys/trusted-keys/trusted_core.c b/security/keys/trusted-keys/trusted_core.c new file mode 100644 index 000000000..fee1ab2c7 --- /dev/null +++ b/security/keys/trusted-keys/trusted_core.c @@ -0,0 +1,394 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2010 IBM Corporation + * Copyright (c) 2019-2021, Linaro Limited + * + * See Documentation/security/keys/trusted-encrypted.rst + */ + +#include <keys/user-type.h> +#include <keys/trusted-type.h> +#include <keys/trusted_tee.h> +#include <keys/trusted_caam.h> +#include <keys/trusted_tpm.h> +#include <linux/capability.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/key-type.h> +#include <linux/module.h> +#include <linux/parser.h> +#include <linux/random.h> +#include <linux/rcupdate.h> +#include <linux/slab.h> +#include <linux/static_call.h> +#include <linux/string.h> +#include <linux/uaccess.h> + +static char *trusted_rng = "default"; +module_param_named(rng, trusted_rng, charp, 0); +MODULE_PARM_DESC(rng, "Select trusted key RNG"); + +static char *trusted_key_source; +module_param_named(source, trusted_key_source, charp, 0); +MODULE_PARM_DESC(source, "Select trusted keys source (tpm, tee or caam)"); + +static const struct trusted_key_source trusted_key_sources[] = { +#if defined(CONFIG_TRUSTED_KEYS_TPM) + { "tpm", &trusted_key_tpm_ops }, +#endif +#if defined(CONFIG_TRUSTED_KEYS_TEE) + { "tee", &trusted_key_tee_ops }, +#endif +#if defined(CONFIG_TRUSTED_KEYS_CAAM) + { "caam", &trusted_key_caam_ops }, +#endif +}; + +DEFINE_STATIC_CALL_NULL(trusted_key_seal, *trusted_key_sources[0].ops->seal); +DEFINE_STATIC_CALL_NULL(trusted_key_unseal, + *trusted_key_sources[0].ops->unseal); +DEFINE_STATIC_CALL_NULL(trusted_key_get_random, + *trusted_key_sources[0].ops->get_random); +static void (*trusted_key_exit)(void); +static unsigned char migratable; + +enum { + Opt_err, + Opt_new, Opt_load, Opt_update, +}; + +static const match_table_t key_tokens = { + {Opt_new, "new"}, + {Opt_load, "load"}, + {Opt_update, "update"}, + {Opt_err, NULL} +}; + +/* + * datablob_parse - parse the keyctl data and fill in the + * payload structure + * + * On success returns 0, otherwise -EINVAL. + */ +static int datablob_parse(char **datablob, struct trusted_key_payload *p) +{ + substring_t args[MAX_OPT_ARGS]; + long keylen; + int ret = -EINVAL; + int key_cmd; + char *c; + + /* main command */ + c = strsep(datablob, " \t"); + if (!c) + return -EINVAL; + key_cmd = match_token(c, key_tokens, args); + switch (key_cmd) { + case Opt_new: + /* first argument is key size */ + c = strsep(datablob, " \t"); + if (!c) + return -EINVAL; + ret = kstrtol(c, 10, &keylen); + if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE) + return -EINVAL; + p->key_len = keylen; + ret = Opt_new; + break; + case Opt_load: + /* first argument is sealed blob */ + c = strsep(datablob, " \t"); + if (!c) + return -EINVAL; + p->blob_len = strlen(c) / 2; + if (p->blob_len > MAX_BLOB_SIZE) + return -EINVAL; + ret = hex2bin(p->blob, c, p->blob_len); + if (ret < 0) + return -EINVAL; + ret = Opt_load; + break; + case Opt_update: + ret = Opt_update; + break; + case Opt_err: + return -EINVAL; + } + return ret; +} + +static struct trusted_key_payload *trusted_payload_alloc(struct key *key) +{ + struct trusted_key_payload *p = NULL; + int ret; + + ret = key_payload_reserve(key, sizeof(*p)); + if (ret < 0) + goto err; + p = kzalloc(sizeof(*p), GFP_KERNEL); + if (!p) + goto err; + + p->migratable = migratable; +err: + return p; +} + +/* + * trusted_instantiate - create a new trusted key + * + * Unseal an existing trusted blob or, for a new key, get a + * random key, then seal and create a trusted key-type key, + * adding it to the specified keyring. + * + * On success, return 0. Otherwise return errno. + */ +static int trusted_instantiate(struct key *key, + struct key_preparsed_payload *prep) +{ + struct trusted_key_payload *payload = NULL; + size_t datalen = prep->datalen; + char *datablob, *orig_datablob; + int ret = 0; + int key_cmd; + size_t key_len; + + if (datalen <= 0 || datalen > 32767 || !prep->data) + return -EINVAL; + + orig_datablob = datablob = kmalloc(datalen + 1, GFP_KERNEL); + if (!datablob) + return -ENOMEM; + memcpy(datablob, prep->data, datalen); + datablob[datalen] = '\0'; + + payload = trusted_payload_alloc(key); + if (!payload) { + ret = -ENOMEM; + goto out; + } + + key_cmd = datablob_parse(&datablob, payload); + if (key_cmd < 0) { + ret = key_cmd; + goto out; + } + + dump_payload(payload); + + switch (key_cmd) { + case Opt_load: + ret = static_call(trusted_key_unseal)(payload, datablob); + dump_payload(payload); + if (ret < 0) + pr_info("key_unseal failed (%d)\n", ret); + break; + case Opt_new: + key_len = payload->key_len; + ret = static_call(trusted_key_get_random)(payload->key, + key_len); + if (ret < 0) + goto out; + + if (ret != key_len) { + pr_info("key_create failed (%d)\n", ret); + ret = -EIO; + goto out; + } + + ret = static_call(trusted_key_seal)(payload, datablob); + if (ret < 0) + pr_info("key_seal failed (%d)\n", ret); + break; + default: + ret = -EINVAL; + } +out: + kfree_sensitive(orig_datablob); + if (!ret) + rcu_assign_keypointer(key, payload); + else + kfree_sensitive(payload); + return ret; +} + +static void trusted_rcu_free(struct rcu_head *rcu) +{ + struct trusted_key_payload *p; + + p = container_of(rcu, struct trusted_key_payload, rcu); + kfree_sensitive(p); +} + +/* + * trusted_update - reseal an existing key with new PCR values + */ +static int trusted_update(struct key *key, struct key_preparsed_payload *prep) +{ + struct trusted_key_payload *p; + struct trusted_key_payload *new_p; + size_t datalen = prep->datalen; + char *datablob, *orig_datablob; + int ret = 0; + + if (key_is_negative(key)) + return -ENOKEY; + p = key->payload.data[0]; + if (!p->migratable) + return -EPERM; + if (datalen <= 0 || datalen > 32767 || !prep->data) + return -EINVAL; + + orig_datablob = datablob = kmalloc(datalen + 1, GFP_KERNEL); + if (!datablob) + return -ENOMEM; + + new_p = trusted_payload_alloc(key); + if (!new_p) { + ret = -ENOMEM; + goto out; + } + + memcpy(datablob, prep->data, datalen); + datablob[datalen] = '\0'; + ret = datablob_parse(&datablob, new_p); + if (ret != Opt_update) { + ret = -EINVAL; + kfree_sensitive(new_p); + goto out; + } + + /* copy old key values, and reseal with new pcrs */ + new_p->migratable = p->migratable; + new_p->key_len = p->key_len; + memcpy(new_p->key, p->key, p->key_len); + dump_payload(p); + dump_payload(new_p); + + ret = static_call(trusted_key_seal)(new_p, datablob); + if (ret < 0) { + pr_info("key_seal failed (%d)\n", ret); + kfree_sensitive(new_p); + goto out; + } + + rcu_assign_keypointer(key, new_p); + call_rcu(&p->rcu, trusted_rcu_free); +out: + kfree_sensitive(orig_datablob); + return ret; +} + +/* + * trusted_read - copy the sealed blob data to userspace in hex. + * On success, return to userspace the trusted key datablob size. + */ +static long trusted_read(const struct key *key, char *buffer, + size_t buflen) +{ + const struct trusted_key_payload *p; + char *bufp; + int i; + + p = dereference_key_locked(key); + if (!p) + return -EINVAL; + + if (buffer && buflen >= 2 * p->blob_len) { + bufp = buffer; + for (i = 0; i < p->blob_len; i++) + bufp = hex_byte_pack(bufp, p->blob[i]); + } + return 2 * p->blob_len; +} + +/* + * trusted_destroy - clear and free the key's payload + */ +static void trusted_destroy(struct key *key) +{ + kfree_sensitive(key->payload.data[0]); +} + +struct key_type key_type_trusted = { + .name = "trusted", + .instantiate = trusted_instantiate, + .update = trusted_update, + .destroy = trusted_destroy, + .describe = user_describe, + .read = trusted_read, +}; +EXPORT_SYMBOL_GPL(key_type_trusted); + +static int kernel_get_random(unsigned char *key, size_t key_len) +{ + return get_random_bytes_wait(key, key_len) ?: key_len; +} + +static int __init init_trusted(void) +{ + int (*get_random)(unsigned char *key, size_t key_len); + int i, ret = 0; + + for (i = 0; i < ARRAY_SIZE(trusted_key_sources); i++) { + if (trusted_key_source && + strncmp(trusted_key_source, trusted_key_sources[i].name, + strlen(trusted_key_sources[i].name))) + continue; + + /* + * We always support trusted.rng="kernel" and "default" as + * well as trusted.rng=$trusted.source if the trust source + * defines its own get_random callback. + */ + get_random = trusted_key_sources[i].ops->get_random; + if (trusted_rng && strcmp(trusted_rng, "default")) { + if (!strcmp(trusted_rng, "kernel")) { + get_random = kernel_get_random; + } else if (strcmp(trusted_rng, trusted_key_sources[i].name) || + !get_random) { + pr_warn("Unsupported RNG. Supported: kernel"); + if (get_random) + pr_cont(", %s", trusted_key_sources[i].name); + pr_cont(", default\n"); + return -EINVAL; + } + } + + if (!get_random) + get_random = kernel_get_random; + + ret = trusted_key_sources[i].ops->init(); + if (!ret) { + static_call_update(trusted_key_seal, trusted_key_sources[i].ops->seal); + static_call_update(trusted_key_unseal, trusted_key_sources[i].ops->unseal); + static_call_update(trusted_key_get_random, get_random); + + trusted_key_exit = trusted_key_sources[i].ops->exit; + migratable = trusted_key_sources[i].ops->migratable; + } + + if (!ret || ret != -ENODEV) + break; + } + + /* + * encrypted_keys.ko depends on successful load of this module even if + * trusted key implementation is not found. + */ + if (ret == -ENODEV) + return 0; + + return ret; +} + +static void __exit cleanup_trusted(void) +{ + if (trusted_key_exit) + (*trusted_key_exit)(); +} + +late_initcall(init_trusted); +module_exit(cleanup_trusted); + +MODULE_LICENSE("GPL"); diff --git a/security/keys/trusted-keys/trusted_tee.c b/security/keys/trusted-keys/trusted_tee.c new file mode 100644 index 000000000..24f67ca8d --- /dev/null +++ b/security/keys/trusted-keys/trusted_tee.c @@ -0,0 +1,289 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2019-2021 Linaro Ltd. + * + * Author: + * Sumit Garg <sumit.garg@linaro.org> + */ + +#include <linux/err.h> +#include <linux/key-type.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/tee_drv.h> +#include <linux/uuid.h> + +#include <keys/trusted_tee.h> + +#define DRIVER_NAME "trusted-key-tee" + +/* + * Get random data for symmetric key + * + * [out] memref[0] Random data + */ +#define TA_CMD_GET_RANDOM 0x0 + +/* + * Seal trusted key using hardware unique key + * + * [in] memref[0] Plain key + * [out] memref[1] Sealed key datablob + */ +#define TA_CMD_SEAL 0x1 + +/* + * Unseal trusted key using hardware unique key + * + * [in] memref[0] Sealed key datablob + * [out] memref[1] Plain key + */ +#define TA_CMD_UNSEAL 0x2 + +/** + * struct trusted_key_tee_private - TEE Trusted key private data + * @dev: TEE based Trusted key device. + * @ctx: TEE context handler. + * @session_id: Trusted key TA session identifier. + * @shm_pool: Memory pool shared with TEE device. + */ +struct trusted_key_tee_private { + struct device *dev; + struct tee_context *ctx; + u32 session_id; + struct tee_shm *shm_pool; +}; + +static struct trusted_key_tee_private pvt_data; + +/* + * Have the TEE seal(encrypt) the symmetric key + */ +static int trusted_tee_seal(struct trusted_key_payload *p, char *datablob) +{ + int ret; + struct tee_ioctl_invoke_arg inv_arg; + struct tee_param param[4]; + struct tee_shm *reg_shm = NULL; + + memset(&inv_arg, 0, sizeof(inv_arg)); + memset(¶m, 0, sizeof(param)); + + reg_shm = tee_shm_register_kernel_buf(pvt_data.ctx, p->key, + sizeof(p->key) + sizeof(p->blob)); + if (IS_ERR(reg_shm)) { + dev_err(pvt_data.dev, "shm register failed\n"); + return PTR_ERR(reg_shm); + } + + inv_arg.func = TA_CMD_SEAL; + inv_arg.session = pvt_data.session_id; + inv_arg.num_params = 4; + + param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT; + param[0].u.memref.shm = reg_shm; + param[0].u.memref.size = p->key_len; + param[0].u.memref.shm_offs = 0; + param[1].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT; + param[1].u.memref.shm = reg_shm; + param[1].u.memref.size = sizeof(p->blob); + param[1].u.memref.shm_offs = sizeof(p->key); + + ret = tee_client_invoke_func(pvt_data.ctx, &inv_arg, param); + if ((ret < 0) || (inv_arg.ret != 0)) { + dev_err(pvt_data.dev, "TA_CMD_SEAL invoke err: %x\n", + inv_arg.ret); + ret = -EFAULT; + } else { + p->blob_len = param[1].u.memref.size; + } + + tee_shm_free(reg_shm); + + return ret; +} + +/* + * Have the TEE unseal(decrypt) the symmetric key + */ +static int trusted_tee_unseal(struct trusted_key_payload *p, char *datablob) +{ + int ret; + struct tee_ioctl_invoke_arg inv_arg; + struct tee_param param[4]; + struct tee_shm *reg_shm = NULL; + + memset(&inv_arg, 0, sizeof(inv_arg)); + memset(¶m, 0, sizeof(param)); + + reg_shm = tee_shm_register_kernel_buf(pvt_data.ctx, p->key, + sizeof(p->key) + sizeof(p->blob)); + if (IS_ERR(reg_shm)) { + dev_err(pvt_data.dev, "shm register failed\n"); + return PTR_ERR(reg_shm); + } + + inv_arg.func = TA_CMD_UNSEAL; + inv_arg.session = pvt_data.session_id; + inv_arg.num_params = 4; + + param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT; + param[0].u.memref.shm = reg_shm; + param[0].u.memref.size = p->blob_len; + param[0].u.memref.shm_offs = sizeof(p->key); + param[1].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT; + param[1].u.memref.shm = reg_shm; + param[1].u.memref.size = sizeof(p->key); + param[1].u.memref.shm_offs = 0; + + ret = tee_client_invoke_func(pvt_data.ctx, &inv_arg, param); + if ((ret < 0) || (inv_arg.ret != 0)) { + dev_err(pvt_data.dev, "TA_CMD_UNSEAL invoke err: %x\n", + inv_arg.ret); + ret = -EFAULT; + } else { + p->key_len = param[1].u.memref.size; + } + + tee_shm_free(reg_shm); + + return ret; +} + +/* + * Have the TEE generate random symmetric key + */ +static int trusted_tee_get_random(unsigned char *key, size_t key_len) +{ + int ret; + struct tee_ioctl_invoke_arg inv_arg; + struct tee_param param[4]; + struct tee_shm *reg_shm = NULL; + + memset(&inv_arg, 0, sizeof(inv_arg)); + memset(¶m, 0, sizeof(param)); + + reg_shm = tee_shm_register_kernel_buf(pvt_data.ctx, key, key_len); + if (IS_ERR(reg_shm)) { + dev_err(pvt_data.dev, "key shm register failed\n"); + return PTR_ERR(reg_shm); + } + + inv_arg.func = TA_CMD_GET_RANDOM; + inv_arg.session = pvt_data.session_id; + inv_arg.num_params = 4; + + param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT; + param[0].u.memref.shm = reg_shm; + param[0].u.memref.size = key_len; + param[0].u.memref.shm_offs = 0; + + ret = tee_client_invoke_func(pvt_data.ctx, &inv_arg, param); + if ((ret < 0) || (inv_arg.ret != 0)) { + dev_err(pvt_data.dev, "TA_CMD_GET_RANDOM invoke err: %x\n", + inv_arg.ret); + ret = -EFAULT; + } else { + ret = param[0].u.memref.size; + } + + tee_shm_free(reg_shm); + + return ret; +} + +static int optee_ctx_match(struct tee_ioctl_version_data *ver, const void *data) +{ + if (ver->impl_id == TEE_IMPL_ID_OPTEE) + return 1; + else + return 0; +} + +static int trusted_key_probe(struct device *dev) +{ + struct tee_client_device *rng_device = to_tee_client_device(dev); + int ret; + struct tee_ioctl_open_session_arg sess_arg; + + memset(&sess_arg, 0, sizeof(sess_arg)); + + pvt_data.ctx = tee_client_open_context(NULL, optee_ctx_match, NULL, + NULL); + if (IS_ERR(pvt_data.ctx)) + return -ENODEV; + + memcpy(sess_arg.uuid, rng_device->id.uuid.b, TEE_IOCTL_UUID_LEN); + sess_arg.clnt_login = TEE_IOCTL_LOGIN_REE_KERNEL; + sess_arg.num_params = 0; + + ret = tee_client_open_session(pvt_data.ctx, &sess_arg, NULL); + if ((ret < 0) || (sess_arg.ret != 0)) { + dev_err(dev, "tee_client_open_session failed, err: %x\n", + sess_arg.ret); + ret = -EINVAL; + goto out_ctx; + } + pvt_data.session_id = sess_arg.session; + + ret = register_key_type(&key_type_trusted); + if (ret < 0) + goto out_sess; + + pvt_data.dev = dev; + + return 0; + +out_sess: + tee_client_close_session(pvt_data.ctx, pvt_data.session_id); +out_ctx: + tee_client_close_context(pvt_data.ctx); + + return ret; +} + +static int trusted_key_remove(struct device *dev) +{ + unregister_key_type(&key_type_trusted); + tee_client_close_session(pvt_data.ctx, pvt_data.session_id); + tee_client_close_context(pvt_data.ctx); + + return 0; +} + +static const struct tee_client_device_id trusted_key_id_table[] = { + {UUID_INIT(0xf04a0fe7, 0x1f5d, 0x4b9b, + 0xab, 0xf7, 0x61, 0x9b, 0x85, 0xb4, 0xce, 0x8c)}, + {} +}; +MODULE_DEVICE_TABLE(tee, trusted_key_id_table); + +static struct tee_client_driver trusted_key_driver = { + .id_table = trusted_key_id_table, + .driver = { + .name = DRIVER_NAME, + .bus = &tee_bus_type, + .probe = trusted_key_probe, + .remove = trusted_key_remove, + }, +}; + +static int trusted_tee_init(void) +{ + return driver_register(&trusted_key_driver.driver); +} + +static void trusted_tee_exit(void) +{ + driver_unregister(&trusted_key_driver.driver); +} + +struct trusted_key_ops trusted_key_tee_ops = { + .migratable = 0, /* non-migratable */ + .init = trusted_tee_init, + .seal = trusted_tee_seal, + .unseal = trusted_tee_unseal, + .get_random = trusted_tee_get_random, + .exit = trusted_tee_exit, +}; diff --git a/security/keys/trusted-keys/trusted_tpm1.c b/security/keys/trusted-keys/trusted_tpm1.c new file mode 100644 index 000000000..aa108bea6 --- /dev/null +++ b/security/keys/trusted-keys/trusted_tpm1.c @@ -0,0 +1,1074 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2010 IBM Corporation + * Copyright (c) 2019-2021, Linaro Limited + * + * See Documentation/security/keys/trusted-encrypted.rst + */ + +#include <crypto/hash_info.h> +#include <linux/init.h> +#include <linux/slab.h> +#include <linux/parser.h> +#include <linux/string.h> +#include <linux/err.h> +#include <keys/trusted-type.h> +#include <linux/key-type.h> +#include <linux/crypto.h> +#include <crypto/hash.h> +#include <crypto/sha1.h> +#include <linux/tpm.h> +#include <linux/tpm_command.h> + +#include <keys/trusted_tpm.h> + +static const char hmac_alg[] = "hmac(sha1)"; +static const char hash_alg[] = "sha1"; +static struct tpm_chip *chip; +static struct tpm_digest *digests; + +struct sdesc { + struct shash_desc shash; + char ctx[]; +}; + +static struct crypto_shash *hashalg; +static struct crypto_shash *hmacalg; + +static struct sdesc *init_sdesc(struct crypto_shash *alg) +{ + struct sdesc *sdesc; + int size; + + size = sizeof(struct shash_desc) + crypto_shash_descsize(alg); + sdesc = kmalloc(size, GFP_KERNEL); + if (!sdesc) + return ERR_PTR(-ENOMEM); + sdesc->shash.tfm = alg; + return sdesc; +} + +static int TSS_sha1(const unsigned char *data, unsigned int datalen, + unsigned char *digest) +{ + struct sdesc *sdesc; + int ret; + + sdesc = init_sdesc(hashalg); + if (IS_ERR(sdesc)) { + pr_info("can't alloc %s\n", hash_alg); + return PTR_ERR(sdesc); + } + + ret = crypto_shash_digest(&sdesc->shash, data, datalen, digest); + kfree_sensitive(sdesc); + return ret; +} + +static int TSS_rawhmac(unsigned char *digest, const unsigned char *key, + unsigned int keylen, ...) +{ + struct sdesc *sdesc; + va_list argp; + unsigned int dlen; + unsigned char *data; + int ret; + + sdesc = init_sdesc(hmacalg); + if (IS_ERR(sdesc)) { + pr_info("can't alloc %s\n", hmac_alg); + return PTR_ERR(sdesc); + } + + ret = crypto_shash_setkey(hmacalg, key, keylen); + if (ret < 0) + goto out; + ret = crypto_shash_init(&sdesc->shash); + if (ret < 0) + goto out; + + va_start(argp, keylen); + for (;;) { + dlen = va_arg(argp, unsigned int); + if (dlen == 0) + break; + data = va_arg(argp, unsigned char *); + if (data == NULL) { + ret = -EINVAL; + break; + } + ret = crypto_shash_update(&sdesc->shash, data, dlen); + if (ret < 0) + break; + } + va_end(argp); + if (!ret) + ret = crypto_shash_final(&sdesc->shash, digest); +out: + kfree_sensitive(sdesc); + return ret; +} + +/* + * calculate authorization info fields to send to TPM + */ +int TSS_authhmac(unsigned char *digest, const unsigned char *key, + unsigned int keylen, unsigned char *h1, + unsigned char *h2, unsigned int h3, ...) +{ + unsigned char paramdigest[SHA1_DIGEST_SIZE]; + struct sdesc *sdesc; + unsigned int dlen; + unsigned char *data; + unsigned char c; + int ret; + va_list argp; + + if (!chip) + return -ENODEV; + + sdesc = init_sdesc(hashalg); + if (IS_ERR(sdesc)) { + pr_info("can't alloc %s\n", hash_alg); + return PTR_ERR(sdesc); + } + + c = !!h3; + ret = crypto_shash_init(&sdesc->shash); + if (ret < 0) + goto out; + va_start(argp, h3); + for (;;) { + dlen = va_arg(argp, unsigned int); + if (dlen == 0) + break; + data = va_arg(argp, unsigned char *); + if (!data) { + ret = -EINVAL; + break; + } + ret = crypto_shash_update(&sdesc->shash, data, dlen); + if (ret < 0) + break; + } + va_end(argp); + if (!ret) + ret = crypto_shash_final(&sdesc->shash, paramdigest); + if (!ret) + ret = TSS_rawhmac(digest, key, keylen, SHA1_DIGEST_SIZE, + paramdigest, TPM_NONCE_SIZE, h1, + TPM_NONCE_SIZE, h2, 1, &c, 0, 0); +out: + kfree_sensitive(sdesc); + return ret; +} +EXPORT_SYMBOL_GPL(TSS_authhmac); + +/* + * verify the AUTH1_COMMAND (Seal) result from TPM + */ +int TSS_checkhmac1(unsigned char *buffer, + const uint32_t command, + const unsigned char *ononce, + const unsigned char *key, + unsigned int keylen, ...) +{ + uint32_t bufsize; + uint16_t tag; + uint32_t ordinal; + uint32_t result; + unsigned char *enonce; + unsigned char *continueflag; + unsigned char *authdata; + unsigned char testhmac[SHA1_DIGEST_SIZE]; + unsigned char paramdigest[SHA1_DIGEST_SIZE]; + struct sdesc *sdesc; + unsigned int dlen; + unsigned int dpos; + va_list argp; + int ret; + + if (!chip) + return -ENODEV; + + bufsize = LOAD32(buffer, TPM_SIZE_OFFSET); + tag = LOAD16(buffer, 0); + ordinal = command; + result = LOAD32N(buffer, TPM_RETURN_OFFSET); + if (tag == TPM_TAG_RSP_COMMAND) + return 0; + if (tag != TPM_TAG_RSP_AUTH1_COMMAND) + return -EINVAL; + authdata = buffer + bufsize - SHA1_DIGEST_SIZE; + continueflag = authdata - 1; + enonce = continueflag - TPM_NONCE_SIZE; + + sdesc = init_sdesc(hashalg); + if (IS_ERR(sdesc)) { + pr_info("can't alloc %s\n", hash_alg); + return PTR_ERR(sdesc); + } + ret = crypto_shash_init(&sdesc->shash); + if (ret < 0) + goto out; + ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result, + sizeof result); + if (ret < 0) + goto out; + ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal, + sizeof ordinal); + if (ret < 0) + goto out; + va_start(argp, keylen); + for (;;) { + dlen = va_arg(argp, unsigned int); + if (dlen == 0) + break; + dpos = va_arg(argp, unsigned int); + ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen); + if (ret < 0) + break; + } + va_end(argp); + if (!ret) + ret = crypto_shash_final(&sdesc->shash, paramdigest); + if (ret < 0) + goto out; + + ret = TSS_rawhmac(testhmac, key, keylen, SHA1_DIGEST_SIZE, paramdigest, + TPM_NONCE_SIZE, enonce, TPM_NONCE_SIZE, ononce, + 1, continueflag, 0, 0); + if (ret < 0) + goto out; + + if (memcmp(testhmac, authdata, SHA1_DIGEST_SIZE)) + ret = -EINVAL; +out: + kfree_sensitive(sdesc); + return ret; +} +EXPORT_SYMBOL_GPL(TSS_checkhmac1); + +/* + * verify the AUTH2_COMMAND (unseal) result from TPM + */ +static int TSS_checkhmac2(unsigned char *buffer, + const uint32_t command, + const unsigned char *ononce, + const unsigned char *key1, + unsigned int keylen1, + const unsigned char *key2, + unsigned int keylen2, ...) +{ + uint32_t bufsize; + uint16_t tag; + uint32_t ordinal; + uint32_t result; + unsigned char *enonce1; + unsigned char *continueflag1; + unsigned char *authdata1; + unsigned char *enonce2; + unsigned char *continueflag2; + unsigned char *authdata2; + unsigned char testhmac1[SHA1_DIGEST_SIZE]; + unsigned char testhmac2[SHA1_DIGEST_SIZE]; + unsigned char paramdigest[SHA1_DIGEST_SIZE]; + struct sdesc *sdesc; + unsigned int dlen; + unsigned int dpos; + va_list argp; + int ret; + + bufsize = LOAD32(buffer, TPM_SIZE_OFFSET); + tag = LOAD16(buffer, 0); + ordinal = command; + result = LOAD32N(buffer, TPM_RETURN_OFFSET); + + if (tag == TPM_TAG_RSP_COMMAND) + return 0; + if (tag != TPM_TAG_RSP_AUTH2_COMMAND) + return -EINVAL; + authdata1 = buffer + bufsize - (SHA1_DIGEST_SIZE + 1 + + SHA1_DIGEST_SIZE + SHA1_DIGEST_SIZE); + authdata2 = buffer + bufsize - (SHA1_DIGEST_SIZE); + continueflag1 = authdata1 - 1; + continueflag2 = authdata2 - 1; + enonce1 = continueflag1 - TPM_NONCE_SIZE; + enonce2 = continueflag2 - TPM_NONCE_SIZE; + + sdesc = init_sdesc(hashalg); + if (IS_ERR(sdesc)) { + pr_info("can't alloc %s\n", hash_alg); + return PTR_ERR(sdesc); + } + ret = crypto_shash_init(&sdesc->shash); + if (ret < 0) + goto out; + ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result, + sizeof result); + if (ret < 0) + goto out; + ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal, + sizeof ordinal); + if (ret < 0) + goto out; + + va_start(argp, keylen2); + for (;;) { + dlen = va_arg(argp, unsigned int); + if (dlen == 0) + break; + dpos = va_arg(argp, unsigned int); + ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen); + if (ret < 0) + break; + } + va_end(argp); + if (!ret) + ret = crypto_shash_final(&sdesc->shash, paramdigest); + if (ret < 0) + goto out; + + ret = TSS_rawhmac(testhmac1, key1, keylen1, SHA1_DIGEST_SIZE, + paramdigest, TPM_NONCE_SIZE, enonce1, + TPM_NONCE_SIZE, ononce, 1, continueflag1, 0, 0); + if (ret < 0) + goto out; + if (memcmp(testhmac1, authdata1, SHA1_DIGEST_SIZE)) { + ret = -EINVAL; + goto out; + } + ret = TSS_rawhmac(testhmac2, key2, keylen2, SHA1_DIGEST_SIZE, + paramdigest, TPM_NONCE_SIZE, enonce2, + TPM_NONCE_SIZE, ononce, 1, continueflag2, 0, 0); + if (ret < 0) + goto out; + if (memcmp(testhmac2, authdata2, SHA1_DIGEST_SIZE)) + ret = -EINVAL; +out: + kfree_sensitive(sdesc); + return ret; +} + +/* + * For key specific tpm requests, we will generate and send our + * own TPM command packets using the drivers send function. + */ +int trusted_tpm_send(unsigned char *cmd, size_t buflen) +{ + int rc; + + if (!chip) + return -ENODEV; + + dump_tpm_buf(cmd); + rc = tpm_send(chip, cmd, buflen); + dump_tpm_buf(cmd); + if (rc > 0) + /* Can't return positive return codes values to keyctl */ + rc = -EPERM; + return rc; +} +EXPORT_SYMBOL_GPL(trusted_tpm_send); + +/* + * Lock a trusted key, by extending a selected PCR. + * + * Prevents a trusted key that is sealed to PCRs from being accessed. + * This uses the tpm driver's extend function. + */ +static int pcrlock(const int pcrnum) +{ + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + return tpm_pcr_extend(chip, pcrnum, digests) ? -EINVAL : 0; +} + +/* + * Create an object specific authorisation protocol (OSAP) session + */ +static int osap(struct tpm_buf *tb, struct osapsess *s, + const unsigned char *key, uint16_t type, uint32_t handle) +{ + unsigned char enonce[TPM_NONCE_SIZE]; + unsigned char ononce[TPM_NONCE_SIZE]; + int ret; + + ret = tpm_get_random(chip, ononce, TPM_NONCE_SIZE); + if (ret < 0) + return ret; + + if (ret != TPM_NONCE_SIZE) + return -EIO; + + tpm_buf_reset(tb, TPM_TAG_RQU_COMMAND, TPM_ORD_OSAP); + tpm_buf_append_u16(tb, type); + tpm_buf_append_u32(tb, handle); + tpm_buf_append(tb, ononce, TPM_NONCE_SIZE); + + ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE); + if (ret < 0) + return ret; + + s->handle = LOAD32(tb->data, TPM_DATA_OFFSET); + memcpy(s->enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)]), + TPM_NONCE_SIZE); + memcpy(enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t) + + TPM_NONCE_SIZE]), TPM_NONCE_SIZE); + return TSS_rawhmac(s->secret, key, SHA1_DIGEST_SIZE, TPM_NONCE_SIZE, + enonce, TPM_NONCE_SIZE, ononce, 0, 0); +} + +/* + * Create an object independent authorisation protocol (oiap) session + */ +int oiap(struct tpm_buf *tb, uint32_t *handle, unsigned char *nonce) +{ + int ret; + + if (!chip) + return -ENODEV; + + tpm_buf_reset(tb, TPM_TAG_RQU_COMMAND, TPM_ORD_OIAP); + ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE); + if (ret < 0) + return ret; + + *handle = LOAD32(tb->data, TPM_DATA_OFFSET); + memcpy(nonce, &tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)], + TPM_NONCE_SIZE); + return 0; +} +EXPORT_SYMBOL_GPL(oiap); + +struct tpm_digests { + unsigned char encauth[SHA1_DIGEST_SIZE]; + unsigned char pubauth[SHA1_DIGEST_SIZE]; + unsigned char xorwork[SHA1_DIGEST_SIZE * 2]; + unsigned char xorhash[SHA1_DIGEST_SIZE]; + unsigned char nonceodd[TPM_NONCE_SIZE]; +}; + +/* + * Have the TPM seal(encrypt) the trusted key, possibly based on + * Platform Configuration Registers (PCRs). AUTH1 for sealing key. + */ +static int tpm_seal(struct tpm_buf *tb, uint16_t keytype, + uint32_t keyhandle, const unsigned char *keyauth, + const unsigned char *data, uint32_t datalen, + unsigned char *blob, uint32_t *bloblen, + const unsigned char *blobauth, + const unsigned char *pcrinfo, uint32_t pcrinfosize) +{ + struct osapsess sess; + struct tpm_digests *td; + unsigned char cont; + uint32_t ordinal; + uint32_t pcrsize; + uint32_t datsize; + int sealinfosize; + int encdatasize; + int storedsize; + int ret; + int i; + + /* alloc some work space for all the hashes */ + td = kmalloc(sizeof *td, GFP_KERNEL); + if (!td) + return -ENOMEM; + + /* get session for sealing key */ + ret = osap(tb, &sess, keyauth, keytype, keyhandle); + if (ret < 0) + goto out; + dump_sess(&sess); + + /* calculate encrypted authorization value */ + memcpy(td->xorwork, sess.secret, SHA1_DIGEST_SIZE); + memcpy(td->xorwork + SHA1_DIGEST_SIZE, sess.enonce, SHA1_DIGEST_SIZE); + ret = TSS_sha1(td->xorwork, SHA1_DIGEST_SIZE * 2, td->xorhash); + if (ret < 0) + goto out; + + ret = tpm_get_random(chip, td->nonceodd, TPM_NONCE_SIZE); + if (ret < 0) + goto out; + + if (ret != TPM_NONCE_SIZE) { + ret = -EIO; + goto out; + } + + ordinal = htonl(TPM_ORD_SEAL); + datsize = htonl(datalen); + pcrsize = htonl(pcrinfosize); + cont = 0; + + /* encrypt data authorization key */ + for (i = 0; i < SHA1_DIGEST_SIZE; ++i) + td->encauth[i] = td->xorhash[i] ^ blobauth[i]; + + /* calculate authorization HMAC value */ + if (pcrinfosize == 0) { + /* no pcr info specified */ + ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE, + sess.enonce, td->nonceodd, cont, + sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE, + td->encauth, sizeof(uint32_t), &pcrsize, + sizeof(uint32_t), &datsize, datalen, data, 0, + 0); + } else { + /* pcr info specified */ + ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE, + sess.enonce, td->nonceodd, cont, + sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE, + td->encauth, sizeof(uint32_t), &pcrsize, + pcrinfosize, pcrinfo, sizeof(uint32_t), + &datsize, datalen, data, 0, 0); + } + if (ret < 0) + goto out; + + /* build and send the TPM request packet */ + tpm_buf_reset(tb, TPM_TAG_RQU_AUTH1_COMMAND, TPM_ORD_SEAL); + tpm_buf_append_u32(tb, keyhandle); + tpm_buf_append(tb, td->encauth, SHA1_DIGEST_SIZE); + tpm_buf_append_u32(tb, pcrinfosize); + tpm_buf_append(tb, pcrinfo, pcrinfosize); + tpm_buf_append_u32(tb, datalen); + tpm_buf_append(tb, data, datalen); + tpm_buf_append_u32(tb, sess.handle); + tpm_buf_append(tb, td->nonceodd, TPM_NONCE_SIZE); + tpm_buf_append_u8(tb, cont); + tpm_buf_append(tb, td->pubauth, SHA1_DIGEST_SIZE); + + ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE); + if (ret < 0) + goto out; + + /* calculate the size of the returned Blob */ + sealinfosize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t)); + encdatasize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t) + + sizeof(uint32_t) + sealinfosize); + storedsize = sizeof(uint32_t) + sizeof(uint32_t) + sealinfosize + + sizeof(uint32_t) + encdatasize; + + /* check the HMAC in the response */ + ret = TSS_checkhmac1(tb->data, ordinal, td->nonceodd, sess.secret, + SHA1_DIGEST_SIZE, storedsize, TPM_DATA_OFFSET, 0, + 0); + + /* copy the returned blob to caller */ + if (!ret) { + memcpy(blob, tb->data + TPM_DATA_OFFSET, storedsize); + *bloblen = storedsize; + } +out: + kfree_sensitive(td); + return ret; +} + +/* + * use the AUTH2_COMMAND form of unseal, to authorize both key and blob + */ +static int tpm_unseal(struct tpm_buf *tb, + uint32_t keyhandle, const unsigned char *keyauth, + const unsigned char *blob, int bloblen, + const unsigned char *blobauth, + unsigned char *data, unsigned int *datalen) +{ + unsigned char nonceodd[TPM_NONCE_SIZE]; + unsigned char enonce1[TPM_NONCE_SIZE]; + unsigned char enonce2[TPM_NONCE_SIZE]; + unsigned char authdata1[SHA1_DIGEST_SIZE]; + unsigned char authdata2[SHA1_DIGEST_SIZE]; + uint32_t authhandle1 = 0; + uint32_t authhandle2 = 0; + unsigned char cont = 0; + uint32_t ordinal; + int ret; + + /* sessions for unsealing key and data */ + ret = oiap(tb, &authhandle1, enonce1); + if (ret < 0) { + pr_info("oiap failed (%d)\n", ret); + return ret; + } + ret = oiap(tb, &authhandle2, enonce2); + if (ret < 0) { + pr_info("oiap failed (%d)\n", ret); + return ret; + } + + ordinal = htonl(TPM_ORD_UNSEAL); + ret = tpm_get_random(chip, nonceodd, TPM_NONCE_SIZE); + if (ret < 0) + return ret; + + if (ret != TPM_NONCE_SIZE) { + pr_info("tpm_get_random failed (%d)\n", ret); + return -EIO; + } + ret = TSS_authhmac(authdata1, keyauth, TPM_NONCE_SIZE, + enonce1, nonceodd, cont, sizeof(uint32_t), + &ordinal, bloblen, blob, 0, 0); + if (ret < 0) + return ret; + ret = TSS_authhmac(authdata2, blobauth, TPM_NONCE_SIZE, + enonce2, nonceodd, cont, sizeof(uint32_t), + &ordinal, bloblen, blob, 0, 0); + if (ret < 0) + return ret; + + /* build and send TPM request packet */ + tpm_buf_reset(tb, TPM_TAG_RQU_AUTH2_COMMAND, TPM_ORD_UNSEAL); + tpm_buf_append_u32(tb, keyhandle); + tpm_buf_append(tb, blob, bloblen); + tpm_buf_append_u32(tb, authhandle1); + tpm_buf_append(tb, nonceodd, TPM_NONCE_SIZE); + tpm_buf_append_u8(tb, cont); + tpm_buf_append(tb, authdata1, SHA1_DIGEST_SIZE); + tpm_buf_append_u32(tb, authhandle2); + tpm_buf_append(tb, nonceodd, TPM_NONCE_SIZE); + tpm_buf_append_u8(tb, cont); + tpm_buf_append(tb, authdata2, SHA1_DIGEST_SIZE); + + ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE); + if (ret < 0) { + pr_info("authhmac failed (%d)\n", ret); + return ret; + } + + *datalen = LOAD32(tb->data, TPM_DATA_OFFSET); + ret = TSS_checkhmac2(tb->data, ordinal, nonceodd, + keyauth, SHA1_DIGEST_SIZE, + blobauth, SHA1_DIGEST_SIZE, + sizeof(uint32_t), TPM_DATA_OFFSET, + *datalen, TPM_DATA_OFFSET + sizeof(uint32_t), 0, + 0); + if (ret < 0) { + pr_info("TSS_checkhmac2 failed (%d)\n", ret); + return ret; + } + memcpy(data, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t), *datalen); + return 0; +} + +/* + * Have the TPM seal(encrypt) the symmetric key + */ +static int key_seal(struct trusted_key_payload *p, + struct trusted_key_options *o) +{ + struct tpm_buf tb; + int ret; + + ret = tpm_buf_init(&tb, 0, 0); + if (ret) + return ret; + + /* include migratable flag at end of sealed key */ + p->key[p->key_len] = p->migratable; + + ret = tpm_seal(&tb, o->keytype, o->keyhandle, o->keyauth, + p->key, p->key_len + 1, p->blob, &p->blob_len, + o->blobauth, o->pcrinfo, o->pcrinfo_len); + if (ret < 0) + pr_info("srkseal failed (%d)\n", ret); + + tpm_buf_destroy(&tb); + return ret; +} + +/* + * Have the TPM unseal(decrypt) the symmetric key + */ +static int key_unseal(struct trusted_key_payload *p, + struct trusted_key_options *o) +{ + struct tpm_buf tb; + int ret; + + ret = tpm_buf_init(&tb, 0, 0); + if (ret) + return ret; + + ret = tpm_unseal(&tb, o->keyhandle, o->keyauth, p->blob, p->blob_len, + o->blobauth, p->key, &p->key_len); + if (ret < 0) + pr_info("srkunseal failed (%d)\n", ret); + else + /* pull migratable flag out of sealed key */ + p->migratable = p->key[--p->key_len]; + + tpm_buf_destroy(&tb); + return ret; +} + +enum { + Opt_err, + Opt_keyhandle, Opt_keyauth, Opt_blobauth, + Opt_pcrinfo, Opt_pcrlock, Opt_migratable, + Opt_hash, + Opt_policydigest, + Opt_policyhandle, +}; + +static const match_table_t key_tokens = { + {Opt_keyhandle, "keyhandle=%s"}, + {Opt_keyauth, "keyauth=%s"}, + {Opt_blobauth, "blobauth=%s"}, + {Opt_pcrinfo, "pcrinfo=%s"}, + {Opt_pcrlock, "pcrlock=%s"}, + {Opt_migratable, "migratable=%s"}, + {Opt_hash, "hash=%s"}, + {Opt_policydigest, "policydigest=%s"}, + {Opt_policyhandle, "policyhandle=%s"}, + {Opt_err, NULL} +}; + +/* can have zero or more token= options */ +static int getoptions(char *c, struct trusted_key_payload *pay, + struct trusted_key_options *opt) +{ + substring_t args[MAX_OPT_ARGS]; + char *p = c; + int token; + int res; + unsigned long handle; + unsigned long lock; + unsigned long token_mask = 0; + unsigned int digest_len; + int i; + int tpm2; + + tpm2 = tpm_is_tpm2(chip); + if (tpm2 < 0) + return tpm2; + + opt->hash = tpm2 ? HASH_ALGO_SHA256 : HASH_ALGO_SHA1; + + if (!c) + return 0; + + while ((p = strsep(&c, " \t"))) { + if (*p == '\0' || *p == ' ' || *p == '\t') + continue; + token = match_token(p, key_tokens, args); + if (test_and_set_bit(token, &token_mask)) + return -EINVAL; + + switch (token) { + case Opt_pcrinfo: + opt->pcrinfo_len = strlen(args[0].from) / 2; + if (opt->pcrinfo_len > MAX_PCRINFO_SIZE) + return -EINVAL; + res = hex2bin(opt->pcrinfo, args[0].from, + opt->pcrinfo_len); + if (res < 0) + return -EINVAL; + break; + case Opt_keyhandle: + res = kstrtoul(args[0].from, 16, &handle); + if (res < 0) + return -EINVAL; + opt->keytype = SEAL_keytype; + opt->keyhandle = handle; + break; + case Opt_keyauth: + if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE) + return -EINVAL; + res = hex2bin(opt->keyauth, args[0].from, + SHA1_DIGEST_SIZE); + if (res < 0) + return -EINVAL; + break; + case Opt_blobauth: + /* + * TPM 1.2 authorizations are sha1 hashes passed in as + * hex strings. TPM 2.0 authorizations are simple + * passwords (although it can take a hash as well) + */ + opt->blobauth_len = strlen(args[0].from); + + if (opt->blobauth_len == 2 * TPM_DIGEST_SIZE) { + res = hex2bin(opt->blobauth, args[0].from, + TPM_DIGEST_SIZE); + if (res < 0) + return -EINVAL; + + opt->blobauth_len = TPM_DIGEST_SIZE; + break; + } + + if (tpm2 && opt->blobauth_len <= sizeof(opt->blobauth)) { + memcpy(opt->blobauth, args[0].from, + opt->blobauth_len); + break; + } + + return -EINVAL; + + break; + + case Opt_migratable: + if (*args[0].from == '0') + pay->migratable = 0; + else if (*args[0].from != '1') + return -EINVAL; + break; + case Opt_pcrlock: + res = kstrtoul(args[0].from, 10, &lock); + if (res < 0) + return -EINVAL; + opt->pcrlock = lock; + break; + case Opt_hash: + if (test_bit(Opt_policydigest, &token_mask)) + return -EINVAL; + for (i = 0; i < HASH_ALGO__LAST; i++) { + if (!strcmp(args[0].from, hash_algo_name[i])) { + opt->hash = i; + break; + } + } + if (i == HASH_ALGO__LAST) + return -EINVAL; + if (!tpm2 && i != HASH_ALGO_SHA1) { + pr_info("TPM 1.x only supports SHA-1.\n"); + return -EINVAL; + } + break; + case Opt_policydigest: + digest_len = hash_digest_size[opt->hash]; + if (!tpm2 || strlen(args[0].from) != (2 * digest_len)) + return -EINVAL; + res = hex2bin(opt->policydigest, args[0].from, + digest_len); + if (res < 0) + return -EINVAL; + opt->policydigest_len = digest_len; + break; + case Opt_policyhandle: + if (!tpm2) + return -EINVAL; + res = kstrtoul(args[0].from, 16, &handle); + if (res < 0) + return -EINVAL; + opt->policyhandle = handle; + break; + default: + return -EINVAL; + } + } + return 0; +} + +static struct trusted_key_options *trusted_options_alloc(void) +{ + struct trusted_key_options *options; + int tpm2; + + tpm2 = tpm_is_tpm2(chip); + if (tpm2 < 0) + return NULL; + + options = kzalloc(sizeof *options, GFP_KERNEL); + if (options) { + /* set any non-zero defaults */ + options->keytype = SRK_keytype; + + if (!tpm2) + options->keyhandle = SRKHANDLE; + } + return options; +} + +static int trusted_tpm_seal(struct trusted_key_payload *p, char *datablob) +{ + struct trusted_key_options *options = NULL; + int ret = 0; + int tpm2; + + tpm2 = tpm_is_tpm2(chip); + if (tpm2 < 0) + return tpm2; + + options = trusted_options_alloc(); + if (!options) + return -ENOMEM; + + ret = getoptions(datablob, p, options); + if (ret < 0) + goto out; + dump_options(options); + + if (!options->keyhandle && !tpm2) { + ret = -EINVAL; + goto out; + } + + if (tpm2) + ret = tpm2_seal_trusted(chip, p, options); + else + ret = key_seal(p, options); + if (ret < 0) { + pr_info("key_seal failed (%d)\n", ret); + goto out; + } + + if (options->pcrlock) { + ret = pcrlock(options->pcrlock); + if (ret < 0) { + pr_info("pcrlock failed (%d)\n", ret); + goto out; + } + } +out: + kfree_sensitive(options); + return ret; +} + +static int trusted_tpm_unseal(struct trusted_key_payload *p, char *datablob) +{ + struct trusted_key_options *options = NULL; + int ret = 0; + int tpm2; + + tpm2 = tpm_is_tpm2(chip); + if (tpm2 < 0) + return tpm2; + + options = trusted_options_alloc(); + if (!options) + return -ENOMEM; + + ret = getoptions(datablob, p, options); + if (ret < 0) + goto out; + dump_options(options); + + if (!options->keyhandle && !tpm2) { + ret = -EINVAL; + goto out; + } + + if (tpm2) + ret = tpm2_unseal_trusted(chip, p, options); + else + ret = key_unseal(p, options); + if (ret < 0) + pr_info("key_unseal failed (%d)\n", ret); + + if (options->pcrlock) { + ret = pcrlock(options->pcrlock); + if (ret < 0) { + pr_info("pcrlock failed (%d)\n", ret); + goto out; + } + } +out: + kfree_sensitive(options); + return ret; +} + +static int trusted_tpm_get_random(unsigned char *key, size_t key_len) +{ + return tpm_get_random(chip, key, key_len); +} + +static void trusted_shash_release(void) +{ + if (hashalg) + crypto_free_shash(hashalg); + if (hmacalg) + crypto_free_shash(hmacalg); +} + +static int __init trusted_shash_alloc(void) +{ + int ret; + + hmacalg = crypto_alloc_shash(hmac_alg, 0, 0); + if (IS_ERR(hmacalg)) { + pr_info("could not allocate crypto %s\n", + hmac_alg); + return PTR_ERR(hmacalg); + } + + hashalg = crypto_alloc_shash(hash_alg, 0, 0); + if (IS_ERR(hashalg)) { + pr_info("could not allocate crypto %s\n", + hash_alg); + ret = PTR_ERR(hashalg); + goto hashalg_fail; + } + + return 0; + +hashalg_fail: + crypto_free_shash(hmacalg); + return ret; +} + +static int __init init_digests(void) +{ + int i; + + digests = kcalloc(chip->nr_allocated_banks, sizeof(*digests), + GFP_KERNEL); + if (!digests) + return -ENOMEM; + + for (i = 0; i < chip->nr_allocated_banks; i++) + digests[i].alg_id = chip->allocated_banks[i].alg_id; + + return 0; +} + +static int __init trusted_tpm_init(void) +{ + int ret; + + chip = tpm_default_chip(); + if (!chip) + return -ENODEV; + + ret = init_digests(); + if (ret < 0) + goto err_put; + ret = trusted_shash_alloc(); + if (ret < 0) + goto err_free; + ret = register_key_type(&key_type_trusted); + if (ret < 0) + goto err_release; + return 0; +err_release: + trusted_shash_release(); +err_free: + kfree(digests); +err_put: + put_device(&chip->dev); + return ret; +} + +static void trusted_tpm_exit(void) +{ + if (chip) { + put_device(&chip->dev); + kfree(digests); + trusted_shash_release(); + unregister_key_type(&key_type_trusted); + } +} + +struct trusted_key_ops trusted_key_tpm_ops = { + .migratable = 1, /* migratable by default */ + .init = trusted_tpm_init, + .seal = trusted_tpm_seal, + .unseal = trusted_tpm_unseal, + .get_random = trusted_tpm_get_random, + .exit = trusted_tpm_exit, +}; diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c new file mode 100644 index 000000000..bc700f85f --- /dev/null +++ b/security/keys/trusted-keys/trusted_tpm2.c @@ -0,0 +1,550 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2004 IBM Corporation + * Copyright (C) 2014 Intel Corporation + */ + +#include <linux/asn1_encoder.h> +#include <linux/oid_registry.h> +#include <linux/string.h> +#include <linux/err.h> +#include <linux/tpm.h> +#include <linux/tpm_command.h> + +#include <keys/trusted-type.h> +#include <keys/trusted_tpm.h> + +#include <asm/unaligned.h> + +#include "tpm2key.asn1.h" + +static struct tpm2_hash tpm2_hash_map[] = { + {HASH_ALGO_SHA1, TPM_ALG_SHA1}, + {HASH_ALGO_SHA256, TPM_ALG_SHA256}, + {HASH_ALGO_SHA384, TPM_ALG_SHA384}, + {HASH_ALGO_SHA512, TPM_ALG_SHA512}, + {HASH_ALGO_SM3_256, TPM_ALG_SM3_256}, +}; + +static u32 tpm2key_oid[] = { 2, 23, 133, 10, 1, 5 }; + +static int tpm2_key_encode(struct trusted_key_payload *payload, + struct trusted_key_options *options, + u8 *src, u32 len) +{ + const int SCRATCH_SIZE = PAGE_SIZE; + u8 *scratch = kmalloc(SCRATCH_SIZE, GFP_KERNEL); + u8 *work = scratch, *work1; + u8 *end_work = scratch + SCRATCH_SIZE; + u8 *priv, *pub; + u16 priv_len, pub_len; + + priv_len = get_unaligned_be16(src) + 2; + priv = src; + + src += priv_len; + + pub_len = get_unaligned_be16(src) + 2; + pub = src; + + if (!scratch) + return -ENOMEM; + + work = asn1_encode_oid(work, end_work, tpm2key_oid, + asn1_oid_len(tpm2key_oid)); + + if (options->blobauth_len == 0) { + unsigned char bool[3], *w = bool; + /* tag 0 is emptyAuth */ + w = asn1_encode_boolean(w, w + sizeof(bool), true); + if (WARN(IS_ERR(w), "BUG: Boolean failed to encode")) + return PTR_ERR(w); + work = asn1_encode_tag(work, end_work, 0, bool, w - bool); + } + + /* + * Assume both octet strings will encode to a 2 byte definite length + * + * Note: For a well behaved TPM, this warning should never + * trigger, so if it does there's something nefarious going on + */ + if (WARN(work - scratch + pub_len + priv_len + 14 > SCRATCH_SIZE, + "BUG: scratch buffer is too small")) + return -EINVAL; + + work = asn1_encode_integer(work, end_work, options->keyhandle); + work = asn1_encode_octet_string(work, end_work, pub, pub_len); + work = asn1_encode_octet_string(work, end_work, priv, priv_len); + + work1 = payload->blob; + work1 = asn1_encode_sequence(work1, work1 + sizeof(payload->blob), + scratch, work - scratch); + if (WARN(IS_ERR(work1), "BUG: ASN.1 encoder failed")) + return PTR_ERR(work1); + + return work1 - payload->blob; +} + +struct tpm2_key_context { + u32 parent; + const u8 *pub; + u32 pub_len; + const u8 *priv; + u32 priv_len; +}; + +static int tpm2_key_decode(struct trusted_key_payload *payload, + struct trusted_key_options *options, + u8 **buf) +{ + int ret; + struct tpm2_key_context ctx; + u8 *blob; + + memset(&ctx, 0, sizeof(ctx)); + + ret = asn1_ber_decoder(&tpm2key_decoder, &ctx, payload->blob, + payload->blob_len); + if (ret < 0) + return ret; + + if (ctx.priv_len + ctx.pub_len > MAX_BLOB_SIZE) + return -EINVAL; + + blob = kmalloc(ctx.priv_len + ctx.pub_len + 4, GFP_KERNEL); + if (!blob) + return -ENOMEM; + + *buf = blob; + options->keyhandle = ctx.parent; + + memcpy(blob, ctx.priv, ctx.priv_len); + blob += ctx.priv_len; + + memcpy(blob, ctx.pub, ctx.pub_len); + + return 0; +} + +int tpm2_key_parent(void *context, size_t hdrlen, + unsigned char tag, + const void *value, size_t vlen) +{ + struct tpm2_key_context *ctx = context; + const u8 *v = value; + int i; + + ctx->parent = 0; + for (i = 0; i < vlen; i++) { + ctx->parent <<= 8; + ctx->parent |= v[i]; + } + + return 0; +} + +int tpm2_key_type(void *context, size_t hdrlen, + unsigned char tag, + const void *value, size_t vlen) +{ + enum OID oid = look_up_OID(value, vlen); + + if (oid != OID_TPMSealedData) { + char buffer[50]; + + sprint_oid(value, vlen, buffer, sizeof(buffer)); + pr_debug("OID is \"%s\" which is not TPMSealedData\n", + buffer); + return -EINVAL; + } + + return 0; +} + +int tpm2_key_pub(void *context, size_t hdrlen, + unsigned char tag, + const void *value, size_t vlen) +{ + struct tpm2_key_context *ctx = context; + + ctx->pub = value; + ctx->pub_len = vlen; + + return 0; +} + +int tpm2_key_priv(void *context, size_t hdrlen, + unsigned char tag, + const void *value, size_t vlen) +{ + struct tpm2_key_context *ctx = context; + + ctx->priv = value; + ctx->priv_len = vlen; + + return 0; +} + +/** + * tpm2_buf_append_auth() - append TPMS_AUTH_COMMAND to the buffer. + * + * @buf: an allocated tpm_buf instance + * @session_handle: session handle + * @nonce: the session nonce, may be NULL if not used + * @nonce_len: the session nonce length, may be 0 if not used + * @attributes: the session attributes + * @hmac: the session HMAC or password, may be NULL if not used + * @hmac_len: the session HMAC or password length, maybe 0 if not used + */ +static void tpm2_buf_append_auth(struct tpm_buf *buf, u32 session_handle, + const u8 *nonce, u16 nonce_len, + u8 attributes, + const u8 *hmac, u16 hmac_len) +{ + tpm_buf_append_u32(buf, 9 + nonce_len + hmac_len); + tpm_buf_append_u32(buf, session_handle); + tpm_buf_append_u16(buf, nonce_len); + + if (nonce && nonce_len) + tpm_buf_append(buf, nonce, nonce_len); + + tpm_buf_append_u8(buf, attributes); + tpm_buf_append_u16(buf, hmac_len); + + if (hmac && hmac_len) + tpm_buf_append(buf, hmac, hmac_len); +} + +/** + * tpm2_seal_trusted() - seal the payload of a trusted key + * + * @chip: TPM chip to use + * @payload: the key data in clear and encrypted form + * @options: authentication values and other options + * + * Return: < 0 on error and 0 on success. + */ +int tpm2_seal_trusted(struct tpm_chip *chip, + struct trusted_key_payload *payload, + struct trusted_key_options *options) +{ + int blob_len = 0; + struct tpm_buf buf; + u32 hash; + u32 flags; + int i; + int rc; + + for (i = 0; i < ARRAY_SIZE(tpm2_hash_map); i++) { + if (options->hash == tpm2_hash_map[i].crypto_id) { + hash = tpm2_hash_map[i].tpm_id; + break; + } + } + + if (i == ARRAY_SIZE(tpm2_hash_map)) + return -EINVAL; + + if (!options->keyhandle) + return -EINVAL; + + rc = tpm_try_get_ops(chip); + if (rc) + return rc; + + rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_CREATE); + if (rc) { + tpm_put_ops(chip); + return rc; + } + + tpm_buf_append_u32(&buf, options->keyhandle); + tpm2_buf_append_auth(&buf, TPM2_RS_PW, + NULL /* nonce */, 0, + 0 /* session_attributes */, + options->keyauth /* hmac */, + TPM_DIGEST_SIZE); + + /* sensitive */ + tpm_buf_append_u16(&buf, 4 + options->blobauth_len + payload->key_len); + + tpm_buf_append_u16(&buf, options->blobauth_len); + if (options->blobauth_len) + tpm_buf_append(&buf, options->blobauth, options->blobauth_len); + + tpm_buf_append_u16(&buf, payload->key_len); + tpm_buf_append(&buf, payload->key, payload->key_len); + + /* public */ + tpm_buf_append_u16(&buf, 14 + options->policydigest_len); + tpm_buf_append_u16(&buf, TPM_ALG_KEYEDHASH); + tpm_buf_append_u16(&buf, hash); + + /* key properties */ + flags = 0; + flags |= options->policydigest_len ? 0 : TPM2_OA_USER_WITH_AUTH; + flags |= payload->migratable ? 0 : (TPM2_OA_FIXED_TPM | + TPM2_OA_FIXED_PARENT); + tpm_buf_append_u32(&buf, flags); + + /* policy */ + tpm_buf_append_u16(&buf, options->policydigest_len); + if (options->policydigest_len) + tpm_buf_append(&buf, options->policydigest, + options->policydigest_len); + + /* public parameters */ + tpm_buf_append_u16(&buf, TPM_ALG_NULL); + tpm_buf_append_u16(&buf, 0); + + /* outside info */ + tpm_buf_append_u16(&buf, 0); + + /* creation PCR */ + tpm_buf_append_u32(&buf, 0); + + if (buf.flags & TPM_BUF_OVERFLOW) { + rc = -E2BIG; + goto out; + } + + rc = tpm_transmit_cmd(chip, &buf, 4, "sealing data"); + if (rc) + goto out; + + blob_len = be32_to_cpup((__be32 *) &buf.data[TPM_HEADER_SIZE]); + if (blob_len > MAX_BLOB_SIZE) { + rc = -E2BIG; + goto out; + } + if (tpm_buf_length(&buf) < TPM_HEADER_SIZE + 4 + blob_len) { + rc = -EFAULT; + goto out; + } + + blob_len = tpm2_key_encode(payload, options, + &buf.data[TPM_HEADER_SIZE + 4], + blob_len); + +out: + tpm_buf_destroy(&buf); + + if (rc > 0) { + if (tpm2_rc_value(rc) == TPM2_RC_HASH) + rc = -EINVAL; + else + rc = -EPERM; + } + if (blob_len < 0) + rc = blob_len; + else + payload->blob_len = blob_len; + + tpm_put_ops(chip); + return rc; +} + +/** + * tpm2_load_cmd() - execute a TPM2_Load command + * + * @chip: TPM chip to use + * @payload: the key data in clear and encrypted form + * @options: authentication values and other options + * @blob_handle: returned blob handle + * + * Return: 0 on success. + * -E2BIG on wrong payload size. + * -EPERM on tpm error status. + * < 0 error from tpm_send. + */ +static int tpm2_load_cmd(struct tpm_chip *chip, + struct trusted_key_payload *payload, + struct trusted_key_options *options, + u32 *blob_handle) +{ + struct tpm_buf buf; + unsigned int private_len; + unsigned int public_len; + unsigned int blob_len; + u8 *blob, *pub; + int rc; + u32 attrs; + + rc = tpm2_key_decode(payload, options, &blob); + if (rc) { + /* old form */ + blob = payload->blob; + payload->old_format = 1; + } + + /* new format carries keyhandle but old format doesn't */ + if (!options->keyhandle) + return -EINVAL; + + /* must be big enough for at least the two be16 size counts */ + if (payload->blob_len < 4) + return -EINVAL; + + private_len = get_unaligned_be16(blob); + + /* must be big enough for following public_len */ + if (private_len + 2 + 2 > (payload->blob_len)) + return -E2BIG; + + public_len = get_unaligned_be16(blob + 2 + private_len); + if (private_len + 2 + public_len + 2 > payload->blob_len) + return -E2BIG; + + pub = blob + 2 + private_len + 2; + /* key attributes are always at offset 4 */ + attrs = get_unaligned_be32(pub + 4); + + if ((attrs & (TPM2_OA_FIXED_TPM | TPM2_OA_FIXED_PARENT)) == + (TPM2_OA_FIXED_TPM | TPM2_OA_FIXED_PARENT)) + payload->migratable = 0; + else + payload->migratable = 1; + + blob_len = private_len + public_len + 4; + if (blob_len > payload->blob_len) + return -E2BIG; + + rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_LOAD); + if (rc) + return rc; + + tpm_buf_append_u32(&buf, options->keyhandle); + tpm2_buf_append_auth(&buf, TPM2_RS_PW, + NULL /* nonce */, 0, + 0 /* session_attributes */, + options->keyauth /* hmac */, + TPM_DIGEST_SIZE); + + tpm_buf_append(&buf, blob, blob_len); + + if (buf.flags & TPM_BUF_OVERFLOW) { + rc = -E2BIG; + goto out; + } + + rc = tpm_transmit_cmd(chip, &buf, 4, "loading blob"); + if (!rc) + *blob_handle = be32_to_cpup( + (__be32 *) &buf.data[TPM_HEADER_SIZE]); + +out: + if (blob != payload->blob) + kfree(blob); + tpm_buf_destroy(&buf); + + if (rc > 0) + rc = -EPERM; + + return rc; +} + +/** + * tpm2_unseal_cmd() - execute a TPM2_Unload command + * + * @chip: TPM chip to use + * @payload: the key data in clear and encrypted form + * @options: authentication values and other options + * @blob_handle: blob handle + * + * Return: 0 on success + * -EPERM on tpm error status + * < 0 error from tpm_send + */ +static int tpm2_unseal_cmd(struct tpm_chip *chip, + struct trusted_key_payload *payload, + struct trusted_key_options *options, + u32 blob_handle) +{ + struct tpm_buf buf; + u16 data_len; + u8 *data; + int rc; + + rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_UNSEAL); + if (rc) + return rc; + + tpm_buf_append_u32(&buf, blob_handle); + tpm2_buf_append_auth(&buf, + options->policyhandle ? + options->policyhandle : TPM2_RS_PW, + NULL /* nonce */, 0, + TPM2_SA_CONTINUE_SESSION, + options->blobauth /* hmac */, + options->blobauth_len); + + rc = tpm_transmit_cmd(chip, &buf, 6, "unsealing"); + if (rc > 0) + rc = -EPERM; + + if (!rc) { + data_len = be16_to_cpup( + (__be16 *) &buf.data[TPM_HEADER_SIZE + 4]); + if (data_len < MIN_KEY_SIZE || data_len > MAX_KEY_SIZE) { + rc = -EFAULT; + goto out; + } + + if (tpm_buf_length(&buf) < TPM_HEADER_SIZE + 6 + data_len) { + rc = -EFAULT; + goto out; + } + data = &buf.data[TPM_HEADER_SIZE + 6]; + + if (payload->old_format) { + /* migratable flag is at the end of the key */ + memcpy(payload->key, data, data_len - 1); + payload->key_len = data_len - 1; + payload->migratable = data[data_len - 1]; + } else { + /* + * migratable flag already collected from key + * attributes + */ + memcpy(payload->key, data, data_len); + payload->key_len = data_len; + } + } + +out: + tpm_buf_destroy(&buf); + return rc; +} + +/** + * tpm2_unseal_trusted() - unseal the payload of a trusted key + * + * @chip: TPM chip to use + * @payload: the key data in clear and encrypted form + * @options: authentication values and other options + * + * Return: Same as with tpm_send. + */ +int tpm2_unseal_trusted(struct tpm_chip *chip, + struct trusted_key_payload *payload, + struct trusted_key_options *options) +{ + u32 blob_handle; + int rc; + + rc = tpm_try_get_ops(chip); + if (rc) + return rc; + + rc = tpm2_load_cmd(chip, payload, options, &blob_handle); + if (rc) + goto out; + + rc = tpm2_unseal_cmd(chip, payload, options, blob_handle); + tpm2_flush_context(chip, blob_handle); + +out: + tpm_put_ops(chip); + + return rc; +} diff --git a/security/keys/user_defined.c b/security/keys/user_defined.c new file mode 100644 index 000000000..749e2a4dc --- /dev/null +++ b/security/keys/user_defined.c @@ -0,0 +1,207 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* user_defined.c: user defined key type + * + * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#include <linux/export.h> +#include <linux/init.h> +#include <linux/slab.h> +#include <linux/seq_file.h> +#include <linux/err.h> +#include <keys/user-type.h> +#include <linux/uaccess.h> +#include "internal.h" + +static int logon_vet_description(const char *desc); + +/* + * user defined keys take an arbitrary string as the description and an + * arbitrary blob of data as the payload + */ +struct key_type key_type_user = { + .name = "user", + .preparse = user_preparse, + .free_preparse = user_free_preparse, + .instantiate = generic_key_instantiate, + .update = user_update, + .revoke = user_revoke, + .destroy = user_destroy, + .describe = user_describe, + .read = user_read, +}; + +EXPORT_SYMBOL_GPL(key_type_user); + +/* + * This key type is essentially the same as key_type_user, but it does + * not define a .read op. This is suitable for storing username and + * password pairs in the keyring that you do not want to be readable + * from userspace. + */ +struct key_type key_type_logon = { + .name = "logon", + .preparse = user_preparse, + .free_preparse = user_free_preparse, + .instantiate = generic_key_instantiate, + .update = user_update, + .revoke = user_revoke, + .destroy = user_destroy, + .describe = user_describe, + .vet_description = logon_vet_description, +}; +EXPORT_SYMBOL_GPL(key_type_logon); + +/* + * Preparse a user defined key payload + */ +int user_preparse(struct key_preparsed_payload *prep) +{ + struct user_key_payload *upayload; + size_t datalen = prep->datalen; + + if (datalen <= 0 || datalen > 32767 || !prep->data) + return -EINVAL; + + upayload = kmalloc(sizeof(*upayload) + datalen, GFP_KERNEL); + if (!upayload) + return -ENOMEM; + + /* attach the data */ + prep->quotalen = datalen; + prep->payload.data[0] = upayload; + upayload->datalen = datalen; + memcpy(upayload->data, prep->data, datalen); + return 0; +} +EXPORT_SYMBOL_GPL(user_preparse); + +/* + * Free a preparse of a user defined key payload + */ +void user_free_preparse(struct key_preparsed_payload *prep) +{ + kfree_sensitive(prep->payload.data[0]); +} +EXPORT_SYMBOL_GPL(user_free_preparse); + +static void user_free_payload_rcu(struct rcu_head *head) +{ + struct user_key_payload *payload; + + payload = container_of(head, struct user_key_payload, rcu); + kfree_sensitive(payload); +} + +/* + * update a user defined key + * - the key's semaphore is write-locked + */ +int user_update(struct key *key, struct key_preparsed_payload *prep) +{ + struct user_key_payload *zap = NULL; + int ret; + + /* check the quota and attach the new data */ + ret = key_payload_reserve(key, prep->datalen); + if (ret < 0) + return ret; + + /* attach the new data, displacing the old */ + key->expiry = prep->expiry; + if (key_is_positive(key)) + zap = dereference_key_locked(key); + rcu_assign_keypointer(key, prep->payload.data[0]); + prep->payload.data[0] = NULL; + + if (zap) + call_rcu(&zap->rcu, user_free_payload_rcu); + return ret; +} +EXPORT_SYMBOL_GPL(user_update); + +/* + * dispose of the links from a revoked keyring + * - called with the key sem write-locked + */ +void user_revoke(struct key *key) +{ + struct user_key_payload *upayload = user_key_payload_locked(key); + + /* clear the quota */ + key_payload_reserve(key, 0); + + if (upayload) { + rcu_assign_keypointer(key, NULL); + call_rcu(&upayload->rcu, user_free_payload_rcu); + } +} + +EXPORT_SYMBOL(user_revoke); + +/* + * dispose of the data dangling from the corpse of a user key + */ +void user_destroy(struct key *key) +{ + struct user_key_payload *upayload = key->payload.data[0]; + + kfree_sensitive(upayload); +} + +EXPORT_SYMBOL_GPL(user_destroy); + +/* + * describe the user key + */ +void user_describe(const struct key *key, struct seq_file *m) +{ + seq_puts(m, key->description); + if (key_is_positive(key)) + seq_printf(m, ": %u", key->datalen); +} + +EXPORT_SYMBOL_GPL(user_describe); + +/* + * read the key data + * - the key's semaphore is read-locked + */ +long user_read(const struct key *key, char *buffer, size_t buflen) +{ + const struct user_key_payload *upayload; + long ret; + + upayload = user_key_payload_locked(key); + ret = upayload->datalen; + + /* we can return the data as is */ + if (buffer && buflen > 0) { + if (buflen > upayload->datalen) + buflen = upayload->datalen; + + memcpy(buffer, upayload->data, buflen); + } + + return ret; +} + +EXPORT_SYMBOL_GPL(user_read); + +/* Vet the description for a "logon" key */ +static int logon_vet_description(const char *desc) +{ + char *p; + + /* require a "qualified" description string */ + p = strchr(desc, ':'); + if (!p) + return -EINVAL; + + /* also reject description with ':' as first char */ + if (p == desc) + return -EINVAL; + + return 0; +} diff --git a/security/landlock/Kconfig b/security/landlock/Kconfig new file mode 100644 index 000000000..8e33c4e8f --- /dev/null +++ b/security/landlock/Kconfig @@ -0,0 +1,21 @@ +# SPDX-License-Identifier: GPL-2.0-only + +config SECURITY_LANDLOCK + bool "Landlock support" + depends on SECURITY && !ARCH_EPHEMERAL_INODES + select SECURITY_PATH + help + Landlock is a sandboxing mechanism that enables processes to restrict + themselves (and their future children) by gradually enforcing + tailored access control policies. A Landlock security policy is a + set of access rights (e.g. open a file in read-only, make a + directory, etc.) tied to a file hierarchy. Such policy can be + configured and enforced by any processes for themselves using the + dedicated system calls: landlock_create_ruleset(), + landlock_add_rule(), and landlock_restrict_self(). + + See Documentation/userspace-api/landlock.rst for further information. + + If you are unsure how to answer this question, answer N. Otherwise, + you should also prepend "landlock," to the content of CONFIG_LSM to + enable Landlock at boot time. diff --git a/security/landlock/Makefile b/security/landlock/Makefile new file mode 100644 index 000000000..7bbd2f413 --- /dev/null +++ b/security/landlock/Makefile @@ -0,0 +1,4 @@ +obj-$(CONFIG_SECURITY_LANDLOCK) := landlock.o + +landlock-y := setup.o syscalls.o object.o ruleset.o \ + cred.o ptrace.o fs.o diff --git a/security/landlock/common.h b/security/landlock/common.h new file mode 100644 index 000000000..5dc0fe157 --- /dev/null +++ b/security/landlock/common.h @@ -0,0 +1,20 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Landlock LSM - Common constants and helpers + * + * Copyright © 2016-2020 Mickaël Salaün <mic@digikod.net> + * Copyright © 2018-2020 ANSSI + */ + +#ifndef _SECURITY_LANDLOCK_COMMON_H +#define _SECURITY_LANDLOCK_COMMON_H + +#define LANDLOCK_NAME "landlock" + +#ifdef pr_fmt +#undef pr_fmt +#endif + +#define pr_fmt(fmt) LANDLOCK_NAME ": " fmt + +#endif /* _SECURITY_LANDLOCK_COMMON_H */ diff --git a/security/landlock/cred.c b/security/landlock/cred.c new file mode 100644 index 000000000..ec6c37f04 --- /dev/null +++ b/security/landlock/cred.c @@ -0,0 +1,46 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Landlock LSM - Credential hooks + * + * Copyright © 2017-2020 Mickaël Salaün <mic@digikod.net> + * Copyright © 2018-2020 ANSSI + */ + +#include <linux/cred.h> +#include <linux/lsm_hooks.h> + +#include "common.h" +#include "cred.h" +#include "ruleset.h" +#include "setup.h" + +static int hook_cred_prepare(struct cred *const new, + const struct cred *const old, const gfp_t gfp) +{ + struct landlock_ruleset *const old_dom = landlock_cred(old)->domain; + + if (old_dom) { + landlock_get_ruleset(old_dom); + landlock_cred(new)->domain = old_dom; + } + return 0; +} + +static void hook_cred_free(struct cred *const cred) +{ + struct landlock_ruleset *const dom = landlock_cred(cred)->domain; + + if (dom) + landlock_put_ruleset_deferred(dom); +} + +static struct security_hook_list landlock_hooks[] __lsm_ro_after_init = { + LSM_HOOK_INIT(cred_prepare, hook_cred_prepare), + LSM_HOOK_INIT(cred_free, hook_cred_free), +}; + +__init void landlock_add_cred_hooks(void) +{ + security_add_hooks(landlock_hooks, ARRAY_SIZE(landlock_hooks), + LANDLOCK_NAME); +} diff --git a/security/landlock/cred.h b/security/landlock/cred.h new file mode 100644 index 000000000..af89ab00e --- /dev/null +++ b/security/landlock/cred.h @@ -0,0 +1,58 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Landlock LSM - Credential hooks + * + * Copyright © 2019-2020 Mickaël Salaün <mic@digikod.net> + * Copyright © 2019-2020 ANSSI + */ + +#ifndef _SECURITY_LANDLOCK_CRED_H +#define _SECURITY_LANDLOCK_CRED_H + +#include <linux/cred.h> +#include <linux/init.h> +#include <linux/rcupdate.h> + +#include "ruleset.h" +#include "setup.h" + +struct landlock_cred_security { + struct landlock_ruleset *domain; +}; + +static inline struct landlock_cred_security * +landlock_cred(const struct cred *cred) +{ + return cred->security + landlock_blob_sizes.lbs_cred; +} + +static inline const struct landlock_ruleset *landlock_get_current_domain(void) +{ + return landlock_cred(current_cred())->domain; +} + +/* + * The call needs to come from an RCU read-side critical section. + */ +static inline const struct landlock_ruleset * +landlock_get_task_domain(const struct task_struct *const task) +{ + return landlock_cred(__task_cred(task))->domain; +} + +static inline bool landlocked(const struct task_struct *const task) +{ + bool has_dom; + + if (task == current) + return !!landlock_get_current_domain(); + + rcu_read_lock(); + has_dom = !!landlock_get_task_domain(task); + rcu_read_unlock(); + return has_dom; +} + +__init void landlock_add_cred_hooks(void); + +#endif /* _SECURITY_LANDLOCK_CRED_H */ diff --git a/security/landlock/fs.c b/security/landlock/fs.c new file mode 100644 index 000000000..64ed76654 --- /dev/null +++ b/security/landlock/fs.c @@ -0,0 +1,1205 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Landlock LSM - Filesystem management and hooks + * + * Copyright © 2016-2020 Mickaël Salaün <mic@digikod.net> + * Copyright © 2018-2020 ANSSI + * Copyright © 2021-2022 Microsoft Corporation + */ + +#include <linux/atomic.h> +#include <linux/bitops.h> +#include <linux/bits.h> +#include <linux/compiler_types.h> +#include <linux/dcache.h> +#include <linux/err.h> +#include <linux/fs.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/limits.h> +#include <linux/list.h> +#include <linux/lsm_hooks.h> +#include <linux/mount.h> +#include <linux/namei.h> +#include <linux/path.h> +#include <linux/rcupdate.h> +#include <linux/spinlock.h> +#include <linux/stat.h> +#include <linux/types.h> +#include <linux/wait_bit.h> +#include <linux/workqueue.h> +#include <uapi/linux/landlock.h> + +#include "common.h" +#include "cred.h" +#include "fs.h" +#include "limits.h" +#include "object.h" +#include "ruleset.h" +#include "setup.h" + +/* Underlying object management */ + +static void release_inode(struct landlock_object *const object) + __releases(object->lock) +{ + struct inode *const inode = object->underobj; + struct super_block *sb; + + if (!inode) { + spin_unlock(&object->lock); + return; + } + + /* + * Protects against concurrent use by hook_sb_delete() of the reference + * to the underlying inode. + */ + object->underobj = NULL; + /* + * Makes sure that if the filesystem is concurrently unmounted, + * hook_sb_delete() will wait for us to finish iput(). + */ + sb = inode->i_sb; + atomic_long_inc(&landlock_superblock(sb)->inode_refs); + spin_unlock(&object->lock); + /* + * Because object->underobj was not NULL, hook_sb_delete() and + * get_inode_object() guarantee that it is safe to reset + * landlock_inode(inode)->object while it is not NULL. It is therefore + * not necessary to lock inode->i_lock. + */ + rcu_assign_pointer(landlock_inode(inode)->object, NULL); + /* + * Now, new rules can safely be tied to @inode with get_inode_object(). + */ + + iput(inode); + if (atomic_long_dec_and_test(&landlock_superblock(sb)->inode_refs)) + wake_up_var(&landlock_superblock(sb)->inode_refs); +} + +static const struct landlock_object_underops landlock_fs_underops = { + .release = release_inode +}; + +/* Ruleset management */ + +static struct landlock_object *get_inode_object(struct inode *const inode) +{ + struct landlock_object *object, *new_object; + struct landlock_inode_security *inode_sec = landlock_inode(inode); + + rcu_read_lock(); +retry: + object = rcu_dereference(inode_sec->object); + if (object) { + if (likely(refcount_inc_not_zero(&object->usage))) { + rcu_read_unlock(); + return object; + } + /* + * We are racing with release_inode(), the object is going + * away. Wait for release_inode(), then retry. + */ + spin_lock(&object->lock); + spin_unlock(&object->lock); + goto retry; + } + rcu_read_unlock(); + + /* + * If there is no object tied to @inode, then create a new one (without + * holding any locks). + */ + new_object = landlock_create_object(&landlock_fs_underops, inode); + if (IS_ERR(new_object)) + return new_object; + + /* + * Protects against concurrent calls to get_inode_object() or + * hook_sb_delete(). + */ + spin_lock(&inode->i_lock); + if (unlikely(rcu_access_pointer(inode_sec->object))) { + /* Someone else just created the object, bail out and retry. */ + spin_unlock(&inode->i_lock); + kfree(new_object); + + rcu_read_lock(); + goto retry; + } + + /* + * @inode will be released by hook_sb_delete() on its superblock + * shutdown, or by release_inode() when no more ruleset references the + * related object. + */ + ihold(inode); + rcu_assign_pointer(inode_sec->object, new_object); + spin_unlock(&inode->i_lock); + return new_object; +} + +/* All access rights that can be tied to files. */ +/* clang-format off */ +#define ACCESS_FILE ( \ + LANDLOCK_ACCESS_FS_EXECUTE | \ + LANDLOCK_ACCESS_FS_WRITE_FILE | \ + LANDLOCK_ACCESS_FS_READ_FILE) +/* clang-format on */ + +/* + * All access rights that are denied by default whether they are handled or not + * by a ruleset/layer. This must be ORed with all ruleset->fs_access_masks[] + * entries when we need to get the absolute handled access masks. + */ +/* clang-format off */ +#define ACCESS_INITIALLY_DENIED ( \ + LANDLOCK_ACCESS_FS_REFER) +/* clang-format on */ + +/* + * @path: Should have been checked by get_path_from_fd(). + */ +int landlock_append_fs_rule(struct landlock_ruleset *const ruleset, + const struct path *const path, + access_mask_t access_rights) +{ + int err; + struct landlock_object *object; + + /* Files only get access rights that make sense. */ + if (!d_is_dir(path->dentry) && + (access_rights | ACCESS_FILE) != ACCESS_FILE) + return -EINVAL; + if (WARN_ON_ONCE(ruleset->num_layers != 1)) + return -EINVAL; + + /* Transforms relative access rights to absolute ones. */ + access_rights |= + LANDLOCK_MASK_ACCESS_FS & + ~(ruleset->fs_access_masks[0] | ACCESS_INITIALLY_DENIED); + object = get_inode_object(d_backing_inode(path->dentry)); + if (IS_ERR(object)) + return PTR_ERR(object); + mutex_lock(&ruleset->lock); + err = landlock_insert_rule(ruleset, object, access_rights); + mutex_unlock(&ruleset->lock); + /* + * No need to check for an error because landlock_insert_rule() + * increments the refcount for the new object if needed. + */ + landlock_put_object(object); + return err; +} + +/* Access-control management */ + +/* + * The lifetime of the returned rule is tied to @domain. + * + * Returns NULL if no rule is found or if @dentry is negative. + */ +static inline const struct landlock_rule * +find_rule(const struct landlock_ruleset *const domain, + const struct dentry *const dentry) +{ + const struct landlock_rule *rule; + const struct inode *inode; + + /* Ignores nonexistent leafs. */ + if (d_is_negative(dentry)) + return NULL; + + inode = d_backing_inode(dentry); + rcu_read_lock(); + rule = landlock_find_rule( + domain, rcu_dereference(landlock_inode(inode)->object)); + rcu_read_unlock(); + return rule; +} + +/* + * @layer_masks is read and may be updated according to the access request and + * the matching rule. + * + * Returns true if the request is allowed (i.e. relevant layer masks for the + * request are empty). + */ +static inline bool +unmask_layers(const struct landlock_rule *const rule, + const access_mask_t access_request, + layer_mask_t (*const layer_masks)[LANDLOCK_NUM_ACCESS_FS]) +{ + size_t layer_level; + + if (!access_request || !layer_masks) + return true; + if (!rule) + return false; + + /* + * An access is granted if, for each policy layer, at least one rule + * encountered on the pathwalk grants the requested access, + * regardless of its position in the layer stack. We must then check + * the remaining layers for each inode, from the first added layer to + * the last one. When there is multiple requested accesses, for each + * policy layer, the full set of requested accesses may not be granted + * by only one rule, but by the union (binary OR) of multiple rules. + * E.g. /a/b <execute> + /a <read> => /a/b <execute + read> + */ + for (layer_level = 0; layer_level < rule->num_layers; layer_level++) { + const struct landlock_layer *const layer = + &rule->layers[layer_level]; + const layer_mask_t layer_bit = BIT_ULL(layer->level - 1); + const unsigned long access_req = access_request; + unsigned long access_bit; + bool is_empty; + + /* + * Records in @layer_masks which layer grants access to each + * requested access. + */ + is_empty = true; + for_each_set_bit(access_bit, &access_req, + ARRAY_SIZE(*layer_masks)) { + if (layer->access & BIT_ULL(access_bit)) + (*layer_masks)[access_bit] &= ~layer_bit; + is_empty = is_empty && !(*layer_masks)[access_bit]; + } + if (is_empty) + return true; + } + return false; +} + +/* + * Allows access to pseudo filesystems that will never be mountable (e.g. + * sockfs, pipefs), but can still be reachable through + * /proc/<pid>/fd/<file-descriptor> + */ +static inline bool is_nouser_or_private(const struct dentry *dentry) +{ + return (dentry->d_sb->s_flags & SB_NOUSER) || + (d_is_positive(dentry) && + unlikely(IS_PRIVATE(d_backing_inode(dentry)))); +} + +static inline access_mask_t +get_handled_accesses(const struct landlock_ruleset *const domain) +{ + access_mask_t access_dom = ACCESS_INITIALLY_DENIED; + size_t layer_level; + + for (layer_level = 0; layer_level < domain->num_layers; layer_level++) + access_dom |= domain->fs_access_masks[layer_level]; + return access_dom & LANDLOCK_MASK_ACCESS_FS; +} + +static inline access_mask_t +init_layer_masks(const struct landlock_ruleset *const domain, + const access_mask_t access_request, + layer_mask_t (*const layer_masks)[LANDLOCK_NUM_ACCESS_FS]) +{ + access_mask_t handled_accesses = 0; + size_t layer_level; + + memset(layer_masks, 0, sizeof(*layer_masks)); + /* An empty access request can happen because of O_WRONLY | O_RDWR. */ + if (!access_request) + return 0; + + /* Saves all handled accesses per layer. */ + for (layer_level = 0; layer_level < domain->num_layers; layer_level++) { + const unsigned long access_req = access_request; + unsigned long access_bit; + + for_each_set_bit(access_bit, &access_req, + ARRAY_SIZE(*layer_masks)) { + /* + * Artificially handles all initially denied by default + * access rights. + */ + if (BIT_ULL(access_bit) & + (domain->fs_access_masks[layer_level] | + ACCESS_INITIALLY_DENIED)) { + (*layer_masks)[access_bit] |= + BIT_ULL(layer_level); + handled_accesses |= BIT_ULL(access_bit); + } + } + } + return handled_accesses; +} + +/* + * Check that a destination file hierarchy has more restrictions than a source + * file hierarchy. This is only used for link and rename actions. + * + * @layer_masks_child2: Optional child masks. + */ +static inline bool no_more_access( + const layer_mask_t (*const layer_masks_parent1)[LANDLOCK_NUM_ACCESS_FS], + const layer_mask_t (*const layer_masks_child1)[LANDLOCK_NUM_ACCESS_FS], + const bool child1_is_directory, + const layer_mask_t (*const layer_masks_parent2)[LANDLOCK_NUM_ACCESS_FS], + const layer_mask_t (*const layer_masks_child2)[LANDLOCK_NUM_ACCESS_FS], + const bool child2_is_directory) +{ + unsigned long access_bit; + + for (access_bit = 0; access_bit < ARRAY_SIZE(*layer_masks_parent2); + access_bit++) { + /* Ignores accesses that only make sense for directories. */ + const bool is_file_access = + !!(BIT_ULL(access_bit) & ACCESS_FILE); + + if (child1_is_directory || is_file_access) { + /* + * Checks if the destination restrictions are a + * superset of the source ones (i.e. inherited access + * rights without child exceptions): + * restrictions(parent2) >= restrictions(child1) + */ + if ((((*layer_masks_parent1)[access_bit] & + (*layer_masks_child1)[access_bit]) | + (*layer_masks_parent2)[access_bit]) != + (*layer_masks_parent2)[access_bit]) + return false; + } + + if (!layer_masks_child2) + continue; + if (child2_is_directory || is_file_access) { + /* + * Checks inverted restrictions for RENAME_EXCHANGE: + * restrictions(parent1) >= restrictions(child2) + */ + if ((((*layer_masks_parent2)[access_bit] & + (*layer_masks_child2)[access_bit]) | + (*layer_masks_parent1)[access_bit]) != + (*layer_masks_parent1)[access_bit]) + return false; + } + } + return true; +} + +/* + * Removes @layer_masks accesses that are not requested. + * + * Returns true if the request is allowed, false otherwise. + */ +static inline bool +scope_to_request(const access_mask_t access_request, + layer_mask_t (*const layer_masks)[LANDLOCK_NUM_ACCESS_FS]) +{ + const unsigned long access_req = access_request; + unsigned long access_bit; + + if (WARN_ON_ONCE(!layer_masks)) + return true; + + for_each_clear_bit(access_bit, &access_req, ARRAY_SIZE(*layer_masks)) + (*layer_masks)[access_bit] = 0; + return !memchr_inv(layer_masks, 0, sizeof(*layer_masks)); +} + +/* + * Returns true if there is at least one access right different than + * LANDLOCK_ACCESS_FS_REFER. + */ +static inline bool +is_eacces(const layer_mask_t (*const layer_masks)[LANDLOCK_NUM_ACCESS_FS], + const access_mask_t access_request) +{ + unsigned long access_bit; + /* LANDLOCK_ACCESS_FS_REFER alone must return -EXDEV. */ + const unsigned long access_check = access_request & + ~LANDLOCK_ACCESS_FS_REFER; + + if (!layer_masks) + return false; + + for_each_set_bit(access_bit, &access_check, ARRAY_SIZE(*layer_masks)) { + if ((*layer_masks)[access_bit]) + return true; + } + return false; +} + +/** + * check_access_path_dual - Check accesses for requests with a common path + * + * @domain: Domain to check against. + * @path: File hierarchy to walk through. + * @access_request_parent1: Accesses to check, once @layer_masks_parent1 is + * equal to @layer_masks_parent2 (if any). This is tied to the unique + * requested path for most actions, or the source in case of a refer action + * (i.e. rename or link), or the source and destination in case of + * RENAME_EXCHANGE. + * @layer_masks_parent1: Pointer to a matrix of layer masks per access + * masks, identifying the layers that forbid a specific access. Bits from + * this matrix can be unset according to the @path walk. An empty matrix + * means that @domain allows all possible Landlock accesses (i.e. not only + * those identified by @access_request_parent1). This matrix can + * initially refer to domain layer masks and, when the accesses for the + * destination and source are the same, to requested layer masks. + * @dentry_child1: Dentry to the initial child of the parent1 path. This + * pointer must be NULL for non-refer actions (i.e. not link nor rename). + * @access_request_parent2: Similar to @access_request_parent1 but for a + * request involving a source and a destination. This refers to the + * destination, except in case of RENAME_EXCHANGE where it also refers to + * the source. Must be set to 0 when using a simple path request. + * @layer_masks_parent2: Similar to @layer_masks_parent1 but for a refer + * action. This must be NULL otherwise. + * @dentry_child2: Dentry to the initial child of the parent2 path. This + * pointer is only set for RENAME_EXCHANGE actions and must be NULL + * otherwise. + * + * This helper first checks that the destination has a superset of restrictions + * compared to the source (if any) for a common path. Because of + * RENAME_EXCHANGE actions, source and destinations may be swapped. It then + * checks that the collected accesses and the remaining ones are enough to + * allow the request. + * + * Returns: + * - 0 if the access request is granted; + * - -EACCES if it is denied because of access right other than + * LANDLOCK_ACCESS_FS_REFER; + * - -EXDEV if the renaming or linking would be a privileged escalation + * (according to each layered policies), or if LANDLOCK_ACCESS_FS_REFER is + * not allowed by the source or the destination. + */ +static int check_access_path_dual( + const struct landlock_ruleset *const domain, + const struct path *const path, + const access_mask_t access_request_parent1, + layer_mask_t (*const layer_masks_parent1)[LANDLOCK_NUM_ACCESS_FS], + const struct dentry *const dentry_child1, + const access_mask_t access_request_parent2, + layer_mask_t (*const layer_masks_parent2)[LANDLOCK_NUM_ACCESS_FS], + const struct dentry *const dentry_child2) +{ + bool allowed_parent1 = false, allowed_parent2 = false, is_dom_check, + child1_is_directory = true, child2_is_directory = true; + struct path walker_path; + access_mask_t access_masked_parent1, access_masked_parent2; + layer_mask_t _layer_masks_child1[LANDLOCK_NUM_ACCESS_FS], + _layer_masks_child2[LANDLOCK_NUM_ACCESS_FS]; + layer_mask_t(*layer_masks_child1)[LANDLOCK_NUM_ACCESS_FS] = NULL, + (*layer_masks_child2)[LANDLOCK_NUM_ACCESS_FS] = NULL; + + if (!access_request_parent1 && !access_request_parent2) + return 0; + if (WARN_ON_ONCE(!domain || !path)) + return 0; + if (is_nouser_or_private(path->dentry)) + return 0; + if (WARN_ON_ONCE(domain->num_layers < 1 || !layer_masks_parent1)) + return -EACCES; + + if (unlikely(layer_masks_parent2)) { + if (WARN_ON_ONCE(!dentry_child1)) + return -EACCES; + /* + * For a double request, first check for potential privilege + * escalation by looking at domain handled accesses (which are + * a superset of the meaningful requested accesses). + */ + access_masked_parent1 = access_masked_parent2 = + get_handled_accesses(domain); + is_dom_check = true; + } else { + if (WARN_ON_ONCE(dentry_child1 || dentry_child2)) + return -EACCES; + /* For a simple request, only check for requested accesses. */ + access_masked_parent1 = access_request_parent1; + access_masked_parent2 = access_request_parent2; + is_dom_check = false; + } + + if (unlikely(dentry_child1)) { + unmask_layers(find_rule(domain, dentry_child1), + init_layer_masks(domain, LANDLOCK_MASK_ACCESS_FS, + &_layer_masks_child1), + &_layer_masks_child1); + layer_masks_child1 = &_layer_masks_child1; + child1_is_directory = d_is_dir(dentry_child1); + } + if (unlikely(dentry_child2)) { + unmask_layers(find_rule(domain, dentry_child2), + init_layer_masks(domain, LANDLOCK_MASK_ACCESS_FS, + &_layer_masks_child2), + &_layer_masks_child2); + layer_masks_child2 = &_layer_masks_child2; + child2_is_directory = d_is_dir(dentry_child2); + } + + walker_path = *path; + path_get(&walker_path); + /* + * We need to walk through all the hierarchy to not miss any relevant + * restriction. + */ + while (true) { + struct dentry *parent_dentry; + const struct landlock_rule *rule; + + /* + * If at least all accesses allowed on the destination are + * already allowed on the source, respectively if there is at + * least as much as restrictions on the destination than on the + * source, then we can safely refer files from the source to + * the destination without risking a privilege escalation. + * This also applies in the case of RENAME_EXCHANGE, which + * implies checks on both direction. This is crucial for + * standalone multilayered security policies. Furthermore, + * this helps avoid policy writers to shoot themselves in the + * foot. + */ + if (unlikely(is_dom_check && + no_more_access( + layer_masks_parent1, layer_masks_child1, + child1_is_directory, layer_masks_parent2, + layer_masks_child2, + child2_is_directory))) { + allowed_parent1 = scope_to_request( + access_request_parent1, layer_masks_parent1); + allowed_parent2 = scope_to_request( + access_request_parent2, layer_masks_parent2); + + /* Stops when all accesses are granted. */ + if (allowed_parent1 && allowed_parent2) + break; + + /* + * Now, downgrades the remaining checks from domain + * handled accesses to requested accesses. + */ + is_dom_check = false; + access_masked_parent1 = access_request_parent1; + access_masked_parent2 = access_request_parent2; + } + + rule = find_rule(domain, walker_path.dentry); + allowed_parent1 = unmask_layers(rule, access_masked_parent1, + layer_masks_parent1); + allowed_parent2 = unmask_layers(rule, access_masked_parent2, + layer_masks_parent2); + + /* Stops when a rule from each layer grants access. */ + if (allowed_parent1 && allowed_parent2) + break; + +jump_up: + if (walker_path.dentry == walker_path.mnt->mnt_root) { + if (follow_up(&walker_path)) { + /* Ignores hidden mount points. */ + goto jump_up; + } else { + /* + * Stops at the real root. Denies access + * because not all layers have granted access. + */ + break; + } + } + if (unlikely(IS_ROOT(walker_path.dentry))) { + /* + * Stops at disconnected root directories. Only allows + * access to internal filesystems (e.g. nsfs, which is + * reachable through /proc/<pid>/ns/<namespace>). + */ + allowed_parent1 = allowed_parent2 = + !!(walker_path.mnt->mnt_flags & MNT_INTERNAL); + break; + } + parent_dentry = dget_parent(walker_path.dentry); + dput(walker_path.dentry); + walker_path.dentry = parent_dentry; + } + path_put(&walker_path); + + if (allowed_parent1 && allowed_parent2) + return 0; + + /* + * This prioritizes EACCES over EXDEV for all actions, including + * renames with RENAME_EXCHANGE. + */ + if (likely(is_eacces(layer_masks_parent1, access_request_parent1) || + is_eacces(layer_masks_parent2, access_request_parent2))) + return -EACCES; + + /* + * Gracefully forbids reparenting if the destination directory + * hierarchy is not a superset of restrictions of the source directory + * hierarchy, or if LANDLOCK_ACCESS_FS_REFER is not allowed by the + * source or the destination. + */ + return -EXDEV; +} + +static inline int check_access_path(const struct landlock_ruleset *const domain, + const struct path *const path, + access_mask_t access_request) +{ + layer_mask_t layer_masks[LANDLOCK_NUM_ACCESS_FS] = {}; + + access_request = init_layer_masks(domain, access_request, &layer_masks); + return check_access_path_dual(domain, path, access_request, + &layer_masks, NULL, 0, NULL, NULL); +} + +static inline int current_check_access_path(const struct path *const path, + const access_mask_t access_request) +{ + const struct landlock_ruleset *const dom = + landlock_get_current_domain(); + + if (!dom) + return 0; + return check_access_path(dom, path, access_request); +} + +static inline access_mask_t get_mode_access(const umode_t mode) +{ + switch (mode & S_IFMT) { + case S_IFLNK: + return LANDLOCK_ACCESS_FS_MAKE_SYM; + case 0: + /* A zero mode translates to S_IFREG. */ + case S_IFREG: + return LANDLOCK_ACCESS_FS_MAKE_REG; + case S_IFDIR: + return LANDLOCK_ACCESS_FS_MAKE_DIR; + case S_IFCHR: + return LANDLOCK_ACCESS_FS_MAKE_CHAR; + case S_IFBLK: + return LANDLOCK_ACCESS_FS_MAKE_BLOCK; + case S_IFIFO: + return LANDLOCK_ACCESS_FS_MAKE_FIFO; + case S_IFSOCK: + return LANDLOCK_ACCESS_FS_MAKE_SOCK; + default: + WARN_ON_ONCE(1); + return 0; + } +} + +static inline access_mask_t maybe_remove(const struct dentry *const dentry) +{ + if (d_is_negative(dentry)) + return 0; + return d_is_dir(dentry) ? LANDLOCK_ACCESS_FS_REMOVE_DIR : + LANDLOCK_ACCESS_FS_REMOVE_FILE; +} + +/** + * collect_domain_accesses - Walk through a file path and collect accesses + * + * @domain: Domain to check against. + * @mnt_root: Last directory to check. + * @dir: Directory to start the walk from. + * @layer_masks_dom: Where to store the collected accesses. + * + * This helper is useful to begin a path walk from the @dir directory to a + * @mnt_root directory used as a mount point. This mount point is the common + * ancestor between the source and the destination of a renamed and linked + * file. While walking from @dir to @mnt_root, we record all the domain's + * allowed accesses in @layer_masks_dom. + * + * This is similar to check_access_path_dual() but much simpler because it only + * handles walking on the same mount point and only checks one set of accesses. + * + * Returns: + * - true if all the domain access rights are allowed for @dir; + * - false if the walk reached @mnt_root. + */ +static bool collect_domain_accesses( + const struct landlock_ruleset *const domain, + const struct dentry *const mnt_root, struct dentry *dir, + layer_mask_t (*const layer_masks_dom)[LANDLOCK_NUM_ACCESS_FS]) +{ + unsigned long access_dom; + bool ret = false; + + if (WARN_ON_ONCE(!domain || !mnt_root || !dir || !layer_masks_dom)) + return true; + if (is_nouser_or_private(dir)) + return true; + + access_dom = init_layer_masks(domain, LANDLOCK_MASK_ACCESS_FS, + layer_masks_dom); + + dget(dir); + while (true) { + struct dentry *parent_dentry; + + /* Gets all layers allowing all domain accesses. */ + if (unmask_layers(find_rule(domain, dir), access_dom, + layer_masks_dom)) { + /* + * Stops when all handled accesses are allowed by at + * least one rule in each layer. + */ + ret = true; + break; + } + + /* We should not reach a root other than @mnt_root. */ + if (dir == mnt_root || WARN_ON_ONCE(IS_ROOT(dir))) + break; + + parent_dentry = dget_parent(dir); + dput(dir); + dir = parent_dentry; + } + dput(dir); + return ret; +} + +/** + * current_check_refer_path - Check if a rename or link action is allowed + * + * @old_dentry: File or directory requested to be moved or linked. + * @new_dir: Destination parent directory. + * @new_dentry: Destination file or directory. + * @removable: Sets to true if it is a rename operation. + * @exchange: Sets to true if it is a rename operation with RENAME_EXCHANGE. + * + * Because of its unprivileged constraints, Landlock relies on file hierarchies + * (and not only inodes) to tie access rights to files. Being able to link or + * rename a file hierarchy brings some challenges. Indeed, moving or linking a + * file (i.e. creating a new reference to an inode) can have an impact on the + * actions allowed for a set of files if it would change its parent directory + * (i.e. reparenting). + * + * To avoid trivial access right bypasses, Landlock first checks if the file or + * directory requested to be moved would gain new access rights inherited from + * its new hierarchy. Before returning any error, Landlock then checks that + * the parent source hierarchy and the destination hierarchy would allow the + * link or rename action. If it is not the case, an error with EACCES is + * returned to inform user space that there is no way to remove or create the + * requested source file type. If it should be allowed but the new inherited + * access rights would be greater than the source access rights, then the + * kernel returns an error with EXDEV. Prioritizing EACCES over EXDEV enables + * user space to abort the whole operation if there is no way to do it, or to + * manually copy the source to the destination if this remains allowed, e.g. + * because file creation is allowed on the destination directory but not direct + * linking. + * + * To achieve this goal, the kernel needs to compare two file hierarchies: the + * one identifying the source file or directory (including itself), and the + * destination one. This can be seen as a multilayer partial ordering problem. + * The kernel walks through these paths and collects in a matrix the access + * rights that are denied per layer. These matrices are then compared to see + * if the destination one has more (or the same) restrictions as the source + * one. If this is the case, the requested action will not return EXDEV, which + * doesn't mean the action is allowed. The parent hierarchy of the source + * (i.e. parent directory), and the destination hierarchy must also be checked + * to verify that they explicitly allow such action (i.e. referencing, + * creation and potentially removal rights). The kernel implementation is then + * required to rely on potentially four matrices of access rights: one for the + * source file or directory (i.e. the child), a potentially other one for the + * other source/destination (in case of RENAME_EXCHANGE), one for the source + * parent hierarchy and a last one for the destination hierarchy. These + * ephemeral matrices take some space on the stack, which limits the number of + * layers to a deemed reasonable number: 16. + * + * Returns: + * - 0 if access is allowed; + * - -EXDEV if @old_dentry would inherit new access rights from @new_dir; + * - -EACCES if file removal or creation is denied. + */ +static int current_check_refer_path(struct dentry *const old_dentry, + const struct path *const new_dir, + struct dentry *const new_dentry, + const bool removable, const bool exchange) +{ + const struct landlock_ruleset *const dom = + landlock_get_current_domain(); + bool allow_parent1, allow_parent2; + access_mask_t access_request_parent1, access_request_parent2; + struct path mnt_dir; + layer_mask_t layer_masks_parent1[LANDLOCK_NUM_ACCESS_FS], + layer_masks_parent2[LANDLOCK_NUM_ACCESS_FS]; + + if (!dom) + return 0; + if (WARN_ON_ONCE(dom->num_layers < 1)) + return -EACCES; + if (unlikely(d_is_negative(old_dentry))) + return -ENOENT; + if (exchange) { + if (unlikely(d_is_negative(new_dentry))) + return -ENOENT; + access_request_parent1 = + get_mode_access(d_backing_inode(new_dentry)->i_mode); + } else { + access_request_parent1 = 0; + } + access_request_parent2 = + get_mode_access(d_backing_inode(old_dentry)->i_mode); + if (removable) { + access_request_parent1 |= maybe_remove(old_dentry); + access_request_parent2 |= maybe_remove(new_dentry); + } + + /* The mount points are the same for old and new paths, cf. EXDEV. */ + if (old_dentry->d_parent == new_dir->dentry) { + /* + * The LANDLOCK_ACCESS_FS_REFER access right is not required + * for same-directory referer (i.e. no reparenting). + */ + access_request_parent1 = init_layer_masks( + dom, access_request_parent1 | access_request_parent2, + &layer_masks_parent1); + return check_access_path_dual(dom, new_dir, + access_request_parent1, + &layer_masks_parent1, NULL, 0, + NULL, NULL); + } + + access_request_parent1 |= LANDLOCK_ACCESS_FS_REFER; + access_request_parent2 |= LANDLOCK_ACCESS_FS_REFER; + + /* Saves the common mount point. */ + mnt_dir.mnt = new_dir->mnt; + mnt_dir.dentry = new_dir->mnt->mnt_root; + + /* new_dir->dentry is equal to new_dentry->d_parent */ + allow_parent1 = collect_domain_accesses(dom, mnt_dir.dentry, + old_dentry->d_parent, + &layer_masks_parent1); + allow_parent2 = collect_domain_accesses( + dom, mnt_dir.dentry, new_dir->dentry, &layer_masks_parent2); + + if (allow_parent1 && allow_parent2) + return 0; + + /* + * To be able to compare source and destination domain access rights, + * take into account the @old_dentry access rights aggregated with its + * parent access rights. This will be useful to compare with the + * destination parent access rights. + */ + return check_access_path_dual(dom, &mnt_dir, access_request_parent1, + &layer_masks_parent1, old_dentry, + access_request_parent2, + &layer_masks_parent2, + exchange ? new_dentry : NULL); +} + +/* Inode hooks */ + +static void hook_inode_free_security(struct inode *const inode) +{ + /* + * All inodes must already have been untied from their object by + * release_inode() or hook_sb_delete(). + */ + WARN_ON_ONCE(landlock_inode(inode)->object); +} + +/* Super-block hooks */ + +/* + * Release the inodes used in a security policy. + * + * Cf. fsnotify_unmount_inodes() and invalidate_inodes() + */ +static void hook_sb_delete(struct super_block *const sb) +{ + struct inode *inode, *prev_inode = NULL; + + if (!landlock_initialized) + return; + + spin_lock(&sb->s_inode_list_lock); + list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { + struct landlock_object *object; + + /* Only handles referenced inodes. */ + if (!atomic_read(&inode->i_count)) + continue; + + /* + * Protects against concurrent modification of inode (e.g. + * from get_inode_object()). + */ + spin_lock(&inode->i_lock); + /* + * Checks I_FREEING and I_WILL_FREE to protect against a race + * condition when release_inode() just called iput(), which + * could lead to a NULL dereference of inode->security or a + * second call to iput() for the same Landlock object. Also + * checks I_NEW because such inode cannot be tied to an object. + */ + if (inode->i_state & (I_FREEING | I_WILL_FREE | I_NEW)) { + spin_unlock(&inode->i_lock); + continue; + } + + rcu_read_lock(); + object = rcu_dereference(landlock_inode(inode)->object); + if (!object) { + rcu_read_unlock(); + spin_unlock(&inode->i_lock); + continue; + } + /* Keeps a reference to this inode until the next loop walk. */ + __iget(inode); + spin_unlock(&inode->i_lock); + + /* + * If there is no concurrent release_inode() ongoing, then we + * are in charge of calling iput() on this inode, otherwise we + * will just wait for it to finish. + */ + spin_lock(&object->lock); + if (object->underobj == inode) { + object->underobj = NULL; + spin_unlock(&object->lock); + rcu_read_unlock(); + + /* + * Because object->underobj was not NULL, + * release_inode() and get_inode_object() guarantee + * that it is safe to reset + * landlock_inode(inode)->object while it is not NULL. + * It is therefore not necessary to lock inode->i_lock. + */ + rcu_assign_pointer(landlock_inode(inode)->object, NULL); + /* + * At this point, we own the ihold() reference that was + * originally set up by get_inode_object() and the + * __iget() reference that we just set in this loop + * walk. Therefore the following call to iput() will + * not sleep nor drop the inode because there is now at + * least two references to it. + */ + iput(inode); + } else { + spin_unlock(&object->lock); + rcu_read_unlock(); + } + + if (prev_inode) { + /* + * At this point, we still own the __iget() reference + * that we just set in this loop walk. Therefore we + * can drop the list lock and know that the inode won't + * disappear from under us until the next loop walk. + */ + spin_unlock(&sb->s_inode_list_lock); + /* + * We can now actually put the inode reference from the + * previous loop walk, which is not needed anymore. + */ + iput(prev_inode); + cond_resched(); + spin_lock(&sb->s_inode_list_lock); + } + prev_inode = inode; + } + spin_unlock(&sb->s_inode_list_lock); + + /* Puts the inode reference from the last loop walk, if any. */ + if (prev_inode) + iput(prev_inode); + /* Waits for pending iput() in release_inode(). */ + wait_var_event(&landlock_superblock(sb)->inode_refs, + !atomic_long_read(&landlock_superblock(sb)->inode_refs)); +} + +/* + * Because a Landlock security policy is defined according to the filesystem + * topology (i.e. the mount namespace), changing it may grant access to files + * not previously allowed. + * + * To make it simple, deny any filesystem topology modification by landlocked + * processes. Non-landlocked processes may still change the namespace of a + * landlocked process, but this kind of threat must be handled by a system-wide + * access-control security policy. + * + * This could be lifted in the future if Landlock can safely handle mount + * namespace updates requested by a landlocked process. Indeed, we could + * update the current domain (which is currently read-only) by taking into + * account the accesses of the source and the destination of a new mount point. + * However, it would also require to make all the child domains dynamically + * inherit these new constraints. Anyway, for backward compatibility reasons, + * a dedicated user space option would be required (e.g. as a ruleset flag). + */ +static int hook_sb_mount(const char *const dev_name, + const struct path *const path, const char *const type, + const unsigned long flags, void *const data) +{ + if (!landlock_get_current_domain()) + return 0; + return -EPERM; +} + +static int hook_move_mount(const struct path *const from_path, + const struct path *const to_path) +{ + if (!landlock_get_current_domain()) + return 0; + return -EPERM; +} + +/* + * Removing a mount point may reveal a previously hidden file hierarchy, which + * may then grant access to files, which may have previously been forbidden. + */ +static int hook_sb_umount(struct vfsmount *const mnt, const int flags) +{ + if (!landlock_get_current_domain()) + return 0; + return -EPERM; +} + +static int hook_sb_remount(struct super_block *const sb, void *const mnt_opts) +{ + if (!landlock_get_current_domain()) + return 0; + return -EPERM; +} + +/* + * pivot_root(2), like mount(2), changes the current mount namespace. It must + * then be forbidden for a landlocked process. + * + * However, chroot(2) may be allowed because it only changes the relative root + * directory of the current process. Moreover, it can be used to restrict the + * view of the filesystem. + */ +static int hook_sb_pivotroot(const struct path *const old_path, + const struct path *const new_path) +{ + if (!landlock_get_current_domain()) + return 0; + return -EPERM; +} + +/* Path hooks */ + +static int hook_path_link(struct dentry *const old_dentry, + const struct path *const new_dir, + struct dentry *const new_dentry) +{ + return current_check_refer_path(old_dentry, new_dir, new_dentry, false, + false); +} + +static int hook_path_rename(const struct path *const old_dir, + struct dentry *const old_dentry, + const struct path *const new_dir, + struct dentry *const new_dentry, + const unsigned int flags) +{ + /* old_dir refers to old_dentry->d_parent and new_dir->mnt */ + return current_check_refer_path(old_dentry, new_dir, new_dentry, true, + !!(flags & RENAME_EXCHANGE)); +} + +static int hook_path_mkdir(const struct path *const dir, + struct dentry *const dentry, const umode_t mode) +{ + return current_check_access_path(dir, LANDLOCK_ACCESS_FS_MAKE_DIR); +} + +static int hook_path_mknod(const struct path *const dir, + struct dentry *const dentry, const umode_t mode, + const unsigned int dev) +{ + const struct landlock_ruleset *const dom = + landlock_get_current_domain(); + + if (!dom) + return 0; + return check_access_path(dom, dir, get_mode_access(mode)); +} + +static int hook_path_symlink(const struct path *const dir, + struct dentry *const dentry, + const char *const old_name) +{ + return current_check_access_path(dir, LANDLOCK_ACCESS_FS_MAKE_SYM); +} + +static int hook_path_unlink(const struct path *const dir, + struct dentry *const dentry) +{ + return current_check_access_path(dir, LANDLOCK_ACCESS_FS_REMOVE_FILE); +} + +static int hook_path_rmdir(const struct path *const dir, + struct dentry *const dentry) +{ + return current_check_access_path(dir, LANDLOCK_ACCESS_FS_REMOVE_DIR); +} + +/* File hooks */ + +static inline access_mask_t get_file_access(const struct file *const file) +{ + access_mask_t access = 0; + + if (file->f_mode & FMODE_READ) { + /* A directory can only be opened in read mode. */ + if (S_ISDIR(file_inode(file)->i_mode)) + return LANDLOCK_ACCESS_FS_READ_DIR; + access = LANDLOCK_ACCESS_FS_READ_FILE; + } + if (file->f_mode & FMODE_WRITE) + access |= LANDLOCK_ACCESS_FS_WRITE_FILE; + /* __FMODE_EXEC is indeed part of f_flags, not f_mode. */ + if (file->f_flags & __FMODE_EXEC) + access |= LANDLOCK_ACCESS_FS_EXECUTE; + return access; +} + +static int hook_file_open(struct file *const file) +{ + const struct landlock_ruleset *const dom = + landlock_get_current_domain(); + + if (!dom) + return 0; + /* + * Because a file may be opened with O_PATH, get_file_access() may + * return 0. This case will be handled with a future Landlock + * evolution. + */ + return check_access_path(dom, &file->f_path, get_file_access(file)); +} + +static struct security_hook_list landlock_hooks[] __lsm_ro_after_init = { + LSM_HOOK_INIT(inode_free_security, hook_inode_free_security), + + LSM_HOOK_INIT(sb_delete, hook_sb_delete), + LSM_HOOK_INIT(sb_mount, hook_sb_mount), + LSM_HOOK_INIT(move_mount, hook_move_mount), + LSM_HOOK_INIT(sb_umount, hook_sb_umount), + LSM_HOOK_INIT(sb_remount, hook_sb_remount), + LSM_HOOK_INIT(sb_pivotroot, hook_sb_pivotroot), + + LSM_HOOK_INIT(path_link, hook_path_link), + LSM_HOOK_INIT(path_rename, hook_path_rename), + LSM_HOOK_INIT(path_mkdir, hook_path_mkdir), + LSM_HOOK_INIT(path_mknod, hook_path_mknod), + LSM_HOOK_INIT(path_symlink, hook_path_symlink), + LSM_HOOK_INIT(path_unlink, hook_path_unlink), + LSM_HOOK_INIT(path_rmdir, hook_path_rmdir), + + LSM_HOOK_INIT(file_open, hook_file_open), +}; + +__init void landlock_add_fs_hooks(void) +{ + security_add_hooks(landlock_hooks, ARRAY_SIZE(landlock_hooks), + LANDLOCK_NAME); +} diff --git a/security/landlock/fs.h b/security/landlock/fs.h new file mode 100644 index 000000000..8db7acf91 --- /dev/null +++ b/security/landlock/fs.h @@ -0,0 +1,71 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Landlock LSM - Filesystem management and hooks + * + * Copyright © 2017-2020 Mickaël Salaün <mic@digikod.net> + * Copyright © 2018-2020 ANSSI + */ + +#ifndef _SECURITY_LANDLOCK_FS_H +#define _SECURITY_LANDLOCK_FS_H + +#include <linux/fs.h> +#include <linux/init.h> +#include <linux/rcupdate.h> + +#include "ruleset.h" +#include "setup.h" + +/** + * struct landlock_inode_security - Inode security blob + * + * Enable to reference a &struct landlock_object tied to an inode (i.e. + * underlying object). + */ +struct landlock_inode_security { + /** + * @object: Weak pointer to an allocated object. All assignments of a + * new object are protected by the underlying inode->i_lock. However, + * atomically disassociating @object from the inode is only protected + * by @object->lock, from the time @object's usage refcount drops to + * zero to the time this pointer is nulled out (cf. release_inode() and + * hook_sb_delete()). Indeed, such disassociation doesn't require + * inode->i_lock thanks to the careful rcu_access_pointer() check + * performed by get_inode_object(). + */ + struct landlock_object __rcu *object; +}; + +/** + * struct landlock_superblock_security - Superblock security blob + * + * Enable hook_sb_delete() to wait for concurrent calls to release_inode(). + */ +struct landlock_superblock_security { + /** + * @inode_refs: Number of pending inodes (from this superblock) that + * are being released by release_inode(). + * Cf. struct super_block->s_fsnotify_inode_refs . + */ + atomic_long_t inode_refs; +}; + +static inline struct landlock_inode_security * +landlock_inode(const struct inode *const inode) +{ + return inode->i_security + landlock_blob_sizes.lbs_inode; +} + +static inline struct landlock_superblock_security * +landlock_superblock(const struct super_block *const superblock) +{ + return superblock->s_security + landlock_blob_sizes.lbs_superblock; +} + +__init void landlock_add_fs_hooks(void); + +int landlock_append_fs_rule(struct landlock_ruleset *const ruleset, + const struct path *const path, + access_mask_t access_hierarchy); + +#endif /* _SECURITY_LANDLOCK_FS_H */ diff --git a/security/landlock/limits.h b/security/landlock/limits.h new file mode 100644 index 000000000..b54184ab9 --- /dev/null +++ b/security/landlock/limits.h @@ -0,0 +1,27 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Landlock LSM - Limits for different components + * + * Copyright © 2016-2020 Mickaël Salaün <mic@digikod.net> + * Copyright © 2018-2020 ANSSI + */ + +#ifndef _SECURITY_LANDLOCK_LIMITS_H +#define _SECURITY_LANDLOCK_LIMITS_H + +#include <linux/bitops.h> +#include <linux/limits.h> +#include <uapi/linux/landlock.h> + +/* clang-format off */ + +#define LANDLOCK_MAX_NUM_LAYERS 16 +#define LANDLOCK_MAX_NUM_RULES U32_MAX + +#define LANDLOCK_LAST_ACCESS_FS LANDLOCK_ACCESS_FS_REFER +#define LANDLOCK_MASK_ACCESS_FS ((LANDLOCK_LAST_ACCESS_FS << 1) - 1) +#define LANDLOCK_NUM_ACCESS_FS __const_hweight64(LANDLOCK_MASK_ACCESS_FS) + +/* clang-format on */ + +#endif /* _SECURITY_LANDLOCK_LIMITS_H */ diff --git a/security/landlock/object.c b/security/landlock/object.c new file mode 100644 index 000000000..1f50612f0 --- /dev/null +++ b/security/landlock/object.c @@ -0,0 +1,67 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Landlock LSM - Object management + * + * Copyright © 2016-2020 Mickaël Salaün <mic@digikod.net> + * Copyright © 2018-2020 ANSSI + */ + +#include <linux/bug.h> +#include <linux/compiler_types.h> +#include <linux/err.h> +#include <linux/kernel.h> +#include <linux/rcupdate.h> +#include <linux/refcount.h> +#include <linux/slab.h> +#include <linux/spinlock.h> + +#include "object.h" + +struct landlock_object * +landlock_create_object(const struct landlock_object_underops *const underops, + void *const underobj) +{ + struct landlock_object *new_object; + + if (WARN_ON_ONCE(!underops || !underobj)) + return ERR_PTR(-ENOENT); + new_object = kzalloc(sizeof(*new_object), GFP_KERNEL_ACCOUNT); + if (!new_object) + return ERR_PTR(-ENOMEM); + refcount_set(&new_object->usage, 1); + spin_lock_init(&new_object->lock); + new_object->underops = underops; + new_object->underobj = underobj; + return new_object; +} + +/* + * The caller must own the object (i.e. thanks to object->usage) to safely put + * it. + */ +void landlock_put_object(struct landlock_object *const object) +{ + /* + * The call to @object->underops->release(object) might sleep, e.g. + * because of iput(). + */ + might_sleep(); + if (!object) + return; + + /* + * If the @object's refcount cannot drop to zero, we can just decrement + * the refcount without holding a lock. Otherwise, the decrement must + * happen under @object->lock for synchronization with things like + * get_inode_object(). + */ + if (refcount_dec_and_lock(&object->usage, &object->lock)) { + __acquire(&object->lock); + /* + * With @object->lock initially held, remove the reference from + * @object->underobj to @object (if it still exists). + */ + object->underops->release(object); + kfree_rcu(object, rcu_free); + } +} diff --git a/security/landlock/object.h b/security/landlock/object.h new file mode 100644 index 000000000..5f28c35e8 --- /dev/null +++ b/security/landlock/object.h @@ -0,0 +1,91 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Landlock LSM - Object management + * + * Copyright © 2016-2020 Mickaël Salaün <mic@digikod.net> + * Copyright © 2018-2020 ANSSI + */ + +#ifndef _SECURITY_LANDLOCK_OBJECT_H +#define _SECURITY_LANDLOCK_OBJECT_H + +#include <linux/compiler_types.h> +#include <linux/refcount.h> +#include <linux/spinlock.h> + +struct landlock_object; + +/** + * struct landlock_object_underops - Operations on an underlying object + */ +struct landlock_object_underops { + /** + * @release: Releases the underlying object (e.g. iput() for an inode). + */ + void (*release)(struct landlock_object *const object) + __releases(object->lock); +}; + +/** + * struct landlock_object - Security blob tied to a kernel object + * + * The goal of this structure is to enable to tie a set of ephemeral access + * rights (pertaining to different domains) to a kernel object (e.g an inode) + * in a safe way. This implies to handle concurrent use and modification. + * + * The lifetime of a &struct landlock_object depends on the rules referring to + * it. + */ +struct landlock_object { + /** + * @usage: This counter is used to tie an object to the rules matching + * it or to keep it alive while adding a new rule. If this counter + * reaches zero, this struct must not be modified, but this counter can + * still be read from within an RCU read-side critical section. When + * adding a new rule to an object with a usage counter of zero, we must + * wait until the pointer to this object is set to NULL (or recycled). + */ + refcount_t usage; + /** + * @lock: Protects against concurrent modifications. This lock must be + * held from the time @usage drops to zero until any weak references + * from @underobj to this object have been cleaned up. + * + * Lock ordering: inode->i_lock nests inside this. + */ + spinlock_t lock; + /** + * @underobj: Used when cleaning up an object and to mark an object as + * tied to its underlying kernel structure. This pointer is protected + * by @lock. Cf. landlock_release_inodes() and release_inode(). + */ + void *underobj; + union { + /** + * @rcu_free: Enables lockless use of @usage, @lock and + * @underobj from within an RCU read-side critical section. + * @rcu_free and @underops are only used by + * landlock_put_object(). + */ + struct rcu_head rcu_free; + /** + * @underops: Enables landlock_put_object() to release the + * underlying object (e.g. inode). + */ + const struct landlock_object_underops *underops; + }; +}; + +struct landlock_object * +landlock_create_object(const struct landlock_object_underops *const underops, + void *const underobj); + +void landlock_put_object(struct landlock_object *const object); + +static inline void landlock_get_object(struct landlock_object *const object) +{ + if (object) + refcount_inc(&object->usage); +} + +#endif /* _SECURITY_LANDLOCK_OBJECT_H */ diff --git a/security/landlock/ptrace.c b/security/landlock/ptrace.c new file mode 100644 index 000000000..4c5b9cd71 --- /dev/null +++ b/security/landlock/ptrace.c @@ -0,0 +1,120 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Landlock LSM - Ptrace hooks + * + * Copyright © 2017-2020 Mickaël Salaün <mic@digikod.net> + * Copyright © 2019-2020 ANSSI + */ + +#include <asm/current.h> +#include <linux/cred.h> +#include <linux/errno.h> +#include <linux/kernel.h> +#include <linux/lsm_hooks.h> +#include <linux/rcupdate.h> +#include <linux/sched.h> + +#include "common.h" +#include "cred.h" +#include "ptrace.h" +#include "ruleset.h" +#include "setup.h" + +/** + * domain_scope_le - Checks domain ordering for scoped ptrace + * + * @parent: Parent domain. + * @child: Potential child of @parent. + * + * Checks if the @parent domain is less or equal to (i.e. an ancestor, which + * means a subset of) the @child domain. + */ +static bool domain_scope_le(const struct landlock_ruleset *const parent, + const struct landlock_ruleset *const child) +{ + const struct landlock_hierarchy *walker; + + if (!parent) + return true; + if (!child) + return false; + for (walker = child->hierarchy; walker; walker = walker->parent) { + if (walker == parent->hierarchy) + /* @parent is in the scoped hierarchy of @child. */ + return true; + } + /* There is no relationship between @parent and @child. */ + return false; +} + +static bool task_is_scoped(const struct task_struct *const parent, + const struct task_struct *const child) +{ + bool is_scoped; + const struct landlock_ruleset *dom_parent, *dom_child; + + rcu_read_lock(); + dom_parent = landlock_get_task_domain(parent); + dom_child = landlock_get_task_domain(child); + is_scoped = domain_scope_le(dom_parent, dom_child); + rcu_read_unlock(); + return is_scoped; +} + +static int task_ptrace(const struct task_struct *const parent, + const struct task_struct *const child) +{ + /* Quick return for non-landlocked tasks. */ + if (!landlocked(parent)) + return 0; + if (task_is_scoped(parent, child)) + return 0; + return -EPERM; +} + +/** + * hook_ptrace_access_check - Determines whether the current process may access + * another + * + * @child: Process to be accessed. + * @mode: Mode of attachment. + * + * If the current task has Landlock rules, then the child must have at least + * the same rules. Else denied. + * + * Determines whether a process may access another, returning 0 if permission + * granted, -errno if denied. + */ +static int hook_ptrace_access_check(struct task_struct *const child, + const unsigned int mode) +{ + return task_ptrace(current, child); +} + +/** + * hook_ptrace_traceme - Determines whether another process may trace the + * current one + * + * @parent: Task proposed to be the tracer. + * + * If the parent has Landlock rules, then the current task must have the same + * or more rules. Else denied. + * + * Determines whether the nominated task is permitted to trace the current + * process, returning 0 if permission is granted, -errno if denied. + */ +static int hook_ptrace_traceme(struct task_struct *const parent) +{ + return task_ptrace(parent, current); +} + +static struct security_hook_list landlock_hooks[] __lsm_ro_after_init = { + LSM_HOOK_INIT(ptrace_access_check, hook_ptrace_access_check), + LSM_HOOK_INIT(ptrace_traceme, hook_ptrace_traceme), +}; + +__init void landlock_add_ptrace_hooks(void) +{ + security_add_hooks(landlock_hooks, ARRAY_SIZE(landlock_hooks), + LANDLOCK_NAME); +} diff --git a/security/landlock/ptrace.h b/security/landlock/ptrace.h new file mode 100644 index 000000000..265b220ae --- /dev/null +++ b/security/landlock/ptrace.h @@ -0,0 +1,14 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Landlock LSM - Ptrace hooks + * + * Copyright © 2017-2019 Mickaël Salaün <mic@digikod.net> + * Copyright © 2019 ANSSI + */ + +#ifndef _SECURITY_LANDLOCK_PTRACE_H +#define _SECURITY_LANDLOCK_PTRACE_H + +__init void landlock_add_ptrace_hooks(void); + +#endif /* _SECURITY_LANDLOCK_PTRACE_H */ diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c new file mode 100644 index 000000000..996484f98 --- /dev/null +++ b/security/landlock/ruleset.c @@ -0,0 +1,475 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Landlock LSM - Ruleset management + * + * Copyright © 2016-2020 Mickaël Salaün <mic@digikod.net> + * Copyright © 2018-2020 ANSSI + */ + +#include <linux/bits.h> +#include <linux/bug.h> +#include <linux/compiler_types.h> +#include <linux/err.h> +#include <linux/errno.h> +#include <linux/kernel.h> +#include <linux/lockdep.h> +#include <linux/overflow.h> +#include <linux/rbtree.h> +#include <linux/refcount.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/workqueue.h> + +#include "limits.h" +#include "object.h" +#include "ruleset.h" + +static struct landlock_ruleset *create_ruleset(const u32 num_layers) +{ + struct landlock_ruleset *new_ruleset; + + new_ruleset = + kzalloc(struct_size(new_ruleset, fs_access_masks, num_layers), + GFP_KERNEL_ACCOUNT); + if (!new_ruleset) + return ERR_PTR(-ENOMEM); + refcount_set(&new_ruleset->usage, 1); + mutex_init(&new_ruleset->lock); + new_ruleset->root = RB_ROOT; + new_ruleset->num_layers = num_layers; + /* + * hierarchy = NULL + * num_rules = 0 + * fs_access_masks[] = 0 + */ + return new_ruleset; +} + +struct landlock_ruleset * +landlock_create_ruleset(const access_mask_t fs_access_mask) +{ + struct landlock_ruleset *new_ruleset; + + /* Informs about useless ruleset. */ + if (!fs_access_mask) + return ERR_PTR(-ENOMSG); + new_ruleset = create_ruleset(1); + if (!IS_ERR(new_ruleset)) + new_ruleset->fs_access_masks[0] = fs_access_mask; + return new_ruleset; +} + +static void build_check_rule(void) +{ + const struct landlock_rule rule = { + .num_layers = ~0, + }; + + BUILD_BUG_ON(rule.num_layers < LANDLOCK_MAX_NUM_LAYERS); +} + +static struct landlock_rule * +create_rule(struct landlock_object *const object, + const struct landlock_layer (*const layers)[], const u32 num_layers, + const struct landlock_layer *const new_layer) +{ + struct landlock_rule *new_rule; + u32 new_num_layers; + + build_check_rule(); + if (new_layer) { + /* Should already be checked by landlock_merge_ruleset(). */ + if (WARN_ON_ONCE(num_layers >= LANDLOCK_MAX_NUM_LAYERS)) + return ERR_PTR(-E2BIG); + new_num_layers = num_layers + 1; + } else { + new_num_layers = num_layers; + } + new_rule = kzalloc(struct_size(new_rule, layers, new_num_layers), + GFP_KERNEL_ACCOUNT); + if (!new_rule) + return ERR_PTR(-ENOMEM); + RB_CLEAR_NODE(&new_rule->node); + landlock_get_object(object); + new_rule->object = object; + new_rule->num_layers = new_num_layers; + /* Copies the original layer stack. */ + memcpy(new_rule->layers, layers, + flex_array_size(new_rule, layers, num_layers)); + if (new_layer) + /* Adds a copy of @new_layer on the layer stack. */ + new_rule->layers[new_rule->num_layers - 1] = *new_layer; + return new_rule; +} + +static void free_rule(struct landlock_rule *const rule) +{ + might_sleep(); + if (!rule) + return; + landlock_put_object(rule->object); + kfree(rule); +} + +static void build_check_ruleset(void) +{ + const struct landlock_ruleset ruleset = { + .num_rules = ~0, + .num_layers = ~0, + }; + typeof(ruleset.fs_access_masks[0]) fs_access_mask = ~0; + + BUILD_BUG_ON(ruleset.num_rules < LANDLOCK_MAX_NUM_RULES); + BUILD_BUG_ON(ruleset.num_layers < LANDLOCK_MAX_NUM_LAYERS); + BUILD_BUG_ON(fs_access_mask < LANDLOCK_MASK_ACCESS_FS); +} + +/** + * insert_rule - Create and insert a rule in a ruleset + * + * @ruleset: The ruleset to be updated. + * @object: The object to build the new rule with. The underlying kernel + * object must be held by the caller. + * @layers: One or multiple layers to be copied into the new rule. + * @num_layers: The number of @layers entries. + * + * When user space requests to add a new rule to a ruleset, @layers only + * contains one entry and this entry is not assigned to any level. In this + * case, the new rule will extend @ruleset, similarly to a boolean OR between + * access rights. + * + * When merging a ruleset in a domain, or copying a domain, @layers will be + * added to @ruleset as new constraints, similarly to a boolean AND between + * access rights. + */ +static int insert_rule(struct landlock_ruleset *const ruleset, + struct landlock_object *const object, + const struct landlock_layer (*const layers)[], + size_t num_layers) +{ + struct rb_node **walker_node; + struct rb_node *parent_node = NULL; + struct landlock_rule *new_rule; + + might_sleep(); + lockdep_assert_held(&ruleset->lock); + if (WARN_ON_ONCE(!object || !layers)) + return -ENOENT; + walker_node = &(ruleset->root.rb_node); + while (*walker_node) { + struct landlock_rule *const this = + rb_entry(*walker_node, struct landlock_rule, node); + + if (this->object != object) { + parent_node = *walker_node; + if (this->object < object) + walker_node = &((*walker_node)->rb_right); + else + walker_node = &((*walker_node)->rb_left); + continue; + } + + /* Only a single-level layer should match an existing rule. */ + if (WARN_ON_ONCE(num_layers != 1)) + return -EINVAL; + + /* If there is a matching rule, updates it. */ + if ((*layers)[0].level == 0) { + /* + * Extends access rights when the request comes from + * landlock_add_rule(2), i.e. @ruleset is not a domain. + */ + if (WARN_ON_ONCE(this->num_layers != 1)) + return -EINVAL; + if (WARN_ON_ONCE(this->layers[0].level != 0)) + return -EINVAL; + this->layers[0].access |= (*layers)[0].access; + return 0; + } + + if (WARN_ON_ONCE(this->layers[0].level == 0)) + return -EINVAL; + + /* + * Intersects access rights when it is a merge between a + * ruleset and a domain. + */ + new_rule = create_rule(object, &this->layers, this->num_layers, + &(*layers)[0]); + if (IS_ERR(new_rule)) + return PTR_ERR(new_rule); + rb_replace_node(&this->node, &new_rule->node, &ruleset->root); + free_rule(this); + return 0; + } + + /* There is no match for @object. */ + build_check_ruleset(); + if (ruleset->num_rules >= LANDLOCK_MAX_NUM_RULES) + return -E2BIG; + new_rule = create_rule(object, layers, num_layers, NULL); + if (IS_ERR(new_rule)) + return PTR_ERR(new_rule); + rb_link_node(&new_rule->node, parent_node, walker_node); + rb_insert_color(&new_rule->node, &ruleset->root); + ruleset->num_rules++; + return 0; +} + +static void build_check_layer(void) +{ + const struct landlock_layer layer = { + .level = ~0, + .access = ~0, + }; + + BUILD_BUG_ON(layer.level < LANDLOCK_MAX_NUM_LAYERS); + BUILD_BUG_ON(layer.access < LANDLOCK_MASK_ACCESS_FS); +} + +/* @ruleset must be locked by the caller. */ +int landlock_insert_rule(struct landlock_ruleset *const ruleset, + struct landlock_object *const object, + const access_mask_t access) +{ + struct landlock_layer layers[] = { { + .access = access, + /* When @level is zero, insert_rule() extends @ruleset. */ + .level = 0, + } }; + + build_check_layer(); + return insert_rule(ruleset, object, &layers, ARRAY_SIZE(layers)); +} + +static inline void get_hierarchy(struct landlock_hierarchy *const hierarchy) +{ + if (hierarchy) + refcount_inc(&hierarchy->usage); +} + +static void put_hierarchy(struct landlock_hierarchy *hierarchy) +{ + while (hierarchy && refcount_dec_and_test(&hierarchy->usage)) { + const struct landlock_hierarchy *const freeme = hierarchy; + + hierarchy = hierarchy->parent; + kfree(freeme); + } +} + +static int merge_ruleset(struct landlock_ruleset *const dst, + struct landlock_ruleset *const src) +{ + struct landlock_rule *walker_rule, *next_rule; + int err = 0; + + might_sleep(); + /* Should already be checked by landlock_merge_ruleset() */ + if (WARN_ON_ONCE(!src)) + return 0; + /* Only merge into a domain. */ + if (WARN_ON_ONCE(!dst || !dst->hierarchy)) + return -EINVAL; + + /* Locks @dst first because we are its only owner. */ + mutex_lock(&dst->lock); + mutex_lock_nested(&src->lock, SINGLE_DEPTH_NESTING); + + /* Stacks the new layer. */ + if (WARN_ON_ONCE(src->num_layers != 1 || dst->num_layers < 1)) { + err = -EINVAL; + goto out_unlock; + } + dst->fs_access_masks[dst->num_layers - 1] = src->fs_access_masks[0]; + + /* Merges the @src tree. */ + rbtree_postorder_for_each_entry_safe(walker_rule, next_rule, &src->root, + node) { + struct landlock_layer layers[] = { { + .level = dst->num_layers, + } }; + + if (WARN_ON_ONCE(walker_rule->num_layers != 1)) { + err = -EINVAL; + goto out_unlock; + } + if (WARN_ON_ONCE(walker_rule->layers[0].level != 0)) { + err = -EINVAL; + goto out_unlock; + } + layers[0].access = walker_rule->layers[0].access; + err = insert_rule(dst, walker_rule->object, &layers, + ARRAY_SIZE(layers)); + if (err) + goto out_unlock; + } + +out_unlock: + mutex_unlock(&src->lock); + mutex_unlock(&dst->lock); + return err; +} + +static int inherit_ruleset(struct landlock_ruleset *const parent, + struct landlock_ruleset *const child) +{ + struct landlock_rule *walker_rule, *next_rule; + int err = 0; + + might_sleep(); + if (!parent) + return 0; + + /* Locks @child first because we are its only owner. */ + mutex_lock(&child->lock); + mutex_lock_nested(&parent->lock, SINGLE_DEPTH_NESTING); + + /* Copies the @parent tree. */ + rbtree_postorder_for_each_entry_safe(walker_rule, next_rule, + &parent->root, node) { + err = insert_rule(child, walker_rule->object, + &walker_rule->layers, + walker_rule->num_layers); + if (err) + goto out_unlock; + } + + if (WARN_ON_ONCE(child->num_layers <= parent->num_layers)) { + err = -EINVAL; + goto out_unlock; + } + /* Copies the parent layer stack and leaves a space for the new layer. */ + memcpy(child->fs_access_masks, parent->fs_access_masks, + flex_array_size(parent, fs_access_masks, parent->num_layers)); + + if (WARN_ON_ONCE(!parent->hierarchy)) { + err = -EINVAL; + goto out_unlock; + } + get_hierarchy(parent->hierarchy); + child->hierarchy->parent = parent->hierarchy; + +out_unlock: + mutex_unlock(&parent->lock); + mutex_unlock(&child->lock); + return err; +} + +static void free_ruleset(struct landlock_ruleset *const ruleset) +{ + struct landlock_rule *freeme, *next; + + might_sleep(); + rbtree_postorder_for_each_entry_safe(freeme, next, &ruleset->root, node) + free_rule(freeme); + put_hierarchy(ruleset->hierarchy); + kfree(ruleset); +} + +void landlock_put_ruleset(struct landlock_ruleset *const ruleset) +{ + might_sleep(); + if (ruleset && refcount_dec_and_test(&ruleset->usage)) + free_ruleset(ruleset); +} + +static void free_ruleset_work(struct work_struct *const work) +{ + struct landlock_ruleset *ruleset; + + ruleset = container_of(work, struct landlock_ruleset, work_free); + free_ruleset(ruleset); +} + +void landlock_put_ruleset_deferred(struct landlock_ruleset *const ruleset) +{ + if (ruleset && refcount_dec_and_test(&ruleset->usage)) { + INIT_WORK(&ruleset->work_free, free_ruleset_work); + schedule_work(&ruleset->work_free); + } +} + +/** + * landlock_merge_ruleset - Merge a ruleset with a domain + * + * @parent: Parent domain. + * @ruleset: New ruleset to be merged. + * + * Returns the intersection of @parent and @ruleset, or returns @parent if + * @ruleset is empty, or returns a duplicate of @ruleset if @parent is empty. + */ +struct landlock_ruleset * +landlock_merge_ruleset(struct landlock_ruleset *const parent, + struct landlock_ruleset *const ruleset) +{ + struct landlock_ruleset *new_dom; + u32 num_layers; + int err; + + might_sleep(); + if (WARN_ON_ONCE(!ruleset || parent == ruleset)) + return ERR_PTR(-EINVAL); + + if (parent) { + if (parent->num_layers >= LANDLOCK_MAX_NUM_LAYERS) + return ERR_PTR(-E2BIG); + num_layers = parent->num_layers + 1; + } else { + num_layers = 1; + } + + /* Creates a new domain... */ + new_dom = create_ruleset(num_layers); + if (IS_ERR(new_dom)) + return new_dom; + new_dom->hierarchy = + kzalloc(sizeof(*new_dom->hierarchy), GFP_KERNEL_ACCOUNT); + if (!new_dom->hierarchy) { + err = -ENOMEM; + goto out_put_dom; + } + refcount_set(&new_dom->hierarchy->usage, 1); + + /* ...as a child of @parent... */ + err = inherit_ruleset(parent, new_dom); + if (err) + goto out_put_dom; + + /* ...and including @ruleset. */ + err = merge_ruleset(new_dom, ruleset); + if (err) + goto out_put_dom; + + return new_dom; + +out_put_dom: + landlock_put_ruleset(new_dom); + return ERR_PTR(err); +} + +/* + * The returned access has the same lifetime as @ruleset. + */ +const struct landlock_rule * +landlock_find_rule(const struct landlock_ruleset *const ruleset, + const struct landlock_object *const object) +{ + const struct rb_node *node; + + if (!object) + return NULL; + node = ruleset->root.rb_node; + while (node) { + struct landlock_rule *this = + rb_entry(node, struct landlock_rule, node); + + if (this->object == object) + return this; + if (this->object < object) + node = node->rb_right; + else + node = node->rb_left; + } + return NULL; +} diff --git a/security/landlock/ruleset.h b/security/landlock/ruleset.h new file mode 100644 index 000000000..d43231b78 --- /dev/null +++ b/security/landlock/ruleset.h @@ -0,0 +1,180 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Landlock LSM - Ruleset management + * + * Copyright © 2016-2020 Mickaël Salaün <mic@digikod.net> + * Copyright © 2018-2020 ANSSI + */ + +#ifndef _SECURITY_LANDLOCK_RULESET_H +#define _SECURITY_LANDLOCK_RULESET_H + +#include <linux/bitops.h> +#include <linux/build_bug.h> +#include <linux/mutex.h> +#include <linux/rbtree.h> +#include <linux/refcount.h> +#include <linux/workqueue.h> + +#include "limits.h" +#include "object.h" + +typedef u16 access_mask_t; +/* Makes sure all filesystem access rights can be stored. */ +static_assert(BITS_PER_TYPE(access_mask_t) >= LANDLOCK_NUM_ACCESS_FS); +/* Makes sure for_each_set_bit() and for_each_clear_bit() calls are OK. */ +static_assert(sizeof(unsigned long) >= sizeof(access_mask_t)); + +typedef u16 layer_mask_t; +/* Makes sure all layers can be checked. */ +static_assert(BITS_PER_TYPE(layer_mask_t) >= LANDLOCK_MAX_NUM_LAYERS); + +/** + * struct landlock_layer - Access rights for a given layer + */ +struct landlock_layer { + /** + * @level: Position of this layer in the layer stack. + */ + u16 level; + /** + * @access: Bitfield of allowed actions on the kernel object. They are + * relative to the object type (e.g. %LANDLOCK_ACTION_FS_READ). + */ + access_mask_t access; +}; + +/** + * struct landlock_rule - Access rights tied to an object + */ +struct landlock_rule { + /** + * @node: Node in the ruleset's red-black tree. + */ + struct rb_node node; + /** + * @object: Pointer to identify a kernel object (e.g. an inode). This + * is used as a key for this ruleset element. This pointer is set once + * and never modified. It always points to an allocated object because + * each rule increments the refcount of its object. + */ + struct landlock_object *object; + /** + * @num_layers: Number of entries in @layers. + */ + u32 num_layers; + /** + * @layers: Stack of layers, from the latest to the newest, implemented + * as a flexible array member (FAM). + */ + struct landlock_layer layers[]; +}; + +/** + * struct landlock_hierarchy - Node in a ruleset hierarchy + */ +struct landlock_hierarchy { + /** + * @parent: Pointer to the parent node, or NULL if it is a root + * Landlock domain. + */ + struct landlock_hierarchy *parent; + /** + * @usage: Number of potential children domains plus their parent + * domain. + */ + refcount_t usage; +}; + +/** + * struct landlock_ruleset - Landlock ruleset + * + * This data structure must contain unique entries, be updatable, and quick to + * match an object. + */ +struct landlock_ruleset { + /** + * @root: Root of a red-black tree containing &struct landlock_rule + * nodes. Once a ruleset is tied to a process (i.e. as a domain), this + * tree is immutable until @usage reaches zero. + */ + struct rb_root root; + /** + * @hierarchy: Enables hierarchy identification even when a parent + * domain vanishes. This is needed for the ptrace protection. + */ + struct landlock_hierarchy *hierarchy; + union { + /** + * @work_free: Enables to free a ruleset within a lockless + * section. This is only used by + * landlock_put_ruleset_deferred() when @usage reaches zero. + * The fields @lock, @usage, @num_rules, @num_layers and + * @fs_access_masks are then unused. + */ + struct work_struct work_free; + struct { + /** + * @lock: Protects against concurrent modifications of + * @root, if @usage is greater than zero. + */ + struct mutex lock; + /** + * @usage: Number of processes (i.e. domains) or file + * descriptors referencing this ruleset. + */ + refcount_t usage; + /** + * @num_rules: Number of non-overlapping (i.e. not for + * the same object) rules in this ruleset. + */ + u32 num_rules; + /** + * @num_layers: Number of layers that are used in this + * ruleset. This enables to check that all the layers + * allow an access request. A value of 0 identifies a + * non-merged ruleset (i.e. not a domain). + */ + u32 num_layers; + /** + * @fs_access_masks: Contains the subset of filesystem + * actions that are restricted by a ruleset. A domain + * saves all layers of merged rulesets in a stack + * (FAM), starting from the first layer to the last + * one. These layers are used when merging rulesets, + * for user space backward compatibility (i.e. + * future-proof), and to properly handle merged + * rulesets without overlapping access rights. These + * layers are set once and never changed for the + * lifetime of the ruleset. + */ + access_mask_t fs_access_masks[]; + }; + }; +}; + +struct landlock_ruleset * +landlock_create_ruleset(const access_mask_t fs_access_mask); + +void landlock_put_ruleset(struct landlock_ruleset *const ruleset); +void landlock_put_ruleset_deferred(struct landlock_ruleset *const ruleset); + +int landlock_insert_rule(struct landlock_ruleset *const ruleset, + struct landlock_object *const object, + const access_mask_t access); + +struct landlock_ruleset * +landlock_merge_ruleset(struct landlock_ruleset *const parent, + struct landlock_ruleset *const ruleset); + +const struct landlock_rule * +landlock_find_rule(const struct landlock_ruleset *const ruleset, + const struct landlock_object *const object); + +static inline void landlock_get_ruleset(struct landlock_ruleset *const ruleset) +{ + if (ruleset) + refcount_inc(&ruleset->usage); +} + +#endif /* _SECURITY_LANDLOCK_RULESET_H */ diff --git a/security/landlock/setup.c b/security/landlock/setup.c new file mode 100644 index 000000000..f8e8e9804 --- /dev/null +++ b/security/landlock/setup.c @@ -0,0 +1,40 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Landlock LSM - Security framework setup + * + * Copyright © 2016-2020 Mickaël Salaün <mic@digikod.net> + * Copyright © 2018-2020 ANSSI + */ + +#include <linux/init.h> +#include <linux/lsm_hooks.h> + +#include "common.h" +#include "cred.h" +#include "fs.h" +#include "ptrace.h" +#include "setup.h" + +bool landlock_initialized __lsm_ro_after_init = false; + +struct lsm_blob_sizes landlock_blob_sizes __lsm_ro_after_init = { + .lbs_cred = sizeof(struct landlock_cred_security), + .lbs_inode = sizeof(struct landlock_inode_security), + .lbs_superblock = sizeof(struct landlock_superblock_security), +}; + +static int __init landlock_init(void) +{ + landlock_add_cred_hooks(); + landlock_add_ptrace_hooks(); + landlock_add_fs_hooks(); + landlock_initialized = true; + pr_info("Up and running.\n"); + return 0; +} + +DEFINE_LSM(LANDLOCK_NAME) = { + .name = LANDLOCK_NAME, + .init = landlock_init, + .blobs = &landlock_blob_sizes, +}; diff --git a/security/landlock/setup.h b/security/landlock/setup.h new file mode 100644 index 000000000..1daffab1a --- /dev/null +++ b/security/landlock/setup.h @@ -0,0 +1,18 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Landlock LSM - Security framework setup + * + * Copyright © 2016-2020 Mickaël Salaün <mic@digikod.net> + * Copyright © 2018-2020 ANSSI + */ + +#ifndef _SECURITY_LANDLOCK_SETUP_H +#define _SECURITY_LANDLOCK_SETUP_H + +#include <linux/lsm_hooks.h> + +extern bool landlock_initialized; + +extern struct lsm_blob_sizes landlock_blob_sizes; + +#endif /* _SECURITY_LANDLOCK_SETUP_H */ diff --git a/security/landlock/syscalls.c b/security/landlock/syscalls.c new file mode 100644 index 000000000..2ca0ccbd9 --- /dev/null +++ b/security/landlock/syscalls.c @@ -0,0 +1,456 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Landlock LSM - System call implementations and user space interfaces + * + * Copyright © 2016-2020 Mickaël Salaün <mic@digikod.net> + * Copyright © 2018-2020 ANSSI + */ + +#include <asm/current.h> +#include <linux/anon_inodes.h> +#include <linux/build_bug.h> +#include <linux/capability.h> +#include <linux/compiler_types.h> +#include <linux/dcache.h> +#include <linux/err.h> +#include <linux/errno.h> +#include <linux/fs.h> +#include <linux/limits.h> +#include <linux/mount.h> +#include <linux/path.h> +#include <linux/sched.h> +#include <linux/security.h> +#include <linux/stddef.h> +#include <linux/syscalls.h> +#include <linux/types.h> +#include <linux/uaccess.h> +#include <uapi/linux/landlock.h> + +#include "cred.h" +#include "fs.h" +#include "limits.h" +#include "ruleset.h" +#include "setup.h" + +/** + * copy_min_struct_from_user - Safe future-proof argument copying + * + * Extend copy_struct_from_user() to check for consistent user buffer. + * + * @dst: Kernel space pointer or NULL. + * @ksize: Actual size of the data pointed to by @dst. + * @ksize_min: Minimal required size to be copied. + * @src: User space pointer or NULL. + * @usize: (Alleged) size of the data pointed to by @src. + */ +static __always_inline int +copy_min_struct_from_user(void *const dst, const size_t ksize, + const size_t ksize_min, const void __user *const src, + const size_t usize) +{ + /* Checks buffer inconsistencies. */ + BUILD_BUG_ON(!dst); + if (!src) + return -EFAULT; + + /* Checks size ranges. */ + BUILD_BUG_ON(ksize <= 0); + BUILD_BUG_ON(ksize < ksize_min); + if (usize < ksize_min) + return -EINVAL; + if (usize > PAGE_SIZE) + return -E2BIG; + + /* Copies user buffer and fills with zeros. */ + return copy_struct_from_user(dst, ksize, src, usize); +} + +/* + * This function only contains arithmetic operations with constants, leading to + * BUILD_BUG_ON(). The related code is evaluated and checked at build time, + * but it is then ignored thanks to compiler optimizations. + */ +static void build_check_abi(void) +{ + struct landlock_ruleset_attr ruleset_attr; + struct landlock_path_beneath_attr path_beneath_attr; + size_t ruleset_size, path_beneath_size; + + /* + * For each user space ABI structures, first checks that there is no + * hole in them, then checks that all architectures have the same + * struct size. + */ + ruleset_size = sizeof(ruleset_attr.handled_access_fs); + BUILD_BUG_ON(sizeof(ruleset_attr) != ruleset_size); + BUILD_BUG_ON(sizeof(ruleset_attr) != 8); + + path_beneath_size = sizeof(path_beneath_attr.allowed_access); + path_beneath_size += sizeof(path_beneath_attr.parent_fd); + BUILD_BUG_ON(sizeof(path_beneath_attr) != path_beneath_size); + BUILD_BUG_ON(sizeof(path_beneath_attr) != 12); +} + +/* Ruleset handling */ + +static int fop_ruleset_release(struct inode *const inode, + struct file *const filp) +{ + struct landlock_ruleset *ruleset = filp->private_data; + + landlock_put_ruleset(ruleset); + return 0; +} + +static ssize_t fop_dummy_read(struct file *const filp, char __user *const buf, + const size_t size, loff_t *const ppos) +{ + /* Dummy handler to enable FMODE_CAN_READ. */ + return -EINVAL; +} + +static ssize_t fop_dummy_write(struct file *const filp, + const char __user *const buf, const size_t size, + loff_t *const ppos) +{ + /* Dummy handler to enable FMODE_CAN_WRITE. */ + return -EINVAL; +} + +/* + * A ruleset file descriptor enables to build a ruleset by adding (i.e. + * writing) rule after rule, without relying on the task's context. This + * reentrant design is also used in a read way to enforce the ruleset on the + * current task. + */ +static const struct file_operations ruleset_fops = { + .release = fop_ruleset_release, + .read = fop_dummy_read, + .write = fop_dummy_write, +}; + +#define LANDLOCK_ABI_VERSION 2 + +/** + * sys_landlock_create_ruleset - Create a new ruleset + * + * @attr: Pointer to a &struct landlock_ruleset_attr identifying the scope of + * the new ruleset. + * @size: Size of the pointed &struct landlock_ruleset_attr (needed for + * backward and forward compatibility). + * @flags: Supported value: %LANDLOCK_CREATE_RULESET_VERSION. + * + * This system call enables to create a new Landlock ruleset, and returns the + * related file descriptor on success. + * + * If @flags is %LANDLOCK_CREATE_RULESET_VERSION and @attr is NULL and @size is + * 0, then the returned value is the highest supported Landlock ABI version + * (starting at 1). + * + * Possible returned errors are: + * + * - %EOPNOTSUPP: Landlock is supported by the kernel but disabled at boot time; + * - %EINVAL: unknown @flags, or unknown access, or too small @size; + * - %E2BIG or %EFAULT: @attr or @size inconsistencies; + * - %ENOMSG: empty &landlock_ruleset_attr.handled_access_fs. + */ +SYSCALL_DEFINE3(landlock_create_ruleset, + const struct landlock_ruleset_attr __user *const, attr, + const size_t, size, const __u32, flags) +{ + struct landlock_ruleset_attr ruleset_attr; + struct landlock_ruleset *ruleset; + int err, ruleset_fd; + + /* Build-time checks. */ + build_check_abi(); + + if (!landlock_initialized) + return -EOPNOTSUPP; + + if (flags) { + if ((flags == LANDLOCK_CREATE_RULESET_VERSION) && !attr && + !size) + return LANDLOCK_ABI_VERSION; + return -EINVAL; + } + + /* Copies raw user space buffer. */ + err = copy_min_struct_from_user(&ruleset_attr, sizeof(ruleset_attr), + offsetofend(typeof(ruleset_attr), + handled_access_fs), + attr, size); + if (err) + return err; + + /* Checks content (and 32-bits cast). */ + if ((ruleset_attr.handled_access_fs | LANDLOCK_MASK_ACCESS_FS) != + LANDLOCK_MASK_ACCESS_FS) + return -EINVAL; + + /* Checks arguments and transforms to kernel struct. */ + ruleset = landlock_create_ruleset(ruleset_attr.handled_access_fs); + if (IS_ERR(ruleset)) + return PTR_ERR(ruleset); + + /* Creates anonymous FD referring to the ruleset. */ + ruleset_fd = anon_inode_getfd("[landlock-ruleset]", &ruleset_fops, + ruleset, O_RDWR | O_CLOEXEC); + if (ruleset_fd < 0) + landlock_put_ruleset(ruleset); + return ruleset_fd; +} + +/* + * Returns an owned ruleset from a FD. It is thus needed to call + * landlock_put_ruleset() on the return value. + */ +static struct landlock_ruleset *get_ruleset_from_fd(const int fd, + const fmode_t mode) +{ + struct fd ruleset_f; + struct landlock_ruleset *ruleset; + + ruleset_f = fdget(fd); + if (!ruleset_f.file) + return ERR_PTR(-EBADF); + + /* Checks FD type and access right. */ + if (ruleset_f.file->f_op != &ruleset_fops) { + ruleset = ERR_PTR(-EBADFD); + goto out_fdput; + } + if (!(ruleset_f.file->f_mode & mode)) { + ruleset = ERR_PTR(-EPERM); + goto out_fdput; + } + ruleset = ruleset_f.file->private_data; + if (WARN_ON_ONCE(ruleset->num_layers != 1)) { + ruleset = ERR_PTR(-EINVAL); + goto out_fdput; + } + landlock_get_ruleset(ruleset); + +out_fdput: + fdput(ruleset_f); + return ruleset; +} + +/* Path handling */ + +/* + * @path: Must call put_path(@path) after the call if it succeeded. + */ +static int get_path_from_fd(const s32 fd, struct path *const path) +{ + struct fd f; + int err = 0; + + BUILD_BUG_ON(!__same_type( + fd, ((struct landlock_path_beneath_attr *)NULL)->parent_fd)); + + /* Handles O_PATH. */ + f = fdget_raw(fd); + if (!f.file) + return -EBADF; + /* + * Forbids ruleset FDs, internal filesystems (e.g. nsfs), including + * pseudo filesystems that will never be mountable (e.g. sockfs, + * pipefs). + */ + if ((f.file->f_op == &ruleset_fops) || + (f.file->f_path.mnt->mnt_flags & MNT_INTERNAL) || + (f.file->f_path.dentry->d_sb->s_flags & SB_NOUSER) || + d_is_negative(f.file->f_path.dentry) || + IS_PRIVATE(d_backing_inode(f.file->f_path.dentry))) { + err = -EBADFD; + goto out_fdput; + } + *path = f.file->f_path; + path_get(path); + +out_fdput: + fdput(f); + return err; +} + +/** + * sys_landlock_add_rule - Add a new rule to a ruleset + * + * @ruleset_fd: File descriptor tied to the ruleset that should be extended + * with the new rule. + * @rule_type: Identify the structure type pointed to by @rule_attr (only + * %LANDLOCK_RULE_PATH_BENEATH for now). + * @rule_attr: Pointer to a rule (only of type &struct + * landlock_path_beneath_attr for now). + * @flags: Must be 0. + * + * This system call enables to define a new rule and add it to an existing + * ruleset. + * + * Possible returned errors are: + * + * - %EOPNOTSUPP: Landlock is supported by the kernel but disabled at boot time; + * - %EINVAL: @flags is not 0, or inconsistent access in the rule (i.e. + * &landlock_path_beneath_attr.allowed_access is not a subset of the + * ruleset handled accesses); + * - %ENOMSG: Empty accesses (e.g. &landlock_path_beneath_attr.allowed_access); + * - %EBADF: @ruleset_fd is not a file descriptor for the current thread, or a + * member of @rule_attr is not a file descriptor as expected; + * - %EBADFD: @ruleset_fd is not a ruleset file descriptor, or a member of + * @rule_attr is not the expected file descriptor type; + * - %EPERM: @ruleset_fd has no write access to the underlying ruleset; + * - %EFAULT: @rule_attr inconsistency. + */ +SYSCALL_DEFINE4(landlock_add_rule, const int, ruleset_fd, + const enum landlock_rule_type, rule_type, + const void __user *const, rule_attr, const __u32, flags) +{ + struct landlock_path_beneath_attr path_beneath_attr; + struct path path; + struct landlock_ruleset *ruleset; + int res, err; + + if (!landlock_initialized) + return -EOPNOTSUPP; + + /* No flag for now. */ + if (flags) + return -EINVAL; + + /* Gets and checks the ruleset. */ + ruleset = get_ruleset_from_fd(ruleset_fd, FMODE_CAN_WRITE); + if (IS_ERR(ruleset)) + return PTR_ERR(ruleset); + + if (rule_type != LANDLOCK_RULE_PATH_BENEATH) { + err = -EINVAL; + goto out_put_ruleset; + } + + /* Copies raw user space buffer, only one type for now. */ + res = copy_from_user(&path_beneath_attr, rule_attr, + sizeof(path_beneath_attr)); + if (res) { + err = -EFAULT; + goto out_put_ruleset; + } + + /* + * Informs about useless rule: empty allowed_access (i.e. deny rules) + * are ignored in path walks. + */ + if (!path_beneath_attr.allowed_access) { + err = -ENOMSG; + goto out_put_ruleset; + } + /* + * Checks that allowed_access matches the @ruleset constraints + * (ruleset->fs_access_masks[0] is automatically upgraded to 64-bits). + */ + if ((path_beneath_attr.allowed_access | ruleset->fs_access_masks[0]) != + ruleset->fs_access_masks[0]) { + err = -EINVAL; + goto out_put_ruleset; + } + + /* Gets and checks the new rule. */ + err = get_path_from_fd(path_beneath_attr.parent_fd, &path); + if (err) + goto out_put_ruleset; + + /* Imports the new rule. */ + err = landlock_append_fs_rule(ruleset, &path, + path_beneath_attr.allowed_access); + path_put(&path); + +out_put_ruleset: + landlock_put_ruleset(ruleset); + return err; +} + +/* Enforcement */ + +/** + * sys_landlock_restrict_self - Enforce a ruleset on the calling thread + * + * @ruleset_fd: File descriptor tied to the ruleset to merge with the target. + * @flags: Must be 0. + * + * This system call enables to enforce a Landlock ruleset on the current + * thread. Enforcing a ruleset requires that the task has %CAP_SYS_ADMIN in its + * namespace or is running with no_new_privs. This avoids scenarios where + * unprivileged tasks can affect the behavior of privileged children. + * + * Possible returned errors are: + * + * - %EOPNOTSUPP: Landlock is supported by the kernel but disabled at boot time; + * - %EINVAL: @flags is not 0. + * - %EBADF: @ruleset_fd is not a file descriptor for the current thread; + * - %EBADFD: @ruleset_fd is not a ruleset file descriptor; + * - %EPERM: @ruleset_fd has no read access to the underlying ruleset, or the + * current thread is not running with no_new_privs, or it doesn't have + * %CAP_SYS_ADMIN in its namespace. + * - %E2BIG: The maximum number of stacked rulesets is reached for the current + * thread. + */ +SYSCALL_DEFINE2(landlock_restrict_self, const int, ruleset_fd, const __u32, + flags) +{ + struct landlock_ruleset *new_dom, *ruleset; + struct cred *new_cred; + struct landlock_cred_security *new_llcred; + int err; + + if (!landlock_initialized) + return -EOPNOTSUPP; + + /* + * Similar checks as for seccomp(2), except that an -EPERM may be + * returned. + */ + if (!task_no_new_privs(current) && + !ns_capable_noaudit(current_user_ns(), CAP_SYS_ADMIN)) + return -EPERM; + + /* No flag for now. */ + if (flags) + return -EINVAL; + + /* Gets and checks the ruleset. */ + ruleset = get_ruleset_from_fd(ruleset_fd, FMODE_CAN_READ); + if (IS_ERR(ruleset)) + return PTR_ERR(ruleset); + + /* Prepares new credentials. */ + new_cred = prepare_creds(); + if (!new_cred) { + err = -ENOMEM; + goto out_put_ruleset; + } + new_llcred = landlock_cred(new_cred); + + /* + * There is no possible race condition while copying and manipulating + * the current credentials because they are dedicated per thread. + */ + new_dom = landlock_merge_ruleset(new_llcred->domain, ruleset); + if (IS_ERR(new_dom)) { + err = PTR_ERR(new_dom); + goto out_put_creds; + } + + /* Replaces the old (prepared) domain. */ + landlock_put_ruleset(new_llcred->domain); + new_llcred->domain = new_dom; + + landlock_put_ruleset(ruleset); + return commit_creds(new_cred); + +out_put_creds: + abort_creds(new_cred); + +out_put_ruleset: + landlock_put_ruleset(ruleset); + return err; +} diff --git a/security/loadpin/Kconfig b/security/loadpin/Kconfig new file mode 100644 index 000000000..6724eaba3 --- /dev/null +++ b/security/loadpin/Kconfig @@ -0,0 +1,41 @@ +# SPDX-License-Identifier: GPL-2.0-only +config SECURITY_LOADPIN + bool "Pin load of kernel files (modules, fw, etc) to one filesystem" + depends on SECURITY && BLOCK + help + Any files read through the kernel file reading interface + (kernel modules, firmware, kexec images, security policy) + can be pinned to the first filesystem used for loading. When + enabled, any files that come from other filesystems will be + rejected. This is best used on systems without an initrd that + have a root filesystem backed by a read-only device such as + dm-verity or a CDROM. + +config SECURITY_LOADPIN_ENFORCE + bool "Enforce LoadPin at boot" + depends on SECURITY_LOADPIN + help + If selected, LoadPin will enforce pinning at boot. If not + selected, it can be enabled at boot with the kernel parameter + "loadpin.enforce=1". + +config SECURITY_LOADPIN_VERITY + bool "Allow reading files from certain other filesystems that use dm-verity" + depends on SECURITY_LOADPIN && DM_VERITY=y && SECURITYFS + help + If selected LoadPin can allow reading files from filesystems + that use dm-verity. LoadPin maintains a list of verity root + digests it considers trusted. A verity backed filesystem is + considered trusted if its root digest is found in the list + of trusted digests. + + The list of trusted verity can be populated through an ioctl + on the LoadPin securityfs entry 'dm-verity'. The ioctl + expects a file descriptor of a file with verity digests as + parameter. The file must be located on the pinned root and + start with the line: + + # LOADPIN_TRUSTED_VERITY_ROOT_DIGESTS + + This is followed by the verity digests, with one digest per + line. diff --git a/security/loadpin/Makefile b/security/loadpin/Makefile new file mode 100644 index 000000000..0ead1c310 --- /dev/null +++ b/security/loadpin/Makefile @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0-only +obj-$(CONFIG_SECURITY_LOADPIN) += loadpin.o diff --git a/security/loadpin/loadpin.c b/security/loadpin/loadpin.c new file mode 100644 index 000000000..110a5ab2b --- /dev/null +++ b/security/loadpin/loadpin.c @@ -0,0 +1,435 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Module and Firmware Pinning Security Module + * + * Copyright 2011-2016 Google Inc. + * + * Author: Kees Cook <keescook@chromium.org> + */ + +#define pr_fmt(fmt) "LoadPin: " fmt + +#include <linux/module.h> +#include <linux/fs.h> +#include <linux/kernel_read_file.h> +#include <linux/lsm_hooks.h> +#include <linux/mount.h> +#include <linux/blkdev.h> +#include <linux/path.h> +#include <linux/sched.h> /* current */ +#include <linux/string_helpers.h> +#include <linux/dm-verity-loadpin.h> +#include <uapi/linux/loadpin.h> + +#define VERITY_DIGEST_FILE_HEADER "# LOADPIN_TRUSTED_VERITY_ROOT_DIGESTS" + +static void report_load(const char *origin, struct file *file, char *operation) +{ + char *cmdline, *pathname; + + pathname = kstrdup_quotable_file(file, GFP_KERNEL); + cmdline = kstrdup_quotable_cmdline(current, GFP_KERNEL); + + pr_notice("%s %s obj=%s%s%s pid=%d cmdline=%s%s%s\n", + origin, operation, + (pathname && pathname[0] != '<') ? "\"" : "", + pathname, + (pathname && pathname[0] != '<') ? "\"" : "", + task_pid_nr(current), + cmdline ? "\"" : "", cmdline, cmdline ? "\"" : ""); + + kfree(cmdline); + kfree(pathname); +} + +static int enforce = IS_ENABLED(CONFIG_SECURITY_LOADPIN_ENFORCE); +static char *exclude_read_files[READING_MAX_ID]; +static int ignore_read_file_id[READING_MAX_ID] __ro_after_init; +static struct super_block *pinned_root; +static DEFINE_SPINLOCK(pinned_root_spinlock); +#ifdef CONFIG_SECURITY_LOADPIN_VERITY +static bool deny_reading_verity_digests; +#endif + +#ifdef CONFIG_SYSCTL + +static struct ctl_path loadpin_sysctl_path[] = { + { .procname = "kernel", }, + { .procname = "loadpin", }, + { } +}; + +static struct ctl_table loadpin_sysctl_table[] = { + { + .procname = "enforce", + .data = &enforce, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_ONE, + }, + { } +}; + +/* + * This must be called after early kernel init, since then the rootdev + * is available. + */ +static void check_pinning_enforcement(struct super_block *mnt_sb) +{ + bool ro = false; + + /* + * If load pinning is not enforced via a read-only block + * device, allow sysctl to change modes for testing. + */ + if (mnt_sb->s_bdev) { + ro = bdev_read_only(mnt_sb->s_bdev); + pr_info("%pg (%u:%u): %s\n", mnt_sb->s_bdev, + MAJOR(mnt_sb->s_bdev->bd_dev), + MINOR(mnt_sb->s_bdev->bd_dev), + ro ? "read-only" : "writable"); + } else + pr_info("mnt_sb lacks block device, treating as: writable\n"); + + if (!ro) { + if (!register_sysctl_paths(loadpin_sysctl_path, + loadpin_sysctl_table)) + pr_notice("sysctl registration failed!\n"); + else + pr_info("enforcement can be disabled.\n"); + } else + pr_info("load pinning engaged.\n"); +} +#else +static void check_pinning_enforcement(struct super_block *mnt_sb) +{ + pr_info("load pinning engaged.\n"); +} +#endif + +static void loadpin_sb_free_security(struct super_block *mnt_sb) +{ + /* + * When unmounting the filesystem we were using for load + * pinning, we acknowledge the superblock release, but make sure + * no other modules or firmware can be loaded. + */ + if (!IS_ERR_OR_NULL(pinned_root) && mnt_sb == pinned_root) { + pinned_root = ERR_PTR(-EIO); + pr_info("umount pinned fs: refusing further loads\n"); + } +} + +static int loadpin_check(struct file *file, enum kernel_read_file_id id) +{ + struct super_block *load_root; + const char *origin = kernel_read_file_id_str(id); + + /* If the file id is excluded, ignore the pinning. */ + if ((unsigned int)id < ARRAY_SIZE(ignore_read_file_id) && + ignore_read_file_id[id]) { + report_load(origin, file, "pinning-excluded"); + return 0; + } + + /* This handles the older init_module API that has a NULL file. */ + if (!file) { + if (!enforce) { + report_load(origin, NULL, "old-api-pinning-ignored"); + return 0; + } + + report_load(origin, NULL, "old-api-denied"); + return -EPERM; + } + + load_root = file->f_path.mnt->mnt_sb; + + /* First loaded module/firmware defines the root for all others. */ + spin_lock(&pinned_root_spinlock); + /* + * pinned_root is only NULL at startup. Otherwise, it is either + * a valid reference, or an ERR_PTR. + */ + if (!pinned_root) { + pinned_root = load_root; + /* + * Unlock now since it's only pinned_root we care about. + * In the worst case, we will (correctly) report pinning + * failures before we have announced that pinning is + * enforcing. This would be purely cosmetic. + */ + spin_unlock(&pinned_root_spinlock); + check_pinning_enforcement(pinned_root); + report_load(origin, file, "pinned"); + } else { + spin_unlock(&pinned_root_spinlock); + } + + if (IS_ERR_OR_NULL(pinned_root) || + ((load_root != pinned_root) && !dm_verity_loadpin_is_bdev_trusted(load_root->s_bdev))) { + if (unlikely(!enforce)) { + report_load(origin, file, "pinning-ignored"); + return 0; + } + + report_load(origin, file, "denied"); + return -EPERM; + } + + return 0; +} + +static int loadpin_read_file(struct file *file, enum kernel_read_file_id id, + bool contents) +{ + /* + * LoadPin only cares about the _origin_ of a file, not its + * contents, so we can ignore the "are full contents available" + * argument here. + */ + return loadpin_check(file, id); +} + +static int loadpin_load_data(enum kernel_load_data_id id, bool contents) +{ + /* + * LoadPin only cares about the _origin_ of a file, not its + * contents, so a NULL file is passed, and we can ignore the + * state of "contents". + */ + return loadpin_check(NULL, (enum kernel_read_file_id) id); +} + +static struct security_hook_list loadpin_hooks[] __lsm_ro_after_init = { + LSM_HOOK_INIT(sb_free_security, loadpin_sb_free_security), + LSM_HOOK_INIT(kernel_read_file, loadpin_read_file), + LSM_HOOK_INIT(kernel_load_data, loadpin_load_data), +}; + +static void __init parse_exclude(void) +{ + int i, j; + char *cur; + + /* + * Make sure all the arrays stay within expected sizes. This + * is slightly weird because kernel_read_file_str[] includes + * READING_MAX_ID, which isn't actually meaningful here. + */ + BUILD_BUG_ON(ARRAY_SIZE(exclude_read_files) != + ARRAY_SIZE(ignore_read_file_id)); + BUILD_BUG_ON(ARRAY_SIZE(kernel_read_file_str) < + ARRAY_SIZE(ignore_read_file_id)); + + for (i = 0; i < ARRAY_SIZE(exclude_read_files); i++) { + cur = exclude_read_files[i]; + if (!cur) + break; + if (*cur == '\0') + continue; + + for (j = 0; j < ARRAY_SIZE(ignore_read_file_id); j++) { + if (strcmp(cur, kernel_read_file_str[j]) == 0) { + pr_info("excluding: %s\n", + kernel_read_file_str[j]); + ignore_read_file_id[j] = 1; + /* + * Can not break, because one read_file_str + * may map to more than on read_file_id. + */ + } + } + } +} + +static int __init loadpin_init(void) +{ + pr_info("ready to pin (currently %senforcing)\n", + enforce ? "" : "not "); + parse_exclude(); + security_add_hooks(loadpin_hooks, ARRAY_SIZE(loadpin_hooks), "loadpin"); + + return 0; +} + +DEFINE_LSM(loadpin) = { + .name = "loadpin", + .init = loadpin_init, +}; + +#ifdef CONFIG_SECURITY_LOADPIN_VERITY + +enum loadpin_securityfs_interface_index { + LOADPIN_DM_VERITY, +}; + +static int read_trusted_verity_root_digests(unsigned int fd) +{ + struct fd f; + void *data; + int rc; + char *p, *d; + + if (deny_reading_verity_digests) + return -EPERM; + + /* The list of trusted root digests can only be set up once */ + if (!list_empty(&dm_verity_loadpin_trusted_root_digests)) + return -EPERM; + + f = fdget(fd); + if (!f.file) + return -EINVAL; + + data = kzalloc(SZ_4K, GFP_KERNEL); + if (!data) { + rc = -ENOMEM; + goto err; + } + + rc = kernel_read_file(f.file, 0, (void **)&data, SZ_4K - 1, NULL, READING_POLICY); + if (rc < 0) + goto err; + + p = data; + p[rc] = '\0'; + p = strim(p); + + p = strim(data); + while ((d = strsep(&p, "\n")) != NULL) { + int len; + struct dm_verity_loadpin_trusted_root_digest *trd; + + if (d == data) { + /* first line, validate header */ + if (strcmp(d, VERITY_DIGEST_FILE_HEADER)) { + rc = -EPROTO; + goto err; + } + + continue; + } + + len = strlen(d); + + if (len % 2) { + rc = -EPROTO; + goto err; + } + + len /= 2; + + trd = kzalloc(struct_size(trd, data, len), GFP_KERNEL); + if (!trd) { + rc = -ENOMEM; + goto err; + } + + if (hex2bin(trd->data, d, len)) { + kfree(trd); + rc = -EPROTO; + goto err; + } + + trd->len = len; + + list_add_tail(&trd->node, &dm_verity_loadpin_trusted_root_digests); + } + + if (list_empty(&dm_verity_loadpin_trusted_root_digests)) { + rc = -EPROTO; + goto err; + } + + kfree(data); + fdput(f); + + return 0; + +err: + kfree(data); + + /* any failure in loading/parsing invalidates the entire list */ + { + struct dm_verity_loadpin_trusted_root_digest *trd, *tmp; + + list_for_each_entry_safe(trd, tmp, &dm_verity_loadpin_trusted_root_digests, node) { + list_del(&trd->node); + kfree(trd); + } + } + + /* disallow further attempts after reading a corrupt/invalid file */ + deny_reading_verity_digests = true; + + fdput(f); + + return rc; +} + +/******************************** securityfs ********************************/ + +static long dm_verity_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) +{ + void __user *uarg = (void __user *)arg; + unsigned int fd; + + switch (cmd) { + case LOADPIN_IOC_SET_TRUSTED_VERITY_DIGESTS: + if (copy_from_user(&fd, uarg, sizeof(fd))) + return -EFAULT; + + return read_trusted_verity_root_digests(fd); + + default: + return -EINVAL; + } +} + +static const struct file_operations loadpin_dm_verity_ops = { + .unlocked_ioctl = dm_verity_ioctl, + .compat_ioctl = compat_ptr_ioctl, +}; + +/** + * init_loadpin_securityfs - create the securityfs directory for LoadPin + * + * We can not put this method normally under the loadpin_init() code path since + * the security subsystem gets initialized before the vfs caches. + * + * Returns 0 if the securityfs directory creation was successful. + */ +static int __init init_loadpin_securityfs(void) +{ + struct dentry *loadpin_dir, *dentry; + + loadpin_dir = securityfs_create_dir("loadpin", NULL); + if (IS_ERR(loadpin_dir)) { + pr_err("LoadPin: could not create securityfs dir: %ld\n", + PTR_ERR(loadpin_dir)); + return PTR_ERR(loadpin_dir); + } + + dentry = securityfs_create_file("dm-verity", 0600, loadpin_dir, + (void *)LOADPIN_DM_VERITY, &loadpin_dm_verity_ops); + if (IS_ERR(dentry)) { + pr_err("LoadPin: could not create securityfs entry 'dm-verity': %ld\n", + PTR_ERR(dentry)); + return PTR_ERR(dentry); + } + + return 0; +} + +fs_initcall(init_loadpin_securityfs); + +#endif /* CONFIG_SECURITY_LOADPIN_VERITY */ + +/* Should not be mutable after boot, so not listed in sysfs (perm == 0). */ +module_param(enforce, int, 0); +MODULE_PARM_DESC(enforce, "Enforce module/firmware pinning"); +module_param_array_named(exclude, exclude_read_files, charp, NULL, 0); +MODULE_PARM_DESC(exclude, "Exclude pinning specific read file types"); diff --git a/security/lockdown/Kconfig b/security/lockdown/Kconfig new file mode 100644 index 000000000..e84ddf484 --- /dev/null +++ b/security/lockdown/Kconfig @@ -0,0 +1,47 @@ +config SECURITY_LOCKDOWN_LSM + bool "Basic module for enforcing kernel lockdown" + depends on SECURITY + select MODULE_SIG if MODULES + help + Build support for an LSM that enforces a coarse kernel lockdown + behaviour. + +config SECURITY_LOCKDOWN_LSM_EARLY + bool "Enable lockdown LSM early in init" + depends on SECURITY_LOCKDOWN_LSM + help + Enable the lockdown LSM early in boot. This is necessary in order + to ensure that lockdown enforcement can be carried out on kernel + boot parameters that are otherwise parsed before the security + subsystem is fully initialised. If enabled, lockdown will + unconditionally be called before any other LSMs. + +choice + prompt "Kernel default lockdown mode" + default LOCK_DOWN_KERNEL_FORCE_NONE + depends on SECURITY_LOCKDOWN_LSM + help + The kernel can be configured to default to differing levels of + lockdown. + +config LOCK_DOWN_KERNEL_FORCE_NONE + bool "None" + help + No lockdown functionality is enabled by default. Lockdown may be + enabled via the kernel commandline or /sys/kernel/security/lockdown. + +config LOCK_DOWN_KERNEL_FORCE_INTEGRITY + bool "Integrity" + help + The kernel runs in integrity mode by default. Features that allow + the kernel to be modified at runtime are disabled. + +config LOCK_DOWN_KERNEL_FORCE_CONFIDENTIALITY + bool "Confidentiality" + help + The kernel runs in confidentiality mode by default. Features that + allow the kernel to be modified at runtime or that permit userland + code to read confidential material held inside the kernel are + disabled. + +endchoice diff --git a/security/lockdown/Makefile b/security/lockdown/Makefile new file mode 100644 index 000000000..e3634b901 --- /dev/null +++ b/security/lockdown/Makefile @@ -0,0 +1 @@ +obj-$(CONFIG_SECURITY_LOCKDOWN_LSM) += lockdown.o diff --git a/security/lockdown/lockdown.c b/security/lockdown/lockdown.c new file mode 100644 index 000000000..a79b985e9 --- /dev/null +++ b/security/lockdown/lockdown.c @@ -0,0 +1,167 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Lock down the kernel + * + * Copyright (C) 2016 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public Licence + * as published by the Free Software Foundation; either version + * 2 of the Licence, or (at your option) any later version. + */ + +#include <linux/security.h> +#include <linux/export.h> +#include <linux/lsm_hooks.h> + +static enum lockdown_reason kernel_locked_down; + +static const enum lockdown_reason lockdown_levels[] = {LOCKDOWN_NONE, + LOCKDOWN_INTEGRITY_MAX, + LOCKDOWN_CONFIDENTIALITY_MAX}; + +/* + * Put the kernel into lock-down mode. + */ +static int lock_kernel_down(const char *where, enum lockdown_reason level) +{ + if (kernel_locked_down >= level) + return -EPERM; + + kernel_locked_down = level; + pr_notice("Kernel is locked down from %s; see man kernel_lockdown.7\n", + where); + return 0; +} + +static int __init lockdown_param(char *level) +{ + if (!level) + return -EINVAL; + + if (strcmp(level, "integrity") == 0) + lock_kernel_down("command line", LOCKDOWN_INTEGRITY_MAX); + else if (strcmp(level, "confidentiality") == 0) + lock_kernel_down("command line", LOCKDOWN_CONFIDENTIALITY_MAX); + else + return -EINVAL; + + return 0; +} + +early_param("lockdown", lockdown_param); + +/** + * lockdown_is_locked_down - Find out if the kernel is locked down + * @what: Tag to use in notice generated if lockdown is in effect + */ +static int lockdown_is_locked_down(enum lockdown_reason what) +{ + if (WARN(what >= LOCKDOWN_CONFIDENTIALITY_MAX, + "Invalid lockdown reason")) + return -EPERM; + + if (kernel_locked_down >= what) { + if (lockdown_reasons[what]) + pr_notice_ratelimited("Lockdown: %s: %s is restricted; see man kernel_lockdown.7\n", + current->comm, lockdown_reasons[what]); + return -EPERM; + } + + return 0; +} + +static struct security_hook_list lockdown_hooks[] __lsm_ro_after_init = { + LSM_HOOK_INIT(locked_down, lockdown_is_locked_down), +}; + +static int __init lockdown_lsm_init(void) +{ +#if defined(CONFIG_LOCK_DOWN_KERNEL_FORCE_INTEGRITY) + lock_kernel_down("Kernel configuration", LOCKDOWN_INTEGRITY_MAX); +#elif defined(CONFIG_LOCK_DOWN_KERNEL_FORCE_CONFIDENTIALITY) + lock_kernel_down("Kernel configuration", LOCKDOWN_CONFIDENTIALITY_MAX); +#endif + security_add_hooks(lockdown_hooks, ARRAY_SIZE(lockdown_hooks), + "lockdown"); + return 0; +} + +static ssize_t lockdown_read(struct file *filp, char __user *buf, size_t count, + loff_t *ppos) +{ + char temp[80]; + int i, offset = 0; + + for (i = 0; i < ARRAY_SIZE(lockdown_levels); i++) { + enum lockdown_reason level = lockdown_levels[i]; + + if (lockdown_reasons[level]) { + const char *label = lockdown_reasons[level]; + + if (kernel_locked_down == level) + offset += sprintf(temp+offset, "[%s] ", label); + else + offset += sprintf(temp+offset, "%s ", label); + } + } + + /* Convert the last space to a newline if needed. */ + if (offset > 0) + temp[offset-1] = '\n'; + + return simple_read_from_buffer(buf, count, ppos, temp, strlen(temp)); +} + +static ssize_t lockdown_write(struct file *file, const char __user *buf, + size_t n, loff_t *ppos) +{ + char *state; + int i, len, err = -EINVAL; + + state = memdup_user_nul(buf, n); + if (IS_ERR(state)) + return PTR_ERR(state); + + len = strlen(state); + if (len && state[len-1] == '\n') { + state[len-1] = '\0'; + len--; + } + + for (i = 0; i < ARRAY_SIZE(lockdown_levels); i++) { + enum lockdown_reason level = lockdown_levels[i]; + const char *label = lockdown_reasons[level]; + + if (label && !strcmp(state, label)) + err = lock_kernel_down("securityfs", level); + } + + kfree(state); + return err ? err : n; +} + +static const struct file_operations lockdown_ops = { + .read = lockdown_read, + .write = lockdown_write, +}; + +static int __init lockdown_secfs_init(void) +{ + struct dentry *dentry; + + dentry = securityfs_create_file("lockdown", 0644, NULL, NULL, + &lockdown_ops); + return PTR_ERR_OR_ZERO(dentry); +} + +core_initcall(lockdown_secfs_init); + +#ifdef CONFIG_SECURITY_LOCKDOWN_LSM_EARLY +DEFINE_EARLY_LSM(lockdown) = { +#else +DEFINE_LSM(lockdown) = { +#endif + .name = "lockdown", + .init = lockdown_lsm_init, +}; diff --git a/security/lsm_audit.c b/security/lsm_audit.c new file mode 100644 index 000000000..75cc3f8d2 --- /dev/null +++ b/security/lsm_audit.c @@ -0,0 +1,463 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * common LSM auditing functions + * + * Based on code written for SELinux by : + * Stephen Smalley, <sds@tycho.nsa.gov> + * James Morris <jmorris@redhat.com> + * Author : Etienne Basset, <etienne.basset@ensta.org> + */ + +#include <linux/types.h> +#include <linux/stddef.h> +#include <linux/kernel.h> +#include <linux/gfp.h> +#include <linux/fs.h> +#include <linux/init.h> +#include <net/sock.h> +#include <linux/un.h> +#include <net/af_unix.h> +#include <linux/audit.h> +#include <linux/ipv6.h> +#include <linux/ip.h> +#include <net/ip.h> +#include <net/ipv6.h> +#include <linux/tcp.h> +#include <linux/udp.h> +#include <linux/dccp.h> +#include <linux/sctp.h> +#include <linux/lsm_audit.h> +#include <linux/security.h> + +/** + * ipv4_skb_to_auditdata : fill auditdata from skb + * @skb : the skb + * @ad : the audit data to fill + * @proto : the layer 4 protocol + * + * return 0 on success + */ +int ipv4_skb_to_auditdata(struct sk_buff *skb, + struct common_audit_data *ad, u8 *proto) +{ + int ret = 0; + struct iphdr *ih; + + ih = ip_hdr(skb); + ad->u.net->v4info.saddr = ih->saddr; + ad->u.net->v4info.daddr = ih->daddr; + + if (proto) + *proto = ih->protocol; + /* non initial fragment */ + if (ntohs(ih->frag_off) & IP_OFFSET) + return 0; + + switch (ih->protocol) { + case IPPROTO_TCP: { + struct tcphdr *th = tcp_hdr(skb); + + ad->u.net->sport = th->source; + ad->u.net->dport = th->dest; + break; + } + case IPPROTO_UDP: { + struct udphdr *uh = udp_hdr(skb); + + ad->u.net->sport = uh->source; + ad->u.net->dport = uh->dest; + break; + } + case IPPROTO_DCCP: { + struct dccp_hdr *dh = dccp_hdr(skb); + + ad->u.net->sport = dh->dccph_sport; + ad->u.net->dport = dh->dccph_dport; + break; + } + case IPPROTO_SCTP: { + struct sctphdr *sh = sctp_hdr(skb); + + ad->u.net->sport = sh->source; + ad->u.net->dport = sh->dest; + break; + } + default: + ret = -EINVAL; + } + return ret; +} +#if IS_ENABLED(CONFIG_IPV6) +/** + * ipv6_skb_to_auditdata : fill auditdata from skb + * @skb : the skb + * @ad : the audit data to fill + * @proto : the layer 4 protocol + * + * return 0 on success + */ +int ipv6_skb_to_auditdata(struct sk_buff *skb, + struct common_audit_data *ad, u8 *proto) +{ + int offset, ret = 0; + struct ipv6hdr *ip6; + u8 nexthdr; + __be16 frag_off; + + ip6 = ipv6_hdr(skb); + ad->u.net->v6info.saddr = ip6->saddr; + ad->u.net->v6info.daddr = ip6->daddr; + /* IPv6 can have several extension header before the Transport header + * skip them */ + offset = skb_network_offset(skb); + offset += sizeof(*ip6); + nexthdr = ip6->nexthdr; + offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off); + if (offset < 0) + return 0; + if (proto) + *proto = nexthdr; + switch (nexthdr) { + case IPPROTO_TCP: { + struct tcphdr _tcph, *th; + + th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph); + if (th == NULL) + break; + + ad->u.net->sport = th->source; + ad->u.net->dport = th->dest; + break; + } + case IPPROTO_UDP: { + struct udphdr _udph, *uh; + + uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph); + if (uh == NULL) + break; + + ad->u.net->sport = uh->source; + ad->u.net->dport = uh->dest; + break; + } + case IPPROTO_DCCP: { + struct dccp_hdr _dccph, *dh; + + dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph); + if (dh == NULL) + break; + + ad->u.net->sport = dh->dccph_sport; + ad->u.net->dport = dh->dccph_dport; + break; + } + case IPPROTO_SCTP: { + struct sctphdr _sctph, *sh; + + sh = skb_header_pointer(skb, offset, sizeof(_sctph), &_sctph); + if (sh == NULL) + break; + ad->u.net->sport = sh->source; + ad->u.net->dport = sh->dest; + break; + } + default: + ret = -EINVAL; + } + return ret; +} +#endif + + +static inline void print_ipv6_addr(struct audit_buffer *ab, + const struct in6_addr *addr, __be16 port, + char *name1, char *name2) +{ + if (!ipv6_addr_any(addr)) + audit_log_format(ab, " %s=%pI6c", name1, addr); + if (port) + audit_log_format(ab, " %s=%d", name2, ntohs(port)); +} + +static inline void print_ipv4_addr(struct audit_buffer *ab, __be32 addr, + __be16 port, char *name1, char *name2) +{ + if (addr) + audit_log_format(ab, " %s=%pI4", name1, &addr); + if (port) + audit_log_format(ab, " %s=%d", name2, ntohs(port)); +} + +/** + * dump_common_audit_data - helper to dump common audit data + * @a : common audit data + * + */ +static void dump_common_audit_data(struct audit_buffer *ab, + struct common_audit_data *a) +{ + char comm[sizeof(current->comm)]; + + /* + * To keep stack sizes in check force programers to notice if they + * start making this union too large! See struct lsm_network_audit + * as an example of how to deal with large data. + */ + BUILD_BUG_ON(sizeof(a->u) > sizeof(void *)*2); + + audit_log_format(ab, " pid=%d comm=", task_tgid_nr(current)); + audit_log_untrustedstring(ab, memcpy(comm, current->comm, sizeof(comm))); + + switch (a->type) { + case LSM_AUDIT_DATA_NONE: + return; + case LSM_AUDIT_DATA_IPC: + audit_log_format(ab, " ipc_key=%d ", a->u.ipc_id); + break; + case LSM_AUDIT_DATA_CAP: + audit_log_format(ab, " capability=%d ", a->u.cap); + break; + case LSM_AUDIT_DATA_PATH: { + struct inode *inode; + + audit_log_d_path(ab, " path=", &a->u.path); + + inode = d_backing_inode(a->u.path.dentry); + if (inode) { + audit_log_format(ab, " dev="); + audit_log_untrustedstring(ab, inode->i_sb->s_id); + audit_log_format(ab, " ino=%lu", inode->i_ino); + } + break; + } + case LSM_AUDIT_DATA_FILE: { + struct inode *inode; + + audit_log_d_path(ab, " path=", &a->u.file->f_path); + + inode = file_inode(a->u.file); + if (inode) { + audit_log_format(ab, " dev="); + audit_log_untrustedstring(ab, inode->i_sb->s_id); + audit_log_format(ab, " ino=%lu", inode->i_ino); + } + break; + } + case LSM_AUDIT_DATA_IOCTL_OP: { + struct inode *inode; + + audit_log_d_path(ab, " path=", &a->u.op->path); + + inode = a->u.op->path.dentry->d_inode; + if (inode) { + audit_log_format(ab, " dev="); + audit_log_untrustedstring(ab, inode->i_sb->s_id); + audit_log_format(ab, " ino=%lu", inode->i_ino); + } + + audit_log_format(ab, " ioctlcmd=0x%hx", a->u.op->cmd); + break; + } + case LSM_AUDIT_DATA_DENTRY: { + struct inode *inode; + + audit_log_format(ab, " name="); + spin_lock(&a->u.dentry->d_lock); + audit_log_untrustedstring(ab, a->u.dentry->d_name.name); + spin_unlock(&a->u.dentry->d_lock); + + inode = d_backing_inode(a->u.dentry); + if (inode) { + audit_log_format(ab, " dev="); + audit_log_untrustedstring(ab, inode->i_sb->s_id); + audit_log_format(ab, " ino=%lu", inode->i_ino); + } + break; + } + case LSM_AUDIT_DATA_INODE: { + struct dentry *dentry; + struct inode *inode; + + rcu_read_lock(); + inode = a->u.inode; + dentry = d_find_alias_rcu(inode); + if (dentry) { + audit_log_format(ab, " name="); + spin_lock(&dentry->d_lock); + audit_log_untrustedstring(ab, dentry->d_name.name); + spin_unlock(&dentry->d_lock); + } + audit_log_format(ab, " dev="); + audit_log_untrustedstring(ab, inode->i_sb->s_id); + audit_log_format(ab, " ino=%lu", inode->i_ino); + rcu_read_unlock(); + break; + } + case LSM_AUDIT_DATA_TASK: { + struct task_struct *tsk = a->u.tsk; + if (tsk) { + pid_t pid = task_tgid_nr(tsk); + if (pid) { + char comm[sizeof(tsk->comm)]; + audit_log_format(ab, " opid=%d ocomm=", pid); + audit_log_untrustedstring(ab, + memcpy(comm, tsk->comm, sizeof(comm))); + } + } + break; + } + case LSM_AUDIT_DATA_NET: + if (a->u.net->sk) { + const struct sock *sk = a->u.net->sk; + struct unix_sock *u; + struct unix_address *addr; + int len = 0; + char *p = NULL; + + switch (sk->sk_family) { + case AF_INET: { + struct inet_sock *inet = inet_sk(sk); + + print_ipv4_addr(ab, inet->inet_rcv_saddr, + inet->inet_sport, + "laddr", "lport"); + print_ipv4_addr(ab, inet->inet_daddr, + inet->inet_dport, + "faddr", "fport"); + break; + } +#if IS_ENABLED(CONFIG_IPV6) + case AF_INET6: { + struct inet_sock *inet = inet_sk(sk); + + print_ipv6_addr(ab, &sk->sk_v6_rcv_saddr, + inet->inet_sport, + "laddr", "lport"); + print_ipv6_addr(ab, &sk->sk_v6_daddr, + inet->inet_dport, + "faddr", "fport"); + break; + } +#endif + case AF_UNIX: + u = unix_sk(sk); + addr = smp_load_acquire(&u->addr); + if (!addr) + break; + if (u->path.dentry) { + audit_log_d_path(ab, " path=", &u->path); + break; + } + len = addr->len-sizeof(short); + p = &addr->name->sun_path[0]; + audit_log_format(ab, " path="); + if (*p) + audit_log_untrustedstring(ab, p); + else + audit_log_n_hex(ab, p, len); + break; + } + } + + switch (a->u.net->family) { + case AF_INET: + print_ipv4_addr(ab, a->u.net->v4info.saddr, + a->u.net->sport, + "saddr", "src"); + print_ipv4_addr(ab, a->u.net->v4info.daddr, + a->u.net->dport, + "daddr", "dest"); + break; + case AF_INET6: + print_ipv6_addr(ab, &a->u.net->v6info.saddr, + a->u.net->sport, + "saddr", "src"); + print_ipv6_addr(ab, &a->u.net->v6info.daddr, + a->u.net->dport, + "daddr", "dest"); + break; + } + if (a->u.net->netif > 0) { + struct net_device *dev; + + /* NOTE: we always use init's namespace */ + dev = dev_get_by_index(&init_net, a->u.net->netif); + if (dev) { + audit_log_format(ab, " netif=%s", dev->name); + dev_put(dev); + } + } + break; +#ifdef CONFIG_KEYS + case LSM_AUDIT_DATA_KEY: + audit_log_format(ab, " key_serial=%u", a->u.key_struct.key); + if (a->u.key_struct.key_desc) { + audit_log_format(ab, " key_desc="); + audit_log_untrustedstring(ab, a->u.key_struct.key_desc); + } + break; +#endif + case LSM_AUDIT_DATA_KMOD: + audit_log_format(ab, " kmod="); + audit_log_untrustedstring(ab, a->u.kmod_name); + break; + case LSM_AUDIT_DATA_IBPKEY: { + struct in6_addr sbn_pfx; + + memset(&sbn_pfx.s6_addr, 0, + sizeof(sbn_pfx.s6_addr)); + memcpy(&sbn_pfx.s6_addr, &a->u.ibpkey->subnet_prefix, + sizeof(a->u.ibpkey->subnet_prefix)); + audit_log_format(ab, " pkey=0x%x subnet_prefix=%pI6c", + a->u.ibpkey->pkey, &sbn_pfx); + break; + } + case LSM_AUDIT_DATA_IBENDPORT: + audit_log_format(ab, " device=%s port_num=%u", + a->u.ibendport->dev_name, + a->u.ibendport->port); + break; + case LSM_AUDIT_DATA_LOCKDOWN: + audit_log_format(ab, " lockdown_reason=\"%s\"", + lockdown_reasons[a->u.reason]); + break; + case LSM_AUDIT_DATA_ANONINODE: + audit_log_format(ab, " anonclass=%s", a->u.anonclass); + break; + } /* switch (a->type) */ +} + +/** + * common_lsm_audit - generic LSM auditing function + * @a: auxiliary audit data + * @pre_audit: lsm-specific pre-audit callback + * @post_audit: lsm-specific post-audit callback + * + * setup the audit buffer for common security information + * uses callback to print LSM specific information + */ +void common_lsm_audit(struct common_audit_data *a, + void (*pre_audit)(struct audit_buffer *, void *), + void (*post_audit)(struct audit_buffer *, void *)) +{ + struct audit_buffer *ab; + + if (a == NULL) + return; + /* we use GFP_ATOMIC so we won't sleep */ + ab = audit_log_start(audit_context(), GFP_ATOMIC | __GFP_NOWARN, + AUDIT_AVC); + + if (ab == NULL) + return; + + if (pre_audit) + pre_audit(ab, a); + + dump_common_audit_data(ab, a); + + if (post_audit) + post_audit(ab, a); + + audit_log_end(ab); +} diff --git a/security/min_addr.c b/security/min_addr.c new file mode 100644 index 000000000..88c9a6a21 --- /dev/null +++ b/security/min_addr.c @@ -0,0 +1,53 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/init.h> +#include <linux/mm.h> +#include <linux/security.h> +#include <linux/sysctl.h> + +/* amount of vm to protect from userspace access by both DAC and the LSM*/ +unsigned long mmap_min_addr; +/* amount of vm to protect from userspace using CAP_SYS_RAWIO (DAC) */ +unsigned long dac_mmap_min_addr = CONFIG_DEFAULT_MMAP_MIN_ADDR; +/* amount of vm to protect from userspace using the LSM = CONFIG_LSM_MMAP_MIN_ADDR */ + +/* + * Update mmap_min_addr = max(dac_mmap_min_addr, CONFIG_LSM_MMAP_MIN_ADDR) + */ +static void update_mmap_min_addr(void) +{ +#ifdef CONFIG_LSM_MMAP_MIN_ADDR + if (dac_mmap_min_addr > CONFIG_LSM_MMAP_MIN_ADDR) + mmap_min_addr = dac_mmap_min_addr; + else + mmap_min_addr = CONFIG_LSM_MMAP_MIN_ADDR; +#else + mmap_min_addr = dac_mmap_min_addr; +#endif +} + +/* + * sysctl handler which just sets dac_mmap_min_addr = the new value and then + * calls update_mmap_min_addr() so non MAP_FIXED hints get rounded properly + */ +int mmap_min_addr_handler(struct ctl_table *table, int write, + void *buffer, size_t *lenp, loff_t *ppos) +{ + int ret; + + if (write && !capable(CAP_SYS_RAWIO)) + return -EPERM; + + ret = proc_doulongvec_minmax(table, write, buffer, lenp, ppos); + + update_mmap_min_addr(); + + return ret; +} + +static int __init init_mmap_min_addr(void) +{ + update_mmap_min_addr(); + + return 0; +} +pure_initcall(init_mmap_min_addr); diff --git a/security/safesetid/Kconfig b/security/safesetid/Kconfig new file mode 100644 index 000000000..18b5fb904 --- /dev/null +++ b/security/safesetid/Kconfig @@ -0,0 +1,15 @@ +# SPDX-License-Identifier: GPL-2.0-only +config SECURITY_SAFESETID + bool "Gate setid transitions to limit CAP_SET{U/G}ID capabilities" + depends on SECURITY + select SECURITYFS + default n + help + SafeSetID is an LSM module that gates the setid family of syscalls to + restrict UID/GID transitions from a given UID/GID to only those + approved by a system-wide whitelist. These restrictions also prohibit + the given UIDs/GIDs from obtaining auxiliary privileges associated + with CAP_SET{U/G}ID, such as allowing a user to set up user namespace + UID mappings. + + If you are unsure how to answer this question, answer N. diff --git a/security/safesetid/Makefile b/security/safesetid/Makefile new file mode 100644 index 000000000..6b0660321 --- /dev/null +++ b/security/safesetid/Makefile @@ -0,0 +1,7 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Makefile for the safesetid LSM. +# + +obj-$(CONFIG_SECURITY_SAFESETID) := safesetid.o +safesetid-y := lsm.o securityfs.o diff --git a/security/safesetid/lsm.c b/security/safesetid/lsm.c new file mode 100644 index 000000000..e806739f7 --- /dev/null +++ b/security/safesetid/lsm.c @@ -0,0 +1,285 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * SafeSetID Linux Security Module + * + * Author: Micah Morton <mortonm@chromium.org> + * + * Copyright (C) 2018 The Chromium OS Authors. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2, as + * published by the Free Software Foundation. + * + */ + +#define pr_fmt(fmt) "SafeSetID: " fmt + +#include <linux/lsm_hooks.h> +#include <linux/module.h> +#include <linux/ptrace.h> +#include <linux/sched/task_stack.h> +#include <linux/security.h> +#include "lsm.h" + +/* Flag indicating whether initialization completed */ +int safesetid_initialized __initdata; + +struct setid_ruleset __rcu *safesetid_setuid_rules; +struct setid_ruleset __rcu *safesetid_setgid_rules; + + +/* Compute a decision for a transition from @src to @dst under @policy. */ +enum sid_policy_type _setid_policy_lookup(struct setid_ruleset *policy, + kid_t src, kid_t dst) +{ + struct setid_rule *rule; + enum sid_policy_type result = SIDPOL_DEFAULT; + + if (policy->type == UID) { + hash_for_each_possible(policy->rules, rule, next, __kuid_val(src.uid)) { + if (!uid_eq(rule->src_id.uid, src.uid)) + continue; + if (uid_eq(rule->dst_id.uid, dst.uid)) + return SIDPOL_ALLOWED; + result = SIDPOL_CONSTRAINED; + } + } else if (policy->type == GID) { + hash_for_each_possible(policy->rules, rule, next, __kgid_val(src.gid)) { + if (!gid_eq(rule->src_id.gid, src.gid)) + continue; + if (gid_eq(rule->dst_id.gid, dst.gid)){ + return SIDPOL_ALLOWED; + } + result = SIDPOL_CONSTRAINED; + } + } else { + /* Should not reach here, report the ID as contrainsted */ + result = SIDPOL_CONSTRAINED; + } + return result; +} + +/* + * Compute a decision for a transition from @src to @dst under the active + * policy. + */ +static enum sid_policy_type setid_policy_lookup(kid_t src, kid_t dst, enum setid_type new_type) +{ + enum sid_policy_type result = SIDPOL_DEFAULT; + struct setid_ruleset *pol; + + rcu_read_lock(); + if (new_type == UID) + pol = rcu_dereference(safesetid_setuid_rules); + else if (new_type == GID) + pol = rcu_dereference(safesetid_setgid_rules); + else { /* Should not reach here */ + result = SIDPOL_CONSTRAINED; + rcu_read_unlock(); + return result; + } + + if (pol) { + pol->type = new_type; + result = _setid_policy_lookup(pol, src, dst); + } + rcu_read_unlock(); + return result; +} + +static int safesetid_security_capable(const struct cred *cred, + struct user_namespace *ns, + int cap, + unsigned int opts) +{ + /* We're only interested in CAP_SETUID and CAP_SETGID. */ + if (cap != CAP_SETUID && cap != CAP_SETGID) + return 0; + + /* + * If CAP_SET{U/G}ID is currently used for a setid or setgroups syscall, we + * want to let it go through here; the real security check happens later, in + * the task_fix_set{u/g}id or task_fix_setgroups hooks. + */ + if ((opts & CAP_OPT_INSETID) != 0) + return 0; + + switch (cap) { + case CAP_SETUID: + /* + * If no policy applies to this task, allow the use of CAP_SETUID for + * other purposes. + */ + if (setid_policy_lookup((kid_t){.uid = cred->uid}, INVALID_ID, UID) == SIDPOL_DEFAULT) + return 0; + /* + * Reject use of CAP_SETUID for functionality other than calling + * set*uid() (e.g. setting up userns uid mappings). + */ + pr_warn("Operation requires CAP_SETUID, which is not available to UID %u for operations besides approved set*uid transitions\n", + __kuid_val(cred->uid)); + return -EPERM; + case CAP_SETGID: + /* + * If no policy applies to this task, allow the use of CAP_SETGID for + * other purposes. + */ + if (setid_policy_lookup((kid_t){.gid = cred->gid}, INVALID_ID, GID) == SIDPOL_DEFAULT) + return 0; + /* + * Reject use of CAP_SETUID for functionality other than calling + * set*gid() (e.g. setting up userns gid mappings). + */ + pr_warn("Operation requires CAP_SETGID, which is not available to GID %u for operations besides approved set*gid transitions\n", + __kuid_val(cred->uid)); + return -EPERM; + default: + /* Error, the only capabilities were checking for is CAP_SETUID/GID */ + return 0; + } + return 0; +} + +/* + * Check whether a caller with old credentials @old is allowed to switch to + * credentials that contain @new_id. + */ +static bool id_permitted_for_cred(const struct cred *old, kid_t new_id, enum setid_type new_type) +{ + bool permitted; + + /* If our old creds already had this ID in it, it's fine. */ + if (new_type == UID) { + if (uid_eq(new_id.uid, old->uid) || uid_eq(new_id.uid, old->euid) || + uid_eq(new_id.uid, old->suid)) + return true; + } else if (new_type == GID){ + if (gid_eq(new_id.gid, old->gid) || gid_eq(new_id.gid, old->egid) || + gid_eq(new_id.gid, old->sgid)) + return true; + } else /* Error, new_type is an invalid type */ + return false; + + /* + * Transitions to new UIDs require a check against the policy of the old + * RUID. + */ + permitted = + setid_policy_lookup((kid_t){.uid = old->uid}, new_id, new_type) != SIDPOL_CONSTRAINED; + + if (!permitted) { + if (new_type == UID) { + pr_warn("UID transition ((%d,%d,%d) -> %d) blocked\n", + __kuid_val(old->uid), __kuid_val(old->euid), + __kuid_val(old->suid), __kuid_val(new_id.uid)); + } else if (new_type == GID) { + pr_warn("GID transition ((%d,%d,%d) -> %d) blocked\n", + __kgid_val(old->gid), __kgid_val(old->egid), + __kgid_val(old->sgid), __kgid_val(new_id.gid)); + } else /* Error, new_type is an invalid type */ + return false; + } + return permitted; +} + +/* + * Check whether there is either an exception for user under old cred struct to + * set*uid to user under new cred struct, or the UID transition is allowed (by + * Linux set*uid rules) even without CAP_SETUID. + */ +static int safesetid_task_fix_setuid(struct cred *new, + const struct cred *old, + int flags) +{ + + /* Do nothing if there are no setuid restrictions for our old RUID. */ + if (setid_policy_lookup((kid_t){.uid = old->uid}, INVALID_ID, UID) == SIDPOL_DEFAULT) + return 0; + + if (id_permitted_for_cred(old, (kid_t){.uid = new->uid}, UID) && + id_permitted_for_cred(old, (kid_t){.uid = new->euid}, UID) && + id_permitted_for_cred(old, (kid_t){.uid = new->suid}, UID) && + id_permitted_for_cred(old, (kid_t){.uid = new->fsuid}, UID)) + return 0; + + /* + * Kill this process to avoid potential security vulnerabilities + * that could arise from a missing allowlist entry preventing a + * privileged process from dropping to a lesser-privileged one. + */ + force_sig(SIGKILL); + return -EACCES; +} + +static int safesetid_task_fix_setgid(struct cred *new, + const struct cred *old, + int flags) +{ + + /* Do nothing if there are no setgid restrictions for our old RGID. */ + if (setid_policy_lookup((kid_t){.gid = old->gid}, INVALID_ID, GID) == SIDPOL_DEFAULT) + return 0; + + if (id_permitted_for_cred(old, (kid_t){.gid = new->gid}, GID) && + id_permitted_for_cred(old, (kid_t){.gid = new->egid}, GID) && + id_permitted_for_cred(old, (kid_t){.gid = new->sgid}, GID) && + id_permitted_for_cred(old, (kid_t){.gid = new->fsgid}, GID)) + return 0; + + /* + * Kill this process to avoid potential security vulnerabilities + * that could arise from a missing allowlist entry preventing a + * privileged process from dropping to a lesser-privileged one. + */ + force_sig(SIGKILL); + return -EACCES; +} + +static int safesetid_task_fix_setgroups(struct cred *new, const struct cred *old) +{ + int i; + + /* Do nothing if there are no setgid restrictions for our old RGID. */ + if (setid_policy_lookup((kid_t){.gid = old->gid}, INVALID_ID, GID) == SIDPOL_DEFAULT) + return 0; + + get_group_info(new->group_info); + for (i = 0; i < new->group_info->ngroups; i++) { + if (!id_permitted_for_cred(old, (kid_t){.gid = new->group_info->gid[i]}, GID)) { + put_group_info(new->group_info); + /* + * Kill this process to avoid potential security vulnerabilities + * that could arise from a missing allowlist entry preventing a + * privileged process from dropping to a lesser-privileged one. + */ + force_sig(SIGKILL); + return -EACCES; + } + } + + put_group_info(new->group_info); + return 0; +} + +static struct security_hook_list safesetid_security_hooks[] = { + LSM_HOOK_INIT(task_fix_setuid, safesetid_task_fix_setuid), + LSM_HOOK_INIT(task_fix_setgid, safesetid_task_fix_setgid), + LSM_HOOK_INIT(task_fix_setgroups, safesetid_task_fix_setgroups), + LSM_HOOK_INIT(capable, safesetid_security_capable) +}; + +static int __init safesetid_security_init(void) +{ + security_add_hooks(safesetid_security_hooks, + ARRAY_SIZE(safesetid_security_hooks), "safesetid"); + + /* Report that SafeSetID successfully initialized */ + safesetid_initialized = 1; + + return 0; +} + +DEFINE_LSM(safesetid_security_init) = { + .init = safesetid_security_init, + .name = "safesetid", +}; diff --git a/security/safesetid/lsm.h b/security/safesetid/lsm.h new file mode 100644 index 000000000..d346f4849 --- /dev/null +++ b/security/safesetid/lsm.h @@ -0,0 +1,73 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * SafeSetID Linux Security Module + * + * Author: Micah Morton <mortonm@chromium.org> + * + * Copyright (C) 2018 The Chromium OS Authors. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2, as + * published by the Free Software Foundation. + * + */ +#ifndef _SAFESETID_H +#define _SAFESETID_H + +#include <linux/types.h> +#include <linux/uidgid.h> +#include <linux/hashtable.h> + +/* Flag indicating whether initialization completed */ +extern int safesetid_initialized __initdata; + +enum sid_policy_type { + SIDPOL_DEFAULT, /* source ID is unaffected by policy */ + SIDPOL_CONSTRAINED, /* source ID is affected by policy */ + SIDPOL_ALLOWED /* target ID explicitly allowed */ +}; + +typedef union { + kuid_t uid; + kgid_t gid; +} kid_t; + +enum setid_type { + UID, + GID +}; + +/* + * Hash table entry to store safesetid policy signifying that 'src_id' + * can set*id to 'dst_id'. + */ +struct setid_rule { + struct hlist_node next; + kid_t src_id; + kid_t dst_id; + + /* Flag to signal if rule is for UID's or GID's */ + enum setid_type type; +}; + +#define SETID_HASH_BITS 8 /* 256 buckets in hash table */ + +/* Extension of INVALID_UID/INVALID_GID for kid_t type */ +#define INVALID_ID (kid_t){.uid = INVALID_UID} + +struct setid_ruleset { + DECLARE_HASHTABLE(rules, SETID_HASH_BITS); + char *policy_str; + struct rcu_head rcu; + + //Flag to signal if ruleset is for UID's or GID's + enum setid_type type; +}; + +enum sid_policy_type _setid_policy_lookup(struct setid_ruleset *policy, + kid_t src, kid_t dst); + +extern struct setid_ruleset __rcu *safesetid_setuid_rules; +extern struct setid_ruleset __rcu *safesetid_setgid_rules; + +#endif /* _SAFESETID_H */ diff --git a/security/safesetid/securityfs.c b/security/safesetid/securityfs.c new file mode 100644 index 000000000..25310468b --- /dev/null +++ b/security/safesetid/securityfs.c @@ -0,0 +1,345 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * SafeSetID Linux Security Module + * + * Author: Micah Morton <mortonm@chromium.org> + * + * Copyright (C) 2018 The Chromium OS Authors. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2, as + * published by the Free Software Foundation. + * + */ + +#define pr_fmt(fmt) "SafeSetID: " fmt + +#include <linux/security.h> +#include <linux/cred.h> + +#include "lsm.h" + +static DEFINE_MUTEX(uid_policy_update_lock); +static DEFINE_MUTEX(gid_policy_update_lock); + +/* + * In the case the input buffer contains one or more invalid IDs, the kid_t + * variables pointed to by @parent and @child will get updated but this + * function will return an error. + * Contents of @buf may be modified. + */ +static int parse_policy_line(struct file *file, char *buf, + struct setid_rule *rule) +{ + char *child_str; + int ret; + u32 parsed_parent, parsed_child; + + /* Format of |buf| string should be <UID>:<UID> or <GID>:<GID> */ + child_str = strchr(buf, ':'); + if (child_str == NULL) + return -EINVAL; + *child_str = '\0'; + child_str++; + + ret = kstrtou32(buf, 0, &parsed_parent); + if (ret) + return ret; + + ret = kstrtou32(child_str, 0, &parsed_child); + if (ret) + return ret; + + if (rule->type == UID){ + rule->src_id.uid = make_kuid(file->f_cred->user_ns, parsed_parent); + rule->dst_id.uid = make_kuid(file->f_cred->user_ns, parsed_child); + if (!uid_valid(rule->src_id.uid) || !uid_valid(rule->dst_id.uid)) + return -EINVAL; + } else if (rule->type == GID){ + rule->src_id.gid = make_kgid(file->f_cred->user_ns, parsed_parent); + rule->dst_id.gid = make_kgid(file->f_cred->user_ns, parsed_child); + if (!gid_valid(rule->src_id.gid) || !gid_valid(rule->dst_id.gid)) + return -EINVAL; + } else { + /* Error, rule->type is an invalid type */ + return -EINVAL; + } + return 0; +} + +static void __release_ruleset(struct rcu_head *rcu) +{ + struct setid_ruleset *pol = + container_of(rcu, struct setid_ruleset, rcu); + int bucket; + struct setid_rule *rule; + struct hlist_node *tmp; + + hash_for_each_safe(pol->rules, bucket, tmp, rule, next) + kfree(rule); + kfree(pol->policy_str); + kfree(pol); +} + +static void release_ruleset(struct setid_ruleset *pol){ + call_rcu(&pol->rcu, __release_ruleset); +} + +static void insert_rule(struct setid_ruleset *pol, struct setid_rule *rule) +{ + if (pol->type == UID) + hash_add(pol->rules, &rule->next, __kuid_val(rule->src_id.uid)); + else if (pol->type == GID) + hash_add(pol->rules, &rule->next, __kgid_val(rule->src_id.gid)); + else /* Error, pol->type is neither UID or GID */ + return; +} + +static int verify_ruleset(struct setid_ruleset *pol) +{ + int bucket; + struct setid_rule *rule, *nrule; + int res = 0; + + hash_for_each(pol->rules, bucket, rule, next) { + if (_setid_policy_lookup(pol, rule->dst_id, INVALID_ID) == SIDPOL_DEFAULT) { + if (pol->type == UID) { + pr_warn("insecure policy detected: uid %d is constrained but transitively unconstrained through uid %d\n", + __kuid_val(rule->src_id.uid), + __kuid_val(rule->dst_id.uid)); + } else if (pol->type == GID) { + pr_warn("insecure policy detected: gid %d is constrained but transitively unconstrained through gid %d\n", + __kgid_val(rule->src_id.gid), + __kgid_val(rule->dst_id.gid)); + } else { /* pol->type is an invalid type */ + res = -EINVAL; + return res; + } + res = -EINVAL; + + /* fix it up */ + nrule = kmalloc(sizeof(struct setid_rule), GFP_KERNEL); + if (!nrule) + return -ENOMEM; + if (pol->type == UID){ + nrule->src_id.uid = rule->dst_id.uid; + nrule->dst_id.uid = rule->dst_id.uid; + nrule->type = UID; + } else { /* pol->type must be GID if we've made it to here */ + nrule->src_id.gid = rule->dst_id.gid; + nrule->dst_id.gid = rule->dst_id.gid; + nrule->type = GID; + } + insert_rule(pol, nrule); + } + } + return res; +} + +static ssize_t handle_policy_update(struct file *file, + const char __user *ubuf, size_t len, enum setid_type policy_type) +{ + struct setid_ruleset *pol; + char *buf, *p, *end; + int err; + + pol = kmalloc(sizeof(struct setid_ruleset), GFP_KERNEL); + if (!pol) + return -ENOMEM; + pol->policy_str = NULL; + pol->type = policy_type; + hash_init(pol->rules); + + p = buf = memdup_user_nul(ubuf, len); + if (IS_ERR(buf)) { + err = PTR_ERR(buf); + goto out_free_pol; + } + pol->policy_str = kstrdup(buf, GFP_KERNEL); + if (pol->policy_str == NULL) { + err = -ENOMEM; + goto out_free_buf; + } + + /* policy lines, including the last one, end with \n */ + while (*p != '\0') { + struct setid_rule *rule; + + end = strchr(p, '\n'); + if (end == NULL) { + err = -EINVAL; + goto out_free_buf; + } + *end = '\0'; + + rule = kmalloc(sizeof(struct setid_rule), GFP_KERNEL); + if (!rule) { + err = -ENOMEM; + goto out_free_buf; + } + + rule->type = policy_type; + err = parse_policy_line(file, p, rule); + if (err) + goto out_free_rule; + + if (_setid_policy_lookup(pol, rule->src_id, rule->dst_id) == SIDPOL_ALLOWED) { + pr_warn("bad policy: duplicate entry\n"); + err = -EEXIST; + goto out_free_rule; + } + + insert_rule(pol, rule); + p = end + 1; + continue; + +out_free_rule: + kfree(rule); + goto out_free_buf; + } + + err = verify_ruleset(pol); + /* bogus policy falls through after fixing it up */ + if (err && err != -EINVAL) + goto out_free_buf; + + /* + * Everything looks good, apply the policy and release the old one. + * What we really want here is an xchg() wrapper for RCU, but since that + * doesn't currently exist, just use a spinlock for now. + */ + if (policy_type == UID) { + mutex_lock(&uid_policy_update_lock); + pol = rcu_replace_pointer(safesetid_setuid_rules, pol, + lockdep_is_held(&uid_policy_update_lock)); + mutex_unlock(&uid_policy_update_lock); + } else if (policy_type == GID) { + mutex_lock(&gid_policy_update_lock); + pol = rcu_replace_pointer(safesetid_setgid_rules, pol, + lockdep_is_held(&gid_policy_update_lock)); + mutex_unlock(&gid_policy_update_lock); + } else { + /* Error, policy type is neither UID or GID */ + pr_warn("error: bad policy type"); + } + err = len; + +out_free_buf: + kfree(buf); +out_free_pol: + if (pol) + release_ruleset(pol); + return err; +} + +static ssize_t safesetid_uid_file_write(struct file *file, + const char __user *buf, + size_t len, + loff_t *ppos) +{ + if (!file_ns_capable(file, &init_user_ns, CAP_MAC_ADMIN)) + return -EPERM; + + if (*ppos != 0) + return -EINVAL; + + return handle_policy_update(file, buf, len, UID); +} + +static ssize_t safesetid_gid_file_write(struct file *file, + const char __user *buf, + size_t len, + loff_t *ppos) +{ + if (!file_ns_capable(file, &init_user_ns, CAP_MAC_ADMIN)) + return -EPERM; + + if (*ppos != 0) + return -EINVAL; + + return handle_policy_update(file, buf, len, GID); +} + +static ssize_t safesetid_file_read(struct file *file, char __user *buf, + size_t len, loff_t *ppos, struct mutex *policy_update_lock, struct __rcu setid_ruleset* ruleset) +{ + ssize_t res = 0; + struct setid_ruleset *pol; + const char *kbuf; + + mutex_lock(policy_update_lock); + pol = rcu_dereference_protected(ruleset, lockdep_is_held(policy_update_lock)); + if (pol) { + kbuf = pol->policy_str; + res = simple_read_from_buffer(buf, len, ppos, + kbuf, strlen(kbuf)); + } + mutex_unlock(policy_update_lock); + + return res; +} + +static ssize_t safesetid_uid_file_read(struct file *file, char __user *buf, + size_t len, loff_t *ppos) +{ + return safesetid_file_read(file, buf, len, ppos, + &uid_policy_update_lock, safesetid_setuid_rules); +} + +static ssize_t safesetid_gid_file_read(struct file *file, char __user *buf, + size_t len, loff_t *ppos) +{ + return safesetid_file_read(file, buf, len, ppos, + &gid_policy_update_lock, safesetid_setgid_rules); +} + + + +static const struct file_operations safesetid_uid_file_fops = { + .read = safesetid_uid_file_read, + .write = safesetid_uid_file_write, +}; + +static const struct file_operations safesetid_gid_file_fops = { + .read = safesetid_gid_file_read, + .write = safesetid_gid_file_write, +}; + +static int __init safesetid_init_securityfs(void) +{ + int ret; + struct dentry *policy_dir; + struct dentry *uid_policy_file; + struct dentry *gid_policy_file; + + if (!safesetid_initialized) + return 0; + + policy_dir = securityfs_create_dir("safesetid", NULL); + if (IS_ERR(policy_dir)) { + ret = PTR_ERR(policy_dir); + goto error; + } + + uid_policy_file = securityfs_create_file("uid_allowlist_policy", 0600, + policy_dir, NULL, &safesetid_uid_file_fops); + if (IS_ERR(uid_policy_file)) { + ret = PTR_ERR(uid_policy_file); + goto error; + } + + gid_policy_file = securityfs_create_file("gid_allowlist_policy", 0600, + policy_dir, NULL, &safesetid_gid_file_fops); + if (IS_ERR(gid_policy_file)) { + ret = PTR_ERR(gid_policy_file); + goto error; + } + + + return 0; + +error: + securityfs_remove(policy_dir); + return ret; +} +fs_initcall(safesetid_init_securityfs); diff --git a/security/security.c b/security/security.c new file mode 100644 index 000000000..fc15b963e --- /dev/null +++ b/security/security.c @@ -0,0 +1,2707 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Security plug functions + * + * Copyright (C) 2001 WireX Communications, Inc <chris@wirex.com> + * Copyright (C) 2001-2002 Greg Kroah-Hartman <greg@kroah.com> + * Copyright (C) 2001 Networks Associates Technology, Inc <ssmalley@nai.com> + * Copyright (C) 2016 Mellanox Technologies + */ + +#define pr_fmt(fmt) "LSM: " fmt + +#include <linux/bpf.h> +#include <linux/capability.h> +#include <linux/dcache.h> +#include <linux/export.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/kernel_read_file.h> +#include <linux/lsm_hooks.h> +#include <linux/integrity.h> +#include <linux/ima.h> +#include <linux/evm.h> +#include <linux/fsnotify.h> +#include <linux/mman.h> +#include <linux/mount.h> +#include <linux/personality.h> +#include <linux/backing-dev.h> +#include <linux/string.h> +#include <linux/msg.h> +#include <net/flow.h> + +#define MAX_LSM_EVM_XATTR 2 + +/* How many LSMs were built into the kernel? */ +#define LSM_COUNT (__end_lsm_info - __start_lsm_info) + +/* + * These are descriptions of the reasons that can be passed to the + * security_locked_down() LSM hook. Placing this array here allows + * all security modules to use the same descriptions for auditing + * purposes. + */ +const char *const lockdown_reasons[LOCKDOWN_CONFIDENTIALITY_MAX+1] = { + [LOCKDOWN_NONE] = "none", + [LOCKDOWN_MODULE_SIGNATURE] = "unsigned module loading", + [LOCKDOWN_DEV_MEM] = "/dev/mem,kmem,port", + [LOCKDOWN_EFI_TEST] = "/dev/efi_test access", + [LOCKDOWN_KEXEC] = "kexec of unsigned images", + [LOCKDOWN_HIBERNATION] = "hibernation", + [LOCKDOWN_PCI_ACCESS] = "direct PCI access", + [LOCKDOWN_IOPORT] = "raw io port access", + [LOCKDOWN_MSR] = "raw MSR access", + [LOCKDOWN_ACPI_TABLES] = "modifying ACPI tables", + [LOCKDOWN_DEVICE_TREE] = "modifying device tree contents", + [LOCKDOWN_PCMCIA_CIS] = "direct PCMCIA CIS storage", + [LOCKDOWN_TIOCSSERIAL] = "reconfiguration of serial port IO", + [LOCKDOWN_MODULE_PARAMETERS] = "unsafe module parameters", + [LOCKDOWN_MMIOTRACE] = "unsafe mmio", + [LOCKDOWN_DEBUGFS] = "debugfs access", + [LOCKDOWN_XMON_WR] = "xmon write access", + [LOCKDOWN_BPF_WRITE_USER] = "use of bpf to write user RAM", + [LOCKDOWN_DBG_WRITE_KERNEL] = "use of kgdb/kdb to write kernel RAM", + [LOCKDOWN_RTAS_ERROR_INJECTION] = "RTAS error injection", + [LOCKDOWN_INTEGRITY_MAX] = "integrity", + [LOCKDOWN_KCORE] = "/proc/kcore access", + [LOCKDOWN_KPROBES] = "use of kprobes", + [LOCKDOWN_BPF_READ_KERNEL] = "use of bpf to read kernel RAM", + [LOCKDOWN_DBG_READ_KERNEL] = "use of kgdb/kdb to read kernel RAM", + [LOCKDOWN_PERF] = "unsafe use of perf", + [LOCKDOWN_TRACEFS] = "use of tracefs", + [LOCKDOWN_XMON_RW] = "xmon read and write access", + [LOCKDOWN_XFRM_SECRET] = "xfrm SA secret", + [LOCKDOWN_CONFIDENTIALITY_MAX] = "confidentiality", +}; + +struct security_hook_heads security_hook_heads __lsm_ro_after_init; +static BLOCKING_NOTIFIER_HEAD(blocking_lsm_notifier_chain); + +static struct kmem_cache *lsm_file_cache; +static struct kmem_cache *lsm_inode_cache; + +char *lsm_names; +static struct lsm_blob_sizes blob_sizes __lsm_ro_after_init; + +/* Boot-time LSM user choice */ +static __initdata const char *chosen_lsm_order; +static __initdata const char *chosen_major_lsm; + +static __initconst const char * const builtin_lsm_order = CONFIG_LSM; + +/* Ordered list of LSMs to initialize. */ +static __initdata struct lsm_info **ordered_lsms; +static __initdata struct lsm_info *exclusive; + +static __initdata bool debug; +#define init_debug(...) \ + do { \ + if (debug) \ + pr_info(__VA_ARGS__); \ + } while (0) + +static bool __init is_enabled(struct lsm_info *lsm) +{ + if (!lsm->enabled) + return false; + + return *lsm->enabled; +} + +/* Mark an LSM's enabled flag. */ +static int lsm_enabled_true __initdata = 1; +static int lsm_enabled_false __initdata = 0; +static void __init set_enabled(struct lsm_info *lsm, bool enabled) +{ + /* + * When an LSM hasn't configured an enable variable, we can use + * a hard-coded location for storing the default enabled state. + */ + if (!lsm->enabled) { + if (enabled) + lsm->enabled = &lsm_enabled_true; + else + lsm->enabled = &lsm_enabled_false; + } else if (lsm->enabled == &lsm_enabled_true) { + if (!enabled) + lsm->enabled = &lsm_enabled_false; + } else if (lsm->enabled == &lsm_enabled_false) { + if (enabled) + lsm->enabled = &lsm_enabled_true; + } else { + *lsm->enabled = enabled; + } +} + +/* Is an LSM already listed in the ordered LSMs list? */ +static bool __init exists_ordered_lsm(struct lsm_info *lsm) +{ + struct lsm_info **check; + + for (check = ordered_lsms; *check; check++) + if (*check == lsm) + return true; + + return false; +} + +/* Append an LSM to the list of ordered LSMs to initialize. */ +static int last_lsm __initdata; +static void __init append_ordered_lsm(struct lsm_info *lsm, const char *from) +{ + /* Ignore duplicate selections. */ + if (exists_ordered_lsm(lsm)) + return; + + if (WARN(last_lsm == LSM_COUNT, "%s: out of LSM slots!?\n", from)) + return; + + /* Enable this LSM, if it is not already set. */ + if (!lsm->enabled) + lsm->enabled = &lsm_enabled_true; + ordered_lsms[last_lsm++] = lsm; + + init_debug("%s ordering: %s (%sabled)\n", from, lsm->name, + is_enabled(lsm) ? "en" : "dis"); +} + +/* Is an LSM allowed to be initialized? */ +static bool __init lsm_allowed(struct lsm_info *lsm) +{ + /* Skip if the LSM is disabled. */ + if (!is_enabled(lsm)) + return false; + + /* Not allowed if another exclusive LSM already initialized. */ + if ((lsm->flags & LSM_FLAG_EXCLUSIVE) && exclusive) { + init_debug("exclusive disabled: %s\n", lsm->name); + return false; + } + + return true; +} + +static void __init lsm_set_blob_size(int *need, int *lbs) +{ + int offset; + + if (*need > 0) { + offset = *lbs; + *lbs += *need; + *need = offset; + } +} + +static void __init lsm_set_blob_sizes(struct lsm_blob_sizes *needed) +{ + if (!needed) + return; + + lsm_set_blob_size(&needed->lbs_cred, &blob_sizes.lbs_cred); + lsm_set_blob_size(&needed->lbs_file, &blob_sizes.lbs_file); + /* + * The inode blob gets an rcu_head in addition to + * what the modules might need. + */ + if (needed->lbs_inode && blob_sizes.lbs_inode == 0) + blob_sizes.lbs_inode = sizeof(struct rcu_head); + lsm_set_blob_size(&needed->lbs_inode, &blob_sizes.lbs_inode); + lsm_set_blob_size(&needed->lbs_ipc, &blob_sizes.lbs_ipc); + lsm_set_blob_size(&needed->lbs_msg_msg, &blob_sizes.lbs_msg_msg); + lsm_set_blob_size(&needed->lbs_superblock, &blob_sizes.lbs_superblock); + lsm_set_blob_size(&needed->lbs_task, &blob_sizes.lbs_task); +} + +/* Prepare LSM for initialization. */ +static void __init prepare_lsm(struct lsm_info *lsm) +{ + int enabled = lsm_allowed(lsm); + + /* Record enablement (to handle any following exclusive LSMs). */ + set_enabled(lsm, enabled); + + /* If enabled, do pre-initialization work. */ + if (enabled) { + if ((lsm->flags & LSM_FLAG_EXCLUSIVE) && !exclusive) { + exclusive = lsm; + init_debug("exclusive chosen: %s\n", lsm->name); + } + + lsm_set_blob_sizes(lsm->blobs); + } +} + +/* Initialize a given LSM, if it is enabled. */ +static void __init initialize_lsm(struct lsm_info *lsm) +{ + if (is_enabled(lsm)) { + int ret; + + init_debug("initializing %s\n", lsm->name); + ret = lsm->init(); + WARN(ret, "%s failed to initialize: %d\n", lsm->name, ret); + } +} + +/* Populate ordered LSMs list from comma-separated LSM name list. */ +static void __init ordered_lsm_parse(const char *order, const char *origin) +{ + struct lsm_info *lsm; + char *sep, *name, *next; + + /* LSM_ORDER_FIRST is always first. */ + for (lsm = __start_lsm_info; lsm < __end_lsm_info; lsm++) { + if (lsm->order == LSM_ORDER_FIRST) + append_ordered_lsm(lsm, "first"); + } + + /* Process "security=", if given. */ + if (chosen_major_lsm) { + struct lsm_info *major; + + /* + * To match the original "security=" behavior, this + * explicitly does NOT fallback to another Legacy Major + * if the selected one was separately disabled: disable + * all non-matching Legacy Major LSMs. + */ + for (major = __start_lsm_info; major < __end_lsm_info; + major++) { + if ((major->flags & LSM_FLAG_LEGACY_MAJOR) && + strcmp(major->name, chosen_major_lsm) != 0) { + set_enabled(major, false); + init_debug("security=%s disabled: %s\n", + chosen_major_lsm, major->name); + } + } + } + + sep = kstrdup(order, GFP_KERNEL); + next = sep; + /* Walk the list, looking for matching LSMs. */ + while ((name = strsep(&next, ",")) != NULL) { + bool found = false; + + for (lsm = __start_lsm_info; lsm < __end_lsm_info; lsm++) { + if (lsm->order == LSM_ORDER_MUTABLE && + strcmp(lsm->name, name) == 0) { + append_ordered_lsm(lsm, origin); + found = true; + } + } + + if (!found) + init_debug("%s ignored: %s\n", origin, name); + } + + /* Process "security=", if given. */ + if (chosen_major_lsm) { + for (lsm = __start_lsm_info; lsm < __end_lsm_info; lsm++) { + if (exists_ordered_lsm(lsm)) + continue; + if (strcmp(lsm->name, chosen_major_lsm) == 0) + append_ordered_lsm(lsm, "security="); + } + } + + /* Disable all LSMs not in the ordered list. */ + for (lsm = __start_lsm_info; lsm < __end_lsm_info; lsm++) { + if (exists_ordered_lsm(lsm)) + continue; + set_enabled(lsm, false); + init_debug("%s disabled: %s\n", origin, lsm->name); + } + + kfree(sep); +} + +static void __init lsm_early_cred(struct cred *cred); +static void __init lsm_early_task(struct task_struct *task); + +static int lsm_append(const char *new, char **result); + +static void __init ordered_lsm_init(void) +{ + struct lsm_info **lsm; + + ordered_lsms = kcalloc(LSM_COUNT + 1, sizeof(*ordered_lsms), + GFP_KERNEL); + + if (chosen_lsm_order) { + if (chosen_major_lsm) { + pr_info("security= is ignored because it is superseded by lsm=\n"); + chosen_major_lsm = NULL; + } + ordered_lsm_parse(chosen_lsm_order, "cmdline"); + } else + ordered_lsm_parse(builtin_lsm_order, "builtin"); + + for (lsm = ordered_lsms; *lsm; lsm++) + prepare_lsm(*lsm); + + init_debug("cred blob size = %d\n", blob_sizes.lbs_cred); + init_debug("file blob size = %d\n", blob_sizes.lbs_file); + init_debug("inode blob size = %d\n", blob_sizes.lbs_inode); + init_debug("ipc blob size = %d\n", blob_sizes.lbs_ipc); + init_debug("msg_msg blob size = %d\n", blob_sizes.lbs_msg_msg); + init_debug("superblock blob size = %d\n", blob_sizes.lbs_superblock); + init_debug("task blob size = %d\n", blob_sizes.lbs_task); + + /* + * Create any kmem_caches needed for blobs + */ + if (blob_sizes.lbs_file) + lsm_file_cache = kmem_cache_create("lsm_file_cache", + blob_sizes.lbs_file, 0, + SLAB_PANIC, NULL); + if (blob_sizes.lbs_inode) + lsm_inode_cache = kmem_cache_create("lsm_inode_cache", + blob_sizes.lbs_inode, 0, + SLAB_PANIC, NULL); + + lsm_early_cred((struct cred *) current->cred); + lsm_early_task(current); + for (lsm = ordered_lsms; *lsm; lsm++) + initialize_lsm(*lsm); + + kfree(ordered_lsms); +} + +int __init early_security_init(void) +{ + struct lsm_info *lsm; + +#define LSM_HOOK(RET, DEFAULT, NAME, ...) \ + INIT_HLIST_HEAD(&security_hook_heads.NAME); +#include "linux/lsm_hook_defs.h" +#undef LSM_HOOK + + for (lsm = __start_early_lsm_info; lsm < __end_early_lsm_info; lsm++) { + if (!lsm->enabled) + lsm->enabled = &lsm_enabled_true; + prepare_lsm(lsm); + initialize_lsm(lsm); + } + + return 0; +} + +/** + * security_init - initializes the security framework + * + * This should be called early in the kernel initialization sequence. + */ +int __init security_init(void) +{ + struct lsm_info *lsm; + + pr_info("Security Framework initializing\n"); + + /* + * Append the names of the early LSM modules now that kmalloc() is + * available + */ + for (lsm = __start_early_lsm_info; lsm < __end_early_lsm_info; lsm++) { + if (lsm->enabled) + lsm_append(lsm->name, &lsm_names); + } + + /* Load LSMs in specified order. */ + ordered_lsm_init(); + + return 0; +} + +/* Save user chosen LSM */ +static int __init choose_major_lsm(char *str) +{ + chosen_major_lsm = str; + return 1; +} +__setup("security=", choose_major_lsm); + +/* Explicitly choose LSM initialization order. */ +static int __init choose_lsm_order(char *str) +{ + chosen_lsm_order = str; + return 1; +} +__setup("lsm=", choose_lsm_order); + +/* Enable LSM order debugging. */ +static int __init enable_debug(char *str) +{ + debug = true; + return 1; +} +__setup("lsm.debug", enable_debug); + +static bool match_last_lsm(const char *list, const char *lsm) +{ + const char *last; + + if (WARN_ON(!list || !lsm)) + return false; + last = strrchr(list, ','); + if (last) + /* Pass the comma, strcmp() will check for '\0' */ + last++; + else + last = list; + return !strcmp(last, lsm); +} + +static int lsm_append(const char *new, char **result) +{ + char *cp; + + if (*result == NULL) { + *result = kstrdup(new, GFP_KERNEL); + if (*result == NULL) + return -ENOMEM; + } else { + /* Check if it is the last registered name */ + if (match_last_lsm(*result, new)) + return 0; + cp = kasprintf(GFP_KERNEL, "%s,%s", *result, new); + if (cp == NULL) + return -ENOMEM; + kfree(*result); + *result = cp; + } + return 0; +} + +/** + * security_add_hooks - Add a modules hooks to the hook lists. + * @hooks: the hooks to add + * @count: the number of hooks to add + * @lsm: the name of the security module + * + * Each LSM has to register its hooks with the infrastructure. + */ +void __init security_add_hooks(struct security_hook_list *hooks, int count, + const char *lsm) +{ + int i; + + for (i = 0; i < count; i++) { + hooks[i].lsm = lsm; + hlist_add_tail_rcu(&hooks[i].list, hooks[i].head); + } + + /* + * Don't try to append during early_security_init(), we'll come back + * and fix this up afterwards. + */ + if (slab_is_available()) { + if (lsm_append(lsm, &lsm_names) < 0) + panic("%s - Cannot get early memory.\n", __func__); + } +} + +int call_blocking_lsm_notifier(enum lsm_event event, void *data) +{ + return blocking_notifier_call_chain(&blocking_lsm_notifier_chain, + event, data); +} +EXPORT_SYMBOL(call_blocking_lsm_notifier); + +int register_blocking_lsm_notifier(struct notifier_block *nb) +{ + return blocking_notifier_chain_register(&blocking_lsm_notifier_chain, + nb); +} +EXPORT_SYMBOL(register_blocking_lsm_notifier); + +int unregister_blocking_lsm_notifier(struct notifier_block *nb) +{ + return blocking_notifier_chain_unregister(&blocking_lsm_notifier_chain, + nb); +} +EXPORT_SYMBOL(unregister_blocking_lsm_notifier); + +/** + * lsm_cred_alloc - allocate a composite cred blob + * @cred: the cred that needs a blob + * @gfp: allocation type + * + * Allocate the cred blob for all the modules + * + * Returns 0, or -ENOMEM if memory can't be allocated. + */ +static int lsm_cred_alloc(struct cred *cred, gfp_t gfp) +{ + if (blob_sizes.lbs_cred == 0) { + cred->security = NULL; + return 0; + } + + cred->security = kzalloc(blob_sizes.lbs_cred, gfp); + if (cred->security == NULL) + return -ENOMEM; + return 0; +} + +/** + * lsm_early_cred - during initialization allocate a composite cred blob + * @cred: the cred that needs a blob + * + * Allocate the cred blob for all the modules + */ +static void __init lsm_early_cred(struct cred *cred) +{ + int rc = lsm_cred_alloc(cred, GFP_KERNEL); + + if (rc) + panic("%s: Early cred alloc failed.\n", __func__); +} + +/** + * lsm_file_alloc - allocate a composite file blob + * @file: the file that needs a blob + * + * Allocate the file blob for all the modules + * + * Returns 0, or -ENOMEM if memory can't be allocated. + */ +static int lsm_file_alloc(struct file *file) +{ + if (!lsm_file_cache) { + file->f_security = NULL; + return 0; + } + + file->f_security = kmem_cache_zalloc(lsm_file_cache, GFP_KERNEL); + if (file->f_security == NULL) + return -ENOMEM; + return 0; +} + +/** + * lsm_inode_alloc - allocate a composite inode blob + * @inode: the inode that needs a blob + * + * Allocate the inode blob for all the modules + * + * Returns 0, or -ENOMEM if memory can't be allocated. + */ +int lsm_inode_alloc(struct inode *inode) +{ + if (!lsm_inode_cache) { + inode->i_security = NULL; + return 0; + } + + inode->i_security = kmem_cache_zalloc(lsm_inode_cache, GFP_NOFS); + if (inode->i_security == NULL) + return -ENOMEM; + return 0; +} + +/** + * lsm_task_alloc - allocate a composite task blob + * @task: the task that needs a blob + * + * Allocate the task blob for all the modules + * + * Returns 0, or -ENOMEM if memory can't be allocated. + */ +static int lsm_task_alloc(struct task_struct *task) +{ + if (blob_sizes.lbs_task == 0) { + task->security = NULL; + return 0; + } + + task->security = kzalloc(blob_sizes.lbs_task, GFP_KERNEL); + if (task->security == NULL) + return -ENOMEM; + return 0; +} + +/** + * lsm_ipc_alloc - allocate a composite ipc blob + * @kip: the ipc that needs a blob + * + * Allocate the ipc blob for all the modules + * + * Returns 0, or -ENOMEM if memory can't be allocated. + */ +static int lsm_ipc_alloc(struct kern_ipc_perm *kip) +{ + if (blob_sizes.lbs_ipc == 0) { + kip->security = NULL; + return 0; + } + + kip->security = kzalloc(blob_sizes.lbs_ipc, GFP_KERNEL); + if (kip->security == NULL) + return -ENOMEM; + return 0; +} + +/** + * lsm_msg_msg_alloc - allocate a composite msg_msg blob + * @mp: the msg_msg that needs a blob + * + * Allocate the ipc blob for all the modules + * + * Returns 0, or -ENOMEM if memory can't be allocated. + */ +static int lsm_msg_msg_alloc(struct msg_msg *mp) +{ + if (blob_sizes.lbs_msg_msg == 0) { + mp->security = NULL; + return 0; + } + + mp->security = kzalloc(blob_sizes.lbs_msg_msg, GFP_KERNEL); + if (mp->security == NULL) + return -ENOMEM; + return 0; +} + +/** + * lsm_early_task - during initialization allocate a composite task blob + * @task: the task that needs a blob + * + * Allocate the task blob for all the modules + */ +static void __init lsm_early_task(struct task_struct *task) +{ + int rc = lsm_task_alloc(task); + + if (rc) + panic("%s: Early task alloc failed.\n", __func__); +} + +/** + * lsm_superblock_alloc - allocate a composite superblock blob + * @sb: the superblock that needs a blob + * + * Allocate the superblock blob for all the modules + * + * Returns 0, or -ENOMEM if memory can't be allocated. + */ +static int lsm_superblock_alloc(struct super_block *sb) +{ + if (blob_sizes.lbs_superblock == 0) { + sb->s_security = NULL; + return 0; + } + + sb->s_security = kzalloc(blob_sizes.lbs_superblock, GFP_KERNEL); + if (sb->s_security == NULL) + return -ENOMEM; + return 0; +} + +/* + * The default value of the LSM hook is defined in linux/lsm_hook_defs.h and + * can be accessed with: + * + * LSM_RET_DEFAULT(<hook_name>) + * + * The macros below define static constants for the default value of each + * LSM hook. + */ +#define LSM_RET_DEFAULT(NAME) (NAME##_default) +#define DECLARE_LSM_RET_DEFAULT_void(DEFAULT, NAME) +#define DECLARE_LSM_RET_DEFAULT_int(DEFAULT, NAME) \ + static const int __maybe_unused LSM_RET_DEFAULT(NAME) = (DEFAULT); +#define LSM_HOOK(RET, DEFAULT, NAME, ...) \ + DECLARE_LSM_RET_DEFAULT_##RET(DEFAULT, NAME) + +#include <linux/lsm_hook_defs.h> +#undef LSM_HOOK + +/* + * Hook list operation macros. + * + * call_void_hook: + * This is a hook that does not return a value. + * + * call_int_hook: + * This is a hook that returns a value. + */ + +#define call_void_hook(FUNC, ...) \ + do { \ + struct security_hook_list *P; \ + \ + hlist_for_each_entry(P, &security_hook_heads.FUNC, list) \ + P->hook.FUNC(__VA_ARGS__); \ + } while (0) + +#define call_int_hook(FUNC, IRC, ...) ({ \ + int RC = IRC; \ + do { \ + struct security_hook_list *P; \ + \ + hlist_for_each_entry(P, &security_hook_heads.FUNC, list) { \ + RC = P->hook.FUNC(__VA_ARGS__); \ + if (RC != 0) \ + break; \ + } \ + } while (0); \ + RC; \ +}) + +/* Security operations */ + +int security_binder_set_context_mgr(const struct cred *mgr) +{ + return call_int_hook(binder_set_context_mgr, 0, mgr); +} + +int security_binder_transaction(const struct cred *from, + const struct cred *to) +{ + return call_int_hook(binder_transaction, 0, from, to); +} + +int security_binder_transfer_binder(const struct cred *from, + const struct cred *to) +{ + return call_int_hook(binder_transfer_binder, 0, from, to); +} + +int security_binder_transfer_file(const struct cred *from, + const struct cred *to, struct file *file) +{ + return call_int_hook(binder_transfer_file, 0, from, to, file); +} + +int security_ptrace_access_check(struct task_struct *child, unsigned int mode) +{ + return call_int_hook(ptrace_access_check, 0, child, mode); +} + +int security_ptrace_traceme(struct task_struct *parent) +{ + return call_int_hook(ptrace_traceme, 0, parent); +} + +int security_capget(struct task_struct *target, + kernel_cap_t *effective, + kernel_cap_t *inheritable, + kernel_cap_t *permitted) +{ + return call_int_hook(capget, 0, target, + effective, inheritable, permitted); +} + +int security_capset(struct cred *new, const struct cred *old, + const kernel_cap_t *effective, + const kernel_cap_t *inheritable, + const kernel_cap_t *permitted) +{ + return call_int_hook(capset, 0, new, old, + effective, inheritable, permitted); +} + +int security_capable(const struct cred *cred, + struct user_namespace *ns, + int cap, + unsigned int opts) +{ + return call_int_hook(capable, 0, cred, ns, cap, opts); +} + +int security_quotactl(int cmds, int type, int id, struct super_block *sb) +{ + return call_int_hook(quotactl, 0, cmds, type, id, sb); +} + +int security_quota_on(struct dentry *dentry) +{ + return call_int_hook(quota_on, 0, dentry); +} + +int security_syslog(int type) +{ + return call_int_hook(syslog, 0, type); +} + +int security_settime64(const struct timespec64 *ts, const struct timezone *tz) +{ + return call_int_hook(settime, 0, ts, tz); +} + +int security_vm_enough_memory_mm(struct mm_struct *mm, long pages) +{ + struct security_hook_list *hp; + int cap_sys_admin = 1; + int rc; + + /* + * The module will respond with a positive value if + * it thinks the __vm_enough_memory() call should be + * made with the cap_sys_admin set. If all of the modules + * agree that it should be set it will. If any module + * thinks it should not be set it won't. + */ + hlist_for_each_entry(hp, &security_hook_heads.vm_enough_memory, list) { + rc = hp->hook.vm_enough_memory(mm, pages); + if (rc <= 0) { + cap_sys_admin = 0; + break; + } + } + return __vm_enough_memory(mm, pages, cap_sys_admin); +} + +int security_bprm_creds_for_exec(struct linux_binprm *bprm) +{ + return call_int_hook(bprm_creds_for_exec, 0, bprm); +} + +int security_bprm_creds_from_file(struct linux_binprm *bprm, struct file *file) +{ + return call_int_hook(bprm_creds_from_file, 0, bprm, file); +} + +int security_bprm_check(struct linux_binprm *bprm) +{ + int ret; + + ret = call_int_hook(bprm_check_security, 0, bprm); + if (ret) + return ret; + return ima_bprm_check(bprm); +} + +void security_bprm_committing_creds(struct linux_binprm *bprm) +{ + call_void_hook(bprm_committing_creds, bprm); +} + +void security_bprm_committed_creds(struct linux_binprm *bprm) +{ + call_void_hook(bprm_committed_creds, bprm); +} + +/** + * security_fs_context_submount() - Initialise fc->security + * @fc: new filesystem context + * @reference: dentry reference for submount/remount + * + * Fill out the ->security field for a new fs_context. + * + * Return: Returns 0 on success or negative error code on failure. + */ +int security_fs_context_submount(struct fs_context *fc, struct super_block *reference) +{ + return call_int_hook(fs_context_submount, 0, fc, reference); +} + +int security_fs_context_dup(struct fs_context *fc, struct fs_context *src_fc) +{ + return call_int_hook(fs_context_dup, 0, fc, src_fc); +} + +int security_fs_context_parse_param(struct fs_context *fc, + struct fs_parameter *param) +{ + struct security_hook_list *hp; + int trc; + int rc = -ENOPARAM; + + hlist_for_each_entry(hp, &security_hook_heads.fs_context_parse_param, + list) { + trc = hp->hook.fs_context_parse_param(fc, param); + if (trc == 0) + rc = 0; + else if (trc != -ENOPARAM) + return trc; + } + return rc; +} + +int security_sb_alloc(struct super_block *sb) +{ + int rc = lsm_superblock_alloc(sb); + + if (unlikely(rc)) + return rc; + rc = call_int_hook(sb_alloc_security, 0, sb); + if (unlikely(rc)) + security_sb_free(sb); + return rc; +} + +void security_sb_delete(struct super_block *sb) +{ + call_void_hook(sb_delete, sb); +} + +void security_sb_free(struct super_block *sb) +{ + call_void_hook(sb_free_security, sb); + kfree(sb->s_security); + sb->s_security = NULL; +} + +void security_free_mnt_opts(void **mnt_opts) +{ + if (!*mnt_opts) + return; + call_void_hook(sb_free_mnt_opts, *mnt_opts); + *mnt_opts = NULL; +} +EXPORT_SYMBOL(security_free_mnt_opts); + +int security_sb_eat_lsm_opts(char *options, void **mnt_opts) +{ + return call_int_hook(sb_eat_lsm_opts, 0, options, mnt_opts); +} +EXPORT_SYMBOL(security_sb_eat_lsm_opts); + +int security_sb_mnt_opts_compat(struct super_block *sb, + void *mnt_opts) +{ + return call_int_hook(sb_mnt_opts_compat, 0, sb, mnt_opts); +} +EXPORT_SYMBOL(security_sb_mnt_opts_compat); + +int security_sb_remount(struct super_block *sb, + void *mnt_opts) +{ + return call_int_hook(sb_remount, 0, sb, mnt_opts); +} +EXPORT_SYMBOL(security_sb_remount); + +int security_sb_kern_mount(struct super_block *sb) +{ + return call_int_hook(sb_kern_mount, 0, sb); +} + +int security_sb_show_options(struct seq_file *m, struct super_block *sb) +{ + return call_int_hook(sb_show_options, 0, m, sb); +} + +int security_sb_statfs(struct dentry *dentry) +{ + return call_int_hook(sb_statfs, 0, dentry); +} + +int security_sb_mount(const char *dev_name, const struct path *path, + const char *type, unsigned long flags, void *data) +{ + return call_int_hook(sb_mount, 0, dev_name, path, type, flags, data); +} + +int security_sb_umount(struct vfsmount *mnt, int flags) +{ + return call_int_hook(sb_umount, 0, mnt, flags); +} + +int security_sb_pivotroot(const struct path *old_path, const struct path *new_path) +{ + return call_int_hook(sb_pivotroot, 0, old_path, new_path); +} + +int security_sb_set_mnt_opts(struct super_block *sb, + void *mnt_opts, + unsigned long kern_flags, + unsigned long *set_kern_flags) +{ + return call_int_hook(sb_set_mnt_opts, + mnt_opts ? -EOPNOTSUPP : 0, sb, + mnt_opts, kern_flags, set_kern_flags); +} +EXPORT_SYMBOL(security_sb_set_mnt_opts); + +int security_sb_clone_mnt_opts(const struct super_block *oldsb, + struct super_block *newsb, + unsigned long kern_flags, + unsigned long *set_kern_flags) +{ + return call_int_hook(sb_clone_mnt_opts, 0, oldsb, newsb, + kern_flags, set_kern_flags); +} +EXPORT_SYMBOL(security_sb_clone_mnt_opts); + +int security_move_mount(const struct path *from_path, const struct path *to_path) +{ + return call_int_hook(move_mount, 0, from_path, to_path); +} + +int security_path_notify(const struct path *path, u64 mask, + unsigned int obj_type) +{ + return call_int_hook(path_notify, 0, path, mask, obj_type); +} + +int security_inode_alloc(struct inode *inode) +{ + int rc = lsm_inode_alloc(inode); + + if (unlikely(rc)) + return rc; + rc = call_int_hook(inode_alloc_security, 0, inode); + if (unlikely(rc)) + security_inode_free(inode); + return rc; +} + +static void inode_free_by_rcu(struct rcu_head *head) +{ + /* + * The rcu head is at the start of the inode blob + */ + kmem_cache_free(lsm_inode_cache, head); +} + +void security_inode_free(struct inode *inode) +{ + integrity_inode_free(inode); + call_void_hook(inode_free_security, inode); + /* + * The inode may still be referenced in a path walk and + * a call to security_inode_permission() can be made + * after inode_free_security() is called. Ideally, the VFS + * wouldn't do this, but fixing that is a much harder + * job. For now, simply free the i_security via RCU, and + * leave the current inode->i_security pointer intact. + * The inode will be freed after the RCU grace period too. + */ + if (inode->i_security) + call_rcu((struct rcu_head *)inode->i_security, + inode_free_by_rcu); +} + +int security_dentry_init_security(struct dentry *dentry, int mode, + const struct qstr *name, + const char **xattr_name, void **ctx, + u32 *ctxlen) +{ + struct security_hook_list *hp; + int rc; + + /* + * Only one module will provide a security context. + */ + hlist_for_each_entry(hp, &security_hook_heads.dentry_init_security, list) { + rc = hp->hook.dentry_init_security(dentry, mode, name, + xattr_name, ctx, ctxlen); + if (rc != LSM_RET_DEFAULT(dentry_init_security)) + return rc; + } + return LSM_RET_DEFAULT(dentry_init_security); +} +EXPORT_SYMBOL(security_dentry_init_security); + +int security_dentry_create_files_as(struct dentry *dentry, int mode, + struct qstr *name, + const struct cred *old, struct cred *new) +{ + return call_int_hook(dentry_create_files_as, 0, dentry, mode, + name, old, new); +} +EXPORT_SYMBOL(security_dentry_create_files_as); + +int security_inode_init_security(struct inode *inode, struct inode *dir, + const struct qstr *qstr, + const initxattrs initxattrs, void *fs_data) +{ + struct xattr new_xattrs[MAX_LSM_EVM_XATTR + 1]; + struct xattr *lsm_xattr, *evm_xattr, *xattr; + int ret; + + if (unlikely(IS_PRIVATE(inode))) + return 0; + + if (!initxattrs) + return call_int_hook(inode_init_security, -EOPNOTSUPP, inode, + dir, qstr, NULL, NULL, NULL); + memset(new_xattrs, 0, sizeof(new_xattrs)); + lsm_xattr = new_xattrs; + ret = call_int_hook(inode_init_security, -EOPNOTSUPP, inode, dir, qstr, + &lsm_xattr->name, + &lsm_xattr->value, + &lsm_xattr->value_len); + if (ret) + goto out; + + evm_xattr = lsm_xattr + 1; + ret = evm_inode_init_security(inode, lsm_xattr, evm_xattr); + if (ret) + goto out; + ret = initxattrs(inode, new_xattrs, fs_data); +out: + for (xattr = new_xattrs; xattr->value != NULL; xattr++) + kfree(xattr->value); + return (ret == -EOPNOTSUPP) ? 0 : ret; +} +EXPORT_SYMBOL(security_inode_init_security); + +int security_inode_init_security_anon(struct inode *inode, + const struct qstr *name, + const struct inode *context_inode) +{ + return call_int_hook(inode_init_security_anon, 0, inode, name, + context_inode); +} + +int security_old_inode_init_security(struct inode *inode, struct inode *dir, + const struct qstr *qstr, const char **name, + void **value, size_t *len) +{ + if (unlikely(IS_PRIVATE(inode))) + return -EOPNOTSUPP; + return call_int_hook(inode_init_security, -EOPNOTSUPP, inode, dir, + qstr, name, value, len); +} +EXPORT_SYMBOL(security_old_inode_init_security); + +#ifdef CONFIG_SECURITY_PATH +int security_path_mknod(const struct path *dir, struct dentry *dentry, umode_t mode, + unsigned int dev) +{ + if (unlikely(IS_PRIVATE(d_backing_inode(dir->dentry)))) + return 0; + return call_int_hook(path_mknod, 0, dir, dentry, mode, dev); +} +EXPORT_SYMBOL(security_path_mknod); + +int security_path_mkdir(const struct path *dir, struct dentry *dentry, umode_t mode) +{ + if (unlikely(IS_PRIVATE(d_backing_inode(dir->dentry)))) + return 0; + return call_int_hook(path_mkdir, 0, dir, dentry, mode); +} +EXPORT_SYMBOL(security_path_mkdir); + +int security_path_rmdir(const struct path *dir, struct dentry *dentry) +{ + if (unlikely(IS_PRIVATE(d_backing_inode(dir->dentry)))) + return 0; + return call_int_hook(path_rmdir, 0, dir, dentry); +} + +int security_path_unlink(const struct path *dir, struct dentry *dentry) +{ + if (unlikely(IS_PRIVATE(d_backing_inode(dir->dentry)))) + return 0; + return call_int_hook(path_unlink, 0, dir, dentry); +} +EXPORT_SYMBOL(security_path_unlink); + +int security_path_symlink(const struct path *dir, struct dentry *dentry, + const char *old_name) +{ + if (unlikely(IS_PRIVATE(d_backing_inode(dir->dentry)))) + return 0; + return call_int_hook(path_symlink, 0, dir, dentry, old_name); +} + +int security_path_link(struct dentry *old_dentry, const struct path *new_dir, + struct dentry *new_dentry) +{ + if (unlikely(IS_PRIVATE(d_backing_inode(old_dentry)))) + return 0; + return call_int_hook(path_link, 0, old_dentry, new_dir, new_dentry); +} + +int security_path_rename(const struct path *old_dir, struct dentry *old_dentry, + const struct path *new_dir, struct dentry *new_dentry, + unsigned int flags) +{ + if (unlikely(IS_PRIVATE(d_backing_inode(old_dentry)) || + (d_is_positive(new_dentry) && IS_PRIVATE(d_backing_inode(new_dentry))))) + return 0; + + return call_int_hook(path_rename, 0, old_dir, old_dentry, new_dir, + new_dentry, flags); +} +EXPORT_SYMBOL(security_path_rename); + +int security_path_truncate(const struct path *path) +{ + if (unlikely(IS_PRIVATE(d_backing_inode(path->dentry)))) + return 0; + return call_int_hook(path_truncate, 0, path); +} + +int security_path_chmod(const struct path *path, umode_t mode) +{ + if (unlikely(IS_PRIVATE(d_backing_inode(path->dentry)))) + return 0; + return call_int_hook(path_chmod, 0, path, mode); +} + +int security_path_chown(const struct path *path, kuid_t uid, kgid_t gid) +{ + if (unlikely(IS_PRIVATE(d_backing_inode(path->dentry)))) + return 0; + return call_int_hook(path_chown, 0, path, uid, gid); +} + +int security_path_chroot(const struct path *path) +{ + return call_int_hook(path_chroot, 0, path); +} +#endif + +int security_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode) +{ + if (unlikely(IS_PRIVATE(dir))) + return 0; + return call_int_hook(inode_create, 0, dir, dentry, mode); +} +EXPORT_SYMBOL_GPL(security_inode_create); + +int security_inode_link(struct dentry *old_dentry, struct inode *dir, + struct dentry *new_dentry) +{ + if (unlikely(IS_PRIVATE(d_backing_inode(old_dentry)))) + return 0; + return call_int_hook(inode_link, 0, old_dentry, dir, new_dentry); +} + +int security_inode_unlink(struct inode *dir, struct dentry *dentry) +{ + if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) + return 0; + return call_int_hook(inode_unlink, 0, dir, dentry); +} + +int security_inode_symlink(struct inode *dir, struct dentry *dentry, + const char *old_name) +{ + if (unlikely(IS_PRIVATE(dir))) + return 0; + return call_int_hook(inode_symlink, 0, dir, dentry, old_name); +} + +int security_inode_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) +{ + if (unlikely(IS_PRIVATE(dir))) + return 0; + return call_int_hook(inode_mkdir, 0, dir, dentry, mode); +} +EXPORT_SYMBOL_GPL(security_inode_mkdir); + +int security_inode_rmdir(struct inode *dir, struct dentry *dentry) +{ + if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) + return 0; + return call_int_hook(inode_rmdir, 0, dir, dentry); +} + +int security_inode_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) +{ + if (unlikely(IS_PRIVATE(dir))) + return 0; + return call_int_hook(inode_mknod, 0, dir, dentry, mode, dev); +} + +int security_inode_rename(struct inode *old_dir, struct dentry *old_dentry, + struct inode *new_dir, struct dentry *new_dentry, + unsigned int flags) +{ + if (unlikely(IS_PRIVATE(d_backing_inode(old_dentry)) || + (d_is_positive(new_dentry) && IS_PRIVATE(d_backing_inode(new_dentry))))) + return 0; + + if (flags & RENAME_EXCHANGE) { + int err = call_int_hook(inode_rename, 0, new_dir, new_dentry, + old_dir, old_dentry); + if (err) + return err; + } + + return call_int_hook(inode_rename, 0, old_dir, old_dentry, + new_dir, new_dentry); +} + +int security_inode_readlink(struct dentry *dentry) +{ + if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) + return 0; + return call_int_hook(inode_readlink, 0, dentry); +} + +int security_inode_follow_link(struct dentry *dentry, struct inode *inode, + bool rcu) +{ + if (unlikely(IS_PRIVATE(inode))) + return 0; + return call_int_hook(inode_follow_link, 0, dentry, inode, rcu); +} + +int security_inode_permission(struct inode *inode, int mask) +{ + if (unlikely(IS_PRIVATE(inode))) + return 0; + return call_int_hook(inode_permission, 0, inode, mask); +} + +int security_inode_setattr(struct user_namespace *mnt_userns, + struct dentry *dentry, struct iattr *attr) +{ + int ret; + + if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) + return 0; + ret = call_int_hook(inode_setattr, 0, dentry, attr); + if (ret) + return ret; + return evm_inode_setattr(mnt_userns, dentry, attr); +} +EXPORT_SYMBOL_GPL(security_inode_setattr); + +int security_inode_getattr(const struct path *path) +{ + if (unlikely(IS_PRIVATE(d_backing_inode(path->dentry)))) + return 0; + return call_int_hook(inode_getattr, 0, path); +} + +int security_inode_setxattr(struct user_namespace *mnt_userns, + struct dentry *dentry, const char *name, + const void *value, size_t size, int flags) +{ + int ret; + + if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) + return 0; + /* + * SELinux and Smack integrate the cap call, + * so assume that all LSMs supplying this call do so. + */ + ret = call_int_hook(inode_setxattr, 1, mnt_userns, dentry, name, value, + size, flags); + + if (ret == 1) + ret = cap_inode_setxattr(dentry, name, value, size, flags); + if (ret) + return ret; + ret = ima_inode_setxattr(dentry, name, value, size); + if (ret) + return ret; + return evm_inode_setxattr(mnt_userns, dentry, name, value, size); +} + +void security_inode_post_setxattr(struct dentry *dentry, const char *name, + const void *value, size_t size, int flags) +{ + if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) + return; + call_void_hook(inode_post_setxattr, dentry, name, value, size, flags); + evm_inode_post_setxattr(dentry, name, value, size); +} + +int security_inode_getxattr(struct dentry *dentry, const char *name) +{ + if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) + return 0; + return call_int_hook(inode_getxattr, 0, dentry, name); +} + +int security_inode_listxattr(struct dentry *dentry) +{ + if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) + return 0; + return call_int_hook(inode_listxattr, 0, dentry); +} + +int security_inode_removexattr(struct user_namespace *mnt_userns, + struct dentry *dentry, const char *name) +{ + int ret; + + if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) + return 0; + /* + * SELinux and Smack integrate the cap call, + * so assume that all LSMs supplying this call do so. + */ + ret = call_int_hook(inode_removexattr, 1, mnt_userns, dentry, name); + if (ret == 1) + ret = cap_inode_removexattr(mnt_userns, dentry, name); + if (ret) + return ret; + ret = ima_inode_removexattr(dentry, name); + if (ret) + return ret; + return evm_inode_removexattr(mnt_userns, dentry, name); +} + +int security_inode_need_killpriv(struct dentry *dentry) +{ + return call_int_hook(inode_need_killpriv, 0, dentry); +} + +int security_inode_killpriv(struct user_namespace *mnt_userns, + struct dentry *dentry) +{ + return call_int_hook(inode_killpriv, 0, mnt_userns, dentry); +} + +int security_inode_getsecurity(struct user_namespace *mnt_userns, + struct inode *inode, const char *name, + void **buffer, bool alloc) +{ + struct security_hook_list *hp; + int rc; + + if (unlikely(IS_PRIVATE(inode))) + return LSM_RET_DEFAULT(inode_getsecurity); + /* + * Only one module will provide an attribute with a given name. + */ + hlist_for_each_entry(hp, &security_hook_heads.inode_getsecurity, list) { + rc = hp->hook.inode_getsecurity(mnt_userns, inode, name, buffer, alloc); + if (rc != LSM_RET_DEFAULT(inode_getsecurity)) + return rc; + } + return LSM_RET_DEFAULT(inode_getsecurity); +} + +int security_inode_setsecurity(struct inode *inode, const char *name, const void *value, size_t size, int flags) +{ + struct security_hook_list *hp; + int rc; + + if (unlikely(IS_PRIVATE(inode))) + return LSM_RET_DEFAULT(inode_setsecurity); + /* + * Only one module will provide an attribute with a given name. + */ + hlist_for_each_entry(hp, &security_hook_heads.inode_setsecurity, list) { + rc = hp->hook.inode_setsecurity(inode, name, value, size, + flags); + if (rc != LSM_RET_DEFAULT(inode_setsecurity)) + return rc; + } + return LSM_RET_DEFAULT(inode_setsecurity); +} + +int security_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size) +{ + if (unlikely(IS_PRIVATE(inode))) + return 0; + return call_int_hook(inode_listsecurity, 0, inode, buffer, buffer_size); +} +EXPORT_SYMBOL(security_inode_listsecurity); + +void security_inode_getsecid(struct inode *inode, u32 *secid) +{ + call_void_hook(inode_getsecid, inode, secid); +} + +int security_inode_copy_up(struct dentry *src, struct cred **new) +{ + return call_int_hook(inode_copy_up, 0, src, new); +} +EXPORT_SYMBOL(security_inode_copy_up); + +int security_inode_copy_up_xattr(const char *name) +{ + struct security_hook_list *hp; + int rc; + + /* + * The implementation can return 0 (accept the xattr), 1 (discard the + * xattr), -EOPNOTSUPP if it does not know anything about the xattr or + * any other error code incase of an error. + */ + hlist_for_each_entry(hp, + &security_hook_heads.inode_copy_up_xattr, list) { + rc = hp->hook.inode_copy_up_xattr(name); + if (rc != LSM_RET_DEFAULT(inode_copy_up_xattr)) + return rc; + } + + return LSM_RET_DEFAULT(inode_copy_up_xattr); +} +EXPORT_SYMBOL(security_inode_copy_up_xattr); + +int security_kernfs_init_security(struct kernfs_node *kn_dir, + struct kernfs_node *kn) +{ + return call_int_hook(kernfs_init_security, 0, kn_dir, kn); +} + +int security_file_permission(struct file *file, int mask) +{ + int ret; + + ret = call_int_hook(file_permission, 0, file, mask); + if (ret) + return ret; + + return fsnotify_perm(file, mask); +} + +int security_file_alloc(struct file *file) +{ + int rc = lsm_file_alloc(file); + + if (rc) + return rc; + rc = call_int_hook(file_alloc_security, 0, file); + if (unlikely(rc)) + security_file_free(file); + return rc; +} + +void security_file_free(struct file *file) +{ + void *blob; + + call_void_hook(file_free_security, file); + + blob = file->f_security; + if (blob) { + file->f_security = NULL; + kmem_cache_free(lsm_file_cache, blob); + } +} + +int security_file_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + return call_int_hook(file_ioctl, 0, file, cmd, arg); +} +EXPORT_SYMBOL_GPL(security_file_ioctl); + +/** + * security_file_ioctl_compat() - Check if an ioctl is allowed in compat mode + * @file: associated file + * @cmd: ioctl cmd + * @arg: ioctl arguments + * + * Compat version of security_file_ioctl() that correctly handles 32-bit + * processes running on 64-bit kernels. + * + * Return: Returns 0 if permission is granted. + */ +int security_file_ioctl_compat(struct file *file, unsigned int cmd, + unsigned long arg) +{ + return call_int_hook(file_ioctl_compat, 0, file, cmd, arg); +} +EXPORT_SYMBOL_GPL(security_file_ioctl_compat); + +static inline unsigned long mmap_prot(struct file *file, unsigned long prot) +{ + /* + * Does we have PROT_READ and does the application expect + * it to imply PROT_EXEC? If not, nothing to talk about... + */ + if ((prot & (PROT_READ | PROT_EXEC)) != PROT_READ) + return prot; + if (!(current->personality & READ_IMPLIES_EXEC)) + return prot; + /* + * if that's an anonymous mapping, let it. + */ + if (!file) + return prot | PROT_EXEC; + /* + * ditto if it's not on noexec mount, except that on !MMU we need + * NOMMU_MAP_EXEC (== VM_MAYEXEC) in this case + */ + if (!path_noexec(&file->f_path)) { +#ifndef CONFIG_MMU + if (file->f_op->mmap_capabilities) { + unsigned caps = file->f_op->mmap_capabilities(file); + if (!(caps & NOMMU_MAP_EXEC)) + return prot; + } +#endif + return prot | PROT_EXEC; + } + /* anything on noexec mount won't get PROT_EXEC */ + return prot; +} + +int security_mmap_file(struct file *file, unsigned long prot, + unsigned long flags) +{ + unsigned long prot_adj = mmap_prot(file, prot); + int ret; + + ret = call_int_hook(mmap_file, 0, file, prot, prot_adj, flags); + if (ret) + return ret; + return ima_file_mmap(file, prot, prot_adj, flags); +} + +int security_mmap_addr(unsigned long addr) +{ + return call_int_hook(mmap_addr, 0, addr); +} + +int security_file_mprotect(struct vm_area_struct *vma, unsigned long reqprot, + unsigned long prot) +{ + int ret; + + ret = call_int_hook(file_mprotect, 0, vma, reqprot, prot); + if (ret) + return ret; + return ima_file_mprotect(vma, prot); +} + +int security_file_lock(struct file *file, unsigned int cmd) +{ + return call_int_hook(file_lock, 0, file, cmd); +} + +int security_file_fcntl(struct file *file, unsigned int cmd, unsigned long arg) +{ + return call_int_hook(file_fcntl, 0, file, cmd, arg); +} + +void security_file_set_fowner(struct file *file) +{ + call_void_hook(file_set_fowner, file); +} + +int security_file_send_sigiotask(struct task_struct *tsk, + struct fown_struct *fown, int sig) +{ + return call_int_hook(file_send_sigiotask, 0, tsk, fown, sig); +} + +int security_file_receive(struct file *file) +{ + return call_int_hook(file_receive, 0, file); +} + +int security_file_open(struct file *file) +{ + int ret; + + ret = call_int_hook(file_open, 0, file); + if (ret) + return ret; + + return fsnotify_perm(file, MAY_OPEN); +} + +int security_task_alloc(struct task_struct *task, unsigned long clone_flags) +{ + int rc = lsm_task_alloc(task); + + if (rc) + return rc; + rc = call_int_hook(task_alloc, 0, task, clone_flags); + if (unlikely(rc)) + security_task_free(task); + return rc; +} + +void security_task_free(struct task_struct *task) +{ + call_void_hook(task_free, task); + + kfree(task->security); + task->security = NULL; +} + +int security_cred_alloc_blank(struct cred *cred, gfp_t gfp) +{ + int rc = lsm_cred_alloc(cred, gfp); + + if (rc) + return rc; + + rc = call_int_hook(cred_alloc_blank, 0, cred, gfp); + if (unlikely(rc)) + security_cred_free(cred); + return rc; +} + +void security_cred_free(struct cred *cred) +{ + /* + * There is a failure case in prepare_creds() that + * may result in a call here with ->security being NULL. + */ + if (unlikely(cred->security == NULL)) + return; + + call_void_hook(cred_free, cred); + + kfree(cred->security); + cred->security = NULL; +} + +int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp) +{ + int rc = lsm_cred_alloc(new, gfp); + + if (rc) + return rc; + + rc = call_int_hook(cred_prepare, 0, new, old, gfp); + if (unlikely(rc)) + security_cred_free(new); + return rc; +} + +void security_transfer_creds(struct cred *new, const struct cred *old) +{ + call_void_hook(cred_transfer, new, old); +} + +void security_cred_getsecid(const struct cred *c, u32 *secid) +{ + *secid = 0; + call_void_hook(cred_getsecid, c, secid); +} +EXPORT_SYMBOL(security_cred_getsecid); + +int security_kernel_act_as(struct cred *new, u32 secid) +{ + return call_int_hook(kernel_act_as, 0, new, secid); +} + +int security_kernel_create_files_as(struct cred *new, struct inode *inode) +{ + return call_int_hook(kernel_create_files_as, 0, new, inode); +} + +int security_kernel_module_request(char *kmod_name) +{ + int ret; + + ret = call_int_hook(kernel_module_request, 0, kmod_name); + if (ret) + return ret; + return integrity_kernel_module_request(kmod_name); +} + +int security_kernel_read_file(struct file *file, enum kernel_read_file_id id, + bool contents) +{ + int ret; + + ret = call_int_hook(kernel_read_file, 0, file, id, contents); + if (ret) + return ret; + return ima_read_file(file, id, contents); +} +EXPORT_SYMBOL_GPL(security_kernel_read_file); + +int security_kernel_post_read_file(struct file *file, char *buf, loff_t size, + enum kernel_read_file_id id) +{ + int ret; + + ret = call_int_hook(kernel_post_read_file, 0, file, buf, size, id); + if (ret) + return ret; + return ima_post_read_file(file, buf, size, id); +} +EXPORT_SYMBOL_GPL(security_kernel_post_read_file); + +int security_kernel_load_data(enum kernel_load_data_id id, bool contents) +{ + int ret; + + ret = call_int_hook(kernel_load_data, 0, id, contents); + if (ret) + return ret; + return ima_load_data(id, contents); +} +EXPORT_SYMBOL_GPL(security_kernel_load_data); + +int security_kernel_post_load_data(char *buf, loff_t size, + enum kernel_load_data_id id, + char *description) +{ + int ret; + + ret = call_int_hook(kernel_post_load_data, 0, buf, size, id, + description); + if (ret) + return ret; + return ima_post_load_data(buf, size, id, description); +} +EXPORT_SYMBOL_GPL(security_kernel_post_load_data); + +int security_task_fix_setuid(struct cred *new, const struct cred *old, + int flags) +{ + return call_int_hook(task_fix_setuid, 0, new, old, flags); +} + +int security_task_fix_setgid(struct cred *new, const struct cred *old, + int flags) +{ + return call_int_hook(task_fix_setgid, 0, new, old, flags); +} + +int security_task_fix_setgroups(struct cred *new, const struct cred *old) +{ + return call_int_hook(task_fix_setgroups, 0, new, old); +} + +int security_task_setpgid(struct task_struct *p, pid_t pgid) +{ + return call_int_hook(task_setpgid, 0, p, pgid); +} + +int security_task_getpgid(struct task_struct *p) +{ + return call_int_hook(task_getpgid, 0, p); +} + +int security_task_getsid(struct task_struct *p) +{ + return call_int_hook(task_getsid, 0, p); +} + +void security_current_getsecid_subj(u32 *secid) +{ + *secid = 0; + call_void_hook(current_getsecid_subj, secid); +} +EXPORT_SYMBOL(security_current_getsecid_subj); + +void security_task_getsecid_obj(struct task_struct *p, u32 *secid) +{ + *secid = 0; + call_void_hook(task_getsecid_obj, p, secid); +} +EXPORT_SYMBOL(security_task_getsecid_obj); + +int security_task_setnice(struct task_struct *p, int nice) +{ + return call_int_hook(task_setnice, 0, p, nice); +} + +int security_task_setioprio(struct task_struct *p, int ioprio) +{ + return call_int_hook(task_setioprio, 0, p, ioprio); +} + +int security_task_getioprio(struct task_struct *p) +{ + return call_int_hook(task_getioprio, 0, p); +} + +int security_task_prlimit(const struct cred *cred, const struct cred *tcred, + unsigned int flags) +{ + return call_int_hook(task_prlimit, 0, cred, tcred, flags); +} + +int security_task_setrlimit(struct task_struct *p, unsigned int resource, + struct rlimit *new_rlim) +{ + return call_int_hook(task_setrlimit, 0, p, resource, new_rlim); +} + +int security_task_setscheduler(struct task_struct *p) +{ + return call_int_hook(task_setscheduler, 0, p); +} + +int security_task_getscheduler(struct task_struct *p) +{ + return call_int_hook(task_getscheduler, 0, p); +} + +int security_task_movememory(struct task_struct *p) +{ + return call_int_hook(task_movememory, 0, p); +} + +int security_task_kill(struct task_struct *p, struct kernel_siginfo *info, + int sig, const struct cred *cred) +{ + return call_int_hook(task_kill, 0, p, info, sig, cred); +} + +int security_task_prctl(int option, unsigned long arg2, unsigned long arg3, + unsigned long arg4, unsigned long arg5) +{ + int thisrc; + int rc = LSM_RET_DEFAULT(task_prctl); + struct security_hook_list *hp; + + hlist_for_each_entry(hp, &security_hook_heads.task_prctl, list) { + thisrc = hp->hook.task_prctl(option, arg2, arg3, arg4, arg5); + if (thisrc != LSM_RET_DEFAULT(task_prctl)) { + rc = thisrc; + if (thisrc != 0) + break; + } + } + return rc; +} + +void security_task_to_inode(struct task_struct *p, struct inode *inode) +{ + call_void_hook(task_to_inode, p, inode); +} + +int security_create_user_ns(const struct cred *cred) +{ + return call_int_hook(userns_create, 0, cred); +} + +int security_ipc_permission(struct kern_ipc_perm *ipcp, short flag) +{ + return call_int_hook(ipc_permission, 0, ipcp, flag); +} + +void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid) +{ + *secid = 0; + call_void_hook(ipc_getsecid, ipcp, secid); +} + +int security_msg_msg_alloc(struct msg_msg *msg) +{ + int rc = lsm_msg_msg_alloc(msg); + + if (unlikely(rc)) + return rc; + rc = call_int_hook(msg_msg_alloc_security, 0, msg); + if (unlikely(rc)) + security_msg_msg_free(msg); + return rc; +} + +void security_msg_msg_free(struct msg_msg *msg) +{ + call_void_hook(msg_msg_free_security, msg); + kfree(msg->security); + msg->security = NULL; +} + +int security_msg_queue_alloc(struct kern_ipc_perm *msq) +{ + int rc = lsm_ipc_alloc(msq); + + if (unlikely(rc)) + return rc; + rc = call_int_hook(msg_queue_alloc_security, 0, msq); + if (unlikely(rc)) + security_msg_queue_free(msq); + return rc; +} + +void security_msg_queue_free(struct kern_ipc_perm *msq) +{ + call_void_hook(msg_queue_free_security, msq); + kfree(msq->security); + msq->security = NULL; +} + +int security_msg_queue_associate(struct kern_ipc_perm *msq, int msqflg) +{ + return call_int_hook(msg_queue_associate, 0, msq, msqflg); +} + +int security_msg_queue_msgctl(struct kern_ipc_perm *msq, int cmd) +{ + return call_int_hook(msg_queue_msgctl, 0, msq, cmd); +} + +int security_msg_queue_msgsnd(struct kern_ipc_perm *msq, + struct msg_msg *msg, int msqflg) +{ + return call_int_hook(msg_queue_msgsnd, 0, msq, msg, msqflg); +} + +int security_msg_queue_msgrcv(struct kern_ipc_perm *msq, struct msg_msg *msg, + struct task_struct *target, long type, int mode) +{ + return call_int_hook(msg_queue_msgrcv, 0, msq, msg, target, type, mode); +} + +int security_shm_alloc(struct kern_ipc_perm *shp) +{ + int rc = lsm_ipc_alloc(shp); + + if (unlikely(rc)) + return rc; + rc = call_int_hook(shm_alloc_security, 0, shp); + if (unlikely(rc)) + security_shm_free(shp); + return rc; +} + +void security_shm_free(struct kern_ipc_perm *shp) +{ + call_void_hook(shm_free_security, shp); + kfree(shp->security); + shp->security = NULL; +} + +int security_shm_associate(struct kern_ipc_perm *shp, int shmflg) +{ + return call_int_hook(shm_associate, 0, shp, shmflg); +} + +int security_shm_shmctl(struct kern_ipc_perm *shp, int cmd) +{ + return call_int_hook(shm_shmctl, 0, shp, cmd); +} + +int security_shm_shmat(struct kern_ipc_perm *shp, char __user *shmaddr, int shmflg) +{ + return call_int_hook(shm_shmat, 0, shp, shmaddr, shmflg); +} + +int security_sem_alloc(struct kern_ipc_perm *sma) +{ + int rc = lsm_ipc_alloc(sma); + + if (unlikely(rc)) + return rc; + rc = call_int_hook(sem_alloc_security, 0, sma); + if (unlikely(rc)) + security_sem_free(sma); + return rc; +} + +void security_sem_free(struct kern_ipc_perm *sma) +{ + call_void_hook(sem_free_security, sma); + kfree(sma->security); + sma->security = NULL; +} + +int security_sem_associate(struct kern_ipc_perm *sma, int semflg) +{ + return call_int_hook(sem_associate, 0, sma, semflg); +} + +int security_sem_semctl(struct kern_ipc_perm *sma, int cmd) +{ + return call_int_hook(sem_semctl, 0, sma, cmd); +} + +int security_sem_semop(struct kern_ipc_perm *sma, struct sembuf *sops, + unsigned nsops, int alter) +{ + return call_int_hook(sem_semop, 0, sma, sops, nsops, alter); +} + +void security_d_instantiate(struct dentry *dentry, struct inode *inode) +{ + if (unlikely(inode && IS_PRIVATE(inode))) + return; + call_void_hook(d_instantiate, dentry, inode); +} +EXPORT_SYMBOL(security_d_instantiate); + +int security_getprocattr(struct task_struct *p, const char *lsm, + const char *name, char **value) +{ + struct security_hook_list *hp; + + hlist_for_each_entry(hp, &security_hook_heads.getprocattr, list) { + if (lsm != NULL && strcmp(lsm, hp->lsm)) + continue; + return hp->hook.getprocattr(p, name, value); + } + return LSM_RET_DEFAULT(getprocattr); +} + +int security_setprocattr(const char *lsm, const char *name, void *value, + size_t size) +{ + struct security_hook_list *hp; + + hlist_for_each_entry(hp, &security_hook_heads.setprocattr, list) { + if (lsm != NULL && strcmp(lsm, hp->lsm)) + continue; + return hp->hook.setprocattr(name, value, size); + } + return LSM_RET_DEFAULT(setprocattr); +} + +int security_netlink_send(struct sock *sk, struct sk_buff *skb) +{ + return call_int_hook(netlink_send, 0, sk, skb); +} + +int security_ismaclabel(const char *name) +{ + return call_int_hook(ismaclabel, 0, name); +} +EXPORT_SYMBOL(security_ismaclabel); + +int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) +{ + struct security_hook_list *hp; + int rc; + + /* + * Currently, only one LSM can implement secid_to_secctx (i.e this + * LSM hook is not "stackable"). + */ + hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list) { + rc = hp->hook.secid_to_secctx(secid, secdata, seclen); + if (rc != LSM_RET_DEFAULT(secid_to_secctx)) + return rc; + } + + return LSM_RET_DEFAULT(secid_to_secctx); +} +EXPORT_SYMBOL(security_secid_to_secctx); + +int security_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid) +{ + *secid = 0; + return call_int_hook(secctx_to_secid, 0, secdata, seclen, secid); +} +EXPORT_SYMBOL(security_secctx_to_secid); + +void security_release_secctx(char *secdata, u32 seclen) +{ + call_void_hook(release_secctx, secdata, seclen); +} +EXPORT_SYMBOL(security_release_secctx); + +void security_inode_invalidate_secctx(struct inode *inode) +{ + call_void_hook(inode_invalidate_secctx, inode); +} +EXPORT_SYMBOL(security_inode_invalidate_secctx); + +int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen) +{ + return call_int_hook(inode_notifysecctx, 0, inode, ctx, ctxlen); +} +EXPORT_SYMBOL(security_inode_notifysecctx); + +int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen) +{ + return call_int_hook(inode_setsecctx, 0, dentry, ctx, ctxlen); +} +EXPORT_SYMBOL(security_inode_setsecctx); + +int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen) +{ + return call_int_hook(inode_getsecctx, -EOPNOTSUPP, inode, ctx, ctxlen); +} +EXPORT_SYMBOL(security_inode_getsecctx); + +#ifdef CONFIG_WATCH_QUEUE +int security_post_notification(const struct cred *w_cred, + const struct cred *cred, + struct watch_notification *n) +{ + return call_int_hook(post_notification, 0, w_cred, cred, n); +} +#endif /* CONFIG_WATCH_QUEUE */ + +#ifdef CONFIG_KEY_NOTIFICATIONS +int security_watch_key(struct key *key) +{ + return call_int_hook(watch_key, 0, key); +} +#endif + +#ifdef CONFIG_SECURITY_NETWORK + +int security_unix_stream_connect(struct sock *sock, struct sock *other, struct sock *newsk) +{ + return call_int_hook(unix_stream_connect, 0, sock, other, newsk); +} +EXPORT_SYMBOL(security_unix_stream_connect); + +int security_unix_may_send(struct socket *sock, struct socket *other) +{ + return call_int_hook(unix_may_send, 0, sock, other); +} +EXPORT_SYMBOL(security_unix_may_send); + +int security_socket_create(int family, int type, int protocol, int kern) +{ + return call_int_hook(socket_create, 0, family, type, protocol, kern); +} + +int security_socket_post_create(struct socket *sock, int family, + int type, int protocol, int kern) +{ + return call_int_hook(socket_post_create, 0, sock, family, type, + protocol, kern); +} + +int security_socket_socketpair(struct socket *socka, struct socket *sockb) +{ + return call_int_hook(socket_socketpair, 0, socka, sockb); +} +EXPORT_SYMBOL(security_socket_socketpair); + +int security_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen) +{ + return call_int_hook(socket_bind, 0, sock, address, addrlen); +} + +int security_socket_connect(struct socket *sock, struct sockaddr *address, int addrlen) +{ + return call_int_hook(socket_connect, 0, sock, address, addrlen); +} + +int security_socket_listen(struct socket *sock, int backlog) +{ + return call_int_hook(socket_listen, 0, sock, backlog); +} + +int security_socket_accept(struct socket *sock, struct socket *newsock) +{ + return call_int_hook(socket_accept, 0, sock, newsock); +} + +int security_socket_sendmsg(struct socket *sock, struct msghdr *msg, int size) +{ + return call_int_hook(socket_sendmsg, 0, sock, msg, size); +} + +int security_socket_recvmsg(struct socket *sock, struct msghdr *msg, + int size, int flags) +{ + return call_int_hook(socket_recvmsg, 0, sock, msg, size, flags); +} + +int security_socket_getsockname(struct socket *sock) +{ + return call_int_hook(socket_getsockname, 0, sock); +} + +int security_socket_getpeername(struct socket *sock) +{ + return call_int_hook(socket_getpeername, 0, sock); +} + +int security_socket_getsockopt(struct socket *sock, int level, int optname) +{ + return call_int_hook(socket_getsockopt, 0, sock, level, optname); +} + +int security_socket_setsockopt(struct socket *sock, int level, int optname) +{ + return call_int_hook(socket_setsockopt, 0, sock, level, optname); +} + +int security_socket_shutdown(struct socket *sock, int how) +{ + return call_int_hook(socket_shutdown, 0, sock, how); +} + +int security_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) +{ + return call_int_hook(socket_sock_rcv_skb, 0, sk, skb); +} +EXPORT_SYMBOL(security_sock_rcv_skb); + +int security_socket_getpeersec_stream(struct socket *sock, char __user *optval, + int __user *optlen, unsigned len) +{ + return call_int_hook(socket_getpeersec_stream, -ENOPROTOOPT, sock, + optval, optlen, len); +} + +int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid) +{ + return call_int_hook(socket_getpeersec_dgram, -ENOPROTOOPT, sock, + skb, secid); +} +EXPORT_SYMBOL(security_socket_getpeersec_dgram); + +int security_sk_alloc(struct sock *sk, int family, gfp_t priority) +{ + return call_int_hook(sk_alloc_security, 0, sk, family, priority); +} + +void security_sk_free(struct sock *sk) +{ + call_void_hook(sk_free_security, sk); +} + +void security_sk_clone(const struct sock *sk, struct sock *newsk) +{ + call_void_hook(sk_clone_security, sk, newsk); +} +EXPORT_SYMBOL(security_sk_clone); + +void security_sk_classify_flow(struct sock *sk, struct flowi_common *flic) +{ + call_void_hook(sk_getsecid, sk, &flic->flowic_secid); +} +EXPORT_SYMBOL(security_sk_classify_flow); + +void security_req_classify_flow(const struct request_sock *req, + struct flowi_common *flic) +{ + call_void_hook(req_classify_flow, req, flic); +} +EXPORT_SYMBOL(security_req_classify_flow); + +void security_sock_graft(struct sock *sk, struct socket *parent) +{ + call_void_hook(sock_graft, sk, parent); +} +EXPORT_SYMBOL(security_sock_graft); + +int security_inet_conn_request(const struct sock *sk, + struct sk_buff *skb, struct request_sock *req) +{ + return call_int_hook(inet_conn_request, 0, sk, skb, req); +} +EXPORT_SYMBOL(security_inet_conn_request); + +void security_inet_csk_clone(struct sock *newsk, + const struct request_sock *req) +{ + call_void_hook(inet_csk_clone, newsk, req); +} + +void security_inet_conn_established(struct sock *sk, + struct sk_buff *skb) +{ + call_void_hook(inet_conn_established, sk, skb); +} +EXPORT_SYMBOL(security_inet_conn_established); + +int security_secmark_relabel_packet(u32 secid) +{ + return call_int_hook(secmark_relabel_packet, 0, secid); +} +EXPORT_SYMBOL(security_secmark_relabel_packet); + +void security_secmark_refcount_inc(void) +{ + call_void_hook(secmark_refcount_inc); +} +EXPORT_SYMBOL(security_secmark_refcount_inc); + +void security_secmark_refcount_dec(void) +{ + call_void_hook(secmark_refcount_dec); +} +EXPORT_SYMBOL(security_secmark_refcount_dec); + +int security_tun_dev_alloc_security(void **security) +{ + return call_int_hook(tun_dev_alloc_security, 0, security); +} +EXPORT_SYMBOL(security_tun_dev_alloc_security); + +void security_tun_dev_free_security(void *security) +{ + call_void_hook(tun_dev_free_security, security); +} +EXPORT_SYMBOL(security_tun_dev_free_security); + +int security_tun_dev_create(void) +{ + return call_int_hook(tun_dev_create, 0); +} +EXPORT_SYMBOL(security_tun_dev_create); + +int security_tun_dev_attach_queue(void *security) +{ + return call_int_hook(tun_dev_attach_queue, 0, security); +} +EXPORT_SYMBOL(security_tun_dev_attach_queue); + +int security_tun_dev_attach(struct sock *sk, void *security) +{ + return call_int_hook(tun_dev_attach, 0, sk, security); +} +EXPORT_SYMBOL(security_tun_dev_attach); + +int security_tun_dev_open(void *security) +{ + return call_int_hook(tun_dev_open, 0, security); +} +EXPORT_SYMBOL(security_tun_dev_open); + +int security_sctp_assoc_request(struct sctp_association *asoc, struct sk_buff *skb) +{ + return call_int_hook(sctp_assoc_request, 0, asoc, skb); +} +EXPORT_SYMBOL(security_sctp_assoc_request); + +int security_sctp_bind_connect(struct sock *sk, int optname, + struct sockaddr *address, int addrlen) +{ + return call_int_hook(sctp_bind_connect, 0, sk, optname, + address, addrlen); +} +EXPORT_SYMBOL(security_sctp_bind_connect); + +void security_sctp_sk_clone(struct sctp_association *asoc, struct sock *sk, + struct sock *newsk) +{ + call_void_hook(sctp_sk_clone, asoc, sk, newsk); +} +EXPORT_SYMBOL(security_sctp_sk_clone); + +int security_sctp_assoc_established(struct sctp_association *asoc, + struct sk_buff *skb) +{ + return call_int_hook(sctp_assoc_established, 0, asoc, skb); +} +EXPORT_SYMBOL(security_sctp_assoc_established); + +#endif /* CONFIG_SECURITY_NETWORK */ + +#ifdef CONFIG_SECURITY_INFINIBAND + +int security_ib_pkey_access(void *sec, u64 subnet_prefix, u16 pkey) +{ + return call_int_hook(ib_pkey_access, 0, sec, subnet_prefix, pkey); +} +EXPORT_SYMBOL(security_ib_pkey_access); + +int security_ib_endport_manage_subnet(void *sec, const char *dev_name, u8 port_num) +{ + return call_int_hook(ib_endport_manage_subnet, 0, sec, dev_name, port_num); +} +EXPORT_SYMBOL(security_ib_endport_manage_subnet); + +int security_ib_alloc_security(void **sec) +{ + return call_int_hook(ib_alloc_security, 0, sec); +} +EXPORT_SYMBOL(security_ib_alloc_security); + +void security_ib_free_security(void *sec) +{ + call_void_hook(ib_free_security, sec); +} +EXPORT_SYMBOL(security_ib_free_security); +#endif /* CONFIG_SECURITY_INFINIBAND */ + +#ifdef CONFIG_SECURITY_NETWORK_XFRM + +int security_xfrm_policy_alloc(struct xfrm_sec_ctx **ctxp, + struct xfrm_user_sec_ctx *sec_ctx, + gfp_t gfp) +{ + return call_int_hook(xfrm_policy_alloc_security, 0, ctxp, sec_ctx, gfp); +} +EXPORT_SYMBOL(security_xfrm_policy_alloc); + +int security_xfrm_policy_clone(struct xfrm_sec_ctx *old_ctx, + struct xfrm_sec_ctx **new_ctxp) +{ + return call_int_hook(xfrm_policy_clone_security, 0, old_ctx, new_ctxp); +} + +void security_xfrm_policy_free(struct xfrm_sec_ctx *ctx) +{ + call_void_hook(xfrm_policy_free_security, ctx); +} +EXPORT_SYMBOL(security_xfrm_policy_free); + +int security_xfrm_policy_delete(struct xfrm_sec_ctx *ctx) +{ + return call_int_hook(xfrm_policy_delete_security, 0, ctx); +} + +int security_xfrm_state_alloc(struct xfrm_state *x, + struct xfrm_user_sec_ctx *sec_ctx) +{ + return call_int_hook(xfrm_state_alloc, 0, x, sec_ctx); +} +EXPORT_SYMBOL(security_xfrm_state_alloc); + +int security_xfrm_state_alloc_acquire(struct xfrm_state *x, + struct xfrm_sec_ctx *polsec, u32 secid) +{ + return call_int_hook(xfrm_state_alloc_acquire, 0, x, polsec, secid); +} + +int security_xfrm_state_delete(struct xfrm_state *x) +{ + return call_int_hook(xfrm_state_delete_security, 0, x); +} +EXPORT_SYMBOL(security_xfrm_state_delete); + +void security_xfrm_state_free(struct xfrm_state *x) +{ + call_void_hook(xfrm_state_free_security, x); +} + +int security_xfrm_policy_lookup(struct xfrm_sec_ctx *ctx, u32 fl_secid) +{ + return call_int_hook(xfrm_policy_lookup, 0, ctx, fl_secid); +} + +int security_xfrm_state_pol_flow_match(struct xfrm_state *x, + struct xfrm_policy *xp, + const struct flowi_common *flic) +{ + struct security_hook_list *hp; + int rc = LSM_RET_DEFAULT(xfrm_state_pol_flow_match); + + /* + * Since this function is expected to return 0 or 1, the judgment + * becomes difficult if multiple LSMs supply this call. Fortunately, + * we can use the first LSM's judgment because currently only SELinux + * supplies this call. + * + * For speed optimization, we explicitly break the loop rather than + * using the macro + */ + hlist_for_each_entry(hp, &security_hook_heads.xfrm_state_pol_flow_match, + list) { + rc = hp->hook.xfrm_state_pol_flow_match(x, xp, flic); + break; + } + return rc; +} + +int security_xfrm_decode_session(struct sk_buff *skb, u32 *secid) +{ + return call_int_hook(xfrm_decode_session, 0, skb, secid, 1); +} + +void security_skb_classify_flow(struct sk_buff *skb, struct flowi_common *flic) +{ + int rc = call_int_hook(xfrm_decode_session, 0, skb, &flic->flowic_secid, + 0); + + BUG_ON(rc); +} +EXPORT_SYMBOL(security_skb_classify_flow); + +#endif /* CONFIG_SECURITY_NETWORK_XFRM */ + +#ifdef CONFIG_KEYS + +int security_key_alloc(struct key *key, const struct cred *cred, + unsigned long flags) +{ + return call_int_hook(key_alloc, 0, key, cred, flags); +} + +void security_key_free(struct key *key) +{ + call_void_hook(key_free, key); +} + +int security_key_permission(key_ref_t key_ref, const struct cred *cred, + enum key_need_perm need_perm) +{ + return call_int_hook(key_permission, 0, key_ref, cred, need_perm); +} + +int security_key_getsecurity(struct key *key, char **_buffer) +{ + *_buffer = NULL; + return call_int_hook(key_getsecurity, 0, key, _buffer); +} + +#endif /* CONFIG_KEYS */ + +#ifdef CONFIG_AUDIT + +int security_audit_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule) +{ + return call_int_hook(audit_rule_init, 0, field, op, rulestr, lsmrule); +} + +int security_audit_rule_known(struct audit_krule *krule) +{ + return call_int_hook(audit_rule_known, 0, krule); +} + +void security_audit_rule_free(void *lsmrule) +{ + call_void_hook(audit_rule_free, lsmrule); +} + +int security_audit_rule_match(u32 secid, u32 field, u32 op, void *lsmrule) +{ + return call_int_hook(audit_rule_match, 0, secid, field, op, lsmrule); +} +#endif /* CONFIG_AUDIT */ + +#ifdef CONFIG_BPF_SYSCALL +int security_bpf(int cmd, union bpf_attr *attr, unsigned int size) +{ + return call_int_hook(bpf, 0, cmd, attr, size); +} +int security_bpf_map(struct bpf_map *map, fmode_t fmode) +{ + return call_int_hook(bpf_map, 0, map, fmode); +} +int security_bpf_prog(struct bpf_prog *prog) +{ + return call_int_hook(bpf_prog, 0, prog); +} +int security_bpf_map_alloc(struct bpf_map *map) +{ + return call_int_hook(bpf_map_alloc_security, 0, map); +} +int security_bpf_prog_alloc(struct bpf_prog_aux *aux) +{ + return call_int_hook(bpf_prog_alloc_security, 0, aux); +} +void security_bpf_map_free(struct bpf_map *map) +{ + call_void_hook(bpf_map_free_security, map); +} +void security_bpf_prog_free(struct bpf_prog_aux *aux) +{ + call_void_hook(bpf_prog_free_security, aux); +} +#endif /* CONFIG_BPF_SYSCALL */ + +int security_locked_down(enum lockdown_reason what) +{ + return call_int_hook(locked_down, 0, what); +} +EXPORT_SYMBOL(security_locked_down); + +#ifdef CONFIG_PERF_EVENTS +int security_perf_event_open(struct perf_event_attr *attr, int type) +{ + return call_int_hook(perf_event_open, 0, attr, type); +} + +int security_perf_event_alloc(struct perf_event *event) +{ + return call_int_hook(perf_event_alloc, 0, event); +} + +void security_perf_event_free(struct perf_event *event) +{ + call_void_hook(perf_event_free, event); +} + +int security_perf_event_read(struct perf_event *event) +{ + return call_int_hook(perf_event_read, 0, event); +} + +int security_perf_event_write(struct perf_event *event) +{ + return call_int_hook(perf_event_write, 0, event); +} +#endif /* CONFIG_PERF_EVENTS */ + +#ifdef CONFIG_IO_URING +int security_uring_override_creds(const struct cred *new) +{ + return call_int_hook(uring_override_creds, 0, new); +} + +int security_uring_sqpoll(void) +{ + return call_int_hook(uring_sqpoll, 0); +} +int security_uring_cmd(struct io_uring_cmd *ioucmd) +{ + return call_int_hook(uring_cmd, 0, ioucmd); +} +#endif /* CONFIG_IO_URING */ diff --git a/security/selinux/.gitignore b/security/selinux/.gitignore new file mode 100644 index 000000000..168fae13c --- /dev/null +++ b/security/selinux/.gitignore @@ -0,0 +1,3 @@ +# SPDX-License-Identifier: GPL-2.0-only +av_permissions.h +flask.h diff --git a/security/selinux/Kconfig b/security/selinux/Kconfig new file mode 100644 index 000000000..9e921fc72 --- /dev/null +++ b/security/selinux/Kconfig @@ -0,0 +1,117 @@ +# SPDX-License-Identifier: GPL-2.0-only +config SECURITY_SELINUX + bool "NSA SELinux Support" + depends on SECURITY_NETWORK && AUDIT && NET && INET + select NETWORK_SECMARK + default n + help + This selects NSA Security-Enhanced Linux (SELinux). + You will also need a policy configuration and a labeled filesystem. + If you are unsure how to answer this question, answer N. + +config SECURITY_SELINUX_BOOTPARAM + bool "NSA SELinux boot parameter" + depends on SECURITY_SELINUX + default n + help + This option adds a kernel parameter 'selinux', which allows SELinux + to be disabled at boot. If this option is selected, SELinux + functionality can be disabled with selinux=0 on the kernel + command line. The purpose of this option is to allow a single + kernel image to be distributed with SELinux built in, but not + necessarily enabled. + + If you are unsure how to answer this question, answer N. + +config SECURITY_SELINUX_DISABLE + bool "NSA SELinux runtime disable" + depends on SECURITY_SELINUX + select SECURITY_WRITABLE_HOOKS + default n + help + This option enables writing to a selinuxfs node 'disable', which + allows SELinux to be disabled at runtime prior to the policy load. + SELinux will then remain disabled until the next boot. + This option is similar to the selinux=0 boot parameter, but is to + support runtime disabling of SELinux, e.g. from /sbin/init, for + portability across platforms where boot parameters are difficult + to employ. + + NOTE: selecting this option will disable the '__ro_after_init' + kernel hardening feature for security hooks. Please consider + using the selinux=0 boot parameter instead of enabling this + option. + + WARNING: this option is deprecated and will be removed in a future + kernel release. + + If you are unsure how to answer this question, answer N. + +config SECURITY_SELINUX_DEVELOP + bool "NSA SELinux Development Support" + depends on SECURITY_SELINUX + default y + help + This enables the development support option of NSA SELinux, + which is useful for experimenting with SELinux and developing + policies. If unsure, say Y. With this option enabled, the + kernel will start in permissive mode (log everything, deny nothing) + unless you specify enforcing=1 on the kernel command line. You + can interactively toggle the kernel between enforcing mode and + permissive mode (if permitted by the policy) via + /sys/fs/selinux/enforce. + +config SECURITY_SELINUX_AVC_STATS + bool "NSA SELinux AVC Statistics" + depends on SECURITY_SELINUX + default y + help + This option collects access vector cache statistics to + /sys/fs/selinux/avc/cache_stats, which may be monitored via + tools such as avcstat. + +config SECURITY_SELINUX_CHECKREQPROT_VALUE + int "NSA SELinux checkreqprot default value" + depends on SECURITY_SELINUX + range 0 1 + default 0 + help + This option sets the default value for the 'checkreqprot' flag + that determines whether SELinux checks the protection requested + by the application or the protection that will be applied by the + kernel (including any implied execute for read-implies-exec) for + mmap and mprotect calls. If this option is set to 0 (zero), + SELinux will default to checking the protection that will be applied + by the kernel. If this option is set to 1 (one), SELinux will + default to checking the protection requested by the application. + The checkreqprot flag may be changed from the default via the + 'checkreqprot=' boot parameter. It may also be changed at runtime + via /sys/fs/selinux/checkreqprot if authorized by policy. + + WARNING: this option is deprecated and will be removed in a future + kernel release. + + If you are unsure how to answer this question, answer 0. + +config SECURITY_SELINUX_SIDTAB_HASH_BITS + int "NSA SELinux sidtab hashtable size" + depends on SECURITY_SELINUX + range 8 13 + default 9 + help + This option sets the number of buckets used in the sidtab hashtable + to 2^SECURITY_SELINUX_SIDTAB_HASH_BITS buckets. The number of hash + collisions may be viewed at /sys/fs/selinux/ss/sidtab_hash_stats. If + chain lengths are high (e.g. > 20) then selecting a higher value here + will ensure that lookups times are short and stable. + +config SECURITY_SELINUX_SID2STR_CACHE_SIZE + int "NSA SELinux SID to context string translation cache size" + depends on SECURITY_SELINUX + default 256 + help + This option defines the size of the internal SID -> context string + cache, which improves the performance of context to string + conversion. Setting this option to 0 disables the cache completely. + + If unsure, keep the default value. diff --git a/security/selinux/Makefile b/security/selinux/Makefile new file mode 100644 index 000000000..8b21520bd --- /dev/null +++ b/security/selinux/Makefile @@ -0,0 +1,34 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Makefile for building the SELinux module as part of the kernel tree. +# + +obj-$(CONFIG_SECURITY_SELINUX) := selinux.o + +selinux-y := avc.o hooks.o selinuxfs.o netlink.o nlmsgtab.o netif.o \ + netnode.o netport.o status.o \ + ss/ebitmap.o ss/hashtab.o ss/symtab.o ss/sidtab.o ss/avtab.o \ + ss/policydb.o ss/services.o ss/conditional.o ss/mls.o ss/context.o + +selinux-$(CONFIG_SECURITY_NETWORK_XFRM) += xfrm.o + +selinux-$(CONFIG_NETLABEL) += netlabel.o + +selinux-$(CONFIG_SECURITY_INFINIBAND) += ibpkey.o + +selinux-$(CONFIG_IMA) += ima.o + +ccflags-y := -I$(srctree)/security/selinux -I$(srctree)/security/selinux/include + +$(addprefix $(obj)/,$(selinux-y)): $(obj)/flask.h + +quiet_cmd_flask = GEN $(obj)/flask.h $(obj)/av_permissions.h + cmd_flask = $< $(obj)/flask.h $(obj)/av_permissions.h + +targets += flask.h av_permissions.h +# once make >= 4.3 is required, we can use grouped targets in the rule below, +# which basically involves adding both headers and a '&' before the colon, see +# the example below: +# $(obj)/flask.h $(obj)/av_permissions.h &: scripts/selinux/... +$(obj)/flask.h: scripts/selinux/genheaders/genheaders FORCE + $(call if_changed,flask) diff --git a/security/selinux/avc.c b/security/selinux/avc.c new file mode 100644 index 000000000..9a43af0eb --- /dev/null +++ b/security/selinux/avc.c @@ -0,0 +1,1222 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Implementation of the kernel access vector cache (AVC). + * + * Authors: Stephen Smalley, <sds@tycho.nsa.gov> + * James Morris <jmorris@redhat.com> + * + * Update: KaiGai, Kohei <kaigai@ak.jp.nec.com> + * Replaced the avc_lock spinlock by RCU. + * + * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com> + */ +#include <linux/types.h> +#include <linux/stddef.h> +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/fs.h> +#include <linux/dcache.h> +#include <linux/init.h> +#include <linux/skbuff.h> +#include <linux/percpu.h> +#include <linux/list.h> +#include <net/sock.h> +#include <linux/un.h> +#include <net/af_unix.h> +#include <linux/ip.h> +#include <linux/audit.h> +#include <linux/ipv6.h> +#include <net/ipv6.h> +#include "avc.h" +#include "avc_ss.h" +#include "classmap.h" + +#define CREATE_TRACE_POINTS +#include <trace/events/avc.h> + +#define AVC_CACHE_SLOTS 512 +#define AVC_DEF_CACHE_THRESHOLD 512 +#define AVC_CACHE_RECLAIM 16 + +#ifdef CONFIG_SECURITY_SELINUX_AVC_STATS +#define avc_cache_stats_incr(field) this_cpu_inc(avc_cache_stats.field) +#else +#define avc_cache_stats_incr(field) do {} while (0) +#endif + +struct avc_entry { + u32 ssid; + u32 tsid; + u16 tclass; + struct av_decision avd; + struct avc_xperms_node *xp_node; +}; + +struct avc_node { + struct avc_entry ae; + struct hlist_node list; /* anchored in avc_cache->slots[i] */ + struct rcu_head rhead; +}; + +struct avc_xperms_decision_node { + struct extended_perms_decision xpd; + struct list_head xpd_list; /* list of extended_perms_decision */ +}; + +struct avc_xperms_node { + struct extended_perms xp; + struct list_head xpd_head; /* list head of extended_perms_decision */ +}; + +struct avc_cache { + struct hlist_head slots[AVC_CACHE_SLOTS]; /* head for avc_node->list */ + spinlock_t slots_lock[AVC_CACHE_SLOTS]; /* lock for writes */ + atomic_t lru_hint; /* LRU hint for reclaim scan */ + atomic_t active_nodes; + u32 latest_notif; /* latest revocation notification */ +}; + +struct avc_callback_node { + int (*callback) (u32 event); + u32 events; + struct avc_callback_node *next; +}; + +#ifdef CONFIG_SECURITY_SELINUX_AVC_STATS +DEFINE_PER_CPU(struct avc_cache_stats, avc_cache_stats) = { 0 }; +#endif + +struct selinux_avc { + unsigned int avc_cache_threshold; + struct avc_cache avc_cache; +}; + +static struct selinux_avc selinux_avc; + +void selinux_avc_init(struct selinux_avc **avc) +{ + int i; + + selinux_avc.avc_cache_threshold = AVC_DEF_CACHE_THRESHOLD; + for (i = 0; i < AVC_CACHE_SLOTS; i++) { + INIT_HLIST_HEAD(&selinux_avc.avc_cache.slots[i]); + spin_lock_init(&selinux_avc.avc_cache.slots_lock[i]); + } + atomic_set(&selinux_avc.avc_cache.active_nodes, 0); + atomic_set(&selinux_avc.avc_cache.lru_hint, 0); + *avc = &selinux_avc; +} + +unsigned int avc_get_cache_threshold(struct selinux_avc *avc) +{ + return avc->avc_cache_threshold; +} + +void avc_set_cache_threshold(struct selinux_avc *avc, + unsigned int cache_threshold) +{ + avc->avc_cache_threshold = cache_threshold; +} + +static struct avc_callback_node *avc_callbacks __ro_after_init; +static struct kmem_cache *avc_node_cachep __ro_after_init; +static struct kmem_cache *avc_xperms_data_cachep __ro_after_init; +static struct kmem_cache *avc_xperms_decision_cachep __ro_after_init; +static struct kmem_cache *avc_xperms_cachep __ro_after_init; + +static inline int avc_hash(u32 ssid, u32 tsid, u16 tclass) +{ + return (ssid ^ (tsid<<2) ^ (tclass<<4)) & (AVC_CACHE_SLOTS - 1); +} + +/** + * avc_init - Initialize the AVC. + * + * Initialize the access vector cache. + */ +void __init avc_init(void) +{ + avc_node_cachep = kmem_cache_create("avc_node", sizeof(struct avc_node), + 0, SLAB_PANIC, NULL); + avc_xperms_cachep = kmem_cache_create("avc_xperms_node", + sizeof(struct avc_xperms_node), + 0, SLAB_PANIC, NULL); + avc_xperms_decision_cachep = kmem_cache_create( + "avc_xperms_decision_node", + sizeof(struct avc_xperms_decision_node), + 0, SLAB_PANIC, NULL); + avc_xperms_data_cachep = kmem_cache_create("avc_xperms_data", + sizeof(struct extended_perms_data), + 0, SLAB_PANIC, NULL); +} + +int avc_get_hash_stats(struct selinux_avc *avc, char *page) +{ + int i, chain_len, max_chain_len, slots_used; + struct avc_node *node; + struct hlist_head *head; + + rcu_read_lock(); + + slots_used = 0; + max_chain_len = 0; + for (i = 0; i < AVC_CACHE_SLOTS; i++) { + head = &avc->avc_cache.slots[i]; + if (!hlist_empty(head)) { + slots_used++; + chain_len = 0; + hlist_for_each_entry_rcu(node, head, list) + chain_len++; + if (chain_len > max_chain_len) + max_chain_len = chain_len; + } + } + + rcu_read_unlock(); + + return scnprintf(page, PAGE_SIZE, "entries: %d\nbuckets used: %d/%d\n" + "longest chain: %d\n", + atomic_read(&avc->avc_cache.active_nodes), + slots_used, AVC_CACHE_SLOTS, max_chain_len); +} + +/* + * using a linked list for extended_perms_decision lookup because the list is + * always small. i.e. less than 5, typically 1 + */ +static struct extended_perms_decision *avc_xperms_decision_lookup(u8 driver, + struct avc_xperms_node *xp_node) +{ + struct avc_xperms_decision_node *xpd_node; + + list_for_each_entry(xpd_node, &xp_node->xpd_head, xpd_list) { + if (xpd_node->xpd.driver == driver) + return &xpd_node->xpd; + } + return NULL; +} + +static inline unsigned int +avc_xperms_has_perm(struct extended_perms_decision *xpd, + u8 perm, u8 which) +{ + unsigned int rc = 0; + + if ((which == XPERMS_ALLOWED) && + (xpd->used & XPERMS_ALLOWED)) + rc = security_xperm_test(xpd->allowed->p, perm); + else if ((which == XPERMS_AUDITALLOW) && + (xpd->used & XPERMS_AUDITALLOW)) + rc = security_xperm_test(xpd->auditallow->p, perm); + else if ((which == XPERMS_DONTAUDIT) && + (xpd->used & XPERMS_DONTAUDIT)) + rc = security_xperm_test(xpd->dontaudit->p, perm); + return rc; +} + +static void avc_xperms_allow_perm(struct avc_xperms_node *xp_node, + u8 driver, u8 perm) +{ + struct extended_perms_decision *xpd; + security_xperm_set(xp_node->xp.drivers.p, driver); + xpd = avc_xperms_decision_lookup(driver, xp_node); + if (xpd && xpd->allowed) + security_xperm_set(xpd->allowed->p, perm); +} + +static void avc_xperms_decision_free(struct avc_xperms_decision_node *xpd_node) +{ + struct extended_perms_decision *xpd; + + xpd = &xpd_node->xpd; + if (xpd->allowed) + kmem_cache_free(avc_xperms_data_cachep, xpd->allowed); + if (xpd->auditallow) + kmem_cache_free(avc_xperms_data_cachep, xpd->auditallow); + if (xpd->dontaudit) + kmem_cache_free(avc_xperms_data_cachep, xpd->dontaudit); + kmem_cache_free(avc_xperms_decision_cachep, xpd_node); +} + +static void avc_xperms_free(struct avc_xperms_node *xp_node) +{ + struct avc_xperms_decision_node *xpd_node, *tmp; + + if (!xp_node) + return; + + list_for_each_entry_safe(xpd_node, tmp, &xp_node->xpd_head, xpd_list) { + list_del(&xpd_node->xpd_list); + avc_xperms_decision_free(xpd_node); + } + kmem_cache_free(avc_xperms_cachep, xp_node); +} + +static void avc_copy_xperms_decision(struct extended_perms_decision *dest, + struct extended_perms_decision *src) +{ + dest->driver = src->driver; + dest->used = src->used; + if (dest->used & XPERMS_ALLOWED) + memcpy(dest->allowed->p, src->allowed->p, + sizeof(src->allowed->p)); + if (dest->used & XPERMS_AUDITALLOW) + memcpy(dest->auditallow->p, src->auditallow->p, + sizeof(src->auditallow->p)); + if (dest->used & XPERMS_DONTAUDIT) + memcpy(dest->dontaudit->p, src->dontaudit->p, + sizeof(src->dontaudit->p)); +} + +/* + * similar to avc_copy_xperms_decision, but only copy decision + * information relevant to this perm + */ +static inline void avc_quick_copy_xperms_decision(u8 perm, + struct extended_perms_decision *dest, + struct extended_perms_decision *src) +{ + /* + * compute index of the u32 of the 256 bits (8 u32s) that contain this + * command permission + */ + u8 i = perm >> 5; + + dest->used = src->used; + if (dest->used & XPERMS_ALLOWED) + dest->allowed->p[i] = src->allowed->p[i]; + if (dest->used & XPERMS_AUDITALLOW) + dest->auditallow->p[i] = src->auditallow->p[i]; + if (dest->used & XPERMS_DONTAUDIT) + dest->dontaudit->p[i] = src->dontaudit->p[i]; +} + +static struct avc_xperms_decision_node + *avc_xperms_decision_alloc(u8 which) +{ + struct avc_xperms_decision_node *xpd_node; + struct extended_perms_decision *xpd; + + xpd_node = kmem_cache_zalloc(avc_xperms_decision_cachep, + GFP_NOWAIT | __GFP_NOWARN); + if (!xpd_node) + return NULL; + + xpd = &xpd_node->xpd; + if (which & XPERMS_ALLOWED) { + xpd->allowed = kmem_cache_zalloc(avc_xperms_data_cachep, + GFP_NOWAIT | __GFP_NOWARN); + if (!xpd->allowed) + goto error; + } + if (which & XPERMS_AUDITALLOW) { + xpd->auditallow = kmem_cache_zalloc(avc_xperms_data_cachep, + GFP_NOWAIT | __GFP_NOWARN); + if (!xpd->auditallow) + goto error; + } + if (which & XPERMS_DONTAUDIT) { + xpd->dontaudit = kmem_cache_zalloc(avc_xperms_data_cachep, + GFP_NOWAIT | __GFP_NOWARN); + if (!xpd->dontaudit) + goto error; + } + return xpd_node; +error: + avc_xperms_decision_free(xpd_node); + return NULL; +} + +static int avc_add_xperms_decision(struct avc_node *node, + struct extended_perms_decision *src) +{ + struct avc_xperms_decision_node *dest_xpd; + + node->ae.xp_node->xp.len++; + dest_xpd = avc_xperms_decision_alloc(src->used); + if (!dest_xpd) + return -ENOMEM; + avc_copy_xperms_decision(&dest_xpd->xpd, src); + list_add(&dest_xpd->xpd_list, &node->ae.xp_node->xpd_head); + return 0; +} + +static struct avc_xperms_node *avc_xperms_alloc(void) +{ + struct avc_xperms_node *xp_node; + + xp_node = kmem_cache_zalloc(avc_xperms_cachep, GFP_NOWAIT | __GFP_NOWARN); + if (!xp_node) + return xp_node; + INIT_LIST_HEAD(&xp_node->xpd_head); + return xp_node; +} + +static int avc_xperms_populate(struct avc_node *node, + struct avc_xperms_node *src) +{ + struct avc_xperms_node *dest; + struct avc_xperms_decision_node *dest_xpd; + struct avc_xperms_decision_node *src_xpd; + + if (src->xp.len == 0) + return 0; + dest = avc_xperms_alloc(); + if (!dest) + return -ENOMEM; + + memcpy(dest->xp.drivers.p, src->xp.drivers.p, sizeof(dest->xp.drivers.p)); + dest->xp.len = src->xp.len; + + /* for each source xpd allocate a destination xpd and copy */ + list_for_each_entry(src_xpd, &src->xpd_head, xpd_list) { + dest_xpd = avc_xperms_decision_alloc(src_xpd->xpd.used); + if (!dest_xpd) + goto error; + avc_copy_xperms_decision(&dest_xpd->xpd, &src_xpd->xpd); + list_add(&dest_xpd->xpd_list, &dest->xpd_head); + } + node->ae.xp_node = dest; + return 0; +error: + avc_xperms_free(dest); + return -ENOMEM; + +} + +static inline u32 avc_xperms_audit_required(u32 requested, + struct av_decision *avd, + struct extended_perms_decision *xpd, + u8 perm, + int result, + u32 *deniedp) +{ + u32 denied, audited; + + denied = requested & ~avd->allowed; + if (unlikely(denied)) { + audited = denied & avd->auditdeny; + if (audited && xpd) { + if (avc_xperms_has_perm(xpd, perm, XPERMS_DONTAUDIT)) + audited &= ~requested; + } + } else if (result) { + audited = denied = requested; + } else { + audited = requested & avd->auditallow; + if (audited && xpd) { + if (!avc_xperms_has_perm(xpd, perm, XPERMS_AUDITALLOW)) + audited &= ~requested; + } + } + + *deniedp = denied; + return audited; +} + +static inline int avc_xperms_audit(struct selinux_state *state, + u32 ssid, u32 tsid, u16 tclass, + u32 requested, struct av_decision *avd, + struct extended_perms_decision *xpd, + u8 perm, int result, + struct common_audit_data *ad) +{ + u32 audited, denied; + + audited = avc_xperms_audit_required( + requested, avd, xpd, perm, result, &denied); + if (likely(!audited)) + return 0; + return slow_avc_audit(state, ssid, tsid, tclass, requested, + audited, denied, result, ad); +} + +static void avc_node_free(struct rcu_head *rhead) +{ + struct avc_node *node = container_of(rhead, struct avc_node, rhead); + avc_xperms_free(node->ae.xp_node); + kmem_cache_free(avc_node_cachep, node); + avc_cache_stats_incr(frees); +} + +static void avc_node_delete(struct selinux_avc *avc, struct avc_node *node) +{ + hlist_del_rcu(&node->list); + call_rcu(&node->rhead, avc_node_free); + atomic_dec(&avc->avc_cache.active_nodes); +} + +static void avc_node_kill(struct selinux_avc *avc, struct avc_node *node) +{ + avc_xperms_free(node->ae.xp_node); + kmem_cache_free(avc_node_cachep, node); + avc_cache_stats_incr(frees); + atomic_dec(&avc->avc_cache.active_nodes); +} + +static void avc_node_replace(struct selinux_avc *avc, + struct avc_node *new, struct avc_node *old) +{ + hlist_replace_rcu(&old->list, &new->list); + call_rcu(&old->rhead, avc_node_free); + atomic_dec(&avc->avc_cache.active_nodes); +} + +static inline int avc_reclaim_node(struct selinux_avc *avc) +{ + struct avc_node *node; + int hvalue, try, ecx; + unsigned long flags; + struct hlist_head *head; + spinlock_t *lock; + + for (try = 0, ecx = 0; try < AVC_CACHE_SLOTS; try++) { + hvalue = atomic_inc_return(&avc->avc_cache.lru_hint) & + (AVC_CACHE_SLOTS - 1); + head = &avc->avc_cache.slots[hvalue]; + lock = &avc->avc_cache.slots_lock[hvalue]; + + if (!spin_trylock_irqsave(lock, flags)) + continue; + + rcu_read_lock(); + hlist_for_each_entry(node, head, list) { + avc_node_delete(avc, node); + avc_cache_stats_incr(reclaims); + ecx++; + if (ecx >= AVC_CACHE_RECLAIM) { + rcu_read_unlock(); + spin_unlock_irqrestore(lock, flags); + goto out; + } + } + rcu_read_unlock(); + spin_unlock_irqrestore(lock, flags); + } +out: + return ecx; +} + +static struct avc_node *avc_alloc_node(struct selinux_avc *avc) +{ + struct avc_node *node; + + node = kmem_cache_zalloc(avc_node_cachep, GFP_NOWAIT | __GFP_NOWARN); + if (!node) + goto out; + + INIT_HLIST_NODE(&node->list); + avc_cache_stats_incr(allocations); + + if (atomic_inc_return(&avc->avc_cache.active_nodes) > + avc->avc_cache_threshold) + avc_reclaim_node(avc); + +out: + return node; +} + +static void avc_node_populate(struct avc_node *node, u32 ssid, u32 tsid, u16 tclass, struct av_decision *avd) +{ + node->ae.ssid = ssid; + node->ae.tsid = tsid; + node->ae.tclass = tclass; + memcpy(&node->ae.avd, avd, sizeof(node->ae.avd)); +} + +static inline struct avc_node *avc_search_node(struct selinux_avc *avc, + u32 ssid, u32 tsid, u16 tclass) +{ + struct avc_node *node, *ret = NULL; + int hvalue; + struct hlist_head *head; + + hvalue = avc_hash(ssid, tsid, tclass); + head = &avc->avc_cache.slots[hvalue]; + hlist_for_each_entry_rcu(node, head, list) { + if (ssid == node->ae.ssid && + tclass == node->ae.tclass && + tsid == node->ae.tsid) { + ret = node; + break; + } + } + + return ret; +} + +/** + * avc_lookup - Look up an AVC entry. + * @avc: the access vector cache + * @ssid: source security identifier + * @tsid: target security identifier + * @tclass: target security class + * + * Look up an AVC entry that is valid for the + * (@ssid, @tsid), interpreting the permissions + * based on @tclass. If a valid AVC entry exists, + * then this function returns the avc_node. + * Otherwise, this function returns NULL. + */ +static struct avc_node *avc_lookup(struct selinux_avc *avc, + u32 ssid, u32 tsid, u16 tclass) +{ + struct avc_node *node; + + avc_cache_stats_incr(lookups); + node = avc_search_node(avc, ssid, tsid, tclass); + + if (node) + return node; + + avc_cache_stats_incr(misses); + return NULL; +} + +static int avc_latest_notif_update(struct selinux_avc *avc, + int seqno, int is_insert) +{ + int ret = 0; + static DEFINE_SPINLOCK(notif_lock); + unsigned long flag; + + spin_lock_irqsave(¬if_lock, flag); + if (is_insert) { + if (seqno < avc->avc_cache.latest_notif) { + pr_warn("SELinux: avc: seqno %d < latest_notif %d\n", + seqno, avc->avc_cache.latest_notif); + ret = -EAGAIN; + } + } else { + if (seqno > avc->avc_cache.latest_notif) + avc->avc_cache.latest_notif = seqno; + } + spin_unlock_irqrestore(¬if_lock, flag); + + return ret; +} + +/** + * avc_insert - Insert an AVC entry. + * @avc: the access vector cache + * @ssid: source security identifier + * @tsid: target security identifier + * @tclass: target security class + * @avd: resulting av decision + * @xp_node: resulting extended permissions + * + * Insert an AVC entry for the SID pair + * (@ssid, @tsid) and class @tclass. + * The access vectors and the sequence number are + * normally provided by the security server in + * response to a security_compute_av() call. If the + * sequence number @avd->seqno is not less than the latest + * revocation notification, then the function copies + * the access vectors into a cache entry, returns + * avc_node inserted. Otherwise, this function returns NULL. + */ +static struct avc_node *avc_insert(struct selinux_avc *avc, + u32 ssid, u32 tsid, u16 tclass, + struct av_decision *avd, + struct avc_xperms_node *xp_node) +{ + struct avc_node *pos, *node = NULL; + int hvalue; + unsigned long flag; + spinlock_t *lock; + struct hlist_head *head; + + if (avc_latest_notif_update(avc, avd->seqno, 1)) + return NULL; + + node = avc_alloc_node(avc); + if (!node) + return NULL; + + avc_node_populate(node, ssid, tsid, tclass, avd); + if (avc_xperms_populate(node, xp_node)) { + avc_node_kill(avc, node); + return NULL; + } + + hvalue = avc_hash(ssid, tsid, tclass); + head = &avc->avc_cache.slots[hvalue]; + lock = &avc->avc_cache.slots_lock[hvalue]; + spin_lock_irqsave(lock, flag); + hlist_for_each_entry(pos, head, list) { + if (pos->ae.ssid == ssid && + pos->ae.tsid == tsid && + pos->ae.tclass == tclass) { + avc_node_replace(avc, node, pos); + goto found; + } + } + hlist_add_head_rcu(&node->list, head); +found: + spin_unlock_irqrestore(lock, flag); + return node; +} + +/** + * avc_audit_pre_callback - SELinux specific information + * will be called by generic audit code + * @ab: the audit buffer + * @a: audit_data + */ +static void avc_audit_pre_callback(struct audit_buffer *ab, void *a) +{ + struct common_audit_data *ad = a; + struct selinux_audit_data *sad = ad->selinux_audit_data; + u32 av = sad->audited; + const char *const *perms; + int i, perm; + + audit_log_format(ab, "avc: %s ", sad->denied ? "denied" : "granted"); + + if (av == 0) { + audit_log_format(ab, " null"); + return; + } + + perms = secclass_map[sad->tclass-1].perms; + + audit_log_format(ab, " {"); + i = 0; + perm = 1; + while (i < (sizeof(av) * 8)) { + if ((perm & av) && perms[i]) { + audit_log_format(ab, " %s", perms[i]); + av &= ~perm; + } + i++; + perm <<= 1; + } + + if (av) + audit_log_format(ab, " 0x%x", av); + + audit_log_format(ab, " } for "); +} + +/** + * avc_audit_post_callback - SELinux specific information + * will be called by generic audit code + * @ab: the audit buffer + * @a: audit_data + */ +static void avc_audit_post_callback(struct audit_buffer *ab, void *a) +{ + struct common_audit_data *ad = a; + struct selinux_audit_data *sad = ad->selinux_audit_data; + char *scontext = NULL; + char *tcontext = NULL; + const char *tclass = NULL; + u32 scontext_len; + u32 tcontext_len; + int rc; + + rc = security_sid_to_context(sad->state, sad->ssid, &scontext, + &scontext_len); + if (rc) + audit_log_format(ab, " ssid=%d", sad->ssid); + else + audit_log_format(ab, " scontext=%s", scontext); + + rc = security_sid_to_context(sad->state, sad->tsid, &tcontext, + &tcontext_len); + if (rc) + audit_log_format(ab, " tsid=%d", sad->tsid); + else + audit_log_format(ab, " tcontext=%s", tcontext); + + tclass = secclass_map[sad->tclass-1].name; + audit_log_format(ab, " tclass=%s", tclass); + + if (sad->denied) + audit_log_format(ab, " permissive=%u", sad->result ? 0 : 1); + + trace_selinux_audited(sad, scontext, tcontext, tclass); + kfree(tcontext); + kfree(scontext); + + /* in case of invalid context report also the actual context string */ + rc = security_sid_to_context_inval(sad->state, sad->ssid, &scontext, + &scontext_len); + if (!rc && scontext) { + if (scontext_len && scontext[scontext_len - 1] == '\0') + scontext_len--; + audit_log_format(ab, " srawcon="); + audit_log_n_untrustedstring(ab, scontext, scontext_len); + kfree(scontext); + } + + rc = security_sid_to_context_inval(sad->state, sad->tsid, &scontext, + &scontext_len); + if (!rc && scontext) { + if (scontext_len && scontext[scontext_len - 1] == '\0') + scontext_len--; + audit_log_format(ab, " trawcon="); + audit_log_n_untrustedstring(ab, scontext, scontext_len); + kfree(scontext); + } +} + +/* + * This is the slow part of avc audit with big stack footprint. + * Note that it is non-blocking and can be called from under + * rcu_read_lock(). + */ +noinline int slow_avc_audit(struct selinux_state *state, + u32 ssid, u32 tsid, u16 tclass, + u32 requested, u32 audited, u32 denied, int result, + struct common_audit_data *a) +{ + struct common_audit_data stack_data; + struct selinux_audit_data sad; + + if (WARN_ON(!tclass || tclass >= ARRAY_SIZE(secclass_map))) + return -EINVAL; + + if (!a) { + a = &stack_data; + a->type = LSM_AUDIT_DATA_NONE; + } + + sad.tclass = tclass; + sad.requested = requested; + sad.ssid = ssid; + sad.tsid = tsid; + sad.audited = audited; + sad.denied = denied; + sad.result = result; + sad.state = state; + + a->selinux_audit_data = &sad; + + common_lsm_audit(a, avc_audit_pre_callback, avc_audit_post_callback); + return 0; +} + +/** + * avc_add_callback - Register a callback for security events. + * @callback: callback function + * @events: security events + * + * Register a callback function for events in the set @events. + * Returns %0 on success or -%ENOMEM if insufficient memory + * exists to add the callback. + */ +int __init avc_add_callback(int (*callback)(u32 event), u32 events) +{ + struct avc_callback_node *c; + int rc = 0; + + c = kmalloc(sizeof(*c), GFP_KERNEL); + if (!c) { + rc = -ENOMEM; + goto out; + } + + c->callback = callback; + c->events = events; + c->next = avc_callbacks; + avc_callbacks = c; +out: + return rc; +} + +/** + * avc_update_node - Update an AVC entry + * @avc: the access vector cache + * @event : Updating event + * @perms : Permission mask bits + * @driver: xperm driver information + * @xperm: xperm permissions + * @ssid: AVC entry source sid + * @tsid: AVC entry target sid + * @tclass : AVC entry target object class + * @seqno : sequence number when decision was made + * @xpd: extended_perms_decision to be added to the node + * @flags: the AVC_* flags, e.g. AVC_EXTENDED_PERMS, or 0. + * + * if a valid AVC entry doesn't exist,this function returns -ENOENT. + * if kmalloc() called internal returns NULL, this function returns -ENOMEM. + * otherwise, this function updates the AVC entry. The original AVC-entry object + * will release later by RCU. + */ +static int avc_update_node(struct selinux_avc *avc, + u32 event, u32 perms, u8 driver, u8 xperm, u32 ssid, + u32 tsid, u16 tclass, u32 seqno, + struct extended_perms_decision *xpd, + u32 flags) +{ + int hvalue, rc = 0; + unsigned long flag; + struct avc_node *pos, *node, *orig = NULL; + struct hlist_head *head; + spinlock_t *lock; + + node = avc_alloc_node(avc); + if (!node) { + rc = -ENOMEM; + goto out; + } + + /* Lock the target slot */ + hvalue = avc_hash(ssid, tsid, tclass); + + head = &avc->avc_cache.slots[hvalue]; + lock = &avc->avc_cache.slots_lock[hvalue]; + + spin_lock_irqsave(lock, flag); + + hlist_for_each_entry(pos, head, list) { + if (ssid == pos->ae.ssid && + tsid == pos->ae.tsid && + tclass == pos->ae.tclass && + seqno == pos->ae.avd.seqno){ + orig = pos; + break; + } + } + + if (!orig) { + rc = -ENOENT; + avc_node_kill(avc, node); + goto out_unlock; + } + + /* + * Copy and replace original node. + */ + + avc_node_populate(node, ssid, tsid, tclass, &orig->ae.avd); + + if (orig->ae.xp_node) { + rc = avc_xperms_populate(node, orig->ae.xp_node); + if (rc) { + avc_node_kill(avc, node); + goto out_unlock; + } + } + + switch (event) { + case AVC_CALLBACK_GRANT: + node->ae.avd.allowed |= perms; + if (node->ae.xp_node && (flags & AVC_EXTENDED_PERMS)) + avc_xperms_allow_perm(node->ae.xp_node, driver, xperm); + break; + case AVC_CALLBACK_TRY_REVOKE: + case AVC_CALLBACK_REVOKE: + node->ae.avd.allowed &= ~perms; + break; + case AVC_CALLBACK_AUDITALLOW_ENABLE: + node->ae.avd.auditallow |= perms; + break; + case AVC_CALLBACK_AUDITALLOW_DISABLE: + node->ae.avd.auditallow &= ~perms; + break; + case AVC_CALLBACK_AUDITDENY_ENABLE: + node->ae.avd.auditdeny |= perms; + break; + case AVC_CALLBACK_AUDITDENY_DISABLE: + node->ae.avd.auditdeny &= ~perms; + break; + case AVC_CALLBACK_ADD_XPERMS: + avc_add_xperms_decision(node, xpd); + break; + } + avc_node_replace(avc, node, orig); +out_unlock: + spin_unlock_irqrestore(lock, flag); +out: + return rc; +} + +/** + * avc_flush - Flush the cache + * @avc: the access vector cache + */ +static void avc_flush(struct selinux_avc *avc) +{ + struct hlist_head *head; + struct avc_node *node; + spinlock_t *lock; + unsigned long flag; + int i; + + for (i = 0; i < AVC_CACHE_SLOTS; i++) { + head = &avc->avc_cache.slots[i]; + lock = &avc->avc_cache.slots_lock[i]; + + spin_lock_irqsave(lock, flag); + /* + * With preemptable RCU, the outer spinlock does not + * prevent RCU grace periods from ending. + */ + rcu_read_lock(); + hlist_for_each_entry(node, head, list) + avc_node_delete(avc, node); + rcu_read_unlock(); + spin_unlock_irqrestore(lock, flag); + } +} + +/** + * avc_ss_reset - Flush the cache and revalidate migrated permissions. + * @avc: the access vector cache + * @seqno: policy sequence number + */ +int avc_ss_reset(struct selinux_avc *avc, u32 seqno) +{ + struct avc_callback_node *c; + int rc = 0, tmprc; + + avc_flush(avc); + + for (c = avc_callbacks; c; c = c->next) { + if (c->events & AVC_CALLBACK_RESET) { + tmprc = c->callback(AVC_CALLBACK_RESET); + /* save the first error encountered for the return + value and continue processing the callbacks */ + if (!rc) + rc = tmprc; + } + } + + avc_latest_notif_update(avc, seqno, 0); + return rc; +} + +/* + * Slow-path helper function for avc_has_perm_noaudit, + * when the avc_node lookup fails. We get called with + * the RCU read lock held, and need to return with it + * still held, but drop if for the security compute. + * + * Don't inline this, since it's the slow-path and just + * results in a bigger stack frame. + */ +static noinline +struct avc_node *avc_compute_av(struct selinux_state *state, + u32 ssid, u32 tsid, + u16 tclass, struct av_decision *avd, + struct avc_xperms_node *xp_node) +{ + rcu_read_unlock(); + INIT_LIST_HEAD(&xp_node->xpd_head); + security_compute_av(state, ssid, tsid, tclass, avd, &xp_node->xp); + rcu_read_lock(); + return avc_insert(state->avc, ssid, tsid, tclass, avd, xp_node); +} + +static noinline int avc_denied(struct selinux_state *state, + u32 ssid, u32 tsid, + u16 tclass, u32 requested, + u8 driver, u8 xperm, unsigned int flags, + struct av_decision *avd) +{ + if (flags & AVC_STRICT) + return -EACCES; + + if (enforcing_enabled(state) && + !(avd->flags & AVD_FLAGS_PERMISSIVE)) + return -EACCES; + + avc_update_node(state->avc, AVC_CALLBACK_GRANT, requested, driver, + xperm, ssid, tsid, tclass, avd->seqno, NULL, flags); + return 0; +} + +/* + * The avc extended permissions logic adds an additional 256 bits of + * permissions to an avc node when extended permissions for that node are + * specified in the avtab. If the additional 256 permissions is not adequate, + * as-is the case with ioctls, then multiple may be chained together and the + * driver field is used to specify which set contains the permission. + */ +int avc_has_extended_perms(struct selinux_state *state, + u32 ssid, u32 tsid, u16 tclass, u32 requested, + u8 driver, u8 xperm, struct common_audit_data *ad) +{ + struct avc_node *node; + struct av_decision avd; + u32 denied; + struct extended_perms_decision local_xpd; + struct extended_perms_decision *xpd = NULL; + struct extended_perms_data allowed; + struct extended_perms_data auditallow; + struct extended_perms_data dontaudit; + struct avc_xperms_node local_xp_node; + struct avc_xperms_node *xp_node; + int rc = 0, rc2; + + xp_node = &local_xp_node; + if (WARN_ON(!requested)) + return -EACCES; + + rcu_read_lock(); + + node = avc_lookup(state->avc, ssid, tsid, tclass); + if (unlikely(!node)) { + avc_compute_av(state, ssid, tsid, tclass, &avd, xp_node); + } else { + memcpy(&avd, &node->ae.avd, sizeof(avd)); + xp_node = node->ae.xp_node; + } + /* if extended permissions are not defined, only consider av_decision */ + if (!xp_node || !xp_node->xp.len) + goto decision; + + local_xpd.allowed = &allowed; + local_xpd.auditallow = &auditallow; + local_xpd.dontaudit = &dontaudit; + + xpd = avc_xperms_decision_lookup(driver, xp_node); + if (unlikely(!xpd)) { + /* + * Compute the extended_perms_decision only if the driver + * is flagged + */ + if (!security_xperm_test(xp_node->xp.drivers.p, driver)) { + avd.allowed &= ~requested; + goto decision; + } + rcu_read_unlock(); + security_compute_xperms_decision(state, ssid, tsid, tclass, + driver, &local_xpd); + rcu_read_lock(); + avc_update_node(state->avc, AVC_CALLBACK_ADD_XPERMS, requested, + driver, xperm, ssid, tsid, tclass, avd.seqno, + &local_xpd, 0); + } else { + avc_quick_copy_xperms_decision(xperm, &local_xpd, xpd); + } + xpd = &local_xpd; + + if (!avc_xperms_has_perm(xpd, xperm, XPERMS_ALLOWED)) + avd.allowed &= ~requested; + +decision: + denied = requested & ~(avd.allowed); + if (unlikely(denied)) + rc = avc_denied(state, ssid, tsid, tclass, requested, + driver, xperm, AVC_EXTENDED_PERMS, &avd); + + rcu_read_unlock(); + + rc2 = avc_xperms_audit(state, ssid, tsid, tclass, requested, + &avd, xpd, xperm, rc, ad); + if (rc2) + return rc2; + return rc; +} + +/** + * avc_has_perm_noaudit - Check permissions but perform no auditing. + * @state: SELinux state + * @ssid: source security identifier + * @tsid: target security identifier + * @tclass: target security class + * @requested: requested permissions, interpreted based on @tclass + * @flags: AVC_STRICT or 0 + * @avd: access vector decisions + * + * Check the AVC to determine whether the @requested permissions are granted + * for the SID pair (@ssid, @tsid), interpreting the permissions + * based on @tclass, and call the security server on a cache miss to obtain + * a new decision and add it to the cache. Return a copy of the decisions + * in @avd. Return %0 if all @requested permissions are granted, + * -%EACCES if any permissions are denied, or another -errno upon + * other errors. This function is typically called by avc_has_perm(), + * but may also be called directly to separate permission checking from + * auditing, e.g. in cases where a lock must be held for the check but + * should be released for the auditing. + */ +inline int avc_has_perm_noaudit(struct selinux_state *state, + u32 ssid, u32 tsid, + u16 tclass, u32 requested, + unsigned int flags, + struct av_decision *avd) +{ + struct avc_node *node; + struct avc_xperms_node xp_node; + int rc = 0; + u32 denied; + + if (WARN_ON(!requested)) + return -EACCES; + + rcu_read_lock(); + + node = avc_lookup(state->avc, ssid, tsid, tclass); + if (unlikely(!node)) + avc_compute_av(state, ssid, tsid, tclass, avd, &xp_node); + else + memcpy(avd, &node->ae.avd, sizeof(*avd)); + + denied = requested & ~(avd->allowed); + if (unlikely(denied)) + rc = avc_denied(state, ssid, tsid, tclass, requested, 0, 0, + flags, avd); + + rcu_read_unlock(); + return rc; +} + +/** + * avc_has_perm - Check permissions and perform any appropriate auditing. + * @state: SELinux state + * @ssid: source security identifier + * @tsid: target security identifier + * @tclass: target security class + * @requested: requested permissions, interpreted based on @tclass + * @auditdata: auxiliary audit data + * + * Check the AVC to determine whether the @requested permissions are granted + * for the SID pair (@ssid, @tsid), interpreting the permissions + * based on @tclass, and call the security server on a cache miss to obtain + * a new decision and add it to the cache. Audit the granting or denial of + * permissions in accordance with the policy. Return %0 if all @requested + * permissions are granted, -%EACCES if any permissions are denied, or + * another -errno upon other errors. + */ +int avc_has_perm(struct selinux_state *state, u32 ssid, u32 tsid, u16 tclass, + u32 requested, struct common_audit_data *auditdata) +{ + struct av_decision avd; + int rc, rc2; + + rc = avc_has_perm_noaudit(state, ssid, tsid, tclass, requested, 0, + &avd); + + rc2 = avc_audit(state, ssid, tsid, tclass, requested, &avd, rc, + auditdata); + if (rc2) + return rc2; + return rc; +} + +u32 avc_policy_seqno(struct selinux_state *state) +{ + return state->avc->avc_cache.latest_notif; +} + +void avc_disable(void) +{ + /* + * If you are looking at this because you have realized that we are + * not destroying the avc_node_cachep it might be easy to fix, but + * I don't know the memory barrier semantics well enough to know. It's + * possible that some other task dereferenced security_ops when + * it still pointed to selinux operations. If that is the case it's + * possible that it is about to use the avc and is about to need the + * avc_node_cachep. I know I could wrap the security.c security_ops call + * in an rcu_lock, but seriously, it's not worth it. Instead I just flush + * the cache and get that memory back. + */ + if (avc_node_cachep) { + avc_flush(selinux_state.avc); + /* kmem_cache_destroy(avc_node_cachep); */ + } +} diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c new file mode 100644 index 000000000..78f3da39b --- /dev/null +++ b/security/selinux/hooks.c @@ -0,0 +1,7570 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * NSA Security-Enhanced Linux (SELinux) security module + * + * This file contains the SELinux hook function implementations. + * + * Authors: Stephen Smalley, <sds@tycho.nsa.gov> + * Chris Vance, <cvance@nai.com> + * Wayne Salamon, <wsalamon@nai.com> + * James Morris <jmorris@redhat.com> + * + * Copyright (C) 2001,2002 Networks Associates Technology, Inc. + * Copyright (C) 2003-2008 Red Hat, Inc., James Morris <jmorris@redhat.com> + * Eric Paris <eparis@redhat.com> + * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc. + * <dgoeddel@trustedcs.com> + * Copyright (C) 2006, 2007, 2009 Hewlett-Packard Development Company, L.P. + * Paul Moore <paul@paul-moore.com> + * Copyright (C) 2007 Hitachi Software Engineering Co., Ltd. + * Yuichi Nakamura <ynakam@hitachisoft.jp> + * Copyright (C) 2016 Mellanox Technologies + */ + +#include <linux/init.h> +#include <linux/kd.h> +#include <linux/kernel.h> +#include <linux/kernel_read_file.h> +#include <linux/errno.h> +#include <linux/sched/signal.h> +#include <linux/sched/task.h> +#include <linux/lsm_hooks.h> +#include <linux/xattr.h> +#include <linux/capability.h> +#include <linux/unistd.h> +#include <linux/mm.h> +#include <linux/mman.h> +#include <linux/slab.h> +#include <linux/pagemap.h> +#include <linux/proc_fs.h> +#include <linux/swap.h> +#include <linux/spinlock.h> +#include <linux/syscalls.h> +#include <linux/dcache.h> +#include <linux/file.h> +#include <linux/fdtable.h> +#include <linux/namei.h> +#include <linux/mount.h> +#include <linux/fs_context.h> +#include <linux/fs_parser.h> +#include <linux/netfilter_ipv4.h> +#include <linux/netfilter_ipv6.h> +#include <linux/tty.h> +#include <net/icmp.h> +#include <net/ip.h> /* for local_port_range[] */ +#include <net/tcp.h> /* struct or_callable used in sock_rcv_skb */ +#include <net/inet_connection_sock.h> +#include <net/net_namespace.h> +#include <net/netlabel.h> +#include <linux/uaccess.h> +#include <asm/ioctls.h> +#include <linux/atomic.h> +#include <linux/bitops.h> +#include <linux/interrupt.h> +#include <linux/netdevice.h> /* for network interface checks */ +#include <net/netlink.h> +#include <linux/tcp.h> +#include <linux/udp.h> +#include <linux/dccp.h> +#include <linux/sctp.h> +#include <net/sctp/structs.h> +#include <linux/quota.h> +#include <linux/un.h> /* for Unix socket types */ +#include <net/af_unix.h> /* for Unix socket types */ +#include <linux/parser.h> +#include <linux/nfs_mount.h> +#include <net/ipv6.h> +#include <linux/hugetlb.h> +#include <linux/personality.h> +#include <linux/audit.h> +#include <linux/string.h> +#include <linux/mutex.h> +#include <linux/posix-timers.h> +#include <linux/syslog.h> +#include <linux/user_namespace.h> +#include <linux/export.h> +#include <linux/msg.h> +#include <linux/shm.h> +#include <linux/bpf.h> +#include <linux/kernfs.h> +#include <linux/stringhash.h> /* for hashlen_string() */ +#include <uapi/linux/mount.h> +#include <linux/fsnotify.h> +#include <linux/fanotify.h> +#include <linux/io_uring.h> + +#include "avc.h" +#include "objsec.h" +#include "netif.h" +#include "netnode.h" +#include "netport.h" +#include "ibpkey.h" +#include "xfrm.h" +#include "netlabel.h" +#include "audit.h" +#include "avc_ss.h" + +struct selinux_state selinux_state; + +/* SECMARK reference count */ +static atomic_t selinux_secmark_refcount = ATOMIC_INIT(0); + +#ifdef CONFIG_SECURITY_SELINUX_DEVELOP +static int selinux_enforcing_boot __initdata; + +static int __init enforcing_setup(char *str) +{ + unsigned long enforcing; + if (!kstrtoul(str, 0, &enforcing)) + selinux_enforcing_boot = enforcing ? 1 : 0; + return 1; +} +__setup("enforcing=", enforcing_setup); +#else +#define selinux_enforcing_boot 1 +#endif + +int selinux_enabled_boot __initdata = 1; +#ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM +static int __init selinux_enabled_setup(char *str) +{ + unsigned long enabled; + if (!kstrtoul(str, 0, &enabled)) + selinux_enabled_boot = enabled ? 1 : 0; + return 1; +} +__setup("selinux=", selinux_enabled_setup); +#endif + +static unsigned int selinux_checkreqprot_boot = + CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE; + +static int __init checkreqprot_setup(char *str) +{ + unsigned long checkreqprot; + + if (!kstrtoul(str, 0, &checkreqprot)) { + selinux_checkreqprot_boot = checkreqprot ? 1 : 0; + if (checkreqprot) + pr_err("SELinux: checkreqprot set to 1 via kernel parameter. This is deprecated and will be rejected in a future kernel release.\n"); + } + return 1; +} +__setup("checkreqprot=", checkreqprot_setup); + +/** + * selinux_secmark_enabled - Check to see if SECMARK is currently enabled + * + * Description: + * This function checks the SECMARK reference counter to see if any SECMARK + * targets are currently configured, if the reference counter is greater than + * zero SECMARK is considered to be enabled. Returns true (1) if SECMARK is + * enabled, false (0) if SECMARK is disabled. If the always_check_network + * policy capability is enabled, SECMARK is always considered enabled. + * + */ +static int selinux_secmark_enabled(void) +{ + return (selinux_policycap_alwaysnetwork() || + atomic_read(&selinux_secmark_refcount)); +} + +/** + * selinux_peerlbl_enabled - Check to see if peer labeling is currently enabled + * + * Description: + * This function checks if NetLabel or labeled IPSEC is enabled. Returns true + * (1) if any are enabled or false (0) if neither are enabled. If the + * always_check_network policy capability is enabled, peer labeling + * is always considered enabled. + * + */ +static int selinux_peerlbl_enabled(void) +{ + return (selinux_policycap_alwaysnetwork() || + netlbl_enabled() || selinux_xfrm_enabled()); +} + +static int selinux_netcache_avc_callback(u32 event) +{ + if (event == AVC_CALLBACK_RESET) { + sel_netif_flush(); + sel_netnode_flush(); + sel_netport_flush(); + synchronize_net(); + } + return 0; +} + +static int selinux_lsm_notifier_avc_callback(u32 event) +{ + if (event == AVC_CALLBACK_RESET) { + sel_ib_pkey_flush(); + call_blocking_lsm_notifier(LSM_POLICY_CHANGE, NULL); + } + + return 0; +} + +/* + * initialise the security for the init task + */ +static void cred_init_security(void) +{ + struct task_security_struct *tsec; + + tsec = selinux_cred(unrcu_pointer(current->real_cred)); + tsec->osid = tsec->sid = SECINITSID_KERNEL; +} + +/* + * get the security ID of a set of credentials + */ +static inline u32 cred_sid(const struct cred *cred) +{ + const struct task_security_struct *tsec; + + tsec = selinux_cred(cred); + return tsec->sid; +} + +/* + * get the objective security ID of a task + */ +static inline u32 task_sid_obj(const struct task_struct *task) +{ + u32 sid; + + rcu_read_lock(); + sid = cred_sid(__task_cred(task)); + rcu_read_unlock(); + return sid; +} + +static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry); + +/* + * Try reloading inode security labels that have been marked as invalid. The + * @may_sleep parameter indicates when sleeping and thus reloading labels is + * allowed; when set to false, returns -ECHILD when the label is + * invalid. The @dentry parameter should be set to a dentry of the inode. + */ +static int __inode_security_revalidate(struct inode *inode, + struct dentry *dentry, + bool may_sleep) +{ + struct inode_security_struct *isec = selinux_inode(inode); + + might_sleep_if(may_sleep); + + if (selinux_initialized(&selinux_state) && + isec->initialized != LABEL_INITIALIZED) { + if (!may_sleep) + return -ECHILD; + + /* + * Try reloading the inode security label. This will fail if + * @opt_dentry is NULL and no dentry for this inode can be + * found; in that case, continue using the old label. + */ + inode_doinit_with_dentry(inode, dentry); + } + return 0; +} + +static struct inode_security_struct *inode_security_novalidate(struct inode *inode) +{ + return selinux_inode(inode); +} + +static struct inode_security_struct *inode_security_rcu(struct inode *inode, bool rcu) +{ + int error; + + error = __inode_security_revalidate(inode, NULL, !rcu); + if (error) + return ERR_PTR(error); + return selinux_inode(inode); +} + +/* + * Get the security label of an inode. + */ +static struct inode_security_struct *inode_security(struct inode *inode) +{ + __inode_security_revalidate(inode, NULL, true); + return selinux_inode(inode); +} + +static struct inode_security_struct *backing_inode_security_novalidate(struct dentry *dentry) +{ + struct inode *inode = d_backing_inode(dentry); + + return selinux_inode(inode); +} + +/* + * Get the security label of a dentry's backing inode. + */ +static struct inode_security_struct *backing_inode_security(struct dentry *dentry) +{ + struct inode *inode = d_backing_inode(dentry); + + __inode_security_revalidate(inode, dentry, true); + return selinux_inode(inode); +} + +static void inode_free_security(struct inode *inode) +{ + struct inode_security_struct *isec = selinux_inode(inode); + struct superblock_security_struct *sbsec; + + if (!isec) + return; + sbsec = selinux_superblock(inode->i_sb); + /* + * As not all inode security structures are in a list, we check for + * empty list outside of the lock to make sure that we won't waste + * time taking a lock doing nothing. + * + * The list_del_init() function can be safely called more than once. + * It should not be possible for this function to be called with + * concurrent list_add(), but for better safety against future changes + * in the code, we use list_empty_careful() here. + */ + if (!list_empty_careful(&isec->list)) { + spin_lock(&sbsec->isec_lock); + list_del_init(&isec->list); + spin_unlock(&sbsec->isec_lock); + } +} + +struct selinux_mnt_opts { + u32 fscontext_sid; + u32 context_sid; + u32 rootcontext_sid; + u32 defcontext_sid; +}; + +static void selinux_free_mnt_opts(void *mnt_opts) +{ + kfree(mnt_opts); +} + +enum { + Opt_error = -1, + Opt_context = 0, + Opt_defcontext = 1, + Opt_fscontext = 2, + Opt_rootcontext = 3, + Opt_seclabel = 4, +}; + +#define A(s, has_arg) {#s, sizeof(#s) - 1, Opt_##s, has_arg} +static struct { + const char *name; + int len; + int opt; + bool has_arg; +} tokens[] = { + A(context, true), + A(fscontext, true), + A(defcontext, true), + A(rootcontext, true), + A(seclabel, false), +}; +#undef A + +static int match_opt_prefix(char *s, int l, char **arg) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(tokens); i++) { + size_t len = tokens[i].len; + if (len > l || memcmp(s, tokens[i].name, len)) + continue; + if (tokens[i].has_arg) { + if (len == l || s[len] != '=') + continue; + *arg = s + len + 1; + } else if (len != l) + continue; + return tokens[i].opt; + } + return Opt_error; +} + +#define SEL_MOUNT_FAIL_MSG "SELinux: duplicate or incompatible mount options\n" + +static int may_context_mount_sb_relabel(u32 sid, + struct superblock_security_struct *sbsec, + const struct cred *cred) +{ + const struct task_security_struct *tsec = selinux_cred(cred); + int rc; + + rc = avc_has_perm(&selinux_state, + tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM, + FILESYSTEM__RELABELFROM, NULL); + if (rc) + return rc; + + rc = avc_has_perm(&selinux_state, + tsec->sid, sid, SECCLASS_FILESYSTEM, + FILESYSTEM__RELABELTO, NULL); + return rc; +} + +static int may_context_mount_inode_relabel(u32 sid, + struct superblock_security_struct *sbsec, + const struct cred *cred) +{ + const struct task_security_struct *tsec = selinux_cred(cred); + int rc; + rc = avc_has_perm(&selinux_state, + tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM, + FILESYSTEM__RELABELFROM, NULL); + if (rc) + return rc; + + rc = avc_has_perm(&selinux_state, + sid, sbsec->sid, SECCLASS_FILESYSTEM, + FILESYSTEM__ASSOCIATE, NULL); + return rc; +} + +static int selinux_is_genfs_special_handling(struct super_block *sb) +{ + /* Special handling. Genfs but also in-core setxattr handler */ + return !strcmp(sb->s_type->name, "sysfs") || + !strcmp(sb->s_type->name, "pstore") || + !strcmp(sb->s_type->name, "debugfs") || + !strcmp(sb->s_type->name, "tracefs") || + !strcmp(sb->s_type->name, "rootfs") || + (selinux_policycap_cgroupseclabel() && + (!strcmp(sb->s_type->name, "cgroup") || + !strcmp(sb->s_type->name, "cgroup2"))); +} + +static int selinux_is_sblabel_mnt(struct super_block *sb) +{ + struct superblock_security_struct *sbsec = selinux_superblock(sb); + + /* + * IMPORTANT: Double-check logic in this function when adding a new + * SECURITY_FS_USE_* definition! + */ + BUILD_BUG_ON(SECURITY_FS_USE_MAX != 7); + + switch (sbsec->behavior) { + case SECURITY_FS_USE_XATTR: + case SECURITY_FS_USE_TRANS: + case SECURITY_FS_USE_TASK: + case SECURITY_FS_USE_NATIVE: + return 1; + + case SECURITY_FS_USE_GENFS: + return selinux_is_genfs_special_handling(sb); + + /* Never allow relabeling on context mounts */ + case SECURITY_FS_USE_MNTPOINT: + case SECURITY_FS_USE_NONE: + default: + return 0; + } +} + +static int sb_check_xattr_support(struct super_block *sb) +{ + struct superblock_security_struct *sbsec = selinux_superblock(sb); + struct dentry *root = sb->s_root; + struct inode *root_inode = d_backing_inode(root); + u32 sid; + int rc; + + /* + * Make sure that the xattr handler exists and that no + * error other than -ENODATA is returned by getxattr on + * the root directory. -ENODATA is ok, as this may be + * the first boot of the SELinux kernel before we have + * assigned xattr values to the filesystem. + */ + if (!(root_inode->i_opflags & IOP_XATTR)) { + pr_warn("SELinux: (dev %s, type %s) has no xattr support\n", + sb->s_id, sb->s_type->name); + goto fallback; + } + + rc = __vfs_getxattr(root, root_inode, XATTR_NAME_SELINUX, NULL, 0); + if (rc < 0 && rc != -ENODATA) { + if (rc == -EOPNOTSUPP) { + pr_warn("SELinux: (dev %s, type %s) has no security xattr handler\n", + sb->s_id, sb->s_type->name); + goto fallback; + } else { + pr_warn("SELinux: (dev %s, type %s) getxattr errno %d\n", + sb->s_id, sb->s_type->name, -rc); + return rc; + } + } + return 0; + +fallback: + /* No xattr support - try to fallback to genfs if possible. */ + rc = security_genfs_sid(&selinux_state, sb->s_type->name, "/", + SECCLASS_DIR, &sid); + if (rc) + return -EOPNOTSUPP; + + pr_warn("SELinux: (dev %s, type %s) falling back to genfs\n", + sb->s_id, sb->s_type->name); + sbsec->behavior = SECURITY_FS_USE_GENFS; + sbsec->sid = sid; + return 0; +} + +static int sb_finish_set_opts(struct super_block *sb) +{ + struct superblock_security_struct *sbsec = selinux_superblock(sb); + struct dentry *root = sb->s_root; + struct inode *root_inode = d_backing_inode(root); + int rc = 0; + + if (sbsec->behavior == SECURITY_FS_USE_XATTR) { + rc = sb_check_xattr_support(sb); + if (rc) + return rc; + } + + sbsec->flags |= SE_SBINITIALIZED; + + /* + * Explicitly set or clear SBLABEL_MNT. It's not sufficient to simply + * leave the flag untouched because sb_clone_mnt_opts might be handing + * us a superblock that needs the flag to be cleared. + */ + if (selinux_is_sblabel_mnt(sb)) + sbsec->flags |= SBLABEL_MNT; + else + sbsec->flags &= ~SBLABEL_MNT; + + /* Initialize the root inode. */ + rc = inode_doinit_with_dentry(root_inode, root); + + /* Initialize any other inodes associated with the superblock, e.g. + inodes created prior to initial policy load or inodes created + during get_sb by a pseudo filesystem that directly + populates itself. */ + spin_lock(&sbsec->isec_lock); + while (!list_empty(&sbsec->isec_head)) { + struct inode_security_struct *isec = + list_first_entry(&sbsec->isec_head, + struct inode_security_struct, list); + struct inode *inode = isec->inode; + list_del_init(&isec->list); + spin_unlock(&sbsec->isec_lock); + inode = igrab(inode); + if (inode) { + if (!IS_PRIVATE(inode)) + inode_doinit_with_dentry(inode, NULL); + iput(inode); + } + spin_lock(&sbsec->isec_lock); + } + spin_unlock(&sbsec->isec_lock); + return rc; +} + +static int bad_option(struct superblock_security_struct *sbsec, char flag, + u32 old_sid, u32 new_sid) +{ + char mnt_flags = sbsec->flags & SE_MNTMASK; + + /* check if the old mount command had the same options */ + if (sbsec->flags & SE_SBINITIALIZED) + if (!(sbsec->flags & flag) || + (old_sid != new_sid)) + return 1; + + /* check if we were passed the same options twice, + * aka someone passed context=a,context=b + */ + if (!(sbsec->flags & SE_SBINITIALIZED)) + if (mnt_flags & flag) + return 1; + return 0; +} + +/* + * Allow filesystems with binary mount data to explicitly set mount point + * labeling information. + */ +static int selinux_set_mnt_opts(struct super_block *sb, + void *mnt_opts, + unsigned long kern_flags, + unsigned long *set_kern_flags) +{ + const struct cred *cred = current_cred(); + struct superblock_security_struct *sbsec = selinux_superblock(sb); + struct dentry *root = sb->s_root; + struct selinux_mnt_opts *opts = mnt_opts; + struct inode_security_struct *root_isec; + u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0; + u32 defcontext_sid = 0; + int rc = 0; + + mutex_lock(&sbsec->lock); + + if (!selinux_initialized(&selinux_state)) { + if (!opts) { + /* Defer initialization until selinux_complete_init, + after the initial policy is loaded and the security + server is ready to handle calls. */ + goto out; + } + rc = -EINVAL; + pr_warn("SELinux: Unable to set superblock options " + "before the security server is initialized\n"); + goto out; + } + if (kern_flags && !set_kern_flags) { + /* Specifying internal flags without providing a place to + * place the results is not allowed */ + rc = -EINVAL; + goto out; + } + + /* + * Binary mount data FS will come through this function twice. Once + * from an explicit call and once from the generic calls from the vfs. + * Since the generic VFS calls will not contain any security mount data + * we need to skip the double mount verification. + * + * This does open a hole in which we will not notice if the first + * mount using this sb set explicit options and a second mount using + * this sb does not set any security options. (The first options + * will be used for both mounts) + */ + if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA) + && !opts) + goto out; + + root_isec = backing_inode_security_novalidate(root); + + /* + * parse the mount options, check if they are valid sids. + * also check if someone is trying to mount the same sb more + * than once with different security options. + */ + if (opts) { + if (opts->fscontext_sid) { + fscontext_sid = opts->fscontext_sid; + if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, + fscontext_sid)) + goto out_double_mount; + sbsec->flags |= FSCONTEXT_MNT; + } + if (opts->context_sid) { + context_sid = opts->context_sid; + if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, + context_sid)) + goto out_double_mount; + sbsec->flags |= CONTEXT_MNT; + } + if (opts->rootcontext_sid) { + rootcontext_sid = opts->rootcontext_sid; + if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, + rootcontext_sid)) + goto out_double_mount; + sbsec->flags |= ROOTCONTEXT_MNT; + } + if (opts->defcontext_sid) { + defcontext_sid = opts->defcontext_sid; + if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, + defcontext_sid)) + goto out_double_mount; + sbsec->flags |= DEFCONTEXT_MNT; + } + } + + if (sbsec->flags & SE_SBINITIALIZED) { + /* previously mounted with options, but not on this attempt? */ + if ((sbsec->flags & SE_MNTMASK) && !opts) + goto out_double_mount; + rc = 0; + goto out; + } + + if (strcmp(sb->s_type->name, "proc") == 0) + sbsec->flags |= SE_SBPROC | SE_SBGENFS; + + if (!strcmp(sb->s_type->name, "debugfs") || + !strcmp(sb->s_type->name, "tracefs") || + !strcmp(sb->s_type->name, "binder") || + !strcmp(sb->s_type->name, "bpf") || + !strcmp(sb->s_type->name, "pstore") || + !strcmp(sb->s_type->name, "securityfs")) + sbsec->flags |= SE_SBGENFS; + + if (!strcmp(sb->s_type->name, "sysfs") || + !strcmp(sb->s_type->name, "cgroup") || + !strcmp(sb->s_type->name, "cgroup2")) + sbsec->flags |= SE_SBGENFS | SE_SBGENFS_XATTR; + + if (!sbsec->behavior) { + /* + * Determine the labeling behavior to use for this + * filesystem type. + */ + rc = security_fs_use(&selinux_state, sb); + if (rc) { + pr_warn("%s: security_fs_use(%s) returned %d\n", + __func__, sb->s_type->name, rc); + goto out; + } + } + + /* + * If this is a user namespace mount and the filesystem type is not + * explicitly whitelisted, then no contexts are allowed on the command + * line and security labels must be ignored. + */ + if (sb->s_user_ns != &init_user_ns && + strcmp(sb->s_type->name, "tmpfs") && + strcmp(sb->s_type->name, "ramfs") && + strcmp(sb->s_type->name, "devpts") && + strcmp(sb->s_type->name, "overlay")) { + if (context_sid || fscontext_sid || rootcontext_sid || + defcontext_sid) { + rc = -EACCES; + goto out; + } + if (sbsec->behavior == SECURITY_FS_USE_XATTR) { + sbsec->behavior = SECURITY_FS_USE_MNTPOINT; + rc = security_transition_sid(&selinux_state, + current_sid(), + current_sid(), + SECCLASS_FILE, NULL, + &sbsec->mntpoint_sid); + if (rc) + goto out; + } + goto out_set_opts; + } + + /* sets the context of the superblock for the fs being mounted. */ + if (fscontext_sid) { + rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred); + if (rc) + goto out; + + sbsec->sid = fscontext_sid; + } + + /* + * Switch to using mount point labeling behavior. + * sets the label used on all file below the mountpoint, and will set + * the superblock context if not already set. + */ + if (kern_flags & SECURITY_LSM_NATIVE_LABELS && !context_sid) { + sbsec->behavior = SECURITY_FS_USE_NATIVE; + *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS; + } + + if (context_sid) { + if (!fscontext_sid) { + rc = may_context_mount_sb_relabel(context_sid, sbsec, + cred); + if (rc) + goto out; + sbsec->sid = context_sid; + } else { + rc = may_context_mount_inode_relabel(context_sid, sbsec, + cred); + if (rc) + goto out; + } + if (!rootcontext_sid) + rootcontext_sid = context_sid; + + sbsec->mntpoint_sid = context_sid; + sbsec->behavior = SECURITY_FS_USE_MNTPOINT; + } + + if (rootcontext_sid) { + rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec, + cred); + if (rc) + goto out; + + root_isec->sid = rootcontext_sid; + root_isec->initialized = LABEL_INITIALIZED; + } + + if (defcontext_sid) { + if (sbsec->behavior != SECURITY_FS_USE_XATTR && + sbsec->behavior != SECURITY_FS_USE_NATIVE) { + rc = -EINVAL; + pr_warn("SELinux: defcontext option is " + "invalid for this filesystem type\n"); + goto out; + } + + if (defcontext_sid != sbsec->def_sid) { + rc = may_context_mount_inode_relabel(defcontext_sid, + sbsec, cred); + if (rc) + goto out; + } + + sbsec->def_sid = defcontext_sid; + } + +out_set_opts: + rc = sb_finish_set_opts(sb); +out: + mutex_unlock(&sbsec->lock); + return rc; +out_double_mount: + rc = -EINVAL; + pr_warn("SELinux: mount invalid. Same superblock, different " + "security settings for (dev %s, type %s)\n", sb->s_id, + sb->s_type->name); + goto out; +} + +static int selinux_cmp_sb_context(const struct super_block *oldsb, + const struct super_block *newsb) +{ + struct superblock_security_struct *old = selinux_superblock(oldsb); + struct superblock_security_struct *new = selinux_superblock(newsb); + char oldflags = old->flags & SE_MNTMASK; + char newflags = new->flags & SE_MNTMASK; + + if (oldflags != newflags) + goto mismatch; + if ((oldflags & FSCONTEXT_MNT) && old->sid != new->sid) + goto mismatch; + if ((oldflags & CONTEXT_MNT) && old->mntpoint_sid != new->mntpoint_sid) + goto mismatch; + if ((oldflags & DEFCONTEXT_MNT) && old->def_sid != new->def_sid) + goto mismatch; + if (oldflags & ROOTCONTEXT_MNT) { + struct inode_security_struct *oldroot = backing_inode_security(oldsb->s_root); + struct inode_security_struct *newroot = backing_inode_security(newsb->s_root); + if (oldroot->sid != newroot->sid) + goto mismatch; + } + return 0; +mismatch: + pr_warn("SELinux: mount invalid. Same superblock, " + "different security settings for (dev %s, " + "type %s)\n", newsb->s_id, newsb->s_type->name); + return -EBUSY; +} + +static int selinux_sb_clone_mnt_opts(const struct super_block *oldsb, + struct super_block *newsb, + unsigned long kern_flags, + unsigned long *set_kern_flags) +{ + int rc = 0; + const struct superblock_security_struct *oldsbsec = + selinux_superblock(oldsb); + struct superblock_security_struct *newsbsec = selinux_superblock(newsb); + + int set_fscontext = (oldsbsec->flags & FSCONTEXT_MNT); + int set_context = (oldsbsec->flags & CONTEXT_MNT); + int set_rootcontext = (oldsbsec->flags & ROOTCONTEXT_MNT); + + /* + * if the parent was able to be mounted it clearly had no special lsm + * mount options. thus we can safely deal with this superblock later + */ + if (!selinux_initialized(&selinux_state)) + return 0; + + /* + * Specifying internal flags without providing a place to + * place the results is not allowed. + */ + if (kern_flags && !set_kern_flags) + return -EINVAL; + + /* how can we clone if the old one wasn't set up?? */ + BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED)); + + /* if fs is reusing a sb, make sure that the contexts match */ + if (newsbsec->flags & SE_SBINITIALIZED) { + if ((kern_flags & SECURITY_LSM_NATIVE_LABELS) && !set_context) + *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS; + return selinux_cmp_sb_context(oldsb, newsb); + } + + mutex_lock(&newsbsec->lock); + + newsbsec->flags = oldsbsec->flags; + + newsbsec->sid = oldsbsec->sid; + newsbsec->def_sid = oldsbsec->def_sid; + newsbsec->behavior = oldsbsec->behavior; + + if (newsbsec->behavior == SECURITY_FS_USE_NATIVE && + !(kern_flags & SECURITY_LSM_NATIVE_LABELS) && !set_context) { + rc = security_fs_use(&selinux_state, newsb); + if (rc) + goto out; + } + + if (kern_flags & SECURITY_LSM_NATIVE_LABELS && !set_context) { + newsbsec->behavior = SECURITY_FS_USE_NATIVE; + *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS; + } + + if (set_context) { + u32 sid = oldsbsec->mntpoint_sid; + + if (!set_fscontext) + newsbsec->sid = sid; + if (!set_rootcontext) { + struct inode_security_struct *newisec = backing_inode_security(newsb->s_root); + newisec->sid = sid; + } + newsbsec->mntpoint_sid = sid; + } + if (set_rootcontext) { + const struct inode_security_struct *oldisec = backing_inode_security(oldsb->s_root); + struct inode_security_struct *newisec = backing_inode_security(newsb->s_root); + + newisec->sid = oldisec->sid; + } + + sb_finish_set_opts(newsb); +out: + mutex_unlock(&newsbsec->lock); + return rc; +} + +/* + * NOTE: the caller is resposible for freeing the memory even if on error. + */ +static int selinux_add_opt(int token, const char *s, void **mnt_opts) +{ + struct selinux_mnt_opts *opts = *mnt_opts; + u32 *dst_sid; + int rc; + + if (token == Opt_seclabel) + /* eaten and completely ignored */ + return 0; + if (!s) + return -EINVAL; + + if (!selinux_initialized(&selinux_state)) { + pr_warn("SELinux: Unable to set superblock options before the security server is initialized\n"); + return -EINVAL; + } + + if (!opts) { + opts = kzalloc(sizeof(*opts), GFP_KERNEL); + if (!opts) + return -ENOMEM; + *mnt_opts = opts; + } + + switch (token) { + case Opt_context: + if (opts->context_sid || opts->defcontext_sid) + goto err; + dst_sid = &opts->context_sid; + break; + case Opt_fscontext: + if (opts->fscontext_sid) + goto err; + dst_sid = &opts->fscontext_sid; + break; + case Opt_rootcontext: + if (opts->rootcontext_sid) + goto err; + dst_sid = &opts->rootcontext_sid; + break; + case Opt_defcontext: + if (opts->context_sid || opts->defcontext_sid) + goto err; + dst_sid = &opts->defcontext_sid; + break; + default: + WARN_ON(1); + return -EINVAL; + } + rc = security_context_str_to_sid(&selinux_state, s, dst_sid, GFP_KERNEL); + if (rc) + pr_warn("SELinux: security_context_str_to_sid (%s) failed with errno=%d\n", + s, rc); + return rc; + +err: + pr_warn(SEL_MOUNT_FAIL_MSG); + return -EINVAL; +} + +static int show_sid(struct seq_file *m, u32 sid) +{ + char *context = NULL; + u32 len; + int rc; + + rc = security_sid_to_context(&selinux_state, sid, + &context, &len); + if (!rc) { + bool has_comma = strchr(context, ','); + + seq_putc(m, '='); + if (has_comma) + seq_putc(m, '\"'); + seq_escape(m, context, "\"\n\\"); + if (has_comma) + seq_putc(m, '\"'); + } + kfree(context); + return rc; +} + +static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb) +{ + struct superblock_security_struct *sbsec = selinux_superblock(sb); + int rc; + + if (!(sbsec->flags & SE_SBINITIALIZED)) + return 0; + + if (!selinux_initialized(&selinux_state)) + return 0; + + if (sbsec->flags & FSCONTEXT_MNT) { + seq_putc(m, ','); + seq_puts(m, FSCONTEXT_STR); + rc = show_sid(m, sbsec->sid); + if (rc) + return rc; + } + if (sbsec->flags & CONTEXT_MNT) { + seq_putc(m, ','); + seq_puts(m, CONTEXT_STR); + rc = show_sid(m, sbsec->mntpoint_sid); + if (rc) + return rc; + } + if (sbsec->flags & DEFCONTEXT_MNT) { + seq_putc(m, ','); + seq_puts(m, DEFCONTEXT_STR); + rc = show_sid(m, sbsec->def_sid); + if (rc) + return rc; + } + if (sbsec->flags & ROOTCONTEXT_MNT) { + struct dentry *root = sb->s_root; + struct inode_security_struct *isec = backing_inode_security(root); + seq_putc(m, ','); + seq_puts(m, ROOTCONTEXT_STR); + rc = show_sid(m, isec->sid); + if (rc) + return rc; + } + if (sbsec->flags & SBLABEL_MNT) { + seq_putc(m, ','); + seq_puts(m, SECLABEL_STR); + } + return 0; +} + +static inline u16 inode_mode_to_security_class(umode_t mode) +{ + switch (mode & S_IFMT) { + case S_IFSOCK: + return SECCLASS_SOCK_FILE; + case S_IFLNK: + return SECCLASS_LNK_FILE; + case S_IFREG: + return SECCLASS_FILE; + case S_IFBLK: + return SECCLASS_BLK_FILE; + case S_IFDIR: + return SECCLASS_DIR; + case S_IFCHR: + return SECCLASS_CHR_FILE; + case S_IFIFO: + return SECCLASS_FIFO_FILE; + + } + + return SECCLASS_FILE; +} + +static inline int default_protocol_stream(int protocol) +{ + return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP || + protocol == IPPROTO_MPTCP); +} + +static inline int default_protocol_dgram(int protocol) +{ + return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP); +} + +static inline u16 socket_type_to_security_class(int family, int type, int protocol) +{ + int extsockclass = selinux_policycap_extsockclass(); + + switch (family) { + case PF_UNIX: + switch (type) { + case SOCK_STREAM: + case SOCK_SEQPACKET: + return SECCLASS_UNIX_STREAM_SOCKET; + case SOCK_DGRAM: + case SOCK_RAW: + return SECCLASS_UNIX_DGRAM_SOCKET; + } + break; + case PF_INET: + case PF_INET6: + switch (type) { + case SOCK_STREAM: + case SOCK_SEQPACKET: + if (default_protocol_stream(protocol)) + return SECCLASS_TCP_SOCKET; + else if (extsockclass && protocol == IPPROTO_SCTP) + return SECCLASS_SCTP_SOCKET; + else + return SECCLASS_RAWIP_SOCKET; + case SOCK_DGRAM: + if (default_protocol_dgram(protocol)) + return SECCLASS_UDP_SOCKET; + else if (extsockclass && (protocol == IPPROTO_ICMP || + protocol == IPPROTO_ICMPV6)) + return SECCLASS_ICMP_SOCKET; + else + return SECCLASS_RAWIP_SOCKET; + case SOCK_DCCP: + return SECCLASS_DCCP_SOCKET; + default: + return SECCLASS_RAWIP_SOCKET; + } + break; + case PF_NETLINK: + switch (protocol) { + case NETLINK_ROUTE: + return SECCLASS_NETLINK_ROUTE_SOCKET; + case NETLINK_SOCK_DIAG: + return SECCLASS_NETLINK_TCPDIAG_SOCKET; + case NETLINK_NFLOG: + return SECCLASS_NETLINK_NFLOG_SOCKET; + case NETLINK_XFRM: + return SECCLASS_NETLINK_XFRM_SOCKET; + case NETLINK_SELINUX: + return SECCLASS_NETLINK_SELINUX_SOCKET; + case NETLINK_ISCSI: + return SECCLASS_NETLINK_ISCSI_SOCKET; + case NETLINK_AUDIT: + return SECCLASS_NETLINK_AUDIT_SOCKET; + case NETLINK_FIB_LOOKUP: + return SECCLASS_NETLINK_FIB_LOOKUP_SOCKET; + case NETLINK_CONNECTOR: + return SECCLASS_NETLINK_CONNECTOR_SOCKET; + case NETLINK_NETFILTER: + return SECCLASS_NETLINK_NETFILTER_SOCKET; + case NETLINK_DNRTMSG: + return SECCLASS_NETLINK_DNRT_SOCKET; + case NETLINK_KOBJECT_UEVENT: + return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET; + case NETLINK_GENERIC: + return SECCLASS_NETLINK_GENERIC_SOCKET; + case NETLINK_SCSITRANSPORT: + return SECCLASS_NETLINK_SCSITRANSPORT_SOCKET; + case NETLINK_RDMA: + return SECCLASS_NETLINK_RDMA_SOCKET; + case NETLINK_CRYPTO: + return SECCLASS_NETLINK_CRYPTO_SOCKET; + default: + return SECCLASS_NETLINK_SOCKET; + } + case PF_PACKET: + return SECCLASS_PACKET_SOCKET; + case PF_KEY: + return SECCLASS_KEY_SOCKET; + case PF_APPLETALK: + return SECCLASS_APPLETALK_SOCKET; + } + + if (extsockclass) { + switch (family) { + case PF_AX25: + return SECCLASS_AX25_SOCKET; + case PF_IPX: + return SECCLASS_IPX_SOCKET; + case PF_NETROM: + return SECCLASS_NETROM_SOCKET; + case PF_ATMPVC: + return SECCLASS_ATMPVC_SOCKET; + case PF_X25: + return SECCLASS_X25_SOCKET; + case PF_ROSE: + return SECCLASS_ROSE_SOCKET; + case PF_DECnet: + return SECCLASS_DECNET_SOCKET; + case PF_ATMSVC: + return SECCLASS_ATMSVC_SOCKET; + case PF_RDS: + return SECCLASS_RDS_SOCKET; + case PF_IRDA: + return SECCLASS_IRDA_SOCKET; + case PF_PPPOX: + return SECCLASS_PPPOX_SOCKET; + case PF_LLC: + return SECCLASS_LLC_SOCKET; + case PF_CAN: + return SECCLASS_CAN_SOCKET; + case PF_TIPC: + return SECCLASS_TIPC_SOCKET; + case PF_BLUETOOTH: + return SECCLASS_BLUETOOTH_SOCKET; + case PF_IUCV: + return SECCLASS_IUCV_SOCKET; + case PF_RXRPC: + return SECCLASS_RXRPC_SOCKET; + case PF_ISDN: + return SECCLASS_ISDN_SOCKET; + case PF_PHONET: + return SECCLASS_PHONET_SOCKET; + case PF_IEEE802154: + return SECCLASS_IEEE802154_SOCKET; + case PF_CAIF: + return SECCLASS_CAIF_SOCKET; + case PF_ALG: + return SECCLASS_ALG_SOCKET; + case PF_NFC: + return SECCLASS_NFC_SOCKET; + case PF_VSOCK: + return SECCLASS_VSOCK_SOCKET; + case PF_KCM: + return SECCLASS_KCM_SOCKET; + case PF_QIPCRTR: + return SECCLASS_QIPCRTR_SOCKET; + case PF_SMC: + return SECCLASS_SMC_SOCKET; + case PF_XDP: + return SECCLASS_XDP_SOCKET; + case PF_MCTP: + return SECCLASS_MCTP_SOCKET; +#if PF_MAX > 46 +#error New address family defined, please update this function. +#endif + } + } + + return SECCLASS_SOCKET; +} + +static int selinux_genfs_get_sid(struct dentry *dentry, + u16 tclass, + u16 flags, + u32 *sid) +{ + int rc; + struct super_block *sb = dentry->d_sb; + char *buffer, *path; + + buffer = (char *)__get_free_page(GFP_KERNEL); + if (!buffer) + return -ENOMEM; + + path = dentry_path_raw(dentry, buffer, PAGE_SIZE); + if (IS_ERR(path)) + rc = PTR_ERR(path); + else { + if (flags & SE_SBPROC) { + /* each process gets a /proc/PID/ entry. Strip off the + * PID part to get a valid selinux labeling. + * e.g. /proc/1/net/rpc/nfs -> /net/rpc/nfs */ + while (path[1] >= '0' && path[1] <= '9') { + path[1] = '/'; + path++; + } + } + rc = security_genfs_sid(&selinux_state, sb->s_type->name, + path, tclass, sid); + if (rc == -ENOENT) { + /* No match in policy, mark as unlabeled. */ + *sid = SECINITSID_UNLABELED; + rc = 0; + } + } + free_page((unsigned long)buffer); + return rc; +} + +static int inode_doinit_use_xattr(struct inode *inode, struct dentry *dentry, + u32 def_sid, u32 *sid) +{ +#define INITCONTEXTLEN 255 + char *context; + unsigned int len; + int rc; + + len = INITCONTEXTLEN; + context = kmalloc(len + 1, GFP_NOFS); + if (!context) + return -ENOMEM; + + context[len] = '\0'; + rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, context, len); + if (rc == -ERANGE) { + kfree(context); + + /* Need a larger buffer. Query for the right size. */ + rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, NULL, 0); + if (rc < 0) + return rc; + + len = rc; + context = kmalloc(len + 1, GFP_NOFS); + if (!context) + return -ENOMEM; + + context[len] = '\0'; + rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, + context, len); + } + if (rc < 0) { + kfree(context); + if (rc != -ENODATA) { + pr_warn("SELinux: %s: getxattr returned %d for dev=%s ino=%ld\n", + __func__, -rc, inode->i_sb->s_id, inode->i_ino); + return rc; + } + *sid = def_sid; + return 0; + } + + rc = security_context_to_sid_default(&selinux_state, context, rc, sid, + def_sid, GFP_NOFS); + if (rc) { + char *dev = inode->i_sb->s_id; + unsigned long ino = inode->i_ino; + + if (rc == -EINVAL) { + pr_notice_ratelimited("SELinux: inode=%lu on dev=%s was found to have an invalid context=%s. This indicates you may need to relabel the inode or the filesystem in question.\n", + ino, dev, context); + } else { + pr_warn("SELinux: %s: context_to_sid(%s) returned %d for dev=%s ino=%ld\n", + __func__, context, -rc, dev, ino); + } + } + kfree(context); + return 0; +} + +/* The inode's security attributes must be initialized before first use. */ +static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry) +{ + struct superblock_security_struct *sbsec = NULL; + struct inode_security_struct *isec = selinux_inode(inode); + u32 task_sid, sid = 0; + u16 sclass; + struct dentry *dentry; + int rc = 0; + + if (isec->initialized == LABEL_INITIALIZED) + return 0; + + spin_lock(&isec->lock); + if (isec->initialized == LABEL_INITIALIZED) + goto out_unlock; + + if (isec->sclass == SECCLASS_FILE) + isec->sclass = inode_mode_to_security_class(inode->i_mode); + + sbsec = selinux_superblock(inode->i_sb); + if (!(sbsec->flags & SE_SBINITIALIZED)) { + /* Defer initialization until selinux_complete_init, + after the initial policy is loaded and the security + server is ready to handle calls. */ + spin_lock(&sbsec->isec_lock); + if (list_empty(&isec->list)) + list_add(&isec->list, &sbsec->isec_head); + spin_unlock(&sbsec->isec_lock); + goto out_unlock; + } + + sclass = isec->sclass; + task_sid = isec->task_sid; + sid = isec->sid; + isec->initialized = LABEL_PENDING; + spin_unlock(&isec->lock); + + switch (sbsec->behavior) { + case SECURITY_FS_USE_NATIVE: + break; + case SECURITY_FS_USE_XATTR: + if (!(inode->i_opflags & IOP_XATTR)) { + sid = sbsec->def_sid; + break; + } + /* Need a dentry, since the xattr API requires one. + Life would be simpler if we could just pass the inode. */ + if (opt_dentry) { + /* Called from d_instantiate or d_splice_alias. */ + dentry = dget(opt_dentry); + } else { + /* + * Called from selinux_complete_init, try to find a dentry. + * Some filesystems really want a connected one, so try + * that first. We could split SECURITY_FS_USE_XATTR in + * two, depending upon that... + */ + dentry = d_find_alias(inode); + if (!dentry) + dentry = d_find_any_alias(inode); + } + if (!dentry) { + /* + * this is can be hit on boot when a file is accessed + * before the policy is loaded. When we load policy we + * may find inodes that have no dentry on the + * sbsec->isec_head list. No reason to complain as these + * will get fixed up the next time we go through + * inode_doinit with a dentry, before these inodes could + * be used again by userspace. + */ + goto out_invalid; + } + + rc = inode_doinit_use_xattr(inode, dentry, sbsec->def_sid, + &sid); + dput(dentry); + if (rc) + goto out; + break; + case SECURITY_FS_USE_TASK: + sid = task_sid; + break; + case SECURITY_FS_USE_TRANS: + /* Default to the fs SID. */ + sid = sbsec->sid; + + /* Try to obtain a transition SID. */ + rc = security_transition_sid(&selinux_state, task_sid, sid, + sclass, NULL, &sid); + if (rc) + goto out; + break; + case SECURITY_FS_USE_MNTPOINT: + sid = sbsec->mntpoint_sid; + break; + default: + /* Default to the fs superblock SID. */ + sid = sbsec->sid; + + if ((sbsec->flags & SE_SBGENFS) && + (!S_ISLNK(inode->i_mode) || + selinux_policycap_genfs_seclabel_symlinks())) { + /* We must have a dentry to determine the label on + * procfs inodes */ + if (opt_dentry) { + /* Called from d_instantiate or + * d_splice_alias. */ + dentry = dget(opt_dentry); + } else { + /* Called from selinux_complete_init, try to + * find a dentry. Some filesystems really want + * a connected one, so try that first. + */ + dentry = d_find_alias(inode); + if (!dentry) + dentry = d_find_any_alias(inode); + } + /* + * This can be hit on boot when a file is accessed + * before the policy is loaded. When we load policy we + * may find inodes that have no dentry on the + * sbsec->isec_head list. No reason to complain as + * these will get fixed up the next time we go through + * inode_doinit() with a dentry, before these inodes + * could be used again by userspace. + */ + if (!dentry) + goto out_invalid; + rc = selinux_genfs_get_sid(dentry, sclass, + sbsec->flags, &sid); + if (rc) { + dput(dentry); + goto out; + } + + if ((sbsec->flags & SE_SBGENFS_XATTR) && + (inode->i_opflags & IOP_XATTR)) { + rc = inode_doinit_use_xattr(inode, dentry, + sid, &sid); + if (rc) { + dput(dentry); + goto out; + } + } + dput(dentry); + } + break; + } + +out: + spin_lock(&isec->lock); + if (isec->initialized == LABEL_PENDING) { + if (rc) { + isec->initialized = LABEL_INVALID; + goto out_unlock; + } + isec->initialized = LABEL_INITIALIZED; + isec->sid = sid; + } + +out_unlock: + spin_unlock(&isec->lock); + return rc; + +out_invalid: + spin_lock(&isec->lock); + if (isec->initialized == LABEL_PENDING) { + isec->initialized = LABEL_INVALID; + isec->sid = sid; + } + spin_unlock(&isec->lock); + return 0; +} + +/* Convert a Linux signal to an access vector. */ +static inline u32 signal_to_av(int sig) +{ + u32 perm = 0; + + switch (sig) { + case SIGCHLD: + /* Commonly granted from child to parent. */ + perm = PROCESS__SIGCHLD; + break; + case SIGKILL: + /* Cannot be caught or ignored */ + perm = PROCESS__SIGKILL; + break; + case SIGSTOP: + /* Cannot be caught or ignored */ + perm = PROCESS__SIGSTOP; + break; + default: + /* All other signals. */ + perm = PROCESS__SIGNAL; + break; + } + + return perm; +} + +#if CAP_LAST_CAP > 63 +#error Fix SELinux to handle capabilities > 63. +#endif + +/* Check whether a task is allowed to use a capability. */ +static int cred_has_capability(const struct cred *cred, + int cap, unsigned int opts, bool initns) +{ + struct common_audit_data ad; + struct av_decision avd; + u16 sclass; + u32 sid = cred_sid(cred); + u32 av = CAP_TO_MASK(cap); + int rc; + + ad.type = LSM_AUDIT_DATA_CAP; + ad.u.cap = cap; + + switch (CAP_TO_INDEX(cap)) { + case 0: + sclass = initns ? SECCLASS_CAPABILITY : SECCLASS_CAP_USERNS; + break; + case 1: + sclass = initns ? SECCLASS_CAPABILITY2 : SECCLASS_CAP2_USERNS; + break; + default: + pr_err("SELinux: out of range capability %d\n", cap); + BUG(); + return -EINVAL; + } + + rc = avc_has_perm_noaudit(&selinux_state, + sid, sid, sclass, av, 0, &avd); + if (!(opts & CAP_OPT_NOAUDIT)) { + int rc2 = avc_audit(&selinux_state, + sid, sid, sclass, av, &avd, rc, &ad); + if (rc2) + return rc2; + } + return rc; +} + +/* Check whether a task has a particular permission to an inode. + The 'adp' parameter is optional and allows other audit + data to be passed (e.g. the dentry). */ +static int inode_has_perm(const struct cred *cred, + struct inode *inode, + u32 perms, + struct common_audit_data *adp) +{ + struct inode_security_struct *isec; + u32 sid; + + validate_creds(cred); + + if (unlikely(IS_PRIVATE(inode))) + return 0; + + sid = cred_sid(cred); + isec = selinux_inode(inode); + + return avc_has_perm(&selinux_state, + sid, isec->sid, isec->sclass, perms, adp); +} + +/* Same as inode_has_perm, but pass explicit audit data containing + the dentry to help the auditing code to more easily generate the + pathname if needed. */ +static inline int dentry_has_perm(const struct cred *cred, + struct dentry *dentry, + u32 av) +{ + struct inode *inode = d_backing_inode(dentry); + struct common_audit_data ad; + + ad.type = LSM_AUDIT_DATA_DENTRY; + ad.u.dentry = dentry; + __inode_security_revalidate(inode, dentry, true); + return inode_has_perm(cred, inode, av, &ad); +} + +/* Same as inode_has_perm, but pass explicit audit data containing + the path to help the auditing code to more easily generate the + pathname if needed. */ +static inline int path_has_perm(const struct cred *cred, + const struct path *path, + u32 av) +{ + struct inode *inode = d_backing_inode(path->dentry); + struct common_audit_data ad; + + ad.type = LSM_AUDIT_DATA_PATH; + ad.u.path = *path; + __inode_security_revalidate(inode, path->dentry, true); + return inode_has_perm(cred, inode, av, &ad); +} + +/* Same as path_has_perm, but uses the inode from the file struct. */ +static inline int file_path_has_perm(const struct cred *cred, + struct file *file, + u32 av) +{ + struct common_audit_data ad; + + ad.type = LSM_AUDIT_DATA_FILE; + ad.u.file = file; + return inode_has_perm(cred, file_inode(file), av, &ad); +} + +#ifdef CONFIG_BPF_SYSCALL +static int bpf_fd_pass(struct file *file, u32 sid); +#endif + +/* Check whether a task can use an open file descriptor to + access an inode in a given way. Check access to the + descriptor itself, and then use dentry_has_perm to + check a particular permission to the file. + Access to the descriptor is implicitly granted if it + has the same SID as the process. If av is zero, then + access to the file is not checked, e.g. for cases + where only the descriptor is affected like seek. */ +static int file_has_perm(const struct cred *cred, + struct file *file, + u32 av) +{ + struct file_security_struct *fsec = selinux_file(file); + struct inode *inode = file_inode(file); + struct common_audit_data ad; + u32 sid = cred_sid(cred); + int rc; + + ad.type = LSM_AUDIT_DATA_FILE; + ad.u.file = file; + + if (sid != fsec->sid) { + rc = avc_has_perm(&selinux_state, + sid, fsec->sid, + SECCLASS_FD, + FD__USE, + &ad); + if (rc) + goto out; + } + +#ifdef CONFIG_BPF_SYSCALL + rc = bpf_fd_pass(file, cred_sid(cred)); + if (rc) + return rc; +#endif + + /* av is zero if only checking access to the descriptor. */ + rc = 0; + if (av) + rc = inode_has_perm(cred, inode, av, &ad); + +out: + return rc; +} + +/* + * Determine the label for an inode that might be unioned. + */ +static int +selinux_determine_inode_label(const struct task_security_struct *tsec, + struct inode *dir, + const struct qstr *name, u16 tclass, + u32 *_new_isid) +{ + const struct superblock_security_struct *sbsec = + selinux_superblock(dir->i_sb); + + if ((sbsec->flags & SE_SBINITIALIZED) && + (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)) { + *_new_isid = sbsec->mntpoint_sid; + } else if ((sbsec->flags & SBLABEL_MNT) && + tsec->create_sid) { + *_new_isid = tsec->create_sid; + } else { + const struct inode_security_struct *dsec = inode_security(dir); + return security_transition_sid(&selinux_state, tsec->sid, + dsec->sid, tclass, + name, _new_isid); + } + + return 0; +} + +/* Check whether a task can create a file. */ +static int may_create(struct inode *dir, + struct dentry *dentry, + u16 tclass) +{ + const struct task_security_struct *tsec = selinux_cred(current_cred()); + struct inode_security_struct *dsec; + struct superblock_security_struct *sbsec; + u32 sid, newsid; + struct common_audit_data ad; + int rc; + + dsec = inode_security(dir); + sbsec = selinux_superblock(dir->i_sb); + + sid = tsec->sid; + + ad.type = LSM_AUDIT_DATA_DENTRY; + ad.u.dentry = dentry; + + rc = avc_has_perm(&selinux_state, + sid, dsec->sid, SECCLASS_DIR, + DIR__ADD_NAME | DIR__SEARCH, + &ad); + if (rc) + return rc; + + rc = selinux_determine_inode_label(tsec, dir, &dentry->d_name, tclass, + &newsid); + if (rc) + return rc; + + rc = avc_has_perm(&selinux_state, + sid, newsid, tclass, FILE__CREATE, &ad); + if (rc) + return rc; + + return avc_has_perm(&selinux_state, + newsid, sbsec->sid, + SECCLASS_FILESYSTEM, + FILESYSTEM__ASSOCIATE, &ad); +} + +#define MAY_LINK 0 +#define MAY_UNLINK 1 +#define MAY_RMDIR 2 + +/* Check whether a task can link, unlink, or rmdir a file/directory. */ +static int may_link(struct inode *dir, + struct dentry *dentry, + int kind) + +{ + struct inode_security_struct *dsec, *isec; + struct common_audit_data ad; + u32 sid = current_sid(); + u32 av; + int rc; + + dsec = inode_security(dir); + isec = backing_inode_security(dentry); + + ad.type = LSM_AUDIT_DATA_DENTRY; + ad.u.dentry = dentry; + + av = DIR__SEARCH; + av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME); + rc = avc_has_perm(&selinux_state, + sid, dsec->sid, SECCLASS_DIR, av, &ad); + if (rc) + return rc; + + switch (kind) { + case MAY_LINK: + av = FILE__LINK; + break; + case MAY_UNLINK: + av = FILE__UNLINK; + break; + case MAY_RMDIR: + av = DIR__RMDIR; + break; + default: + pr_warn("SELinux: %s: unrecognized kind %d\n", + __func__, kind); + return 0; + } + + rc = avc_has_perm(&selinux_state, + sid, isec->sid, isec->sclass, av, &ad); + return rc; +} + +static inline int may_rename(struct inode *old_dir, + struct dentry *old_dentry, + struct inode *new_dir, + struct dentry *new_dentry) +{ + struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec; + struct common_audit_data ad; + u32 sid = current_sid(); + u32 av; + int old_is_dir, new_is_dir; + int rc; + + old_dsec = inode_security(old_dir); + old_isec = backing_inode_security(old_dentry); + old_is_dir = d_is_dir(old_dentry); + new_dsec = inode_security(new_dir); + + ad.type = LSM_AUDIT_DATA_DENTRY; + + ad.u.dentry = old_dentry; + rc = avc_has_perm(&selinux_state, + sid, old_dsec->sid, SECCLASS_DIR, + DIR__REMOVE_NAME | DIR__SEARCH, &ad); + if (rc) + return rc; + rc = avc_has_perm(&selinux_state, + sid, old_isec->sid, + old_isec->sclass, FILE__RENAME, &ad); + if (rc) + return rc; + if (old_is_dir && new_dir != old_dir) { + rc = avc_has_perm(&selinux_state, + sid, old_isec->sid, + old_isec->sclass, DIR__REPARENT, &ad); + if (rc) + return rc; + } + + ad.u.dentry = new_dentry; + av = DIR__ADD_NAME | DIR__SEARCH; + if (d_is_positive(new_dentry)) + av |= DIR__REMOVE_NAME; + rc = avc_has_perm(&selinux_state, + sid, new_dsec->sid, SECCLASS_DIR, av, &ad); + if (rc) + return rc; + if (d_is_positive(new_dentry)) { + new_isec = backing_inode_security(new_dentry); + new_is_dir = d_is_dir(new_dentry); + rc = avc_has_perm(&selinux_state, + sid, new_isec->sid, + new_isec->sclass, + (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad); + if (rc) + return rc; + } + + return 0; +} + +/* Check whether a task can perform a filesystem operation. */ +static int superblock_has_perm(const struct cred *cred, + struct super_block *sb, + u32 perms, + struct common_audit_data *ad) +{ + struct superblock_security_struct *sbsec; + u32 sid = cred_sid(cred); + + sbsec = selinux_superblock(sb); + return avc_has_perm(&selinux_state, + sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad); +} + +/* Convert a Linux mode and permission mask to an access vector. */ +static inline u32 file_mask_to_av(int mode, int mask) +{ + u32 av = 0; + + if (!S_ISDIR(mode)) { + if (mask & MAY_EXEC) + av |= FILE__EXECUTE; + if (mask & MAY_READ) + av |= FILE__READ; + + if (mask & MAY_APPEND) + av |= FILE__APPEND; + else if (mask & MAY_WRITE) + av |= FILE__WRITE; + + } else { + if (mask & MAY_EXEC) + av |= DIR__SEARCH; + if (mask & MAY_WRITE) + av |= DIR__WRITE; + if (mask & MAY_READ) + av |= DIR__READ; + } + + return av; +} + +/* Convert a Linux file to an access vector. */ +static inline u32 file_to_av(struct file *file) +{ + u32 av = 0; + + if (file->f_mode & FMODE_READ) + av |= FILE__READ; + if (file->f_mode & FMODE_WRITE) { + if (file->f_flags & O_APPEND) + av |= FILE__APPEND; + else + av |= FILE__WRITE; + } + if (!av) { + /* + * Special file opened with flags 3 for ioctl-only use. + */ + av = FILE__IOCTL; + } + + return av; +} + +/* + * Convert a file to an access vector and include the correct + * open permission. + */ +static inline u32 open_file_to_av(struct file *file) +{ + u32 av = file_to_av(file); + struct inode *inode = file_inode(file); + + if (selinux_policycap_openperm() && + inode->i_sb->s_magic != SOCKFS_MAGIC) + av |= FILE__OPEN; + + return av; +} + +/* Hook functions begin here. */ + +static int selinux_binder_set_context_mgr(const struct cred *mgr) +{ + return avc_has_perm(&selinux_state, + current_sid(), cred_sid(mgr), SECCLASS_BINDER, + BINDER__SET_CONTEXT_MGR, NULL); +} + +static int selinux_binder_transaction(const struct cred *from, + const struct cred *to) +{ + u32 mysid = current_sid(); + u32 fromsid = cred_sid(from); + u32 tosid = cred_sid(to); + int rc; + + if (mysid != fromsid) { + rc = avc_has_perm(&selinux_state, + mysid, fromsid, SECCLASS_BINDER, + BINDER__IMPERSONATE, NULL); + if (rc) + return rc; + } + + return avc_has_perm(&selinux_state, fromsid, tosid, + SECCLASS_BINDER, BINDER__CALL, NULL); +} + +static int selinux_binder_transfer_binder(const struct cred *from, + const struct cred *to) +{ + return avc_has_perm(&selinux_state, + cred_sid(from), cred_sid(to), + SECCLASS_BINDER, BINDER__TRANSFER, + NULL); +} + +static int selinux_binder_transfer_file(const struct cred *from, + const struct cred *to, + struct file *file) +{ + u32 sid = cred_sid(to); + struct file_security_struct *fsec = selinux_file(file); + struct dentry *dentry = file->f_path.dentry; + struct inode_security_struct *isec; + struct common_audit_data ad; + int rc; + + ad.type = LSM_AUDIT_DATA_PATH; + ad.u.path = file->f_path; + + if (sid != fsec->sid) { + rc = avc_has_perm(&selinux_state, + sid, fsec->sid, + SECCLASS_FD, + FD__USE, + &ad); + if (rc) + return rc; + } + +#ifdef CONFIG_BPF_SYSCALL + rc = bpf_fd_pass(file, sid); + if (rc) + return rc; +#endif + + if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) + return 0; + + isec = backing_inode_security(dentry); + return avc_has_perm(&selinux_state, + sid, isec->sid, isec->sclass, file_to_av(file), + &ad); +} + +static int selinux_ptrace_access_check(struct task_struct *child, + unsigned int mode) +{ + u32 sid = current_sid(); + u32 csid = task_sid_obj(child); + + if (mode & PTRACE_MODE_READ) + return avc_has_perm(&selinux_state, + sid, csid, SECCLASS_FILE, FILE__READ, NULL); + + return avc_has_perm(&selinux_state, + sid, csid, SECCLASS_PROCESS, PROCESS__PTRACE, NULL); +} + +static int selinux_ptrace_traceme(struct task_struct *parent) +{ + return avc_has_perm(&selinux_state, + task_sid_obj(parent), task_sid_obj(current), + SECCLASS_PROCESS, PROCESS__PTRACE, NULL); +} + +static int selinux_capget(struct task_struct *target, kernel_cap_t *effective, + kernel_cap_t *inheritable, kernel_cap_t *permitted) +{ + return avc_has_perm(&selinux_state, + current_sid(), task_sid_obj(target), SECCLASS_PROCESS, + PROCESS__GETCAP, NULL); +} + +static int selinux_capset(struct cred *new, const struct cred *old, + const kernel_cap_t *effective, + const kernel_cap_t *inheritable, + const kernel_cap_t *permitted) +{ + return avc_has_perm(&selinux_state, + cred_sid(old), cred_sid(new), SECCLASS_PROCESS, + PROCESS__SETCAP, NULL); +} + +/* + * (This comment used to live with the selinux_task_setuid hook, + * which was removed). + * + * Since setuid only affects the current process, and since the SELinux + * controls are not based on the Linux identity attributes, SELinux does not + * need to control this operation. However, SELinux does control the use of + * the CAP_SETUID and CAP_SETGID capabilities using the capable hook. + */ + +static int selinux_capable(const struct cred *cred, struct user_namespace *ns, + int cap, unsigned int opts) +{ + return cred_has_capability(cred, cap, opts, ns == &init_user_ns); +} + +static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb) +{ + const struct cred *cred = current_cred(); + int rc = 0; + + if (!sb) + return 0; + + switch (cmds) { + case Q_SYNC: + case Q_QUOTAON: + case Q_QUOTAOFF: + case Q_SETINFO: + case Q_SETQUOTA: + case Q_XQUOTAOFF: + case Q_XQUOTAON: + case Q_XSETQLIM: + rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAMOD, NULL); + break; + case Q_GETFMT: + case Q_GETINFO: + case Q_GETQUOTA: + case Q_XGETQUOTA: + case Q_XGETQSTAT: + case Q_XGETQSTATV: + case Q_XGETNEXTQUOTA: + rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAGET, NULL); + break; + default: + rc = 0; /* let the kernel handle invalid cmds */ + break; + } + return rc; +} + +static int selinux_quota_on(struct dentry *dentry) +{ + const struct cred *cred = current_cred(); + + return dentry_has_perm(cred, dentry, FILE__QUOTAON); +} + +static int selinux_syslog(int type) +{ + switch (type) { + case SYSLOG_ACTION_READ_ALL: /* Read last kernel messages */ + case SYSLOG_ACTION_SIZE_BUFFER: /* Return size of the log buffer */ + return avc_has_perm(&selinux_state, + current_sid(), SECINITSID_KERNEL, + SECCLASS_SYSTEM, SYSTEM__SYSLOG_READ, NULL); + case SYSLOG_ACTION_CONSOLE_OFF: /* Disable logging to console */ + case SYSLOG_ACTION_CONSOLE_ON: /* Enable logging to console */ + /* Set level of messages printed to console */ + case SYSLOG_ACTION_CONSOLE_LEVEL: + return avc_has_perm(&selinux_state, + current_sid(), SECINITSID_KERNEL, + SECCLASS_SYSTEM, SYSTEM__SYSLOG_CONSOLE, + NULL); + } + /* All other syslog types */ + return avc_has_perm(&selinux_state, + current_sid(), SECINITSID_KERNEL, + SECCLASS_SYSTEM, SYSTEM__SYSLOG_MOD, NULL); +} + +/* + * Check that a process has enough memory to allocate a new virtual + * mapping. 0 means there is enough memory for the allocation to + * succeed and -ENOMEM implies there is not. + * + * Do not audit the selinux permission check, as this is applied to all + * processes that allocate mappings. + */ +static int selinux_vm_enough_memory(struct mm_struct *mm, long pages) +{ + int rc, cap_sys_admin = 0; + + rc = cred_has_capability(current_cred(), CAP_SYS_ADMIN, + CAP_OPT_NOAUDIT, true); + if (rc == 0) + cap_sys_admin = 1; + + return cap_sys_admin; +} + +/* binprm security operations */ + +static u32 ptrace_parent_sid(void) +{ + u32 sid = 0; + struct task_struct *tracer; + + rcu_read_lock(); + tracer = ptrace_parent(current); + if (tracer) + sid = task_sid_obj(tracer); + rcu_read_unlock(); + + return sid; +} + +static int check_nnp_nosuid(const struct linux_binprm *bprm, + const struct task_security_struct *old_tsec, + const struct task_security_struct *new_tsec) +{ + int nnp = (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS); + int nosuid = !mnt_may_suid(bprm->file->f_path.mnt); + int rc; + u32 av; + + if (!nnp && !nosuid) + return 0; /* neither NNP nor nosuid */ + + if (new_tsec->sid == old_tsec->sid) + return 0; /* No change in credentials */ + + /* + * If the policy enables the nnp_nosuid_transition policy capability, + * then we permit transitions under NNP or nosuid if the + * policy allows the corresponding permission between + * the old and new contexts. + */ + if (selinux_policycap_nnp_nosuid_transition()) { + av = 0; + if (nnp) + av |= PROCESS2__NNP_TRANSITION; + if (nosuid) + av |= PROCESS2__NOSUID_TRANSITION; + rc = avc_has_perm(&selinux_state, + old_tsec->sid, new_tsec->sid, + SECCLASS_PROCESS2, av, NULL); + if (!rc) + return 0; + } + + /* + * We also permit NNP or nosuid transitions to bounded SIDs, + * i.e. SIDs that are guaranteed to only be allowed a subset + * of the permissions of the current SID. + */ + rc = security_bounded_transition(&selinux_state, old_tsec->sid, + new_tsec->sid); + if (!rc) + return 0; + + /* + * On failure, preserve the errno values for NNP vs nosuid. + * NNP: Operation not permitted for caller. + * nosuid: Permission denied to file. + */ + if (nnp) + return -EPERM; + return -EACCES; +} + +static int selinux_bprm_creds_for_exec(struct linux_binprm *bprm) +{ + const struct task_security_struct *old_tsec; + struct task_security_struct *new_tsec; + struct inode_security_struct *isec; + struct common_audit_data ad; + struct inode *inode = file_inode(bprm->file); + int rc; + + /* SELinux context only depends on initial program or script and not + * the script interpreter */ + + old_tsec = selinux_cred(current_cred()); + new_tsec = selinux_cred(bprm->cred); + isec = inode_security(inode); + + /* Default to the current task SID. */ + new_tsec->sid = old_tsec->sid; + new_tsec->osid = old_tsec->sid; + + /* Reset fs, key, and sock SIDs on execve. */ + new_tsec->create_sid = 0; + new_tsec->keycreate_sid = 0; + new_tsec->sockcreate_sid = 0; + + if (old_tsec->exec_sid) { + new_tsec->sid = old_tsec->exec_sid; + /* Reset exec SID on execve. */ + new_tsec->exec_sid = 0; + + /* Fail on NNP or nosuid if not an allowed transition. */ + rc = check_nnp_nosuid(bprm, old_tsec, new_tsec); + if (rc) + return rc; + } else { + /* Check for a default transition on this program. */ + rc = security_transition_sid(&selinux_state, old_tsec->sid, + isec->sid, SECCLASS_PROCESS, NULL, + &new_tsec->sid); + if (rc) + return rc; + + /* + * Fallback to old SID on NNP or nosuid if not an allowed + * transition. + */ + rc = check_nnp_nosuid(bprm, old_tsec, new_tsec); + if (rc) + new_tsec->sid = old_tsec->sid; + } + + ad.type = LSM_AUDIT_DATA_FILE; + ad.u.file = bprm->file; + + if (new_tsec->sid == old_tsec->sid) { + rc = avc_has_perm(&selinux_state, + old_tsec->sid, isec->sid, + SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad); + if (rc) + return rc; + } else { + /* Check permissions for the transition. */ + rc = avc_has_perm(&selinux_state, + old_tsec->sid, new_tsec->sid, + SECCLASS_PROCESS, PROCESS__TRANSITION, &ad); + if (rc) + return rc; + + rc = avc_has_perm(&selinux_state, + new_tsec->sid, isec->sid, + SECCLASS_FILE, FILE__ENTRYPOINT, &ad); + if (rc) + return rc; + + /* Check for shared state */ + if (bprm->unsafe & LSM_UNSAFE_SHARE) { + rc = avc_has_perm(&selinux_state, + old_tsec->sid, new_tsec->sid, + SECCLASS_PROCESS, PROCESS__SHARE, + NULL); + if (rc) + return -EPERM; + } + + /* Make sure that anyone attempting to ptrace over a task that + * changes its SID has the appropriate permit */ + if (bprm->unsafe & LSM_UNSAFE_PTRACE) { + u32 ptsid = ptrace_parent_sid(); + if (ptsid != 0) { + rc = avc_has_perm(&selinux_state, + ptsid, new_tsec->sid, + SECCLASS_PROCESS, + PROCESS__PTRACE, NULL); + if (rc) + return -EPERM; + } + } + + /* Clear any possibly unsafe personality bits on exec: */ + bprm->per_clear |= PER_CLEAR_ON_SETID; + + /* Enable secure mode for SIDs transitions unless + the noatsecure permission is granted between + the two SIDs, i.e. ahp returns 0. */ + rc = avc_has_perm(&selinux_state, + old_tsec->sid, new_tsec->sid, + SECCLASS_PROCESS, PROCESS__NOATSECURE, + NULL); + bprm->secureexec |= !!rc; + } + + return 0; +} + +static int match_file(const void *p, struct file *file, unsigned fd) +{ + return file_has_perm(p, file, file_to_av(file)) ? fd + 1 : 0; +} + +/* Derived from fs/exec.c:flush_old_files. */ +static inline void flush_unauthorized_files(const struct cred *cred, + struct files_struct *files) +{ + struct file *file, *devnull = NULL; + struct tty_struct *tty; + int drop_tty = 0; + unsigned n; + + tty = get_current_tty(); + if (tty) { + spin_lock(&tty->files_lock); + if (!list_empty(&tty->tty_files)) { + struct tty_file_private *file_priv; + + /* Revalidate access to controlling tty. + Use file_path_has_perm on the tty path directly + rather than using file_has_perm, as this particular + open file may belong to another process and we are + only interested in the inode-based check here. */ + file_priv = list_first_entry(&tty->tty_files, + struct tty_file_private, list); + file = file_priv->file; + if (file_path_has_perm(cred, file, FILE__READ | FILE__WRITE)) + drop_tty = 1; + } + spin_unlock(&tty->files_lock); + tty_kref_put(tty); + } + /* Reset controlling tty. */ + if (drop_tty) + no_tty(); + + /* Revalidate access to inherited open files. */ + n = iterate_fd(files, 0, match_file, cred); + if (!n) /* none found? */ + return; + + devnull = dentry_open(&selinux_null, O_RDWR, cred); + if (IS_ERR(devnull)) + devnull = NULL; + /* replace all the matching ones with this */ + do { + replace_fd(n - 1, devnull, 0); + } while ((n = iterate_fd(files, n, match_file, cred)) != 0); + if (devnull) + fput(devnull); +} + +/* + * Prepare a process for imminent new credential changes due to exec + */ +static void selinux_bprm_committing_creds(struct linux_binprm *bprm) +{ + struct task_security_struct *new_tsec; + struct rlimit *rlim, *initrlim; + int rc, i; + + new_tsec = selinux_cred(bprm->cred); + if (new_tsec->sid == new_tsec->osid) + return; + + /* Close files for which the new task SID is not authorized. */ + flush_unauthorized_files(bprm->cred, current->files); + + /* Always clear parent death signal on SID transitions. */ + current->pdeath_signal = 0; + + /* Check whether the new SID can inherit resource limits from the old + * SID. If not, reset all soft limits to the lower of the current + * task's hard limit and the init task's soft limit. + * + * Note that the setting of hard limits (even to lower them) can be + * controlled by the setrlimit check. The inclusion of the init task's + * soft limit into the computation is to avoid resetting soft limits + * higher than the default soft limit for cases where the default is + * lower than the hard limit, e.g. RLIMIT_CORE or RLIMIT_STACK. + */ + rc = avc_has_perm(&selinux_state, + new_tsec->osid, new_tsec->sid, SECCLASS_PROCESS, + PROCESS__RLIMITINH, NULL); + if (rc) { + /* protect against do_prlimit() */ + task_lock(current); + for (i = 0; i < RLIM_NLIMITS; i++) { + rlim = current->signal->rlim + i; + initrlim = init_task.signal->rlim + i; + rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur); + } + task_unlock(current); + if (IS_ENABLED(CONFIG_POSIX_TIMERS)) + update_rlimit_cpu(current, rlimit(RLIMIT_CPU)); + } +} + +/* + * Clean up the process immediately after the installation of new credentials + * due to exec + */ +static void selinux_bprm_committed_creds(struct linux_binprm *bprm) +{ + const struct task_security_struct *tsec = selinux_cred(current_cred()); + u32 osid, sid; + int rc; + + osid = tsec->osid; + sid = tsec->sid; + + if (sid == osid) + return; + + /* Check whether the new SID can inherit signal state from the old SID. + * If not, clear itimers to avoid subsequent signal generation and + * flush and unblock signals. + * + * This must occur _after_ the task SID has been updated so that any + * kill done after the flush will be checked against the new SID. + */ + rc = avc_has_perm(&selinux_state, + osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL); + if (rc) { + clear_itimer(); + + spin_lock_irq(&unrcu_pointer(current->sighand)->siglock); + if (!fatal_signal_pending(current)) { + flush_sigqueue(¤t->pending); + flush_sigqueue(¤t->signal->shared_pending); + flush_signal_handlers(current, 1); + sigemptyset(¤t->blocked); + recalc_sigpending(); + } + spin_unlock_irq(&unrcu_pointer(current->sighand)->siglock); + } + + /* Wake up the parent if it is waiting so that it can recheck + * wait permission to the new task SID. */ + read_lock(&tasklist_lock); + __wake_up_parent(current, unrcu_pointer(current->real_parent)); + read_unlock(&tasklist_lock); +} + +/* superblock security operations */ + +static int selinux_sb_alloc_security(struct super_block *sb) +{ + struct superblock_security_struct *sbsec = selinux_superblock(sb); + + mutex_init(&sbsec->lock); + INIT_LIST_HEAD(&sbsec->isec_head); + spin_lock_init(&sbsec->isec_lock); + sbsec->sid = SECINITSID_UNLABELED; + sbsec->def_sid = SECINITSID_FILE; + sbsec->mntpoint_sid = SECINITSID_UNLABELED; + + return 0; +} + +static inline int opt_len(const char *s) +{ + bool open_quote = false; + int len; + char c; + + for (len = 0; (c = s[len]) != '\0'; len++) { + if (c == '"') + open_quote = !open_quote; + if (c == ',' && !open_quote) + break; + } + return len; +} + +static int selinux_sb_eat_lsm_opts(char *options, void **mnt_opts) +{ + char *from = options; + char *to = options; + bool first = true; + int rc; + + while (1) { + int len = opt_len(from); + int token; + char *arg = NULL; + + token = match_opt_prefix(from, len, &arg); + + if (token != Opt_error) { + char *p, *q; + + /* strip quotes */ + if (arg) { + for (p = q = arg; p < from + len; p++) { + char c = *p; + if (c != '"') + *q++ = c; + } + arg = kmemdup_nul(arg, q - arg, GFP_KERNEL); + if (!arg) { + rc = -ENOMEM; + goto free_opt; + } + } + rc = selinux_add_opt(token, arg, mnt_opts); + kfree(arg); + arg = NULL; + if (unlikely(rc)) { + goto free_opt; + } + } else { + if (!first) { // copy with preceding comma + from--; + len++; + } + if (to != from) + memmove(to, from, len); + to += len; + first = false; + } + if (!from[len]) + break; + from += len + 1; + } + *to = '\0'; + return 0; + +free_opt: + if (*mnt_opts) { + selinux_free_mnt_opts(*mnt_opts); + *mnt_opts = NULL; + } + return rc; +} + +static int selinux_sb_mnt_opts_compat(struct super_block *sb, void *mnt_opts) +{ + struct selinux_mnt_opts *opts = mnt_opts; + struct superblock_security_struct *sbsec = selinux_superblock(sb); + + /* + * Superblock not initialized (i.e. no options) - reject if any + * options specified, otherwise accept. + */ + if (!(sbsec->flags & SE_SBINITIALIZED)) + return opts ? 1 : 0; + + /* + * Superblock initialized and no options specified - reject if + * superblock has any options set, otherwise accept. + */ + if (!opts) + return (sbsec->flags & SE_MNTMASK) ? 1 : 0; + + if (opts->fscontext_sid) { + if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, + opts->fscontext_sid)) + return 1; + } + if (opts->context_sid) { + if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, + opts->context_sid)) + return 1; + } + if (opts->rootcontext_sid) { + struct inode_security_struct *root_isec; + + root_isec = backing_inode_security(sb->s_root); + if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, + opts->rootcontext_sid)) + return 1; + } + if (opts->defcontext_sid) { + if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, + opts->defcontext_sid)) + return 1; + } + return 0; +} + +static int selinux_sb_remount(struct super_block *sb, void *mnt_opts) +{ + struct selinux_mnt_opts *opts = mnt_opts; + struct superblock_security_struct *sbsec = selinux_superblock(sb); + + if (!(sbsec->flags & SE_SBINITIALIZED)) + return 0; + + if (!opts) + return 0; + + if (opts->fscontext_sid) { + if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, + opts->fscontext_sid)) + goto out_bad_option; + } + if (opts->context_sid) { + if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, + opts->context_sid)) + goto out_bad_option; + } + if (opts->rootcontext_sid) { + struct inode_security_struct *root_isec; + root_isec = backing_inode_security(sb->s_root); + if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, + opts->rootcontext_sid)) + goto out_bad_option; + } + if (opts->defcontext_sid) { + if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, + opts->defcontext_sid)) + goto out_bad_option; + } + return 0; + +out_bad_option: + pr_warn("SELinux: unable to change security options " + "during remount (dev %s, type=%s)\n", sb->s_id, + sb->s_type->name); + return -EINVAL; +} + +static int selinux_sb_kern_mount(struct super_block *sb) +{ + const struct cred *cred = current_cred(); + struct common_audit_data ad; + + ad.type = LSM_AUDIT_DATA_DENTRY; + ad.u.dentry = sb->s_root; + return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad); +} + +static int selinux_sb_statfs(struct dentry *dentry) +{ + const struct cred *cred = current_cred(); + struct common_audit_data ad; + + ad.type = LSM_AUDIT_DATA_DENTRY; + ad.u.dentry = dentry->d_sb->s_root; + return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad); +} + +static int selinux_mount(const char *dev_name, + const struct path *path, + const char *type, + unsigned long flags, + void *data) +{ + const struct cred *cred = current_cred(); + + if (flags & MS_REMOUNT) + return superblock_has_perm(cred, path->dentry->d_sb, + FILESYSTEM__REMOUNT, NULL); + else + return path_has_perm(cred, path, FILE__MOUNTON); +} + +static int selinux_move_mount(const struct path *from_path, + const struct path *to_path) +{ + const struct cred *cred = current_cred(); + + return path_has_perm(cred, to_path, FILE__MOUNTON); +} + +static int selinux_umount(struct vfsmount *mnt, int flags) +{ + const struct cred *cred = current_cred(); + + return superblock_has_perm(cred, mnt->mnt_sb, + FILESYSTEM__UNMOUNT, NULL); +} + +static int selinux_fs_context_submount(struct fs_context *fc, + struct super_block *reference) +{ + const struct superblock_security_struct *sbsec = selinux_superblock(reference); + struct selinux_mnt_opts *opts; + + /* + * Ensure that fc->security remains NULL when no options are set + * as expected by selinux_set_mnt_opts(). + */ + if (!(sbsec->flags & (FSCONTEXT_MNT|CONTEXT_MNT|DEFCONTEXT_MNT))) + return 0; + + opts = kzalloc(sizeof(*opts), GFP_KERNEL); + if (!opts) + return -ENOMEM; + + if (sbsec->flags & FSCONTEXT_MNT) + opts->fscontext_sid = sbsec->sid; + if (sbsec->flags & CONTEXT_MNT) + opts->context_sid = sbsec->mntpoint_sid; + if (sbsec->flags & DEFCONTEXT_MNT) + opts->defcontext_sid = sbsec->def_sid; + fc->security = opts; + return 0; +} + +static int selinux_fs_context_dup(struct fs_context *fc, + struct fs_context *src_fc) +{ + const struct selinux_mnt_opts *src = src_fc->security; + + if (!src) + return 0; + + fc->security = kmemdup(src, sizeof(*src), GFP_KERNEL); + return fc->security ? 0 : -ENOMEM; +} + +static const struct fs_parameter_spec selinux_fs_parameters[] = { + fsparam_string(CONTEXT_STR, Opt_context), + fsparam_string(DEFCONTEXT_STR, Opt_defcontext), + fsparam_string(FSCONTEXT_STR, Opt_fscontext), + fsparam_string(ROOTCONTEXT_STR, Opt_rootcontext), + fsparam_flag (SECLABEL_STR, Opt_seclabel), + {} +}; + +static int selinux_fs_context_parse_param(struct fs_context *fc, + struct fs_parameter *param) +{ + struct fs_parse_result result; + int opt; + + opt = fs_parse(fc, selinux_fs_parameters, param, &result); + if (opt < 0) + return opt; + + return selinux_add_opt(opt, param->string, &fc->security); +} + +/* inode security operations */ + +static int selinux_inode_alloc_security(struct inode *inode) +{ + struct inode_security_struct *isec = selinux_inode(inode); + u32 sid = current_sid(); + + spin_lock_init(&isec->lock); + INIT_LIST_HEAD(&isec->list); + isec->inode = inode; + isec->sid = SECINITSID_UNLABELED; + isec->sclass = SECCLASS_FILE; + isec->task_sid = sid; + isec->initialized = LABEL_INVALID; + + return 0; +} + +static void selinux_inode_free_security(struct inode *inode) +{ + inode_free_security(inode); +} + +static int selinux_dentry_init_security(struct dentry *dentry, int mode, + const struct qstr *name, + const char **xattr_name, void **ctx, + u32 *ctxlen) +{ + u32 newsid; + int rc; + + rc = selinux_determine_inode_label(selinux_cred(current_cred()), + d_inode(dentry->d_parent), name, + inode_mode_to_security_class(mode), + &newsid); + if (rc) + return rc; + + if (xattr_name) + *xattr_name = XATTR_NAME_SELINUX; + + return security_sid_to_context(&selinux_state, newsid, (char **)ctx, + ctxlen); +} + +static int selinux_dentry_create_files_as(struct dentry *dentry, int mode, + struct qstr *name, + const struct cred *old, + struct cred *new) +{ + u32 newsid; + int rc; + struct task_security_struct *tsec; + + rc = selinux_determine_inode_label(selinux_cred(old), + d_inode(dentry->d_parent), name, + inode_mode_to_security_class(mode), + &newsid); + if (rc) + return rc; + + tsec = selinux_cred(new); + tsec->create_sid = newsid; + return 0; +} + +static int selinux_inode_init_security(struct inode *inode, struct inode *dir, + const struct qstr *qstr, + const char **name, + void **value, size_t *len) +{ + const struct task_security_struct *tsec = selinux_cred(current_cred()); + struct superblock_security_struct *sbsec; + u32 newsid, clen; + int rc; + char *context; + + sbsec = selinux_superblock(dir->i_sb); + + newsid = tsec->create_sid; + + rc = selinux_determine_inode_label(tsec, dir, qstr, + inode_mode_to_security_class(inode->i_mode), + &newsid); + if (rc) + return rc; + + /* Possibly defer initialization to selinux_complete_init. */ + if (sbsec->flags & SE_SBINITIALIZED) { + struct inode_security_struct *isec = selinux_inode(inode); + isec->sclass = inode_mode_to_security_class(inode->i_mode); + isec->sid = newsid; + isec->initialized = LABEL_INITIALIZED; + } + + if (!selinux_initialized(&selinux_state) || + !(sbsec->flags & SBLABEL_MNT)) + return -EOPNOTSUPP; + + if (name) + *name = XATTR_SELINUX_SUFFIX; + + if (value && len) { + rc = security_sid_to_context_force(&selinux_state, newsid, + &context, &clen); + if (rc) + return rc; + *value = context; + *len = clen; + } + + return 0; +} + +static int selinux_inode_init_security_anon(struct inode *inode, + const struct qstr *name, + const struct inode *context_inode) +{ + const struct task_security_struct *tsec = selinux_cred(current_cred()); + struct common_audit_data ad; + struct inode_security_struct *isec; + int rc; + + if (unlikely(!selinux_initialized(&selinux_state))) + return 0; + + isec = selinux_inode(inode); + + /* + * We only get here once per ephemeral inode. The inode has + * been initialized via inode_alloc_security but is otherwise + * untouched. + */ + + if (context_inode) { + struct inode_security_struct *context_isec = + selinux_inode(context_inode); + if (context_isec->initialized != LABEL_INITIALIZED) { + pr_err("SELinux: context_inode is not initialized"); + return -EACCES; + } + + isec->sclass = context_isec->sclass; + isec->sid = context_isec->sid; + } else { + isec->sclass = SECCLASS_ANON_INODE; + rc = security_transition_sid( + &selinux_state, tsec->sid, tsec->sid, + isec->sclass, name, &isec->sid); + if (rc) + return rc; + } + + isec->initialized = LABEL_INITIALIZED; + /* + * Now that we've initialized security, check whether we're + * allowed to actually create this type of anonymous inode. + */ + + ad.type = LSM_AUDIT_DATA_ANONINODE; + ad.u.anonclass = name ? (const char *)name->name : "?"; + + return avc_has_perm(&selinux_state, + tsec->sid, + isec->sid, + isec->sclass, + FILE__CREATE, + &ad); +} + +static int selinux_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode) +{ + return may_create(dir, dentry, SECCLASS_FILE); +} + +static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry) +{ + return may_link(dir, old_dentry, MAY_LINK); +} + +static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry) +{ + return may_link(dir, dentry, MAY_UNLINK); +} + +static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name) +{ + return may_create(dir, dentry, SECCLASS_LNK_FILE); +} + +static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, umode_t mask) +{ + return may_create(dir, dentry, SECCLASS_DIR); +} + +static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry) +{ + return may_link(dir, dentry, MAY_RMDIR); +} + +static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) +{ + return may_create(dir, dentry, inode_mode_to_security_class(mode)); +} + +static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry, + struct inode *new_inode, struct dentry *new_dentry) +{ + return may_rename(old_inode, old_dentry, new_inode, new_dentry); +} + +static int selinux_inode_readlink(struct dentry *dentry) +{ + const struct cred *cred = current_cred(); + + return dentry_has_perm(cred, dentry, FILE__READ); +} + +static int selinux_inode_follow_link(struct dentry *dentry, struct inode *inode, + bool rcu) +{ + const struct cred *cred = current_cred(); + struct common_audit_data ad; + struct inode_security_struct *isec; + u32 sid; + + validate_creds(cred); + + ad.type = LSM_AUDIT_DATA_DENTRY; + ad.u.dentry = dentry; + sid = cred_sid(cred); + isec = inode_security_rcu(inode, rcu); + if (IS_ERR(isec)) + return PTR_ERR(isec); + + return avc_has_perm(&selinux_state, + sid, isec->sid, isec->sclass, FILE__READ, &ad); +} + +static noinline int audit_inode_permission(struct inode *inode, + u32 perms, u32 audited, u32 denied, + int result) +{ + struct common_audit_data ad; + struct inode_security_struct *isec = selinux_inode(inode); + + ad.type = LSM_AUDIT_DATA_INODE; + ad.u.inode = inode; + + return slow_avc_audit(&selinux_state, + current_sid(), isec->sid, isec->sclass, perms, + audited, denied, result, &ad); +} + +static int selinux_inode_permission(struct inode *inode, int mask) +{ + const struct cred *cred = current_cred(); + u32 perms; + bool from_access; + bool no_block = mask & MAY_NOT_BLOCK; + struct inode_security_struct *isec; + u32 sid; + struct av_decision avd; + int rc, rc2; + u32 audited, denied; + + from_access = mask & MAY_ACCESS; + mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND); + + /* No permission to check. Existence test. */ + if (!mask) + return 0; + + validate_creds(cred); + + if (unlikely(IS_PRIVATE(inode))) + return 0; + + perms = file_mask_to_av(inode->i_mode, mask); + + sid = cred_sid(cred); + isec = inode_security_rcu(inode, no_block); + if (IS_ERR(isec)) + return PTR_ERR(isec); + + rc = avc_has_perm_noaudit(&selinux_state, + sid, isec->sid, isec->sclass, perms, 0, + &avd); + audited = avc_audit_required(perms, &avd, rc, + from_access ? FILE__AUDIT_ACCESS : 0, + &denied); + if (likely(!audited)) + return rc; + + rc2 = audit_inode_permission(inode, perms, audited, denied, rc); + if (rc2) + return rc2; + return rc; +} + +static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr) +{ + const struct cred *cred = current_cred(); + struct inode *inode = d_backing_inode(dentry); + unsigned int ia_valid = iattr->ia_valid; + __u32 av = FILE__WRITE; + + /* ATTR_FORCE is just used for ATTR_KILL_S[UG]ID. */ + if (ia_valid & ATTR_FORCE) { + ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE | + ATTR_FORCE); + if (!ia_valid) + return 0; + } + + if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID | + ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET)) + return dentry_has_perm(cred, dentry, FILE__SETATTR); + + if (selinux_policycap_openperm() && + inode->i_sb->s_magic != SOCKFS_MAGIC && + (ia_valid & ATTR_SIZE) && + !(ia_valid & ATTR_FILE)) + av |= FILE__OPEN; + + return dentry_has_perm(cred, dentry, av); +} + +static int selinux_inode_getattr(const struct path *path) +{ + return path_has_perm(current_cred(), path, FILE__GETATTR); +} + +static bool has_cap_mac_admin(bool audit) +{ + const struct cred *cred = current_cred(); + unsigned int opts = audit ? CAP_OPT_NONE : CAP_OPT_NOAUDIT; + + if (cap_capable(cred, &init_user_ns, CAP_MAC_ADMIN, opts)) + return false; + if (cred_has_capability(cred, CAP_MAC_ADMIN, opts, true)) + return false; + return true; +} + +static int selinux_inode_setxattr(struct user_namespace *mnt_userns, + struct dentry *dentry, const char *name, + const void *value, size_t size, int flags) +{ + struct inode *inode = d_backing_inode(dentry); + struct inode_security_struct *isec; + struct superblock_security_struct *sbsec; + struct common_audit_data ad; + u32 newsid, sid = current_sid(); + int rc = 0; + + if (strcmp(name, XATTR_NAME_SELINUX)) { + rc = cap_inode_setxattr(dentry, name, value, size, flags); + if (rc) + return rc; + + /* Not an attribute we recognize, so just check the + ordinary setattr permission. */ + return dentry_has_perm(current_cred(), dentry, FILE__SETATTR); + } + + if (!selinux_initialized(&selinux_state)) + return (inode_owner_or_capable(mnt_userns, inode) ? 0 : -EPERM); + + sbsec = selinux_superblock(inode->i_sb); + if (!(sbsec->flags & SBLABEL_MNT)) + return -EOPNOTSUPP; + + if (!inode_owner_or_capable(mnt_userns, inode)) + return -EPERM; + + ad.type = LSM_AUDIT_DATA_DENTRY; + ad.u.dentry = dentry; + + isec = backing_inode_security(dentry); + rc = avc_has_perm(&selinux_state, + sid, isec->sid, isec->sclass, + FILE__RELABELFROM, &ad); + if (rc) + return rc; + + rc = security_context_to_sid(&selinux_state, value, size, &newsid, + GFP_KERNEL); + if (rc == -EINVAL) { + if (!has_cap_mac_admin(true)) { + struct audit_buffer *ab; + size_t audit_size; + + /* We strip a nul only if it is at the end, otherwise the + * context contains a nul and we should audit that */ + if (value) { + const char *str = value; + + if (str[size - 1] == '\0') + audit_size = size - 1; + else + audit_size = size; + } else { + audit_size = 0; + } + ab = audit_log_start(audit_context(), + GFP_ATOMIC, AUDIT_SELINUX_ERR); + if (!ab) + return rc; + audit_log_format(ab, "op=setxattr invalid_context="); + audit_log_n_untrustedstring(ab, value, audit_size); + audit_log_end(ab); + + return rc; + } + rc = security_context_to_sid_force(&selinux_state, value, + size, &newsid); + } + if (rc) + return rc; + + rc = avc_has_perm(&selinux_state, + sid, newsid, isec->sclass, + FILE__RELABELTO, &ad); + if (rc) + return rc; + + rc = security_validate_transition(&selinux_state, isec->sid, newsid, + sid, isec->sclass); + if (rc) + return rc; + + return avc_has_perm(&selinux_state, + newsid, + sbsec->sid, + SECCLASS_FILESYSTEM, + FILESYSTEM__ASSOCIATE, + &ad); +} + +static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name, + const void *value, size_t size, + int flags) +{ + struct inode *inode = d_backing_inode(dentry); + struct inode_security_struct *isec; + u32 newsid; + int rc; + + if (strcmp(name, XATTR_NAME_SELINUX)) { + /* Not an attribute we recognize, so nothing to do. */ + return; + } + + if (!selinux_initialized(&selinux_state)) { + /* If we haven't even been initialized, then we can't validate + * against a policy, so leave the label as invalid. It may + * resolve to a valid label on the next revalidation try if + * we've since initialized. + */ + return; + } + + rc = security_context_to_sid_force(&selinux_state, value, size, + &newsid); + if (rc) { + pr_err("SELinux: unable to map context to SID" + "for (%s, %lu), rc=%d\n", + inode->i_sb->s_id, inode->i_ino, -rc); + return; + } + + isec = backing_inode_security(dentry); + spin_lock(&isec->lock); + isec->sclass = inode_mode_to_security_class(inode->i_mode); + isec->sid = newsid; + isec->initialized = LABEL_INITIALIZED; + spin_unlock(&isec->lock); +} + +static int selinux_inode_getxattr(struct dentry *dentry, const char *name) +{ + const struct cred *cred = current_cred(); + + return dentry_has_perm(cred, dentry, FILE__GETATTR); +} + +static int selinux_inode_listxattr(struct dentry *dentry) +{ + const struct cred *cred = current_cred(); + + return dentry_has_perm(cred, dentry, FILE__GETATTR); +} + +static int selinux_inode_removexattr(struct user_namespace *mnt_userns, + struct dentry *dentry, const char *name) +{ + if (strcmp(name, XATTR_NAME_SELINUX)) { + int rc = cap_inode_removexattr(mnt_userns, dentry, name); + if (rc) + return rc; + + /* Not an attribute we recognize, so just check the + ordinary setattr permission. */ + return dentry_has_perm(current_cred(), dentry, FILE__SETATTR); + } + + if (!selinux_initialized(&selinux_state)) + return 0; + + /* No one is allowed to remove a SELinux security label. + You can change the label, but all data must be labeled. */ + return -EACCES; +} + +static int selinux_path_notify(const struct path *path, u64 mask, + unsigned int obj_type) +{ + int ret; + u32 perm; + + struct common_audit_data ad; + + ad.type = LSM_AUDIT_DATA_PATH; + ad.u.path = *path; + + /* + * Set permission needed based on the type of mark being set. + * Performs an additional check for sb watches. + */ + switch (obj_type) { + case FSNOTIFY_OBJ_TYPE_VFSMOUNT: + perm = FILE__WATCH_MOUNT; + break; + case FSNOTIFY_OBJ_TYPE_SB: + perm = FILE__WATCH_SB; + ret = superblock_has_perm(current_cred(), path->dentry->d_sb, + FILESYSTEM__WATCH, &ad); + if (ret) + return ret; + break; + case FSNOTIFY_OBJ_TYPE_INODE: + perm = FILE__WATCH; + break; + default: + return -EINVAL; + } + + /* blocking watches require the file:watch_with_perm permission */ + if (mask & (ALL_FSNOTIFY_PERM_EVENTS)) + perm |= FILE__WATCH_WITH_PERM; + + /* watches on read-like events need the file:watch_reads permission */ + if (mask & (FS_ACCESS | FS_ACCESS_PERM | FS_CLOSE_NOWRITE)) + perm |= FILE__WATCH_READS; + + return path_has_perm(current_cred(), path, perm); +} + +/* + * Copy the inode security context value to the user. + * + * Permission check is handled by selinux_inode_getxattr hook. + */ +static int selinux_inode_getsecurity(struct user_namespace *mnt_userns, + struct inode *inode, const char *name, + void **buffer, bool alloc) +{ + u32 size; + int error; + char *context = NULL; + struct inode_security_struct *isec; + + /* + * If we're not initialized yet, then we can't validate contexts, so + * just let vfs_getxattr fall back to using the on-disk xattr. + */ + if (!selinux_initialized(&selinux_state) || + strcmp(name, XATTR_SELINUX_SUFFIX)) + return -EOPNOTSUPP; + + /* + * If the caller has CAP_MAC_ADMIN, then get the raw context + * value even if it is not defined by current policy; otherwise, + * use the in-core value under current policy. + * Use the non-auditing forms of the permission checks since + * getxattr may be called by unprivileged processes commonly + * and lack of permission just means that we fall back to the + * in-core context value, not a denial. + */ + isec = inode_security(inode); + if (has_cap_mac_admin(false)) + error = security_sid_to_context_force(&selinux_state, + isec->sid, &context, + &size); + else + error = security_sid_to_context(&selinux_state, isec->sid, + &context, &size); + if (error) + return error; + error = size; + if (alloc) { + *buffer = context; + goto out_nofree; + } + kfree(context); +out_nofree: + return error; +} + +static int selinux_inode_setsecurity(struct inode *inode, const char *name, + const void *value, size_t size, int flags) +{ + struct inode_security_struct *isec = inode_security_novalidate(inode); + struct superblock_security_struct *sbsec; + u32 newsid; + int rc; + + if (strcmp(name, XATTR_SELINUX_SUFFIX)) + return -EOPNOTSUPP; + + sbsec = selinux_superblock(inode->i_sb); + if (!(sbsec->flags & SBLABEL_MNT)) + return -EOPNOTSUPP; + + if (!value || !size) + return -EACCES; + + rc = security_context_to_sid(&selinux_state, value, size, &newsid, + GFP_KERNEL); + if (rc) + return rc; + + spin_lock(&isec->lock); + isec->sclass = inode_mode_to_security_class(inode->i_mode); + isec->sid = newsid; + isec->initialized = LABEL_INITIALIZED; + spin_unlock(&isec->lock); + return 0; +} + +static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size) +{ + const int len = sizeof(XATTR_NAME_SELINUX); + + if (!selinux_initialized(&selinux_state)) + return 0; + + if (buffer && len <= buffer_size) + memcpy(buffer, XATTR_NAME_SELINUX, len); + return len; +} + +static void selinux_inode_getsecid(struct inode *inode, u32 *secid) +{ + struct inode_security_struct *isec = inode_security_novalidate(inode); + *secid = isec->sid; +} + +static int selinux_inode_copy_up(struct dentry *src, struct cred **new) +{ + u32 sid; + struct task_security_struct *tsec; + struct cred *new_creds = *new; + + if (new_creds == NULL) { + new_creds = prepare_creds(); + if (!new_creds) + return -ENOMEM; + } + + tsec = selinux_cred(new_creds); + /* Get label from overlay inode and set it in create_sid */ + selinux_inode_getsecid(d_inode(src), &sid); + tsec->create_sid = sid; + *new = new_creds; + return 0; +} + +static int selinux_inode_copy_up_xattr(const char *name) +{ + /* The copy_up hook above sets the initial context on an inode, but we + * don't then want to overwrite it by blindly copying all the lower + * xattrs up. Instead, we have to filter out SELinux-related xattrs. + */ + if (strcmp(name, XATTR_NAME_SELINUX) == 0) + return 1; /* Discard */ + /* + * Any other attribute apart from SELINUX is not claimed, supported + * by selinux. + */ + return -EOPNOTSUPP; +} + +/* kernfs node operations */ + +static int selinux_kernfs_init_security(struct kernfs_node *kn_dir, + struct kernfs_node *kn) +{ + const struct task_security_struct *tsec = selinux_cred(current_cred()); + u32 parent_sid, newsid, clen; + int rc; + char *context; + + rc = kernfs_xattr_get(kn_dir, XATTR_NAME_SELINUX, NULL, 0); + if (rc == -ENODATA) + return 0; + else if (rc < 0) + return rc; + + clen = (u32)rc; + context = kmalloc(clen, GFP_KERNEL); + if (!context) + return -ENOMEM; + + rc = kernfs_xattr_get(kn_dir, XATTR_NAME_SELINUX, context, clen); + if (rc < 0) { + kfree(context); + return rc; + } + + rc = security_context_to_sid(&selinux_state, context, clen, &parent_sid, + GFP_KERNEL); + kfree(context); + if (rc) + return rc; + + if (tsec->create_sid) { + newsid = tsec->create_sid; + } else { + u16 secclass = inode_mode_to_security_class(kn->mode); + struct qstr q; + + q.name = kn->name; + q.hash_len = hashlen_string(kn_dir, kn->name); + + rc = security_transition_sid(&selinux_state, tsec->sid, + parent_sid, secclass, &q, + &newsid); + if (rc) + return rc; + } + + rc = security_sid_to_context_force(&selinux_state, newsid, + &context, &clen); + if (rc) + return rc; + + rc = kernfs_xattr_set(kn, XATTR_NAME_SELINUX, context, clen, + XATTR_CREATE); + kfree(context); + return rc; +} + + +/* file security operations */ + +static int selinux_revalidate_file_permission(struct file *file, int mask) +{ + const struct cred *cred = current_cred(); + struct inode *inode = file_inode(file); + + /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */ + if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE)) + mask |= MAY_APPEND; + + return file_has_perm(cred, file, + file_mask_to_av(inode->i_mode, mask)); +} + +static int selinux_file_permission(struct file *file, int mask) +{ + struct inode *inode = file_inode(file); + struct file_security_struct *fsec = selinux_file(file); + struct inode_security_struct *isec; + u32 sid = current_sid(); + + if (!mask) + /* No permission to check. Existence test. */ + return 0; + + isec = inode_security(inode); + if (sid == fsec->sid && fsec->isid == isec->sid && + fsec->pseqno == avc_policy_seqno(&selinux_state)) + /* No change since file_open check. */ + return 0; + + return selinux_revalidate_file_permission(file, mask); +} + +static int selinux_file_alloc_security(struct file *file) +{ + struct file_security_struct *fsec = selinux_file(file); + u32 sid = current_sid(); + + fsec->sid = sid; + fsec->fown_sid = sid; + + return 0; +} + +/* + * Check whether a task has the ioctl permission and cmd + * operation to an inode. + */ +static int ioctl_has_perm(const struct cred *cred, struct file *file, + u32 requested, u16 cmd) +{ + struct common_audit_data ad; + struct file_security_struct *fsec = selinux_file(file); + struct inode *inode = file_inode(file); + struct inode_security_struct *isec; + struct lsm_ioctlop_audit ioctl; + u32 ssid = cred_sid(cred); + int rc; + u8 driver = cmd >> 8; + u8 xperm = cmd & 0xff; + + ad.type = LSM_AUDIT_DATA_IOCTL_OP; + ad.u.op = &ioctl; + ad.u.op->cmd = cmd; + ad.u.op->path = file->f_path; + + if (ssid != fsec->sid) { + rc = avc_has_perm(&selinux_state, + ssid, fsec->sid, + SECCLASS_FD, + FD__USE, + &ad); + if (rc) + goto out; + } + + if (unlikely(IS_PRIVATE(inode))) + return 0; + + isec = inode_security(inode); + rc = avc_has_extended_perms(&selinux_state, + ssid, isec->sid, isec->sclass, + requested, driver, xperm, &ad); +out: + return rc; +} + +static int selinux_file_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + const struct cred *cred = current_cred(); + int error = 0; + + switch (cmd) { + case FIONREAD: + case FIBMAP: + case FIGETBSZ: + case FS_IOC_GETFLAGS: + case FS_IOC_GETVERSION: + error = file_has_perm(cred, file, FILE__GETATTR); + break; + + case FS_IOC_SETFLAGS: + case FS_IOC_SETVERSION: + error = file_has_perm(cred, file, FILE__SETATTR); + break; + + /* sys_ioctl() checks */ + case FIONBIO: + case FIOASYNC: + error = file_has_perm(cred, file, 0); + break; + + case KDSKBENT: + case KDSKBSENT: + error = cred_has_capability(cred, CAP_SYS_TTY_CONFIG, + CAP_OPT_NONE, true); + break; + + case FIOCLEX: + case FIONCLEX: + if (!selinux_policycap_ioctl_skip_cloexec()) + error = ioctl_has_perm(cred, file, FILE__IOCTL, (u16) cmd); + break; + + /* default case assumes that the command will go + * to the file's ioctl() function. + */ + default: + error = ioctl_has_perm(cred, file, FILE__IOCTL, (u16) cmd); + } + return error; +} + +static int selinux_file_ioctl_compat(struct file *file, unsigned int cmd, + unsigned long arg) +{ + /* + * If we are in a 64-bit kernel running 32-bit userspace, we need to + * make sure we don't compare 32-bit flags to 64-bit flags. + */ + switch (cmd) { + case FS_IOC32_GETFLAGS: + cmd = FS_IOC_GETFLAGS; + break; + case FS_IOC32_SETFLAGS: + cmd = FS_IOC_SETFLAGS; + break; + case FS_IOC32_GETVERSION: + cmd = FS_IOC_GETVERSION; + break; + case FS_IOC32_SETVERSION: + cmd = FS_IOC_SETVERSION; + break; + default: + break; + } + + return selinux_file_ioctl(file, cmd, arg); +} + +static int default_noexec __ro_after_init; + +static int file_map_prot_check(struct file *file, unsigned long prot, int shared) +{ + const struct cred *cred = current_cred(); + u32 sid = cred_sid(cred); + int rc = 0; + + if (default_noexec && + (prot & PROT_EXEC) && (!file || IS_PRIVATE(file_inode(file)) || + (!shared && (prot & PROT_WRITE)))) { + /* + * We are making executable an anonymous mapping or a + * private file mapping that will also be writable. + * This has an additional check. + */ + rc = avc_has_perm(&selinux_state, + sid, sid, SECCLASS_PROCESS, + PROCESS__EXECMEM, NULL); + if (rc) + goto error; + } + + if (file) { + /* read access is always possible with a mapping */ + u32 av = FILE__READ; + + /* write access only matters if the mapping is shared */ + if (shared && (prot & PROT_WRITE)) + av |= FILE__WRITE; + + if (prot & PROT_EXEC) + av |= FILE__EXECUTE; + + return file_has_perm(cred, file, av); + } + +error: + return rc; +} + +static int selinux_mmap_addr(unsigned long addr) +{ + int rc = 0; + + if (addr < CONFIG_LSM_MMAP_MIN_ADDR) { + u32 sid = current_sid(); + rc = avc_has_perm(&selinux_state, + sid, sid, SECCLASS_MEMPROTECT, + MEMPROTECT__MMAP_ZERO, NULL); + } + + return rc; +} + +static int selinux_mmap_file(struct file *file, unsigned long reqprot, + unsigned long prot, unsigned long flags) +{ + struct common_audit_data ad; + int rc; + + if (file) { + ad.type = LSM_AUDIT_DATA_FILE; + ad.u.file = file; + rc = inode_has_perm(current_cred(), file_inode(file), + FILE__MAP, &ad); + if (rc) + return rc; + } + + if (checkreqprot_get(&selinux_state)) + prot = reqprot; + + return file_map_prot_check(file, prot, + (flags & MAP_TYPE) == MAP_SHARED); +} + +static int selinux_file_mprotect(struct vm_area_struct *vma, + unsigned long reqprot, + unsigned long prot) +{ + const struct cred *cred = current_cred(); + u32 sid = cred_sid(cred); + + if (checkreqprot_get(&selinux_state)) + prot = reqprot; + + if (default_noexec && + (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) { + int rc = 0; + if (vma->vm_start >= vma->vm_mm->start_brk && + vma->vm_end <= vma->vm_mm->brk) { + rc = avc_has_perm(&selinux_state, + sid, sid, SECCLASS_PROCESS, + PROCESS__EXECHEAP, NULL); + } else if (!vma->vm_file && + ((vma->vm_start <= vma->vm_mm->start_stack && + vma->vm_end >= vma->vm_mm->start_stack) || + vma_is_stack_for_current(vma))) { + rc = avc_has_perm(&selinux_state, + sid, sid, SECCLASS_PROCESS, + PROCESS__EXECSTACK, NULL); + } else if (vma->vm_file && vma->anon_vma) { + /* + * We are making executable a file mapping that has + * had some COW done. Since pages might have been + * written, check ability to execute the possibly + * modified content. This typically should only + * occur for text relocations. + */ + rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD); + } + if (rc) + return rc; + } + + return file_map_prot_check(vma->vm_file, prot, vma->vm_flags&VM_SHARED); +} + +static int selinux_file_lock(struct file *file, unsigned int cmd) +{ + const struct cred *cred = current_cred(); + + return file_has_perm(cred, file, FILE__LOCK); +} + +static int selinux_file_fcntl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + const struct cred *cred = current_cred(); + int err = 0; + + switch (cmd) { + case F_SETFL: + if ((file->f_flags & O_APPEND) && !(arg & O_APPEND)) { + err = file_has_perm(cred, file, FILE__WRITE); + break; + } + fallthrough; + case F_SETOWN: + case F_SETSIG: + case F_GETFL: + case F_GETOWN: + case F_GETSIG: + case F_GETOWNER_UIDS: + /* Just check FD__USE permission */ + err = file_has_perm(cred, file, 0); + break; + case F_GETLK: + case F_SETLK: + case F_SETLKW: + case F_OFD_GETLK: + case F_OFD_SETLK: + case F_OFD_SETLKW: +#if BITS_PER_LONG == 32 + case F_GETLK64: + case F_SETLK64: + case F_SETLKW64: +#endif + err = file_has_perm(cred, file, FILE__LOCK); + break; + } + + return err; +} + +static void selinux_file_set_fowner(struct file *file) +{ + struct file_security_struct *fsec; + + fsec = selinux_file(file); + fsec->fown_sid = current_sid(); +} + +static int selinux_file_send_sigiotask(struct task_struct *tsk, + struct fown_struct *fown, int signum) +{ + struct file *file; + u32 sid = task_sid_obj(tsk); + u32 perm; + struct file_security_struct *fsec; + + /* struct fown_struct is never outside the context of a struct file */ + file = container_of(fown, struct file, f_owner); + + fsec = selinux_file(file); + + if (!signum) + perm = signal_to_av(SIGIO); /* as per send_sigio_to_task */ + else + perm = signal_to_av(signum); + + return avc_has_perm(&selinux_state, + fsec->fown_sid, sid, + SECCLASS_PROCESS, perm, NULL); +} + +static int selinux_file_receive(struct file *file) +{ + const struct cred *cred = current_cred(); + + return file_has_perm(cred, file, file_to_av(file)); +} + +static int selinux_file_open(struct file *file) +{ + struct file_security_struct *fsec; + struct inode_security_struct *isec; + + fsec = selinux_file(file); + isec = inode_security(file_inode(file)); + /* + * Save inode label and policy sequence number + * at open-time so that selinux_file_permission + * can determine whether revalidation is necessary. + * Task label is already saved in the file security + * struct as its SID. + */ + fsec->isid = isec->sid; + fsec->pseqno = avc_policy_seqno(&selinux_state); + /* + * Since the inode label or policy seqno may have changed + * between the selinux_inode_permission check and the saving + * of state above, recheck that access is still permitted. + * Otherwise, access might never be revalidated against the + * new inode label or new policy. + * This check is not redundant - do not remove. + */ + return file_path_has_perm(file->f_cred, file, open_file_to_av(file)); +} + +/* task security operations */ + +static int selinux_task_alloc(struct task_struct *task, + unsigned long clone_flags) +{ + u32 sid = current_sid(); + + return avc_has_perm(&selinux_state, + sid, sid, SECCLASS_PROCESS, PROCESS__FORK, NULL); +} + +/* + * prepare a new set of credentials for modification + */ +static int selinux_cred_prepare(struct cred *new, const struct cred *old, + gfp_t gfp) +{ + const struct task_security_struct *old_tsec = selinux_cred(old); + struct task_security_struct *tsec = selinux_cred(new); + + *tsec = *old_tsec; + return 0; +} + +/* + * transfer the SELinux data to a blank set of creds + */ +static void selinux_cred_transfer(struct cred *new, const struct cred *old) +{ + const struct task_security_struct *old_tsec = selinux_cred(old); + struct task_security_struct *tsec = selinux_cred(new); + + *tsec = *old_tsec; +} + +static void selinux_cred_getsecid(const struct cred *c, u32 *secid) +{ + *secid = cred_sid(c); +} + +/* + * set the security data for a kernel service + * - all the creation contexts are set to unlabelled + */ +static int selinux_kernel_act_as(struct cred *new, u32 secid) +{ + struct task_security_struct *tsec = selinux_cred(new); + u32 sid = current_sid(); + int ret; + + ret = avc_has_perm(&selinux_state, + sid, secid, + SECCLASS_KERNEL_SERVICE, + KERNEL_SERVICE__USE_AS_OVERRIDE, + NULL); + if (ret == 0) { + tsec->sid = secid; + tsec->create_sid = 0; + tsec->keycreate_sid = 0; + tsec->sockcreate_sid = 0; + } + return ret; +} + +/* + * set the file creation context in a security record to the same as the + * objective context of the specified inode + */ +static int selinux_kernel_create_files_as(struct cred *new, struct inode *inode) +{ + struct inode_security_struct *isec = inode_security(inode); + struct task_security_struct *tsec = selinux_cred(new); + u32 sid = current_sid(); + int ret; + + ret = avc_has_perm(&selinux_state, + sid, isec->sid, + SECCLASS_KERNEL_SERVICE, + KERNEL_SERVICE__CREATE_FILES_AS, + NULL); + + if (ret == 0) + tsec->create_sid = isec->sid; + return ret; +} + +static int selinux_kernel_module_request(char *kmod_name) +{ + struct common_audit_data ad; + + ad.type = LSM_AUDIT_DATA_KMOD; + ad.u.kmod_name = kmod_name; + + return avc_has_perm(&selinux_state, + current_sid(), SECINITSID_KERNEL, SECCLASS_SYSTEM, + SYSTEM__MODULE_REQUEST, &ad); +} + +static int selinux_kernel_module_from_file(struct file *file) +{ + struct common_audit_data ad; + struct inode_security_struct *isec; + struct file_security_struct *fsec; + u32 sid = current_sid(); + int rc; + + /* init_module */ + if (file == NULL) + return avc_has_perm(&selinux_state, + sid, sid, SECCLASS_SYSTEM, + SYSTEM__MODULE_LOAD, NULL); + + /* finit_module */ + + ad.type = LSM_AUDIT_DATA_FILE; + ad.u.file = file; + + fsec = selinux_file(file); + if (sid != fsec->sid) { + rc = avc_has_perm(&selinux_state, + sid, fsec->sid, SECCLASS_FD, FD__USE, &ad); + if (rc) + return rc; + } + + isec = inode_security(file_inode(file)); + return avc_has_perm(&selinux_state, + sid, isec->sid, SECCLASS_SYSTEM, + SYSTEM__MODULE_LOAD, &ad); +} + +static int selinux_kernel_read_file(struct file *file, + enum kernel_read_file_id id, + bool contents) +{ + int rc = 0; + + switch (id) { + case READING_MODULE: + rc = selinux_kernel_module_from_file(contents ? file : NULL); + break; + default: + break; + } + + return rc; +} + +static int selinux_kernel_load_data(enum kernel_load_data_id id, bool contents) +{ + int rc = 0; + + switch (id) { + case LOADING_MODULE: + rc = selinux_kernel_module_from_file(NULL); + break; + default: + break; + } + + return rc; +} + +static int selinux_task_setpgid(struct task_struct *p, pid_t pgid) +{ + return avc_has_perm(&selinux_state, + current_sid(), task_sid_obj(p), SECCLASS_PROCESS, + PROCESS__SETPGID, NULL); +} + +static int selinux_task_getpgid(struct task_struct *p) +{ + return avc_has_perm(&selinux_state, + current_sid(), task_sid_obj(p), SECCLASS_PROCESS, + PROCESS__GETPGID, NULL); +} + +static int selinux_task_getsid(struct task_struct *p) +{ + return avc_has_perm(&selinux_state, + current_sid(), task_sid_obj(p), SECCLASS_PROCESS, + PROCESS__GETSESSION, NULL); +} + +static void selinux_current_getsecid_subj(u32 *secid) +{ + *secid = current_sid(); +} + +static void selinux_task_getsecid_obj(struct task_struct *p, u32 *secid) +{ + *secid = task_sid_obj(p); +} + +static int selinux_task_setnice(struct task_struct *p, int nice) +{ + return avc_has_perm(&selinux_state, + current_sid(), task_sid_obj(p), SECCLASS_PROCESS, + PROCESS__SETSCHED, NULL); +} + +static int selinux_task_setioprio(struct task_struct *p, int ioprio) +{ + return avc_has_perm(&selinux_state, + current_sid(), task_sid_obj(p), SECCLASS_PROCESS, + PROCESS__SETSCHED, NULL); +} + +static int selinux_task_getioprio(struct task_struct *p) +{ + return avc_has_perm(&selinux_state, + current_sid(), task_sid_obj(p), SECCLASS_PROCESS, + PROCESS__GETSCHED, NULL); +} + +static int selinux_task_prlimit(const struct cred *cred, const struct cred *tcred, + unsigned int flags) +{ + u32 av = 0; + + if (!flags) + return 0; + if (flags & LSM_PRLIMIT_WRITE) + av |= PROCESS__SETRLIMIT; + if (flags & LSM_PRLIMIT_READ) + av |= PROCESS__GETRLIMIT; + return avc_has_perm(&selinux_state, + cred_sid(cred), cred_sid(tcred), + SECCLASS_PROCESS, av, NULL); +} + +static int selinux_task_setrlimit(struct task_struct *p, unsigned int resource, + struct rlimit *new_rlim) +{ + struct rlimit *old_rlim = p->signal->rlim + resource; + + /* Control the ability to change the hard limit (whether + lowering or raising it), so that the hard limit can + later be used as a safe reset point for the soft limit + upon context transitions. See selinux_bprm_committing_creds. */ + if (old_rlim->rlim_max != new_rlim->rlim_max) + return avc_has_perm(&selinux_state, + current_sid(), task_sid_obj(p), + SECCLASS_PROCESS, PROCESS__SETRLIMIT, NULL); + + return 0; +} + +static int selinux_task_setscheduler(struct task_struct *p) +{ + return avc_has_perm(&selinux_state, + current_sid(), task_sid_obj(p), SECCLASS_PROCESS, + PROCESS__SETSCHED, NULL); +} + +static int selinux_task_getscheduler(struct task_struct *p) +{ + return avc_has_perm(&selinux_state, + current_sid(), task_sid_obj(p), SECCLASS_PROCESS, + PROCESS__GETSCHED, NULL); +} + +static int selinux_task_movememory(struct task_struct *p) +{ + return avc_has_perm(&selinux_state, + current_sid(), task_sid_obj(p), SECCLASS_PROCESS, + PROCESS__SETSCHED, NULL); +} + +static int selinux_task_kill(struct task_struct *p, struct kernel_siginfo *info, + int sig, const struct cred *cred) +{ + u32 secid; + u32 perm; + + if (!sig) + perm = PROCESS__SIGNULL; /* null signal; existence test */ + else + perm = signal_to_av(sig); + if (!cred) + secid = current_sid(); + else + secid = cred_sid(cred); + return avc_has_perm(&selinux_state, + secid, task_sid_obj(p), SECCLASS_PROCESS, perm, NULL); +} + +static void selinux_task_to_inode(struct task_struct *p, + struct inode *inode) +{ + struct inode_security_struct *isec = selinux_inode(inode); + u32 sid = task_sid_obj(p); + + spin_lock(&isec->lock); + isec->sclass = inode_mode_to_security_class(inode->i_mode); + isec->sid = sid; + isec->initialized = LABEL_INITIALIZED; + spin_unlock(&isec->lock); +} + +static int selinux_userns_create(const struct cred *cred) +{ + u32 sid = current_sid(); + + return avc_has_perm(&selinux_state, sid, sid, SECCLASS_USER_NAMESPACE, + USER_NAMESPACE__CREATE, NULL); +} + +/* Returns error only if unable to parse addresses */ +static int selinux_parse_skb_ipv4(struct sk_buff *skb, + struct common_audit_data *ad, u8 *proto) +{ + int offset, ihlen, ret = -EINVAL; + struct iphdr _iph, *ih; + + offset = skb_network_offset(skb); + ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph); + if (ih == NULL) + goto out; + + ihlen = ih->ihl * 4; + if (ihlen < sizeof(_iph)) + goto out; + + ad->u.net->v4info.saddr = ih->saddr; + ad->u.net->v4info.daddr = ih->daddr; + ret = 0; + + if (proto) + *proto = ih->protocol; + + switch (ih->protocol) { + case IPPROTO_TCP: { + struct tcphdr _tcph, *th; + + if (ntohs(ih->frag_off) & IP_OFFSET) + break; + + offset += ihlen; + th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph); + if (th == NULL) + break; + + ad->u.net->sport = th->source; + ad->u.net->dport = th->dest; + break; + } + + case IPPROTO_UDP: { + struct udphdr _udph, *uh; + + if (ntohs(ih->frag_off) & IP_OFFSET) + break; + + offset += ihlen; + uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph); + if (uh == NULL) + break; + + ad->u.net->sport = uh->source; + ad->u.net->dport = uh->dest; + break; + } + + case IPPROTO_DCCP: { + struct dccp_hdr _dccph, *dh; + + if (ntohs(ih->frag_off) & IP_OFFSET) + break; + + offset += ihlen; + dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph); + if (dh == NULL) + break; + + ad->u.net->sport = dh->dccph_sport; + ad->u.net->dport = dh->dccph_dport; + break; + } + +#if IS_ENABLED(CONFIG_IP_SCTP) + case IPPROTO_SCTP: { + struct sctphdr _sctph, *sh; + + if (ntohs(ih->frag_off) & IP_OFFSET) + break; + + offset += ihlen; + sh = skb_header_pointer(skb, offset, sizeof(_sctph), &_sctph); + if (sh == NULL) + break; + + ad->u.net->sport = sh->source; + ad->u.net->dport = sh->dest; + break; + } +#endif + default: + break; + } +out: + return ret; +} + +#if IS_ENABLED(CONFIG_IPV6) + +/* Returns error only if unable to parse addresses */ +static int selinux_parse_skb_ipv6(struct sk_buff *skb, + struct common_audit_data *ad, u8 *proto) +{ + u8 nexthdr; + int ret = -EINVAL, offset; + struct ipv6hdr _ipv6h, *ip6; + __be16 frag_off; + + offset = skb_network_offset(skb); + ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h); + if (ip6 == NULL) + goto out; + + ad->u.net->v6info.saddr = ip6->saddr; + ad->u.net->v6info.daddr = ip6->daddr; + ret = 0; + + nexthdr = ip6->nexthdr; + offset += sizeof(_ipv6h); + offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off); + if (offset < 0) + goto out; + + if (proto) + *proto = nexthdr; + + switch (nexthdr) { + case IPPROTO_TCP: { + struct tcphdr _tcph, *th; + + th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph); + if (th == NULL) + break; + + ad->u.net->sport = th->source; + ad->u.net->dport = th->dest; + break; + } + + case IPPROTO_UDP: { + struct udphdr _udph, *uh; + + uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph); + if (uh == NULL) + break; + + ad->u.net->sport = uh->source; + ad->u.net->dport = uh->dest; + break; + } + + case IPPROTO_DCCP: { + struct dccp_hdr _dccph, *dh; + + dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph); + if (dh == NULL) + break; + + ad->u.net->sport = dh->dccph_sport; + ad->u.net->dport = dh->dccph_dport; + break; + } + +#if IS_ENABLED(CONFIG_IP_SCTP) + case IPPROTO_SCTP: { + struct sctphdr _sctph, *sh; + + sh = skb_header_pointer(skb, offset, sizeof(_sctph), &_sctph); + if (sh == NULL) + break; + + ad->u.net->sport = sh->source; + ad->u.net->dport = sh->dest; + break; + } +#endif + /* includes fragments */ + default: + break; + } +out: + return ret; +} + +#endif /* IPV6 */ + +static int selinux_parse_skb(struct sk_buff *skb, struct common_audit_data *ad, + char **_addrp, int src, u8 *proto) +{ + char *addrp; + int ret; + + switch (ad->u.net->family) { + case PF_INET: + ret = selinux_parse_skb_ipv4(skb, ad, proto); + if (ret) + goto parse_error; + addrp = (char *)(src ? &ad->u.net->v4info.saddr : + &ad->u.net->v4info.daddr); + goto okay; + +#if IS_ENABLED(CONFIG_IPV6) + case PF_INET6: + ret = selinux_parse_skb_ipv6(skb, ad, proto); + if (ret) + goto parse_error; + addrp = (char *)(src ? &ad->u.net->v6info.saddr : + &ad->u.net->v6info.daddr); + goto okay; +#endif /* IPV6 */ + default: + addrp = NULL; + goto okay; + } + +parse_error: + pr_warn( + "SELinux: failure in selinux_parse_skb()," + " unable to parse packet\n"); + return ret; + +okay: + if (_addrp) + *_addrp = addrp; + return 0; +} + +/** + * selinux_skb_peerlbl_sid - Determine the peer label of a packet + * @skb: the packet + * @family: protocol family + * @sid: the packet's peer label SID + * + * Description: + * Check the various different forms of network peer labeling and determine + * the peer label/SID for the packet; most of the magic actually occurs in + * the security server function security_net_peersid_cmp(). The function + * returns zero if the value in @sid is valid (although it may be SECSID_NULL) + * or -EACCES if @sid is invalid due to inconsistencies with the different + * peer labels. + * + */ +static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid) +{ + int err; + u32 xfrm_sid; + u32 nlbl_sid; + u32 nlbl_type; + + err = selinux_xfrm_skb_sid(skb, &xfrm_sid); + if (unlikely(err)) + return -EACCES; + err = selinux_netlbl_skbuff_getsid(skb, family, &nlbl_type, &nlbl_sid); + if (unlikely(err)) + return -EACCES; + + err = security_net_peersid_resolve(&selinux_state, nlbl_sid, + nlbl_type, xfrm_sid, sid); + if (unlikely(err)) { + pr_warn( + "SELinux: failure in selinux_skb_peerlbl_sid()," + " unable to determine packet's peer label\n"); + return -EACCES; + } + + return 0; +} + +/** + * selinux_conn_sid - Determine the child socket label for a connection + * @sk_sid: the parent socket's SID + * @skb_sid: the packet's SID + * @conn_sid: the resulting connection SID + * + * If @skb_sid is valid then the user:role:type information from @sk_sid is + * combined with the MLS information from @skb_sid in order to create + * @conn_sid. If @skb_sid is not valid then @conn_sid is simply a copy + * of @sk_sid. Returns zero on success, negative values on failure. + * + */ +static int selinux_conn_sid(u32 sk_sid, u32 skb_sid, u32 *conn_sid) +{ + int err = 0; + + if (skb_sid != SECSID_NULL) + err = security_sid_mls_copy(&selinux_state, sk_sid, skb_sid, + conn_sid); + else + *conn_sid = sk_sid; + + return err; +} + +/* socket security operations */ + +static int socket_sockcreate_sid(const struct task_security_struct *tsec, + u16 secclass, u32 *socksid) +{ + if (tsec->sockcreate_sid > SECSID_NULL) { + *socksid = tsec->sockcreate_sid; + return 0; + } + + return security_transition_sid(&selinux_state, tsec->sid, tsec->sid, + secclass, NULL, socksid); +} + +static int sock_has_perm(struct sock *sk, u32 perms) +{ + struct sk_security_struct *sksec = sk->sk_security; + struct common_audit_data ad; + struct lsm_network_audit net = {0,}; + + if (sksec->sid == SECINITSID_KERNEL) + return 0; + + ad.type = LSM_AUDIT_DATA_NET; + ad.u.net = &net; + ad.u.net->sk = sk; + + return avc_has_perm(&selinux_state, + current_sid(), sksec->sid, sksec->sclass, perms, + &ad); +} + +static int selinux_socket_create(int family, int type, + int protocol, int kern) +{ + const struct task_security_struct *tsec = selinux_cred(current_cred()); + u32 newsid; + u16 secclass; + int rc; + + if (kern) + return 0; + + secclass = socket_type_to_security_class(family, type, protocol); + rc = socket_sockcreate_sid(tsec, secclass, &newsid); + if (rc) + return rc; + + return avc_has_perm(&selinux_state, + tsec->sid, newsid, secclass, SOCKET__CREATE, NULL); +} + +static int selinux_socket_post_create(struct socket *sock, int family, + int type, int protocol, int kern) +{ + const struct task_security_struct *tsec = selinux_cred(current_cred()); + struct inode_security_struct *isec = inode_security_novalidate(SOCK_INODE(sock)); + struct sk_security_struct *sksec; + u16 sclass = socket_type_to_security_class(family, type, protocol); + u32 sid = SECINITSID_KERNEL; + int err = 0; + + if (!kern) { + err = socket_sockcreate_sid(tsec, sclass, &sid); + if (err) + return err; + } + + isec->sclass = sclass; + isec->sid = sid; + isec->initialized = LABEL_INITIALIZED; + + if (sock->sk) { + sksec = sock->sk->sk_security; + sksec->sclass = sclass; + sksec->sid = sid; + /* Allows detection of the first association on this socket */ + if (sksec->sclass == SECCLASS_SCTP_SOCKET) + sksec->sctp_assoc_state = SCTP_ASSOC_UNSET; + + err = selinux_netlbl_socket_post_create(sock->sk, family); + } + + return err; +} + +static int selinux_socket_socketpair(struct socket *socka, + struct socket *sockb) +{ + struct sk_security_struct *sksec_a = socka->sk->sk_security; + struct sk_security_struct *sksec_b = sockb->sk->sk_security; + + sksec_a->peer_sid = sksec_b->sid; + sksec_b->peer_sid = sksec_a->sid; + + return 0; +} + +/* Range of port numbers used to automatically bind. + Need to determine whether we should perform a name_bind + permission check between the socket and the port number. */ + +static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen) +{ + struct sock *sk = sock->sk; + struct sk_security_struct *sksec = sk->sk_security; + u16 family; + int err; + + err = sock_has_perm(sk, SOCKET__BIND); + if (err) + goto out; + + /* If PF_INET or PF_INET6, check name_bind permission for the port. */ + family = sk->sk_family; + if (family == PF_INET || family == PF_INET6) { + char *addrp; + struct common_audit_data ad; + struct lsm_network_audit net = {0,}; + struct sockaddr_in *addr4 = NULL; + struct sockaddr_in6 *addr6 = NULL; + u16 family_sa; + unsigned short snum; + u32 sid, node_perm; + + /* + * sctp_bindx(3) calls via selinux_sctp_bind_connect() + * that validates multiple binding addresses. Because of this + * need to check address->sa_family as it is possible to have + * sk->sk_family = PF_INET6 with addr->sa_family = AF_INET. + */ + if (addrlen < offsetofend(struct sockaddr, sa_family)) + return -EINVAL; + family_sa = address->sa_family; + switch (family_sa) { + case AF_UNSPEC: + case AF_INET: + if (addrlen < sizeof(struct sockaddr_in)) + return -EINVAL; + addr4 = (struct sockaddr_in *)address; + if (family_sa == AF_UNSPEC) { + if (family == PF_INET6) { + /* Length check from inet6_bind_sk() */ + if (addrlen < SIN6_LEN_RFC2133) + return -EINVAL; + /* Family check from __inet6_bind() */ + goto err_af; + } + /* see __inet_bind(), we only want to allow + * AF_UNSPEC if the address is INADDR_ANY + */ + if (addr4->sin_addr.s_addr != htonl(INADDR_ANY)) + goto err_af; + family_sa = AF_INET; + } + snum = ntohs(addr4->sin_port); + addrp = (char *)&addr4->sin_addr.s_addr; + break; + case AF_INET6: + if (addrlen < SIN6_LEN_RFC2133) + return -EINVAL; + addr6 = (struct sockaddr_in6 *)address; + snum = ntohs(addr6->sin6_port); + addrp = (char *)&addr6->sin6_addr.s6_addr; + break; + default: + goto err_af; + } + + ad.type = LSM_AUDIT_DATA_NET; + ad.u.net = &net; + ad.u.net->sport = htons(snum); + ad.u.net->family = family_sa; + + if (snum) { + int low, high; + + inet_get_local_port_range(sock_net(sk), &low, &high); + + if (inet_port_requires_bind_service(sock_net(sk), snum) || + snum < low || snum > high) { + err = sel_netport_sid(sk->sk_protocol, + snum, &sid); + if (err) + goto out; + err = avc_has_perm(&selinux_state, + sksec->sid, sid, + sksec->sclass, + SOCKET__NAME_BIND, &ad); + if (err) + goto out; + } + } + + switch (sksec->sclass) { + case SECCLASS_TCP_SOCKET: + node_perm = TCP_SOCKET__NODE_BIND; + break; + + case SECCLASS_UDP_SOCKET: + node_perm = UDP_SOCKET__NODE_BIND; + break; + + case SECCLASS_DCCP_SOCKET: + node_perm = DCCP_SOCKET__NODE_BIND; + break; + + case SECCLASS_SCTP_SOCKET: + node_perm = SCTP_SOCKET__NODE_BIND; + break; + + default: + node_perm = RAWIP_SOCKET__NODE_BIND; + break; + } + + err = sel_netnode_sid(addrp, family_sa, &sid); + if (err) + goto out; + + if (family_sa == AF_INET) + ad.u.net->v4info.saddr = addr4->sin_addr.s_addr; + else + ad.u.net->v6info.saddr = addr6->sin6_addr; + + err = avc_has_perm(&selinux_state, + sksec->sid, sid, + sksec->sclass, node_perm, &ad); + if (err) + goto out; + } +out: + return err; +err_af: + /* Note that SCTP services expect -EINVAL, others -EAFNOSUPPORT. */ + if (sksec->sclass == SECCLASS_SCTP_SOCKET) + return -EINVAL; + return -EAFNOSUPPORT; +} + +/* This supports connect(2) and SCTP connect services such as sctp_connectx(3) + * and sctp_sendmsg(3) as described in Documentation/security/SCTP.rst + */ +static int selinux_socket_connect_helper(struct socket *sock, + struct sockaddr *address, int addrlen) +{ + struct sock *sk = sock->sk; + struct sk_security_struct *sksec = sk->sk_security; + int err; + + err = sock_has_perm(sk, SOCKET__CONNECT); + if (err) + return err; + if (addrlen < offsetofend(struct sockaddr, sa_family)) + return -EINVAL; + + /* connect(AF_UNSPEC) has special handling, as it is a documented + * way to disconnect the socket + */ + if (address->sa_family == AF_UNSPEC) + return 0; + + /* + * If a TCP, DCCP or SCTP socket, check name_connect permission + * for the port. + */ + if (sksec->sclass == SECCLASS_TCP_SOCKET || + sksec->sclass == SECCLASS_DCCP_SOCKET || + sksec->sclass == SECCLASS_SCTP_SOCKET) { + struct common_audit_data ad; + struct lsm_network_audit net = {0,}; + struct sockaddr_in *addr4 = NULL; + struct sockaddr_in6 *addr6 = NULL; + unsigned short snum; + u32 sid, perm; + + /* sctp_connectx(3) calls via selinux_sctp_bind_connect() + * that validates multiple connect addresses. Because of this + * need to check address->sa_family as it is possible to have + * sk->sk_family = PF_INET6 with addr->sa_family = AF_INET. + */ + switch (address->sa_family) { + case AF_INET: + addr4 = (struct sockaddr_in *)address; + if (addrlen < sizeof(struct sockaddr_in)) + return -EINVAL; + snum = ntohs(addr4->sin_port); + break; + case AF_INET6: + addr6 = (struct sockaddr_in6 *)address; + if (addrlen < SIN6_LEN_RFC2133) + return -EINVAL; + snum = ntohs(addr6->sin6_port); + break; + default: + /* Note that SCTP services expect -EINVAL, whereas + * others expect -EAFNOSUPPORT. + */ + if (sksec->sclass == SECCLASS_SCTP_SOCKET) + return -EINVAL; + else + return -EAFNOSUPPORT; + } + + err = sel_netport_sid(sk->sk_protocol, snum, &sid); + if (err) + return err; + + switch (sksec->sclass) { + case SECCLASS_TCP_SOCKET: + perm = TCP_SOCKET__NAME_CONNECT; + break; + case SECCLASS_DCCP_SOCKET: + perm = DCCP_SOCKET__NAME_CONNECT; + break; + case SECCLASS_SCTP_SOCKET: + perm = SCTP_SOCKET__NAME_CONNECT; + break; + } + + ad.type = LSM_AUDIT_DATA_NET; + ad.u.net = &net; + ad.u.net->dport = htons(snum); + ad.u.net->family = address->sa_family; + err = avc_has_perm(&selinux_state, + sksec->sid, sid, sksec->sclass, perm, &ad); + if (err) + return err; + } + + return 0; +} + +/* Supports connect(2), see comments in selinux_socket_connect_helper() */ +static int selinux_socket_connect(struct socket *sock, + struct sockaddr *address, int addrlen) +{ + int err; + struct sock *sk = sock->sk; + + err = selinux_socket_connect_helper(sock, address, addrlen); + if (err) + return err; + + return selinux_netlbl_socket_connect(sk, address); +} + +static int selinux_socket_listen(struct socket *sock, int backlog) +{ + return sock_has_perm(sock->sk, SOCKET__LISTEN); +} + +static int selinux_socket_accept(struct socket *sock, struct socket *newsock) +{ + int err; + struct inode_security_struct *isec; + struct inode_security_struct *newisec; + u16 sclass; + u32 sid; + + err = sock_has_perm(sock->sk, SOCKET__ACCEPT); + if (err) + return err; + + isec = inode_security_novalidate(SOCK_INODE(sock)); + spin_lock(&isec->lock); + sclass = isec->sclass; + sid = isec->sid; + spin_unlock(&isec->lock); + + newisec = inode_security_novalidate(SOCK_INODE(newsock)); + newisec->sclass = sclass; + newisec->sid = sid; + newisec->initialized = LABEL_INITIALIZED; + + return 0; +} + +static int selinux_socket_sendmsg(struct socket *sock, struct msghdr *msg, + int size) +{ + return sock_has_perm(sock->sk, SOCKET__WRITE); +} + +static int selinux_socket_recvmsg(struct socket *sock, struct msghdr *msg, + int size, int flags) +{ + return sock_has_perm(sock->sk, SOCKET__READ); +} + +static int selinux_socket_getsockname(struct socket *sock) +{ + return sock_has_perm(sock->sk, SOCKET__GETATTR); +} + +static int selinux_socket_getpeername(struct socket *sock) +{ + return sock_has_perm(sock->sk, SOCKET__GETATTR); +} + +static int selinux_socket_setsockopt(struct socket *sock, int level, int optname) +{ + int err; + + err = sock_has_perm(sock->sk, SOCKET__SETOPT); + if (err) + return err; + + return selinux_netlbl_socket_setsockopt(sock, level, optname); +} + +static int selinux_socket_getsockopt(struct socket *sock, int level, + int optname) +{ + return sock_has_perm(sock->sk, SOCKET__GETOPT); +} + +static int selinux_socket_shutdown(struct socket *sock, int how) +{ + return sock_has_perm(sock->sk, SOCKET__SHUTDOWN); +} + +static int selinux_socket_unix_stream_connect(struct sock *sock, + struct sock *other, + struct sock *newsk) +{ + struct sk_security_struct *sksec_sock = sock->sk_security; + struct sk_security_struct *sksec_other = other->sk_security; + struct sk_security_struct *sksec_new = newsk->sk_security; + struct common_audit_data ad; + struct lsm_network_audit net = {0,}; + int err; + + ad.type = LSM_AUDIT_DATA_NET; + ad.u.net = &net; + ad.u.net->sk = other; + + err = avc_has_perm(&selinux_state, + sksec_sock->sid, sksec_other->sid, + sksec_other->sclass, + UNIX_STREAM_SOCKET__CONNECTTO, &ad); + if (err) + return err; + + /* server child socket */ + sksec_new->peer_sid = sksec_sock->sid; + err = security_sid_mls_copy(&selinux_state, sksec_other->sid, + sksec_sock->sid, &sksec_new->sid); + if (err) + return err; + + /* connecting socket */ + sksec_sock->peer_sid = sksec_new->sid; + + return 0; +} + +static int selinux_socket_unix_may_send(struct socket *sock, + struct socket *other) +{ + struct sk_security_struct *ssec = sock->sk->sk_security; + struct sk_security_struct *osec = other->sk->sk_security; + struct common_audit_data ad; + struct lsm_network_audit net = {0,}; + + ad.type = LSM_AUDIT_DATA_NET; + ad.u.net = &net; + ad.u.net->sk = other->sk; + + return avc_has_perm(&selinux_state, + ssec->sid, osec->sid, osec->sclass, SOCKET__SENDTO, + &ad); +} + +static int selinux_inet_sys_rcv_skb(struct net *ns, int ifindex, + char *addrp, u16 family, u32 peer_sid, + struct common_audit_data *ad) +{ + int err; + u32 if_sid; + u32 node_sid; + + err = sel_netif_sid(ns, ifindex, &if_sid); + if (err) + return err; + err = avc_has_perm(&selinux_state, + peer_sid, if_sid, + SECCLASS_NETIF, NETIF__INGRESS, ad); + if (err) + return err; + + err = sel_netnode_sid(addrp, family, &node_sid); + if (err) + return err; + return avc_has_perm(&selinux_state, + peer_sid, node_sid, + SECCLASS_NODE, NODE__RECVFROM, ad); +} + +static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb, + u16 family) +{ + int err = 0; + struct sk_security_struct *sksec = sk->sk_security; + u32 sk_sid = sksec->sid; + struct common_audit_data ad; + struct lsm_network_audit net = {0,}; + char *addrp; + + ad.type = LSM_AUDIT_DATA_NET; + ad.u.net = &net; + ad.u.net->netif = skb->skb_iif; + ad.u.net->family = family; + err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL); + if (err) + return err; + + if (selinux_secmark_enabled()) { + err = avc_has_perm(&selinux_state, + sk_sid, skb->secmark, SECCLASS_PACKET, + PACKET__RECV, &ad); + if (err) + return err; + } + + err = selinux_netlbl_sock_rcv_skb(sksec, skb, family, &ad); + if (err) + return err; + err = selinux_xfrm_sock_rcv_skb(sksec->sid, skb, &ad); + + return err; +} + +static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) +{ + int err; + struct sk_security_struct *sksec = sk->sk_security; + u16 family = sk->sk_family; + u32 sk_sid = sksec->sid; + struct common_audit_data ad; + struct lsm_network_audit net = {0,}; + char *addrp; + u8 secmark_active; + u8 peerlbl_active; + + if (family != PF_INET && family != PF_INET6) + return 0; + + /* Handle mapped IPv4 packets arriving via IPv6 sockets */ + if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP)) + family = PF_INET; + + /* If any sort of compatibility mode is enabled then handoff processing + * to the selinux_sock_rcv_skb_compat() function to deal with the + * special handling. We do this in an attempt to keep this function + * as fast and as clean as possible. */ + if (!selinux_policycap_netpeer()) + return selinux_sock_rcv_skb_compat(sk, skb, family); + + secmark_active = selinux_secmark_enabled(); + peerlbl_active = selinux_peerlbl_enabled(); + if (!secmark_active && !peerlbl_active) + return 0; + + ad.type = LSM_AUDIT_DATA_NET; + ad.u.net = &net; + ad.u.net->netif = skb->skb_iif; + ad.u.net->family = family; + err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL); + if (err) + return err; + + if (peerlbl_active) { + u32 peer_sid; + + err = selinux_skb_peerlbl_sid(skb, family, &peer_sid); + if (err) + return err; + err = selinux_inet_sys_rcv_skb(sock_net(sk), skb->skb_iif, + addrp, family, peer_sid, &ad); + if (err) { + selinux_netlbl_err(skb, family, err, 0); + return err; + } + err = avc_has_perm(&selinux_state, + sk_sid, peer_sid, SECCLASS_PEER, + PEER__RECV, &ad); + if (err) { + selinux_netlbl_err(skb, family, err, 0); + return err; + } + } + + if (secmark_active) { + err = avc_has_perm(&selinux_state, + sk_sid, skb->secmark, SECCLASS_PACKET, + PACKET__RECV, &ad); + if (err) + return err; + } + + return err; +} + +static int selinux_socket_getpeersec_stream(struct socket *sock, char __user *optval, + int __user *optlen, unsigned len) +{ + int err = 0; + char *scontext; + u32 scontext_len; + struct sk_security_struct *sksec = sock->sk->sk_security; + u32 peer_sid = SECSID_NULL; + + if (sksec->sclass == SECCLASS_UNIX_STREAM_SOCKET || + sksec->sclass == SECCLASS_TCP_SOCKET || + sksec->sclass == SECCLASS_SCTP_SOCKET) + peer_sid = sksec->peer_sid; + if (peer_sid == SECSID_NULL) + return -ENOPROTOOPT; + + err = security_sid_to_context(&selinux_state, peer_sid, &scontext, + &scontext_len); + if (err) + return err; + + if (scontext_len > len) { + err = -ERANGE; + goto out_len; + } + + if (copy_to_user(optval, scontext, scontext_len)) + err = -EFAULT; + +out_len: + if (put_user(scontext_len, optlen)) + err = -EFAULT; + kfree(scontext); + return err; +} + +static int selinux_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid) +{ + u32 peer_secid = SECSID_NULL; + u16 family; + struct inode_security_struct *isec; + + if (skb && skb->protocol == htons(ETH_P_IP)) + family = PF_INET; + else if (skb && skb->protocol == htons(ETH_P_IPV6)) + family = PF_INET6; + else if (sock) + family = sock->sk->sk_family; + else + goto out; + + if (sock && family == PF_UNIX) { + isec = inode_security_novalidate(SOCK_INODE(sock)); + peer_secid = isec->sid; + } else if (skb) + selinux_skb_peerlbl_sid(skb, family, &peer_secid); + +out: + *secid = peer_secid; + if (peer_secid == SECSID_NULL) + return -EINVAL; + return 0; +} + +static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority) +{ + struct sk_security_struct *sksec; + + sksec = kzalloc(sizeof(*sksec), priority); + if (!sksec) + return -ENOMEM; + + sksec->peer_sid = SECINITSID_UNLABELED; + sksec->sid = SECINITSID_UNLABELED; + sksec->sclass = SECCLASS_SOCKET; + selinux_netlbl_sk_security_reset(sksec); + sk->sk_security = sksec; + + return 0; +} + +static void selinux_sk_free_security(struct sock *sk) +{ + struct sk_security_struct *sksec = sk->sk_security; + + sk->sk_security = NULL; + selinux_netlbl_sk_security_free(sksec); + kfree(sksec); +} + +static void selinux_sk_clone_security(const struct sock *sk, struct sock *newsk) +{ + struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *newsksec = newsk->sk_security; + + newsksec->sid = sksec->sid; + newsksec->peer_sid = sksec->peer_sid; + newsksec->sclass = sksec->sclass; + + selinux_netlbl_sk_security_reset(newsksec); +} + +static void selinux_sk_getsecid(struct sock *sk, u32 *secid) +{ + if (!sk) + *secid = SECINITSID_ANY_SOCKET; + else { + struct sk_security_struct *sksec = sk->sk_security; + + *secid = sksec->sid; + } +} + +static void selinux_sock_graft(struct sock *sk, struct socket *parent) +{ + struct inode_security_struct *isec = + inode_security_novalidate(SOCK_INODE(parent)); + struct sk_security_struct *sksec = sk->sk_security; + + if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 || + sk->sk_family == PF_UNIX) + isec->sid = sksec->sid; + sksec->sclass = isec->sclass; +} + +/* + * Determines peer_secid for the asoc and updates socket's peer label + * if it's the first association on the socket. + */ +static int selinux_sctp_process_new_assoc(struct sctp_association *asoc, + struct sk_buff *skb) +{ + struct sock *sk = asoc->base.sk; + u16 family = sk->sk_family; + struct sk_security_struct *sksec = sk->sk_security; + struct common_audit_data ad; + struct lsm_network_audit net = {0,}; + int err; + + /* handle mapped IPv4 packets arriving via IPv6 sockets */ + if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP)) + family = PF_INET; + + if (selinux_peerlbl_enabled()) { + asoc->peer_secid = SECSID_NULL; + + /* This will return peer_sid = SECSID_NULL if there are + * no peer labels, see security_net_peersid_resolve(). + */ + err = selinux_skb_peerlbl_sid(skb, family, &asoc->peer_secid); + if (err) + return err; + + if (asoc->peer_secid == SECSID_NULL) + asoc->peer_secid = SECINITSID_UNLABELED; + } else { + asoc->peer_secid = SECINITSID_UNLABELED; + } + + if (sksec->sctp_assoc_state == SCTP_ASSOC_UNSET) { + sksec->sctp_assoc_state = SCTP_ASSOC_SET; + + /* Here as first association on socket. As the peer SID + * was allowed by peer recv (and the netif/node checks), + * then it is approved by policy and used as the primary + * peer SID for getpeercon(3). + */ + sksec->peer_sid = asoc->peer_secid; + } else if (sksec->peer_sid != asoc->peer_secid) { + /* Other association peer SIDs are checked to enforce + * consistency among the peer SIDs. + */ + ad.type = LSM_AUDIT_DATA_NET; + ad.u.net = &net; + ad.u.net->sk = asoc->base.sk; + err = avc_has_perm(&selinux_state, + sksec->peer_sid, asoc->peer_secid, + sksec->sclass, SCTP_SOCKET__ASSOCIATION, + &ad); + if (err) + return err; + } + return 0; +} + +/* Called whenever SCTP receives an INIT or COOKIE ECHO chunk. This + * happens on an incoming connect(2), sctp_connectx(3) or + * sctp_sendmsg(3) (with no association already present). + */ +static int selinux_sctp_assoc_request(struct sctp_association *asoc, + struct sk_buff *skb) +{ + struct sk_security_struct *sksec = asoc->base.sk->sk_security; + u32 conn_sid; + int err; + + if (!selinux_policycap_extsockclass()) + return 0; + + err = selinux_sctp_process_new_assoc(asoc, skb); + if (err) + return err; + + /* Compute the MLS component for the connection and store + * the information in asoc. This will be used by SCTP TCP type + * sockets and peeled off connections as they cause a new + * socket to be generated. selinux_sctp_sk_clone() will then + * plug this into the new socket. + */ + err = selinux_conn_sid(sksec->sid, asoc->peer_secid, &conn_sid); + if (err) + return err; + + asoc->secid = conn_sid; + + /* Set any NetLabel labels including CIPSO/CALIPSO options. */ + return selinux_netlbl_sctp_assoc_request(asoc, skb); +} + +/* Called when SCTP receives a COOKIE ACK chunk as the final + * response to an association request (initited by us). + */ +static int selinux_sctp_assoc_established(struct sctp_association *asoc, + struct sk_buff *skb) +{ + struct sk_security_struct *sksec = asoc->base.sk->sk_security; + + if (!selinux_policycap_extsockclass()) + return 0; + + /* Inherit secid from the parent socket - this will be picked up + * by selinux_sctp_sk_clone() if the association gets peeled off + * into a new socket. + */ + asoc->secid = sksec->sid; + + return selinux_sctp_process_new_assoc(asoc, skb); +} + +/* Check if sctp IPv4/IPv6 addresses are valid for binding or connecting + * based on their @optname. + */ +static int selinux_sctp_bind_connect(struct sock *sk, int optname, + struct sockaddr *address, + int addrlen) +{ + int len, err = 0, walk_size = 0; + void *addr_buf; + struct sockaddr *addr; + struct socket *sock; + + if (!selinux_policycap_extsockclass()) + return 0; + + /* Process one or more addresses that may be IPv4 or IPv6 */ + sock = sk->sk_socket; + addr_buf = address; + + while (walk_size < addrlen) { + if (walk_size + sizeof(sa_family_t) > addrlen) + return -EINVAL; + + addr = addr_buf; + switch (addr->sa_family) { + case AF_UNSPEC: + case AF_INET: + len = sizeof(struct sockaddr_in); + break; + case AF_INET6: + len = sizeof(struct sockaddr_in6); + break; + default: + return -EINVAL; + } + + if (walk_size + len > addrlen) + return -EINVAL; + + err = -EINVAL; + switch (optname) { + /* Bind checks */ + case SCTP_PRIMARY_ADDR: + case SCTP_SET_PEER_PRIMARY_ADDR: + case SCTP_SOCKOPT_BINDX_ADD: + err = selinux_socket_bind(sock, addr, len); + break; + /* Connect checks */ + case SCTP_SOCKOPT_CONNECTX: + case SCTP_PARAM_SET_PRIMARY: + case SCTP_PARAM_ADD_IP: + case SCTP_SENDMSG_CONNECT: + err = selinux_socket_connect_helper(sock, addr, len); + if (err) + return err; + + /* As selinux_sctp_bind_connect() is called by the + * SCTP protocol layer, the socket is already locked, + * therefore selinux_netlbl_socket_connect_locked() + * is called here. The situations handled are: + * sctp_connectx(3), sctp_sendmsg(3), sendmsg(2), + * whenever a new IP address is added or when a new + * primary address is selected. + * Note that an SCTP connect(2) call happens before + * the SCTP protocol layer and is handled via + * selinux_socket_connect(). + */ + err = selinux_netlbl_socket_connect_locked(sk, addr); + break; + } + + if (err) + return err; + + addr_buf += len; + walk_size += len; + } + + return 0; +} + +/* Called whenever a new socket is created by accept(2) or sctp_peeloff(3). */ +static void selinux_sctp_sk_clone(struct sctp_association *asoc, struct sock *sk, + struct sock *newsk) +{ + struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *newsksec = newsk->sk_security; + + /* If policy does not support SECCLASS_SCTP_SOCKET then call + * the non-sctp clone version. + */ + if (!selinux_policycap_extsockclass()) + return selinux_sk_clone_security(sk, newsk); + + newsksec->sid = asoc->secid; + newsksec->peer_sid = asoc->peer_secid; + newsksec->sclass = sksec->sclass; + selinux_netlbl_sctp_sk_clone(sk, newsk); +} + +static int selinux_inet_conn_request(const struct sock *sk, struct sk_buff *skb, + struct request_sock *req) +{ + struct sk_security_struct *sksec = sk->sk_security; + int err; + u16 family = req->rsk_ops->family; + u32 connsid; + u32 peersid; + + err = selinux_skb_peerlbl_sid(skb, family, &peersid); + if (err) + return err; + err = selinux_conn_sid(sksec->sid, peersid, &connsid); + if (err) + return err; + req->secid = connsid; + req->peer_secid = peersid; + + return selinux_netlbl_inet_conn_request(req, family); +} + +static void selinux_inet_csk_clone(struct sock *newsk, + const struct request_sock *req) +{ + struct sk_security_struct *newsksec = newsk->sk_security; + + newsksec->sid = req->secid; + newsksec->peer_sid = req->peer_secid; + /* NOTE: Ideally, we should also get the isec->sid for the + new socket in sync, but we don't have the isec available yet. + So we will wait until sock_graft to do it, by which + time it will have been created and available. */ + + /* We don't need to take any sort of lock here as we are the only + * thread with access to newsksec */ + selinux_netlbl_inet_csk_clone(newsk, req->rsk_ops->family); +} + +static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb) +{ + u16 family = sk->sk_family; + struct sk_security_struct *sksec = sk->sk_security; + + /* handle mapped IPv4 packets arriving via IPv6 sockets */ + if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP)) + family = PF_INET; + + selinux_skb_peerlbl_sid(skb, family, &sksec->peer_sid); +} + +static int selinux_secmark_relabel_packet(u32 sid) +{ + const struct task_security_struct *__tsec; + u32 tsid; + + __tsec = selinux_cred(current_cred()); + tsid = __tsec->sid; + + return avc_has_perm(&selinux_state, + tsid, sid, SECCLASS_PACKET, PACKET__RELABELTO, + NULL); +} + +static void selinux_secmark_refcount_inc(void) +{ + atomic_inc(&selinux_secmark_refcount); +} + +static void selinux_secmark_refcount_dec(void) +{ + atomic_dec(&selinux_secmark_refcount); +} + +static void selinux_req_classify_flow(const struct request_sock *req, + struct flowi_common *flic) +{ + flic->flowic_secid = req->secid; +} + +static int selinux_tun_dev_alloc_security(void **security) +{ + struct tun_security_struct *tunsec; + + tunsec = kzalloc(sizeof(*tunsec), GFP_KERNEL); + if (!tunsec) + return -ENOMEM; + tunsec->sid = current_sid(); + + *security = tunsec; + return 0; +} + +static void selinux_tun_dev_free_security(void *security) +{ + kfree(security); +} + +static int selinux_tun_dev_create(void) +{ + u32 sid = current_sid(); + + /* we aren't taking into account the "sockcreate" SID since the socket + * that is being created here is not a socket in the traditional sense, + * instead it is a private sock, accessible only to the kernel, and + * representing a wide range of network traffic spanning multiple + * connections unlike traditional sockets - check the TUN driver to + * get a better understanding of why this socket is special */ + + return avc_has_perm(&selinux_state, + sid, sid, SECCLASS_TUN_SOCKET, TUN_SOCKET__CREATE, + NULL); +} + +static int selinux_tun_dev_attach_queue(void *security) +{ + struct tun_security_struct *tunsec = security; + + return avc_has_perm(&selinux_state, + current_sid(), tunsec->sid, SECCLASS_TUN_SOCKET, + TUN_SOCKET__ATTACH_QUEUE, NULL); +} + +static int selinux_tun_dev_attach(struct sock *sk, void *security) +{ + struct tun_security_struct *tunsec = security; + struct sk_security_struct *sksec = sk->sk_security; + + /* we don't currently perform any NetLabel based labeling here and it + * isn't clear that we would want to do so anyway; while we could apply + * labeling without the support of the TUN user the resulting labeled + * traffic from the other end of the connection would almost certainly + * cause confusion to the TUN user that had no idea network labeling + * protocols were being used */ + + sksec->sid = tunsec->sid; + sksec->sclass = SECCLASS_TUN_SOCKET; + + return 0; +} + +static int selinux_tun_dev_open(void *security) +{ + struct tun_security_struct *tunsec = security; + u32 sid = current_sid(); + int err; + + err = avc_has_perm(&selinux_state, + sid, tunsec->sid, SECCLASS_TUN_SOCKET, + TUN_SOCKET__RELABELFROM, NULL); + if (err) + return err; + err = avc_has_perm(&selinux_state, + sid, sid, SECCLASS_TUN_SOCKET, + TUN_SOCKET__RELABELTO, NULL); + if (err) + return err; + tunsec->sid = sid; + + return 0; +} + +#ifdef CONFIG_NETFILTER + +static unsigned int selinux_ip_forward(void *priv, struct sk_buff *skb, + const struct nf_hook_state *state) +{ + int ifindex; + u16 family; + char *addrp; + u32 peer_sid; + struct common_audit_data ad; + struct lsm_network_audit net = {0,}; + int secmark_active, peerlbl_active; + + if (!selinux_policycap_netpeer()) + return NF_ACCEPT; + + secmark_active = selinux_secmark_enabled(); + peerlbl_active = selinux_peerlbl_enabled(); + if (!secmark_active && !peerlbl_active) + return NF_ACCEPT; + + family = state->pf; + if (selinux_skb_peerlbl_sid(skb, family, &peer_sid) != 0) + return NF_DROP; + + ifindex = state->in->ifindex; + ad.type = LSM_AUDIT_DATA_NET; + ad.u.net = &net; + ad.u.net->netif = ifindex; + ad.u.net->family = family; + if (selinux_parse_skb(skb, &ad, &addrp, 1, NULL) != 0) + return NF_DROP; + + if (peerlbl_active) { + int err; + + err = selinux_inet_sys_rcv_skb(state->net, ifindex, + addrp, family, peer_sid, &ad); + if (err) { + selinux_netlbl_err(skb, family, err, 1); + return NF_DROP; + } + } + + if (secmark_active) + if (avc_has_perm(&selinux_state, + peer_sid, skb->secmark, + SECCLASS_PACKET, PACKET__FORWARD_IN, &ad)) + return NF_DROP; + + if (netlbl_enabled()) + /* we do this in the FORWARD path and not the POST_ROUTING + * path because we want to make sure we apply the necessary + * labeling before IPsec is applied so we can leverage AH + * protection */ + if (selinux_netlbl_skbuff_setsid(skb, family, peer_sid) != 0) + return NF_DROP; + + return NF_ACCEPT; +} + +static unsigned int selinux_ip_output(void *priv, struct sk_buff *skb, + const struct nf_hook_state *state) +{ + struct sock *sk; + u32 sid; + + if (!netlbl_enabled()) + return NF_ACCEPT; + + /* we do this in the LOCAL_OUT path and not the POST_ROUTING path + * because we want to make sure we apply the necessary labeling + * before IPsec is applied so we can leverage AH protection */ + sk = skb->sk; + if (sk) { + struct sk_security_struct *sksec; + + if (sk_listener(sk)) + /* if the socket is the listening state then this + * packet is a SYN-ACK packet which means it needs to + * be labeled based on the connection/request_sock and + * not the parent socket. unfortunately, we can't + * lookup the request_sock yet as it isn't queued on + * the parent socket until after the SYN-ACK is sent. + * the "solution" is to simply pass the packet as-is + * as any IP option based labeling should be copied + * from the initial connection request (in the IP + * layer). it is far from ideal, but until we get a + * security label in the packet itself this is the + * best we can do. */ + return NF_ACCEPT; + + /* standard practice, label using the parent socket */ + sksec = sk->sk_security; + sid = sksec->sid; + } else + sid = SECINITSID_KERNEL; + if (selinux_netlbl_skbuff_setsid(skb, state->pf, sid) != 0) + return NF_DROP; + + return NF_ACCEPT; +} + + +static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb, + const struct nf_hook_state *state) +{ + struct sock *sk; + struct sk_security_struct *sksec; + struct common_audit_data ad; + struct lsm_network_audit net = {0,}; + u8 proto = 0; + + sk = skb_to_full_sk(skb); + if (sk == NULL) + return NF_ACCEPT; + sksec = sk->sk_security; + + ad.type = LSM_AUDIT_DATA_NET; + ad.u.net = &net; + ad.u.net->netif = state->out->ifindex; + ad.u.net->family = state->pf; + if (selinux_parse_skb(skb, &ad, NULL, 0, &proto)) + return NF_DROP; + + if (selinux_secmark_enabled()) + if (avc_has_perm(&selinux_state, + sksec->sid, skb->secmark, + SECCLASS_PACKET, PACKET__SEND, &ad)) + return NF_DROP_ERR(-ECONNREFUSED); + + if (selinux_xfrm_postroute_last(sksec->sid, skb, &ad, proto)) + return NF_DROP_ERR(-ECONNREFUSED); + + return NF_ACCEPT; +} + +static unsigned int selinux_ip_postroute(void *priv, + struct sk_buff *skb, + const struct nf_hook_state *state) +{ + u16 family; + u32 secmark_perm; + u32 peer_sid; + int ifindex; + struct sock *sk; + struct common_audit_data ad; + struct lsm_network_audit net = {0,}; + char *addrp; + int secmark_active, peerlbl_active; + + /* If any sort of compatibility mode is enabled then handoff processing + * to the selinux_ip_postroute_compat() function to deal with the + * special handling. We do this in an attempt to keep this function + * as fast and as clean as possible. */ + if (!selinux_policycap_netpeer()) + return selinux_ip_postroute_compat(skb, state); + + secmark_active = selinux_secmark_enabled(); + peerlbl_active = selinux_peerlbl_enabled(); + if (!secmark_active && !peerlbl_active) + return NF_ACCEPT; + + sk = skb_to_full_sk(skb); + +#ifdef CONFIG_XFRM + /* If skb->dst->xfrm is non-NULL then the packet is undergoing an IPsec + * packet transformation so allow the packet to pass without any checks + * since we'll have another chance to perform access control checks + * when the packet is on it's final way out. + * NOTE: there appear to be some IPv6 multicast cases where skb->dst + * is NULL, in this case go ahead and apply access control. + * NOTE: if this is a local socket (skb->sk != NULL) that is in the + * TCP listening state we cannot wait until the XFRM processing + * is done as we will miss out on the SA label if we do; + * unfortunately, this means more work, but it is only once per + * connection. */ + if (skb_dst(skb) != NULL && skb_dst(skb)->xfrm != NULL && + !(sk && sk_listener(sk))) + return NF_ACCEPT; +#endif + + family = state->pf; + if (sk == NULL) { + /* Without an associated socket the packet is either coming + * from the kernel or it is being forwarded; check the packet + * to determine which and if the packet is being forwarded + * query the packet directly to determine the security label. */ + if (skb->skb_iif) { + secmark_perm = PACKET__FORWARD_OUT; + if (selinux_skb_peerlbl_sid(skb, family, &peer_sid)) + return NF_DROP; + } else { + secmark_perm = PACKET__SEND; + peer_sid = SECINITSID_KERNEL; + } + } else if (sk_listener(sk)) { + /* Locally generated packet but the associated socket is in the + * listening state which means this is a SYN-ACK packet. In + * this particular case the correct security label is assigned + * to the connection/request_sock but unfortunately we can't + * query the request_sock as it isn't queued on the parent + * socket until after the SYN-ACK packet is sent; the only + * viable choice is to regenerate the label like we do in + * selinux_inet_conn_request(). See also selinux_ip_output() + * for similar problems. */ + u32 skb_sid; + struct sk_security_struct *sksec; + + sksec = sk->sk_security; + if (selinux_skb_peerlbl_sid(skb, family, &skb_sid)) + return NF_DROP; + /* At this point, if the returned skb peerlbl is SECSID_NULL + * and the packet has been through at least one XFRM + * transformation then we must be dealing with the "final" + * form of labeled IPsec packet; since we've already applied + * all of our access controls on this packet we can safely + * pass the packet. */ + if (skb_sid == SECSID_NULL) { + switch (family) { + case PF_INET: + if (IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED) + return NF_ACCEPT; + break; + case PF_INET6: + if (IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) + return NF_ACCEPT; + break; + default: + return NF_DROP_ERR(-ECONNREFUSED); + } + } + if (selinux_conn_sid(sksec->sid, skb_sid, &peer_sid)) + return NF_DROP; + secmark_perm = PACKET__SEND; + } else { + /* Locally generated packet, fetch the security label from the + * associated socket. */ + struct sk_security_struct *sksec = sk->sk_security; + peer_sid = sksec->sid; + secmark_perm = PACKET__SEND; + } + + ifindex = state->out->ifindex; + ad.type = LSM_AUDIT_DATA_NET; + ad.u.net = &net; + ad.u.net->netif = ifindex; + ad.u.net->family = family; + if (selinux_parse_skb(skb, &ad, &addrp, 0, NULL)) + return NF_DROP; + + if (secmark_active) + if (avc_has_perm(&selinux_state, + peer_sid, skb->secmark, + SECCLASS_PACKET, secmark_perm, &ad)) + return NF_DROP_ERR(-ECONNREFUSED); + + if (peerlbl_active) { + u32 if_sid; + u32 node_sid; + + if (sel_netif_sid(state->net, ifindex, &if_sid)) + return NF_DROP; + if (avc_has_perm(&selinux_state, + peer_sid, if_sid, + SECCLASS_NETIF, NETIF__EGRESS, &ad)) + return NF_DROP_ERR(-ECONNREFUSED); + + if (sel_netnode_sid(addrp, family, &node_sid)) + return NF_DROP; + if (avc_has_perm(&selinux_state, + peer_sid, node_sid, + SECCLASS_NODE, NODE__SENDTO, &ad)) + return NF_DROP_ERR(-ECONNREFUSED); + } + + return NF_ACCEPT; +} +#endif /* CONFIG_NETFILTER */ + +static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb) +{ + int rc = 0; + unsigned int msg_len; + unsigned int data_len = skb->len; + unsigned char *data = skb->data; + struct nlmsghdr *nlh; + struct sk_security_struct *sksec = sk->sk_security; + u16 sclass = sksec->sclass; + u32 perm; + + while (data_len >= nlmsg_total_size(0)) { + nlh = (struct nlmsghdr *)data; + + /* NOTE: the nlmsg_len field isn't reliably set by some netlink + * users which means we can't reject skb's with bogus + * length fields; our solution is to follow what + * netlink_rcv_skb() does and simply skip processing at + * messages with length fields that are clearly junk + */ + if (nlh->nlmsg_len < NLMSG_HDRLEN || nlh->nlmsg_len > data_len) + return 0; + + rc = selinux_nlmsg_lookup(sclass, nlh->nlmsg_type, &perm); + if (rc == 0) { + rc = sock_has_perm(sk, perm); + if (rc) + return rc; + } else if (rc == -EINVAL) { + /* -EINVAL is a missing msg/perm mapping */ + pr_warn_ratelimited("SELinux: unrecognized netlink" + " message: protocol=%hu nlmsg_type=%hu sclass=%s" + " pid=%d comm=%s\n", + sk->sk_protocol, nlh->nlmsg_type, + secclass_map[sclass - 1].name, + task_pid_nr(current), current->comm); + if (enforcing_enabled(&selinux_state) && + !security_get_allow_unknown(&selinux_state)) + return rc; + rc = 0; + } else if (rc == -ENOENT) { + /* -ENOENT is a missing socket/class mapping, ignore */ + rc = 0; + } else { + return rc; + } + + /* move to the next message after applying netlink padding */ + msg_len = NLMSG_ALIGN(nlh->nlmsg_len); + if (msg_len >= data_len) + return 0; + data_len -= msg_len; + data += msg_len; + } + + return rc; +} + +static void ipc_init_security(struct ipc_security_struct *isec, u16 sclass) +{ + isec->sclass = sclass; + isec->sid = current_sid(); +} + +static int ipc_has_perm(struct kern_ipc_perm *ipc_perms, + u32 perms) +{ + struct ipc_security_struct *isec; + struct common_audit_data ad; + u32 sid = current_sid(); + + isec = selinux_ipc(ipc_perms); + + ad.type = LSM_AUDIT_DATA_IPC; + ad.u.ipc_id = ipc_perms->key; + + return avc_has_perm(&selinux_state, + sid, isec->sid, isec->sclass, perms, &ad); +} + +static int selinux_msg_msg_alloc_security(struct msg_msg *msg) +{ + struct msg_security_struct *msec; + + msec = selinux_msg_msg(msg); + msec->sid = SECINITSID_UNLABELED; + + return 0; +} + +/* message queue security operations */ +static int selinux_msg_queue_alloc_security(struct kern_ipc_perm *msq) +{ + struct ipc_security_struct *isec; + struct common_audit_data ad; + u32 sid = current_sid(); + + isec = selinux_ipc(msq); + ipc_init_security(isec, SECCLASS_MSGQ); + + ad.type = LSM_AUDIT_DATA_IPC; + ad.u.ipc_id = msq->key; + + return avc_has_perm(&selinux_state, + sid, isec->sid, SECCLASS_MSGQ, + MSGQ__CREATE, &ad); +} + +static int selinux_msg_queue_associate(struct kern_ipc_perm *msq, int msqflg) +{ + struct ipc_security_struct *isec; + struct common_audit_data ad; + u32 sid = current_sid(); + + isec = selinux_ipc(msq); + + ad.type = LSM_AUDIT_DATA_IPC; + ad.u.ipc_id = msq->key; + + return avc_has_perm(&selinux_state, + sid, isec->sid, SECCLASS_MSGQ, + MSGQ__ASSOCIATE, &ad); +} + +static int selinux_msg_queue_msgctl(struct kern_ipc_perm *msq, int cmd) +{ + int err; + int perms; + + switch (cmd) { + case IPC_INFO: + case MSG_INFO: + /* No specific object, just general system-wide information. */ + return avc_has_perm(&selinux_state, + current_sid(), SECINITSID_KERNEL, + SECCLASS_SYSTEM, SYSTEM__IPC_INFO, NULL); + case IPC_STAT: + case MSG_STAT: + case MSG_STAT_ANY: + perms = MSGQ__GETATTR | MSGQ__ASSOCIATE; + break; + case IPC_SET: + perms = MSGQ__SETATTR; + break; + case IPC_RMID: + perms = MSGQ__DESTROY; + break; + default: + return 0; + } + + err = ipc_has_perm(msq, perms); + return err; +} + +static int selinux_msg_queue_msgsnd(struct kern_ipc_perm *msq, struct msg_msg *msg, int msqflg) +{ + struct ipc_security_struct *isec; + struct msg_security_struct *msec; + struct common_audit_data ad; + u32 sid = current_sid(); + int rc; + + isec = selinux_ipc(msq); + msec = selinux_msg_msg(msg); + + /* + * First time through, need to assign label to the message + */ + if (msec->sid == SECINITSID_UNLABELED) { + /* + * Compute new sid based on current process and + * message queue this message will be stored in + */ + rc = security_transition_sid(&selinux_state, sid, isec->sid, + SECCLASS_MSG, NULL, &msec->sid); + if (rc) + return rc; + } + + ad.type = LSM_AUDIT_DATA_IPC; + ad.u.ipc_id = msq->key; + + /* Can this process write to the queue? */ + rc = avc_has_perm(&selinux_state, + sid, isec->sid, SECCLASS_MSGQ, + MSGQ__WRITE, &ad); + if (!rc) + /* Can this process send the message */ + rc = avc_has_perm(&selinux_state, + sid, msec->sid, SECCLASS_MSG, + MSG__SEND, &ad); + if (!rc) + /* Can the message be put in the queue? */ + rc = avc_has_perm(&selinux_state, + msec->sid, isec->sid, SECCLASS_MSGQ, + MSGQ__ENQUEUE, &ad); + + return rc; +} + +static int selinux_msg_queue_msgrcv(struct kern_ipc_perm *msq, struct msg_msg *msg, + struct task_struct *target, + long type, int mode) +{ + struct ipc_security_struct *isec; + struct msg_security_struct *msec; + struct common_audit_data ad; + u32 sid = task_sid_obj(target); + int rc; + + isec = selinux_ipc(msq); + msec = selinux_msg_msg(msg); + + ad.type = LSM_AUDIT_DATA_IPC; + ad.u.ipc_id = msq->key; + + rc = avc_has_perm(&selinux_state, + sid, isec->sid, + SECCLASS_MSGQ, MSGQ__READ, &ad); + if (!rc) + rc = avc_has_perm(&selinux_state, + sid, msec->sid, + SECCLASS_MSG, MSG__RECEIVE, &ad); + return rc; +} + +/* Shared Memory security operations */ +static int selinux_shm_alloc_security(struct kern_ipc_perm *shp) +{ + struct ipc_security_struct *isec; + struct common_audit_data ad; + u32 sid = current_sid(); + + isec = selinux_ipc(shp); + ipc_init_security(isec, SECCLASS_SHM); + + ad.type = LSM_AUDIT_DATA_IPC; + ad.u.ipc_id = shp->key; + + return avc_has_perm(&selinux_state, + sid, isec->sid, SECCLASS_SHM, + SHM__CREATE, &ad); +} + +static int selinux_shm_associate(struct kern_ipc_perm *shp, int shmflg) +{ + struct ipc_security_struct *isec; + struct common_audit_data ad; + u32 sid = current_sid(); + + isec = selinux_ipc(shp); + + ad.type = LSM_AUDIT_DATA_IPC; + ad.u.ipc_id = shp->key; + + return avc_has_perm(&selinux_state, + sid, isec->sid, SECCLASS_SHM, + SHM__ASSOCIATE, &ad); +} + +/* Note, at this point, shp is locked down */ +static int selinux_shm_shmctl(struct kern_ipc_perm *shp, int cmd) +{ + int perms; + int err; + + switch (cmd) { + case IPC_INFO: + case SHM_INFO: + /* No specific object, just general system-wide information. */ + return avc_has_perm(&selinux_state, + current_sid(), SECINITSID_KERNEL, + SECCLASS_SYSTEM, SYSTEM__IPC_INFO, NULL); + case IPC_STAT: + case SHM_STAT: + case SHM_STAT_ANY: + perms = SHM__GETATTR | SHM__ASSOCIATE; + break; + case IPC_SET: + perms = SHM__SETATTR; + break; + case SHM_LOCK: + case SHM_UNLOCK: + perms = SHM__LOCK; + break; + case IPC_RMID: + perms = SHM__DESTROY; + break; + default: + return 0; + } + + err = ipc_has_perm(shp, perms); + return err; +} + +static int selinux_shm_shmat(struct kern_ipc_perm *shp, + char __user *shmaddr, int shmflg) +{ + u32 perms; + + if (shmflg & SHM_RDONLY) + perms = SHM__READ; + else + perms = SHM__READ | SHM__WRITE; + + return ipc_has_perm(shp, perms); +} + +/* Semaphore security operations */ +static int selinux_sem_alloc_security(struct kern_ipc_perm *sma) +{ + struct ipc_security_struct *isec; + struct common_audit_data ad; + u32 sid = current_sid(); + + isec = selinux_ipc(sma); + ipc_init_security(isec, SECCLASS_SEM); + + ad.type = LSM_AUDIT_DATA_IPC; + ad.u.ipc_id = sma->key; + + return avc_has_perm(&selinux_state, + sid, isec->sid, SECCLASS_SEM, + SEM__CREATE, &ad); +} + +static int selinux_sem_associate(struct kern_ipc_perm *sma, int semflg) +{ + struct ipc_security_struct *isec; + struct common_audit_data ad; + u32 sid = current_sid(); + + isec = selinux_ipc(sma); + + ad.type = LSM_AUDIT_DATA_IPC; + ad.u.ipc_id = sma->key; + + return avc_has_perm(&selinux_state, + sid, isec->sid, SECCLASS_SEM, + SEM__ASSOCIATE, &ad); +} + +/* Note, at this point, sma is locked down */ +static int selinux_sem_semctl(struct kern_ipc_perm *sma, int cmd) +{ + int err; + u32 perms; + + switch (cmd) { + case IPC_INFO: + case SEM_INFO: + /* No specific object, just general system-wide information. */ + return avc_has_perm(&selinux_state, + current_sid(), SECINITSID_KERNEL, + SECCLASS_SYSTEM, SYSTEM__IPC_INFO, NULL); + case GETPID: + case GETNCNT: + case GETZCNT: + perms = SEM__GETATTR; + break; + case GETVAL: + case GETALL: + perms = SEM__READ; + break; + case SETVAL: + case SETALL: + perms = SEM__WRITE; + break; + case IPC_RMID: + perms = SEM__DESTROY; + break; + case IPC_SET: + perms = SEM__SETATTR; + break; + case IPC_STAT: + case SEM_STAT: + case SEM_STAT_ANY: + perms = SEM__GETATTR | SEM__ASSOCIATE; + break; + default: + return 0; + } + + err = ipc_has_perm(sma, perms); + return err; +} + +static int selinux_sem_semop(struct kern_ipc_perm *sma, + struct sembuf *sops, unsigned nsops, int alter) +{ + u32 perms; + + if (alter) + perms = SEM__READ | SEM__WRITE; + else + perms = SEM__READ; + + return ipc_has_perm(sma, perms); +} + +static int selinux_ipc_permission(struct kern_ipc_perm *ipcp, short flag) +{ + u32 av = 0; + + av = 0; + if (flag & S_IRUGO) + av |= IPC__UNIX_READ; + if (flag & S_IWUGO) + av |= IPC__UNIX_WRITE; + + if (av == 0) + return 0; + + return ipc_has_perm(ipcp, av); +} + +static void selinux_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid) +{ + struct ipc_security_struct *isec = selinux_ipc(ipcp); + *secid = isec->sid; +} + +static void selinux_d_instantiate(struct dentry *dentry, struct inode *inode) +{ + if (inode) + inode_doinit_with_dentry(inode, dentry); +} + +static int selinux_getprocattr(struct task_struct *p, + const char *name, char **value) +{ + const struct task_security_struct *__tsec; + u32 sid; + int error; + unsigned len; + + rcu_read_lock(); + __tsec = selinux_cred(__task_cred(p)); + + if (current != p) { + error = avc_has_perm(&selinux_state, + current_sid(), __tsec->sid, + SECCLASS_PROCESS, PROCESS__GETATTR, NULL); + if (error) + goto bad; + } + + if (!strcmp(name, "current")) + sid = __tsec->sid; + else if (!strcmp(name, "prev")) + sid = __tsec->osid; + else if (!strcmp(name, "exec")) + sid = __tsec->exec_sid; + else if (!strcmp(name, "fscreate")) + sid = __tsec->create_sid; + else if (!strcmp(name, "keycreate")) + sid = __tsec->keycreate_sid; + else if (!strcmp(name, "sockcreate")) + sid = __tsec->sockcreate_sid; + else { + error = -EINVAL; + goto bad; + } + rcu_read_unlock(); + + if (!sid) + return 0; + + error = security_sid_to_context(&selinux_state, sid, value, &len); + if (error) + return error; + return len; + +bad: + rcu_read_unlock(); + return error; +} + +static int selinux_setprocattr(const char *name, void *value, size_t size) +{ + struct task_security_struct *tsec; + struct cred *new; + u32 mysid = current_sid(), sid = 0, ptsid; + int error; + char *str = value; + + /* + * Basic control over ability to set these attributes at all. + */ + if (!strcmp(name, "exec")) + error = avc_has_perm(&selinux_state, + mysid, mysid, SECCLASS_PROCESS, + PROCESS__SETEXEC, NULL); + else if (!strcmp(name, "fscreate")) + error = avc_has_perm(&selinux_state, + mysid, mysid, SECCLASS_PROCESS, + PROCESS__SETFSCREATE, NULL); + else if (!strcmp(name, "keycreate")) + error = avc_has_perm(&selinux_state, + mysid, mysid, SECCLASS_PROCESS, + PROCESS__SETKEYCREATE, NULL); + else if (!strcmp(name, "sockcreate")) + error = avc_has_perm(&selinux_state, + mysid, mysid, SECCLASS_PROCESS, + PROCESS__SETSOCKCREATE, NULL); + else if (!strcmp(name, "current")) + error = avc_has_perm(&selinux_state, + mysid, mysid, SECCLASS_PROCESS, + PROCESS__SETCURRENT, NULL); + else + error = -EINVAL; + if (error) + return error; + + /* Obtain a SID for the context, if one was specified. */ + if (size && str[0] && str[0] != '\n') { + if (str[size-1] == '\n') { + str[size-1] = 0; + size--; + } + error = security_context_to_sid(&selinux_state, value, size, + &sid, GFP_KERNEL); + if (error == -EINVAL && !strcmp(name, "fscreate")) { + if (!has_cap_mac_admin(true)) { + struct audit_buffer *ab; + size_t audit_size; + + /* We strip a nul only if it is at the end, otherwise the + * context contains a nul and we should audit that */ + if (str[size - 1] == '\0') + audit_size = size - 1; + else + audit_size = size; + ab = audit_log_start(audit_context(), + GFP_ATOMIC, + AUDIT_SELINUX_ERR); + if (!ab) + return error; + audit_log_format(ab, "op=fscreate invalid_context="); + audit_log_n_untrustedstring(ab, value, audit_size); + audit_log_end(ab); + + return error; + } + error = security_context_to_sid_force( + &selinux_state, + value, size, &sid); + } + if (error) + return error; + } + + new = prepare_creds(); + if (!new) + return -ENOMEM; + + /* Permission checking based on the specified context is + performed during the actual operation (execve, + open/mkdir/...), when we know the full context of the + operation. See selinux_bprm_creds_for_exec for the execve + checks and may_create for the file creation checks. The + operation will then fail if the context is not permitted. */ + tsec = selinux_cred(new); + if (!strcmp(name, "exec")) { + tsec->exec_sid = sid; + } else if (!strcmp(name, "fscreate")) { + tsec->create_sid = sid; + } else if (!strcmp(name, "keycreate")) { + if (sid) { + error = avc_has_perm(&selinux_state, mysid, sid, + SECCLASS_KEY, KEY__CREATE, NULL); + if (error) + goto abort_change; + } + tsec->keycreate_sid = sid; + } else if (!strcmp(name, "sockcreate")) { + tsec->sockcreate_sid = sid; + } else if (!strcmp(name, "current")) { + error = -EINVAL; + if (sid == 0) + goto abort_change; + + /* Only allow single threaded processes to change context */ + if (!current_is_single_threaded()) { + error = security_bounded_transition(&selinux_state, + tsec->sid, sid); + if (error) + goto abort_change; + } + + /* Check permissions for the transition. */ + error = avc_has_perm(&selinux_state, + tsec->sid, sid, SECCLASS_PROCESS, + PROCESS__DYNTRANSITION, NULL); + if (error) + goto abort_change; + + /* Check for ptracing, and update the task SID if ok. + Otherwise, leave SID unchanged and fail. */ + ptsid = ptrace_parent_sid(); + if (ptsid != 0) { + error = avc_has_perm(&selinux_state, + ptsid, sid, SECCLASS_PROCESS, + PROCESS__PTRACE, NULL); + if (error) + goto abort_change; + } + + tsec->sid = sid; + } else { + error = -EINVAL; + goto abort_change; + } + + commit_creds(new); + return size; + +abort_change: + abort_creds(new); + return error; +} + +static int selinux_ismaclabel(const char *name) +{ + return (strcmp(name, XATTR_SELINUX_SUFFIX) == 0); +} + +static int selinux_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) +{ + return security_sid_to_context(&selinux_state, secid, + secdata, seclen); +} + +static int selinux_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid) +{ + return security_context_to_sid(&selinux_state, secdata, seclen, + secid, GFP_KERNEL); +} + +static void selinux_release_secctx(char *secdata, u32 seclen) +{ + kfree(secdata); +} + +static void selinux_inode_invalidate_secctx(struct inode *inode) +{ + struct inode_security_struct *isec = selinux_inode(inode); + + spin_lock(&isec->lock); + isec->initialized = LABEL_INVALID; + spin_unlock(&isec->lock); +} + +/* + * called with inode->i_mutex locked + */ +static int selinux_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen) +{ + int rc = selinux_inode_setsecurity(inode, XATTR_SELINUX_SUFFIX, + ctx, ctxlen, 0); + /* Do not return error when suppressing label (SBLABEL_MNT not set). */ + return rc == -EOPNOTSUPP ? 0 : rc; +} + +/* + * called with inode->i_mutex locked + */ +static int selinux_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen) +{ + return __vfs_setxattr_noperm(&init_user_ns, dentry, XATTR_NAME_SELINUX, + ctx, ctxlen, 0); +} + +static int selinux_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen) +{ + int len = 0; + len = selinux_inode_getsecurity(&init_user_ns, inode, + XATTR_SELINUX_SUFFIX, ctx, true); + if (len < 0) + return len; + *ctxlen = len; + return 0; +} +#ifdef CONFIG_KEYS + +static int selinux_key_alloc(struct key *k, const struct cred *cred, + unsigned long flags) +{ + const struct task_security_struct *tsec; + struct key_security_struct *ksec; + + ksec = kzalloc(sizeof(struct key_security_struct), GFP_KERNEL); + if (!ksec) + return -ENOMEM; + + tsec = selinux_cred(cred); + if (tsec->keycreate_sid) + ksec->sid = tsec->keycreate_sid; + else + ksec->sid = tsec->sid; + + k->security = ksec; + return 0; +} + +static void selinux_key_free(struct key *k) +{ + struct key_security_struct *ksec = k->security; + + k->security = NULL; + kfree(ksec); +} + +static int selinux_key_permission(key_ref_t key_ref, + const struct cred *cred, + enum key_need_perm need_perm) +{ + struct key *key; + struct key_security_struct *ksec; + u32 perm, sid; + + switch (need_perm) { + case KEY_NEED_VIEW: + perm = KEY__VIEW; + break; + case KEY_NEED_READ: + perm = KEY__READ; + break; + case KEY_NEED_WRITE: + perm = KEY__WRITE; + break; + case KEY_NEED_SEARCH: + perm = KEY__SEARCH; + break; + case KEY_NEED_LINK: + perm = KEY__LINK; + break; + case KEY_NEED_SETATTR: + perm = KEY__SETATTR; + break; + case KEY_NEED_UNLINK: + case KEY_SYSADMIN_OVERRIDE: + case KEY_AUTHTOKEN_OVERRIDE: + case KEY_DEFER_PERM_CHECK: + return 0; + default: + WARN_ON(1); + return -EPERM; + + } + + sid = cred_sid(cred); + key = key_ref_to_ptr(key_ref); + ksec = key->security; + + return avc_has_perm(&selinux_state, + sid, ksec->sid, SECCLASS_KEY, perm, NULL); +} + +static int selinux_key_getsecurity(struct key *key, char **_buffer) +{ + struct key_security_struct *ksec = key->security; + char *context = NULL; + unsigned len; + int rc; + + rc = security_sid_to_context(&selinux_state, ksec->sid, + &context, &len); + if (!rc) + rc = len; + *_buffer = context; + return rc; +} + +#ifdef CONFIG_KEY_NOTIFICATIONS +static int selinux_watch_key(struct key *key) +{ + struct key_security_struct *ksec = key->security; + u32 sid = current_sid(); + + return avc_has_perm(&selinux_state, + sid, ksec->sid, SECCLASS_KEY, KEY__VIEW, NULL); +} +#endif +#endif + +#ifdef CONFIG_SECURITY_INFINIBAND +static int selinux_ib_pkey_access(void *ib_sec, u64 subnet_prefix, u16 pkey_val) +{ + struct common_audit_data ad; + int err; + u32 sid = 0; + struct ib_security_struct *sec = ib_sec; + struct lsm_ibpkey_audit ibpkey; + + err = sel_ib_pkey_sid(subnet_prefix, pkey_val, &sid); + if (err) + return err; + + ad.type = LSM_AUDIT_DATA_IBPKEY; + ibpkey.subnet_prefix = subnet_prefix; + ibpkey.pkey = pkey_val; + ad.u.ibpkey = &ibpkey; + return avc_has_perm(&selinux_state, + sec->sid, sid, + SECCLASS_INFINIBAND_PKEY, + INFINIBAND_PKEY__ACCESS, &ad); +} + +static int selinux_ib_endport_manage_subnet(void *ib_sec, const char *dev_name, + u8 port_num) +{ + struct common_audit_data ad; + int err; + u32 sid = 0; + struct ib_security_struct *sec = ib_sec; + struct lsm_ibendport_audit ibendport; + + err = security_ib_endport_sid(&selinux_state, dev_name, port_num, + &sid); + + if (err) + return err; + + ad.type = LSM_AUDIT_DATA_IBENDPORT; + ibendport.dev_name = dev_name; + ibendport.port = port_num; + ad.u.ibendport = &ibendport; + return avc_has_perm(&selinux_state, + sec->sid, sid, + SECCLASS_INFINIBAND_ENDPORT, + INFINIBAND_ENDPORT__MANAGE_SUBNET, &ad); +} + +static int selinux_ib_alloc_security(void **ib_sec) +{ + struct ib_security_struct *sec; + + sec = kzalloc(sizeof(*sec), GFP_KERNEL); + if (!sec) + return -ENOMEM; + sec->sid = current_sid(); + + *ib_sec = sec; + return 0; +} + +static void selinux_ib_free_security(void *ib_sec) +{ + kfree(ib_sec); +} +#endif + +#ifdef CONFIG_BPF_SYSCALL +static int selinux_bpf(int cmd, union bpf_attr *attr, + unsigned int size) +{ + u32 sid = current_sid(); + int ret; + + switch (cmd) { + case BPF_MAP_CREATE: + ret = avc_has_perm(&selinux_state, + sid, sid, SECCLASS_BPF, BPF__MAP_CREATE, + NULL); + break; + case BPF_PROG_LOAD: + ret = avc_has_perm(&selinux_state, + sid, sid, SECCLASS_BPF, BPF__PROG_LOAD, + NULL); + break; + default: + ret = 0; + break; + } + + return ret; +} + +static u32 bpf_map_fmode_to_av(fmode_t fmode) +{ + u32 av = 0; + + if (fmode & FMODE_READ) + av |= BPF__MAP_READ; + if (fmode & FMODE_WRITE) + av |= BPF__MAP_WRITE; + return av; +} + +/* This function will check the file pass through unix socket or binder to see + * if it is a bpf related object. And apply corresponding checks on the bpf + * object based on the type. The bpf maps and programs, not like other files and + * socket, are using a shared anonymous inode inside the kernel as their inode. + * So checking that inode cannot identify if the process have privilege to + * access the bpf object and that's why we have to add this additional check in + * selinux_file_receive and selinux_binder_transfer_files. + */ +static int bpf_fd_pass(struct file *file, u32 sid) +{ + struct bpf_security_struct *bpfsec; + struct bpf_prog *prog; + struct bpf_map *map; + int ret; + + if (file->f_op == &bpf_map_fops) { + map = file->private_data; + bpfsec = map->security; + ret = avc_has_perm(&selinux_state, + sid, bpfsec->sid, SECCLASS_BPF, + bpf_map_fmode_to_av(file->f_mode), NULL); + if (ret) + return ret; + } else if (file->f_op == &bpf_prog_fops) { + prog = file->private_data; + bpfsec = prog->aux->security; + ret = avc_has_perm(&selinux_state, + sid, bpfsec->sid, SECCLASS_BPF, + BPF__PROG_RUN, NULL); + if (ret) + return ret; + } + return 0; +} + +static int selinux_bpf_map(struct bpf_map *map, fmode_t fmode) +{ + u32 sid = current_sid(); + struct bpf_security_struct *bpfsec; + + bpfsec = map->security; + return avc_has_perm(&selinux_state, + sid, bpfsec->sid, SECCLASS_BPF, + bpf_map_fmode_to_av(fmode), NULL); +} + +static int selinux_bpf_prog(struct bpf_prog *prog) +{ + u32 sid = current_sid(); + struct bpf_security_struct *bpfsec; + + bpfsec = prog->aux->security; + return avc_has_perm(&selinux_state, + sid, bpfsec->sid, SECCLASS_BPF, + BPF__PROG_RUN, NULL); +} + +static int selinux_bpf_map_alloc(struct bpf_map *map) +{ + struct bpf_security_struct *bpfsec; + + bpfsec = kzalloc(sizeof(*bpfsec), GFP_KERNEL); + if (!bpfsec) + return -ENOMEM; + + bpfsec->sid = current_sid(); + map->security = bpfsec; + + return 0; +} + +static void selinux_bpf_map_free(struct bpf_map *map) +{ + struct bpf_security_struct *bpfsec = map->security; + + map->security = NULL; + kfree(bpfsec); +} + +static int selinux_bpf_prog_alloc(struct bpf_prog_aux *aux) +{ + struct bpf_security_struct *bpfsec; + + bpfsec = kzalloc(sizeof(*bpfsec), GFP_KERNEL); + if (!bpfsec) + return -ENOMEM; + + bpfsec->sid = current_sid(); + aux->security = bpfsec; + + return 0; +} + +static void selinux_bpf_prog_free(struct bpf_prog_aux *aux) +{ + struct bpf_security_struct *bpfsec = aux->security; + + aux->security = NULL; + kfree(bpfsec); +} +#endif + +struct lsm_blob_sizes selinux_blob_sizes __lsm_ro_after_init = { + .lbs_cred = sizeof(struct task_security_struct), + .lbs_file = sizeof(struct file_security_struct), + .lbs_inode = sizeof(struct inode_security_struct), + .lbs_ipc = sizeof(struct ipc_security_struct), + .lbs_msg_msg = sizeof(struct msg_security_struct), + .lbs_superblock = sizeof(struct superblock_security_struct), +}; + +#ifdef CONFIG_PERF_EVENTS +static int selinux_perf_event_open(struct perf_event_attr *attr, int type) +{ + u32 requested, sid = current_sid(); + + if (type == PERF_SECURITY_OPEN) + requested = PERF_EVENT__OPEN; + else if (type == PERF_SECURITY_CPU) + requested = PERF_EVENT__CPU; + else if (type == PERF_SECURITY_KERNEL) + requested = PERF_EVENT__KERNEL; + else if (type == PERF_SECURITY_TRACEPOINT) + requested = PERF_EVENT__TRACEPOINT; + else + return -EINVAL; + + return avc_has_perm(&selinux_state, sid, sid, SECCLASS_PERF_EVENT, + requested, NULL); +} + +static int selinux_perf_event_alloc(struct perf_event *event) +{ + struct perf_event_security_struct *perfsec; + + perfsec = kzalloc(sizeof(*perfsec), GFP_KERNEL); + if (!perfsec) + return -ENOMEM; + + perfsec->sid = current_sid(); + event->security = perfsec; + + return 0; +} + +static void selinux_perf_event_free(struct perf_event *event) +{ + struct perf_event_security_struct *perfsec = event->security; + + event->security = NULL; + kfree(perfsec); +} + +static int selinux_perf_event_read(struct perf_event *event) +{ + struct perf_event_security_struct *perfsec = event->security; + u32 sid = current_sid(); + + return avc_has_perm(&selinux_state, sid, perfsec->sid, + SECCLASS_PERF_EVENT, PERF_EVENT__READ, NULL); +} + +static int selinux_perf_event_write(struct perf_event *event) +{ + struct perf_event_security_struct *perfsec = event->security; + u32 sid = current_sid(); + + return avc_has_perm(&selinux_state, sid, perfsec->sid, + SECCLASS_PERF_EVENT, PERF_EVENT__WRITE, NULL); +} +#endif + +#ifdef CONFIG_IO_URING +/** + * selinux_uring_override_creds - check the requested cred override + * @new: the target creds + * + * Check to see if the current task is allowed to override it's credentials + * to service an io_uring operation. + */ +static int selinux_uring_override_creds(const struct cred *new) +{ + return avc_has_perm(&selinux_state, current_sid(), cred_sid(new), + SECCLASS_IO_URING, IO_URING__OVERRIDE_CREDS, NULL); +} + +/** + * selinux_uring_sqpoll - check if a io_uring polling thread can be created + * + * Check to see if the current task is allowed to create a new io_uring + * kernel polling thread. + */ +static int selinux_uring_sqpoll(void) +{ + int sid = current_sid(); + + return avc_has_perm(&selinux_state, sid, sid, + SECCLASS_IO_URING, IO_URING__SQPOLL, NULL); +} + +/** + * selinux_uring_cmd - check if IORING_OP_URING_CMD is allowed + * @ioucmd: the io_uring command structure + * + * Check to see if the current domain is allowed to execute an + * IORING_OP_URING_CMD against the device/file specified in @ioucmd. + * + */ +static int selinux_uring_cmd(struct io_uring_cmd *ioucmd) +{ + struct file *file = ioucmd->file; + struct inode *inode = file_inode(file); + struct inode_security_struct *isec = selinux_inode(inode); + struct common_audit_data ad; + + ad.type = LSM_AUDIT_DATA_FILE; + ad.u.file = file; + + return avc_has_perm(&selinux_state, current_sid(), isec->sid, + SECCLASS_IO_URING, IO_URING__CMD, &ad); +} +#endif /* CONFIG_IO_URING */ + +/* + * IMPORTANT NOTE: When adding new hooks, please be careful to keep this order: + * 1. any hooks that don't belong to (2.) or (3.) below, + * 2. hooks that both access structures allocated by other hooks, and allocate + * structures that can be later accessed by other hooks (mostly "cloning" + * hooks), + * 3. hooks that only allocate structures that can be later accessed by other + * hooks ("allocating" hooks). + * + * Please follow block comment delimiters in the list to keep this order. + * + * This ordering is needed for SELinux runtime disable to work at least somewhat + * safely. Breaking the ordering rules above might lead to NULL pointer derefs + * when disabling SELinux at runtime. + */ +static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = { + LSM_HOOK_INIT(binder_set_context_mgr, selinux_binder_set_context_mgr), + LSM_HOOK_INIT(binder_transaction, selinux_binder_transaction), + LSM_HOOK_INIT(binder_transfer_binder, selinux_binder_transfer_binder), + LSM_HOOK_INIT(binder_transfer_file, selinux_binder_transfer_file), + + LSM_HOOK_INIT(ptrace_access_check, selinux_ptrace_access_check), + LSM_HOOK_INIT(ptrace_traceme, selinux_ptrace_traceme), + LSM_HOOK_INIT(capget, selinux_capget), + LSM_HOOK_INIT(capset, selinux_capset), + LSM_HOOK_INIT(capable, selinux_capable), + LSM_HOOK_INIT(quotactl, selinux_quotactl), + LSM_HOOK_INIT(quota_on, selinux_quota_on), + LSM_HOOK_INIT(syslog, selinux_syslog), + LSM_HOOK_INIT(vm_enough_memory, selinux_vm_enough_memory), + + LSM_HOOK_INIT(netlink_send, selinux_netlink_send), + + LSM_HOOK_INIT(bprm_creds_for_exec, selinux_bprm_creds_for_exec), + LSM_HOOK_INIT(bprm_committing_creds, selinux_bprm_committing_creds), + LSM_HOOK_INIT(bprm_committed_creds, selinux_bprm_committed_creds), + + LSM_HOOK_INIT(sb_free_mnt_opts, selinux_free_mnt_opts), + LSM_HOOK_INIT(sb_mnt_opts_compat, selinux_sb_mnt_opts_compat), + LSM_HOOK_INIT(sb_remount, selinux_sb_remount), + LSM_HOOK_INIT(sb_kern_mount, selinux_sb_kern_mount), + LSM_HOOK_INIT(sb_show_options, selinux_sb_show_options), + LSM_HOOK_INIT(sb_statfs, selinux_sb_statfs), + LSM_HOOK_INIT(sb_mount, selinux_mount), + LSM_HOOK_INIT(sb_umount, selinux_umount), + LSM_HOOK_INIT(sb_set_mnt_opts, selinux_set_mnt_opts), + LSM_HOOK_INIT(sb_clone_mnt_opts, selinux_sb_clone_mnt_opts), + + LSM_HOOK_INIT(move_mount, selinux_move_mount), + + LSM_HOOK_INIT(dentry_init_security, selinux_dentry_init_security), + LSM_HOOK_INIT(dentry_create_files_as, selinux_dentry_create_files_as), + + LSM_HOOK_INIT(inode_free_security, selinux_inode_free_security), + LSM_HOOK_INIT(inode_init_security, selinux_inode_init_security), + LSM_HOOK_INIT(inode_init_security_anon, selinux_inode_init_security_anon), + LSM_HOOK_INIT(inode_create, selinux_inode_create), + LSM_HOOK_INIT(inode_link, selinux_inode_link), + LSM_HOOK_INIT(inode_unlink, selinux_inode_unlink), + LSM_HOOK_INIT(inode_symlink, selinux_inode_symlink), + LSM_HOOK_INIT(inode_mkdir, selinux_inode_mkdir), + LSM_HOOK_INIT(inode_rmdir, selinux_inode_rmdir), + LSM_HOOK_INIT(inode_mknod, selinux_inode_mknod), + LSM_HOOK_INIT(inode_rename, selinux_inode_rename), + LSM_HOOK_INIT(inode_readlink, selinux_inode_readlink), + LSM_HOOK_INIT(inode_follow_link, selinux_inode_follow_link), + LSM_HOOK_INIT(inode_permission, selinux_inode_permission), + LSM_HOOK_INIT(inode_setattr, selinux_inode_setattr), + LSM_HOOK_INIT(inode_getattr, selinux_inode_getattr), + LSM_HOOK_INIT(inode_setxattr, selinux_inode_setxattr), + LSM_HOOK_INIT(inode_post_setxattr, selinux_inode_post_setxattr), + LSM_HOOK_INIT(inode_getxattr, selinux_inode_getxattr), + LSM_HOOK_INIT(inode_listxattr, selinux_inode_listxattr), + LSM_HOOK_INIT(inode_removexattr, selinux_inode_removexattr), + LSM_HOOK_INIT(inode_getsecurity, selinux_inode_getsecurity), + LSM_HOOK_INIT(inode_setsecurity, selinux_inode_setsecurity), + LSM_HOOK_INIT(inode_listsecurity, selinux_inode_listsecurity), + LSM_HOOK_INIT(inode_getsecid, selinux_inode_getsecid), + LSM_HOOK_INIT(inode_copy_up, selinux_inode_copy_up), + LSM_HOOK_INIT(inode_copy_up_xattr, selinux_inode_copy_up_xattr), + LSM_HOOK_INIT(path_notify, selinux_path_notify), + + LSM_HOOK_INIT(kernfs_init_security, selinux_kernfs_init_security), + + LSM_HOOK_INIT(file_permission, selinux_file_permission), + LSM_HOOK_INIT(file_alloc_security, selinux_file_alloc_security), + LSM_HOOK_INIT(file_ioctl, selinux_file_ioctl), + LSM_HOOK_INIT(file_ioctl_compat, selinux_file_ioctl_compat), + LSM_HOOK_INIT(mmap_file, selinux_mmap_file), + LSM_HOOK_INIT(mmap_addr, selinux_mmap_addr), + LSM_HOOK_INIT(file_mprotect, selinux_file_mprotect), + LSM_HOOK_INIT(file_lock, selinux_file_lock), + LSM_HOOK_INIT(file_fcntl, selinux_file_fcntl), + LSM_HOOK_INIT(file_set_fowner, selinux_file_set_fowner), + LSM_HOOK_INIT(file_send_sigiotask, selinux_file_send_sigiotask), + LSM_HOOK_INIT(file_receive, selinux_file_receive), + + LSM_HOOK_INIT(file_open, selinux_file_open), + + LSM_HOOK_INIT(task_alloc, selinux_task_alloc), + LSM_HOOK_INIT(cred_prepare, selinux_cred_prepare), + LSM_HOOK_INIT(cred_transfer, selinux_cred_transfer), + LSM_HOOK_INIT(cred_getsecid, selinux_cred_getsecid), + LSM_HOOK_INIT(kernel_act_as, selinux_kernel_act_as), + LSM_HOOK_INIT(kernel_create_files_as, selinux_kernel_create_files_as), + LSM_HOOK_INIT(kernel_module_request, selinux_kernel_module_request), + LSM_HOOK_INIT(kernel_load_data, selinux_kernel_load_data), + LSM_HOOK_INIT(kernel_read_file, selinux_kernel_read_file), + LSM_HOOK_INIT(task_setpgid, selinux_task_setpgid), + LSM_HOOK_INIT(task_getpgid, selinux_task_getpgid), + LSM_HOOK_INIT(task_getsid, selinux_task_getsid), + LSM_HOOK_INIT(current_getsecid_subj, selinux_current_getsecid_subj), + LSM_HOOK_INIT(task_getsecid_obj, selinux_task_getsecid_obj), + LSM_HOOK_INIT(task_setnice, selinux_task_setnice), + LSM_HOOK_INIT(task_setioprio, selinux_task_setioprio), + LSM_HOOK_INIT(task_getioprio, selinux_task_getioprio), + LSM_HOOK_INIT(task_prlimit, selinux_task_prlimit), + LSM_HOOK_INIT(task_setrlimit, selinux_task_setrlimit), + LSM_HOOK_INIT(task_setscheduler, selinux_task_setscheduler), + LSM_HOOK_INIT(task_getscheduler, selinux_task_getscheduler), + LSM_HOOK_INIT(task_movememory, selinux_task_movememory), + LSM_HOOK_INIT(task_kill, selinux_task_kill), + LSM_HOOK_INIT(task_to_inode, selinux_task_to_inode), + LSM_HOOK_INIT(userns_create, selinux_userns_create), + + LSM_HOOK_INIT(ipc_permission, selinux_ipc_permission), + LSM_HOOK_INIT(ipc_getsecid, selinux_ipc_getsecid), + + LSM_HOOK_INIT(msg_queue_associate, selinux_msg_queue_associate), + LSM_HOOK_INIT(msg_queue_msgctl, selinux_msg_queue_msgctl), + LSM_HOOK_INIT(msg_queue_msgsnd, selinux_msg_queue_msgsnd), + LSM_HOOK_INIT(msg_queue_msgrcv, selinux_msg_queue_msgrcv), + + LSM_HOOK_INIT(shm_associate, selinux_shm_associate), + LSM_HOOK_INIT(shm_shmctl, selinux_shm_shmctl), + LSM_HOOK_INIT(shm_shmat, selinux_shm_shmat), + + LSM_HOOK_INIT(sem_associate, selinux_sem_associate), + LSM_HOOK_INIT(sem_semctl, selinux_sem_semctl), + LSM_HOOK_INIT(sem_semop, selinux_sem_semop), + + LSM_HOOK_INIT(d_instantiate, selinux_d_instantiate), + + LSM_HOOK_INIT(getprocattr, selinux_getprocattr), + LSM_HOOK_INIT(setprocattr, selinux_setprocattr), + + LSM_HOOK_INIT(ismaclabel, selinux_ismaclabel), + LSM_HOOK_INIT(secctx_to_secid, selinux_secctx_to_secid), + LSM_HOOK_INIT(release_secctx, selinux_release_secctx), + LSM_HOOK_INIT(inode_invalidate_secctx, selinux_inode_invalidate_secctx), + LSM_HOOK_INIT(inode_notifysecctx, selinux_inode_notifysecctx), + LSM_HOOK_INIT(inode_setsecctx, selinux_inode_setsecctx), + + LSM_HOOK_INIT(unix_stream_connect, selinux_socket_unix_stream_connect), + LSM_HOOK_INIT(unix_may_send, selinux_socket_unix_may_send), + + LSM_HOOK_INIT(socket_create, selinux_socket_create), + LSM_HOOK_INIT(socket_post_create, selinux_socket_post_create), + LSM_HOOK_INIT(socket_socketpair, selinux_socket_socketpair), + LSM_HOOK_INIT(socket_bind, selinux_socket_bind), + LSM_HOOK_INIT(socket_connect, selinux_socket_connect), + LSM_HOOK_INIT(socket_listen, selinux_socket_listen), + LSM_HOOK_INIT(socket_accept, selinux_socket_accept), + LSM_HOOK_INIT(socket_sendmsg, selinux_socket_sendmsg), + LSM_HOOK_INIT(socket_recvmsg, selinux_socket_recvmsg), + LSM_HOOK_INIT(socket_getsockname, selinux_socket_getsockname), + LSM_HOOK_INIT(socket_getpeername, selinux_socket_getpeername), + LSM_HOOK_INIT(socket_getsockopt, selinux_socket_getsockopt), + LSM_HOOK_INIT(socket_setsockopt, selinux_socket_setsockopt), + LSM_HOOK_INIT(socket_shutdown, selinux_socket_shutdown), + LSM_HOOK_INIT(socket_sock_rcv_skb, selinux_socket_sock_rcv_skb), + LSM_HOOK_INIT(socket_getpeersec_stream, + selinux_socket_getpeersec_stream), + LSM_HOOK_INIT(socket_getpeersec_dgram, selinux_socket_getpeersec_dgram), + LSM_HOOK_INIT(sk_free_security, selinux_sk_free_security), + LSM_HOOK_INIT(sk_clone_security, selinux_sk_clone_security), + LSM_HOOK_INIT(sk_getsecid, selinux_sk_getsecid), + LSM_HOOK_INIT(sock_graft, selinux_sock_graft), + LSM_HOOK_INIT(sctp_assoc_request, selinux_sctp_assoc_request), + LSM_HOOK_INIT(sctp_sk_clone, selinux_sctp_sk_clone), + LSM_HOOK_INIT(sctp_bind_connect, selinux_sctp_bind_connect), + LSM_HOOK_INIT(sctp_assoc_established, selinux_sctp_assoc_established), + LSM_HOOK_INIT(inet_conn_request, selinux_inet_conn_request), + LSM_HOOK_INIT(inet_csk_clone, selinux_inet_csk_clone), + LSM_HOOK_INIT(inet_conn_established, selinux_inet_conn_established), + LSM_HOOK_INIT(secmark_relabel_packet, selinux_secmark_relabel_packet), + LSM_HOOK_INIT(secmark_refcount_inc, selinux_secmark_refcount_inc), + LSM_HOOK_INIT(secmark_refcount_dec, selinux_secmark_refcount_dec), + LSM_HOOK_INIT(req_classify_flow, selinux_req_classify_flow), + LSM_HOOK_INIT(tun_dev_free_security, selinux_tun_dev_free_security), + LSM_HOOK_INIT(tun_dev_create, selinux_tun_dev_create), + LSM_HOOK_INIT(tun_dev_attach_queue, selinux_tun_dev_attach_queue), + LSM_HOOK_INIT(tun_dev_attach, selinux_tun_dev_attach), + LSM_HOOK_INIT(tun_dev_open, selinux_tun_dev_open), +#ifdef CONFIG_SECURITY_INFINIBAND + LSM_HOOK_INIT(ib_pkey_access, selinux_ib_pkey_access), + LSM_HOOK_INIT(ib_endport_manage_subnet, + selinux_ib_endport_manage_subnet), + LSM_HOOK_INIT(ib_free_security, selinux_ib_free_security), +#endif +#ifdef CONFIG_SECURITY_NETWORK_XFRM + LSM_HOOK_INIT(xfrm_policy_free_security, selinux_xfrm_policy_free), + LSM_HOOK_INIT(xfrm_policy_delete_security, selinux_xfrm_policy_delete), + LSM_HOOK_INIT(xfrm_state_free_security, selinux_xfrm_state_free), + LSM_HOOK_INIT(xfrm_state_delete_security, selinux_xfrm_state_delete), + LSM_HOOK_INIT(xfrm_policy_lookup, selinux_xfrm_policy_lookup), + LSM_HOOK_INIT(xfrm_state_pol_flow_match, + selinux_xfrm_state_pol_flow_match), + LSM_HOOK_INIT(xfrm_decode_session, selinux_xfrm_decode_session), +#endif + +#ifdef CONFIG_KEYS + LSM_HOOK_INIT(key_free, selinux_key_free), + LSM_HOOK_INIT(key_permission, selinux_key_permission), + LSM_HOOK_INIT(key_getsecurity, selinux_key_getsecurity), +#ifdef CONFIG_KEY_NOTIFICATIONS + LSM_HOOK_INIT(watch_key, selinux_watch_key), +#endif +#endif + +#ifdef CONFIG_AUDIT + LSM_HOOK_INIT(audit_rule_known, selinux_audit_rule_known), + LSM_HOOK_INIT(audit_rule_match, selinux_audit_rule_match), + LSM_HOOK_INIT(audit_rule_free, selinux_audit_rule_free), +#endif + +#ifdef CONFIG_BPF_SYSCALL + LSM_HOOK_INIT(bpf, selinux_bpf), + LSM_HOOK_INIT(bpf_map, selinux_bpf_map), + LSM_HOOK_INIT(bpf_prog, selinux_bpf_prog), + LSM_HOOK_INIT(bpf_map_free_security, selinux_bpf_map_free), + LSM_HOOK_INIT(bpf_prog_free_security, selinux_bpf_prog_free), +#endif + +#ifdef CONFIG_PERF_EVENTS + LSM_HOOK_INIT(perf_event_open, selinux_perf_event_open), + LSM_HOOK_INIT(perf_event_free, selinux_perf_event_free), + LSM_HOOK_INIT(perf_event_read, selinux_perf_event_read), + LSM_HOOK_INIT(perf_event_write, selinux_perf_event_write), +#endif + +#ifdef CONFIG_IO_URING + LSM_HOOK_INIT(uring_override_creds, selinux_uring_override_creds), + LSM_HOOK_INIT(uring_sqpoll, selinux_uring_sqpoll), + LSM_HOOK_INIT(uring_cmd, selinux_uring_cmd), +#endif + + /* + * PUT "CLONING" (ACCESSING + ALLOCATING) HOOKS HERE + */ + LSM_HOOK_INIT(fs_context_submount, selinux_fs_context_submount), + LSM_HOOK_INIT(fs_context_dup, selinux_fs_context_dup), + LSM_HOOK_INIT(fs_context_parse_param, selinux_fs_context_parse_param), + LSM_HOOK_INIT(sb_eat_lsm_opts, selinux_sb_eat_lsm_opts), +#ifdef CONFIG_SECURITY_NETWORK_XFRM + LSM_HOOK_INIT(xfrm_policy_clone_security, selinux_xfrm_policy_clone), +#endif + + /* + * PUT "ALLOCATING" HOOKS HERE + */ + LSM_HOOK_INIT(msg_msg_alloc_security, selinux_msg_msg_alloc_security), + LSM_HOOK_INIT(msg_queue_alloc_security, + selinux_msg_queue_alloc_security), + LSM_HOOK_INIT(shm_alloc_security, selinux_shm_alloc_security), + LSM_HOOK_INIT(sb_alloc_security, selinux_sb_alloc_security), + LSM_HOOK_INIT(inode_alloc_security, selinux_inode_alloc_security), + LSM_HOOK_INIT(sem_alloc_security, selinux_sem_alloc_security), + LSM_HOOK_INIT(secid_to_secctx, selinux_secid_to_secctx), + LSM_HOOK_INIT(inode_getsecctx, selinux_inode_getsecctx), + LSM_HOOK_INIT(sk_alloc_security, selinux_sk_alloc_security), + LSM_HOOK_INIT(tun_dev_alloc_security, selinux_tun_dev_alloc_security), +#ifdef CONFIG_SECURITY_INFINIBAND + LSM_HOOK_INIT(ib_alloc_security, selinux_ib_alloc_security), +#endif +#ifdef CONFIG_SECURITY_NETWORK_XFRM + LSM_HOOK_INIT(xfrm_policy_alloc_security, selinux_xfrm_policy_alloc), + LSM_HOOK_INIT(xfrm_state_alloc, selinux_xfrm_state_alloc), + LSM_HOOK_INIT(xfrm_state_alloc_acquire, + selinux_xfrm_state_alloc_acquire), +#endif +#ifdef CONFIG_KEYS + LSM_HOOK_INIT(key_alloc, selinux_key_alloc), +#endif +#ifdef CONFIG_AUDIT + LSM_HOOK_INIT(audit_rule_init, selinux_audit_rule_init), +#endif +#ifdef CONFIG_BPF_SYSCALL + LSM_HOOK_INIT(bpf_map_alloc_security, selinux_bpf_map_alloc), + LSM_HOOK_INIT(bpf_prog_alloc_security, selinux_bpf_prog_alloc), +#endif +#ifdef CONFIG_PERF_EVENTS + LSM_HOOK_INIT(perf_event_alloc, selinux_perf_event_alloc), +#endif +}; + +static __init int selinux_init(void) +{ + pr_info("SELinux: Initializing.\n"); + + memset(&selinux_state, 0, sizeof(selinux_state)); + enforcing_set(&selinux_state, selinux_enforcing_boot); + if (CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE) + pr_err("SELinux: CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE is non-zero. This is deprecated and will be rejected in a future kernel release.\n"); + checkreqprot_set(&selinux_state, selinux_checkreqprot_boot); + selinux_avc_init(&selinux_state.avc); + mutex_init(&selinux_state.status_lock); + mutex_init(&selinux_state.policy_mutex); + + /* Set the security state for the initial task. */ + cred_init_security(); + + default_noexec = !(VM_DATA_DEFAULT_FLAGS & VM_EXEC); + + avc_init(); + + avtab_cache_init(); + + ebitmap_cache_init(); + + hashtab_cache_init(); + + security_add_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks), "selinux"); + + if (avc_add_callback(selinux_netcache_avc_callback, AVC_CALLBACK_RESET)) + panic("SELinux: Unable to register AVC netcache callback\n"); + + if (avc_add_callback(selinux_lsm_notifier_avc_callback, AVC_CALLBACK_RESET)) + panic("SELinux: Unable to register AVC LSM notifier callback\n"); + + if (selinux_enforcing_boot) + pr_debug("SELinux: Starting in enforcing mode\n"); + else + pr_debug("SELinux: Starting in permissive mode\n"); + + fs_validate_description("selinux", selinux_fs_parameters); + + return 0; +} + +static void delayed_superblock_init(struct super_block *sb, void *unused) +{ + selinux_set_mnt_opts(sb, NULL, 0, NULL); +} + +void selinux_complete_init(void) +{ + pr_debug("SELinux: Completing initialization.\n"); + + /* Set up any superblocks initialized prior to the policy load. */ + pr_debug("SELinux: Setting up existing superblocks.\n"); + iterate_supers(delayed_superblock_init, NULL); +} + +/* SELinux requires early initialization in order to label + all processes and objects when they are created. */ +DEFINE_LSM(selinux) = { + .name = "selinux", + .flags = LSM_FLAG_LEGACY_MAJOR | LSM_FLAG_EXCLUSIVE, + .enabled = &selinux_enabled_boot, + .blobs = &selinux_blob_sizes, + .init = selinux_init, +}; + +#if defined(CONFIG_NETFILTER) + +static const struct nf_hook_ops selinux_nf_ops[] = { + { + .hook = selinux_ip_postroute, + .pf = NFPROTO_IPV4, + .hooknum = NF_INET_POST_ROUTING, + .priority = NF_IP_PRI_SELINUX_LAST, + }, + { + .hook = selinux_ip_forward, + .pf = NFPROTO_IPV4, + .hooknum = NF_INET_FORWARD, + .priority = NF_IP_PRI_SELINUX_FIRST, + }, + { + .hook = selinux_ip_output, + .pf = NFPROTO_IPV4, + .hooknum = NF_INET_LOCAL_OUT, + .priority = NF_IP_PRI_SELINUX_FIRST, + }, +#if IS_ENABLED(CONFIG_IPV6) + { + .hook = selinux_ip_postroute, + .pf = NFPROTO_IPV6, + .hooknum = NF_INET_POST_ROUTING, + .priority = NF_IP6_PRI_SELINUX_LAST, + }, + { + .hook = selinux_ip_forward, + .pf = NFPROTO_IPV6, + .hooknum = NF_INET_FORWARD, + .priority = NF_IP6_PRI_SELINUX_FIRST, + }, + { + .hook = selinux_ip_output, + .pf = NFPROTO_IPV6, + .hooknum = NF_INET_LOCAL_OUT, + .priority = NF_IP6_PRI_SELINUX_FIRST, + }, +#endif /* IPV6 */ +}; + +static int __net_init selinux_nf_register(struct net *net) +{ + return nf_register_net_hooks(net, selinux_nf_ops, + ARRAY_SIZE(selinux_nf_ops)); +} + +static void __net_exit selinux_nf_unregister(struct net *net) +{ + nf_unregister_net_hooks(net, selinux_nf_ops, + ARRAY_SIZE(selinux_nf_ops)); +} + +static struct pernet_operations selinux_net_ops = { + .init = selinux_nf_register, + .exit = selinux_nf_unregister, +}; + +static int __init selinux_nf_ip_init(void) +{ + int err; + + if (!selinux_enabled_boot) + return 0; + + pr_debug("SELinux: Registering netfilter hooks\n"); + + err = register_pernet_subsys(&selinux_net_ops); + if (err) + panic("SELinux: register_pernet_subsys: error %d\n", err); + + return 0; +} +__initcall(selinux_nf_ip_init); + +#ifdef CONFIG_SECURITY_SELINUX_DISABLE +static void selinux_nf_ip_exit(void) +{ + pr_debug("SELinux: Unregistering netfilter hooks\n"); + + unregister_pernet_subsys(&selinux_net_ops); +} +#endif + +#else /* CONFIG_NETFILTER */ + +#ifdef CONFIG_SECURITY_SELINUX_DISABLE +#define selinux_nf_ip_exit() +#endif + +#endif /* CONFIG_NETFILTER */ + +#ifdef CONFIG_SECURITY_SELINUX_DISABLE +int selinux_disable(struct selinux_state *state) +{ + if (selinux_initialized(state)) { + /* Not permitted after initial policy load. */ + return -EINVAL; + } + + if (selinux_disabled(state)) { + /* Only do this once. */ + return -EINVAL; + } + + selinux_mark_disabled(state); + + pr_info("SELinux: Disabled at runtime.\n"); + + /* + * Unregister netfilter hooks. + * Must be done before security_delete_hooks() to avoid breaking + * runtime disable. + */ + selinux_nf_ip_exit(); + + security_delete_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks)); + + /* Try to destroy the avc node cache */ + avc_disable(); + + /* Unregister selinuxfs. */ + exit_sel_fs(); + + return 0; +} +#endif diff --git a/security/selinux/ibpkey.c b/security/selinux/ibpkey.c new file mode 100644 index 000000000..5839ca7bb --- /dev/null +++ b/security/selinux/ibpkey.c @@ -0,0 +1,237 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Pkey table + * + * SELinux must keep a mapping of Infinband PKEYs to labels/SIDs. This + * mapping is maintained as part of the normal policy but a fast cache is + * needed to reduce the lookup overhead. + * + * This code is heavily based on the "netif" and "netport" concept originally + * developed by + * James Morris <jmorris@redhat.com> and + * Paul Moore <paul@paul-moore.com> + * (see security/selinux/netif.c and security/selinux/netport.c for more + * information) + */ + +/* + * (c) Mellanox Technologies, 2016 + */ + +#include <linux/types.h> +#include <linux/rcupdate.h> +#include <linux/list.h> +#include <linux/spinlock.h> + +#include "ibpkey.h" +#include "objsec.h" + +#define SEL_PKEY_HASH_SIZE 256 +#define SEL_PKEY_HASH_BKT_LIMIT 16 + +struct sel_ib_pkey_bkt { + int size; + struct list_head list; +}; + +struct sel_ib_pkey { + struct pkey_security_struct psec; + struct list_head list; + struct rcu_head rcu; +}; + +static DEFINE_SPINLOCK(sel_ib_pkey_lock); +static struct sel_ib_pkey_bkt sel_ib_pkey_hash[SEL_PKEY_HASH_SIZE]; + +/** + * sel_ib_pkey_hashfn - Hashing function for the pkey table + * @pkey: pkey number + * + * Description: + * This is the hashing function for the pkey table, it returns the bucket + * number for the given pkey. + * + */ +static unsigned int sel_ib_pkey_hashfn(u16 pkey) +{ + return (pkey & (SEL_PKEY_HASH_SIZE - 1)); +} + +/** + * sel_ib_pkey_find - Search for a pkey record + * @subnet_prefix: subnet_prefix + * @pkey_num: pkey_num + * + * Description: + * Search the pkey table and return the matching record. If an entry + * can not be found in the table return NULL. + * + */ +static struct sel_ib_pkey *sel_ib_pkey_find(u64 subnet_prefix, u16 pkey_num) +{ + unsigned int idx; + struct sel_ib_pkey *pkey; + + idx = sel_ib_pkey_hashfn(pkey_num); + list_for_each_entry_rcu(pkey, &sel_ib_pkey_hash[idx].list, list) { + if (pkey->psec.pkey == pkey_num && + pkey->psec.subnet_prefix == subnet_prefix) + return pkey; + } + + return NULL; +} + +/** + * sel_ib_pkey_insert - Insert a new pkey into the table + * @pkey: the new pkey record + * + * Description: + * Add a new pkey record to the hash table. + * + */ +static void sel_ib_pkey_insert(struct sel_ib_pkey *pkey) +{ + unsigned int idx; + + /* we need to impose a limit on the growth of the hash table so check + * this bucket to make sure it is within the specified bounds + */ + idx = sel_ib_pkey_hashfn(pkey->psec.pkey); + list_add_rcu(&pkey->list, &sel_ib_pkey_hash[idx].list); + if (sel_ib_pkey_hash[idx].size == SEL_PKEY_HASH_BKT_LIMIT) { + struct sel_ib_pkey *tail; + + tail = list_entry( + rcu_dereference_protected( + list_tail_rcu(&sel_ib_pkey_hash[idx].list), + lockdep_is_held(&sel_ib_pkey_lock)), + struct sel_ib_pkey, list); + list_del_rcu(&tail->list); + kfree_rcu(tail, rcu); + } else { + sel_ib_pkey_hash[idx].size++; + } +} + +/** + * sel_ib_pkey_sid_slow - Lookup the SID of a pkey using the policy + * @subnet_prefix: subnet prefix + * @pkey_num: pkey number + * @sid: pkey SID + * + * Description: + * This function determines the SID of a pkey by querying the security + * policy. The result is added to the pkey table to speedup future + * queries. Returns zero on success, negative values on failure. + * + */ +static int sel_ib_pkey_sid_slow(u64 subnet_prefix, u16 pkey_num, u32 *sid) +{ + int ret; + struct sel_ib_pkey *pkey; + struct sel_ib_pkey *new = NULL; + unsigned long flags; + + spin_lock_irqsave(&sel_ib_pkey_lock, flags); + pkey = sel_ib_pkey_find(subnet_prefix, pkey_num); + if (pkey) { + *sid = pkey->psec.sid; + spin_unlock_irqrestore(&sel_ib_pkey_lock, flags); + return 0; + } + + ret = security_ib_pkey_sid(&selinux_state, subnet_prefix, pkey_num, + sid); + if (ret) + goto out; + + /* If this memory allocation fails still return 0. The SID + * is valid, it just won't be added to the cache. + */ + new = kzalloc(sizeof(*new), GFP_ATOMIC); + if (!new) { + ret = -ENOMEM; + goto out; + } + + new->psec.subnet_prefix = subnet_prefix; + new->psec.pkey = pkey_num; + new->psec.sid = *sid; + sel_ib_pkey_insert(new); + +out: + spin_unlock_irqrestore(&sel_ib_pkey_lock, flags); + return ret; +} + +/** + * sel_ib_pkey_sid - Lookup the SID of a PKEY + * @subnet_prefix: subnet_prefix + * @pkey_num: pkey number + * @sid: pkey SID + * + * Description: + * This function determines the SID of a PKEY using the fastest method + * possible. First the pkey table is queried, but if an entry can't be found + * then the policy is queried and the result is added to the table to speedup + * future queries. Returns zero on success, negative values on failure. + * + */ +int sel_ib_pkey_sid(u64 subnet_prefix, u16 pkey_num, u32 *sid) +{ + struct sel_ib_pkey *pkey; + + rcu_read_lock(); + pkey = sel_ib_pkey_find(subnet_prefix, pkey_num); + if (pkey) { + *sid = pkey->psec.sid; + rcu_read_unlock(); + return 0; + } + rcu_read_unlock(); + + return sel_ib_pkey_sid_slow(subnet_prefix, pkey_num, sid); +} + +/** + * sel_ib_pkey_flush - Flush the entire pkey table + * + * Description: + * Remove all entries from the pkey table + * + */ +void sel_ib_pkey_flush(void) +{ + unsigned int idx; + struct sel_ib_pkey *pkey, *pkey_tmp; + unsigned long flags; + + spin_lock_irqsave(&sel_ib_pkey_lock, flags); + for (idx = 0; idx < SEL_PKEY_HASH_SIZE; idx++) { + list_for_each_entry_safe(pkey, pkey_tmp, + &sel_ib_pkey_hash[idx].list, list) { + list_del_rcu(&pkey->list); + kfree_rcu(pkey, rcu); + } + sel_ib_pkey_hash[idx].size = 0; + } + spin_unlock_irqrestore(&sel_ib_pkey_lock, flags); +} + +static __init int sel_ib_pkey_init(void) +{ + int iter; + + if (!selinux_enabled_boot) + return 0; + + for (iter = 0; iter < SEL_PKEY_HASH_SIZE; iter++) { + INIT_LIST_HEAD(&sel_ib_pkey_hash[iter].list); + sel_ib_pkey_hash[iter].size = 0; + } + + return 0; +} + +subsys_initcall(sel_ib_pkey_init); diff --git a/security/selinux/ima.c b/security/selinux/ima.c new file mode 100644 index 000000000..a915b89d5 --- /dev/null +++ b/security/selinux/ima.c @@ -0,0 +1,125 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2021 Microsoft Corporation + * + * Author: Lakshmi Ramasubramanian (nramas@linux.microsoft.com) + * + * Measure critical data structures maintainted by SELinux + * using IMA subsystem. + */ +#include <linux/vmalloc.h> +#include <linux/ima.h> +#include "security.h" +#include "ima.h" + +/* + * selinux_ima_collect_state - Read selinux configuration settings + * + * @state: selinux_state + * + * On success returns the configuration settings string. + * On error, returns NULL. + */ +static char *selinux_ima_collect_state(struct selinux_state *state) +{ + const char *on = "=1;", *off = "=0;"; + char *buf; + int buf_len, len, i, rc; + + buf_len = strlen("initialized=0;enforcing=0;checkreqprot=0;") + 1; + + len = strlen(on); + for (i = 0; i < __POLICYDB_CAP_MAX; i++) + buf_len += strlen(selinux_policycap_names[i]) + len; + + buf = kzalloc(buf_len, GFP_KERNEL); + if (!buf) + return NULL; + + rc = strscpy(buf, "initialized", buf_len); + WARN_ON(rc < 0); + + rc = strlcat(buf, selinux_initialized(state) ? on : off, buf_len); + WARN_ON(rc >= buf_len); + + rc = strlcat(buf, "enforcing", buf_len); + WARN_ON(rc >= buf_len); + + rc = strlcat(buf, enforcing_enabled(state) ? on : off, buf_len); + WARN_ON(rc >= buf_len); + + rc = strlcat(buf, "checkreqprot", buf_len); + WARN_ON(rc >= buf_len); + + rc = strlcat(buf, checkreqprot_get(state) ? on : off, buf_len); + WARN_ON(rc >= buf_len); + + for (i = 0; i < __POLICYDB_CAP_MAX; i++) { + rc = strlcat(buf, selinux_policycap_names[i], buf_len); + WARN_ON(rc >= buf_len); + + rc = strlcat(buf, state->policycap[i] ? on : off, buf_len); + WARN_ON(rc >= buf_len); + } + + return buf; +} + +/* + * selinux_ima_measure_state_locked - Measure SELinux state and hash of policy + * + * @state: selinux state struct + */ +void selinux_ima_measure_state_locked(struct selinux_state *state) +{ + char *state_str = NULL; + void *policy = NULL; + size_t policy_len; + int rc = 0; + + lockdep_assert_held(&state->policy_mutex); + + state_str = selinux_ima_collect_state(state); + if (!state_str) { + pr_err("SELinux: %s: failed to read state.\n", __func__); + return; + } + + ima_measure_critical_data("selinux", "selinux-state", + state_str, strlen(state_str), false, + NULL, 0); + + kfree(state_str); + + /* + * Measure SELinux policy only after initialization is completed. + */ + if (!selinux_initialized(state)) + return; + + rc = security_read_state_kernel(state, &policy, &policy_len); + if (rc) { + pr_err("SELinux: %s: failed to read policy %d.\n", __func__, rc); + return; + } + + ima_measure_critical_data("selinux", "selinux-policy-hash", + policy, policy_len, true, + NULL, 0); + + vfree(policy); +} + +/* + * selinux_ima_measure_state - Measure SELinux state and hash of policy + * + * @state: selinux state struct + */ +void selinux_ima_measure_state(struct selinux_state *state) +{ + lockdep_assert_not_held(&state->policy_mutex); + + mutex_lock(&state->policy_mutex); + selinux_ima_measure_state_locked(state); + mutex_unlock(&state->policy_mutex); +} diff --git a/security/selinux/include/audit.h b/security/selinux/include/audit.h new file mode 100644 index 000000000..406bceb90 --- /dev/null +++ b/security/selinux/include/audit.h @@ -0,0 +1,60 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * SELinux support for the Audit LSM hooks + * + * Author: James Morris <jmorris@redhat.com> + * + * Copyright (C) 2005 Red Hat, Inc., James Morris <jmorris@redhat.com> + * Copyright (C) 2006 Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com> + * Copyright (C) 2006 IBM Corporation, Timothy R. Chavez <tinytim@us.ibm.com> + */ + +#ifndef _SELINUX_AUDIT_H +#define _SELINUX_AUDIT_H + +#include <linux/audit.h> +#include <linux/types.h> + +/** + * selinux_audit_rule_init - alloc/init an selinux audit rule structure. + * @field: the field this rule refers to + * @op: the operator the rule uses + * @rulestr: the text "target" of the rule + * @rule: pointer to the new rule structure returned via this + * + * Returns 0 if successful, -errno if not. On success, the rule structure + * will be allocated internally. The caller must free this structure with + * selinux_audit_rule_free() after use. + */ +int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **rule); + +/** + * selinux_audit_rule_free - free an selinux audit rule structure. + * @rule: pointer to the audit rule to be freed + * + * This will free all memory associated with the given rule. + * If @rule is NULL, no operation is performed. + */ +void selinux_audit_rule_free(void *rule); + +/** + * selinux_audit_rule_match - determine if a context ID matches a rule. + * @sid: the context ID to check + * @field: the field this rule refers to + * @op: the operater the rule uses + * @rule: pointer to the audit rule to check against + * + * Returns 1 if the context id matches the rule, 0 if it does not, and + * -errno on failure. + */ +int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *rule); + +/** + * selinux_audit_rule_known - check to see if rule contains selinux fields. + * @rule: rule to be checked + * Returns 1 if there are selinux fields specified in the rule, 0 otherwise. + */ +int selinux_audit_rule_known(struct audit_krule *rule); + +#endif /* _SELINUX_AUDIT_H */ + diff --git a/security/selinux/include/avc.h b/security/selinux/include/avc.h new file mode 100644 index 000000000..5525b94fd --- /dev/null +++ b/security/selinux/include/avc.h @@ -0,0 +1,188 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Access vector cache interface for object managers. + * + * Author : Stephen Smalley, <sds@tycho.nsa.gov> + */ +#ifndef _SELINUX_AVC_H_ +#define _SELINUX_AVC_H_ + +#include <linux/stddef.h> +#include <linux/errno.h> +#include <linux/kernel.h> +#include <linux/kdev_t.h> +#include <linux/spinlock.h> +#include <linux/init.h> +#include <linux/audit.h> +#include <linux/lsm_audit.h> +#include <linux/in6.h> +#include "flask.h" +#include "av_permissions.h" +#include "security.h" + +/* + * An entry in the AVC. + */ +struct avc_entry; + +struct task_struct; +struct inode; +struct sock; +struct sk_buff; + +/* + * AVC statistics + */ +struct avc_cache_stats { + unsigned int lookups; + unsigned int misses; + unsigned int allocations; + unsigned int reclaims; + unsigned int frees; +}; + +/* + * We only need this data after we have decided to send an audit message. + */ +struct selinux_audit_data { + u32 ssid; + u32 tsid; + u16 tclass; + u32 requested; + u32 audited; + u32 denied; + int result; + struct selinux_state *state; +} __randomize_layout; + +/* + * AVC operations + */ + +void __init avc_init(void); + +static inline u32 avc_audit_required(u32 requested, + struct av_decision *avd, + int result, + u32 auditdeny, + u32 *deniedp) +{ + u32 denied, audited; + denied = requested & ~avd->allowed; + if (unlikely(denied)) { + audited = denied & avd->auditdeny; + /* + * auditdeny is TRICKY! Setting a bit in + * this field means that ANY denials should NOT be audited if + * the policy contains an explicit dontaudit rule for that + * permission. Take notice that this is unrelated to the + * actual permissions that were denied. As an example lets + * assume: + * + * denied == READ + * avd.auditdeny & ACCESS == 0 (not set means explicit rule) + * auditdeny & ACCESS == 1 + * + * We will NOT audit the denial even though the denied + * permission was READ and the auditdeny checks were for + * ACCESS + */ + if (auditdeny && !(auditdeny & avd->auditdeny)) + audited = 0; + } else if (result) + audited = denied = requested; + else + audited = requested & avd->auditallow; + *deniedp = denied; + return audited; +} + +int slow_avc_audit(struct selinux_state *state, + u32 ssid, u32 tsid, u16 tclass, + u32 requested, u32 audited, u32 denied, int result, + struct common_audit_data *a); + +/** + * avc_audit - Audit the granting or denial of permissions. + * @state: SELinux state + * @ssid: source security identifier + * @tsid: target security identifier + * @tclass: target security class + * @requested: requested permissions + * @avd: access vector decisions + * @result: result from avc_has_perm_noaudit + * @a: auxiliary audit data + * + * Audit the granting or denial of permissions in accordance + * with the policy. This function is typically called by + * avc_has_perm() after a permission check, but can also be + * called directly by callers who use avc_has_perm_noaudit() + * in order to separate the permission check from the auditing. + * For example, this separation is useful when the permission check must + * be performed under a lock, to allow the lock to be released + * before calling the auditing code. + */ +static inline int avc_audit(struct selinux_state *state, + u32 ssid, u32 tsid, + u16 tclass, u32 requested, + struct av_decision *avd, + int result, + struct common_audit_data *a) +{ + u32 audited, denied; + audited = avc_audit_required(requested, avd, result, 0, &denied); + if (likely(!audited)) + return 0; + return slow_avc_audit(state, ssid, tsid, tclass, + requested, audited, denied, result, + a); +} + +#define AVC_STRICT 1 /* Ignore permissive mode. */ +#define AVC_EXTENDED_PERMS 2 /* update extended permissions */ +int avc_has_perm_noaudit(struct selinux_state *state, + u32 ssid, u32 tsid, + u16 tclass, u32 requested, + unsigned flags, + struct av_decision *avd); + +int avc_has_perm(struct selinux_state *state, + u32 ssid, u32 tsid, + u16 tclass, u32 requested, + struct common_audit_data *auditdata); + +int avc_has_extended_perms(struct selinux_state *state, + u32 ssid, u32 tsid, u16 tclass, u32 requested, + u8 driver, u8 perm, struct common_audit_data *ad); + + +u32 avc_policy_seqno(struct selinux_state *state); + +#define AVC_CALLBACK_GRANT 1 +#define AVC_CALLBACK_TRY_REVOKE 2 +#define AVC_CALLBACK_REVOKE 4 +#define AVC_CALLBACK_RESET 8 +#define AVC_CALLBACK_AUDITALLOW_ENABLE 16 +#define AVC_CALLBACK_AUDITALLOW_DISABLE 32 +#define AVC_CALLBACK_AUDITDENY_ENABLE 64 +#define AVC_CALLBACK_AUDITDENY_DISABLE 128 +#define AVC_CALLBACK_ADD_XPERMS 256 + +int avc_add_callback(int (*callback)(u32 event), u32 events); + +/* Exported to selinuxfs */ +struct selinux_avc; +int avc_get_hash_stats(struct selinux_avc *avc, char *page); +unsigned int avc_get_cache_threshold(struct selinux_avc *avc); +void avc_set_cache_threshold(struct selinux_avc *avc, + unsigned int cache_threshold); + +/* Attempt to free avc node cache */ +void avc_disable(void); + +#ifdef CONFIG_SECURITY_SELINUX_AVC_STATS +DECLARE_PER_CPU(struct avc_cache_stats, avc_cache_stats); +#endif + +#endif /* _SELINUX_AVC_H_ */ + diff --git a/security/selinux/include/avc_ss.h b/security/selinux/include/avc_ss.h new file mode 100644 index 000000000..42912c917 --- /dev/null +++ b/security/selinux/include/avc_ss.h @@ -0,0 +1,24 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Access vector cache interface for the security server. + * + * Author : Stephen Smalley, <sds@tycho.nsa.gov> + */ +#ifndef _SELINUX_AVC_SS_H_ +#define _SELINUX_AVC_SS_H_ + +#include <linux/types.h> + +struct selinux_avc; +int avc_ss_reset(struct selinux_avc *avc, u32 seqno); + +/* Class/perm mapping support */ +struct security_class_mapping { + const char *name; + const char *perms[sizeof(u32) * 8 + 1]; +}; + +extern const struct security_class_mapping secclass_map[]; + +#endif /* _SELINUX_AVC_SS_H_ */ + diff --git a/security/selinux/include/classmap.h b/security/selinux/include/classmap.h new file mode 100644 index 000000000..a3c380775 --- /dev/null +++ b/security/selinux/include/classmap.h @@ -0,0 +1,264 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#include <linux/capability.h> +#include <linux/socket.h> + +#define COMMON_FILE_SOCK_PERMS "ioctl", "read", "write", "create", \ + "getattr", "setattr", "lock", "relabelfrom", "relabelto", "append", "map" + +#define COMMON_FILE_PERMS COMMON_FILE_SOCK_PERMS, "unlink", "link", \ + "rename", "execute", "quotaon", "mounton", "audit_access", \ + "open", "execmod", "watch", "watch_mount", "watch_sb", \ + "watch_with_perm", "watch_reads" + +#define COMMON_SOCK_PERMS COMMON_FILE_SOCK_PERMS, "bind", "connect", \ + "listen", "accept", "getopt", "setopt", "shutdown", "recvfrom", \ + "sendto", "name_bind" + +#define COMMON_IPC_PERMS "create", "destroy", "getattr", "setattr", "read", \ + "write", "associate", "unix_read", "unix_write" + +#define COMMON_CAP_PERMS "chown", "dac_override", "dac_read_search", \ + "fowner", "fsetid", "kill", "setgid", "setuid", "setpcap", \ + "linux_immutable", "net_bind_service", "net_broadcast", \ + "net_admin", "net_raw", "ipc_lock", "ipc_owner", "sys_module", \ + "sys_rawio", "sys_chroot", "sys_ptrace", "sys_pacct", "sys_admin", \ + "sys_boot", "sys_nice", "sys_resource", "sys_time", \ + "sys_tty_config", "mknod", "lease", "audit_write", \ + "audit_control", "setfcap" + +#define COMMON_CAP2_PERMS "mac_override", "mac_admin", "syslog", \ + "wake_alarm", "block_suspend", "audit_read", "perfmon", "bpf", \ + "checkpoint_restore" + +#if CAP_LAST_CAP > CAP_CHECKPOINT_RESTORE +#error New capability defined, please update COMMON_CAP2_PERMS. +#endif + +/* + * Note: The name for any socket class should be suffixed by "socket", + * and doesn't contain more than one substr of "socket". + */ +const struct security_class_mapping secclass_map[] = { + { "security", + { "compute_av", "compute_create", "compute_member", + "check_context", "load_policy", "compute_relabel", + "compute_user", "setenforce", "setbool", "setsecparam", + "setcheckreqprot", "read_policy", "validate_trans", NULL } }, + { "process", + { "fork", "transition", "sigchld", "sigkill", + "sigstop", "signull", "signal", "ptrace", "getsched", "setsched", + "getsession", "getpgid", "setpgid", "getcap", "setcap", "share", + "getattr", "setexec", "setfscreate", "noatsecure", "siginh", + "setrlimit", "rlimitinh", "dyntransition", "setcurrent", + "execmem", "execstack", "execheap", "setkeycreate", + "setsockcreate", "getrlimit", NULL } }, + { "process2", + { "nnp_transition", "nosuid_transition", NULL } }, + { "system", + { "ipc_info", "syslog_read", "syslog_mod", + "syslog_console", "module_request", "module_load", NULL } }, + { "capability", + { COMMON_CAP_PERMS, NULL } }, + { "filesystem", + { "mount", "remount", "unmount", "getattr", + "relabelfrom", "relabelto", "associate", "quotamod", + "quotaget", "watch", NULL } }, + { "file", + { COMMON_FILE_PERMS, + "execute_no_trans", "entrypoint", NULL } }, + { "dir", + { COMMON_FILE_PERMS, "add_name", "remove_name", + "reparent", "search", "rmdir", NULL } }, + { "fd", { "use", NULL } }, + { "lnk_file", + { COMMON_FILE_PERMS, NULL } }, + { "chr_file", + { COMMON_FILE_PERMS, NULL } }, + { "blk_file", + { COMMON_FILE_PERMS, NULL } }, + { "sock_file", + { COMMON_FILE_PERMS, NULL } }, + { "fifo_file", + { COMMON_FILE_PERMS, NULL } }, + { "socket", + { COMMON_SOCK_PERMS, NULL } }, + { "tcp_socket", + { COMMON_SOCK_PERMS, + "node_bind", "name_connect", + NULL } }, + { "udp_socket", + { COMMON_SOCK_PERMS, + "node_bind", NULL } }, + { "rawip_socket", + { COMMON_SOCK_PERMS, + "node_bind", NULL } }, + { "node", + { "recvfrom", "sendto", NULL } }, + { "netif", + { "ingress", "egress", NULL } }, + { "netlink_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "packet_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "key_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "unix_stream_socket", + { COMMON_SOCK_PERMS, "connectto", NULL } }, + { "unix_dgram_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "sem", + { COMMON_IPC_PERMS, NULL } }, + { "msg", { "send", "receive", NULL } }, + { "msgq", + { COMMON_IPC_PERMS, "enqueue", NULL } }, + { "shm", + { COMMON_IPC_PERMS, "lock", NULL } }, + { "ipc", + { COMMON_IPC_PERMS, NULL } }, + { "netlink_route_socket", + { COMMON_SOCK_PERMS, + "nlmsg_read", "nlmsg_write", NULL } }, + { "netlink_tcpdiag_socket", + { COMMON_SOCK_PERMS, + "nlmsg_read", "nlmsg_write", NULL } }, + { "netlink_nflog_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "netlink_xfrm_socket", + { COMMON_SOCK_PERMS, + "nlmsg_read", "nlmsg_write", NULL } }, + { "netlink_selinux_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "netlink_iscsi_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "netlink_audit_socket", + { COMMON_SOCK_PERMS, + "nlmsg_read", "nlmsg_write", "nlmsg_relay", "nlmsg_readpriv", + "nlmsg_tty_audit", NULL } }, + { "netlink_fib_lookup_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "netlink_connector_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "netlink_netfilter_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "netlink_dnrt_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "association", + { "sendto", "recvfrom", "setcontext", "polmatch", NULL } }, + { "netlink_kobject_uevent_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "netlink_generic_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "netlink_scsitransport_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "netlink_rdma_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "netlink_crypto_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "appletalk_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "packet", + { "send", "recv", "relabelto", "forward_in", "forward_out", NULL } }, + { "key", + { "view", "read", "write", "search", "link", "setattr", "create", + NULL } }, + { "dccp_socket", + { COMMON_SOCK_PERMS, + "node_bind", "name_connect", NULL } }, + { "memprotect", { "mmap_zero", NULL } }, + { "peer", { "recv", NULL } }, + { "capability2", + { COMMON_CAP2_PERMS, NULL } }, + { "kernel_service", { "use_as_override", "create_files_as", NULL } }, + { "tun_socket", + { COMMON_SOCK_PERMS, "attach_queue", NULL } }, + { "binder", { "impersonate", "call", "set_context_mgr", "transfer", + NULL } }, + { "cap_userns", + { COMMON_CAP_PERMS, NULL } }, + { "cap2_userns", + { COMMON_CAP2_PERMS, NULL } }, + { "sctp_socket", + { COMMON_SOCK_PERMS, + "node_bind", "name_connect", "association", NULL } }, + { "icmp_socket", + { COMMON_SOCK_PERMS, + "node_bind", NULL } }, + { "ax25_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "ipx_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "netrom_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "atmpvc_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "x25_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "rose_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "decnet_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "atmsvc_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "rds_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "irda_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "pppox_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "llc_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "can_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "tipc_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "bluetooth_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "iucv_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "rxrpc_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "isdn_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "phonet_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "ieee802154_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "caif_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "alg_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "nfc_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "vsock_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "kcm_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "qipcrtr_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "smc_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "infiniband_pkey", + { "access", NULL } }, + { "infiniband_endport", + { "manage_subnet", NULL } }, + { "bpf", + { "map_create", "map_read", "map_write", "prog_load", "prog_run", + NULL } }, + { "xdp_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "mctp_socket", + { COMMON_SOCK_PERMS, NULL } }, + { "perf_event", + { "open", "cpu", "kernel", "tracepoint", "read", "write", NULL } }, + { "anon_inode", + { COMMON_FILE_PERMS, NULL } }, + { "io_uring", + { "override_creds", "sqpoll", "cmd", NULL } }, + { "user_namespace", + { "create", NULL } }, + { NULL } + }; + +#if PF_MAX > 46 +#error New address family defined, please update secclass_map. +#endif diff --git a/security/selinux/include/conditional.h b/security/selinux/include/conditional.h new file mode 100644 index 000000000..b09343346 --- /dev/null +++ b/security/selinux/include/conditional.h @@ -0,0 +1,23 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Interface to booleans in the security server. This is exported + * for the selinuxfs. + * + * Author: Karl MacMillan <kmacmillan@tresys.com> + * + * Copyright (C) 2003 - 2004 Tresys Technology, LLC + */ + +#ifndef _SELINUX_CONDITIONAL_H_ +#define _SELINUX_CONDITIONAL_H_ + +#include "security.h" + +int security_get_bools(struct selinux_policy *policy, + u32 *len, char ***names, int **values); + +int security_set_bools(struct selinux_state *state, u32 len, int *values); + +int security_get_bool_value(struct selinux_state *state, u32 index); + +#endif diff --git a/security/selinux/include/ibpkey.h b/security/selinux/include/ibpkey.h new file mode 100644 index 000000000..c992f83b0 --- /dev/null +++ b/security/selinux/include/ibpkey.h @@ -0,0 +1,34 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * pkey table + * + * SELinux must keep a mapping of pkeys to labels/SIDs. This + * mapping is maintained as part of the normal policy but a fast cache is + * needed to reduce the lookup overhead. + */ + +/* + * (c) Mellanox Technologies, 2016 + */ + +#ifndef _SELINUX_IB_PKEY_H +#define _SELINUX_IB_PKEY_H + +#include <linux/types.h> + +#ifdef CONFIG_SECURITY_INFINIBAND +void sel_ib_pkey_flush(void); +int sel_ib_pkey_sid(u64 subnet_prefix, u16 pkey, u32 *sid); +#else +static inline void sel_ib_pkey_flush(void) +{ + return; +} +static inline int sel_ib_pkey_sid(u64 subnet_prefix, u16 pkey, u32 *sid) +{ + *sid = SECINITSID_UNLABELED; + return 0; +} +#endif + +#endif diff --git a/security/selinux/include/ima.h b/security/selinux/include/ima.h new file mode 100644 index 000000000..75ca92b4a --- /dev/null +++ b/security/selinux/include/ima.h @@ -0,0 +1,30 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Copyright (C) 2021 Microsoft Corporation + * + * Author: Lakshmi Ramasubramanian (nramas@linux.microsoft.com) + * + * Measure critical data structures maintainted by SELinux + * using IMA subsystem. + */ + +#ifndef _SELINUX_IMA_H_ +#define _SELINUX_IMA_H_ + +#include "security.h" + +#ifdef CONFIG_IMA +extern void selinux_ima_measure_state(struct selinux_state *selinux_state); +extern void selinux_ima_measure_state_locked( + struct selinux_state *selinux_state); +#else +static inline void selinux_ima_measure_state(struct selinux_state *selinux_state) +{ +} +static inline void selinux_ima_measure_state_locked( + struct selinux_state *selinux_state) +{ +} +#endif + +#endif /* _SELINUX_IMA_H_ */ diff --git a/security/selinux/include/initial_sid_to_string.h b/security/selinux/include/initial_sid_to_string.h new file mode 100644 index 000000000..60820517a --- /dev/null +++ b/security/selinux/include/initial_sid_to_string.h @@ -0,0 +1,32 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +static const char *const initial_sid_to_string[] = { + NULL, + "kernel", + "security", + "unlabeled", + NULL, + "file", + NULL, + NULL, + "any_socket", + "port", + "netif", + "netmsg", + "node", + NULL, + NULL, + NULL, + NULL, + NULL, + NULL, + NULL, + NULL, + NULL, + NULL, + NULL, + NULL, + NULL, + NULL, + "devnull", +}; + diff --git a/security/selinux/include/netif.h b/security/selinux/include/netif.h new file mode 100644 index 000000000..85ec30d11 --- /dev/null +++ b/security/selinux/include/netif.h @@ -0,0 +1,24 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Network interface table. + * + * Network interfaces (devices) do not have a security field, so we + * maintain a table associating each interface with a SID. + * + * Author: James Morris <jmorris@redhat.com> + * + * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com> + * Copyright (C) 2007 Hewlett-Packard Development Company, L.P. + * Paul Moore <paul@paul-moore.com> + */ +#ifndef _SELINUX_NETIF_H_ +#define _SELINUX_NETIF_H_ + +#include <net/net_namespace.h> + +void sel_netif_flush(void); + +int sel_netif_sid(struct net *ns, int ifindex, u32 *sid); + +#endif /* _SELINUX_NETIF_H_ */ + diff --git a/security/selinux/include/netlabel.h b/security/selinux/include/netlabel.h new file mode 100644 index 000000000..4d0456d3d --- /dev/null +++ b/security/selinux/include/netlabel.h @@ -0,0 +1,150 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * SELinux interface to the NetLabel subsystem + * + * Author: Paul Moore <paul@paul-moore.com> + */ + +/* + * (c) Copyright Hewlett-Packard Development Company, L.P., 2006 + */ + +#ifndef _SELINUX_NETLABEL_H_ +#define _SELINUX_NETLABEL_H_ + +#include <linux/types.h> +#include <linux/fs.h> +#include <linux/net.h> +#include <linux/skbuff.h> +#include <net/sock.h> +#include <net/request_sock.h> +#include <net/sctp/structs.h> + +#include "avc.h" +#include "objsec.h" + +#ifdef CONFIG_NETLABEL +void selinux_netlbl_cache_invalidate(void); + +void selinux_netlbl_err(struct sk_buff *skb, u16 family, int error, + int gateway); + +void selinux_netlbl_sk_security_free(struct sk_security_struct *sksec); +void selinux_netlbl_sk_security_reset(struct sk_security_struct *sksec); + +int selinux_netlbl_skbuff_getsid(struct sk_buff *skb, + u16 family, + u32 *type, + u32 *sid); +int selinux_netlbl_skbuff_setsid(struct sk_buff *skb, + u16 family, + u32 sid); +int selinux_netlbl_sctp_assoc_request(struct sctp_association *asoc, + struct sk_buff *skb); +int selinux_netlbl_inet_conn_request(struct request_sock *req, u16 family); +void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family); +void selinux_netlbl_sctp_sk_clone(struct sock *sk, struct sock *newsk); +int selinux_netlbl_socket_post_create(struct sock *sk, u16 family); +int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec, + struct sk_buff *skb, + u16 family, + struct common_audit_data *ad); +int selinux_netlbl_socket_setsockopt(struct socket *sock, + int level, + int optname); +int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr); +int selinux_netlbl_socket_connect_locked(struct sock *sk, + struct sockaddr *addr); + +#else +static inline void selinux_netlbl_cache_invalidate(void) +{ + return; +} + +static inline void selinux_netlbl_err(struct sk_buff *skb, + u16 family, + int error, + int gateway) +{ + return; +} + +static inline void selinux_netlbl_sk_security_free( + struct sk_security_struct *sksec) +{ + return; +} + +static inline void selinux_netlbl_sk_security_reset( + struct sk_security_struct *sksec) +{ + return; +} + +static inline int selinux_netlbl_skbuff_getsid(struct sk_buff *skb, + u16 family, + u32 *type, + u32 *sid) +{ + *type = NETLBL_NLTYPE_NONE; + *sid = SECSID_NULL; + return 0; +} +static inline int selinux_netlbl_skbuff_setsid(struct sk_buff *skb, + u16 family, + u32 sid) +{ + return 0; +} + +static inline int selinux_netlbl_sctp_assoc_request(struct sctp_association *asoc, + struct sk_buff *skb) +{ + return 0; +} +static inline int selinux_netlbl_inet_conn_request(struct request_sock *req, + u16 family) +{ + return 0; +} +static inline void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family) +{ + return; +} +static inline void selinux_netlbl_sctp_sk_clone(struct sock *sk, + struct sock *newsk) +{ + return; +} +static inline int selinux_netlbl_socket_post_create(struct sock *sk, + u16 family) +{ + return 0; +} +static inline int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec, + struct sk_buff *skb, + u16 family, + struct common_audit_data *ad) +{ + return 0; +} +static inline int selinux_netlbl_socket_setsockopt(struct socket *sock, + int level, + int optname) +{ + return 0; +} +static inline int selinux_netlbl_socket_connect(struct sock *sk, + struct sockaddr *addr) +{ + return 0; +} +static inline int selinux_netlbl_socket_connect_locked(struct sock *sk, + struct sockaddr *addr) +{ + return 0; +} +#endif /* CONFIG_NETLABEL */ + +#endif diff --git a/security/selinux/include/netnode.h b/security/selinux/include/netnode.h new file mode 100644 index 000000000..9b8b655a8 --- /dev/null +++ b/security/selinux/include/netnode.h @@ -0,0 +1,26 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Network node table + * + * SELinux must keep a mapping of network nodes to labels/SIDs. This + * mapping is maintained as part of the normal policy but a fast cache is + * needed to reduce the lookup overhead since most of these queries happen on + * a per-packet basis. + * + * Author: Paul Moore <paul@paul-moore.com> + */ + +/* + * (c) Copyright Hewlett-Packard Development Company, L.P., 2007 + */ + +#ifndef _SELINUX_NETNODE_H +#define _SELINUX_NETNODE_H + +#include <linux/types.h> + +void sel_netnode_flush(void); + +int sel_netnode_sid(void *addr, u16 family, u32 *sid); + +#endif diff --git a/security/selinux/include/netport.h b/security/selinux/include/netport.h new file mode 100644 index 000000000..9096a8289 --- /dev/null +++ b/security/selinux/include/netport.h @@ -0,0 +1,25 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Network port table + * + * SELinux must keep a mapping of network ports to labels/SIDs. This + * mapping is maintained as part of the normal policy but a fast cache is + * needed to reduce the lookup overhead. + * + * Author: Paul Moore <paul@paul-moore.com> + */ + +/* + * (c) Copyright Hewlett-Packard Development Company, L.P., 2008 + */ + +#ifndef _SELINUX_NETPORT_H +#define _SELINUX_NETPORT_H + +#include <linux/types.h> + +void sel_netport_flush(void); + +int sel_netport_sid(u8 protocol, u16 pnum, u32 *sid); + +#endif diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h new file mode 100644 index 000000000..295313240 --- /dev/null +++ b/security/selinux/include/objsec.h @@ -0,0 +1,197 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * NSA Security-Enhanced Linux (SELinux) security module + * + * This file contains the SELinux security data structures for kernel objects. + * + * Author(s): Stephen Smalley, <sds@tycho.nsa.gov> + * Chris Vance, <cvance@nai.com> + * Wayne Salamon, <wsalamon@nai.com> + * James Morris <jmorris@redhat.com> + * + * Copyright (C) 2001,2002 Networks Associates Technology, Inc. + * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com> + * Copyright (C) 2016 Mellanox Technologies + */ +#ifndef _SELINUX_OBJSEC_H_ +#define _SELINUX_OBJSEC_H_ + +#include <linux/list.h> +#include <linux/sched.h> +#include <linux/fs.h> +#include <linux/binfmts.h> +#include <linux/in.h> +#include <linux/spinlock.h> +#include <linux/lsm_hooks.h> +#include <linux/msg.h> +#include <net/net_namespace.h> +#include "flask.h" +#include "avc.h" + +struct task_security_struct { + u32 osid; /* SID prior to last execve */ + u32 sid; /* current SID */ + u32 exec_sid; /* exec SID */ + u32 create_sid; /* fscreate SID */ + u32 keycreate_sid; /* keycreate SID */ + u32 sockcreate_sid; /* fscreate SID */ +} __randomize_layout; + +enum label_initialized { + LABEL_INVALID, /* invalid or not initialized */ + LABEL_INITIALIZED, /* initialized */ + LABEL_PENDING +}; + +struct inode_security_struct { + struct inode *inode; /* back pointer to inode object */ + struct list_head list; /* list of inode_security_struct */ + u32 task_sid; /* SID of creating task */ + u32 sid; /* SID of this object */ + u16 sclass; /* security class of this object */ + unsigned char initialized; /* initialization flag */ + spinlock_t lock; +}; + +struct file_security_struct { + u32 sid; /* SID of open file description */ + u32 fown_sid; /* SID of file owner (for SIGIO) */ + u32 isid; /* SID of inode at the time of file open */ + u32 pseqno; /* Policy seqno at the time of file open */ +}; + +struct superblock_security_struct { + u32 sid; /* SID of file system superblock */ + u32 def_sid; /* default SID for labeling */ + u32 mntpoint_sid; /* SECURITY_FS_USE_MNTPOINT context for files */ + unsigned short behavior; /* labeling behavior */ + unsigned short flags; /* which mount options were specified */ + struct mutex lock; + struct list_head isec_head; + spinlock_t isec_lock; +}; + +struct msg_security_struct { + u32 sid; /* SID of message */ +}; + +struct ipc_security_struct { + u16 sclass; /* security class of this object */ + u32 sid; /* SID of IPC resource */ +}; + +struct netif_security_struct { + struct net *ns; /* network namespace */ + int ifindex; /* device index */ + u32 sid; /* SID for this interface */ +}; + +struct netnode_security_struct { + union { + __be32 ipv4; /* IPv4 node address */ + struct in6_addr ipv6; /* IPv6 node address */ + } addr; + u32 sid; /* SID for this node */ + u16 family; /* address family */ +}; + +struct netport_security_struct { + u32 sid; /* SID for this node */ + u16 port; /* port number */ + u8 protocol; /* transport protocol */ +}; + +struct sk_security_struct { +#ifdef CONFIG_NETLABEL + enum { /* NetLabel state */ + NLBL_UNSET = 0, + NLBL_REQUIRE, + NLBL_LABELED, + NLBL_REQSKB, + NLBL_CONNLABELED, + } nlbl_state; + struct netlbl_lsm_secattr *nlbl_secattr; /* NetLabel sec attributes */ +#endif + u32 sid; /* SID of this object */ + u32 peer_sid; /* SID of peer */ + u16 sclass; /* sock security class */ + enum { /* SCTP association state */ + SCTP_ASSOC_UNSET = 0, + SCTP_ASSOC_SET, + } sctp_assoc_state; +}; + +struct tun_security_struct { + u32 sid; /* SID for the tun device sockets */ +}; + +struct key_security_struct { + u32 sid; /* SID of key */ +}; + +struct ib_security_struct { + u32 sid; /* SID of the queue pair or MAD agent */ +}; + +struct pkey_security_struct { + u64 subnet_prefix; /* Port subnet prefix */ + u16 pkey; /* PKey number */ + u32 sid; /* SID of pkey */ +}; + +struct bpf_security_struct { + u32 sid; /* SID of bpf obj creator */ +}; + +struct perf_event_security_struct { + u32 sid; /* SID of perf_event obj creator */ +}; + +extern struct lsm_blob_sizes selinux_blob_sizes; +static inline struct task_security_struct *selinux_cred(const struct cred *cred) +{ + return cred->security + selinux_blob_sizes.lbs_cred; +} + +static inline struct file_security_struct *selinux_file(const struct file *file) +{ + return file->f_security + selinux_blob_sizes.lbs_file; +} + +static inline struct inode_security_struct *selinux_inode( + const struct inode *inode) +{ + if (unlikely(!inode->i_security)) + return NULL; + return inode->i_security + selinux_blob_sizes.lbs_inode; +} + +static inline struct msg_security_struct *selinux_msg_msg( + const struct msg_msg *msg_msg) +{ + return msg_msg->security + selinux_blob_sizes.lbs_msg_msg; +} + +static inline struct ipc_security_struct *selinux_ipc( + const struct kern_ipc_perm *ipc) +{ + return ipc->security + selinux_blob_sizes.lbs_ipc; +} + +/* + * get the subjective security ID of the current task + */ +static inline u32 current_sid(void) +{ + const struct task_security_struct *tsec = selinux_cred(current_cred()); + + return tsec->sid; +} + +static inline struct superblock_security_struct *selinux_superblock( + const struct super_block *superblock) +{ + return superblock->s_security + selinux_blob_sizes.lbs_superblock; +} + +#endif /* _SELINUX_OBJSEC_H_ */ diff --git a/security/selinux/include/policycap.h b/security/selinux/include/policycap.h new file mode 100644 index 000000000..f35d3458e --- /dev/null +++ b/security/selinux/include/policycap.h @@ -0,0 +1,21 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _SELINUX_POLICYCAP_H_ +#define _SELINUX_POLICYCAP_H_ + +/* Policy capabilities */ +enum { + POLICYDB_CAP_NETPEER, + POLICYDB_CAP_OPENPERM, + POLICYDB_CAP_EXTSOCKCLASS, + POLICYDB_CAP_ALWAYSNETWORK, + POLICYDB_CAP_CGROUPSECLABEL, + POLICYDB_CAP_NNP_NOSUID_TRANSITION, + POLICYDB_CAP_GENFS_SECLABEL_SYMLINKS, + POLICYDB_CAP_IOCTL_SKIP_CLOEXEC, + __POLICYDB_CAP_MAX +}; +#define POLICYDB_CAP_MAX (__POLICYDB_CAP_MAX - 1) + +extern const char *const selinux_policycap_names[__POLICYDB_CAP_MAX]; + +#endif /* _SELINUX_POLICYCAP_H_ */ diff --git a/security/selinux/include/policycap_names.h b/security/selinux/include/policycap_names.h new file mode 100644 index 000000000..2a87fc370 --- /dev/null +++ b/security/selinux/include/policycap_names.h @@ -0,0 +1,19 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _SELINUX_POLICYCAP_NAMES_H_ +#define _SELINUX_POLICYCAP_NAMES_H_ + +#include "policycap.h" + +/* Policy capability names */ +const char *const selinux_policycap_names[__POLICYDB_CAP_MAX] = { + "network_peer_controls", + "open_perms", + "extended_socket_class", + "always_check_network", + "cgroup_seclabel", + "nnp_nosuid_transition", + "genfs_seclabel_symlinks", + "ioctl_skip_cloexec" +}; + +#endif /* _SELINUX_POLICYCAP_NAMES_H_ */ diff --git a/security/selinux/include/security.h b/security/selinux/include/security.h new file mode 100644 index 000000000..393aff41d --- /dev/null +++ b/security/selinux/include/security.h @@ -0,0 +1,467 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Security server interface. + * + * Author : Stephen Smalley, <sds@tycho.nsa.gov> + * + */ + +#ifndef _SELINUX_SECURITY_H_ +#define _SELINUX_SECURITY_H_ + +#include <linux/compiler.h> +#include <linux/dcache.h> +#include <linux/magic.h> +#include <linux/types.h> +#include <linux/rcupdate.h> +#include <linux/refcount.h> +#include <linux/workqueue.h> +#include <linux/delay.h> +#include <linux/printk.h> +#include "flask.h" +#include "policycap.h" + +#define SECSID_NULL 0x00000000 /* unspecified SID */ +#define SECSID_WILD 0xffffffff /* wildcard SID */ +#define SECCLASS_NULL 0x0000 /* no class */ + +/* Identify specific policy version changes */ +#define POLICYDB_VERSION_BASE 15 +#define POLICYDB_VERSION_BOOL 16 +#define POLICYDB_VERSION_IPV6 17 +#define POLICYDB_VERSION_NLCLASS 18 +#define POLICYDB_VERSION_VALIDATETRANS 19 +#define POLICYDB_VERSION_MLS 19 +#define POLICYDB_VERSION_AVTAB 20 +#define POLICYDB_VERSION_RANGETRANS 21 +#define POLICYDB_VERSION_POLCAP 22 +#define POLICYDB_VERSION_PERMISSIVE 23 +#define POLICYDB_VERSION_BOUNDARY 24 +#define POLICYDB_VERSION_FILENAME_TRANS 25 +#define POLICYDB_VERSION_ROLETRANS 26 +#define POLICYDB_VERSION_NEW_OBJECT_DEFAULTS 27 +#define POLICYDB_VERSION_DEFAULT_TYPE 28 +#define POLICYDB_VERSION_CONSTRAINT_NAMES 29 +#define POLICYDB_VERSION_XPERMS_IOCTL 30 +#define POLICYDB_VERSION_INFINIBAND 31 +#define POLICYDB_VERSION_GLBLUB 32 +#define POLICYDB_VERSION_COMP_FTRANS 33 /* compressed filename transitions */ + +/* Range of policy versions we understand*/ +#define POLICYDB_VERSION_MIN POLICYDB_VERSION_BASE +#define POLICYDB_VERSION_MAX POLICYDB_VERSION_COMP_FTRANS + +/* Mask for just the mount related flags */ +#define SE_MNTMASK 0x0f +/* Super block security struct flags for mount options */ +/* BE CAREFUL, these need to be the low order bits for selinux_get_mnt_opts */ +#define CONTEXT_MNT 0x01 +#define FSCONTEXT_MNT 0x02 +#define ROOTCONTEXT_MNT 0x04 +#define DEFCONTEXT_MNT 0x08 +#define SBLABEL_MNT 0x10 +/* Non-mount related flags */ +#define SE_SBINITIALIZED 0x0100 +#define SE_SBPROC 0x0200 +#define SE_SBGENFS 0x0400 +#define SE_SBGENFS_XATTR 0x0800 + +#define CONTEXT_STR "context" +#define FSCONTEXT_STR "fscontext" +#define ROOTCONTEXT_STR "rootcontext" +#define DEFCONTEXT_STR "defcontext" +#define SECLABEL_STR "seclabel" + +struct netlbl_lsm_secattr; + +extern int selinux_enabled_boot; + +/* + * type_datum properties + * available at the kernel policy version >= POLICYDB_VERSION_BOUNDARY + */ +#define TYPEDATUM_PROPERTY_PRIMARY 0x0001 +#define TYPEDATUM_PROPERTY_ATTRIBUTE 0x0002 + +/* limitation of boundary depth */ +#define POLICYDB_BOUNDS_MAXDEPTH 4 + +struct selinux_avc; +struct selinux_policy; + +struct selinux_state { +#ifdef CONFIG_SECURITY_SELINUX_DISABLE + bool disabled; +#endif +#ifdef CONFIG_SECURITY_SELINUX_DEVELOP + bool enforcing; +#endif + bool checkreqprot; + bool initialized; + bool policycap[__POLICYDB_CAP_MAX]; + + struct page *status_page; + struct mutex status_lock; + + struct selinux_avc *avc; + struct selinux_policy __rcu *policy; + struct mutex policy_mutex; +} __randomize_layout; + +void selinux_avc_init(struct selinux_avc **avc); + +extern struct selinux_state selinux_state; + +static inline bool selinux_initialized(const struct selinux_state *state) +{ + /* do a synchronized load to avoid race conditions */ + return smp_load_acquire(&state->initialized); +} + +static inline void selinux_mark_initialized(struct selinux_state *state) +{ + /* do a synchronized write to avoid race conditions */ + smp_store_release(&state->initialized, true); +} + +#ifdef CONFIG_SECURITY_SELINUX_DEVELOP +static inline bool enforcing_enabled(struct selinux_state *state) +{ + return READ_ONCE(state->enforcing); +} + +static inline void enforcing_set(struct selinux_state *state, bool value) +{ + WRITE_ONCE(state->enforcing, value); +} +#else +static inline bool enforcing_enabled(struct selinux_state *state) +{ + return true; +} + +static inline void enforcing_set(struct selinux_state *state, bool value) +{ +} +#endif + +static inline bool checkreqprot_get(const struct selinux_state *state) +{ + return READ_ONCE(state->checkreqprot); +} + +static inline void checkreqprot_set(struct selinux_state *state, bool value) +{ + if (value) + pr_err("SELinux: https://github.com/SELinuxProject/selinux-kernel/wiki/DEPRECATE-checkreqprot\n"); + WRITE_ONCE(state->checkreqprot, value); +} + +#ifdef CONFIG_SECURITY_SELINUX_DISABLE +static inline bool selinux_disabled(struct selinux_state *state) +{ + return READ_ONCE(state->disabled); +} + +static inline void selinux_mark_disabled(struct selinux_state *state) +{ + WRITE_ONCE(state->disabled, true); +} +#else +static inline bool selinux_disabled(struct selinux_state *state) +{ + return false; +} +#endif + +static inline bool selinux_policycap_netpeer(void) +{ + struct selinux_state *state = &selinux_state; + + return READ_ONCE(state->policycap[POLICYDB_CAP_NETPEER]); +} + +static inline bool selinux_policycap_openperm(void) +{ + struct selinux_state *state = &selinux_state; + + return READ_ONCE(state->policycap[POLICYDB_CAP_OPENPERM]); +} + +static inline bool selinux_policycap_extsockclass(void) +{ + struct selinux_state *state = &selinux_state; + + return READ_ONCE(state->policycap[POLICYDB_CAP_EXTSOCKCLASS]); +} + +static inline bool selinux_policycap_alwaysnetwork(void) +{ + struct selinux_state *state = &selinux_state; + + return READ_ONCE(state->policycap[POLICYDB_CAP_ALWAYSNETWORK]); +} + +static inline bool selinux_policycap_cgroupseclabel(void) +{ + struct selinux_state *state = &selinux_state; + + return READ_ONCE(state->policycap[POLICYDB_CAP_CGROUPSECLABEL]); +} + +static inline bool selinux_policycap_nnp_nosuid_transition(void) +{ + struct selinux_state *state = &selinux_state; + + return READ_ONCE(state->policycap[POLICYDB_CAP_NNP_NOSUID_TRANSITION]); +} + +static inline bool selinux_policycap_genfs_seclabel_symlinks(void) +{ + struct selinux_state *state = &selinux_state; + + return READ_ONCE(state->policycap[POLICYDB_CAP_GENFS_SECLABEL_SYMLINKS]); +} + +static inline bool selinux_policycap_ioctl_skip_cloexec(void) +{ + struct selinux_state *state = &selinux_state; + + return READ_ONCE(state->policycap[POLICYDB_CAP_IOCTL_SKIP_CLOEXEC]); +} + +struct selinux_policy_convert_data; + +struct selinux_load_state { + struct selinux_policy *policy; + struct selinux_policy_convert_data *convert_data; +}; + +int security_mls_enabled(struct selinux_state *state); +int security_load_policy(struct selinux_state *state, + void *data, size_t len, + struct selinux_load_state *load_state); +void selinux_policy_commit(struct selinux_state *state, + struct selinux_load_state *load_state); +void selinux_policy_cancel(struct selinux_state *state, + struct selinux_load_state *load_state); +int security_read_policy(struct selinux_state *state, + void **data, size_t *len); +int security_read_state_kernel(struct selinux_state *state, + void **data, size_t *len); +int security_policycap_supported(struct selinux_state *state, + unsigned int req_cap); + +#define SEL_VEC_MAX 32 +struct av_decision { + u32 allowed; + u32 auditallow; + u32 auditdeny; + u32 seqno; + u32 flags; +}; + +#define XPERMS_ALLOWED 1 +#define XPERMS_AUDITALLOW 2 +#define XPERMS_DONTAUDIT 4 + +#define security_xperm_set(perms, x) ((perms)[(x) >> 5] |= 1 << ((x) & 0x1f)) +#define security_xperm_test(perms, x) (1 & ((perms)[(x) >> 5] >> ((x) & 0x1f))) +struct extended_perms_data { + u32 p[8]; +}; + +struct extended_perms_decision { + u8 used; + u8 driver; + struct extended_perms_data *allowed; + struct extended_perms_data *auditallow; + struct extended_perms_data *dontaudit; +}; + +struct extended_perms { + u16 len; /* length associated decision chain */ + struct extended_perms_data drivers; /* flag drivers that are used */ +}; + +/* definitions of av_decision.flags */ +#define AVD_FLAGS_PERMISSIVE 0x0001 + +void security_compute_av(struct selinux_state *state, + u32 ssid, u32 tsid, + u16 tclass, struct av_decision *avd, + struct extended_perms *xperms); + +void security_compute_xperms_decision(struct selinux_state *state, + u32 ssid, u32 tsid, u16 tclass, + u8 driver, + struct extended_perms_decision *xpermd); + +void security_compute_av_user(struct selinux_state *state, + u32 ssid, u32 tsid, + u16 tclass, struct av_decision *avd); + +int security_transition_sid(struct selinux_state *state, + u32 ssid, u32 tsid, u16 tclass, + const struct qstr *qstr, u32 *out_sid); + +int security_transition_sid_user(struct selinux_state *state, + u32 ssid, u32 tsid, u16 tclass, + const char *objname, u32 *out_sid); + +int security_member_sid(struct selinux_state *state, u32 ssid, u32 tsid, + u16 tclass, u32 *out_sid); + +int security_change_sid(struct selinux_state *state, u32 ssid, u32 tsid, + u16 tclass, u32 *out_sid); + +int security_sid_to_context(struct selinux_state *state, u32 sid, + char **scontext, u32 *scontext_len); + +int security_sid_to_context_force(struct selinux_state *state, + u32 sid, char **scontext, u32 *scontext_len); + +int security_sid_to_context_inval(struct selinux_state *state, + u32 sid, char **scontext, u32 *scontext_len); + +int security_context_to_sid(struct selinux_state *state, + const char *scontext, u32 scontext_len, + u32 *out_sid, gfp_t gfp); + +int security_context_str_to_sid(struct selinux_state *state, + const char *scontext, u32 *out_sid, gfp_t gfp); + +int security_context_to_sid_default(struct selinux_state *state, + const char *scontext, u32 scontext_len, + u32 *out_sid, u32 def_sid, gfp_t gfp_flags); + +int security_context_to_sid_force(struct selinux_state *state, + const char *scontext, u32 scontext_len, + u32 *sid); + +int security_get_user_sids(struct selinux_state *state, + u32 callsid, char *username, + u32 **sids, u32 *nel); + +int security_port_sid(struct selinux_state *state, + u8 protocol, u16 port, u32 *out_sid); + +int security_ib_pkey_sid(struct selinux_state *state, + u64 subnet_prefix, u16 pkey_num, u32 *out_sid); + +int security_ib_endport_sid(struct selinux_state *state, + const char *dev_name, u8 port_num, u32 *out_sid); + +int security_netif_sid(struct selinux_state *state, + char *name, u32 *if_sid); + +int security_node_sid(struct selinux_state *state, + u16 domain, void *addr, u32 addrlen, + u32 *out_sid); + +int security_validate_transition(struct selinux_state *state, + u32 oldsid, u32 newsid, u32 tasksid, + u16 tclass); + +int security_validate_transition_user(struct selinux_state *state, + u32 oldsid, u32 newsid, u32 tasksid, + u16 tclass); + +int security_bounded_transition(struct selinux_state *state, + u32 oldsid, u32 newsid); + +int security_sid_mls_copy(struct selinux_state *state, + u32 sid, u32 mls_sid, u32 *new_sid); + +int security_net_peersid_resolve(struct selinux_state *state, + u32 nlbl_sid, u32 nlbl_type, + u32 xfrm_sid, + u32 *peer_sid); + +int security_get_classes(struct selinux_policy *policy, + char ***classes, int *nclasses); +int security_get_permissions(struct selinux_policy *policy, + char *class, char ***perms, int *nperms); +int security_get_reject_unknown(struct selinux_state *state); +int security_get_allow_unknown(struct selinux_state *state); + +#define SECURITY_FS_USE_XATTR 1 /* use xattr */ +#define SECURITY_FS_USE_TRANS 2 /* use transition SIDs, e.g. devpts/tmpfs */ +#define SECURITY_FS_USE_TASK 3 /* use task SIDs, e.g. pipefs/sockfs */ +#define SECURITY_FS_USE_GENFS 4 /* use the genfs support */ +#define SECURITY_FS_USE_NONE 5 /* no labeling support */ +#define SECURITY_FS_USE_MNTPOINT 6 /* use mountpoint labeling */ +#define SECURITY_FS_USE_NATIVE 7 /* use native label support */ +#define SECURITY_FS_USE_MAX 7 /* Highest SECURITY_FS_USE_XXX */ + +int security_fs_use(struct selinux_state *state, struct super_block *sb); + +int security_genfs_sid(struct selinux_state *state, + const char *fstype, const char *path, u16 sclass, + u32 *sid); + +int selinux_policy_genfs_sid(struct selinux_policy *policy, + const char *fstype, const char *path, u16 sclass, + u32 *sid); + +#ifdef CONFIG_NETLABEL +int security_netlbl_secattr_to_sid(struct selinux_state *state, + struct netlbl_lsm_secattr *secattr, + u32 *sid); + +int security_netlbl_sid_to_secattr(struct selinux_state *state, + u32 sid, + struct netlbl_lsm_secattr *secattr); +#else +static inline int security_netlbl_secattr_to_sid(struct selinux_state *state, + struct netlbl_lsm_secattr *secattr, + u32 *sid) +{ + return -EIDRM; +} + +static inline int security_netlbl_sid_to_secattr(struct selinux_state *state, + u32 sid, + struct netlbl_lsm_secattr *secattr) +{ + return -ENOENT; +} +#endif /* CONFIG_NETLABEL */ + +const char *security_get_initial_sid_context(u32 sid); + +/* + * status notifier using mmap interface + */ +extern struct page *selinux_kernel_status_page(struct selinux_state *state); + +#define SELINUX_KERNEL_STATUS_VERSION 1 +struct selinux_kernel_status { + u32 version; /* version number of the structure */ + u32 sequence; /* sequence number of seqlock logic */ + u32 enforcing; /* current setting of enforcing mode */ + u32 policyload; /* times of policy reloaded */ + u32 deny_unknown; /* current setting of deny_unknown */ + /* + * The version > 0 supports above members. + */ +} __packed; + +extern void selinux_status_update_setenforce(struct selinux_state *state, + int enforcing); +extern void selinux_status_update_policyload(struct selinux_state *state, + int seqno); +extern void selinux_complete_init(void); +extern int selinux_disable(struct selinux_state *state); +extern void exit_sel_fs(void); +extern struct path selinux_null; +extern void selnl_notify_setenforce(int val); +extern void selnl_notify_policyload(u32 seqno); +extern int selinux_nlmsg_lookup(u16 sclass, u16 nlmsg_type, u32 *perm); + +extern void avtab_cache_init(void); +extern void ebitmap_cache_init(void); +extern void hashtab_cache_init(void); +extern int security_sidtab_hash_stats(struct selinux_state *state, char *page); + +#endif /* _SELINUX_SECURITY_H_ */ diff --git a/security/selinux/include/xfrm.h b/security/selinux/include/xfrm.h new file mode 100644 index 000000000..c75839860 --- /dev/null +++ b/security/selinux/include/xfrm.h @@ -0,0 +1,94 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * SELinux support for the XFRM LSM hooks + * + * Author : Trent Jaeger, <jaegert@us.ibm.com> + * Updated : Venkat Yekkirala, <vyekkirala@TrustedCS.com> + */ +#ifndef _SELINUX_XFRM_H_ +#define _SELINUX_XFRM_H_ + +#include <linux/lsm_audit.h> +#include <net/flow.h> +#include <net/xfrm.h> + +int selinux_xfrm_policy_alloc(struct xfrm_sec_ctx **ctxp, + struct xfrm_user_sec_ctx *uctx, + gfp_t gfp); +int selinux_xfrm_policy_clone(struct xfrm_sec_ctx *old_ctx, + struct xfrm_sec_ctx **new_ctxp); +void selinux_xfrm_policy_free(struct xfrm_sec_ctx *ctx); +int selinux_xfrm_policy_delete(struct xfrm_sec_ctx *ctx); +int selinux_xfrm_state_alloc(struct xfrm_state *x, + struct xfrm_user_sec_ctx *uctx); +int selinux_xfrm_state_alloc_acquire(struct xfrm_state *x, + struct xfrm_sec_ctx *polsec, u32 secid); +void selinux_xfrm_state_free(struct xfrm_state *x); +int selinux_xfrm_state_delete(struct xfrm_state *x); +int selinux_xfrm_policy_lookup(struct xfrm_sec_ctx *ctx, u32 fl_secid); +int selinux_xfrm_state_pol_flow_match(struct xfrm_state *x, + struct xfrm_policy *xp, + const struct flowi_common *flic); + +#ifdef CONFIG_SECURITY_NETWORK_XFRM +extern atomic_t selinux_xfrm_refcount; + +static inline int selinux_xfrm_enabled(void) +{ + return (atomic_read(&selinux_xfrm_refcount) > 0); +} + +int selinux_xfrm_sock_rcv_skb(u32 sk_sid, struct sk_buff *skb, + struct common_audit_data *ad); +int selinux_xfrm_postroute_last(u32 sk_sid, struct sk_buff *skb, + struct common_audit_data *ad, u8 proto); +int selinux_xfrm_decode_session(struct sk_buff *skb, u32 *sid, int ckall); +int selinux_xfrm_skb_sid(struct sk_buff *skb, u32 *sid); + +static inline void selinux_xfrm_notify_policyload(void) +{ + struct net *net; + + down_read(&net_rwsem); + for_each_net(net) + rt_genid_bump_all(net); + up_read(&net_rwsem); +} +#else +static inline int selinux_xfrm_enabled(void) +{ + return 0; +} + +static inline int selinux_xfrm_sock_rcv_skb(u32 sk_sid, struct sk_buff *skb, + struct common_audit_data *ad) +{ + return 0; +} + +static inline int selinux_xfrm_postroute_last(u32 sk_sid, struct sk_buff *skb, + struct common_audit_data *ad, + u8 proto) +{ + return 0; +} + +static inline int selinux_xfrm_decode_session(struct sk_buff *skb, u32 *sid, + int ckall) +{ + *sid = SECSID_NULL; + return 0; +} + +static inline void selinux_xfrm_notify_policyload(void) +{ +} + +static inline int selinux_xfrm_skb_sid(struct sk_buff *skb, u32 *sid) +{ + *sid = SECSID_NULL; + return 0; +} +#endif + +#endif /* _SELINUX_XFRM_H_ */ diff --git a/security/selinux/netif.c b/security/selinux/netif.c new file mode 100644 index 000000000..1ab03efe7 --- /dev/null +++ b/security/selinux/netif.c @@ -0,0 +1,280 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Network interface table. + * + * Network interfaces (devices) do not have a security field, so we + * maintain a table associating each interface with a SID. + * + * Author: James Morris <jmorris@redhat.com> + * + * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com> + * Copyright (C) 2007 Hewlett-Packard Development Company, L.P. + * Paul Moore <paul@paul-moore.com> + */ +#include <linux/init.h> +#include <linux/types.h> +#include <linux/slab.h> +#include <linux/stddef.h> +#include <linux/kernel.h> +#include <linux/list.h> +#include <linux/notifier.h> +#include <linux/netdevice.h> +#include <linux/rcupdate.h> +#include <net/net_namespace.h> + +#include "security.h" +#include "objsec.h" +#include "netif.h" + +#define SEL_NETIF_HASH_SIZE 64 +#define SEL_NETIF_HASH_MAX 1024 + +struct sel_netif { + struct list_head list; + struct netif_security_struct nsec; + struct rcu_head rcu_head; +}; + +static u32 sel_netif_total; +static DEFINE_SPINLOCK(sel_netif_lock); +static struct list_head sel_netif_hash[SEL_NETIF_HASH_SIZE]; + +/** + * sel_netif_hashfn - Hashing function for the interface table + * @ns: the network namespace + * @ifindex: the network interface + * + * Description: + * This is the hashing function for the network interface table, it returns the + * bucket number for the given interface. + * + */ +static inline u32 sel_netif_hashfn(const struct net *ns, int ifindex) +{ + return (((uintptr_t)ns + ifindex) & (SEL_NETIF_HASH_SIZE - 1)); +} + +/** + * sel_netif_find - Search for an interface record + * @ns: the network namespace + * @ifindex: the network interface + * + * Description: + * Search the network interface table and return the record matching @ifindex. + * If an entry can not be found in the table return NULL. + * + */ +static inline struct sel_netif *sel_netif_find(const struct net *ns, + int ifindex) +{ + int idx = sel_netif_hashfn(ns, ifindex); + struct sel_netif *netif; + + list_for_each_entry_rcu(netif, &sel_netif_hash[idx], list) + if (net_eq(netif->nsec.ns, ns) && + netif->nsec.ifindex == ifindex) + return netif; + + return NULL; +} + +/** + * sel_netif_insert - Insert a new interface into the table + * @netif: the new interface record + * + * Description: + * Add a new interface record to the network interface hash table. Returns + * zero on success, negative values on failure. + * + */ +static int sel_netif_insert(struct sel_netif *netif) +{ + int idx; + + if (sel_netif_total >= SEL_NETIF_HASH_MAX) + return -ENOSPC; + + idx = sel_netif_hashfn(netif->nsec.ns, netif->nsec.ifindex); + list_add_rcu(&netif->list, &sel_netif_hash[idx]); + sel_netif_total++; + + return 0; +} + +/** + * sel_netif_destroy - Remove an interface record from the table + * @netif: the existing interface record + * + * Description: + * Remove an existing interface record from the network interface table. + * + */ +static void sel_netif_destroy(struct sel_netif *netif) +{ + list_del_rcu(&netif->list); + sel_netif_total--; + kfree_rcu(netif, rcu_head); +} + +/** + * sel_netif_sid_slow - Lookup the SID of a network interface using the policy + * @ns: the network namespace + * @ifindex: the network interface + * @sid: interface SID + * + * Description: + * This function determines the SID of a network interface by querying the + * security policy. The result is added to the network interface table to + * speedup future queries. Returns zero on success, negative values on + * failure. + * + */ +static int sel_netif_sid_slow(struct net *ns, int ifindex, u32 *sid) +{ + int ret = 0; + struct sel_netif *netif; + struct sel_netif *new; + struct net_device *dev; + + /* NOTE: we always use init's network namespace since we don't + * currently support containers */ + + dev = dev_get_by_index(ns, ifindex); + if (unlikely(dev == NULL)) { + pr_warn("SELinux: failure in %s(), invalid network interface (%d)\n", + __func__, ifindex); + return -ENOENT; + } + + spin_lock_bh(&sel_netif_lock); + netif = sel_netif_find(ns, ifindex); + if (netif != NULL) { + *sid = netif->nsec.sid; + goto out; + } + + ret = security_netif_sid(&selinux_state, dev->name, sid); + if (ret != 0) + goto out; + new = kzalloc(sizeof(*new), GFP_ATOMIC); + if (new) { + new->nsec.ns = ns; + new->nsec.ifindex = ifindex; + new->nsec.sid = *sid; + if (sel_netif_insert(new)) + kfree(new); + } + +out: + spin_unlock_bh(&sel_netif_lock); + dev_put(dev); + if (unlikely(ret)) + pr_warn("SELinux: failure in %s(), unable to determine network interface label (%d)\n", + __func__, ifindex); + return ret; +} + +/** + * sel_netif_sid - Lookup the SID of a network interface + * @ns: the network namespace + * @ifindex: the network interface + * @sid: interface SID + * + * Description: + * This function determines the SID of a network interface using the fastest + * method possible. First the interface table is queried, but if an entry + * can't be found then the policy is queried and the result is added to the + * table to speedup future queries. Returns zero on success, negative values + * on failure. + * + */ +int sel_netif_sid(struct net *ns, int ifindex, u32 *sid) +{ + struct sel_netif *netif; + + rcu_read_lock(); + netif = sel_netif_find(ns, ifindex); + if (likely(netif != NULL)) { + *sid = netif->nsec.sid; + rcu_read_unlock(); + return 0; + } + rcu_read_unlock(); + + return sel_netif_sid_slow(ns, ifindex, sid); +} + +/** + * sel_netif_kill - Remove an entry from the network interface table + * @ns: the network namespace + * @ifindex: the network interface + * + * Description: + * This function removes the entry matching @ifindex from the network interface + * table if it exists. + * + */ +static void sel_netif_kill(const struct net *ns, int ifindex) +{ + struct sel_netif *netif; + + rcu_read_lock(); + spin_lock_bh(&sel_netif_lock); + netif = sel_netif_find(ns, ifindex); + if (netif) + sel_netif_destroy(netif); + spin_unlock_bh(&sel_netif_lock); + rcu_read_unlock(); +} + +/** + * sel_netif_flush - Flush the entire network interface table + * + * Description: + * Remove all entries from the network interface table. + * + */ +void sel_netif_flush(void) +{ + int idx; + struct sel_netif *netif; + + spin_lock_bh(&sel_netif_lock); + for (idx = 0; idx < SEL_NETIF_HASH_SIZE; idx++) + list_for_each_entry(netif, &sel_netif_hash[idx], list) + sel_netif_destroy(netif); + spin_unlock_bh(&sel_netif_lock); +} + +static int sel_netif_netdev_notifier_handler(struct notifier_block *this, + unsigned long event, void *ptr) +{ + struct net_device *dev = netdev_notifier_info_to_dev(ptr); + + if (event == NETDEV_DOWN) + sel_netif_kill(dev_net(dev), dev->ifindex); + + return NOTIFY_DONE; +} + +static struct notifier_block sel_netif_netdev_notifier = { + .notifier_call = sel_netif_netdev_notifier_handler, +}; + +static __init int sel_netif_init(void) +{ + int i; + + if (!selinux_enabled_boot) + return 0; + + for (i = 0; i < SEL_NETIF_HASH_SIZE; i++) + INIT_LIST_HEAD(&sel_netif_hash[i]); + + register_netdevice_notifier(&sel_netif_netdev_notifier); + + return 0; +} + +__initcall(sel_netif_init); + diff --git a/security/selinux/netlabel.c b/security/selinux/netlabel.c new file mode 100644 index 000000000..1321f1579 --- /dev/null +++ b/security/selinux/netlabel.c @@ -0,0 +1,615 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * SELinux NetLabel Support + * + * This file provides the necessary glue to tie NetLabel into the SELinux + * subsystem. + * + * Author: Paul Moore <paul@paul-moore.com> + */ + +/* + * (c) Copyright Hewlett-Packard Development Company, L.P., 2007, 2008 + */ + +#include <linux/spinlock.h> +#include <linux/rcupdate.h> +#include <linux/gfp.h> +#include <linux/ip.h> +#include <linux/ipv6.h> +#include <net/sock.h> +#include <net/netlabel.h> +#include <net/ip.h> +#include <net/ipv6.h> + +#include "objsec.h" +#include "security.h" +#include "netlabel.h" + +/** + * selinux_netlbl_sidlookup_cached - Cache a SID lookup + * @skb: the packet + * @family: the packet's address family + * @secattr: the NetLabel security attributes + * @sid: the SID + * + * Description: + * Query the SELinux security server to lookup the correct SID for the given + * security attributes. If the query is successful, cache the result to speed + * up future lookups. Returns zero on success, negative values on failure. + * + */ +static int selinux_netlbl_sidlookup_cached(struct sk_buff *skb, + u16 family, + struct netlbl_lsm_secattr *secattr, + u32 *sid) +{ + int rc; + + rc = security_netlbl_secattr_to_sid(&selinux_state, secattr, sid); + if (rc == 0 && + (secattr->flags & NETLBL_SECATTR_CACHEABLE) && + (secattr->flags & NETLBL_SECATTR_CACHE)) + netlbl_cache_add(skb, family, secattr); + + return rc; +} + +/** + * selinux_netlbl_sock_genattr - Generate the NetLabel socket secattr + * @sk: the socket + * + * Description: + * Generate the NetLabel security attributes for a socket, making full use of + * the socket's attribute cache. Returns a pointer to the security attributes + * on success, NULL on failure. + * + */ +static struct netlbl_lsm_secattr *selinux_netlbl_sock_genattr(struct sock *sk) +{ + int rc; + struct sk_security_struct *sksec = sk->sk_security; + struct netlbl_lsm_secattr *secattr; + + if (sksec->nlbl_secattr != NULL) + return sksec->nlbl_secattr; + + secattr = netlbl_secattr_alloc(GFP_ATOMIC); + if (secattr == NULL) + return NULL; + rc = security_netlbl_sid_to_secattr(&selinux_state, sksec->sid, + secattr); + if (rc != 0) { + netlbl_secattr_free(secattr); + return NULL; + } + sksec->nlbl_secattr = secattr; + + return secattr; +} + +/** + * selinux_netlbl_sock_getattr - Get the cached NetLabel secattr + * @sk: the socket + * @sid: the SID + * + * Query the socket's cached secattr and if the SID matches the cached value + * return the cache, otherwise return NULL. + * + */ +static struct netlbl_lsm_secattr *selinux_netlbl_sock_getattr( + const struct sock *sk, + u32 sid) +{ + struct sk_security_struct *sksec = sk->sk_security; + struct netlbl_lsm_secattr *secattr = sksec->nlbl_secattr; + + if (secattr == NULL) + return NULL; + + if ((secattr->flags & NETLBL_SECATTR_SECID) && + (secattr->attr.secid == sid)) + return secattr; + + return NULL; +} + +/** + * selinux_netlbl_cache_invalidate - Invalidate the NetLabel cache + * + * Description: + * Invalidate the NetLabel security attribute mapping cache. + * + */ +void selinux_netlbl_cache_invalidate(void) +{ + netlbl_cache_invalidate(); +} + +/** + * selinux_netlbl_err - Handle a NetLabel packet error + * @skb: the packet + * @family: the packet's address family + * @error: the error code + * @gateway: true if host is acting as a gateway, false otherwise + * + * Description: + * When a packet is dropped due to a call to avc_has_perm() pass the error + * code to the NetLabel subsystem so any protocol specific processing can be + * done. This is safe to call even if you are unsure if NetLabel labeling is + * present on the packet, NetLabel is smart enough to only act when it should. + * + */ +void selinux_netlbl_err(struct sk_buff *skb, u16 family, int error, int gateway) +{ + netlbl_skbuff_err(skb, family, error, gateway); +} + +/** + * selinux_netlbl_sk_security_free - Free the NetLabel fields + * @sksec: the sk_security_struct + * + * Description: + * Free all of the memory in the NetLabel fields of a sk_security_struct. + * + */ +void selinux_netlbl_sk_security_free(struct sk_security_struct *sksec) +{ + if (sksec->nlbl_secattr != NULL) + netlbl_secattr_free(sksec->nlbl_secattr); +} + +/** + * selinux_netlbl_sk_security_reset - Reset the NetLabel fields + * @sksec: the sk_security_struct + * + * Description: + * Called when the NetLabel state of a sk_security_struct needs to be reset. + * The caller is responsible for all the NetLabel sk_security_struct locking. + * + */ +void selinux_netlbl_sk_security_reset(struct sk_security_struct *sksec) +{ + sksec->nlbl_state = NLBL_UNSET; +} + +/** + * selinux_netlbl_skbuff_getsid - Get the sid of a packet using NetLabel + * @skb: the packet + * @family: protocol family + * @type: NetLabel labeling protocol type + * @sid: the SID + * + * Description: + * Call the NetLabel mechanism to get the security attributes of the given + * packet and use those attributes to determine the correct context/SID to + * assign to the packet. Returns zero on success, negative values on failure. + * + */ +int selinux_netlbl_skbuff_getsid(struct sk_buff *skb, + u16 family, + u32 *type, + u32 *sid) +{ + int rc; + struct netlbl_lsm_secattr secattr; + + if (!netlbl_enabled()) { + *sid = SECSID_NULL; + return 0; + } + + netlbl_secattr_init(&secattr); + rc = netlbl_skbuff_getattr(skb, family, &secattr); + if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE) + rc = selinux_netlbl_sidlookup_cached(skb, family, + &secattr, sid); + else + *sid = SECSID_NULL; + *type = secattr.type; + netlbl_secattr_destroy(&secattr); + + return rc; +} + +/** + * selinux_netlbl_skbuff_setsid - Set the NetLabel on a packet given a sid + * @skb: the packet + * @family: protocol family + * @sid: the SID + * + * Description + * Call the NetLabel mechanism to set the label of a packet using @sid. + * Returns zero on success, negative values on failure. + * + */ +int selinux_netlbl_skbuff_setsid(struct sk_buff *skb, + u16 family, + u32 sid) +{ + int rc; + struct netlbl_lsm_secattr secattr_storage; + struct netlbl_lsm_secattr *secattr = NULL; + struct sock *sk; + + /* if this is a locally generated packet check to see if it is already + * being labeled by it's parent socket, if it is just exit */ + sk = skb_to_full_sk(skb); + if (sk != NULL) { + struct sk_security_struct *sksec = sk->sk_security; + + if (sksec->nlbl_state != NLBL_REQSKB) + return 0; + secattr = selinux_netlbl_sock_getattr(sk, sid); + } + if (secattr == NULL) { + secattr = &secattr_storage; + netlbl_secattr_init(secattr); + rc = security_netlbl_sid_to_secattr(&selinux_state, sid, + secattr); + if (rc != 0) + goto skbuff_setsid_return; + } + + rc = netlbl_skbuff_setattr(skb, family, secattr); + +skbuff_setsid_return: + if (secattr == &secattr_storage) + netlbl_secattr_destroy(secattr); + return rc; +} + +/** + * selinux_netlbl_sctp_assoc_request - Label an incoming sctp association. + * @asoc: incoming association. + * @skb: the packet. + * + * Description: + * A new incoming connection is represented by @asoc, ...... + * Returns zero on success, negative values on failure. + * + */ +int selinux_netlbl_sctp_assoc_request(struct sctp_association *asoc, + struct sk_buff *skb) +{ + int rc; + struct netlbl_lsm_secattr secattr; + struct sk_security_struct *sksec = asoc->base.sk->sk_security; + struct sockaddr_in addr4; + struct sockaddr_in6 addr6; + + if (asoc->base.sk->sk_family != PF_INET && + asoc->base.sk->sk_family != PF_INET6) + return 0; + + netlbl_secattr_init(&secattr); + rc = security_netlbl_sid_to_secattr(&selinux_state, + asoc->secid, &secattr); + if (rc != 0) + goto assoc_request_return; + + /* Move skb hdr address info to a struct sockaddr and then call + * netlbl_conn_setattr(). + */ + if (ip_hdr(skb)->version == 4) { + addr4.sin_family = AF_INET; + addr4.sin_addr.s_addr = ip_hdr(skb)->saddr; + rc = netlbl_conn_setattr(asoc->base.sk, (void *)&addr4, &secattr); + } else if (IS_ENABLED(CONFIG_IPV6) && ip_hdr(skb)->version == 6) { + addr6.sin6_family = AF_INET6; + addr6.sin6_addr = ipv6_hdr(skb)->saddr; + rc = netlbl_conn_setattr(asoc->base.sk, (void *)&addr6, &secattr); + } else { + rc = -EAFNOSUPPORT; + } + + if (rc == 0) + sksec->nlbl_state = NLBL_LABELED; + +assoc_request_return: + netlbl_secattr_destroy(&secattr); + return rc; +} + +/** + * selinux_netlbl_inet_conn_request - Label an incoming stream connection + * @req: incoming connection request socket + * @family: the request socket's address family + * + * Description: + * A new incoming connection request is represented by @req, we need to label + * the new request_sock here and the stack will ensure the on-the-wire label + * will get preserved when a full sock is created once the connection handshake + * is complete. Returns zero on success, negative values on failure. + * + */ +int selinux_netlbl_inet_conn_request(struct request_sock *req, u16 family) +{ + int rc; + struct netlbl_lsm_secattr secattr; + + if (family != PF_INET && family != PF_INET6) + return 0; + + netlbl_secattr_init(&secattr); + rc = security_netlbl_sid_to_secattr(&selinux_state, req->secid, + &secattr); + if (rc != 0) + goto inet_conn_request_return; + rc = netlbl_req_setattr(req, &secattr); +inet_conn_request_return: + netlbl_secattr_destroy(&secattr); + return rc; +} + +/** + * selinux_netlbl_inet_csk_clone - Initialize the newly created sock + * @sk: the new sock + * @family: the sock's address family + * + * Description: + * A new connection has been established using @sk, we've already labeled the + * socket via the request_sock struct in selinux_netlbl_inet_conn_request() but + * we need to set the NetLabel state here since we now have a sock structure. + * + */ +void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family) +{ + struct sk_security_struct *sksec = sk->sk_security; + + if (family == PF_INET) + sksec->nlbl_state = NLBL_LABELED; + else + sksec->nlbl_state = NLBL_UNSET; +} + +/** + * selinux_netlbl_sctp_sk_clone - Copy state to the newly created sock + * @sk: current sock + * @newsk: the new sock + * + * Description: + * Called whenever a new socket is created by accept(2) or sctp_peeloff(3). + */ +void selinux_netlbl_sctp_sk_clone(struct sock *sk, struct sock *newsk) +{ + struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *newsksec = newsk->sk_security; + + newsksec->nlbl_state = sksec->nlbl_state; +} + +/** + * selinux_netlbl_socket_post_create - Label a socket using NetLabel + * @sk: the sock to label + * @family: protocol family + * + * Description: + * Attempt to label a socket using the NetLabel mechanism using the given + * SID. Returns zero values on success, negative values on failure. + * + */ +int selinux_netlbl_socket_post_create(struct sock *sk, u16 family) +{ + int rc; + struct sk_security_struct *sksec = sk->sk_security; + struct netlbl_lsm_secattr *secattr; + + if (family != PF_INET && family != PF_INET6) + return 0; + + secattr = selinux_netlbl_sock_genattr(sk); + if (secattr == NULL) + return -ENOMEM; + rc = netlbl_sock_setattr(sk, family, secattr); + switch (rc) { + case 0: + sksec->nlbl_state = NLBL_LABELED; + break; + case -EDESTADDRREQ: + sksec->nlbl_state = NLBL_REQSKB; + rc = 0; + break; + } + + return rc; +} + +/** + * selinux_netlbl_sock_rcv_skb - Do an inbound access check using NetLabel + * @sksec: the sock's sk_security_struct + * @skb: the packet + * @family: protocol family + * @ad: the audit data + * + * Description: + * Fetch the NetLabel security attributes from @skb and perform an access check + * against the receiving socket. Returns zero on success, negative values on + * error. + * + */ +int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec, + struct sk_buff *skb, + u16 family, + struct common_audit_data *ad) +{ + int rc; + u32 nlbl_sid; + u32 perm; + struct netlbl_lsm_secattr secattr; + + if (!netlbl_enabled()) + return 0; + + netlbl_secattr_init(&secattr); + rc = netlbl_skbuff_getattr(skb, family, &secattr); + if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE) + rc = selinux_netlbl_sidlookup_cached(skb, family, + &secattr, &nlbl_sid); + else + nlbl_sid = SECINITSID_UNLABELED; + netlbl_secattr_destroy(&secattr); + if (rc != 0) + return rc; + + switch (sksec->sclass) { + case SECCLASS_UDP_SOCKET: + perm = UDP_SOCKET__RECVFROM; + break; + case SECCLASS_TCP_SOCKET: + perm = TCP_SOCKET__RECVFROM; + break; + default: + perm = RAWIP_SOCKET__RECVFROM; + } + + rc = avc_has_perm(&selinux_state, + sksec->sid, nlbl_sid, sksec->sclass, perm, ad); + if (rc == 0) + return 0; + + if (nlbl_sid != SECINITSID_UNLABELED) + netlbl_skbuff_err(skb, family, rc, 0); + return rc; +} + +/** + * selinux_netlbl_option - Is this a NetLabel option + * @level: the socket level or protocol + * @optname: the socket option name + * + * Description: + * Returns true if @level and @optname refer to a NetLabel option. + * Helper for selinux_netlbl_socket_setsockopt(). + */ +static inline int selinux_netlbl_option(int level, int optname) +{ + return (level == IPPROTO_IP && optname == IP_OPTIONS) || + (level == IPPROTO_IPV6 && optname == IPV6_HOPOPTS); +} + +/** + * selinux_netlbl_socket_setsockopt - Do not allow users to remove a NetLabel + * @sock: the socket + * @level: the socket level or protocol + * @optname: the socket option name + * + * Description: + * Check the setsockopt() call and if the user is trying to replace the IP + * options on a socket and a NetLabel is in place for the socket deny the + * access; otherwise allow the access. Returns zero when the access is + * allowed, -EACCES when denied, and other negative values on error. + * + */ +int selinux_netlbl_socket_setsockopt(struct socket *sock, + int level, + int optname) +{ + int rc = 0; + struct sock *sk = sock->sk; + struct sk_security_struct *sksec = sk->sk_security; + struct netlbl_lsm_secattr secattr; + + if (selinux_netlbl_option(level, optname) && + (sksec->nlbl_state == NLBL_LABELED || + sksec->nlbl_state == NLBL_CONNLABELED)) { + netlbl_secattr_init(&secattr); + lock_sock(sk); + /* call the netlabel function directly as we want to see the + * on-the-wire label that is assigned via the socket's options + * and not the cached netlabel/lsm attributes */ + rc = netlbl_sock_getattr(sk, &secattr); + release_sock(sk); + if (rc == 0) + rc = -EACCES; + else if (rc == -ENOMSG) + rc = 0; + netlbl_secattr_destroy(&secattr); + } + + return rc; +} + +/** + * selinux_netlbl_socket_connect_helper - Help label a client-side socket on + * connect + * @sk: the socket to label + * @addr: the destination address + * + * Description: + * Attempt to label a connected socket with NetLabel using the given address. + * Returns zero values on success, negative values on failure. + * + */ +static int selinux_netlbl_socket_connect_helper(struct sock *sk, + struct sockaddr *addr) +{ + int rc; + struct sk_security_struct *sksec = sk->sk_security; + struct netlbl_lsm_secattr *secattr; + + /* connected sockets are allowed to disconnect when the address family + * is set to AF_UNSPEC, if that is what is happening we want to reset + * the socket */ + if (addr->sa_family == AF_UNSPEC) { + netlbl_sock_delattr(sk); + sksec->nlbl_state = NLBL_REQSKB; + rc = 0; + return rc; + } + secattr = selinux_netlbl_sock_genattr(sk); + if (secattr == NULL) { + rc = -ENOMEM; + return rc; + } + rc = netlbl_conn_setattr(sk, addr, secattr); + if (rc == 0) + sksec->nlbl_state = NLBL_CONNLABELED; + + return rc; +} + +/** + * selinux_netlbl_socket_connect_locked - Label a client-side socket on + * connect + * @sk: the socket to label + * @addr: the destination address + * + * Description: + * Attempt to label a connected socket that already has the socket locked + * with NetLabel using the given address. + * Returns zero values on success, negative values on failure. + * + */ +int selinux_netlbl_socket_connect_locked(struct sock *sk, + struct sockaddr *addr) +{ + struct sk_security_struct *sksec = sk->sk_security; + + if (sksec->nlbl_state != NLBL_REQSKB && + sksec->nlbl_state != NLBL_CONNLABELED) + return 0; + + return selinux_netlbl_socket_connect_helper(sk, addr); +} + +/** + * selinux_netlbl_socket_connect - Label a client-side socket on connect + * @sk: the socket to label + * @addr: the destination address + * + * Description: + * Attempt to label a connected socket with NetLabel using the given address. + * Returns zero values on success, negative values on failure. + * + */ +int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr) +{ + int rc; + + lock_sock(sk); + rc = selinux_netlbl_socket_connect_locked(sk, addr); + release_sock(sk); + + return rc; +} diff --git a/security/selinux/netlink.c b/security/selinux/netlink.c new file mode 100644 index 000000000..1760aee71 --- /dev/null +++ b/security/selinux/netlink.c @@ -0,0 +1,121 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Netlink event notifications for SELinux. + * + * Author: James Morris <jmorris@redhat.com> + * + * Copyright (C) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com> + */ +#include <linux/init.h> +#include <linux/types.h> +#include <linux/slab.h> +#include <linux/stddef.h> +#include <linux/kernel.h> +#include <linux/export.h> +#include <linux/skbuff.h> +#include <linux/selinux_netlink.h> +#include <net/net_namespace.h> +#include <net/netlink.h> + +#include "security.h" + +static struct sock *selnl __ro_after_init; + +static int selnl_msglen(int msgtype) +{ + int ret = 0; + + switch (msgtype) { + case SELNL_MSG_SETENFORCE: + ret = sizeof(struct selnl_msg_setenforce); + break; + + case SELNL_MSG_POLICYLOAD: + ret = sizeof(struct selnl_msg_policyload); + break; + + default: + BUG(); + } + return ret; +} + +static void selnl_add_payload(struct nlmsghdr *nlh, int len, int msgtype, void *data) +{ + switch (msgtype) { + case SELNL_MSG_SETENFORCE: { + struct selnl_msg_setenforce *msg = nlmsg_data(nlh); + + memset(msg, 0, len); + msg->val = *((int *)data); + break; + } + + case SELNL_MSG_POLICYLOAD: { + struct selnl_msg_policyload *msg = nlmsg_data(nlh); + + memset(msg, 0, len); + msg->seqno = *((u32 *)data); + break; + } + + default: + BUG(); + } +} + +static void selnl_notify(int msgtype, void *data) +{ + int len; + sk_buff_data_t tmp; + struct sk_buff *skb; + struct nlmsghdr *nlh; + + len = selnl_msglen(msgtype); + + skb = nlmsg_new(len, GFP_USER); + if (!skb) + goto oom; + + tmp = skb->tail; + nlh = nlmsg_put(skb, 0, 0, msgtype, len, 0); + if (!nlh) + goto out_kfree_skb; + selnl_add_payload(nlh, len, msgtype, data); + nlh->nlmsg_len = skb->tail - tmp; + NETLINK_CB(skb).dst_group = SELNLGRP_AVC; + netlink_broadcast(selnl, skb, 0, SELNLGRP_AVC, GFP_USER); +out: + return; + +out_kfree_skb: + kfree_skb(skb); +oom: + pr_err("SELinux: OOM in %s\n", __func__); + goto out; +} + +void selnl_notify_setenforce(int val) +{ + selnl_notify(SELNL_MSG_SETENFORCE, &val); +} + +void selnl_notify_policyload(u32 seqno) +{ + selnl_notify(SELNL_MSG_POLICYLOAD, &seqno); +} + +static int __init selnl_init(void) +{ + struct netlink_kernel_cfg cfg = { + .groups = SELNLGRP_MAX, + .flags = NL_CFG_F_NONROOT_RECV, + }; + + selnl = netlink_kernel_create(&init_net, NETLINK_SELINUX, &cfg); + if (selnl == NULL) + panic("SELinux: Cannot create netlink socket."); + return 0; +} + +__initcall(selnl_init); diff --git a/security/selinux/netnode.c b/security/selinux/netnode.c new file mode 100644 index 000000000..0ac7df9a9 --- /dev/null +++ b/security/selinux/netnode.c @@ -0,0 +1,305 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Network node table + * + * SELinux must keep a mapping of network nodes to labels/SIDs. This + * mapping is maintained as part of the normal policy but a fast cache is + * needed to reduce the lookup overhead since most of these queries happen on + * a per-packet basis. + * + * Author: Paul Moore <paul@paul-moore.com> + * + * This code is heavily based on the "netif" concept originally developed by + * James Morris <jmorris@redhat.com> + * (see security/selinux/netif.c for more information) + */ + +/* + * (c) Copyright Hewlett-Packard Development Company, L.P., 2007 + */ + +#include <linux/types.h> +#include <linux/rcupdate.h> +#include <linux/list.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/in.h> +#include <linux/in6.h> +#include <linux/ip.h> +#include <linux/ipv6.h> +#include <net/ip.h> +#include <net/ipv6.h> + +#include "netnode.h" +#include "objsec.h" + +#define SEL_NETNODE_HASH_SIZE 256 +#define SEL_NETNODE_HASH_BKT_LIMIT 16 + +struct sel_netnode_bkt { + unsigned int size; + struct list_head list; +}; + +struct sel_netnode { + struct netnode_security_struct nsec; + + struct list_head list; + struct rcu_head rcu; +}; + +/* NOTE: we are using a combined hash table for both IPv4 and IPv6, the reason + * for this is that I suspect most users will not make heavy use of both + * address families at the same time so one table will usually end up wasted, + * if this becomes a problem we can always add a hash table for each address + * family later */ + +static DEFINE_SPINLOCK(sel_netnode_lock); +static struct sel_netnode_bkt sel_netnode_hash[SEL_NETNODE_HASH_SIZE]; + +/** + * sel_netnode_hashfn_ipv4 - IPv4 hashing function for the node table + * @addr: IPv4 address + * + * Description: + * This is the IPv4 hashing function for the node interface table, it returns + * the bucket number for the given IP address. + * + */ +static unsigned int sel_netnode_hashfn_ipv4(__be32 addr) +{ + /* at some point we should determine if the mismatch in byte order + * affects the hash function dramatically */ + return (addr & (SEL_NETNODE_HASH_SIZE - 1)); +} + +/** + * sel_netnode_hashfn_ipv6 - IPv6 hashing function for the node table + * @addr: IPv6 address + * + * Description: + * This is the IPv6 hashing function for the node interface table, it returns + * the bucket number for the given IP address. + * + */ +static unsigned int sel_netnode_hashfn_ipv6(const struct in6_addr *addr) +{ + /* just hash the least significant 32 bits to keep things fast (they + * are the most likely to be different anyway), we can revisit this + * later if needed */ + return (addr->s6_addr32[3] & (SEL_NETNODE_HASH_SIZE - 1)); +} + +/** + * sel_netnode_find - Search for a node record + * @addr: IP address + * @family: address family + * + * Description: + * Search the network node table and return the record matching @addr. If an + * entry can not be found in the table return NULL. + * + */ +static struct sel_netnode *sel_netnode_find(const void *addr, u16 family) +{ + unsigned int idx; + struct sel_netnode *node; + + switch (family) { + case PF_INET: + idx = sel_netnode_hashfn_ipv4(*(const __be32 *)addr); + break; + case PF_INET6: + idx = sel_netnode_hashfn_ipv6(addr); + break; + default: + BUG(); + return NULL; + } + + list_for_each_entry_rcu(node, &sel_netnode_hash[idx].list, list) + if (node->nsec.family == family) + switch (family) { + case PF_INET: + if (node->nsec.addr.ipv4 == *(const __be32 *)addr) + return node; + break; + case PF_INET6: + if (ipv6_addr_equal(&node->nsec.addr.ipv6, + addr)) + return node; + break; + } + + return NULL; +} + +/** + * sel_netnode_insert - Insert a new node into the table + * @node: the new node record + * + * Description: + * Add a new node record to the network address hash table. + * + */ +static void sel_netnode_insert(struct sel_netnode *node) +{ + unsigned int idx; + + switch (node->nsec.family) { + case PF_INET: + idx = sel_netnode_hashfn_ipv4(node->nsec.addr.ipv4); + break; + case PF_INET6: + idx = sel_netnode_hashfn_ipv6(&node->nsec.addr.ipv6); + break; + default: + BUG(); + return; + } + + /* we need to impose a limit on the growth of the hash table so check + * this bucket to make sure it is within the specified bounds */ + list_add_rcu(&node->list, &sel_netnode_hash[idx].list); + if (sel_netnode_hash[idx].size == SEL_NETNODE_HASH_BKT_LIMIT) { + struct sel_netnode *tail; + tail = list_entry( + rcu_dereference_protected( + list_tail_rcu(&sel_netnode_hash[idx].list), + lockdep_is_held(&sel_netnode_lock)), + struct sel_netnode, list); + list_del_rcu(&tail->list); + kfree_rcu(tail, rcu); + } else + sel_netnode_hash[idx].size++; +} + +/** + * sel_netnode_sid_slow - Lookup the SID of a network address using the policy + * @addr: the IP address + * @family: the address family + * @sid: node SID + * + * Description: + * This function determines the SID of a network address by querying the + * security policy. The result is added to the network address table to + * speedup future queries. Returns zero on success, negative values on + * failure. + * + */ +static int sel_netnode_sid_slow(void *addr, u16 family, u32 *sid) +{ + int ret; + struct sel_netnode *node; + struct sel_netnode *new; + + spin_lock_bh(&sel_netnode_lock); + node = sel_netnode_find(addr, family); + if (node != NULL) { + *sid = node->nsec.sid; + spin_unlock_bh(&sel_netnode_lock); + return 0; + } + + new = kzalloc(sizeof(*new), GFP_ATOMIC); + switch (family) { + case PF_INET: + ret = security_node_sid(&selinux_state, PF_INET, + addr, sizeof(struct in_addr), sid); + if (new) + new->nsec.addr.ipv4 = *(__be32 *)addr; + break; + case PF_INET6: + ret = security_node_sid(&selinux_state, PF_INET6, + addr, sizeof(struct in6_addr), sid); + if (new) + new->nsec.addr.ipv6 = *(struct in6_addr *)addr; + break; + default: + BUG(); + ret = -EINVAL; + } + if (ret == 0 && new) { + new->nsec.family = family; + new->nsec.sid = *sid; + sel_netnode_insert(new); + } else + kfree(new); + + spin_unlock_bh(&sel_netnode_lock); + if (unlikely(ret)) + pr_warn("SELinux: failure in %s(), unable to determine network node label\n", + __func__); + return ret; +} + +/** + * sel_netnode_sid - Lookup the SID of a network address + * @addr: the IP address + * @family: the address family + * @sid: node SID + * + * Description: + * This function determines the SID of a network address using the fastest + * method possible. First the address table is queried, but if an entry + * can't be found then the policy is queried and the result is added to the + * table to speedup future queries. Returns zero on success, negative values + * on failure. + * + */ +int sel_netnode_sid(void *addr, u16 family, u32 *sid) +{ + struct sel_netnode *node; + + rcu_read_lock(); + node = sel_netnode_find(addr, family); + if (node != NULL) { + *sid = node->nsec.sid; + rcu_read_unlock(); + return 0; + } + rcu_read_unlock(); + + return sel_netnode_sid_slow(addr, family, sid); +} + +/** + * sel_netnode_flush - Flush the entire network address table + * + * Description: + * Remove all entries from the network address table. + * + */ +void sel_netnode_flush(void) +{ + unsigned int idx; + struct sel_netnode *node, *node_tmp; + + spin_lock_bh(&sel_netnode_lock); + for (idx = 0; idx < SEL_NETNODE_HASH_SIZE; idx++) { + list_for_each_entry_safe(node, node_tmp, + &sel_netnode_hash[idx].list, list) { + list_del_rcu(&node->list); + kfree_rcu(node, rcu); + } + sel_netnode_hash[idx].size = 0; + } + spin_unlock_bh(&sel_netnode_lock); +} + +static __init int sel_netnode_init(void) +{ + int iter; + + if (!selinux_enabled_boot) + return 0; + + for (iter = 0; iter < SEL_NETNODE_HASH_SIZE; iter++) { + INIT_LIST_HEAD(&sel_netnode_hash[iter].list); + sel_netnode_hash[iter].size = 0; + } + + return 0; +} + +__initcall(sel_netnode_init); diff --git a/security/selinux/netport.c b/security/selinux/netport.c new file mode 100644 index 000000000..8eec6347c --- /dev/null +++ b/security/selinux/netport.c @@ -0,0 +1,238 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Network port table + * + * SELinux must keep a mapping of network ports to labels/SIDs. This + * mapping is maintained as part of the normal policy but a fast cache is + * needed to reduce the lookup overhead. + * + * Author: Paul Moore <paul@paul-moore.com> + * + * This code is heavily based on the "netif" concept originally developed by + * James Morris <jmorris@redhat.com> + * (see security/selinux/netif.c for more information) + */ + +/* + * (c) Copyright Hewlett-Packard Development Company, L.P., 2008 + */ + +#include <linux/types.h> +#include <linux/rcupdate.h> +#include <linux/list.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/in.h> +#include <linux/in6.h> +#include <linux/ip.h> +#include <linux/ipv6.h> +#include <net/ip.h> +#include <net/ipv6.h> + +#include "netport.h" +#include "objsec.h" + +#define SEL_NETPORT_HASH_SIZE 256 +#define SEL_NETPORT_HASH_BKT_LIMIT 16 + +struct sel_netport_bkt { + int size; + struct list_head list; +}; + +struct sel_netport { + struct netport_security_struct psec; + + struct list_head list; + struct rcu_head rcu; +}; + +/* NOTE: we are using a combined hash table for both IPv4 and IPv6, the reason + * for this is that I suspect most users will not make heavy use of both + * address families at the same time so one table will usually end up wasted, + * if this becomes a problem we can always add a hash table for each address + * family later */ + +static DEFINE_SPINLOCK(sel_netport_lock); +static struct sel_netport_bkt sel_netport_hash[SEL_NETPORT_HASH_SIZE]; + +/** + * sel_netport_hashfn - Hashing function for the port table + * @pnum: port number + * + * Description: + * This is the hashing function for the port table, it returns the bucket + * number for the given port. + * + */ +static unsigned int sel_netport_hashfn(u16 pnum) +{ + return (pnum & (SEL_NETPORT_HASH_SIZE - 1)); +} + +/** + * sel_netport_find - Search for a port record + * @protocol: protocol + * @pnum: port + * + * Description: + * Search the network port table and return the matching record. If an entry + * can not be found in the table return NULL. + * + */ +static struct sel_netport *sel_netport_find(u8 protocol, u16 pnum) +{ + unsigned int idx; + struct sel_netport *port; + + idx = sel_netport_hashfn(pnum); + list_for_each_entry_rcu(port, &sel_netport_hash[idx].list, list) + if (port->psec.port == pnum && port->psec.protocol == protocol) + return port; + + return NULL; +} + +/** + * sel_netport_insert - Insert a new port into the table + * @port: the new port record + * + * Description: + * Add a new port record to the network address hash table. + * + */ +static void sel_netport_insert(struct sel_netport *port) +{ + unsigned int idx; + + /* we need to impose a limit on the growth of the hash table so check + * this bucket to make sure it is within the specified bounds */ + idx = sel_netport_hashfn(port->psec.port); + list_add_rcu(&port->list, &sel_netport_hash[idx].list); + if (sel_netport_hash[idx].size == SEL_NETPORT_HASH_BKT_LIMIT) { + struct sel_netport *tail; + tail = list_entry( + rcu_dereference_protected( + list_tail_rcu(&sel_netport_hash[idx].list), + lockdep_is_held(&sel_netport_lock)), + struct sel_netport, list); + list_del_rcu(&tail->list); + kfree_rcu(tail, rcu); + } else + sel_netport_hash[idx].size++; +} + +/** + * sel_netport_sid_slow - Lookup the SID of a network address using the policy + * @protocol: protocol + * @pnum: port + * @sid: port SID + * + * Description: + * This function determines the SID of a network port by querying the security + * policy. The result is added to the network port table to speedup future + * queries. Returns zero on success, negative values on failure. + * + */ +static int sel_netport_sid_slow(u8 protocol, u16 pnum, u32 *sid) +{ + int ret; + struct sel_netport *port; + struct sel_netport *new; + + spin_lock_bh(&sel_netport_lock); + port = sel_netport_find(protocol, pnum); + if (port != NULL) { + *sid = port->psec.sid; + spin_unlock_bh(&sel_netport_lock); + return 0; + } + + ret = security_port_sid(&selinux_state, protocol, pnum, sid); + if (ret != 0) + goto out; + new = kzalloc(sizeof(*new), GFP_ATOMIC); + if (new) { + new->psec.port = pnum; + new->psec.protocol = protocol; + new->psec.sid = *sid; + sel_netport_insert(new); + } + +out: + spin_unlock_bh(&sel_netport_lock); + if (unlikely(ret)) + pr_warn("SELinux: failure in %s(), unable to determine network port label\n", + __func__); + return ret; +} + +/** + * sel_netport_sid - Lookup the SID of a network port + * @protocol: protocol + * @pnum: port + * @sid: port SID + * + * Description: + * This function determines the SID of a network port using the fastest method + * possible. First the port table is queried, but if an entry can't be found + * then the policy is queried and the result is added to the table to speedup + * future queries. Returns zero on success, negative values on failure. + * + */ +int sel_netport_sid(u8 protocol, u16 pnum, u32 *sid) +{ + struct sel_netport *port; + + rcu_read_lock(); + port = sel_netport_find(protocol, pnum); + if (port != NULL) { + *sid = port->psec.sid; + rcu_read_unlock(); + return 0; + } + rcu_read_unlock(); + + return sel_netport_sid_slow(protocol, pnum, sid); +} + +/** + * sel_netport_flush - Flush the entire network port table + * + * Description: + * Remove all entries from the network address table. + * + */ +void sel_netport_flush(void) +{ + unsigned int idx; + struct sel_netport *port, *port_tmp; + + spin_lock_bh(&sel_netport_lock); + for (idx = 0; idx < SEL_NETPORT_HASH_SIZE; idx++) { + list_for_each_entry_safe(port, port_tmp, + &sel_netport_hash[idx].list, list) { + list_del_rcu(&port->list); + kfree_rcu(port, rcu); + } + sel_netport_hash[idx].size = 0; + } + spin_unlock_bh(&sel_netport_lock); +} + +static __init int sel_netport_init(void) +{ + int iter; + + if (!selinux_enabled_boot) + return 0; + + for (iter = 0; iter < SEL_NETPORT_HASH_SIZE; iter++) { + INIT_LIST_HEAD(&sel_netport_hash[iter].list); + sel_netport_hash[iter].size = 0; + } + + return 0; +} + +__initcall(sel_netport_init); diff --git a/security/selinux/nlmsgtab.c b/security/selinux/nlmsgtab.c new file mode 100644 index 000000000..2ee7b4ed4 --- /dev/null +++ b/security/selinux/nlmsgtab.c @@ -0,0 +1,218 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Netlink message type permission tables, for user generated messages. + * + * Author: James Morris <jmorris@redhat.com> + * + * Copyright (C) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com> + */ +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/netlink.h> +#include <linux/rtnetlink.h> +#include <linux/if.h> +#include <linux/inet_diag.h> +#include <linux/xfrm.h> +#include <linux/audit.h> +#include <linux/sock_diag.h> + +#include "flask.h" +#include "av_permissions.h" +#include "security.h" + +struct nlmsg_perm { + u16 nlmsg_type; + u32 perm; +}; + +static const struct nlmsg_perm nlmsg_route_perms[] = { + { RTM_NEWLINK, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_DELLINK, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_GETLINK, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_SETLINK, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_NEWADDR, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_DELADDR, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_GETADDR, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_NEWROUTE, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_DELROUTE, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_GETROUTE, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_NEWNEIGH, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_DELNEIGH, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_GETNEIGH, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_NEWRULE, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_DELRULE, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_GETRULE, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_NEWQDISC, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_DELQDISC, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_GETQDISC, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_NEWTCLASS, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_DELTCLASS, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_GETTCLASS, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_NEWTFILTER, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_DELTFILTER, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_GETTFILTER, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_NEWACTION, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_DELACTION, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_GETACTION, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_NEWPREFIX, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_GETMULTICAST, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_GETANYCAST, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_GETNEIGHTBL, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_SETNEIGHTBL, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_NEWADDRLABEL, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_DELADDRLABEL, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_GETADDRLABEL, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_GETDCB, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_SETDCB, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_NEWNETCONF, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_DELNETCONF, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_GETNETCONF, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_NEWMDB, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_DELMDB, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_GETMDB, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_NEWNSID, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_DELNSID, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_GETNSID, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_NEWSTATS, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_GETSTATS, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_SETSTATS, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_NEWCACHEREPORT, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_NEWCHAIN, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_DELCHAIN, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_GETCHAIN, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_NEWNEXTHOP, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_DELNEXTHOP, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_GETNEXTHOP, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_NEWLINKPROP, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_DELLINKPROP, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_NEWVLAN, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_DELVLAN, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_GETVLAN, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_NEWNEXTHOPBUCKET, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_DELNEXTHOPBUCKET, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_GETNEXTHOPBUCKET, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_NEWTUNNEL, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_DELTUNNEL, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_GETTUNNEL, NETLINK_ROUTE_SOCKET__NLMSG_READ }, +}; + +static const struct nlmsg_perm nlmsg_tcpdiag_perms[] = { + { TCPDIAG_GETSOCK, NETLINK_TCPDIAG_SOCKET__NLMSG_READ }, + { DCCPDIAG_GETSOCK, NETLINK_TCPDIAG_SOCKET__NLMSG_READ }, + { SOCK_DIAG_BY_FAMILY, NETLINK_TCPDIAG_SOCKET__NLMSG_READ }, + { SOCK_DESTROY, NETLINK_TCPDIAG_SOCKET__NLMSG_WRITE }, +}; + +static const struct nlmsg_perm nlmsg_xfrm_perms[] = { + { XFRM_MSG_NEWSA, NETLINK_XFRM_SOCKET__NLMSG_WRITE }, + { XFRM_MSG_DELSA, NETLINK_XFRM_SOCKET__NLMSG_WRITE }, + { XFRM_MSG_GETSA, NETLINK_XFRM_SOCKET__NLMSG_READ }, + { XFRM_MSG_NEWPOLICY, NETLINK_XFRM_SOCKET__NLMSG_WRITE }, + { XFRM_MSG_DELPOLICY, NETLINK_XFRM_SOCKET__NLMSG_WRITE }, + { XFRM_MSG_GETPOLICY, NETLINK_XFRM_SOCKET__NLMSG_READ }, + { XFRM_MSG_ALLOCSPI, NETLINK_XFRM_SOCKET__NLMSG_WRITE }, + { XFRM_MSG_ACQUIRE, NETLINK_XFRM_SOCKET__NLMSG_WRITE }, + { XFRM_MSG_EXPIRE, NETLINK_XFRM_SOCKET__NLMSG_WRITE }, + { XFRM_MSG_UPDPOLICY, NETLINK_XFRM_SOCKET__NLMSG_WRITE }, + { XFRM_MSG_UPDSA, NETLINK_XFRM_SOCKET__NLMSG_WRITE }, + { XFRM_MSG_POLEXPIRE, NETLINK_XFRM_SOCKET__NLMSG_WRITE }, + { XFRM_MSG_FLUSHSA, NETLINK_XFRM_SOCKET__NLMSG_WRITE }, + { XFRM_MSG_FLUSHPOLICY, NETLINK_XFRM_SOCKET__NLMSG_WRITE }, + { XFRM_MSG_NEWAE, NETLINK_XFRM_SOCKET__NLMSG_WRITE }, + { XFRM_MSG_GETAE, NETLINK_XFRM_SOCKET__NLMSG_READ }, + { XFRM_MSG_REPORT, NETLINK_XFRM_SOCKET__NLMSG_READ }, + { XFRM_MSG_MIGRATE, NETLINK_XFRM_SOCKET__NLMSG_WRITE }, + { XFRM_MSG_NEWSADINFO, NETLINK_XFRM_SOCKET__NLMSG_READ }, + { XFRM_MSG_GETSADINFO, NETLINK_XFRM_SOCKET__NLMSG_READ }, + { XFRM_MSG_NEWSPDINFO, NETLINK_XFRM_SOCKET__NLMSG_WRITE }, + { XFRM_MSG_GETSPDINFO, NETLINK_XFRM_SOCKET__NLMSG_READ }, + { XFRM_MSG_MAPPING, NETLINK_XFRM_SOCKET__NLMSG_READ }, + { XFRM_MSG_SETDEFAULT, NETLINK_XFRM_SOCKET__NLMSG_WRITE }, + { XFRM_MSG_GETDEFAULT, NETLINK_XFRM_SOCKET__NLMSG_READ }, +}; + +static const struct nlmsg_perm nlmsg_audit_perms[] = { + { AUDIT_GET, NETLINK_AUDIT_SOCKET__NLMSG_READ }, + { AUDIT_SET, NETLINK_AUDIT_SOCKET__NLMSG_WRITE }, + { AUDIT_LIST, NETLINK_AUDIT_SOCKET__NLMSG_READPRIV }, + { AUDIT_ADD, NETLINK_AUDIT_SOCKET__NLMSG_WRITE }, + { AUDIT_DEL, NETLINK_AUDIT_SOCKET__NLMSG_WRITE }, + { AUDIT_LIST_RULES, NETLINK_AUDIT_SOCKET__NLMSG_READPRIV }, + { AUDIT_ADD_RULE, NETLINK_AUDIT_SOCKET__NLMSG_WRITE }, + { AUDIT_DEL_RULE, NETLINK_AUDIT_SOCKET__NLMSG_WRITE }, + { AUDIT_USER, NETLINK_AUDIT_SOCKET__NLMSG_RELAY }, + { AUDIT_SIGNAL_INFO, NETLINK_AUDIT_SOCKET__NLMSG_READ }, + { AUDIT_TRIM, NETLINK_AUDIT_SOCKET__NLMSG_WRITE }, + { AUDIT_MAKE_EQUIV, NETLINK_AUDIT_SOCKET__NLMSG_WRITE }, + { AUDIT_TTY_GET, NETLINK_AUDIT_SOCKET__NLMSG_READ }, + { AUDIT_TTY_SET, NETLINK_AUDIT_SOCKET__NLMSG_TTY_AUDIT }, + { AUDIT_GET_FEATURE, NETLINK_AUDIT_SOCKET__NLMSG_READ }, + { AUDIT_SET_FEATURE, NETLINK_AUDIT_SOCKET__NLMSG_WRITE }, +}; + + +static int nlmsg_perm(u16 nlmsg_type, u32 *perm, const struct nlmsg_perm *tab, size_t tabsize) +{ + int i, err = -EINVAL; + + for (i = 0; i < tabsize/sizeof(struct nlmsg_perm); i++) + if (nlmsg_type == tab[i].nlmsg_type) { + *perm = tab[i].perm; + err = 0; + break; + } + + return err; +} + +int selinux_nlmsg_lookup(u16 sclass, u16 nlmsg_type, u32 *perm) +{ + int err = 0; + + switch (sclass) { + case SECCLASS_NETLINK_ROUTE_SOCKET: + /* RTM_MAX always points to RTM_SETxxxx, ie RTM_NEWxxx + 3. + * If the BUILD_BUG_ON() below fails you must update the + * structures at the top of this file with the new mappings + * before updating the BUILD_BUG_ON() macro! + */ + BUILD_BUG_ON(RTM_MAX != (RTM_NEWTUNNEL + 3)); + err = nlmsg_perm(nlmsg_type, perm, nlmsg_route_perms, + sizeof(nlmsg_route_perms)); + break; + + case SECCLASS_NETLINK_TCPDIAG_SOCKET: + err = nlmsg_perm(nlmsg_type, perm, nlmsg_tcpdiag_perms, + sizeof(nlmsg_tcpdiag_perms)); + break; + + case SECCLASS_NETLINK_XFRM_SOCKET: + /* If the BUILD_BUG_ON() below fails you must update the + * structures at the top of this file with the new mappings + * before updating the BUILD_BUG_ON() macro! + */ + BUILD_BUG_ON(XFRM_MSG_MAX != XFRM_MSG_GETDEFAULT); + err = nlmsg_perm(nlmsg_type, perm, nlmsg_xfrm_perms, + sizeof(nlmsg_xfrm_perms)); + break; + + case SECCLASS_NETLINK_AUDIT_SOCKET: + if ((nlmsg_type >= AUDIT_FIRST_USER_MSG && + nlmsg_type <= AUDIT_LAST_USER_MSG) || + (nlmsg_type >= AUDIT_FIRST_USER_MSG2 && + nlmsg_type <= AUDIT_LAST_USER_MSG2)) { + *perm = NETLINK_AUDIT_SOCKET__NLMSG_RELAY; + } else { + err = nlmsg_perm(nlmsg_type, perm, nlmsg_audit_perms, + sizeof(nlmsg_audit_perms)); + } + break; + + /* No messaging from userspace, or class unknown/unhandled */ + default: + err = -ENOENT; + break; + } + + return err; +} diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c new file mode 100644 index 000000000..a00d19139 --- /dev/null +++ b/security/selinux/selinuxfs.c @@ -0,0 +1,2261 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Updated: Karl MacMillan <kmacmillan@tresys.com> + * + * Added conditional policy language extensions + * + * Updated: Hewlett-Packard <paul@paul-moore.com> + * + * Added support for the policy capability bitmap + * + * Copyright (C) 2007 Hewlett-Packard Development Company, L.P. + * Copyright (C) 2003 - 2004 Tresys Technology, LLC + * Copyright (C) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com> + */ + +#include <linux/kernel.h> +#include <linux/pagemap.h> +#include <linux/slab.h> +#include <linux/vmalloc.h> +#include <linux/fs.h> +#include <linux/fs_context.h> +#include <linux/mount.h> +#include <linux/mutex.h> +#include <linux/namei.h> +#include <linux/init.h> +#include <linux/string.h> +#include <linux/security.h> +#include <linux/major.h> +#include <linux/seq_file.h> +#include <linux/percpu.h> +#include <linux/audit.h> +#include <linux/uaccess.h> +#include <linux/kobject.h> +#include <linux/ctype.h> + +/* selinuxfs pseudo filesystem for exporting the security policy API. + Based on the proc code and the fs/nfsd/nfsctl.c code. */ + +#include "flask.h" +#include "avc.h" +#include "avc_ss.h" +#include "security.h" +#include "objsec.h" +#include "conditional.h" +#include "ima.h" + +enum sel_inos { + SEL_ROOT_INO = 2, + SEL_LOAD, /* load policy */ + SEL_ENFORCE, /* get or set enforcing status */ + SEL_CONTEXT, /* validate context */ + SEL_ACCESS, /* compute access decision */ + SEL_CREATE, /* compute create labeling decision */ + SEL_RELABEL, /* compute relabeling decision */ + SEL_USER, /* compute reachable user contexts */ + SEL_POLICYVERS, /* return policy version for this kernel */ + SEL_COMMIT_BOOLS, /* commit new boolean values */ + SEL_MLS, /* return if MLS policy is enabled */ + SEL_DISABLE, /* disable SELinux until next reboot */ + SEL_MEMBER, /* compute polyinstantiation membership decision */ + SEL_CHECKREQPROT, /* check requested protection, not kernel-applied one */ + SEL_COMPAT_NET, /* whether to use old compat network packet controls */ + SEL_REJECT_UNKNOWN, /* export unknown reject handling to userspace */ + SEL_DENY_UNKNOWN, /* export unknown deny handling to userspace */ + SEL_STATUS, /* export current status using mmap() */ + SEL_POLICY, /* allow userspace to read the in kernel policy */ + SEL_VALIDATE_TRANS, /* compute validatetrans decision */ + SEL_INO_NEXT, /* The next inode number to use */ +}; + +struct selinux_fs_info { + struct dentry *bool_dir; + unsigned int bool_num; + char **bool_pending_names; + int *bool_pending_values; + struct dentry *class_dir; + unsigned long last_class_ino; + bool policy_opened; + struct dentry *policycap_dir; + unsigned long last_ino; + struct selinux_state *state; + struct super_block *sb; +}; + +static int selinux_fs_info_create(struct super_block *sb) +{ + struct selinux_fs_info *fsi; + + fsi = kzalloc(sizeof(*fsi), GFP_KERNEL); + if (!fsi) + return -ENOMEM; + + fsi->last_ino = SEL_INO_NEXT - 1; + fsi->state = &selinux_state; + fsi->sb = sb; + sb->s_fs_info = fsi; + return 0; +} + +static void selinux_fs_info_free(struct super_block *sb) +{ + struct selinux_fs_info *fsi = sb->s_fs_info; + int i; + + if (fsi) { + for (i = 0; i < fsi->bool_num; i++) + kfree(fsi->bool_pending_names[i]); + kfree(fsi->bool_pending_names); + kfree(fsi->bool_pending_values); + } + kfree(sb->s_fs_info); + sb->s_fs_info = NULL; +} + +#define SEL_INITCON_INO_OFFSET 0x01000000 +#define SEL_BOOL_INO_OFFSET 0x02000000 +#define SEL_CLASS_INO_OFFSET 0x04000000 +#define SEL_POLICYCAP_INO_OFFSET 0x08000000 +#define SEL_INO_MASK 0x00ffffff + +#define BOOL_DIR_NAME "booleans" +#define CLASS_DIR_NAME "class" +#define POLICYCAP_DIR_NAME "policy_capabilities" + +#define TMPBUFLEN 12 +static ssize_t sel_read_enforce(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + struct selinux_fs_info *fsi = file_inode(filp)->i_sb->s_fs_info; + char tmpbuf[TMPBUFLEN]; + ssize_t length; + + length = scnprintf(tmpbuf, TMPBUFLEN, "%d", + enforcing_enabled(fsi->state)); + return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); +} + +#ifdef CONFIG_SECURITY_SELINUX_DEVELOP +static ssize_t sel_write_enforce(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) + +{ + struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info; + struct selinux_state *state = fsi->state; + char *page = NULL; + ssize_t length; + int old_value, new_value; + + if (count >= PAGE_SIZE) + return -ENOMEM; + + /* No partial writes. */ + if (*ppos != 0) + return -EINVAL; + + page = memdup_user_nul(buf, count); + if (IS_ERR(page)) + return PTR_ERR(page); + + length = -EINVAL; + if (sscanf(page, "%d", &new_value) != 1) + goto out; + + new_value = !!new_value; + + old_value = enforcing_enabled(state); + if (new_value != old_value) { + length = avc_has_perm(&selinux_state, + current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__SETENFORCE, + NULL); + if (length) + goto out; + audit_log(audit_context(), GFP_KERNEL, AUDIT_MAC_STATUS, + "enforcing=%d old_enforcing=%d auid=%u ses=%u" + " enabled=1 old-enabled=1 lsm=selinux res=1", + new_value, old_value, + from_kuid(&init_user_ns, audit_get_loginuid(current)), + audit_get_sessionid(current)); + enforcing_set(state, new_value); + if (new_value) + avc_ss_reset(state->avc, 0); + selnl_notify_setenforce(new_value); + selinux_status_update_setenforce(state, new_value); + if (!new_value) + call_blocking_lsm_notifier(LSM_POLICY_CHANGE, NULL); + + selinux_ima_measure_state(state); + } + length = count; +out: + kfree(page); + return length; +} +#else +#define sel_write_enforce NULL +#endif + +static const struct file_operations sel_enforce_ops = { + .read = sel_read_enforce, + .write = sel_write_enforce, + .llseek = generic_file_llseek, +}; + +static ssize_t sel_read_handle_unknown(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + struct selinux_fs_info *fsi = file_inode(filp)->i_sb->s_fs_info; + struct selinux_state *state = fsi->state; + char tmpbuf[TMPBUFLEN]; + ssize_t length; + ino_t ino = file_inode(filp)->i_ino; + int handle_unknown = (ino == SEL_REJECT_UNKNOWN) ? + security_get_reject_unknown(state) : + !security_get_allow_unknown(state); + + length = scnprintf(tmpbuf, TMPBUFLEN, "%d", handle_unknown); + return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); +} + +static const struct file_operations sel_handle_unknown_ops = { + .read = sel_read_handle_unknown, + .llseek = generic_file_llseek, +}; + +static int sel_open_handle_status(struct inode *inode, struct file *filp) +{ + struct selinux_fs_info *fsi = file_inode(filp)->i_sb->s_fs_info; + struct page *status = selinux_kernel_status_page(fsi->state); + + if (!status) + return -ENOMEM; + + filp->private_data = status; + + return 0; +} + +static ssize_t sel_read_handle_status(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + struct page *status = filp->private_data; + + BUG_ON(!status); + + return simple_read_from_buffer(buf, count, ppos, + page_address(status), + sizeof(struct selinux_kernel_status)); +} + +static int sel_mmap_handle_status(struct file *filp, + struct vm_area_struct *vma) +{ + struct page *status = filp->private_data; + unsigned long size = vma->vm_end - vma->vm_start; + + BUG_ON(!status); + + /* only allows one page from the head */ + if (vma->vm_pgoff > 0 || size != PAGE_SIZE) + return -EIO; + /* disallow writable mapping */ + if (vma->vm_flags & VM_WRITE) + return -EPERM; + /* disallow mprotect() turns it into writable */ + vma->vm_flags &= ~VM_MAYWRITE; + + return remap_pfn_range(vma, vma->vm_start, + page_to_pfn(status), + size, vma->vm_page_prot); +} + +static const struct file_operations sel_handle_status_ops = { + .open = sel_open_handle_status, + .read = sel_read_handle_status, + .mmap = sel_mmap_handle_status, + .llseek = generic_file_llseek, +}; + +#ifdef CONFIG_SECURITY_SELINUX_DISABLE +static ssize_t sel_write_disable(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) + +{ + struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info; + char *page; + ssize_t length; + int new_value; + int enforcing; + + /* NOTE: we are now officially considering runtime disable as + * deprecated, and using it will become increasingly painful + * (e.g. sleeping/blocking) as we progress through future + * kernel releases until eventually it is removed + */ + pr_err("SELinux: Runtime disable is deprecated, use selinux=0 on the kernel cmdline.\n"); + pr_err("SELinux: https://github.com/SELinuxProject/selinux-kernel/wiki/DEPRECATE-runtime-disable\n"); + ssleep(5); + + if (count >= PAGE_SIZE) + return -ENOMEM; + + /* No partial writes. */ + if (*ppos != 0) + return -EINVAL; + + page = memdup_user_nul(buf, count); + if (IS_ERR(page)) + return PTR_ERR(page); + + length = -EINVAL; + if (sscanf(page, "%d", &new_value) != 1) + goto out; + + if (new_value) { + enforcing = enforcing_enabled(fsi->state); + length = selinux_disable(fsi->state); + if (length) + goto out; + audit_log(audit_context(), GFP_KERNEL, AUDIT_MAC_STATUS, + "enforcing=%d old_enforcing=%d auid=%u ses=%u" + " enabled=0 old-enabled=1 lsm=selinux res=1", + enforcing, enforcing, + from_kuid(&init_user_ns, audit_get_loginuid(current)), + audit_get_sessionid(current)); + } + + length = count; +out: + kfree(page); + return length; +} +#else +#define sel_write_disable NULL +#endif + +static const struct file_operations sel_disable_ops = { + .write = sel_write_disable, + .llseek = generic_file_llseek, +}; + +static ssize_t sel_read_policyvers(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + char tmpbuf[TMPBUFLEN]; + ssize_t length; + + length = scnprintf(tmpbuf, TMPBUFLEN, "%u", POLICYDB_VERSION_MAX); + return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); +} + +static const struct file_operations sel_policyvers_ops = { + .read = sel_read_policyvers, + .llseek = generic_file_llseek, +}; + +/* declaration for sel_write_load */ +static int sel_make_bools(struct selinux_policy *newpolicy, struct dentry *bool_dir, + unsigned int *bool_num, char ***bool_pending_names, + int **bool_pending_values); +static int sel_make_classes(struct selinux_policy *newpolicy, + struct dentry *class_dir, + unsigned long *last_class_ino); + +/* declaration for sel_make_class_dirs */ +static struct dentry *sel_make_dir(struct dentry *dir, const char *name, + unsigned long *ino); + +/* declaration for sel_make_policy_nodes */ +static struct dentry *sel_make_disconnected_dir(struct super_block *sb, + unsigned long *ino); + +/* declaration for sel_make_policy_nodes */ +static void sel_remove_entries(struct dentry *de); + +static ssize_t sel_read_mls(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + struct selinux_fs_info *fsi = file_inode(filp)->i_sb->s_fs_info; + char tmpbuf[TMPBUFLEN]; + ssize_t length; + + length = scnprintf(tmpbuf, TMPBUFLEN, "%d", + security_mls_enabled(fsi->state)); + return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); +} + +static const struct file_operations sel_mls_ops = { + .read = sel_read_mls, + .llseek = generic_file_llseek, +}; + +struct policy_load_memory { + size_t len; + void *data; +}; + +static int sel_open_policy(struct inode *inode, struct file *filp) +{ + struct selinux_fs_info *fsi = inode->i_sb->s_fs_info; + struct selinux_state *state = fsi->state; + struct policy_load_memory *plm = NULL; + int rc; + + BUG_ON(filp->private_data); + + mutex_lock(&fsi->state->policy_mutex); + + rc = avc_has_perm(&selinux_state, + current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__READ_POLICY, NULL); + if (rc) + goto err; + + rc = -EBUSY; + if (fsi->policy_opened) + goto err; + + rc = -ENOMEM; + plm = kzalloc(sizeof(*plm), GFP_KERNEL); + if (!plm) + goto err; + + rc = security_read_policy(state, &plm->data, &plm->len); + if (rc) + goto err; + + if ((size_t)i_size_read(inode) != plm->len) { + inode_lock(inode); + i_size_write(inode, plm->len); + inode_unlock(inode); + } + + fsi->policy_opened = 1; + + filp->private_data = plm; + + mutex_unlock(&fsi->state->policy_mutex); + + return 0; +err: + mutex_unlock(&fsi->state->policy_mutex); + + if (plm) + vfree(plm->data); + kfree(plm); + return rc; +} + +static int sel_release_policy(struct inode *inode, struct file *filp) +{ + struct selinux_fs_info *fsi = inode->i_sb->s_fs_info; + struct policy_load_memory *plm = filp->private_data; + + BUG_ON(!plm); + + fsi->policy_opened = 0; + + vfree(plm->data); + kfree(plm); + + return 0; +} + +static ssize_t sel_read_policy(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + struct policy_load_memory *plm = filp->private_data; + int ret; + + ret = avc_has_perm(&selinux_state, + current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__READ_POLICY, NULL); + if (ret) + return ret; + + return simple_read_from_buffer(buf, count, ppos, plm->data, plm->len); +} + +static vm_fault_t sel_mmap_policy_fault(struct vm_fault *vmf) +{ + struct policy_load_memory *plm = vmf->vma->vm_file->private_data; + unsigned long offset; + struct page *page; + + if (vmf->flags & (FAULT_FLAG_MKWRITE | FAULT_FLAG_WRITE)) + return VM_FAULT_SIGBUS; + + offset = vmf->pgoff << PAGE_SHIFT; + if (offset >= roundup(plm->len, PAGE_SIZE)) + return VM_FAULT_SIGBUS; + + page = vmalloc_to_page(plm->data + offset); + get_page(page); + + vmf->page = page; + + return 0; +} + +static const struct vm_operations_struct sel_mmap_policy_ops = { + .fault = sel_mmap_policy_fault, + .page_mkwrite = sel_mmap_policy_fault, +}; + +static int sel_mmap_policy(struct file *filp, struct vm_area_struct *vma) +{ + if (vma->vm_flags & VM_SHARED) { + /* do not allow mprotect to make mapping writable */ + vma->vm_flags &= ~VM_MAYWRITE; + + if (vma->vm_flags & VM_WRITE) + return -EACCES; + } + + vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP; + vma->vm_ops = &sel_mmap_policy_ops; + + return 0; +} + +static const struct file_operations sel_policy_ops = { + .open = sel_open_policy, + .read = sel_read_policy, + .mmap = sel_mmap_policy, + .release = sel_release_policy, + .llseek = generic_file_llseek, +}; + +static void sel_remove_old_bool_data(unsigned int bool_num, char **bool_names, + int *bool_values) +{ + u32 i; + + /* bool_dir cleanup */ + for (i = 0; i < bool_num; i++) + kfree(bool_names[i]); + kfree(bool_names); + kfree(bool_values); +} + +static int sel_make_policy_nodes(struct selinux_fs_info *fsi, + struct selinux_policy *newpolicy) +{ + int ret = 0; + struct dentry *tmp_parent, *tmp_bool_dir, *tmp_class_dir, *old_dentry; + unsigned int tmp_bool_num, old_bool_num; + char **tmp_bool_names, **old_bool_names; + int *tmp_bool_values, *old_bool_values; + unsigned long tmp_ino = fsi->last_ino; /* Don't increment last_ino in this function */ + + tmp_parent = sel_make_disconnected_dir(fsi->sb, &tmp_ino); + if (IS_ERR(tmp_parent)) + return PTR_ERR(tmp_parent); + + tmp_ino = fsi->bool_dir->d_inode->i_ino - 1; /* sel_make_dir will increment and set */ + tmp_bool_dir = sel_make_dir(tmp_parent, BOOL_DIR_NAME, &tmp_ino); + if (IS_ERR(tmp_bool_dir)) { + ret = PTR_ERR(tmp_bool_dir); + goto out; + } + + tmp_ino = fsi->class_dir->d_inode->i_ino - 1; /* sel_make_dir will increment and set */ + tmp_class_dir = sel_make_dir(tmp_parent, CLASS_DIR_NAME, &tmp_ino); + if (IS_ERR(tmp_class_dir)) { + ret = PTR_ERR(tmp_class_dir); + goto out; + } + + ret = sel_make_bools(newpolicy, tmp_bool_dir, &tmp_bool_num, + &tmp_bool_names, &tmp_bool_values); + if (ret) + goto out; + + ret = sel_make_classes(newpolicy, tmp_class_dir, + &fsi->last_class_ino); + if (ret) + goto out; + + /* booleans */ + old_dentry = fsi->bool_dir; + lock_rename(tmp_bool_dir, old_dentry); + d_exchange(tmp_bool_dir, fsi->bool_dir); + + old_bool_num = fsi->bool_num; + old_bool_names = fsi->bool_pending_names; + old_bool_values = fsi->bool_pending_values; + + fsi->bool_num = tmp_bool_num; + fsi->bool_pending_names = tmp_bool_names; + fsi->bool_pending_values = tmp_bool_values; + + sel_remove_old_bool_data(old_bool_num, old_bool_names, old_bool_values); + + fsi->bool_dir = tmp_bool_dir; + unlock_rename(tmp_bool_dir, old_dentry); + + /* classes */ + old_dentry = fsi->class_dir; + lock_rename(tmp_class_dir, old_dentry); + d_exchange(tmp_class_dir, fsi->class_dir); + fsi->class_dir = tmp_class_dir; + unlock_rename(tmp_class_dir, old_dentry); + +out: + /* Since the other temporary dirs are children of tmp_parent + * this will handle all the cleanup in the case of a failure before + * the swapover + */ + sel_remove_entries(tmp_parent); + dput(tmp_parent); /* d_genocide() only handles the children */ + + return ret; +} + +static ssize_t sel_write_load(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) + +{ + struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info; + struct selinux_load_state load_state; + ssize_t length; + void *data = NULL; + + mutex_lock(&fsi->state->policy_mutex); + + length = avc_has_perm(&selinux_state, + current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__LOAD_POLICY, NULL); + if (length) + goto out; + + /* No partial writes. */ + length = -EINVAL; + if (*ppos != 0) + goto out; + + length = -ENOMEM; + data = vmalloc(count); + if (!data) + goto out; + + length = -EFAULT; + if (copy_from_user(data, buf, count) != 0) + goto out; + + length = security_load_policy(fsi->state, data, count, &load_state); + if (length) { + pr_warn_ratelimited("SELinux: failed to load policy\n"); + goto out; + } + + length = sel_make_policy_nodes(fsi, load_state.policy); + if (length) { + pr_warn_ratelimited("SELinux: failed to initialize selinuxfs\n"); + selinux_policy_cancel(fsi->state, &load_state); + goto out; + } + + selinux_policy_commit(fsi->state, &load_state); + + length = count; + + audit_log(audit_context(), GFP_KERNEL, AUDIT_MAC_POLICY_LOAD, + "auid=%u ses=%u lsm=selinux res=1", + from_kuid(&init_user_ns, audit_get_loginuid(current)), + audit_get_sessionid(current)); +out: + mutex_unlock(&fsi->state->policy_mutex); + vfree(data); + return length; +} + +static const struct file_operations sel_load_ops = { + .write = sel_write_load, + .llseek = generic_file_llseek, +}; + +static ssize_t sel_write_context(struct file *file, char *buf, size_t size) +{ + struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info; + struct selinux_state *state = fsi->state; + char *canon = NULL; + u32 sid, len; + ssize_t length; + + length = avc_has_perm(&selinux_state, + current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__CHECK_CONTEXT, NULL); + if (length) + goto out; + + length = security_context_to_sid(state, buf, size, &sid, GFP_KERNEL); + if (length) + goto out; + + length = security_sid_to_context(state, sid, &canon, &len); + if (length) + goto out; + + length = -ERANGE; + if (len > SIMPLE_TRANSACTION_LIMIT) { + pr_err("SELinux: %s: context size (%u) exceeds " + "payload max\n", __func__, len); + goto out; + } + + memcpy(buf, canon, len); + length = len; +out: + kfree(canon); + return length; +} + +static ssize_t sel_read_checkreqprot(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + struct selinux_fs_info *fsi = file_inode(filp)->i_sb->s_fs_info; + char tmpbuf[TMPBUFLEN]; + ssize_t length; + + length = scnprintf(tmpbuf, TMPBUFLEN, "%u", + checkreqprot_get(fsi->state)); + return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); +} + +static ssize_t sel_write_checkreqprot(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info; + char *page; + ssize_t length; + unsigned int new_value; + + length = avc_has_perm(&selinux_state, + current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__SETCHECKREQPROT, + NULL); + if (length) + return length; + + if (count >= PAGE_SIZE) + return -ENOMEM; + + /* No partial writes. */ + if (*ppos != 0) + return -EINVAL; + + page = memdup_user_nul(buf, count); + if (IS_ERR(page)) + return PTR_ERR(page); + + length = -EINVAL; + if (sscanf(page, "%u", &new_value) != 1) + goto out; + + if (new_value) { + char comm[sizeof(current->comm)]; + + memcpy(comm, current->comm, sizeof(comm)); + pr_err("SELinux: %s (%d) set checkreqprot to 1. This is deprecated and will be rejected in a future kernel release.\n", + comm, current->pid); + } + + checkreqprot_set(fsi->state, (new_value ? 1 : 0)); + if (new_value) + ssleep(5); + length = count; + + selinux_ima_measure_state(fsi->state); + +out: + kfree(page); + return length; +} +static const struct file_operations sel_checkreqprot_ops = { + .read = sel_read_checkreqprot, + .write = sel_write_checkreqprot, + .llseek = generic_file_llseek, +}; + +static ssize_t sel_write_validatetrans(struct file *file, + const char __user *buf, + size_t count, loff_t *ppos) +{ + struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info; + struct selinux_state *state = fsi->state; + char *oldcon = NULL, *newcon = NULL, *taskcon = NULL; + char *req = NULL; + u32 osid, nsid, tsid; + u16 tclass; + int rc; + + rc = avc_has_perm(&selinux_state, + current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__VALIDATE_TRANS, NULL); + if (rc) + goto out; + + rc = -ENOMEM; + if (count >= PAGE_SIZE) + goto out; + + /* No partial writes. */ + rc = -EINVAL; + if (*ppos != 0) + goto out; + + req = memdup_user_nul(buf, count); + if (IS_ERR(req)) { + rc = PTR_ERR(req); + req = NULL; + goto out; + } + + rc = -ENOMEM; + oldcon = kzalloc(count + 1, GFP_KERNEL); + if (!oldcon) + goto out; + + newcon = kzalloc(count + 1, GFP_KERNEL); + if (!newcon) + goto out; + + taskcon = kzalloc(count + 1, GFP_KERNEL); + if (!taskcon) + goto out; + + rc = -EINVAL; + if (sscanf(req, "%s %s %hu %s", oldcon, newcon, &tclass, taskcon) != 4) + goto out; + + rc = security_context_str_to_sid(state, oldcon, &osid, GFP_KERNEL); + if (rc) + goto out; + + rc = security_context_str_to_sid(state, newcon, &nsid, GFP_KERNEL); + if (rc) + goto out; + + rc = security_context_str_to_sid(state, taskcon, &tsid, GFP_KERNEL); + if (rc) + goto out; + + rc = security_validate_transition_user(state, osid, nsid, tsid, tclass); + if (!rc) + rc = count; +out: + kfree(req); + kfree(oldcon); + kfree(newcon); + kfree(taskcon); + return rc; +} + +static const struct file_operations sel_transition_ops = { + .write = sel_write_validatetrans, + .llseek = generic_file_llseek, +}; + +/* + * Remaining nodes use transaction based IO methods like nfsd/nfsctl.c + */ +static ssize_t sel_write_access(struct file *file, char *buf, size_t size); +static ssize_t sel_write_create(struct file *file, char *buf, size_t size); +static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size); +static ssize_t sel_write_user(struct file *file, char *buf, size_t size); +static ssize_t sel_write_member(struct file *file, char *buf, size_t size); + +static ssize_t (*const write_op[])(struct file *, char *, size_t) = { + [SEL_ACCESS] = sel_write_access, + [SEL_CREATE] = sel_write_create, + [SEL_RELABEL] = sel_write_relabel, + [SEL_USER] = sel_write_user, + [SEL_MEMBER] = sel_write_member, + [SEL_CONTEXT] = sel_write_context, +}; + +static ssize_t selinux_transaction_write(struct file *file, const char __user *buf, size_t size, loff_t *pos) +{ + ino_t ino = file_inode(file)->i_ino; + char *data; + ssize_t rv; + + if (ino >= ARRAY_SIZE(write_op) || !write_op[ino]) + return -EINVAL; + + data = simple_transaction_get(file, buf, size); + if (IS_ERR(data)) + return PTR_ERR(data); + + rv = write_op[ino](file, data, size); + if (rv > 0) { + simple_transaction_set(file, rv); + rv = size; + } + return rv; +} + +static const struct file_operations transaction_ops = { + .write = selinux_transaction_write, + .read = simple_transaction_read, + .release = simple_transaction_release, + .llseek = generic_file_llseek, +}; + +/* + * payload - write methods + * If the method has a response, the response should be put in buf, + * and the length returned. Otherwise return 0 or and -error. + */ + +static ssize_t sel_write_access(struct file *file, char *buf, size_t size) +{ + struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info; + struct selinux_state *state = fsi->state; + char *scon = NULL, *tcon = NULL; + u32 ssid, tsid; + u16 tclass; + struct av_decision avd; + ssize_t length; + + length = avc_has_perm(&selinux_state, + current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__COMPUTE_AV, NULL); + if (length) + goto out; + + length = -ENOMEM; + scon = kzalloc(size + 1, GFP_KERNEL); + if (!scon) + goto out; + + length = -ENOMEM; + tcon = kzalloc(size + 1, GFP_KERNEL); + if (!tcon) + goto out; + + length = -EINVAL; + if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3) + goto out; + + length = security_context_str_to_sid(state, scon, &ssid, GFP_KERNEL); + if (length) + goto out; + + length = security_context_str_to_sid(state, tcon, &tsid, GFP_KERNEL); + if (length) + goto out; + + security_compute_av_user(state, ssid, tsid, tclass, &avd); + + length = scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, + "%x %x %x %x %u %x", + avd.allowed, 0xffffffff, + avd.auditallow, avd.auditdeny, + avd.seqno, avd.flags); +out: + kfree(tcon); + kfree(scon); + return length; +} + +static ssize_t sel_write_create(struct file *file, char *buf, size_t size) +{ + struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info; + struct selinux_state *state = fsi->state; + char *scon = NULL, *tcon = NULL; + char *namebuf = NULL, *objname = NULL; + u32 ssid, tsid, newsid; + u16 tclass; + ssize_t length; + char *newcon = NULL; + u32 len; + int nargs; + + length = avc_has_perm(&selinux_state, + current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__COMPUTE_CREATE, + NULL); + if (length) + goto out; + + length = -ENOMEM; + scon = kzalloc(size + 1, GFP_KERNEL); + if (!scon) + goto out; + + length = -ENOMEM; + tcon = kzalloc(size + 1, GFP_KERNEL); + if (!tcon) + goto out; + + length = -ENOMEM; + namebuf = kzalloc(size + 1, GFP_KERNEL); + if (!namebuf) + goto out; + + length = -EINVAL; + nargs = sscanf(buf, "%s %s %hu %s", scon, tcon, &tclass, namebuf); + if (nargs < 3 || nargs > 4) + goto out; + if (nargs == 4) { + /* + * If and when the name of new object to be queried contains + * either whitespace or multibyte characters, they shall be + * encoded based on the percentage-encoding rule. + * If not encoded, the sscanf logic picks up only left-half + * of the supplied name; splitted by a whitespace unexpectedly. + */ + char *r, *w; + int c1, c2; + + r = w = namebuf; + do { + c1 = *r++; + if (c1 == '+') + c1 = ' '; + else if (c1 == '%') { + c1 = hex_to_bin(*r++); + if (c1 < 0) + goto out; + c2 = hex_to_bin(*r++); + if (c2 < 0) + goto out; + c1 = (c1 << 4) | c2; + } + *w++ = c1; + } while (c1 != '\0'); + + objname = namebuf; + } + + length = security_context_str_to_sid(state, scon, &ssid, GFP_KERNEL); + if (length) + goto out; + + length = security_context_str_to_sid(state, tcon, &tsid, GFP_KERNEL); + if (length) + goto out; + + length = security_transition_sid_user(state, ssid, tsid, tclass, + objname, &newsid); + if (length) + goto out; + + length = security_sid_to_context(state, newsid, &newcon, &len); + if (length) + goto out; + + length = -ERANGE; + if (len > SIMPLE_TRANSACTION_LIMIT) { + pr_err("SELinux: %s: context size (%u) exceeds " + "payload max\n", __func__, len); + goto out; + } + + memcpy(buf, newcon, len); + length = len; +out: + kfree(newcon); + kfree(namebuf); + kfree(tcon); + kfree(scon); + return length; +} + +static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size) +{ + struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info; + struct selinux_state *state = fsi->state; + char *scon = NULL, *tcon = NULL; + u32 ssid, tsid, newsid; + u16 tclass; + ssize_t length; + char *newcon = NULL; + u32 len; + + length = avc_has_perm(&selinux_state, + current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__COMPUTE_RELABEL, + NULL); + if (length) + goto out; + + length = -ENOMEM; + scon = kzalloc(size + 1, GFP_KERNEL); + if (!scon) + goto out; + + length = -ENOMEM; + tcon = kzalloc(size + 1, GFP_KERNEL); + if (!tcon) + goto out; + + length = -EINVAL; + if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3) + goto out; + + length = security_context_str_to_sid(state, scon, &ssid, GFP_KERNEL); + if (length) + goto out; + + length = security_context_str_to_sid(state, tcon, &tsid, GFP_KERNEL); + if (length) + goto out; + + length = security_change_sid(state, ssid, tsid, tclass, &newsid); + if (length) + goto out; + + length = security_sid_to_context(state, newsid, &newcon, &len); + if (length) + goto out; + + length = -ERANGE; + if (len > SIMPLE_TRANSACTION_LIMIT) + goto out; + + memcpy(buf, newcon, len); + length = len; +out: + kfree(newcon); + kfree(tcon); + kfree(scon); + return length; +} + +static ssize_t sel_write_user(struct file *file, char *buf, size_t size) +{ + struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info; + struct selinux_state *state = fsi->state; + char *con = NULL, *user = NULL, *ptr; + u32 sid, *sids = NULL; + ssize_t length; + char *newcon; + int i, rc; + u32 len, nsids; + + length = avc_has_perm(&selinux_state, + current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__COMPUTE_USER, + NULL); + if (length) + goto out; + + length = -ENOMEM; + con = kzalloc(size + 1, GFP_KERNEL); + if (!con) + goto out; + + length = -ENOMEM; + user = kzalloc(size + 1, GFP_KERNEL); + if (!user) + goto out; + + length = -EINVAL; + if (sscanf(buf, "%s %s", con, user) != 2) + goto out; + + length = security_context_str_to_sid(state, con, &sid, GFP_KERNEL); + if (length) + goto out; + + length = security_get_user_sids(state, sid, user, &sids, &nsids); + if (length) + goto out; + + length = sprintf(buf, "%u", nsids) + 1; + ptr = buf + length; + for (i = 0; i < nsids; i++) { + rc = security_sid_to_context(state, sids[i], &newcon, &len); + if (rc) { + length = rc; + goto out; + } + if ((length + len) >= SIMPLE_TRANSACTION_LIMIT) { + kfree(newcon); + length = -ERANGE; + goto out; + } + memcpy(ptr, newcon, len); + kfree(newcon); + ptr += len; + length += len; + } +out: + kfree(sids); + kfree(user); + kfree(con); + return length; +} + +static ssize_t sel_write_member(struct file *file, char *buf, size_t size) +{ + struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info; + struct selinux_state *state = fsi->state; + char *scon = NULL, *tcon = NULL; + u32 ssid, tsid, newsid; + u16 tclass; + ssize_t length; + char *newcon = NULL; + u32 len; + + length = avc_has_perm(&selinux_state, + current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__COMPUTE_MEMBER, + NULL); + if (length) + goto out; + + length = -ENOMEM; + scon = kzalloc(size + 1, GFP_KERNEL); + if (!scon) + goto out; + + length = -ENOMEM; + tcon = kzalloc(size + 1, GFP_KERNEL); + if (!tcon) + goto out; + + length = -EINVAL; + if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3) + goto out; + + length = security_context_str_to_sid(state, scon, &ssid, GFP_KERNEL); + if (length) + goto out; + + length = security_context_str_to_sid(state, tcon, &tsid, GFP_KERNEL); + if (length) + goto out; + + length = security_member_sid(state, ssid, tsid, tclass, &newsid); + if (length) + goto out; + + length = security_sid_to_context(state, newsid, &newcon, &len); + if (length) + goto out; + + length = -ERANGE; + if (len > SIMPLE_TRANSACTION_LIMIT) { + pr_err("SELinux: %s: context size (%u) exceeds " + "payload max\n", __func__, len); + goto out; + } + + memcpy(buf, newcon, len); + length = len; +out: + kfree(newcon); + kfree(tcon); + kfree(scon); + return length; +} + +static struct inode *sel_make_inode(struct super_block *sb, int mode) +{ + struct inode *ret = new_inode(sb); + + if (ret) { + ret->i_mode = mode; + ret->i_atime = ret->i_mtime = ret->i_ctime = current_time(ret); + } + return ret; +} + +static ssize_t sel_read_bool(struct file *filep, char __user *buf, + size_t count, loff_t *ppos) +{ + struct selinux_fs_info *fsi = file_inode(filep)->i_sb->s_fs_info; + char *page = NULL; + ssize_t length; + ssize_t ret; + int cur_enforcing; + unsigned index = file_inode(filep)->i_ino & SEL_INO_MASK; + const char *name = filep->f_path.dentry->d_name.name; + + mutex_lock(&fsi->state->policy_mutex); + + ret = -EINVAL; + if (index >= fsi->bool_num || strcmp(name, + fsi->bool_pending_names[index])) + goto out_unlock; + + ret = -ENOMEM; + page = (char *)get_zeroed_page(GFP_KERNEL); + if (!page) + goto out_unlock; + + cur_enforcing = security_get_bool_value(fsi->state, index); + if (cur_enforcing < 0) { + ret = cur_enforcing; + goto out_unlock; + } + length = scnprintf(page, PAGE_SIZE, "%d %d", cur_enforcing, + fsi->bool_pending_values[index]); + mutex_unlock(&fsi->state->policy_mutex); + ret = simple_read_from_buffer(buf, count, ppos, page, length); +out_free: + free_page((unsigned long)page); + return ret; + +out_unlock: + mutex_unlock(&fsi->state->policy_mutex); + goto out_free; +} + +static ssize_t sel_write_bool(struct file *filep, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct selinux_fs_info *fsi = file_inode(filep)->i_sb->s_fs_info; + char *page = NULL; + ssize_t length; + int new_value; + unsigned index = file_inode(filep)->i_ino & SEL_INO_MASK; + const char *name = filep->f_path.dentry->d_name.name; + + if (count >= PAGE_SIZE) + return -ENOMEM; + + /* No partial writes. */ + if (*ppos != 0) + return -EINVAL; + + page = memdup_user_nul(buf, count); + if (IS_ERR(page)) + return PTR_ERR(page); + + mutex_lock(&fsi->state->policy_mutex); + + length = avc_has_perm(&selinux_state, + current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__SETBOOL, + NULL); + if (length) + goto out; + + length = -EINVAL; + if (index >= fsi->bool_num || strcmp(name, + fsi->bool_pending_names[index])) + goto out; + + length = -EINVAL; + if (sscanf(page, "%d", &new_value) != 1) + goto out; + + if (new_value) + new_value = 1; + + fsi->bool_pending_values[index] = new_value; + length = count; + +out: + mutex_unlock(&fsi->state->policy_mutex); + kfree(page); + return length; +} + +static const struct file_operations sel_bool_ops = { + .read = sel_read_bool, + .write = sel_write_bool, + .llseek = generic_file_llseek, +}; + +static ssize_t sel_commit_bools_write(struct file *filep, + const char __user *buf, + size_t count, loff_t *ppos) +{ + struct selinux_fs_info *fsi = file_inode(filep)->i_sb->s_fs_info; + char *page = NULL; + ssize_t length; + int new_value; + + if (count >= PAGE_SIZE) + return -ENOMEM; + + /* No partial writes. */ + if (*ppos != 0) + return -EINVAL; + + page = memdup_user_nul(buf, count); + if (IS_ERR(page)) + return PTR_ERR(page); + + mutex_lock(&fsi->state->policy_mutex); + + length = avc_has_perm(&selinux_state, + current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__SETBOOL, + NULL); + if (length) + goto out; + + length = -EINVAL; + if (sscanf(page, "%d", &new_value) != 1) + goto out; + + length = 0; + if (new_value && fsi->bool_pending_values) + length = security_set_bools(fsi->state, fsi->bool_num, + fsi->bool_pending_values); + + if (!length) + length = count; + +out: + mutex_unlock(&fsi->state->policy_mutex); + kfree(page); + return length; +} + +static const struct file_operations sel_commit_bools_ops = { + .write = sel_commit_bools_write, + .llseek = generic_file_llseek, +}; + +static void sel_remove_entries(struct dentry *de) +{ + d_genocide(de); + shrink_dcache_parent(de); +} + +static int sel_make_bools(struct selinux_policy *newpolicy, struct dentry *bool_dir, + unsigned int *bool_num, char ***bool_pending_names, + int **bool_pending_values) +{ + int ret; + ssize_t len; + struct dentry *dentry = NULL; + struct inode *inode = NULL; + struct inode_security_struct *isec; + char **names = NULL, *page; + u32 i, num; + int *values = NULL; + u32 sid; + + ret = -ENOMEM; + page = (char *)get_zeroed_page(GFP_KERNEL); + if (!page) + goto out; + + ret = security_get_bools(newpolicy, &num, &names, &values); + if (ret) + goto out; + + for (i = 0; i < num; i++) { + ret = -ENOMEM; + dentry = d_alloc_name(bool_dir, names[i]); + if (!dentry) + goto out; + + ret = -ENOMEM; + inode = sel_make_inode(bool_dir->d_sb, S_IFREG | S_IRUGO | S_IWUSR); + if (!inode) { + dput(dentry); + goto out; + } + + ret = -ENAMETOOLONG; + len = snprintf(page, PAGE_SIZE, "/%s/%s", BOOL_DIR_NAME, names[i]); + if (len >= PAGE_SIZE) { + dput(dentry); + iput(inode); + goto out; + } + + isec = selinux_inode(inode); + ret = selinux_policy_genfs_sid(newpolicy, "selinuxfs", page, + SECCLASS_FILE, &sid); + if (ret) { + pr_warn_ratelimited("SELinux: no sid found, defaulting to security isid for %s\n", + page); + sid = SECINITSID_SECURITY; + } + + isec->sid = sid; + isec->initialized = LABEL_INITIALIZED; + inode->i_fop = &sel_bool_ops; + inode->i_ino = i|SEL_BOOL_INO_OFFSET; + d_add(dentry, inode); + } + *bool_num = num; + *bool_pending_names = names; + *bool_pending_values = values; + + free_page((unsigned long)page); + return 0; +out: + free_page((unsigned long)page); + + if (names) { + for (i = 0; i < num; i++) + kfree(names[i]); + kfree(names); + } + kfree(values); + sel_remove_entries(bool_dir); + + return ret; +} + +static ssize_t sel_read_avc_cache_threshold(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + struct selinux_fs_info *fsi = file_inode(filp)->i_sb->s_fs_info; + struct selinux_state *state = fsi->state; + char tmpbuf[TMPBUFLEN]; + ssize_t length; + + length = scnprintf(tmpbuf, TMPBUFLEN, "%u", + avc_get_cache_threshold(state->avc)); + return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); +} + +static ssize_t sel_write_avc_cache_threshold(struct file *file, + const char __user *buf, + size_t count, loff_t *ppos) + +{ + struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info; + struct selinux_state *state = fsi->state; + char *page; + ssize_t ret; + unsigned int new_value; + + ret = avc_has_perm(&selinux_state, + current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__SETSECPARAM, + NULL); + if (ret) + return ret; + + if (count >= PAGE_SIZE) + return -ENOMEM; + + /* No partial writes. */ + if (*ppos != 0) + return -EINVAL; + + page = memdup_user_nul(buf, count); + if (IS_ERR(page)) + return PTR_ERR(page); + + ret = -EINVAL; + if (sscanf(page, "%u", &new_value) != 1) + goto out; + + avc_set_cache_threshold(state->avc, new_value); + + ret = count; +out: + kfree(page); + return ret; +} + +static ssize_t sel_read_avc_hash_stats(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + struct selinux_fs_info *fsi = file_inode(filp)->i_sb->s_fs_info; + struct selinux_state *state = fsi->state; + char *page; + ssize_t length; + + page = (char *)__get_free_page(GFP_KERNEL); + if (!page) + return -ENOMEM; + + length = avc_get_hash_stats(state->avc, page); + if (length >= 0) + length = simple_read_from_buffer(buf, count, ppos, page, length); + free_page((unsigned long)page); + + return length; +} + +static ssize_t sel_read_sidtab_hash_stats(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + struct selinux_fs_info *fsi = file_inode(filp)->i_sb->s_fs_info; + struct selinux_state *state = fsi->state; + char *page; + ssize_t length; + + page = (char *)__get_free_page(GFP_KERNEL); + if (!page) + return -ENOMEM; + + length = security_sidtab_hash_stats(state, page); + if (length >= 0) + length = simple_read_from_buffer(buf, count, ppos, page, + length); + free_page((unsigned long)page); + + return length; +} + +static const struct file_operations sel_sidtab_hash_stats_ops = { + .read = sel_read_sidtab_hash_stats, + .llseek = generic_file_llseek, +}; + +static const struct file_operations sel_avc_cache_threshold_ops = { + .read = sel_read_avc_cache_threshold, + .write = sel_write_avc_cache_threshold, + .llseek = generic_file_llseek, +}; + +static const struct file_operations sel_avc_hash_stats_ops = { + .read = sel_read_avc_hash_stats, + .llseek = generic_file_llseek, +}; + +#ifdef CONFIG_SECURITY_SELINUX_AVC_STATS +static struct avc_cache_stats *sel_avc_get_stat_idx(loff_t *idx) +{ + int cpu; + + for (cpu = *idx; cpu < nr_cpu_ids; ++cpu) { + if (!cpu_possible(cpu)) + continue; + *idx = cpu + 1; + return &per_cpu(avc_cache_stats, cpu); + } + (*idx)++; + return NULL; +} + +static void *sel_avc_stats_seq_start(struct seq_file *seq, loff_t *pos) +{ + loff_t n = *pos - 1; + + if (*pos == 0) + return SEQ_START_TOKEN; + + return sel_avc_get_stat_idx(&n); +} + +static void *sel_avc_stats_seq_next(struct seq_file *seq, void *v, loff_t *pos) +{ + return sel_avc_get_stat_idx(pos); +} + +static int sel_avc_stats_seq_show(struct seq_file *seq, void *v) +{ + struct avc_cache_stats *st = v; + + if (v == SEQ_START_TOKEN) { + seq_puts(seq, + "lookups hits misses allocations reclaims frees\n"); + } else { + unsigned int lookups = st->lookups; + unsigned int misses = st->misses; + unsigned int hits = lookups - misses; + seq_printf(seq, "%u %u %u %u %u %u\n", lookups, + hits, misses, st->allocations, + st->reclaims, st->frees); + } + return 0; +} + +static void sel_avc_stats_seq_stop(struct seq_file *seq, void *v) +{ } + +static const struct seq_operations sel_avc_cache_stats_seq_ops = { + .start = sel_avc_stats_seq_start, + .next = sel_avc_stats_seq_next, + .show = sel_avc_stats_seq_show, + .stop = sel_avc_stats_seq_stop, +}; + +static int sel_open_avc_cache_stats(struct inode *inode, struct file *file) +{ + return seq_open(file, &sel_avc_cache_stats_seq_ops); +} + +static const struct file_operations sel_avc_cache_stats_ops = { + .open = sel_open_avc_cache_stats, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; +#endif + +static int sel_make_avc_files(struct dentry *dir) +{ + struct super_block *sb = dir->d_sb; + struct selinux_fs_info *fsi = sb->s_fs_info; + int i; + static const struct tree_descr files[] = { + { "cache_threshold", + &sel_avc_cache_threshold_ops, S_IRUGO|S_IWUSR }, + { "hash_stats", &sel_avc_hash_stats_ops, S_IRUGO }, +#ifdef CONFIG_SECURITY_SELINUX_AVC_STATS + { "cache_stats", &sel_avc_cache_stats_ops, S_IRUGO }, +#endif + }; + + for (i = 0; i < ARRAY_SIZE(files); i++) { + struct inode *inode; + struct dentry *dentry; + + dentry = d_alloc_name(dir, files[i].name); + if (!dentry) + return -ENOMEM; + + inode = sel_make_inode(dir->d_sb, S_IFREG|files[i].mode); + if (!inode) { + dput(dentry); + return -ENOMEM; + } + + inode->i_fop = files[i].ops; + inode->i_ino = ++fsi->last_ino; + d_add(dentry, inode); + } + + return 0; +} + +static int sel_make_ss_files(struct dentry *dir) +{ + struct super_block *sb = dir->d_sb; + struct selinux_fs_info *fsi = sb->s_fs_info; + int i; + static struct tree_descr files[] = { + { "sidtab_hash_stats", &sel_sidtab_hash_stats_ops, S_IRUGO }, + }; + + for (i = 0; i < ARRAY_SIZE(files); i++) { + struct inode *inode; + struct dentry *dentry; + + dentry = d_alloc_name(dir, files[i].name); + if (!dentry) + return -ENOMEM; + + inode = sel_make_inode(dir->d_sb, S_IFREG|files[i].mode); + if (!inode) { + dput(dentry); + return -ENOMEM; + } + + inode->i_fop = files[i].ops; + inode->i_ino = ++fsi->last_ino; + d_add(dentry, inode); + } + + return 0; +} + +static ssize_t sel_read_initcon(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info; + char *con; + u32 sid, len; + ssize_t ret; + + sid = file_inode(file)->i_ino&SEL_INO_MASK; + ret = security_sid_to_context(fsi->state, sid, &con, &len); + if (ret) + return ret; + + ret = simple_read_from_buffer(buf, count, ppos, con, len); + kfree(con); + return ret; +} + +static const struct file_operations sel_initcon_ops = { + .read = sel_read_initcon, + .llseek = generic_file_llseek, +}; + +static int sel_make_initcon_files(struct dentry *dir) +{ + int i; + + for (i = 1; i <= SECINITSID_NUM; i++) { + struct inode *inode; + struct dentry *dentry; + const char *s = security_get_initial_sid_context(i); + + if (!s) + continue; + dentry = d_alloc_name(dir, s); + if (!dentry) + return -ENOMEM; + + inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO); + if (!inode) { + dput(dentry); + return -ENOMEM; + } + + inode->i_fop = &sel_initcon_ops; + inode->i_ino = i|SEL_INITCON_INO_OFFSET; + d_add(dentry, inode); + } + + return 0; +} + +static inline unsigned long sel_class_to_ino(u16 class) +{ + return (class * (SEL_VEC_MAX + 1)) | SEL_CLASS_INO_OFFSET; +} + +static inline u16 sel_ino_to_class(unsigned long ino) +{ + return (ino & SEL_INO_MASK) / (SEL_VEC_MAX + 1); +} + +static inline unsigned long sel_perm_to_ino(u16 class, u32 perm) +{ + return (class * (SEL_VEC_MAX + 1) + perm) | SEL_CLASS_INO_OFFSET; +} + +static inline u32 sel_ino_to_perm(unsigned long ino) +{ + return (ino & SEL_INO_MASK) % (SEL_VEC_MAX + 1); +} + +static ssize_t sel_read_class(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + unsigned long ino = file_inode(file)->i_ino; + char res[TMPBUFLEN]; + ssize_t len = scnprintf(res, sizeof(res), "%d", sel_ino_to_class(ino)); + return simple_read_from_buffer(buf, count, ppos, res, len); +} + +static const struct file_operations sel_class_ops = { + .read = sel_read_class, + .llseek = generic_file_llseek, +}; + +static ssize_t sel_read_perm(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + unsigned long ino = file_inode(file)->i_ino; + char res[TMPBUFLEN]; + ssize_t len = scnprintf(res, sizeof(res), "%d", sel_ino_to_perm(ino)); + return simple_read_from_buffer(buf, count, ppos, res, len); +} + +static const struct file_operations sel_perm_ops = { + .read = sel_read_perm, + .llseek = generic_file_llseek, +}; + +static ssize_t sel_read_policycap(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info; + int value; + char tmpbuf[TMPBUFLEN]; + ssize_t length; + unsigned long i_ino = file_inode(file)->i_ino; + + value = security_policycap_supported(fsi->state, i_ino & SEL_INO_MASK); + length = scnprintf(tmpbuf, TMPBUFLEN, "%d", value); + + return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); +} + +static const struct file_operations sel_policycap_ops = { + .read = sel_read_policycap, + .llseek = generic_file_llseek, +}; + +static int sel_make_perm_files(struct selinux_policy *newpolicy, + char *objclass, int classvalue, + struct dentry *dir) +{ + int i, rc, nperms; + char **perms; + + rc = security_get_permissions(newpolicy, objclass, &perms, &nperms); + if (rc) + return rc; + + for (i = 0; i < nperms; i++) { + struct inode *inode; + struct dentry *dentry; + + rc = -ENOMEM; + dentry = d_alloc_name(dir, perms[i]); + if (!dentry) + goto out; + + rc = -ENOMEM; + inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO); + if (!inode) { + dput(dentry); + goto out; + } + + inode->i_fop = &sel_perm_ops; + /* i+1 since perm values are 1-indexed */ + inode->i_ino = sel_perm_to_ino(classvalue, i + 1); + d_add(dentry, inode); + } + rc = 0; +out: + for (i = 0; i < nperms; i++) + kfree(perms[i]); + kfree(perms); + return rc; +} + +static int sel_make_class_dir_entries(struct selinux_policy *newpolicy, + char *classname, int index, + struct dentry *dir) +{ + struct super_block *sb = dir->d_sb; + struct selinux_fs_info *fsi = sb->s_fs_info; + struct dentry *dentry = NULL; + struct inode *inode = NULL; + + dentry = d_alloc_name(dir, "index"); + if (!dentry) + return -ENOMEM; + + inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO); + if (!inode) { + dput(dentry); + return -ENOMEM; + } + + inode->i_fop = &sel_class_ops; + inode->i_ino = sel_class_to_ino(index); + d_add(dentry, inode); + + dentry = sel_make_dir(dir, "perms", &fsi->last_class_ino); + if (IS_ERR(dentry)) + return PTR_ERR(dentry); + + return sel_make_perm_files(newpolicy, classname, index, dentry); +} + +static int sel_make_classes(struct selinux_policy *newpolicy, + struct dentry *class_dir, + unsigned long *last_class_ino) +{ + + int rc, nclasses, i; + char **classes; + + rc = security_get_classes(newpolicy, &classes, &nclasses); + if (rc) + return rc; + + /* +2 since classes are 1-indexed */ + *last_class_ino = sel_class_to_ino(nclasses + 2); + + for (i = 0; i < nclasses; i++) { + struct dentry *class_name_dir; + + class_name_dir = sel_make_dir(class_dir, classes[i], + last_class_ino); + if (IS_ERR(class_name_dir)) { + rc = PTR_ERR(class_name_dir); + goto out; + } + + /* i+1 since class values are 1-indexed */ + rc = sel_make_class_dir_entries(newpolicy, classes[i], i + 1, + class_name_dir); + if (rc) + goto out; + } + rc = 0; +out: + for (i = 0; i < nclasses; i++) + kfree(classes[i]); + kfree(classes); + return rc; +} + +static int sel_make_policycap(struct selinux_fs_info *fsi) +{ + unsigned int iter; + struct dentry *dentry = NULL; + struct inode *inode = NULL; + + for (iter = 0; iter <= POLICYDB_CAP_MAX; iter++) { + if (iter < ARRAY_SIZE(selinux_policycap_names)) + dentry = d_alloc_name(fsi->policycap_dir, + selinux_policycap_names[iter]); + else + dentry = d_alloc_name(fsi->policycap_dir, "unknown"); + + if (dentry == NULL) + return -ENOMEM; + + inode = sel_make_inode(fsi->sb, S_IFREG | 0444); + if (inode == NULL) { + dput(dentry); + return -ENOMEM; + } + + inode->i_fop = &sel_policycap_ops; + inode->i_ino = iter | SEL_POLICYCAP_INO_OFFSET; + d_add(dentry, inode); + } + + return 0; +} + +static struct dentry *sel_make_dir(struct dentry *dir, const char *name, + unsigned long *ino) +{ + struct dentry *dentry = d_alloc_name(dir, name); + struct inode *inode; + + if (!dentry) + return ERR_PTR(-ENOMEM); + + inode = sel_make_inode(dir->d_sb, S_IFDIR | S_IRUGO | S_IXUGO); + if (!inode) { + dput(dentry); + return ERR_PTR(-ENOMEM); + } + + inode->i_op = &simple_dir_inode_operations; + inode->i_fop = &simple_dir_operations; + inode->i_ino = ++(*ino); + /* directory inodes start off with i_nlink == 2 (for "." entry) */ + inc_nlink(inode); + d_add(dentry, inode); + /* bump link count on parent directory, too */ + inc_nlink(d_inode(dir)); + + return dentry; +} + +static struct dentry *sel_make_disconnected_dir(struct super_block *sb, + unsigned long *ino) +{ + struct inode *inode = sel_make_inode(sb, S_IFDIR | S_IRUGO | S_IXUGO); + + if (!inode) + return ERR_PTR(-ENOMEM); + + inode->i_op = &simple_dir_inode_operations; + inode->i_fop = &simple_dir_operations; + inode->i_ino = ++(*ino); + /* directory inodes start off with i_nlink == 2 (for "." entry) */ + inc_nlink(inode); + return d_obtain_alias(inode); +} + +#define NULL_FILE_NAME "null" + +static int sel_fill_super(struct super_block *sb, struct fs_context *fc) +{ + struct selinux_fs_info *fsi; + int ret; + struct dentry *dentry; + struct inode *inode; + struct inode_security_struct *isec; + + static const struct tree_descr selinux_files[] = { + [SEL_LOAD] = {"load", &sel_load_ops, S_IRUSR|S_IWUSR}, + [SEL_ENFORCE] = {"enforce", &sel_enforce_ops, S_IRUGO|S_IWUSR}, + [SEL_CONTEXT] = {"context", &transaction_ops, S_IRUGO|S_IWUGO}, + [SEL_ACCESS] = {"access", &transaction_ops, S_IRUGO|S_IWUGO}, + [SEL_CREATE] = {"create", &transaction_ops, S_IRUGO|S_IWUGO}, + [SEL_RELABEL] = {"relabel", &transaction_ops, S_IRUGO|S_IWUGO}, + [SEL_USER] = {"user", &transaction_ops, S_IRUGO|S_IWUGO}, + [SEL_POLICYVERS] = {"policyvers", &sel_policyvers_ops, S_IRUGO}, + [SEL_COMMIT_BOOLS] = {"commit_pending_bools", &sel_commit_bools_ops, S_IWUSR}, + [SEL_MLS] = {"mls", &sel_mls_ops, S_IRUGO}, + [SEL_DISABLE] = {"disable", &sel_disable_ops, S_IWUSR}, + [SEL_MEMBER] = {"member", &transaction_ops, S_IRUGO|S_IWUGO}, + [SEL_CHECKREQPROT] = {"checkreqprot", &sel_checkreqprot_ops, S_IRUGO|S_IWUSR}, + [SEL_REJECT_UNKNOWN] = {"reject_unknown", &sel_handle_unknown_ops, S_IRUGO}, + [SEL_DENY_UNKNOWN] = {"deny_unknown", &sel_handle_unknown_ops, S_IRUGO}, + [SEL_STATUS] = {"status", &sel_handle_status_ops, S_IRUGO}, + [SEL_POLICY] = {"policy", &sel_policy_ops, S_IRUGO}, + [SEL_VALIDATE_TRANS] = {"validatetrans", &sel_transition_ops, + S_IWUGO}, + /* last one */ {""} + }; + + ret = selinux_fs_info_create(sb); + if (ret) + goto err; + + ret = simple_fill_super(sb, SELINUX_MAGIC, selinux_files); + if (ret) + goto err; + + fsi = sb->s_fs_info; + fsi->bool_dir = sel_make_dir(sb->s_root, BOOL_DIR_NAME, &fsi->last_ino); + if (IS_ERR(fsi->bool_dir)) { + ret = PTR_ERR(fsi->bool_dir); + fsi->bool_dir = NULL; + goto err; + } + + ret = -ENOMEM; + dentry = d_alloc_name(sb->s_root, NULL_FILE_NAME); + if (!dentry) + goto err; + + ret = -ENOMEM; + inode = sel_make_inode(sb, S_IFCHR | S_IRUGO | S_IWUGO); + if (!inode) { + dput(dentry); + goto err; + } + + inode->i_ino = ++fsi->last_ino; + isec = selinux_inode(inode); + isec->sid = SECINITSID_DEVNULL; + isec->sclass = SECCLASS_CHR_FILE; + isec->initialized = LABEL_INITIALIZED; + + init_special_inode(inode, S_IFCHR | S_IRUGO | S_IWUGO, MKDEV(MEM_MAJOR, 3)); + d_add(dentry, inode); + + dentry = sel_make_dir(sb->s_root, "avc", &fsi->last_ino); + if (IS_ERR(dentry)) { + ret = PTR_ERR(dentry); + goto err; + } + + ret = sel_make_avc_files(dentry); + if (ret) + goto err; + + dentry = sel_make_dir(sb->s_root, "ss", &fsi->last_ino); + if (IS_ERR(dentry)) { + ret = PTR_ERR(dentry); + goto err; + } + + ret = sel_make_ss_files(dentry); + if (ret) + goto err; + + dentry = sel_make_dir(sb->s_root, "initial_contexts", &fsi->last_ino); + if (IS_ERR(dentry)) { + ret = PTR_ERR(dentry); + goto err; + } + + ret = sel_make_initcon_files(dentry); + if (ret) + goto err; + + fsi->class_dir = sel_make_dir(sb->s_root, CLASS_DIR_NAME, &fsi->last_ino); + if (IS_ERR(fsi->class_dir)) { + ret = PTR_ERR(fsi->class_dir); + fsi->class_dir = NULL; + goto err; + } + + fsi->policycap_dir = sel_make_dir(sb->s_root, POLICYCAP_DIR_NAME, + &fsi->last_ino); + if (IS_ERR(fsi->policycap_dir)) { + ret = PTR_ERR(fsi->policycap_dir); + fsi->policycap_dir = NULL; + goto err; + } + + ret = sel_make_policycap(fsi); + if (ret) { + pr_err("SELinux: failed to load policy capabilities\n"); + goto err; + } + + return 0; +err: + pr_err("SELinux: %s: failed while creating inodes\n", + __func__); + + selinux_fs_info_free(sb); + + return ret; +} + +static int sel_get_tree(struct fs_context *fc) +{ + return get_tree_single(fc, sel_fill_super); +} + +static const struct fs_context_operations sel_context_ops = { + .get_tree = sel_get_tree, +}; + +static int sel_init_fs_context(struct fs_context *fc) +{ + fc->ops = &sel_context_ops; + return 0; +} + +static void sel_kill_sb(struct super_block *sb) +{ + selinux_fs_info_free(sb); + kill_litter_super(sb); +} + +static struct file_system_type sel_fs_type = { + .name = "selinuxfs", + .init_fs_context = sel_init_fs_context, + .kill_sb = sel_kill_sb, +}; + +static struct vfsmount *selinuxfs_mount __ro_after_init; +struct path selinux_null __ro_after_init; + +static int __init init_sel_fs(void) +{ + struct qstr null_name = QSTR_INIT(NULL_FILE_NAME, + sizeof(NULL_FILE_NAME)-1); + int err; + + if (!selinux_enabled_boot) + return 0; + + err = sysfs_create_mount_point(fs_kobj, "selinux"); + if (err) + return err; + + err = register_filesystem(&sel_fs_type); + if (err) { + sysfs_remove_mount_point(fs_kobj, "selinux"); + return err; + } + + selinux_null.mnt = selinuxfs_mount = kern_mount(&sel_fs_type); + if (IS_ERR(selinuxfs_mount)) { + pr_err("selinuxfs: could not mount!\n"); + err = PTR_ERR(selinuxfs_mount); + selinuxfs_mount = NULL; + } + selinux_null.dentry = d_hash_and_lookup(selinux_null.mnt->mnt_root, + &null_name); + if (IS_ERR(selinux_null.dentry)) { + pr_err("selinuxfs: could not lookup null!\n"); + err = PTR_ERR(selinux_null.dentry); + selinux_null.dentry = NULL; + } + + return err; +} + +__initcall(init_sel_fs); + +#ifdef CONFIG_SECURITY_SELINUX_DISABLE +void exit_sel_fs(void) +{ + sysfs_remove_mount_point(fs_kobj, "selinux"); + dput(selinux_null.dentry); + kern_unmount(selinuxfs_mount); + unregister_filesystem(&sel_fs_type); +} +#endif diff --git a/security/selinux/ss/avtab.c b/security/selinux/ss/avtab.c new file mode 100644 index 000000000..8480ec6c6 --- /dev/null +++ b/security/selinux/ss/avtab.c @@ -0,0 +1,679 @@ +/* + * Implementation of the access vector table type. + * + * Author : Stephen Smalley, <sds@tycho.nsa.gov> + */ + +/* Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com> + * + * Added conditional policy language extensions + * + * Copyright (C) 2003 Tresys Technology, LLC + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, version 2. + * + * Updated: Yuichi Nakamura <ynakam@hitachisoft.jp> + * Tuned number of hash slots for avtab to reduce memory usage + */ + +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/errno.h> +#include "avtab.h" +#include "policydb.h" + +static struct kmem_cache *avtab_node_cachep __ro_after_init; +static struct kmem_cache *avtab_xperms_cachep __ro_after_init; + +/* Based on MurmurHash3, written by Austin Appleby and placed in the + * public domain. + */ +static inline int avtab_hash(const struct avtab_key *keyp, u32 mask) +{ + static const u32 c1 = 0xcc9e2d51; + static const u32 c2 = 0x1b873593; + static const u32 r1 = 15; + static const u32 r2 = 13; + static const u32 m = 5; + static const u32 n = 0xe6546b64; + + u32 hash = 0; + +#define mix(input) do { \ + u32 v = input; \ + v *= c1; \ + v = (v << r1) | (v >> (32 - r1)); \ + v *= c2; \ + hash ^= v; \ + hash = (hash << r2) | (hash >> (32 - r2)); \ + hash = hash * m + n; \ + } while (0) + + mix(keyp->target_class); + mix(keyp->target_type); + mix(keyp->source_type); + +#undef mix + + hash ^= hash >> 16; + hash *= 0x85ebca6b; + hash ^= hash >> 13; + hash *= 0xc2b2ae35; + hash ^= hash >> 16; + + return hash & mask; +} + +static struct avtab_node* +avtab_insert_node(struct avtab *h, int hvalue, + struct avtab_node *prev, + const struct avtab_key *key, const struct avtab_datum *datum) +{ + struct avtab_node *newnode; + struct avtab_extended_perms *xperms; + newnode = kmem_cache_zalloc(avtab_node_cachep, GFP_KERNEL); + if (newnode == NULL) + return NULL; + newnode->key = *key; + + if (key->specified & AVTAB_XPERMS) { + xperms = kmem_cache_zalloc(avtab_xperms_cachep, GFP_KERNEL); + if (xperms == NULL) { + kmem_cache_free(avtab_node_cachep, newnode); + return NULL; + } + *xperms = *(datum->u.xperms); + newnode->datum.u.xperms = xperms; + } else { + newnode->datum.u.data = datum->u.data; + } + + if (prev) { + newnode->next = prev->next; + prev->next = newnode; + } else { + struct avtab_node **n = &h->htable[hvalue]; + + newnode->next = *n; + *n = newnode; + } + + h->nel++; + return newnode; +} + +static int avtab_insert(struct avtab *h, const struct avtab_key *key, + const struct avtab_datum *datum) +{ + int hvalue; + struct avtab_node *prev, *cur, *newnode; + u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD); + + if (!h || !h->nslot) + return -EINVAL; + + hvalue = avtab_hash(key, h->mask); + for (prev = NULL, cur = h->htable[hvalue]; + cur; + prev = cur, cur = cur->next) { + if (key->source_type == cur->key.source_type && + key->target_type == cur->key.target_type && + key->target_class == cur->key.target_class && + (specified & cur->key.specified)) { + /* extended perms may not be unique */ + if (specified & AVTAB_XPERMS) + break; + return -EEXIST; + } + if (key->source_type < cur->key.source_type) + break; + if (key->source_type == cur->key.source_type && + key->target_type < cur->key.target_type) + break; + if (key->source_type == cur->key.source_type && + key->target_type == cur->key.target_type && + key->target_class < cur->key.target_class) + break; + } + + newnode = avtab_insert_node(h, hvalue, prev, key, datum); + if (!newnode) + return -ENOMEM; + + return 0; +} + +/* Unlike avtab_insert(), this function allow multiple insertions of the same + * key/specified mask into the table, as needed by the conditional avtab. + * It also returns a pointer to the node inserted. + */ +struct avtab_node *avtab_insert_nonunique(struct avtab *h, + const struct avtab_key *key, + const struct avtab_datum *datum) +{ + int hvalue; + struct avtab_node *prev, *cur; + u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD); + + if (!h || !h->nslot) + return NULL; + hvalue = avtab_hash(key, h->mask); + for (prev = NULL, cur = h->htable[hvalue]; + cur; + prev = cur, cur = cur->next) { + if (key->source_type == cur->key.source_type && + key->target_type == cur->key.target_type && + key->target_class == cur->key.target_class && + (specified & cur->key.specified)) + break; + if (key->source_type < cur->key.source_type) + break; + if (key->source_type == cur->key.source_type && + key->target_type < cur->key.target_type) + break; + if (key->source_type == cur->key.source_type && + key->target_type == cur->key.target_type && + key->target_class < cur->key.target_class) + break; + } + return avtab_insert_node(h, hvalue, prev, key, datum); +} + +struct avtab_datum *avtab_search(struct avtab *h, const struct avtab_key *key) +{ + int hvalue; + struct avtab_node *cur; + u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD); + + if (!h || !h->nslot) + return NULL; + + hvalue = avtab_hash(key, h->mask); + for (cur = h->htable[hvalue]; cur; + cur = cur->next) { + if (key->source_type == cur->key.source_type && + key->target_type == cur->key.target_type && + key->target_class == cur->key.target_class && + (specified & cur->key.specified)) + return &cur->datum; + + if (key->source_type < cur->key.source_type) + break; + if (key->source_type == cur->key.source_type && + key->target_type < cur->key.target_type) + break; + if (key->source_type == cur->key.source_type && + key->target_type == cur->key.target_type && + key->target_class < cur->key.target_class) + break; + } + + return NULL; +} + +/* This search function returns a node pointer, and can be used in + * conjunction with avtab_search_next_node() + */ +struct avtab_node *avtab_search_node(struct avtab *h, + const struct avtab_key *key) +{ + int hvalue; + struct avtab_node *cur; + u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD); + + if (!h || !h->nslot) + return NULL; + + hvalue = avtab_hash(key, h->mask); + for (cur = h->htable[hvalue]; cur; + cur = cur->next) { + if (key->source_type == cur->key.source_type && + key->target_type == cur->key.target_type && + key->target_class == cur->key.target_class && + (specified & cur->key.specified)) + return cur; + + if (key->source_type < cur->key.source_type) + break; + if (key->source_type == cur->key.source_type && + key->target_type < cur->key.target_type) + break; + if (key->source_type == cur->key.source_type && + key->target_type == cur->key.target_type && + key->target_class < cur->key.target_class) + break; + } + return NULL; +} + +struct avtab_node* +avtab_search_node_next(struct avtab_node *node, int specified) +{ + struct avtab_node *cur; + + if (!node) + return NULL; + + specified &= ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD); + for (cur = node->next; cur; cur = cur->next) { + if (node->key.source_type == cur->key.source_type && + node->key.target_type == cur->key.target_type && + node->key.target_class == cur->key.target_class && + (specified & cur->key.specified)) + return cur; + + if (node->key.source_type < cur->key.source_type) + break; + if (node->key.source_type == cur->key.source_type && + node->key.target_type < cur->key.target_type) + break; + if (node->key.source_type == cur->key.source_type && + node->key.target_type == cur->key.target_type && + node->key.target_class < cur->key.target_class) + break; + } + return NULL; +} + +void avtab_destroy(struct avtab *h) +{ + int i; + struct avtab_node *cur, *temp; + + if (!h) + return; + + for (i = 0; i < h->nslot; i++) { + cur = h->htable[i]; + while (cur) { + temp = cur; + cur = cur->next; + if (temp->key.specified & AVTAB_XPERMS) + kmem_cache_free(avtab_xperms_cachep, + temp->datum.u.xperms); + kmem_cache_free(avtab_node_cachep, temp); + } + } + kvfree(h->htable); + h->htable = NULL; + h->nel = 0; + h->nslot = 0; + h->mask = 0; +} + +void avtab_init(struct avtab *h) +{ + h->htable = NULL; + h->nel = 0; + h->nslot = 0; + h->mask = 0; +} + +static int avtab_alloc_common(struct avtab *h, u32 nslot) +{ + if (!nslot) + return 0; + + h->htable = kvcalloc(nslot, sizeof(void *), GFP_KERNEL); + if (!h->htable) + return -ENOMEM; + + h->nslot = nslot; + h->mask = nslot - 1; + return 0; +} + +int avtab_alloc(struct avtab *h, u32 nrules) +{ + int rc; + u32 nslot = 0; + + if (nrules != 0) { + u32 shift = 1; + u32 work = nrules >> 3; + while (work) { + work >>= 1; + shift++; + } + nslot = 1 << shift; + if (nslot > MAX_AVTAB_HASH_BUCKETS) + nslot = MAX_AVTAB_HASH_BUCKETS; + + rc = avtab_alloc_common(h, nslot); + if (rc) + return rc; + } + + pr_debug("SELinux: %d avtab hash slots, %d rules.\n", nslot, nrules); + return 0; +} + +int avtab_alloc_dup(struct avtab *new, const struct avtab *orig) +{ + return avtab_alloc_common(new, orig->nslot); +} + +void avtab_hash_eval(struct avtab *h, char *tag) +{ + int i, chain_len, slots_used, max_chain_len; + unsigned long long chain2_len_sum; + struct avtab_node *cur; + + slots_used = 0; + max_chain_len = 0; + chain2_len_sum = 0; + for (i = 0; i < h->nslot; i++) { + cur = h->htable[i]; + if (cur) { + slots_used++; + chain_len = 0; + while (cur) { + chain_len++; + cur = cur->next; + } + + if (chain_len > max_chain_len) + max_chain_len = chain_len; + chain2_len_sum += chain_len * chain_len; + } + } + + pr_debug("SELinux: %s: %d entries and %d/%d buckets used, " + "longest chain length %d sum of chain length^2 %llu\n", + tag, h->nel, slots_used, h->nslot, max_chain_len, + chain2_len_sum); +} + +static const uint16_t spec_order[] = { + AVTAB_ALLOWED, + AVTAB_AUDITDENY, + AVTAB_AUDITALLOW, + AVTAB_TRANSITION, + AVTAB_CHANGE, + AVTAB_MEMBER, + AVTAB_XPERMS_ALLOWED, + AVTAB_XPERMS_AUDITALLOW, + AVTAB_XPERMS_DONTAUDIT +}; + +int avtab_read_item(struct avtab *a, void *fp, struct policydb *pol, + int (*insertf)(struct avtab *a, const struct avtab_key *k, + const struct avtab_datum *d, void *p), + void *p) +{ + __le16 buf16[4]; + u16 enabled; + u32 items, items2, val, vers = pol->policyvers; + struct avtab_key key; + struct avtab_datum datum; + struct avtab_extended_perms xperms; + __le32 buf32[ARRAY_SIZE(xperms.perms.p)]; + int i, rc; + unsigned set; + + memset(&key, 0, sizeof(struct avtab_key)); + memset(&datum, 0, sizeof(struct avtab_datum)); + + if (vers < POLICYDB_VERSION_AVTAB) { + rc = next_entry(buf32, fp, sizeof(u32)); + if (rc) { + pr_err("SELinux: avtab: truncated entry\n"); + return rc; + } + items2 = le32_to_cpu(buf32[0]); + if (items2 > ARRAY_SIZE(buf32)) { + pr_err("SELinux: avtab: entry overflow\n"); + return -EINVAL; + + } + rc = next_entry(buf32, fp, sizeof(u32)*items2); + if (rc) { + pr_err("SELinux: avtab: truncated entry\n"); + return rc; + } + items = 0; + + val = le32_to_cpu(buf32[items++]); + key.source_type = (u16)val; + if (key.source_type != val) { + pr_err("SELinux: avtab: truncated source type\n"); + return -EINVAL; + } + val = le32_to_cpu(buf32[items++]); + key.target_type = (u16)val; + if (key.target_type != val) { + pr_err("SELinux: avtab: truncated target type\n"); + return -EINVAL; + } + val = le32_to_cpu(buf32[items++]); + key.target_class = (u16)val; + if (key.target_class != val) { + pr_err("SELinux: avtab: truncated target class\n"); + return -EINVAL; + } + + val = le32_to_cpu(buf32[items++]); + enabled = (val & AVTAB_ENABLED_OLD) ? AVTAB_ENABLED : 0; + + if (!(val & (AVTAB_AV | AVTAB_TYPE))) { + pr_err("SELinux: avtab: null entry\n"); + return -EINVAL; + } + if ((val & AVTAB_AV) && + (val & AVTAB_TYPE)) { + pr_err("SELinux: avtab: entry has both access vectors and types\n"); + return -EINVAL; + } + if (val & AVTAB_XPERMS) { + pr_err("SELinux: avtab: entry has extended permissions\n"); + return -EINVAL; + } + + for (i = 0; i < ARRAY_SIZE(spec_order); i++) { + if (val & spec_order[i]) { + key.specified = spec_order[i] | enabled; + datum.u.data = le32_to_cpu(buf32[items++]); + rc = insertf(a, &key, &datum, p); + if (rc) + return rc; + } + } + + if (items != items2) { + pr_err("SELinux: avtab: entry only had %d items, expected %d\n", + items2, items); + return -EINVAL; + } + return 0; + } + + rc = next_entry(buf16, fp, sizeof(u16)*4); + if (rc) { + pr_err("SELinux: avtab: truncated entry\n"); + return rc; + } + + items = 0; + key.source_type = le16_to_cpu(buf16[items++]); + key.target_type = le16_to_cpu(buf16[items++]); + key.target_class = le16_to_cpu(buf16[items++]); + key.specified = le16_to_cpu(buf16[items++]); + + if (!policydb_type_isvalid(pol, key.source_type) || + !policydb_type_isvalid(pol, key.target_type) || + !policydb_class_isvalid(pol, key.target_class)) { + pr_err("SELinux: avtab: invalid type or class\n"); + return -EINVAL; + } + + set = 0; + for (i = 0; i < ARRAY_SIZE(spec_order); i++) { + if (key.specified & spec_order[i]) + set++; + } + if (!set || set > 1) { + pr_err("SELinux: avtab: more than one specifier\n"); + return -EINVAL; + } + + if ((vers < POLICYDB_VERSION_XPERMS_IOCTL) && + (key.specified & AVTAB_XPERMS)) { + pr_err("SELinux: avtab: policy version %u does not " + "support extended permissions rules and one " + "was specified\n", vers); + return -EINVAL; + } else if (key.specified & AVTAB_XPERMS) { + memset(&xperms, 0, sizeof(struct avtab_extended_perms)); + rc = next_entry(&xperms.specified, fp, sizeof(u8)); + if (rc) { + pr_err("SELinux: avtab: truncated entry\n"); + return rc; + } + rc = next_entry(&xperms.driver, fp, sizeof(u8)); + if (rc) { + pr_err("SELinux: avtab: truncated entry\n"); + return rc; + } + rc = next_entry(buf32, fp, sizeof(u32)*ARRAY_SIZE(xperms.perms.p)); + if (rc) { + pr_err("SELinux: avtab: truncated entry\n"); + return rc; + } + for (i = 0; i < ARRAY_SIZE(xperms.perms.p); i++) + xperms.perms.p[i] = le32_to_cpu(buf32[i]); + datum.u.xperms = &xperms; + } else { + rc = next_entry(buf32, fp, sizeof(u32)); + if (rc) { + pr_err("SELinux: avtab: truncated entry\n"); + return rc; + } + datum.u.data = le32_to_cpu(*buf32); + } + if ((key.specified & AVTAB_TYPE) && + !policydb_type_isvalid(pol, datum.u.data)) { + pr_err("SELinux: avtab: invalid type\n"); + return -EINVAL; + } + return insertf(a, &key, &datum, p); +} + +static int avtab_insertf(struct avtab *a, const struct avtab_key *k, + const struct avtab_datum *d, void *p) +{ + return avtab_insert(a, k, d); +} + +int avtab_read(struct avtab *a, void *fp, struct policydb *pol) +{ + int rc; + __le32 buf[1]; + u32 nel, i; + + + rc = next_entry(buf, fp, sizeof(u32)); + if (rc < 0) { + pr_err("SELinux: avtab: truncated table\n"); + goto bad; + } + nel = le32_to_cpu(buf[0]); + if (!nel) { + pr_err("SELinux: avtab: table is empty\n"); + rc = -EINVAL; + goto bad; + } + + rc = avtab_alloc(a, nel); + if (rc) + goto bad; + + for (i = 0; i < nel; i++) { + rc = avtab_read_item(a, fp, pol, avtab_insertf, NULL); + if (rc) { + if (rc == -ENOMEM) + pr_err("SELinux: avtab: out of memory\n"); + else if (rc == -EEXIST) + pr_err("SELinux: avtab: duplicate entry\n"); + + goto bad; + } + } + + rc = 0; +out: + return rc; + +bad: + avtab_destroy(a); + goto out; +} + +int avtab_write_item(struct policydb *p, const struct avtab_node *cur, void *fp) +{ + __le16 buf16[4]; + __le32 buf32[ARRAY_SIZE(cur->datum.u.xperms->perms.p)]; + int rc; + unsigned int i; + + buf16[0] = cpu_to_le16(cur->key.source_type); + buf16[1] = cpu_to_le16(cur->key.target_type); + buf16[2] = cpu_to_le16(cur->key.target_class); + buf16[3] = cpu_to_le16(cur->key.specified); + rc = put_entry(buf16, sizeof(u16), 4, fp); + if (rc) + return rc; + + if (cur->key.specified & AVTAB_XPERMS) { + rc = put_entry(&cur->datum.u.xperms->specified, sizeof(u8), 1, fp); + if (rc) + return rc; + rc = put_entry(&cur->datum.u.xperms->driver, sizeof(u8), 1, fp); + if (rc) + return rc; + for (i = 0; i < ARRAY_SIZE(cur->datum.u.xperms->perms.p); i++) + buf32[i] = cpu_to_le32(cur->datum.u.xperms->perms.p[i]); + rc = put_entry(buf32, sizeof(u32), + ARRAY_SIZE(cur->datum.u.xperms->perms.p), fp); + } else { + buf32[0] = cpu_to_le32(cur->datum.u.data); + rc = put_entry(buf32, sizeof(u32), 1, fp); + } + if (rc) + return rc; + return 0; +} + +int avtab_write(struct policydb *p, struct avtab *a, void *fp) +{ + unsigned int i; + int rc = 0; + struct avtab_node *cur; + __le32 buf[1]; + + buf[0] = cpu_to_le32(a->nel); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + + for (i = 0; i < a->nslot; i++) { + for (cur = a->htable[i]; cur; + cur = cur->next) { + rc = avtab_write_item(p, cur, fp); + if (rc) + return rc; + } + } + + return rc; +} + +void __init avtab_cache_init(void) +{ + avtab_node_cachep = kmem_cache_create("avtab_node", + sizeof(struct avtab_node), + 0, SLAB_PANIC, NULL); + avtab_xperms_cachep = kmem_cache_create("avtab_extended_perms", + sizeof(struct avtab_extended_perms), + 0, SLAB_PANIC, NULL); +} diff --git a/security/selinux/ss/avtab.h b/security/selinux/ss/avtab.h new file mode 100644 index 000000000..d3ebea8d1 --- /dev/null +++ b/security/selinux/ss/avtab.h @@ -0,0 +1,120 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * An access vector table (avtab) is a hash table + * of access vectors and transition types indexed + * by a type pair and a class. An access vector + * table is used to represent the type enforcement + * tables. + * + * Author : Stephen Smalley, <sds@tycho.nsa.gov> + */ + +/* Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com> + * + * Added conditional policy language extensions + * + * Copyright (C) 2003 Tresys Technology, LLC + * + * Updated: Yuichi Nakamura <ynakam@hitachisoft.jp> + * Tuned number of hash slots for avtab to reduce memory usage + */ +#ifndef _SS_AVTAB_H_ +#define _SS_AVTAB_H_ + +#include "security.h" + +struct avtab_key { + u16 source_type; /* source type */ + u16 target_type; /* target type */ + u16 target_class; /* target object class */ +#define AVTAB_ALLOWED 0x0001 +#define AVTAB_AUDITALLOW 0x0002 +#define AVTAB_AUDITDENY 0x0004 +#define AVTAB_AV (AVTAB_ALLOWED | AVTAB_AUDITALLOW | AVTAB_AUDITDENY) +#define AVTAB_TRANSITION 0x0010 +#define AVTAB_MEMBER 0x0020 +#define AVTAB_CHANGE 0x0040 +#define AVTAB_TYPE (AVTAB_TRANSITION | AVTAB_MEMBER | AVTAB_CHANGE) +/* extended permissions */ +#define AVTAB_XPERMS_ALLOWED 0x0100 +#define AVTAB_XPERMS_AUDITALLOW 0x0200 +#define AVTAB_XPERMS_DONTAUDIT 0x0400 +#define AVTAB_XPERMS (AVTAB_XPERMS_ALLOWED | \ + AVTAB_XPERMS_AUDITALLOW | \ + AVTAB_XPERMS_DONTAUDIT) +#define AVTAB_ENABLED_OLD 0x80000000 /* reserved for used in cond_avtab */ +#define AVTAB_ENABLED 0x8000 /* reserved for used in cond_avtab */ + u16 specified; /* what field is specified */ +}; + +/* + * For operations that require more than the 32 permissions provided by the avc + * extended permissions may be used to provide 256 bits of permissions. + */ +struct avtab_extended_perms { +/* These are not flags. All 256 values may be used */ +#define AVTAB_XPERMS_IOCTLFUNCTION 0x01 +#define AVTAB_XPERMS_IOCTLDRIVER 0x02 + /* extension of the avtab_key specified */ + u8 specified; /* ioctl, netfilter, ... */ + /* + * if 256 bits is not adequate as is often the case with ioctls, then + * multiple extended perms may be used and the driver field + * specifies which permissions are included. + */ + u8 driver; + /* 256 bits of permissions */ + struct extended_perms_data perms; +}; + +struct avtab_datum { + union { + u32 data; /* access vector or type value */ + struct avtab_extended_perms *xperms; + } u; +}; + +struct avtab_node { + struct avtab_key key; + struct avtab_datum datum; + struct avtab_node *next; +}; + +struct avtab { + struct avtab_node **htable; + u32 nel; /* number of elements */ + u32 nslot; /* number of hash slots */ + u32 mask; /* mask to compute hash func */ +}; + +void avtab_init(struct avtab *h); +int avtab_alloc(struct avtab *, u32); +int avtab_alloc_dup(struct avtab *new, const struct avtab *orig); +struct avtab_datum *avtab_search(struct avtab *h, const struct avtab_key *k); +void avtab_destroy(struct avtab *h); +void avtab_hash_eval(struct avtab *h, char *tag); + +struct policydb; +int avtab_read_item(struct avtab *a, void *fp, struct policydb *pol, + int (*insert)(struct avtab *a, const struct avtab_key *k, + const struct avtab_datum *d, void *p), + void *p); + +int avtab_read(struct avtab *a, void *fp, struct policydb *pol); +int avtab_write_item(struct policydb *p, const struct avtab_node *cur, void *fp); +int avtab_write(struct policydb *p, struct avtab *a, void *fp); + +struct avtab_node *avtab_insert_nonunique(struct avtab *h, + const struct avtab_key *key, + const struct avtab_datum *datum); + +struct avtab_node *avtab_search_node(struct avtab *h, + const struct avtab_key *key); + +struct avtab_node *avtab_search_node_next(struct avtab_node *node, int specified); + +#define MAX_AVTAB_HASH_BITS 16 +#define MAX_AVTAB_HASH_BUCKETS (1 << MAX_AVTAB_HASH_BITS) + +#endif /* _SS_AVTAB_H_ */ + diff --git a/security/selinux/ss/conditional.c b/security/selinux/ss/conditional.c new file mode 100644 index 000000000..e11219fdf --- /dev/null +++ b/security/selinux/ss/conditional.c @@ -0,0 +1,758 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Authors: Karl MacMillan <kmacmillan@tresys.com> + * Frank Mayer <mayerf@tresys.com> + * + * Copyright (C) 2003 - 2004 Tresys Technology, LLC + */ + +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/string.h> +#include <linux/spinlock.h> +#include <linux/slab.h> + +#include "security.h" +#include "conditional.h" +#include "services.h" + +/* + * cond_evaluate_expr evaluates a conditional expr + * in reverse polish notation. It returns true (1), false (0), + * or undefined (-1). Undefined occurs when the expression + * exceeds the stack depth of COND_EXPR_MAXDEPTH. + */ +static int cond_evaluate_expr(struct policydb *p, struct cond_expr *expr) +{ + u32 i; + int s[COND_EXPR_MAXDEPTH]; + int sp = -1; + + if (expr->len == 0) + return -1; + + for (i = 0; i < expr->len; i++) { + struct cond_expr_node *node = &expr->nodes[i]; + + switch (node->expr_type) { + case COND_BOOL: + if (sp == (COND_EXPR_MAXDEPTH - 1)) + return -1; + sp++; + s[sp] = p->bool_val_to_struct[node->bool - 1]->state; + break; + case COND_NOT: + if (sp < 0) + return -1; + s[sp] = !s[sp]; + break; + case COND_OR: + if (sp < 1) + return -1; + sp--; + s[sp] |= s[sp + 1]; + break; + case COND_AND: + if (sp < 1) + return -1; + sp--; + s[sp] &= s[sp + 1]; + break; + case COND_XOR: + if (sp < 1) + return -1; + sp--; + s[sp] ^= s[sp + 1]; + break; + case COND_EQ: + if (sp < 1) + return -1; + sp--; + s[sp] = (s[sp] == s[sp + 1]); + break; + case COND_NEQ: + if (sp < 1) + return -1; + sp--; + s[sp] = (s[sp] != s[sp + 1]); + break; + default: + return -1; + } + } + return s[0]; +} + +/* + * evaluate_cond_node evaluates the conditional stored in + * a struct cond_node and if the result is different than the + * current state of the node it sets the rules in the true/false + * list appropriately. If the result of the expression is undefined + * all of the rules are disabled for safety. + */ +static void evaluate_cond_node(struct policydb *p, struct cond_node *node) +{ + struct avtab_node *avnode; + int new_state; + u32 i; + + new_state = cond_evaluate_expr(p, &node->expr); + if (new_state != node->cur_state) { + node->cur_state = new_state; + if (new_state == -1) + pr_err("SELinux: expression result was undefined - disabling all rules.\n"); + /* turn the rules on or off */ + for (i = 0; i < node->true_list.len; i++) { + avnode = node->true_list.nodes[i]; + if (new_state <= 0) + avnode->key.specified &= ~AVTAB_ENABLED; + else + avnode->key.specified |= AVTAB_ENABLED; + } + + for (i = 0; i < node->false_list.len; i++) { + avnode = node->false_list.nodes[i]; + /* -1 or 1 */ + if (new_state) + avnode->key.specified &= ~AVTAB_ENABLED; + else + avnode->key.specified |= AVTAB_ENABLED; + } + } +} + +void evaluate_cond_nodes(struct policydb *p) +{ + u32 i; + + for (i = 0; i < p->cond_list_len; i++) + evaluate_cond_node(p, &p->cond_list[i]); +} + +void cond_policydb_init(struct policydb *p) +{ + p->bool_val_to_struct = NULL; + p->cond_list = NULL; + p->cond_list_len = 0; + + avtab_init(&p->te_cond_avtab); +} + +static void cond_node_destroy(struct cond_node *node) +{ + kfree(node->expr.nodes); + /* the avtab_ptr_t nodes are destroyed by the avtab */ + kfree(node->true_list.nodes); + kfree(node->false_list.nodes); +} + +static void cond_list_destroy(struct policydb *p) +{ + u32 i; + + for (i = 0; i < p->cond_list_len; i++) + cond_node_destroy(&p->cond_list[i]); + kfree(p->cond_list); + p->cond_list = NULL; + p->cond_list_len = 0; +} + +void cond_policydb_destroy(struct policydb *p) +{ + kfree(p->bool_val_to_struct); + avtab_destroy(&p->te_cond_avtab); + cond_list_destroy(p); +} + +int cond_init_bool_indexes(struct policydb *p) +{ + kfree(p->bool_val_to_struct); + p->bool_val_to_struct = kmalloc_array(p->p_bools.nprim, + sizeof(*p->bool_val_to_struct), + GFP_KERNEL); + if (!p->bool_val_to_struct) + return -ENOMEM; + return 0; +} + +int cond_destroy_bool(void *key, void *datum, void *p) +{ + kfree(key); + kfree(datum); + return 0; +} + +int cond_index_bool(void *key, void *datum, void *datap) +{ + struct policydb *p; + struct cond_bool_datum *booldatum; + + booldatum = datum; + p = datap; + + if (!booldatum->value || booldatum->value > p->p_bools.nprim) + return -EINVAL; + + p->sym_val_to_name[SYM_BOOLS][booldatum->value - 1] = key; + p->bool_val_to_struct[booldatum->value - 1] = booldatum; + + return 0; +} + +static int bool_isvalid(struct cond_bool_datum *b) +{ + if (!(b->state == 0 || b->state == 1)) + return 0; + return 1; +} + +int cond_read_bool(struct policydb *p, struct symtab *s, void *fp) +{ + char *key = NULL; + struct cond_bool_datum *booldatum; + __le32 buf[3]; + u32 len; + int rc; + + booldatum = kzalloc(sizeof(*booldatum), GFP_KERNEL); + if (!booldatum) + return -ENOMEM; + + rc = next_entry(buf, fp, sizeof(buf)); + if (rc) + goto err; + + booldatum->value = le32_to_cpu(buf[0]); + booldatum->state = le32_to_cpu(buf[1]); + + rc = -EINVAL; + if (!bool_isvalid(booldatum)) + goto err; + + len = le32_to_cpu(buf[2]); + if (((len == 0) || (len == (u32)-1))) + goto err; + + rc = -ENOMEM; + key = kmalloc(len + 1, GFP_KERNEL); + if (!key) + goto err; + rc = next_entry(key, fp, len); + if (rc) + goto err; + key[len] = '\0'; + rc = symtab_insert(s, key, booldatum); + if (rc) + goto err; + + return 0; +err: + cond_destroy_bool(key, booldatum, NULL); + return rc; +} + +struct cond_insertf_data { + struct policydb *p; + struct avtab_node **dst; + struct cond_av_list *other; +}; + +static int cond_insertf(struct avtab *a, const struct avtab_key *k, + const struct avtab_datum *d, void *ptr) +{ + struct cond_insertf_data *data = ptr; + struct policydb *p = data->p; + struct cond_av_list *other = data->other; + struct avtab_node *node_ptr; + u32 i; + bool found; + + /* + * For type rules we have to make certain there aren't any + * conflicting rules by searching the te_avtab and the + * cond_te_avtab. + */ + if (k->specified & AVTAB_TYPE) { + if (avtab_search(&p->te_avtab, k)) { + pr_err("SELinux: type rule already exists outside of a conditional.\n"); + return -EINVAL; + } + /* + * If we are reading the false list other will be a pointer to + * the true list. We can have duplicate entries if there is only + * 1 other entry and it is in our true list. + * + * If we are reading the true list (other == NULL) there shouldn't + * be any other entries. + */ + if (other) { + node_ptr = avtab_search_node(&p->te_cond_avtab, k); + if (node_ptr) { + if (avtab_search_node_next(node_ptr, k->specified)) { + pr_err("SELinux: too many conflicting type rules.\n"); + return -EINVAL; + } + found = false; + for (i = 0; i < other->len; i++) { + if (other->nodes[i] == node_ptr) { + found = true; + break; + } + } + if (!found) { + pr_err("SELinux: conflicting type rules.\n"); + return -EINVAL; + } + } + } else { + if (avtab_search(&p->te_cond_avtab, k)) { + pr_err("SELinux: conflicting type rules when adding type rule for true.\n"); + return -EINVAL; + } + } + } + + node_ptr = avtab_insert_nonunique(&p->te_cond_avtab, k, d); + if (!node_ptr) { + pr_err("SELinux: could not insert rule.\n"); + return -ENOMEM; + } + + *data->dst = node_ptr; + return 0; +} + +static int cond_read_av_list(struct policydb *p, void *fp, + struct cond_av_list *list, + struct cond_av_list *other) +{ + int rc; + __le32 buf[1]; + u32 i, len; + struct cond_insertf_data data; + + rc = next_entry(buf, fp, sizeof(u32)); + if (rc) + return rc; + + len = le32_to_cpu(buf[0]); + if (len == 0) + return 0; + + list->nodes = kcalloc(len, sizeof(*list->nodes), GFP_KERNEL); + if (!list->nodes) + return -ENOMEM; + + data.p = p; + data.other = other; + for (i = 0; i < len; i++) { + data.dst = &list->nodes[i]; + rc = avtab_read_item(&p->te_cond_avtab, fp, p, cond_insertf, + &data); + if (rc) { + kfree(list->nodes); + list->nodes = NULL; + return rc; + } + } + + list->len = len; + return 0; +} + +static int expr_node_isvalid(struct policydb *p, struct cond_expr_node *expr) +{ + if (expr->expr_type <= 0 || expr->expr_type > COND_LAST) { + pr_err("SELinux: conditional expressions uses unknown operator.\n"); + return 0; + } + + if (expr->bool > p->p_bools.nprim) { + pr_err("SELinux: conditional expressions uses unknown bool.\n"); + return 0; + } + return 1; +} + +static int cond_read_node(struct policydb *p, struct cond_node *node, void *fp) +{ + __le32 buf[2]; + u32 i, len; + int rc; + + rc = next_entry(buf, fp, sizeof(u32) * 2); + if (rc) + return rc; + + node->cur_state = le32_to_cpu(buf[0]); + + /* expr */ + len = le32_to_cpu(buf[1]); + node->expr.nodes = kcalloc(len, sizeof(*node->expr.nodes), GFP_KERNEL); + if (!node->expr.nodes) + return -ENOMEM; + + node->expr.len = len; + + for (i = 0; i < len; i++) { + struct cond_expr_node *expr = &node->expr.nodes[i]; + + rc = next_entry(buf, fp, sizeof(u32) * 2); + if (rc) + return rc; + + expr->expr_type = le32_to_cpu(buf[0]); + expr->bool = le32_to_cpu(buf[1]); + + if (!expr_node_isvalid(p, expr)) + return -EINVAL; + } + + rc = cond_read_av_list(p, fp, &node->true_list, NULL); + if (rc) + return rc; + return cond_read_av_list(p, fp, &node->false_list, &node->true_list); +} + +int cond_read_list(struct policydb *p, void *fp) +{ + __le32 buf[1]; + u32 i, len; + int rc; + + rc = next_entry(buf, fp, sizeof(buf)); + if (rc) + return rc; + + len = le32_to_cpu(buf[0]); + + p->cond_list = kcalloc(len, sizeof(*p->cond_list), GFP_KERNEL); + if (!p->cond_list) + return -ENOMEM; + + rc = avtab_alloc(&(p->te_cond_avtab), p->te_avtab.nel); + if (rc) + goto err; + + p->cond_list_len = len; + + for (i = 0; i < len; i++) { + rc = cond_read_node(p, &p->cond_list[i], fp); + if (rc) + goto err; + } + return 0; +err: + cond_list_destroy(p); + return rc; +} + +int cond_write_bool(void *vkey, void *datum, void *ptr) +{ + char *key = vkey; + struct cond_bool_datum *booldatum = datum; + struct policy_data *pd = ptr; + void *fp = pd->fp; + __le32 buf[3]; + u32 len; + int rc; + + len = strlen(key); + buf[0] = cpu_to_le32(booldatum->value); + buf[1] = cpu_to_le32(booldatum->state); + buf[2] = cpu_to_le32(len); + rc = put_entry(buf, sizeof(u32), 3, fp); + if (rc) + return rc; + rc = put_entry(key, 1, len, fp); + if (rc) + return rc; + return 0; +} + +/* + * cond_write_cond_av_list doesn't write out the av_list nodes. + * Instead it writes out the key/value pairs from the avtab. This + * is necessary because there is no way to uniquely identifying rules + * in the avtab so it is not possible to associate individual rules + * in the avtab with a conditional without saving them as part of + * the conditional. This means that the avtab with the conditional + * rules will not be saved but will be rebuilt on policy load. + */ +static int cond_write_av_list(struct policydb *p, + struct cond_av_list *list, struct policy_file *fp) +{ + __le32 buf[1]; + u32 i; + int rc; + + buf[0] = cpu_to_le32(list->len); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + + for (i = 0; i < list->len; i++) { + rc = avtab_write_item(p, list->nodes[i], fp); + if (rc) + return rc; + } + + return 0; +} + +static int cond_write_node(struct policydb *p, struct cond_node *node, + struct policy_file *fp) +{ + __le32 buf[2]; + int rc; + u32 i; + + buf[0] = cpu_to_le32(node->cur_state); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + + buf[0] = cpu_to_le32(node->expr.len); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + + for (i = 0; i < node->expr.len; i++) { + buf[0] = cpu_to_le32(node->expr.nodes[i].expr_type); + buf[1] = cpu_to_le32(node->expr.nodes[i].bool); + rc = put_entry(buf, sizeof(u32), 2, fp); + if (rc) + return rc; + } + + rc = cond_write_av_list(p, &node->true_list, fp); + if (rc) + return rc; + rc = cond_write_av_list(p, &node->false_list, fp); + if (rc) + return rc; + + return 0; +} + +int cond_write_list(struct policydb *p, void *fp) +{ + u32 i; + __le32 buf[1]; + int rc; + + buf[0] = cpu_to_le32(p->cond_list_len); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + + for (i = 0; i < p->cond_list_len; i++) { + rc = cond_write_node(p, &p->cond_list[i], fp); + if (rc) + return rc; + } + + return 0; +} + +void cond_compute_xperms(struct avtab *ctab, struct avtab_key *key, + struct extended_perms_decision *xpermd) +{ + struct avtab_node *node; + + if (!ctab || !key || !xpermd) + return; + + for (node = avtab_search_node(ctab, key); node; + node = avtab_search_node_next(node, key->specified)) { + if (node->key.specified & AVTAB_ENABLED) + services_compute_xperms_decision(xpermd, node); + } +} +/* Determine whether additional permissions are granted by the conditional + * av table, and if so, add them to the result + */ +void cond_compute_av(struct avtab *ctab, struct avtab_key *key, + struct av_decision *avd, struct extended_perms *xperms) +{ + struct avtab_node *node; + + if (!ctab || !key || !avd) + return; + + for (node = avtab_search_node(ctab, key); node; + node = avtab_search_node_next(node, key->specified)) { + if ((u16)(AVTAB_ALLOWED|AVTAB_ENABLED) == + (node->key.specified & (AVTAB_ALLOWED|AVTAB_ENABLED))) + avd->allowed |= node->datum.u.data; + if ((u16)(AVTAB_AUDITDENY|AVTAB_ENABLED) == + (node->key.specified & (AVTAB_AUDITDENY|AVTAB_ENABLED))) + /* Since a '0' in an auditdeny mask represents a + * permission we do NOT want to audit (dontaudit), we use + * the '&' operand to ensure that all '0's in the mask + * are retained (much unlike the allow and auditallow cases). + */ + avd->auditdeny &= node->datum.u.data; + if ((u16)(AVTAB_AUDITALLOW|AVTAB_ENABLED) == + (node->key.specified & (AVTAB_AUDITALLOW|AVTAB_ENABLED))) + avd->auditallow |= node->datum.u.data; + if (xperms && (node->key.specified & AVTAB_ENABLED) && + (node->key.specified & AVTAB_XPERMS)) + services_compute_xperms_drivers(xperms, node); + } +} + +static int cond_dup_av_list(struct cond_av_list *new, + struct cond_av_list *orig, + struct avtab *avtab) +{ + u32 i; + + memset(new, 0, sizeof(*new)); + + new->nodes = kcalloc(orig->len, sizeof(*new->nodes), GFP_KERNEL); + if (!new->nodes) + return -ENOMEM; + + for (i = 0; i < orig->len; i++) { + new->nodes[i] = avtab_insert_nonunique(avtab, + &orig->nodes[i]->key, + &orig->nodes[i]->datum); + if (!new->nodes[i]) + return -ENOMEM; + new->len++; + } + + return 0; +} + +static int duplicate_policydb_cond_list(struct policydb *newp, + struct policydb *origp) +{ + int rc; + u32 i; + + rc = avtab_alloc_dup(&newp->te_cond_avtab, &origp->te_cond_avtab); + if (rc) + return rc; + + newp->cond_list_len = 0; + newp->cond_list = kcalloc(origp->cond_list_len, + sizeof(*newp->cond_list), + GFP_KERNEL); + if (!newp->cond_list) + goto error; + + for (i = 0; i < origp->cond_list_len; i++) { + struct cond_node *newn = &newp->cond_list[i]; + struct cond_node *orign = &origp->cond_list[i]; + + newp->cond_list_len++; + + newn->cur_state = orign->cur_state; + newn->expr.nodes = kmemdup(orign->expr.nodes, + orign->expr.len * sizeof(*orign->expr.nodes), + GFP_KERNEL); + if (!newn->expr.nodes) + goto error; + + newn->expr.len = orign->expr.len; + + rc = cond_dup_av_list(&newn->true_list, &orign->true_list, + &newp->te_cond_avtab); + if (rc) + goto error; + + rc = cond_dup_av_list(&newn->false_list, &orign->false_list, + &newp->te_cond_avtab); + if (rc) + goto error; + } + + return 0; + +error: + avtab_destroy(&newp->te_cond_avtab); + cond_list_destroy(newp); + return -ENOMEM; +} + +static int cond_bools_destroy(void *key, void *datum, void *args) +{ + /* key was not copied so no need to free here */ + kfree(datum); + return 0; +} + +static int cond_bools_copy(struct hashtab_node *new, struct hashtab_node *orig, void *args) +{ + struct cond_bool_datum *datum; + + datum = kmemdup(orig->datum, sizeof(struct cond_bool_datum), + GFP_KERNEL); + if (!datum) + return -ENOMEM; + + new->key = orig->key; /* No need to copy, never modified */ + new->datum = datum; + return 0; +} + +static int cond_bools_index(void *key, void *datum, void *args) +{ + struct cond_bool_datum *booldatum, **cond_bool_array; + + booldatum = datum; + cond_bool_array = args; + cond_bool_array[booldatum->value - 1] = booldatum; + + return 0; +} + +static int duplicate_policydb_bools(struct policydb *newdb, + struct policydb *orig) +{ + struct cond_bool_datum **cond_bool_array; + int rc; + + cond_bool_array = kmalloc_array(orig->p_bools.nprim, + sizeof(*orig->bool_val_to_struct), + GFP_KERNEL); + if (!cond_bool_array) + return -ENOMEM; + + rc = hashtab_duplicate(&newdb->p_bools.table, &orig->p_bools.table, + cond_bools_copy, cond_bools_destroy, NULL); + if (rc) { + kfree(cond_bool_array); + return -ENOMEM; + } + + hashtab_map(&newdb->p_bools.table, cond_bools_index, cond_bool_array); + newdb->bool_val_to_struct = cond_bool_array; + + newdb->p_bools.nprim = orig->p_bools.nprim; + + return 0; +} + +void cond_policydb_destroy_dup(struct policydb *p) +{ + hashtab_map(&p->p_bools.table, cond_bools_destroy, NULL); + hashtab_destroy(&p->p_bools.table); + cond_policydb_destroy(p); +} + +int cond_policydb_dup(struct policydb *new, struct policydb *orig) +{ + cond_policydb_init(new); + + if (duplicate_policydb_bools(new, orig)) + return -ENOMEM; + + if (duplicate_policydb_cond_list(new, orig)) { + cond_policydb_destroy_dup(new); + return -ENOMEM; + } + + return 0; +} diff --git a/security/selinux/ss/conditional.h b/security/selinux/ss/conditional.h new file mode 100644 index 000000000..e47ec6dde --- /dev/null +++ b/security/selinux/ss/conditional.h @@ -0,0 +1,85 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* Authors: Karl MacMillan <kmacmillan@tresys.com> + * Frank Mayer <mayerf@tresys.com> + * + * Copyright (C) 2003 - 2004 Tresys Technology, LLC + */ + +#ifndef _CONDITIONAL_H_ +#define _CONDITIONAL_H_ + +#include "avtab.h" +#include "symtab.h" +#include "policydb.h" +#include "../include/conditional.h" + +#define COND_EXPR_MAXDEPTH 10 + +/* + * A conditional expression is a list of operators and operands + * in reverse polish notation. + */ +struct cond_expr_node { +#define COND_BOOL 1 /* plain bool */ +#define COND_NOT 2 /* !bool */ +#define COND_OR 3 /* bool || bool */ +#define COND_AND 4 /* bool && bool */ +#define COND_XOR 5 /* bool ^ bool */ +#define COND_EQ 6 /* bool == bool */ +#define COND_NEQ 7 /* bool != bool */ +#define COND_LAST COND_NEQ + u32 expr_type; + u32 bool; +}; + +struct cond_expr { + struct cond_expr_node *nodes; + u32 len; +}; + +/* + * Each cond_node contains a list of rules to be enabled/disabled + * depending on the current value of the conditional expression. This + * struct is for that list. + */ +struct cond_av_list { + struct avtab_node **nodes; + u32 len; +}; + +/* + * A cond node represents a conditional block in a policy. It + * contains a conditional expression, the current state of the expression, + * two lists of rules to enable/disable depending on the value of the + * expression (the true list corresponds to if and the false list corresponds + * to else).. + */ +struct cond_node { + int cur_state; + struct cond_expr expr; + struct cond_av_list true_list; + struct cond_av_list false_list; +}; + +void cond_policydb_init(struct policydb *p); +void cond_policydb_destroy(struct policydb *p); + +int cond_init_bool_indexes(struct policydb *p); +int cond_destroy_bool(void *key, void *datum, void *p); + +int cond_index_bool(void *key, void *datum, void *datap); + +int cond_read_bool(struct policydb *p, struct symtab *s, void *fp); +int cond_read_list(struct policydb *p, void *fp); +int cond_write_bool(void *key, void *datum, void *ptr); +int cond_write_list(struct policydb *p, void *fp); + +void cond_compute_av(struct avtab *ctab, struct avtab_key *key, + struct av_decision *avd, struct extended_perms *xperms); +void cond_compute_xperms(struct avtab *ctab, struct avtab_key *key, + struct extended_perms_decision *xpermd); +void evaluate_cond_nodes(struct policydb *p); +void cond_policydb_destroy_dup(struct policydb *p); +int cond_policydb_dup(struct policydb *new, struct policydb *orig); + +#endif /* _CONDITIONAL_H_ */ diff --git a/security/selinux/ss/constraint.h b/security/selinux/ss/constraint.h new file mode 100644 index 000000000..4e563be9e --- /dev/null +++ b/security/selinux/ss/constraint.h @@ -0,0 +1,63 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * A constraint is a condition that must be satisfied in + * order for one or more permissions to be granted. + * Constraints are used to impose additional restrictions + * beyond the type-based rules in `te' or the role-based + * transition rules in `rbac'. Constraints are typically + * used to prevent a process from transitioning to a new user + * identity or role unless it is in a privileged type. + * Constraints are likewise typically used to prevent a + * process from labeling an object with a different user + * identity. + * + * Author : Stephen Smalley, <sds@tycho.nsa.gov> + */ +#ifndef _SS_CONSTRAINT_H_ +#define _SS_CONSTRAINT_H_ + +#include "ebitmap.h" + +#define CEXPR_MAXDEPTH 5 + +struct constraint_expr { +#define CEXPR_NOT 1 /* not expr */ +#define CEXPR_AND 2 /* expr and expr */ +#define CEXPR_OR 3 /* expr or expr */ +#define CEXPR_ATTR 4 /* attr op attr */ +#define CEXPR_NAMES 5 /* attr op names */ + u32 expr_type; /* expression type */ + +#define CEXPR_USER 1 /* user */ +#define CEXPR_ROLE 2 /* role */ +#define CEXPR_TYPE 4 /* type */ +#define CEXPR_TARGET 8 /* target if set, source otherwise */ +#define CEXPR_XTARGET 16 /* special 3rd target for validatetrans rule */ +#define CEXPR_L1L2 32 /* low level 1 vs. low level 2 */ +#define CEXPR_L1H2 64 /* low level 1 vs. high level 2 */ +#define CEXPR_H1L2 128 /* high level 1 vs. low level 2 */ +#define CEXPR_H1H2 256 /* high level 1 vs. high level 2 */ +#define CEXPR_L1H1 512 /* low level 1 vs. high level 1 */ +#define CEXPR_L2H2 1024 /* low level 2 vs. high level 2 */ + u32 attr; /* attribute */ + +#define CEXPR_EQ 1 /* == or eq */ +#define CEXPR_NEQ 2 /* != */ +#define CEXPR_DOM 3 /* dom */ +#define CEXPR_DOMBY 4 /* domby */ +#define CEXPR_INCOMP 5 /* incomp */ + u32 op; /* operator */ + + struct ebitmap names; /* names */ + struct type_set *type_names; + + struct constraint_expr *next; /* next expression */ +}; + +struct constraint_node { + u32 permissions; /* constrained permissions */ + struct constraint_expr *expr; /* constraint on permissions */ + struct constraint_node *next; /* next constraint */ +}; + +#endif /* _SS_CONSTRAINT_H_ */ diff --git a/security/selinux/ss/context.c b/security/selinux/ss/context.c new file mode 100644 index 000000000..38bc0aa52 --- /dev/null +++ b/security/selinux/ss/context.c @@ -0,0 +1,32 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Implementations of the security context functions. + * + * Author: Ondrej Mosnacek <omosnacek@gmail.com> + * Copyright (C) 2020 Red Hat, Inc. + */ + +#include <linux/jhash.h> + +#include "context.h" +#include "mls.h" + +u32 context_compute_hash(const struct context *c) +{ + u32 hash = 0; + + /* + * If a context is invalid, it will always be represented by a + * context struct with only the len & str set (and vice versa) + * under a given policy. Since context structs from different + * policies should never meet, it is safe to hash valid and + * invalid contexts differently. The context_cmp() function + * already operates under the same assumption. + */ + if (c->len) + return full_name_hash(NULL, c->str, c->len); + + hash = jhash_3words(c->user, c->role, c->type, hash); + hash = mls_range_hash(&c->range, hash); + return hash; +} diff --git a/security/selinux/ss/context.h b/security/selinux/ss/context.h new file mode 100644 index 000000000..eda32c3d4 --- /dev/null +++ b/security/selinux/ss/context.h @@ -0,0 +1,199 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * A security context is a set of security attributes + * associated with each subject and object controlled + * by the security policy. Security contexts are + * externally represented as variable-length strings + * that can be interpreted by a user or application + * with an understanding of the security policy. + * Internally, the security server uses a simple + * structure. This structure is private to the + * security server and can be changed without affecting + * clients of the security server. + * + * Author : Stephen Smalley, <sds@tycho.nsa.gov> + */ +#ifndef _SS_CONTEXT_H_ +#define _SS_CONTEXT_H_ + +#include "ebitmap.h" +#include "mls_types.h" +#include "security.h" + +/* + * A security context consists of an authenticated user + * identity, a role, a type and a MLS range. + */ +struct context { + u32 user; + u32 role; + u32 type; + u32 len; /* length of string in bytes */ + struct mls_range range; + char *str; /* string representation if context cannot be mapped. */ +}; + +static inline void mls_context_init(struct context *c) +{ + memset(&c->range, 0, sizeof(c->range)); +} + +static inline int mls_context_cpy(struct context *dst, const struct context *src) +{ + int rc; + + dst->range.level[0].sens = src->range.level[0].sens; + rc = ebitmap_cpy(&dst->range.level[0].cat, &src->range.level[0].cat); + if (rc) + goto out; + + dst->range.level[1].sens = src->range.level[1].sens; + rc = ebitmap_cpy(&dst->range.level[1].cat, &src->range.level[1].cat); + if (rc) + ebitmap_destroy(&dst->range.level[0].cat); +out: + return rc; +} + +/* + * Sets both levels in the MLS range of 'dst' to the low level of 'src'. + */ +static inline int mls_context_cpy_low(struct context *dst, const struct context *src) +{ + int rc; + + dst->range.level[0].sens = src->range.level[0].sens; + rc = ebitmap_cpy(&dst->range.level[0].cat, &src->range.level[0].cat); + if (rc) + goto out; + + dst->range.level[1].sens = src->range.level[0].sens; + rc = ebitmap_cpy(&dst->range.level[1].cat, &src->range.level[0].cat); + if (rc) + ebitmap_destroy(&dst->range.level[0].cat); +out: + return rc; +} + +/* + * Sets both levels in the MLS range of 'dst' to the high level of 'src'. + */ +static inline int mls_context_cpy_high(struct context *dst, const struct context *src) +{ + int rc; + + dst->range.level[0].sens = src->range.level[1].sens; + rc = ebitmap_cpy(&dst->range.level[0].cat, &src->range.level[1].cat); + if (rc) + goto out; + + dst->range.level[1].sens = src->range.level[1].sens; + rc = ebitmap_cpy(&dst->range.level[1].cat, &src->range.level[1].cat); + if (rc) + ebitmap_destroy(&dst->range.level[0].cat); +out: + return rc; +} + + +static inline int mls_context_glblub(struct context *dst, + const struct context *c1, const struct context *c2) +{ + struct mls_range *dr = &dst->range; + const struct mls_range *r1 = &c1->range, *r2 = &c2->range; + int rc = 0; + + if (r1->level[1].sens < r2->level[0].sens || + r2->level[1].sens < r1->level[0].sens) + /* These ranges have no common sensitivities */ + return -EINVAL; + + /* Take the greatest of the low */ + dr->level[0].sens = max(r1->level[0].sens, r2->level[0].sens); + + /* Take the least of the high */ + dr->level[1].sens = min(r1->level[1].sens, r2->level[1].sens); + + rc = ebitmap_and(&dr->level[0].cat, + &r1->level[0].cat, &r2->level[0].cat); + if (rc) + goto out; + + rc = ebitmap_and(&dr->level[1].cat, + &r1->level[1].cat, &r2->level[1].cat); + if (rc) + goto out; + +out: + return rc; +} + +static inline int mls_context_cmp(const struct context *c1, const struct context *c2) +{ + return ((c1->range.level[0].sens == c2->range.level[0].sens) && + ebitmap_cmp(&c1->range.level[0].cat, &c2->range.level[0].cat) && + (c1->range.level[1].sens == c2->range.level[1].sens) && + ebitmap_cmp(&c1->range.level[1].cat, &c2->range.level[1].cat)); +} + +static inline void mls_context_destroy(struct context *c) +{ + ebitmap_destroy(&c->range.level[0].cat); + ebitmap_destroy(&c->range.level[1].cat); + mls_context_init(c); +} + +static inline void context_init(struct context *c) +{ + memset(c, 0, sizeof(*c)); +} + +static inline int context_cpy(struct context *dst, const struct context *src) +{ + int rc; + + dst->user = src->user; + dst->role = src->role; + dst->type = src->type; + if (src->str) { + dst->str = kstrdup(src->str, GFP_ATOMIC); + if (!dst->str) + return -ENOMEM; + dst->len = src->len; + } else { + dst->str = NULL; + dst->len = 0; + } + rc = mls_context_cpy(dst, src); + if (rc) { + kfree(dst->str); + return rc; + } + return 0; +} + +static inline void context_destroy(struct context *c) +{ + c->user = c->role = c->type = 0; + kfree(c->str); + c->str = NULL; + c->len = 0; + mls_context_destroy(c); +} + +static inline int context_cmp(const struct context *c1, const struct context *c2) +{ + if (c1->len && c2->len) + return (c1->len == c2->len && !strcmp(c1->str, c2->str)); + if (c1->len || c2->len) + return 0; + return ((c1->user == c2->user) && + (c1->role == c2->role) && + (c1->type == c2->type) && + mls_context_cmp(c1, c2)); +} + +u32 context_compute_hash(const struct context *c); + +#endif /* _SS_CONTEXT_H_ */ + diff --git a/security/selinux/ss/ebitmap.c b/security/selinux/ss/ebitmap.c new file mode 100644 index 000000000..d31b87be9 --- /dev/null +++ b/security/selinux/ss/ebitmap.c @@ -0,0 +1,564 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Implementation of the extensible bitmap type. + * + * Author : Stephen Smalley, <sds@tycho.nsa.gov> + */ +/* + * Updated: Hewlett-Packard <paul@paul-moore.com> + * + * Added support to import/export the NetLabel category bitmap + * + * (c) Copyright Hewlett-Packard Development Company, L.P., 2006 + */ +/* + * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com> + * Applied standard bit operations to improve bitmap scanning. + */ + +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/errno.h> +#include <linux/jhash.h> +#include <net/netlabel.h> +#include "ebitmap.h" +#include "policydb.h" + +#define BITS_PER_U64 (sizeof(u64) * 8) + +static struct kmem_cache *ebitmap_node_cachep __ro_after_init; + +int ebitmap_cmp(const struct ebitmap *e1, const struct ebitmap *e2) +{ + const struct ebitmap_node *n1, *n2; + + if (e1->highbit != e2->highbit) + return 0; + + n1 = e1->node; + n2 = e2->node; + while (n1 && n2 && + (n1->startbit == n2->startbit) && + !memcmp(n1->maps, n2->maps, EBITMAP_SIZE / 8)) { + n1 = n1->next; + n2 = n2->next; + } + + if (n1 || n2) + return 0; + + return 1; +} + +int ebitmap_cpy(struct ebitmap *dst, const struct ebitmap *src) +{ + struct ebitmap_node *new, *prev; + const struct ebitmap_node *n; + + ebitmap_init(dst); + n = src->node; + prev = NULL; + while (n) { + new = kmem_cache_zalloc(ebitmap_node_cachep, GFP_ATOMIC); + if (!new) { + ebitmap_destroy(dst); + return -ENOMEM; + } + new->startbit = n->startbit; + memcpy(new->maps, n->maps, EBITMAP_SIZE / 8); + new->next = NULL; + if (prev) + prev->next = new; + else + dst->node = new; + prev = new; + n = n->next; + } + + dst->highbit = src->highbit; + return 0; +} + +int ebitmap_and(struct ebitmap *dst, const struct ebitmap *e1, const struct ebitmap *e2) +{ + struct ebitmap_node *n; + int bit, rc; + + ebitmap_init(dst); + + ebitmap_for_each_positive_bit(e1, n, bit) { + if (ebitmap_get_bit(e2, bit)) { + rc = ebitmap_set_bit(dst, bit, 1); + if (rc < 0) + return rc; + } + } + return 0; +} + + +#ifdef CONFIG_NETLABEL +/** + * ebitmap_netlbl_export - Export an ebitmap into a NetLabel category bitmap + * @ebmap: the ebitmap to export + * @catmap: the NetLabel category bitmap + * + * Description: + * Export a SELinux extensibile bitmap into a NetLabel category bitmap. + * Returns zero on success, negative values on error. + * + */ +int ebitmap_netlbl_export(struct ebitmap *ebmap, + struct netlbl_lsm_catmap **catmap) +{ + struct ebitmap_node *e_iter = ebmap->node; + unsigned long e_map; + u32 offset; + unsigned int iter; + int rc; + + if (e_iter == NULL) { + *catmap = NULL; + return 0; + } + + if (*catmap != NULL) + netlbl_catmap_free(*catmap); + *catmap = NULL; + + while (e_iter) { + offset = e_iter->startbit; + for (iter = 0; iter < EBITMAP_UNIT_NUMS; iter++) { + e_map = e_iter->maps[iter]; + if (e_map != 0) { + rc = netlbl_catmap_setlong(catmap, + offset, + e_map, + GFP_ATOMIC); + if (rc != 0) + goto netlbl_export_failure; + } + offset += EBITMAP_UNIT_SIZE; + } + e_iter = e_iter->next; + } + + return 0; + +netlbl_export_failure: + netlbl_catmap_free(*catmap); + return -ENOMEM; +} + +/** + * ebitmap_netlbl_import - Import a NetLabel category bitmap into an ebitmap + * @ebmap: the ebitmap to import + * @catmap: the NetLabel category bitmap + * + * Description: + * Import a NetLabel category bitmap into a SELinux extensibile bitmap. + * Returns zero on success, negative values on error. + * + */ +int ebitmap_netlbl_import(struct ebitmap *ebmap, + struct netlbl_lsm_catmap *catmap) +{ + int rc; + struct ebitmap_node *e_iter = NULL; + struct ebitmap_node *e_prev = NULL; + u32 offset = 0, idx; + unsigned long bitmap; + + for (;;) { + rc = netlbl_catmap_getlong(catmap, &offset, &bitmap); + if (rc < 0) + goto netlbl_import_failure; + if (offset == (u32)-1) + return 0; + + /* don't waste ebitmap space if the netlabel bitmap is empty */ + if (bitmap == 0) { + offset += EBITMAP_UNIT_SIZE; + continue; + } + + if (e_iter == NULL || + offset >= e_iter->startbit + EBITMAP_SIZE) { + e_prev = e_iter; + e_iter = kmem_cache_zalloc(ebitmap_node_cachep, GFP_ATOMIC); + if (e_iter == NULL) + goto netlbl_import_failure; + e_iter->startbit = offset - (offset % EBITMAP_SIZE); + if (e_prev == NULL) + ebmap->node = e_iter; + else + e_prev->next = e_iter; + ebmap->highbit = e_iter->startbit + EBITMAP_SIZE; + } + + /* offset will always be aligned to an unsigned long */ + idx = EBITMAP_NODE_INDEX(e_iter, offset); + e_iter->maps[idx] = bitmap; + + /* next */ + offset += EBITMAP_UNIT_SIZE; + } + + /* NOTE: we should never reach this return */ + return 0; + +netlbl_import_failure: + ebitmap_destroy(ebmap); + return -ENOMEM; +} +#endif /* CONFIG_NETLABEL */ + +/* + * Check to see if all the bits set in e2 are also set in e1. Optionally, + * if last_e2bit is non-zero, the highest set bit in e2 cannot exceed + * last_e2bit. + */ +int ebitmap_contains(const struct ebitmap *e1, const struct ebitmap *e2, u32 last_e2bit) +{ + const struct ebitmap_node *n1, *n2; + int i; + + if (e1->highbit < e2->highbit) + return 0; + + n1 = e1->node; + n2 = e2->node; + + while (n1 && n2 && (n1->startbit <= n2->startbit)) { + if (n1->startbit < n2->startbit) { + n1 = n1->next; + continue; + } + for (i = EBITMAP_UNIT_NUMS - 1; (i >= 0) && !n2->maps[i]; ) + i--; /* Skip trailing NULL map entries */ + if (last_e2bit && (i >= 0)) { + u32 lastsetbit = n2->startbit + i * EBITMAP_UNIT_SIZE + + __fls(n2->maps[i]); + if (lastsetbit > last_e2bit) + return 0; + } + + while (i >= 0) { + if ((n1->maps[i] & n2->maps[i]) != n2->maps[i]) + return 0; + i--; + } + + n1 = n1->next; + n2 = n2->next; + } + + if (n2) + return 0; + + return 1; +} + +int ebitmap_get_bit(const struct ebitmap *e, unsigned long bit) +{ + const struct ebitmap_node *n; + + if (e->highbit < bit) + return 0; + + n = e->node; + while (n && (n->startbit <= bit)) { + if ((n->startbit + EBITMAP_SIZE) > bit) + return ebitmap_node_get_bit(n, bit); + n = n->next; + } + + return 0; +} + +int ebitmap_set_bit(struct ebitmap *e, unsigned long bit, int value) +{ + struct ebitmap_node *n, *prev, *new; + + prev = NULL; + n = e->node; + while (n && n->startbit <= bit) { + if ((n->startbit + EBITMAP_SIZE) > bit) { + if (value) { + ebitmap_node_set_bit(n, bit); + } else { + unsigned int s; + + ebitmap_node_clr_bit(n, bit); + + s = find_first_bit(n->maps, EBITMAP_SIZE); + if (s < EBITMAP_SIZE) + return 0; + + /* drop this node from the bitmap */ + if (!n->next) { + /* + * this was the highest map + * within the bitmap + */ + if (prev) + e->highbit = prev->startbit + + EBITMAP_SIZE; + else + e->highbit = 0; + } + if (prev) + prev->next = n->next; + else + e->node = n->next; + kmem_cache_free(ebitmap_node_cachep, n); + } + return 0; + } + prev = n; + n = n->next; + } + + if (!value) + return 0; + + new = kmem_cache_zalloc(ebitmap_node_cachep, GFP_ATOMIC); + if (!new) + return -ENOMEM; + + new->startbit = bit - (bit % EBITMAP_SIZE); + ebitmap_node_set_bit(new, bit); + + if (!n) + /* this node will be the highest map within the bitmap */ + e->highbit = new->startbit + EBITMAP_SIZE; + + if (prev) { + new->next = prev->next; + prev->next = new; + } else { + new->next = e->node; + e->node = new; + } + + return 0; +} + +void ebitmap_destroy(struct ebitmap *e) +{ + struct ebitmap_node *n, *temp; + + if (!e) + return; + + n = e->node; + while (n) { + temp = n; + n = n->next; + kmem_cache_free(ebitmap_node_cachep, temp); + } + + e->highbit = 0; + e->node = NULL; +} + +int ebitmap_read(struct ebitmap *e, void *fp) +{ + struct ebitmap_node *n = NULL; + u32 mapunit, count, startbit, index; + __le32 ebitmap_start; + u64 map; + __le64 mapbits; + __le32 buf[3]; + int rc, i; + + ebitmap_init(e); + + rc = next_entry(buf, fp, sizeof buf); + if (rc < 0) + goto out; + + mapunit = le32_to_cpu(buf[0]); + e->highbit = le32_to_cpu(buf[1]); + count = le32_to_cpu(buf[2]); + + if (mapunit != BITS_PER_U64) { + pr_err("SELinux: ebitmap: map size %u does not " + "match my size %zd (high bit was %d)\n", + mapunit, BITS_PER_U64, e->highbit); + goto bad; + } + + /* round up e->highbit */ + e->highbit += EBITMAP_SIZE - 1; + e->highbit -= (e->highbit % EBITMAP_SIZE); + + if (!e->highbit) { + e->node = NULL; + goto ok; + } + + if (e->highbit && !count) + goto bad; + + for (i = 0; i < count; i++) { + rc = next_entry(&ebitmap_start, fp, sizeof(u32)); + if (rc < 0) { + pr_err("SELinux: ebitmap: truncated map\n"); + goto bad; + } + startbit = le32_to_cpu(ebitmap_start); + + if (startbit & (mapunit - 1)) { + pr_err("SELinux: ebitmap start bit (%d) is " + "not a multiple of the map unit size (%u)\n", + startbit, mapunit); + goto bad; + } + if (startbit > e->highbit - mapunit) { + pr_err("SELinux: ebitmap start bit (%d) is " + "beyond the end of the bitmap (%u)\n", + startbit, (e->highbit - mapunit)); + goto bad; + } + + if (!n || startbit >= n->startbit + EBITMAP_SIZE) { + struct ebitmap_node *tmp; + tmp = kmem_cache_zalloc(ebitmap_node_cachep, GFP_KERNEL); + if (!tmp) { + pr_err("SELinux: ebitmap: out of memory\n"); + rc = -ENOMEM; + goto bad; + } + /* round down */ + tmp->startbit = startbit - (startbit % EBITMAP_SIZE); + if (n) + n->next = tmp; + else + e->node = tmp; + n = tmp; + } else if (startbit <= n->startbit) { + pr_err("SELinux: ebitmap: start bit %d" + " comes after start bit %d\n", + startbit, n->startbit); + goto bad; + } + + rc = next_entry(&mapbits, fp, sizeof(u64)); + if (rc < 0) { + pr_err("SELinux: ebitmap: truncated map\n"); + goto bad; + } + map = le64_to_cpu(mapbits); + + index = (startbit - n->startbit) / EBITMAP_UNIT_SIZE; + while (map) { + n->maps[index++] = map & (-1UL); + map = EBITMAP_SHIFT_UNIT_SIZE(map); + } + } +ok: + rc = 0; +out: + return rc; +bad: + if (!rc) + rc = -EINVAL; + ebitmap_destroy(e); + goto out; +} + +int ebitmap_write(const struct ebitmap *e, void *fp) +{ + struct ebitmap_node *n; + u32 count; + __le32 buf[3]; + u64 map; + int bit, last_bit, last_startbit, rc; + + buf[0] = cpu_to_le32(BITS_PER_U64); + + count = 0; + last_bit = 0; + last_startbit = -1; + ebitmap_for_each_positive_bit(e, n, bit) { + if (rounddown(bit, (int)BITS_PER_U64) > last_startbit) { + count++; + last_startbit = rounddown(bit, BITS_PER_U64); + } + last_bit = roundup(bit + 1, BITS_PER_U64); + } + buf[1] = cpu_to_le32(last_bit); + buf[2] = cpu_to_le32(count); + + rc = put_entry(buf, sizeof(u32), 3, fp); + if (rc) + return rc; + + map = 0; + last_startbit = INT_MIN; + ebitmap_for_each_positive_bit(e, n, bit) { + if (rounddown(bit, (int)BITS_PER_U64) > last_startbit) { + __le64 buf64[1]; + + /* this is the very first bit */ + if (!map) { + last_startbit = rounddown(bit, BITS_PER_U64); + map = (u64)1 << (bit - last_startbit); + continue; + } + + /* write the last node */ + buf[0] = cpu_to_le32(last_startbit); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + + buf64[0] = cpu_to_le64(map); + rc = put_entry(buf64, sizeof(u64), 1, fp); + if (rc) + return rc; + + /* set up for the next node */ + map = 0; + last_startbit = rounddown(bit, BITS_PER_U64); + } + map |= (u64)1 << (bit - last_startbit); + } + /* write the last node */ + if (map) { + __le64 buf64[1]; + + /* write the last node */ + buf[0] = cpu_to_le32(last_startbit); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + + buf64[0] = cpu_to_le64(map); + rc = put_entry(buf64, sizeof(u64), 1, fp); + if (rc) + return rc; + } + return 0; +} + +u32 ebitmap_hash(const struct ebitmap *e, u32 hash) +{ + struct ebitmap_node *node; + + /* need to change hash even if ebitmap is empty */ + hash = jhash_1word(e->highbit, hash); + for (node = e->node; node; node = node->next) { + hash = jhash_1word(node->startbit, hash); + hash = jhash(node->maps, sizeof(node->maps), hash); + } + return hash; +} + +void __init ebitmap_cache_init(void) +{ + ebitmap_node_cachep = kmem_cache_create("ebitmap_node", + sizeof(struct ebitmap_node), + 0, SLAB_PANIC, NULL); +} diff --git a/security/selinux/ss/ebitmap.h b/security/selinux/ss/ebitmap.h new file mode 100644 index 000000000..e5b57dc3f --- /dev/null +++ b/security/selinux/ss/ebitmap.h @@ -0,0 +1,154 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * An extensible bitmap is a bitmap that supports an + * arbitrary number of bits. Extensible bitmaps are + * used to represent sets of values, such as types, + * roles, categories, and classes. + * + * Each extensible bitmap is implemented as a linked + * list of bitmap nodes, where each bitmap node has + * an explicitly specified starting bit position within + * the total bitmap. + * + * Author : Stephen Smalley, <sds@tycho.nsa.gov> + */ +#ifndef _SS_EBITMAP_H_ +#define _SS_EBITMAP_H_ + +#include <net/netlabel.h> + +#ifdef CONFIG_64BIT +#define EBITMAP_NODE_SIZE 64 +#else +#define EBITMAP_NODE_SIZE 32 +#endif + +#define EBITMAP_UNIT_NUMS ((EBITMAP_NODE_SIZE-sizeof(void *)-sizeof(u32))\ + / sizeof(unsigned long)) +#define EBITMAP_UNIT_SIZE BITS_PER_LONG +#define EBITMAP_SIZE (EBITMAP_UNIT_NUMS * EBITMAP_UNIT_SIZE) +#define EBITMAP_BIT 1ULL +#define EBITMAP_SHIFT_UNIT_SIZE(x) \ + (((x) >> EBITMAP_UNIT_SIZE / 2) >> EBITMAP_UNIT_SIZE / 2) + +struct ebitmap_node { + struct ebitmap_node *next; + unsigned long maps[EBITMAP_UNIT_NUMS]; + u32 startbit; +}; + +struct ebitmap { + struct ebitmap_node *node; /* first node in the bitmap */ + u32 highbit; /* highest position in the total bitmap */ +}; + +#define ebitmap_length(e) ((e)->highbit) + +static inline unsigned int ebitmap_start_positive(const struct ebitmap *e, + struct ebitmap_node **n) +{ + unsigned int ofs; + + for (*n = e->node; *n; *n = (*n)->next) { + ofs = find_first_bit((*n)->maps, EBITMAP_SIZE); + if (ofs < EBITMAP_SIZE) + return (*n)->startbit + ofs; + } + return ebitmap_length(e); +} + +static inline void ebitmap_init(struct ebitmap *e) +{ + memset(e, 0, sizeof(*e)); +} + +static inline unsigned int ebitmap_next_positive(const struct ebitmap *e, + struct ebitmap_node **n, + unsigned int bit) +{ + unsigned int ofs; + + ofs = find_next_bit((*n)->maps, EBITMAP_SIZE, bit - (*n)->startbit + 1); + if (ofs < EBITMAP_SIZE) + return ofs + (*n)->startbit; + + for (*n = (*n)->next; *n; *n = (*n)->next) { + ofs = find_first_bit((*n)->maps, EBITMAP_SIZE); + if (ofs < EBITMAP_SIZE) + return ofs + (*n)->startbit; + } + return ebitmap_length(e); +} + +#define EBITMAP_NODE_INDEX(node, bit) \ + (((bit) - (node)->startbit) / EBITMAP_UNIT_SIZE) +#define EBITMAP_NODE_OFFSET(node, bit) \ + (((bit) - (node)->startbit) % EBITMAP_UNIT_SIZE) + +static inline int ebitmap_node_get_bit(const struct ebitmap_node *n, + unsigned int bit) +{ + unsigned int index = EBITMAP_NODE_INDEX(n, bit); + unsigned int ofs = EBITMAP_NODE_OFFSET(n, bit); + + BUG_ON(index >= EBITMAP_UNIT_NUMS); + if ((n->maps[index] & (EBITMAP_BIT << ofs))) + return 1; + return 0; +} + +static inline void ebitmap_node_set_bit(struct ebitmap_node *n, + unsigned int bit) +{ + unsigned int index = EBITMAP_NODE_INDEX(n, bit); + unsigned int ofs = EBITMAP_NODE_OFFSET(n, bit); + + BUG_ON(index >= EBITMAP_UNIT_NUMS); + n->maps[index] |= (EBITMAP_BIT << ofs); +} + +static inline void ebitmap_node_clr_bit(struct ebitmap_node *n, + unsigned int bit) +{ + unsigned int index = EBITMAP_NODE_INDEX(n, bit); + unsigned int ofs = EBITMAP_NODE_OFFSET(n, bit); + + BUG_ON(index >= EBITMAP_UNIT_NUMS); + n->maps[index] &= ~(EBITMAP_BIT << ofs); +} + +#define ebitmap_for_each_positive_bit(e, n, bit) \ + for ((bit) = ebitmap_start_positive(e, &(n)); \ + (bit) < ebitmap_length(e); \ + (bit) = ebitmap_next_positive(e, &(n), bit)) \ + +int ebitmap_cmp(const struct ebitmap *e1, const struct ebitmap *e2); +int ebitmap_cpy(struct ebitmap *dst, const struct ebitmap *src); +int ebitmap_and(struct ebitmap *dst, const struct ebitmap *e1, const struct ebitmap *e2); +int ebitmap_contains(const struct ebitmap *e1, const struct ebitmap *e2, u32 last_e2bit); +int ebitmap_get_bit(const struct ebitmap *e, unsigned long bit); +int ebitmap_set_bit(struct ebitmap *e, unsigned long bit, int value); +void ebitmap_destroy(struct ebitmap *e); +int ebitmap_read(struct ebitmap *e, void *fp); +int ebitmap_write(const struct ebitmap *e, void *fp); +u32 ebitmap_hash(const struct ebitmap *e, u32 hash); + +#ifdef CONFIG_NETLABEL +int ebitmap_netlbl_export(struct ebitmap *ebmap, + struct netlbl_lsm_catmap **catmap); +int ebitmap_netlbl_import(struct ebitmap *ebmap, + struct netlbl_lsm_catmap *catmap); +#else +static inline int ebitmap_netlbl_export(struct ebitmap *ebmap, + struct netlbl_lsm_catmap **catmap) +{ + return -ENOMEM; +} +static inline int ebitmap_netlbl_import(struct ebitmap *ebmap, + struct netlbl_lsm_catmap *catmap) +{ + return -ENOMEM; +} +#endif + +#endif /* _SS_EBITMAP_H_ */ diff --git a/security/selinux/ss/hashtab.c b/security/selinux/ss/hashtab.c new file mode 100644 index 000000000..3fb8f9026 --- /dev/null +++ b/security/selinux/ss/hashtab.c @@ -0,0 +1,192 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Implementation of the hash table type. + * + * Author : Stephen Smalley, <sds@tycho.nsa.gov> + */ +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/errno.h> +#include "hashtab.h" +#include "security.h" + +static struct kmem_cache *hashtab_node_cachep __ro_after_init; + +/* + * Here we simply round the number of elements up to the nearest power of two. + * I tried also other options like rounding down or rounding to the closest + * power of two (up or down based on which is closer), but I was unable to + * find any significant difference in lookup/insert performance that would + * justify switching to a different (less intuitive) formula. It could be that + * a different formula is actually more optimal, but any future changes here + * should be supported with performance/memory usage data. + * + * The total memory used by the htable arrays (only) with Fedora policy loaded + * is approximately 163 KB at the time of writing. + */ +static u32 hashtab_compute_size(u32 nel) +{ + return nel == 0 ? 0 : roundup_pow_of_two(nel); +} + +int hashtab_init(struct hashtab *h, u32 nel_hint) +{ + u32 size = hashtab_compute_size(nel_hint); + + /* should already be zeroed, but better be safe */ + h->nel = 0; + h->size = 0; + h->htable = NULL; + + if (size) { + h->htable = kcalloc(size, sizeof(*h->htable), GFP_KERNEL); + if (!h->htable) + return -ENOMEM; + h->size = size; + } + return 0; +} + +int __hashtab_insert(struct hashtab *h, struct hashtab_node **dst, + void *key, void *datum) +{ + struct hashtab_node *newnode; + + newnode = kmem_cache_zalloc(hashtab_node_cachep, GFP_KERNEL); + if (!newnode) + return -ENOMEM; + newnode->key = key; + newnode->datum = datum; + newnode->next = *dst; + *dst = newnode; + + h->nel++; + return 0; +} + +void hashtab_destroy(struct hashtab *h) +{ + u32 i; + struct hashtab_node *cur, *temp; + + for (i = 0; i < h->size; i++) { + cur = h->htable[i]; + while (cur) { + temp = cur; + cur = cur->next; + kmem_cache_free(hashtab_node_cachep, temp); + } + h->htable[i] = NULL; + } + + kfree(h->htable); + h->htable = NULL; +} + +int hashtab_map(struct hashtab *h, + int (*apply)(void *k, void *d, void *args), + void *args) +{ + u32 i; + int ret; + struct hashtab_node *cur; + + for (i = 0; i < h->size; i++) { + cur = h->htable[i]; + while (cur) { + ret = apply(cur->key, cur->datum, args); + if (ret) + return ret; + cur = cur->next; + } + } + return 0; +} + + +void hashtab_stat(struct hashtab *h, struct hashtab_info *info) +{ + u32 i, chain_len, slots_used, max_chain_len; + struct hashtab_node *cur; + + slots_used = 0; + max_chain_len = 0; + for (i = 0; i < h->size; i++) { + cur = h->htable[i]; + if (cur) { + slots_used++; + chain_len = 0; + while (cur) { + chain_len++; + cur = cur->next; + } + + if (chain_len > max_chain_len) + max_chain_len = chain_len; + } + } + + info->slots_used = slots_used; + info->max_chain_len = max_chain_len; +} + +int hashtab_duplicate(struct hashtab *new, struct hashtab *orig, + int (*copy)(struct hashtab_node *new, + struct hashtab_node *orig, void *args), + int (*destroy)(void *k, void *d, void *args), + void *args) +{ + struct hashtab_node *cur, *tmp, *tail; + int i, rc; + + memset(new, 0, sizeof(*new)); + + new->htable = kcalloc(orig->size, sizeof(*new->htable), GFP_KERNEL); + if (!new->htable) + return -ENOMEM; + + new->size = orig->size; + + for (i = 0; i < orig->size; i++) { + tail = NULL; + for (cur = orig->htable[i]; cur; cur = cur->next) { + tmp = kmem_cache_zalloc(hashtab_node_cachep, + GFP_KERNEL); + if (!tmp) + goto error; + rc = copy(tmp, cur, args); + if (rc) { + kmem_cache_free(hashtab_node_cachep, tmp); + goto error; + } + tmp->next = NULL; + if (!tail) + new->htable[i] = tmp; + else + tail->next = tmp; + tail = tmp; + new->nel++; + } + } + + return 0; + + error: + for (i = 0; i < new->size; i++) { + for (cur = new->htable[i]; cur; cur = tmp) { + tmp = cur->next; + destroy(cur->key, cur->datum, args); + kmem_cache_free(hashtab_node_cachep, cur); + } + } + kfree(new->htable); + memset(new, 0, sizeof(*new)); + return -ENOMEM; +} + +void __init hashtab_cache_init(void) +{ + hashtab_node_cachep = kmem_cache_create("hashtab_node", + sizeof(struct hashtab_node), + 0, SLAB_PANIC, NULL); +} diff --git a/security/selinux/ss/hashtab.h b/security/selinux/ss/hashtab.h new file mode 100644 index 000000000..043a773bf --- /dev/null +++ b/security/selinux/ss/hashtab.h @@ -0,0 +1,148 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * A hash table (hashtab) maintains associations between + * key values and datum values. The type of the key values + * and the type of the datum values is arbitrary. The + * functions for hash computation and key comparison are + * provided by the creator of the table. + * + * Author : Stephen Smalley, <sds@tycho.nsa.gov> + */ +#ifndef _SS_HASHTAB_H_ +#define _SS_HASHTAB_H_ + +#include <linux/types.h> +#include <linux/errno.h> +#include <linux/sched.h> + +#define HASHTAB_MAX_NODES U32_MAX + +struct hashtab_key_params { + u32 (*hash)(const void *key); /* hash function */ + int (*cmp)(const void *key1, const void *key2); + /* key comparison function */ +}; + +struct hashtab_node { + void *key; + void *datum; + struct hashtab_node *next; +}; + +struct hashtab { + struct hashtab_node **htable; /* hash table */ + u32 size; /* number of slots in hash table */ + u32 nel; /* number of elements in hash table */ +}; + +struct hashtab_info { + u32 slots_used; + u32 max_chain_len; +}; + +/* + * Initializes a new hash table with the specified characteristics. + * + * Returns -ENOMEM if insufficient space is available or 0 otherwise. + */ +int hashtab_init(struct hashtab *h, u32 nel_hint); + +int __hashtab_insert(struct hashtab *h, struct hashtab_node **dst, + void *key, void *datum); + +/* + * Inserts the specified (key, datum) pair into the specified hash table. + * + * Returns -ENOMEM on memory allocation error, + * -EEXIST if there is already an entry with the same key, + * -EINVAL for general errors or + 0 otherwise. + */ +static inline int hashtab_insert(struct hashtab *h, void *key, void *datum, + struct hashtab_key_params key_params) +{ + u32 hvalue; + struct hashtab_node *prev, *cur; + + cond_resched(); + + if (!h->size || h->nel == HASHTAB_MAX_NODES) + return -EINVAL; + + hvalue = key_params.hash(key) & (h->size - 1); + prev = NULL; + cur = h->htable[hvalue]; + while (cur) { + int cmp = key_params.cmp(key, cur->key); + + if (cmp == 0) + return -EEXIST; + if (cmp < 0) + break; + prev = cur; + cur = cur->next; + } + + return __hashtab_insert(h, prev ? &prev->next : &h->htable[hvalue], + key, datum); +} + +/* + * Searches for the entry with the specified key in the hash table. + * + * Returns NULL if no entry has the specified key or + * the datum of the entry otherwise. + */ +static inline void *hashtab_search(struct hashtab *h, const void *key, + struct hashtab_key_params key_params) +{ + u32 hvalue; + struct hashtab_node *cur; + + if (!h->size) + return NULL; + + hvalue = key_params.hash(key) & (h->size - 1); + cur = h->htable[hvalue]; + while (cur) { + int cmp = key_params.cmp(key, cur->key); + + if (cmp == 0) + return cur->datum; + if (cmp < 0) + break; + cur = cur->next; + } + return NULL; +} + +/* + * Destroys the specified hash table. + */ +void hashtab_destroy(struct hashtab *h); + +/* + * Applies the specified apply function to (key,datum,args) + * for each entry in the specified hash table. + * + * The order in which the function is applied to the entries + * is dependent upon the internal structure of the hash table. + * + * If apply returns a non-zero status, then hashtab_map will cease + * iterating through the hash table and will propagate the error + * return to its caller. + */ +int hashtab_map(struct hashtab *h, + int (*apply)(void *k, void *d, void *args), + void *args); + +int hashtab_duplicate(struct hashtab *new, struct hashtab *orig, + int (*copy)(struct hashtab_node *new, + struct hashtab_node *orig, void *args), + int (*destroy)(void *k, void *d, void *args), + void *args); + +/* Fill info with some hash table statistics */ +void hashtab_stat(struct hashtab *h, struct hashtab_info *info); + +#endif /* _SS_HASHTAB_H */ diff --git a/security/selinux/ss/mls.c b/security/selinux/ss/mls.c new file mode 100644 index 000000000..99571b19d --- /dev/null +++ b/security/selinux/ss/mls.c @@ -0,0 +1,660 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Implementation of the multi-level security (MLS) policy. + * + * Author : Stephen Smalley, <sds@tycho.nsa.gov> + */ +/* + * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com> + * + * Support for enhanced MLS infrastructure. + * + * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc. + */ +/* + * Updated: Hewlett-Packard <paul@paul-moore.com> + * + * Added support to import/export the MLS label from NetLabel + * + * (c) Copyright Hewlett-Packard Development Company, L.P., 2006 + */ + +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/errno.h> +#include <net/netlabel.h> +#include "sidtab.h" +#include "mls.h" +#include "policydb.h" +#include "services.h" + +/* + * Return the length in bytes for the MLS fields of the + * security context string representation of `context'. + */ +int mls_compute_context_len(struct policydb *p, struct context *context) +{ + int i, l, len, head, prev; + char *nm; + struct ebitmap *e; + struct ebitmap_node *node; + + if (!p->mls_enabled) + return 0; + + len = 1; /* for the beginning ":" */ + for (l = 0; l < 2; l++) { + int index_sens = context->range.level[l].sens; + len += strlen(sym_name(p, SYM_LEVELS, index_sens - 1)); + + /* categories */ + head = -2; + prev = -2; + e = &context->range.level[l].cat; + ebitmap_for_each_positive_bit(e, node, i) { + if (i - prev > 1) { + /* one or more negative bits are skipped */ + if (head != prev) { + nm = sym_name(p, SYM_CATS, prev); + len += strlen(nm) + 1; + } + nm = sym_name(p, SYM_CATS, i); + len += strlen(nm) + 1; + head = i; + } + prev = i; + } + if (prev != head) { + nm = sym_name(p, SYM_CATS, prev); + len += strlen(nm) + 1; + } + if (l == 0) { + if (mls_level_eq(&context->range.level[0], + &context->range.level[1])) + break; + else + len++; + } + } + + return len; +} + +/* + * Write the security context string representation of + * the MLS fields of `context' into the string `*scontext'. + * Update `*scontext' to point to the end of the MLS fields. + */ +void mls_sid_to_context(struct policydb *p, + struct context *context, + char **scontext) +{ + char *scontextp, *nm; + int i, l, head, prev; + struct ebitmap *e; + struct ebitmap_node *node; + + if (!p->mls_enabled) + return; + + scontextp = *scontext; + + *scontextp = ':'; + scontextp++; + + for (l = 0; l < 2; l++) { + strcpy(scontextp, sym_name(p, SYM_LEVELS, + context->range.level[l].sens - 1)); + scontextp += strlen(scontextp); + + /* categories */ + head = -2; + prev = -2; + e = &context->range.level[l].cat; + ebitmap_for_each_positive_bit(e, node, i) { + if (i - prev > 1) { + /* one or more negative bits are skipped */ + if (prev != head) { + if (prev - head > 1) + *scontextp++ = '.'; + else + *scontextp++ = ','; + nm = sym_name(p, SYM_CATS, prev); + strcpy(scontextp, nm); + scontextp += strlen(nm); + } + if (prev < 0) + *scontextp++ = ':'; + else + *scontextp++ = ','; + nm = sym_name(p, SYM_CATS, i); + strcpy(scontextp, nm); + scontextp += strlen(nm); + head = i; + } + prev = i; + } + + if (prev != head) { + if (prev - head > 1) + *scontextp++ = '.'; + else + *scontextp++ = ','; + nm = sym_name(p, SYM_CATS, prev); + strcpy(scontextp, nm); + scontextp += strlen(nm); + } + + if (l == 0) { + if (mls_level_eq(&context->range.level[0], + &context->range.level[1])) + break; + else + *scontextp++ = '-'; + } + } + + *scontext = scontextp; +} + +int mls_level_isvalid(struct policydb *p, struct mls_level *l) +{ + struct level_datum *levdatum; + + if (!l->sens || l->sens > p->p_levels.nprim) + return 0; + levdatum = symtab_search(&p->p_levels, + sym_name(p, SYM_LEVELS, l->sens - 1)); + if (!levdatum) + return 0; + + /* + * Return 1 iff all the bits set in l->cat are also be set in + * levdatum->level->cat and no bit in l->cat is larger than + * p->p_cats.nprim. + */ + return ebitmap_contains(&levdatum->level->cat, &l->cat, + p->p_cats.nprim); +} + +int mls_range_isvalid(struct policydb *p, struct mls_range *r) +{ + return (mls_level_isvalid(p, &r->level[0]) && + mls_level_isvalid(p, &r->level[1]) && + mls_level_dom(&r->level[1], &r->level[0])); +} + +/* + * Return 1 if the MLS fields in the security context + * structure `c' are valid. Return 0 otherwise. + */ +int mls_context_isvalid(struct policydb *p, struct context *c) +{ + struct user_datum *usrdatum; + + if (!p->mls_enabled) + return 1; + + if (!mls_range_isvalid(p, &c->range)) + return 0; + + if (c->role == OBJECT_R_VAL) + return 1; + + /* + * User must be authorized for the MLS range. + */ + if (!c->user || c->user > p->p_users.nprim) + return 0; + usrdatum = p->user_val_to_struct[c->user - 1]; + if (!mls_range_contains(usrdatum->range, c->range)) + return 0; /* user may not be associated with range */ + + return 1; +} + +/* + * Set the MLS fields in the security context structure + * `context' based on the string representation in + * the string `scontext'. + * + * This function modifies the string in place, inserting + * NULL characters to terminate the MLS fields. + * + * If a def_sid is provided and no MLS field is present, + * copy the MLS field of the associated default context. + * Used for upgraded to MLS systems where objects may lack + * MLS fields. + * + * Policy read-lock must be held for sidtab lookup. + * + */ +int mls_context_to_sid(struct policydb *pol, + char oldc, + char *scontext, + struct context *context, + struct sidtab *s, + u32 def_sid) +{ + char *sensitivity, *cur_cat, *next_cat, *rngptr; + struct level_datum *levdatum; + struct cat_datum *catdatum, *rngdatum; + int l, rc, i; + char *rangep[2]; + + if (!pol->mls_enabled) { + /* + * With no MLS, only return -EINVAL if there is a MLS field + * and it did not come from an xattr. + */ + if (oldc && def_sid == SECSID_NULL) + return -EINVAL; + return 0; + } + + /* + * No MLS component to the security context, try and map to + * default if provided. + */ + if (!oldc) { + struct context *defcon; + + if (def_sid == SECSID_NULL) + return -EINVAL; + + defcon = sidtab_search(s, def_sid); + if (!defcon) + return -EINVAL; + + return mls_context_cpy(context, defcon); + } + + /* + * If we're dealing with a range, figure out where the two parts + * of the range begin. + */ + rangep[0] = scontext; + rangep[1] = strchr(scontext, '-'); + if (rangep[1]) { + rangep[1][0] = '\0'; + rangep[1]++; + } + + /* For each part of the range: */ + for (l = 0; l < 2; l++) { + /* Split sensitivity and category set. */ + sensitivity = rangep[l]; + if (sensitivity == NULL) + break; + next_cat = strchr(sensitivity, ':'); + if (next_cat) + *(next_cat++) = '\0'; + + /* Parse sensitivity. */ + levdatum = symtab_search(&pol->p_levels, sensitivity); + if (!levdatum) + return -EINVAL; + context->range.level[l].sens = levdatum->level->sens; + + /* Extract category set. */ + while (next_cat != NULL) { + cur_cat = next_cat; + next_cat = strchr(next_cat, ','); + if (next_cat != NULL) + *(next_cat++) = '\0'; + + /* Separate into range if exists */ + rngptr = strchr(cur_cat, '.'); + if (rngptr != NULL) { + /* Remove '.' */ + *rngptr++ = '\0'; + } + + catdatum = symtab_search(&pol->p_cats, cur_cat); + if (!catdatum) + return -EINVAL; + + rc = ebitmap_set_bit(&context->range.level[l].cat, + catdatum->value - 1, 1); + if (rc) + return rc; + + /* If range, set all categories in range */ + if (rngptr == NULL) + continue; + + rngdatum = symtab_search(&pol->p_cats, rngptr); + if (!rngdatum) + return -EINVAL; + + if (catdatum->value >= rngdatum->value) + return -EINVAL; + + for (i = catdatum->value; i < rngdatum->value; i++) { + rc = ebitmap_set_bit(&context->range.level[l].cat, i, 1); + if (rc) + return rc; + } + } + } + + /* If we didn't see a '-', the range start is also the range end. */ + if (rangep[1] == NULL) { + context->range.level[1].sens = context->range.level[0].sens; + rc = ebitmap_cpy(&context->range.level[1].cat, + &context->range.level[0].cat); + if (rc) + return rc; + } + + return 0; +} + +/* + * Set the MLS fields in the security context structure + * `context' based on the string representation in + * the string `str'. This function will allocate temporary memory with the + * given constraints of gfp_mask. + */ +int mls_from_string(struct policydb *p, char *str, struct context *context, + gfp_t gfp_mask) +{ + char *tmpstr; + int rc; + + if (!p->mls_enabled) + return -EINVAL; + + tmpstr = kstrdup(str, gfp_mask); + if (!tmpstr) { + rc = -ENOMEM; + } else { + rc = mls_context_to_sid(p, ':', tmpstr, context, + NULL, SECSID_NULL); + kfree(tmpstr); + } + + return rc; +} + +/* + * Copies the MLS range `range' into `context'. + */ +int mls_range_set(struct context *context, + struct mls_range *range) +{ + int l, rc = 0; + + /* Copy the MLS range into the context */ + for (l = 0; l < 2; l++) { + context->range.level[l].sens = range->level[l].sens; + rc = ebitmap_cpy(&context->range.level[l].cat, + &range->level[l].cat); + if (rc) + break; + } + + return rc; +} + +int mls_setup_user_range(struct policydb *p, + struct context *fromcon, struct user_datum *user, + struct context *usercon) +{ + if (p->mls_enabled) { + struct mls_level *fromcon_sen = &(fromcon->range.level[0]); + struct mls_level *fromcon_clr = &(fromcon->range.level[1]); + struct mls_level *user_low = &(user->range.level[0]); + struct mls_level *user_clr = &(user->range.level[1]); + struct mls_level *user_def = &(user->dfltlevel); + struct mls_level *usercon_sen = &(usercon->range.level[0]); + struct mls_level *usercon_clr = &(usercon->range.level[1]); + + /* Honor the user's default level if we can */ + if (mls_level_between(user_def, fromcon_sen, fromcon_clr)) + *usercon_sen = *user_def; + else if (mls_level_between(fromcon_sen, user_def, user_clr)) + *usercon_sen = *fromcon_sen; + else if (mls_level_between(fromcon_clr, user_low, user_def)) + *usercon_sen = *user_low; + else + return -EINVAL; + + /* Lower the clearance of available contexts + if the clearance of "fromcon" is lower than + that of the user's default clearance (but + only if the "fromcon" clearance dominates + the user's computed sensitivity level) */ + if (mls_level_dom(user_clr, fromcon_clr)) + *usercon_clr = *fromcon_clr; + else if (mls_level_dom(fromcon_clr, user_clr)) + *usercon_clr = *user_clr; + else + return -EINVAL; + } + + return 0; +} + +/* + * Convert the MLS fields in the security context + * structure `oldc' from the values specified in the + * policy `oldp' to the values specified in the policy `newp', + * storing the resulting context in `newc'. + */ +int mls_convert_context(struct policydb *oldp, + struct policydb *newp, + struct context *oldc, + struct context *newc) +{ + struct level_datum *levdatum; + struct cat_datum *catdatum; + struct ebitmap_node *node; + int l, i; + + if (!oldp->mls_enabled || !newp->mls_enabled) + return 0; + + for (l = 0; l < 2; l++) { + char *name = sym_name(oldp, SYM_LEVELS, + oldc->range.level[l].sens - 1); + + levdatum = symtab_search(&newp->p_levels, name); + + if (!levdatum) + return -EINVAL; + newc->range.level[l].sens = levdatum->level->sens; + + ebitmap_for_each_positive_bit(&oldc->range.level[l].cat, + node, i) { + int rc; + + catdatum = symtab_search(&newp->p_cats, + sym_name(oldp, SYM_CATS, i)); + if (!catdatum) + return -EINVAL; + rc = ebitmap_set_bit(&newc->range.level[l].cat, + catdatum->value - 1, 1); + if (rc) + return rc; + } + } + + return 0; +} + +int mls_compute_sid(struct policydb *p, + struct context *scontext, + struct context *tcontext, + u16 tclass, + u32 specified, + struct context *newcontext, + bool sock) +{ + struct range_trans rtr; + struct mls_range *r; + struct class_datum *cladatum; + int default_range = 0; + + if (!p->mls_enabled) + return 0; + + switch (specified) { + case AVTAB_TRANSITION: + /* Look for a range transition rule. */ + rtr.source_type = scontext->type; + rtr.target_type = tcontext->type; + rtr.target_class = tclass; + r = policydb_rangetr_search(p, &rtr); + if (r) + return mls_range_set(newcontext, r); + + if (tclass && tclass <= p->p_classes.nprim) { + cladatum = p->class_val_to_struct[tclass - 1]; + if (cladatum) + default_range = cladatum->default_range; + } + + switch (default_range) { + case DEFAULT_SOURCE_LOW: + return mls_context_cpy_low(newcontext, scontext); + case DEFAULT_SOURCE_HIGH: + return mls_context_cpy_high(newcontext, scontext); + case DEFAULT_SOURCE_LOW_HIGH: + return mls_context_cpy(newcontext, scontext); + case DEFAULT_TARGET_LOW: + return mls_context_cpy_low(newcontext, tcontext); + case DEFAULT_TARGET_HIGH: + return mls_context_cpy_high(newcontext, tcontext); + case DEFAULT_TARGET_LOW_HIGH: + return mls_context_cpy(newcontext, tcontext); + case DEFAULT_GLBLUB: + return mls_context_glblub(newcontext, + scontext, tcontext); + } + + fallthrough; + case AVTAB_CHANGE: + if ((tclass == p->process_class) || sock) + /* Use the process MLS attributes. */ + return mls_context_cpy(newcontext, scontext); + else + /* Use the process effective MLS attributes. */ + return mls_context_cpy_low(newcontext, scontext); + case AVTAB_MEMBER: + /* Use the process effective MLS attributes. */ + return mls_context_cpy_low(newcontext, scontext); + } + return -EINVAL; +} + +#ifdef CONFIG_NETLABEL +/** + * mls_export_netlbl_lvl - Export the MLS sensitivity levels to NetLabel + * @p: the policy + * @context: the security context + * @secattr: the NetLabel security attributes + * + * Description: + * Given the security context copy the low MLS sensitivity level into the + * NetLabel MLS sensitivity level field. + * + */ +void mls_export_netlbl_lvl(struct policydb *p, + struct context *context, + struct netlbl_lsm_secattr *secattr) +{ + if (!p->mls_enabled) + return; + + secattr->attr.mls.lvl = context->range.level[0].sens - 1; + secattr->flags |= NETLBL_SECATTR_MLS_LVL; +} + +/** + * mls_import_netlbl_lvl - Import the NetLabel MLS sensitivity levels + * @p: the policy + * @context: the security context + * @secattr: the NetLabel security attributes + * + * Description: + * Given the security context and the NetLabel security attributes, copy the + * NetLabel MLS sensitivity level into the context. + * + */ +void mls_import_netlbl_lvl(struct policydb *p, + struct context *context, + struct netlbl_lsm_secattr *secattr) +{ + if (!p->mls_enabled) + return; + + context->range.level[0].sens = secattr->attr.mls.lvl + 1; + context->range.level[1].sens = context->range.level[0].sens; +} + +/** + * mls_export_netlbl_cat - Export the MLS categories to NetLabel + * @p: the policy + * @context: the security context + * @secattr: the NetLabel security attributes + * + * Description: + * Given the security context copy the low MLS categories into the NetLabel + * MLS category field. Returns zero on success, negative values on failure. + * + */ +int mls_export_netlbl_cat(struct policydb *p, + struct context *context, + struct netlbl_lsm_secattr *secattr) +{ + int rc; + + if (!p->mls_enabled) + return 0; + + rc = ebitmap_netlbl_export(&context->range.level[0].cat, + &secattr->attr.mls.cat); + if (rc == 0 && secattr->attr.mls.cat != NULL) + secattr->flags |= NETLBL_SECATTR_MLS_CAT; + + return rc; +} + +/** + * mls_import_netlbl_cat - Import the MLS categories from NetLabel + * @p: the policy + * @context: the security context + * @secattr: the NetLabel security attributes + * + * Description: + * Copy the NetLabel security attributes into the SELinux context; since the + * NetLabel security attribute only contains a single MLS category use it for + * both the low and high categories of the context. Returns zero on success, + * negative values on failure. + * + */ +int mls_import_netlbl_cat(struct policydb *p, + struct context *context, + struct netlbl_lsm_secattr *secattr) +{ + int rc; + + if (!p->mls_enabled) + return 0; + + rc = ebitmap_netlbl_import(&context->range.level[0].cat, + secattr->attr.mls.cat); + if (rc) + goto import_netlbl_cat_failure; + memcpy(&context->range.level[1].cat, &context->range.level[0].cat, + sizeof(context->range.level[0].cat)); + + return 0; + +import_netlbl_cat_failure: + ebitmap_destroy(&context->range.level[0].cat); + return rc; +} +#endif /* CONFIG_NETLABEL */ diff --git a/security/selinux/ss/mls.h b/security/selinux/ss/mls.h new file mode 100644 index 000000000..15cacde0f --- /dev/null +++ b/security/selinux/ss/mls.h @@ -0,0 +1,116 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Multi-level security (MLS) policy operations. + * + * Author : Stephen Smalley, <sds@tycho.nsa.gov> + */ +/* + * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com> + * + * Support for enhanced MLS infrastructure. + * + * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc. + */ +/* + * Updated: Hewlett-Packard <paul@paul-moore.com> + * + * Added support to import/export the MLS label from NetLabel + * + * (c) Copyright Hewlett-Packard Development Company, L.P., 2006 + */ + +#ifndef _SS_MLS_H_ +#define _SS_MLS_H_ + +#include <linux/jhash.h> + +#include "context.h" +#include "ebitmap.h" +#include "policydb.h" + +int mls_compute_context_len(struct policydb *p, struct context *context); +void mls_sid_to_context(struct policydb *p, struct context *context, + char **scontext); +int mls_context_isvalid(struct policydb *p, struct context *c); +int mls_range_isvalid(struct policydb *p, struct mls_range *r); +int mls_level_isvalid(struct policydb *p, struct mls_level *l); + +int mls_context_to_sid(struct policydb *p, + char oldc, + char *scontext, + struct context *context, + struct sidtab *s, + u32 def_sid); + +int mls_from_string(struct policydb *p, char *str, struct context *context, + gfp_t gfp_mask); + +int mls_range_set(struct context *context, struct mls_range *range); + +int mls_convert_context(struct policydb *oldp, + struct policydb *newp, + struct context *oldc, + struct context *newc); + +int mls_compute_sid(struct policydb *p, + struct context *scontext, + struct context *tcontext, + u16 tclass, + u32 specified, + struct context *newcontext, + bool sock); + +int mls_setup_user_range(struct policydb *p, + struct context *fromcon, struct user_datum *user, + struct context *usercon); + +#ifdef CONFIG_NETLABEL +void mls_export_netlbl_lvl(struct policydb *p, + struct context *context, + struct netlbl_lsm_secattr *secattr); +void mls_import_netlbl_lvl(struct policydb *p, + struct context *context, + struct netlbl_lsm_secattr *secattr); +int mls_export_netlbl_cat(struct policydb *p, + struct context *context, + struct netlbl_lsm_secattr *secattr); +int mls_import_netlbl_cat(struct policydb *p, + struct context *context, + struct netlbl_lsm_secattr *secattr); +#else +static inline void mls_export_netlbl_lvl(struct policydb *p, + struct context *context, + struct netlbl_lsm_secattr *secattr) +{ + return; +} +static inline void mls_import_netlbl_lvl(struct policydb *p, + struct context *context, + struct netlbl_lsm_secattr *secattr) +{ + return; +} +static inline int mls_export_netlbl_cat(struct policydb *p, + struct context *context, + struct netlbl_lsm_secattr *secattr) +{ + return -ENOMEM; +} +static inline int mls_import_netlbl_cat(struct policydb *p, + struct context *context, + struct netlbl_lsm_secattr *secattr) +{ + return -ENOMEM; +} +#endif + +static inline u32 mls_range_hash(const struct mls_range *r, u32 hash) +{ + hash = jhash_2words(r->level[0].sens, r->level[1].sens, hash); + hash = ebitmap_hash(&r->level[0].cat, hash); + hash = ebitmap_hash(&r->level[1].cat, hash); + return hash; +} + +#endif /* _SS_MLS_H */ + diff --git a/security/selinux/ss/mls_types.h b/security/selinux/ss/mls_types.h new file mode 100644 index 000000000..7d48d5e52 --- /dev/null +++ b/security/selinux/ss/mls_types.h @@ -0,0 +1,52 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Type definitions for the multi-level security (MLS) policy. + * + * Author : Stephen Smalley, <sds@tycho.nsa.gov> + */ +/* + * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com> + * + * Support for enhanced MLS infrastructure. + * + * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc. + */ + +#ifndef _SS_MLS_TYPES_H_ +#define _SS_MLS_TYPES_H_ + +#include "security.h" +#include "ebitmap.h" + +struct mls_level { + u32 sens; /* sensitivity */ + struct ebitmap cat; /* category set */ +}; + +struct mls_range { + struct mls_level level[2]; /* low == level[0], high == level[1] */ +}; + +static inline int mls_level_eq(const struct mls_level *l1, const struct mls_level *l2) +{ + return ((l1->sens == l2->sens) && + ebitmap_cmp(&l1->cat, &l2->cat)); +} + +static inline int mls_level_dom(const struct mls_level *l1, const struct mls_level *l2) +{ + return ((l1->sens >= l2->sens) && + ebitmap_contains(&l1->cat, &l2->cat, 0)); +} + +#define mls_level_incomp(l1, l2) \ +(!mls_level_dom((l1), (l2)) && !mls_level_dom((l2), (l1))) + +#define mls_level_between(l1, l2, l3) \ +(mls_level_dom((l1), (l2)) && mls_level_dom((l3), (l1))) + +#define mls_range_contains(r1, r2) \ +(mls_level_dom(&(r2).level[0], &(r1).level[0]) && \ + mls_level_dom(&(r1).level[1], &(r2).level[1])) + +#endif /* _SS_MLS_TYPES_H_ */ diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c new file mode 100644 index 000000000..6f9ff4643 --- /dev/null +++ b/security/selinux/ss/policydb.c @@ -0,0 +1,3731 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Implementation of the policy database. + * + * Author : Stephen Smalley, <sds@tycho.nsa.gov> + */ + +/* + * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com> + * + * Support for enhanced MLS infrastructure. + * + * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com> + * + * Added conditional policy language extensions + * + * Updated: Hewlett-Packard <paul@paul-moore.com> + * + * Added support for the policy capability bitmap + * + * Update: Mellanox Techonologies + * + * Added Infiniband support + * + * Copyright (C) 2016 Mellanox Techonologies + * Copyright (C) 2007 Hewlett-Packard Development Company, L.P. + * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc. + * Copyright (C) 2003 - 2004 Tresys Technology, LLC + */ + +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/errno.h> +#include <linux/audit.h> +#include "security.h" + +#include "policydb.h" +#include "conditional.h" +#include "mls.h" +#include "services.h" + +#ifdef DEBUG_HASHES +static const char *symtab_name[SYM_NUM] = { + "common prefixes", + "classes", + "roles", + "types", + "users", + "bools", + "levels", + "categories", +}; +#endif + +struct policydb_compat_info { + int version; + int sym_num; + int ocon_num; +}; + +/* These need to be updated if SYM_NUM or OCON_NUM changes */ +static const struct policydb_compat_info policydb_compat[] = { + { + .version = POLICYDB_VERSION_BASE, + .sym_num = SYM_NUM - 3, + .ocon_num = OCON_NUM - 3, + }, + { + .version = POLICYDB_VERSION_BOOL, + .sym_num = SYM_NUM - 2, + .ocon_num = OCON_NUM - 3, + }, + { + .version = POLICYDB_VERSION_IPV6, + .sym_num = SYM_NUM - 2, + .ocon_num = OCON_NUM - 2, + }, + { + .version = POLICYDB_VERSION_NLCLASS, + .sym_num = SYM_NUM - 2, + .ocon_num = OCON_NUM - 2, + }, + { + .version = POLICYDB_VERSION_MLS, + .sym_num = SYM_NUM, + .ocon_num = OCON_NUM - 2, + }, + { + .version = POLICYDB_VERSION_AVTAB, + .sym_num = SYM_NUM, + .ocon_num = OCON_NUM - 2, + }, + { + .version = POLICYDB_VERSION_RANGETRANS, + .sym_num = SYM_NUM, + .ocon_num = OCON_NUM - 2, + }, + { + .version = POLICYDB_VERSION_POLCAP, + .sym_num = SYM_NUM, + .ocon_num = OCON_NUM - 2, + }, + { + .version = POLICYDB_VERSION_PERMISSIVE, + .sym_num = SYM_NUM, + .ocon_num = OCON_NUM - 2, + }, + { + .version = POLICYDB_VERSION_BOUNDARY, + .sym_num = SYM_NUM, + .ocon_num = OCON_NUM - 2, + }, + { + .version = POLICYDB_VERSION_FILENAME_TRANS, + .sym_num = SYM_NUM, + .ocon_num = OCON_NUM - 2, + }, + { + .version = POLICYDB_VERSION_ROLETRANS, + .sym_num = SYM_NUM, + .ocon_num = OCON_NUM - 2, + }, + { + .version = POLICYDB_VERSION_NEW_OBJECT_DEFAULTS, + .sym_num = SYM_NUM, + .ocon_num = OCON_NUM - 2, + }, + { + .version = POLICYDB_VERSION_DEFAULT_TYPE, + .sym_num = SYM_NUM, + .ocon_num = OCON_NUM - 2, + }, + { + .version = POLICYDB_VERSION_CONSTRAINT_NAMES, + .sym_num = SYM_NUM, + .ocon_num = OCON_NUM - 2, + }, + { + .version = POLICYDB_VERSION_XPERMS_IOCTL, + .sym_num = SYM_NUM, + .ocon_num = OCON_NUM - 2, + }, + { + .version = POLICYDB_VERSION_INFINIBAND, + .sym_num = SYM_NUM, + .ocon_num = OCON_NUM, + }, + { + .version = POLICYDB_VERSION_GLBLUB, + .sym_num = SYM_NUM, + .ocon_num = OCON_NUM, + }, + { + .version = POLICYDB_VERSION_COMP_FTRANS, + .sym_num = SYM_NUM, + .ocon_num = OCON_NUM, + }, +}; + +static const struct policydb_compat_info *policydb_lookup_compat(int version) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(policydb_compat); i++) { + if (policydb_compat[i].version == version) + return &policydb_compat[i]; + } + + return NULL; +} + +/* + * The following *_destroy functions are used to + * free any memory allocated for each kind of + * symbol data in the policy database. + */ + +static int perm_destroy(void *key, void *datum, void *p) +{ + kfree(key); + kfree(datum); + return 0; +} + +static int common_destroy(void *key, void *datum, void *p) +{ + struct common_datum *comdatum; + + kfree(key); + if (datum) { + comdatum = datum; + hashtab_map(&comdatum->permissions.table, perm_destroy, NULL); + hashtab_destroy(&comdatum->permissions.table); + } + kfree(datum); + return 0; +} + +static void constraint_expr_destroy(struct constraint_expr *expr) +{ + if (expr) { + ebitmap_destroy(&expr->names); + if (expr->type_names) { + ebitmap_destroy(&expr->type_names->types); + ebitmap_destroy(&expr->type_names->negset); + kfree(expr->type_names); + } + kfree(expr); + } +} + +static int cls_destroy(void *key, void *datum, void *p) +{ + struct class_datum *cladatum; + struct constraint_node *constraint, *ctemp; + struct constraint_expr *e, *etmp; + + kfree(key); + if (datum) { + cladatum = datum; + hashtab_map(&cladatum->permissions.table, perm_destroy, NULL); + hashtab_destroy(&cladatum->permissions.table); + constraint = cladatum->constraints; + while (constraint) { + e = constraint->expr; + while (e) { + etmp = e; + e = e->next; + constraint_expr_destroy(etmp); + } + ctemp = constraint; + constraint = constraint->next; + kfree(ctemp); + } + + constraint = cladatum->validatetrans; + while (constraint) { + e = constraint->expr; + while (e) { + etmp = e; + e = e->next; + constraint_expr_destroy(etmp); + } + ctemp = constraint; + constraint = constraint->next; + kfree(ctemp); + } + kfree(cladatum->comkey); + } + kfree(datum); + return 0; +} + +static int role_destroy(void *key, void *datum, void *p) +{ + struct role_datum *role; + + kfree(key); + if (datum) { + role = datum; + ebitmap_destroy(&role->dominates); + ebitmap_destroy(&role->types); + } + kfree(datum); + return 0; +} + +static int type_destroy(void *key, void *datum, void *p) +{ + kfree(key); + kfree(datum); + return 0; +} + +static int user_destroy(void *key, void *datum, void *p) +{ + struct user_datum *usrdatum; + + kfree(key); + if (datum) { + usrdatum = datum; + ebitmap_destroy(&usrdatum->roles); + ebitmap_destroy(&usrdatum->range.level[0].cat); + ebitmap_destroy(&usrdatum->range.level[1].cat); + ebitmap_destroy(&usrdatum->dfltlevel.cat); + } + kfree(datum); + return 0; +} + +static int sens_destroy(void *key, void *datum, void *p) +{ + struct level_datum *levdatum; + + kfree(key); + if (datum) { + levdatum = datum; + if (levdatum->level) + ebitmap_destroy(&levdatum->level->cat); + kfree(levdatum->level); + } + kfree(datum); + return 0; +} + +static int cat_destroy(void *key, void *datum, void *p) +{ + kfree(key); + kfree(datum); + return 0; +} + +static int (*const destroy_f[SYM_NUM]) (void *key, void *datum, void *datap) = { + common_destroy, + cls_destroy, + role_destroy, + type_destroy, + user_destroy, + cond_destroy_bool, + sens_destroy, + cat_destroy, +}; + +static int filenametr_destroy(void *key, void *datum, void *p) +{ + struct filename_trans_key *ft = key; + struct filename_trans_datum *next, *d = datum; + + kfree(ft->name); + kfree(key); + do { + ebitmap_destroy(&d->stypes); + next = d->next; + kfree(d); + d = next; + } while (unlikely(d)); + cond_resched(); + return 0; +} + +static int range_tr_destroy(void *key, void *datum, void *p) +{ + struct mls_range *rt = datum; + + kfree(key); + ebitmap_destroy(&rt->level[0].cat); + ebitmap_destroy(&rt->level[1].cat); + kfree(datum); + cond_resched(); + return 0; +} + +static int role_tr_destroy(void *key, void *datum, void *p) +{ + kfree(key); + kfree(datum); + return 0; +} + +static void ocontext_destroy(struct ocontext *c, int i) +{ + if (!c) + return; + + context_destroy(&c->context[0]); + context_destroy(&c->context[1]); + if (i == OCON_ISID || i == OCON_FS || + i == OCON_NETIF || i == OCON_FSUSE) + kfree(c->u.name); + kfree(c); +} + +/* + * Initialize the role table. + */ +static int roles_init(struct policydb *p) +{ + char *key = NULL; + int rc; + struct role_datum *role; + + role = kzalloc(sizeof(*role), GFP_KERNEL); + if (!role) + return -ENOMEM; + + rc = -EINVAL; + role->value = ++p->p_roles.nprim; + if (role->value != OBJECT_R_VAL) + goto out; + + rc = -ENOMEM; + key = kstrdup(OBJECT_R, GFP_KERNEL); + if (!key) + goto out; + + rc = symtab_insert(&p->p_roles, key, role); + if (rc) + goto out; + + return 0; +out: + kfree(key); + kfree(role); + return rc; +} + +static u32 filenametr_hash(const void *k) +{ + const struct filename_trans_key *ft = k; + unsigned long hash; + unsigned int byte_num; + unsigned char focus; + + hash = ft->ttype ^ ft->tclass; + + byte_num = 0; + while ((focus = ft->name[byte_num++])) + hash = partial_name_hash(focus, hash); + return hash; +} + +static int filenametr_cmp(const void *k1, const void *k2) +{ + const struct filename_trans_key *ft1 = k1; + const struct filename_trans_key *ft2 = k2; + int v; + + v = ft1->ttype - ft2->ttype; + if (v) + return v; + + v = ft1->tclass - ft2->tclass; + if (v) + return v; + + return strcmp(ft1->name, ft2->name); + +} + +static const struct hashtab_key_params filenametr_key_params = { + .hash = filenametr_hash, + .cmp = filenametr_cmp, +}; + +struct filename_trans_datum *policydb_filenametr_search( + struct policydb *p, struct filename_trans_key *key) +{ + return hashtab_search(&p->filename_trans, key, filenametr_key_params); +} + +static u32 rangetr_hash(const void *k) +{ + const struct range_trans *key = k; + + return key->source_type + (key->target_type << 3) + + (key->target_class << 5); +} + +static int rangetr_cmp(const void *k1, const void *k2) +{ + const struct range_trans *key1 = k1, *key2 = k2; + int v; + + v = key1->source_type - key2->source_type; + if (v) + return v; + + v = key1->target_type - key2->target_type; + if (v) + return v; + + v = key1->target_class - key2->target_class; + + return v; +} + +static const struct hashtab_key_params rangetr_key_params = { + .hash = rangetr_hash, + .cmp = rangetr_cmp, +}; + +struct mls_range *policydb_rangetr_search(struct policydb *p, + struct range_trans *key) +{ + return hashtab_search(&p->range_tr, key, rangetr_key_params); +} + +static u32 role_trans_hash(const void *k) +{ + const struct role_trans_key *key = k; + + return key->role + (key->type << 3) + (key->tclass << 5); +} + +static int role_trans_cmp(const void *k1, const void *k2) +{ + const struct role_trans_key *key1 = k1, *key2 = k2; + int v; + + v = key1->role - key2->role; + if (v) + return v; + + v = key1->type - key2->type; + if (v) + return v; + + return key1->tclass - key2->tclass; +} + +static const struct hashtab_key_params roletr_key_params = { + .hash = role_trans_hash, + .cmp = role_trans_cmp, +}; + +struct role_trans_datum *policydb_roletr_search(struct policydb *p, + struct role_trans_key *key) +{ + return hashtab_search(&p->role_tr, key, roletr_key_params); +} + +/* + * Initialize a policy database structure. + */ +static void policydb_init(struct policydb *p) +{ + memset(p, 0, sizeof(*p)); + + avtab_init(&p->te_avtab); + cond_policydb_init(p); + + ebitmap_init(&p->filename_trans_ttypes); + ebitmap_init(&p->policycaps); + ebitmap_init(&p->permissive_map); +} + +/* + * The following *_index functions are used to + * define the val_to_name and val_to_struct arrays + * in a policy database structure. The val_to_name + * arrays are used when converting security context + * structures into string representations. The + * val_to_struct arrays are used when the attributes + * of a class, role, or user are needed. + */ + +static int common_index(void *key, void *datum, void *datap) +{ + struct policydb *p; + struct common_datum *comdatum; + + comdatum = datum; + p = datap; + if (!comdatum->value || comdatum->value > p->p_commons.nprim) + return -EINVAL; + + p->sym_val_to_name[SYM_COMMONS][comdatum->value - 1] = key; + + return 0; +} + +static int class_index(void *key, void *datum, void *datap) +{ + struct policydb *p; + struct class_datum *cladatum; + + cladatum = datum; + p = datap; + if (!cladatum->value || cladatum->value > p->p_classes.nprim) + return -EINVAL; + + p->sym_val_to_name[SYM_CLASSES][cladatum->value - 1] = key; + p->class_val_to_struct[cladatum->value - 1] = cladatum; + return 0; +} + +static int role_index(void *key, void *datum, void *datap) +{ + struct policydb *p; + struct role_datum *role; + + role = datum; + p = datap; + if (!role->value + || role->value > p->p_roles.nprim + || role->bounds > p->p_roles.nprim) + return -EINVAL; + + p->sym_val_to_name[SYM_ROLES][role->value - 1] = key; + p->role_val_to_struct[role->value - 1] = role; + return 0; +} + +static int type_index(void *key, void *datum, void *datap) +{ + struct policydb *p; + struct type_datum *typdatum; + + typdatum = datum; + p = datap; + + if (typdatum->primary) { + if (!typdatum->value + || typdatum->value > p->p_types.nprim + || typdatum->bounds > p->p_types.nprim) + return -EINVAL; + p->sym_val_to_name[SYM_TYPES][typdatum->value - 1] = key; + p->type_val_to_struct[typdatum->value - 1] = typdatum; + } + + return 0; +} + +static int user_index(void *key, void *datum, void *datap) +{ + struct policydb *p; + struct user_datum *usrdatum; + + usrdatum = datum; + p = datap; + if (!usrdatum->value + || usrdatum->value > p->p_users.nprim + || usrdatum->bounds > p->p_users.nprim) + return -EINVAL; + + p->sym_val_to_name[SYM_USERS][usrdatum->value - 1] = key; + p->user_val_to_struct[usrdatum->value - 1] = usrdatum; + return 0; +} + +static int sens_index(void *key, void *datum, void *datap) +{ + struct policydb *p; + struct level_datum *levdatum; + + levdatum = datum; + p = datap; + + if (!levdatum->isalias) { + if (!levdatum->level->sens || + levdatum->level->sens > p->p_levels.nprim) + return -EINVAL; + + p->sym_val_to_name[SYM_LEVELS][levdatum->level->sens - 1] = key; + } + + return 0; +} + +static int cat_index(void *key, void *datum, void *datap) +{ + struct policydb *p; + struct cat_datum *catdatum; + + catdatum = datum; + p = datap; + + if (!catdatum->isalias) { + if (!catdatum->value || catdatum->value > p->p_cats.nprim) + return -EINVAL; + + p->sym_val_to_name[SYM_CATS][catdatum->value - 1] = key; + } + + return 0; +} + +static int (*const index_f[SYM_NUM]) (void *key, void *datum, void *datap) = { + common_index, + class_index, + role_index, + type_index, + user_index, + cond_index_bool, + sens_index, + cat_index, +}; + +#ifdef DEBUG_HASHES +static void hash_eval(struct hashtab *h, const char *hash_name) +{ + struct hashtab_info info; + + hashtab_stat(h, &info); + pr_debug("SELinux: %s: %d entries and %d/%d buckets used, longest chain length %d\n", + hash_name, h->nel, info.slots_used, h->size, + info.max_chain_len); +} + +static void symtab_hash_eval(struct symtab *s) +{ + int i; + + for (i = 0; i < SYM_NUM; i++) + hash_eval(&s[i].table, symtab_name[i]); +} + +#else +static inline void hash_eval(struct hashtab *h, const char *hash_name) +{ +} +#endif + +/* + * Define the other val_to_name and val_to_struct arrays + * in a policy database structure. + * + * Caller must clean up on failure. + */ +static int policydb_index(struct policydb *p) +{ + int i, rc; + + if (p->mls_enabled) + pr_debug("SELinux: %d users, %d roles, %d types, %d bools, %d sens, %d cats\n", + p->p_users.nprim, p->p_roles.nprim, p->p_types.nprim, + p->p_bools.nprim, p->p_levels.nprim, p->p_cats.nprim); + else + pr_debug("SELinux: %d users, %d roles, %d types, %d bools\n", + p->p_users.nprim, p->p_roles.nprim, p->p_types.nprim, + p->p_bools.nprim); + + pr_debug("SELinux: %d classes, %d rules\n", + p->p_classes.nprim, p->te_avtab.nel); + +#ifdef DEBUG_HASHES + avtab_hash_eval(&p->te_avtab, "rules"); + symtab_hash_eval(p->symtab); +#endif + + p->class_val_to_struct = kcalloc(p->p_classes.nprim, + sizeof(*p->class_val_to_struct), + GFP_KERNEL); + if (!p->class_val_to_struct) + return -ENOMEM; + + p->role_val_to_struct = kcalloc(p->p_roles.nprim, + sizeof(*p->role_val_to_struct), + GFP_KERNEL); + if (!p->role_val_to_struct) + return -ENOMEM; + + p->user_val_to_struct = kcalloc(p->p_users.nprim, + sizeof(*p->user_val_to_struct), + GFP_KERNEL); + if (!p->user_val_to_struct) + return -ENOMEM; + + p->type_val_to_struct = kvcalloc(p->p_types.nprim, + sizeof(*p->type_val_to_struct), + GFP_KERNEL); + if (!p->type_val_to_struct) + return -ENOMEM; + + rc = cond_init_bool_indexes(p); + if (rc) + goto out; + + for (i = 0; i < SYM_NUM; i++) { + p->sym_val_to_name[i] = kvcalloc(p->symtab[i].nprim, + sizeof(char *), + GFP_KERNEL); + if (!p->sym_val_to_name[i]) + return -ENOMEM; + + rc = hashtab_map(&p->symtab[i].table, index_f[i], p); + if (rc) + goto out; + } + rc = 0; +out: + return rc; +} + +/* + * Free any memory allocated by a policy database structure. + */ +void policydb_destroy(struct policydb *p) +{ + struct ocontext *c, *ctmp; + struct genfs *g, *gtmp; + int i; + struct role_allow *ra, *lra = NULL; + + for (i = 0; i < SYM_NUM; i++) { + cond_resched(); + hashtab_map(&p->symtab[i].table, destroy_f[i], NULL); + hashtab_destroy(&p->symtab[i].table); + } + + for (i = 0; i < SYM_NUM; i++) + kvfree(p->sym_val_to_name[i]); + + kfree(p->class_val_to_struct); + kfree(p->role_val_to_struct); + kfree(p->user_val_to_struct); + kvfree(p->type_val_to_struct); + + avtab_destroy(&p->te_avtab); + + for (i = 0; i < OCON_NUM; i++) { + cond_resched(); + c = p->ocontexts[i]; + while (c) { + ctmp = c; + c = c->next; + ocontext_destroy(ctmp, i); + } + p->ocontexts[i] = NULL; + } + + g = p->genfs; + while (g) { + cond_resched(); + kfree(g->fstype); + c = g->head; + while (c) { + ctmp = c; + c = c->next; + ocontext_destroy(ctmp, OCON_FSUSE); + } + gtmp = g; + g = g->next; + kfree(gtmp); + } + p->genfs = NULL; + + cond_policydb_destroy(p); + + hashtab_map(&p->role_tr, role_tr_destroy, NULL); + hashtab_destroy(&p->role_tr); + + for (ra = p->role_allow; ra; ra = ra->next) { + cond_resched(); + kfree(lra); + lra = ra; + } + kfree(lra); + + hashtab_map(&p->filename_trans, filenametr_destroy, NULL); + hashtab_destroy(&p->filename_trans); + + hashtab_map(&p->range_tr, range_tr_destroy, NULL); + hashtab_destroy(&p->range_tr); + + if (p->type_attr_map_array) { + for (i = 0; i < p->p_types.nprim; i++) + ebitmap_destroy(&p->type_attr_map_array[i]); + kvfree(p->type_attr_map_array); + } + + ebitmap_destroy(&p->filename_trans_ttypes); + ebitmap_destroy(&p->policycaps); + ebitmap_destroy(&p->permissive_map); +} + +/* + * Load the initial SIDs specified in a policy database + * structure into a SID table. + */ +int policydb_load_isids(struct policydb *p, struct sidtab *s) +{ + struct ocontext *head, *c; + int rc; + + rc = sidtab_init(s); + if (rc) { + pr_err("SELinux: out of memory on SID table init\n"); + return rc; + } + + head = p->ocontexts[OCON_ISID]; + for (c = head; c; c = c->next) { + u32 sid = c->sid[0]; + const char *name = security_get_initial_sid_context(sid); + + if (sid == SECSID_NULL) { + pr_err("SELinux: SID 0 was assigned a context.\n"); + sidtab_destroy(s); + return -EINVAL; + } + + /* Ignore initial SIDs unused by this kernel. */ + if (!name) + continue; + + rc = sidtab_set_initial(s, sid, &c->context[0]); + if (rc) { + pr_err("SELinux: unable to load initial SID %s.\n", + name); + sidtab_destroy(s); + return rc; + } + } + return 0; +} + +int policydb_class_isvalid(struct policydb *p, unsigned int class) +{ + if (!class || class > p->p_classes.nprim) + return 0; + return 1; +} + +int policydb_role_isvalid(struct policydb *p, unsigned int role) +{ + if (!role || role > p->p_roles.nprim) + return 0; + return 1; +} + +int policydb_type_isvalid(struct policydb *p, unsigned int type) +{ + if (!type || type > p->p_types.nprim) + return 0; + return 1; +} + +/* + * Return 1 if the fields in the security context + * structure `c' are valid. Return 0 otherwise. + */ +int policydb_context_isvalid(struct policydb *p, struct context *c) +{ + struct role_datum *role; + struct user_datum *usrdatum; + + if (!c->role || c->role > p->p_roles.nprim) + return 0; + + if (!c->user || c->user > p->p_users.nprim) + return 0; + + if (!c->type || c->type > p->p_types.nprim) + return 0; + + if (c->role != OBJECT_R_VAL) { + /* + * Role must be authorized for the type. + */ + role = p->role_val_to_struct[c->role - 1]; + if (!role || !ebitmap_get_bit(&role->types, c->type - 1)) + /* role may not be associated with type */ + return 0; + + /* + * User must be authorized for the role. + */ + usrdatum = p->user_val_to_struct[c->user - 1]; + if (!usrdatum) + return 0; + + if (!ebitmap_get_bit(&usrdatum->roles, c->role - 1)) + /* user may not be associated with role */ + return 0; + } + + if (!mls_context_isvalid(p, c)) + return 0; + + return 1; +} + +/* + * Read a MLS range structure from a policydb binary + * representation file. + */ +static int mls_read_range_helper(struct mls_range *r, void *fp) +{ + __le32 buf[2]; + u32 items; + int rc; + + rc = next_entry(buf, fp, sizeof(u32)); + if (rc) + goto out; + + rc = -EINVAL; + items = le32_to_cpu(buf[0]); + if (items > ARRAY_SIZE(buf)) { + pr_err("SELinux: mls: range overflow\n"); + goto out; + } + + rc = next_entry(buf, fp, sizeof(u32) * items); + if (rc) { + pr_err("SELinux: mls: truncated range\n"); + goto out; + } + + r->level[0].sens = le32_to_cpu(buf[0]); + if (items > 1) + r->level[1].sens = le32_to_cpu(buf[1]); + else + r->level[1].sens = r->level[0].sens; + + rc = ebitmap_read(&r->level[0].cat, fp); + if (rc) { + pr_err("SELinux: mls: error reading low categories\n"); + goto out; + } + if (items > 1) { + rc = ebitmap_read(&r->level[1].cat, fp); + if (rc) { + pr_err("SELinux: mls: error reading high categories\n"); + goto bad_high; + } + } else { + rc = ebitmap_cpy(&r->level[1].cat, &r->level[0].cat); + if (rc) { + pr_err("SELinux: mls: out of memory\n"); + goto bad_high; + } + } + + return 0; +bad_high: + ebitmap_destroy(&r->level[0].cat); +out: + return rc; +} + +/* + * Read and validate a security context structure + * from a policydb binary representation file. + */ +static int context_read_and_validate(struct context *c, + struct policydb *p, + void *fp) +{ + __le32 buf[3]; + int rc; + + rc = next_entry(buf, fp, sizeof buf); + if (rc) { + pr_err("SELinux: context truncated\n"); + goto out; + } + c->user = le32_to_cpu(buf[0]); + c->role = le32_to_cpu(buf[1]); + c->type = le32_to_cpu(buf[2]); + if (p->policyvers >= POLICYDB_VERSION_MLS) { + rc = mls_read_range_helper(&c->range, fp); + if (rc) { + pr_err("SELinux: error reading MLS range of context\n"); + goto out; + } + } + + rc = -EINVAL; + if (!policydb_context_isvalid(p, c)) { + pr_err("SELinux: invalid security context\n"); + context_destroy(c); + goto out; + } + rc = 0; +out: + return rc; +} + +/* + * The following *_read functions are used to + * read the symbol data from a policy database + * binary representation file. + */ + +static int str_read(char **strp, gfp_t flags, void *fp, u32 len) +{ + int rc; + char *str; + + if ((len == 0) || (len == (u32)-1)) + return -EINVAL; + + str = kmalloc(len + 1, flags | __GFP_NOWARN); + if (!str) + return -ENOMEM; + + rc = next_entry(str, fp, len); + if (rc) { + kfree(str); + return rc; + } + + str[len] = '\0'; + *strp = str; + return 0; +} + +static int perm_read(struct policydb *p, struct symtab *s, void *fp) +{ + char *key = NULL; + struct perm_datum *perdatum; + int rc; + __le32 buf[2]; + u32 len; + + perdatum = kzalloc(sizeof(*perdatum), GFP_KERNEL); + if (!perdatum) + return -ENOMEM; + + rc = next_entry(buf, fp, sizeof buf); + if (rc) + goto bad; + + len = le32_to_cpu(buf[0]); + perdatum->value = le32_to_cpu(buf[1]); + + rc = str_read(&key, GFP_KERNEL, fp, len); + if (rc) + goto bad; + + rc = symtab_insert(s, key, perdatum); + if (rc) + goto bad; + + return 0; +bad: + perm_destroy(key, perdatum, NULL); + return rc; +} + +static int common_read(struct policydb *p, struct symtab *s, void *fp) +{ + char *key = NULL; + struct common_datum *comdatum; + __le32 buf[4]; + u32 len, nel; + int i, rc; + + comdatum = kzalloc(sizeof(*comdatum), GFP_KERNEL); + if (!comdatum) + return -ENOMEM; + + rc = next_entry(buf, fp, sizeof buf); + if (rc) + goto bad; + + len = le32_to_cpu(buf[0]); + comdatum->value = le32_to_cpu(buf[1]); + nel = le32_to_cpu(buf[3]); + + rc = symtab_init(&comdatum->permissions, nel); + if (rc) + goto bad; + comdatum->permissions.nprim = le32_to_cpu(buf[2]); + + rc = str_read(&key, GFP_KERNEL, fp, len); + if (rc) + goto bad; + + for (i = 0; i < nel; i++) { + rc = perm_read(p, &comdatum->permissions, fp); + if (rc) + goto bad; + } + + rc = symtab_insert(s, key, comdatum); + if (rc) + goto bad; + return 0; +bad: + common_destroy(key, comdatum, NULL); + return rc; +} + +static void type_set_init(struct type_set *t) +{ + ebitmap_init(&t->types); + ebitmap_init(&t->negset); +} + +static int type_set_read(struct type_set *t, void *fp) +{ + __le32 buf[1]; + int rc; + + if (ebitmap_read(&t->types, fp)) + return -EINVAL; + if (ebitmap_read(&t->negset, fp)) + return -EINVAL; + + rc = next_entry(buf, fp, sizeof(u32)); + if (rc < 0) + return -EINVAL; + t->flags = le32_to_cpu(buf[0]); + + return 0; +} + + +static int read_cons_helper(struct policydb *p, + struct constraint_node **nodep, + int ncons, int allowxtarget, void *fp) +{ + struct constraint_node *c, *lc; + struct constraint_expr *e, *le; + __le32 buf[3]; + u32 nexpr; + int rc, i, j, depth; + + lc = NULL; + for (i = 0; i < ncons; i++) { + c = kzalloc(sizeof(*c), GFP_KERNEL); + if (!c) + return -ENOMEM; + + if (lc) + lc->next = c; + else + *nodep = c; + + rc = next_entry(buf, fp, (sizeof(u32) * 2)); + if (rc) + return rc; + c->permissions = le32_to_cpu(buf[0]); + nexpr = le32_to_cpu(buf[1]); + le = NULL; + depth = -1; + for (j = 0; j < nexpr; j++) { + e = kzalloc(sizeof(*e), GFP_KERNEL); + if (!e) + return -ENOMEM; + + if (le) + le->next = e; + else + c->expr = e; + + rc = next_entry(buf, fp, (sizeof(u32) * 3)); + if (rc) + return rc; + e->expr_type = le32_to_cpu(buf[0]); + e->attr = le32_to_cpu(buf[1]); + e->op = le32_to_cpu(buf[2]); + + switch (e->expr_type) { + case CEXPR_NOT: + if (depth < 0) + return -EINVAL; + break; + case CEXPR_AND: + case CEXPR_OR: + if (depth < 1) + return -EINVAL; + depth--; + break; + case CEXPR_ATTR: + if (depth == (CEXPR_MAXDEPTH - 1)) + return -EINVAL; + depth++; + break; + case CEXPR_NAMES: + if (!allowxtarget && (e->attr & CEXPR_XTARGET)) + return -EINVAL; + if (depth == (CEXPR_MAXDEPTH - 1)) + return -EINVAL; + depth++; + rc = ebitmap_read(&e->names, fp); + if (rc) + return rc; + if (p->policyvers >= + POLICYDB_VERSION_CONSTRAINT_NAMES) { + e->type_names = kzalloc(sizeof + (*e->type_names), GFP_KERNEL); + if (!e->type_names) + return -ENOMEM; + type_set_init(e->type_names); + rc = type_set_read(e->type_names, fp); + if (rc) + return rc; + } + break; + default: + return -EINVAL; + } + le = e; + } + if (depth != 0) + return -EINVAL; + lc = c; + } + + return 0; +} + +static int class_read(struct policydb *p, struct symtab *s, void *fp) +{ + char *key = NULL; + struct class_datum *cladatum; + __le32 buf[6]; + u32 len, len2, ncons, nel; + int i, rc; + + cladatum = kzalloc(sizeof(*cladatum), GFP_KERNEL); + if (!cladatum) + return -ENOMEM; + + rc = next_entry(buf, fp, sizeof(u32)*6); + if (rc) + goto bad; + + len = le32_to_cpu(buf[0]); + len2 = le32_to_cpu(buf[1]); + cladatum->value = le32_to_cpu(buf[2]); + nel = le32_to_cpu(buf[4]); + + rc = symtab_init(&cladatum->permissions, nel); + if (rc) + goto bad; + cladatum->permissions.nprim = le32_to_cpu(buf[3]); + + ncons = le32_to_cpu(buf[5]); + + rc = str_read(&key, GFP_KERNEL, fp, len); + if (rc) + goto bad; + + if (len2) { + rc = str_read(&cladatum->comkey, GFP_KERNEL, fp, len2); + if (rc) + goto bad; + + rc = -EINVAL; + cladatum->comdatum = symtab_search(&p->p_commons, + cladatum->comkey); + if (!cladatum->comdatum) { + pr_err("SELinux: unknown common %s\n", + cladatum->comkey); + goto bad; + } + } + for (i = 0; i < nel; i++) { + rc = perm_read(p, &cladatum->permissions, fp); + if (rc) + goto bad; + } + + rc = read_cons_helper(p, &cladatum->constraints, ncons, 0, fp); + if (rc) + goto bad; + + if (p->policyvers >= POLICYDB_VERSION_VALIDATETRANS) { + /* grab the validatetrans rules */ + rc = next_entry(buf, fp, sizeof(u32)); + if (rc) + goto bad; + ncons = le32_to_cpu(buf[0]); + rc = read_cons_helper(p, &cladatum->validatetrans, + ncons, 1, fp); + if (rc) + goto bad; + } + + if (p->policyvers >= POLICYDB_VERSION_NEW_OBJECT_DEFAULTS) { + rc = next_entry(buf, fp, sizeof(u32) * 3); + if (rc) + goto bad; + + cladatum->default_user = le32_to_cpu(buf[0]); + cladatum->default_role = le32_to_cpu(buf[1]); + cladatum->default_range = le32_to_cpu(buf[2]); + } + + if (p->policyvers >= POLICYDB_VERSION_DEFAULT_TYPE) { + rc = next_entry(buf, fp, sizeof(u32) * 1); + if (rc) + goto bad; + cladatum->default_type = le32_to_cpu(buf[0]); + } + + rc = symtab_insert(s, key, cladatum); + if (rc) + goto bad; + + return 0; +bad: + cls_destroy(key, cladatum, NULL); + return rc; +} + +static int role_read(struct policydb *p, struct symtab *s, void *fp) +{ + char *key = NULL; + struct role_datum *role; + int rc, to_read = 2; + __le32 buf[3]; + u32 len; + + role = kzalloc(sizeof(*role), GFP_KERNEL); + if (!role) + return -ENOMEM; + + if (p->policyvers >= POLICYDB_VERSION_BOUNDARY) + to_read = 3; + + rc = next_entry(buf, fp, sizeof(buf[0]) * to_read); + if (rc) + goto bad; + + len = le32_to_cpu(buf[0]); + role->value = le32_to_cpu(buf[1]); + if (p->policyvers >= POLICYDB_VERSION_BOUNDARY) + role->bounds = le32_to_cpu(buf[2]); + + rc = str_read(&key, GFP_KERNEL, fp, len); + if (rc) + goto bad; + + rc = ebitmap_read(&role->dominates, fp); + if (rc) + goto bad; + + rc = ebitmap_read(&role->types, fp); + if (rc) + goto bad; + + if (strcmp(key, OBJECT_R) == 0) { + rc = -EINVAL; + if (role->value != OBJECT_R_VAL) { + pr_err("SELinux: Role %s has wrong value %d\n", + OBJECT_R, role->value); + goto bad; + } + rc = 0; + goto bad; + } + + rc = symtab_insert(s, key, role); + if (rc) + goto bad; + return 0; +bad: + role_destroy(key, role, NULL); + return rc; +} + +static int type_read(struct policydb *p, struct symtab *s, void *fp) +{ + char *key = NULL; + struct type_datum *typdatum; + int rc, to_read = 3; + __le32 buf[4]; + u32 len; + + typdatum = kzalloc(sizeof(*typdatum), GFP_KERNEL); + if (!typdatum) + return -ENOMEM; + + if (p->policyvers >= POLICYDB_VERSION_BOUNDARY) + to_read = 4; + + rc = next_entry(buf, fp, sizeof(buf[0]) * to_read); + if (rc) + goto bad; + + len = le32_to_cpu(buf[0]); + typdatum->value = le32_to_cpu(buf[1]); + if (p->policyvers >= POLICYDB_VERSION_BOUNDARY) { + u32 prop = le32_to_cpu(buf[2]); + + if (prop & TYPEDATUM_PROPERTY_PRIMARY) + typdatum->primary = 1; + if (prop & TYPEDATUM_PROPERTY_ATTRIBUTE) + typdatum->attribute = 1; + + typdatum->bounds = le32_to_cpu(buf[3]); + } else { + typdatum->primary = le32_to_cpu(buf[2]); + } + + rc = str_read(&key, GFP_KERNEL, fp, len); + if (rc) + goto bad; + + rc = symtab_insert(s, key, typdatum); + if (rc) + goto bad; + return 0; +bad: + type_destroy(key, typdatum, NULL); + return rc; +} + + +/* + * Read a MLS level structure from a policydb binary + * representation file. + */ +static int mls_read_level(struct mls_level *lp, void *fp) +{ + __le32 buf[1]; + int rc; + + memset(lp, 0, sizeof(*lp)); + + rc = next_entry(buf, fp, sizeof buf); + if (rc) { + pr_err("SELinux: mls: truncated level\n"); + return rc; + } + lp->sens = le32_to_cpu(buf[0]); + + rc = ebitmap_read(&lp->cat, fp); + if (rc) { + pr_err("SELinux: mls: error reading level categories\n"); + return rc; + } + return 0; +} + +static int user_read(struct policydb *p, struct symtab *s, void *fp) +{ + char *key = NULL; + struct user_datum *usrdatum; + int rc, to_read = 2; + __le32 buf[3]; + u32 len; + + usrdatum = kzalloc(sizeof(*usrdatum), GFP_KERNEL); + if (!usrdatum) + return -ENOMEM; + + if (p->policyvers >= POLICYDB_VERSION_BOUNDARY) + to_read = 3; + + rc = next_entry(buf, fp, sizeof(buf[0]) * to_read); + if (rc) + goto bad; + + len = le32_to_cpu(buf[0]); + usrdatum->value = le32_to_cpu(buf[1]); + if (p->policyvers >= POLICYDB_VERSION_BOUNDARY) + usrdatum->bounds = le32_to_cpu(buf[2]); + + rc = str_read(&key, GFP_KERNEL, fp, len); + if (rc) + goto bad; + + rc = ebitmap_read(&usrdatum->roles, fp); + if (rc) + goto bad; + + if (p->policyvers >= POLICYDB_VERSION_MLS) { + rc = mls_read_range_helper(&usrdatum->range, fp); + if (rc) + goto bad; + rc = mls_read_level(&usrdatum->dfltlevel, fp); + if (rc) + goto bad; + } + + rc = symtab_insert(s, key, usrdatum); + if (rc) + goto bad; + return 0; +bad: + user_destroy(key, usrdatum, NULL); + return rc; +} + +static int sens_read(struct policydb *p, struct symtab *s, void *fp) +{ + char *key = NULL; + struct level_datum *levdatum; + int rc; + __le32 buf[2]; + u32 len; + + levdatum = kzalloc(sizeof(*levdatum), GFP_ATOMIC); + if (!levdatum) + return -ENOMEM; + + rc = next_entry(buf, fp, sizeof buf); + if (rc) + goto bad; + + len = le32_to_cpu(buf[0]); + levdatum->isalias = le32_to_cpu(buf[1]); + + rc = str_read(&key, GFP_ATOMIC, fp, len); + if (rc) + goto bad; + + rc = -ENOMEM; + levdatum->level = kmalloc(sizeof(*levdatum->level), GFP_ATOMIC); + if (!levdatum->level) + goto bad; + + rc = mls_read_level(levdatum->level, fp); + if (rc) + goto bad; + + rc = symtab_insert(s, key, levdatum); + if (rc) + goto bad; + return 0; +bad: + sens_destroy(key, levdatum, NULL); + return rc; +} + +static int cat_read(struct policydb *p, struct symtab *s, void *fp) +{ + char *key = NULL; + struct cat_datum *catdatum; + int rc; + __le32 buf[3]; + u32 len; + + catdatum = kzalloc(sizeof(*catdatum), GFP_ATOMIC); + if (!catdatum) + return -ENOMEM; + + rc = next_entry(buf, fp, sizeof buf); + if (rc) + goto bad; + + len = le32_to_cpu(buf[0]); + catdatum->value = le32_to_cpu(buf[1]); + catdatum->isalias = le32_to_cpu(buf[2]); + + rc = str_read(&key, GFP_ATOMIC, fp, len); + if (rc) + goto bad; + + rc = symtab_insert(s, key, catdatum); + if (rc) + goto bad; + return 0; +bad: + cat_destroy(key, catdatum, NULL); + return rc; +} + +static int (*const read_f[SYM_NUM]) (struct policydb *p, + struct symtab *s, void *fp) = { + common_read, + class_read, + role_read, + type_read, + user_read, + cond_read_bool, + sens_read, + cat_read, +}; + +static int user_bounds_sanity_check(void *key, void *datum, void *datap) +{ + struct user_datum *upper, *user; + struct policydb *p = datap; + int depth = 0; + + upper = user = datum; + while (upper->bounds) { + struct ebitmap_node *node; + unsigned long bit; + + if (++depth == POLICYDB_BOUNDS_MAXDEPTH) { + pr_err("SELinux: user %s: " + "too deep or looped boundary", + (char *) key); + return -EINVAL; + } + + upper = p->user_val_to_struct[upper->bounds - 1]; + ebitmap_for_each_positive_bit(&user->roles, node, bit) { + if (ebitmap_get_bit(&upper->roles, bit)) + continue; + + pr_err("SELinux: boundary violated policy: " + "user=%s role=%s bounds=%s\n", + sym_name(p, SYM_USERS, user->value - 1), + sym_name(p, SYM_ROLES, bit), + sym_name(p, SYM_USERS, upper->value - 1)); + + return -EINVAL; + } + } + + return 0; +} + +static int role_bounds_sanity_check(void *key, void *datum, void *datap) +{ + struct role_datum *upper, *role; + struct policydb *p = datap; + int depth = 0; + + upper = role = datum; + while (upper->bounds) { + struct ebitmap_node *node; + unsigned long bit; + + if (++depth == POLICYDB_BOUNDS_MAXDEPTH) { + pr_err("SELinux: role %s: " + "too deep or looped bounds\n", + (char *) key); + return -EINVAL; + } + + upper = p->role_val_to_struct[upper->bounds - 1]; + ebitmap_for_each_positive_bit(&role->types, node, bit) { + if (ebitmap_get_bit(&upper->types, bit)) + continue; + + pr_err("SELinux: boundary violated policy: " + "role=%s type=%s bounds=%s\n", + sym_name(p, SYM_ROLES, role->value - 1), + sym_name(p, SYM_TYPES, bit), + sym_name(p, SYM_ROLES, upper->value - 1)); + + return -EINVAL; + } + } + + return 0; +} + +static int type_bounds_sanity_check(void *key, void *datum, void *datap) +{ + struct type_datum *upper; + struct policydb *p = datap; + int depth = 0; + + upper = datum; + while (upper->bounds) { + if (++depth == POLICYDB_BOUNDS_MAXDEPTH) { + pr_err("SELinux: type %s: " + "too deep or looped boundary\n", + (char *) key); + return -EINVAL; + } + + upper = p->type_val_to_struct[upper->bounds - 1]; + BUG_ON(!upper); + + if (upper->attribute) { + pr_err("SELinux: type %s: " + "bounded by attribute %s", + (char *) key, + sym_name(p, SYM_TYPES, upper->value - 1)); + return -EINVAL; + } + } + + return 0; +} + +static int policydb_bounds_sanity_check(struct policydb *p) +{ + int rc; + + if (p->policyvers < POLICYDB_VERSION_BOUNDARY) + return 0; + + rc = hashtab_map(&p->p_users.table, user_bounds_sanity_check, p); + if (rc) + return rc; + + rc = hashtab_map(&p->p_roles.table, role_bounds_sanity_check, p); + if (rc) + return rc; + + rc = hashtab_map(&p->p_types.table, type_bounds_sanity_check, p); + if (rc) + return rc; + + return 0; +} + +u16 string_to_security_class(struct policydb *p, const char *name) +{ + struct class_datum *cladatum; + + cladatum = symtab_search(&p->p_classes, name); + if (!cladatum) + return 0; + + return cladatum->value; +} + +u32 string_to_av_perm(struct policydb *p, u16 tclass, const char *name) +{ + struct class_datum *cladatum; + struct perm_datum *perdatum = NULL; + struct common_datum *comdatum; + + if (!tclass || tclass > p->p_classes.nprim) + return 0; + + cladatum = p->class_val_to_struct[tclass-1]; + comdatum = cladatum->comdatum; + if (comdatum) + perdatum = symtab_search(&comdatum->permissions, name); + if (!perdatum) + perdatum = symtab_search(&cladatum->permissions, name); + if (!perdatum) + return 0; + + return 1U << (perdatum->value-1); +} + +static int range_read(struct policydb *p, void *fp) +{ + struct range_trans *rt = NULL; + struct mls_range *r = NULL; + int i, rc; + __le32 buf[2]; + u32 nel; + + if (p->policyvers < POLICYDB_VERSION_MLS) + return 0; + + rc = next_entry(buf, fp, sizeof(u32)); + if (rc) + return rc; + + nel = le32_to_cpu(buf[0]); + + rc = hashtab_init(&p->range_tr, nel); + if (rc) + return rc; + + for (i = 0; i < nel; i++) { + rc = -ENOMEM; + rt = kzalloc(sizeof(*rt), GFP_KERNEL); + if (!rt) + goto out; + + rc = next_entry(buf, fp, (sizeof(u32) * 2)); + if (rc) + goto out; + + rt->source_type = le32_to_cpu(buf[0]); + rt->target_type = le32_to_cpu(buf[1]); + if (p->policyvers >= POLICYDB_VERSION_RANGETRANS) { + rc = next_entry(buf, fp, sizeof(u32)); + if (rc) + goto out; + rt->target_class = le32_to_cpu(buf[0]); + } else + rt->target_class = p->process_class; + + rc = -EINVAL; + if (!policydb_type_isvalid(p, rt->source_type) || + !policydb_type_isvalid(p, rt->target_type) || + !policydb_class_isvalid(p, rt->target_class)) + goto out; + + rc = -ENOMEM; + r = kzalloc(sizeof(*r), GFP_KERNEL); + if (!r) + goto out; + + rc = mls_read_range_helper(r, fp); + if (rc) + goto out; + + rc = -EINVAL; + if (!mls_range_isvalid(p, r)) { + pr_warn("SELinux: rangetrans: invalid range\n"); + goto out; + } + + rc = hashtab_insert(&p->range_tr, rt, r, rangetr_key_params); + if (rc) + goto out; + + rt = NULL; + r = NULL; + } + hash_eval(&p->range_tr, "rangetr"); + rc = 0; +out: + kfree(rt); + kfree(r); + return rc; +} + +static int filename_trans_read_helper_compat(struct policydb *p, void *fp) +{ + struct filename_trans_key key, *ft = NULL; + struct filename_trans_datum *last, *datum = NULL; + char *name = NULL; + u32 len, stype, otype; + __le32 buf[4]; + int rc; + + /* length of the path component string */ + rc = next_entry(buf, fp, sizeof(u32)); + if (rc) + return rc; + len = le32_to_cpu(buf[0]); + + /* path component string */ + rc = str_read(&name, GFP_KERNEL, fp, len); + if (rc) + return rc; + + rc = next_entry(buf, fp, sizeof(u32) * 4); + if (rc) + goto out; + + stype = le32_to_cpu(buf[0]); + key.ttype = le32_to_cpu(buf[1]); + key.tclass = le32_to_cpu(buf[2]); + key.name = name; + + otype = le32_to_cpu(buf[3]); + + last = NULL; + datum = policydb_filenametr_search(p, &key); + while (datum) { + if (unlikely(ebitmap_get_bit(&datum->stypes, stype - 1))) { + /* conflicting/duplicate rules are ignored */ + datum = NULL; + goto out; + } + if (likely(datum->otype == otype)) + break; + last = datum; + datum = datum->next; + } + if (!datum) { + rc = -ENOMEM; + datum = kmalloc(sizeof(*datum), GFP_KERNEL); + if (!datum) + goto out; + + ebitmap_init(&datum->stypes); + datum->otype = otype; + datum->next = NULL; + + if (unlikely(last)) { + last->next = datum; + } else { + rc = -ENOMEM; + ft = kmemdup(&key, sizeof(key), GFP_KERNEL); + if (!ft) + goto out; + + rc = hashtab_insert(&p->filename_trans, ft, datum, + filenametr_key_params); + if (rc) + goto out; + name = NULL; + + rc = ebitmap_set_bit(&p->filename_trans_ttypes, + key.ttype, 1); + if (rc) + return rc; + } + } + kfree(name); + return ebitmap_set_bit(&datum->stypes, stype - 1, 1); + +out: + kfree(ft); + kfree(name); + kfree(datum); + return rc; +} + +static int filename_trans_read_helper(struct policydb *p, void *fp) +{ + struct filename_trans_key *ft = NULL; + struct filename_trans_datum **dst, *datum, *first = NULL; + char *name = NULL; + u32 len, ttype, tclass, ndatum, i; + __le32 buf[3]; + int rc; + + /* length of the path component string */ + rc = next_entry(buf, fp, sizeof(u32)); + if (rc) + return rc; + len = le32_to_cpu(buf[0]); + + /* path component string */ + rc = str_read(&name, GFP_KERNEL, fp, len); + if (rc) + return rc; + + rc = next_entry(buf, fp, sizeof(u32) * 3); + if (rc) + goto out; + + ttype = le32_to_cpu(buf[0]); + tclass = le32_to_cpu(buf[1]); + + ndatum = le32_to_cpu(buf[2]); + if (ndatum == 0) { + pr_err("SELinux: Filename transition key with no datum\n"); + rc = -ENOENT; + goto out; + } + + dst = &first; + for (i = 0; i < ndatum; i++) { + rc = -ENOMEM; + datum = kmalloc(sizeof(*datum), GFP_KERNEL); + if (!datum) + goto out; + + datum->next = NULL; + *dst = datum; + + /* ebitmap_read() will at least init the bitmap */ + rc = ebitmap_read(&datum->stypes, fp); + if (rc) + goto out; + + rc = next_entry(buf, fp, sizeof(u32)); + if (rc) + goto out; + + datum->otype = le32_to_cpu(buf[0]); + + dst = &datum->next; + } + + rc = -ENOMEM; + ft = kmalloc(sizeof(*ft), GFP_KERNEL); + if (!ft) + goto out; + + ft->ttype = ttype; + ft->tclass = tclass; + ft->name = name; + + rc = hashtab_insert(&p->filename_trans, ft, first, + filenametr_key_params); + if (rc == -EEXIST) + pr_err("SELinux: Duplicate filename transition key\n"); + if (rc) + goto out; + + return ebitmap_set_bit(&p->filename_trans_ttypes, ttype, 1); + +out: + kfree(ft); + kfree(name); + while (first) { + datum = first; + first = first->next; + + ebitmap_destroy(&datum->stypes); + kfree(datum); + } + return rc; +} + +static int filename_trans_read(struct policydb *p, void *fp) +{ + u32 nel; + __le32 buf[1]; + int rc, i; + + if (p->policyvers < POLICYDB_VERSION_FILENAME_TRANS) + return 0; + + rc = next_entry(buf, fp, sizeof(u32)); + if (rc) + return rc; + nel = le32_to_cpu(buf[0]); + + if (p->policyvers < POLICYDB_VERSION_COMP_FTRANS) { + p->compat_filename_trans_count = nel; + + rc = hashtab_init(&p->filename_trans, (1 << 11)); + if (rc) + return rc; + + for (i = 0; i < nel; i++) { + rc = filename_trans_read_helper_compat(p, fp); + if (rc) + return rc; + } + } else { + rc = hashtab_init(&p->filename_trans, nel); + if (rc) + return rc; + + for (i = 0; i < nel; i++) { + rc = filename_trans_read_helper(p, fp); + if (rc) + return rc; + } + } + hash_eval(&p->filename_trans, "filenametr"); + return 0; +} + +static int genfs_read(struct policydb *p, void *fp) +{ + int i, j, rc; + u32 nel, nel2, len, len2; + __le32 buf[1]; + struct ocontext *l, *c; + struct ocontext *newc = NULL; + struct genfs *genfs_p, *genfs; + struct genfs *newgenfs = NULL; + + rc = next_entry(buf, fp, sizeof(u32)); + if (rc) + return rc; + nel = le32_to_cpu(buf[0]); + + for (i = 0; i < nel; i++) { + rc = next_entry(buf, fp, sizeof(u32)); + if (rc) + goto out; + len = le32_to_cpu(buf[0]); + + rc = -ENOMEM; + newgenfs = kzalloc(sizeof(*newgenfs), GFP_KERNEL); + if (!newgenfs) + goto out; + + rc = str_read(&newgenfs->fstype, GFP_KERNEL, fp, len); + if (rc) + goto out; + + for (genfs_p = NULL, genfs = p->genfs; genfs; + genfs_p = genfs, genfs = genfs->next) { + rc = -EINVAL; + if (strcmp(newgenfs->fstype, genfs->fstype) == 0) { + pr_err("SELinux: dup genfs fstype %s\n", + newgenfs->fstype); + goto out; + } + if (strcmp(newgenfs->fstype, genfs->fstype) < 0) + break; + } + newgenfs->next = genfs; + if (genfs_p) + genfs_p->next = newgenfs; + else + p->genfs = newgenfs; + genfs = newgenfs; + newgenfs = NULL; + + rc = next_entry(buf, fp, sizeof(u32)); + if (rc) + goto out; + + nel2 = le32_to_cpu(buf[0]); + for (j = 0; j < nel2; j++) { + rc = next_entry(buf, fp, sizeof(u32)); + if (rc) + goto out; + len = le32_to_cpu(buf[0]); + + rc = -ENOMEM; + newc = kzalloc(sizeof(*newc), GFP_KERNEL); + if (!newc) + goto out; + + rc = str_read(&newc->u.name, GFP_KERNEL, fp, len); + if (rc) + goto out; + + rc = next_entry(buf, fp, sizeof(u32)); + if (rc) + goto out; + + newc->v.sclass = le32_to_cpu(buf[0]); + rc = context_read_and_validate(&newc->context[0], p, fp); + if (rc) + goto out; + + for (l = NULL, c = genfs->head; c; + l = c, c = c->next) { + rc = -EINVAL; + if (!strcmp(newc->u.name, c->u.name) && + (!c->v.sclass || !newc->v.sclass || + newc->v.sclass == c->v.sclass)) { + pr_err("SELinux: dup genfs entry (%s,%s)\n", + genfs->fstype, c->u.name); + goto out; + } + len = strlen(newc->u.name); + len2 = strlen(c->u.name); + if (len > len2) + break; + } + + newc->next = c; + if (l) + l->next = newc; + else + genfs->head = newc; + newc = NULL; + } + } + rc = 0; +out: + if (newgenfs) { + kfree(newgenfs->fstype); + kfree(newgenfs); + } + ocontext_destroy(newc, OCON_FSUSE); + + return rc; +} + +static int ocontext_read(struct policydb *p, const struct policydb_compat_info *info, + void *fp) +{ + int i, j, rc; + u32 nel, len; + __be64 prefixbuf[1]; + __le32 buf[3]; + struct ocontext *l, *c; + u32 nodebuf[8]; + + for (i = 0; i < info->ocon_num; i++) { + rc = next_entry(buf, fp, sizeof(u32)); + if (rc) + goto out; + nel = le32_to_cpu(buf[0]); + + l = NULL; + for (j = 0; j < nel; j++) { + rc = -ENOMEM; + c = kzalloc(sizeof(*c), GFP_KERNEL); + if (!c) + goto out; + if (l) + l->next = c; + else + p->ocontexts[i] = c; + l = c; + + switch (i) { + case OCON_ISID: + rc = next_entry(buf, fp, sizeof(u32)); + if (rc) + goto out; + + c->sid[0] = le32_to_cpu(buf[0]); + rc = context_read_and_validate(&c->context[0], p, fp); + if (rc) + goto out; + break; + case OCON_FS: + case OCON_NETIF: + rc = next_entry(buf, fp, sizeof(u32)); + if (rc) + goto out; + len = le32_to_cpu(buf[0]); + + rc = str_read(&c->u.name, GFP_KERNEL, fp, len); + if (rc) + goto out; + + rc = context_read_and_validate(&c->context[0], p, fp); + if (rc) + goto out; + rc = context_read_and_validate(&c->context[1], p, fp); + if (rc) + goto out; + break; + case OCON_PORT: + rc = next_entry(buf, fp, sizeof(u32)*3); + if (rc) + goto out; + c->u.port.protocol = le32_to_cpu(buf[0]); + c->u.port.low_port = le32_to_cpu(buf[1]); + c->u.port.high_port = le32_to_cpu(buf[2]); + rc = context_read_and_validate(&c->context[0], p, fp); + if (rc) + goto out; + break; + case OCON_NODE: + rc = next_entry(nodebuf, fp, sizeof(u32) * 2); + if (rc) + goto out; + c->u.node.addr = nodebuf[0]; /* network order */ + c->u.node.mask = nodebuf[1]; /* network order */ + rc = context_read_and_validate(&c->context[0], p, fp); + if (rc) + goto out; + break; + case OCON_FSUSE: + rc = next_entry(buf, fp, sizeof(u32)*2); + if (rc) + goto out; + + rc = -EINVAL; + c->v.behavior = le32_to_cpu(buf[0]); + /* Determined at runtime, not in policy DB. */ + if (c->v.behavior == SECURITY_FS_USE_MNTPOINT) + goto out; + if (c->v.behavior > SECURITY_FS_USE_MAX) + goto out; + + len = le32_to_cpu(buf[1]); + rc = str_read(&c->u.name, GFP_KERNEL, fp, len); + if (rc) + goto out; + + rc = context_read_and_validate(&c->context[0], p, fp); + if (rc) + goto out; + break; + case OCON_NODE6: { + int k; + + rc = next_entry(nodebuf, fp, sizeof(u32) * 8); + if (rc) + goto out; + for (k = 0; k < 4; k++) + c->u.node6.addr[k] = nodebuf[k]; + for (k = 0; k < 4; k++) + c->u.node6.mask[k] = nodebuf[k+4]; + rc = context_read_and_validate(&c->context[0], p, fp); + if (rc) + goto out; + break; + } + case OCON_IBPKEY: { + u32 pkey_lo, pkey_hi; + + rc = next_entry(prefixbuf, fp, sizeof(u64)); + if (rc) + goto out; + + /* we need to have subnet_prefix in CPU order */ + c->u.ibpkey.subnet_prefix = be64_to_cpu(prefixbuf[0]); + + rc = next_entry(buf, fp, sizeof(u32) * 2); + if (rc) + goto out; + + pkey_lo = le32_to_cpu(buf[0]); + pkey_hi = le32_to_cpu(buf[1]); + + if (pkey_lo > U16_MAX || pkey_hi > U16_MAX) { + rc = -EINVAL; + goto out; + } + + c->u.ibpkey.low_pkey = pkey_lo; + c->u.ibpkey.high_pkey = pkey_hi; + + rc = context_read_and_validate(&c->context[0], + p, + fp); + if (rc) + goto out; + break; + } + case OCON_IBENDPORT: { + u32 port; + + rc = next_entry(buf, fp, sizeof(u32) * 2); + if (rc) + goto out; + len = le32_to_cpu(buf[0]); + + rc = str_read(&c->u.ibendport.dev_name, GFP_KERNEL, fp, len); + if (rc) + goto out; + + port = le32_to_cpu(buf[1]); + if (port > U8_MAX || port == 0) { + rc = -EINVAL; + goto out; + } + + c->u.ibendport.port = port; + + rc = context_read_and_validate(&c->context[0], + p, + fp); + if (rc) + goto out; + break; + } /* end case */ + } /* end switch */ + } + } + rc = 0; +out: + return rc; +} + +/* + * Read the configuration data from a policy database binary + * representation file into a policy database structure. + */ +int policydb_read(struct policydb *p, void *fp) +{ + struct role_allow *ra, *lra; + struct role_trans_key *rtk = NULL; + struct role_trans_datum *rtd = NULL; + int i, j, rc; + __le32 buf[4]; + u32 len, nprim, nel, perm; + + char *policydb_str; + const struct policydb_compat_info *info; + + policydb_init(p); + + /* Read the magic number and string length. */ + rc = next_entry(buf, fp, sizeof(u32) * 2); + if (rc) + goto bad; + + rc = -EINVAL; + if (le32_to_cpu(buf[0]) != POLICYDB_MAGIC) { + pr_err("SELinux: policydb magic number 0x%x does " + "not match expected magic number 0x%x\n", + le32_to_cpu(buf[0]), POLICYDB_MAGIC); + goto bad; + } + + rc = -EINVAL; + len = le32_to_cpu(buf[1]); + if (len != strlen(POLICYDB_STRING)) { + pr_err("SELinux: policydb string length %d does not " + "match expected length %zu\n", + len, strlen(POLICYDB_STRING)); + goto bad; + } + + rc = -ENOMEM; + policydb_str = kmalloc(len + 1, GFP_KERNEL); + if (!policydb_str) { + pr_err("SELinux: unable to allocate memory for policydb " + "string of length %d\n", len); + goto bad; + } + + rc = next_entry(policydb_str, fp, len); + if (rc) { + pr_err("SELinux: truncated policydb string identifier\n"); + kfree(policydb_str); + goto bad; + } + + rc = -EINVAL; + policydb_str[len] = '\0'; + if (strcmp(policydb_str, POLICYDB_STRING)) { + pr_err("SELinux: policydb string %s does not match " + "my string %s\n", policydb_str, POLICYDB_STRING); + kfree(policydb_str); + goto bad; + } + /* Done with policydb_str. */ + kfree(policydb_str); + policydb_str = NULL; + + /* Read the version and table sizes. */ + rc = next_entry(buf, fp, sizeof(u32)*4); + if (rc) + goto bad; + + rc = -EINVAL; + p->policyvers = le32_to_cpu(buf[0]); + if (p->policyvers < POLICYDB_VERSION_MIN || + p->policyvers > POLICYDB_VERSION_MAX) { + pr_err("SELinux: policydb version %d does not match " + "my version range %d-%d\n", + le32_to_cpu(buf[0]), POLICYDB_VERSION_MIN, POLICYDB_VERSION_MAX); + goto bad; + } + + if ((le32_to_cpu(buf[1]) & POLICYDB_CONFIG_MLS)) { + p->mls_enabled = 1; + + rc = -EINVAL; + if (p->policyvers < POLICYDB_VERSION_MLS) { + pr_err("SELinux: security policydb version %d " + "(MLS) not backwards compatible\n", + p->policyvers); + goto bad; + } + } + p->reject_unknown = !!(le32_to_cpu(buf[1]) & REJECT_UNKNOWN); + p->allow_unknown = !!(le32_to_cpu(buf[1]) & ALLOW_UNKNOWN); + + if (p->policyvers >= POLICYDB_VERSION_POLCAP) { + rc = ebitmap_read(&p->policycaps, fp); + if (rc) + goto bad; + } + + if (p->policyvers >= POLICYDB_VERSION_PERMISSIVE) { + rc = ebitmap_read(&p->permissive_map, fp); + if (rc) + goto bad; + } + + rc = -EINVAL; + info = policydb_lookup_compat(p->policyvers); + if (!info) { + pr_err("SELinux: unable to find policy compat info " + "for version %d\n", p->policyvers); + goto bad; + } + + rc = -EINVAL; + if (le32_to_cpu(buf[2]) != info->sym_num || + le32_to_cpu(buf[3]) != info->ocon_num) { + pr_err("SELinux: policydb table sizes (%d,%d) do " + "not match mine (%d,%d)\n", le32_to_cpu(buf[2]), + le32_to_cpu(buf[3]), + info->sym_num, info->ocon_num); + goto bad; + } + + for (i = 0; i < info->sym_num; i++) { + rc = next_entry(buf, fp, sizeof(u32)*2); + if (rc) + goto bad; + nprim = le32_to_cpu(buf[0]); + nel = le32_to_cpu(buf[1]); + + rc = symtab_init(&p->symtab[i], nel); + if (rc) + goto out; + + if (i == SYM_ROLES) { + rc = roles_init(p); + if (rc) + goto out; + } + + for (j = 0; j < nel; j++) { + rc = read_f[i](p, &p->symtab[i], fp); + if (rc) + goto bad; + } + + p->symtab[i].nprim = nprim; + } + + rc = -EINVAL; + p->process_class = string_to_security_class(p, "process"); + if (!p->process_class) { + pr_err("SELinux: process class is required, not defined in policy\n"); + goto bad; + } + + rc = avtab_read(&p->te_avtab, fp, p); + if (rc) + goto bad; + + if (p->policyvers >= POLICYDB_VERSION_BOOL) { + rc = cond_read_list(p, fp); + if (rc) + goto bad; + } + + rc = next_entry(buf, fp, sizeof(u32)); + if (rc) + goto bad; + nel = le32_to_cpu(buf[0]); + + rc = hashtab_init(&p->role_tr, nel); + if (rc) + goto bad; + for (i = 0; i < nel; i++) { + rc = -ENOMEM; + rtk = kmalloc(sizeof(*rtk), GFP_KERNEL); + if (!rtk) + goto bad; + + rc = -ENOMEM; + rtd = kmalloc(sizeof(*rtd), GFP_KERNEL); + if (!rtd) + goto bad; + + rc = next_entry(buf, fp, sizeof(u32)*3); + if (rc) + goto bad; + + rtk->role = le32_to_cpu(buf[0]); + rtk->type = le32_to_cpu(buf[1]); + rtd->new_role = le32_to_cpu(buf[2]); + if (p->policyvers >= POLICYDB_VERSION_ROLETRANS) { + rc = next_entry(buf, fp, sizeof(u32)); + if (rc) + goto bad; + rtk->tclass = le32_to_cpu(buf[0]); + } else + rtk->tclass = p->process_class; + + rc = -EINVAL; + if (!policydb_role_isvalid(p, rtk->role) || + !policydb_type_isvalid(p, rtk->type) || + !policydb_class_isvalid(p, rtk->tclass) || + !policydb_role_isvalid(p, rtd->new_role)) + goto bad; + + rc = hashtab_insert(&p->role_tr, rtk, rtd, roletr_key_params); + if (rc) + goto bad; + + rtk = NULL; + rtd = NULL; + } + + rc = next_entry(buf, fp, sizeof(u32)); + if (rc) + goto bad; + nel = le32_to_cpu(buf[0]); + lra = NULL; + for (i = 0; i < nel; i++) { + rc = -ENOMEM; + ra = kzalloc(sizeof(*ra), GFP_KERNEL); + if (!ra) + goto bad; + if (lra) + lra->next = ra; + else + p->role_allow = ra; + rc = next_entry(buf, fp, sizeof(u32)*2); + if (rc) + goto bad; + + rc = -EINVAL; + ra->role = le32_to_cpu(buf[0]); + ra->new_role = le32_to_cpu(buf[1]); + if (!policydb_role_isvalid(p, ra->role) || + !policydb_role_isvalid(p, ra->new_role)) + goto bad; + lra = ra; + } + + rc = filename_trans_read(p, fp); + if (rc) + goto bad; + + rc = policydb_index(p); + if (rc) + goto bad; + + rc = -EINVAL; + perm = string_to_av_perm(p, p->process_class, "transition"); + if (!perm) { + pr_err("SELinux: process transition permission is required, not defined in policy\n"); + goto bad; + } + p->process_trans_perms = perm; + perm = string_to_av_perm(p, p->process_class, "dyntransition"); + if (!perm) { + pr_err("SELinux: process dyntransition permission is required, not defined in policy\n"); + goto bad; + } + p->process_trans_perms |= perm; + + rc = ocontext_read(p, info, fp); + if (rc) + goto bad; + + rc = genfs_read(p, fp); + if (rc) + goto bad; + + rc = range_read(p, fp); + if (rc) + goto bad; + + rc = -ENOMEM; + p->type_attr_map_array = kvcalloc(p->p_types.nprim, + sizeof(*p->type_attr_map_array), + GFP_KERNEL); + if (!p->type_attr_map_array) + goto bad; + + /* just in case ebitmap_init() becomes more than just a memset(0): */ + for (i = 0; i < p->p_types.nprim; i++) + ebitmap_init(&p->type_attr_map_array[i]); + + for (i = 0; i < p->p_types.nprim; i++) { + struct ebitmap *e = &p->type_attr_map_array[i]; + + if (p->policyvers >= POLICYDB_VERSION_AVTAB) { + rc = ebitmap_read(e, fp); + if (rc) + goto bad; + } + /* add the type itself as the degenerate case */ + rc = ebitmap_set_bit(e, i, 1); + if (rc) + goto bad; + } + + rc = policydb_bounds_sanity_check(p); + if (rc) + goto bad; + + rc = 0; +out: + return rc; +bad: + kfree(rtk); + kfree(rtd); + policydb_destroy(p); + goto out; +} + +/* + * Write a MLS level structure to a policydb binary + * representation file. + */ +static int mls_write_level(struct mls_level *l, void *fp) +{ + __le32 buf[1]; + int rc; + + buf[0] = cpu_to_le32(l->sens); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + + rc = ebitmap_write(&l->cat, fp); + if (rc) + return rc; + + return 0; +} + +/* + * Write a MLS range structure to a policydb binary + * representation file. + */ +static int mls_write_range_helper(struct mls_range *r, void *fp) +{ + __le32 buf[3]; + size_t items; + int rc, eq; + + eq = mls_level_eq(&r->level[1], &r->level[0]); + + if (eq) + items = 2; + else + items = 3; + buf[0] = cpu_to_le32(items-1); + buf[1] = cpu_to_le32(r->level[0].sens); + if (!eq) + buf[2] = cpu_to_le32(r->level[1].sens); + + BUG_ON(items > ARRAY_SIZE(buf)); + + rc = put_entry(buf, sizeof(u32), items, fp); + if (rc) + return rc; + + rc = ebitmap_write(&r->level[0].cat, fp); + if (rc) + return rc; + if (!eq) { + rc = ebitmap_write(&r->level[1].cat, fp); + if (rc) + return rc; + } + + return 0; +} + +static int sens_write(void *vkey, void *datum, void *ptr) +{ + char *key = vkey; + struct level_datum *levdatum = datum; + struct policy_data *pd = ptr; + void *fp = pd->fp; + __le32 buf[2]; + size_t len; + int rc; + + len = strlen(key); + buf[0] = cpu_to_le32(len); + buf[1] = cpu_to_le32(levdatum->isalias); + rc = put_entry(buf, sizeof(u32), 2, fp); + if (rc) + return rc; + + rc = put_entry(key, 1, len, fp); + if (rc) + return rc; + + rc = mls_write_level(levdatum->level, fp); + if (rc) + return rc; + + return 0; +} + +static int cat_write(void *vkey, void *datum, void *ptr) +{ + char *key = vkey; + struct cat_datum *catdatum = datum; + struct policy_data *pd = ptr; + void *fp = pd->fp; + __le32 buf[3]; + size_t len; + int rc; + + len = strlen(key); + buf[0] = cpu_to_le32(len); + buf[1] = cpu_to_le32(catdatum->value); + buf[2] = cpu_to_le32(catdatum->isalias); + rc = put_entry(buf, sizeof(u32), 3, fp); + if (rc) + return rc; + + rc = put_entry(key, 1, len, fp); + if (rc) + return rc; + + return 0; +} + +static int role_trans_write_one(void *key, void *datum, void *ptr) +{ + struct role_trans_key *rtk = key; + struct role_trans_datum *rtd = datum; + struct policy_data *pd = ptr; + void *fp = pd->fp; + struct policydb *p = pd->p; + __le32 buf[3]; + int rc; + + buf[0] = cpu_to_le32(rtk->role); + buf[1] = cpu_to_le32(rtk->type); + buf[2] = cpu_to_le32(rtd->new_role); + rc = put_entry(buf, sizeof(u32), 3, fp); + if (rc) + return rc; + if (p->policyvers >= POLICYDB_VERSION_ROLETRANS) { + buf[0] = cpu_to_le32(rtk->tclass); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + } + return 0; +} + +static int role_trans_write(struct policydb *p, void *fp) +{ + struct policy_data pd = { .p = p, .fp = fp }; + __le32 buf[1]; + int rc; + + buf[0] = cpu_to_le32(p->role_tr.nel); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + + return hashtab_map(&p->role_tr, role_trans_write_one, &pd); +} + +static int role_allow_write(struct role_allow *r, void *fp) +{ + struct role_allow *ra; + __le32 buf[2]; + size_t nel; + int rc; + + nel = 0; + for (ra = r; ra; ra = ra->next) + nel++; + buf[0] = cpu_to_le32(nel); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + for (ra = r; ra; ra = ra->next) { + buf[0] = cpu_to_le32(ra->role); + buf[1] = cpu_to_le32(ra->new_role); + rc = put_entry(buf, sizeof(u32), 2, fp); + if (rc) + return rc; + } + return 0; +} + +/* + * Write a security context structure + * to a policydb binary representation file. + */ +static int context_write(struct policydb *p, struct context *c, + void *fp) +{ + int rc; + __le32 buf[3]; + + buf[0] = cpu_to_le32(c->user); + buf[1] = cpu_to_le32(c->role); + buf[2] = cpu_to_le32(c->type); + + rc = put_entry(buf, sizeof(u32), 3, fp); + if (rc) + return rc; + + rc = mls_write_range_helper(&c->range, fp); + if (rc) + return rc; + + return 0; +} + +/* + * The following *_write functions are used to + * write the symbol data to a policy database + * binary representation file. + */ + +static int perm_write(void *vkey, void *datum, void *fp) +{ + char *key = vkey; + struct perm_datum *perdatum = datum; + __le32 buf[2]; + size_t len; + int rc; + + len = strlen(key); + buf[0] = cpu_to_le32(len); + buf[1] = cpu_to_le32(perdatum->value); + rc = put_entry(buf, sizeof(u32), 2, fp); + if (rc) + return rc; + + rc = put_entry(key, 1, len, fp); + if (rc) + return rc; + + return 0; +} + +static int common_write(void *vkey, void *datum, void *ptr) +{ + char *key = vkey; + struct common_datum *comdatum = datum; + struct policy_data *pd = ptr; + void *fp = pd->fp; + __le32 buf[4]; + size_t len; + int rc; + + len = strlen(key); + buf[0] = cpu_to_le32(len); + buf[1] = cpu_to_le32(comdatum->value); + buf[2] = cpu_to_le32(comdatum->permissions.nprim); + buf[3] = cpu_to_le32(comdatum->permissions.table.nel); + rc = put_entry(buf, sizeof(u32), 4, fp); + if (rc) + return rc; + + rc = put_entry(key, 1, len, fp); + if (rc) + return rc; + + rc = hashtab_map(&comdatum->permissions.table, perm_write, fp); + if (rc) + return rc; + + return 0; +} + +static int type_set_write(struct type_set *t, void *fp) +{ + int rc; + __le32 buf[1]; + + if (ebitmap_write(&t->types, fp)) + return -EINVAL; + if (ebitmap_write(&t->negset, fp)) + return -EINVAL; + + buf[0] = cpu_to_le32(t->flags); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return -EINVAL; + + return 0; +} + +static int write_cons_helper(struct policydb *p, struct constraint_node *node, + void *fp) +{ + struct constraint_node *c; + struct constraint_expr *e; + __le32 buf[3]; + u32 nel; + int rc; + + for (c = node; c; c = c->next) { + nel = 0; + for (e = c->expr; e; e = e->next) + nel++; + buf[0] = cpu_to_le32(c->permissions); + buf[1] = cpu_to_le32(nel); + rc = put_entry(buf, sizeof(u32), 2, fp); + if (rc) + return rc; + for (e = c->expr; e; e = e->next) { + buf[0] = cpu_to_le32(e->expr_type); + buf[1] = cpu_to_le32(e->attr); + buf[2] = cpu_to_le32(e->op); + rc = put_entry(buf, sizeof(u32), 3, fp); + if (rc) + return rc; + + switch (e->expr_type) { + case CEXPR_NAMES: + rc = ebitmap_write(&e->names, fp); + if (rc) + return rc; + if (p->policyvers >= + POLICYDB_VERSION_CONSTRAINT_NAMES) { + rc = type_set_write(e->type_names, fp); + if (rc) + return rc; + } + break; + default: + break; + } + } + } + + return 0; +} + +static int class_write(void *vkey, void *datum, void *ptr) +{ + char *key = vkey; + struct class_datum *cladatum = datum; + struct policy_data *pd = ptr; + void *fp = pd->fp; + struct policydb *p = pd->p; + struct constraint_node *c; + __le32 buf[6]; + u32 ncons; + size_t len, len2; + int rc; + + len = strlen(key); + if (cladatum->comkey) + len2 = strlen(cladatum->comkey); + else + len2 = 0; + + ncons = 0; + for (c = cladatum->constraints; c; c = c->next) + ncons++; + + buf[0] = cpu_to_le32(len); + buf[1] = cpu_to_le32(len2); + buf[2] = cpu_to_le32(cladatum->value); + buf[3] = cpu_to_le32(cladatum->permissions.nprim); + buf[4] = cpu_to_le32(cladatum->permissions.table.nel); + buf[5] = cpu_to_le32(ncons); + rc = put_entry(buf, sizeof(u32), 6, fp); + if (rc) + return rc; + + rc = put_entry(key, 1, len, fp); + if (rc) + return rc; + + if (cladatum->comkey) { + rc = put_entry(cladatum->comkey, 1, len2, fp); + if (rc) + return rc; + } + + rc = hashtab_map(&cladatum->permissions.table, perm_write, fp); + if (rc) + return rc; + + rc = write_cons_helper(p, cladatum->constraints, fp); + if (rc) + return rc; + + /* write out the validatetrans rule */ + ncons = 0; + for (c = cladatum->validatetrans; c; c = c->next) + ncons++; + + buf[0] = cpu_to_le32(ncons); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + + rc = write_cons_helper(p, cladatum->validatetrans, fp); + if (rc) + return rc; + + if (p->policyvers >= POLICYDB_VERSION_NEW_OBJECT_DEFAULTS) { + buf[0] = cpu_to_le32(cladatum->default_user); + buf[1] = cpu_to_le32(cladatum->default_role); + buf[2] = cpu_to_le32(cladatum->default_range); + + rc = put_entry(buf, sizeof(uint32_t), 3, fp); + if (rc) + return rc; + } + + if (p->policyvers >= POLICYDB_VERSION_DEFAULT_TYPE) { + buf[0] = cpu_to_le32(cladatum->default_type); + rc = put_entry(buf, sizeof(uint32_t), 1, fp); + if (rc) + return rc; + } + + return 0; +} + +static int role_write(void *vkey, void *datum, void *ptr) +{ + char *key = vkey; + struct role_datum *role = datum; + struct policy_data *pd = ptr; + void *fp = pd->fp; + struct policydb *p = pd->p; + __le32 buf[3]; + size_t items, len; + int rc; + + len = strlen(key); + items = 0; + buf[items++] = cpu_to_le32(len); + buf[items++] = cpu_to_le32(role->value); + if (p->policyvers >= POLICYDB_VERSION_BOUNDARY) + buf[items++] = cpu_to_le32(role->bounds); + + BUG_ON(items > ARRAY_SIZE(buf)); + + rc = put_entry(buf, sizeof(u32), items, fp); + if (rc) + return rc; + + rc = put_entry(key, 1, len, fp); + if (rc) + return rc; + + rc = ebitmap_write(&role->dominates, fp); + if (rc) + return rc; + + rc = ebitmap_write(&role->types, fp); + if (rc) + return rc; + + return 0; +} + +static int type_write(void *vkey, void *datum, void *ptr) +{ + char *key = vkey; + struct type_datum *typdatum = datum; + struct policy_data *pd = ptr; + struct policydb *p = pd->p; + void *fp = pd->fp; + __le32 buf[4]; + int rc; + size_t items, len; + + len = strlen(key); + items = 0; + buf[items++] = cpu_to_le32(len); + buf[items++] = cpu_to_le32(typdatum->value); + if (p->policyvers >= POLICYDB_VERSION_BOUNDARY) { + u32 properties = 0; + + if (typdatum->primary) + properties |= TYPEDATUM_PROPERTY_PRIMARY; + + if (typdatum->attribute) + properties |= TYPEDATUM_PROPERTY_ATTRIBUTE; + + buf[items++] = cpu_to_le32(properties); + buf[items++] = cpu_to_le32(typdatum->bounds); + } else { + buf[items++] = cpu_to_le32(typdatum->primary); + } + BUG_ON(items > ARRAY_SIZE(buf)); + rc = put_entry(buf, sizeof(u32), items, fp); + if (rc) + return rc; + + rc = put_entry(key, 1, len, fp); + if (rc) + return rc; + + return 0; +} + +static int user_write(void *vkey, void *datum, void *ptr) +{ + char *key = vkey; + struct user_datum *usrdatum = datum; + struct policy_data *pd = ptr; + struct policydb *p = pd->p; + void *fp = pd->fp; + __le32 buf[3]; + size_t items, len; + int rc; + + len = strlen(key); + items = 0; + buf[items++] = cpu_to_le32(len); + buf[items++] = cpu_to_le32(usrdatum->value); + if (p->policyvers >= POLICYDB_VERSION_BOUNDARY) + buf[items++] = cpu_to_le32(usrdatum->bounds); + BUG_ON(items > ARRAY_SIZE(buf)); + rc = put_entry(buf, sizeof(u32), items, fp); + if (rc) + return rc; + + rc = put_entry(key, 1, len, fp); + if (rc) + return rc; + + rc = ebitmap_write(&usrdatum->roles, fp); + if (rc) + return rc; + + rc = mls_write_range_helper(&usrdatum->range, fp); + if (rc) + return rc; + + rc = mls_write_level(&usrdatum->dfltlevel, fp); + if (rc) + return rc; + + return 0; +} + +static int (*const write_f[SYM_NUM]) (void *key, void *datum, void *datap) = { + common_write, + class_write, + role_write, + type_write, + user_write, + cond_write_bool, + sens_write, + cat_write, +}; + +static int ocontext_write(struct policydb *p, const struct policydb_compat_info *info, + void *fp) +{ + unsigned int i, j, rc; + size_t nel, len; + __be64 prefixbuf[1]; + __le32 buf[3]; + u32 nodebuf[8]; + struct ocontext *c; + for (i = 0; i < info->ocon_num; i++) { + nel = 0; + for (c = p->ocontexts[i]; c; c = c->next) + nel++; + buf[0] = cpu_to_le32(nel); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + for (c = p->ocontexts[i]; c; c = c->next) { + switch (i) { + case OCON_ISID: + buf[0] = cpu_to_le32(c->sid[0]); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + rc = context_write(p, &c->context[0], fp); + if (rc) + return rc; + break; + case OCON_FS: + case OCON_NETIF: + len = strlen(c->u.name); + buf[0] = cpu_to_le32(len); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + rc = put_entry(c->u.name, 1, len, fp); + if (rc) + return rc; + rc = context_write(p, &c->context[0], fp); + if (rc) + return rc; + rc = context_write(p, &c->context[1], fp); + if (rc) + return rc; + break; + case OCON_PORT: + buf[0] = cpu_to_le32(c->u.port.protocol); + buf[1] = cpu_to_le32(c->u.port.low_port); + buf[2] = cpu_to_le32(c->u.port.high_port); + rc = put_entry(buf, sizeof(u32), 3, fp); + if (rc) + return rc; + rc = context_write(p, &c->context[0], fp); + if (rc) + return rc; + break; + case OCON_NODE: + nodebuf[0] = c->u.node.addr; /* network order */ + nodebuf[1] = c->u.node.mask; /* network order */ + rc = put_entry(nodebuf, sizeof(u32), 2, fp); + if (rc) + return rc; + rc = context_write(p, &c->context[0], fp); + if (rc) + return rc; + break; + case OCON_FSUSE: + buf[0] = cpu_to_le32(c->v.behavior); + len = strlen(c->u.name); + buf[1] = cpu_to_le32(len); + rc = put_entry(buf, sizeof(u32), 2, fp); + if (rc) + return rc; + rc = put_entry(c->u.name, 1, len, fp); + if (rc) + return rc; + rc = context_write(p, &c->context[0], fp); + if (rc) + return rc; + break; + case OCON_NODE6: + for (j = 0; j < 4; j++) + nodebuf[j] = c->u.node6.addr[j]; /* network order */ + for (j = 0; j < 4; j++) + nodebuf[j + 4] = c->u.node6.mask[j]; /* network order */ + rc = put_entry(nodebuf, sizeof(u32), 8, fp); + if (rc) + return rc; + rc = context_write(p, &c->context[0], fp); + if (rc) + return rc; + break; + case OCON_IBPKEY: + /* subnet_prefix is in CPU order */ + prefixbuf[0] = cpu_to_be64(c->u.ibpkey.subnet_prefix); + + rc = put_entry(prefixbuf, sizeof(u64), 1, fp); + if (rc) + return rc; + + buf[0] = cpu_to_le32(c->u.ibpkey.low_pkey); + buf[1] = cpu_to_le32(c->u.ibpkey.high_pkey); + + rc = put_entry(buf, sizeof(u32), 2, fp); + if (rc) + return rc; + rc = context_write(p, &c->context[0], fp); + if (rc) + return rc; + break; + case OCON_IBENDPORT: + len = strlen(c->u.ibendport.dev_name); + buf[0] = cpu_to_le32(len); + buf[1] = cpu_to_le32(c->u.ibendport.port); + rc = put_entry(buf, sizeof(u32), 2, fp); + if (rc) + return rc; + rc = put_entry(c->u.ibendport.dev_name, 1, len, fp); + if (rc) + return rc; + rc = context_write(p, &c->context[0], fp); + if (rc) + return rc; + break; + } + } + } + return 0; +} + +static int genfs_write(struct policydb *p, void *fp) +{ + struct genfs *genfs; + struct ocontext *c; + size_t len; + __le32 buf[1]; + int rc; + + len = 0; + for (genfs = p->genfs; genfs; genfs = genfs->next) + len++; + buf[0] = cpu_to_le32(len); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + for (genfs = p->genfs; genfs; genfs = genfs->next) { + len = strlen(genfs->fstype); + buf[0] = cpu_to_le32(len); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + rc = put_entry(genfs->fstype, 1, len, fp); + if (rc) + return rc; + len = 0; + for (c = genfs->head; c; c = c->next) + len++; + buf[0] = cpu_to_le32(len); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + for (c = genfs->head; c; c = c->next) { + len = strlen(c->u.name); + buf[0] = cpu_to_le32(len); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + rc = put_entry(c->u.name, 1, len, fp); + if (rc) + return rc; + buf[0] = cpu_to_le32(c->v.sclass); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + rc = context_write(p, &c->context[0], fp); + if (rc) + return rc; + } + } + return 0; +} + +static int range_write_helper(void *key, void *data, void *ptr) +{ + __le32 buf[2]; + struct range_trans *rt = key; + struct mls_range *r = data; + struct policy_data *pd = ptr; + void *fp = pd->fp; + struct policydb *p = pd->p; + int rc; + + buf[0] = cpu_to_le32(rt->source_type); + buf[1] = cpu_to_le32(rt->target_type); + rc = put_entry(buf, sizeof(u32), 2, fp); + if (rc) + return rc; + if (p->policyvers >= POLICYDB_VERSION_RANGETRANS) { + buf[0] = cpu_to_le32(rt->target_class); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + } + rc = mls_write_range_helper(r, fp); + if (rc) + return rc; + + return 0; +} + +static int range_write(struct policydb *p, void *fp) +{ + __le32 buf[1]; + int rc; + struct policy_data pd; + + pd.p = p; + pd.fp = fp; + + buf[0] = cpu_to_le32(p->range_tr.nel); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + + /* actually write all of the entries */ + rc = hashtab_map(&p->range_tr, range_write_helper, &pd); + if (rc) + return rc; + + return 0; +} + +static int filename_write_helper_compat(void *key, void *data, void *ptr) +{ + struct filename_trans_key *ft = key; + struct filename_trans_datum *datum = data; + struct ebitmap_node *node; + void *fp = ptr; + __le32 buf[4]; + int rc; + u32 bit, len = strlen(ft->name); + + do { + ebitmap_for_each_positive_bit(&datum->stypes, node, bit) { + buf[0] = cpu_to_le32(len); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + + rc = put_entry(ft->name, sizeof(char), len, fp); + if (rc) + return rc; + + buf[0] = cpu_to_le32(bit + 1); + buf[1] = cpu_to_le32(ft->ttype); + buf[2] = cpu_to_le32(ft->tclass); + buf[3] = cpu_to_le32(datum->otype); + + rc = put_entry(buf, sizeof(u32), 4, fp); + if (rc) + return rc; + } + + datum = datum->next; + } while (unlikely(datum)); + + return 0; +} + +static int filename_write_helper(void *key, void *data, void *ptr) +{ + struct filename_trans_key *ft = key; + struct filename_trans_datum *datum; + void *fp = ptr; + __le32 buf[3]; + int rc; + u32 ndatum, len = strlen(ft->name); + + buf[0] = cpu_to_le32(len); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + + rc = put_entry(ft->name, sizeof(char), len, fp); + if (rc) + return rc; + + ndatum = 0; + datum = data; + do { + ndatum++; + datum = datum->next; + } while (unlikely(datum)); + + buf[0] = cpu_to_le32(ft->ttype); + buf[1] = cpu_to_le32(ft->tclass); + buf[2] = cpu_to_le32(ndatum); + rc = put_entry(buf, sizeof(u32), 3, fp); + if (rc) + return rc; + + datum = data; + do { + rc = ebitmap_write(&datum->stypes, fp); + if (rc) + return rc; + + buf[0] = cpu_to_le32(datum->otype); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + + datum = datum->next; + } while (unlikely(datum)); + + return 0; +} + +static int filename_trans_write(struct policydb *p, void *fp) +{ + __le32 buf[1]; + int rc; + + if (p->policyvers < POLICYDB_VERSION_FILENAME_TRANS) + return 0; + + if (p->policyvers < POLICYDB_VERSION_COMP_FTRANS) { + buf[0] = cpu_to_le32(p->compat_filename_trans_count); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + + rc = hashtab_map(&p->filename_trans, + filename_write_helper_compat, fp); + } else { + buf[0] = cpu_to_le32(p->filename_trans.nel); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + + rc = hashtab_map(&p->filename_trans, filename_write_helper, fp); + } + return rc; +} + +/* + * Write the configuration data in a policy database + * structure to a policy database binary representation + * file. + */ +int policydb_write(struct policydb *p, void *fp) +{ + unsigned int i, num_syms; + int rc; + __le32 buf[4]; + u32 config; + size_t len; + const struct policydb_compat_info *info; + + /* + * refuse to write policy older than compressed avtab + * to simplify the writer. There are other tests dropped + * since we assume this throughout the writer code. Be + * careful if you ever try to remove this restriction + */ + if (p->policyvers < POLICYDB_VERSION_AVTAB) { + pr_err("SELinux: refusing to write policy version %d." + " Because it is less than version %d\n", p->policyvers, + POLICYDB_VERSION_AVTAB); + return -EINVAL; + } + + config = 0; + if (p->mls_enabled) + config |= POLICYDB_CONFIG_MLS; + + if (p->reject_unknown) + config |= REJECT_UNKNOWN; + if (p->allow_unknown) + config |= ALLOW_UNKNOWN; + + /* Write the magic number and string identifiers. */ + buf[0] = cpu_to_le32(POLICYDB_MAGIC); + len = strlen(POLICYDB_STRING); + buf[1] = cpu_to_le32(len); + rc = put_entry(buf, sizeof(u32), 2, fp); + if (rc) + return rc; + rc = put_entry(POLICYDB_STRING, 1, len, fp); + if (rc) + return rc; + + /* Write the version, config, and table sizes. */ + info = policydb_lookup_compat(p->policyvers); + if (!info) { + pr_err("SELinux: compatibility lookup failed for policy " + "version %d", p->policyvers); + return -EINVAL; + } + + buf[0] = cpu_to_le32(p->policyvers); + buf[1] = cpu_to_le32(config); + buf[2] = cpu_to_le32(info->sym_num); + buf[3] = cpu_to_le32(info->ocon_num); + + rc = put_entry(buf, sizeof(u32), 4, fp); + if (rc) + return rc; + + if (p->policyvers >= POLICYDB_VERSION_POLCAP) { + rc = ebitmap_write(&p->policycaps, fp); + if (rc) + return rc; + } + + if (p->policyvers >= POLICYDB_VERSION_PERMISSIVE) { + rc = ebitmap_write(&p->permissive_map, fp); + if (rc) + return rc; + } + + num_syms = info->sym_num; + for (i = 0; i < num_syms; i++) { + struct policy_data pd; + + pd.fp = fp; + pd.p = p; + + buf[0] = cpu_to_le32(p->symtab[i].nprim); + buf[1] = cpu_to_le32(p->symtab[i].table.nel); + + rc = put_entry(buf, sizeof(u32), 2, fp); + if (rc) + return rc; + rc = hashtab_map(&p->symtab[i].table, write_f[i], &pd); + if (rc) + return rc; + } + + rc = avtab_write(p, &p->te_avtab, fp); + if (rc) + return rc; + + rc = cond_write_list(p, fp); + if (rc) + return rc; + + rc = role_trans_write(p, fp); + if (rc) + return rc; + + rc = role_allow_write(p->role_allow, fp); + if (rc) + return rc; + + rc = filename_trans_write(p, fp); + if (rc) + return rc; + + rc = ocontext_write(p, info, fp); + if (rc) + return rc; + + rc = genfs_write(p, fp); + if (rc) + return rc; + + rc = range_write(p, fp); + if (rc) + return rc; + + for (i = 0; i < p->p_types.nprim; i++) { + struct ebitmap *e = &p->type_attr_map_array[i]; + + rc = ebitmap_write(e, fp); + if (rc) + return rc; + } + + return 0; +} diff --git a/security/selinux/ss/policydb.h b/security/selinux/ss/policydb.h new file mode 100644 index 000000000..ffc4e7bad --- /dev/null +++ b/security/selinux/ss/policydb.h @@ -0,0 +1,391 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * A policy database (policydb) specifies the + * configuration data for the security policy. + * + * Author : Stephen Smalley, <sds@tycho.nsa.gov> + */ + +/* + * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com> + * + * Support for enhanced MLS infrastructure. + * + * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com> + * + * Added conditional policy language extensions + * + * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc. + * Copyright (C) 2003 - 2004 Tresys Technology, LLC + */ + +#ifndef _SS_POLICYDB_H_ +#define _SS_POLICYDB_H_ + +#include "symtab.h" +#include "avtab.h" +#include "sidtab.h" +#include "ebitmap.h" +#include "mls_types.h" +#include "context.h" +#include "constraint.h" + +/* + * A datum type is defined for each kind of symbol + * in the configuration data: individual permissions, + * common prefixes for access vectors, classes, + * users, roles, types, sensitivities, categories, etc. + */ + +/* Permission attributes */ +struct perm_datum { + u32 value; /* permission bit + 1 */ +}; + +/* Attributes of a common prefix for access vectors */ +struct common_datum { + u32 value; /* internal common value */ + struct symtab permissions; /* common permissions */ +}; + +/* Class attributes */ +struct class_datum { + u32 value; /* class value */ + char *comkey; /* common name */ + struct common_datum *comdatum; /* common datum */ + struct symtab permissions; /* class-specific permission symbol table */ + struct constraint_node *constraints; /* constraints on class permissions */ + struct constraint_node *validatetrans; /* special transition rules */ +/* Options how a new object user, role, and type should be decided */ +#define DEFAULT_SOURCE 1 +#define DEFAULT_TARGET 2 + char default_user; + char default_role; + char default_type; +/* Options how a new object range should be decided */ +#define DEFAULT_SOURCE_LOW 1 +#define DEFAULT_SOURCE_HIGH 2 +#define DEFAULT_SOURCE_LOW_HIGH 3 +#define DEFAULT_TARGET_LOW 4 +#define DEFAULT_TARGET_HIGH 5 +#define DEFAULT_TARGET_LOW_HIGH 6 +#define DEFAULT_GLBLUB 7 + char default_range; +}; + +/* Role attributes */ +struct role_datum { + u32 value; /* internal role value */ + u32 bounds; /* boundary of role */ + struct ebitmap dominates; /* set of roles dominated by this role */ + struct ebitmap types; /* set of authorized types for role */ +}; + +struct role_trans_key { + u32 role; /* current role */ + u32 type; /* program executable type, or new object type */ + u32 tclass; /* process class, or new object class */ +}; + +struct role_trans_datum { + u32 new_role; /* new role */ +}; + +struct filename_trans_key { + u32 ttype; /* parent dir context */ + u16 tclass; /* class of new object */ + const char *name; /* last path component */ +}; + +struct filename_trans_datum { + struct ebitmap stypes; /* bitmap of source types for this otype */ + u32 otype; /* resulting type of new object */ + struct filename_trans_datum *next; /* record for next otype*/ +}; + +struct role_allow { + u32 role; /* current role */ + u32 new_role; /* new role */ + struct role_allow *next; +}; + +/* Type attributes */ +struct type_datum { + u32 value; /* internal type value */ + u32 bounds; /* boundary of type */ + unsigned char primary; /* primary name? */ + unsigned char attribute;/* attribute ?*/ +}; + +/* User attributes */ +struct user_datum { + u32 value; /* internal user value */ + u32 bounds; /* bounds of user */ + struct ebitmap roles; /* set of authorized roles for user */ + struct mls_range range; /* MLS range (min - max) for user */ + struct mls_level dfltlevel; /* default login MLS level for user */ +}; + + +/* Sensitivity attributes */ +struct level_datum { + struct mls_level *level; /* sensitivity and associated categories */ + unsigned char isalias; /* is this sensitivity an alias for another? */ +}; + +/* Category attributes */ +struct cat_datum { + u32 value; /* internal category bit + 1 */ + unsigned char isalias; /* is this category an alias for another? */ +}; + +struct range_trans { + u32 source_type; + u32 target_type; + u32 target_class; +}; + +/* Boolean data type */ +struct cond_bool_datum { + __u32 value; /* internal type value */ + int state; +}; + +struct cond_node; + +/* + * type set preserves data needed to determine constraint info from + * policy source. This is not used by the kernel policy but allows + * utilities such as audit2allow to determine constraint denials. + */ +struct type_set { + struct ebitmap types; + struct ebitmap negset; + u32 flags; +}; + +/* + * The configuration data includes security contexts for + * initial SIDs, unlabeled file systems, TCP and UDP port numbers, + * network interfaces, and nodes. This structure stores the + * relevant data for one such entry. Entries of the same kind + * (e.g. all initial SIDs) are linked together into a list. + */ +struct ocontext { + union { + char *name; /* name of initial SID, fs, netif, fstype, path */ + struct { + u8 protocol; + u16 low_port; + u16 high_port; + } port; /* TCP or UDP port information */ + struct { + u32 addr; + u32 mask; + } node; /* node information */ + struct { + u32 addr[4]; + u32 mask[4]; + } node6; /* IPv6 node information */ + struct { + u64 subnet_prefix; + u16 low_pkey; + u16 high_pkey; + } ibpkey; + struct { + char *dev_name; + u8 port; + } ibendport; + } u; + union { + u32 sclass; /* security class for genfs */ + u32 behavior; /* labeling behavior for fs_use */ + } v; + struct context context[2]; /* security context(s) */ + u32 sid[2]; /* SID(s) */ + struct ocontext *next; +}; + +struct genfs { + char *fstype; + struct ocontext *head; + struct genfs *next; +}; + +/* symbol table array indices */ +#define SYM_COMMONS 0 +#define SYM_CLASSES 1 +#define SYM_ROLES 2 +#define SYM_TYPES 3 +#define SYM_USERS 4 +#define SYM_BOOLS 5 +#define SYM_LEVELS 6 +#define SYM_CATS 7 +#define SYM_NUM 8 + +/* object context array indices */ +#define OCON_ISID 0 /* initial SIDs */ +#define OCON_FS 1 /* unlabeled file systems */ +#define OCON_PORT 2 /* TCP and UDP port numbers */ +#define OCON_NETIF 3 /* network interfaces */ +#define OCON_NODE 4 /* nodes */ +#define OCON_FSUSE 5 /* fs_use */ +#define OCON_NODE6 6 /* IPv6 nodes */ +#define OCON_IBPKEY 7 /* Infiniband PKeys */ +#define OCON_IBENDPORT 8 /* Infiniband end ports */ +#define OCON_NUM 9 + +/* The policy database */ +struct policydb { + int mls_enabled; + + /* symbol tables */ + struct symtab symtab[SYM_NUM]; +#define p_commons symtab[SYM_COMMONS] +#define p_classes symtab[SYM_CLASSES] +#define p_roles symtab[SYM_ROLES] +#define p_types symtab[SYM_TYPES] +#define p_users symtab[SYM_USERS] +#define p_bools symtab[SYM_BOOLS] +#define p_levels symtab[SYM_LEVELS] +#define p_cats symtab[SYM_CATS] + + /* symbol names indexed by (value - 1) */ + char **sym_val_to_name[SYM_NUM]; + + /* class, role, and user attributes indexed by (value - 1) */ + struct class_datum **class_val_to_struct; + struct role_datum **role_val_to_struct; + struct user_datum **user_val_to_struct; + struct type_datum **type_val_to_struct; + + /* type enforcement access vectors and transitions */ + struct avtab te_avtab; + + /* role transitions */ + struct hashtab role_tr; + + /* file transitions with the last path component */ + /* quickly exclude lookups when parent ttype has no rules */ + struct ebitmap filename_trans_ttypes; + /* actual set of filename_trans rules */ + struct hashtab filename_trans; + /* only used if policyvers < POLICYDB_VERSION_COMP_FTRANS */ + u32 compat_filename_trans_count; + + /* bools indexed by (value - 1) */ + struct cond_bool_datum **bool_val_to_struct; + /* type enforcement conditional access vectors and transitions */ + struct avtab te_cond_avtab; + /* array indexing te_cond_avtab by conditional */ + struct cond_node *cond_list; + u32 cond_list_len; + + /* role allows */ + struct role_allow *role_allow; + + /* security contexts of initial SIDs, unlabeled file systems, + TCP or UDP port numbers, network interfaces and nodes */ + struct ocontext *ocontexts[OCON_NUM]; + + /* security contexts for files in filesystems that cannot support + a persistent label mapping or use another + fixed labeling behavior. */ + struct genfs *genfs; + + /* range transitions table (range_trans_key -> mls_range) */ + struct hashtab range_tr; + + /* type -> attribute reverse mapping */ + struct ebitmap *type_attr_map_array; + + struct ebitmap policycaps; + + struct ebitmap permissive_map; + + /* length of this policy when it was loaded */ + size_t len; + + unsigned int policyvers; + + unsigned int reject_unknown : 1; + unsigned int allow_unknown : 1; + + u16 process_class; + u32 process_trans_perms; +} __randomize_layout; + +extern void policydb_destroy(struct policydb *p); +extern int policydb_load_isids(struct policydb *p, struct sidtab *s); +extern int policydb_context_isvalid(struct policydb *p, struct context *c); +extern int policydb_class_isvalid(struct policydb *p, unsigned int class); +extern int policydb_type_isvalid(struct policydb *p, unsigned int type); +extern int policydb_role_isvalid(struct policydb *p, unsigned int role); +extern int policydb_read(struct policydb *p, void *fp); +extern int policydb_write(struct policydb *p, void *fp); + +extern struct filename_trans_datum *policydb_filenametr_search( + struct policydb *p, struct filename_trans_key *key); + +extern struct mls_range *policydb_rangetr_search( + struct policydb *p, struct range_trans *key); + +extern struct role_trans_datum *policydb_roletr_search( + struct policydb *p, struct role_trans_key *key); + +#define POLICYDB_CONFIG_MLS 1 + +/* the config flags related to unknown classes/perms are bits 2 and 3 */ +#define REJECT_UNKNOWN 0x00000002 +#define ALLOW_UNKNOWN 0x00000004 + +#define OBJECT_R "object_r" +#define OBJECT_R_VAL 1 + +#define POLICYDB_MAGIC SELINUX_MAGIC +#define POLICYDB_STRING "SE Linux" + +struct policy_file { + char *data; + size_t len; +}; + +struct policy_data { + struct policydb *p; + void *fp; +}; + +static inline int next_entry(void *buf, struct policy_file *fp, size_t bytes) +{ + if (bytes > fp->len) + return -EINVAL; + + memcpy(buf, fp->data, bytes); + fp->data += bytes; + fp->len -= bytes; + return 0; +} + +static inline int put_entry(const void *buf, size_t bytes, int num, struct policy_file *fp) +{ + size_t len = bytes * num; + + if (len > fp->len) + return -EINVAL; + memcpy(fp->data, buf, len); + fp->data += len; + fp->len -= len; + + return 0; +} + +static inline char *sym_name(struct policydb *p, unsigned int sym_num, unsigned int element_nr) +{ + return p->sym_val_to_name[sym_num][element_nr]; +} + +extern u16 string_to_security_class(struct policydb *p, const char *name); +extern u32 string_to_av_perm(struct policydb *p, u16 tclass, const char *name); + +#endif /* _SS_POLICYDB_H_ */ + diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c new file mode 100644 index 000000000..64a6a37dc --- /dev/null +++ b/security/selinux/ss/services.c @@ -0,0 +1,4072 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Implementation of the security services. + * + * Authors : Stephen Smalley, <sds@tycho.nsa.gov> + * James Morris <jmorris@redhat.com> + * + * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com> + * + * Support for enhanced MLS infrastructure. + * Support for context based audit filters. + * + * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com> + * + * Added conditional policy language extensions + * + * Updated: Hewlett-Packard <paul@paul-moore.com> + * + * Added support for NetLabel + * Added support for the policy capability bitmap + * + * Updated: Chad Sellers <csellers@tresys.com> + * + * Added validation of kernel classes and permissions + * + * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com> + * + * Added support for bounds domain and audit messaged on masked permissions + * + * Updated: Guido Trentalancia <guido@trentalancia.com> + * + * Added support for runtime switching of the policy type + * + * Copyright (C) 2008, 2009 NEC Corporation + * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P. + * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc. + * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC + * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com> + */ +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/spinlock.h> +#include <linux/rcupdate.h> +#include <linux/errno.h> +#include <linux/in.h> +#include <linux/sched.h> +#include <linux/audit.h> +#include <linux/vmalloc.h> +#include <linux/lsm_hooks.h> +#include <net/netlabel.h> + +#include "flask.h" +#include "avc.h" +#include "avc_ss.h" +#include "security.h" +#include "context.h" +#include "policydb.h" +#include "sidtab.h" +#include "services.h" +#include "conditional.h" +#include "mls.h" +#include "objsec.h" +#include "netlabel.h" +#include "xfrm.h" +#include "ebitmap.h" +#include "audit.h" +#include "policycap_names.h" +#include "ima.h" + +struct convert_context_args { + struct selinux_state *state; + struct policydb *oldp; + struct policydb *newp; +}; + +struct selinux_policy_convert_data { + struct convert_context_args args; + struct sidtab_convert_params sidtab_params; +}; + +/* Forward declaration. */ +static int context_struct_to_string(struct policydb *policydb, + struct context *context, + char **scontext, + u32 *scontext_len); + +static int sidtab_entry_to_string(struct policydb *policydb, + struct sidtab *sidtab, + struct sidtab_entry *entry, + char **scontext, + u32 *scontext_len); + +static void context_struct_compute_av(struct policydb *policydb, + struct context *scontext, + struct context *tcontext, + u16 tclass, + struct av_decision *avd, + struct extended_perms *xperms); + +static int selinux_set_mapping(struct policydb *pol, + const struct security_class_mapping *map, + struct selinux_map *out_map) +{ + u16 i, j; + unsigned k; + bool print_unknown_handle = false; + + /* Find number of classes in the input mapping */ + if (!map) + return -EINVAL; + i = 0; + while (map[i].name) + i++; + + /* Allocate space for the class records, plus one for class zero */ + out_map->mapping = kcalloc(++i, sizeof(*out_map->mapping), GFP_ATOMIC); + if (!out_map->mapping) + return -ENOMEM; + + /* Store the raw class and permission values */ + j = 0; + while (map[j].name) { + const struct security_class_mapping *p_in = map + (j++); + struct selinux_mapping *p_out = out_map->mapping + j; + + /* An empty class string skips ahead */ + if (!strcmp(p_in->name, "")) { + p_out->num_perms = 0; + continue; + } + + p_out->value = string_to_security_class(pol, p_in->name); + if (!p_out->value) { + pr_info("SELinux: Class %s not defined in policy.\n", + p_in->name); + if (pol->reject_unknown) + goto err; + p_out->num_perms = 0; + print_unknown_handle = true; + continue; + } + + k = 0; + while (p_in->perms[k]) { + /* An empty permission string skips ahead */ + if (!*p_in->perms[k]) { + k++; + continue; + } + p_out->perms[k] = string_to_av_perm(pol, p_out->value, + p_in->perms[k]); + if (!p_out->perms[k]) { + pr_info("SELinux: Permission %s in class %s not defined in policy.\n", + p_in->perms[k], p_in->name); + if (pol->reject_unknown) + goto err; + print_unknown_handle = true; + } + + k++; + } + p_out->num_perms = k; + } + + if (print_unknown_handle) + pr_info("SELinux: the above unknown classes and permissions will be %s\n", + pol->allow_unknown ? "allowed" : "denied"); + + out_map->size = i; + return 0; +err: + kfree(out_map->mapping); + out_map->mapping = NULL; + return -EINVAL; +} + +/* + * Get real, policy values from mapped values + */ + +static u16 unmap_class(struct selinux_map *map, u16 tclass) +{ + if (tclass < map->size) + return map->mapping[tclass].value; + + return tclass; +} + +/* + * Get kernel value for class from its policy value + */ +static u16 map_class(struct selinux_map *map, u16 pol_value) +{ + u16 i; + + for (i = 1; i < map->size; i++) { + if (map->mapping[i].value == pol_value) + return i; + } + + return SECCLASS_NULL; +} + +static void map_decision(struct selinux_map *map, + u16 tclass, struct av_decision *avd, + int allow_unknown) +{ + if (tclass < map->size) { + struct selinux_mapping *mapping = &map->mapping[tclass]; + unsigned int i, n = mapping->num_perms; + u32 result; + + for (i = 0, result = 0; i < n; i++) { + if (avd->allowed & mapping->perms[i]) + result |= 1<<i; + if (allow_unknown && !mapping->perms[i]) + result |= 1<<i; + } + avd->allowed = result; + + for (i = 0, result = 0; i < n; i++) + if (avd->auditallow & mapping->perms[i]) + result |= 1<<i; + avd->auditallow = result; + + for (i = 0, result = 0; i < n; i++) { + if (avd->auditdeny & mapping->perms[i]) + result |= 1<<i; + if (!allow_unknown && !mapping->perms[i]) + result |= 1<<i; + } + /* + * In case the kernel has a bug and requests a permission + * between num_perms and the maximum permission number, we + * should audit that denial + */ + for (; i < (sizeof(u32)*8); i++) + result |= 1<<i; + avd->auditdeny = result; + } +} + +int security_mls_enabled(struct selinux_state *state) +{ + int mls_enabled; + struct selinux_policy *policy; + + if (!selinux_initialized(state)) + return 0; + + rcu_read_lock(); + policy = rcu_dereference(state->policy); + mls_enabled = policy->policydb.mls_enabled; + rcu_read_unlock(); + return mls_enabled; +} + +/* + * Return the boolean value of a constraint expression + * when it is applied to the specified source and target + * security contexts. + * + * xcontext is a special beast... It is used by the validatetrans rules + * only. For these rules, scontext is the context before the transition, + * tcontext is the context after the transition, and xcontext is the context + * of the process performing the transition. All other callers of + * constraint_expr_eval should pass in NULL for xcontext. + */ +static int constraint_expr_eval(struct policydb *policydb, + struct context *scontext, + struct context *tcontext, + struct context *xcontext, + struct constraint_expr *cexpr) +{ + u32 val1, val2; + struct context *c; + struct role_datum *r1, *r2; + struct mls_level *l1, *l2; + struct constraint_expr *e; + int s[CEXPR_MAXDEPTH]; + int sp = -1; + + for (e = cexpr; e; e = e->next) { + switch (e->expr_type) { + case CEXPR_NOT: + BUG_ON(sp < 0); + s[sp] = !s[sp]; + break; + case CEXPR_AND: + BUG_ON(sp < 1); + sp--; + s[sp] &= s[sp + 1]; + break; + case CEXPR_OR: + BUG_ON(sp < 1); + sp--; + s[sp] |= s[sp + 1]; + break; + case CEXPR_ATTR: + if (sp == (CEXPR_MAXDEPTH - 1)) + return 0; + switch (e->attr) { + case CEXPR_USER: + val1 = scontext->user; + val2 = tcontext->user; + break; + case CEXPR_TYPE: + val1 = scontext->type; + val2 = tcontext->type; + break; + case CEXPR_ROLE: + val1 = scontext->role; + val2 = tcontext->role; + r1 = policydb->role_val_to_struct[val1 - 1]; + r2 = policydb->role_val_to_struct[val2 - 1]; + switch (e->op) { + case CEXPR_DOM: + s[++sp] = ebitmap_get_bit(&r1->dominates, + val2 - 1); + continue; + case CEXPR_DOMBY: + s[++sp] = ebitmap_get_bit(&r2->dominates, + val1 - 1); + continue; + case CEXPR_INCOMP: + s[++sp] = (!ebitmap_get_bit(&r1->dominates, + val2 - 1) && + !ebitmap_get_bit(&r2->dominates, + val1 - 1)); + continue; + default: + break; + } + break; + case CEXPR_L1L2: + l1 = &(scontext->range.level[0]); + l2 = &(tcontext->range.level[0]); + goto mls_ops; + case CEXPR_L1H2: + l1 = &(scontext->range.level[0]); + l2 = &(tcontext->range.level[1]); + goto mls_ops; + case CEXPR_H1L2: + l1 = &(scontext->range.level[1]); + l2 = &(tcontext->range.level[0]); + goto mls_ops; + case CEXPR_H1H2: + l1 = &(scontext->range.level[1]); + l2 = &(tcontext->range.level[1]); + goto mls_ops; + case CEXPR_L1H1: + l1 = &(scontext->range.level[0]); + l2 = &(scontext->range.level[1]); + goto mls_ops; + case CEXPR_L2H2: + l1 = &(tcontext->range.level[0]); + l2 = &(tcontext->range.level[1]); + goto mls_ops; +mls_ops: + switch (e->op) { + case CEXPR_EQ: + s[++sp] = mls_level_eq(l1, l2); + continue; + case CEXPR_NEQ: + s[++sp] = !mls_level_eq(l1, l2); + continue; + case CEXPR_DOM: + s[++sp] = mls_level_dom(l1, l2); + continue; + case CEXPR_DOMBY: + s[++sp] = mls_level_dom(l2, l1); + continue; + case CEXPR_INCOMP: + s[++sp] = mls_level_incomp(l2, l1); + continue; + default: + BUG(); + return 0; + } + break; + default: + BUG(); + return 0; + } + + switch (e->op) { + case CEXPR_EQ: + s[++sp] = (val1 == val2); + break; + case CEXPR_NEQ: + s[++sp] = (val1 != val2); + break; + default: + BUG(); + return 0; + } + break; + case CEXPR_NAMES: + if (sp == (CEXPR_MAXDEPTH-1)) + return 0; + c = scontext; + if (e->attr & CEXPR_TARGET) + c = tcontext; + else if (e->attr & CEXPR_XTARGET) { + c = xcontext; + if (!c) { + BUG(); + return 0; + } + } + if (e->attr & CEXPR_USER) + val1 = c->user; + else if (e->attr & CEXPR_ROLE) + val1 = c->role; + else if (e->attr & CEXPR_TYPE) + val1 = c->type; + else { + BUG(); + return 0; + } + + switch (e->op) { + case CEXPR_EQ: + s[++sp] = ebitmap_get_bit(&e->names, val1 - 1); + break; + case CEXPR_NEQ: + s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1); + break; + default: + BUG(); + return 0; + } + break; + default: + BUG(); + return 0; + } + } + + BUG_ON(sp != 0); + return s[0]; +} + +/* + * security_dump_masked_av - dumps masked permissions during + * security_compute_av due to RBAC, MLS/Constraint and Type bounds. + */ +static int dump_masked_av_helper(void *k, void *d, void *args) +{ + struct perm_datum *pdatum = d; + char **permission_names = args; + + BUG_ON(pdatum->value < 1 || pdatum->value > 32); + + permission_names[pdatum->value - 1] = (char *)k; + + return 0; +} + +static void security_dump_masked_av(struct policydb *policydb, + struct context *scontext, + struct context *tcontext, + u16 tclass, + u32 permissions, + const char *reason) +{ + struct common_datum *common_dat; + struct class_datum *tclass_dat; + struct audit_buffer *ab; + char *tclass_name; + char *scontext_name = NULL; + char *tcontext_name = NULL; + char *permission_names[32]; + int index; + u32 length; + bool need_comma = false; + + if (!permissions) + return; + + tclass_name = sym_name(policydb, SYM_CLASSES, tclass - 1); + tclass_dat = policydb->class_val_to_struct[tclass - 1]; + common_dat = tclass_dat->comdatum; + + /* init permission_names */ + if (common_dat && + hashtab_map(&common_dat->permissions.table, + dump_masked_av_helper, permission_names) < 0) + goto out; + + if (hashtab_map(&tclass_dat->permissions.table, + dump_masked_av_helper, permission_names) < 0) + goto out; + + /* get scontext/tcontext in text form */ + if (context_struct_to_string(policydb, scontext, + &scontext_name, &length) < 0) + goto out; + + if (context_struct_to_string(policydb, tcontext, + &tcontext_name, &length) < 0) + goto out; + + /* audit a message */ + ab = audit_log_start(audit_context(), + GFP_ATOMIC, AUDIT_SELINUX_ERR); + if (!ab) + goto out; + + audit_log_format(ab, "op=security_compute_av reason=%s " + "scontext=%s tcontext=%s tclass=%s perms=", + reason, scontext_name, tcontext_name, tclass_name); + + for (index = 0; index < 32; index++) { + u32 mask = (1 << index); + + if ((mask & permissions) == 0) + continue; + + audit_log_format(ab, "%s%s", + need_comma ? "," : "", + permission_names[index] + ? permission_names[index] : "????"); + need_comma = true; + } + audit_log_end(ab); +out: + /* release scontext/tcontext */ + kfree(tcontext_name); + kfree(scontext_name); +} + +/* + * security_boundary_permission - drops violated permissions + * on boundary constraint. + */ +static void type_attribute_bounds_av(struct policydb *policydb, + struct context *scontext, + struct context *tcontext, + u16 tclass, + struct av_decision *avd) +{ + struct context lo_scontext; + struct context lo_tcontext, *tcontextp = tcontext; + struct av_decision lo_avd; + struct type_datum *source; + struct type_datum *target; + u32 masked = 0; + + source = policydb->type_val_to_struct[scontext->type - 1]; + BUG_ON(!source); + + if (!source->bounds) + return; + + target = policydb->type_val_to_struct[tcontext->type - 1]; + BUG_ON(!target); + + memset(&lo_avd, 0, sizeof(lo_avd)); + + memcpy(&lo_scontext, scontext, sizeof(lo_scontext)); + lo_scontext.type = source->bounds; + + if (target->bounds) { + memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext)); + lo_tcontext.type = target->bounds; + tcontextp = &lo_tcontext; + } + + context_struct_compute_av(policydb, &lo_scontext, + tcontextp, + tclass, + &lo_avd, + NULL); + + masked = ~lo_avd.allowed & avd->allowed; + + if (likely(!masked)) + return; /* no masked permission */ + + /* mask violated permissions */ + avd->allowed &= ~masked; + + /* audit masked permissions */ + security_dump_masked_av(policydb, scontext, tcontext, + tclass, masked, "bounds"); +} + +/* + * flag which drivers have permissions + * only looking for ioctl based extended permssions + */ +void services_compute_xperms_drivers( + struct extended_perms *xperms, + struct avtab_node *node) +{ + unsigned int i; + + if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { + /* if one or more driver has all permissions allowed */ + for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++) + xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i]; + } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { + /* if allowing permissions within a driver */ + security_xperm_set(xperms->drivers.p, + node->datum.u.xperms->driver); + } + + xperms->len = 1; +} + +/* + * Compute access vectors and extended permissions based on a context + * structure pair for the permissions in a particular class. + */ +static void context_struct_compute_av(struct policydb *policydb, + struct context *scontext, + struct context *tcontext, + u16 tclass, + struct av_decision *avd, + struct extended_perms *xperms) +{ + struct constraint_node *constraint; + struct role_allow *ra; + struct avtab_key avkey; + struct avtab_node *node; + struct class_datum *tclass_datum; + struct ebitmap *sattr, *tattr; + struct ebitmap_node *snode, *tnode; + unsigned int i, j; + + avd->allowed = 0; + avd->auditallow = 0; + avd->auditdeny = 0xffffffff; + if (xperms) { + memset(&xperms->drivers, 0, sizeof(xperms->drivers)); + xperms->len = 0; + } + + if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) { + if (printk_ratelimit()) + pr_warn("SELinux: Invalid class %hu\n", tclass); + return; + } + + tclass_datum = policydb->class_val_to_struct[tclass - 1]; + + /* + * If a specific type enforcement rule was defined for + * this permission check, then use it. + */ + avkey.target_class = tclass; + avkey.specified = AVTAB_AV | AVTAB_XPERMS; + sattr = &policydb->type_attr_map_array[scontext->type - 1]; + tattr = &policydb->type_attr_map_array[tcontext->type - 1]; + ebitmap_for_each_positive_bit(sattr, snode, i) { + ebitmap_for_each_positive_bit(tattr, tnode, j) { + avkey.source_type = i + 1; + avkey.target_type = j + 1; + for (node = avtab_search_node(&policydb->te_avtab, + &avkey); + node; + node = avtab_search_node_next(node, avkey.specified)) { + if (node->key.specified == AVTAB_ALLOWED) + avd->allowed |= node->datum.u.data; + else if (node->key.specified == AVTAB_AUDITALLOW) + avd->auditallow |= node->datum.u.data; + else if (node->key.specified == AVTAB_AUDITDENY) + avd->auditdeny &= node->datum.u.data; + else if (xperms && (node->key.specified & AVTAB_XPERMS)) + services_compute_xperms_drivers(xperms, node); + } + + /* Check conditional av table for additional permissions */ + cond_compute_av(&policydb->te_cond_avtab, &avkey, + avd, xperms); + + } + } + + /* + * Remove any permissions prohibited by a constraint (this includes + * the MLS policy). + */ + constraint = tclass_datum->constraints; + while (constraint) { + if ((constraint->permissions & (avd->allowed)) && + !constraint_expr_eval(policydb, scontext, tcontext, NULL, + constraint->expr)) { + avd->allowed &= ~(constraint->permissions); + } + constraint = constraint->next; + } + + /* + * If checking process transition permission and the + * role is changing, then check the (current_role, new_role) + * pair. + */ + if (tclass == policydb->process_class && + (avd->allowed & policydb->process_trans_perms) && + scontext->role != tcontext->role) { + for (ra = policydb->role_allow; ra; ra = ra->next) { + if (scontext->role == ra->role && + tcontext->role == ra->new_role) + break; + } + if (!ra) + avd->allowed &= ~policydb->process_trans_perms; + } + + /* + * If the given source and target types have boundary + * constraint, lazy checks have to mask any violated + * permission and notice it to userspace via audit. + */ + type_attribute_bounds_av(policydb, scontext, tcontext, + tclass, avd); +} + +static int security_validtrans_handle_fail(struct selinux_state *state, + struct selinux_policy *policy, + struct sidtab_entry *oentry, + struct sidtab_entry *nentry, + struct sidtab_entry *tentry, + u16 tclass) +{ + struct policydb *p = &policy->policydb; + struct sidtab *sidtab = policy->sidtab; + char *o = NULL, *n = NULL, *t = NULL; + u32 olen, nlen, tlen; + + if (sidtab_entry_to_string(p, sidtab, oentry, &o, &olen)) + goto out; + if (sidtab_entry_to_string(p, sidtab, nentry, &n, &nlen)) + goto out; + if (sidtab_entry_to_string(p, sidtab, tentry, &t, &tlen)) + goto out; + audit_log(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR, + "op=security_validate_transition seresult=denied" + " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s", + o, n, t, sym_name(p, SYM_CLASSES, tclass-1)); +out: + kfree(o); + kfree(n); + kfree(t); + + if (!enforcing_enabled(state)) + return 0; + return -EPERM; +} + +static int security_compute_validatetrans(struct selinux_state *state, + u32 oldsid, u32 newsid, u32 tasksid, + u16 orig_tclass, bool user) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + struct sidtab_entry *oentry; + struct sidtab_entry *nentry; + struct sidtab_entry *tentry; + struct class_datum *tclass_datum; + struct constraint_node *constraint; + u16 tclass; + int rc = 0; + + + if (!selinux_initialized(state)) + return 0; + + rcu_read_lock(); + + policy = rcu_dereference(state->policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + + if (!user) + tclass = unmap_class(&policy->map, orig_tclass); + else + tclass = orig_tclass; + + if (!tclass || tclass > policydb->p_classes.nprim) { + rc = -EINVAL; + goto out; + } + tclass_datum = policydb->class_val_to_struct[tclass - 1]; + + oentry = sidtab_search_entry(sidtab, oldsid); + if (!oentry) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, oldsid); + rc = -EINVAL; + goto out; + } + + nentry = sidtab_search_entry(sidtab, newsid); + if (!nentry) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, newsid); + rc = -EINVAL; + goto out; + } + + tentry = sidtab_search_entry(sidtab, tasksid); + if (!tentry) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, tasksid); + rc = -EINVAL; + goto out; + } + + constraint = tclass_datum->validatetrans; + while (constraint) { + if (!constraint_expr_eval(policydb, &oentry->context, + &nentry->context, &tentry->context, + constraint->expr)) { + if (user) + rc = -EPERM; + else + rc = security_validtrans_handle_fail(state, + policy, + oentry, + nentry, + tentry, + tclass); + goto out; + } + constraint = constraint->next; + } + +out: + rcu_read_unlock(); + return rc; +} + +int security_validate_transition_user(struct selinux_state *state, + u32 oldsid, u32 newsid, u32 tasksid, + u16 tclass) +{ + return security_compute_validatetrans(state, oldsid, newsid, tasksid, + tclass, true); +} + +int security_validate_transition(struct selinux_state *state, + u32 oldsid, u32 newsid, u32 tasksid, + u16 orig_tclass) +{ + return security_compute_validatetrans(state, oldsid, newsid, tasksid, + orig_tclass, false); +} + +/* + * security_bounded_transition - check whether the given + * transition is directed to bounded, or not. + * It returns 0, if @newsid is bounded by @oldsid. + * Otherwise, it returns error code. + * + * @state: SELinux state + * @oldsid : current security identifier + * @newsid : destinated security identifier + */ +int security_bounded_transition(struct selinux_state *state, + u32 old_sid, u32 new_sid) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + struct sidtab_entry *old_entry, *new_entry; + struct type_datum *type; + int index; + int rc; + + if (!selinux_initialized(state)) + return 0; + + rcu_read_lock(); + policy = rcu_dereference(state->policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + + rc = -EINVAL; + old_entry = sidtab_search_entry(sidtab, old_sid); + if (!old_entry) { + pr_err("SELinux: %s: unrecognized SID %u\n", + __func__, old_sid); + goto out; + } + + rc = -EINVAL; + new_entry = sidtab_search_entry(sidtab, new_sid); + if (!new_entry) { + pr_err("SELinux: %s: unrecognized SID %u\n", + __func__, new_sid); + goto out; + } + + rc = 0; + /* type/domain unchanged */ + if (old_entry->context.type == new_entry->context.type) + goto out; + + index = new_entry->context.type; + while (true) { + type = policydb->type_val_to_struct[index - 1]; + BUG_ON(!type); + + /* not bounded anymore */ + rc = -EPERM; + if (!type->bounds) + break; + + /* @newsid is bounded by @oldsid */ + rc = 0; + if (type->bounds == old_entry->context.type) + break; + + index = type->bounds; + } + + if (rc) { + char *old_name = NULL; + char *new_name = NULL; + u32 length; + + if (!sidtab_entry_to_string(policydb, sidtab, old_entry, + &old_name, &length) && + !sidtab_entry_to_string(policydb, sidtab, new_entry, + &new_name, &length)) { + audit_log(audit_context(), + GFP_ATOMIC, AUDIT_SELINUX_ERR, + "op=security_bounded_transition " + "seresult=denied " + "oldcontext=%s newcontext=%s", + old_name, new_name); + } + kfree(new_name); + kfree(old_name); + } +out: + rcu_read_unlock(); + + return rc; +} + +static void avd_init(struct selinux_policy *policy, struct av_decision *avd) +{ + avd->allowed = 0; + avd->auditallow = 0; + avd->auditdeny = 0xffffffff; + if (policy) + avd->seqno = policy->latest_granting; + else + avd->seqno = 0; + avd->flags = 0; +} + +void services_compute_xperms_decision(struct extended_perms_decision *xpermd, + struct avtab_node *node) +{ + unsigned int i; + + if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { + if (xpermd->driver != node->datum.u.xperms->driver) + return; + } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { + if (!security_xperm_test(node->datum.u.xperms->perms.p, + xpermd->driver)) + return; + } else { + BUG(); + } + + if (node->key.specified == AVTAB_XPERMS_ALLOWED) { + xpermd->used |= XPERMS_ALLOWED; + if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { + memset(xpermd->allowed->p, 0xff, + sizeof(xpermd->allowed->p)); + } + if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { + for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++) + xpermd->allowed->p[i] |= + node->datum.u.xperms->perms.p[i]; + } + } else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) { + xpermd->used |= XPERMS_AUDITALLOW; + if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { + memset(xpermd->auditallow->p, 0xff, + sizeof(xpermd->auditallow->p)); + } + if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { + for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++) + xpermd->auditallow->p[i] |= + node->datum.u.xperms->perms.p[i]; + } + } else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) { + xpermd->used |= XPERMS_DONTAUDIT; + if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { + memset(xpermd->dontaudit->p, 0xff, + sizeof(xpermd->dontaudit->p)); + } + if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { + for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++) + xpermd->dontaudit->p[i] |= + node->datum.u.xperms->perms.p[i]; + } + } else { + BUG(); + } +} + +void security_compute_xperms_decision(struct selinux_state *state, + u32 ssid, + u32 tsid, + u16 orig_tclass, + u8 driver, + struct extended_perms_decision *xpermd) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + u16 tclass; + struct context *scontext, *tcontext; + struct avtab_key avkey; + struct avtab_node *node; + struct ebitmap *sattr, *tattr; + struct ebitmap_node *snode, *tnode; + unsigned int i, j; + + xpermd->driver = driver; + xpermd->used = 0; + memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p)); + memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p)); + memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p)); + + rcu_read_lock(); + if (!selinux_initialized(state)) + goto allow; + + policy = rcu_dereference(state->policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + + scontext = sidtab_search(sidtab, ssid); + if (!scontext) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, ssid); + goto out; + } + + tcontext = sidtab_search(sidtab, tsid); + if (!tcontext) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, tsid); + goto out; + } + + tclass = unmap_class(&policy->map, orig_tclass); + if (unlikely(orig_tclass && !tclass)) { + if (policydb->allow_unknown) + goto allow; + goto out; + } + + + if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) { + pr_warn_ratelimited("SELinux: Invalid class %hu\n", tclass); + goto out; + } + + avkey.target_class = tclass; + avkey.specified = AVTAB_XPERMS; + sattr = &policydb->type_attr_map_array[scontext->type - 1]; + tattr = &policydb->type_attr_map_array[tcontext->type - 1]; + ebitmap_for_each_positive_bit(sattr, snode, i) { + ebitmap_for_each_positive_bit(tattr, tnode, j) { + avkey.source_type = i + 1; + avkey.target_type = j + 1; + for (node = avtab_search_node(&policydb->te_avtab, + &avkey); + node; + node = avtab_search_node_next(node, avkey.specified)) + services_compute_xperms_decision(xpermd, node); + + cond_compute_xperms(&policydb->te_cond_avtab, + &avkey, xpermd); + } + } +out: + rcu_read_unlock(); + return; +allow: + memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p)); + goto out; +} + +/** + * security_compute_av - Compute access vector decisions. + * @state: SELinux state + * @ssid: source security identifier + * @tsid: target security identifier + * @orig_tclass: target security class + * @avd: access vector decisions + * @xperms: extended permissions + * + * Compute a set of access vector decisions based on the + * SID pair (@ssid, @tsid) for the permissions in @tclass. + */ +void security_compute_av(struct selinux_state *state, + u32 ssid, + u32 tsid, + u16 orig_tclass, + struct av_decision *avd, + struct extended_perms *xperms) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + u16 tclass; + struct context *scontext = NULL, *tcontext = NULL; + + rcu_read_lock(); + policy = rcu_dereference(state->policy); + avd_init(policy, avd); + xperms->len = 0; + if (!selinux_initialized(state)) + goto allow; + + policydb = &policy->policydb; + sidtab = policy->sidtab; + + scontext = sidtab_search(sidtab, ssid); + if (!scontext) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, ssid); + goto out; + } + + /* permissive domain? */ + if (ebitmap_get_bit(&policydb->permissive_map, scontext->type)) + avd->flags |= AVD_FLAGS_PERMISSIVE; + + tcontext = sidtab_search(sidtab, tsid); + if (!tcontext) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, tsid); + goto out; + } + + tclass = unmap_class(&policy->map, orig_tclass); + if (unlikely(orig_tclass && !tclass)) { + if (policydb->allow_unknown) + goto allow; + goto out; + } + context_struct_compute_av(policydb, scontext, tcontext, tclass, avd, + xperms); + map_decision(&policy->map, orig_tclass, avd, + policydb->allow_unknown); +out: + rcu_read_unlock(); + return; +allow: + avd->allowed = 0xffffffff; + goto out; +} + +void security_compute_av_user(struct selinux_state *state, + u32 ssid, + u32 tsid, + u16 tclass, + struct av_decision *avd) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + struct context *scontext = NULL, *tcontext = NULL; + + rcu_read_lock(); + policy = rcu_dereference(state->policy); + avd_init(policy, avd); + if (!selinux_initialized(state)) + goto allow; + + policydb = &policy->policydb; + sidtab = policy->sidtab; + + scontext = sidtab_search(sidtab, ssid); + if (!scontext) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, ssid); + goto out; + } + + /* permissive domain? */ + if (ebitmap_get_bit(&policydb->permissive_map, scontext->type)) + avd->flags |= AVD_FLAGS_PERMISSIVE; + + tcontext = sidtab_search(sidtab, tsid); + if (!tcontext) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, tsid); + goto out; + } + + if (unlikely(!tclass)) { + if (policydb->allow_unknown) + goto allow; + goto out; + } + + context_struct_compute_av(policydb, scontext, tcontext, tclass, avd, + NULL); + out: + rcu_read_unlock(); + return; +allow: + avd->allowed = 0xffffffff; + goto out; +} + +/* + * Write the security context string representation of + * the context structure `context' into a dynamically + * allocated string of the correct size. Set `*scontext' + * to point to this string and set `*scontext_len' to + * the length of the string. + */ +static int context_struct_to_string(struct policydb *p, + struct context *context, + char **scontext, u32 *scontext_len) +{ + char *scontextp; + + if (scontext) + *scontext = NULL; + *scontext_len = 0; + + if (context->len) { + *scontext_len = context->len; + if (scontext) { + *scontext = kstrdup(context->str, GFP_ATOMIC); + if (!(*scontext)) + return -ENOMEM; + } + return 0; + } + + /* Compute the size of the context. */ + *scontext_len += strlen(sym_name(p, SYM_USERS, context->user - 1)) + 1; + *scontext_len += strlen(sym_name(p, SYM_ROLES, context->role - 1)) + 1; + *scontext_len += strlen(sym_name(p, SYM_TYPES, context->type - 1)) + 1; + *scontext_len += mls_compute_context_len(p, context); + + if (!scontext) + return 0; + + /* Allocate space for the context; caller must free this space. */ + scontextp = kmalloc(*scontext_len, GFP_ATOMIC); + if (!scontextp) + return -ENOMEM; + *scontext = scontextp; + + /* + * Copy the user name, role name and type name into the context. + */ + scontextp += sprintf(scontextp, "%s:%s:%s", + sym_name(p, SYM_USERS, context->user - 1), + sym_name(p, SYM_ROLES, context->role - 1), + sym_name(p, SYM_TYPES, context->type - 1)); + + mls_sid_to_context(p, context, &scontextp); + + *scontextp = 0; + + return 0; +} + +static int sidtab_entry_to_string(struct policydb *p, + struct sidtab *sidtab, + struct sidtab_entry *entry, + char **scontext, u32 *scontext_len) +{ + int rc = sidtab_sid2str_get(sidtab, entry, scontext, scontext_len); + + if (rc != -ENOENT) + return rc; + + rc = context_struct_to_string(p, &entry->context, scontext, + scontext_len); + if (!rc && scontext) + sidtab_sid2str_put(sidtab, entry, *scontext, *scontext_len); + return rc; +} + +#include "initial_sid_to_string.h" + +int security_sidtab_hash_stats(struct selinux_state *state, char *page) +{ + struct selinux_policy *policy; + int rc; + + if (!selinux_initialized(state)) { + pr_err("SELinux: %s: called before initial load_policy\n", + __func__); + return -EINVAL; + } + + rcu_read_lock(); + policy = rcu_dereference(state->policy); + rc = sidtab_hash_stats(policy->sidtab, page); + rcu_read_unlock(); + + return rc; +} + +const char *security_get_initial_sid_context(u32 sid) +{ + if (unlikely(sid > SECINITSID_NUM)) + return NULL; + return initial_sid_to_string[sid]; +} + +static int security_sid_to_context_core(struct selinux_state *state, + u32 sid, char **scontext, + u32 *scontext_len, int force, + int only_invalid) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + struct sidtab_entry *entry; + int rc = 0; + + if (scontext) + *scontext = NULL; + *scontext_len = 0; + + if (!selinux_initialized(state)) { + if (sid <= SECINITSID_NUM) { + char *scontextp; + const char *s = initial_sid_to_string[sid]; + + if (!s) + return -EINVAL; + *scontext_len = strlen(s) + 1; + if (!scontext) + return 0; + scontextp = kmemdup(s, *scontext_len, GFP_ATOMIC); + if (!scontextp) + return -ENOMEM; + *scontext = scontextp; + return 0; + } + pr_err("SELinux: %s: called before initial " + "load_policy on unknown SID %d\n", __func__, sid); + return -EINVAL; + } + rcu_read_lock(); + policy = rcu_dereference(state->policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + + if (force) + entry = sidtab_search_entry_force(sidtab, sid); + else + entry = sidtab_search_entry(sidtab, sid); + if (!entry) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, sid); + rc = -EINVAL; + goto out_unlock; + } + if (only_invalid && !entry->context.len) + goto out_unlock; + + rc = sidtab_entry_to_string(policydb, sidtab, entry, scontext, + scontext_len); + +out_unlock: + rcu_read_unlock(); + return rc; + +} + +/** + * security_sid_to_context - Obtain a context for a given SID. + * @state: SELinux state + * @sid: security identifier, SID + * @scontext: security context + * @scontext_len: length in bytes + * + * Write the string representation of the context associated with @sid + * into a dynamically allocated string of the correct size. Set @scontext + * to point to this string and set @scontext_len to the length of the string. + */ +int security_sid_to_context(struct selinux_state *state, + u32 sid, char **scontext, u32 *scontext_len) +{ + return security_sid_to_context_core(state, sid, scontext, + scontext_len, 0, 0); +} + +int security_sid_to_context_force(struct selinux_state *state, u32 sid, + char **scontext, u32 *scontext_len) +{ + return security_sid_to_context_core(state, sid, scontext, + scontext_len, 1, 0); +} + +/** + * security_sid_to_context_inval - Obtain a context for a given SID if it + * is invalid. + * @state: SELinux state + * @sid: security identifier, SID + * @scontext: security context + * @scontext_len: length in bytes + * + * Write the string representation of the context associated with @sid + * into a dynamically allocated string of the correct size, but only if the + * context is invalid in the current policy. Set @scontext to point to + * this string (or NULL if the context is valid) and set @scontext_len to + * the length of the string (or 0 if the context is valid). + */ +int security_sid_to_context_inval(struct selinux_state *state, u32 sid, + char **scontext, u32 *scontext_len) +{ + return security_sid_to_context_core(state, sid, scontext, + scontext_len, 1, 1); +} + +/* + * Caveat: Mutates scontext. + */ +static int string_to_context_struct(struct policydb *pol, + struct sidtab *sidtabp, + char *scontext, + struct context *ctx, + u32 def_sid) +{ + struct role_datum *role; + struct type_datum *typdatum; + struct user_datum *usrdatum; + char *scontextp, *p, oldc; + int rc = 0; + + context_init(ctx); + + /* Parse the security context. */ + + rc = -EINVAL; + scontextp = scontext; + + /* Extract the user. */ + p = scontextp; + while (*p && *p != ':') + p++; + + if (*p == 0) + goto out; + + *p++ = 0; + + usrdatum = symtab_search(&pol->p_users, scontextp); + if (!usrdatum) + goto out; + + ctx->user = usrdatum->value; + + /* Extract role. */ + scontextp = p; + while (*p && *p != ':') + p++; + + if (*p == 0) + goto out; + + *p++ = 0; + + role = symtab_search(&pol->p_roles, scontextp); + if (!role) + goto out; + ctx->role = role->value; + + /* Extract type. */ + scontextp = p; + while (*p && *p != ':') + p++; + oldc = *p; + *p++ = 0; + + typdatum = symtab_search(&pol->p_types, scontextp); + if (!typdatum || typdatum->attribute) + goto out; + + ctx->type = typdatum->value; + + rc = mls_context_to_sid(pol, oldc, p, ctx, sidtabp, def_sid); + if (rc) + goto out; + + /* Check the validity of the new context. */ + rc = -EINVAL; + if (!policydb_context_isvalid(pol, ctx)) + goto out; + rc = 0; +out: + if (rc) + context_destroy(ctx); + return rc; +} + +static int security_context_to_sid_core(struct selinux_state *state, + const char *scontext, u32 scontext_len, + u32 *sid, u32 def_sid, gfp_t gfp_flags, + int force) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + char *scontext2, *str = NULL; + struct context context; + int rc = 0; + + /* An empty security context is never valid. */ + if (!scontext_len) + return -EINVAL; + + /* Copy the string to allow changes and ensure a NUL terminator */ + scontext2 = kmemdup_nul(scontext, scontext_len, gfp_flags); + if (!scontext2) + return -ENOMEM; + + if (!selinux_initialized(state)) { + int i; + + for (i = 1; i < SECINITSID_NUM; i++) { + const char *s = initial_sid_to_string[i]; + + if (s && !strcmp(s, scontext2)) { + *sid = i; + goto out; + } + } + *sid = SECINITSID_KERNEL; + goto out; + } + *sid = SECSID_NULL; + + if (force) { + /* Save another copy for storing in uninterpreted form */ + rc = -ENOMEM; + str = kstrdup(scontext2, gfp_flags); + if (!str) + goto out; + } +retry: + rcu_read_lock(); + policy = rcu_dereference(state->policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + rc = string_to_context_struct(policydb, sidtab, scontext2, + &context, def_sid); + if (rc == -EINVAL && force) { + context.str = str; + context.len = strlen(str) + 1; + str = NULL; + } else if (rc) + goto out_unlock; + rc = sidtab_context_to_sid(sidtab, &context, sid); + if (rc == -ESTALE) { + rcu_read_unlock(); + if (context.str) { + str = context.str; + context.str = NULL; + } + context_destroy(&context); + goto retry; + } + context_destroy(&context); +out_unlock: + rcu_read_unlock(); +out: + kfree(scontext2); + kfree(str); + return rc; +} + +/** + * security_context_to_sid - Obtain a SID for a given security context. + * @state: SELinux state + * @scontext: security context + * @scontext_len: length in bytes + * @sid: security identifier, SID + * @gfp: context for the allocation + * + * Obtains a SID associated with the security context that + * has the string representation specified by @scontext. + * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient + * memory is available, or 0 on success. + */ +int security_context_to_sid(struct selinux_state *state, + const char *scontext, u32 scontext_len, u32 *sid, + gfp_t gfp) +{ + return security_context_to_sid_core(state, scontext, scontext_len, + sid, SECSID_NULL, gfp, 0); +} + +int security_context_str_to_sid(struct selinux_state *state, + const char *scontext, u32 *sid, gfp_t gfp) +{ + return security_context_to_sid(state, scontext, strlen(scontext), + sid, gfp); +} + +/** + * security_context_to_sid_default - Obtain a SID for a given security context, + * falling back to specified default if needed. + * + * @state: SELinux state + * @scontext: security context + * @scontext_len: length in bytes + * @sid: security identifier, SID + * @def_sid: default SID to assign on error + * @gfp_flags: the allocator get-free-page (GFP) flags + * + * Obtains a SID associated with the security context that + * has the string representation specified by @scontext. + * The default SID is passed to the MLS layer to be used to allow + * kernel labeling of the MLS field if the MLS field is not present + * (for upgrading to MLS without full relabel). + * Implicitly forces adding of the context even if it cannot be mapped yet. + * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient + * memory is available, or 0 on success. + */ +int security_context_to_sid_default(struct selinux_state *state, + const char *scontext, u32 scontext_len, + u32 *sid, u32 def_sid, gfp_t gfp_flags) +{ + return security_context_to_sid_core(state, scontext, scontext_len, + sid, def_sid, gfp_flags, 1); +} + +int security_context_to_sid_force(struct selinux_state *state, + const char *scontext, u32 scontext_len, + u32 *sid) +{ + return security_context_to_sid_core(state, scontext, scontext_len, + sid, SECSID_NULL, GFP_KERNEL, 1); +} + +static int compute_sid_handle_invalid_context( + struct selinux_state *state, + struct selinux_policy *policy, + struct sidtab_entry *sentry, + struct sidtab_entry *tentry, + u16 tclass, + struct context *newcontext) +{ + struct policydb *policydb = &policy->policydb; + struct sidtab *sidtab = policy->sidtab; + char *s = NULL, *t = NULL, *n = NULL; + u32 slen, tlen, nlen; + struct audit_buffer *ab; + + if (sidtab_entry_to_string(policydb, sidtab, sentry, &s, &slen)) + goto out; + if (sidtab_entry_to_string(policydb, sidtab, tentry, &t, &tlen)) + goto out; + if (context_struct_to_string(policydb, newcontext, &n, &nlen)) + goto out; + ab = audit_log_start(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR); + if (!ab) + goto out; + audit_log_format(ab, + "op=security_compute_sid invalid_context="); + /* no need to record the NUL with untrusted strings */ + audit_log_n_untrustedstring(ab, n, nlen - 1); + audit_log_format(ab, " scontext=%s tcontext=%s tclass=%s", + s, t, sym_name(policydb, SYM_CLASSES, tclass-1)); + audit_log_end(ab); +out: + kfree(s); + kfree(t); + kfree(n); + if (!enforcing_enabled(state)) + return 0; + return -EACCES; +} + +static void filename_compute_type(struct policydb *policydb, + struct context *newcontext, + u32 stype, u32 ttype, u16 tclass, + const char *objname) +{ + struct filename_trans_key ft; + struct filename_trans_datum *datum; + + /* + * Most filename trans rules are going to live in specific directories + * like /dev or /var/run. This bitmap will quickly skip rule searches + * if the ttype does not contain any rules. + */ + if (!ebitmap_get_bit(&policydb->filename_trans_ttypes, ttype)) + return; + + ft.ttype = ttype; + ft.tclass = tclass; + ft.name = objname; + + datum = policydb_filenametr_search(policydb, &ft); + while (datum) { + if (ebitmap_get_bit(&datum->stypes, stype - 1)) { + newcontext->type = datum->otype; + return; + } + datum = datum->next; + } +} + +static int security_compute_sid(struct selinux_state *state, + u32 ssid, + u32 tsid, + u16 orig_tclass, + u32 specified, + const char *objname, + u32 *out_sid, + bool kern) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + struct class_datum *cladatum; + struct context *scontext, *tcontext, newcontext; + struct sidtab_entry *sentry, *tentry; + struct avtab_key avkey; + struct avtab_datum *avdatum; + struct avtab_node *node; + u16 tclass; + int rc = 0; + bool sock; + + if (!selinux_initialized(state)) { + switch (orig_tclass) { + case SECCLASS_PROCESS: /* kernel value */ + *out_sid = ssid; + break; + default: + *out_sid = tsid; + break; + } + goto out; + } + +retry: + cladatum = NULL; + context_init(&newcontext); + + rcu_read_lock(); + + policy = rcu_dereference(state->policy); + + if (kern) { + tclass = unmap_class(&policy->map, orig_tclass); + sock = security_is_socket_class(orig_tclass); + } else { + tclass = orig_tclass; + sock = security_is_socket_class(map_class(&policy->map, + tclass)); + } + + policydb = &policy->policydb; + sidtab = policy->sidtab; + + sentry = sidtab_search_entry(sidtab, ssid); + if (!sentry) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, ssid); + rc = -EINVAL; + goto out_unlock; + } + tentry = sidtab_search_entry(sidtab, tsid); + if (!tentry) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, tsid); + rc = -EINVAL; + goto out_unlock; + } + + scontext = &sentry->context; + tcontext = &tentry->context; + + if (tclass && tclass <= policydb->p_classes.nprim) + cladatum = policydb->class_val_to_struct[tclass - 1]; + + /* Set the user identity. */ + switch (specified) { + case AVTAB_TRANSITION: + case AVTAB_CHANGE: + if (cladatum && cladatum->default_user == DEFAULT_TARGET) { + newcontext.user = tcontext->user; + } else { + /* notice this gets both DEFAULT_SOURCE and unset */ + /* Use the process user identity. */ + newcontext.user = scontext->user; + } + break; + case AVTAB_MEMBER: + /* Use the related object owner. */ + newcontext.user = tcontext->user; + break; + } + + /* Set the role to default values. */ + if (cladatum && cladatum->default_role == DEFAULT_SOURCE) { + newcontext.role = scontext->role; + } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) { + newcontext.role = tcontext->role; + } else { + if ((tclass == policydb->process_class) || sock) + newcontext.role = scontext->role; + else + newcontext.role = OBJECT_R_VAL; + } + + /* Set the type to default values. */ + if (cladatum && cladatum->default_type == DEFAULT_SOURCE) { + newcontext.type = scontext->type; + } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) { + newcontext.type = tcontext->type; + } else { + if ((tclass == policydb->process_class) || sock) { + /* Use the type of process. */ + newcontext.type = scontext->type; + } else { + /* Use the type of the related object. */ + newcontext.type = tcontext->type; + } + } + + /* Look for a type transition/member/change rule. */ + avkey.source_type = scontext->type; + avkey.target_type = tcontext->type; + avkey.target_class = tclass; + avkey.specified = specified; + avdatum = avtab_search(&policydb->te_avtab, &avkey); + + /* If no permanent rule, also check for enabled conditional rules */ + if (!avdatum) { + node = avtab_search_node(&policydb->te_cond_avtab, &avkey); + for (; node; node = avtab_search_node_next(node, specified)) { + if (node->key.specified & AVTAB_ENABLED) { + avdatum = &node->datum; + break; + } + } + } + + if (avdatum) { + /* Use the type from the type transition/member/change rule. */ + newcontext.type = avdatum->u.data; + } + + /* if we have a objname this is a file trans check so check those rules */ + if (objname) + filename_compute_type(policydb, &newcontext, scontext->type, + tcontext->type, tclass, objname); + + /* Check for class-specific changes. */ + if (specified & AVTAB_TRANSITION) { + /* Look for a role transition rule. */ + struct role_trans_datum *rtd; + struct role_trans_key rtk = { + .role = scontext->role, + .type = tcontext->type, + .tclass = tclass, + }; + + rtd = policydb_roletr_search(policydb, &rtk); + if (rtd) + newcontext.role = rtd->new_role; + } + + /* Set the MLS attributes. + This is done last because it may allocate memory. */ + rc = mls_compute_sid(policydb, scontext, tcontext, tclass, specified, + &newcontext, sock); + if (rc) + goto out_unlock; + + /* Check the validity of the context. */ + if (!policydb_context_isvalid(policydb, &newcontext)) { + rc = compute_sid_handle_invalid_context(state, policy, sentry, + tentry, tclass, + &newcontext); + if (rc) + goto out_unlock; + } + /* Obtain the sid for the context. */ + rc = sidtab_context_to_sid(sidtab, &newcontext, out_sid); + if (rc == -ESTALE) { + rcu_read_unlock(); + context_destroy(&newcontext); + goto retry; + } +out_unlock: + rcu_read_unlock(); + context_destroy(&newcontext); +out: + return rc; +} + +/** + * security_transition_sid - Compute the SID for a new subject/object. + * @state: SELinux state + * @ssid: source security identifier + * @tsid: target security identifier + * @tclass: target security class + * @qstr: object name + * @out_sid: security identifier for new subject/object + * + * Compute a SID to use for labeling a new subject or object in the + * class @tclass based on a SID pair (@ssid, @tsid). + * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM + * if insufficient memory is available, or %0 if the new SID was + * computed successfully. + */ +int security_transition_sid(struct selinux_state *state, + u32 ssid, u32 tsid, u16 tclass, + const struct qstr *qstr, u32 *out_sid) +{ + return security_compute_sid(state, ssid, tsid, tclass, + AVTAB_TRANSITION, + qstr ? qstr->name : NULL, out_sid, true); +} + +int security_transition_sid_user(struct selinux_state *state, + u32 ssid, u32 tsid, u16 tclass, + const char *objname, u32 *out_sid) +{ + return security_compute_sid(state, ssid, tsid, tclass, + AVTAB_TRANSITION, + objname, out_sid, false); +} + +/** + * security_member_sid - Compute the SID for member selection. + * @state: SELinux state + * @ssid: source security identifier + * @tsid: target security identifier + * @tclass: target security class + * @out_sid: security identifier for selected member + * + * Compute a SID to use when selecting a member of a polyinstantiated + * object of class @tclass based on a SID pair (@ssid, @tsid). + * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM + * if insufficient memory is available, or %0 if the SID was + * computed successfully. + */ +int security_member_sid(struct selinux_state *state, + u32 ssid, + u32 tsid, + u16 tclass, + u32 *out_sid) +{ + return security_compute_sid(state, ssid, tsid, tclass, + AVTAB_MEMBER, NULL, + out_sid, false); +} + +/** + * security_change_sid - Compute the SID for object relabeling. + * @state: SELinux state + * @ssid: source security identifier + * @tsid: target security identifier + * @tclass: target security class + * @out_sid: security identifier for selected member + * + * Compute a SID to use for relabeling an object of class @tclass + * based on a SID pair (@ssid, @tsid). + * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM + * if insufficient memory is available, or %0 if the SID was + * computed successfully. + */ +int security_change_sid(struct selinux_state *state, + u32 ssid, + u32 tsid, + u16 tclass, + u32 *out_sid) +{ + return security_compute_sid(state, + ssid, tsid, tclass, AVTAB_CHANGE, NULL, + out_sid, false); +} + +static inline int convert_context_handle_invalid_context( + struct selinux_state *state, + struct policydb *policydb, + struct context *context) +{ + char *s; + u32 len; + + if (enforcing_enabled(state)) + return -EINVAL; + + if (!context_struct_to_string(policydb, context, &s, &len)) { + pr_warn("SELinux: Context %s would be invalid if enforcing\n", + s); + kfree(s); + } + return 0; +} + +/* + * Convert the values in the security context + * structure `oldc' from the values specified + * in the policy `p->oldp' to the values specified + * in the policy `p->newp', storing the new context + * in `newc'. Verify that the context is valid + * under the new policy. + */ +static int convert_context(struct context *oldc, struct context *newc, void *p, + gfp_t gfp_flags) +{ + struct convert_context_args *args; + struct ocontext *oc; + struct role_datum *role; + struct type_datum *typdatum; + struct user_datum *usrdatum; + char *s; + u32 len; + int rc; + + args = p; + + if (oldc->str) { + s = kstrdup(oldc->str, gfp_flags); + if (!s) + return -ENOMEM; + + rc = string_to_context_struct(args->newp, NULL, s, + newc, SECSID_NULL); + if (rc == -EINVAL) { + /* + * Retain string representation for later mapping. + * + * IMPORTANT: We need to copy the contents of oldc->str + * back into s again because string_to_context_struct() + * may have garbled it. + */ + memcpy(s, oldc->str, oldc->len); + context_init(newc); + newc->str = s; + newc->len = oldc->len; + return 0; + } + kfree(s); + if (rc) { + /* Other error condition, e.g. ENOMEM. */ + pr_err("SELinux: Unable to map context %s, rc = %d.\n", + oldc->str, -rc); + return rc; + } + pr_info("SELinux: Context %s became valid (mapped).\n", + oldc->str); + return 0; + } + + context_init(newc); + + /* Convert the user. */ + usrdatum = symtab_search(&args->newp->p_users, + sym_name(args->oldp, + SYM_USERS, oldc->user - 1)); + if (!usrdatum) + goto bad; + newc->user = usrdatum->value; + + /* Convert the role. */ + role = symtab_search(&args->newp->p_roles, + sym_name(args->oldp, SYM_ROLES, oldc->role - 1)); + if (!role) + goto bad; + newc->role = role->value; + + /* Convert the type. */ + typdatum = symtab_search(&args->newp->p_types, + sym_name(args->oldp, + SYM_TYPES, oldc->type - 1)); + if (!typdatum) + goto bad; + newc->type = typdatum->value; + + /* Convert the MLS fields if dealing with MLS policies */ + if (args->oldp->mls_enabled && args->newp->mls_enabled) { + rc = mls_convert_context(args->oldp, args->newp, oldc, newc); + if (rc) + goto bad; + } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) { + /* + * Switching between non-MLS and MLS policy: + * ensure that the MLS fields of the context for all + * existing entries in the sidtab are filled in with a + * suitable default value, likely taken from one of the + * initial SIDs. + */ + oc = args->newp->ocontexts[OCON_ISID]; + while (oc && oc->sid[0] != SECINITSID_UNLABELED) + oc = oc->next; + if (!oc) { + pr_err("SELinux: unable to look up" + " the initial SIDs list\n"); + goto bad; + } + rc = mls_range_set(newc, &oc->context[0].range); + if (rc) + goto bad; + } + + /* Check the validity of the new context. */ + if (!policydb_context_isvalid(args->newp, newc)) { + rc = convert_context_handle_invalid_context(args->state, + args->oldp, + oldc); + if (rc) + goto bad; + } + + return 0; +bad: + /* Map old representation to string and save it. */ + rc = context_struct_to_string(args->oldp, oldc, &s, &len); + if (rc) + return rc; + context_destroy(newc); + newc->str = s; + newc->len = len; + pr_info("SELinux: Context %s became invalid (unmapped).\n", + newc->str); + return 0; +} + +static void security_load_policycaps(struct selinux_state *state, + struct selinux_policy *policy) +{ + struct policydb *p; + unsigned int i; + struct ebitmap_node *node; + + p = &policy->policydb; + + for (i = 0; i < ARRAY_SIZE(state->policycap); i++) + WRITE_ONCE(state->policycap[i], + ebitmap_get_bit(&p->policycaps, i)); + + for (i = 0; i < ARRAY_SIZE(selinux_policycap_names); i++) + pr_info("SELinux: policy capability %s=%d\n", + selinux_policycap_names[i], + ebitmap_get_bit(&p->policycaps, i)); + + ebitmap_for_each_positive_bit(&p->policycaps, node, i) { + if (i >= ARRAY_SIZE(selinux_policycap_names)) + pr_info("SELinux: unknown policy capability %u\n", + i); + } +} + +static int security_preserve_bools(struct selinux_policy *oldpolicy, + struct selinux_policy *newpolicy); + +static void selinux_policy_free(struct selinux_policy *policy) +{ + if (!policy) + return; + + sidtab_destroy(policy->sidtab); + kfree(policy->map.mapping); + policydb_destroy(&policy->policydb); + kfree(policy->sidtab); + kfree(policy); +} + +static void selinux_policy_cond_free(struct selinux_policy *policy) +{ + cond_policydb_destroy_dup(&policy->policydb); + kfree(policy); +} + +void selinux_policy_cancel(struct selinux_state *state, + struct selinux_load_state *load_state) +{ + struct selinux_policy *oldpolicy; + + oldpolicy = rcu_dereference_protected(state->policy, + lockdep_is_held(&state->policy_mutex)); + + sidtab_cancel_convert(oldpolicy->sidtab); + selinux_policy_free(load_state->policy); + kfree(load_state->convert_data); +} + +static void selinux_notify_policy_change(struct selinux_state *state, + u32 seqno) +{ + /* Flush external caches and notify userspace of policy load */ + avc_ss_reset(state->avc, seqno); + selnl_notify_policyload(seqno); + selinux_status_update_policyload(state, seqno); + selinux_netlbl_cache_invalidate(); + selinux_xfrm_notify_policyload(); + selinux_ima_measure_state_locked(state); +} + +void selinux_policy_commit(struct selinux_state *state, + struct selinux_load_state *load_state) +{ + struct selinux_policy *oldpolicy, *newpolicy = load_state->policy; + unsigned long flags; + u32 seqno; + + oldpolicy = rcu_dereference_protected(state->policy, + lockdep_is_held(&state->policy_mutex)); + + /* If switching between different policy types, log MLS status */ + if (oldpolicy) { + if (oldpolicy->policydb.mls_enabled && !newpolicy->policydb.mls_enabled) + pr_info("SELinux: Disabling MLS support...\n"); + else if (!oldpolicy->policydb.mls_enabled && newpolicy->policydb.mls_enabled) + pr_info("SELinux: Enabling MLS support...\n"); + } + + /* Set latest granting seqno for new policy. */ + if (oldpolicy) + newpolicy->latest_granting = oldpolicy->latest_granting + 1; + else + newpolicy->latest_granting = 1; + seqno = newpolicy->latest_granting; + + /* Install the new policy. */ + if (oldpolicy) { + sidtab_freeze_begin(oldpolicy->sidtab, &flags); + rcu_assign_pointer(state->policy, newpolicy); + sidtab_freeze_end(oldpolicy->sidtab, &flags); + } else { + rcu_assign_pointer(state->policy, newpolicy); + } + + /* Load the policycaps from the new policy */ + security_load_policycaps(state, newpolicy); + + if (!selinux_initialized(state)) { + /* + * After first policy load, the security server is + * marked as initialized and ready to handle requests and + * any objects created prior to policy load are then labeled. + */ + selinux_mark_initialized(state); + selinux_complete_init(); + } + + /* Free the old policy */ + synchronize_rcu(); + selinux_policy_free(oldpolicy); + kfree(load_state->convert_data); + + /* Notify others of the policy change */ + selinux_notify_policy_change(state, seqno); +} + +/** + * security_load_policy - Load a security policy configuration. + * @state: SELinux state + * @data: binary policy data + * @len: length of data in bytes + * @load_state: policy load state + * + * Load a new set of security policy configuration data, + * validate it and convert the SID table as necessary. + * This function will flush the access vector cache after + * loading the new policy. + */ +int security_load_policy(struct selinux_state *state, void *data, size_t len, + struct selinux_load_state *load_state) +{ + struct selinux_policy *newpolicy, *oldpolicy; + struct selinux_policy_convert_data *convert_data; + int rc = 0; + struct policy_file file = { data, len }, *fp = &file; + + newpolicy = kzalloc(sizeof(*newpolicy), GFP_KERNEL); + if (!newpolicy) + return -ENOMEM; + + newpolicy->sidtab = kzalloc(sizeof(*newpolicy->sidtab), GFP_KERNEL); + if (!newpolicy->sidtab) { + rc = -ENOMEM; + goto err_policy; + } + + rc = policydb_read(&newpolicy->policydb, fp); + if (rc) + goto err_sidtab; + + newpolicy->policydb.len = len; + rc = selinux_set_mapping(&newpolicy->policydb, secclass_map, + &newpolicy->map); + if (rc) + goto err_policydb; + + rc = policydb_load_isids(&newpolicy->policydb, newpolicy->sidtab); + if (rc) { + pr_err("SELinux: unable to load the initial SIDs\n"); + goto err_mapping; + } + + if (!selinux_initialized(state)) { + /* First policy load, so no need to preserve state from old policy */ + load_state->policy = newpolicy; + load_state->convert_data = NULL; + return 0; + } + + oldpolicy = rcu_dereference_protected(state->policy, + lockdep_is_held(&state->policy_mutex)); + + /* Preserve active boolean values from the old policy */ + rc = security_preserve_bools(oldpolicy, newpolicy); + if (rc) { + pr_err("SELinux: unable to preserve booleans\n"); + goto err_free_isids; + } + + convert_data = kmalloc(sizeof(*convert_data), GFP_KERNEL); + if (!convert_data) { + rc = -ENOMEM; + goto err_free_isids; + } + + /* + * Convert the internal representations of contexts + * in the new SID table. + */ + convert_data->args.state = state; + convert_data->args.oldp = &oldpolicy->policydb; + convert_data->args.newp = &newpolicy->policydb; + + convert_data->sidtab_params.func = convert_context; + convert_data->sidtab_params.args = &convert_data->args; + convert_data->sidtab_params.target = newpolicy->sidtab; + + rc = sidtab_convert(oldpolicy->sidtab, &convert_data->sidtab_params); + if (rc) { + pr_err("SELinux: unable to convert the internal" + " representation of contexts in the new SID" + " table\n"); + goto err_free_convert_data; + } + + load_state->policy = newpolicy; + load_state->convert_data = convert_data; + return 0; + +err_free_convert_data: + kfree(convert_data); +err_free_isids: + sidtab_destroy(newpolicy->sidtab); +err_mapping: + kfree(newpolicy->map.mapping); +err_policydb: + policydb_destroy(&newpolicy->policydb); +err_sidtab: + kfree(newpolicy->sidtab); +err_policy: + kfree(newpolicy); + + return rc; +} + +/** + * ocontext_to_sid - Helper to safely get sid for an ocontext + * @sidtab: SID table + * @c: ocontext structure + * @index: index of the context entry (0 or 1) + * @out_sid: pointer to the resulting SID value + * + * For all ocontexts except OCON_ISID the SID fields are populated + * on-demand when needed. Since updating the SID value is an SMP-sensitive + * operation, this helper must be used to do that safely. + * + * WARNING: This function may return -ESTALE, indicating that the caller + * must retry the operation after re-acquiring the policy pointer! + */ +static int ocontext_to_sid(struct sidtab *sidtab, struct ocontext *c, + size_t index, u32 *out_sid) +{ + int rc; + u32 sid; + + /* Ensure the associated sidtab entry is visible to this thread. */ + sid = smp_load_acquire(&c->sid[index]); + if (!sid) { + rc = sidtab_context_to_sid(sidtab, &c->context[index], &sid); + if (rc) + return rc; + + /* + * Ensure the new sidtab entry is visible to other threads + * when they see the SID. + */ + smp_store_release(&c->sid[index], sid); + } + *out_sid = sid; + return 0; +} + +/** + * security_port_sid - Obtain the SID for a port. + * @state: SELinux state + * @protocol: protocol number + * @port: port number + * @out_sid: security identifier + */ +int security_port_sid(struct selinux_state *state, + u8 protocol, u16 port, u32 *out_sid) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + struct ocontext *c; + int rc; + + if (!selinux_initialized(state)) { + *out_sid = SECINITSID_PORT; + return 0; + } + +retry: + rc = 0; + rcu_read_lock(); + policy = rcu_dereference(state->policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + + c = policydb->ocontexts[OCON_PORT]; + while (c) { + if (c->u.port.protocol == protocol && + c->u.port.low_port <= port && + c->u.port.high_port >= port) + break; + c = c->next; + } + + if (c) { + rc = ocontext_to_sid(sidtab, c, 0, out_sid); + if (rc == -ESTALE) { + rcu_read_unlock(); + goto retry; + } + if (rc) + goto out; + } else { + *out_sid = SECINITSID_PORT; + } + +out: + rcu_read_unlock(); + return rc; +} + +/** + * security_ib_pkey_sid - Obtain the SID for a pkey. + * @state: SELinux state + * @subnet_prefix: Subnet Prefix + * @pkey_num: pkey number + * @out_sid: security identifier + */ +int security_ib_pkey_sid(struct selinux_state *state, + u64 subnet_prefix, u16 pkey_num, u32 *out_sid) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + struct ocontext *c; + int rc; + + if (!selinux_initialized(state)) { + *out_sid = SECINITSID_UNLABELED; + return 0; + } + +retry: + rc = 0; + rcu_read_lock(); + policy = rcu_dereference(state->policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + + c = policydb->ocontexts[OCON_IBPKEY]; + while (c) { + if (c->u.ibpkey.low_pkey <= pkey_num && + c->u.ibpkey.high_pkey >= pkey_num && + c->u.ibpkey.subnet_prefix == subnet_prefix) + break; + + c = c->next; + } + + if (c) { + rc = ocontext_to_sid(sidtab, c, 0, out_sid); + if (rc == -ESTALE) { + rcu_read_unlock(); + goto retry; + } + if (rc) + goto out; + } else + *out_sid = SECINITSID_UNLABELED; + +out: + rcu_read_unlock(); + return rc; +} + +/** + * security_ib_endport_sid - Obtain the SID for a subnet management interface. + * @state: SELinux state + * @dev_name: device name + * @port_num: port number + * @out_sid: security identifier + */ +int security_ib_endport_sid(struct selinux_state *state, + const char *dev_name, u8 port_num, u32 *out_sid) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + struct ocontext *c; + int rc; + + if (!selinux_initialized(state)) { + *out_sid = SECINITSID_UNLABELED; + return 0; + } + +retry: + rc = 0; + rcu_read_lock(); + policy = rcu_dereference(state->policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + + c = policydb->ocontexts[OCON_IBENDPORT]; + while (c) { + if (c->u.ibendport.port == port_num && + !strncmp(c->u.ibendport.dev_name, + dev_name, + IB_DEVICE_NAME_MAX)) + break; + + c = c->next; + } + + if (c) { + rc = ocontext_to_sid(sidtab, c, 0, out_sid); + if (rc == -ESTALE) { + rcu_read_unlock(); + goto retry; + } + if (rc) + goto out; + } else + *out_sid = SECINITSID_UNLABELED; + +out: + rcu_read_unlock(); + return rc; +} + +/** + * security_netif_sid - Obtain the SID for a network interface. + * @state: SELinux state + * @name: interface name + * @if_sid: interface SID + */ +int security_netif_sid(struct selinux_state *state, + char *name, u32 *if_sid) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + int rc; + struct ocontext *c; + + if (!selinux_initialized(state)) { + *if_sid = SECINITSID_NETIF; + return 0; + } + +retry: + rc = 0; + rcu_read_lock(); + policy = rcu_dereference(state->policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + + c = policydb->ocontexts[OCON_NETIF]; + while (c) { + if (strcmp(name, c->u.name) == 0) + break; + c = c->next; + } + + if (c) { + rc = ocontext_to_sid(sidtab, c, 0, if_sid); + if (rc == -ESTALE) { + rcu_read_unlock(); + goto retry; + } + if (rc) + goto out; + } else + *if_sid = SECINITSID_NETIF; + +out: + rcu_read_unlock(); + return rc; +} + +static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask) +{ + int i, fail = 0; + + for (i = 0; i < 4; i++) + if (addr[i] != (input[i] & mask[i])) { + fail = 1; + break; + } + + return !fail; +} + +/** + * security_node_sid - Obtain the SID for a node (host). + * @state: SELinux state + * @domain: communication domain aka address family + * @addrp: address + * @addrlen: address length in bytes + * @out_sid: security identifier + */ +int security_node_sid(struct selinux_state *state, + u16 domain, + void *addrp, + u32 addrlen, + u32 *out_sid) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + int rc; + struct ocontext *c; + + if (!selinux_initialized(state)) { + *out_sid = SECINITSID_NODE; + return 0; + } + +retry: + rcu_read_lock(); + policy = rcu_dereference(state->policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + + switch (domain) { + case AF_INET: { + u32 addr; + + rc = -EINVAL; + if (addrlen != sizeof(u32)) + goto out; + + addr = *((u32 *)addrp); + + c = policydb->ocontexts[OCON_NODE]; + while (c) { + if (c->u.node.addr == (addr & c->u.node.mask)) + break; + c = c->next; + } + break; + } + + case AF_INET6: + rc = -EINVAL; + if (addrlen != sizeof(u64) * 2) + goto out; + c = policydb->ocontexts[OCON_NODE6]; + while (c) { + if (match_ipv6_addrmask(addrp, c->u.node6.addr, + c->u.node6.mask)) + break; + c = c->next; + } + break; + + default: + rc = 0; + *out_sid = SECINITSID_NODE; + goto out; + } + + if (c) { + rc = ocontext_to_sid(sidtab, c, 0, out_sid); + if (rc == -ESTALE) { + rcu_read_unlock(); + goto retry; + } + if (rc) + goto out; + } else { + *out_sid = SECINITSID_NODE; + } + + rc = 0; +out: + rcu_read_unlock(); + return rc; +} + +#define SIDS_NEL 25 + +/** + * security_get_user_sids - Obtain reachable SIDs for a user. + * @state: SELinux state + * @fromsid: starting SID + * @username: username + * @sids: array of reachable SIDs for user + * @nel: number of elements in @sids + * + * Generate the set of SIDs for legal security contexts + * for a given user that can be reached by @fromsid. + * Set *@sids to point to a dynamically allocated + * array containing the set of SIDs. Set *@nel to the + * number of elements in the array. + */ + +int security_get_user_sids(struct selinux_state *state, + u32 fromsid, + char *username, + u32 **sids, + u32 *nel) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + struct context *fromcon, usercon; + u32 *mysids = NULL, *mysids2, sid; + u32 i, j, mynel, maxnel = SIDS_NEL; + struct user_datum *user; + struct role_datum *role; + struct ebitmap_node *rnode, *tnode; + int rc; + + *sids = NULL; + *nel = 0; + + if (!selinux_initialized(state)) + return 0; + + mysids = kcalloc(maxnel, sizeof(*mysids), GFP_KERNEL); + if (!mysids) + return -ENOMEM; + +retry: + mynel = 0; + rcu_read_lock(); + policy = rcu_dereference(state->policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + + context_init(&usercon); + + rc = -EINVAL; + fromcon = sidtab_search(sidtab, fromsid); + if (!fromcon) + goto out_unlock; + + rc = -EINVAL; + user = symtab_search(&policydb->p_users, username); + if (!user) + goto out_unlock; + + usercon.user = user->value; + + ebitmap_for_each_positive_bit(&user->roles, rnode, i) { + role = policydb->role_val_to_struct[i]; + usercon.role = i + 1; + ebitmap_for_each_positive_bit(&role->types, tnode, j) { + usercon.type = j + 1; + + if (mls_setup_user_range(policydb, fromcon, user, + &usercon)) + continue; + + rc = sidtab_context_to_sid(sidtab, &usercon, &sid); + if (rc == -ESTALE) { + rcu_read_unlock(); + goto retry; + } + if (rc) + goto out_unlock; + if (mynel < maxnel) { + mysids[mynel++] = sid; + } else { + rc = -ENOMEM; + maxnel += SIDS_NEL; + mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC); + if (!mysids2) + goto out_unlock; + memcpy(mysids2, mysids, mynel * sizeof(*mysids2)); + kfree(mysids); + mysids = mysids2; + mysids[mynel++] = sid; + } + } + } + rc = 0; +out_unlock: + rcu_read_unlock(); + if (rc || !mynel) { + kfree(mysids); + return rc; + } + + rc = -ENOMEM; + mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL); + if (!mysids2) { + kfree(mysids); + return rc; + } + for (i = 0, j = 0; i < mynel; i++) { + struct av_decision dummy_avd; + rc = avc_has_perm_noaudit(state, + fromsid, mysids[i], + SECCLASS_PROCESS, /* kernel value */ + PROCESS__TRANSITION, AVC_STRICT, + &dummy_avd); + if (!rc) + mysids2[j++] = mysids[i]; + cond_resched(); + } + kfree(mysids); + *sids = mysids2; + *nel = j; + return 0; +} + +/** + * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem + * @policy: policy + * @fstype: filesystem type + * @path: path from root of mount + * @orig_sclass: file security class + * @sid: SID for path + * + * Obtain a SID to use for a file in a filesystem that + * cannot support xattr or use a fixed labeling behavior like + * transition SIDs or task SIDs. + * + * WARNING: This function may return -ESTALE, indicating that the caller + * must retry the operation after re-acquiring the policy pointer! + */ +static inline int __security_genfs_sid(struct selinux_policy *policy, + const char *fstype, + const char *path, + u16 orig_sclass, + u32 *sid) +{ + struct policydb *policydb = &policy->policydb; + struct sidtab *sidtab = policy->sidtab; + int len; + u16 sclass; + struct genfs *genfs; + struct ocontext *c; + int cmp = 0; + + while (path[0] == '/' && path[1] == '/') + path++; + + sclass = unmap_class(&policy->map, orig_sclass); + *sid = SECINITSID_UNLABELED; + + for (genfs = policydb->genfs; genfs; genfs = genfs->next) { + cmp = strcmp(fstype, genfs->fstype); + if (cmp <= 0) + break; + } + + if (!genfs || cmp) + return -ENOENT; + + for (c = genfs->head; c; c = c->next) { + len = strlen(c->u.name); + if ((!c->v.sclass || sclass == c->v.sclass) && + (strncmp(c->u.name, path, len) == 0)) + break; + } + + if (!c) + return -ENOENT; + + return ocontext_to_sid(sidtab, c, 0, sid); +} + +/** + * security_genfs_sid - Obtain a SID for a file in a filesystem + * @state: SELinux state + * @fstype: filesystem type + * @path: path from root of mount + * @orig_sclass: file security class + * @sid: SID for path + * + * Acquire policy_rwlock before calling __security_genfs_sid() and release + * it afterward. + */ +int security_genfs_sid(struct selinux_state *state, + const char *fstype, + const char *path, + u16 orig_sclass, + u32 *sid) +{ + struct selinux_policy *policy; + int retval; + + if (!selinux_initialized(state)) { + *sid = SECINITSID_UNLABELED; + return 0; + } + + do { + rcu_read_lock(); + policy = rcu_dereference(state->policy); + retval = __security_genfs_sid(policy, fstype, path, + orig_sclass, sid); + rcu_read_unlock(); + } while (retval == -ESTALE); + return retval; +} + +int selinux_policy_genfs_sid(struct selinux_policy *policy, + const char *fstype, + const char *path, + u16 orig_sclass, + u32 *sid) +{ + /* no lock required, policy is not yet accessible by other threads */ + return __security_genfs_sid(policy, fstype, path, orig_sclass, sid); +} + +/** + * security_fs_use - Determine how to handle labeling for a filesystem. + * @state: SELinux state + * @sb: superblock in question + */ +int security_fs_use(struct selinux_state *state, struct super_block *sb) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + int rc; + struct ocontext *c; + struct superblock_security_struct *sbsec = selinux_superblock(sb); + const char *fstype = sb->s_type->name; + + if (!selinux_initialized(state)) { + sbsec->behavior = SECURITY_FS_USE_NONE; + sbsec->sid = SECINITSID_UNLABELED; + return 0; + } + +retry: + rcu_read_lock(); + policy = rcu_dereference(state->policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + + c = policydb->ocontexts[OCON_FSUSE]; + while (c) { + if (strcmp(fstype, c->u.name) == 0) + break; + c = c->next; + } + + if (c) { + sbsec->behavior = c->v.behavior; + rc = ocontext_to_sid(sidtab, c, 0, &sbsec->sid); + if (rc == -ESTALE) { + rcu_read_unlock(); + goto retry; + } + if (rc) + goto out; + } else { + rc = __security_genfs_sid(policy, fstype, "/", + SECCLASS_DIR, &sbsec->sid); + if (rc == -ESTALE) { + rcu_read_unlock(); + goto retry; + } + if (rc) { + sbsec->behavior = SECURITY_FS_USE_NONE; + rc = 0; + } else { + sbsec->behavior = SECURITY_FS_USE_GENFS; + } + } + +out: + rcu_read_unlock(); + return rc; +} + +int security_get_bools(struct selinux_policy *policy, + u32 *len, char ***names, int **values) +{ + struct policydb *policydb; + u32 i; + int rc; + + policydb = &policy->policydb; + + *names = NULL; + *values = NULL; + + rc = 0; + *len = policydb->p_bools.nprim; + if (!*len) + goto out; + + rc = -ENOMEM; + *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC); + if (!*names) + goto err; + + rc = -ENOMEM; + *values = kcalloc(*len, sizeof(int), GFP_ATOMIC); + if (!*values) + goto err; + + for (i = 0; i < *len; i++) { + (*values)[i] = policydb->bool_val_to_struct[i]->state; + + rc = -ENOMEM; + (*names)[i] = kstrdup(sym_name(policydb, SYM_BOOLS, i), + GFP_ATOMIC); + if (!(*names)[i]) + goto err; + } + rc = 0; +out: + return rc; +err: + if (*names) { + for (i = 0; i < *len; i++) + kfree((*names)[i]); + kfree(*names); + } + kfree(*values); + *len = 0; + *names = NULL; + *values = NULL; + goto out; +} + + +int security_set_bools(struct selinux_state *state, u32 len, int *values) +{ + struct selinux_policy *newpolicy, *oldpolicy; + int rc; + u32 i, seqno = 0; + + if (!selinux_initialized(state)) + return -EINVAL; + + oldpolicy = rcu_dereference_protected(state->policy, + lockdep_is_held(&state->policy_mutex)); + + /* Consistency check on number of booleans, should never fail */ + if (WARN_ON(len != oldpolicy->policydb.p_bools.nprim)) + return -EINVAL; + + newpolicy = kmemdup(oldpolicy, sizeof(*newpolicy), GFP_KERNEL); + if (!newpolicy) + return -ENOMEM; + + /* + * Deep copy only the parts of the policydb that might be + * modified as a result of changing booleans. + */ + rc = cond_policydb_dup(&newpolicy->policydb, &oldpolicy->policydb); + if (rc) { + kfree(newpolicy); + return -ENOMEM; + } + + /* Update the boolean states in the copy */ + for (i = 0; i < len; i++) { + int new_state = !!values[i]; + int old_state = newpolicy->policydb.bool_val_to_struct[i]->state; + + if (new_state != old_state) { + audit_log(audit_context(), GFP_ATOMIC, + AUDIT_MAC_CONFIG_CHANGE, + "bool=%s val=%d old_val=%d auid=%u ses=%u", + sym_name(&newpolicy->policydb, SYM_BOOLS, i), + new_state, + old_state, + from_kuid(&init_user_ns, audit_get_loginuid(current)), + audit_get_sessionid(current)); + newpolicy->policydb.bool_val_to_struct[i]->state = new_state; + } + } + + /* Re-evaluate the conditional rules in the copy */ + evaluate_cond_nodes(&newpolicy->policydb); + + /* Set latest granting seqno for new policy */ + newpolicy->latest_granting = oldpolicy->latest_granting + 1; + seqno = newpolicy->latest_granting; + + /* Install the new policy */ + rcu_assign_pointer(state->policy, newpolicy); + + /* + * Free the conditional portions of the old policydb + * that were copied for the new policy, and the oldpolicy + * structure itself but not what it references. + */ + synchronize_rcu(); + selinux_policy_cond_free(oldpolicy); + + /* Notify others of the policy change */ + selinux_notify_policy_change(state, seqno); + return 0; +} + +int security_get_bool_value(struct selinux_state *state, + u32 index) +{ + struct selinux_policy *policy; + struct policydb *policydb; + int rc; + u32 len; + + if (!selinux_initialized(state)) + return 0; + + rcu_read_lock(); + policy = rcu_dereference(state->policy); + policydb = &policy->policydb; + + rc = -EFAULT; + len = policydb->p_bools.nprim; + if (index >= len) + goto out; + + rc = policydb->bool_val_to_struct[index]->state; +out: + rcu_read_unlock(); + return rc; +} + +static int security_preserve_bools(struct selinux_policy *oldpolicy, + struct selinux_policy *newpolicy) +{ + int rc, *bvalues = NULL; + char **bnames = NULL; + struct cond_bool_datum *booldatum; + u32 i, nbools = 0; + + rc = security_get_bools(oldpolicy, &nbools, &bnames, &bvalues); + if (rc) + goto out; + for (i = 0; i < nbools; i++) { + booldatum = symtab_search(&newpolicy->policydb.p_bools, + bnames[i]); + if (booldatum) + booldatum->state = bvalues[i]; + } + evaluate_cond_nodes(&newpolicy->policydb); + +out: + if (bnames) { + for (i = 0; i < nbools; i++) + kfree(bnames[i]); + } + kfree(bnames); + kfree(bvalues); + return rc; +} + +/* + * security_sid_mls_copy() - computes a new sid based on the given + * sid and the mls portion of mls_sid. + */ +int security_sid_mls_copy(struct selinux_state *state, + u32 sid, u32 mls_sid, u32 *new_sid) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + struct context *context1; + struct context *context2; + struct context newcon; + char *s; + u32 len; + int rc; + + if (!selinux_initialized(state)) { + *new_sid = sid; + return 0; + } + +retry: + rc = 0; + context_init(&newcon); + + rcu_read_lock(); + policy = rcu_dereference(state->policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + + if (!policydb->mls_enabled) { + *new_sid = sid; + goto out_unlock; + } + + rc = -EINVAL; + context1 = sidtab_search(sidtab, sid); + if (!context1) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, sid); + goto out_unlock; + } + + rc = -EINVAL; + context2 = sidtab_search(sidtab, mls_sid); + if (!context2) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, mls_sid); + goto out_unlock; + } + + newcon.user = context1->user; + newcon.role = context1->role; + newcon.type = context1->type; + rc = mls_context_cpy(&newcon, context2); + if (rc) + goto out_unlock; + + /* Check the validity of the new context. */ + if (!policydb_context_isvalid(policydb, &newcon)) { + rc = convert_context_handle_invalid_context(state, policydb, + &newcon); + if (rc) { + if (!context_struct_to_string(policydb, &newcon, &s, + &len)) { + struct audit_buffer *ab; + + ab = audit_log_start(audit_context(), + GFP_ATOMIC, + AUDIT_SELINUX_ERR); + audit_log_format(ab, + "op=security_sid_mls_copy invalid_context="); + /* don't record NUL with untrusted strings */ + audit_log_n_untrustedstring(ab, s, len - 1); + audit_log_end(ab); + kfree(s); + } + goto out_unlock; + } + } + rc = sidtab_context_to_sid(sidtab, &newcon, new_sid); + if (rc == -ESTALE) { + rcu_read_unlock(); + context_destroy(&newcon); + goto retry; + } +out_unlock: + rcu_read_unlock(); + context_destroy(&newcon); + return rc; +} + +/** + * security_net_peersid_resolve - Compare and resolve two network peer SIDs + * @state: SELinux state + * @nlbl_sid: NetLabel SID + * @nlbl_type: NetLabel labeling protocol type + * @xfrm_sid: XFRM SID + * @peer_sid: network peer sid + * + * Description: + * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be + * resolved into a single SID it is returned via @peer_sid and the function + * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function + * returns a negative value. A table summarizing the behavior is below: + * + * | function return | @sid + * ------------------------------+-----------------+----------------- + * no peer labels | 0 | SECSID_NULL + * single peer label | 0 | <peer_label> + * multiple, consistent labels | 0 | <peer_label> + * multiple, inconsistent labels | -<errno> | SECSID_NULL + * + */ +int security_net_peersid_resolve(struct selinux_state *state, + u32 nlbl_sid, u32 nlbl_type, + u32 xfrm_sid, + u32 *peer_sid) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + int rc; + struct context *nlbl_ctx; + struct context *xfrm_ctx; + + *peer_sid = SECSID_NULL; + + /* handle the common (which also happens to be the set of easy) cases + * right away, these two if statements catch everything involving a + * single or absent peer SID/label */ + if (xfrm_sid == SECSID_NULL) { + *peer_sid = nlbl_sid; + return 0; + } + /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label + * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label + * is present */ + if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) { + *peer_sid = xfrm_sid; + return 0; + } + + if (!selinux_initialized(state)) + return 0; + + rcu_read_lock(); + policy = rcu_dereference(state->policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + + /* + * We don't need to check initialized here since the only way both + * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the + * security server was initialized and state->initialized was true. + */ + if (!policydb->mls_enabled) { + rc = 0; + goto out; + } + + rc = -EINVAL; + nlbl_ctx = sidtab_search(sidtab, nlbl_sid); + if (!nlbl_ctx) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, nlbl_sid); + goto out; + } + rc = -EINVAL; + xfrm_ctx = sidtab_search(sidtab, xfrm_sid); + if (!xfrm_ctx) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, xfrm_sid); + goto out; + } + rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES); + if (rc) + goto out; + + /* at present NetLabel SIDs/labels really only carry MLS + * information so if the MLS portion of the NetLabel SID + * matches the MLS portion of the labeled XFRM SID/label + * then pass along the XFRM SID as it is the most + * expressive */ + *peer_sid = xfrm_sid; +out: + rcu_read_unlock(); + return rc; +} + +static int get_classes_callback(void *k, void *d, void *args) +{ + struct class_datum *datum = d; + char *name = k, **classes = args; + int value = datum->value - 1; + + classes[value] = kstrdup(name, GFP_ATOMIC); + if (!classes[value]) + return -ENOMEM; + + return 0; +} + +int security_get_classes(struct selinux_policy *policy, + char ***classes, int *nclasses) +{ + struct policydb *policydb; + int rc; + + policydb = &policy->policydb; + + rc = -ENOMEM; + *nclasses = policydb->p_classes.nprim; + *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC); + if (!*classes) + goto out; + + rc = hashtab_map(&policydb->p_classes.table, get_classes_callback, + *classes); + if (rc) { + int i; + for (i = 0; i < *nclasses; i++) + kfree((*classes)[i]); + kfree(*classes); + } + +out: + return rc; +} + +static int get_permissions_callback(void *k, void *d, void *args) +{ + struct perm_datum *datum = d; + char *name = k, **perms = args; + int value = datum->value - 1; + + perms[value] = kstrdup(name, GFP_ATOMIC); + if (!perms[value]) + return -ENOMEM; + + return 0; +} + +int security_get_permissions(struct selinux_policy *policy, + char *class, char ***perms, int *nperms) +{ + struct policydb *policydb; + int rc, i; + struct class_datum *match; + + policydb = &policy->policydb; + + rc = -EINVAL; + match = symtab_search(&policydb->p_classes, class); + if (!match) { + pr_err("SELinux: %s: unrecognized class %s\n", + __func__, class); + goto out; + } + + rc = -ENOMEM; + *nperms = match->permissions.nprim; + *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC); + if (!*perms) + goto out; + + if (match->comdatum) { + rc = hashtab_map(&match->comdatum->permissions.table, + get_permissions_callback, *perms); + if (rc) + goto err; + } + + rc = hashtab_map(&match->permissions.table, get_permissions_callback, + *perms); + if (rc) + goto err; + +out: + return rc; + +err: + for (i = 0; i < *nperms; i++) + kfree((*perms)[i]); + kfree(*perms); + return rc; +} + +int security_get_reject_unknown(struct selinux_state *state) +{ + struct selinux_policy *policy; + int value; + + if (!selinux_initialized(state)) + return 0; + + rcu_read_lock(); + policy = rcu_dereference(state->policy); + value = policy->policydb.reject_unknown; + rcu_read_unlock(); + return value; +} + +int security_get_allow_unknown(struct selinux_state *state) +{ + struct selinux_policy *policy; + int value; + + if (!selinux_initialized(state)) + return 0; + + rcu_read_lock(); + policy = rcu_dereference(state->policy); + value = policy->policydb.allow_unknown; + rcu_read_unlock(); + return value; +} + +/** + * security_policycap_supported - Check for a specific policy capability + * @state: SELinux state + * @req_cap: capability + * + * Description: + * This function queries the currently loaded policy to see if it supports the + * capability specified by @req_cap. Returns true (1) if the capability is + * supported, false (0) if it isn't supported. + * + */ +int security_policycap_supported(struct selinux_state *state, + unsigned int req_cap) +{ + struct selinux_policy *policy; + int rc; + + if (!selinux_initialized(state)) + return 0; + + rcu_read_lock(); + policy = rcu_dereference(state->policy); + rc = ebitmap_get_bit(&policy->policydb.policycaps, req_cap); + rcu_read_unlock(); + + return rc; +} + +struct selinux_audit_rule { + u32 au_seqno; + struct context au_ctxt; +}; + +void selinux_audit_rule_free(void *vrule) +{ + struct selinux_audit_rule *rule = vrule; + + if (rule) { + context_destroy(&rule->au_ctxt); + kfree(rule); + } +} + +int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule) +{ + struct selinux_state *state = &selinux_state; + struct selinux_policy *policy; + struct policydb *policydb; + struct selinux_audit_rule *tmprule; + struct role_datum *roledatum; + struct type_datum *typedatum; + struct user_datum *userdatum; + struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule; + int rc = 0; + + *rule = NULL; + + if (!selinux_initialized(state)) + return -EOPNOTSUPP; + + switch (field) { + case AUDIT_SUBJ_USER: + case AUDIT_SUBJ_ROLE: + case AUDIT_SUBJ_TYPE: + case AUDIT_OBJ_USER: + case AUDIT_OBJ_ROLE: + case AUDIT_OBJ_TYPE: + /* only 'equals' and 'not equals' fit user, role, and type */ + if (op != Audit_equal && op != Audit_not_equal) + return -EINVAL; + break; + case AUDIT_SUBJ_SEN: + case AUDIT_SUBJ_CLR: + case AUDIT_OBJ_LEV_LOW: + case AUDIT_OBJ_LEV_HIGH: + /* we do not allow a range, indicated by the presence of '-' */ + if (strchr(rulestr, '-')) + return -EINVAL; + break; + default: + /* only the above fields are valid */ + return -EINVAL; + } + + tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL); + if (!tmprule) + return -ENOMEM; + + context_init(&tmprule->au_ctxt); + + rcu_read_lock(); + policy = rcu_dereference(state->policy); + policydb = &policy->policydb; + + tmprule->au_seqno = policy->latest_granting; + + switch (field) { + case AUDIT_SUBJ_USER: + case AUDIT_OBJ_USER: + rc = -EINVAL; + userdatum = symtab_search(&policydb->p_users, rulestr); + if (!userdatum) + goto out; + tmprule->au_ctxt.user = userdatum->value; + break; + case AUDIT_SUBJ_ROLE: + case AUDIT_OBJ_ROLE: + rc = -EINVAL; + roledatum = symtab_search(&policydb->p_roles, rulestr); + if (!roledatum) + goto out; + tmprule->au_ctxt.role = roledatum->value; + break; + case AUDIT_SUBJ_TYPE: + case AUDIT_OBJ_TYPE: + rc = -EINVAL; + typedatum = symtab_search(&policydb->p_types, rulestr); + if (!typedatum) + goto out; + tmprule->au_ctxt.type = typedatum->value; + break; + case AUDIT_SUBJ_SEN: + case AUDIT_SUBJ_CLR: + case AUDIT_OBJ_LEV_LOW: + case AUDIT_OBJ_LEV_HIGH: + rc = mls_from_string(policydb, rulestr, &tmprule->au_ctxt, + GFP_ATOMIC); + if (rc) + goto out; + break; + } + rc = 0; +out: + rcu_read_unlock(); + + if (rc) { + selinux_audit_rule_free(tmprule); + tmprule = NULL; + } + + *rule = tmprule; + + return rc; +} + +/* Check to see if the rule contains any selinux fields */ +int selinux_audit_rule_known(struct audit_krule *rule) +{ + int i; + + for (i = 0; i < rule->field_count; i++) { + struct audit_field *f = &rule->fields[i]; + switch (f->type) { + case AUDIT_SUBJ_USER: + case AUDIT_SUBJ_ROLE: + case AUDIT_SUBJ_TYPE: + case AUDIT_SUBJ_SEN: + case AUDIT_SUBJ_CLR: + case AUDIT_OBJ_USER: + case AUDIT_OBJ_ROLE: + case AUDIT_OBJ_TYPE: + case AUDIT_OBJ_LEV_LOW: + case AUDIT_OBJ_LEV_HIGH: + return 1; + } + } + + return 0; +} + +int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule) +{ + struct selinux_state *state = &selinux_state; + struct selinux_policy *policy; + struct context *ctxt; + struct mls_level *level; + struct selinux_audit_rule *rule = vrule; + int match = 0; + + if (unlikely(!rule)) { + WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n"); + return -ENOENT; + } + + if (!selinux_initialized(state)) + return 0; + + rcu_read_lock(); + + policy = rcu_dereference(state->policy); + + if (rule->au_seqno < policy->latest_granting) { + match = -ESTALE; + goto out; + } + + ctxt = sidtab_search(policy->sidtab, sid); + if (unlikely(!ctxt)) { + WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n", + sid); + match = -ENOENT; + goto out; + } + + /* a field/op pair that is not caught here will simply fall through + without a match */ + switch (field) { + case AUDIT_SUBJ_USER: + case AUDIT_OBJ_USER: + switch (op) { + case Audit_equal: + match = (ctxt->user == rule->au_ctxt.user); + break; + case Audit_not_equal: + match = (ctxt->user != rule->au_ctxt.user); + break; + } + break; + case AUDIT_SUBJ_ROLE: + case AUDIT_OBJ_ROLE: + switch (op) { + case Audit_equal: + match = (ctxt->role == rule->au_ctxt.role); + break; + case Audit_not_equal: + match = (ctxt->role != rule->au_ctxt.role); + break; + } + break; + case AUDIT_SUBJ_TYPE: + case AUDIT_OBJ_TYPE: + switch (op) { + case Audit_equal: + match = (ctxt->type == rule->au_ctxt.type); + break; + case Audit_not_equal: + match = (ctxt->type != rule->au_ctxt.type); + break; + } + break; + case AUDIT_SUBJ_SEN: + case AUDIT_SUBJ_CLR: + case AUDIT_OBJ_LEV_LOW: + case AUDIT_OBJ_LEV_HIGH: + level = ((field == AUDIT_SUBJ_SEN || + field == AUDIT_OBJ_LEV_LOW) ? + &ctxt->range.level[0] : &ctxt->range.level[1]); + switch (op) { + case Audit_equal: + match = mls_level_eq(&rule->au_ctxt.range.level[0], + level); + break; + case Audit_not_equal: + match = !mls_level_eq(&rule->au_ctxt.range.level[0], + level); + break; + case Audit_lt: + match = (mls_level_dom(&rule->au_ctxt.range.level[0], + level) && + !mls_level_eq(&rule->au_ctxt.range.level[0], + level)); + break; + case Audit_le: + match = mls_level_dom(&rule->au_ctxt.range.level[0], + level); + break; + case Audit_gt: + match = (mls_level_dom(level, + &rule->au_ctxt.range.level[0]) && + !mls_level_eq(level, + &rule->au_ctxt.range.level[0])); + break; + case Audit_ge: + match = mls_level_dom(level, + &rule->au_ctxt.range.level[0]); + break; + } + } + +out: + rcu_read_unlock(); + return match; +} + +static int aurule_avc_callback(u32 event) +{ + if (event == AVC_CALLBACK_RESET) + return audit_update_lsm_rules(); + return 0; +} + +static int __init aurule_init(void) +{ + int err; + + err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET); + if (err) + panic("avc_add_callback() failed, error %d\n", err); + + return err; +} +__initcall(aurule_init); + +#ifdef CONFIG_NETLABEL +/** + * security_netlbl_cache_add - Add an entry to the NetLabel cache + * @secattr: the NetLabel packet security attributes + * @sid: the SELinux SID + * + * Description: + * Attempt to cache the context in @ctx, which was derived from the packet in + * @skb, in the NetLabel subsystem cache. This function assumes @secattr has + * already been initialized. + * + */ +static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr, + u32 sid) +{ + u32 *sid_cache; + + sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC); + if (sid_cache == NULL) + return; + secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC); + if (secattr->cache == NULL) { + kfree(sid_cache); + return; + } + + *sid_cache = sid; + secattr->cache->free = kfree; + secattr->cache->data = sid_cache; + secattr->flags |= NETLBL_SECATTR_CACHE; +} + +/** + * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID + * @state: SELinux state + * @secattr: the NetLabel packet security attributes + * @sid: the SELinux SID + * + * Description: + * Convert the given NetLabel security attributes in @secattr into a + * SELinux SID. If the @secattr field does not contain a full SELinux + * SID/context then use SECINITSID_NETMSG as the foundation. If possible the + * 'cache' field of @secattr is set and the CACHE flag is set; this is to + * allow the @secattr to be used by NetLabel to cache the secattr to SID + * conversion for future lookups. Returns zero on success, negative values on + * failure. + * + */ +int security_netlbl_secattr_to_sid(struct selinux_state *state, + struct netlbl_lsm_secattr *secattr, + u32 *sid) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + int rc; + struct context *ctx; + struct context ctx_new; + + if (!selinux_initialized(state)) { + *sid = SECSID_NULL; + return 0; + } + +retry: + rc = 0; + rcu_read_lock(); + policy = rcu_dereference(state->policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + + if (secattr->flags & NETLBL_SECATTR_CACHE) + *sid = *(u32 *)secattr->cache->data; + else if (secattr->flags & NETLBL_SECATTR_SECID) + *sid = secattr->attr.secid; + else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) { + rc = -EIDRM; + ctx = sidtab_search(sidtab, SECINITSID_NETMSG); + if (ctx == NULL) + goto out; + + context_init(&ctx_new); + ctx_new.user = ctx->user; + ctx_new.role = ctx->role; + ctx_new.type = ctx->type; + mls_import_netlbl_lvl(policydb, &ctx_new, secattr); + if (secattr->flags & NETLBL_SECATTR_MLS_CAT) { + rc = mls_import_netlbl_cat(policydb, &ctx_new, secattr); + if (rc) + goto out; + } + rc = -EIDRM; + if (!mls_context_isvalid(policydb, &ctx_new)) { + ebitmap_destroy(&ctx_new.range.level[0].cat); + goto out; + } + + rc = sidtab_context_to_sid(sidtab, &ctx_new, sid); + ebitmap_destroy(&ctx_new.range.level[0].cat); + if (rc == -ESTALE) { + rcu_read_unlock(); + goto retry; + } + if (rc) + goto out; + + security_netlbl_cache_add(secattr, *sid); + } else + *sid = SECSID_NULL; + +out: + rcu_read_unlock(); + return rc; +} + +/** + * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr + * @state: SELinux state + * @sid: the SELinux SID + * @secattr: the NetLabel packet security attributes + * + * Description: + * Convert the given SELinux SID in @sid into a NetLabel security attribute. + * Returns zero on success, negative values on failure. + * + */ +int security_netlbl_sid_to_secattr(struct selinux_state *state, + u32 sid, struct netlbl_lsm_secattr *secattr) +{ + struct selinux_policy *policy; + struct policydb *policydb; + int rc; + struct context *ctx; + + if (!selinux_initialized(state)) + return 0; + + rcu_read_lock(); + policy = rcu_dereference(state->policy); + policydb = &policy->policydb; + + rc = -ENOENT; + ctx = sidtab_search(policy->sidtab, sid); + if (ctx == NULL) + goto out; + + rc = -ENOMEM; + secattr->domain = kstrdup(sym_name(policydb, SYM_TYPES, ctx->type - 1), + GFP_ATOMIC); + if (secattr->domain == NULL) + goto out; + + secattr->attr.secid = sid; + secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID; + mls_export_netlbl_lvl(policydb, ctx, secattr); + rc = mls_export_netlbl_cat(policydb, ctx, secattr); +out: + rcu_read_unlock(); + return rc; +} +#endif /* CONFIG_NETLABEL */ + +/** + * __security_read_policy - read the policy. + * @policy: SELinux policy + * @data: binary policy data + * @len: length of data in bytes + * + */ +static int __security_read_policy(struct selinux_policy *policy, + void *data, size_t *len) +{ + int rc; + struct policy_file fp; + + fp.data = data; + fp.len = *len; + + rc = policydb_write(&policy->policydb, &fp); + if (rc) + return rc; + + *len = (unsigned long)fp.data - (unsigned long)data; + return 0; +} + +/** + * security_read_policy - read the policy. + * @state: selinux_state + * @data: binary policy data + * @len: length of data in bytes + * + */ +int security_read_policy(struct selinux_state *state, + void **data, size_t *len) +{ + struct selinux_policy *policy; + + policy = rcu_dereference_protected( + state->policy, lockdep_is_held(&state->policy_mutex)); + if (!policy) + return -EINVAL; + + *len = policy->policydb.len; + *data = vmalloc_user(*len); + if (!*data) + return -ENOMEM; + + return __security_read_policy(policy, *data, len); +} + +/** + * security_read_state_kernel - read the policy. + * @state: selinux_state + * @data: binary policy data + * @len: length of data in bytes + * + * Allocates kernel memory for reading SELinux policy. + * This function is for internal use only and should not + * be used for returning data to user space. + * + * This function must be called with policy_mutex held. + */ +int security_read_state_kernel(struct selinux_state *state, + void **data, size_t *len) +{ + int err; + struct selinux_policy *policy; + + policy = rcu_dereference_protected( + state->policy, lockdep_is_held(&state->policy_mutex)); + if (!policy) + return -EINVAL; + + *len = policy->policydb.len; + *data = vmalloc(*len); + if (!*data) + return -ENOMEM; + + err = __security_read_policy(policy, *data, len); + if (err) { + vfree(*data); + *data = NULL; + *len = 0; + } + return err; +} diff --git a/security/selinux/ss/services.h b/security/selinux/ss/services.h new file mode 100644 index 000000000..9555ad074 --- /dev/null +++ b/security/selinux/ss/services.h @@ -0,0 +1,38 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Implementation of the security services. + * + * Author : Stephen Smalley, <sds@tycho.nsa.gov> + */ +#ifndef _SS_SERVICES_H_ +#define _SS_SERVICES_H_ + +#include "policydb.h" + +/* Mapping for a single class */ +struct selinux_mapping { + u16 value; /* policy value for class */ + unsigned int num_perms; /* number of permissions in class */ + u32 perms[sizeof(u32) * 8]; /* policy values for permissions */ +}; + +/* Map for all of the classes, with array size */ +struct selinux_map { + struct selinux_mapping *mapping; /* indexed by class */ + u16 size; /* array size of mapping */ +}; + +struct selinux_policy { + struct sidtab *sidtab; + struct policydb policydb; + struct selinux_map map; + u32 latest_granting; +} __randomize_layout; + +void services_compute_xperms_drivers(struct extended_perms *xperms, + struct avtab_node *node); + +void services_compute_xperms_decision(struct extended_perms_decision *xpermd, + struct avtab_node *node); + +#endif /* _SS_SERVICES_H_ */ diff --git a/security/selinux/ss/sidtab.c b/security/selinux/ss/sidtab.c new file mode 100644 index 000000000..db5cce385 --- /dev/null +++ b/security/selinux/ss/sidtab.c @@ -0,0 +1,628 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Implementation of the SID table type. + * + * Original author: Stephen Smalley, <sds@tycho.nsa.gov> + * Author: Ondrej Mosnacek, <omosnacek@gmail.com> + * + * Copyright (C) 2018 Red Hat, Inc. + */ +#include <linux/errno.h> +#include <linux/kernel.h> +#include <linux/list.h> +#include <linux/rcupdate.h> +#include <linux/slab.h> +#include <linux/sched.h> +#include <linux/spinlock.h> +#include <asm/barrier.h> +#include "flask.h" +#include "security.h" +#include "sidtab.h" + +struct sidtab_str_cache { + struct rcu_head rcu_member; + struct list_head lru_member; + struct sidtab_entry *parent; + u32 len; + char str[]; +}; + +#define index_to_sid(index) ((index) + SECINITSID_NUM + 1) +#define sid_to_index(sid) ((sid) - (SECINITSID_NUM + 1)) + +int sidtab_init(struct sidtab *s) +{ + u32 i; + + memset(s->roots, 0, sizeof(s->roots)); + + for (i = 0; i < SECINITSID_NUM; i++) + s->isids[i].set = 0; + + s->frozen = false; + s->count = 0; + s->convert = NULL; + hash_init(s->context_to_sid); + + spin_lock_init(&s->lock); + +#if CONFIG_SECURITY_SELINUX_SID2STR_CACHE_SIZE > 0 + s->cache_free_slots = CONFIG_SECURITY_SELINUX_SID2STR_CACHE_SIZE; + INIT_LIST_HEAD(&s->cache_lru_list); + spin_lock_init(&s->cache_lock); +#endif + + return 0; +} + +static u32 context_to_sid(struct sidtab *s, struct context *context, u32 hash) +{ + struct sidtab_entry *entry; + u32 sid = 0; + + rcu_read_lock(); + hash_for_each_possible_rcu(s->context_to_sid, entry, list, hash) { + if (entry->hash != hash) + continue; + if (context_cmp(&entry->context, context)) { + sid = entry->sid; + break; + } + } + rcu_read_unlock(); + return sid; +} + +int sidtab_set_initial(struct sidtab *s, u32 sid, struct context *context) +{ + struct sidtab_isid_entry *isid; + u32 hash; + int rc; + + if (sid == 0 || sid > SECINITSID_NUM) + return -EINVAL; + + isid = &s->isids[sid - 1]; + + rc = context_cpy(&isid->entry.context, context); + if (rc) + return rc; + +#if CONFIG_SECURITY_SELINUX_SID2STR_CACHE_SIZE > 0 + isid->entry.cache = NULL; +#endif + isid->set = 1; + + hash = context_compute_hash(context); + + /* + * Multiple initial sids may map to the same context. Check that this + * context is not already represented in the context_to_sid hashtable + * to avoid duplicate entries and long linked lists upon hash + * collision. + */ + if (!context_to_sid(s, context, hash)) { + isid->entry.sid = sid; + isid->entry.hash = hash; + hash_add(s->context_to_sid, &isid->entry.list, hash); + } + + return 0; +} + +int sidtab_hash_stats(struct sidtab *sidtab, char *page) +{ + int i; + int chain_len = 0; + int slots_used = 0; + int entries = 0; + int max_chain_len = 0; + int cur_bucket = 0; + struct sidtab_entry *entry; + + rcu_read_lock(); + hash_for_each_rcu(sidtab->context_to_sid, i, entry, list) { + entries++; + if (i == cur_bucket) { + chain_len++; + if (chain_len == 1) + slots_used++; + } else { + cur_bucket = i; + if (chain_len > max_chain_len) + max_chain_len = chain_len; + chain_len = 0; + } + } + rcu_read_unlock(); + + if (chain_len > max_chain_len) + max_chain_len = chain_len; + + return scnprintf(page, PAGE_SIZE, "entries: %d\nbuckets used: %d/%d\n" + "longest chain: %d\n", entries, + slots_used, SIDTAB_HASH_BUCKETS, max_chain_len); +} + +static u32 sidtab_level_from_count(u32 count) +{ + u32 capacity = SIDTAB_LEAF_ENTRIES; + u32 level = 0; + + while (count > capacity) { + capacity <<= SIDTAB_INNER_SHIFT; + ++level; + } + return level; +} + +static int sidtab_alloc_roots(struct sidtab *s, u32 level) +{ + u32 l; + + if (!s->roots[0].ptr_leaf) { + s->roots[0].ptr_leaf = kzalloc(SIDTAB_NODE_ALLOC_SIZE, + GFP_ATOMIC); + if (!s->roots[0].ptr_leaf) + return -ENOMEM; + } + for (l = 1; l <= level; ++l) + if (!s->roots[l].ptr_inner) { + s->roots[l].ptr_inner = kzalloc(SIDTAB_NODE_ALLOC_SIZE, + GFP_ATOMIC); + if (!s->roots[l].ptr_inner) + return -ENOMEM; + s->roots[l].ptr_inner->entries[0] = s->roots[l - 1]; + } + return 0; +} + +static struct sidtab_entry *sidtab_do_lookup(struct sidtab *s, u32 index, + int alloc) +{ + union sidtab_entry_inner *entry; + u32 level, capacity_shift, leaf_index = index / SIDTAB_LEAF_ENTRIES; + + /* find the level of the subtree we need */ + level = sidtab_level_from_count(index + 1); + capacity_shift = level * SIDTAB_INNER_SHIFT; + + /* allocate roots if needed */ + if (alloc && sidtab_alloc_roots(s, level) != 0) + return NULL; + + /* lookup inside the subtree */ + entry = &s->roots[level]; + while (level != 0) { + capacity_shift -= SIDTAB_INNER_SHIFT; + --level; + + entry = &entry->ptr_inner->entries[leaf_index >> capacity_shift]; + leaf_index &= ((u32)1 << capacity_shift) - 1; + + if (!entry->ptr_inner) { + if (alloc) + entry->ptr_inner = kzalloc(SIDTAB_NODE_ALLOC_SIZE, + GFP_ATOMIC); + if (!entry->ptr_inner) + return NULL; + } + } + if (!entry->ptr_leaf) { + if (alloc) + entry->ptr_leaf = kzalloc(SIDTAB_NODE_ALLOC_SIZE, + GFP_ATOMIC); + if (!entry->ptr_leaf) + return NULL; + } + return &entry->ptr_leaf->entries[index % SIDTAB_LEAF_ENTRIES]; +} + +static struct sidtab_entry *sidtab_lookup(struct sidtab *s, u32 index) +{ + /* read entries only after reading count */ + u32 count = smp_load_acquire(&s->count); + + if (index >= count) + return NULL; + + return sidtab_do_lookup(s, index, 0); +} + +static struct sidtab_entry *sidtab_lookup_initial(struct sidtab *s, u32 sid) +{ + return s->isids[sid - 1].set ? &s->isids[sid - 1].entry : NULL; +} + +static struct sidtab_entry *sidtab_search_core(struct sidtab *s, u32 sid, + int force) +{ + if (sid != 0) { + struct sidtab_entry *entry; + + if (sid > SECINITSID_NUM) + entry = sidtab_lookup(s, sid_to_index(sid)); + else + entry = sidtab_lookup_initial(s, sid); + if (entry && (!entry->context.len || force)) + return entry; + } + + return sidtab_lookup_initial(s, SECINITSID_UNLABELED); +} + +struct sidtab_entry *sidtab_search_entry(struct sidtab *s, u32 sid) +{ + return sidtab_search_core(s, sid, 0); +} + +struct sidtab_entry *sidtab_search_entry_force(struct sidtab *s, u32 sid) +{ + return sidtab_search_core(s, sid, 1); +} + +int sidtab_context_to_sid(struct sidtab *s, struct context *context, + u32 *sid) +{ + unsigned long flags; + u32 count, hash = context_compute_hash(context); + struct sidtab_convert_params *convert; + struct sidtab_entry *dst, *dst_convert; + int rc; + + *sid = context_to_sid(s, context, hash); + if (*sid) + return 0; + + /* lock-free search failed: lock, re-search, and insert if not found */ + spin_lock_irqsave(&s->lock, flags); + + rc = 0; + *sid = context_to_sid(s, context, hash); + if (*sid) + goto out_unlock; + + if (unlikely(s->frozen)) { + /* + * This sidtab is now frozen - tell the caller to abort and + * get the new one. + */ + rc = -ESTALE; + goto out_unlock; + } + + count = s->count; + convert = s->convert; + + /* bail out if we already reached max entries */ + rc = -EOVERFLOW; + if (count >= SIDTAB_MAX) + goto out_unlock; + + /* insert context into new entry */ + rc = -ENOMEM; + dst = sidtab_do_lookup(s, count, 1); + if (!dst) + goto out_unlock; + + dst->sid = index_to_sid(count); + dst->hash = hash; + + rc = context_cpy(&dst->context, context); + if (rc) + goto out_unlock; + + /* + * if we are building a new sidtab, we need to convert the context + * and insert it there as well + */ + if (convert) { + rc = -ENOMEM; + dst_convert = sidtab_do_lookup(convert->target, count, 1); + if (!dst_convert) { + context_destroy(&dst->context); + goto out_unlock; + } + + rc = convert->func(context, &dst_convert->context, + convert->args, GFP_ATOMIC); + if (rc) { + context_destroy(&dst->context); + goto out_unlock; + } + dst_convert->sid = index_to_sid(count); + dst_convert->hash = context_compute_hash(&dst_convert->context); + convert->target->count = count + 1; + + hash_add_rcu(convert->target->context_to_sid, + &dst_convert->list, dst_convert->hash); + } + + if (context->len) + pr_info("SELinux: Context %s is not valid (left unmapped).\n", + context->str); + + *sid = index_to_sid(count); + + /* write entries before updating count */ + smp_store_release(&s->count, count + 1); + hash_add_rcu(s->context_to_sid, &dst->list, dst->hash); + + rc = 0; +out_unlock: + spin_unlock_irqrestore(&s->lock, flags); + return rc; +} + +static void sidtab_convert_hashtable(struct sidtab *s, u32 count) +{ + struct sidtab_entry *entry; + u32 i; + + for (i = 0; i < count; i++) { + entry = sidtab_do_lookup(s, i, 0); + entry->sid = index_to_sid(i); + entry->hash = context_compute_hash(&entry->context); + + hash_add_rcu(s->context_to_sid, &entry->list, entry->hash); + } +} + +static int sidtab_convert_tree(union sidtab_entry_inner *edst, + union sidtab_entry_inner *esrc, + u32 *pos, u32 count, u32 level, + struct sidtab_convert_params *convert) +{ + int rc; + u32 i; + + if (level != 0) { + if (!edst->ptr_inner) { + edst->ptr_inner = kzalloc(SIDTAB_NODE_ALLOC_SIZE, + GFP_KERNEL); + if (!edst->ptr_inner) + return -ENOMEM; + } + i = 0; + while (i < SIDTAB_INNER_ENTRIES && *pos < count) { + rc = sidtab_convert_tree(&edst->ptr_inner->entries[i], + &esrc->ptr_inner->entries[i], + pos, count, level - 1, + convert); + if (rc) + return rc; + i++; + } + } else { + if (!edst->ptr_leaf) { + edst->ptr_leaf = kzalloc(SIDTAB_NODE_ALLOC_SIZE, + GFP_KERNEL); + if (!edst->ptr_leaf) + return -ENOMEM; + } + i = 0; + while (i < SIDTAB_LEAF_ENTRIES && *pos < count) { + rc = convert->func(&esrc->ptr_leaf->entries[i].context, + &edst->ptr_leaf->entries[i].context, + convert->args, GFP_KERNEL); + if (rc) + return rc; + (*pos)++; + i++; + } + cond_resched(); + } + return 0; +} + +int sidtab_convert(struct sidtab *s, struct sidtab_convert_params *params) +{ + unsigned long flags; + u32 count, level, pos; + int rc; + + spin_lock_irqsave(&s->lock, flags); + + /* concurrent policy loads are not allowed */ + if (s->convert) { + spin_unlock_irqrestore(&s->lock, flags); + return -EBUSY; + } + + count = s->count; + level = sidtab_level_from_count(count); + + /* allocate last leaf in the new sidtab (to avoid race with + * live convert) + */ + rc = sidtab_do_lookup(params->target, count - 1, 1) ? 0 : -ENOMEM; + if (rc) { + spin_unlock_irqrestore(&s->lock, flags); + return rc; + } + + /* set count in case no new entries are added during conversion */ + params->target->count = count; + + /* enable live convert of new entries */ + s->convert = params; + + /* we can safely convert the tree outside the lock */ + spin_unlock_irqrestore(&s->lock, flags); + + pr_info("SELinux: Converting %u SID table entries...\n", count); + + /* convert all entries not covered by live convert */ + pos = 0; + rc = sidtab_convert_tree(¶ms->target->roots[level], + &s->roots[level], &pos, count, level, params); + if (rc) { + /* we need to keep the old table - disable live convert */ + spin_lock_irqsave(&s->lock, flags); + s->convert = NULL; + spin_unlock_irqrestore(&s->lock, flags); + return rc; + } + /* + * The hashtable can also be modified in sidtab_context_to_sid() + * so we must re-acquire the lock here. + */ + spin_lock_irqsave(&s->lock, flags); + sidtab_convert_hashtable(params->target, count); + spin_unlock_irqrestore(&s->lock, flags); + + return 0; +} + +void sidtab_cancel_convert(struct sidtab *s) +{ + unsigned long flags; + + /* cancelling policy load - disable live convert of sidtab */ + spin_lock_irqsave(&s->lock, flags); + s->convert = NULL; + spin_unlock_irqrestore(&s->lock, flags); +} + +void sidtab_freeze_begin(struct sidtab *s, unsigned long *flags) __acquires(&s->lock) +{ + spin_lock_irqsave(&s->lock, *flags); + s->frozen = true; + s->convert = NULL; +} +void sidtab_freeze_end(struct sidtab *s, unsigned long *flags) __releases(&s->lock) +{ + spin_unlock_irqrestore(&s->lock, *flags); +} + +static void sidtab_destroy_entry(struct sidtab_entry *entry) +{ + context_destroy(&entry->context); +#if CONFIG_SECURITY_SELINUX_SID2STR_CACHE_SIZE > 0 + kfree(rcu_dereference_raw(entry->cache)); +#endif +} + +static void sidtab_destroy_tree(union sidtab_entry_inner entry, u32 level) +{ + u32 i; + + if (level != 0) { + struct sidtab_node_inner *node = entry.ptr_inner; + + if (!node) + return; + + for (i = 0; i < SIDTAB_INNER_ENTRIES; i++) + sidtab_destroy_tree(node->entries[i], level - 1); + kfree(node); + } else { + struct sidtab_node_leaf *node = entry.ptr_leaf; + + if (!node) + return; + + for (i = 0; i < SIDTAB_LEAF_ENTRIES; i++) + sidtab_destroy_entry(&node->entries[i]); + kfree(node); + } +} + +void sidtab_destroy(struct sidtab *s) +{ + u32 i, level; + + for (i = 0; i < SECINITSID_NUM; i++) + if (s->isids[i].set) + sidtab_destroy_entry(&s->isids[i].entry); + + level = SIDTAB_MAX_LEVEL; + while (level && !s->roots[level].ptr_inner) + --level; + + sidtab_destroy_tree(s->roots[level], level); + /* + * The context_to_sid hashtable's objects are all shared + * with the isids array and context tree, and so don't need + * to be cleaned up here. + */ +} + +#if CONFIG_SECURITY_SELINUX_SID2STR_CACHE_SIZE > 0 + +void sidtab_sid2str_put(struct sidtab *s, struct sidtab_entry *entry, + const char *str, u32 str_len) +{ + struct sidtab_str_cache *cache, *victim = NULL; + unsigned long flags; + + /* do not cache invalid contexts */ + if (entry->context.len) + return; + + spin_lock_irqsave(&s->cache_lock, flags); + + cache = rcu_dereference_protected(entry->cache, + lockdep_is_held(&s->cache_lock)); + if (cache) { + /* entry in cache - just bump to the head of LRU list */ + list_move(&cache->lru_member, &s->cache_lru_list); + goto out_unlock; + } + + cache = kmalloc(struct_size(cache, str, str_len), GFP_ATOMIC); + if (!cache) + goto out_unlock; + + if (s->cache_free_slots == 0) { + /* pop a cache entry from the tail and free it */ + victim = container_of(s->cache_lru_list.prev, + struct sidtab_str_cache, lru_member); + list_del(&victim->lru_member); + rcu_assign_pointer(victim->parent->cache, NULL); + } else { + s->cache_free_slots--; + } + cache->parent = entry; + cache->len = str_len; + memcpy(cache->str, str, str_len); + list_add(&cache->lru_member, &s->cache_lru_list); + + rcu_assign_pointer(entry->cache, cache); + +out_unlock: + spin_unlock_irqrestore(&s->cache_lock, flags); + kfree_rcu(victim, rcu_member); +} + +int sidtab_sid2str_get(struct sidtab *s, struct sidtab_entry *entry, + char **out, u32 *out_len) +{ + struct sidtab_str_cache *cache; + int rc = 0; + + if (entry->context.len) + return -ENOENT; /* do not cache invalid contexts */ + + rcu_read_lock(); + + cache = rcu_dereference(entry->cache); + if (!cache) { + rc = -ENOENT; + } else { + *out_len = cache->len; + if (out) { + *out = kmemdup(cache->str, cache->len, GFP_ATOMIC); + if (!*out) + rc = -ENOMEM; + } + } + + rcu_read_unlock(); + + if (!rc && out) + sidtab_sid2str_put(s, entry, *out, *out_len); + return rc; +} + +#endif /* CONFIG_SECURITY_SELINUX_SID2STR_CACHE_SIZE > 0 */ diff --git a/security/selinux/ss/sidtab.h b/security/selinux/ss/sidtab.h new file mode 100644 index 000000000..9fce0d553 --- /dev/null +++ b/security/selinux/ss/sidtab.h @@ -0,0 +1,159 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * A security identifier table (sidtab) is a lookup table + * of security context structures indexed by SID value. + * + * Original author: Stephen Smalley, <sds@tycho.nsa.gov> + * Author: Ondrej Mosnacek, <omosnacek@gmail.com> + * + * Copyright (C) 2018 Red Hat, Inc. + */ +#ifndef _SS_SIDTAB_H_ +#define _SS_SIDTAB_H_ + +#include <linux/spinlock_types.h> +#include <linux/log2.h> +#include <linux/hashtable.h> + +#include "context.h" + +struct sidtab_entry { + u32 sid; + u32 hash; + struct context context; +#if CONFIG_SECURITY_SELINUX_SID2STR_CACHE_SIZE > 0 + struct sidtab_str_cache __rcu *cache; +#endif + struct hlist_node list; +}; + +union sidtab_entry_inner { + struct sidtab_node_inner *ptr_inner; + struct sidtab_node_leaf *ptr_leaf; +}; + +/* align node size to page boundary */ +#define SIDTAB_NODE_ALLOC_SHIFT PAGE_SHIFT +#define SIDTAB_NODE_ALLOC_SIZE PAGE_SIZE + +#define size_to_shift(size) ((size) == 1 ? 1 : (const_ilog2((size) - 1) + 1)) + +#define SIDTAB_INNER_SHIFT \ + (SIDTAB_NODE_ALLOC_SHIFT - size_to_shift(sizeof(union sidtab_entry_inner))) +#define SIDTAB_INNER_ENTRIES ((size_t)1 << SIDTAB_INNER_SHIFT) +#define SIDTAB_LEAF_ENTRIES \ + (SIDTAB_NODE_ALLOC_SIZE / sizeof(struct sidtab_entry)) + +#define SIDTAB_MAX_BITS 32 +#define SIDTAB_MAX U32_MAX +/* ensure enough tree levels for SIDTAB_MAX entries */ +#define SIDTAB_MAX_LEVEL \ + DIV_ROUND_UP(SIDTAB_MAX_BITS - size_to_shift(SIDTAB_LEAF_ENTRIES), \ + SIDTAB_INNER_SHIFT) + +struct sidtab_node_leaf { + struct sidtab_entry entries[SIDTAB_LEAF_ENTRIES]; +}; + +struct sidtab_node_inner { + union sidtab_entry_inner entries[SIDTAB_INNER_ENTRIES]; +}; + +struct sidtab_isid_entry { + int set; + struct sidtab_entry entry; +}; + +struct sidtab_convert_params { + int (*func)(struct context *oldc, struct context *newc, void *args, gfp_t gfp_flags); + void *args; + struct sidtab *target; +}; + +#define SIDTAB_HASH_BITS CONFIG_SECURITY_SELINUX_SIDTAB_HASH_BITS +#define SIDTAB_HASH_BUCKETS (1 << SIDTAB_HASH_BITS) + +struct sidtab { + /* + * lock-free read access only for as many items as a prior read of + * 'count' + */ + union sidtab_entry_inner roots[SIDTAB_MAX_LEVEL + 1]; + /* + * access atomically via {READ|WRITE}_ONCE(); only increment under + * spinlock + */ + u32 count; + /* access only under spinlock */ + struct sidtab_convert_params *convert; + bool frozen; + spinlock_t lock; + +#if CONFIG_SECURITY_SELINUX_SID2STR_CACHE_SIZE > 0 + /* SID -> context string cache */ + u32 cache_free_slots; + struct list_head cache_lru_list; + spinlock_t cache_lock; +#endif + + /* index == SID - 1 (no entry for SECSID_NULL) */ + struct sidtab_isid_entry isids[SECINITSID_NUM]; + + /* Hash table for fast reverse context-to-sid lookups. */ + DECLARE_HASHTABLE(context_to_sid, SIDTAB_HASH_BITS); +}; + +int sidtab_init(struct sidtab *s); +int sidtab_set_initial(struct sidtab *s, u32 sid, struct context *context); +struct sidtab_entry *sidtab_search_entry(struct sidtab *s, u32 sid); +struct sidtab_entry *sidtab_search_entry_force(struct sidtab *s, u32 sid); + +static inline struct context *sidtab_search(struct sidtab *s, u32 sid) +{ + struct sidtab_entry *entry = sidtab_search_entry(s, sid); + + return entry ? &entry->context : NULL; +} + +static inline struct context *sidtab_search_force(struct sidtab *s, u32 sid) +{ + struct sidtab_entry *entry = sidtab_search_entry_force(s, sid); + + return entry ? &entry->context : NULL; +} + +int sidtab_convert(struct sidtab *s, struct sidtab_convert_params *params); + +void sidtab_cancel_convert(struct sidtab *s); + +void sidtab_freeze_begin(struct sidtab *s, unsigned long *flags) __acquires(&s->lock); +void sidtab_freeze_end(struct sidtab *s, unsigned long *flags) __releases(&s->lock); + +int sidtab_context_to_sid(struct sidtab *s, struct context *context, u32 *sid); + +void sidtab_destroy(struct sidtab *s); + +int sidtab_hash_stats(struct sidtab *sidtab, char *page); + +#if CONFIG_SECURITY_SELINUX_SID2STR_CACHE_SIZE > 0 +void sidtab_sid2str_put(struct sidtab *s, struct sidtab_entry *entry, + const char *str, u32 str_len); +int sidtab_sid2str_get(struct sidtab *s, struct sidtab_entry *entry, + char **out, u32 *out_len); +#else +static inline void sidtab_sid2str_put(struct sidtab *s, + struct sidtab_entry *entry, + const char *str, u32 str_len) +{ +} +static inline int sidtab_sid2str_get(struct sidtab *s, + struct sidtab_entry *entry, + char **out, u32 *out_len) +{ + return -ENOENT; +} +#endif /* CONFIG_SECURITY_SELINUX_SID2STR_CACHE_SIZE > 0 */ + +#endif /* _SS_SIDTAB_H_ */ + + diff --git a/security/selinux/ss/symtab.c b/security/selinux/ss/symtab.c new file mode 100644 index 000000000..c42a6648a --- /dev/null +++ b/security/selinux/ss/symtab.c @@ -0,0 +1,54 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Implementation of the symbol table type. + * + * Author : Stephen Smalley, <sds@tycho.nsa.gov> + */ +#include <linux/kernel.h> +#include <linux/string.h> +#include <linux/errno.h> +#include "symtab.h" + +static unsigned int symhash(const void *key) +{ + const char *p, *keyp; + unsigned int size; + unsigned int val; + + val = 0; + keyp = key; + size = strlen(keyp); + for (p = keyp; (p - keyp) < size; p++) + val = (val << 4 | (val >> (8*sizeof(unsigned int)-4))) ^ (*p); + return val; +} + +static int symcmp(const void *key1, const void *key2) +{ + const char *keyp1, *keyp2; + + keyp1 = key1; + keyp2 = key2; + return strcmp(keyp1, keyp2); +} + +static const struct hashtab_key_params symtab_key_params = { + .hash = symhash, + .cmp = symcmp, +}; + +int symtab_init(struct symtab *s, unsigned int size) +{ + s->nprim = 0; + return hashtab_init(&s->table, size); +} + +int symtab_insert(struct symtab *s, char *name, void *datum) +{ + return hashtab_insert(&s->table, name, datum, symtab_key_params); +} + +void *symtab_search(struct symtab *s, const char *name) +{ + return hashtab_search(&s->table, name, symtab_key_params); +} diff --git a/security/selinux/ss/symtab.h b/security/selinux/ss/symtab.h new file mode 100644 index 000000000..f2614138d --- /dev/null +++ b/security/selinux/ss/symtab.h @@ -0,0 +1,27 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * A symbol table (symtab) maintains associations between symbol + * strings and datum values. The type of the datum values + * is arbitrary. The symbol table type is implemented + * using the hash table type (hashtab). + * + * Author : Stephen Smalley, <sds@tycho.nsa.gov> + */ +#ifndef _SS_SYMTAB_H_ +#define _SS_SYMTAB_H_ + +#include "hashtab.h" + +struct symtab { + struct hashtab table; /* hash table (keyed on a string) */ + u32 nprim; /* number of primary names in table */ +}; + +int symtab_init(struct symtab *s, unsigned int size); + +int symtab_insert(struct symtab *s, char *name, void *datum); +void *symtab_search(struct symtab *s, const char *name); + +#endif /* _SS_SYMTAB_H_ */ + + diff --git a/security/selinux/status.c b/security/selinux/status.c new file mode 100644 index 000000000..4bc8f8099 --- /dev/null +++ b/security/selinux/status.c @@ -0,0 +1,124 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * mmap based event notifications for SELinux + * + * Author: KaiGai Kohei <kaigai@ak.jp.nec.com> + * + * Copyright (C) 2010 NEC corporation + */ +#include <linux/kernel.h> +#include <linux/gfp.h> +#include <linux/mm.h> +#include <linux/mutex.h> +#include "avc.h" +#include "security.h" + +/* + * The selinux_status_page shall be exposed to userspace applications + * using mmap interface on /selinux/status. + * It enables to notify applications a few events that will cause reset + * of userspace access vector without context switching. + * + * The selinux_kernel_status structure on the head of status page is + * protected from concurrent accesses using seqlock logic, so userspace + * application should reference the status page according to the seqlock + * logic. + * + * Typically, application checks status->sequence at the head of access + * control routine. If it is odd-number, kernel is updating the status, + * so please wait for a moment. If it is changed from the last sequence + * number, it means something happen, so application will reset userspace + * avc, if needed. + * In most cases, application shall confirm the kernel status is not + * changed without any system call invocations. + */ + +/* + * selinux_kernel_status_page + * + * It returns a reference to selinux_status_page. If the status page is + * not allocated yet, it also tries to allocate it at the first time. + */ +struct page *selinux_kernel_status_page(struct selinux_state *state) +{ + struct selinux_kernel_status *status; + struct page *result = NULL; + + mutex_lock(&state->status_lock); + if (!state->status_page) { + state->status_page = alloc_page(GFP_KERNEL|__GFP_ZERO); + + if (state->status_page) { + status = page_address(state->status_page); + + status->version = SELINUX_KERNEL_STATUS_VERSION; + status->sequence = 0; + status->enforcing = enforcing_enabled(state); + /* + * NOTE: the next policyload event shall set + * a positive value on the status->policyload, + * although it may not be 1, but never zero. + * So, application can know it was updated. + */ + status->policyload = 0; + status->deny_unknown = + !security_get_allow_unknown(state); + } + } + result = state->status_page; + mutex_unlock(&state->status_lock); + + return result; +} + +/* + * selinux_status_update_setenforce + * + * It updates status of the current enforcing/permissive mode. + */ +void selinux_status_update_setenforce(struct selinux_state *state, + int enforcing) +{ + struct selinux_kernel_status *status; + + mutex_lock(&state->status_lock); + if (state->status_page) { + status = page_address(state->status_page); + + status->sequence++; + smp_wmb(); + + status->enforcing = enforcing; + + smp_wmb(); + status->sequence++; + } + mutex_unlock(&state->status_lock); +} + +/* + * selinux_status_update_policyload + * + * It updates status of the times of policy reloaded, and current + * setting of deny_unknown. + */ +void selinux_status_update_policyload(struct selinux_state *state, + int seqno) +{ + struct selinux_kernel_status *status; + + mutex_lock(&state->status_lock); + if (state->status_page) { + status = page_address(state->status_page); + + status->sequence++; + smp_wmb(); + + status->policyload = seqno; + status->deny_unknown = !security_get_allow_unknown(state); + + smp_wmb(); + status->sequence++; + } + mutex_unlock(&state->status_lock); +} diff --git a/security/selinux/xfrm.c b/security/selinux/xfrm.c new file mode 100644 index 000000000..c576832fe --- /dev/null +++ b/security/selinux/xfrm.c @@ -0,0 +1,473 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * NSA Security-Enhanced Linux (SELinux) security module + * + * This file contains the SELinux XFRM hook function implementations. + * + * Authors: Serge Hallyn <sergeh@us.ibm.com> + * Trent Jaeger <jaegert@us.ibm.com> + * + * Updated: Venkat Yekkirala <vyekkirala@TrustedCS.com> + * + * Granular IPSec Associations for use in MLS environments. + * + * Copyright (C) 2005 International Business Machines Corporation + * Copyright (C) 2006 Trusted Computer Solutions, Inc. + */ + +/* + * USAGE: + * NOTES: + * 1. Make sure to enable the following options in your kernel config: + * CONFIG_SECURITY=y + * CONFIG_SECURITY_NETWORK=y + * CONFIG_SECURITY_NETWORK_XFRM=y + * CONFIG_SECURITY_SELINUX=m/y + * ISSUES: + * 1. Caching packets, so they are not dropped during negotiation + * 2. Emulating a reasonable SO_PEERSEC across machines + * 3. Testing addition of sk_policy's with security context via setsockopt + */ +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/security.h> +#include <linux/types.h> +#include <linux/slab.h> +#include <linux/ip.h> +#include <linux/tcp.h> +#include <linux/skbuff.h> +#include <linux/xfrm.h> +#include <net/xfrm.h> +#include <net/checksum.h> +#include <net/udp.h> +#include <linux/atomic.h> + +#include "avc.h" +#include "objsec.h" +#include "xfrm.h" + +/* Labeled XFRM instance counter */ +atomic_t selinux_xfrm_refcount __read_mostly = ATOMIC_INIT(0); + +/* + * Returns true if the context is an LSM/SELinux context. + */ +static inline int selinux_authorizable_ctx(struct xfrm_sec_ctx *ctx) +{ + return (ctx && + (ctx->ctx_doi == XFRM_SC_DOI_LSM) && + (ctx->ctx_alg == XFRM_SC_ALG_SELINUX)); +} + +/* + * Returns true if the xfrm contains a security blob for SELinux. + */ +static inline int selinux_authorizable_xfrm(struct xfrm_state *x) +{ + return selinux_authorizable_ctx(x->security); +} + +/* + * Allocates a xfrm_sec_state and populates it using the supplied security + * xfrm_user_sec_ctx context. + */ +static int selinux_xfrm_alloc_user(struct xfrm_sec_ctx **ctxp, + struct xfrm_user_sec_ctx *uctx, + gfp_t gfp) +{ + int rc; + const struct task_security_struct *tsec = selinux_cred(current_cred()); + struct xfrm_sec_ctx *ctx = NULL; + u32 str_len; + + if (ctxp == NULL || uctx == NULL || + uctx->ctx_doi != XFRM_SC_DOI_LSM || + uctx->ctx_alg != XFRM_SC_ALG_SELINUX) + return -EINVAL; + + str_len = uctx->ctx_len; + if (str_len >= PAGE_SIZE) + return -ENOMEM; + + ctx = kmalloc(struct_size(ctx, ctx_str, str_len + 1), gfp); + if (!ctx) + return -ENOMEM; + + ctx->ctx_doi = XFRM_SC_DOI_LSM; + ctx->ctx_alg = XFRM_SC_ALG_SELINUX; + ctx->ctx_len = str_len; + memcpy(ctx->ctx_str, &uctx[1], str_len); + ctx->ctx_str[str_len] = '\0'; + rc = security_context_to_sid(&selinux_state, ctx->ctx_str, str_len, + &ctx->ctx_sid, gfp); + if (rc) + goto err; + + rc = avc_has_perm(&selinux_state, + tsec->sid, ctx->ctx_sid, + SECCLASS_ASSOCIATION, ASSOCIATION__SETCONTEXT, NULL); + if (rc) + goto err; + + *ctxp = ctx; + atomic_inc(&selinux_xfrm_refcount); + return 0; + +err: + kfree(ctx); + return rc; +} + +/* + * Free the xfrm_sec_ctx structure. + */ +static void selinux_xfrm_free(struct xfrm_sec_ctx *ctx) +{ + if (!ctx) + return; + + atomic_dec(&selinux_xfrm_refcount); + kfree(ctx); +} + +/* + * Authorize the deletion of a labeled SA or policy rule. + */ +static int selinux_xfrm_delete(struct xfrm_sec_ctx *ctx) +{ + const struct task_security_struct *tsec = selinux_cred(current_cred()); + + if (!ctx) + return 0; + + return avc_has_perm(&selinux_state, + tsec->sid, ctx->ctx_sid, + SECCLASS_ASSOCIATION, ASSOCIATION__SETCONTEXT, + NULL); +} + +/* + * LSM hook implementation that authorizes that a flow can use a xfrm policy + * rule. + */ +int selinux_xfrm_policy_lookup(struct xfrm_sec_ctx *ctx, u32 fl_secid) +{ + int rc; + + /* All flows should be treated as polmatch'ing an otherwise applicable + * "non-labeled" policy. This would prevent inadvertent "leaks". */ + if (!ctx) + return 0; + + /* Context sid is either set to label or ANY_ASSOC */ + if (!selinux_authorizable_ctx(ctx)) + return -EINVAL; + + rc = avc_has_perm(&selinux_state, + fl_secid, ctx->ctx_sid, + SECCLASS_ASSOCIATION, ASSOCIATION__POLMATCH, NULL); + return (rc == -EACCES ? -ESRCH : rc); +} + +/* + * LSM hook implementation that authorizes that a state matches + * the given policy, flow combo. + */ +int selinux_xfrm_state_pol_flow_match(struct xfrm_state *x, + struct xfrm_policy *xp, + const struct flowi_common *flic) +{ + u32 state_sid; + u32 flic_sid; + + if (!xp->security) + if (x->security) + /* unlabeled policy and labeled SA can't match */ + return 0; + else + /* unlabeled policy and unlabeled SA match all flows */ + return 1; + else + if (!x->security) + /* unlabeled SA and labeled policy can't match */ + return 0; + else + if (!selinux_authorizable_xfrm(x)) + /* Not a SELinux-labeled SA */ + return 0; + + state_sid = x->security->ctx_sid; + flic_sid = flic->flowic_secid; + + if (flic_sid != state_sid) + return 0; + + /* We don't need a separate SA Vs. policy polmatch check since the SA + * is now of the same label as the flow and a flow Vs. policy polmatch + * check had already happened in selinux_xfrm_policy_lookup() above. */ + return (avc_has_perm(&selinux_state, flic_sid, state_sid, + SECCLASS_ASSOCIATION, ASSOCIATION__SENDTO, + NULL) ? 0 : 1); +} + +static u32 selinux_xfrm_skb_sid_egress(struct sk_buff *skb) +{ + struct dst_entry *dst = skb_dst(skb); + struct xfrm_state *x; + + if (dst == NULL) + return SECSID_NULL; + x = dst->xfrm; + if (x == NULL || !selinux_authorizable_xfrm(x)) + return SECSID_NULL; + + return x->security->ctx_sid; +} + +static int selinux_xfrm_skb_sid_ingress(struct sk_buff *skb, + u32 *sid, int ckall) +{ + u32 sid_session = SECSID_NULL; + struct sec_path *sp = skb_sec_path(skb); + + if (sp) { + int i; + + for (i = sp->len - 1; i >= 0; i--) { + struct xfrm_state *x = sp->xvec[i]; + if (selinux_authorizable_xfrm(x)) { + struct xfrm_sec_ctx *ctx = x->security; + + if (sid_session == SECSID_NULL) { + sid_session = ctx->ctx_sid; + if (!ckall) + goto out; + } else if (sid_session != ctx->ctx_sid) { + *sid = SECSID_NULL; + return -EINVAL; + } + } + } + } + +out: + *sid = sid_session; + return 0; +} + +/* + * LSM hook implementation that checks and/or returns the xfrm sid for the + * incoming packet. + */ +int selinux_xfrm_decode_session(struct sk_buff *skb, u32 *sid, int ckall) +{ + if (skb == NULL) { + *sid = SECSID_NULL; + return 0; + } + return selinux_xfrm_skb_sid_ingress(skb, sid, ckall); +} + +int selinux_xfrm_skb_sid(struct sk_buff *skb, u32 *sid) +{ + int rc; + + rc = selinux_xfrm_skb_sid_ingress(skb, sid, 0); + if (rc == 0 && *sid == SECSID_NULL) + *sid = selinux_xfrm_skb_sid_egress(skb); + + return rc; +} + +/* + * LSM hook implementation that allocs and transfers uctx spec to xfrm_policy. + */ +int selinux_xfrm_policy_alloc(struct xfrm_sec_ctx **ctxp, + struct xfrm_user_sec_ctx *uctx, + gfp_t gfp) +{ + return selinux_xfrm_alloc_user(ctxp, uctx, gfp); +} + +/* + * LSM hook implementation that copies security data structure from old to new + * for policy cloning. + */ +int selinux_xfrm_policy_clone(struct xfrm_sec_ctx *old_ctx, + struct xfrm_sec_ctx **new_ctxp) +{ + struct xfrm_sec_ctx *new_ctx; + + if (!old_ctx) + return 0; + + new_ctx = kmemdup(old_ctx, sizeof(*old_ctx) + old_ctx->ctx_len, + GFP_ATOMIC); + if (!new_ctx) + return -ENOMEM; + atomic_inc(&selinux_xfrm_refcount); + *new_ctxp = new_ctx; + + return 0; +} + +/* + * LSM hook implementation that frees xfrm_sec_ctx security information. + */ +void selinux_xfrm_policy_free(struct xfrm_sec_ctx *ctx) +{ + selinux_xfrm_free(ctx); +} + +/* + * LSM hook implementation that authorizes deletion of labeled policies. + */ +int selinux_xfrm_policy_delete(struct xfrm_sec_ctx *ctx) +{ + return selinux_xfrm_delete(ctx); +} + +/* + * LSM hook implementation that allocates a xfrm_sec_state, populates it using + * the supplied security context, and assigns it to the xfrm_state. + */ +int selinux_xfrm_state_alloc(struct xfrm_state *x, + struct xfrm_user_sec_ctx *uctx) +{ + return selinux_xfrm_alloc_user(&x->security, uctx, GFP_KERNEL); +} + +/* + * LSM hook implementation that allocates a xfrm_sec_state and populates based + * on a secid. + */ +int selinux_xfrm_state_alloc_acquire(struct xfrm_state *x, + struct xfrm_sec_ctx *polsec, u32 secid) +{ + int rc; + struct xfrm_sec_ctx *ctx; + char *ctx_str = NULL; + u32 str_len; + + if (!polsec) + return 0; + + if (secid == 0) + return -EINVAL; + + rc = security_sid_to_context(&selinux_state, secid, &ctx_str, + &str_len); + if (rc) + return rc; + + ctx = kmalloc(struct_size(ctx, ctx_str, str_len), GFP_ATOMIC); + if (!ctx) { + rc = -ENOMEM; + goto out; + } + + ctx->ctx_doi = XFRM_SC_DOI_LSM; + ctx->ctx_alg = XFRM_SC_ALG_SELINUX; + ctx->ctx_sid = secid; + ctx->ctx_len = str_len; + memcpy(ctx->ctx_str, ctx_str, str_len); + + x->security = ctx; + atomic_inc(&selinux_xfrm_refcount); +out: + kfree(ctx_str); + return rc; +} + +/* + * LSM hook implementation that frees xfrm_state security information. + */ +void selinux_xfrm_state_free(struct xfrm_state *x) +{ + selinux_xfrm_free(x->security); +} + +/* + * LSM hook implementation that authorizes deletion of labeled SAs. + */ +int selinux_xfrm_state_delete(struct xfrm_state *x) +{ + return selinux_xfrm_delete(x->security); +} + +/* + * LSM hook that controls access to unlabelled packets. If + * a xfrm_state is authorizable (defined by macro) then it was + * already authorized by the IPSec process. If not, then + * we need to check for unlabelled access since this may not have + * gone thru the IPSec process. + */ +int selinux_xfrm_sock_rcv_skb(u32 sk_sid, struct sk_buff *skb, + struct common_audit_data *ad) +{ + int i; + struct sec_path *sp = skb_sec_path(skb); + u32 peer_sid = SECINITSID_UNLABELED; + + if (sp) { + for (i = 0; i < sp->len; i++) { + struct xfrm_state *x = sp->xvec[i]; + + if (x && selinux_authorizable_xfrm(x)) { + struct xfrm_sec_ctx *ctx = x->security; + peer_sid = ctx->ctx_sid; + break; + } + } + } + + /* This check even when there's no association involved is intended, + * according to Trent Jaeger, to make sure a process can't engage in + * non-IPsec communication unless explicitly allowed by policy. */ + return avc_has_perm(&selinux_state, + sk_sid, peer_sid, + SECCLASS_ASSOCIATION, ASSOCIATION__RECVFROM, ad); +} + +/* + * POSTROUTE_LAST hook's XFRM processing: + * If we have no security association, then we need to determine + * whether the socket is allowed to send to an unlabelled destination. + * If we do have a authorizable security association, then it has already been + * checked in the selinux_xfrm_state_pol_flow_match hook above. + */ +int selinux_xfrm_postroute_last(u32 sk_sid, struct sk_buff *skb, + struct common_audit_data *ad, u8 proto) +{ + struct dst_entry *dst; + + switch (proto) { + case IPPROTO_AH: + case IPPROTO_ESP: + case IPPROTO_COMP: + /* We should have already seen this packet once before it + * underwent xfrm(s). No need to subject it to the unlabeled + * check. */ + return 0; + default: + break; + } + + dst = skb_dst(skb); + if (dst) { + struct dst_entry *iter; + + for (iter = dst; iter != NULL; iter = xfrm_dst_child(iter)) { + struct xfrm_state *x = iter->xfrm; + + if (x && selinux_authorizable_xfrm(x)) + return 0; + } + } + + /* This check even when there's no association involved is intended, + * according to Trent Jaeger, to make sure a process can't engage in + * non-IPsec communication unless explicitly allowed by policy. */ + return avc_has_perm(&selinux_state, sk_sid, SECINITSID_UNLABELED, + SECCLASS_ASSOCIATION, ASSOCIATION__SENDTO, ad); +} diff --git a/security/smack/Kconfig b/security/smack/Kconfig new file mode 100644 index 000000000..5a8dfad46 --- /dev/null +++ b/security/smack/Kconfig @@ -0,0 +1,55 @@ +# SPDX-License-Identifier: GPL-2.0-only +config SECURITY_SMACK + bool "Simplified Mandatory Access Control Kernel Support" + depends on NET + depends on INET + depends on SECURITY + select NETLABEL + select SECURITY_NETWORK + default n + help + This selects the Simplified Mandatory Access Control Kernel. + Smack is useful for sensitivity, integrity, and a variety + of other mandatory security schemes. + If you are unsure how to answer this question, answer N. + +config SECURITY_SMACK_BRINGUP + bool "Reporting on access granted by Smack rules" + depends on SECURITY_SMACK + default n + help + Enable the bring-up ("b") access mode in Smack rules. + When access is granted by a rule with the "b" mode a + message about the access requested is generated. The + intention is that a process can be granted a wide set + of access initially with the bringup mode set on the + rules. The developer can use the information to + identify which rules are necessary and what accesses + may be inappropriate. The developer can reduce the + access rule set once the behavior is well understood. + This is a superior mechanism to the oft abused + "permissive" mode of other systems. + If you are unsure how to answer this question, answer N. + +config SECURITY_SMACK_NETFILTER + bool "Packet marking using secmarks for netfilter" + depends on SECURITY_SMACK + depends on NETWORK_SECMARK + depends on NETFILTER + default n + help + This enables security marking of network packets using + Smack labels. + If you are unsure how to answer this question, answer N. + +config SECURITY_SMACK_APPEND_SIGNALS + bool "Treat delivering signals as an append operation" + depends on SECURITY_SMACK + default n + help + Sending a signal has been treated as a write operation to the + receiving process. If this option is selected, the delivery + will be an append operation instead. This makes it possible + to differentiate between delivering a network packet and + delivering a signal in the Smack rules. + If you are unsure how to answer this question, answer N. diff --git a/security/smack/Makefile b/security/smack/Makefile new file mode 100644 index 000000000..6dbf6e22a --- /dev/null +++ b/security/smack/Makefile @@ -0,0 +1,9 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +# Makefile for the SMACK LSM +# + +obj-$(CONFIG_SECURITY_SMACK) := smack.o + +smack-y := smack_lsm.o smack_access.o smackfs.o +smack-$(CONFIG_SECURITY_SMACK_NETFILTER) += smack_netfilter.o diff --git a/security/smack/smack.h b/security/smack/smack.h new file mode 100644 index 000000000..aa15ff56e --- /dev/null +++ b/security/smack/smack.h @@ -0,0 +1,505 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com> + * + * Author: + * Casey Schaufler <casey@schaufler-ca.com> + */ + +#ifndef _SECURITY_SMACK_H +#define _SECURITY_SMACK_H + +#include <linux/capability.h> +#include <linux/spinlock.h> +#include <linux/lsm_hooks.h> +#include <linux/in.h> +#if IS_ENABLED(CONFIG_IPV6) +#include <linux/in6.h> +#endif /* CONFIG_IPV6 */ +#include <net/netlabel.h> +#include <linux/list.h> +#include <linux/rculist.h> +#include <linux/lsm_audit.h> +#include <linux/msg.h> + +/* + * Use IPv6 port labeling if IPv6 is enabled and secmarks + * are not being used. + */ +#if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER) +#define SMACK_IPV6_PORT_LABELING 1 +#endif + +#if IS_ENABLED(CONFIG_IPV6) && defined(CONFIG_SECURITY_SMACK_NETFILTER) +#define SMACK_IPV6_SECMARK_LABELING 1 +#endif + +/* + * Smack labels were limited to 23 characters for a long time. + */ +#define SMK_LABELLEN 24 +#define SMK_LONGLABEL 256 + +/* + * This is the repository for labels seen so that it is + * not necessary to keep allocating tiny chuncks of memory + * and so that they can be shared. + * + * Labels are never modified in place. Anytime a label + * is imported (e.g. xattrset on a file) the list is checked + * for it and it is added if it doesn't exist. The address + * is passed out in either case. Entries are added, but + * never deleted. + * + * Since labels are hanging around anyway it doesn't + * hurt to maintain a secid for those awkward situations + * where kernel components that ought to use LSM independent + * interfaces don't. The secid should go away when all of + * these components have been repaired. + * + * The cipso value associated with the label gets stored here, too. + * + * Keep the access rules for this subject label here so that + * the entire set of rules does not need to be examined every + * time. + */ +struct smack_known { + struct list_head list; + struct hlist_node smk_hashed; + char *smk_known; + u32 smk_secid; + struct netlbl_lsm_secattr smk_netlabel; /* on wire labels */ + struct list_head smk_rules; /* access rules */ + struct mutex smk_rules_lock; /* lock for rules */ +}; + +/* + * Maximum number of bytes for the levels in a CIPSO IP option. + * Why 23? CIPSO is constrained to 30, so a 32 byte buffer is + * bigger than can be used, and 24 is the next lower multiple + * of 8, and there are too many issues if there isn't space set + * aside for the terminating null byte. + */ +#define SMK_CIPSOLEN 24 + +struct superblock_smack { + struct smack_known *smk_root; + struct smack_known *smk_floor; + struct smack_known *smk_hat; + struct smack_known *smk_default; + int smk_flags; +}; + +/* + * Superblock flags + */ +#define SMK_SB_INITIALIZED 0x01 +#define SMK_SB_UNTRUSTED 0x02 + +struct socket_smack { + struct smack_known *smk_out; /* outbound label */ + struct smack_known *smk_in; /* inbound label */ + struct smack_known *smk_packet; /* TCP peer label */ + int smk_state; /* netlabel socket states */ +}; +#define SMK_NETLBL_UNSET 0 +#define SMK_NETLBL_UNLABELED 1 +#define SMK_NETLBL_LABELED 2 +#define SMK_NETLBL_REQSKB 3 + +/* + * Inode smack data + */ +struct inode_smack { + struct smack_known *smk_inode; /* label of the fso */ + struct smack_known *smk_task; /* label of the task */ + struct smack_known *smk_mmap; /* label of the mmap domain */ + int smk_flags; /* smack inode flags */ +}; + +struct task_smack { + struct smack_known *smk_task; /* label for access control */ + struct smack_known *smk_forked; /* label when forked */ + struct smack_known *smk_transmuted;/* label when transmuted */ + struct list_head smk_rules; /* per task access rules */ + struct mutex smk_rules_lock; /* lock for the rules */ + struct list_head smk_relabel; /* transit allowed labels */ +}; + +#define SMK_INODE_INSTANT 0x01 /* inode is instantiated */ +#define SMK_INODE_TRANSMUTE 0x02 /* directory is transmuting */ +#define SMK_INODE_CHANGED 0x04 /* smack was transmuted */ +#define SMK_INODE_IMPURE 0x08 /* involved in an impure transaction */ + +/* + * A label access rule. + */ +struct smack_rule { + struct list_head list; + struct smack_known *smk_subject; + struct smack_known *smk_object; + int smk_access; +}; + +/* + * An entry in the table identifying IPv4 hosts. + */ +struct smk_net4addr { + struct list_head list; + struct in_addr smk_host; /* network address */ + struct in_addr smk_mask; /* network mask */ + int smk_masks; /* mask size */ + struct smack_known *smk_label; /* label */ +}; + +/* + * An entry in the table identifying IPv6 hosts. + */ +struct smk_net6addr { + struct list_head list; + struct in6_addr smk_host; /* network address */ + struct in6_addr smk_mask; /* network mask */ + int smk_masks; /* mask size */ + struct smack_known *smk_label; /* label */ +}; + +/* + * An entry in the table identifying ports. + */ +struct smk_port_label { + struct list_head list; + struct sock *smk_sock; /* socket initialized on */ + unsigned short smk_port; /* the port number */ + struct smack_known *smk_in; /* inbound label */ + struct smack_known *smk_out; /* outgoing label */ + short smk_sock_type; /* Socket type */ + short smk_can_reuse; +}; + +struct smack_known_list_elem { + struct list_head list; + struct smack_known *smk_label; +}; + +enum { + Opt_error = -1, + Opt_fsdefault = 0, + Opt_fsfloor = 1, + Opt_fshat = 2, + Opt_fsroot = 3, + Opt_fstransmute = 4, +}; + +#define SMACK_DELETE_OPTION "-DELETE" +#define SMACK_CIPSO_OPTION "-CIPSO" + +/* + * CIPSO defaults. + */ +#define SMACK_CIPSO_DOI_DEFAULT 3 /* Historical */ +#define SMACK_CIPSO_DOI_INVALID -1 /* Not a DOI */ +#define SMACK_CIPSO_DIRECT_DEFAULT 250 /* Arbitrary */ +#define SMACK_CIPSO_MAPPED_DEFAULT 251 /* Also arbitrary */ +#define SMACK_CIPSO_MAXLEVEL 255 /* CIPSO 2.2 standard */ +/* + * CIPSO 2.2 standard is 239, but Smack wants to use the + * categories in a structured way that limits the value to + * the bits in 23 bytes, hence the unusual number. + */ +#define SMACK_CIPSO_MAXCATNUM 184 /* 23 * 8 */ + +/* + * Ptrace rules + */ +#define SMACK_PTRACE_DEFAULT 0 +#define SMACK_PTRACE_EXACT 1 +#define SMACK_PTRACE_DRACONIAN 2 +#define SMACK_PTRACE_MAX SMACK_PTRACE_DRACONIAN + +/* + * Flags for untraditional access modes. + * It shouldn't be necessary to avoid conflicts with definitions + * in fs.h, but do so anyway. + */ +#define MAY_TRANSMUTE 0x00001000 /* Controls directory labeling */ +#define MAY_LOCK 0x00002000 /* Locks should be writes, but ... */ +#define MAY_BRINGUP 0x00004000 /* Report use of this rule */ + +/* + * The policy for delivering signals is configurable. + * It is usually "write", but can be "append". + */ +#ifdef CONFIG_SECURITY_SMACK_APPEND_SIGNALS +#define MAY_DELIVER MAY_APPEND /* Signal delivery requires append */ +#else +#define MAY_DELIVER MAY_WRITE /* Signal delivery requires write */ +#endif + +#define SMACK_BRINGUP_ALLOW 1 /* Allow bringup mode */ +#define SMACK_UNCONFINED_SUBJECT 2 /* Allow unconfined label */ +#define SMACK_UNCONFINED_OBJECT 3 /* Allow unconfined label */ + +/* + * Just to make the common cases easier to deal with + */ +#define MAY_ANYREAD (MAY_READ | MAY_EXEC) +#define MAY_READWRITE (MAY_READ | MAY_WRITE) +#define MAY_NOT 0 + +/* + * Number of access types used by Smack (rwxatlb) + */ +#define SMK_NUM_ACCESS_TYPE 7 + +/* SMACK data */ +struct smack_audit_data { + const char *function; + char *subject; + char *object; + char *request; + int result; +}; + +/* + * Smack audit data; is empty if CONFIG_AUDIT not set + * to save some stack + */ +struct smk_audit_info { +#ifdef CONFIG_AUDIT + struct common_audit_data a; + struct smack_audit_data sad; +#endif +}; + +/* + * These functions are in smack_access.c + */ +int smk_access_entry(char *, char *, struct list_head *); +int smk_access(struct smack_known *, struct smack_known *, + int, struct smk_audit_info *); +int smk_tskacc(struct task_smack *, struct smack_known *, + u32, struct smk_audit_info *); +int smk_curacc(struct smack_known *, u32, struct smk_audit_info *); +struct smack_known *smack_from_secid(const u32); +char *smk_parse_smack(const char *string, int len); +int smk_netlbl_mls(int, char *, struct netlbl_lsm_secattr *, int); +struct smack_known *smk_import_entry(const char *, int); +void smk_insert_entry(struct smack_known *skp); +struct smack_known *smk_find_entry(const char *); +bool smack_privileged(int cap); +bool smack_privileged_cred(int cap, const struct cred *cred); +void smk_destroy_label_list(struct list_head *list); +int smack_populate_secattr(struct smack_known *skp); + +/* + * Shared data. + */ +extern int smack_enabled __initdata; +extern int smack_cipso_direct; +extern int smack_cipso_mapped; +extern struct smack_known *smack_net_ambient; +extern struct smack_known *smack_syslog_label; +#ifdef CONFIG_SECURITY_SMACK_BRINGUP +extern struct smack_known *smack_unconfined; +#endif +extern int smack_ptrace_rule; +extern struct lsm_blob_sizes smack_blob_sizes; + +extern struct smack_known smack_known_floor; +extern struct smack_known smack_known_hat; +extern struct smack_known smack_known_huh; +extern struct smack_known smack_known_star; +extern struct smack_known smack_known_web; + +extern struct mutex smack_known_lock; +extern struct list_head smack_known_list; +extern struct list_head smk_net4addr_list; +extern struct list_head smk_net6addr_list; + +extern struct mutex smack_onlycap_lock; +extern struct list_head smack_onlycap_list; + +#define SMACK_HASH_SLOTS 16 +extern struct hlist_head smack_known_hash[SMACK_HASH_SLOTS]; +extern struct kmem_cache *smack_rule_cache; + +static inline struct task_smack *smack_cred(const struct cred *cred) +{ + return cred->security + smack_blob_sizes.lbs_cred; +} + +static inline struct smack_known **smack_file(const struct file *file) +{ + return (struct smack_known **)(file->f_security + + smack_blob_sizes.lbs_file); +} + +static inline struct inode_smack *smack_inode(const struct inode *inode) +{ + return inode->i_security + smack_blob_sizes.lbs_inode; +} + +static inline struct smack_known **smack_msg_msg(const struct msg_msg *msg) +{ + return msg->security + smack_blob_sizes.lbs_msg_msg; +} + +static inline struct smack_known **smack_ipc(const struct kern_ipc_perm *ipc) +{ + return ipc->security + smack_blob_sizes.lbs_ipc; +} + +static inline struct superblock_smack *smack_superblock( + const struct super_block *superblock) +{ + return superblock->s_security + smack_blob_sizes.lbs_superblock; +} + +/* + * Is the directory transmuting? + */ +static inline int smk_inode_transmutable(const struct inode *isp) +{ + struct inode_smack *sip = smack_inode(isp); + return (sip->smk_flags & SMK_INODE_TRANSMUTE) != 0; +} + +/* + * Present a pointer to the smack label entry in an inode blob. + */ +static inline struct smack_known *smk_of_inode(const struct inode *isp) +{ + struct inode_smack *sip = smack_inode(isp); + return sip->smk_inode; +} + +/* + * Present a pointer to the smack label entry in an task blob. + */ +static inline struct smack_known *smk_of_task(const struct task_smack *tsp) +{ + return tsp->smk_task; +} + +static inline struct smack_known *smk_of_task_struct_obj( + const struct task_struct *t) +{ + struct smack_known *skp; + const struct cred *cred; + + rcu_read_lock(); + + cred = __task_cred(t); + skp = smk_of_task(smack_cred(cred)); + + rcu_read_unlock(); + + return skp; +} + +/* + * Present a pointer to the forked smack label entry in an task blob. + */ +static inline struct smack_known *smk_of_forked(const struct task_smack *tsp) +{ + return tsp->smk_forked; +} + +/* + * Present a pointer to the smack label in the current task blob. + */ +static inline struct smack_known *smk_of_current(void) +{ + return smk_of_task(smack_cred(current_cred())); +} + +/* + * logging functions + */ +#define SMACK_AUDIT_DENIED 0x1 +#define SMACK_AUDIT_ACCEPT 0x2 +extern int log_policy; + +void smack_log(char *subject_label, char *object_label, + int request, + int result, struct smk_audit_info *auditdata); + +#ifdef CONFIG_AUDIT + +/* + * some inline functions to set up audit data + * they do nothing if CONFIG_AUDIT is not set + * + */ +static inline void smk_ad_init(struct smk_audit_info *a, const char *func, + char type) +{ + memset(&a->sad, 0, sizeof(a->sad)); + a->a.type = type; + a->a.smack_audit_data = &a->sad; + a->a.smack_audit_data->function = func; +} + +static inline void smk_ad_init_net(struct smk_audit_info *a, const char *func, + char type, struct lsm_network_audit *net) +{ + smk_ad_init(a, func, type); + memset(net, 0, sizeof(*net)); + a->a.u.net = net; +} + +static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, + struct task_struct *t) +{ + a->a.u.tsk = t; +} +static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, + struct dentry *d) +{ + a->a.u.dentry = d; +} +static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, + struct inode *i) +{ + a->a.u.inode = i; +} +static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, + struct path p) +{ + a->a.u.path = p; +} +static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, + struct sock *sk) +{ + a->a.u.net->sk = sk; +} + +#else /* no AUDIT */ + +static inline void smk_ad_init(struct smk_audit_info *a, const char *func, + char type) +{ +} +static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, + struct task_struct *t) +{ +} +static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, + struct dentry *d) +{ +} +static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, + struct inode *i) +{ +} +static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, + struct path p) +{ +} +static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, + struct sock *sk) +{ +} +#endif + +#endif /* _SECURITY_SMACK_H */ diff --git a/security/smack/smack_access.c b/security/smack/smack_access.c new file mode 100644 index 000000000..585e5e357 --- /dev/null +++ b/security/smack/smack_access.c @@ -0,0 +1,696 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com> + * + * Author: + * Casey Schaufler <casey@schaufler-ca.com> + */ + +#include <linux/types.h> +#include <linux/slab.h> +#include <linux/fs.h> +#include <linux/sched.h> +#include "smack.h" + +struct smack_known smack_known_huh = { + .smk_known = "?", + .smk_secid = 2, +}; + +struct smack_known smack_known_hat = { + .smk_known = "^", + .smk_secid = 3, +}; + +struct smack_known smack_known_star = { + .smk_known = "*", + .smk_secid = 4, +}; + +struct smack_known smack_known_floor = { + .smk_known = "_", + .smk_secid = 5, +}; + +struct smack_known smack_known_web = { + .smk_known = "@", + .smk_secid = 7, +}; + +LIST_HEAD(smack_known_list); + +/* + * The initial value needs to be bigger than any of the + * known values above. + */ +static u32 smack_next_secid = 10; + +/* + * what events do we log + * can be overwritten at run-time by /smack/logging + */ +int log_policy = SMACK_AUDIT_DENIED; + +/** + * smk_access_entry - look up matching access rule + * @subject_label: a pointer to the subject's Smack label + * @object_label: a pointer to the object's Smack label + * @rule_list: the list of rules to search + * + * This function looks up the subject/object pair in the + * access rule list and returns the access mode. If no + * entry is found returns -ENOENT. + * + * NOTE: + * + * Earlier versions of this function allowed for labels that + * were not on the label list. This was done to allow for + * labels to come over the network that had never been seen + * before on this host. Unless the receiving socket has the + * star label this will always result in a failure check. The + * star labeled socket case is now handled in the networking + * hooks so there is no case where the label is not on the + * label list. Checking to see if the address of two labels + * is the same is now a reliable test. + * + * Do the object check first because that is more + * likely to differ. + * + * Allowing write access implies allowing locking. + */ +int smk_access_entry(char *subject_label, char *object_label, + struct list_head *rule_list) +{ + struct smack_rule *srp; + + list_for_each_entry_rcu(srp, rule_list, list) { + if (srp->smk_object->smk_known == object_label && + srp->smk_subject->smk_known == subject_label) { + int may = srp->smk_access; + /* + * MAY_WRITE implies MAY_LOCK. + */ + if ((may & MAY_WRITE) == MAY_WRITE) + may |= MAY_LOCK; + return may; + } + } + + return -ENOENT; +} + +/** + * smk_access - determine if a subject has a specific access to an object + * @subject: a pointer to the subject's Smack label entry + * @object: a pointer to the object's Smack label entry + * @request: the access requested, in "MAY" format + * @a : a pointer to the audit data + * + * This function looks up the subject/object pair in the + * access rule list and returns 0 if the access is permitted, + * non zero otherwise. + * + * Smack labels are shared on smack_list + */ +int smk_access(struct smack_known *subject, struct smack_known *object, + int request, struct smk_audit_info *a) +{ + int may = MAY_NOT; + int rc = 0; + + /* + * Hardcoded comparisons. + */ + /* + * A star subject can't access any object. + */ + if (subject == &smack_known_star) { + rc = -EACCES; + goto out_audit; + } + /* + * An internet object can be accessed by any subject. + * Tasks cannot be assigned the internet label. + * An internet subject can access any object. + */ + if (object == &smack_known_web || subject == &smack_known_web) + goto out_audit; + /* + * A star object can be accessed by any subject. + */ + if (object == &smack_known_star) + goto out_audit; + /* + * An object can be accessed in any way by a subject + * with the same label. + */ + if (subject->smk_known == object->smk_known) + goto out_audit; + /* + * A hat subject can read or lock any object. + * A floor object can be read or locked by any subject. + */ + if ((request & MAY_ANYREAD) == request || + (request & MAY_LOCK) == request) { + if (object == &smack_known_floor) + goto out_audit; + if (subject == &smack_known_hat) + goto out_audit; + } + /* + * Beyond here an explicit relationship is required. + * If the requested access is contained in the available + * access (e.g. read is included in readwrite) it's + * good. A negative response from smk_access_entry() + * indicates there is no entry for this pair. + */ + rcu_read_lock(); + may = smk_access_entry(subject->smk_known, object->smk_known, + &subject->smk_rules); + rcu_read_unlock(); + + if (may <= 0 || (request & may) != request) { + rc = -EACCES; + goto out_audit; + } +#ifdef CONFIG_SECURITY_SMACK_BRINGUP + /* + * Return a positive value if using bringup mode. + * This allows the hooks to identify checks that + * succeed because of "b" rules. + */ + if (may & MAY_BRINGUP) + rc = SMACK_BRINGUP_ALLOW; +#endif + +out_audit: + +#ifdef CONFIG_SECURITY_SMACK_BRINGUP + if (rc < 0) { + if (object == smack_unconfined) + rc = SMACK_UNCONFINED_OBJECT; + if (subject == smack_unconfined) + rc = SMACK_UNCONFINED_SUBJECT; + } +#endif + +#ifdef CONFIG_AUDIT + if (a) + smack_log(subject->smk_known, object->smk_known, + request, rc, a); +#endif + + return rc; +} + +/** + * smk_tskacc - determine if a task has a specific access to an object + * @tsp: a pointer to the subject's task + * @obj_known: a pointer to the object's label entry + * @mode: the access requested, in "MAY" format + * @a : common audit data + * + * This function checks the subject task's label/object label pair + * in the access rule list and returns 0 if the access is permitted, + * non zero otherwise. It allows that the task may have the capability + * to override the rules. + */ +int smk_tskacc(struct task_smack *tsp, struct smack_known *obj_known, + u32 mode, struct smk_audit_info *a) +{ + struct smack_known *sbj_known = smk_of_task(tsp); + int may; + int rc; + + /* + * Check the global rule list + */ + rc = smk_access(sbj_known, obj_known, mode, NULL); + if (rc >= 0) { + /* + * If there is an entry in the task's rule list + * it can further restrict access. + */ + may = smk_access_entry(sbj_known->smk_known, + obj_known->smk_known, + &tsp->smk_rules); + if (may < 0) + goto out_audit; + if ((mode & may) == mode) + goto out_audit; + rc = -EACCES; + } + + /* + * Allow for priviliged to override policy. + */ + if (rc != 0 && smack_privileged(CAP_MAC_OVERRIDE)) + rc = 0; + +out_audit: +#ifdef CONFIG_AUDIT + if (a) + smack_log(sbj_known->smk_known, obj_known->smk_known, + mode, rc, a); +#endif + return rc; +} + +/** + * smk_curacc - determine if current has a specific access to an object + * @obj_known: a pointer to the object's Smack label entry + * @mode: the access requested, in "MAY" format + * @a : common audit data + * + * This function checks the current subject label/object label pair + * in the access rule list and returns 0 if the access is permitted, + * non zero otherwise. It allows that current may have the capability + * to override the rules. + */ +int smk_curacc(struct smack_known *obj_known, + u32 mode, struct smk_audit_info *a) +{ + struct task_smack *tsp = smack_cred(current_cred()); + + return smk_tskacc(tsp, obj_known, mode, a); +} + +#ifdef CONFIG_AUDIT +/** + * smack_str_from_perm : helper to transalate an int to a + * readable string + * @string : the string to fill + * @access : the int + * + */ +static inline void smack_str_from_perm(char *string, int access) +{ + int i = 0; + + if (access & MAY_READ) + string[i++] = 'r'; + if (access & MAY_WRITE) + string[i++] = 'w'; + if (access & MAY_EXEC) + string[i++] = 'x'; + if (access & MAY_APPEND) + string[i++] = 'a'; + if (access & MAY_TRANSMUTE) + string[i++] = 't'; + if (access & MAY_LOCK) + string[i++] = 'l'; + string[i] = '\0'; +} +/** + * smack_log_callback - SMACK specific information + * will be called by generic audit code + * @ab : the audit_buffer + * @a : audit_data + * + */ +static void smack_log_callback(struct audit_buffer *ab, void *a) +{ + struct common_audit_data *ad = a; + struct smack_audit_data *sad = ad->smack_audit_data; + audit_log_format(ab, "lsm=SMACK fn=%s action=%s", + ad->smack_audit_data->function, + sad->result ? "denied" : "granted"); + audit_log_format(ab, " subject="); + audit_log_untrustedstring(ab, sad->subject); + audit_log_format(ab, " object="); + audit_log_untrustedstring(ab, sad->object); + if (sad->request[0] == '\0') + audit_log_format(ab, " labels_differ"); + else + audit_log_format(ab, " requested=%s", sad->request); +} + +/** + * smack_log - Audit the granting or denial of permissions. + * @subject_label : smack label of the requester + * @object_label : smack label of the object being accessed + * @request: requested permissions + * @result: result from smk_access + * @ad: auxiliary audit data + * + * Audit the granting or denial of permissions in accordance + * with the policy. + */ +void smack_log(char *subject_label, char *object_label, int request, + int result, struct smk_audit_info *ad) +{ +#ifdef CONFIG_SECURITY_SMACK_BRINGUP + char request_buffer[SMK_NUM_ACCESS_TYPE + 5]; +#else + char request_buffer[SMK_NUM_ACCESS_TYPE + 1]; +#endif + struct smack_audit_data *sad; + struct common_audit_data *a = &ad->a; + + /* check if we have to log the current event */ + if (result < 0 && (log_policy & SMACK_AUDIT_DENIED) == 0) + return; + if (result == 0 && (log_policy & SMACK_AUDIT_ACCEPT) == 0) + return; + + sad = a->smack_audit_data; + + if (sad->function == NULL) + sad->function = "unknown"; + + /* end preparing the audit data */ + smack_str_from_perm(request_buffer, request); + sad->subject = subject_label; + sad->object = object_label; +#ifdef CONFIG_SECURITY_SMACK_BRINGUP + /* + * The result may be positive in bringup mode. + * A positive result is an allow, but not for normal reasons. + * Mark it as successful, but don't filter it out even if + * the logging policy says to do so. + */ + if (result == SMACK_UNCONFINED_SUBJECT) + strcat(request_buffer, "(US)"); + else if (result == SMACK_UNCONFINED_OBJECT) + strcat(request_buffer, "(UO)"); + + if (result > 0) + result = 0; +#endif + sad->request = request_buffer; + sad->result = result; + + common_lsm_audit(a, smack_log_callback, NULL); +} +#else /* #ifdef CONFIG_AUDIT */ +void smack_log(char *subject_label, char *object_label, int request, + int result, struct smk_audit_info *ad) +{ +} +#endif + +DEFINE_MUTEX(smack_known_lock); + +struct hlist_head smack_known_hash[SMACK_HASH_SLOTS]; + +/** + * smk_insert_entry - insert a smack label into a hash map, + * @skp: smack label + * + * this function must be called under smack_known_lock + */ +void smk_insert_entry(struct smack_known *skp) +{ + unsigned int hash; + struct hlist_head *head; + + hash = full_name_hash(NULL, skp->smk_known, strlen(skp->smk_known)); + head = &smack_known_hash[hash & (SMACK_HASH_SLOTS - 1)]; + + hlist_add_head_rcu(&skp->smk_hashed, head); + list_add_rcu(&skp->list, &smack_known_list); +} + +/** + * smk_find_entry - find a label on the list, return the list entry + * @string: a text string that might be a Smack label + * + * Returns a pointer to the entry in the label list that + * matches the passed string or NULL if not found. + */ +struct smack_known *smk_find_entry(const char *string) +{ + unsigned int hash; + struct hlist_head *head; + struct smack_known *skp; + + hash = full_name_hash(NULL, string, strlen(string)); + head = &smack_known_hash[hash & (SMACK_HASH_SLOTS - 1)]; + + hlist_for_each_entry_rcu(skp, head, smk_hashed) + if (strcmp(skp->smk_known, string) == 0) + return skp; + + return NULL; +} + +/** + * smk_parse_smack - parse smack label from a text string + * @string: a text string that might contain a Smack label + * @len: the maximum size, or zero if it is NULL terminated. + * + * Returns a pointer to the clean label or an error code. + */ +char *smk_parse_smack(const char *string, int len) +{ + char *smack; + int i; + + if (len <= 0) + len = strlen(string) + 1; + + /* + * Reserve a leading '-' as an indicator that + * this isn't a label, but an option to interfaces + * including /smack/cipso and /smack/cipso2 + */ + if (string[0] == '-') + return ERR_PTR(-EINVAL); + + for (i = 0; i < len; i++) + if (string[i] > '~' || string[i] <= ' ' || string[i] == '/' || + string[i] == '"' || string[i] == '\\' || string[i] == '\'') + break; + + if (i == 0 || i >= SMK_LONGLABEL) + return ERR_PTR(-EINVAL); + + smack = kstrndup(string, i, GFP_NOFS); + if (!smack) + return ERR_PTR(-ENOMEM); + return smack; +} + +/** + * smk_netlbl_mls - convert a catset to netlabel mls categories + * @level: MLS sensitivity level + * @catset: the Smack categories + * @sap: where to put the netlabel categories + * @len: number of bytes for the levels in a CIPSO IP option + * + * Allocates and fills attr.mls + * Returns 0 on success, error code on failure. + */ +int smk_netlbl_mls(int level, char *catset, struct netlbl_lsm_secattr *sap, + int len) +{ + unsigned char *cp; + unsigned char m; + int cat; + int rc; + int byte; + + sap->flags |= NETLBL_SECATTR_MLS_CAT; + sap->attr.mls.lvl = level; + sap->attr.mls.cat = NULL; + + for (cat = 1, cp = catset, byte = 0; byte < len; cp++, byte++) + for (m = 0x80; m != 0; m >>= 1, cat++) { + if ((m & *cp) == 0) + continue; + rc = netlbl_catmap_setbit(&sap->attr.mls.cat, + cat, GFP_NOFS); + if (rc < 0) { + netlbl_catmap_free(sap->attr.mls.cat); + return rc; + } + } + + return 0; +} + +/** + * smack_populate_secattr - fill in the smack_known netlabel information + * @skp: pointer to the structure to fill + * + * Populate the netlabel secattr structure for a Smack label. + * + * Returns 0 unless creating the category mapping fails + */ +int smack_populate_secattr(struct smack_known *skp) +{ + int slen; + + skp->smk_netlabel.attr.secid = skp->smk_secid; + skp->smk_netlabel.domain = skp->smk_known; + skp->smk_netlabel.cache = netlbl_secattr_cache_alloc(GFP_ATOMIC); + if (skp->smk_netlabel.cache != NULL) { + skp->smk_netlabel.flags |= NETLBL_SECATTR_CACHE; + skp->smk_netlabel.cache->free = NULL; + skp->smk_netlabel.cache->data = skp; + } + skp->smk_netlabel.flags |= NETLBL_SECATTR_SECID | + NETLBL_SECATTR_MLS_LVL | + NETLBL_SECATTR_DOMAIN; + /* + * If direct labeling works use it. + * Otherwise use mapped labeling. + */ + slen = strlen(skp->smk_known); + if (slen < SMK_CIPSOLEN) + return smk_netlbl_mls(smack_cipso_direct, skp->smk_known, + &skp->smk_netlabel, slen); + + return smk_netlbl_mls(smack_cipso_mapped, (char *)&skp->smk_secid, + &skp->smk_netlabel, sizeof(skp->smk_secid)); +} + +/** + * smk_import_entry - import a label, return the list entry + * @string: a text string that might be a Smack label + * @len: the maximum size, or zero if it is NULL terminated. + * + * Returns a pointer to the entry in the label list that + * matches the passed string, adding it if necessary, + * or an error code. + */ +struct smack_known *smk_import_entry(const char *string, int len) +{ + struct smack_known *skp; + char *smack; + int rc; + + smack = smk_parse_smack(string, len); + if (IS_ERR(smack)) + return ERR_CAST(smack); + + mutex_lock(&smack_known_lock); + + skp = smk_find_entry(smack); + if (skp != NULL) + goto freeout; + + skp = kzalloc(sizeof(*skp), GFP_NOFS); + if (skp == NULL) { + skp = ERR_PTR(-ENOMEM); + goto freeout; + } + + skp->smk_known = smack; + skp->smk_secid = smack_next_secid++; + + rc = smack_populate_secattr(skp); + if (rc >= 0) { + INIT_LIST_HEAD(&skp->smk_rules); + mutex_init(&skp->smk_rules_lock); + /* + * Make sure that the entry is actually + * filled before putting it on the list. + */ + smk_insert_entry(skp); + goto unlockout; + } + kfree(skp); + skp = ERR_PTR(rc); +freeout: + kfree(smack); +unlockout: + mutex_unlock(&smack_known_lock); + + return skp; +} + +/** + * smack_from_secid - find the Smack label associated with a secid + * @secid: an integer that might be associated with a Smack label + * + * Returns a pointer to the appropriate Smack label entry if there is one, + * otherwise a pointer to the invalid Smack label. + */ +struct smack_known *smack_from_secid(const u32 secid) +{ + struct smack_known *skp; + + rcu_read_lock(); + list_for_each_entry_rcu(skp, &smack_known_list, list) { + if (skp->smk_secid == secid) { + rcu_read_unlock(); + return skp; + } + } + + /* + * If we got this far someone asked for the translation + * of a secid that is not on the list. + */ + rcu_read_unlock(); + return &smack_known_huh; +} + +/* + * Unless a process is running with one of these labels + * even having CAP_MAC_OVERRIDE isn't enough to grant + * privilege to violate MAC policy. If no labels are + * designated (the empty list case) capabilities apply to + * everyone. + */ +LIST_HEAD(smack_onlycap_list); +DEFINE_MUTEX(smack_onlycap_lock); + +/** + * smack_privileged_cred - are all privilege requirements met by cred + * @cap: The requested capability + * @cred: the credential to use + * + * Is the task privileged and allowed to be privileged + * by the onlycap rule. + * + * Returns true if the task is allowed to be privileged, false if it's not. + */ +bool smack_privileged_cred(int cap, const struct cred *cred) +{ + struct task_smack *tsp = smack_cred(cred); + struct smack_known *skp = tsp->smk_task; + struct smack_known_list_elem *sklep; + int rc; + + rc = cap_capable(cred, &init_user_ns, cap, CAP_OPT_NONE); + if (rc) + return false; + + rcu_read_lock(); + if (list_empty(&smack_onlycap_list)) { + rcu_read_unlock(); + return true; + } + + list_for_each_entry_rcu(sklep, &smack_onlycap_list, list) { + if (sklep->smk_label == skp) { + rcu_read_unlock(); + return true; + } + } + rcu_read_unlock(); + + return false; +} + +/** + * smack_privileged - are all privilege requirements met + * @cap: The requested capability + * + * Is the task privileged and allowed to be privileged + * by the onlycap rule. + * + * Returns true if the task is allowed to be privileged, false if it's not. + */ +bool smack_privileged(int cap) +{ + /* + * All kernel tasks are privileged + */ + if (unlikely(current->flags & PF_KTHREAD)) + return true; + + return smack_privileged_cred(cap, current_cred()); +} diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c new file mode 100644 index 000000000..fbadc61fe --- /dev/null +++ b/security/smack/smack_lsm.c @@ -0,0 +1,5105 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Simplified MAC Kernel (smack) security module + * + * This file contains the smack hook function implementations. + * + * Authors: + * Casey Schaufler <casey@schaufler-ca.com> + * Jarkko Sakkinen <jarkko.sakkinen@intel.com> + * + * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com> + * Copyright (C) 2009 Hewlett-Packard Development Company, L.P. + * Paul Moore <paul@paul-moore.com> + * Copyright (C) 2010 Nokia Corporation + * Copyright (C) 2011 Intel Corporation. + */ + +#include <linux/xattr.h> +#include <linux/pagemap.h> +#include <linux/mount.h> +#include <linux/stat.h> +#include <linux/kd.h> +#include <asm/ioctls.h> +#include <linux/ip.h> +#include <linux/tcp.h> +#include <linux/udp.h> +#include <linux/dccp.h> +#include <linux/icmpv6.h> +#include <linux/slab.h> +#include <linux/mutex.h> +#include <net/cipso_ipv4.h> +#include <net/ip.h> +#include <net/ipv6.h> +#include <linux/audit.h> +#include <linux/magic.h> +#include <linux/dcache.h> +#include <linux/personality.h> +#include <linux/msg.h> +#include <linux/shm.h> +#include <linux/binfmts.h> +#include <linux/parser.h> +#include <linux/fs_context.h> +#include <linux/fs_parser.h> +#include <linux/watch_queue.h> +#include <linux/io_uring.h> +#include "smack.h" + +#define TRANS_TRUE "TRUE" +#define TRANS_TRUE_SIZE 4 + +#define SMK_CONNECTING 0 +#define SMK_RECEIVING 1 +#define SMK_SENDING 2 + +#ifdef SMACK_IPV6_PORT_LABELING +static DEFINE_MUTEX(smack_ipv6_lock); +static LIST_HEAD(smk_ipv6_port_list); +#endif +struct kmem_cache *smack_rule_cache; +int smack_enabled __initdata; + +#define A(s) {"smack"#s, sizeof("smack"#s) - 1, Opt_##s} +static struct { + const char *name; + int len; + int opt; +} smk_mount_opts[] = { + {"smackfsdef", sizeof("smackfsdef") - 1, Opt_fsdefault}, + A(fsdefault), A(fsfloor), A(fshat), A(fsroot), A(fstransmute) +}; +#undef A + +static int match_opt_prefix(char *s, int l, char **arg) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(smk_mount_opts); i++) { + size_t len = smk_mount_opts[i].len; + if (len > l || memcmp(s, smk_mount_opts[i].name, len)) + continue; + if (len == l || s[len] != '=') + continue; + *arg = s + len + 1; + return smk_mount_opts[i].opt; + } + return Opt_error; +} + +#ifdef CONFIG_SECURITY_SMACK_BRINGUP +static char *smk_bu_mess[] = { + "Bringup Error", /* Unused */ + "Bringup", /* SMACK_BRINGUP_ALLOW */ + "Unconfined Subject", /* SMACK_UNCONFINED_SUBJECT */ + "Unconfined Object", /* SMACK_UNCONFINED_OBJECT */ +}; + +static void smk_bu_mode(int mode, char *s) +{ + int i = 0; + + if (mode & MAY_READ) + s[i++] = 'r'; + if (mode & MAY_WRITE) + s[i++] = 'w'; + if (mode & MAY_EXEC) + s[i++] = 'x'; + if (mode & MAY_APPEND) + s[i++] = 'a'; + if (mode & MAY_TRANSMUTE) + s[i++] = 't'; + if (mode & MAY_LOCK) + s[i++] = 'l'; + if (i == 0) + s[i++] = '-'; + s[i] = '\0'; +} +#endif + +#ifdef CONFIG_SECURITY_SMACK_BRINGUP +static int smk_bu_note(char *note, struct smack_known *sskp, + struct smack_known *oskp, int mode, int rc) +{ + char acc[SMK_NUM_ACCESS_TYPE + 1]; + + if (rc <= 0) + return rc; + if (rc > SMACK_UNCONFINED_OBJECT) + rc = 0; + + smk_bu_mode(mode, acc); + pr_info("Smack %s: (%s %s %s) %s\n", smk_bu_mess[rc], + sskp->smk_known, oskp->smk_known, acc, note); + return 0; +} +#else +#define smk_bu_note(note, sskp, oskp, mode, RC) (RC) +#endif + +#ifdef CONFIG_SECURITY_SMACK_BRINGUP +static int smk_bu_current(char *note, struct smack_known *oskp, + int mode, int rc) +{ + struct task_smack *tsp = smack_cred(current_cred()); + char acc[SMK_NUM_ACCESS_TYPE + 1]; + + if (rc <= 0) + return rc; + if (rc > SMACK_UNCONFINED_OBJECT) + rc = 0; + + smk_bu_mode(mode, acc); + pr_info("Smack %s: (%s %s %s) %s %s\n", smk_bu_mess[rc], + tsp->smk_task->smk_known, oskp->smk_known, + acc, current->comm, note); + return 0; +} +#else +#define smk_bu_current(note, oskp, mode, RC) (RC) +#endif + +#ifdef CONFIG_SECURITY_SMACK_BRINGUP +static int smk_bu_task(struct task_struct *otp, int mode, int rc) +{ + struct task_smack *tsp = smack_cred(current_cred()); + struct smack_known *smk_task = smk_of_task_struct_obj(otp); + char acc[SMK_NUM_ACCESS_TYPE + 1]; + + if (rc <= 0) + return rc; + if (rc > SMACK_UNCONFINED_OBJECT) + rc = 0; + + smk_bu_mode(mode, acc); + pr_info("Smack %s: (%s %s %s) %s to %s\n", smk_bu_mess[rc], + tsp->smk_task->smk_known, smk_task->smk_known, acc, + current->comm, otp->comm); + return 0; +} +#else +#define smk_bu_task(otp, mode, RC) (RC) +#endif + +#ifdef CONFIG_SECURITY_SMACK_BRINGUP +static int smk_bu_inode(struct inode *inode, int mode, int rc) +{ + struct task_smack *tsp = smack_cred(current_cred()); + struct inode_smack *isp = smack_inode(inode); + char acc[SMK_NUM_ACCESS_TYPE + 1]; + + if (isp->smk_flags & SMK_INODE_IMPURE) + pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n", + inode->i_sb->s_id, inode->i_ino, current->comm); + + if (rc <= 0) + return rc; + if (rc > SMACK_UNCONFINED_OBJECT) + rc = 0; + if (rc == SMACK_UNCONFINED_SUBJECT && + (mode & (MAY_WRITE | MAY_APPEND))) + isp->smk_flags |= SMK_INODE_IMPURE; + + smk_bu_mode(mode, acc); + + pr_info("Smack %s: (%s %s %s) inode=(%s %ld) %s\n", smk_bu_mess[rc], + tsp->smk_task->smk_known, isp->smk_inode->smk_known, acc, + inode->i_sb->s_id, inode->i_ino, current->comm); + return 0; +} +#else +#define smk_bu_inode(inode, mode, RC) (RC) +#endif + +#ifdef CONFIG_SECURITY_SMACK_BRINGUP +static int smk_bu_file(struct file *file, int mode, int rc) +{ + struct task_smack *tsp = smack_cred(current_cred()); + struct smack_known *sskp = tsp->smk_task; + struct inode *inode = file_inode(file); + struct inode_smack *isp = smack_inode(inode); + char acc[SMK_NUM_ACCESS_TYPE + 1]; + + if (isp->smk_flags & SMK_INODE_IMPURE) + pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n", + inode->i_sb->s_id, inode->i_ino, current->comm); + + if (rc <= 0) + return rc; + if (rc > SMACK_UNCONFINED_OBJECT) + rc = 0; + + smk_bu_mode(mode, acc); + pr_info("Smack %s: (%s %s %s) file=(%s %ld %pD) %s\n", smk_bu_mess[rc], + sskp->smk_known, smk_of_inode(inode)->smk_known, acc, + inode->i_sb->s_id, inode->i_ino, file, + current->comm); + return 0; +} +#else +#define smk_bu_file(file, mode, RC) (RC) +#endif + +#ifdef CONFIG_SECURITY_SMACK_BRINGUP +static int smk_bu_credfile(const struct cred *cred, struct file *file, + int mode, int rc) +{ + struct task_smack *tsp = smack_cred(cred); + struct smack_known *sskp = tsp->smk_task; + struct inode *inode = file_inode(file); + struct inode_smack *isp = smack_inode(inode); + char acc[SMK_NUM_ACCESS_TYPE + 1]; + + if (isp->smk_flags & SMK_INODE_IMPURE) + pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n", + inode->i_sb->s_id, inode->i_ino, current->comm); + + if (rc <= 0) + return rc; + if (rc > SMACK_UNCONFINED_OBJECT) + rc = 0; + + smk_bu_mode(mode, acc); + pr_info("Smack %s: (%s %s %s) file=(%s %ld %pD) %s\n", smk_bu_mess[rc], + sskp->smk_known, smk_of_inode(inode)->smk_known, acc, + inode->i_sb->s_id, inode->i_ino, file, + current->comm); + return 0; +} +#else +#define smk_bu_credfile(cred, file, mode, RC) (RC) +#endif + +/** + * smk_fetch - Fetch the smack label from a file. + * @name: type of the label (attribute) + * @ip: a pointer to the inode + * @dp: a pointer to the dentry + * + * Returns a pointer to the master list entry for the Smack label, + * NULL if there was no label to fetch, or an error code. + */ +static struct smack_known *smk_fetch(const char *name, struct inode *ip, + struct dentry *dp) +{ + int rc; + char *buffer; + struct smack_known *skp = NULL; + + if (!(ip->i_opflags & IOP_XATTR)) + return ERR_PTR(-EOPNOTSUPP); + + buffer = kzalloc(SMK_LONGLABEL, GFP_NOFS); + if (buffer == NULL) + return ERR_PTR(-ENOMEM); + + rc = __vfs_getxattr(dp, ip, name, buffer, SMK_LONGLABEL); + if (rc < 0) + skp = ERR_PTR(rc); + else if (rc == 0) + skp = NULL; + else + skp = smk_import_entry(buffer, rc); + + kfree(buffer); + + return skp; +} + +/** + * init_inode_smack - initialize an inode security blob + * @inode: inode to extract the info from + * @skp: a pointer to the Smack label entry to use in the blob + * + */ +static void init_inode_smack(struct inode *inode, struct smack_known *skp) +{ + struct inode_smack *isp = smack_inode(inode); + + isp->smk_inode = skp; + isp->smk_flags = 0; +} + +/** + * init_task_smack - initialize a task security blob + * @tsp: blob to initialize + * @task: a pointer to the Smack label for the running task + * @forked: a pointer to the Smack label for the forked task + * + */ +static void init_task_smack(struct task_smack *tsp, struct smack_known *task, + struct smack_known *forked) +{ + tsp->smk_task = task; + tsp->smk_forked = forked; + INIT_LIST_HEAD(&tsp->smk_rules); + INIT_LIST_HEAD(&tsp->smk_relabel); + mutex_init(&tsp->smk_rules_lock); +} + +/** + * smk_copy_rules - copy a rule set + * @nhead: new rules header pointer + * @ohead: old rules header pointer + * @gfp: type of the memory for the allocation + * + * Returns 0 on success, -ENOMEM on error + */ +static int smk_copy_rules(struct list_head *nhead, struct list_head *ohead, + gfp_t gfp) +{ + struct smack_rule *nrp; + struct smack_rule *orp; + int rc = 0; + + list_for_each_entry_rcu(orp, ohead, list) { + nrp = kmem_cache_zalloc(smack_rule_cache, gfp); + if (nrp == NULL) { + rc = -ENOMEM; + break; + } + *nrp = *orp; + list_add_rcu(&nrp->list, nhead); + } + return rc; +} + +/** + * smk_copy_relabel - copy smk_relabel labels list + * @nhead: new rules header pointer + * @ohead: old rules header pointer + * @gfp: type of the memory for the allocation + * + * Returns 0 on success, -ENOMEM on error + */ +static int smk_copy_relabel(struct list_head *nhead, struct list_head *ohead, + gfp_t gfp) +{ + struct smack_known_list_elem *nklep; + struct smack_known_list_elem *oklep; + + list_for_each_entry(oklep, ohead, list) { + nklep = kzalloc(sizeof(struct smack_known_list_elem), gfp); + if (nklep == NULL) { + smk_destroy_label_list(nhead); + return -ENOMEM; + } + nklep->smk_label = oklep->smk_label; + list_add(&nklep->list, nhead); + } + + return 0; +} + +/** + * smk_ptrace_mode - helper function for converting PTRACE_MODE_* into MAY_* + * @mode: input mode in form of PTRACE_MODE_* + * + * Returns a converted MAY_* mode usable by smack rules + */ +static inline unsigned int smk_ptrace_mode(unsigned int mode) +{ + if (mode & PTRACE_MODE_ATTACH) + return MAY_READWRITE; + if (mode & PTRACE_MODE_READ) + return MAY_READ; + + return 0; +} + +/** + * smk_ptrace_rule_check - helper for ptrace access + * @tracer: tracer process + * @tracee_known: label entry of the process that's about to be traced + * @mode: ptrace attachment mode (PTRACE_MODE_*) + * @func: name of the function that called us, used for audit + * + * Returns 0 on access granted, -error on error + */ +static int smk_ptrace_rule_check(struct task_struct *tracer, + struct smack_known *tracee_known, + unsigned int mode, const char *func) +{ + int rc; + struct smk_audit_info ad, *saip = NULL; + struct task_smack *tsp; + struct smack_known *tracer_known; + const struct cred *tracercred; + + if ((mode & PTRACE_MODE_NOAUDIT) == 0) { + smk_ad_init(&ad, func, LSM_AUDIT_DATA_TASK); + smk_ad_setfield_u_tsk(&ad, tracer); + saip = &ad; + } + + rcu_read_lock(); + tracercred = __task_cred(tracer); + tsp = smack_cred(tracercred); + tracer_known = smk_of_task(tsp); + + if ((mode & PTRACE_MODE_ATTACH) && + (smack_ptrace_rule == SMACK_PTRACE_EXACT || + smack_ptrace_rule == SMACK_PTRACE_DRACONIAN)) { + if (tracer_known->smk_known == tracee_known->smk_known) + rc = 0; + else if (smack_ptrace_rule == SMACK_PTRACE_DRACONIAN) + rc = -EACCES; + else if (smack_privileged_cred(CAP_SYS_PTRACE, tracercred)) + rc = 0; + else + rc = -EACCES; + + if (saip) + smack_log(tracer_known->smk_known, + tracee_known->smk_known, + 0, rc, saip); + + rcu_read_unlock(); + return rc; + } + + /* In case of rule==SMACK_PTRACE_DEFAULT or mode==PTRACE_MODE_READ */ + rc = smk_tskacc(tsp, tracee_known, smk_ptrace_mode(mode), saip); + + rcu_read_unlock(); + return rc; +} + +/* + * LSM hooks. + * We he, that is fun! + */ + +/** + * smack_ptrace_access_check - Smack approval on PTRACE_ATTACH + * @ctp: child task pointer + * @mode: ptrace attachment mode (PTRACE_MODE_*) + * + * Returns 0 if access is OK, an error code otherwise + * + * Do the capability checks. + */ +static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode) +{ + struct smack_known *skp; + + skp = smk_of_task_struct_obj(ctp); + + return smk_ptrace_rule_check(current, skp, mode, __func__); +} + +/** + * smack_ptrace_traceme - Smack approval on PTRACE_TRACEME + * @ptp: parent task pointer + * + * Returns 0 if access is OK, an error code otherwise + * + * Do the capability checks, and require PTRACE_MODE_ATTACH. + */ +static int smack_ptrace_traceme(struct task_struct *ptp) +{ + struct smack_known *skp; + + skp = smk_of_task(smack_cred(current_cred())); + + return smk_ptrace_rule_check(ptp, skp, PTRACE_MODE_ATTACH, __func__); +} + +/** + * smack_syslog - Smack approval on syslog + * @typefrom_file: unused + * + * Returns 0 on success, error code otherwise. + */ +static int smack_syslog(int typefrom_file) +{ + int rc = 0; + struct smack_known *skp = smk_of_current(); + + if (smack_privileged(CAP_MAC_OVERRIDE)) + return 0; + + if (smack_syslog_label != NULL && smack_syslog_label != skp) + rc = -EACCES; + + return rc; +} + +/* + * Superblock Hooks. + */ + +/** + * smack_sb_alloc_security - allocate a superblock blob + * @sb: the superblock getting the blob + * + * Returns 0 on success or -ENOMEM on error. + */ +static int smack_sb_alloc_security(struct super_block *sb) +{ + struct superblock_smack *sbsp = smack_superblock(sb); + + sbsp->smk_root = &smack_known_floor; + sbsp->smk_default = &smack_known_floor; + sbsp->smk_floor = &smack_known_floor; + sbsp->smk_hat = &smack_known_hat; + /* + * SMK_SB_INITIALIZED will be zero from kzalloc. + */ + + return 0; +} + +struct smack_mnt_opts { + const char *fsdefault, *fsfloor, *fshat, *fsroot, *fstransmute; +}; + +static void smack_free_mnt_opts(void *mnt_opts) +{ + struct smack_mnt_opts *opts = mnt_opts; + kfree(opts->fsdefault); + kfree(opts->fsfloor); + kfree(opts->fshat); + kfree(opts->fsroot); + kfree(opts->fstransmute); + kfree(opts); +} + +static int smack_add_opt(int token, const char *s, void **mnt_opts) +{ + struct smack_mnt_opts *opts = *mnt_opts; + + if (!opts) { + opts = kzalloc(sizeof(struct smack_mnt_opts), GFP_KERNEL); + if (!opts) + return -ENOMEM; + *mnt_opts = opts; + } + if (!s) + return -ENOMEM; + + switch (token) { + case Opt_fsdefault: + if (opts->fsdefault) + goto out_opt_err; + opts->fsdefault = s; + break; + case Opt_fsfloor: + if (opts->fsfloor) + goto out_opt_err; + opts->fsfloor = s; + break; + case Opt_fshat: + if (opts->fshat) + goto out_opt_err; + opts->fshat = s; + break; + case Opt_fsroot: + if (opts->fsroot) + goto out_opt_err; + opts->fsroot = s; + break; + case Opt_fstransmute: + if (opts->fstransmute) + goto out_opt_err; + opts->fstransmute = s; + break; + } + return 0; + +out_opt_err: + pr_warn("Smack: duplicate mount options\n"); + return -EINVAL; +} + +/** + * smack_fs_context_submount - Initialise security data for a filesystem context + * @fc: The filesystem context. + * @reference: reference superblock + * + * Returns 0 on success or -ENOMEM on error. + */ +static int smack_fs_context_submount(struct fs_context *fc, + struct super_block *reference) +{ + struct superblock_smack *sbsp; + struct smack_mnt_opts *ctx; + struct inode_smack *isp; + + ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); + if (!ctx) + return -ENOMEM; + fc->security = ctx; + + sbsp = smack_superblock(reference); + isp = smack_inode(reference->s_root->d_inode); + + if (sbsp->smk_default) { + ctx->fsdefault = kstrdup(sbsp->smk_default->smk_known, GFP_KERNEL); + if (!ctx->fsdefault) + return -ENOMEM; + } + + if (sbsp->smk_floor) { + ctx->fsfloor = kstrdup(sbsp->smk_floor->smk_known, GFP_KERNEL); + if (!ctx->fsfloor) + return -ENOMEM; + } + + if (sbsp->smk_hat) { + ctx->fshat = kstrdup(sbsp->smk_hat->smk_known, GFP_KERNEL); + if (!ctx->fshat) + return -ENOMEM; + } + + if (isp->smk_flags & SMK_INODE_TRANSMUTE) { + if (sbsp->smk_root) { + ctx->fstransmute = kstrdup(sbsp->smk_root->smk_known, GFP_KERNEL); + if (!ctx->fstransmute) + return -ENOMEM; + } + } + return 0; +} + +/** + * smack_fs_context_dup - Duplicate the security data on fs_context duplication + * @fc: The new filesystem context. + * @src_fc: The source filesystem context being duplicated. + * + * Returns 0 on success or -ENOMEM on error. + */ +static int smack_fs_context_dup(struct fs_context *fc, + struct fs_context *src_fc) +{ + struct smack_mnt_opts *dst, *src = src_fc->security; + + if (!src) + return 0; + + fc->security = kzalloc(sizeof(struct smack_mnt_opts), GFP_KERNEL); + if (!fc->security) + return -ENOMEM; + dst = fc->security; + + if (src->fsdefault) { + dst->fsdefault = kstrdup(src->fsdefault, GFP_KERNEL); + if (!dst->fsdefault) + return -ENOMEM; + } + if (src->fsfloor) { + dst->fsfloor = kstrdup(src->fsfloor, GFP_KERNEL); + if (!dst->fsfloor) + return -ENOMEM; + } + if (src->fshat) { + dst->fshat = kstrdup(src->fshat, GFP_KERNEL); + if (!dst->fshat) + return -ENOMEM; + } + if (src->fsroot) { + dst->fsroot = kstrdup(src->fsroot, GFP_KERNEL); + if (!dst->fsroot) + return -ENOMEM; + } + if (src->fstransmute) { + dst->fstransmute = kstrdup(src->fstransmute, GFP_KERNEL); + if (!dst->fstransmute) + return -ENOMEM; + } + return 0; +} + +static const struct fs_parameter_spec smack_fs_parameters[] = { + fsparam_string("smackfsdef", Opt_fsdefault), + fsparam_string("smackfsdefault", Opt_fsdefault), + fsparam_string("smackfsfloor", Opt_fsfloor), + fsparam_string("smackfshat", Opt_fshat), + fsparam_string("smackfsroot", Opt_fsroot), + fsparam_string("smackfstransmute", Opt_fstransmute), + {} +}; + +/** + * smack_fs_context_parse_param - Parse a single mount parameter + * @fc: The new filesystem context being constructed. + * @param: The parameter. + * + * Returns 0 on success, -ENOPARAM to pass the parameter on or anything else on + * error. + */ +static int smack_fs_context_parse_param(struct fs_context *fc, + struct fs_parameter *param) +{ + struct fs_parse_result result; + int opt, rc; + + opt = fs_parse(fc, smack_fs_parameters, param, &result); + if (opt < 0) + return opt; + + rc = smack_add_opt(opt, param->string, &fc->security); + if (!rc) + param->string = NULL; + return rc; +} + +static int smack_sb_eat_lsm_opts(char *options, void **mnt_opts) +{ + char *from = options, *to = options; + bool first = true; + + while (1) { + char *next = strchr(from, ','); + int token, len, rc; + char *arg = NULL; + + if (next) + len = next - from; + else + len = strlen(from); + + token = match_opt_prefix(from, len, &arg); + if (token != Opt_error) { + arg = kmemdup_nul(arg, from + len - arg, GFP_KERNEL); + rc = smack_add_opt(token, arg, mnt_opts); + if (unlikely(rc)) { + kfree(arg); + if (*mnt_opts) + smack_free_mnt_opts(*mnt_opts); + *mnt_opts = NULL; + return rc; + } + } else { + if (!first) { // copy with preceding comma + from--; + len++; + } + if (to != from) + memmove(to, from, len); + to += len; + first = false; + } + if (!from[len]) + break; + from += len + 1; + } + *to = '\0'; + return 0; +} + +/** + * smack_set_mnt_opts - set Smack specific mount options + * @sb: the file system superblock + * @mnt_opts: Smack mount options + * @kern_flags: mount option from kernel space or user space + * @set_kern_flags: where to store converted mount opts + * + * Returns 0 on success, an error code on failure + * + * Allow filesystems with binary mount data to explicitly set Smack mount + * labels. + */ +static int smack_set_mnt_opts(struct super_block *sb, + void *mnt_opts, + unsigned long kern_flags, + unsigned long *set_kern_flags) +{ + struct dentry *root = sb->s_root; + struct inode *inode = d_backing_inode(root); + struct superblock_smack *sp = smack_superblock(sb); + struct inode_smack *isp; + struct smack_known *skp; + struct smack_mnt_opts *opts = mnt_opts; + bool transmute = false; + + if (sp->smk_flags & SMK_SB_INITIALIZED) + return 0; + + if (!smack_privileged(CAP_MAC_ADMIN)) { + /* + * Unprivileged mounts don't get to specify Smack values. + */ + if (opts) + return -EPERM; + /* + * Unprivileged mounts get root and default from the caller. + */ + skp = smk_of_current(); + sp->smk_root = skp; + sp->smk_default = skp; + /* + * For a handful of fs types with no user-controlled + * backing store it's okay to trust security labels + * in the filesystem. The rest are untrusted. + */ + if (sb->s_user_ns != &init_user_ns && + sb->s_magic != SYSFS_MAGIC && sb->s_magic != TMPFS_MAGIC && + sb->s_magic != RAMFS_MAGIC) { + transmute = true; + sp->smk_flags |= SMK_SB_UNTRUSTED; + } + } + + sp->smk_flags |= SMK_SB_INITIALIZED; + + if (opts) { + if (opts->fsdefault) { + skp = smk_import_entry(opts->fsdefault, 0); + if (IS_ERR(skp)) + return PTR_ERR(skp); + sp->smk_default = skp; + } + if (opts->fsfloor) { + skp = smk_import_entry(opts->fsfloor, 0); + if (IS_ERR(skp)) + return PTR_ERR(skp); + sp->smk_floor = skp; + } + if (opts->fshat) { + skp = smk_import_entry(opts->fshat, 0); + if (IS_ERR(skp)) + return PTR_ERR(skp); + sp->smk_hat = skp; + } + if (opts->fsroot) { + skp = smk_import_entry(opts->fsroot, 0); + if (IS_ERR(skp)) + return PTR_ERR(skp); + sp->smk_root = skp; + } + if (opts->fstransmute) { + skp = smk_import_entry(opts->fstransmute, 0); + if (IS_ERR(skp)) + return PTR_ERR(skp); + sp->smk_root = skp; + transmute = true; + } + } + + /* + * Initialize the root inode. + */ + init_inode_smack(inode, sp->smk_root); + + if (transmute) { + isp = smack_inode(inode); + isp->smk_flags |= SMK_INODE_TRANSMUTE; + } + + return 0; +} + +/** + * smack_sb_statfs - Smack check on statfs + * @dentry: identifies the file system in question + * + * Returns 0 if current can read the floor of the filesystem, + * and error code otherwise + */ +static int smack_sb_statfs(struct dentry *dentry) +{ + struct superblock_smack *sbp = smack_superblock(dentry->d_sb); + int rc; + struct smk_audit_info ad; + + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); + smk_ad_setfield_u_fs_path_dentry(&ad, dentry); + + rc = smk_curacc(sbp->smk_floor, MAY_READ, &ad); + rc = smk_bu_current("statfs", sbp->smk_floor, MAY_READ, rc); + return rc; +} + +/* + * BPRM hooks + */ + +/** + * smack_bprm_creds_for_exec - Update bprm->cred if needed for exec + * @bprm: the exec information + * + * Returns 0 if it gets a blob, -EPERM if exec forbidden and -ENOMEM otherwise + */ +static int smack_bprm_creds_for_exec(struct linux_binprm *bprm) +{ + struct inode *inode = file_inode(bprm->file); + struct task_smack *bsp = smack_cred(bprm->cred); + struct inode_smack *isp; + struct superblock_smack *sbsp; + int rc; + + isp = smack_inode(inode); + if (isp->smk_task == NULL || isp->smk_task == bsp->smk_task) + return 0; + + sbsp = smack_superblock(inode->i_sb); + if ((sbsp->smk_flags & SMK_SB_UNTRUSTED) && + isp->smk_task != sbsp->smk_root) + return 0; + + if (bprm->unsafe & LSM_UNSAFE_PTRACE) { + struct task_struct *tracer; + rc = 0; + + rcu_read_lock(); + tracer = ptrace_parent(current); + if (likely(tracer != NULL)) + rc = smk_ptrace_rule_check(tracer, + isp->smk_task, + PTRACE_MODE_ATTACH, + __func__); + rcu_read_unlock(); + + if (rc != 0) + return rc; + } + if (bprm->unsafe & ~LSM_UNSAFE_PTRACE) + return -EPERM; + + bsp->smk_task = isp->smk_task; + bprm->per_clear |= PER_CLEAR_ON_SETID; + + /* Decide if this is a secure exec. */ + if (bsp->smk_task != bsp->smk_forked) + bprm->secureexec = 1; + + return 0; +} + +/* + * Inode hooks + */ + +/** + * smack_inode_alloc_security - allocate an inode blob + * @inode: the inode in need of a blob + * + * Returns 0 + */ +static int smack_inode_alloc_security(struct inode *inode) +{ + struct smack_known *skp = smk_of_current(); + + init_inode_smack(inode, skp); + return 0; +} + +/** + * smack_inode_init_security - copy out the smack from an inode + * @inode: the newly created inode + * @dir: containing directory object + * @qstr: unused + * @name: where to put the attribute name + * @value: where to put the attribute value + * @len: where to put the length of the attribute + * + * Returns 0 if it all works out, -ENOMEM if there's no memory + */ +static int smack_inode_init_security(struct inode *inode, struct inode *dir, + const struct qstr *qstr, const char **name, + void **value, size_t *len) +{ + struct task_smack *tsp = smack_cred(current_cred()); + struct inode_smack *issp = smack_inode(inode); + struct smack_known *skp = smk_of_task(tsp); + struct smack_known *isp = smk_of_inode(inode); + struct smack_known *dsp = smk_of_inode(dir); + int may; + + if (name) + *name = XATTR_SMACK_SUFFIX; + + if (value && len) { + /* + * If equal, transmuting already occurred in + * smack_dentry_create_files_as(). No need to check again. + */ + if (tsp->smk_task != tsp->smk_transmuted) { + rcu_read_lock(); + may = smk_access_entry(skp->smk_known, dsp->smk_known, + &skp->smk_rules); + rcu_read_unlock(); + } + + /* + * In addition to having smk_task equal to smk_transmuted, + * if the access rule allows transmutation and the directory + * requests transmutation then by all means transmute. + * Mark the inode as changed. + */ + if ((tsp->smk_task == tsp->smk_transmuted) || + (may > 0 && ((may & MAY_TRANSMUTE) != 0) && + smk_inode_transmutable(dir))) { + /* + * The caller of smack_dentry_create_files_as() + * should have overridden the current cred, so the + * inode label was already set correctly in + * smack_inode_alloc_security(). + */ + if (tsp->smk_task != tsp->smk_transmuted) + isp = dsp; + issp->smk_flags |= SMK_INODE_CHANGED; + } + + *value = kstrdup(isp->smk_known, GFP_NOFS); + if (*value == NULL) + return -ENOMEM; + + *len = strlen(isp->smk_known); + } + + return 0; +} + +/** + * smack_inode_link - Smack check on link + * @old_dentry: the existing object + * @dir: unused + * @new_dentry: the new object + * + * Returns 0 if access is permitted, an error code otherwise + */ +static int smack_inode_link(struct dentry *old_dentry, struct inode *dir, + struct dentry *new_dentry) +{ + struct smack_known *isp; + struct smk_audit_info ad; + int rc; + + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); + smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry); + + isp = smk_of_inode(d_backing_inode(old_dentry)); + rc = smk_curacc(isp, MAY_WRITE, &ad); + rc = smk_bu_inode(d_backing_inode(old_dentry), MAY_WRITE, rc); + + if (rc == 0 && d_is_positive(new_dentry)) { + isp = smk_of_inode(d_backing_inode(new_dentry)); + smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry); + rc = smk_curacc(isp, MAY_WRITE, &ad); + rc = smk_bu_inode(d_backing_inode(new_dentry), MAY_WRITE, rc); + } + + return rc; +} + +/** + * smack_inode_unlink - Smack check on inode deletion + * @dir: containing directory object + * @dentry: file to unlink + * + * Returns 0 if current can write the containing directory + * and the object, error code otherwise + */ +static int smack_inode_unlink(struct inode *dir, struct dentry *dentry) +{ + struct inode *ip = d_backing_inode(dentry); + struct smk_audit_info ad; + int rc; + + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); + smk_ad_setfield_u_fs_path_dentry(&ad, dentry); + + /* + * You need write access to the thing you're unlinking + */ + rc = smk_curacc(smk_of_inode(ip), MAY_WRITE, &ad); + rc = smk_bu_inode(ip, MAY_WRITE, rc); + if (rc == 0) { + /* + * You also need write access to the containing directory + */ + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE); + smk_ad_setfield_u_fs_inode(&ad, dir); + rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad); + rc = smk_bu_inode(dir, MAY_WRITE, rc); + } + return rc; +} + +/** + * smack_inode_rmdir - Smack check on directory deletion + * @dir: containing directory object + * @dentry: directory to unlink + * + * Returns 0 if current can write the containing directory + * and the directory, error code otherwise + */ +static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry) +{ + struct smk_audit_info ad; + int rc; + + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); + smk_ad_setfield_u_fs_path_dentry(&ad, dentry); + + /* + * You need write access to the thing you're removing + */ + rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad); + rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc); + if (rc == 0) { + /* + * You also need write access to the containing directory + */ + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE); + smk_ad_setfield_u_fs_inode(&ad, dir); + rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad); + rc = smk_bu_inode(dir, MAY_WRITE, rc); + } + + return rc; +} + +/** + * smack_inode_rename - Smack check on rename + * @old_inode: unused + * @old_dentry: the old object + * @new_inode: unused + * @new_dentry: the new object + * + * Read and write access is required on both the old and + * new directories. + * + * Returns 0 if access is permitted, an error code otherwise + */ +static int smack_inode_rename(struct inode *old_inode, + struct dentry *old_dentry, + struct inode *new_inode, + struct dentry *new_dentry) +{ + int rc; + struct smack_known *isp; + struct smk_audit_info ad; + + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); + smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry); + + isp = smk_of_inode(d_backing_inode(old_dentry)); + rc = smk_curacc(isp, MAY_READWRITE, &ad); + rc = smk_bu_inode(d_backing_inode(old_dentry), MAY_READWRITE, rc); + + if (rc == 0 && d_is_positive(new_dentry)) { + isp = smk_of_inode(d_backing_inode(new_dentry)); + smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry); + rc = smk_curacc(isp, MAY_READWRITE, &ad); + rc = smk_bu_inode(d_backing_inode(new_dentry), MAY_READWRITE, rc); + } + return rc; +} + +/** + * smack_inode_permission - Smack version of permission() + * @inode: the inode in question + * @mask: the access requested + * + * This is the important Smack hook. + * + * Returns 0 if access is permitted, an error code otherwise + */ +static int smack_inode_permission(struct inode *inode, int mask) +{ + struct superblock_smack *sbsp = smack_superblock(inode->i_sb); + struct smk_audit_info ad; + int no_block = mask & MAY_NOT_BLOCK; + int rc; + + mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND); + /* + * No permission to check. Existence test. Yup, it's there. + */ + if (mask == 0) + return 0; + + if (sbsp->smk_flags & SMK_SB_UNTRUSTED) { + if (smk_of_inode(inode) != sbsp->smk_root) + return -EACCES; + } + + /* May be droppable after audit */ + if (no_block) + return -ECHILD; + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE); + smk_ad_setfield_u_fs_inode(&ad, inode); + rc = smk_curacc(smk_of_inode(inode), mask, &ad); + rc = smk_bu_inode(inode, mask, rc); + return rc; +} + +/** + * smack_inode_setattr - Smack check for setting attributes + * @dentry: the object + * @iattr: for the force flag + * + * Returns 0 if access is permitted, an error code otherwise + */ +static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr) +{ + struct smk_audit_info ad; + int rc; + + /* + * Need to allow for clearing the setuid bit. + */ + if (iattr->ia_valid & ATTR_FORCE) + return 0; + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); + smk_ad_setfield_u_fs_path_dentry(&ad, dentry); + + rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad); + rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc); + return rc; +} + +/** + * smack_inode_getattr - Smack check for getting attributes + * @path: path to extract the info from + * + * Returns 0 if access is permitted, an error code otherwise + */ +static int smack_inode_getattr(const struct path *path) +{ + struct smk_audit_info ad; + struct inode *inode = d_backing_inode(path->dentry); + int rc; + + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); + smk_ad_setfield_u_fs_path(&ad, *path); + rc = smk_curacc(smk_of_inode(inode), MAY_READ, &ad); + rc = smk_bu_inode(inode, MAY_READ, rc); + return rc; +} + +/** + * smack_inode_setxattr - Smack check for setting xattrs + * @mnt_userns: active user namespace + * @dentry: the object + * @name: name of the attribute + * @value: value of the attribute + * @size: size of the value + * @flags: unused + * + * This protects the Smack attribute explicitly. + * + * Returns 0 if access is permitted, an error code otherwise + */ +static int smack_inode_setxattr(struct user_namespace *mnt_userns, + struct dentry *dentry, const char *name, + const void *value, size_t size, int flags) +{ + struct smk_audit_info ad; + struct smack_known *skp; + int check_priv = 0; + int check_import = 0; + int check_star = 0; + int rc = 0; + + /* + * Check label validity here so import won't fail in post_setxattr + */ + if (strcmp(name, XATTR_NAME_SMACK) == 0 || + strcmp(name, XATTR_NAME_SMACKIPIN) == 0 || + strcmp(name, XATTR_NAME_SMACKIPOUT) == 0) { + check_priv = 1; + check_import = 1; + } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0 || + strcmp(name, XATTR_NAME_SMACKMMAP) == 0) { + check_priv = 1; + check_import = 1; + check_star = 1; + } else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) { + check_priv = 1; + if (size != TRANS_TRUE_SIZE || + strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0) + rc = -EINVAL; + } else + rc = cap_inode_setxattr(dentry, name, value, size, flags); + + if (check_priv && !smack_privileged(CAP_MAC_ADMIN)) + rc = -EPERM; + + if (rc == 0 && check_import) { + skp = size ? smk_import_entry(value, size) : NULL; + if (IS_ERR(skp)) + rc = PTR_ERR(skp); + else if (skp == NULL || (check_star && + (skp == &smack_known_star || skp == &smack_known_web))) + rc = -EINVAL; + } + + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); + smk_ad_setfield_u_fs_path_dentry(&ad, dentry); + + if (rc == 0) { + rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad); + rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc); + } + + return rc; +} + +/** + * smack_inode_post_setxattr - Apply the Smack update approved above + * @dentry: object + * @name: attribute name + * @value: attribute value + * @size: attribute size + * @flags: unused + * + * Set the pointer in the inode blob to the entry found + * in the master label list. + */ +static void smack_inode_post_setxattr(struct dentry *dentry, const char *name, + const void *value, size_t size, int flags) +{ + struct smack_known *skp; + struct inode_smack *isp = smack_inode(d_backing_inode(dentry)); + + if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) { + isp->smk_flags |= SMK_INODE_TRANSMUTE; + return; + } + + if (strcmp(name, XATTR_NAME_SMACK) == 0) { + skp = smk_import_entry(value, size); + if (!IS_ERR(skp)) + isp->smk_inode = skp; + } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) { + skp = smk_import_entry(value, size); + if (!IS_ERR(skp)) + isp->smk_task = skp; + } else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) { + skp = smk_import_entry(value, size); + if (!IS_ERR(skp)) + isp->smk_mmap = skp; + } + + return; +} + +/** + * smack_inode_getxattr - Smack check on getxattr + * @dentry: the object + * @name: unused + * + * Returns 0 if access is permitted, an error code otherwise + */ +static int smack_inode_getxattr(struct dentry *dentry, const char *name) +{ + struct smk_audit_info ad; + int rc; + + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); + smk_ad_setfield_u_fs_path_dentry(&ad, dentry); + + rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_READ, &ad); + rc = smk_bu_inode(d_backing_inode(dentry), MAY_READ, rc); + return rc; +} + +/** + * smack_inode_removexattr - Smack check on removexattr + * @mnt_userns: active user namespace + * @dentry: the object + * @name: name of the attribute + * + * Removing the Smack attribute requires CAP_MAC_ADMIN + * + * Returns 0 if access is permitted, an error code otherwise + */ +static int smack_inode_removexattr(struct user_namespace *mnt_userns, + struct dentry *dentry, const char *name) +{ + struct inode_smack *isp; + struct smk_audit_info ad; + int rc = 0; + + if (strcmp(name, XATTR_NAME_SMACK) == 0 || + strcmp(name, XATTR_NAME_SMACKIPIN) == 0 || + strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 || + strcmp(name, XATTR_NAME_SMACKEXEC) == 0 || + strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0 || + strcmp(name, XATTR_NAME_SMACKMMAP) == 0) { + if (!smack_privileged(CAP_MAC_ADMIN)) + rc = -EPERM; + } else + rc = cap_inode_removexattr(mnt_userns, dentry, name); + + if (rc != 0) + return rc; + + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); + smk_ad_setfield_u_fs_path_dentry(&ad, dentry); + + rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad); + rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc); + if (rc != 0) + return rc; + + isp = smack_inode(d_backing_inode(dentry)); + /* + * Don't do anything special for these. + * XATTR_NAME_SMACKIPIN + * XATTR_NAME_SMACKIPOUT + */ + if (strcmp(name, XATTR_NAME_SMACK) == 0) { + struct super_block *sbp = dentry->d_sb; + struct superblock_smack *sbsp = smack_superblock(sbp); + + isp->smk_inode = sbsp->smk_default; + } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) + isp->smk_task = NULL; + else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) + isp->smk_mmap = NULL; + else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) + isp->smk_flags &= ~SMK_INODE_TRANSMUTE; + + return 0; +} + +/** + * smack_inode_getsecurity - get smack xattrs + * @mnt_userns: active user namespace + * @inode: the object + * @name: attribute name + * @buffer: where to put the result + * @alloc: duplicate memory + * + * Returns the size of the attribute or an error code + */ +static int smack_inode_getsecurity(struct user_namespace *mnt_userns, + struct inode *inode, const char *name, + void **buffer, bool alloc) +{ + struct socket_smack *ssp; + struct socket *sock; + struct super_block *sbp; + struct inode *ip = (struct inode *)inode; + struct smack_known *isp; + struct inode_smack *ispp; + size_t label_len; + char *label = NULL; + + if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) { + isp = smk_of_inode(inode); + } else if (strcmp(name, XATTR_SMACK_TRANSMUTE) == 0) { + ispp = smack_inode(inode); + if (ispp->smk_flags & SMK_INODE_TRANSMUTE) + label = TRANS_TRUE; + else + label = ""; + } else { + /* + * The rest of the Smack xattrs are only on sockets. + */ + sbp = ip->i_sb; + if (sbp->s_magic != SOCKFS_MAGIC) + return -EOPNOTSUPP; + + sock = SOCKET_I(ip); + if (sock == NULL || sock->sk == NULL) + return -EOPNOTSUPP; + + ssp = sock->sk->sk_security; + + if (strcmp(name, XATTR_SMACK_IPIN) == 0) + isp = ssp->smk_in; + else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) + isp = ssp->smk_out; + else + return -EOPNOTSUPP; + } + + if (!label) + label = isp->smk_known; + + label_len = strlen(label); + + if (alloc) { + *buffer = kstrdup(label, GFP_KERNEL); + if (*buffer == NULL) + return -ENOMEM; + } + + return label_len; +} + + +/** + * smack_inode_listsecurity - list the Smack attributes + * @inode: the object + * @buffer: where they go + * @buffer_size: size of buffer + */ +static int smack_inode_listsecurity(struct inode *inode, char *buffer, + size_t buffer_size) +{ + int len = sizeof(XATTR_NAME_SMACK); + + if (buffer != NULL && len <= buffer_size) + memcpy(buffer, XATTR_NAME_SMACK, len); + + return len; +} + +/** + * smack_inode_getsecid - Extract inode's security id + * @inode: inode to extract the info from + * @secid: where result will be saved + */ +static void smack_inode_getsecid(struct inode *inode, u32 *secid) +{ + struct smack_known *skp = smk_of_inode(inode); + + *secid = skp->smk_secid; +} + +/* + * File Hooks + */ + +/* + * There is no smack_file_permission hook + * + * Should access checks be done on each read or write? + * UNICOS and SELinux say yes. + * Trusted Solaris, Trusted Irix, and just about everyone else says no. + * + * I'll say no for now. Smack does not do the frequent + * label changing that SELinux does. + */ + +/** + * smack_file_alloc_security - assign a file security blob + * @file: the object + * + * The security blob for a file is a pointer to the master + * label list, so no allocation is done. + * + * f_security is the owner security information. It + * isn't used on file access checks, it's for send_sigio. + * + * Returns 0 + */ +static int smack_file_alloc_security(struct file *file) +{ + struct smack_known **blob = smack_file(file); + + *blob = smk_of_current(); + return 0; +} + +/** + * smack_file_ioctl - Smack check on ioctls + * @file: the object + * @cmd: what to do + * @arg: unused + * + * Relies heavily on the correct use of the ioctl command conventions. + * + * Returns 0 if allowed, error code otherwise + */ +static int smack_file_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + int rc = 0; + struct smk_audit_info ad; + struct inode *inode = file_inode(file); + + if (unlikely(IS_PRIVATE(inode))) + return 0; + + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); + smk_ad_setfield_u_fs_path(&ad, file->f_path); + + if (_IOC_DIR(cmd) & _IOC_WRITE) { + rc = smk_curacc(smk_of_inode(inode), MAY_WRITE, &ad); + rc = smk_bu_file(file, MAY_WRITE, rc); + } + + if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ)) { + rc = smk_curacc(smk_of_inode(inode), MAY_READ, &ad); + rc = smk_bu_file(file, MAY_READ, rc); + } + + return rc; +} + +/** + * smack_file_lock - Smack check on file locking + * @file: the object + * @cmd: unused + * + * Returns 0 if current has lock access, error code otherwise + */ +static int smack_file_lock(struct file *file, unsigned int cmd) +{ + struct smk_audit_info ad; + int rc; + struct inode *inode = file_inode(file); + + if (unlikely(IS_PRIVATE(inode))) + return 0; + + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); + smk_ad_setfield_u_fs_path(&ad, file->f_path); + rc = smk_curacc(smk_of_inode(inode), MAY_LOCK, &ad); + rc = smk_bu_file(file, MAY_LOCK, rc); + return rc; +} + +/** + * smack_file_fcntl - Smack check on fcntl + * @file: the object + * @cmd: what action to check + * @arg: unused + * + * Generally these operations are harmless. + * File locking operations present an obvious mechanism + * for passing information, so they require write access. + * + * Returns 0 if current has access, error code otherwise + */ +static int smack_file_fcntl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + struct smk_audit_info ad; + int rc = 0; + struct inode *inode = file_inode(file); + + if (unlikely(IS_PRIVATE(inode))) + return 0; + + switch (cmd) { + case F_GETLK: + break; + case F_SETLK: + case F_SETLKW: + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); + smk_ad_setfield_u_fs_path(&ad, file->f_path); + rc = smk_curacc(smk_of_inode(inode), MAY_LOCK, &ad); + rc = smk_bu_file(file, MAY_LOCK, rc); + break; + case F_SETOWN: + case F_SETSIG: + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); + smk_ad_setfield_u_fs_path(&ad, file->f_path); + rc = smk_curacc(smk_of_inode(inode), MAY_WRITE, &ad); + rc = smk_bu_file(file, MAY_WRITE, rc); + break; + default: + break; + } + + return rc; +} + +/** + * smack_mmap_file - Check permissions for a mmap operation. + * @file: contains the file structure for file to map (may be NULL). + * @reqprot: contains the protection requested by the application. + * @prot: contains the protection that will be applied by the kernel. + * @flags: contains the operational flags. + * + * The @file may be NULL, e.g. if mapping anonymous memory. + * + * Return 0 if permission is granted. + */ +static int smack_mmap_file(struct file *file, + unsigned long reqprot, unsigned long prot, + unsigned long flags) +{ + struct smack_known *skp; + struct smack_known *mkp; + struct smack_rule *srp; + struct task_smack *tsp; + struct smack_known *okp; + struct inode_smack *isp; + struct superblock_smack *sbsp; + int may; + int mmay; + int tmay; + int rc; + + if (file == NULL) + return 0; + + if (unlikely(IS_PRIVATE(file_inode(file)))) + return 0; + + isp = smack_inode(file_inode(file)); + if (isp->smk_mmap == NULL) + return 0; + sbsp = smack_superblock(file_inode(file)->i_sb); + if (sbsp->smk_flags & SMK_SB_UNTRUSTED && + isp->smk_mmap != sbsp->smk_root) + return -EACCES; + mkp = isp->smk_mmap; + + tsp = smack_cred(current_cred()); + skp = smk_of_current(); + rc = 0; + + rcu_read_lock(); + /* + * For each Smack rule associated with the subject + * label verify that the SMACK64MMAP also has access + * to that rule's object label. + */ + list_for_each_entry_rcu(srp, &skp->smk_rules, list) { + okp = srp->smk_object; + /* + * Matching labels always allows access. + */ + if (mkp->smk_known == okp->smk_known) + continue; + /* + * If there is a matching local rule take + * that into account as well. + */ + may = smk_access_entry(srp->smk_subject->smk_known, + okp->smk_known, + &tsp->smk_rules); + if (may == -ENOENT) + may = srp->smk_access; + else + may &= srp->smk_access; + /* + * If may is zero the SMACK64MMAP subject can't + * possibly have less access. + */ + if (may == 0) + continue; + + /* + * Fetch the global list entry. + * If there isn't one a SMACK64MMAP subject + * can't have as much access as current. + */ + mmay = smk_access_entry(mkp->smk_known, okp->smk_known, + &mkp->smk_rules); + if (mmay == -ENOENT) { + rc = -EACCES; + break; + } + /* + * If there is a local entry it modifies the + * potential access, too. + */ + tmay = smk_access_entry(mkp->smk_known, okp->smk_known, + &tsp->smk_rules); + if (tmay != -ENOENT) + mmay &= tmay; + + /* + * If there is any access available to current that is + * not available to a SMACK64MMAP subject + * deny access. + */ + if ((may | mmay) != mmay) { + rc = -EACCES; + break; + } + } + + rcu_read_unlock(); + + return rc; +} + +/** + * smack_file_set_fowner - set the file security blob value + * @file: object in question + * + */ +static void smack_file_set_fowner(struct file *file) +{ + struct smack_known **blob = smack_file(file); + + *blob = smk_of_current(); +} + +/** + * smack_file_send_sigiotask - Smack on sigio + * @tsk: The target task + * @fown: the object the signal come from + * @signum: unused + * + * Allow a privileged task to get signals even if it shouldn't + * + * Returns 0 if a subject with the object's smack could + * write to the task, an error code otherwise. + */ +static int smack_file_send_sigiotask(struct task_struct *tsk, + struct fown_struct *fown, int signum) +{ + struct smack_known **blob; + struct smack_known *skp; + struct smack_known *tkp = smk_of_task(smack_cred(tsk->cred)); + const struct cred *tcred; + struct file *file; + int rc; + struct smk_audit_info ad; + + /* + * struct fown_struct is never outside the context of a struct file + */ + file = container_of(fown, struct file, f_owner); + + /* we don't log here as rc can be overriden */ + blob = smack_file(file); + skp = *blob; + rc = smk_access(skp, tkp, MAY_DELIVER, NULL); + rc = smk_bu_note("sigiotask", skp, tkp, MAY_DELIVER, rc); + + rcu_read_lock(); + tcred = __task_cred(tsk); + if (rc != 0 && smack_privileged_cred(CAP_MAC_OVERRIDE, tcred)) + rc = 0; + rcu_read_unlock(); + + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK); + smk_ad_setfield_u_tsk(&ad, tsk); + smack_log(skp->smk_known, tkp->smk_known, MAY_DELIVER, rc, &ad); + return rc; +} + +/** + * smack_file_receive - Smack file receive check + * @file: the object + * + * Returns 0 if current has access, error code otherwise + */ +static int smack_file_receive(struct file *file) +{ + int rc; + int may = 0; + struct smk_audit_info ad; + struct inode *inode = file_inode(file); + struct socket *sock; + struct task_smack *tsp; + struct socket_smack *ssp; + + if (unlikely(IS_PRIVATE(inode))) + return 0; + + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); + smk_ad_setfield_u_fs_path(&ad, file->f_path); + + if (inode->i_sb->s_magic == SOCKFS_MAGIC) { + sock = SOCKET_I(inode); + ssp = sock->sk->sk_security; + tsp = smack_cred(current_cred()); + /* + * If the receiving process can't write to the + * passed socket or if the passed socket can't + * write to the receiving process don't accept + * the passed socket. + */ + rc = smk_access(tsp->smk_task, ssp->smk_out, MAY_WRITE, &ad); + rc = smk_bu_file(file, may, rc); + if (rc < 0) + return rc; + rc = smk_access(ssp->smk_in, tsp->smk_task, MAY_WRITE, &ad); + rc = smk_bu_file(file, may, rc); + return rc; + } + /* + * This code relies on bitmasks. + */ + if (file->f_mode & FMODE_READ) + may = MAY_READ; + if (file->f_mode & FMODE_WRITE) + may |= MAY_WRITE; + + rc = smk_curacc(smk_of_inode(inode), may, &ad); + rc = smk_bu_file(file, may, rc); + return rc; +} + +/** + * smack_file_open - Smack dentry open processing + * @file: the object + * + * Set the security blob in the file structure. + * Allow the open only if the task has read access. There are + * many read operations (e.g. fstat) that you can do with an + * fd even if you have the file open write-only. + * + * Returns 0 if current has access, error code otherwise + */ +static int smack_file_open(struct file *file) +{ + struct task_smack *tsp = smack_cred(file->f_cred); + struct inode *inode = file_inode(file); + struct smk_audit_info ad; + int rc; + + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); + smk_ad_setfield_u_fs_path(&ad, file->f_path); + rc = smk_tskacc(tsp, smk_of_inode(inode), MAY_READ, &ad); + rc = smk_bu_credfile(file->f_cred, file, MAY_READ, rc); + + return rc; +} + +/* + * Task hooks + */ + +/** + * smack_cred_alloc_blank - "allocate" blank task-level security credentials + * @cred: the new credentials + * @gfp: the atomicity of any memory allocations + * + * Prepare a blank set of credentials for modification. This must allocate all + * the memory the LSM module might require such that cred_transfer() can + * complete without error. + */ +static int smack_cred_alloc_blank(struct cred *cred, gfp_t gfp) +{ + init_task_smack(smack_cred(cred), NULL, NULL); + return 0; +} + + +/** + * smack_cred_free - "free" task-level security credentials + * @cred: the credentials in question + * + */ +static void smack_cred_free(struct cred *cred) +{ + struct task_smack *tsp = smack_cred(cred); + struct smack_rule *rp; + struct list_head *l; + struct list_head *n; + + smk_destroy_label_list(&tsp->smk_relabel); + + list_for_each_safe(l, n, &tsp->smk_rules) { + rp = list_entry(l, struct smack_rule, list); + list_del(&rp->list); + kmem_cache_free(smack_rule_cache, rp); + } +} + +/** + * smack_cred_prepare - prepare new set of credentials for modification + * @new: the new credentials + * @old: the original credentials + * @gfp: the atomicity of any memory allocations + * + * Prepare a new set of credentials for modification. + */ +static int smack_cred_prepare(struct cred *new, const struct cred *old, + gfp_t gfp) +{ + struct task_smack *old_tsp = smack_cred(old); + struct task_smack *new_tsp = smack_cred(new); + int rc; + + init_task_smack(new_tsp, old_tsp->smk_task, old_tsp->smk_task); + + rc = smk_copy_rules(&new_tsp->smk_rules, &old_tsp->smk_rules, gfp); + if (rc != 0) + return rc; + + rc = smk_copy_relabel(&new_tsp->smk_relabel, &old_tsp->smk_relabel, + gfp); + return rc; +} + +/** + * smack_cred_transfer - Transfer the old credentials to the new credentials + * @new: the new credentials + * @old: the original credentials + * + * Fill in a set of blank credentials from another set of credentials. + */ +static void smack_cred_transfer(struct cred *new, const struct cred *old) +{ + struct task_smack *old_tsp = smack_cred(old); + struct task_smack *new_tsp = smack_cred(new); + + new_tsp->smk_task = old_tsp->smk_task; + new_tsp->smk_forked = old_tsp->smk_task; + mutex_init(&new_tsp->smk_rules_lock); + INIT_LIST_HEAD(&new_tsp->smk_rules); + + /* cbs copy rule list */ +} + +/** + * smack_cred_getsecid - get the secid corresponding to a creds structure + * @cred: the object creds + * @secid: where to put the result + * + * Sets the secid to contain a u32 version of the smack label. + */ +static void smack_cred_getsecid(const struct cred *cred, u32 *secid) +{ + struct smack_known *skp; + + rcu_read_lock(); + skp = smk_of_task(smack_cred(cred)); + *secid = skp->smk_secid; + rcu_read_unlock(); +} + +/** + * smack_kernel_act_as - Set the subjective context in a set of credentials + * @new: points to the set of credentials to be modified. + * @secid: specifies the security ID to be set + * + * Set the security data for a kernel service. + */ +static int smack_kernel_act_as(struct cred *new, u32 secid) +{ + struct task_smack *new_tsp = smack_cred(new); + + new_tsp->smk_task = smack_from_secid(secid); + return 0; +} + +/** + * smack_kernel_create_files_as - Set the file creation label in a set of creds + * @new: points to the set of credentials to be modified + * @inode: points to the inode to use as a reference + * + * Set the file creation context in a set of credentials to the same + * as the objective context of the specified inode + */ +static int smack_kernel_create_files_as(struct cred *new, + struct inode *inode) +{ + struct inode_smack *isp = smack_inode(inode); + struct task_smack *tsp = smack_cred(new); + + tsp->smk_forked = isp->smk_inode; + tsp->smk_task = tsp->smk_forked; + return 0; +} + +/** + * smk_curacc_on_task - helper to log task related access + * @p: the task object + * @access: the access requested + * @caller: name of the calling function for audit + * + * Return 0 if access is permitted + */ +static int smk_curacc_on_task(struct task_struct *p, int access, + const char *caller) +{ + struct smk_audit_info ad; + struct smack_known *skp = smk_of_task_struct_obj(p); + int rc; + + smk_ad_init(&ad, caller, LSM_AUDIT_DATA_TASK); + smk_ad_setfield_u_tsk(&ad, p); + rc = smk_curacc(skp, access, &ad); + rc = smk_bu_task(p, access, rc); + return rc; +} + +/** + * smack_task_setpgid - Smack check on setting pgid + * @p: the task object + * @pgid: unused + * + * Return 0 if write access is permitted + */ +static int smack_task_setpgid(struct task_struct *p, pid_t pgid) +{ + return smk_curacc_on_task(p, MAY_WRITE, __func__); +} + +/** + * smack_task_getpgid - Smack access check for getpgid + * @p: the object task + * + * Returns 0 if current can read the object task, error code otherwise + */ +static int smack_task_getpgid(struct task_struct *p) +{ + return smk_curacc_on_task(p, MAY_READ, __func__); +} + +/** + * smack_task_getsid - Smack access check for getsid + * @p: the object task + * + * Returns 0 if current can read the object task, error code otherwise + */ +static int smack_task_getsid(struct task_struct *p) +{ + return smk_curacc_on_task(p, MAY_READ, __func__); +} + +/** + * smack_current_getsecid_subj - get the subjective secid of the current task + * @secid: where to put the result + * + * Sets the secid to contain a u32 version of the task's subjective smack label. + */ +static void smack_current_getsecid_subj(u32 *secid) +{ + struct smack_known *skp = smk_of_current(); + + *secid = skp->smk_secid; +} + +/** + * smack_task_getsecid_obj - get the objective secid of the task + * @p: the task + * @secid: where to put the result + * + * Sets the secid to contain a u32 version of the task's objective smack label. + */ +static void smack_task_getsecid_obj(struct task_struct *p, u32 *secid) +{ + struct smack_known *skp = smk_of_task_struct_obj(p); + + *secid = skp->smk_secid; +} + +/** + * smack_task_setnice - Smack check on setting nice + * @p: the task object + * @nice: unused + * + * Return 0 if write access is permitted + */ +static int smack_task_setnice(struct task_struct *p, int nice) +{ + return smk_curacc_on_task(p, MAY_WRITE, __func__); +} + +/** + * smack_task_setioprio - Smack check on setting ioprio + * @p: the task object + * @ioprio: unused + * + * Return 0 if write access is permitted + */ +static int smack_task_setioprio(struct task_struct *p, int ioprio) +{ + return smk_curacc_on_task(p, MAY_WRITE, __func__); +} + +/** + * smack_task_getioprio - Smack check on reading ioprio + * @p: the task object + * + * Return 0 if read access is permitted + */ +static int smack_task_getioprio(struct task_struct *p) +{ + return smk_curacc_on_task(p, MAY_READ, __func__); +} + +/** + * smack_task_setscheduler - Smack check on setting scheduler + * @p: the task object + * + * Return 0 if read access is permitted + */ +static int smack_task_setscheduler(struct task_struct *p) +{ + return smk_curacc_on_task(p, MAY_WRITE, __func__); +} + +/** + * smack_task_getscheduler - Smack check on reading scheduler + * @p: the task object + * + * Return 0 if read access is permitted + */ +static int smack_task_getscheduler(struct task_struct *p) +{ + return smk_curacc_on_task(p, MAY_READ, __func__); +} + +/** + * smack_task_movememory - Smack check on moving memory + * @p: the task object + * + * Return 0 if write access is permitted + */ +static int smack_task_movememory(struct task_struct *p) +{ + return smk_curacc_on_task(p, MAY_WRITE, __func__); +} + +/** + * smack_task_kill - Smack check on signal delivery + * @p: the task object + * @info: unused + * @sig: unused + * @cred: identifies the cred to use in lieu of current's + * + * Return 0 if write access is permitted + * + */ +static int smack_task_kill(struct task_struct *p, struct kernel_siginfo *info, + int sig, const struct cred *cred) +{ + struct smk_audit_info ad; + struct smack_known *skp; + struct smack_known *tkp = smk_of_task_struct_obj(p); + int rc; + + if (!sig) + return 0; /* null signal; existence test */ + + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK); + smk_ad_setfield_u_tsk(&ad, p); + /* + * Sending a signal requires that the sender + * can write the receiver. + */ + if (cred == NULL) { + rc = smk_curacc(tkp, MAY_DELIVER, &ad); + rc = smk_bu_task(p, MAY_DELIVER, rc); + return rc; + } + /* + * If the cred isn't NULL we're dealing with some USB IO + * specific behavior. This is not clean. For one thing + * we can't take privilege into account. + */ + skp = smk_of_task(smack_cred(cred)); + rc = smk_access(skp, tkp, MAY_DELIVER, &ad); + rc = smk_bu_note("USB signal", skp, tkp, MAY_DELIVER, rc); + return rc; +} + +/** + * smack_task_to_inode - copy task smack into the inode blob + * @p: task to copy from + * @inode: inode to copy to + * + * Sets the smack pointer in the inode security blob + */ +static void smack_task_to_inode(struct task_struct *p, struct inode *inode) +{ + struct inode_smack *isp = smack_inode(inode); + struct smack_known *skp = smk_of_task_struct_obj(p); + + isp->smk_inode = skp; + isp->smk_flags |= SMK_INODE_INSTANT; +} + +/* + * Socket hooks. + */ + +/** + * smack_sk_alloc_security - Allocate a socket blob + * @sk: the socket + * @family: unused + * @gfp_flags: memory allocation flags + * + * Assign Smack pointers to current + * + * Returns 0 on success, -ENOMEM is there's no memory + */ +static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags) +{ + struct smack_known *skp = smk_of_current(); + struct socket_smack *ssp; + + ssp = kzalloc(sizeof(struct socket_smack), gfp_flags); + if (ssp == NULL) + return -ENOMEM; + + /* + * Sockets created by kernel threads receive web label. + */ + if (unlikely(current->flags & PF_KTHREAD)) { + ssp->smk_in = &smack_known_web; + ssp->smk_out = &smack_known_web; + } else { + ssp->smk_in = skp; + ssp->smk_out = skp; + } + ssp->smk_packet = NULL; + + sk->sk_security = ssp; + + return 0; +} + +/** + * smack_sk_free_security - Free a socket blob + * @sk: the socket + * + * Clears the blob pointer + */ +static void smack_sk_free_security(struct sock *sk) +{ +#ifdef SMACK_IPV6_PORT_LABELING + struct smk_port_label *spp; + + if (sk->sk_family == PF_INET6) { + rcu_read_lock(); + list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) { + if (spp->smk_sock != sk) + continue; + spp->smk_can_reuse = 1; + break; + } + rcu_read_unlock(); + } +#endif + kfree(sk->sk_security); +} + +/** + * smack_sk_clone_security - Copy security context + * @sk: the old socket + * @newsk: the new socket + * + * Copy the security context of the old socket pointer to the cloned + */ +static void smack_sk_clone_security(const struct sock *sk, struct sock *newsk) +{ + struct socket_smack *ssp_old = sk->sk_security; + struct socket_smack *ssp_new = newsk->sk_security; + + *ssp_new = *ssp_old; +} + +/** +* smack_ipv4host_label - check host based restrictions +* @sip: the object end +* +* looks for host based access restrictions +* +* This version will only be appropriate for really small sets of single label +* hosts. The caller is responsible for ensuring that the RCU read lock is +* taken before calling this function. +* +* Returns the label of the far end or NULL if it's not special. +*/ +static struct smack_known *smack_ipv4host_label(struct sockaddr_in *sip) +{ + struct smk_net4addr *snp; + struct in_addr *siap = &sip->sin_addr; + + if (siap->s_addr == 0) + return NULL; + + list_for_each_entry_rcu(snp, &smk_net4addr_list, list) + /* + * we break after finding the first match because + * the list is sorted from longest to shortest mask + * so we have found the most specific match + */ + if (snp->smk_host.s_addr == + (siap->s_addr & snp->smk_mask.s_addr)) + return snp->smk_label; + + return NULL; +} + +/* + * smk_ipv6_localhost - Check for local ipv6 host address + * @sip: the address + * + * Returns boolean true if this is the localhost address + */ +static bool smk_ipv6_localhost(struct sockaddr_in6 *sip) +{ + __be16 *be16p = (__be16 *)&sip->sin6_addr; + __be32 *be32p = (__be32 *)&sip->sin6_addr; + + if (be32p[0] == 0 && be32p[1] == 0 && be32p[2] == 0 && be16p[6] == 0 && + ntohs(be16p[7]) == 1) + return true; + return false; +} + +/** +* smack_ipv6host_label - check host based restrictions +* @sip: the object end +* +* looks for host based access restrictions +* +* This version will only be appropriate for really small sets of single label +* hosts. The caller is responsible for ensuring that the RCU read lock is +* taken before calling this function. +* +* Returns the label of the far end or NULL if it's not special. +*/ +static struct smack_known *smack_ipv6host_label(struct sockaddr_in6 *sip) +{ + struct smk_net6addr *snp; + struct in6_addr *sap = &sip->sin6_addr; + int i; + int found = 0; + + /* + * It's local. Don't look for a host label. + */ + if (smk_ipv6_localhost(sip)) + return NULL; + + list_for_each_entry_rcu(snp, &smk_net6addr_list, list) { + /* + * If the label is NULL the entry has + * been renounced. Ignore it. + */ + if (snp->smk_label == NULL) + continue; + /* + * we break after finding the first match because + * the list is sorted from longest to shortest mask + * so we have found the most specific match + */ + for (found = 1, i = 0; i < 8; i++) { + if ((sap->s6_addr16[i] & snp->smk_mask.s6_addr16[i]) != + snp->smk_host.s6_addr16[i]) { + found = 0; + break; + } + } + if (found) + return snp->smk_label; + } + + return NULL; +} + +/** + * smack_netlbl_add - Set the secattr on a socket + * @sk: the socket + * + * Attach the outbound smack value (smk_out) to the socket. + * + * Returns 0 on success or an error code + */ +static int smack_netlbl_add(struct sock *sk) +{ + struct socket_smack *ssp = sk->sk_security; + struct smack_known *skp = ssp->smk_out; + int rc; + + local_bh_disable(); + bh_lock_sock_nested(sk); + + rc = netlbl_sock_setattr(sk, sk->sk_family, &skp->smk_netlabel); + switch (rc) { + case 0: + ssp->smk_state = SMK_NETLBL_LABELED; + break; + case -EDESTADDRREQ: + ssp->smk_state = SMK_NETLBL_REQSKB; + rc = 0; + break; + } + + bh_unlock_sock(sk); + local_bh_enable(); + + return rc; +} + +/** + * smack_netlbl_delete - Remove the secattr from a socket + * @sk: the socket + * + * Remove the outbound smack value from a socket + */ +static void smack_netlbl_delete(struct sock *sk) +{ + struct socket_smack *ssp = sk->sk_security; + + /* + * Take the label off the socket if one is set. + */ + if (ssp->smk_state != SMK_NETLBL_LABELED) + return; + + local_bh_disable(); + bh_lock_sock_nested(sk); + netlbl_sock_delattr(sk); + bh_unlock_sock(sk); + local_bh_enable(); + ssp->smk_state = SMK_NETLBL_UNLABELED; +} + +/** + * smk_ipv4_check - Perform IPv4 host access checks + * @sk: the socket + * @sap: the destination address + * + * Set the correct secattr for the given socket based on the destination + * address and perform any outbound access checks needed. + * + * Returns 0 on success or an error code. + * + */ +static int smk_ipv4_check(struct sock *sk, struct sockaddr_in *sap) +{ + struct smack_known *skp; + int rc = 0; + struct smack_known *hkp; + struct socket_smack *ssp = sk->sk_security; + struct smk_audit_info ad; + + rcu_read_lock(); + hkp = smack_ipv4host_label(sap); + if (hkp != NULL) { +#ifdef CONFIG_AUDIT + struct lsm_network_audit net; + + smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); + ad.a.u.net->family = sap->sin_family; + ad.a.u.net->dport = sap->sin_port; + ad.a.u.net->v4info.daddr = sap->sin_addr.s_addr; +#endif + skp = ssp->smk_out; + rc = smk_access(skp, hkp, MAY_WRITE, &ad); + rc = smk_bu_note("IPv4 host check", skp, hkp, MAY_WRITE, rc); + /* + * Clear the socket netlabel if it's set. + */ + if (!rc) + smack_netlbl_delete(sk); + } + rcu_read_unlock(); + + return rc; +} + +/** + * smk_ipv6_check - check Smack access + * @subject: subject Smack label + * @object: object Smack label + * @address: address + * @act: the action being taken + * + * Check an IPv6 access + */ +static int smk_ipv6_check(struct smack_known *subject, + struct smack_known *object, + struct sockaddr_in6 *address, int act) +{ +#ifdef CONFIG_AUDIT + struct lsm_network_audit net; +#endif + struct smk_audit_info ad; + int rc; + +#ifdef CONFIG_AUDIT + smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); + ad.a.u.net->family = PF_INET6; + ad.a.u.net->dport = address->sin6_port; + if (act == SMK_RECEIVING) + ad.a.u.net->v6info.saddr = address->sin6_addr; + else + ad.a.u.net->v6info.daddr = address->sin6_addr; +#endif + rc = smk_access(subject, object, MAY_WRITE, &ad); + rc = smk_bu_note("IPv6 check", subject, object, MAY_WRITE, rc); + return rc; +} + +#ifdef SMACK_IPV6_PORT_LABELING +/** + * smk_ipv6_port_label - Smack port access table management + * @sock: socket + * @address: address + * + * Create or update the port list entry + */ +static void smk_ipv6_port_label(struct socket *sock, struct sockaddr *address) +{ + struct sock *sk = sock->sk; + struct sockaddr_in6 *addr6; + struct socket_smack *ssp = sock->sk->sk_security; + struct smk_port_label *spp; + unsigned short port = 0; + + if (address == NULL) { + /* + * This operation is changing the Smack information + * on the bound socket. Take the changes to the port + * as well. + */ + rcu_read_lock(); + list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) { + if (sk != spp->smk_sock) + continue; + spp->smk_in = ssp->smk_in; + spp->smk_out = ssp->smk_out; + rcu_read_unlock(); + return; + } + /* + * A NULL address is only used for updating existing + * bound entries. If there isn't one, it's OK. + */ + rcu_read_unlock(); + return; + } + + addr6 = (struct sockaddr_in6 *)address; + port = ntohs(addr6->sin6_port); + /* + * This is a special case that is safely ignored. + */ + if (port == 0) + return; + + /* + * Look for an existing port list entry. + * This is an indication that a port is getting reused. + */ + rcu_read_lock(); + list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) { + if (spp->smk_port != port || spp->smk_sock_type != sock->type) + continue; + if (spp->smk_can_reuse != 1) { + rcu_read_unlock(); + return; + } + spp->smk_port = port; + spp->smk_sock = sk; + spp->smk_in = ssp->smk_in; + spp->smk_out = ssp->smk_out; + spp->smk_can_reuse = 0; + rcu_read_unlock(); + return; + } + rcu_read_unlock(); + /* + * A new port entry is required. + */ + spp = kzalloc(sizeof(*spp), GFP_KERNEL); + if (spp == NULL) + return; + + spp->smk_port = port; + spp->smk_sock = sk; + spp->smk_in = ssp->smk_in; + spp->smk_out = ssp->smk_out; + spp->smk_sock_type = sock->type; + spp->smk_can_reuse = 0; + + mutex_lock(&smack_ipv6_lock); + list_add_rcu(&spp->list, &smk_ipv6_port_list); + mutex_unlock(&smack_ipv6_lock); + return; +} + +/** + * smk_ipv6_port_check - check Smack port access + * @sk: socket + * @address: address + * @act: the action being taken + * + * Create or update the port list entry + */ +static int smk_ipv6_port_check(struct sock *sk, struct sockaddr_in6 *address, + int act) +{ + struct smk_port_label *spp; + struct socket_smack *ssp = sk->sk_security; + struct smack_known *skp = NULL; + unsigned short port; + struct smack_known *object; + + if (act == SMK_RECEIVING) { + skp = smack_ipv6host_label(address); + object = ssp->smk_in; + } else { + skp = ssp->smk_out; + object = smack_ipv6host_label(address); + } + + /* + * The other end is a single label host. + */ + if (skp != NULL && object != NULL) + return smk_ipv6_check(skp, object, address, act); + if (skp == NULL) + skp = smack_net_ambient; + if (object == NULL) + object = smack_net_ambient; + + /* + * It's remote, so port lookup does no good. + */ + if (!smk_ipv6_localhost(address)) + return smk_ipv6_check(skp, object, address, act); + + /* + * It's local so the send check has to have passed. + */ + if (act == SMK_RECEIVING) + return 0; + + port = ntohs(address->sin6_port); + rcu_read_lock(); + list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) { + if (spp->smk_port != port || spp->smk_sock_type != sk->sk_type) + continue; + object = spp->smk_in; + if (act == SMK_CONNECTING) + ssp->smk_packet = spp->smk_out; + break; + } + rcu_read_unlock(); + + return smk_ipv6_check(skp, object, address, act); +} +#endif + +/** + * smack_inode_setsecurity - set smack xattrs + * @inode: the object + * @name: attribute name + * @value: attribute value + * @size: size of the attribute + * @flags: unused + * + * Sets the named attribute in the appropriate blob + * + * Returns 0 on success, or an error code + */ +static int smack_inode_setsecurity(struct inode *inode, const char *name, + const void *value, size_t size, int flags) +{ + struct smack_known *skp; + struct inode_smack *nsp = smack_inode(inode); + struct socket_smack *ssp; + struct socket *sock; + int rc = 0; + + if (value == NULL || size > SMK_LONGLABEL || size == 0) + return -EINVAL; + + skp = smk_import_entry(value, size); + if (IS_ERR(skp)) + return PTR_ERR(skp); + + if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) { + nsp->smk_inode = skp; + nsp->smk_flags |= SMK_INODE_INSTANT; + return 0; + } + /* + * The rest of the Smack xattrs are only on sockets. + */ + if (inode->i_sb->s_magic != SOCKFS_MAGIC) + return -EOPNOTSUPP; + + sock = SOCKET_I(inode); + if (sock == NULL || sock->sk == NULL) + return -EOPNOTSUPP; + + ssp = sock->sk->sk_security; + + if (strcmp(name, XATTR_SMACK_IPIN) == 0) + ssp->smk_in = skp; + else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) { + ssp->smk_out = skp; + if (sock->sk->sk_family == PF_INET) { + rc = smack_netlbl_add(sock->sk); + if (rc != 0) + printk(KERN_WARNING + "Smack: \"%s\" netlbl error %d.\n", + __func__, -rc); + } + } else + return -EOPNOTSUPP; + +#ifdef SMACK_IPV6_PORT_LABELING + if (sock->sk->sk_family == PF_INET6) + smk_ipv6_port_label(sock, NULL); +#endif + + return 0; +} + +/** + * smack_socket_post_create - finish socket setup + * @sock: the socket + * @family: protocol family + * @type: unused + * @protocol: unused + * @kern: unused + * + * Sets the netlabel information on the socket + * + * Returns 0 on success, and error code otherwise + */ +static int smack_socket_post_create(struct socket *sock, int family, + int type, int protocol, int kern) +{ + struct socket_smack *ssp; + + if (sock->sk == NULL) + return 0; + + /* + * Sockets created by kernel threads receive web label. + */ + if (unlikely(current->flags & PF_KTHREAD)) { + ssp = sock->sk->sk_security; + ssp->smk_in = &smack_known_web; + ssp->smk_out = &smack_known_web; + } + + if (family != PF_INET) + return 0; + /* + * Set the outbound netlbl. + */ + return smack_netlbl_add(sock->sk); +} + +/** + * smack_socket_socketpair - create socket pair + * @socka: one socket + * @sockb: another socket + * + * Cross reference the peer labels for SO_PEERSEC + * + * Returns 0 + */ +static int smack_socket_socketpair(struct socket *socka, + struct socket *sockb) +{ + struct socket_smack *asp = socka->sk->sk_security; + struct socket_smack *bsp = sockb->sk->sk_security; + + asp->smk_packet = bsp->smk_out; + bsp->smk_packet = asp->smk_out; + + return 0; +} + +#ifdef SMACK_IPV6_PORT_LABELING +/** + * smack_socket_bind - record port binding information. + * @sock: the socket + * @address: the port address + * @addrlen: size of the address + * + * Records the label bound to a port. + * + * Returns 0 on success, and error code otherwise + */ +static int smack_socket_bind(struct socket *sock, struct sockaddr *address, + int addrlen) +{ + if (sock->sk != NULL && sock->sk->sk_family == PF_INET6) { + if (addrlen < SIN6_LEN_RFC2133 || + address->sa_family != AF_INET6) + return -EINVAL; + smk_ipv6_port_label(sock, address); + } + return 0; +} +#endif /* SMACK_IPV6_PORT_LABELING */ + +/** + * smack_socket_connect - connect access check + * @sock: the socket + * @sap: the other end + * @addrlen: size of sap + * + * Verifies that a connection may be possible + * + * Returns 0 on success, and error code otherwise + */ +static int smack_socket_connect(struct socket *sock, struct sockaddr *sap, + int addrlen) +{ + int rc = 0; + + if (sock->sk == NULL) + return 0; + if (sock->sk->sk_family != PF_INET && + (!IS_ENABLED(CONFIG_IPV6) || sock->sk->sk_family != PF_INET6)) + return 0; + if (addrlen < offsetofend(struct sockaddr, sa_family)) + return 0; + if (IS_ENABLED(CONFIG_IPV6) && sap->sa_family == AF_INET6) { + struct sockaddr_in6 *sip = (struct sockaddr_in6 *)sap; + struct smack_known *rsp = NULL; + + if (addrlen < SIN6_LEN_RFC2133) + return 0; + if (__is_defined(SMACK_IPV6_SECMARK_LABELING)) + rsp = smack_ipv6host_label(sip); + if (rsp != NULL) { + struct socket_smack *ssp = sock->sk->sk_security; + + rc = smk_ipv6_check(ssp->smk_out, rsp, sip, + SMK_CONNECTING); + } +#ifdef SMACK_IPV6_PORT_LABELING + rc = smk_ipv6_port_check(sock->sk, sip, SMK_CONNECTING); +#endif + + return rc; + } + if (sap->sa_family != AF_INET || addrlen < sizeof(struct sockaddr_in)) + return 0; + rc = smk_ipv4_check(sock->sk, (struct sockaddr_in *)sap); + return rc; +} + +/** + * smack_flags_to_may - convert S_ to MAY_ values + * @flags: the S_ value + * + * Returns the equivalent MAY_ value + */ +static int smack_flags_to_may(int flags) +{ + int may = 0; + + if (flags & S_IRUGO) + may |= MAY_READ; + if (flags & S_IWUGO) + may |= MAY_WRITE; + if (flags & S_IXUGO) + may |= MAY_EXEC; + + return may; +} + +/** + * smack_msg_msg_alloc_security - Set the security blob for msg_msg + * @msg: the object + * + * Returns 0 + */ +static int smack_msg_msg_alloc_security(struct msg_msg *msg) +{ + struct smack_known **blob = smack_msg_msg(msg); + + *blob = smk_of_current(); + return 0; +} + +/** + * smack_of_ipc - the smack pointer for the ipc + * @isp: the object + * + * Returns a pointer to the smack value + */ +static struct smack_known *smack_of_ipc(struct kern_ipc_perm *isp) +{ + struct smack_known **blob = smack_ipc(isp); + + return *blob; +} + +/** + * smack_ipc_alloc_security - Set the security blob for ipc + * @isp: the object + * + * Returns 0 + */ +static int smack_ipc_alloc_security(struct kern_ipc_perm *isp) +{ + struct smack_known **blob = smack_ipc(isp); + + *blob = smk_of_current(); + return 0; +} + +/** + * smk_curacc_shm : check if current has access on shm + * @isp : the object + * @access : access requested + * + * Returns 0 if current has the requested access, error code otherwise + */ +static int smk_curacc_shm(struct kern_ipc_perm *isp, int access) +{ + struct smack_known *ssp = smack_of_ipc(isp); + struct smk_audit_info ad; + int rc; + +#ifdef CONFIG_AUDIT + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); + ad.a.u.ipc_id = isp->id; +#endif + rc = smk_curacc(ssp, access, &ad); + rc = smk_bu_current("shm", ssp, access, rc); + return rc; +} + +/** + * smack_shm_associate - Smack access check for shm + * @isp: the object + * @shmflg: access requested + * + * Returns 0 if current has the requested access, error code otherwise + */ +static int smack_shm_associate(struct kern_ipc_perm *isp, int shmflg) +{ + int may; + + may = smack_flags_to_may(shmflg); + return smk_curacc_shm(isp, may); +} + +/** + * smack_shm_shmctl - Smack access check for shm + * @isp: the object + * @cmd: what it wants to do + * + * Returns 0 if current has the requested access, error code otherwise + */ +static int smack_shm_shmctl(struct kern_ipc_perm *isp, int cmd) +{ + int may; + + switch (cmd) { + case IPC_STAT: + case SHM_STAT: + case SHM_STAT_ANY: + may = MAY_READ; + break; + case IPC_SET: + case SHM_LOCK: + case SHM_UNLOCK: + case IPC_RMID: + may = MAY_READWRITE; + break; + case IPC_INFO: + case SHM_INFO: + /* + * System level information. + */ + return 0; + default: + return -EINVAL; + } + return smk_curacc_shm(isp, may); +} + +/** + * smack_shm_shmat - Smack access for shmat + * @isp: the object + * @shmaddr: unused + * @shmflg: access requested + * + * Returns 0 if current has the requested access, error code otherwise + */ +static int smack_shm_shmat(struct kern_ipc_perm *isp, char __user *shmaddr, + int shmflg) +{ + int may; + + may = smack_flags_to_may(shmflg); + return smk_curacc_shm(isp, may); +} + +/** + * smk_curacc_sem : check if current has access on sem + * @isp : the object + * @access : access requested + * + * Returns 0 if current has the requested access, error code otherwise + */ +static int smk_curacc_sem(struct kern_ipc_perm *isp, int access) +{ + struct smack_known *ssp = smack_of_ipc(isp); + struct smk_audit_info ad; + int rc; + +#ifdef CONFIG_AUDIT + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); + ad.a.u.ipc_id = isp->id; +#endif + rc = smk_curacc(ssp, access, &ad); + rc = smk_bu_current("sem", ssp, access, rc); + return rc; +} + +/** + * smack_sem_associate - Smack access check for sem + * @isp: the object + * @semflg: access requested + * + * Returns 0 if current has the requested access, error code otherwise + */ +static int smack_sem_associate(struct kern_ipc_perm *isp, int semflg) +{ + int may; + + may = smack_flags_to_may(semflg); + return smk_curacc_sem(isp, may); +} + +/** + * smack_sem_semctl - Smack access check for sem + * @isp: the object + * @cmd: what it wants to do + * + * Returns 0 if current has the requested access, error code otherwise + */ +static int smack_sem_semctl(struct kern_ipc_perm *isp, int cmd) +{ + int may; + + switch (cmd) { + case GETPID: + case GETNCNT: + case GETZCNT: + case GETVAL: + case GETALL: + case IPC_STAT: + case SEM_STAT: + case SEM_STAT_ANY: + may = MAY_READ; + break; + case SETVAL: + case SETALL: + case IPC_RMID: + case IPC_SET: + may = MAY_READWRITE; + break; + case IPC_INFO: + case SEM_INFO: + /* + * System level information + */ + return 0; + default: + return -EINVAL; + } + + return smk_curacc_sem(isp, may); +} + +/** + * smack_sem_semop - Smack checks of semaphore operations + * @isp: the object + * @sops: unused + * @nsops: unused + * @alter: unused + * + * Treated as read and write in all cases. + * + * Returns 0 if access is allowed, error code otherwise + */ +static int smack_sem_semop(struct kern_ipc_perm *isp, struct sembuf *sops, + unsigned nsops, int alter) +{ + return smk_curacc_sem(isp, MAY_READWRITE); +} + +/** + * smk_curacc_msq : helper to check if current has access on msq + * @isp : the msq + * @access : access requested + * + * return 0 if current has access, error otherwise + */ +static int smk_curacc_msq(struct kern_ipc_perm *isp, int access) +{ + struct smack_known *msp = smack_of_ipc(isp); + struct smk_audit_info ad; + int rc; + +#ifdef CONFIG_AUDIT + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); + ad.a.u.ipc_id = isp->id; +#endif + rc = smk_curacc(msp, access, &ad); + rc = smk_bu_current("msq", msp, access, rc); + return rc; +} + +/** + * smack_msg_queue_associate - Smack access check for msg_queue + * @isp: the object + * @msqflg: access requested + * + * Returns 0 if current has the requested access, error code otherwise + */ +static int smack_msg_queue_associate(struct kern_ipc_perm *isp, int msqflg) +{ + int may; + + may = smack_flags_to_may(msqflg); + return smk_curacc_msq(isp, may); +} + +/** + * smack_msg_queue_msgctl - Smack access check for msg_queue + * @isp: the object + * @cmd: what it wants to do + * + * Returns 0 if current has the requested access, error code otherwise + */ +static int smack_msg_queue_msgctl(struct kern_ipc_perm *isp, int cmd) +{ + int may; + + switch (cmd) { + case IPC_STAT: + case MSG_STAT: + case MSG_STAT_ANY: + may = MAY_READ; + break; + case IPC_SET: + case IPC_RMID: + may = MAY_READWRITE; + break; + case IPC_INFO: + case MSG_INFO: + /* + * System level information + */ + return 0; + default: + return -EINVAL; + } + + return smk_curacc_msq(isp, may); +} + +/** + * smack_msg_queue_msgsnd - Smack access check for msg_queue + * @isp: the object + * @msg: unused + * @msqflg: access requested + * + * Returns 0 if current has the requested access, error code otherwise + */ +static int smack_msg_queue_msgsnd(struct kern_ipc_perm *isp, struct msg_msg *msg, + int msqflg) +{ + int may; + + may = smack_flags_to_may(msqflg); + return smk_curacc_msq(isp, may); +} + +/** + * smack_msg_queue_msgrcv - Smack access check for msg_queue + * @isp: the object + * @msg: unused + * @target: unused + * @type: unused + * @mode: unused + * + * Returns 0 if current has read and write access, error code otherwise + */ +static int smack_msg_queue_msgrcv(struct kern_ipc_perm *isp, + struct msg_msg *msg, + struct task_struct *target, long type, + int mode) +{ + return smk_curacc_msq(isp, MAY_READWRITE); +} + +/** + * smack_ipc_permission - Smack access for ipc_permission() + * @ipp: the object permissions + * @flag: access requested + * + * Returns 0 if current has read and write access, error code otherwise + */ +static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag) +{ + struct smack_known **blob = smack_ipc(ipp); + struct smack_known *iskp = *blob; + int may = smack_flags_to_may(flag); + struct smk_audit_info ad; + int rc; + +#ifdef CONFIG_AUDIT + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); + ad.a.u.ipc_id = ipp->id; +#endif + rc = smk_curacc(iskp, may, &ad); + rc = smk_bu_current("svipc", iskp, may, rc); + return rc; +} + +/** + * smack_ipc_getsecid - Extract smack security id + * @ipp: the object permissions + * @secid: where result will be saved + */ +static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid) +{ + struct smack_known **blob = smack_ipc(ipp); + struct smack_known *iskp = *blob; + + *secid = iskp->smk_secid; +} + +/** + * smack_d_instantiate - Make sure the blob is correct on an inode + * @opt_dentry: dentry where inode will be attached + * @inode: the object + * + * Set the inode's security blob if it hasn't been done already. + */ +static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode) +{ + struct super_block *sbp; + struct superblock_smack *sbsp; + struct inode_smack *isp; + struct smack_known *skp; + struct smack_known *ckp = smk_of_current(); + struct smack_known *final; + char trattr[TRANS_TRUE_SIZE]; + int transflag = 0; + int rc; + struct dentry *dp; + + if (inode == NULL) + return; + + isp = smack_inode(inode); + + /* + * If the inode is already instantiated + * take the quick way out + */ + if (isp->smk_flags & SMK_INODE_INSTANT) + return; + + sbp = inode->i_sb; + sbsp = smack_superblock(sbp); + /* + * We're going to use the superblock default label + * if there's no label on the file. + */ + final = sbsp->smk_default; + + /* + * If this is the root inode the superblock + * may be in the process of initialization. + * If that is the case use the root value out + * of the superblock. + */ + if (opt_dentry->d_parent == opt_dentry) { + switch (sbp->s_magic) { + case CGROUP_SUPER_MAGIC: + case CGROUP2_SUPER_MAGIC: + /* + * The cgroup filesystem is never mounted, + * so there's no opportunity to set the mount + * options. + */ + sbsp->smk_root = &smack_known_star; + sbsp->smk_default = &smack_known_star; + isp->smk_inode = sbsp->smk_root; + break; + case TMPFS_MAGIC: + /* + * What about shmem/tmpfs anonymous files with dentry + * obtained from d_alloc_pseudo()? + */ + isp->smk_inode = smk_of_current(); + break; + case PIPEFS_MAGIC: + isp->smk_inode = smk_of_current(); + break; + case SOCKFS_MAGIC: + /* + * Socket access is controlled by the socket + * structures associated with the task involved. + */ + isp->smk_inode = &smack_known_star; + break; + default: + isp->smk_inode = sbsp->smk_root; + break; + } + isp->smk_flags |= SMK_INODE_INSTANT; + return; + } + + /* + * This is pretty hackish. + * Casey says that we shouldn't have to do + * file system specific code, but it does help + * with keeping it simple. + */ + switch (sbp->s_magic) { + case SMACK_MAGIC: + case CGROUP_SUPER_MAGIC: + case CGROUP2_SUPER_MAGIC: + /* + * Casey says that it's a little embarrassing + * that the smack file system doesn't do + * extended attributes. + * + * Cgroupfs is special + */ + final = &smack_known_star; + break; + case DEVPTS_SUPER_MAGIC: + /* + * devpts seems content with the label of the task. + * Programs that change smack have to treat the + * pty with respect. + */ + final = ckp; + break; + case PROC_SUPER_MAGIC: + /* + * Casey says procfs appears not to care. + * The superblock default suffices. + */ + break; + case TMPFS_MAGIC: + /* + * Device labels should come from the filesystem, + * but watch out, because they're volitile, + * getting recreated on every reboot. + */ + final = &smack_known_star; + /* + * If a smack value has been set we want to use it, + * but since tmpfs isn't giving us the opportunity + * to set mount options simulate setting the + * superblock default. + */ + fallthrough; + default: + /* + * This isn't an understood special case. + * Get the value from the xattr. + */ + + /* + * UNIX domain sockets use lower level socket data. + */ + if (S_ISSOCK(inode->i_mode)) { + final = &smack_known_star; + break; + } + /* + * No xattr support means, alas, no SMACK label. + * Use the aforeapplied default. + * It would be curious if the label of the task + * does not match that assigned. + */ + if (!(inode->i_opflags & IOP_XATTR)) + break; + /* + * Get the dentry for xattr. + */ + dp = dget(opt_dentry); + skp = smk_fetch(XATTR_NAME_SMACK, inode, dp); + if (!IS_ERR_OR_NULL(skp)) + final = skp; + + /* + * Transmuting directory + */ + if (S_ISDIR(inode->i_mode)) { + /* + * If this is a new directory and the label was + * transmuted when the inode was initialized + * set the transmute attribute on the directory + * and mark the inode. + * + * If there is a transmute attribute on the + * directory mark the inode. + */ + if (isp->smk_flags & SMK_INODE_CHANGED) { + isp->smk_flags &= ~SMK_INODE_CHANGED; + rc = __vfs_setxattr(&init_user_ns, dp, inode, + XATTR_NAME_SMACKTRANSMUTE, + TRANS_TRUE, TRANS_TRUE_SIZE, + 0); + } else { + rc = __vfs_getxattr(dp, inode, + XATTR_NAME_SMACKTRANSMUTE, trattr, + TRANS_TRUE_SIZE); + if (rc >= 0 && strncmp(trattr, TRANS_TRUE, + TRANS_TRUE_SIZE) != 0) + rc = -EINVAL; + } + if (rc >= 0) + transflag = SMK_INODE_TRANSMUTE; + } + /* + * Don't let the exec or mmap label be "*" or "@". + */ + skp = smk_fetch(XATTR_NAME_SMACKEXEC, inode, dp); + if (IS_ERR(skp) || skp == &smack_known_star || + skp == &smack_known_web) + skp = NULL; + isp->smk_task = skp; + + skp = smk_fetch(XATTR_NAME_SMACKMMAP, inode, dp); + if (IS_ERR(skp) || skp == &smack_known_star || + skp == &smack_known_web) + skp = NULL; + isp->smk_mmap = skp; + + dput(dp); + break; + } + + if (final == NULL) + isp->smk_inode = ckp; + else + isp->smk_inode = final; + + isp->smk_flags |= (SMK_INODE_INSTANT | transflag); + + return; +} + +/** + * smack_getprocattr - Smack process attribute access + * @p: the object task + * @name: the name of the attribute in /proc/.../attr + * @value: where to put the result + * + * Places a copy of the task Smack into value + * + * Returns the length of the smack label or an error code + */ +static int smack_getprocattr(struct task_struct *p, const char *name, char **value) +{ + struct smack_known *skp = smk_of_task_struct_obj(p); + char *cp; + int slen; + + if (strcmp(name, "current") != 0) + return -EINVAL; + + cp = kstrdup(skp->smk_known, GFP_KERNEL); + if (cp == NULL) + return -ENOMEM; + + slen = strlen(cp); + *value = cp; + return slen; +} + +/** + * smack_setprocattr - Smack process attribute setting + * @name: the name of the attribute in /proc/.../attr + * @value: the value to set + * @size: the size of the value + * + * Sets the Smack value of the task. Only setting self + * is permitted and only with privilege + * + * Returns the length of the smack label or an error code + */ +static int smack_setprocattr(const char *name, void *value, size_t size) +{ + struct task_smack *tsp = smack_cred(current_cred()); + struct cred *new; + struct smack_known *skp; + struct smack_known_list_elem *sklep; + int rc; + + if (!smack_privileged(CAP_MAC_ADMIN) && list_empty(&tsp->smk_relabel)) + return -EPERM; + + if (value == NULL || size == 0 || size >= SMK_LONGLABEL) + return -EINVAL; + + if (strcmp(name, "current") != 0) + return -EINVAL; + + skp = smk_import_entry(value, size); + if (IS_ERR(skp)) + return PTR_ERR(skp); + + /* + * No process is ever allowed the web ("@") label + * and the star ("*") label. + */ + if (skp == &smack_known_web || skp == &smack_known_star) + return -EINVAL; + + if (!smack_privileged(CAP_MAC_ADMIN)) { + rc = -EPERM; + list_for_each_entry(sklep, &tsp->smk_relabel, list) + if (sklep->smk_label == skp) { + rc = 0; + break; + } + if (rc) + return rc; + } + + new = prepare_creds(); + if (new == NULL) + return -ENOMEM; + + tsp = smack_cred(new); + tsp->smk_task = skp; + /* + * process can change its label only once + */ + smk_destroy_label_list(&tsp->smk_relabel); + + commit_creds(new); + return size; +} + +/** + * smack_unix_stream_connect - Smack access on UDS + * @sock: one sock + * @other: the other sock + * @newsk: unused + * + * Return 0 if a subject with the smack of sock could access + * an object with the smack of other, otherwise an error code + */ +static int smack_unix_stream_connect(struct sock *sock, + struct sock *other, struct sock *newsk) +{ + struct smack_known *skp; + struct smack_known *okp; + struct socket_smack *ssp = sock->sk_security; + struct socket_smack *osp = other->sk_security; + struct socket_smack *nsp = newsk->sk_security; + struct smk_audit_info ad; + int rc = 0; +#ifdef CONFIG_AUDIT + struct lsm_network_audit net; +#endif + + if (!smack_privileged(CAP_MAC_OVERRIDE)) { + skp = ssp->smk_out; + okp = osp->smk_in; +#ifdef CONFIG_AUDIT + smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); + smk_ad_setfield_u_net_sk(&ad, other); +#endif + rc = smk_access(skp, okp, MAY_WRITE, &ad); + rc = smk_bu_note("UDS connect", skp, okp, MAY_WRITE, rc); + if (rc == 0) { + okp = osp->smk_out; + skp = ssp->smk_in; + rc = smk_access(okp, skp, MAY_WRITE, &ad); + rc = smk_bu_note("UDS connect", okp, skp, + MAY_WRITE, rc); + } + } + + /* + * Cross reference the peer labels for SO_PEERSEC. + */ + if (rc == 0) { + nsp->smk_packet = ssp->smk_out; + ssp->smk_packet = osp->smk_out; + } + + return rc; +} + +/** + * smack_unix_may_send - Smack access on UDS + * @sock: one socket + * @other: the other socket + * + * Return 0 if a subject with the smack of sock could access + * an object with the smack of other, otherwise an error code + */ +static int smack_unix_may_send(struct socket *sock, struct socket *other) +{ + struct socket_smack *ssp = sock->sk->sk_security; + struct socket_smack *osp = other->sk->sk_security; + struct smk_audit_info ad; + int rc; + +#ifdef CONFIG_AUDIT + struct lsm_network_audit net; + + smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); + smk_ad_setfield_u_net_sk(&ad, other->sk); +#endif + + if (smack_privileged(CAP_MAC_OVERRIDE)) + return 0; + + rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad); + rc = smk_bu_note("UDS send", ssp->smk_out, osp->smk_in, MAY_WRITE, rc); + return rc; +} + +/** + * smack_socket_sendmsg - Smack check based on destination host + * @sock: the socket + * @msg: the message + * @size: the size of the message + * + * Return 0 if the current subject can write to the destination host. + * For IPv4 this is only a question if the destination is a single label host. + * For IPv6 this is a check against the label of the port. + */ +static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg, + int size) +{ + struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name; +#if IS_ENABLED(CONFIG_IPV6) + struct sockaddr_in6 *sap = (struct sockaddr_in6 *) msg->msg_name; +#endif +#ifdef SMACK_IPV6_SECMARK_LABELING + struct socket_smack *ssp = sock->sk->sk_security; + struct smack_known *rsp; +#endif + int rc = 0; + + /* + * Perfectly reasonable for this to be NULL + */ + if (sip == NULL) + return 0; + + switch (sock->sk->sk_family) { + case AF_INET: + if (msg->msg_namelen < sizeof(struct sockaddr_in) || + sip->sin_family != AF_INET) + return -EINVAL; + rc = smk_ipv4_check(sock->sk, sip); + break; +#if IS_ENABLED(CONFIG_IPV6) + case AF_INET6: + if (msg->msg_namelen < SIN6_LEN_RFC2133 || + sap->sin6_family != AF_INET6) + return -EINVAL; +#ifdef SMACK_IPV6_SECMARK_LABELING + rsp = smack_ipv6host_label(sap); + if (rsp != NULL) + rc = smk_ipv6_check(ssp->smk_out, rsp, sap, + SMK_CONNECTING); +#endif +#ifdef SMACK_IPV6_PORT_LABELING + rc = smk_ipv6_port_check(sock->sk, sap, SMK_SENDING); +#endif +#endif /* IS_ENABLED(CONFIG_IPV6) */ + break; + } + return rc; +} + +/** + * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat pair to smack + * @sap: netlabel secattr + * @ssp: socket security information + * + * Returns a pointer to a Smack label entry found on the label list. + */ +static struct smack_known *smack_from_secattr(struct netlbl_lsm_secattr *sap, + struct socket_smack *ssp) +{ + struct smack_known *skp; + int found = 0; + int acat; + int kcat; + + /* + * Netlabel found it in the cache. + */ + if ((sap->flags & NETLBL_SECATTR_CACHE) != 0) + return (struct smack_known *)sap->cache->data; + + if ((sap->flags & NETLBL_SECATTR_SECID) != 0) + /* + * Looks like a fallback, which gives us a secid. + */ + return smack_from_secid(sap->attr.secid); + + if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) { + /* + * Looks like a CIPSO packet. + * If there are flags but no level netlabel isn't + * behaving the way we expect it to. + * + * Look it up in the label table + * Without guidance regarding the smack value + * for the packet fall back on the network + * ambient value. + */ + rcu_read_lock(); + list_for_each_entry_rcu(skp, &smack_known_list, list) { + if (sap->attr.mls.lvl != skp->smk_netlabel.attr.mls.lvl) + continue; + /* + * Compare the catsets. Use the netlbl APIs. + */ + if ((sap->flags & NETLBL_SECATTR_MLS_CAT) == 0) { + if ((skp->smk_netlabel.flags & + NETLBL_SECATTR_MLS_CAT) == 0) + found = 1; + break; + } + for (acat = -1, kcat = -1; acat == kcat; ) { + acat = netlbl_catmap_walk(sap->attr.mls.cat, + acat + 1); + kcat = netlbl_catmap_walk( + skp->smk_netlabel.attr.mls.cat, + kcat + 1); + if (acat < 0 || kcat < 0) + break; + } + if (acat == kcat) { + found = 1; + break; + } + } + rcu_read_unlock(); + + if (found) + return skp; + + if (ssp != NULL && ssp->smk_in == &smack_known_star) + return &smack_known_web; + return &smack_known_star; + } + /* + * Without guidance regarding the smack value + * for the packet fall back on the network + * ambient value. + */ + return smack_net_ambient; +} + +#if IS_ENABLED(CONFIG_IPV6) +static int smk_skb_to_addr_ipv6(struct sk_buff *skb, struct sockaddr_in6 *sip) +{ + u8 nexthdr; + int offset; + int proto = -EINVAL; + struct ipv6hdr _ipv6h; + struct ipv6hdr *ip6; + __be16 frag_off; + struct tcphdr _tcph, *th; + struct udphdr _udph, *uh; + struct dccp_hdr _dccph, *dh; + + sip->sin6_port = 0; + + offset = skb_network_offset(skb); + ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h); + if (ip6 == NULL) + return -EINVAL; + sip->sin6_addr = ip6->saddr; + + nexthdr = ip6->nexthdr; + offset += sizeof(_ipv6h); + offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off); + if (offset < 0) + return -EINVAL; + + proto = nexthdr; + switch (proto) { + case IPPROTO_TCP: + th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph); + if (th != NULL) + sip->sin6_port = th->source; + break; + case IPPROTO_UDP: + case IPPROTO_UDPLITE: + uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph); + if (uh != NULL) + sip->sin6_port = uh->source; + break; + case IPPROTO_DCCP: + dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph); + if (dh != NULL) + sip->sin6_port = dh->dccph_sport; + break; + } + return proto; +} +#endif /* CONFIG_IPV6 */ + +/** + * smack_from_skb - Smack data from the secmark in an skb + * @skb: packet + * + * Returns smack_known of the secmark or NULL if that won't work. + */ +#ifdef CONFIG_NETWORK_SECMARK +static struct smack_known *smack_from_skb(struct sk_buff *skb) +{ + if (skb == NULL || skb->secmark == 0) + return NULL; + + return smack_from_secid(skb->secmark); +} +#else +static inline struct smack_known *smack_from_skb(struct sk_buff *skb) +{ + return NULL; +} +#endif + +/** + * smack_from_netlbl - Smack data from the IP options in an skb + * @sk: socket data came in on + * @family: address family + * @skb: packet + * + * Find the Smack label in the IP options. If it hasn't been + * added to the netlabel cache, add it here. + * + * Returns smack_known of the IP options or NULL if that won't work. + */ +static struct smack_known *smack_from_netlbl(const struct sock *sk, u16 family, + struct sk_buff *skb) +{ + struct netlbl_lsm_secattr secattr; + struct socket_smack *ssp = NULL; + struct smack_known *skp = NULL; + + netlbl_secattr_init(&secattr); + + if (sk) + ssp = sk->sk_security; + + if (netlbl_skbuff_getattr(skb, family, &secattr) == 0) { + skp = smack_from_secattr(&secattr, ssp); + if (secattr.flags & NETLBL_SECATTR_CACHEABLE) + netlbl_cache_add(skb, family, &skp->smk_netlabel); + } + + netlbl_secattr_destroy(&secattr); + + return skp; +} + +/** + * smack_socket_sock_rcv_skb - Smack packet delivery access check + * @sk: socket + * @skb: packet + * + * Returns 0 if the packet should be delivered, an error code otherwise + */ +static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) +{ + struct socket_smack *ssp = sk->sk_security; + struct smack_known *skp = NULL; + int rc = 0; + struct smk_audit_info ad; + u16 family = sk->sk_family; +#ifdef CONFIG_AUDIT + struct lsm_network_audit net; +#endif +#if IS_ENABLED(CONFIG_IPV6) + struct sockaddr_in6 sadd; + int proto; + + if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP)) + family = PF_INET; +#endif /* CONFIG_IPV6 */ + + switch (family) { + case PF_INET: + /* + * If there is a secmark use it rather than the CIPSO label. + * If there is no secmark fall back to CIPSO. + * The secmark is assumed to reflect policy better. + */ + skp = smack_from_skb(skb); + if (skp == NULL) { + skp = smack_from_netlbl(sk, family, skb); + if (skp == NULL) + skp = smack_net_ambient; + } + +#ifdef CONFIG_AUDIT + smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); + ad.a.u.net->family = family; + ad.a.u.net->netif = skb->skb_iif; + ipv4_skb_to_auditdata(skb, &ad.a, NULL); +#endif + /* + * Receiving a packet requires that the other end + * be able to write here. Read access is not required. + * This is the simplist possible security model + * for networking. + */ + rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad); + rc = smk_bu_note("IPv4 delivery", skp, ssp->smk_in, + MAY_WRITE, rc); + if (rc != 0) + netlbl_skbuff_err(skb, family, rc, 0); + break; +#if IS_ENABLED(CONFIG_IPV6) + case PF_INET6: + proto = smk_skb_to_addr_ipv6(skb, &sadd); + if (proto != IPPROTO_UDP && proto != IPPROTO_UDPLITE && + proto != IPPROTO_TCP && proto != IPPROTO_DCCP) + break; +#ifdef SMACK_IPV6_SECMARK_LABELING + skp = smack_from_skb(skb); + if (skp == NULL) { + if (smk_ipv6_localhost(&sadd)) + break; + skp = smack_ipv6host_label(&sadd); + if (skp == NULL) + skp = smack_net_ambient; + } +#ifdef CONFIG_AUDIT + smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); + ad.a.u.net->family = family; + ad.a.u.net->netif = skb->skb_iif; + ipv6_skb_to_auditdata(skb, &ad.a, NULL); +#endif /* CONFIG_AUDIT */ + rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad); + rc = smk_bu_note("IPv6 delivery", skp, ssp->smk_in, + MAY_WRITE, rc); +#endif /* SMACK_IPV6_SECMARK_LABELING */ +#ifdef SMACK_IPV6_PORT_LABELING + rc = smk_ipv6_port_check(sk, &sadd, SMK_RECEIVING); +#endif /* SMACK_IPV6_PORT_LABELING */ + if (rc != 0) + icmpv6_send(skb, ICMPV6_DEST_UNREACH, + ICMPV6_ADM_PROHIBITED, 0); + break; +#endif /* CONFIG_IPV6 */ + } + + return rc; +} + +/** + * smack_socket_getpeersec_stream - pull in packet label + * @sock: the socket + * @optval: user's destination + * @optlen: size thereof + * @len: max thereof + * + * returns zero on success, an error code otherwise + */ +static int smack_socket_getpeersec_stream(struct socket *sock, + char __user *optval, + int __user *optlen, unsigned len) +{ + struct socket_smack *ssp; + char *rcp = ""; + int slen = 1; + int rc = 0; + + ssp = sock->sk->sk_security; + if (ssp->smk_packet != NULL) { + rcp = ssp->smk_packet->smk_known; + slen = strlen(rcp) + 1; + } + + if (slen > len) + rc = -ERANGE; + else if (copy_to_user(optval, rcp, slen) != 0) + rc = -EFAULT; + + if (put_user(slen, optlen) != 0) + rc = -EFAULT; + + return rc; +} + + +/** + * smack_socket_getpeersec_dgram - pull in packet label + * @sock: the peer socket + * @skb: packet data + * @secid: pointer to where to put the secid of the packet + * + * Sets the netlabel socket state on sk from parent + */ +static int smack_socket_getpeersec_dgram(struct socket *sock, + struct sk_buff *skb, u32 *secid) + +{ + struct socket_smack *ssp = NULL; + struct smack_known *skp; + struct sock *sk = NULL; + int family = PF_UNSPEC; + u32 s = 0; /* 0 is the invalid secid */ + + if (skb != NULL) { + if (skb->protocol == htons(ETH_P_IP)) + family = PF_INET; +#if IS_ENABLED(CONFIG_IPV6) + else if (skb->protocol == htons(ETH_P_IPV6)) + family = PF_INET6; +#endif /* CONFIG_IPV6 */ + } + if (family == PF_UNSPEC && sock != NULL) + family = sock->sk->sk_family; + + switch (family) { + case PF_UNIX: + ssp = sock->sk->sk_security; + s = ssp->smk_out->smk_secid; + break; + case PF_INET: + skp = smack_from_skb(skb); + if (skp) { + s = skp->smk_secid; + break; + } + /* + * Translate what netlabel gave us. + */ + if (sock != NULL) + sk = sock->sk; + skp = smack_from_netlbl(sk, family, skb); + if (skp != NULL) + s = skp->smk_secid; + break; + case PF_INET6: +#ifdef SMACK_IPV6_SECMARK_LABELING + skp = smack_from_skb(skb); + if (skp) + s = skp->smk_secid; +#endif + break; + } + *secid = s; + if (s == 0) + return -EINVAL; + return 0; +} + +/** + * smack_sock_graft - Initialize a newly created socket with an existing sock + * @sk: child sock + * @parent: parent socket + * + * Set the smk_{in,out} state of an existing sock based on the process that + * is creating the new socket. + */ +static void smack_sock_graft(struct sock *sk, struct socket *parent) +{ + struct socket_smack *ssp; + struct smack_known *skp = smk_of_current(); + + if (sk == NULL || + (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)) + return; + + ssp = sk->sk_security; + ssp->smk_in = skp; + ssp->smk_out = skp; + /* cssp->smk_packet is already set in smack_inet_csk_clone() */ +} + +/** + * smack_inet_conn_request - Smack access check on connect + * @sk: socket involved + * @skb: packet + * @req: unused + * + * Returns 0 if a task with the packet label could write to + * the socket, otherwise an error code + */ +static int smack_inet_conn_request(const struct sock *sk, struct sk_buff *skb, + struct request_sock *req) +{ + u16 family = sk->sk_family; + struct smack_known *skp; + struct socket_smack *ssp = sk->sk_security; + struct sockaddr_in addr; + struct iphdr *hdr; + struct smack_known *hskp; + int rc; + struct smk_audit_info ad; +#ifdef CONFIG_AUDIT + struct lsm_network_audit net; +#endif + +#if IS_ENABLED(CONFIG_IPV6) + if (family == PF_INET6) { + /* + * Handle mapped IPv4 packets arriving + * via IPv6 sockets. Don't set up netlabel + * processing on IPv6. + */ + if (skb->protocol == htons(ETH_P_IP)) + family = PF_INET; + else + return 0; + } +#endif /* CONFIG_IPV6 */ + + /* + * If there is a secmark use it rather than the CIPSO label. + * If there is no secmark fall back to CIPSO. + * The secmark is assumed to reflect policy better. + */ + skp = smack_from_skb(skb); + if (skp == NULL) { + skp = smack_from_netlbl(sk, family, skb); + if (skp == NULL) + skp = &smack_known_huh; + } + +#ifdef CONFIG_AUDIT + smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); + ad.a.u.net->family = family; + ad.a.u.net->netif = skb->skb_iif; + ipv4_skb_to_auditdata(skb, &ad.a, NULL); +#endif + /* + * Receiving a packet requires that the other end be able to write + * here. Read access is not required. + */ + rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad); + rc = smk_bu_note("IPv4 connect", skp, ssp->smk_in, MAY_WRITE, rc); + if (rc != 0) + return rc; + + /* + * Save the peer's label in the request_sock so we can later setup + * smk_packet in the child socket so that SO_PEERCRED can report it. + */ + req->peer_secid = skp->smk_secid; + + /* + * We need to decide if we want to label the incoming connection here + * if we do we only need to label the request_sock and the stack will + * propagate the wire-label to the sock when it is created. + */ + hdr = ip_hdr(skb); + addr.sin_addr.s_addr = hdr->saddr; + rcu_read_lock(); + hskp = smack_ipv4host_label(&addr); + rcu_read_unlock(); + + if (hskp == NULL) + rc = netlbl_req_setattr(req, &skp->smk_netlabel); + else + netlbl_req_delattr(req); + + return rc; +} + +/** + * smack_inet_csk_clone - Copy the connection information to the new socket + * @sk: the new socket + * @req: the connection's request_sock + * + * Transfer the connection's peer label to the newly created socket. + */ +static void smack_inet_csk_clone(struct sock *sk, + const struct request_sock *req) +{ + struct socket_smack *ssp = sk->sk_security; + struct smack_known *skp; + + if (req->peer_secid != 0) { + skp = smack_from_secid(req->peer_secid); + ssp->smk_packet = skp; + } else + ssp->smk_packet = NULL; +} + +/* + * Key management security hooks + * + * Casey has not tested key support very heavily. + * The permission check is most likely too restrictive. + * If you care about keys please have a look. + */ +#ifdef CONFIG_KEYS + +/** + * smack_key_alloc - Set the key security blob + * @key: object + * @cred: the credentials to use + * @flags: unused + * + * No allocation required + * + * Returns 0 + */ +static int smack_key_alloc(struct key *key, const struct cred *cred, + unsigned long flags) +{ + struct smack_known *skp = smk_of_task(smack_cred(cred)); + + key->security = skp; + return 0; +} + +/** + * smack_key_free - Clear the key security blob + * @key: the object + * + * Clear the blob pointer + */ +static void smack_key_free(struct key *key) +{ + key->security = NULL; +} + +/** + * smack_key_permission - Smack access on a key + * @key_ref: gets to the object + * @cred: the credentials to use + * @need_perm: requested key permission + * + * Return 0 if the task has read and write to the object, + * an error code otherwise + */ +static int smack_key_permission(key_ref_t key_ref, + const struct cred *cred, + enum key_need_perm need_perm) +{ + struct key *keyp; + struct smk_audit_info ad; + struct smack_known *tkp = smk_of_task(smack_cred(cred)); + int request = 0; + int rc; + + /* + * Validate requested permissions + */ + switch (need_perm) { + case KEY_NEED_READ: + case KEY_NEED_SEARCH: + case KEY_NEED_VIEW: + request |= MAY_READ; + break; + case KEY_NEED_WRITE: + case KEY_NEED_LINK: + case KEY_NEED_SETATTR: + request |= MAY_WRITE; + break; + case KEY_NEED_UNSPECIFIED: + case KEY_NEED_UNLINK: + case KEY_SYSADMIN_OVERRIDE: + case KEY_AUTHTOKEN_OVERRIDE: + case KEY_DEFER_PERM_CHECK: + return 0; + default: + return -EINVAL; + } + + keyp = key_ref_to_ptr(key_ref); + if (keyp == NULL) + return -EINVAL; + /* + * If the key hasn't been initialized give it access so that + * it may do so. + */ + if (keyp->security == NULL) + return 0; + /* + * This should not occur + */ + if (tkp == NULL) + return -EACCES; + + if (smack_privileged(CAP_MAC_OVERRIDE)) + return 0; + +#ifdef CONFIG_AUDIT + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY); + ad.a.u.key_struct.key = keyp->serial; + ad.a.u.key_struct.key_desc = keyp->description; +#endif + rc = smk_access(tkp, keyp->security, request, &ad); + rc = smk_bu_note("key access", tkp, keyp->security, request, rc); + return rc; +} + +/* + * smack_key_getsecurity - Smack label tagging the key + * @key points to the key to be queried + * @_buffer points to a pointer that should be set to point to the + * resulting string (if no label or an error occurs). + * Return the length of the string (including terminating NUL) or -ve if + * an error. + * May also return 0 (and a NULL buffer pointer) if there is no label. + */ +static int smack_key_getsecurity(struct key *key, char **_buffer) +{ + struct smack_known *skp = key->security; + size_t length; + char *copy; + + if (key->security == NULL) { + *_buffer = NULL; + return 0; + } + + copy = kstrdup(skp->smk_known, GFP_KERNEL); + if (copy == NULL) + return -ENOMEM; + length = strlen(copy) + 1; + + *_buffer = copy; + return length; +} + + +#ifdef CONFIG_KEY_NOTIFICATIONS +/** + * smack_watch_key - Smack access to watch a key for notifications. + * @key: The key to be watched + * + * Return 0 if the @watch->cred has permission to read from the key object and + * an error otherwise. + */ +static int smack_watch_key(struct key *key) +{ + struct smk_audit_info ad; + struct smack_known *tkp = smk_of_current(); + int rc; + + if (key == NULL) + return -EINVAL; + /* + * If the key hasn't been initialized give it access so that + * it may do so. + */ + if (key->security == NULL) + return 0; + /* + * This should not occur + */ + if (tkp == NULL) + return -EACCES; + + if (smack_privileged_cred(CAP_MAC_OVERRIDE, current_cred())) + return 0; + +#ifdef CONFIG_AUDIT + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY); + ad.a.u.key_struct.key = key->serial; + ad.a.u.key_struct.key_desc = key->description; +#endif + rc = smk_access(tkp, key->security, MAY_READ, &ad); + rc = smk_bu_note("key watch", tkp, key->security, MAY_READ, rc); + return rc; +} +#endif /* CONFIG_KEY_NOTIFICATIONS */ +#endif /* CONFIG_KEYS */ + +#ifdef CONFIG_WATCH_QUEUE +/** + * smack_post_notification - Smack access to post a notification to a queue + * @w_cred: The credentials of the watcher. + * @cred: The credentials of the event source (may be NULL). + * @n: The notification message to be posted. + */ +static int smack_post_notification(const struct cred *w_cred, + const struct cred *cred, + struct watch_notification *n) +{ + struct smk_audit_info ad; + struct smack_known *subj, *obj; + int rc; + + /* Always let maintenance notifications through. */ + if (n->type == WATCH_TYPE_META) + return 0; + + if (!cred) + return 0; + subj = smk_of_task(smack_cred(cred)); + obj = smk_of_task(smack_cred(w_cred)); + + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NOTIFICATION); + rc = smk_access(subj, obj, MAY_WRITE, &ad); + rc = smk_bu_note("notification", subj, obj, MAY_WRITE, rc); + return rc; +} +#endif /* CONFIG_WATCH_QUEUE */ + +/* + * Smack Audit hooks + * + * Audit requires a unique representation of each Smack specific + * rule. This unique representation is used to distinguish the + * object to be audited from remaining kernel objects and also + * works as a glue between the audit hooks. + * + * Since repository entries are added but never deleted, we'll use + * the smack_known label address related to the given audit rule as + * the needed unique representation. This also better fits the smack + * model where nearly everything is a label. + */ +#ifdef CONFIG_AUDIT + +/** + * smack_audit_rule_init - Initialize a smack audit rule + * @field: audit rule fields given from user-space (audit.h) + * @op: required testing operator (=, !=, >, <, ...) + * @rulestr: smack label to be audited + * @vrule: pointer to save our own audit rule representation + * + * Prepare to audit cases where (@field @op @rulestr) is true. + * The label to be audited is created if necessay. + */ +static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule) +{ + struct smack_known *skp; + char **rule = (char **)vrule; + *rule = NULL; + + if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER) + return -EINVAL; + + if (op != Audit_equal && op != Audit_not_equal) + return -EINVAL; + + skp = smk_import_entry(rulestr, 0); + if (IS_ERR(skp)) + return PTR_ERR(skp); + + *rule = skp->smk_known; + + return 0; +} + +/** + * smack_audit_rule_known - Distinguish Smack audit rules + * @krule: rule of interest, in Audit kernel representation format + * + * This is used to filter Smack rules from remaining Audit ones. + * If it's proved that this rule belongs to us, the + * audit_rule_match hook will be called to do the final judgement. + */ +static int smack_audit_rule_known(struct audit_krule *krule) +{ + struct audit_field *f; + int i; + + for (i = 0; i < krule->field_count; i++) { + f = &krule->fields[i]; + + if (f->type == AUDIT_SUBJ_USER || f->type == AUDIT_OBJ_USER) + return 1; + } + + return 0; +} + +/** + * smack_audit_rule_match - Audit given object ? + * @secid: security id for identifying the object to test + * @field: audit rule flags given from user-space + * @op: required testing operator + * @vrule: smack internal rule presentation + * + * The core Audit hook. It's used to take the decision of + * whether to audit or not to audit a given object. + */ +static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule) +{ + struct smack_known *skp; + char *rule = vrule; + + if (unlikely(!rule)) { + WARN_ONCE(1, "Smack: missing rule\n"); + return -ENOENT; + } + + if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER) + return 0; + + skp = smack_from_secid(secid); + + /* + * No need to do string comparisons. If a match occurs, + * both pointers will point to the same smack_known + * label. + */ + if (op == Audit_equal) + return (rule == skp->smk_known); + if (op == Audit_not_equal) + return (rule != skp->smk_known); + + return 0; +} + +/* + * There is no need for a smack_audit_rule_free hook. + * No memory was allocated. + */ + +#endif /* CONFIG_AUDIT */ + +/** + * smack_ismaclabel - check if xattr @name references a smack MAC label + * @name: Full xattr name to check. + */ +static int smack_ismaclabel(const char *name) +{ + return (strcmp(name, XATTR_SMACK_SUFFIX) == 0); +} + + +/** + * smack_secid_to_secctx - return the smack label for a secid + * @secid: incoming integer + * @secdata: destination + * @seclen: how long it is + * + * Exists for networking code. + */ +static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) +{ + struct smack_known *skp = smack_from_secid(secid); + + if (secdata) + *secdata = skp->smk_known; + *seclen = strlen(skp->smk_known); + return 0; +} + +/** + * smack_secctx_to_secid - return the secid for a smack label + * @secdata: smack label + * @seclen: how long result is + * @secid: outgoing integer + * + * Exists for audit and networking code. + */ +static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid) +{ + struct smack_known *skp = smk_find_entry(secdata); + + if (skp) + *secid = skp->smk_secid; + else + *secid = 0; + return 0; +} + +/* + * There used to be a smack_release_secctx hook + * that did nothing back when hooks were in a vector. + * Now that there's a list such a hook adds cost. + */ + +static int smack_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen) +{ + return smack_inode_setsecurity(inode, XATTR_SMACK_SUFFIX, ctx, + ctxlen, 0); +} + +static int smack_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen) +{ + return __vfs_setxattr_noperm(&init_user_ns, dentry, XATTR_NAME_SMACK, + ctx, ctxlen, 0); +} + +static int smack_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen) +{ + struct smack_known *skp = smk_of_inode(inode); + + *ctx = skp->smk_known; + *ctxlen = strlen(skp->smk_known); + return 0; +} + +static int smack_inode_copy_up(struct dentry *dentry, struct cred **new) +{ + + struct task_smack *tsp; + struct smack_known *skp; + struct inode_smack *isp; + struct cred *new_creds = *new; + + if (new_creds == NULL) { + new_creds = prepare_creds(); + if (new_creds == NULL) + return -ENOMEM; + } + + tsp = smack_cred(new_creds); + + /* + * Get label from overlay inode and set it in create_sid + */ + isp = smack_inode(d_inode(dentry)); + skp = isp->smk_inode; + tsp->smk_task = skp; + *new = new_creds; + return 0; +} + +static int smack_inode_copy_up_xattr(const char *name) +{ + /* + * Return 1 if this is the smack access Smack attribute. + */ + if (strcmp(name, XATTR_NAME_SMACK) == 0) + return 1; + + return -EOPNOTSUPP; +} + +static int smack_dentry_create_files_as(struct dentry *dentry, int mode, + struct qstr *name, + const struct cred *old, + struct cred *new) +{ + struct task_smack *otsp = smack_cred(old); + struct task_smack *ntsp = smack_cred(new); + struct inode_smack *isp; + int may; + + /* + * Use the process credential unless all of + * the transmuting criteria are met + */ + ntsp->smk_task = otsp->smk_task; + + /* + * the attribute of the containing directory + */ + isp = smack_inode(d_inode(dentry->d_parent)); + + if (isp->smk_flags & SMK_INODE_TRANSMUTE) { + rcu_read_lock(); + may = smk_access_entry(otsp->smk_task->smk_known, + isp->smk_inode->smk_known, + &otsp->smk_task->smk_rules); + rcu_read_unlock(); + + /* + * If the directory is transmuting and the rule + * providing access is transmuting use the containing + * directory label instead of the process label. + */ + if (may > 0 && (may & MAY_TRANSMUTE)) { + ntsp->smk_task = isp->smk_inode; + ntsp->smk_transmuted = ntsp->smk_task; + } + } + return 0; +} + +#ifdef CONFIG_IO_URING +/** + * smack_uring_override_creds - Is io_uring cred override allowed? + * @new: the target creds + * + * Check to see if the current task is allowed to override it's credentials + * to service an io_uring operation. + */ +static int smack_uring_override_creds(const struct cred *new) +{ + struct task_smack *tsp = smack_cred(current_cred()); + struct task_smack *nsp = smack_cred(new); + + /* + * Allow the degenerate case where the new Smack value is + * the same as the current Smack value. + */ + if (tsp->smk_task == nsp->smk_task) + return 0; + + if (smack_privileged_cred(CAP_MAC_OVERRIDE, current_cred())) + return 0; + + return -EPERM; +} + +/** + * smack_uring_sqpoll - check if a io_uring polling thread can be created + * + * Check to see if the current task is allowed to create a new io_uring + * kernel polling thread. + */ +static int smack_uring_sqpoll(void) +{ + if (smack_privileged_cred(CAP_MAC_ADMIN, current_cred())) + return 0; + + return -EPERM; +} + +/** + * smack_uring_cmd - check on file operations for io_uring + * @ioucmd: the command in question + * + * Make a best guess about whether a io_uring "command" should + * be allowed. Use the same logic used for determining if the + * file could be opened for read in the absence of better criteria. + */ +static int smack_uring_cmd(struct io_uring_cmd *ioucmd) +{ + struct file *file = ioucmd->file; + struct smk_audit_info ad; + struct task_smack *tsp; + struct inode *inode; + int rc; + + if (!file) + return -EINVAL; + + tsp = smack_cred(file->f_cred); + inode = file_inode(file); + + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); + smk_ad_setfield_u_fs_path(&ad, file->f_path); + rc = smk_tskacc(tsp, smk_of_inode(inode), MAY_READ, &ad); + rc = smk_bu_credfile(file->f_cred, file, MAY_READ, rc); + + return rc; +} + +#endif /* CONFIG_IO_URING */ + +struct lsm_blob_sizes smack_blob_sizes __lsm_ro_after_init = { + .lbs_cred = sizeof(struct task_smack), + .lbs_file = sizeof(struct smack_known *), + .lbs_inode = sizeof(struct inode_smack), + .lbs_ipc = sizeof(struct smack_known *), + .lbs_msg_msg = sizeof(struct smack_known *), + .lbs_superblock = sizeof(struct superblock_smack), +}; + +static struct security_hook_list smack_hooks[] __lsm_ro_after_init = { + LSM_HOOK_INIT(ptrace_access_check, smack_ptrace_access_check), + LSM_HOOK_INIT(ptrace_traceme, smack_ptrace_traceme), + LSM_HOOK_INIT(syslog, smack_syslog), + + LSM_HOOK_INIT(fs_context_submount, smack_fs_context_submount), + LSM_HOOK_INIT(fs_context_dup, smack_fs_context_dup), + LSM_HOOK_INIT(fs_context_parse_param, smack_fs_context_parse_param), + + LSM_HOOK_INIT(sb_alloc_security, smack_sb_alloc_security), + LSM_HOOK_INIT(sb_free_mnt_opts, smack_free_mnt_opts), + LSM_HOOK_INIT(sb_eat_lsm_opts, smack_sb_eat_lsm_opts), + LSM_HOOK_INIT(sb_statfs, smack_sb_statfs), + LSM_HOOK_INIT(sb_set_mnt_opts, smack_set_mnt_opts), + + LSM_HOOK_INIT(bprm_creds_for_exec, smack_bprm_creds_for_exec), + + LSM_HOOK_INIT(inode_alloc_security, smack_inode_alloc_security), + LSM_HOOK_INIT(inode_init_security, smack_inode_init_security), + LSM_HOOK_INIT(inode_link, smack_inode_link), + LSM_HOOK_INIT(inode_unlink, smack_inode_unlink), + LSM_HOOK_INIT(inode_rmdir, smack_inode_rmdir), + LSM_HOOK_INIT(inode_rename, smack_inode_rename), + LSM_HOOK_INIT(inode_permission, smack_inode_permission), + LSM_HOOK_INIT(inode_setattr, smack_inode_setattr), + LSM_HOOK_INIT(inode_getattr, smack_inode_getattr), + LSM_HOOK_INIT(inode_setxattr, smack_inode_setxattr), + LSM_HOOK_INIT(inode_post_setxattr, smack_inode_post_setxattr), + LSM_HOOK_INIT(inode_getxattr, smack_inode_getxattr), + LSM_HOOK_INIT(inode_removexattr, smack_inode_removexattr), + LSM_HOOK_INIT(inode_getsecurity, smack_inode_getsecurity), + LSM_HOOK_INIT(inode_setsecurity, smack_inode_setsecurity), + LSM_HOOK_INIT(inode_listsecurity, smack_inode_listsecurity), + LSM_HOOK_INIT(inode_getsecid, smack_inode_getsecid), + + LSM_HOOK_INIT(file_alloc_security, smack_file_alloc_security), + LSM_HOOK_INIT(file_ioctl, smack_file_ioctl), + LSM_HOOK_INIT(file_ioctl_compat, smack_file_ioctl), + LSM_HOOK_INIT(file_lock, smack_file_lock), + LSM_HOOK_INIT(file_fcntl, smack_file_fcntl), + LSM_HOOK_INIT(mmap_file, smack_mmap_file), + LSM_HOOK_INIT(mmap_addr, cap_mmap_addr), + LSM_HOOK_INIT(file_set_fowner, smack_file_set_fowner), + LSM_HOOK_INIT(file_send_sigiotask, smack_file_send_sigiotask), + LSM_HOOK_INIT(file_receive, smack_file_receive), + + LSM_HOOK_INIT(file_open, smack_file_open), + + LSM_HOOK_INIT(cred_alloc_blank, smack_cred_alloc_blank), + LSM_HOOK_INIT(cred_free, smack_cred_free), + LSM_HOOK_INIT(cred_prepare, smack_cred_prepare), + LSM_HOOK_INIT(cred_transfer, smack_cred_transfer), + LSM_HOOK_INIT(cred_getsecid, smack_cred_getsecid), + LSM_HOOK_INIT(kernel_act_as, smack_kernel_act_as), + LSM_HOOK_INIT(kernel_create_files_as, smack_kernel_create_files_as), + LSM_HOOK_INIT(task_setpgid, smack_task_setpgid), + LSM_HOOK_INIT(task_getpgid, smack_task_getpgid), + LSM_HOOK_INIT(task_getsid, smack_task_getsid), + LSM_HOOK_INIT(current_getsecid_subj, smack_current_getsecid_subj), + LSM_HOOK_INIT(task_getsecid_obj, smack_task_getsecid_obj), + LSM_HOOK_INIT(task_setnice, smack_task_setnice), + LSM_HOOK_INIT(task_setioprio, smack_task_setioprio), + LSM_HOOK_INIT(task_getioprio, smack_task_getioprio), + LSM_HOOK_INIT(task_setscheduler, smack_task_setscheduler), + LSM_HOOK_INIT(task_getscheduler, smack_task_getscheduler), + LSM_HOOK_INIT(task_movememory, smack_task_movememory), + LSM_HOOK_INIT(task_kill, smack_task_kill), + LSM_HOOK_INIT(task_to_inode, smack_task_to_inode), + + LSM_HOOK_INIT(ipc_permission, smack_ipc_permission), + LSM_HOOK_INIT(ipc_getsecid, smack_ipc_getsecid), + + LSM_HOOK_INIT(msg_msg_alloc_security, smack_msg_msg_alloc_security), + + LSM_HOOK_INIT(msg_queue_alloc_security, smack_ipc_alloc_security), + LSM_HOOK_INIT(msg_queue_associate, smack_msg_queue_associate), + LSM_HOOK_INIT(msg_queue_msgctl, smack_msg_queue_msgctl), + LSM_HOOK_INIT(msg_queue_msgsnd, smack_msg_queue_msgsnd), + LSM_HOOK_INIT(msg_queue_msgrcv, smack_msg_queue_msgrcv), + + LSM_HOOK_INIT(shm_alloc_security, smack_ipc_alloc_security), + LSM_HOOK_INIT(shm_associate, smack_shm_associate), + LSM_HOOK_INIT(shm_shmctl, smack_shm_shmctl), + LSM_HOOK_INIT(shm_shmat, smack_shm_shmat), + + LSM_HOOK_INIT(sem_alloc_security, smack_ipc_alloc_security), + LSM_HOOK_INIT(sem_associate, smack_sem_associate), + LSM_HOOK_INIT(sem_semctl, smack_sem_semctl), + LSM_HOOK_INIT(sem_semop, smack_sem_semop), + + LSM_HOOK_INIT(d_instantiate, smack_d_instantiate), + + LSM_HOOK_INIT(getprocattr, smack_getprocattr), + LSM_HOOK_INIT(setprocattr, smack_setprocattr), + + LSM_HOOK_INIT(unix_stream_connect, smack_unix_stream_connect), + LSM_HOOK_INIT(unix_may_send, smack_unix_may_send), + + LSM_HOOK_INIT(socket_post_create, smack_socket_post_create), + LSM_HOOK_INIT(socket_socketpair, smack_socket_socketpair), +#ifdef SMACK_IPV6_PORT_LABELING + LSM_HOOK_INIT(socket_bind, smack_socket_bind), +#endif + LSM_HOOK_INIT(socket_connect, smack_socket_connect), + LSM_HOOK_INIT(socket_sendmsg, smack_socket_sendmsg), + LSM_HOOK_INIT(socket_sock_rcv_skb, smack_socket_sock_rcv_skb), + LSM_HOOK_INIT(socket_getpeersec_stream, smack_socket_getpeersec_stream), + LSM_HOOK_INIT(socket_getpeersec_dgram, smack_socket_getpeersec_dgram), + LSM_HOOK_INIT(sk_alloc_security, smack_sk_alloc_security), + LSM_HOOK_INIT(sk_free_security, smack_sk_free_security), + LSM_HOOK_INIT(sk_clone_security, smack_sk_clone_security), + LSM_HOOK_INIT(sock_graft, smack_sock_graft), + LSM_HOOK_INIT(inet_conn_request, smack_inet_conn_request), + LSM_HOOK_INIT(inet_csk_clone, smack_inet_csk_clone), + + /* key management security hooks */ +#ifdef CONFIG_KEYS + LSM_HOOK_INIT(key_alloc, smack_key_alloc), + LSM_HOOK_INIT(key_free, smack_key_free), + LSM_HOOK_INIT(key_permission, smack_key_permission), + LSM_HOOK_INIT(key_getsecurity, smack_key_getsecurity), +#ifdef CONFIG_KEY_NOTIFICATIONS + LSM_HOOK_INIT(watch_key, smack_watch_key), +#endif +#endif /* CONFIG_KEYS */ + +#ifdef CONFIG_WATCH_QUEUE + LSM_HOOK_INIT(post_notification, smack_post_notification), +#endif + + /* Audit hooks */ +#ifdef CONFIG_AUDIT + LSM_HOOK_INIT(audit_rule_init, smack_audit_rule_init), + LSM_HOOK_INIT(audit_rule_known, smack_audit_rule_known), + LSM_HOOK_INIT(audit_rule_match, smack_audit_rule_match), +#endif /* CONFIG_AUDIT */ + + LSM_HOOK_INIT(ismaclabel, smack_ismaclabel), + LSM_HOOK_INIT(secid_to_secctx, smack_secid_to_secctx), + LSM_HOOK_INIT(secctx_to_secid, smack_secctx_to_secid), + LSM_HOOK_INIT(inode_notifysecctx, smack_inode_notifysecctx), + LSM_HOOK_INIT(inode_setsecctx, smack_inode_setsecctx), + LSM_HOOK_INIT(inode_getsecctx, smack_inode_getsecctx), + LSM_HOOK_INIT(inode_copy_up, smack_inode_copy_up), + LSM_HOOK_INIT(inode_copy_up_xattr, smack_inode_copy_up_xattr), + LSM_HOOK_INIT(dentry_create_files_as, smack_dentry_create_files_as), +#ifdef CONFIG_IO_URING + LSM_HOOK_INIT(uring_override_creds, smack_uring_override_creds), + LSM_HOOK_INIT(uring_sqpoll, smack_uring_sqpoll), + LSM_HOOK_INIT(uring_cmd, smack_uring_cmd), +#endif +}; + + +static __init void init_smack_known_list(void) +{ + /* + * Initialize rule list locks + */ + mutex_init(&smack_known_huh.smk_rules_lock); + mutex_init(&smack_known_hat.smk_rules_lock); + mutex_init(&smack_known_floor.smk_rules_lock); + mutex_init(&smack_known_star.smk_rules_lock); + mutex_init(&smack_known_web.smk_rules_lock); + /* + * Initialize rule lists + */ + INIT_LIST_HEAD(&smack_known_huh.smk_rules); + INIT_LIST_HEAD(&smack_known_hat.smk_rules); + INIT_LIST_HEAD(&smack_known_star.smk_rules); + INIT_LIST_HEAD(&smack_known_floor.smk_rules); + INIT_LIST_HEAD(&smack_known_web.smk_rules); + /* + * Create the known labels list + */ + smk_insert_entry(&smack_known_huh); + smk_insert_entry(&smack_known_hat); + smk_insert_entry(&smack_known_star); + smk_insert_entry(&smack_known_floor); + smk_insert_entry(&smack_known_web); +} + +/** + * smack_init - initialize the smack system + * + * Returns 0 on success, -ENOMEM is there's no memory + */ +static __init int smack_init(void) +{ + struct cred *cred = (struct cred *) current->cred; + struct task_smack *tsp; + + smack_rule_cache = KMEM_CACHE(smack_rule, 0); + if (!smack_rule_cache) + return -ENOMEM; + + /* + * Set the security state for the initial task. + */ + tsp = smack_cred(cred); + init_task_smack(tsp, &smack_known_floor, &smack_known_floor); + + /* + * Register with LSM + */ + security_add_hooks(smack_hooks, ARRAY_SIZE(smack_hooks), "smack"); + smack_enabled = 1; + + pr_info("Smack: Initializing.\n"); +#ifdef CONFIG_SECURITY_SMACK_NETFILTER + pr_info("Smack: Netfilter enabled.\n"); +#endif +#ifdef SMACK_IPV6_PORT_LABELING + pr_info("Smack: IPv6 port labeling enabled.\n"); +#endif +#ifdef SMACK_IPV6_SECMARK_LABELING + pr_info("Smack: IPv6 Netfilter enabled.\n"); +#endif + + /* initialize the smack_known_list */ + init_smack_known_list(); + + return 0; +} + +/* + * Smack requires early initialization in order to label + * all processes and objects when they are created. + */ +DEFINE_LSM(smack) = { + .name = "smack", + .flags = LSM_FLAG_LEGACY_MAJOR | LSM_FLAG_EXCLUSIVE, + .blobs = &smack_blob_sizes, + .init = smack_init, +}; diff --git a/security/smack/smack_netfilter.c b/security/smack/smack_netfilter.c new file mode 100644 index 000000000..b945c1d3a --- /dev/null +++ b/security/smack/smack_netfilter.c @@ -0,0 +1,80 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Simplified MAC Kernel (smack) security module + * + * This file contains the Smack netfilter implementation + * + * Author: + * Casey Schaufler <casey@schaufler-ca.com> + * + * Copyright (C) 2014 Casey Schaufler <casey@schaufler-ca.com> + * Copyright (C) 2014 Intel Corporation. + */ + +#include <linux/netfilter_ipv4.h> +#include <linux/netfilter_ipv6.h> +#include <linux/netdevice.h> +#include <net/inet_sock.h> +#include <net/net_namespace.h> +#include "smack.h" + +static unsigned int smack_ip_output(void *priv, + struct sk_buff *skb, + const struct nf_hook_state *state) +{ + struct sock *sk = skb_to_full_sk(skb); + struct socket_smack *ssp; + struct smack_known *skp; + + if (sk && sk->sk_security) { + ssp = sk->sk_security; + skp = ssp->smk_out; + skb->secmark = skp->smk_secid; + } + + return NF_ACCEPT; +} + +static const struct nf_hook_ops smack_nf_ops[] = { + { + .hook = smack_ip_output, + .pf = NFPROTO_IPV4, + .hooknum = NF_INET_LOCAL_OUT, + .priority = NF_IP_PRI_SELINUX_FIRST, + }, +#if IS_ENABLED(CONFIG_IPV6) + { + .hook = smack_ip_output, + .pf = NFPROTO_IPV6, + .hooknum = NF_INET_LOCAL_OUT, + .priority = NF_IP6_PRI_SELINUX_FIRST, + }, +#endif /* IPV6 */ +}; + +static int __net_init smack_nf_register(struct net *net) +{ + return nf_register_net_hooks(net, smack_nf_ops, + ARRAY_SIZE(smack_nf_ops)); +} + +static void __net_exit smack_nf_unregister(struct net *net) +{ + nf_unregister_net_hooks(net, smack_nf_ops, ARRAY_SIZE(smack_nf_ops)); +} + +static struct pernet_operations smack_net_ops = { + .init = smack_nf_register, + .exit = smack_nf_unregister, +}; + +static int __init smack_nf_ip_init(void) +{ + if (smack_enabled == 0) + return 0; + + printk(KERN_DEBUG "Smack: Registering netfilter hooks\n"); + return register_pernet_subsys(&smack_net_ops); +} + +__initcall(smack_nf_ip_init); diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c new file mode 100644 index 000000000..da7db9e22 --- /dev/null +++ b/security/smack/smackfs.c @@ -0,0 +1,3035 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com> + * + * Authors: + * Casey Schaufler <casey@schaufler-ca.com> + * Ahmed S. Darwish <darwish.07@gmail.com> + * + * Special thanks to the authors of selinuxfs. + * + * Karl MacMillan <kmacmillan@tresys.com> + * James Morris <jmorris@redhat.com> + */ + +#include <linux/kernel.h> +#include <linux/vmalloc.h> +#include <linux/security.h> +#include <linux/mutex.h> +#include <linux/slab.h> +#include <net/net_namespace.h> +#include <net/cipso_ipv4.h> +#include <linux/seq_file.h> +#include <linux/ctype.h> +#include <linux/audit.h> +#include <linux/magic.h> +#include <linux/mount.h> +#include <linux/fs_context.h> +#include "smack.h" + +#define BEBITS (sizeof(__be32) * 8) +/* + * smackfs pseudo filesystem. + */ + +enum smk_inos { + SMK_ROOT_INO = 2, + SMK_LOAD = 3, /* load policy */ + SMK_CIPSO = 4, /* load label -> CIPSO mapping */ + SMK_DOI = 5, /* CIPSO DOI */ + SMK_DIRECT = 6, /* CIPSO level indicating direct label */ + SMK_AMBIENT = 7, /* internet ambient label */ + SMK_NET4ADDR = 8, /* single label hosts */ + SMK_ONLYCAP = 9, /* the only "capable" label */ + SMK_LOGGING = 10, /* logging */ + SMK_LOAD_SELF = 11, /* task specific rules */ + SMK_ACCESSES = 12, /* access policy */ + SMK_MAPPED = 13, /* CIPSO level indicating mapped label */ + SMK_LOAD2 = 14, /* load policy with long labels */ + SMK_LOAD_SELF2 = 15, /* load task specific rules with long labels */ + SMK_ACCESS2 = 16, /* make an access check with long labels */ + SMK_CIPSO2 = 17, /* load long label -> CIPSO mapping */ + SMK_REVOKE_SUBJ = 18, /* set rules with subject label to '-' */ + SMK_CHANGE_RULE = 19, /* change or add rules (long labels) */ + SMK_SYSLOG = 20, /* change syslog label) */ + SMK_PTRACE = 21, /* set ptrace rule */ +#ifdef CONFIG_SECURITY_SMACK_BRINGUP + SMK_UNCONFINED = 22, /* define an unconfined label */ +#endif +#if IS_ENABLED(CONFIG_IPV6) + SMK_NET6ADDR = 23, /* single label IPv6 hosts */ +#endif /* CONFIG_IPV6 */ + SMK_RELABEL_SELF = 24, /* relabel possible without CAP_MAC_ADMIN */ +}; + +/* + * List locks + */ +static DEFINE_MUTEX(smack_cipso_lock); +static DEFINE_MUTEX(smack_ambient_lock); +static DEFINE_MUTEX(smk_net4addr_lock); +#if IS_ENABLED(CONFIG_IPV6) +static DEFINE_MUTEX(smk_net6addr_lock); +#endif /* CONFIG_IPV6 */ + +/* + * This is the "ambient" label for network traffic. + * If it isn't somehow marked, use this. + * It can be reset via smackfs/ambient + */ +struct smack_known *smack_net_ambient; + +/* + * This is the level in a CIPSO header that indicates a + * smack label is contained directly in the category set. + * It can be reset via smackfs/direct + */ +int smack_cipso_direct = SMACK_CIPSO_DIRECT_DEFAULT; + +/* + * This is the level in a CIPSO header that indicates a + * secid is contained directly in the category set. + * It can be reset via smackfs/mapped + */ +int smack_cipso_mapped = SMACK_CIPSO_MAPPED_DEFAULT; + +#ifdef CONFIG_SECURITY_SMACK_BRINGUP +/* + * Allow one label to be unconfined. This is for + * debugging and application bring-up purposes only. + * It is bad and wrong, but everyone seems to expect + * to have it. + */ +struct smack_known *smack_unconfined; +#endif + +/* + * If this value is set restrict syslog use to the label specified. + * It can be reset via smackfs/syslog + */ +struct smack_known *smack_syslog_label; + +/* + * Ptrace current rule + * SMACK_PTRACE_DEFAULT regular smack ptrace rules (/proc based) + * SMACK_PTRACE_EXACT labels must match, but can be overriden with + * CAP_SYS_PTRACE + * SMACK_PTRACE_DRACONIAN lables must match, CAP_SYS_PTRACE has no effect + */ +int smack_ptrace_rule = SMACK_PTRACE_DEFAULT; + +/* + * Certain IP addresses may be designated as single label hosts. + * Packets are sent there unlabeled, but only from tasks that + * can write to the specified label. + */ + +LIST_HEAD(smk_net4addr_list); +#if IS_ENABLED(CONFIG_IPV6) +LIST_HEAD(smk_net6addr_list); +#endif /* CONFIG_IPV6 */ + +/* + * Rule lists are maintained for each label. + */ +struct smack_parsed_rule { + struct smack_known *smk_subject; + struct smack_known *smk_object; + int smk_access1; + int smk_access2; +}; + +static int smk_cipso_doi_value = SMACK_CIPSO_DOI_DEFAULT; + +/* + * Values for parsing cipso rules + * SMK_DIGITLEN: Length of a digit field in a rule. + * SMK_CIPSOMIN: Minimum possible cipso rule length. + * SMK_CIPSOMAX: Maximum possible cipso rule length. + */ +#define SMK_DIGITLEN 4 +#define SMK_CIPSOMIN (SMK_LABELLEN + 2 * SMK_DIGITLEN) +#define SMK_CIPSOMAX (SMK_CIPSOMIN + SMACK_CIPSO_MAXCATNUM * SMK_DIGITLEN) + +/* + * Values for parsing MAC rules + * SMK_ACCESS: Maximum possible combination of access permissions + * SMK_ACCESSLEN: Maximum length for a rule access field + * SMK_LOADLEN: Smack rule length + */ +#define SMK_OACCESS "rwxa" +#define SMK_ACCESS "rwxatl" +#define SMK_OACCESSLEN (sizeof(SMK_OACCESS) - 1) +#define SMK_ACCESSLEN (sizeof(SMK_ACCESS) - 1) +#define SMK_OLOADLEN (SMK_LABELLEN + SMK_LABELLEN + SMK_OACCESSLEN) +#define SMK_LOADLEN (SMK_LABELLEN + SMK_LABELLEN + SMK_ACCESSLEN) + +/* + * Stricly for CIPSO level manipulation. + * Set the category bit number in a smack label sized buffer. + */ +static inline void smack_catset_bit(unsigned int cat, char *catsetp) +{ + if (cat == 0 || cat > (SMK_CIPSOLEN * 8)) + return; + + catsetp[(cat - 1) / 8] |= 0x80 >> ((cat - 1) % 8); +} + +/** + * smk_netlabel_audit_set - fill a netlbl_audit struct + * @nap: structure to fill + */ +static void smk_netlabel_audit_set(struct netlbl_audit *nap) +{ + struct smack_known *skp = smk_of_current(); + + nap->loginuid = audit_get_loginuid(current); + nap->sessionid = audit_get_sessionid(current); + nap->secid = skp->smk_secid; +} + +/* + * Value for parsing single label host rules + * "1.2.3.4 X" + */ +#define SMK_NETLBLADDRMIN 9 + +/** + * smk_set_access - add a rule to the rule list or replace an old rule + * @srp: the rule to add or replace + * @rule_list: the list of rules + * @rule_lock: the rule list lock + * + * Looks through the current subject/object/access list for + * the subject/object pair and replaces the access that was + * there. If the pair isn't found add it with the specified + * access. + * + * Returns 0 if nothing goes wrong or -ENOMEM if it fails + * during the allocation of the new pair to add. + */ +static int smk_set_access(struct smack_parsed_rule *srp, + struct list_head *rule_list, + struct mutex *rule_lock) +{ + struct smack_rule *sp; + int found = 0; + int rc = 0; + + mutex_lock(rule_lock); + + /* + * Because the object label is less likely to match + * than the subject label check it first + */ + list_for_each_entry_rcu(sp, rule_list, list) { + if (sp->smk_object == srp->smk_object && + sp->smk_subject == srp->smk_subject) { + found = 1; + sp->smk_access |= srp->smk_access1; + sp->smk_access &= ~srp->smk_access2; + break; + } + } + + if (found == 0) { + sp = kmem_cache_zalloc(smack_rule_cache, GFP_KERNEL); + if (sp == NULL) { + rc = -ENOMEM; + goto out; + } + + sp->smk_subject = srp->smk_subject; + sp->smk_object = srp->smk_object; + sp->smk_access = srp->smk_access1 & ~srp->smk_access2; + + list_add_rcu(&sp->list, rule_list); + } + +out: + mutex_unlock(rule_lock); + return rc; +} + +/** + * smk_perm_from_str - parse smack accesses from a text string + * @string: a text string that contains a Smack accesses code + * + * Returns an integer with respective bits set for specified accesses. + */ +static int smk_perm_from_str(const char *string) +{ + int perm = 0; + const char *cp; + + for (cp = string; ; cp++) + switch (*cp) { + case '-': + break; + case 'r': + case 'R': + perm |= MAY_READ; + break; + case 'w': + case 'W': + perm |= MAY_WRITE; + break; + case 'x': + case 'X': + perm |= MAY_EXEC; + break; + case 'a': + case 'A': + perm |= MAY_APPEND; + break; + case 't': + case 'T': + perm |= MAY_TRANSMUTE; + break; + case 'l': + case 'L': + perm |= MAY_LOCK; + break; + case 'b': + case 'B': + perm |= MAY_BRINGUP; + break; + default: + return perm; + } +} + +/** + * smk_fill_rule - Fill Smack rule from strings + * @subject: subject label string + * @object: object label string + * @access1: access string + * @access2: string with permissions to be removed + * @rule: Smack rule + * @import: if non-zero, import labels + * @len: label length limit + * + * Returns 0 on success, appropriate error code on failure. + */ +static int smk_fill_rule(const char *subject, const char *object, + const char *access1, const char *access2, + struct smack_parsed_rule *rule, int import, + int len) +{ + const char *cp; + struct smack_known *skp; + + if (import) { + rule->smk_subject = smk_import_entry(subject, len); + if (IS_ERR(rule->smk_subject)) + return PTR_ERR(rule->smk_subject); + + rule->smk_object = smk_import_entry(object, len); + if (IS_ERR(rule->smk_object)) + return PTR_ERR(rule->smk_object); + } else { + cp = smk_parse_smack(subject, len); + if (IS_ERR(cp)) + return PTR_ERR(cp); + skp = smk_find_entry(cp); + kfree(cp); + if (skp == NULL) + return -ENOENT; + rule->smk_subject = skp; + + cp = smk_parse_smack(object, len); + if (IS_ERR(cp)) + return PTR_ERR(cp); + skp = smk_find_entry(cp); + kfree(cp); + if (skp == NULL) + return -ENOENT; + rule->smk_object = skp; + } + + rule->smk_access1 = smk_perm_from_str(access1); + if (access2) + rule->smk_access2 = smk_perm_from_str(access2); + else + rule->smk_access2 = ~rule->smk_access1; + + return 0; +} + +/** + * smk_parse_rule - parse Smack rule from load string + * @data: string to be parsed whose size is SMK_LOADLEN + * @rule: Smack rule + * @import: if non-zero, import labels + * + * Returns 0 on success, -1 on errors. + */ +static int smk_parse_rule(const char *data, struct smack_parsed_rule *rule, + int import) +{ + int rc; + + rc = smk_fill_rule(data, data + SMK_LABELLEN, + data + SMK_LABELLEN + SMK_LABELLEN, NULL, rule, + import, SMK_LABELLEN); + return rc; +} + +/** + * smk_parse_long_rule - parse Smack rule from rule string + * @data: string to be parsed, null terminated + * @rule: Will be filled with Smack parsed rule + * @import: if non-zero, import labels + * @tokens: number of substrings expected in data + * + * Returns number of processed bytes on success, -ERRNO on failure. + */ +static ssize_t smk_parse_long_rule(char *data, struct smack_parsed_rule *rule, + int import, int tokens) +{ + ssize_t cnt = 0; + char *tok[4]; + int rc; + int i; + + /* + * Parsing the rule in-place, filling all white-spaces with '\0' + */ + for (i = 0; i < tokens; ++i) { + while (isspace(data[cnt])) + data[cnt++] = '\0'; + + if (data[cnt] == '\0') + /* Unexpected end of data */ + return -EINVAL; + + tok[i] = data + cnt; + + while (data[cnt] && !isspace(data[cnt])) + ++cnt; + } + while (isspace(data[cnt])) + data[cnt++] = '\0'; + + while (i < 4) + tok[i++] = NULL; + + rc = smk_fill_rule(tok[0], tok[1], tok[2], tok[3], rule, import, 0); + return rc == 0 ? cnt : rc; +} + +#define SMK_FIXED24_FMT 0 /* Fixed 24byte label format */ +#define SMK_LONG_FMT 1 /* Variable long label format */ +#define SMK_CHANGE_FMT 2 /* Rule modification format */ +/** + * smk_write_rules_list - write() for any /smack rule file + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start - must be 0 + * @rule_list: the list of rules to write to + * @rule_lock: lock for the rule list + * @format: /smack/load or /smack/load2 or /smack/change-rule format. + * + * Get one smack access rule from above. + * The format for SMK_LONG_FMT is: + * "subject<whitespace>object<whitespace>access[<whitespace>...]" + * The format for SMK_FIXED24_FMT is exactly: + * "subject object rwxat" + * The format for SMK_CHANGE_FMT is: + * "subject<whitespace>object<whitespace> + * acc_enable<whitespace>acc_disable[<whitespace>...]" + */ +static ssize_t smk_write_rules_list(struct file *file, const char __user *buf, + size_t count, loff_t *ppos, + struct list_head *rule_list, + struct mutex *rule_lock, int format) +{ + struct smack_parsed_rule rule; + char *data; + int rc; + int trunc = 0; + int tokens; + ssize_t cnt = 0; + + /* + * No partial writes. + * Enough data must be present. + */ + if (*ppos != 0) + return -EINVAL; + + if (format == SMK_FIXED24_FMT) { + /* + * Minor hack for backward compatibility + */ + if (count < SMK_OLOADLEN || count > SMK_LOADLEN) + return -EINVAL; + } else { + if (count >= PAGE_SIZE) { + count = PAGE_SIZE - 1; + trunc = 1; + } + } + + data = memdup_user_nul(buf, count); + if (IS_ERR(data)) + return PTR_ERR(data); + + /* + * In case of parsing only part of user buf, + * avoid having partial rule at the data buffer + */ + if (trunc) { + while (count > 0 && (data[count - 1] != '\n')) + --count; + if (count == 0) { + rc = -EINVAL; + goto out; + } + } + + data[count] = '\0'; + tokens = (format == SMK_CHANGE_FMT ? 4 : 3); + while (cnt < count) { + if (format == SMK_FIXED24_FMT) { + rc = smk_parse_rule(data, &rule, 1); + if (rc < 0) + goto out; + cnt = count; + } else { + rc = smk_parse_long_rule(data + cnt, &rule, 1, tokens); + if (rc < 0) + goto out; + if (rc == 0) { + rc = -EINVAL; + goto out; + } + cnt += rc; + } + + if (rule_list == NULL) + rc = smk_set_access(&rule, &rule.smk_subject->smk_rules, + &rule.smk_subject->smk_rules_lock); + else + rc = smk_set_access(&rule, rule_list, rule_lock); + + if (rc) + goto out; + } + + rc = cnt; +out: + kfree(data); + return rc; +} + +/* + * Core logic for smackfs seq list operations. + */ + +static void *smk_seq_start(struct seq_file *s, loff_t *pos, + struct list_head *head) +{ + struct list_head *list; + int i = *pos; + + rcu_read_lock(); + for (list = rcu_dereference(list_next_rcu(head)); + list != head; + list = rcu_dereference(list_next_rcu(list))) { + if (i-- == 0) + return list; + } + + return NULL; +} + +static void *smk_seq_next(struct seq_file *s, void *v, loff_t *pos, + struct list_head *head) +{ + struct list_head *list = v; + + ++*pos; + list = rcu_dereference(list_next_rcu(list)); + + return (list == head) ? NULL : list; +} + +static void smk_seq_stop(struct seq_file *s, void *v) +{ + rcu_read_unlock(); +} + +static void smk_rule_show(struct seq_file *s, struct smack_rule *srp, int max) +{ + /* + * Don't show any rules with label names too long for + * interface file (/smack/load or /smack/load2) + * because you should expect to be able to write + * anything you read back. + */ + if (strlen(srp->smk_subject->smk_known) >= max || + strlen(srp->smk_object->smk_known) >= max) + return; + + if (srp->smk_access == 0) + return; + + seq_printf(s, "%s %s", + srp->smk_subject->smk_known, + srp->smk_object->smk_known); + + seq_putc(s, ' '); + + if (srp->smk_access & MAY_READ) + seq_putc(s, 'r'); + if (srp->smk_access & MAY_WRITE) + seq_putc(s, 'w'); + if (srp->smk_access & MAY_EXEC) + seq_putc(s, 'x'); + if (srp->smk_access & MAY_APPEND) + seq_putc(s, 'a'); + if (srp->smk_access & MAY_TRANSMUTE) + seq_putc(s, 't'); + if (srp->smk_access & MAY_LOCK) + seq_putc(s, 'l'); + if (srp->smk_access & MAY_BRINGUP) + seq_putc(s, 'b'); + + seq_putc(s, '\n'); +} + +/* + * Seq_file read operations for /smack/load + */ + +static void *load2_seq_start(struct seq_file *s, loff_t *pos) +{ + return smk_seq_start(s, pos, &smack_known_list); +} + +static void *load2_seq_next(struct seq_file *s, void *v, loff_t *pos) +{ + return smk_seq_next(s, v, pos, &smack_known_list); +} + +static int load_seq_show(struct seq_file *s, void *v) +{ + struct list_head *list = v; + struct smack_rule *srp; + struct smack_known *skp = + list_entry_rcu(list, struct smack_known, list); + + list_for_each_entry_rcu(srp, &skp->smk_rules, list) + smk_rule_show(s, srp, SMK_LABELLEN); + + return 0; +} + +static const struct seq_operations load_seq_ops = { + .start = load2_seq_start, + .next = load2_seq_next, + .show = load_seq_show, + .stop = smk_seq_stop, +}; + +/** + * smk_open_load - open() for /smack/load + * @inode: inode structure representing file + * @file: "load" file pointer + * + * For reading, use load_seq_* seq_file reading operations. + */ +static int smk_open_load(struct inode *inode, struct file *file) +{ + return seq_open(file, &load_seq_ops); +} + +/** + * smk_write_load - write() for /smack/load + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start - must be 0 + * + */ +static ssize_t smk_write_load(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + /* + * Must have privilege. + * No partial writes. + * Enough data must be present. + */ + if (!smack_privileged(CAP_MAC_ADMIN)) + return -EPERM; + + return smk_write_rules_list(file, buf, count, ppos, NULL, NULL, + SMK_FIXED24_FMT); +} + +static const struct file_operations smk_load_ops = { + .open = smk_open_load, + .read = seq_read, + .llseek = seq_lseek, + .write = smk_write_load, + .release = seq_release, +}; + +/** + * smk_cipso_doi - initialize the CIPSO domain + */ +static void smk_cipso_doi(void) +{ + int rc; + struct cipso_v4_doi *doip; + struct netlbl_audit nai; + + smk_netlabel_audit_set(&nai); + + rc = netlbl_cfg_map_del(NULL, PF_INET, NULL, NULL, &nai); + if (rc != 0) + printk(KERN_WARNING "%s:%d remove rc = %d\n", + __func__, __LINE__, rc); + + doip = kmalloc(sizeof(struct cipso_v4_doi), GFP_KERNEL | __GFP_NOFAIL); + doip->map.std = NULL; + doip->doi = smk_cipso_doi_value; + doip->type = CIPSO_V4_MAP_PASS; + doip->tags[0] = CIPSO_V4_TAG_RBITMAP; + for (rc = 1; rc < CIPSO_V4_TAG_MAXCNT; rc++) + doip->tags[rc] = CIPSO_V4_TAG_INVALID; + + rc = netlbl_cfg_cipsov4_add(doip, &nai); + if (rc != 0) { + printk(KERN_WARNING "%s:%d cipso add rc = %d\n", + __func__, __LINE__, rc); + kfree(doip); + return; + } + rc = netlbl_cfg_cipsov4_map_add(doip->doi, NULL, NULL, NULL, &nai); + if (rc != 0) { + printk(KERN_WARNING "%s:%d map add rc = %d\n", + __func__, __LINE__, rc); + netlbl_cfg_cipsov4_del(doip->doi, &nai); + return; + } +} + +/** + * smk_unlbl_ambient - initialize the unlabeled domain + * @oldambient: previous domain string + */ +static void smk_unlbl_ambient(char *oldambient) +{ + int rc; + struct netlbl_audit nai; + + smk_netlabel_audit_set(&nai); + + if (oldambient != NULL) { + rc = netlbl_cfg_map_del(oldambient, PF_INET, NULL, NULL, &nai); + if (rc != 0) + printk(KERN_WARNING "%s:%d remove rc = %d\n", + __func__, __LINE__, rc); + } + if (smack_net_ambient == NULL) + smack_net_ambient = &smack_known_floor; + + rc = netlbl_cfg_unlbl_map_add(smack_net_ambient->smk_known, PF_INET, + NULL, NULL, &nai); + if (rc != 0) + printk(KERN_WARNING "%s:%d add rc = %d\n", + __func__, __LINE__, rc); +} + +/* + * Seq_file read operations for /smack/cipso + */ + +static void *cipso_seq_start(struct seq_file *s, loff_t *pos) +{ + return smk_seq_start(s, pos, &smack_known_list); +} + +static void *cipso_seq_next(struct seq_file *s, void *v, loff_t *pos) +{ + return smk_seq_next(s, v, pos, &smack_known_list); +} + +/* + * Print cipso labels in format: + * label level[/cat[,cat]] + */ +static int cipso_seq_show(struct seq_file *s, void *v) +{ + struct list_head *list = v; + struct smack_known *skp = + list_entry_rcu(list, struct smack_known, list); + struct netlbl_lsm_catmap *cmp = skp->smk_netlabel.attr.mls.cat; + char sep = '/'; + int i; + + /* + * Don't show a label that could not have been set using + * /smack/cipso. This is in support of the notion that + * anything read from /smack/cipso ought to be writeable + * to /smack/cipso. + * + * /smack/cipso2 should be used instead. + */ + if (strlen(skp->smk_known) >= SMK_LABELLEN) + return 0; + + seq_printf(s, "%s %3d", skp->smk_known, skp->smk_netlabel.attr.mls.lvl); + + for (i = netlbl_catmap_walk(cmp, 0); i >= 0; + i = netlbl_catmap_walk(cmp, i + 1)) { + seq_printf(s, "%c%d", sep, i); + sep = ','; + } + + seq_putc(s, '\n'); + + return 0; +} + +static const struct seq_operations cipso_seq_ops = { + .start = cipso_seq_start, + .next = cipso_seq_next, + .show = cipso_seq_show, + .stop = smk_seq_stop, +}; + +/** + * smk_open_cipso - open() for /smack/cipso + * @inode: inode structure representing file + * @file: "cipso" file pointer + * + * Connect our cipso_seq_* operations with /smack/cipso + * file_operations + */ +static int smk_open_cipso(struct inode *inode, struct file *file) +{ + return seq_open(file, &cipso_seq_ops); +} + +/** + * smk_set_cipso - do the work for write() for cipso and cipso2 + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start + * @format: /smack/cipso or /smack/cipso2 + * + * Accepts only one cipso rule per write call. + * Returns number of bytes written or error code, as appropriate + */ +static ssize_t smk_set_cipso(struct file *file, const char __user *buf, + size_t count, loff_t *ppos, int format) +{ + struct netlbl_lsm_catmap *old_cat; + struct smack_known *skp; + struct netlbl_lsm_secattr ncats; + char mapcatset[SMK_CIPSOLEN]; + int maplevel; + unsigned int cat; + int catlen; + ssize_t rc = -EINVAL; + char *data = NULL; + char *rule; + int ret; + int i; + + /* + * Must have privilege. + * No partial writes. + * Enough data must be present. + */ + if (!smack_privileged(CAP_MAC_ADMIN)) + return -EPERM; + if (*ppos != 0) + return -EINVAL; + if (format == SMK_FIXED24_FMT && + (count < SMK_CIPSOMIN || count > SMK_CIPSOMAX)) + return -EINVAL; + if (count > PAGE_SIZE) + return -EINVAL; + + data = memdup_user_nul(buf, count); + if (IS_ERR(data)) + return PTR_ERR(data); + + rule = data; + /* + * Only allow one writer at a time. Writes should be + * quite rare and small in any case. + */ + mutex_lock(&smack_cipso_lock); + + skp = smk_import_entry(rule, 0); + if (IS_ERR(skp)) { + rc = PTR_ERR(skp); + goto out; + } + + if (format == SMK_FIXED24_FMT) + rule += SMK_LABELLEN; + else + rule += strlen(skp->smk_known) + 1; + + if (rule > data + count) { + rc = -EOVERFLOW; + goto out; + } + + ret = sscanf(rule, "%d", &maplevel); + if (ret != 1 || maplevel < 0 || maplevel > SMACK_CIPSO_MAXLEVEL) + goto out; + + rule += SMK_DIGITLEN; + if (rule > data + count) { + rc = -EOVERFLOW; + goto out; + } + + ret = sscanf(rule, "%d", &catlen); + if (ret != 1 || catlen < 0 || catlen > SMACK_CIPSO_MAXCATNUM) + goto out; + + if (format == SMK_FIXED24_FMT && + count != (SMK_CIPSOMIN + catlen * SMK_DIGITLEN)) + goto out; + + memset(mapcatset, 0, sizeof(mapcatset)); + + for (i = 0; i < catlen; i++) { + rule += SMK_DIGITLEN; + if (rule > data + count) { + rc = -EOVERFLOW; + goto out; + } + ret = sscanf(rule, "%u", &cat); + if (ret != 1 || cat > SMACK_CIPSO_MAXCATNUM) + goto out; + + smack_catset_bit(cat, mapcatset); + } + + rc = smk_netlbl_mls(maplevel, mapcatset, &ncats, SMK_CIPSOLEN); + if (rc >= 0) { + old_cat = skp->smk_netlabel.attr.mls.cat; + skp->smk_netlabel.attr.mls.cat = ncats.attr.mls.cat; + skp->smk_netlabel.attr.mls.lvl = ncats.attr.mls.lvl; + synchronize_rcu(); + netlbl_catmap_free(old_cat); + rc = count; + /* + * This mapping may have been cached, so clear the cache. + */ + netlbl_cache_invalidate(); + } + +out: + mutex_unlock(&smack_cipso_lock); + kfree(data); + return rc; +} + +/** + * smk_write_cipso - write() for /smack/cipso + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start + * + * Accepts only one cipso rule per write call. + * Returns number of bytes written or error code, as appropriate + */ +static ssize_t smk_write_cipso(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + return smk_set_cipso(file, buf, count, ppos, SMK_FIXED24_FMT); +} + +static const struct file_operations smk_cipso_ops = { + .open = smk_open_cipso, + .read = seq_read, + .llseek = seq_lseek, + .write = smk_write_cipso, + .release = seq_release, +}; + +/* + * Seq_file read operations for /smack/cipso2 + */ + +/* + * Print cipso labels in format: + * label level[/cat[,cat]] + */ +static int cipso2_seq_show(struct seq_file *s, void *v) +{ + struct list_head *list = v; + struct smack_known *skp = + list_entry_rcu(list, struct smack_known, list); + struct netlbl_lsm_catmap *cmp = skp->smk_netlabel.attr.mls.cat; + char sep = '/'; + int i; + + seq_printf(s, "%s %3d", skp->smk_known, skp->smk_netlabel.attr.mls.lvl); + + for (i = netlbl_catmap_walk(cmp, 0); i >= 0; + i = netlbl_catmap_walk(cmp, i + 1)) { + seq_printf(s, "%c%d", sep, i); + sep = ','; + } + + seq_putc(s, '\n'); + + return 0; +} + +static const struct seq_operations cipso2_seq_ops = { + .start = cipso_seq_start, + .next = cipso_seq_next, + .show = cipso2_seq_show, + .stop = smk_seq_stop, +}; + +/** + * smk_open_cipso2 - open() for /smack/cipso2 + * @inode: inode structure representing file + * @file: "cipso2" file pointer + * + * Connect our cipso_seq_* operations with /smack/cipso2 + * file_operations + */ +static int smk_open_cipso2(struct inode *inode, struct file *file) +{ + return seq_open(file, &cipso2_seq_ops); +} + +/** + * smk_write_cipso2 - write() for /smack/cipso2 + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start + * + * Accepts only one cipso rule per write call. + * Returns number of bytes written or error code, as appropriate + */ +static ssize_t smk_write_cipso2(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + return smk_set_cipso(file, buf, count, ppos, SMK_LONG_FMT); +} + +static const struct file_operations smk_cipso2_ops = { + .open = smk_open_cipso2, + .read = seq_read, + .llseek = seq_lseek, + .write = smk_write_cipso2, + .release = seq_release, +}; + +/* + * Seq_file read operations for /smack/netlabel + */ + +static void *net4addr_seq_start(struct seq_file *s, loff_t *pos) +{ + return smk_seq_start(s, pos, &smk_net4addr_list); +} + +static void *net4addr_seq_next(struct seq_file *s, void *v, loff_t *pos) +{ + return smk_seq_next(s, v, pos, &smk_net4addr_list); +} + +/* + * Print host/label pairs + */ +static int net4addr_seq_show(struct seq_file *s, void *v) +{ + struct list_head *list = v; + struct smk_net4addr *skp = + list_entry_rcu(list, struct smk_net4addr, list); + char *kp = SMACK_CIPSO_OPTION; + + if (skp->smk_label != NULL) + kp = skp->smk_label->smk_known; + seq_printf(s, "%pI4/%d %s\n", &skp->smk_host.s_addr, + skp->smk_masks, kp); + + return 0; +} + +static const struct seq_operations net4addr_seq_ops = { + .start = net4addr_seq_start, + .next = net4addr_seq_next, + .show = net4addr_seq_show, + .stop = smk_seq_stop, +}; + +/** + * smk_open_net4addr - open() for /smack/netlabel + * @inode: inode structure representing file + * @file: "netlabel" file pointer + * + * Connect our net4addr_seq_* operations with /smack/netlabel + * file_operations + */ +static int smk_open_net4addr(struct inode *inode, struct file *file) +{ + return seq_open(file, &net4addr_seq_ops); +} + +/** + * smk_net4addr_insert + * @new : netlabel to insert + * + * This helper insert netlabel in the smack_net4addrs list + * sorted by netmask length (longest to smallest) + * locked by &smk_net4addr_lock in smk_write_net4addr + * + */ +static void smk_net4addr_insert(struct smk_net4addr *new) +{ + struct smk_net4addr *m; + struct smk_net4addr *m_next; + + if (list_empty(&smk_net4addr_list)) { + list_add_rcu(&new->list, &smk_net4addr_list); + return; + } + + m = list_entry_rcu(smk_net4addr_list.next, + struct smk_net4addr, list); + + /* the comparison '>' is a bit hacky, but works */ + if (new->smk_masks > m->smk_masks) { + list_add_rcu(&new->list, &smk_net4addr_list); + return; + } + + list_for_each_entry_rcu(m, &smk_net4addr_list, list) { + if (list_is_last(&m->list, &smk_net4addr_list)) { + list_add_rcu(&new->list, &m->list); + return; + } + m_next = list_entry_rcu(m->list.next, + struct smk_net4addr, list); + if (new->smk_masks > m_next->smk_masks) { + list_add_rcu(&new->list, &m->list); + return; + } + } +} + + +/** + * smk_write_net4addr - write() for /smack/netlabel + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start + * + * Accepts only one net4addr per write call. + * Returns number of bytes written or error code, as appropriate + */ +static ssize_t smk_write_net4addr(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct smk_net4addr *snp; + struct sockaddr_in newname; + char *smack; + struct smack_known *skp = NULL; + char *data; + char *host = (char *)&newname.sin_addr.s_addr; + int rc; + struct netlbl_audit audit_info; + struct in_addr mask; + unsigned int m; + unsigned int masks; + int found; + u32 mask_bits = (1<<31); + __be32 nsa; + u32 temp_mask; + + /* + * Must have privilege. + * No partial writes. + * Enough data must be present. + * "<addr/mask, as a.b.c.d/e><space><label>" + * "<addr, as a.b.c.d><space><label>" + */ + if (!smack_privileged(CAP_MAC_ADMIN)) + return -EPERM; + if (*ppos != 0) + return -EINVAL; + if (count < SMK_NETLBLADDRMIN || count > PAGE_SIZE - 1) + return -EINVAL; + + data = memdup_user_nul(buf, count); + if (IS_ERR(data)) + return PTR_ERR(data); + + smack = kzalloc(count + 1, GFP_KERNEL); + if (smack == NULL) { + rc = -ENOMEM; + goto free_data_out; + } + + rc = sscanf(data, "%hhd.%hhd.%hhd.%hhd/%u %s", + &host[0], &host[1], &host[2], &host[3], &masks, smack); + if (rc != 6) { + rc = sscanf(data, "%hhd.%hhd.%hhd.%hhd %s", + &host[0], &host[1], &host[2], &host[3], smack); + if (rc != 5) { + rc = -EINVAL; + goto free_out; + } + masks = 32; + } + if (masks > BEBITS) { + rc = -EINVAL; + goto free_out; + } + + /* + * If smack begins with '-', it is an option, don't import it + */ + if (smack[0] != '-') { + skp = smk_import_entry(smack, 0); + if (IS_ERR(skp)) { + rc = PTR_ERR(skp); + goto free_out; + } + } else { + /* + * Only the -CIPSO option is supported for IPv4 + */ + if (strcmp(smack, SMACK_CIPSO_OPTION) != 0) { + rc = -EINVAL; + goto free_out; + } + } + + for (m = masks, temp_mask = 0; m > 0; m--) { + temp_mask |= mask_bits; + mask_bits >>= 1; + } + mask.s_addr = cpu_to_be32(temp_mask); + + newname.sin_addr.s_addr &= mask.s_addr; + /* + * Only allow one writer at a time. Writes should be + * quite rare and small in any case. + */ + mutex_lock(&smk_net4addr_lock); + + nsa = newname.sin_addr.s_addr; + /* try to find if the prefix is already in the list */ + found = 0; + list_for_each_entry_rcu(snp, &smk_net4addr_list, list) { + if (snp->smk_host.s_addr == nsa && snp->smk_masks == masks) { + found = 1; + break; + } + } + smk_netlabel_audit_set(&audit_info); + + if (found == 0) { + snp = kzalloc(sizeof(*snp), GFP_KERNEL); + if (snp == NULL) + rc = -ENOMEM; + else { + rc = 0; + snp->smk_host.s_addr = newname.sin_addr.s_addr; + snp->smk_mask.s_addr = mask.s_addr; + snp->smk_label = skp; + snp->smk_masks = masks; + smk_net4addr_insert(snp); + } + } else { + /* + * Delete the unlabeled entry, only if the previous label + * wasn't the special CIPSO option + */ + if (snp->smk_label != NULL) + rc = netlbl_cfg_unlbl_static_del(&init_net, NULL, + &snp->smk_host, &snp->smk_mask, + PF_INET, &audit_info); + else + rc = 0; + snp->smk_label = skp; + } + + /* + * Now tell netlabel about the single label nature of + * this host so that incoming packets get labeled. + * but only if we didn't get the special CIPSO option + */ + if (rc == 0 && skp != NULL) + rc = netlbl_cfg_unlbl_static_add(&init_net, NULL, + &snp->smk_host, &snp->smk_mask, PF_INET, + snp->smk_label->smk_secid, &audit_info); + + if (rc == 0) + rc = count; + + mutex_unlock(&smk_net4addr_lock); + +free_out: + kfree(smack); +free_data_out: + kfree(data); + + return rc; +} + +static const struct file_operations smk_net4addr_ops = { + .open = smk_open_net4addr, + .read = seq_read, + .llseek = seq_lseek, + .write = smk_write_net4addr, + .release = seq_release, +}; + +#if IS_ENABLED(CONFIG_IPV6) +/* + * Seq_file read operations for /smack/netlabel6 + */ + +static void *net6addr_seq_start(struct seq_file *s, loff_t *pos) +{ + return smk_seq_start(s, pos, &smk_net6addr_list); +} + +static void *net6addr_seq_next(struct seq_file *s, void *v, loff_t *pos) +{ + return smk_seq_next(s, v, pos, &smk_net6addr_list); +} + +/* + * Print host/label pairs + */ +static int net6addr_seq_show(struct seq_file *s, void *v) +{ + struct list_head *list = v; + struct smk_net6addr *skp = + list_entry(list, struct smk_net6addr, list); + + if (skp->smk_label != NULL) + seq_printf(s, "%pI6/%d %s\n", &skp->smk_host, skp->smk_masks, + skp->smk_label->smk_known); + + return 0; +} + +static const struct seq_operations net6addr_seq_ops = { + .start = net6addr_seq_start, + .next = net6addr_seq_next, + .show = net6addr_seq_show, + .stop = smk_seq_stop, +}; + +/** + * smk_open_net6addr - open() for /smack/netlabel + * @inode: inode structure representing file + * @file: "netlabel" file pointer + * + * Connect our net6addr_seq_* operations with /smack/netlabel + * file_operations + */ +static int smk_open_net6addr(struct inode *inode, struct file *file) +{ + return seq_open(file, &net6addr_seq_ops); +} + +/** + * smk_net6addr_insert + * @new : entry to insert + * + * This inserts an entry in the smack_net6addrs list + * sorted by netmask length (longest to smallest) + * locked by &smk_net6addr_lock in smk_write_net6addr + * + */ +static void smk_net6addr_insert(struct smk_net6addr *new) +{ + struct smk_net6addr *m_next; + struct smk_net6addr *m; + + if (list_empty(&smk_net6addr_list)) { + list_add_rcu(&new->list, &smk_net6addr_list); + return; + } + + m = list_entry_rcu(smk_net6addr_list.next, + struct smk_net6addr, list); + + if (new->smk_masks > m->smk_masks) { + list_add_rcu(&new->list, &smk_net6addr_list); + return; + } + + list_for_each_entry_rcu(m, &smk_net6addr_list, list) { + if (list_is_last(&m->list, &smk_net6addr_list)) { + list_add_rcu(&new->list, &m->list); + return; + } + m_next = list_entry_rcu(m->list.next, + struct smk_net6addr, list); + if (new->smk_masks > m_next->smk_masks) { + list_add_rcu(&new->list, &m->list); + return; + } + } +} + + +/** + * smk_write_net6addr - write() for /smack/netlabel + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start + * + * Accepts only one net6addr per write call. + * Returns number of bytes written or error code, as appropriate + */ +static ssize_t smk_write_net6addr(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct smk_net6addr *snp; + struct in6_addr newname; + struct in6_addr fullmask; + struct smack_known *skp = NULL; + char *smack; + char *data; + int rc = 0; + int found = 0; + int i; + unsigned int scanned[8]; + unsigned int m; + unsigned int mask = 128; + + /* + * Must have privilege. + * No partial writes. + * Enough data must be present. + * "<addr/mask, as a:b:c:d:e:f:g:h/e><space><label>" + * "<addr, as a:b:c:d:e:f:g:h><space><label>" + */ + if (!smack_privileged(CAP_MAC_ADMIN)) + return -EPERM; + if (*ppos != 0) + return -EINVAL; + if (count < SMK_NETLBLADDRMIN || count > PAGE_SIZE - 1) + return -EINVAL; + + data = memdup_user_nul(buf, count); + if (IS_ERR(data)) + return PTR_ERR(data); + + smack = kzalloc(count + 1, GFP_KERNEL); + if (smack == NULL) { + rc = -ENOMEM; + goto free_data_out; + } + + i = sscanf(data, "%x:%x:%x:%x:%x:%x:%x:%x/%u %s", + &scanned[0], &scanned[1], &scanned[2], &scanned[3], + &scanned[4], &scanned[5], &scanned[6], &scanned[7], + &mask, smack); + if (i != 10) { + i = sscanf(data, "%x:%x:%x:%x:%x:%x:%x:%x %s", + &scanned[0], &scanned[1], &scanned[2], + &scanned[3], &scanned[4], &scanned[5], + &scanned[6], &scanned[7], smack); + if (i != 9) { + rc = -EINVAL; + goto free_out; + } + } + if (mask > 128) { + rc = -EINVAL; + goto free_out; + } + for (i = 0; i < 8; i++) { + if (scanned[i] > 0xffff) { + rc = -EINVAL; + goto free_out; + } + newname.s6_addr16[i] = htons(scanned[i]); + } + + /* + * If smack begins with '-', it is an option, don't import it + */ + if (smack[0] != '-') { + skp = smk_import_entry(smack, 0); + if (IS_ERR(skp)) { + rc = PTR_ERR(skp); + goto free_out; + } + } else { + /* + * Only -DELETE is supported for IPv6 + */ + if (strcmp(smack, SMACK_DELETE_OPTION) != 0) { + rc = -EINVAL; + goto free_out; + } + } + + for (i = 0, m = mask; i < 8; i++) { + if (m >= 16) { + fullmask.s6_addr16[i] = 0xffff; + m -= 16; + } else if (m > 0) { + fullmask.s6_addr16[i] = (1 << m) - 1; + m = 0; + } else + fullmask.s6_addr16[i] = 0; + newname.s6_addr16[i] &= fullmask.s6_addr16[i]; + } + + /* + * Only allow one writer at a time. Writes should be + * quite rare and small in any case. + */ + mutex_lock(&smk_net6addr_lock); + /* + * Try to find the prefix in the list + */ + list_for_each_entry_rcu(snp, &smk_net6addr_list, list) { + if (mask != snp->smk_masks) + continue; + for (found = 1, i = 0; i < 8; i++) { + if (newname.s6_addr16[i] != + snp->smk_host.s6_addr16[i]) { + found = 0; + break; + } + } + if (found == 1) + break; + } + if (found == 0) { + snp = kzalloc(sizeof(*snp), GFP_KERNEL); + if (snp == NULL) + rc = -ENOMEM; + else { + snp->smk_host = newname; + snp->smk_mask = fullmask; + snp->smk_masks = mask; + snp->smk_label = skp; + smk_net6addr_insert(snp); + } + } else { + snp->smk_label = skp; + } + + if (rc == 0) + rc = count; + + mutex_unlock(&smk_net6addr_lock); + +free_out: + kfree(smack); +free_data_out: + kfree(data); + + return rc; +} + +static const struct file_operations smk_net6addr_ops = { + .open = smk_open_net6addr, + .read = seq_read, + .llseek = seq_lseek, + .write = smk_write_net6addr, + .release = seq_release, +}; +#endif /* CONFIG_IPV6 */ + +/** + * smk_read_doi - read() for /smack/doi + * @filp: file pointer, not actually used + * @buf: where to put the result + * @count: maximum to send along + * @ppos: where to start + * + * Returns number of bytes read or error code, as appropriate + */ +static ssize_t smk_read_doi(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + char temp[80]; + ssize_t rc; + + if (*ppos != 0) + return 0; + + sprintf(temp, "%d", smk_cipso_doi_value); + rc = simple_read_from_buffer(buf, count, ppos, temp, strlen(temp)); + + return rc; +} + +/** + * smk_write_doi - write() for /smack/doi + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start + * + * Returns number of bytes written or error code, as appropriate + */ +static ssize_t smk_write_doi(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + char temp[80]; + int i; + + if (!smack_privileged(CAP_MAC_ADMIN)) + return -EPERM; + + if (count >= sizeof(temp) || count == 0) + return -EINVAL; + + if (copy_from_user(temp, buf, count) != 0) + return -EFAULT; + + temp[count] = '\0'; + + if (sscanf(temp, "%d", &i) != 1) + return -EINVAL; + + smk_cipso_doi_value = i; + + smk_cipso_doi(); + + return count; +} + +static const struct file_operations smk_doi_ops = { + .read = smk_read_doi, + .write = smk_write_doi, + .llseek = default_llseek, +}; + +/** + * smk_read_direct - read() for /smack/direct + * @filp: file pointer, not actually used + * @buf: where to put the result + * @count: maximum to send along + * @ppos: where to start + * + * Returns number of bytes read or error code, as appropriate + */ +static ssize_t smk_read_direct(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + char temp[80]; + ssize_t rc; + + if (*ppos != 0) + return 0; + + sprintf(temp, "%d", smack_cipso_direct); + rc = simple_read_from_buffer(buf, count, ppos, temp, strlen(temp)); + + return rc; +} + +/** + * smk_write_direct - write() for /smack/direct + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start + * + * Returns number of bytes written or error code, as appropriate + */ +static ssize_t smk_write_direct(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct smack_known *skp; + char temp[80]; + int i; + + if (!smack_privileged(CAP_MAC_ADMIN)) + return -EPERM; + + if (count >= sizeof(temp) || count == 0) + return -EINVAL; + + if (copy_from_user(temp, buf, count) != 0) + return -EFAULT; + + temp[count] = '\0'; + + if (sscanf(temp, "%d", &i) != 1) + return -EINVAL; + + /* + * Don't do anything if the value hasn't actually changed. + * If it is changing reset the level on entries that were + * set up to be direct when they were created. + */ + if (smack_cipso_direct != i) { + mutex_lock(&smack_known_lock); + list_for_each_entry_rcu(skp, &smack_known_list, list) + if (skp->smk_netlabel.attr.mls.lvl == + smack_cipso_direct) + skp->smk_netlabel.attr.mls.lvl = i; + smack_cipso_direct = i; + mutex_unlock(&smack_known_lock); + } + + return count; +} + +static const struct file_operations smk_direct_ops = { + .read = smk_read_direct, + .write = smk_write_direct, + .llseek = default_llseek, +}; + +/** + * smk_read_mapped - read() for /smack/mapped + * @filp: file pointer, not actually used + * @buf: where to put the result + * @count: maximum to send along + * @ppos: where to start + * + * Returns number of bytes read or error code, as appropriate + */ +static ssize_t smk_read_mapped(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + char temp[80]; + ssize_t rc; + + if (*ppos != 0) + return 0; + + sprintf(temp, "%d", smack_cipso_mapped); + rc = simple_read_from_buffer(buf, count, ppos, temp, strlen(temp)); + + return rc; +} + +/** + * smk_write_mapped - write() for /smack/mapped + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start + * + * Returns number of bytes written or error code, as appropriate + */ +static ssize_t smk_write_mapped(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct smack_known *skp; + char temp[80]; + int i; + + if (!smack_privileged(CAP_MAC_ADMIN)) + return -EPERM; + + if (count >= sizeof(temp) || count == 0) + return -EINVAL; + + if (copy_from_user(temp, buf, count) != 0) + return -EFAULT; + + temp[count] = '\0'; + + if (sscanf(temp, "%d", &i) != 1) + return -EINVAL; + + /* + * Don't do anything if the value hasn't actually changed. + * If it is changing reset the level on entries that were + * set up to be mapped when they were created. + */ + if (smack_cipso_mapped != i) { + mutex_lock(&smack_known_lock); + list_for_each_entry_rcu(skp, &smack_known_list, list) + if (skp->smk_netlabel.attr.mls.lvl == + smack_cipso_mapped) + skp->smk_netlabel.attr.mls.lvl = i; + smack_cipso_mapped = i; + mutex_unlock(&smack_known_lock); + } + + return count; +} + +static const struct file_operations smk_mapped_ops = { + .read = smk_read_mapped, + .write = smk_write_mapped, + .llseek = default_llseek, +}; + +/** + * smk_read_ambient - read() for /smack/ambient + * @filp: file pointer, not actually used + * @buf: where to put the result + * @cn: maximum to send along + * @ppos: where to start + * + * Returns number of bytes read or error code, as appropriate + */ +static ssize_t smk_read_ambient(struct file *filp, char __user *buf, + size_t cn, loff_t *ppos) +{ + ssize_t rc; + int asize; + + if (*ppos != 0) + return 0; + /* + * Being careful to avoid a problem in the case where + * smack_net_ambient gets changed in midstream. + */ + mutex_lock(&smack_ambient_lock); + + asize = strlen(smack_net_ambient->smk_known) + 1; + + if (cn >= asize) + rc = simple_read_from_buffer(buf, cn, ppos, + smack_net_ambient->smk_known, + asize); + else + rc = -EINVAL; + + mutex_unlock(&smack_ambient_lock); + + return rc; +} + +/** + * smk_write_ambient - write() for /smack/ambient + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start + * + * Returns number of bytes written or error code, as appropriate + */ +static ssize_t smk_write_ambient(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct smack_known *skp; + char *oldambient; + char *data; + int rc = count; + + if (!smack_privileged(CAP_MAC_ADMIN)) + return -EPERM; + + /* Enough data must be present */ + if (count == 0 || count > PAGE_SIZE) + return -EINVAL; + + data = memdup_user_nul(buf, count); + if (IS_ERR(data)) + return PTR_ERR(data); + + skp = smk_import_entry(data, count); + if (IS_ERR(skp)) { + rc = PTR_ERR(skp); + goto out; + } + + mutex_lock(&smack_ambient_lock); + + oldambient = smack_net_ambient->smk_known; + smack_net_ambient = skp; + smk_unlbl_ambient(oldambient); + + mutex_unlock(&smack_ambient_lock); + +out: + kfree(data); + return rc; +} + +static const struct file_operations smk_ambient_ops = { + .read = smk_read_ambient, + .write = smk_write_ambient, + .llseek = default_llseek, +}; + +/* + * Seq_file operations for /smack/onlycap + */ +static void *onlycap_seq_start(struct seq_file *s, loff_t *pos) +{ + return smk_seq_start(s, pos, &smack_onlycap_list); +} + +static void *onlycap_seq_next(struct seq_file *s, void *v, loff_t *pos) +{ + return smk_seq_next(s, v, pos, &smack_onlycap_list); +} + +static int onlycap_seq_show(struct seq_file *s, void *v) +{ + struct list_head *list = v; + struct smack_known_list_elem *sklep = + list_entry_rcu(list, struct smack_known_list_elem, list); + + seq_puts(s, sklep->smk_label->smk_known); + seq_putc(s, ' '); + + return 0; +} + +static const struct seq_operations onlycap_seq_ops = { + .start = onlycap_seq_start, + .next = onlycap_seq_next, + .show = onlycap_seq_show, + .stop = smk_seq_stop, +}; + +static int smk_open_onlycap(struct inode *inode, struct file *file) +{ + return seq_open(file, &onlycap_seq_ops); +} + +/** + * smk_list_swap_rcu - swap public list with a private one in RCU-safe way + * The caller must hold appropriate mutex to prevent concurrent modifications + * to the public list. + * Private list is assumed to be not accessible to other threads yet. + * + * @public: public list + * @private: private list + */ +static void smk_list_swap_rcu(struct list_head *public, + struct list_head *private) +{ + struct list_head *first, *last; + + if (list_empty(public)) { + list_splice_init_rcu(private, public, synchronize_rcu); + } else { + /* Remember public list before replacing it */ + first = public->next; + last = public->prev; + + /* Publish private list in place of public in RCU-safe way */ + private->prev->next = public; + private->next->prev = public; + rcu_assign_pointer(public->next, private->next); + public->prev = private->prev; + + synchronize_rcu(); + + /* When all readers are done with the old public list, + * attach it in place of private */ + private->next = first; + private->prev = last; + first->prev = private; + last->next = private; + } +} + +/** + * smk_parse_label_list - parse list of Smack labels, separated by spaces + * + * @data: the string to parse + * @list: destination list + * + * Returns zero on success or error code, as appropriate + */ +static int smk_parse_label_list(char *data, struct list_head *list) +{ + char *tok; + struct smack_known *skp; + struct smack_known_list_elem *sklep; + + while ((tok = strsep(&data, " ")) != NULL) { + if (!*tok) + continue; + + skp = smk_import_entry(tok, 0); + if (IS_ERR(skp)) + return PTR_ERR(skp); + + sklep = kzalloc(sizeof(*sklep), GFP_KERNEL); + if (sklep == NULL) + return -ENOMEM; + + sklep->smk_label = skp; + list_add(&sklep->list, list); + } + + return 0; +} + +/** + * smk_destroy_label_list - destroy a list of smack_known_list_elem + * @list: header pointer of the list to destroy + */ +void smk_destroy_label_list(struct list_head *list) +{ + struct smack_known_list_elem *sklep; + struct smack_known_list_elem *sklep2; + + list_for_each_entry_safe(sklep, sklep2, list, list) + kfree(sklep); + + INIT_LIST_HEAD(list); +} + +/** + * smk_write_onlycap - write() for smackfs/onlycap + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start + * + * Returns number of bytes written or error code, as appropriate + */ +static ssize_t smk_write_onlycap(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + char *data; + LIST_HEAD(list_tmp); + int rc; + + if (!smack_privileged(CAP_MAC_ADMIN)) + return -EPERM; + + if (count > PAGE_SIZE) + return -EINVAL; + + data = memdup_user_nul(buf, count); + if (IS_ERR(data)) + return PTR_ERR(data); + + rc = smk_parse_label_list(data, &list_tmp); + kfree(data); + + /* + * Clear the smack_onlycap on invalid label errors. This means + * that we can pass a null string to unset the onlycap value. + * + * Importing will also reject a label beginning with '-', + * so "-usecapabilities" will also work. + * + * But do so only on invalid label, not on system errors. + * The invalid label must be first to count as clearing attempt. + */ + if (!rc || (rc == -EINVAL && list_empty(&list_tmp))) { + mutex_lock(&smack_onlycap_lock); + smk_list_swap_rcu(&smack_onlycap_list, &list_tmp); + mutex_unlock(&smack_onlycap_lock); + rc = count; + } + + smk_destroy_label_list(&list_tmp); + + return rc; +} + +static const struct file_operations smk_onlycap_ops = { + .open = smk_open_onlycap, + .read = seq_read, + .write = smk_write_onlycap, + .llseek = seq_lseek, + .release = seq_release, +}; + +#ifdef CONFIG_SECURITY_SMACK_BRINGUP +/** + * smk_read_unconfined - read() for smackfs/unconfined + * @filp: file pointer, not actually used + * @buf: where to put the result + * @cn: maximum to send along + * @ppos: where to start + * + * Returns number of bytes read or error code, as appropriate + */ +static ssize_t smk_read_unconfined(struct file *filp, char __user *buf, + size_t cn, loff_t *ppos) +{ + char *smack = ""; + ssize_t rc = -EINVAL; + int asize; + + if (*ppos != 0) + return 0; + + if (smack_unconfined != NULL) + smack = smack_unconfined->smk_known; + + asize = strlen(smack) + 1; + + if (cn >= asize) + rc = simple_read_from_buffer(buf, cn, ppos, smack, asize); + + return rc; +} + +/** + * smk_write_unconfined - write() for smackfs/unconfined + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start + * + * Returns number of bytes written or error code, as appropriate + */ +static ssize_t smk_write_unconfined(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + char *data; + struct smack_known *skp; + int rc = count; + + if (!smack_privileged(CAP_MAC_ADMIN)) + return -EPERM; + + if (count > PAGE_SIZE) + return -EINVAL; + + data = memdup_user_nul(buf, count); + if (IS_ERR(data)) + return PTR_ERR(data); + + /* + * Clear the smack_unconfined on invalid label errors. This means + * that we can pass a null string to unset the unconfined value. + * + * Importing will also reject a label beginning with '-', + * so "-confine" will also work. + * + * But do so only on invalid label, not on system errors. + */ + skp = smk_import_entry(data, count); + if (PTR_ERR(skp) == -EINVAL) + skp = NULL; + else if (IS_ERR(skp)) { + rc = PTR_ERR(skp); + goto freeout; + } + + smack_unconfined = skp; + +freeout: + kfree(data); + return rc; +} + +static const struct file_operations smk_unconfined_ops = { + .read = smk_read_unconfined, + .write = smk_write_unconfined, + .llseek = default_llseek, +}; +#endif /* CONFIG_SECURITY_SMACK_BRINGUP */ + +/** + * smk_read_logging - read() for /smack/logging + * @filp: file pointer, not actually used + * @buf: where to put the result + * @count: maximum to send along + * @ppos: where to start + * + * Returns number of bytes read or error code, as appropriate + */ +static ssize_t smk_read_logging(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + char temp[32]; + ssize_t rc; + + if (*ppos != 0) + return 0; + + sprintf(temp, "%d\n", log_policy); + rc = simple_read_from_buffer(buf, count, ppos, temp, strlen(temp)); + return rc; +} + +/** + * smk_write_logging - write() for /smack/logging + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start + * + * Returns number of bytes written or error code, as appropriate + */ +static ssize_t smk_write_logging(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + char temp[32]; + int i; + + if (!smack_privileged(CAP_MAC_ADMIN)) + return -EPERM; + + if (count >= sizeof(temp) || count == 0) + return -EINVAL; + + if (copy_from_user(temp, buf, count) != 0) + return -EFAULT; + + temp[count] = '\0'; + + if (sscanf(temp, "%d", &i) != 1) + return -EINVAL; + if (i < 0 || i > 3) + return -EINVAL; + log_policy = i; + return count; +} + + + +static const struct file_operations smk_logging_ops = { + .read = smk_read_logging, + .write = smk_write_logging, + .llseek = default_llseek, +}; + +/* + * Seq_file read operations for /smack/load-self + */ + +static void *load_self_seq_start(struct seq_file *s, loff_t *pos) +{ + struct task_smack *tsp = smack_cred(current_cred()); + + return smk_seq_start(s, pos, &tsp->smk_rules); +} + +static void *load_self_seq_next(struct seq_file *s, void *v, loff_t *pos) +{ + struct task_smack *tsp = smack_cred(current_cred()); + + return smk_seq_next(s, v, pos, &tsp->smk_rules); +} + +static int load_self_seq_show(struct seq_file *s, void *v) +{ + struct list_head *list = v; + struct smack_rule *srp = + list_entry_rcu(list, struct smack_rule, list); + + smk_rule_show(s, srp, SMK_LABELLEN); + + return 0; +} + +static const struct seq_operations load_self_seq_ops = { + .start = load_self_seq_start, + .next = load_self_seq_next, + .show = load_self_seq_show, + .stop = smk_seq_stop, +}; + + +/** + * smk_open_load_self - open() for /smack/load-self2 + * @inode: inode structure representing file + * @file: "load" file pointer + * + * For reading, use load_seq_* seq_file reading operations. + */ +static int smk_open_load_self(struct inode *inode, struct file *file) +{ + return seq_open(file, &load_self_seq_ops); +} + +/** + * smk_write_load_self - write() for /smack/load-self + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start - must be 0 + * + */ +static ssize_t smk_write_load_self(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct task_smack *tsp = smack_cred(current_cred()); + + return smk_write_rules_list(file, buf, count, ppos, &tsp->smk_rules, + &tsp->smk_rules_lock, SMK_FIXED24_FMT); +} + +static const struct file_operations smk_load_self_ops = { + .open = smk_open_load_self, + .read = seq_read, + .llseek = seq_lseek, + .write = smk_write_load_self, + .release = seq_release, +}; + +/** + * smk_user_access - handle access check transaction + * @file: file pointer + * @buf: data from user space + * @count: bytes sent + * @ppos: where to start - must be 0 + * @format: /smack/load or /smack/load2 or /smack/change-rule format. + */ +static ssize_t smk_user_access(struct file *file, const char __user *buf, + size_t count, loff_t *ppos, int format) +{ + struct smack_parsed_rule rule; + char *data; + int res; + + data = simple_transaction_get(file, buf, count); + if (IS_ERR(data)) + return PTR_ERR(data); + + if (format == SMK_FIXED24_FMT) { + if (count < SMK_LOADLEN) + return -EINVAL; + res = smk_parse_rule(data, &rule, 0); + } else { + /* + * simple_transaction_get() returns null-terminated data + */ + res = smk_parse_long_rule(data, &rule, 0, 3); + } + + if (res >= 0) + res = smk_access(rule.smk_subject, rule.smk_object, + rule.smk_access1, NULL); + else if (res != -ENOENT) + return res; + + /* + * smk_access() can return a value > 0 in the "bringup" case. + */ + data[0] = res >= 0 ? '1' : '0'; + data[1] = '\0'; + + simple_transaction_set(file, 2); + + if (format == SMK_FIXED24_FMT) + return SMK_LOADLEN; + return count; +} + +/** + * smk_write_access - handle access check transaction + * @file: file pointer + * @buf: data from user space + * @count: bytes sent + * @ppos: where to start - must be 0 + */ +static ssize_t smk_write_access(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + return smk_user_access(file, buf, count, ppos, SMK_FIXED24_FMT); +} + +static const struct file_operations smk_access_ops = { + .write = smk_write_access, + .read = simple_transaction_read, + .release = simple_transaction_release, + .llseek = generic_file_llseek, +}; + + +/* + * Seq_file read operations for /smack/load2 + */ + +static int load2_seq_show(struct seq_file *s, void *v) +{ + struct list_head *list = v; + struct smack_rule *srp; + struct smack_known *skp = + list_entry_rcu(list, struct smack_known, list); + + list_for_each_entry_rcu(srp, &skp->smk_rules, list) + smk_rule_show(s, srp, SMK_LONGLABEL); + + return 0; +} + +static const struct seq_operations load2_seq_ops = { + .start = load2_seq_start, + .next = load2_seq_next, + .show = load2_seq_show, + .stop = smk_seq_stop, +}; + +/** + * smk_open_load2 - open() for /smack/load2 + * @inode: inode structure representing file + * @file: "load2" file pointer + * + * For reading, use load2_seq_* seq_file reading operations. + */ +static int smk_open_load2(struct inode *inode, struct file *file) +{ + return seq_open(file, &load2_seq_ops); +} + +/** + * smk_write_load2 - write() for /smack/load2 + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start - must be 0 + * + */ +static ssize_t smk_write_load2(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + /* + * Must have privilege. + */ + if (!smack_privileged(CAP_MAC_ADMIN)) + return -EPERM; + + return smk_write_rules_list(file, buf, count, ppos, NULL, NULL, + SMK_LONG_FMT); +} + +static const struct file_operations smk_load2_ops = { + .open = smk_open_load2, + .read = seq_read, + .llseek = seq_lseek, + .write = smk_write_load2, + .release = seq_release, +}; + +/* + * Seq_file read operations for /smack/load-self2 + */ + +static void *load_self2_seq_start(struct seq_file *s, loff_t *pos) +{ + struct task_smack *tsp = smack_cred(current_cred()); + + return smk_seq_start(s, pos, &tsp->smk_rules); +} + +static void *load_self2_seq_next(struct seq_file *s, void *v, loff_t *pos) +{ + struct task_smack *tsp = smack_cred(current_cred()); + + return smk_seq_next(s, v, pos, &tsp->smk_rules); +} + +static int load_self2_seq_show(struct seq_file *s, void *v) +{ + struct list_head *list = v; + struct smack_rule *srp = + list_entry_rcu(list, struct smack_rule, list); + + smk_rule_show(s, srp, SMK_LONGLABEL); + + return 0; +} + +static const struct seq_operations load_self2_seq_ops = { + .start = load_self2_seq_start, + .next = load_self2_seq_next, + .show = load_self2_seq_show, + .stop = smk_seq_stop, +}; + +/** + * smk_open_load_self2 - open() for /smack/load-self2 + * @inode: inode structure representing file + * @file: "load" file pointer + * + * For reading, use load_seq_* seq_file reading operations. + */ +static int smk_open_load_self2(struct inode *inode, struct file *file) +{ + return seq_open(file, &load_self2_seq_ops); +} + +/** + * smk_write_load_self2 - write() for /smack/load-self2 + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start - must be 0 + * + */ +static ssize_t smk_write_load_self2(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct task_smack *tsp = smack_cred(current_cred()); + + return smk_write_rules_list(file, buf, count, ppos, &tsp->smk_rules, + &tsp->smk_rules_lock, SMK_LONG_FMT); +} + +static const struct file_operations smk_load_self2_ops = { + .open = smk_open_load_self2, + .read = seq_read, + .llseek = seq_lseek, + .write = smk_write_load_self2, + .release = seq_release, +}; + +/** + * smk_write_access2 - handle access check transaction + * @file: file pointer + * @buf: data from user space + * @count: bytes sent + * @ppos: where to start - must be 0 + */ +static ssize_t smk_write_access2(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + return smk_user_access(file, buf, count, ppos, SMK_LONG_FMT); +} + +static const struct file_operations smk_access2_ops = { + .write = smk_write_access2, + .read = simple_transaction_read, + .release = simple_transaction_release, + .llseek = generic_file_llseek, +}; + +/** + * smk_write_revoke_subj - write() for /smack/revoke-subject + * @file: file pointer + * @buf: data from user space + * @count: bytes sent + * @ppos: where to start - must be 0 + */ +static ssize_t smk_write_revoke_subj(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + char *data; + const char *cp; + struct smack_known *skp; + struct smack_rule *sp; + struct list_head *rule_list; + struct mutex *rule_lock; + int rc = count; + + if (*ppos != 0) + return -EINVAL; + + if (!smack_privileged(CAP_MAC_ADMIN)) + return -EPERM; + + if (count == 0 || count > SMK_LONGLABEL) + return -EINVAL; + + data = memdup_user(buf, count); + if (IS_ERR(data)) + return PTR_ERR(data); + + cp = smk_parse_smack(data, count); + if (IS_ERR(cp)) { + rc = PTR_ERR(cp); + goto out_data; + } + + skp = smk_find_entry(cp); + if (skp == NULL) + goto out_cp; + + rule_list = &skp->smk_rules; + rule_lock = &skp->smk_rules_lock; + + mutex_lock(rule_lock); + + list_for_each_entry_rcu(sp, rule_list, list) + sp->smk_access = 0; + + mutex_unlock(rule_lock); + +out_cp: + kfree(cp); +out_data: + kfree(data); + + return rc; +} + +static const struct file_operations smk_revoke_subj_ops = { + .write = smk_write_revoke_subj, + .read = simple_transaction_read, + .release = simple_transaction_release, + .llseek = generic_file_llseek, +}; + +/** + * smk_init_sysfs - initialize /sys/fs/smackfs + * + */ +static int smk_init_sysfs(void) +{ + return sysfs_create_mount_point(fs_kobj, "smackfs"); +} + +/** + * smk_write_change_rule - write() for /smack/change-rule + * @file: file pointer + * @buf: data from user space + * @count: bytes sent + * @ppos: where to start - must be 0 + */ +static ssize_t smk_write_change_rule(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + /* + * Must have privilege. + */ + if (!smack_privileged(CAP_MAC_ADMIN)) + return -EPERM; + + return smk_write_rules_list(file, buf, count, ppos, NULL, NULL, + SMK_CHANGE_FMT); +} + +static const struct file_operations smk_change_rule_ops = { + .write = smk_write_change_rule, + .read = simple_transaction_read, + .release = simple_transaction_release, + .llseek = generic_file_llseek, +}; + +/** + * smk_read_syslog - read() for smackfs/syslog + * @filp: file pointer, not actually used + * @buf: where to put the result + * @cn: maximum to send along + * @ppos: where to start + * + * Returns number of bytes read or error code, as appropriate + */ +static ssize_t smk_read_syslog(struct file *filp, char __user *buf, + size_t cn, loff_t *ppos) +{ + struct smack_known *skp; + ssize_t rc = -EINVAL; + int asize; + + if (*ppos != 0) + return 0; + + if (smack_syslog_label == NULL) + skp = &smack_known_star; + else + skp = smack_syslog_label; + + asize = strlen(skp->smk_known) + 1; + + if (cn >= asize) + rc = simple_read_from_buffer(buf, cn, ppos, skp->smk_known, + asize); + + return rc; +} + +/** + * smk_write_syslog - write() for smackfs/syslog + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start + * + * Returns number of bytes written or error code, as appropriate + */ +static ssize_t smk_write_syslog(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + char *data; + struct smack_known *skp; + int rc = count; + + if (!smack_privileged(CAP_MAC_ADMIN)) + return -EPERM; + + /* Enough data must be present */ + if (count == 0 || count > PAGE_SIZE) + return -EINVAL; + + data = memdup_user_nul(buf, count); + if (IS_ERR(data)) + return PTR_ERR(data); + + skp = smk_import_entry(data, count); + if (IS_ERR(skp)) + rc = PTR_ERR(skp); + else + smack_syslog_label = skp; + + kfree(data); + return rc; +} + +static const struct file_operations smk_syslog_ops = { + .read = smk_read_syslog, + .write = smk_write_syslog, + .llseek = default_llseek, +}; + +/* + * Seq_file read operations for /smack/relabel-self + */ + +static void *relabel_self_seq_start(struct seq_file *s, loff_t *pos) +{ + struct task_smack *tsp = smack_cred(current_cred()); + + return smk_seq_start(s, pos, &tsp->smk_relabel); +} + +static void *relabel_self_seq_next(struct seq_file *s, void *v, loff_t *pos) +{ + struct task_smack *tsp = smack_cred(current_cred()); + + return smk_seq_next(s, v, pos, &tsp->smk_relabel); +} + +static int relabel_self_seq_show(struct seq_file *s, void *v) +{ + struct list_head *list = v; + struct smack_known_list_elem *sklep = + list_entry(list, struct smack_known_list_elem, list); + + seq_puts(s, sklep->smk_label->smk_known); + seq_putc(s, ' '); + + return 0; +} + +static const struct seq_operations relabel_self_seq_ops = { + .start = relabel_self_seq_start, + .next = relabel_self_seq_next, + .show = relabel_self_seq_show, + .stop = smk_seq_stop, +}; + +/** + * smk_open_relabel_self - open() for /smack/relabel-self + * @inode: inode structure representing file + * @file: "relabel-self" file pointer + * + * Connect our relabel_self_seq_* operations with /smack/relabel-self + * file_operations + */ +static int smk_open_relabel_self(struct inode *inode, struct file *file) +{ + return seq_open(file, &relabel_self_seq_ops); +} + +/** + * smk_write_relabel_self - write() for /smack/relabel-self + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start - must be 0 + * + */ +static ssize_t smk_write_relabel_self(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + char *data; + int rc; + LIST_HEAD(list_tmp); + + /* + * Must have privilege. + */ + if (!smack_privileged(CAP_MAC_ADMIN)) + return -EPERM; + + /* + * No partial write. + * Enough data must be present. + */ + if (*ppos != 0) + return -EINVAL; + if (count == 0 || count > PAGE_SIZE) + return -EINVAL; + + data = memdup_user_nul(buf, count); + if (IS_ERR(data)) + return PTR_ERR(data); + + rc = smk_parse_label_list(data, &list_tmp); + kfree(data); + + if (!rc || (rc == -EINVAL && list_empty(&list_tmp))) { + struct cred *new; + struct task_smack *tsp; + + new = prepare_creds(); + if (!new) { + rc = -ENOMEM; + goto out; + } + tsp = smack_cred(new); + smk_destroy_label_list(&tsp->smk_relabel); + list_splice(&list_tmp, &tsp->smk_relabel); + commit_creds(new); + return count; + } +out: + smk_destroy_label_list(&list_tmp); + return rc; +} + +static const struct file_operations smk_relabel_self_ops = { + .open = smk_open_relabel_self, + .read = seq_read, + .llseek = seq_lseek, + .write = smk_write_relabel_self, + .release = seq_release, +}; + +/** + * smk_read_ptrace - read() for /smack/ptrace + * @filp: file pointer, not actually used + * @buf: where to put the result + * @count: maximum to send along + * @ppos: where to start + * + * Returns number of bytes read or error code, as appropriate + */ +static ssize_t smk_read_ptrace(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + char temp[32]; + ssize_t rc; + + if (*ppos != 0) + return 0; + + sprintf(temp, "%d\n", smack_ptrace_rule); + rc = simple_read_from_buffer(buf, count, ppos, temp, strlen(temp)); + return rc; +} + +/** + * smk_write_ptrace - write() for /smack/ptrace + * @file: file pointer + * @buf: data from user space + * @count: bytes sent + * @ppos: where to start - must be 0 + */ +static ssize_t smk_write_ptrace(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + char temp[32]; + int i; + + if (!smack_privileged(CAP_MAC_ADMIN)) + return -EPERM; + + if (*ppos != 0 || count >= sizeof(temp) || count == 0) + return -EINVAL; + + if (copy_from_user(temp, buf, count) != 0) + return -EFAULT; + + temp[count] = '\0'; + + if (sscanf(temp, "%d", &i) != 1) + return -EINVAL; + if (i < SMACK_PTRACE_DEFAULT || i > SMACK_PTRACE_MAX) + return -EINVAL; + smack_ptrace_rule = i; + + return count; +} + +static const struct file_operations smk_ptrace_ops = { + .write = smk_write_ptrace, + .read = smk_read_ptrace, + .llseek = default_llseek, +}; + +/** + * smk_fill_super - fill the smackfs superblock + * @sb: the empty superblock + * @fc: unused + * + * Fill in the well known entries for the smack filesystem + * + * Returns 0 on success, an error code on failure + */ +static int smk_fill_super(struct super_block *sb, struct fs_context *fc) +{ + int rc; + + static const struct tree_descr smack_files[] = { + [SMK_LOAD] = { + "load", &smk_load_ops, S_IRUGO|S_IWUSR}, + [SMK_CIPSO] = { + "cipso", &smk_cipso_ops, S_IRUGO|S_IWUSR}, + [SMK_DOI] = { + "doi", &smk_doi_ops, S_IRUGO|S_IWUSR}, + [SMK_DIRECT] = { + "direct", &smk_direct_ops, S_IRUGO|S_IWUSR}, + [SMK_AMBIENT] = { + "ambient", &smk_ambient_ops, S_IRUGO|S_IWUSR}, + [SMK_NET4ADDR] = { + "netlabel", &smk_net4addr_ops, S_IRUGO|S_IWUSR}, + [SMK_ONLYCAP] = { + "onlycap", &smk_onlycap_ops, S_IRUGO|S_IWUSR}, + [SMK_LOGGING] = { + "logging", &smk_logging_ops, S_IRUGO|S_IWUSR}, + [SMK_LOAD_SELF] = { + "load-self", &smk_load_self_ops, S_IRUGO|S_IWUGO}, + [SMK_ACCESSES] = { + "access", &smk_access_ops, S_IRUGO|S_IWUGO}, + [SMK_MAPPED] = { + "mapped", &smk_mapped_ops, S_IRUGO|S_IWUSR}, + [SMK_LOAD2] = { + "load2", &smk_load2_ops, S_IRUGO|S_IWUSR}, + [SMK_LOAD_SELF2] = { + "load-self2", &smk_load_self2_ops, S_IRUGO|S_IWUGO}, + [SMK_ACCESS2] = { + "access2", &smk_access2_ops, S_IRUGO|S_IWUGO}, + [SMK_CIPSO2] = { + "cipso2", &smk_cipso2_ops, S_IRUGO|S_IWUSR}, + [SMK_REVOKE_SUBJ] = { + "revoke-subject", &smk_revoke_subj_ops, + S_IRUGO|S_IWUSR}, + [SMK_CHANGE_RULE] = { + "change-rule", &smk_change_rule_ops, S_IRUGO|S_IWUSR}, + [SMK_SYSLOG] = { + "syslog", &smk_syslog_ops, S_IRUGO|S_IWUSR}, + [SMK_PTRACE] = { + "ptrace", &smk_ptrace_ops, S_IRUGO|S_IWUSR}, +#ifdef CONFIG_SECURITY_SMACK_BRINGUP + [SMK_UNCONFINED] = { + "unconfined", &smk_unconfined_ops, S_IRUGO|S_IWUSR}, +#endif +#if IS_ENABLED(CONFIG_IPV6) + [SMK_NET6ADDR] = { + "ipv6host", &smk_net6addr_ops, S_IRUGO|S_IWUSR}, +#endif /* CONFIG_IPV6 */ + [SMK_RELABEL_SELF] = { + "relabel-self", &smk_relabel_self_ops, + S_IRUGO|S_IWUGO}, + /* last one */ + {""} + }; + + rc = simple_fill_super(sb, SMACK_MAGIC, smack_files); + if (rc != 0) { + printk(KERN_ERR "%s failed %d while creating inodes\n", + __func__, rc); + return rc; + } + + return 0; +} + +/** + * smk_get_tree - get the smackfs superblock + * @fc: The mount context, including any options + * + * Just passes everything along. + * + * Returns what the lower level code does. + */ +static int smk_get_tree(struct fs_context *fc) +{ + return get_tree_single(fc, smk_fill_super); +} + +static const struct fs_context_operations smk_context_ops = { + .get_tree = smk_get_tree, +}; + +/** + * smk_init_fs_context - Initialise a filesystem context for smackfs + * @fc: The blank mount context + */ +static int smk_init_fs_context(struct fs_context *fc) +{ + fc->ops = &smk_context_ops; + return 0; +} + +static struct file_system_type smk_fs_type = { + .name = "smackfs", + .init_fs_context = smk_init_fs_context, + .kill_sb = kill_litter_super, +}; + +static struct vfsmount *smackfs_mount; + +/** + * init_smk_fs - get the smackfs superblock + * + * register the smackfs + * + * Do not register smackfs if Smack wasn't enabled + * on boot. We can not put this method normally under the + * smack_init() code path since the security subsystem get + * initialized before the vfs caches. + * + * Returns true if we were not chosen on boot or if + * we were chosen and filesystem registration succeeded. + */ +static int __init init_smk_fs(void) +{ + int err; + int rc; + + if (smack_enabled == 0) + return 0; + + err = smk_init_sysfs(); + if (err) + printk(KERN_ERR "smackfs: sysfs mountpoint problem.\n"); + + err = register_filesystem(&smk_fs_type); + if (!err) { + smackfs_mount = kern_mount(&smk_fs_type); + if (IS_ERR(smackfs_mount)) { + printk(KERN_ERR "smackfs: could not mount!\n"); + err = PTR_ERR(smackfs_mount); + smackfs_mount = NULL; + } + } + + smk_cipso_doi(); + smk_unlbl_ambient(NULL); + + rc = smack_populate_secattr(&smack_known_floor); + if (err == 0 && rc < 0) + err = rc; + rc = smack_populate_secattr(&smack_known_hat); + if (err == 0 && rc < 0) + err = rc; + rc = smack_populate_secattr(&smack_known_huh); + if (err == 0 && rc < 0) + err = rc; + rc = smack_populate_secattr(&smack_known_star); + if (err == 0 && rc < 0) + err = rc; + rc = smack_populate_secattr(&smack_known_web); + if (err == 0 && rc < 0) + err = rc; + + return err; +} + +__initcall(init_smk_fs); diff --git a/security/tomoyo/.gitignore b/security/tomoyo/.gitignore new file mode 100644 index 000000000..9f300cdce --- /dev/null +++ b/security/tomoyo/.gitignore @@ -0,0 +1,3 @@ +# SPDX-License-Identifier: GPL-2.0-only +builtin-policy.h +policy/*.conf diff --git a/security/tomoyo/Kconfig b/security/tomoyo/Kconfig new file mode 100644 index 000000000..b9f867100 --- /dev/null +++ b/security/tomoyo/Kconfig @@ -0,0 +1,87 @@ +# SPDX-License-Identifier: GPL-2.0-only +config SECURITY_TOMOYO + bool "TOMOYO Linux Support" + depends on SECURITY + depends on NET + select SECURITYFS + select SECURITY_PATH + select SECURITY_NETWORK + select SRCU + select BUILD_BIN2C + default n + help + This selects TOMOYO Linux, pathname-based access control. + Required userspace tools and further information may be + found at <http://tomoyo.sourceforge.jp/>. + If you are unsure how to answer this question, answer N. + +config SECURITY_TOMOYO_MAX_ACCEPT_ENTRY + int "Default maximal count for learning mode" + default 2048 + range 0 2147483647 + depends on SECURITY_TOMOYO + help + This is the default value for maximal ACL entries + that are automatically appended into policy at "learning mode". + Some programs access thousands of objects, so running + such programs in "learning mode" dulls the system response + and consumes much memory. + This is the safeguard for such programs. + +config SECURITY_TOMOYO_MAX_AUDIT_LOG + int "Default maximal count for audit log" + default 1024 + range 0 2147483647 + depends on SECURITY_TOMOYO + help + This is the default value for maximal entries for + audit logs that the kernel can hold on memory. + You can read the log via /sys/kernel/security/tomoyo/audit. + If you don't need audit logs, you may set this value to 0. + +config SECURITY_TOMOYO_OMIT_USERSPACE_LOADER + bool "Activate without calling userspace policy loader." + default n + depends on SECURITY_TOMOYO + help + Say Y here if you want to activate access control as soon as built-in + policy was loaded. This option will be useful for systems where + operations which can lead to the hijacking of the boot sequence are + needed before loading the policy. For example, you can activate + immediately after loading the fixed part of policy which will allow + only operations needed for mounting a partition which contains the + variant part of policy and verifying (e.g. running GPG check) and + loading the variant part of policy. Since you can start using + enforcing mode from the beginning, you can reduce the possibility of + hijacking the boot sequence. + +config SECURITY_TOMOYO_POLICY_LOADER + string "Location of userspace policy loader" + default "/sbin/tomoyo-init" + depends on SECURITY_TOMOYO + depends on !SECURITY_TOMOYO_OMIT_USERSPACE_LOADER + help + This is the default pathname of policy loader which is called before + activation. You can override this setting via TOMOYO_loader= kernel + command line option. + +config SECURITY_TOMOYO_ACTIVATION_TRIGGER + string "Trigger for calling userspace policy loader" + default "/sbin/init" + depends on SECURITY_TOMOYO + depends on !SECURITY_TOMOYO_OMIT_USERSPACE_LOADER + help + This is the default pathname of activation trigger. + You can override this setting via TOMOYO_trigger= kernel command line + option. For example, if you pass init=/bin/systemd option, you may + want to also pass TOMOYO_trigger=/bin/systemd option. + +config SECURITY_TOMOYO_INSECURE_BUILTIN_SETTING + bool "Use insecure built-in settings for fuzzing tests." + default n + depends on SECURITY_TOMOYO + select SECURITY_TOMOYO_OMIT_USERSPACE_LOADER + help + Enabling this option forces minimal built-in policy and disables + domain/program checks for run-time policy modifications. Please enable + this option only if this kernel is built for doing fuzzing tests. diff --git a/security/tomoyo/Makefile b/security/tomoyo/Makefile new file mode 100644 index 000000000..221eaadff --- /dev/null +++ b/security/tomoyo/Makefile @@ -0,0 +1,16 @@ +# SPDX-License-Identifier: GPL-2.0 +obj-y = audit.o common.o condition.o domain.o environ.o file.o gc.o group.o load_policy.o memory.o mount.o network.o realpath.o securityfs_if.o tomoyo.o util.o + +targets += builtin-policy.h +define do_policy +echo "static char tomoyo_builtin_$(1)[] __initdata ="; \ +$(objtree)/scripts/bin2c <$(firstword $(wildcard $(obj)/policy/$(1).conf $(srctree)/$(src)/policy/$(1).conf.default) /dev/null); \ +echo ";" +endef +quiet_cmd_policy = POLICY $@ + cmd_policy = ($(call do_policy,profile); $(call do_policy,exception_policy); $(call do_policy,domain_policy); $(call do_policy,manager); $(call do_policy,stat)) >$@ + +$(obj)/builtin-policy.h: $(wildcard $(obj)/policy/*.conf $(srctree)/$(src)/policy/*.conf.default) FORCE + $(call if_changed,policy) + +$(obj)/common.o: $(obj)/builtin-policy.h diff --git a/security/tomoyo/audit.c b/security/tomoyo/audit.c new file mode 100644 index 000000000..7cf8fdbb2 --- /dev/null +++ b/security/tomoyo/audit.c @@ -0,0 +1,479 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * security/tomoyo/audit.c + * + * Copyright (C) 2005-2011 NTT DATA CORPORATION + */ + +#include "common.h" +#include <linux/slab.h> + +/** + * tomoyo_print_bprm - Print "struct linux_binprm" for auditing. + * + * @bprm: Pointer to "struct linux_binprm". + * @dump: Pointer to "struct tomoyo_page_dump". + * + * Returns the contents of @bprm on success, NULL otherwise. + * + * This function uses kzalloc(), so caller must kfree() if this function + * didn't return NULL. + */ +static char *tomoyo_print_bprm(struct linux_binprm *bprm, + struct tomoyo_page_dump *dump) +{ + static const int tomoyo_buffer_len = 4096 * 2; + char *buffer = kzalloc(tomoyo_buffer_len, GFP_NOFS); + char *cp; + char *last_start; + int len; + unsigned long pos = bprm->p; + int offset = pos % PAGE_SIZE; + int argv_count = bprm->argc; + int envp_count = bprm->envc; + bool truncated = false; + + if (!buffer) + return NULL; + len = snprintf(buffer, tomoyo_buffer_len - 1, "argv[]={ "); + cp = buffer + len; + if (!argv_count) { + memmove(cp, "} envp[]={ ", 11); + cp += 11; + } + last_start = cp; + while (argv_count || envp_count) { + if (!tomoyo_dump_page(bprm, pos, dump)) + goto out; + pos += PAGE_SIZE - offset; + /* Read. */ + while (offset < PAGE_SIZE) { + const char *kaddr = dump->data; + const unsigned char c = kaddr[offset++]; + + if (cp == last_start) + *cp++ = '"'; + if (cp >= buffer + tomoyo_buffer_len - 32) { + /* Reserve some room for "..." string. */ + truncated = true; + } else if (c == '\\') { + *cp++ = '\\'; + *cp++ = '\\'; + } else if (c > ' ' && c < 127) { + *cp++ = c; + } else if (!c) { + *cp++ = '"'; + *cp++ = ' '; + last_start = cp; + } else { + *cp++ = '\\'; + *cp++ = (c >> 6) + '0'; + *cp++ = ((c >> 3) & 7) + '0'; + *cp++ = (c & 7) + '0'; + } + if (c) + continue; + if (argv_count) { + if (--argv_count == 0) { + if (truncated) { + cp = last_start; + memmove(cp, "... ", 4); + cp += 4; + } + memmove(cp, "} envp[]={ ", 11); + cp += 11; + last_start = cp; + truncated = false; + } + } else if (envp_count) { + if (--envp_count == 0) { + if (truncated) { + cp = last_start; + memmove(cp, "... ", 4); + cp += 4; + } + } + } + if (!argv_count && !envp_count) + break; + } + offset = 0; + } + *cp++ = '}'; + *cp = '\0'; + return buffer; +out: + snprintf(buffer, tomoyo_buffer_len - 1, + "argv[]={ ... } envp[]= { ... }"); + return buffer; +} + +/** + * tomoyo_filetype - Get string representation of file type. + * + * @mode: Mode value for stat(). + * + * Returns file type string. + */ +static inline const char *tomoyo_filetype(const umode_t mode) +{ + switch (mode & S_IFMT) { + case S_IFREG: + case 0: + return tomoyo_condition_keyword[TOMOYO_TYPE_IS_FILE]; + case S_IFDIR: + return tomoyo_condition_keyword[TOMOYO_TYPE_IS_DIRECTORY]; + case S_IFLNK: + return tomoyo_condition_keyword[TOMOYO_TYPE_IS_SYMLINK]; + case S_IFIFO: + return tomoyo_condition_keyword[TOMOYO_TYPE_IS_FIFO]; + case S_IFSOCK: + return tomoyo_condition_keyword[TOMOYO_TYPE_IS_SOCKET]; + case S_IFBLK: + return tomoyo_condition_keyword[TOMOYO_TYPE_IS_BLOCK_DEV]; + case S_IFCHR: + return tomoyo_condition_keyword[TOMOYO_TYPE_IS_CHAR_DEV]; + } + return "unknown"; /* This should not happen. */ +} + +/** + * tomoyo_print_header - Get header line of audit log. + * + * @r: Pointer to "struct tomoyo_request_info". + * + * Returns string representation. + * + * This function uses kmalloc(), so caller must kfree() if this function + * didn't return NULL. + */ +static char *tomoyo_print_header(struct tomoyo_request_info *r) +{ + struct tomoyo_time stamp; + const pid_t gpid = task_pid_nr(current); + struct tomoyo_obj_info *obj = r->obj; + static const int tomoyo_buffer_len = 4096; + char *buffer = kmalloc(tomoyo_buffer_len, GFP_NOFS); + int pos; + u8 i; + + if (!buffer) + return NULL; + + tomoyo_convert_time(ktime_get_real_seconds(), &stamp); + + pos = snprintf(buffer, tomoyo_buffer_len - 1, + "#%04u/%02u/%02u %02u:%02u:%02u# profile=%u mode=%s granted=%s (global-pid=%u) task={ pid=%u ppid=%u uid=%u gid=%u euid=%u egid=%u suid=%u sgid=%u fsuid=%u fsgid=%u }", + stamp.year, stamp.month, stamp.day, stamp.hour, + stamp.min, stamp.sec, r->profile, tomoyo_mode[r->mode], + str_yes_no(r->granted), gpid, tomoyo_sys_getpid(), + tomoyo_sys_getppid(), + from_kuid(&init_user_ns, current_uid()), + from_kgid(&init_user_ns, current_gid()), + from_kuid(&init_user_ns, current_euid()), + from_kgid(&init_user_ns, current_egid()), + from_kuid(&init_user_ns, current_suid()), + from_kgid(&init_user_ns, current_sgid()), + from_kuid(&init_user_ns, current_fsuid()), + from_kgid(&init_user_ns, current_fsgid())); + if (!obj) + goto no_obj_info; + if (!obj->validate_done) { + tomoyo_get_attributes(obj); + obj->validate_done = true; + } + for (i = 0; i < TOMOYO_MAX_PATH_STAT; i++) { + struct tomoyo_mini_stat *stat; + unsigned int dev; + umode_t mode; + + if (!obj->stat_valid[i]) + continue; + stat = &obj->stat[i]; + dev = stat->dev; + mode = stat->mode; + if (i & 1) { + pos += snprintf(buffer + pos, + tomoyo_buffer_len - 1 - pos, + " path%u.parent={ uid=%u gid=%u ino=%lu perm=0%o }", + (i >> 1) + 1, + from_kuid(&init_user_ns, stat->uid), + from_kgid(&init_user_ns, stat->gid), + (unsigned long)stat->ino, + stat->mode & S_IALLUGO); + continue; + } + pos += snprintf(buffer + pos, tomoyo_buffer_len - 1 - pos, + " path%u={ uid=%u gid=%u ino=%lu major=%u minor=%u perm=0%o type=%s", + (i >> 1) + 1, + from_kuid(&init_user_ns, stat->uid), + from_kgid(&init_user_ns, stat->gid), + (unsigned long)stat->ino, + MAJOR(dev), MINOR(dev), + mode & S_IALLUGO, tomoyo_filetype(mode)); + if (S_ISCHR(mode) || S_ISBLK(mode)) { + dev = stat->rdev; + pos += snprintf(buffer + pos, + tomoyo_buffer_len - 1 - pos, + " dev_major=%u dev_minor=%u", + MAJOR(dev), MINOR(dev)); + } + pos += snprintf(buffer + pos, tomoyo_buffer_len - 1 - pos, + " }"); + } +no_obj_info: + if (pos < tomoyo_buffer_len - 1) + return buffer; + kfree(buffer); + return NULL; +} + +/** + * tomoyo_init_log - Allocate buffer for audit logs. + * + * @r: Pointer to "struct tomoyo_request_info". + * @len: Buffer size needed for @fmt and @args. + * @fmt: The printf()'s format string. + * @args: va_list structure for @fmt. + * + * Returns pointer to allocated memory. + * + * This function uses kzalloc(), so caller must kfree() if this function + * didn't return NULL. + */ +char *tomoyo_init_log(struct tomoyo_request_info *r, int len, const char *fmt, + va_list args) +{ + char *buf = NULL; + char *bprm_info = NULL; + const char *header = NULL; + char *realpath = NULL; + const char *symlink = NULL; + int pos; + const char *domainname = r->domain->domainname->name; + + header = tomoyo_print_header(r); + if (!header) + return NULL; + /* +10 is for '\n' etc. and '\0'. */ + len += strlen(domainname) + strlen(header) + 10; + if (r->ee) { + struct file *file = r->ee->bprm->file; + + realpath = tomoyo_realpath_from_path(&file->f_path); + bprm_info = tomoyo_print_bprm(r->ee->bprm, &r->ee->dump); + if (!realpath || !bprm_info) + goto out; + /* +80 is for " exec={ realpath=\"%s\" argc=%d envc=%d %s }" */ + len += strlen(realpath) + 80 + strlen(bprm_info); + } else if (r->obj && r->obj->symlink_target) { + symlink = r->obj->symlink_target->name; + /* +18 is for " symlink.target=\"%s\"" */ + len += 18 + strlen(symlink); + } + len = tomoyo_round2(len); + buf = kzalloc(len, GFP_NOFS); + if (!buf) + goto out; + len--; + pos = snprintf(buf, len, "%s", header); + if (realpath) { + struct linux_binprm *bprm = r->ee->bprm; + + pos += snprintf(buf + pos, len - pos, + " exec={ realpath=\"%s\" argc=%d envc=%d %s }", + realpath, bprm->argc, bprm->envc, bprm_info); + } else if (symlink) + pos += snprintf(buf + pos, len - pos, " symlink.target=\"%s\"", + symlink); + pos += snprintf(buf + pos, len - pos, "\n%s\n", domainname); + vsnprintf(buf + pos, len - pos, fmt, args); +out: + kfree(realpath); + kfree(bprm_info); + kfree(header); + return buf; +} + +/* Wait queue for /sys/kernel/security/tomoyo/audit. */ +static DECLARE_WAIT_QUEUE_HEAD(tomoyo_log_wait); + +/* Structure for audit log. */ +struct tomoyo_log { + struct list_head list; + char *log; + int size; +}; + +/* The list for "struct tomoyo_log". */ +static LIST_HEAD(tomoyo_log); + +/* Lock for "struct list_head tomoyo_log". */ +static DEFINE_SPINLOCK(tomoyo_log_lock); + +/* Length of "struct list_head tomoyo_log". */ +static unsigned int tomoyo_log_count; + +/** + * tomoyo_get_audit - Get audit mode. + * + * @ns: Pointer to "struct tomoyo_policy_namespace". + * @profile: Profile number. + * @index: Index number of functionality. + * @matched_acl: Pointer to "struct tomoyo_acl_info". + * @is_granted: True if granted log, false otherwise. + * + * Returns true if this request should be audited, false otherwise. + */ +static bool tomoyo_get_audit(const struct tomoyo_policy_namespace *ns, + const u8 profile, const u8 index, + const struct tomoyo_acl_info *matched_acl, + const bool is_granted) +{ + u8 mode; + const u8 category = tomoyo_index2category[index] + + TOMOYO_MAX_MAC_INDEX; + struct tomoyo_profile *p; + + if (!tomoyo_policy_loaded) + return false; + p = tomoyo_profile(ns, profile); + if (tomoyo_log_count >= p->pref[TOMOYO_PREF_MAX_AUDIT_LOG]) + return false; + if (is_granted && matched_acl && matched_acl->cond && + matched_acl->cond->grant_log != TOMOYO_GRANTLOG_AUTO) + return matched_acl->cond->grant_log == TOMOYO_GRANTLOG_YES; + mode = p->config[index]; + if (mode == TOMOYO_CONFIG_USE_DEFAULT) + mode = p->config[category]; + if (mode == TOMOYO_CONFIG_USE_DEFAULT) + mode = p->default_config; + if (is_granted) + return mode & TOMOYO_CONFIG_WANT_GRANT_LOG; + return mode & TOMOYO_CONFIG_WANT_REJECT_LOG; +} + +/** + * tomoyo_write_log2 - Write an audit log. + * + * @r: Pointer to "struct tomoyo_request_info". + * @len: Buffer size needed for @fmt and @args. + * @fmt: The printf()'s format string. + * @args: va_list structure for @fmt. + * + * Returns nothing. + */ +void tomoyo_write_log2(struct tomoyo_request_info *r, int len, const char *fmt, + va_list args) +{ + char *buf; + struct tomoyo_log *entry; + bool quota_exceeded = false; + + if (!tomoyo_get_audit(r->domain->ns, r->profile, r->type, + r->matched_acl, r->granted)) + goto out; + buf = tomoyo_init_log(r, len, fmt, args); + if (!buf) + goto out; + entry = kzalloc(sizeof(*entry), GFP_NOFS); + if (!entry) { + kfree(buf); + goto out; + } + entry->log = buf; + len = tomoyo_round2(strlen(buf) + 1); + /* + * The entry->size is used for memory quota checks. + * Don't go beyond strlen(entry->log). + */ + entry->size = len + tomoyo_round2(sizeof(*entry)); + spin_lock(&tomoyo_log_lock); + if (tomoyo_memory_quota[TOMOYO_MEMORY_AUDIT] && + tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] + entry->size >= + tomoyo_memory_quota[TOMOYO_MEMORY_AUDIT]) { + quota_exceeded = true; + } else { + tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] += entry->size; + list_add_tail(&entry->list, &tomoyo_log); + tomoyo_log_count++; + } + spin_unlock(&tomoyo_log_lock); + if (quota_exceeded) { + kfree(buf); + kfree(entry); + goto out; + } + wake_up(&tomoyo_log_wait); +out: + return; +} + +/** + * tomoyo_write_log - Write an audit log. + * + * @r: Pointer to "struct tomoyo_request_info". + * @fmt: The printf()'s format string, followed by parameters. + * + * Returns nothing. + */ +void tomoyo_write_log(struct tomoyo_request_info *r, const char *fmt, ...) +{ + va_list args; + int len; + + va_start(args, fmt); + len = vsnprintf(NULL, 0, fmt, args) + 1; + va_end(args); + va_start(args, fmt); + tomoyo_write_log2(r, len, fmt, args); + va_end(args); +} + +/** + * tomoyo_read_log - Read an audit log. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * + * Returns nothing. + */ +void tomoyo_read_log(struct tomoyo_io_buffer *head) +{ + struct tomoyo_log *ptr = NULL; + + if (head->r.w_pos) + return; + kfree(head->read_buf); + head->read_buf = NULL; + spin_lock(&tomoyo_log_lock); + if (!list_empty(&tomoyo_log)) { + ptr = list_entry(tomoyo_log.next, typeof(*ptr), list); + list_del(&ptr->list); + tomoyo_log_count--; + tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] -= ptr->size; + } + spin_unlock(&tomoyo_log_lock); + if (ptr) { + head->read_buf = ptr->log; + head->r.w[head->r.w_pos++] = head->read_buf; + kfree(ptr); + } +} + +/** + * tomoyo_poll_log - Wait for an audit log. + * + * @file: Pointer to "struct file". + * @wait: Pointer to "poll_table". Maybe NULL. + * + * Returns EPOLLIN | EPOLLRDNORM when ready to read an audit log. + */ +__poll_t tomoyo_poll_log(struct file *file, poll_table *wait) +{ + if (tomoyo_log_count) + return EPOLLIN | EPOLLRDNORM; + poll_wait(file, &tomoyo_log_wait, wait); + if (tomoyo_log_count) + return EPOLLIN | EPOLLRDNORM; + return 0; +} diff --git a/security/tomoyo/common.c b/security/tomoyo/common.c new file mode 100644 index 000000000..f4cd9b58b --- /dev/null +++ b/security/tomoyo/common.c @@ -0,0 +1,2870 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * security/tomoyo/common.c + * + * Copyright (C) 2005-2011 NTT DATA CORPORATION + */ + +#include <linux/uaccess.h> +#include <linux/slab.h> +#include <linux/security.h> +#include <linux/string_helpers.h> +#include "common.h" + +/* String table for operation mode. */ +const char * const tomoyo_mode[TOMOYO_CONFIG_MAX_MODE] = { + [TOMOYO_CONFIG_DISABLED] = "disabled", + [TOMOYO_CONFIG_LEARNING] = "learning", + [TOMOYO_CONFIG_PERMISSIVE] = "permissive", + [TOMOYO_CONFIG_ENFORCING] = "enforcing" +}; + +/* String table for /sys/kernel/security/tomoyo/profile */ +const char * const tomoyo_mac_keywords[TOMOYO_MAX_MAC_INDEX + + TOMOYO_MAX_MAC_CATEGORY_INDEX] = { + /* CONFIG::file group */ + [TOMOYO_MAC_FILE_EXECUTE] = "execute", + [TOMOYO_MAC_FILE_OPEN] = "open", + [TOMOYO_MAC_FILE_CREATE] = "create", + [TOMOYO_MAC_FILE_UNLINK] = "unlink", + [TOMOYO_MAC_FILE_GETATTR] = "getattr", + [TOMOYO_MAC_FILE_MKDIR] = "mkdir", + [TOMOYO_MAC_FILE_RMDIR] = "rmdir", + [TOMOYO_MAC_FILE_MKFIFO] = "mkfifo", + [TOMOYO_MAC_FILE_MKSOCK] = "mksock", + [TOMOYO_MAC_FILE_TRUNCATE] = "truncate", + [TOMOYO_MAC_FILE_SYMLINK] = "symlink", + [TOMOYO_MAC_FILE_MKBLOCK] = "mkblock", + [TOMOYO_MAC_FILE_MKCHAR] = "mkchar", + [TOMOYO_MAC_FILE_LINK] = "link", + [TOMOYO_MAC_FILE_RENAME] = "rename", + [TOMOYO_MAC_FILE_CHMOD] = "chmod", + [TOMOYO_MAC_FILE_CHOWN] = "chown", + [TOMOYO_MAC_FILE_CHGRP] = "chgrp", + [TOMOYO_MAC_FILE_IOCTL] = "ioctl", + [TOMOYO_MAC_FILE_CHROOT] = "chroot", + [TOMOYO_MAC_FILE_MOUNT] = "mount", + [TOMOYO_MAC_FILE_UMOUNT] = "unmount", + [TOMOYO_MAC_FILE_PIVOT_ROOT] = "pivot_root", + /* CONFIG::network group */ + [TOMOYO_MAC_NETWORK_INET_STREAM_BIND] = "inet_stream_bind", + [TOMOYO_MAC_NETWORK_INET_STREAM_LISTEN] = "inet_stream_listen", + [TOMOYO_MAC_NETWORK_INET_STREAM_CONNECT] = "inet_stream_connect", + [TOMOYO_MAC_NETWORK_INET_DGRAM_BIND] = "inet_dgram_bind", + [TOMOYO_MAC_NETWORK_INET_DGRAM_SEND] = "inet_dgram_send", + [TOMOYO_MAC_NETWORK_INET_RAW_BIND] = "inet_raw_bind", + [TOMOYO_MAC_NETWORK_INET_RAW_SEND] = "inet_raw_send", + [TOMOYO_MAC_NETWORK_UNIX_STREAM_BIND] = "unix_stream_bind", + [TOMOYO_MAC_NETWORK_UNIX_STREAM_LISTEN] = "unix_stream_listen", + [TOMOYO_MAC_NETWORK_UNIX_STREAM_CONNECT] = "unix_stream_connect", + [TOMOYO_MAC_NETWORK_UNIX_DGRAM_BIND] = "unix_dgram_bind", + [TOMOYO_MAC_NETWORK_UNIX_DGRAM_SEND] = "unix_dgram_send", + [TOMOYO_MAC_NETWORK_UNIX_SEQPACKET_BIND] = "unix_seqpacket_bind", + [TOMOYO_MAC_NETWORK_UNIX_SEQPACKET_LISTEN] = "unix_seqpacket_listen", + [TOMOYO_MAC_NETWORK_UNIX_SEQPACKET_CONNECT] = "unix_seqpacket_connect", + /* CONFIG::misc group */ + [TOMOYO_MAC_ENVIRON] = "env", + /* CONFIG group */ + [TOMOYO_MAX_MAC_INDEX + TOMOYO_MAC_CATEGORY_FILE] = "file", + [TOMOYO_MAX_MAC_INDEX + TOMOYO_MAC_CATEGORY_NETWORK] = "network", + [TOMOYO_MAX_MAC_INDEX + TOMOYO_MAC_CATEGORY_MISC] = "misc", +}; + +/* String table for conditions. */ +const char * const tomoyo_condition_keyword[TOMOYO_MAX_CONDITION_KEYWORD] = { + [TOMOYO_TASK_UID] = "task.uid", + [TOMOYO_TASK_EUID] = "task.euid", + [TOMOYO_TASK_SUID] = "task.suid", + [TOMOYO_TASK_FSUID] = "task.fsuid", + [TOMOYO_TASK_GID] = "task.gid", + [TOMOYO_TASK_EGID] = "task.egid", + [TOMOYO_TASK_SGID] = "task.sgid", + [TOMOYO_TASK_FSGID] = "task.fsgid", + [TOMOYO_TASK_PID] = "task.pid", + [TOMOYO_TASK_PPID] = "task.ppid", + [TOMOYO_EXEC_ARGC] = "exec.argc", + [TOMOYO_EXEC_ENVC] = "exec.envc", + [TOMOYO_TYPE_IS_SOCKET] = "socket", + [TOMOYO_TYPE_IS_SYMLINK] = "symlink", + [TOMOYO_TYPE_IS_FILE] = "file", + [TOMOYO_TYPE_IS_BLOCK_DEV] = "block", + [TOMOYO_TYPE_IS_DIRECTORY] = "directory", + [TOMOYO_TYPE_IS_CHAR_DEV] = "char", + [TOMOYO_TYPE_IS_FIFO] = "fifo", + [TOMOYO_MODE_SETUID] = "setuid", + [TOMOYO_MODE_SETGID] = "setgid", + [TOMOYO_MODE_STICKY] = "sticky", + [TOMOYO_MODE_OWNER_READ] = "owner_read", + [TOMOYO_MODE_OWNER_WRITE] = "owner_write", + [TOMOYO_MODE_OWNER_EXECUTE] = "owner_execute", + [TOMOYO_MODE_GROUP_READ] = "group_read", + [TOMOYO_MODE_GROUP_WRITE] = "group_write", + [TOMOYO_MODE_GROUP_EXECUTE] = "group_execute", + [TOMOYO_MODE_OTHERS_READ] = "others_read", + [TOMOYO_MODE_OTHERS_WRITE] = "others_write", + [TOMOYO_MODE_OTHERS_EXECUTE] = "others_execute", + [TOMOYO_EXEC_REALPATH] = "exec.realpath", + [TOMOYO_SYMLINK_TARGET] = "symlink.target", + [TOMOYO_PATH1_UID] = "path1.uid", + [TOMOYO_PATH1_GID] = "path1.gid", + [TOMOYO_PATH1_INO] = "path1.ino", + [TOMOYO_PATH1_MAJOR] = "path1.major", + [TOMOYO_PATH1_MINOR] = "path1.minor", + [TOMOYO_PATH1_PERM] = "path1.perm", + [TOMOYO_PATH1_TYPE] = "path1.type", + [TOMOYO_PATH1_DEV_MAJOR] = "path1.dev_major", + [TOMOYO_PATH1_DEV_MINOR] = "path1.dev_minor", + [TOMOYO_PATH2_UID] = "path2.uid", + [TOMOYO_PATH2_GID] = "path2.gid", + [TOMOYO_PATH2_INO] = "path2.ino", + [TOMOYO_PATH2_MAJOR] = "path2.major", + [TOMOYO_PATH2_MINOR] = "path2.minor", + [TOMOYO_PATH2_PERM] = "path2.perm", + [TOMOYO_PATH2_TYPE] = "path2.type", + [TOMOYO_PATH2_DEV_MAJOR] = "path2.dev_major", + [TOMOYO_PATH2_DEV_MINOR] = "path2.dev_minor", + [TOMOYO_PATH1_PARENT_UID] = "path1.parent.uid", + [TOMOYO_PATH1_PARENT_GID] = "path1.parent.gid", + [TOMOYO_PATH1_PARENT_INO] = "path1.parent.ino", + [TOMOYO_PATH1_PARENT_PERM] = "path1.parent.perm", + [TOMOYO_PATH2_PARENT_UID] = "path2.parent.uid", + [TOMOYO_PATH2_PARENT_GID] = "path2.parent.gid", + [TOMOYO_PATH2_PARENT_INO] = "path2.parent.ino", + [TOMOYO_PATH2_PARENT_PERM] = "path2.parent.perm", +}; + +/* String table for PREFERENCE keyword. */ +static const char * const tomoyo_pref_keywords[TOMOYO_MAX_PREF] = { + [TOMOYO_PREF_MAX_AUDIT_LOG] = "max_audit_log", + [TOMOYO_PREF_MAX_LEARNING_ENTRY] = "max_learning_entry", +}; + +/* String table for path operation. */ +const char * const tomoyo_path_keyword[TOMOYO_MAX_PATH_OPERATION] = { + [TOMOYO_TYPE_EXECUTE] = "execute", + [TOMOYO_TYPE_READ] = "read", + [TOMOYO_TYPE_WRITE] = "write", + [TOMOYO_TYPE_APPEND] = "append", + [TOMOYO_TYPE_UNLINK] = "unlink", + [TOMOYO_TYPE_GETATTR] = "getattr", + [TOMOYO_TYPE_RMDIR] = "rmdir", + [TOMOYO_TYPE_TRUNCATE] = "truncate", + [TOMOYO_TYPE_SYMLINK] = "symlink", + [TOMOYO_TYPE_CHROOT] = "chroot", + [TOMOYO_TYPE_UMOUNT] = "unmount", +}; + +/* String table for socket's operation. */ +const char * const tomoyo_socket_keyword[TOMOYO_MAX_NETWORK_OPERATION] = { + [TOMOYO_NETWORK_BIND] = "bind", + [TOMOYO_NETWORK_LISTEN] = "listen", + [TOMOYO_NETWORK_CONNECT] = "connect", + [TOMOYO_NETWORK_SEND] = "send", +}; + +/* String table for categories. */ +static const char * const tomoyo_category_keywords +[TOMOYO_MAX_MAC_CATEGORY_INDEX] = { + [TOMOYO_MAC_CATEGORY_FILE] = "file", + [TOMOYO_MAC_CATEGORY_NETWORK] = "network", + [TOMOYO_MAC_CATEGORY_MISC] = "misc", +}; + +/* Permit policy management by non-root user? */ +static bool tomoyo_manage_by_non_root; + +/* Utility functions. */ + +/** + * tomoyo_addprintf - strncat()-like-snprintf(). + * + * @buffer: Buffer to write to. Must be '\0'-terminated. + * @len: Size of @buffer. + * @fmt: The printf()'s format string, followed by parameters. + * + * Returns nothing. + */ +static void tomoyo_addprintf(char *buffer, int len, const char *fmt, ...) +{ + va_list args; + const int pos = strlen(buffer); + + va_start(args, fmt); + vsnprintf(buffer + pos, len - pos - 1, fmt, args); + va_end(args); +} + +/** + * tomoyo_flush - Flush queued string to userspace's buffer. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * + * Returns true if all data was flushed, false otherwise. + */ +static bool tomoyo_flush(struct tomoyo_io_buffer *head) +{ + while (head->r.w_pos) { + const char *w = head->r.w[0]; + size_t len = strlen(w); + + if (len) { + if (len > head->read_user_buf_avail) + len = head->read_user_buf_avail; + if (!len) + return false; + if (copy_to_user(head->read_user_buf, w, len)) + return false; + head->read_user_buf_avail -= len; + head->read_user_buf += len; + w += len; + } + head->r.w[0] = w; + if (*w) + return false; + /* Add '\0' for audit logs and query. */ + if (head->poll) { + if (!head->read_user_buf_avail || + copy_to_user(head->read_user_buf, "", 1)) + return false; + head->read_user_buf_avail--; + head->read_user_buf++; + } + head->r.w_pos--; + for (len = 0; len < head->r.w_pos; len++) + head->r.w[len] = head->r.w[len + 1]; + } + head->r.avail = 0; + return true; +} + +/** + * tomoyo_set_string - Queue string to "struct tomoyo_io_buffer" structure. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * @string: String to print. + * + * Note that @string has to be kept valid until @head is kfree()d. + * This means that char[] allocated on stack memory cannot be passed to + * this function. Use tomoyo_io_printf() for char[] allocated on stack memory. + */ +static void tomoyo_set_string(struct tomoyo_io_buffer *head, const char *string) +{ + if (head->r.w_pos < TOMOYO_MAX_IO_READ_QUEUE) { + head->r.w[head->r.w_pos++] = string; + tomoyo_flush(head); + } else + WARN_ON(1); +} + +static void tomoyo_io_printf(struct tomoyo_io_buffer *head, const char *fmt, + ...) __printf(2, 3); + +/** + * tomoyo_io_printf - printf() to "struct tomoyo_io_buffer" structure. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * @fmt: The printf()'s format string, followed by parameters. + */ +static void tomoyo_io_printf(struct tomoyo_io_buffer *head, const char *fmt, + ...) +{ + va_list args; + size_t len; + size_t pos = head->r.avail; + int size = head->readbuf_size - pos; + + if (size <= 0) + return; + va_start(args, fmt); + len = vsnprintf(head->read_buf + pos, size, fmt, args) + 1; + va_end(args); + if (pos + len >= head->readbuf_size) { + WARN_ON(1); + return; + } + head->r.avail += len; + tomoyo_set_string(head, head->read_buf + pos); +} + +/** + * tomoyo_set_space - Put a space to "struct tomoyo_io_buffer" structure. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * + * Returns nothing. + */ +static void tomoyo_set_space(struct tomoyo_io_buffer *head) +{ + tomoyo_set_string(head, " "); +} + +/** + * tomoyo_set_lf - Put a line feed to "struct tomoyo_io_buffer" structure. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * + * Returns nothing. + */ +static bool tomoyo_set_lf(struct tomoyo_io_buffer *head) +{ + tomoyo_set_string(head, "\n"); + return !head->r.w_pos; +} + +/** + * tomoyo_set_slash - Put a shash to "struct tomoyo_io_buffer" structure. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * + * Returns nothing. + */ +static void tomoyo_set_slash(struct tomoyo_io_buffer *head) +{ + tomoyo_set_string(head, "/"); +} + +/* List of namespaces. */ +LIST_HEAD(tomoyo_namespace_list); +/* True if namespace other than tomoyo_kernel_namespace is defined. */ +static bool tomoyo_namespace_enabled; + +/** + * tomoyo_init_policy_namespace - Initialize namespace. + * + * @ns: Pointer to "struct tomoyo_policy_namespace". + * + * Returns nothing. + */ +void tomoyo_init_policy_namespace(struct tomoyo_policy_namespace *ns) +{ + unsigned int idx; + + for (idx = 0; idx < TOMOYO_MAX_ACL_GROUPS; idx++) + INIT_LIST_HEAD(&ns->acl_group[idx]); + for (idx = 0; idx < TOMOYO_MAX_GROUP; idx++) + INIT_LIST_HEAD(&ns->group_list[idx]); + for (idx = 0; idx < TOMOYO_MAX_POLICY; idx++) + INIT_LIST_HEAD(&ns->policy_list[idx]); + ns->profile_version = 20150505; + tomoyo_namespace_enabled = !list_empty(&tomoyo_namespace_list); + list_add_tail_rcu(&ns->namespace_list, &tomoyo_namespace_list); +} + +/** + * tomoyo_print_namespace - Print namespace header. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * + * Returns nothing. + */ +static void tomoyo_print_namespace(struct tomoyo_io_buffer *head) +{ + if (!tomoyo_namespace_enabled) + return; + tomoyo_set_string(head, + container_of(head->r.ns, + struct tomoyo_policy_namespace, + namespace_list)->name); + tomoyo_set_space(head); +} + +/** + * tomoyo_print_name_union - Print a tomoyo_name_union. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * @ptr: Pointer to "struct tomoyo_name_union". + */ +static void tomoyo_print_name_union(struct tomoyo_io_buffer *head, + const struct tomoyo_name_union *ptr) +{ + tomoyo_set_space(head); + if (ptr->group) { + tomoyo_set_string(head, "@"); + tomoyo_set_string(head, ptr->group->group_name->name); + } else { + tomoyo_set_string(head, ptr->filename->name); + } +} + +/** + * tomoyo_print_name_union_quoted - Print a tomoyo_name_union with a quote. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * @ptr: Pointer to "struct tomoyo_name_union". + * + * Returns nothing. + */ +static void tomoyo_print_name_union_quoted(struct tomoyo_io_buffer *head, + const struct tomoyo_name_union *ptr) +{ + if (ptr->group) { + tomoyo_set_string(head, "@"); + tomoyo_set_string(head, ptr->group->group_name->name); + } else { + tomoyo_set_string(head, "\""); + tomoyo_set_string(head, ptr->filename->name); + tomoyo_set_string(head, "\""); + } +} + +/** + * tomoyo_print_number_union_nospace - Print a tomoyo_number_union without a space. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * @ptr: Pointer to "struct tomoyo_number_union". + * + * Returns nothing. + */ +static void tomoyo_print_number_union_nospace +(struct tomoyo_io_buffer *head, const struct tomoyo_number_union *ptr) +{ + if (ptr->group) { + tomoyo_set_string(head, "@"); + tomoyo_set_string(head, ptr->group->group_name->name); + } else { + int i; + unsigned long min = ptr->values[0]; + const unsigned long max = ptr->values[1]; + u8 min_type = ptr->value_type[0]; + const u8 max_type = ptr->value_type[1]; + char buffer[128]; + + buffer[0] = '\0'; + for (i = 0; i < 2; i++) { + switch (min_type) { + case TOMOYO_VALUE_TYPE_HEXADECIMAL: + tomoyo_addprintf(buffer, sizeof(buffer), + "0x%lX", min); + break; + case TOMOYO_VALUE_TYPE_OCTAL: + tomoyo_addprintf(buffer, sizeof(buffer), + "0%lo", min); + break; + default: + tomoyo_addprintf(buffer, sizeof(buffer), "%lu", + min); + break; + } + if (min == max && min_type == max_type) + break; + tomoyo_addprintf(buffer, sizeof(buffer), "-"); + min_type = max_type; + min = max; + } + tomoyo_io_printf(head, "%s", buffer); + } +} + +/** + * tomoyo_print_number_union - Print a tomoyo_number_union. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * @ptr: Pointer to "struct tomoyo_number_union". + * + * Returns nothing. + */ +static void tomoyo_print_number_union(struct tomoyo_io_buffer *head, + const struct tomoyo_number_union *ptr) +{ + tomoyo_set_space(head); + tomoyo_print_number_union_nospace(head, ptr); +} + +/** + * tomoyo_assign_profile - Create a new profile. + * + * @ns: Pointer to "struct tomoyo_policy_namespace". + * @profile: Profile number to create. + * + * Returns pointer to "struct tomoyo_profile" on success, NULL otherwise. + */ +static struct tomoyo_profile *tomoyo_assign_profile +(struct tomoyo_policy_namespace *ns, const unsigned int profile) +{ + struct tomoyo_profile *ptr; + struct tomoyo_profile *entry; + + if (profile >= TOMOYO_MAX_PROFILES) + return NULL; + ptr = ns->profile_ptr[profile]; + if (ptr) + return ptr; + entry = kzalloc(sizeof(*entry), GFP_NOFS | __GFP_NOWARN); + if (mutex_lock_interruptible(&tomoyo_policy_lock)) + goto out; + ptr = ns->profile_ptr[profile]; + if (!ptr && tomoyo_memory_ok(entry)) { + ptr = entry; + ptr->default_config = TOMOYO_CONFIG_DISABLED | + TOMOYO_CONFIG_WANT_GRANT_LOG | + TOMOYO_CONFIG_WANT_REJECT_LOG; + memset(ptr->config, TOMOYO_CONFIG_USE_DEFAULT, + sizeof(ptr->config)); + ptr->pref[TOMOYO_PREF_MAX_AUDIT_LOG] = + CONFIG_SECURITY_TOMOYO_MAX_AUDIT_LOG; + ptr->pref[TOMOYO_PREF_MAX_LEARNING_ENTRY] = + CONFIG_SECURITY_TOMOYO_MAX_ACCEPT_ENTRY; + mb(); /* Avoid out-of-order execution. */ + ns->profile_ptr[profile] = ptr; + entry = NULL; + } + mutex_unlock(&tomoyo_policy_lock); + out: + kfree(entry); + return ptr; +} + +/** + * tomoyo_profile - Find a profile. + * + * @ns: Pointer to "struct tomoyo_policy_namespace". + * @profile: Profile number to find. + * + * Returns pointer to "struct tomoyo_profile". + */ +struct tomoyo_profile *tomoyo_profile(const struct tomoyo_policy_namespace *ns, + const u8 profile) +{ + static struct tomoyo_profile tomoyo_null_profile; + struct tomoyo_profile *ptr = ns->profile_ptr[profile]; + + if (!ptr) + ptr = &tomoyo_null_profile; + return ptr; +} + +/** + * tomoyo_find_yesno - Find values for specified keyword. + * + * @string: String to check. + * @find: Name of keyword. + * + * Returns 1 if "@find=yes" was found, 0 if "@find=no" was found, -1 otherwise. + */ +static s8 tomoyo_find_yesno(const char *string, const char *find) +{ + const char *cp = strstr(string, find); + + if (cp) { + cp += strlen(find); + if (!strncmp(cp, "=yes", 4)) + return 1; + else if (!strncmp(cp, "=no", 3)) + return 0; + } + return -1; +} + +/** + * tomoyo_set_uint - Set value for specified preference. + * + * @i: Pointer to "unsigned int". + * @string: String to check. + * @find: Name of keyword. + * + * Returns nothing. + */ +static void tomoyo_set_uint(unsigned int *i, const char *string, + const char *find) +{ + const char *cp = strstr(string, find); + + if (cp) + sscanf(cp + strlen(find), "=%u", i); +} + +/** + * tomoyo_set_mode - Set mode for specified profile. + * + * @name: Name of functionality. + * @value: Mode for @name. + * @profile: Pointer to "struct tomoyo_profile". + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_set_mode(char *name, const char *value, + struct tomoyo_profile *profile) +{ + u8 i; + u8 config; + + if (!strcmp(name, "CONFIG")) { + i = TOMOYO_MAX_MAC_INDEX + TOMOYO_MAX_MAC_CATEGORY_INDEX; + config = profile->default_config; + } else if (tomoyo_str_starts(&name, "CONFIG::")) { + config = 0; + for (i = 0; i < TOMOYO_MAX_MAC_INDEX + + TOMOYO_MAX_MAC_CATEGORY_INDEX; i++) { + int len = 0; + + if (i < TOMOYO_MAX_MAC_INDEX) { + const u8 c = tomoyo_index2category[i]; + const char *category = + tomoyo_category_keywords[c]; + + len = strlen(category); + if (strncmp(name, category, len) || + name[len++] != ':' || name[len++] != ':') + continue; + } + if (strcmp(name + len, tomoyo_mac_keywords[i])) + continue; + config = profile->config[i]; + break; + } + if (i == TOMOYO_MAX_MAC_INDEX + TOMOYO_MAX_MAC_CATEGORY_INDEX) + return -EINVAL; + } else { + return -EINVAL; + } + if (strstr(value, "use_default")) { + config = TOMOYO_CONFIG_USE_DEFAULT; + } else { + u8 mode; + + for (mode = 0; mode < 4; mode++) + if (strstr(value, tomoyo_mode[mode])) + /* + * Update lower 3 bits in order to distinguish + * 'config' from 'TOMOYO_CONFIG_USE_DEFAULT'. + */ + config = (config & ~7) | mode; + if (config != TOMOYO_CONFIG_USE_DEFAULT) { + switch (tomoyo_find_yesno(value, "grant_log")) { + case 1: + config |= TOMOYO_CONFIG_WANT_GRANT_LOG; + break; + case 0: + config &= ~TOMOYO_CONFIG_WANT_GRANT_LOG; + break; + } + switch (tomoyo_find_yesno(value, "reject_log")) { + case 1: + config |= TOMOYO_CONFIG_WANT_REJECT_LOG; + break; + case 0: + config &= ~TOMOYO_CONFIG_WANT_REJECT_LOG; + break; + } + } + } + if (i < TOMOYO_MAX_MAC_INDEX + TOMOYO_MAX_MAC_CATEGORY_INDEX) + profile->config[i] = config; + else if (config != TOMOYO_CONFIG_USE_DEFAULT) + profile->default_config = config; + return 0; +} + +/** + * tomoyo_write_profile - Write profile table. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_write_profile(struct tomoyo_io_buffer *head) +{ + char *data = head->write_buf; + unsigned int i; + char *cp; + struct tomoyo_profile *profile; + + if (sscanf(data, "PROFILE_VERSION=%u", &head->w.ns->profile_version) + == 1) + return 0; + i = simple_strtoul(data, &cp, 10); + if (*cp != '-') + return -EINVAL; + data = cp + 1; + profile = tomoyo_assign_profile(head->w.ns, i); + if (!profile) + return -EINVAL; + cp = strchr(data, '='); + if (!cp) + return -EINVAL; + *cp++ = '\0'; + if (!strcmp(data, "COMMENT")) { + static DEFINE_SPINLOCK(lock); + const struct tomoyo_path_info *new_comment + = tomoyo_get_name(cp); + const struct tomoyo_path_info *old_comment; + + if (!new_comment) + return -ENOMEM; + spin_lock(&lock); + old_comment = profile->comment; + profile->comment = new_comment; + spin_unlock(&lock); + tomoyo_put_name(old_comment); + return 0; + } + if (!strcmp(data, "PREFERENCE")) { + for (i = 0; i < TOMOYO_MAX_PREF; i++) + tomoyo_set_uint(&profile->pref[i], cp, + tomoyo_pref_keywords[i]); + return 0; + } + return tomoyo_set_mode(data, cp, profile); +} + +/** + * tomoyo_print_config - Print mode for specified functionality. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * @config: Mode for that functionality. + * + * Returns nothing. + * + * Caller prints functionality's name. + */ +static void tomoyo_print_config(struct tomoyo_io_buffer *head, const u8 config) +{ + tomoyo_io_printf(head, "={ mode=%s grant_log=%s reject_log=%s }\n", + tomoyo_mode[config & 3], + str_yes_no(config & TOMOYO_CONFIG_WANT_GRANT_LOG), + str_yes_no(config & TOMOYO_CONFIG_WANT_REJECT_LOG)); +} + +/** + * tomoyo_read_profile - Read profile table. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * + * Returns nothing. + */ +static void tomoyo_read_profile(struct tomoyo_io_buffer *head) +{ + u8 index; + struct tomoyo_policy_namespace *ns = + container_of(head->r.ns, typeof(*ns), namespace_list); + const struct tomoyo_profile *profile; + + if (head->r.eof) + return; + next: + index = head->r.index; + profile = ns->profile_ptr[index]; + switch (head->r.step) { + case 0: + tomoyo_print_namespace(head); + tomoyo_io_printf(head, "PROFILE_VERSION=%u\n", + ns->profile_version); + head->r.step++; + break; + case 1: + for ( ; head->r.index < TOMOYO_MAX_PROFILES; + head->r.index++) + if (ns->profile_ptr[head->r.index]) + break; + if (head->r.index == TOMOYO_MAX_PROFILES) { + head->r.eof = true; + return; + } + head->r.step++; + break; + case 2: + { + u8 i; + const struct tomoyo_path_info *comment = + profile->comment; + + tomoyo_print_namespace(head); + tomoyo_io_printf(head, "%u-COMMENT=", index); + tomoyo_set_string(head, comment ? comment->name : ""); + tomoyo_set_lf(head); + tomoyo_print_namespace(head); + tomoyo_io_printf(head, "%u-PREFERENCE={ ", index); + for (i = 0; i < TOMOYO_MAX_PREF; i++) + tomoyo_io_printf(head, "%s=%u ", + tomoyo_pref_keywords[i], + profile->pref[i]); + tomoyo_set_string(head, "}\n"); + head->r.step++; + } + break; + case 3: + { + tomoyo_print_namespace(head); + tomoyo_io_printf(head, "%u-%s", index, "CONFIG"); + tomoyo_print_config(head, profile->default_config); + head->r.bit = 0; + head->r.step++; + } + break; + case 4: + for ( ; head->r.bit < TOMOYO_MAX_MAC_INDEX + + TOMOYO_MAX_MAC_CATEGORY_INDEX; head->r.bit++) { + const u8 i = head->r.bit; + const u8 config = profile->config[i]; + + if (config == TOMOYO_CONFIG_USE_DEFAULT) + continue; + tomoyo_print_namespace(head); + if (i < TOMOYO_MAX_MAC_INDEX) + tomoyo_io_printf(head, "%u-CONFIG::%s::%s", + index, + tomoyo_category_keywords + [tomoyo_index2category[i]], + tomoyo_mac_keywords[i]); + else + tomoyo_io_printf(head, "%u-CONFIG::%s", index, + tomoyo_mac_keywords[i]); + tomoyo_print_config(head, config); + head->r.bit++; + break; + } + if (head->r.bit == TOMOYO_MAX_MAC_INDEX + + TOMOYO_MAX_MAC_CATEGORY_INDEX) { + head->r.index++; + head->r.step = 1; + } + break; + } + if (tomoyo_flush(head)) + goto next; +} + +/** + * tomoyo_same_manager - Check for duplicated "struct tomoyo_manager" entry. + * + * @a: Pointer to "struct tomoyo_acl_head". + * @b: Pointer to "struct tomoyo_acl_head". + * + * Returns true if @a == @b, false otherwise. + */ +static bool tomoyo_same_manager(const struct tomoyo_acl_head *a, + const struct tomoyo_acl_head *b) +{ + return container_of(a, struct tomoyo_manager, head)->manager == + container_of(b, struct tomoyo_manager, head)->manager; +} + +/** + * tomoyo_update_manager_entry - Add a manager entry. + * + * @manager: The path to manager or the domainnamme. + * @is_delete: True if it is a delete request. + * + * Returns 0 on success, negative value otherwise. + * + * Caller holds tomoyo_read_lock(). + */ +static int tomoyo_update_manager_entry(const char *manager, + const bool is_delete) +{ + struct tomoyo_manager e = { }; + struct tomoyo_acl_param param = { + /* .ns = &tomoyo_kernel_namespace, */ + .is_delete = is_delete, + .list = &tomoyo_kernel_namespace.policy_list[TOMOYO_ID_MANAGER], + }; + int error = is_delete ? -ENOENT : -ENOMEM; + + if (!tomoyo_correct_domain(manager) && + !tomoyo_correct_word(manager)) + return -EINVAL; + e.manager = tomoyo_get_name(manager); + if (e.manager) { + error = tomoyo_update_policy(&e.head, sizeof(e), ¶m, + tomoyo_same_manager); + tomoyo_put_name(e.manager); + } + return error; +} + +/** + * tomoyo_write_manager - Write manager policy. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * + * Returns 0 on success, negative value otherwise. + * + * Caller holds tomoyo_read_lock(). + */ +static int tomoyo_write_manager(struct tomoyo_io_buffer *head) +{ + char *data = head->write_buf; + + if (!strcmp(data, "manage_by_non_root")) { + tomoyo_manage_by_non_root = !head->w.is_delete; + return 0; + } + return tomoyo_update_manager_entry(data, head->w.is_delete); +} + +/** + * tomoyo_read_manager - Read manager policy. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * + * Caller holds tomoyo_read_lock(). + */ +static void tomoyo_read_manager(struct tomoyo_io_buffer *head) +{ + if (head->r.eof) + return; + list_for_each_cookie(head->r.acl, &tomoyo_kernel_namespace.policy_list[TOMOYO_ID_MANAGER]) { + struct tomoyo_manager *ptr = + list_entry(head->r.acl, typeof(*ptr), head.list); + + if (ptr->head.is_deleted) + continue; + if (!tomoyo_flush(head)) + return; + tomoyo_set_string(head, ptr->manager->name); + tomoyo_set_lf(head); + } + head->r.eof = true; +} + +/** + * tomoyo_manager - Check whether the current process is a policy manager. + * + * Returns true if the current process is permitted to modify policy + * via /sys/kernel/security/tomoyo/ interface. + * + * Caller holds tomoyo_read_lock(). + */ +static bool tomoyo_manager(void) +{ + struct tomoyo_manager *ptr; + const char *exe; + const struct task_struct *task = current; + const struct tomoyo_path_info *domainname = tomoyo_domain()->domainname; + bool found = IS_ENABLED(CONFIG_SECURITY_TOMOYO_INSECURE_BUILTIN_SETTING); + + if (!tomoyo_policy_loaded) + return true; + if (!tomoyo_manage_by_non_root && + (!uid_eq(task->cred->uid, GLOBAL_ROOT_UID) || + !uid_eq(task->cred->euid, GLOBAL_ROOT_UID))) + return false; + exe = tomoyo_get_exe(); + if (!exe) + return false; + list_for_each_entry_rcu(ptr, &tomoyo_kernel_namespace.policy_list[TOMOYO_ID_MANAGER], head.list, + srcu_read_lock_held(&tomoyo_ss)) { + if (!ptr->head.is_deleted && + (!tomoyo_pathcmp(domainname, ptr->manager) || + !strcmp(exe, ptr->manager->name))) { + found = true; + break; + } + } + if (!found) { /* Reduce error messages. */ + static pid_t last_pid; + const pid_t pid = current->pid; + + if (last_pid != pid) { + pr_warn("%s ( %s ) is not permitted to update policies.\n", + domainname->name, exe); + last_pid = pid; + } + } + kfree(exe); + return found; +} + +static struct tomoyo_domain_info *tomoyo_find_domain_by_qid +(unsigned int serial); + +/** + * tomoyo_select_domain - Parse select command. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * @data: String to parse. + * + * Returns true on success, false otherwise. + * + * Caller holds tomoyo_read_lock(). + */ +static bool tomoyo_select_domain(struct tomoyo_io_buffer *head, + const char *data) +{ + unsigned int pid; + struct tomoyo_domain_info *domain = NULL; + bool global_pid = false; + + if (strncmp(data, "select ", 7)) + return false; + data += 7; + if (sscanf(data, "pid=%u", &pid) == 1 || + (global_pid = true, sscanf(data, "global-pid=%u", &pid) == 1)) { + struct task_struct *p; + + rcu_read_lock(); + if (global_pid) + p = find_task_by_pid_ns(pid, &init_pid_ns); + else + p = find_task_by_vpid(pid); + if (p) + domain = tomoyo_task(p)->domain_info; + rcu_read_unlock(); + } else if (!strncmp(data, "domain=", 7)) { + if (tomoyo_domain_def(data + 7)) + domain = tomoyo_find_domain(data + 7); + } else if (sscanf(data, "Q=%u", &pid) == 1) { + domain = tomoyo_find_domain_by_qid(pid); + } else + return false; + head->w.domain = domain; + /* Accessing read_buf is safe because head->io_sem is held. */ + if (!head->read_buf) + return true; /* Do nothing if open(O_WRONLY). */ + memset(&head->r, 0, sizeof(head->r)); + head->r.print_this_domain_only = true; + if (domain) + head->r.domain = &domain->list; + else + head->r.eof = true; + tomoyo_io_printf(head, "# select %s\n", data); + if (domain && domain->is_deleted) + tomoyo_io_printf(head, "# This is a deleted domain.\n"); + return true; +} + +/** + * tomoyo_same_task_acl - Check for duplicated "struct tomoyo_task_acl" entry. + * + * @a: Pointer to "struct tomoyo_acl_info". + * @b: Pointer to "struct tomoyo_acl_info". + * + * Returns true if @a == @b, false otherwise. + */ +static bool tomoyo_same_task_acl(const struct tomoyo_acl_info *a, + const struct tomoyo_acl_info *b) +{ + const struct tomoyo_task_acl *p1 = container_of(a, typeof(*p1), head); + const struct tomoyo_task_acl *p2 = container_of(b, typeof(*p2), head); + + return p1->domainname == p2->domainname; +} + +/** + * tomoyo_write_task - Update task related list. + * + * @param: Pointer to "struct tomoyo_acl_param". + * + * Returns 0 on success, negative value otherwise. + * + * Caller holds tomoyo_read_lock(). + */ +static int tomoyo_write_task(struct tomoyo_acl_param *param) +{ + int error = -EINVAL; + + if (tomoyo_str_starts(¶m->data, "manual_domain_transition ")) { + struct tomoyo_task_acl e = { + .head.type = TOMOYO_TYPE_MANUAL_TASK_ACL, + .domainname = tomoyo_get_domainname(param), + }; + + if (e.domainname) + error = tomoyo_update_domain(&e.head, sizeof(e), param, + tomoyo_same_task_acl, + NULL); + tomoyo_put_name(e.domainname); + } + return error; +} + +/** + * tomoyo_delete_domain - Delete a domain. + * + * @domainname: The name of domain. + * + * Returns 0 on success, negative value otherwise. + * + * Caller holds tomoyo_read_lock(). + */ +static int tomoyo_delete_domain(char *domainname) +{ + struct tomoyo_domain_info *domain; + struct tomoyo_path_info name; + + name.name = domainname; + tomoyo_fill_path_info(&name); + if (mutex_lock_interruptible(&tomoyo_policy_lock)) + return -EINTR; + /* Is there an active domain? */ + list_for_each_entry_rcu(domain, &tomoyo_domain_list, list, + srcu_read_lock_held(&tomoyo_ss)) { + /* Never delete tomoyo_kernel_domain */ + if (domain == &tomoyo_kernel_domain) + continue; + if (domain->is_deleted || + tomoyo_pathcmp(domain->domainname, &name)) + continue; + domain->is_deleted = true; + break; + } + mutex_unlock(&tomoyo_policy_lock); + return 0; +} + +/** + * tomoyo_write_domain2 - Write domain policy. + * + * @ns: Pointer to "struct tomoyo_policy_namespace". + * @list: Pointer to "struct list_head". + * @data: Policy to be interpreted. + * @is_delete: True if it is a delete request. + * + * Returns 0 on success, negative value otherwise. + * + * Caller holds tomoyo_read_lock(). + */ +static int tomoyo_write_domain2(struct tomoyo_policy_namespace *ns, + struct list_head *list, char *data, + const bool is_delete) +{ + struct tomoyo_acl_param param = { + .ns = ns, + .list = list, + .data = data, + .is_delete = is_delete, + }; + static const struct { + const char *keyword; + int (*write)(struct tomoyo_acl_param *param); + } tomoyo_callback[5] = { + { "file ", tomoyo_write_file }, + { "network inet ", tomoyo_write_inet_network }, + { "network unix ", tomoyo_write_unix_network }, + { "misc ", tomoyo_write_misc }, + { "task ", tomoyo_write_task }, + }; + u8 i; + + for (i = 0; i < ARRAY_SIZE(tomoyo_callback); i++) { + if (!tomoyo_str_starts(¶m.data, + tomoyo_callback[i].keyword)) + continue; + return tomoyo_callback[i].write(¶m); + } + return -EINVAL; +} + +/* String table for domain flags. */ +const char * const tomoyo_dif[TOMOYO_MAX_DOMAIN_INFO_FLAGS] = { + [TOMOYO_DIF_QUOTA_WARNED] = "quota_exceeded\n", + [TOMOYO_DIF_TRANSITION_FAILED] = "transition_failed\n", +}; + +/** + * tomoyo_write_domain - Write domain policy. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * + * Returns 0 on success, negative value otherwise. + * + * Caller holds tomoyo_read_lock(). + */ +static int tomoyo_write_domain(struct tomoyo_io_buffer *head) +{ + char *data = head->write_buf; + struct tomoyo_policy_namespace *ns; + struct tomoyo_domain_info *domain = head->w.domain; + const bool is_delete = head->w.is_delete; + bool is_select = !is_delete && tomoyo_str_starts(&data, "select "); + unsigned int idx; + + if (*data == '<') { + int ret = 0; + + domain = NULL; + if (is_delete) + ret = tomoyo_delete_domain(data); + else if (is_select) + domain = tomoyo_find_domain(data); + else + domain = tomoyo_assign_domain(data, false); + head->w.domain = domain; + return ret; + } + if (!domain) + return -EINVAL; + ns = domain->ns; + if (sscanf(data, "use_profile %u", &idx) == 1 + && idx < TOMOYO_MAX_PROFILES) { + if (!tomoyo_policy_loaded || ns->profile_ptr[idx]) + if (!is_delete) + domain->profile = (u8) idx; + return 0; + } + if (sscanf(data, "use_group %u\n", &idx) == 1 + && idx < TOMOYO_MAX_ACL_GROUPS) { + if (!is_delete) + set_bit(idx, domain->group); + else + clear_bit(idx, domain->group); + return 0; + } + for (idx = 0; idx < TOMOYO_MAX_DOMAIN_INFO_FLAGS; idx++) { + const char *cp = tomoyo_dif[idx]; + + if (strncmp(data, cp, strlen(cp) - 1)) + continue; + domain->flags[idx] = !is_delete; + return 0; + } + return tomoyo_write_domain2(ns, &domain->acl_info_list, data, + is_delete); +} + +/** + * tomoyo_print_condition - Print condition part. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * @cond: Pointer to "struct tomoyo_condition". + * + * Returns true on success, false otherwise. + */ +static bool tomoyo_print_condition(struct tomoyo_io_buffer *head, + const struct tomoyo_condition *cond) +{ + switch (head->r.cond_step) { + case 0: + head->r.cond_index = 0; + head->r.cond_step++; + if (cond->transit) { + tomoyo_set_space(head); + tomoyo_set_string(head, cond->transit->name); + } + fallthrough; + case 1: + { + const u16 condc = cond->condc; + const struct tomoyo_condition_element *condp = + (typeof(condp)) (cond + 1); + const struct tomoyo_number_union *numbers_p = + (typeof(numbers_p)) (condp + condc); + const struct tomoyo_name_union *names_p = + (typeof(names_p)) + (numbers_p + cond->numbers_count); + const struct tomoyo_argv *argv = + (typeof(argv)) (names_p + cond->names_count); + const struct tomoyo_envp *envp = + (typeof(envp)) (argv + cond->argc); + u16 skip; + + for (skip = 0; skip < head->r.cond_index; skip++) { + const u8 left = condp->left; + const u8 right = condp->right; + + condp++; + switch (left) { + case TOMOYO_ARGV_ENTRY: + argv++; + continue; + case TOMOYO_ENVP_ENTRY: + envp++; + continue; + case TOMOYO_NUMBER_UNION: + numbers_p++; + break; + } + switch (right) { + case TOMOYO_NAME_UNION: + names_p++; + break; + case TOMOYO_NUMBER_UNION: + numbers_p++; + break; + } + } + while (head->r.cond_index < condc) { + const u8 match = condp->equals; + const u8 left = condp->left; + const u8 right = condp->right; + + if (!tomoyo_flush(head)) + return false; + condp++; + head->r.cond_index++; + tomoyo_set_space(head); + switch (left) { + case TOMOYO_ARGV_ENTRY: + tomoyo_io_printf(head, + "exec.argv[%lu]%s=\"", + argv->index, argv->is_not ? "!" : ""); + tomoyo_set_string(head, + argv->value->name); + tomoyo_set_string(head, "\""); + argv++; + continue; + case TOMOYO_ENVP_ENTRY: + tomoyo_set_string(head, + "exec.envp[\""); + tomoyo_set_string(head, + envp->name->name); + tomoyo_io_printf(head, "\"]%s=", envp->is_not ? "!" : ""); + if (envp->value) { + tomoyo_set_string(head, "\""); + tomoyo_set_string(head, envp->value->name); + tomoyo_set_string(head, "\""); + } else { + tomoyo_set_string(head, + "NULL"); + } + envp++; + continue; + case TOMOYO_NUMBER_UNION: + tomoyo_print_number_union_nospace + (head, numbers_p++); + break; + default: + tomoyo_set_string(head, + tomoyo_condition_keyword[left]); + break; + } + tomoyo_set_string(head, match ? "=" : "!="); + switch (right) { + case TOMOYO_NAME_UNION: + tomoyo_print_name_union_quoted + (head, names_p++); + break; + case TOMOYO_NUMBER_UNION: + tomoyo_print_number_union_nospace + (head, numbers_p++); + break; + default: + tomoyo_set_string(head, + tomoyo_condition_keyword[right]); + break; + } + } + } + head->r.cond_step++; + fallthrough; + case 2: + if (!tomoyo_flush(head)) + break; + head->r.cond_step++; + fallthrough; + case 3: + if (cond->grant_log != TOMOYO_GRANTLOG_AUTO) + tomoyo_io_printf(head, " grant_log=%s", + str_yes_no(cond->grant_log == + TOMOYO_GRANTLOG_YES)); + tomoyo_set_lf(head); + return true; + } + return false; +} + +/** + * tomoyo_set_group - Print "acl_group " header keyword and category name. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * @category: Category name. + * + * Returns nothing. + */ +static void tomoyo_set_group(struct tomoyo_io_buffer *head, + const char *category) +{ + if (head->type == TOMOYO_EXCEPTIONPOLICY) { + tomoyo_print_namespace(head); + tomoyo_io_printf(head, "acl_group %u ", + head->r.acl_group_index); + } + tomoyo_set_string(head, category); +} + +/** + * tomoyo_print_entry - Print an ACL entry. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * @acl: Pointer to an ACL entry. + * + * Returns true on success, false otherwise. + */ +static bool tomoyo_print_entry(struct tomoyo_io_buffer *head, + struct tomoyo_acl_info *acl) +{ + const u8 acl_type = acl->type; + bool first = true; + u8 bit; + + if (head->r.print_cond_part) + goto print_cond_part; + if (acl->is_deleted) + return true; + if (!tomoyo_flush(head)) + return false; + else if (acl_type == TOMOYO_TYPE_PATH_ACL) { + struct tomoyo_path_acl *ptr = + container_of(acl, typeof(*ptr), head); + const u16 perm = ptr->perm; + + for (bit = 0; bit < TOMOYO_MAX_PATH_OPERATION; bit++) { + if (!(perm & (1 << bit))) + continue; + if (head->r.print_transition_related_only && + bit != TOMOYO_TYPE_EXECUTE) + continue; + if (first) { + tomoyo_set_group(head, "file "); + first = false; + } else { + tomoyo_set_slash(head); + } + tomoyo_set_string(head, tomoyo_path_keyword[bit]); + } + if (first) + return true; + tomoyo_print_name_union(head, &ptr->name); + } else if (acl_type == TOMOYO_TYPE_MANUAL_TASK_ACL) { + struct tomoyo_task_acl *ptr = + container_of(acl, typeof(*ptr), head); + + tomoyo_set_group(head, "task "); + tomoyo_set_string(head, "manual_domain_transition "); + tomoyo_set_string(head, ptr->domainname->name); + } else if (head->r.print_transition_related_only) { + return true; + } else if (acl_type == TOMOYO_TYPE_PATH2_ACL) { + struct tomoyo_path2_acl *ptr = + container_of(acl, typeof(*ptr), head); + const u8 perm = ptr->perm; + + for (bit = 0; bit < TOMOYO_MAX_PATH2_OPERATION; bit++) { + if (!(perm & (1 << bit))) + continue; + if (first) { + tomoyo_set_group(head, "file "); + first = false; + } else { + tomoyo_set_slash(head); + } + tomoyo_set_string(head, tomoyo_mac_keywords + [tomoyo_pp2mac[bit]]); + } + if (first) + return true; + tomoyo_print_name_union(head, &ptr->name1); + tomoyo_print_name_union(head, &ptr->name2); + } else if (acl_type == TOMOYO_TYPE_PATH_NUMBER_ACL) { + struct tomoyo_path_number_acl *ptr = + container_of(acl, typeof(*ptr), head); + const u8 perm = ptr->perm; + + for (bit = 0; bit < TOMOYO_MAX_PATH_NUMBER_OPERATION; bit++) { + if (!(perm & (1 << bit))) + continue; + if (first) { + tomoyo_set_group(head, "file "); + first = false; + } else { + tomoyo_set_slash(head); + } + tomoyo_set_string(head, tomoyo_mac_keywords + [tomoyo_pn2mac[bit]]); + } + if (first) + return true; + tomoyo_print_name_union(head, &ptr->name); + tomoyo_print_number_union(head, &ptr->number); + } else if (acl_type == TOMOYO_TYPE_MKDEV_ACL) { + struct tomoyo_mkdev_acl *ptr = + container_of(acl, typeof(*ptr), head); + const u8 perm = ptr->perm; + + for (bit = 0; bit < TOMOYO_MAX_MKDEV_OPERATION; bit++) { + if (!(perm & (1 << bit))) + continue; + if (first) { + tomoyo_set_group(head, "file "); + first = false; + } else { + tomoyo_set_slash(head); + } + tomoyo_set_string(head, tomoyo_mac_keywords + [tomoyo_pnnn2mac[bit]]); + } + if (first) + return true; + tomoyo_print_name_union(head, &ptr->name); + tomoyo_print_number_union(head, &ptr->mode); + tomoyo_print_number_union(head, &ptr->major); + tomoyo_print_number_union(head, &ptr->minor); + } else if (acl_type == TOMOYO_TYPE_INET_ACL) { + struct tomoyo_inet_acl *ptr = + container_of(acl, typeof(*ptr), head); + const u8 perm = ptr->perm; + + for (bit = 0; bit < TOMOYO_MAX_NETWORK_OPERATION; bit++) { + if (!(perm & (1 << bit))) + continue; + if (first) { + tomoyo_set_group(head, "network inet "); + tomoyo_set_string(head, tomoyo_proto_keyword + [ptr->protocol]); + tomoyo_set_space(head); + first = false; + } else { + tomoyo_set_slash(head); + } + tomoyo_set_string(head, tomoyo_socket_keyword[bit]); + } + if (first) + return true; + tomoyo_set_space(head); + if (ptr->address.group) { + tomoyo_set_string(head, "@"); + tomoyo_set_string(head, ptr->address.group->group_name + ->name); + } else { + char buf[128]; + + tomoyo_print_ip(buf, sizeof(buf), &ptr->address); + tomoyo_io_printf(head, "%s", buf); + } + tomoyo_print_number_union(head, &ptr->port); + } else if (acl_type == TOMOYO_TYPE_UNIX_ACL) { + struct tomoyo_unix_acl *ptr = + container_of(acl, typeof(*ptr), head); + const u8 perm = ptr->perm; + + for (bit = 0; bit < TOMOYO_MAX_NETWORK_OPERATION; bit++) { + if (!(perm & (1 << bit))) + continue; + if (first) { + tomoyo_set_group(head, "network unix "); + tomoyo_set_string(head, tomoyo_proto_keyword + [ptr->protocol]); + tomoyo_set_space(head); + first = false; + } else { + tomoyo_set_slash(head); + } + tomoyo_set_string(head, tomoyo_socket_keyword[bit]); + } + if (first) + return true; + tomoyo_print_name_union(head, &ptr->name); + } else if (acl_type == TOMOYO_TYPE_MOUNT_ACL) { + struct tomoyo_mount_acl *ptr = + container_of(acl, typeof(*ptr), head); + + tomoyo_set_group(head, "file mount"); + tomoyo_print_name_union(head, &ptr->dev_name); + tomoyo_print_name_union(head, &ptr->dir_name); + tomoyo_print_name_union(head, &ptr->fs_type); + tomoyo_print_number_union(head, &ptr->flags); + } else if (acl_type == TOMOYO_TYPE_ENV_ACL) { + struct tomoyo_env_acl *ptr = + container_of(acl, typeof(*ptr), head); + + tomoyo_set_group(head, "misc env "); + tomoyo_set_string(head, ptr->env->name); + } + if (acl->cond) { + head->r.print_cond_part = true; + head->r.cond_step = 0; + if (!tomoyo_flush(head)) + return false; +print_cond_part: + if (!tomoyo_print_condition(head, acl->cond)) + return false; + head->r.print_cond_part = false; + } else { + tomoyo_set_lf(head); + } + return true; +} + +/** + * tomoyo_read_domain2 - Read domain policy. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * @list: Pointer to "struct list_head". + * + * Caller holds tomoyo_read_lock(). + * + * Returns true on success, false otherwise. + */ +static bool tomoyo_read_domain2(struct tomoyo_io_buffer *head, + struct list_head *list) +{ + list_for_each_cookie(head->r.acl, list) { + struct tomoyo_acl_info *ptr = + list_entry(head->r.acl, typeof(*ptr), list); + + if (!tomoyo_print_entry(head, ptr)) + return false; + } + head->r.acl = NULL; + return true; +} + +/** + * tomoyo_read_domain - Read domain policy. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * + * Caller holds tomoyo_read_lock(). + */ +static void tomoyo_read_domain(struct tomoyo_io_buffer *head) +{ + if (head->r.eof) + return; + list_for_each_cookie(head->r.domain, &tomoyo_domain_list) { + struct tomoyo_domain_info *domain = + list_entry(head->r.domain, typeof(*domain), list); + u8 i; + + switch (head->r.step) { + case 0: + if (domain->is_deleted && + !head->r.print_this_domain_only) + continue; + /* Print domainname and flags. */ + tomoyo_set_string(head, domain->domainname->name); + tomoyo_set_lf(head); + tomoyo_io_printf(head, "use_profile %u\n", + domain->profile); + for (i = 0; i < TOMOYO_MAX_DOMAIN_INFO_FLAGS; i++) + if (domain->flags[i]) + tomoyo_set_string(head, tomoyo_dif[i]); + head->r.index = 0; + head->r.step++; + fallthrough; + case 1: + while (head->r.index < TOMOYO_MAX_ACL_GROUPS) { + i = head->r.index++; + if (!test_bit(i, domain->group)) + continue; + tomoyo_io_printf(head, "use_group %u\n", i); + if (!tomoyo_flush(head)) + return; + } + head->r.index = 0; + head->r.step++; + tomoyo_set_lf(head); + fallthrough; + case 2: + if (!tomoyo_read_domain2(head, &domain->acl_info_list)) + return; + head->r.step++; + if (!tomoyo_set_lf(head)) + return; + fallthrough; + case 3: + head->r.step = 0; + if (head->r.print_this_domain_only) + goto done; + } + } + done: + head->r.eof = true; +} + +/** + * tomoyo_write_pid: Specify PID to obtain domainname. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * + * Returns 0. + */ +static int tomoyo_write_pid(struct tomoyo_io_buffer *head) +{ + head->r.eof = false; + return 0; +} + +/** + * tomoyo_read_pid - Get domainname of the specified PID. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * + * Returns the domainname which the specified PID is in on success, + * empty string otherwise. + * The PID is specified by tomoyo_write_pid() so that the user can obtain + * using read()/write() interface rather than sysctl() interface. + */ +static void tomoyo_read_pid(struct tomoyo_io_buffer *head) +{ + char *buf = head->write_buf; + bool global_pid = false; + unsigned int pid; + struct task_struct *p; + struct tomoyo_domain_info *domain = NULL; + + /* Accessing write_buf is safe because head->io_sem is held. */ + if (!buf) { + head->r.eof = true; + return; /* Do nothing if open(O_RDONLY). */ + } + if (head->r.w_pos || head->r.eof) + return; + head->r.eof = true; + if (tomoyo_str_starts(&buf, "global-pid ")) + global_pid = true; + if (kstrtouint(buf, 10, &pid)) + return; + rcu_read_lock(); + if (global_pid) + p = find_task_by_pid_ns(pid, &init_pid_ns); + else + p = find_task_by_vpid(pid); + if (p) + domain = tomoyo_task(p)->domain_info; + rcu_read_unlock(); + if (!domain) + return; + tomoyo_io_printf(head, "%u %u ", pid, domain->profile); + tomoyo_set_string(head, domain->domainname->name); +} + +/* String table for domain transition control keywords. */ +static const char *tomoyo_transition_type[TOMOYO_MAX_TRANSITION_TYPE] = { + [TOMOYO_TRANSITION_CONTROL_NO_RESET] = "no_reset_domain ", + [TOMOYO_TRANSITION_CONTROL_RESET] = "reset_domain ", + [TOMOYO_TRANSITION_CONTROL_NO_INITIALIZE] = "no_initialize_domain ", + [TOMOYO_TRANSITION_CONTROL_INITIALIZE] = "initialize_domain ", + [TOMOYO_TRANSITION_CONTROL_NO_KEEP] = "no_keep_domain ", + [TOMOYO_TRANSITION_CONTROL_KEEP] = "keep_domain ", +}; + +/* String table for grouping keywords. */ +static const char *tomoyo_group_name[TOMOYO_MAX_GROUP] = { + [TOMOYO_PATH_GROUP] = "path_group ", + [TOMOYO_NUMBER_GROUP] = "number_group ", + [TOMOYO_ADDRESS_GROUP] = "address_group ", +}; + +/** + * tomoyo_write_exception - Write exception policy. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * + * Returns 0 on success, negative value otherwise. + * + * Caller holds tomoyo_read_lock(). + */ +static int tomoyo_write_exception(struct tomoyo_io_buffer *head) +{ + const bool is_delete = head->w.is_delete; + struct tomoyo_acl_param param = { + .ns = head->w.ns, + .is_delete = is_delete, + .data = head->write_buf, + }; + u8 i; + + if (tomoyo_str_starts(¶m.data, "aggregator ")) + return tomoyo_write_aggregator(¶m); + for (i = 0; i < TOMOYO_MAX_TRANSITION_TYPE; i++) + if (tomoyo_str_starts(¶m.data, tomoyo_transition_type[i])) + return tomoyo_write_transition_control(¶m, i); + for (i = 0; i < TOMOYO_MAX_GROUP; i++) + if (tomoyo_str_starts(¶m.data, tomoyo_group_name[i])) + return tomoyo_write_group(¶m, i); + if (tomoyo_str_starts(¶m.data, "acl_group ")) { + unsigned int group; + char *data; + + group = simple_strtoul(param.data, &data, 10); + if (group < TOMOYO_MAX_ACL_GROUPS && *data++ == ' ') + return tomoyo_write_domain2 + (head->w.ns, &head->w.ns->acl_group[group], + data, is_delete); + } + return -EINVAL; +} + +/** + * tomoyo_read_group - Read "struct tomoyo_path_group"/"struct tomoyo_number_group"/"struct tomoyo_address_group" list. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * @idx: Index number. + * + * Returns true on success, false otherwise. + * + * Caller holds tomoyo_read_lock(). + */ +static bool tomoyo_read_group(struct tomoyo_io_buffer *head, const int idx) +{ + struct tomoyo_policy_namespace *ns = + container_of(head->r.ns, typeof(*ns), namespace_list); + struct list_head *list = &ns->group_list[idx]; + + list_for_each_cookie(head->r.group, list) { + struct tomoyo_group *group = + list_entry(head->r.group, typeof(*group), head.list); + + list_for_each_cookie(head->r.acl, &group->member_list) { + struct tomoyo_acl_head *ptr = + list_entry(head->r.acl, typeof(*ptr), list); + + if (ptr->is_deleted) + continue; + if (!tomoyo_flush(head)) + return false; + tomoyo_print_namespace(head); + tomoyo_set_string(head, tomoyo_group_name[idx]); + tomoyo_set_string(head, group->group_name->name); + if (idx == TOMOYO_PATH_GROUP) { + tomoyo_set_space(head); + tomoyo_set_string(head, container_of + (ptr, struct tomoyo_path_group, + head)->member_name->name); + } else if (idx == TOMOYO_NUMBER_GROUP) { + tomoyo_print_number_union(head, &container_of + (ptr, + struct tomoyo_number_group, + head)->number); + } else if (idx == TOMOYO_ADDRESS_GROUP) { + char buffer[128]; + struct tomoyo_address_group *member = + container_of(ptr, typeof(*member), + head); + + tomoyo_print_ip(buffer, sizeof(buffer), + &member->address); + tomoyo_io_printf(head, " %s", buffer); + } + tomoyo_set_lf(head); + } + head->r.acl = NULL; + } + head->r.group = NULL; + return true; +} + +/** + * tomoyo_read_policy - Read "struct tomoyo_..._entry" list. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * @idx: Index number. + * + * Returns true on success, false otherwise. + * + * Caller holds tomoyo_read_lock(). + */ +static bool tomoyo_read_policy(struct tomoyo_io_buffer *head, const int idx) +{ + struct tomoyo_policy_namespace *ns = + container_of(head->r.ns, typeof(*ns), namespace_list); + struct list_head *list = &ns->policy_list[idx]; + + list_for_each_cookie(head->r.acl, list) { + struct tomoyo_acl_head *acl = + container_of(head->r.acl, typeof(*acl), list); + if (acl->is_deleted) + continue; + if (!tomoyo_flush(head)) + return false; + switch (idx) { + case TOMOYO_ID_TRANSITION_CONTROL: + { + struct tomoyo_transition_control *ptr = + container_of(acl, typeof(*ptr), head); + + tomoyo_print_namespace(head); + tomoyo_set_string(head, tomoyo_transition_type + [ptr->type]); + tomoyo_set_string(head, ptr->program ? + ptr->program->name : "any"); + tomoyo_set_string(head, " from "); + tomoyo_set_string(head, ptr->domainname ? + ptr->domainname->name : + "any"); + } + break; + case TOMOYO_ID_AGGREGATOR: + { + struct tomoyo_aggregator *ptr = + container_of(acl, typeof(*ptr), head); + + tomoyo_print_namespace(head); + tomoyo_set_string(head, "aggregator "); + tomoyo_set_string(head, + ptr->original_name->name); + tomoyo_set_space(head); + tomoyo_set_string(head, + ptr->aggregated_name->name); + } + break; + default: + continue; + } + tomoyo_set_lf(head); + } + head->r.acl = NULL; + return true; +} + +/** + * tomoyo_read_exception - Read exception policy. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * + * Caller holds tomoyo_read_lock(). + */ +static void tomoyo_read_exception(struct tomoyo_io_buffer *head) +{ + struct tomoyo_policy_namespace *ns = + container_of(head->r.ns, typeof(*ns), namespace_list); + + if (head->r.eof) + return; + while (head->r.step < TOMOYO_MAX_POLICY && + tomoyo_read_policy(head, head->r.step)) + head->r.step++; + if (head->r.step < TOMOYO_MAX_POLICY) + return; + while (head->r.step < TOMOYO_MAX_POLICY + TOMOYO_MAX_GROUP && + tomoyo_read_group(head, head->r.step - TOMOYO_MAX_POLICY)) + head->r.step++; + if (head->r.step < TOMOYO_MAX_POLICY + TOMOYO_MAX_GROUP) + return; + while (head->r.step < TOMOYO_MAX_POLICY + TOMOYO_MAX_GROUP + + TOMOYO_MAX_ACL_GROUPS) { + head->r.acl_group_index = head->r.step - TOMOYO_MAX_POLICY + - TOMOYO_MAX_GROUP; + if (!tomoyo_read_domain2(head, &ns->acl_group + [head->r.acl_group_index])) + return; + head->r.step++; + } + head->r.eof = true; +} + +/* Wait queue for kernel -> userspace notification. */ +static DECLARE_WAIT_QUEUE_HEAD(tomoyo_query_wait); +/* Wait queue for userspace -> kernel notification. */ +static DECLARE_WAIT_QUEUE_HEAD(tomoyo_answer_wait); + +/* Structure for query. */ +struct tomoyo_query { + struct list_head list; + struct tomoyo_domain_info *domain; + char *query; + size_t query_len; + unsigned int serial; + u8 timer; + u8 answer; + u8 retry; +}; + +/* The list for "struct tomoyo_query". */ +static LIST_HEAD(tomoyo_query_list); + +/* Lock for manipulating tomoyo_query_list. */ +static DEFINE_SPINLOCK(tomoyo_query_list_lock); + +/* + * Number of "struct file" referring /sys/kernel/security/tomoyo/query + * interface. + */ +static atomic_t tomoyo_query_observers = ATOMIC_INIT(0); + +/** + * tomoyo_truncate - Truncate a line. + * + * @str: String to truncate. + * + * Returns length of truncated @str. + */ +static int tomoyo_truncate(char *str) +{ + char *start = str; + + while (*(unsigned char *) str > (unsigned char) ' ') + str++; + *str = '\0'; + return strlen(start) + 1; +} + +/** + * tomoyo_add_entry - Add an ACL to current thread's domain. Used by learning mode. + * + * @domain: Pointer to "struct tomoyo_domain_info". + * @header: Lines containing ACL. + * + * Returns nothing. + */ +static void tomoyo_add_entry(struct tomoyo_domain_info *domain, char *header) +{ + char *buffer; + char *realpath = NULL; + char *argv0 = NULL; + char *symlink = NULL; + char *cp = strchr(header, '\n'); + int len; + + if (!cp) + return; + cp = strchr(cp + 1, '\n'); + if (!cp) + return; + *cp++ = '\0'; + len = strlen(cp) + 1; + /* strstr() will return NULL if ordering is wrong. */ + if (*cp == 'f') { + argv0 = strstr(header, " argv[]={ \""); + if (argv0) { + argv0 += 10; + len += tomoyo_truncate(argv0) + 14; + } + realpath = strstr(header, " exec={ realpath=\""); + if (realpath) { + realpath += 8; + len += tomoyo_truncate(realpath) + 6; + } + symlink = strstr(header, " symlink.target=\""); + if (symlink) + len += tomoyo_truncate(symlink + 1) + 1; + } + buffer = kmalloc(len, GFP_NOFS); + if (!buffer) + return; + snprintf(buffer, len - 1, "%s", cp); + if (realpath) + tomoyo_addprintf(buffer, len, " exec.%s", realpath); + if (argv0) + tomoyo_addprintf(buffer, len, " exec.argv[0]=%s", argv0); + if (symlink) + tomoyo_addprintf(buffer, len, "%s", symlink); + tomoyo_normalize_line(buffer); + if (!tomoyo_write_domain2(domain->ns, &domain->acl_info_list, buffer, + false)) + tomoyo_update_stat(TOMOYO_STAT_POLICY_UPDATES); + kfree(buffer); +} + +/** + * tomoyo_supervisor - Ask for the supervisor's decision. + * + * @r: Pointer to "struct tomoyo_request_info". + * @fmt: The printf()'s format string, followed by parameters. + * + * Returns 0 if the supervisor decided to permit the access request which + * violated the policy in enforcing mode, TOMOYO_RETRY_REQUEST if the + * supervisor decided to retry the access request which violated the policy in + * enforcing mode, 0 if it is not in enforcing mode, -EPERM otherwise. + */ +int tomoyo_supervisor(struct tomoyo_request_info *r, const char *fmt, ...) +{ + va_list args; + int error; + int len; + static unsigned int tomoyo_serial; + struct tomoyo_query entry = { }; + bool quota_exceeded = false; + + va_start(args, fmt); + len = vsnprintf(NULL, 0, fmt, args) + 1; + va_end(args); + /* Write /sys/kernel/security/tomoyo/audit. */ + va_start(args, fmt); + tomoyo_write_log2(r, len, fmt, args); + va_end(args); + /* Nothing more to do if granted. */ + if (r->granted) + return 0; + if (r->mode) + tomoyo_update_stat(r->mode); + switch (r->mode) { + case TOMOYO_CONFIG_ENFORCING: + error = -EPERM; + if (atomic_read(&tomoyo_query_observers)) + break; + goto out; + case TOMOYO_CONFIG_LEARNING: + error = 0; + /* Check max_learning_entry parameter. */ + if (tomoyo_domain_quota_is_ok(r)) + break; + fallthrough; + default: + return 0; + } + /* Get message. */ + va_start(args, fmt); + entry.query = tomoyo_init_log(r, len, fmt, args); + va_end(args); + if (!entry.query) + goto out; + entry.query_len = strlen(entry.query) + 1; + if (!error) { + tomoyo_add_entry(r->domain, entry.query); + goto out; + } + len = tomoyo_round2(entry.query_len); + entry.domain = r->domain; + spin_lock(&tomoyo_query_list_lock); + if (tomoyo_memory_quota[TOMOYO_MEMORY_QUERY] && + tomoyo_memory_used[TOMOYO_MEMORY_QUERY] + len + >= tomoyo_memory_quota[TOMOYO_MEMORY_QUERY]) { + quota_exceeded = true; + } else { + entry.serial = tomoyo_serial++; + entry.retry = r->retry; + tomoyo_memory_used[TOMOYO_MEMORY_QUERY] += len; + list_add_tail(&entry.list, &tomoyo_query_list); + } + spin_unlock(&tomoyo_query_list_lock); + if (quota_exceeded) + goto out; + /* Give 10 seconds for supervisor's opinion. */ + while (entry.timer < 10) { + wake_up_all(&tomoyo_query_wait); + if (wait_event_interruptible_timeout + (tomoyo_answer_wait, entry.answer || + !atomic_read(&tomoyo_query_observers), HZ)) + break; + entry.timer++; + } + spin_lock(&tomoyo_query_list_lock); + list_del(&entry.list); + tomoyo_memory_used[TOMOYO_MEMORY_QUERY] -= len; + spin_unlock(&tomoyo_query_list_lock); + switch (entry.answer) { + case 3: /* Asked to retry by administrator. */ + error = TOMOYO_RETRY_REQUEST; + r->retry++; + break; + case 1: + /* Granted by administrator. */ + error = 0; + break; + default: + /* Timed out or rejected by administrator. */ + break; + } +out: + kfree(entry.query); + return error; +} + +/** + * tomoyo_find_domain_by_qid - Get domain by query id. + * + * @serial: Query ID assigned by tomoyo_supervisor(). + * + * Returns pointer to "struct tomoyo_domain_info" if found, NULL otherwise. + */ +static struct tomoyo_domain_info *tomoyo_find_domain_by_qid +(unsigned int serial) +{ + struct tomoyo_query *ptr; + struct tomoyo_domain_info *domain = NULL; + + spin_lock(&tomoyo_query_list_lock); + list_for_each_entry(ptr, &tomoyo_query_list, list) { + if (ptr->serial != serial) + continue; + domain = ptr->domain; + break; + } + spin_unlock(&tomoyo_query_list_lock); + return domain; +} + +/** + * tomoyo_poll_query - poll() for /sys/kernel/security/tomoyo/query. + * + * @file: Pointer to "struct file". + * @wait: Pointer to "poll_table". + * + * Returns EPOLLIN | EPOLLRDNORM when ready to read, 0 otherwise. + * + * Waits for access requests which violated policy in enforcing mode. + */ +static __poll_t tomoyo_poll_query(struct file *file, poll_table *wait) +{ + if (!list_empty(&tomoyo_query_list)) + return EPOLLIN | EPOLLRDNORM; + poll_wait(file, &tomoyo_query_wait, wait); + if (!list_empty(&tomoyo_query_list)) + return EPOLLIN | EPOLLRDNORM; + return 0; +} + +/** + * tomoyo_read_query - Read access requests which violated policy in enforcing mode. + * + * @head: Pointer to "struct tomoyo_io_buffer". + */ +static void tomoyo_read_query(struct tomoyo_io_buffer *head) +{ + struct list_head *tmp; + unsigned int pos = 0; + size_t len = 0; + char *buf; + + if (head->r.w_pos) + return; + kfree(head->read_buf); + head->read_buf = NULL; + spin_lock(&tomoyo_query_list_lock); + list_for_each(tmp, &tomoyo_query_list) { + struct tomoyo_query *ptr = list_entry(tmp, typeof(*ptr), list); + + if (pos++ != head->r.query_index) + continue; + len = ptr->query_len; + break; + } + spin_unlock(&tomoyo_query_list_lock); + if (!len) { + head->r.query_index = 0; + return; + } + buf = kzalloc(len + 32, GFP_NOFS); + if (!buf) + return; + pos = 0; + spin_lock(&tomoyo_query_list_lock); + list_for_each(tmp, &tomoyo_query_list) { + struct tomoyo_query *ptr = list_entry(tmp, typeof(*ptr), list); + + if (pos++ != head->r.query_index) + continue; + /* + * Some query can be skipped because tomoyo_query_list + * can change, but I don't care. + */ + if (len == ptr->query_len) + snprintf(buf, len + 31, "Q%u-%hu\n%s", ptr->serial, + ptr->retry, ptr->query); + break; + } + spin_unlock(&tomoyo_query_list_lock); + if (buf[0]) { + head->read_buf = buf; + head->r.w[head->r.w_pos++] = buf; + head->r.query_index++; + } else { + kfree(buf); + } +} + +/** + * tomoyo_write_answer - Write the supervisor's decision. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * + * Returns 0 on success, -EINVAL otherwise. + */ +static int tomoyo_write_answer(struct tomoyo_io_buffer *head) +{ + char *data = head->write_buf; + struct list_head *tmp; + unsigned int serial; + unsigned int answer; + + spin_lock(&tomoyo_query_list_lock); + list_for_each(tmp, &tomoyo_query_list) { + struct tomoyo_query *ptr = list_entry(tmp, typeof(*ptr), list); + + ptr->timer = 0; + } + spin_unlock(&tomoyo_query_list_lock); + if (sscanf(data, "A%u=%u", &serial, &answer) != 2) + return -EINVAL; + spin_lock(&tomoyo_query_list_lock); + list_for_each(tmp, &tomoyo_query_list) { + struct tomoyo_query *ptr = list_entry(tmp, typeof(*ptr), list); + + if (ptr->serial != serial) + continue; + ptr->answer = answer; + /* Remove from tomoyo_query_list. */ + if (ptr->answer) + list_del_init(&ptr->list); + break; + } + spin_unlock(&tomoyo_query_list_lock); + return 0; +} + +/** + * tomoyo_read_version: Get version. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * + * Returns version information. + */ +static void tomoyo_read_version(struct tomoyo_io_buffer *head) +{ + if (!head->r.eof) { + tomoyo_io_printf(head, "2.6.0"); + head->r.eof = true; + } +} + +/* String table for /sys/kernel/security/tomoyo/stat interface. */ +static const char * const tomoyo_policy_headers[TOMOYO_MAX_POLICY_STAT] = { + [TOMOYO_STAT_POLICY_UPDATES] = "update:", + [TOMOYO_STAT_POLICY_LEARNING] = "violation in learning mode:", + [TOMOYO_STAT_POLICY_PERMISSIVE] = "violation in permissive mode:", + [TOMOYO_STAT_POLICY_ENFORCING] = "violation in enforcing mode:", +}; + +/* String table for /sys/kernel/security/tomoyo/stat interface. */ +static const char * const tomoyo_memory_headers[TOMOYO_MAX_MEMORY_STAT] = { + [TOMOYO_MEMORY_POLICY] = "policy:", + [TOMOYO_MEMORY_AUDIT] = "audit log:", + [TOMOYO_MEMORY_QUERY] = "query message:", +}; + +/* Counter for number of updates. */ +static atomic_t tomoyo_stat_updated[TOMOYO_MAX_POLICY_STAT]; +/* Timestamp counter for last updated. */ +static time64_t tomoyo_stat_modified[TOMOYO_MAX_POLICY_STAT]; + +/** + * tomoyo_update_stat - Update statistic counters. + * + * @index: Index for policy type. + * + * Returns nothing. + */ +void tomoyo_update_stat(const u8 index) +{ + atomic_inc(&tomoyo_stat_updated[index]); + tomoyo_stat_modified[index] = ktime_get_real_seconds(); +} + +/** + * tomoyo_read_stat - Read statistic data. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * + * Returns nothing. + */ +static void tomoyo_read_stat(struct tomoyo_io_buffer *head) +{ + u8 i; + unsigned int total = 0; + + if (head->r.eof) + return; + for (i = 0; i < TOMOYO_MAX_POLICY_STAT; i++) { + tomoyo_io_printf(head, "Policy %-30s %10u", + tomoyo_policy_headers[i], + atomic_read(&tomoyo_stat_updated[i])); + if (tomoyo_stat_modified[i]) { + struct tomoyo_time stamp; + + tomoyo_convert_time(tomoyo_stat_modified[i], &stamp); + tomoyo_io_printf(head, " (Last: %04u/%02u/%02u %02u:%02u:%02u)", + stamp.year, stamp.month, stamp.day, + stamp.hour, stamp.min, stamp.sec); + } + tomoyo_set_lf(head); + } + for (i = 0; i < TOMOYO_MAX_MEMORY_STAT; i++) { + unsigned int used = tomoyo_memory_used[i]; + + total += used; + tomoyo_io_printf(head, "Memory used by %-22s %10u", + tomoyo_memory_headers[i], used); + used = tomoyo_memory_quota[i]; + if (used) + tomoyo_io_printf(head, " (Quota: %10u)", used); + tomoyo_set_lf(head); + } + tomoyo_io_printf(head, "Total memory used: %10u\n", + total); + head->r.eof = true; +} + +/** + * tomoyo_write_stat - Set memory quota. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * + * Returns 0. + */ +static int tomoyo_write_stat(struct tomoyo_io_buffer *head) +{ + char *data = head->write_buf; + u8 i; + + if (tomoyo_str_starts(&data, "Memory used by ")) + for (i = 0; i < TOMOYO_MAX_MEMORY_STAT; i++) + if (tomoyo_str_starts(&data, tomoyo_memory_headers[i])) + sscanf(data, "%u", &tomoyo_memory_quota[i]); + return 0; +} + +/** + * tomoyo_open_control - open() for /sys/kernel/security/tomoyo/ interface. + * + * @type: Type of interface. + * @file: Pointer to "struct file". + * + * Returns 0 on success, negative value otherwise. + */ +int tomoyo_open_control(const u8 type, struct file *file) +{ + struct tomoyo_io_buffer *head = kzalloc(sizeof(*head), GFP_NOFS); + + if (!head) + return -ENOMEM; + mutex_init(&head->io_sem); + head->type = type; + switch (type) { + case TOMOYO_DOMAINPOLICY: + /* /sys/kernel/security/tomoyo/domain_policy */ + head->write = tomoyo_write_domain; + head->read = tomoyo_read_domain; + break; + case TOMOYO_EXCEPTIONPOLICY: + /* /sys/kernel/security/tomoyo/exception_policy */ + head->write = tomoyo_write_exception; + head->read = tomoyo_read_exception; + break; + case TOMOYO_AUDIT: + /* /sys/kernel/security/tomoyo/audit */ + head->poll = tomoyo_poll_log; + head->read = tomoyo_read_log; + break; + case TOMOYO_PROCESS_STATUS: + /* /sys/kernel/security/tomoyo/.process_status */ + head->write = tomoyo_write_pid; + head->read = tomoyo_read_pid; + break; + case TOMOYO_VERSION: + /* /sys/kernel/security/tomoyo/version */ + head->read = tomoyo_read_version; + head->readbuf_size = 128; + break; + case TOMOYO_STAT: + /* /sys/kernel/security/tomoyo/stat */ + head->write = tomoyo_write_stat; + head->read = tomoyo_read_stat; + head->readbuf_size = 1024; + break; + case TOMOYO_PROFILE: + /* /sys/kernel/security/tomoyo/profile */ + head->write = tomoyo_write_profile; + head->read = tomoyo_read_profile; + break; + case TOMOYO_QUERY: /* /sys/kernel/security/tomoyo/query */ + head->poll = tomoyo_poll_query; + head->write = tomoyo_write_answer; + head->read = tomoyo_read_query; + break; + case TOMOYO_MANAGER: + /* /sys/kernel/security/tomoyo/manager */ + head->write = tomoyo_write_manager; + head->read = tomoyo_read_manager; + break; + } + if (!(file->f_mode & FMODE_READ)) { + /* + * No need to allocate read_buf since it is not opened + * for reading. + */ + head->read = NULL; + head->poll = NULL; + } else if (!head->poll) { + /* Don't allocate read_buf for poll() access. */ + if (!head->readbuf_size) + head->readbuf_size = 4096 * 2; + head->read_buf = kzalloc(head->readbuf_size, GFP_NOFS); + if (!head->read_buf) { + kfree(head); + return -ENOMEM; + } + } + if (!(file->f_mode & FMODE_WRITE)) { + /* + * No need to allocate write_buf since it is not opened + * for writing. + */ + head->write = NULL; + } else if (head->write) { + head->writebuf_size = 4096 * 2; + head->write_buf = kzalloc(head->writebuf_size, GFP_NOFS); + if (!head->write_buf) { + kfree(head->read_buf); + kfree(head); + return -ENOMEM; + } + } + /* + * If the file is /sys/kernel/security/tomoyo/query , increment the + * observer counter. + * The obserber counter is used by tomoyo_supervisor() to see if + * there is some process monitoring /sys/kernel/security/tomoyo/query. + */ + if (type == TOMOYO_QUERY) + atomic_inc(&tomoyo_query_observers); + file->private_data = head; + tomoyo_notify_gc(head, true); + return 0; +} + +/** + * tomoyo_poll_control - poll() for /sys/kernel/security/tomoyo/ interface. + * + * @file: Pointer to "struct file". + * @wait: Pointer to "poll_table". Maybe NULL. + * + * Returns EPOLLIN | EPOLLRDNORM | EPOLLOUT | EPOLLWRNORM if ready to read/write, + * EPOLLOUT | EPOLLWRNORM otherwise. + */ +__poll_t tomoyo_poll_control(struct file *file, poll_table *wait) +{ + struct tomoyo_io_buffer *head = file->private_data; + + if (head->poll) + return head->poll(file, wait) | EPOLLOUT | EPOLLWRNORM; + return EPOLLIN | EPOLLRDNORM | EPOLLOUT | EPOLLWRNORM; +} + +/** + * tomoyo_set_namespace_cursor - Set namespace to read. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * + * Returns nothing. + */ +static inline void tomoyo_set_namespace_cursor(struct tomoyo_io_buffer *head) +{ + struct list_head *ns; + + if (head->type != TOMOYO_EXCEPTIONPOLICY && + head->type != TOMOYO_PROFILE) + return; + /* + * If this is the first read, or reading previous namespace finished + * and has more namespaces to read, update the namespace cursor. + */ + ns = head->r.ns; + if (!ns || (head->r.eof && ns->next != &tomoyo_namespace_list)) { + /* Clearing is OK because tomoyo_flush() returned true. */ + memset(&head->r, 0, sizeof(head->r)); + head->r.ns = ns ? ns->next : tomoyo_namespace_list.next; + } +} + +/** + * tomoyo_has_more_namespace - Check for unread namespaces. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * + * Returns true if we have more entries to print, false otherwise. + */ +static inline bool tomoyo_has_more_namespace(struct tomoyo_io_buffer *head) +{ + return (head->type == TOMOYO_EXCEPTIONPOLICY || + head->type == TOMOYO_PROFILE) && head->r.eof && + head->r.ns->next != &tomoyo_namespace_list; +} + +/** + * tomoyo_read_control - read() for /sys/kernel/security/tomoyo/ interface. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * @buffer: Pointer to buffer to write to. + * @buffer_len: Size of @buffer. + * + * Returns bytes read on success, negative value otherwise. + */ +ssize_t tomoyo_read_control(struct tomoyo_io_buffer *head, char __user *buffer, + const int buffer_len) +{ + int len; + int idx; + + if (!head->read) + return -EINVAL; + if (mutex_lock_interruptible(&head->io_sem)) + return -EINTR; + head->read_user_buf = buffer; + head->read_user_buf_avail = buffer_len; + idx = tomoyo_read_lock(); + if (tomoyo_flush(head)) + /* Call the policy handler. */ + do { + tomoyo_set_namespace_cursor(head); + head->read(head); + } while (tomoyo_flush(head) && + tomoyo_has_more_namespace(head)); + tomoyo_read_unlock(idx); + len = head->read_user_buf - buffer; + mutex_unlock(&head->io_sem); + return len; +} + +/** + * tomoyo_parse_policy - Parse a policy line. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * @line: Line to parse. + * + * Returns 0 on success, negative value otherwise. + * + * Caller holds tomoyo_read_lock(). + */ +static int tomoyo_parse_policy(struct tomoyo_io_buffer *head, char *line) +{ + /* Delete request? */ + head->w.is_delete = !strncmp(line, "delete ", 7); + if (head->w.is_delete) + memmove(line, line + 7, strlen(line + 7) + 1); + /* Selecting namespace to update. */ + if (head->type == TOMOYO_EXCEPTIONPOLICY || + head->type == TOMOYO_PROFILE) { + if (*line == '<') { + char *cp = strchr(line, ' '); + + if (cp) { + *cp++ = '\0'; + head->w.ns = tomoyo_assign_namespace(line); + memmove(line, cp, strlen(cp) + 1); + } else + head->w.ns = NULL; + } else + head->w.ns = &tomoyo_kernel_namespace; + /* Don't allow updating if namespace is invalid. */ + if (!head->w.ns) + return -ENOENT; + } + /* Do the update. */ + return head->write(head); +} + +/** + * tomoyo_write_control - write() for /sys/kernel/security/tomoyo/ interface. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * @buffer: Pointer to buffer to read from. + * @buffer_len: Size of @buffer. + * + * Returns @buffer_len on success, negative value otherwise. + */ +ssize_t tomoyo_write_control(struct tomoyo_io_buffer *head, + const char __user *buffer, const int buffer_len) +{ + int error = buffer_len; + size_t avail_len = buffer_len; + char *cp0 = head->write_buf; + int idx; + + if (!head->write) + return -EINVAL; + if (mutex_lock_interruptible(&head->io_sem)) + return -EINTR; + head->read_user_buf_avail = 0; + idx = tomoyo_read_lock(); + /* Read a line and dispatch it to the policy handler. */ + while (avail_len > 0) { + char c; + + if (head->w.avail >= head->writebuf_size - 1) { + const int len = head->writebuf_size * 2; + char *cp = kzalloc(len, GFP_NOFS); + + if (!cp) { + error = -ENOMEM; + break; + } + memmove(cp, cp0, head->w.avail); + kfree(cp0); + head->write_buf = cp; + cp0 = cp; + head->writebuf_size = len; + } + if (get_user(c, buffer)) { + error = -EFAULT; + break; + } + buffer++; + avail_len--; + cp0[head->w.avail++] = c; + if (c != '\n') + continue; + cp0[head->w.avail - 1] = '\0'; + head->w.avail = 0; + tomoyo_normalize_line(cp0); + if (!strcmp(cp0, "reset")) { + head->w.ns = &tomoyo_kernel_namespace; + head->w.domain = NULL; + memset(&head->r, 0, sizeof(head->r)); + continue; + } + /* Don't allow updating policies by non manager programs. */ + switch (head->type) { + case TOMOYO_PROCESS_STATUS: + /* This does not write anything. */ + break; + case TOMOYO_DOMAINPOLICY: + if (tomoyo_select_domain(head, cp0)) + continue; + fallthrough; + case TOMOYO_EXCEPTIONPOLICY: + if (!strcmp(cp0, "select transition_only")) { + head->r.print_transition_related_only = true; + continue; + } + fallthrough; + default: + if (!tomoyo_manager()) { + error = -EPERM; + goto out; + } + } + switch (tomoyo_parse_policy(head, cp0)) { + case -EPERM: + error = -EPERM; + goto out; + case 0: + switch (head->type) { + case TOMOYO_DOMAINPOLICY: + case TOMOYO_EXCEPTIONPOLICY: + case TOMOYO_STAT: + case TOMOYO_PROFILE: + case TOMOYO_MANAGER: + tomoyo_update_stat(TOMOYO_STAT_POLICY_UPDATES); + break; + default: + break; + } + break; + } + } +out: + tomoyo_read_unlock(idx); + mutex_unlock(&head->io_sem); + return error; +} + +/** + * tomoyo_close_control - close() for /sys/kernel/security/tomoyo/ interface. + * + * @head: Pointer to "struct tomoyo_io_buffer". + */ +void tomoyo_close_control(struct tomoyo_io_buffer *head) +{ + /* + * If the file is /sys/kernel/security/tomoyo/query , decrement the + * observer counter. + */ + if (head->type == TOMOYO_QUERY && + atomic_dec_and_test(&tomoyo_query_observers)) + wake_up_all(&tomoyo_answer_wait); + tomoyo_notify_gc(head, false); +} + +/** + * tomoyo_check_profile - Check all profiles currently assigned to domains are defined. + */ +void tomoyo_check_profile(void) +{ + struct tomoyo_domain_info *domain; + const int idx = tomoyo_read_lock(); + + tomoyo_policy_loaded = true; + pr_info("TOMOYO: 2.6.0\n"); + list_for_each_entry_rcu(domain, &tomoyo_domain_list, list, + srcu_read_lock_held(&tomoyo_ss)) { + const u8 profile = domain->profile; + struct tomoyo_policy_namespace *ns = domain->ns; + + if (ns->profile_version == 20110903) { + pr_info_once("Converting profile version from %u to %u.\n", + 20110903, 20150505); + ns->profile_version = 20150505; + } + if (ns->profile_version != 20150505) + pr_err("Profile version %u is not supported.\n", + ns->profile_version); + else if (!ns->profile_ptr[profile]) + pr_err("Profile %u (used by '%s') is not defined.\n", + profile, domain->domainname->name); + else + continue; + pr_err("Userland tools for TOMOYO 2.6 must be installed and policy must be initialized.\n"); + pr_err("Please see https://tomoyo.osdn.jp/2.6/ for more information.\n"); + panic("STOP!"); + } + tomoyo_read_unlock(idx); + pr_info("Mandatory Access Control activated.\n"); +} + +/** + * tomoyo_load_builtin_policy - Load built-in policy. + * + * Returns nothing. + */ +void __init tomoyo_load_builtin_policy(void) +{ +#ifdef CONFIG_SECURITY_TOMOYO_INSECURE_BUILTIN_SETTING + static char tomoyo_builtin_profile[] __initdata = + "PROFILE_VERSION=20150505\n" + "0-CONFIG={ mode=learning grant_log=no reject_log=yes }\n"; + static char tomoyo_builtin_exception_policy[] __initdata = + "aggregator proc:/self/exe /proc/self/exe\n"; + static char tomoyo_builtin_domain_policy[] __initdata = ""; + static char tomoyo_builtin_manager[] __initdata = ""; + static char tomoyo_builtin_stat[] __initdata = ""; +#else + /* + * This include file is manually created and contains built-in policy + * named "tomoyo_builtin_profile", "tomoyo_builtin_exception_policy", + * "tomoyo_builtin_domain_policy", "tomoyo_builtin_manager", + * "tomoyo_builtin_stat" in the form of "static char [] __initdata". + */ +#include "builtin-policy.h" +#endif + u8 i; + const int idx = tomoyo_read_lock(); + + for (i = 0; i < 5; i++) { + struct tomoyo_io_buffer head = { }; + char *start = ""; + + switch (i) { + case 0: + start = tomoyo_builtin_profile; + head.type = TOMOYO_PROFILE; + head.write = tomoyo_write_profile; + break; + case 1: + start = tomoyo_builtin_exception_policy; + head.type = TOMOYO_EXCEPTIONPOLICY; + head.write = tomoyo_write_exception; + break; + case 2: + start = tomoyo_builtin_domain_policy; + head.type = TOMOYO_DOMAINPOLICY; + head.write = tomoyo_write_domain; + break; + case 3: + start = tomoyo_builtin_manager; + head.type = TOMOYO_MANAGER; + head.write = tomoyo_write_manager; + break; + case 4: + start = tomoyo_builtin_stat; + head.type = TOMOYO_STAT; + head.write = tomoyo_write_stat; + break; + } + while (1) { + char *end = strchr(start, '\n'); + + if (!end) + break; + *end = '\0'; + tomoyo_normalize_line(start); + head.write_buf = start; + tomoyo_parse_policy(&head, start); + start = end + 1; + } + } + tomoyo_read_unlock(idx); +#ifdef CONFIG_SECURITY_TOMOYO_OMIT_USERSPACE_LOADER + tomoyo_check_profile(); +#endif +} diff --git a/security/tomoyo/common.h b/security/tomoyo/common.h new file mode 100644 index 000000000..ca285f362 --- /dev/null +++ b/security/tomoyo/common.h @@ -0,0 +1,1333 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * security/tomoyo/common.h + * + * Header file for TOMOYO. + * + * Copyright (C) 2005-2011 NTT DATA CORPORATION + */ + +#ifndef _SECURITY_TOMOYO_COMMON_H +#define _SECURITY_TOMOYO_COMMON_H + +#define pr_fmt(fmt) fmt + +#include <linux/ctype.h> +#include <linux/string.h> +#include <linux/mm.h> +#include <linux/file.h> +#include <linux/kmod.h> +#include <linux/fs.h> +#include <linux/sched.h> +#include <linux/namei.h> +#include <linux/mount.h> +#include <linux/list.h> +#include <linux/cred.h> +#include <linux/poll.h> +#include <linux/binfmts.h> +#include <linux/highmem.h> +#include <linux/net.h> +#include <linux/inet.h> +#include <linux/in.h> +#include <linux/in6.h> +#include <linux/un.h> +#include <linux/lsm_hooks.h> +#include <net/sock.h> +#include <net/af_unix.h> +#include <net/ip.h> +#include <net/ipv6.h> +#include <net/udp.h> + +/********** Constants definitions. **********/ + +/* + * TOMOYO uses this hash only when appending a string into the string + * table. Frequency of appending strings is very low. So we don't need + * large (e.g. 64k) hash size. 256 will be sufficient. + */ +#define TOMOYO_HASH_BITS 8 +#define TOMOYO_MAX_HASH (1u<<TOMOYO_HASH_BITS) + +/* + * TOMOYO checks only SOCK_STREAM, SOCK_DGRAM, SOCK_RAW, SOCK_SEQPACKET. + * Therefore, we don't need SOCK_MAX. + */ +#define TOMOYO_SOCK_MAX 6 + +#define TOMOYO_EXEC_TMPSIZE 4096 + +/* Garbage collector is trying to kfree() this element. */ +#define TOMOYO_GC_IN_PROGRESS -1 + +/* Profile number is an integer between 0 and 255. */ +#define TOMOYO_MAX_PROFILES 256 + +/* Group number is an integer between 0 and 255. */ +#define TOMOYO_MAX_ACL_GROUPS 256 + +/* Index numbers for "struct tomoyo_condition". */ +enum tomoyo_conditions_index { + TOMOYO_TASK_UID, /* current_uid() */ + TOMOYO_TASK_EUID, /* current_euid() */ + TOMOYO_TASK_SUID, /* current_suid() */ + TOMOYO_TASK_FSUID, /* current_fsuid() */ + TOMOYO_TASK_GID, /* current_gid() */ + TOMOYO_TASK_EGID, /* current_egid() */ + TOMOYO_TASK_SGID, /* current_sgid() */ + TOMOYO_TASK_FSGID, /* current_fsgid() */ + TOMOYO_TASK_PID, /* sys_getpid() */ + TOMOYO_TASK_PPID, /* sys_getppid() */ + TOMOYO_EXEC_ARGC, /* "struct linux_binprm *"->argc */ + TOMOYO_EXEC_ENVC, /* "struct linux_binprm *"->envc */ + TOMOYO_TYPE_IS_SOCKET, /* S_IFSOCK */ + TOMOYO_TYPE_IS_SYMLINK, /* S_IFLNK */ + TOMOYO_TYPE_IS_FILE, /* S_IFREG */ + TOMOYO_TYPE_IS_BLOCK_DEV, /* S_IFBLK */ + TOMOYO_TYPE_IS_DIRECTORY, /* S_IFDIR */ + TOMOYO_TYPE_IS_CHAR_DEV, /* S_IFCHR */ + TOMOYO_TYPE_IS_FIFO, /* S_IFIFO */ + TOMOYO_MODE_SETUID, /* S_ISUID */ + TOMOYO_MODE_SETGID, /* S_ISGID */ + TOMOYO_MODE_STICKY, /* S_ISVTX */ + TOMOYO_MODE_OWNER_READ, /* S_IRUSR */ + TOMOYO_MODE_OWNER_WRITE, /* S_IWUSR */ + TOMOYO_MODE_OWNER_EXECUTE, /* S_IXUSR */ + TOMOYO_MODE_GROUP_READ, /* S_IRGRP */ + TOMOYO_MODE_GROUP_WRITE, /* S_IWGRP */ + TOMOYO_MODE_GROUP_EXECUTE, /* S_IXGRP */ + TOMOYO_MODE_OTHERS_READ, /* S_IROTH */ + TOMOYO_MODE_OTHERS_WRITE, /* S_IWOTH */ + TOMOYO_MODE_OTHERS_EXECUTE, /* S_IXOTH */ + TOMOYO_EXEC_REALPATH, + TOMOYO_SYMLINK_TARGET, + TOMOYO_PATH1_UID, + TOMOYO_PATH1_GID, + TOMOYO_PATH1_INO, + TOMOYO_PATH1_MAJOR, + TOMOYO_PATH1_MINOR, + TOMOYO_PATH1_PERM, + TOMOYO_PATH1_TYPE, + TOMOYO_PATH1_DEV_MAJOR, + TOMOYO_PATH1_DEV_MINOR, + TOMOYO_PATH2_UID, + TOMOYO_PATH2_GID, + TOMOYO_PATH2_INO, + TOMOYO_PATH2_MAJOR, + TOMOYO_PATH2_MINOR, + TOMOYO_PATH2_PERM, + TOMOYO_PATH2_TYPE, + TOMOYO_PATH2_DEV_MAJOR, + TOMOYO_PATH2_DEV_MINOR, + TOMOYO_PATH1_PARENT_UID, + TOMOYO_PATH1_PARENT_GID, + TOMOYO_PATH1_PARENT_INO, + TOMOYO_PATH1_PARENT_PERM, + TOMOYO_PATH2_PARENT_UID, + TOMOYO_PATH2_PARENT_GID, + TOMOYO_PATH2_PARENT_INO, + TOMOYO_PATH2_PARENT_PERM, + TOMOYO_MAX_CONDITION_KEYWORD, + TOMOYO_NUMBER_UNION, + TOMOYO_NAME_UNION, + TOMOYO_ARGV_ENTRY, + TOMOYO_ENVP_ENTRY, +}; + + +/* Index numbers for stat(). */ +enum tomoyo_path_stat_index { + /* Do not change this order. */ + TOMOYO_PATH1, + TOMOYO_PATH1_PARENT, + TOMOYO_PATH2, + TOMOYO_PATH2_PARENT, + TOMOYO_MAX_PATH_STAT +}; + +/* Index numbers for operation mode. */ +enum tomoyo_mode_index { + TOMOYO_CONFIG_DISABLED, + TOMOYO_CONFIG_LEARNING, + TOMOYO_CONFIG_PERMISSIVE, + TOMOYO_CONFIG_ENFORCING, + TOMOYO_CONFIG_MAX_MODE, + TOMOYO_CONFIG_WANT_REJECT_LOG = 64, + TOMOYO_CONFIG_WANT_GRANT_LOG = 128, + TOMOYO_CONFIG_USE_DEFAULT = 255, +}; + +/* Index numbers for entry type. */ +enum tomoyo_policy_id { + TOMOYO_ID_GROUP, + TOMOYO_ID_ADDRESS_GROUP, + TOMOYO_ID_PATH_GROUP, + TOMOYO_ID_NUMBER_GROUP, + TOMOYO_ID_TRANSITION_CONTROL, + TOMOYO_ID_AGGREGATOR, + TOMOYO_ID_MANAGER, + TOMOYO_ID_CONDITION, + TOMOYO_ID_NAME, + TOMOYO_ID_ACL, + TOMOYO_ID_DOMAIN, + TOMOYO_MAX_POLICY +}; + +/* Index numbers for domain's attributes. */ +enum tomoyo_domain_info_flags_index { + /* Quota warnning flag. */ + TOMOYO_DIF_QUOTA_WARNED, + /* + * This domain was unable to create a new domain at + * tomoyo_find_next_domain() because the name of the domain to be + * created was too long or it could not allocate memory. + * More than one process continued execve() without domain transition. + */ + TOMOYO_DIF_TRANSITION_FAILED, + TOMOYO_MAX_DOMAIN_INFO_FLAGS +}; + +/* Index numbers for audit type. */ +enum tomoyo_grant_log { + /* Follow profile's configuration. */ + TOMOYO_GRANTLOG_AUTO, + /* Do not generate grant log. */ + TOMOYO_GRANTLOG_NO, + /* Generate grant_log. */ + TOMOYO_GRANTLOG_YES, +}; + +/* Index numbers for group entries. */ +enum tomoyo_group_id { + TOMOYO_PATH_GROUP, + TOMOYO_NUMBER_GROUP, + TOMOYO_ADDRESS_GROUP, + TOMOYO_MAX_GROUP +}; + +/* Index numbers for type of numeric values. */ +enum tomoyo_value_type { + TOMOYO_VALUE_TYPE_INVALID, + TOMOYO_VALUE_TYPE_DECIMAL, + TOMOYO_VALUE_TYPE_OCTAL, + TOMOYO_VALUE_TYPE_HEXADECIMAL, +}; + +/* Index numbers for domain transition control keywords. */ +enum tomoyo_transition_type { + /* Do not change this order, */ + TOMOYO_TRANSITION_CONTROL_NO_RESET, + TOMOYO_TRANSITION_CONTROL_RESET, + TOMOYO_TRANSITION_CONTROL_NO_INITIALIZE, + TOMOYO_TRANSITION_CONTROL_INITIALIZE, + TOMOYO_TRANSITION_CONTROL_NO_KEEP, + TOMOYO_TRANSITION_CONTROL_KEEP, + TOMOYO_MAX_TRANSITION_TYPE +}; + +/* Index numbers for Access Controls. */ +enum tomoyo_acl_entry_type_index { + TOMOYO_TYPE_PATH_ACL, + TOMOYO_TYPE_PATH2_ACL, + TOMOYO_TYPE_PATH_NUMBER_ACL, + TOMOYO_TYPE_MKDEV_ACL, + TOMOYO_TYPE_MOUNT_ACL, + TOMOYO_TYPE_INET_ACL, + TOMOYO_TYPE_UNIX_ACL, + TOMOYO_TYPE_ENV_ACL, + TOMOYO_TYPE_MANUAL_TASK_ACL, +}; + +/* Index numbers for access controls with one pathname. */ +enum tomoyo_path_acl_index { + TOMOYO_TYPE_EXECUTE, + TOMOYO_TYPE_READ, + TOMOYO_TYPE_WRITE, + TOMOYO_TYPE_APPEND, + TOMOYO_TYPE_UNLINK, + TOMOYO_TYPE_GETATTR, + TOMOYO_TYPE_RMDIR, + TOMOYO_TYPE_TRUNCATE, + TOMOYO_TYPE_SYMLINK, + TOMOYO_TYPE_CHROOT, + TOMOYO_TYPE_UMOUNT, + TOMOYO_MAX_PATH_OPERATION +}; + +/* Index numbers for /sys/kernel/security/tomoyo/stat interface. */ +enum tomoyo_memory_stat_type { + TOMOYO_MEMORY_POLICY, + TOMOYO_MEMORY_AUDIT, + TOMOYO_MEMORY_QUERY, + TOMOYO_MAX_MEMORY_STAT +}; + +enum tomoyo_mkdev_acl_index { + TOMOYO_TYPE_MKBLOCK, + TOMOYO_TYPE_MKCHAR, + TOMOYO_MAX_MKDEV_OPERATION +}; + +/* Index numbers for socket operations. */ +enum tomoyo_network_acl_index { + TOMOYO_NETWORK_BIND, /* bind() operation. */ + TOMOYO_NETWORK_LISTEN, /* listen() operation. */ + TOMOYO_NETWORK_CONNECT, /* connect() operation. */ + TOMOYO_NETWORK_SEND, /* send() operation. */ + TOMOYO_MAX_NETWORK_OPERATION +}; + +/* Index numbers for access controls with two pathnames. */ +enum tomoyo_path2_acl_index { + TOMOYO_TYPE_LINK, + TOMOYO_TYPE_RENAME, + TOMOYO_TYPE_PIVOT_ROOT, + TOMOYO_MAX_PATH2_OPERATION +}; + +/* Index numbers for access controls with one pathname and one number. */ +enum tomoyo_path_number_acl_index { + TOMOYO_TYPE_CREATE, + TOMOYO_TYPE_MKDIR, + TOMOYO_TYPE_MKFIFO, + TOMOYO_TYPE_MKSOCK, + TOMOYO_TYPE_IOCTL, + TOMOYO_TYPE_CHMOD, + TOMOYO_TYPE_CHOWN, + TOMOYO_TYPE_CHGRP, + TOMOYO_MAX_PATH_NUMBER_OPERATION +}; + +/* Index numbers for /sys/kernel/security/tomoyo/ interfaces. */ +enum tomoyo_securityfs_interface_index { + TOMOYO_DOMAINPOLICY, + TOMOYO_EXCEPTIONPOLICY, + TOMOYO_PROCESS_STATUS, + TOMOYO_STAT, + TOMOYO_AUDIT, + TOMOYO_VERSION, + TOMOYO_PROFILE, + TOMOYO_QUERY, + TOMOYO_MANAGER +}; + +/* Index numbers for special mount operations. */ +enum tomoyo_special_mount { + TOMOYO_MOUNT_BIND, /* mount --bind /source /dest */ + TOMOYO_MOUNT_MOVE, /* mount --move /old /new */ + TOMOYO_MOUNT_REMOUNT, /* mount -o remount /dir */ + TOMOYO_MOUNT_MAKE_UNBINDABLE, /* mount --make-unbindable /dir */ + TOMOYO_MOUNT_MAKE_PRIVATE, /* mount --make-private /dir */ + TOMOYO_MOUNT_MAKE_SLAVE, /* mount --make-slave /dir */ + TOMOYO_MOUNT_MAKE_SHARED, /* mount --make-shared /dir */ + TOMOYO_MAX_SPECIAL_MOUNT +}; + +/* Index numbers for functionality. */ +enum tomoyo_mac_index { + TOMOYO_MAC_FILE_EXECUTE, + TOMOYO_MAC_FILE_OPEN, + TOMOYO_MAC_FILE_CREATE, + TOMOYO_MAC_FILE_UNLINK, + TOMOYO_MAC_FILE_GETATTR, + TOMOYO_MAC_FILE_MKDIR, + TOMOYO_MAC_FILE_RMDIR, + TOMOYO_MAC_FILE_MKFIFO, + TOMOYO_MAC_FILE_MKSOCK, + TOMOYO_MAC_FILE_TRUNCATE, + TOMOYO_MAC_FILE_SYMLINK, + TOMOYO_MAC_FILE_MKBLOCK, + TOMOYO_MAC_FILE_MKCHAR, + TOMOYO_MAC_FILE_LINK, + TOMOYO_MAC_FILE_RENAME, + TOMOYO_MAC_FILE_CHMOD, + TOMOYO_MAC_FILE_CHOWN, + TOMOYO_MAC_FILE_CHGRP, + TOMOYO_MAC_FILE_IOCTL, + TOMOYO_MAC_FILE_CHROOT, + TOMOYO_MAC_FILE_MOUNT, + TOMOYO_MAC_FILE_UMOUNT, + TOMOYO_MAC_FILE_PIVOT_ROOT, + TOMOYO_MAC_NETWORK_INET_STREAM_BIND, + TOMOYO_MAC_NETWORK_INET_STREAM_LISTEN, + TOMOYO_MAC_NETWORK_INET_STREAM_CONNECT, + TOMOYO_MAC_NETWORK_INET_DGRAM_BIND, + TOMOYO_MAC_NETWORK_INET_DGRAM_SEND, + TOMOYO_MAC_NETWORK_INET_RAW_BIND, + TOMOYO_MAC_NETWORK_INET_RAW_SEND, + TOMOYO_MAC_NETWORK_UNIX_STREAM_BIND, + TOMOYO_MAC_NETWORK_UNIX_STREAM_LISTEN, + TOMOYO_MAC_NETWORK_UNIX_STREAM_CONNECT, + TOMOYO_MAC_NETWORK_UNIX_DGRAM_BIND, + TOMOYO_MAC_NETWORK_UNIX_DGRAM_SEND, + TOMOYO_MAC_NETWORK_UNIX_SEQPACKET_BIND, + TOMOYO_MAC_NETWORK_UNIX_SEQPACKET_LISTEN, + TOMOYO_MAC_NETWORK_UNIX_SEQPACKET_CONNECT, + TOMOYO_MAC_ENVIRON, + TOMOYO_MAX_MAC_INDEX +}; + +/* Index numbers for category of functionality. */ +enum tomoyo_mac_category_index { + TOMOYO_MAC_CATEGORY_FILE, + TOMOYO_MAC_CATEGORY_NETWORK, + TOMOYO_MAC_CATEGORY_MISC, + TOMOYO_MAX_MAC_CATEGORY_INDEX +}; + +/* + * Retry this request. Returned by tomoyo_supervisor() if policy violation has + * occurred in enforcing mode and the userspace daemon decided to retry. + * + * We must choose a positive value in order to distinguish "granted" (which is + * 0) and "rejected" (which is a negative value) and "retry". + */ +#define TOMOYO_RETRY_REQUEST 1 + +/* Index numbers for /sys/kernel/security/tomoyo/stat interface. */ +enum tomoyo_policy_stat_type { + /* Do not change this order. */ + TOMOYO_STAT_POLICY_UPDATES, + TOMOYO_STAT_POLICY_LEARNING, /* == TOMOYO_CONFIG_LEARNING */ + TOMOYO_STAT_POLICY_PERMISSIVE, /* == TOMOYO_CONFIG_PERMISSIVE */ + TOMOYO_STAT_POLICY_ENFORCING, /* == TOMOYO_CONFIG_ENFORCING */ + TOMOYO_MAX_POLICY_STAT +}; + +/* Index numbers for profile's PREFERENCE values. */ +enum tomoyo_pref_index { + TOMOYO_PREF_MAX_AUDIT_LOG, + TOMOYO_PREF_MAX_LEARNING_ENTRY, + TOMOYO_MAX_PREF +}; + +/********** Structure definitions. **********/ + +/* Common header for holding ACL entries. */ +struct tomoyo_acl_head { + struct list_head list; + s8 is_deleted; /* true or false or TOMOYO_GC_IN_PROGRESS */ +} __packed; + +/* Common header for shared entries. */ +struct tomoyo_shared_acl_head { + struct list_head list; + atomic_t users; +} __packed; + +struct tomoyo_policy_namespace; + +/* Structure for request info. */ +struct tomoyo_request_info { + /* + * For holding parameters specific to operations which deal files. + * NULL if not dealing files. + */ + struct tomoyo_obj_info *obj; + /* + * For holding parameters specific to execve() request. + * NULL if not dealing execve(). + */ + struct tomoyo_execve *ee; + struct tomoyo_domain_info *domain; + /* For holding parameters. */ + union { + struct { + const struct tomoyo_path_info *filename; + /* For using wildcards at tomoyo_find_next_domain(). */ + const struct tomoyo_path_info *matched_path; + /* One of values in "enum tomoyo_path_acl_index". */ + u8 operation; + } path; + struct { + const struct tomoyo_path_info *filename1; + const struct tomoyo_path_info *filename2; + /* One of values in "enum tomoyo_path2_acl_index". */ + u8 operation; + } path2; + struct { + const struct tomoyo_path_info *filename; + unsigned int mode; + unsigned int major; + unsigned int minor; + /* One of values in "enum tomoyo_mkdev_acl_index". */ + u8 operation; + } mkdev; + struct { + const struct tomoyo_path_info *filename; + unsigned long number; + /* + * One of values in + * "enum tomoyo_path_number_acl_index". + */ + u8 operation; + } path_number; + struct { + const struct tomoyo_path_info *name; + } environ; + struct { + const __be32 *address; + u16 port; + /* One of values smaller than TOMOYO_SOCK_MAX. */ + u8 protocol; + /* One of values in "enum tomoyo_network_acl_index". */ + u8 operation; + bool is_ipv6; + } inet_network; + struct { + const struct tomoyo_path_info *address; + /* One of values smaller than TOMOYO_SOCK_MAX. */ + u8 protocol; + /* One of values in "enum tomoyo_network_acl_index". */ + u8 operation; + } unix_network; + struct { + const struct tomoyo_path_info *type; + const struct tomoyo_path_info *dir; + const struct tomoyo_path_info *dev; + unsigned long flags; + int need_dev; + } mount; + struct { + const struct tomoyo_path_info *domainname; + } task; + } param; + struct tomoyo_acl_info *matched_acl; + u8 param_type; + bool granted; + u8 retry; + u8 profile; + u8 mode; /* One of tomoyo_mode_index . */ + u8 type; +}; + +/* Structure for holding a token. */ +struct tomoyo_path_info { + const char *name; + u32 hash; /* = full_name_hash(name, strlen(name)) */ + u16 const_len; /* = tomoyo_const_part_length(name) */ + bool is_dir; /* = tomoyo_strendswith(name, "/") */ + bool is_patterned; /* = tomoyo_path_contains_pattern(name) */ +}; + +/* Structure for holding string data. */ +struct tomoyo_name { + struct tomoyo_shared_acl_head head; + struct tomoyo_path_info entry; +}; + +/* Structure for holding a word. */ +struct tomoyo_name_union { + /* Either @filename or @group is NULL. */ + const struct tomoyo_path_info *filename; + struct tomoyo_group *group; +}; + +/* Structure for holding a number. */ +struct tomoyo_number_union { + unsigned long values[2]; + struct tomoyo_group *group; /* Maybe NULL. */ + /* One of values in "enum tomoyo_value_type". */ + u8 value_type[2]; +}; + +/* Structure for holding an IP address. */ +struct tomoyo_ipaddr_union { + struct in6_addr ip[2]; /* Big endian. */ + struct tomoyo_group *group; /* Pointer to address group. */ + bool is_ipv6; /* Valid only if @group == NULL. */ +}; + +/* Structure for "path_group"/"number_group"/"address_group" directive. */ +struct tomoyo_group { + struct tomoyo_shared_acl_head head; + const struct tomoyo_path_info *group_name; + struct list_head member_list; +}; + +/* Structure for "path_group" directive. */ +struct tomoyo_path_group { + struct tomoyo_acl_head head; + const struct tomoyo_path_info *member_name; +}; + +/* Structure for "number_group" directive. */ +struct tomoyo_number_group { + struct tomoyo_acl_head head; + struct tomoyo_number_union number; +}; + +/* Structure for "address_group" directive. */ +struct tomoyo_address_group { + struct tomoyo_acl_head head; + /* Structure for holding an IP address. */ + struct tomoyo_ipaddr_union address; +}; + +/* Subset of "struct stat". Used by conditional ACL and audit logs. */ +struct tomoyo_mini_stat { + kuid_t uid; + kgid_t gid; + ino_t ino; + umode_t mode; + dev_t dev; + dev_t rdev; +}; + +/* Structure for dumping argv[] and envp[] of "struct linux_binprm". */ +struct tomoyo_page_dump { + struct page *page; /* Previously dumped page. */ + char *data; /* Contents of "page". Size is PAGE_SIZE. */ +}; + +/* Structure for attribute checks in addition to pathname checks. */ +struct tomoyo_obj_info { + /* + * True if tomoyo_get_attributes() was already called, false otherwise. + */ + bool validate_done; + /* True if @stat[] is valid. */ + bool stat_valid[TOMOYO_MAX_PATH_STAT]; + /* First pathname. Initialized with { NULL, NULL } if no path. */ + struct path path1; + /* Second pathname. Initialized with { NULL, NULL } if no path. */ + struct path path2; + /* + * Information on @path1, @path1's parent directory, @path2, @path2's + * parent directory. + */ + struct tomoyo_mini_stat stat[TOMOYO_MAX_PATH_STAT]; + /* + * Content of symbolic link to be created. NULL for operations other + * than symlink(). + */ + struct tomoyo_path_info *symlink_target; +}; + +/* Structure for argv[]. */ +struct tomoyo_argv { + unsigned long index; + const struct tomoyo_path_info *value; + bool is_not; +}; + +/* Structure for envp[]. */ +struct tomoyo_envp { + const struct tomoyo_path_info *name; + const struct tomoyo_path_info *value; + bool is_not; +}; + +/* Structure for execve() operation. */ +struct tomoyo_execve { + struct tomoyo_request_info r; + struct tomoyo_obj_info obj; + struct linux_binprm *bprm; + const struct tomoyo_path_info *transition; + /* For dumping argv[] and envp[]. */ + struct tomoyo_page_dump dump; + /* For temporary use. */ + char *tmp; /* Size is TOMOYO_EXEC_TMPSIZE bytes */ +}; + +/* Structure for entries which follows "struct tomoyo_condition". */ +struct tomoyo_condition_element { + /* + * Left hand operand. A "struct tomoyo_argv" for TOMOYO_ARGV_ENTRY, a + * "struct tomoyo_envp" for TOMOYO_ENVP_ENTRY is attached to the tail + * of the array of this struct. + */ + u8 left; + /* + * Right hand operand. A "struct tomoyo_number_union" for + * TOMOYO_NUMBER_UNION, a "struct tomoyo_name_union" for + * TOMOYO_NAME_UNION is attached to the tail of the array of this + * struct. + */ + u8 right; + /* Equation operator. True if equals or overlaps, false otherwise. */ + bool equals; +}; + +/* Structure for optional arguments. */ +struct tomoyo_condition { + struct tomoyo_shared_acl_head head; + u32 size; /* Memory size allocated for this entry. */ + u16 condc; /* Number of conditions in this struct. */ + u16 numbers_count; /* Number of "struct tomoyo_number_union values". */ + u16 names_count; /* Number of "struct tomoyo_name_union names". */ + u16 argc; /* Number of "struct tomoyo_argv". */ + u16 envc; /* Number of "struct tomoyo_envp". */ + u8 grant_log; /* One of values in "enum tomoyo_grant_log". */ + const struct tomoyo_path_info *transit; /* Maybe NULL. */ + /* + * struct tomoyo_condition_element condition[condc]; + * struct tomoyo_number_union values[numbers_count]; + * struct tomoyo_name_union names[names_count]; + * struct tomoyo_argv argv[argc]; + * struct tomoyo_envp envp[envc]; + */ +}; + +/* Common header for individual entries. */ +struct tomoyo_acl_info { + struct list_head list; + struct tomoyo_condition *cond; /* Maybe NULL. */ + s8 is_deleted; /* true or false or TOMOYO_GC_IN_PROGRESS */ + u8 type; /* One of values in "enum tomoyo_acl_entry_type_index". */ +} __packed; + +/* Structure for domain information. */ +struct tomoyo_domain_info { + struct list_head list; + struct list_head acl_info_list; + /* Name of this domain. Never NULL. */ + const struct tomoyo_path_info *domainname; + /* Namespace for this domain. Never NULL. */ + struct tomoyo_policy_namespace *ns; + /* Group numbers to use. */ + unsigned long group[TOMOYO_MAX_ACL_GROUPS / BITS_PER_LONG]; + u8 profile; /* Profile number to use. */ + bool is_deleted; /* Delete flag. */ + bool flags[TOMOYO_MAX_DOMAIN_INFO_FLAGS]; + atomic_t users; /* Number of referring tasks. */ +}; + +/* + * Structure for "task manual_domain_transition" directive. + */ +struct tomoyo_task_acl { + struct tomoyo_acl_info head; /* type = TOMOYO_TYPE_MANUAL_TASK_ACL */ + /* Pointer to domainname. */ + const struct tomoyo_path_info *domainname; +}; + +/* + * Structure for "file execute", "file read", "file write", "file append", + * "file unlink", "file getattr", "file rmdir", "file truncate", + * "file symlink", "file chroot" and "file unmount" directive. + */ +struct tomoyo_path_acl { + struct tomoyo_acl_info head; /* type = TOMOYO_TYPE_PATH_ACL */ + u16 perm; /* Bitmask of values in "enum tomoyo_path_acl_index". */ + struct tomoyo_name_union name; +}; + +/* + * Structure for "file create", "file mkdir", "file mkfifo", "file mksock", + * "file ioctl", "file chmod", "file chown" and "file chgrp" directive. + */ +struct tomoyo_path_number_acl { + struct tomoyo_acl_info head; /* type = TOMOYO_TYPE_PATH_NUMBER_ACL */ + /* Bitmask of values in "enum tomoyo_path_number_acl_index". */ + u8 perm; + struct tomoyo_name_union name; + struct tomoyo_number_union number; +}; + +/* Structure for "file mkblock" and "file mkchar" directive. */ +struct tomoyo_mkdev_acl { + struct tomoyo_acl_info head; /* type = TOMOYO_TYPE_MKDEV_ACL */ + u8 perm; /* Bitmask of values in "enum tomoyo_mkdev_acl_index". */ + struct tomoyo_name_union name; + struct tomoyo_number_union mode; + struct tomoyo_number_union major; + struct tomoyo_number_union minor; +}; + +/* + * Structure for "file rename", "file link" and "file pivot_root" directive. + */ +struct tomoyo_path2_acl { + struct tomoyo_acl_info head; /* type = TOMOYO_TYPE_PATH2_ACL */ + u8 perm; /* Bitmask of values in "enum tomoyo_path2_acl_index". */ + struct tomoyo_name_union name1; + struct tomoyo_name_union name2; +}; + +/* Structure for "file mount" directive. */ +struct tomoyo_mount_acl { + struct tomoyo_acl_info head; /* type = TOMOYO_TYPE_MOUNT_ACL */ + struct tomoyo_name_union dev_name; + struct tomoyo_name_union dir_name; + struct tomoyo_name_union fs_type; + struct tomoyo_number_union flags; +}; + +/* Structure for "misc env" directive in domain policy. */ +struct tomoyo_env_acl { + struct tomoyo_acl_info head; /* type = TOMOYO_TYPE_ENV_ACL */ + const struct tomoyo_path_info *env; /* environment variable */ +}; + +/* Structure for "network inet" directive. */ +struct tomoyo_inet_acl { + struct tomoyo_acl_info head; /* type = TOMOYO_TYPE_INET_ACL */ + u8 protocol; + u8 perm; /* Bitmask of values in "enum tomoyo_network_acl_index" */ + struct tomoyo_ipaddr_union address; + struct tomoyo_number_union port; +}; + +/* Structure for "network unix" directive. */ +struct tomoyo_unix_acl { + struct tomoyo_acl_info head; /* type = TOMOYO_TYPE_UNIX_ACL */ + u8 protocol; + u8 perm; /* Bitmask of values in "enum tomoyo_network_acl_index" */ + struct tomoyo_name_union name; +}; + +/* Structure for holding a line from /sys/kernel/security/tomoyo/ interface. */ +struct tomoyo_acl_param { + char *data; + struct list_head *list; + struct tomoyo_policy_namespace *ns; + bool is_delete; +}; + +#define TOMOYO_MAX_IO_READ_QUEUE 64 + +/* + * Structure for reading/writing policy via /sys/kernel/security/tomoyo + * interfaces. + */ +struct tomoyo_io_buffer { + void (*read)(struct tomoyo_io_buffer *head); + int (*write)(struct tomoyo_io_buffer *head); + __poll_t (*poll)(struct file *file, poll_table *wait); + /* Exclusive lock for this structure. */ + struct mutex io_sem; + char __user *read_user_buf; + size_t read_user_buf_avail; + struct { + struct list_head *ns; + struct list_head *domain; + struct list_head *group; + struct list_head *acl; + size_t avail; + unsigned int step; + unsigned int query_index; + u16 index; + u16 cond_index; + u8 acl_group_index; + u8 cond_step; + u8 bit; + u8 w_pos; + bool eof; + bool print_this_domain_only; + bool print_transition_related_only; + bool print_cond_part; + const char *w[TOMOYO_MAX_IO_READ_QUEUE]; + } r; + struct { + struct tomoyo_policy_namespace *ns; + /* The position currently writing to. */ + struct tomoyo_domain_info *domain; + /* Bytes available for writing. */ + size_t avail; + bool is_delete; + } w; + /* Buffer for reading. */ + char *read_buf; + /* Size of read buffer. */ + size_t readbuf_size; + /* Buffer for writing. */ + char *write_buf; + /* Size of write buffer. */ + size_t writebuf_size; + /* Type of this interface. */ + enum tomoyo_securityfs_interface_index type; + /* Users counter protected by tomoyo_io_buffer_list_lock. */ + u8 users; + /* List for telling GC not to kfree() elements. */ + struct list_head list; +}; + +/* + * Structure for "initialize_domain"/"no_initialize_domain"/"keep_domain"/ + * "no_keep_domain" keyword. + */ +struct tomoyo_transition_control { + struct tomoyo_acl_head head; + u8 type; /* One of values in "enum tomoyo_transition_type". */ + /* True if the domainname is tomoyo_get_last_name(). */ + bool is_last_name; + const struct tomoyo_path_info *domainname; /* Maybe NULL */ + const struct tomoyo_path_info *program; /* Maybe NULL */ +}; + +/* Structure for "aggregator" keyword. */ +struct tomoyo_aggregator { + struct tomoyo_acl_head head; + const struct tomoyo_path_info *original_name; + const struct tomoyo_path_info *aggregated_name; +}; + +/* Structure for policy manager. */ +struct tomoyo_manager { + struct tomoyo_acl_head head; + /* A path to program or a domainname. */ + const struct tomoyo_path_info *manager; +}; + +struct tomoyo_preference { + unsigned int learning_max_entry; + bool enforcing_verbose; + bool learning_verbose; + bool permissive_verbose; +}; + +/* Structure for /sys/kernel/security/tomnoyo/profile interface. */ +struct tomoyo_profile { + const struct tomoyo_path_info *comment; + struct tomoyo_preference *learning; + struct tomoyo_preference *permissive; + struct tomoyo_preference *enforcing; + struct tomoyo_preference preference; + u8 default_config; + u8 config[TOMOYO_MAX_MAC_INDEX + TOMOYO_MAX_MAC_CATEGORY_INDEX]; + unsigned int pref[TOMOYO_MAX_PREF]; +}; + +/* Structure for representing YYYY/MM/DD hh/mm/ss. */ +struct tomoyo_time { + u16 year; + u8 month; + u8 day; + u8 hour; + u8 min; + u8 sec; +}; + +/* Structure for policy namespace. */ +struct tomoyo_policy_namespace { + /* Profile table. Memory is allocated as needed. */ + struct tomoyo_profile *profile_ptr[TOMOYO_MAX_PROFILES]; + /* List of "struct tomoyo_group". */ + struct list_head group_list[TOMOYO_MAX_GROUP]; + /* List of policy. */ + struct list_head policy_list[TOMOYO_MAX_POLICY]; + /* The global ACL referred by "use_group" keyword. */ + struct list_head acl_group[TOMOYO_MAX_ACL_GROUPS]; + /* List for connecting to tomoyo_namespace_list list. */ + struct list_head namespace_list; + /* Profile version. Currently only 20150505 is defined. */ + unsigned int profile_version; + /* Name of this namespace (e.g. "<kernel>", "</usr/sbin/httpd>" ). */ + const char *name; +}; + +/* Structure for "struct task_struct"->security. */ +struct tomoyo_task { + struct tomoyo_domain_info *domain_info; + struct tomoyo_domain_info *old_domain_info; +}; + +/********** Function prototypes. **********/ + +bool tomoyo_address_matches_group(const bool is_ipv6, const __be32 *address, + const struct tomoyo_group *group); +bool tomoyo_compare_number_union(const unsigned long value, + const struct tomoyo_number_union *ptr); +bool tomoyo_condition(struct tomoyo_request_info *r, + const struct tomoyo_condition *cond); +bool tomoyo_correct_domain(const unsigned char *domainname); +bool tomoyo_correct_path(const char *filename); +bool tomoyo_correct_word(const char *string); +bool tomoyo_domain_def(const unsigned char *buffer); +bool tomoyo_domain_quota_is_ok(struct tomoyo_request_info *r); +bool tomoyo_dump_page(struct linux_binprm *bprm, unsigned long pos, + struct tomoyo_page_dump *dump); +bool tomoyo_memory_ok(void *ptr); +bool tomoyo_number_matches_group(const unsigned long min, + const unsigned long max, + const struct tomoyo_group *group); +bool tomoyo_parse_ipaddr_union(struct tomoyo_acl_param *param, + struct tomoyo_ipaddr_union *ptr); +bool tomoyo_parse_name_union(struct tomoyo_acl_param *param, + struct tomoyo_name_union *ptr); +bool tomoyo_parse_number_union(struct tomoyo_acl_param *param, + struct tomoyo_number_union *ptr); +bool tomoyo_path_matches_pattern(const struct tomoyo_path_info *filename, + const struct tomoyo_path_info *pattern); +bool tomoyo_permstr(const char *string, const char *keyword); +bool tomoyo_str_starts(char **src, const char *find); +char *tomoyo_encode(const char *str); +char *tomoyo_encode2(const char *str, int str_len); +char *tomoyo_init_log(struct tomoyo_request_info *r, int len, const char *fmt, + va_list args); +char *tomoyo_read_token(struct tomoyo_acl_param *param); +char *tomoyo_realpath_from_path(const struct path *path); +char *tomoyo_realpath_nofollow(const char *pathname); +const char *tomoyo_get_exe(void); +const struct tomoyo_path_info *tomoyo_compare_name_union +(const struct tomoyo_path_info *name, const struct tomoyo_name_union *ptr); +const struct tomoyo_path_info *tomoyo_get_domainname +(struct tomoyo_acl_param *param); +const struct tomoyo_path_info *tomoyo_get_name(const char *name); +const struct tomoyo_path_info *tomoyo_path_matches_group +(const struct tomoyo_path_info *pathname, const struct tomoyo_group *group); +int tomoyo_check_open_permission(struct tomoyo_domain_info *domain, + const struct path *path, const int flag); +void tomoyo_close_control(struct tomoyo_io_buffer *head); +int tomoyo_env_perm(struct tomoyo_request_info *r, const char *env); +int tomoyo_execute_permission(struct tomoyo_request_info *r, + const struct tomoyo_path_info *filename); +int tomoyo_find_next_domain(struct linux_binprm *bprm); +int tomoyo_get_mode(const struct tomoyo_policy_namespace *ns, const u8 profile, + const u8 index); +int tomoyo_init_request_info(struct tomoyo_request_info *r, + struct tomoyo_domain_info *domain, + const u8 index); +int tomoyo_mkdev_perm(const u8 operation, const struct path *path, + const unsigned int mode, unsigned int dev); +int tomoyo_mount_permission(const char *dev_name, const struct path *path, + const char *type, unsigned long flags, + void *data_page); +int tomoyo_open_control(const u8 type, struct file *file); +int tomoyo_path2_perm(const u8 operation, const struct path *path1, + const struct path *path2); +int tomoyo_path_number_perm(const u8 operation, const struct path *path, + unsigned long number); +int tomoyo_path_perm(const u8 operation, const struct path *path, + const char *target); +__poll_t tomoyo_poll_control(struct file *file, poll_table *wait); +__poll_t tomoyo_poll_log(struct file *file, poll_table *wait); +int tomoyo_socket_bind_permission(struct socket *sock, struct sockaddr *addr, + int addr_len); +int tomoyo_socket_connect_permission(struct socket *sock, + struct sockaddr *addr, int addr_len); +int tomoyo_socket_listen_permission(struct socket *sock); +int tomoyo_socket_sendmsg_permission(struct socket *sock, struct msghdr *msg, + int size); +int tomoyo_supervisor(struct tomoyo_request_info *r, const char *fmt, ...) + __printf(2, 3); +int tomoyo_update_domain(struct tomoyo_acl_info *new_entry, const int size, + struct tomoyo_acl_param *param, + bool (*check_duplicate) + (const struct tomoyo_acl_info *, + const struct tomoyo_acl_info *), + bool (*merge_duplicate) + (struct tomoyo_acl_info *, struct tomoyo_acl_info *, + const bool)); +int tomoyo_update_policy(struct tomoyo_acl_head *new_entry, const int size, + struct tomoyo_acl_param *param, + bool (*check_duplicate) + (const struct tomoyo_acl_head *, + const struct tomoyo_acl_head *)); +int tomoyo_write_aggregator(struct tomoyo_acl_param *param); +int tomoyo_write_file(struct tomoyo_acl_param *param); +int tomoyo_write_group(struct tomoyo_acl_param *param, const u8 type); +int tomoyo_write_misc(struct tomoyo_acl_param *param); +int tomoyo_write_inet_network(struct tomoyo_acl_param *param); +int tomoyo_write_transition_control(struct tomoyo_acl_param *param, + const u8 type); +int tomoyo_write_unix_network(struct tomoyo_acl_param *param); +ssize_t tomoyo_read_control(struct tomoyo_io_buffer *head, char __user *buffer, + const int buffer_len); +ssize_t tomoyo_write_control(struct tomoyo_io_buffer *head, + const char __user *buffer, const int buffer_len); +struct tomoyo_condition *tomoyo_get_condition(struct tomoyo_acl_param *param); +struct tomoyo_domain_info *tomoyo_assign_domain(const char *domainname, + const bool transit); +struct tomoyo_domain_info *tomoyo_domain(void); +struct tomoyo_domain_info *tomoyo_find_domain(const char *domainname); +struct tomoyo_group *tomoyo_get_group(struct tomoyo_acl_param *param, + const u8 idx); +struct tomoyo_policy_namespace *tomoyo_assign_namespace +(const char *domainname); +struct tomoyo_profile *tomoyo_profile(const struct tomoyo_policy_namespace *ns, + const u8 profile); +unsigned int tomoyo_check_flags(const struct tomoyo_domain_info *domain, + const u8 index); +u8 tomoyo_parse_ulong(unsigned long *result, char **str); +void *tomoyo_commit_ok(void *data, const unsigned int size); +void __init tomoyo_load_builtin_policy(void); +void __init tomoyo_mm_init(void); +void tomoyo_check_acl(struct tomoyo_request_info *r, + bool (*check_entry)(struct tomoyo_request_info *, + const struct tomoyo_acl_info *)); +void tomoyo_check_profile(void); +void tomoyo_convert_time(time64_t time, struct tomoyo_time *stamp); +void tomoyo_del_condition(struct list_head *element); +void tomoyo_fill_path_info(struct tomoyo_path_info *ptr); +void tomoyo_get_attributes(struct tomoyo_obj_info *obj); +void tomoyo_init_policy_namespace(struct tomoyo_policy_namespace *ns); +void tomoyo_load_policy(const char *filename); +void tomoyo_normalize_line(unsigned char *buffer); +void tomoyo_notify_gc(struct tomoyo_io_buffer *head, const bool is_register); +void tomoyo_print_ip(char *buf, const unsigned int size, + const struct tomoyo_ipaddr_union *ptr); +void tomoyo_print_ulong(char *buffer, const int buffer_len, + const unsigned long value, const u8 type); +void tomoyo_put_name_union(struct tomoyo_name_union *ptr); +void tomoyo_put_number_union(struct tomoyo_number_union *ptr); +void tomoyo_read_log(struct tomoyo_io_buffer *head); +void tomoyo_update_stat(const u8 index); +void tomoyo_warn_oom(const char *function); +void tomoyo_write_log(struct tomoyo_request_info *r, const char *fmt, ...) + __printf(2, 3); +void tomoyo_write_log2(struct tomoyo_request_info *r, int len, const char *fmt, + va_list args); + +/********** External variable definitions. **********/ + +extern bool tomoyo_policy_loaded; +extern int tomoyo_enabled; +extern const char * const tomoyo_condition_keyword +[TOMOYO_MAX_CONDITION_KEYWORD]; +extern const char * const tomoyo_dif[TOMOYO_MAX_DOMAIN_INFO_FLAGS]; +extern const char * const tomoyo_mac_keywords[TOMOYO_MAX_MAC_INDEX + + TOMOYO_MAX_MAC_CATEGORY_INDEX]; +extern const char * const tomoyo_mode[TOMOYO_CONFIG_MAX_MODE]; +extern const char * const tomoyo_path_keyword[TOMOYO_MAX_PATH_OPERATION]; +extern const char * const tomoyo_proto_keyword[TOMOYO_SOCK_MAX]; +extern const char * const tomoyo_socket_keyword[TOMOYO_MAX_NETWORK_OPERATION]; +extern const u8 tomoyo_index2category[TOMOYO_MAX_MAC_INDEX]; +extern const u8 tomoyo_pn2mac[TOMOYO_MAX_PATH_NUMBER_OPERATION]; +extern const u8 tomoyo_pnnn2mac[TOMOYO_MAX_MKDEV_OPERATION]; +extern const u8 tomoyo_pp2mac[TOMOYO_MAX_PATH2_OPERATION]; +extern struct list_head tomoyo_condition_list; +extern struct list_head tomoyo_domain_list; +extern struct list_head tomoyo_name_list[TOMOYO_MAX_HASH]; +extern struct list_head tomoyo_namespace_list; +extern struct mutex tomoyo_policy_lock; +extern struct srcu_struct tomoyo_ss; +extern struct tomoyo_domain_info tomoyo_kernel_domain; +extern struct tomoyo_policy_namespace tomoyo_kernel_namespace; +extern unsigned int tomoyo_memory_quota[TOMOYO_MAX_MEMORY_STAT]; +extern unsigned int tomoyo_memory_used[TOMOYO_MAX_MEMORY_STAT]; +extern struct lsm_blob_sizes tomoyo_blob_sizes; + +/********** Inlined functions. **********/ + +/** + * tomoyo_read_lock - Take lock for protecting policy. + * + * Returns index number for tomoyo_read_unlock(). + */ +static inline int tomoyo_read_lock(void) +{ + return srcu_read_lock(&tomoyo_ss); +} + +/** + * tomoyo_read_unlock - Release lock for protecting policy. + * + * @idx: Index number returned by tomoyo_read_lock(). + * + * Returns nothing. + */ +static inline void tomoyo_read_unlock(int idx) +{ + srcu_read_unlock(&tomoyo_ss, idx); +} + +/** + * tomoyo_sys_getppid - Copy of getppid(). + * + * Returns parent process's PID. + * + * Alpha does not have getppid() defined. To be able to build this module on + * Alpha, I have to copy getppid() from kernel/timer.c. + */ +static inline pid_t tomoyo_sys_getppid(void) +{ + pid_t pid; + + rcu_read_lock(); + pid = task_tgid_vnr(rcu_dereference(current->real_parent)); + rcu_read_unlock(); + return pid; +} + +/** + * tomoyo_sys_getpid - Copy of getpid(). + * + * Returns current thread's PID. + * + * Alpha does not have getpid() defined. To be able to build this module on + * Alpha, I have to copy getpid() from kernel/timer.c. + */ +static inline pid_t tomoyo_sys_getpid(void) +{ + return task_tgid_vnr(current); +} + +/** + * tomoyo_pathcmp - strcmp() for "struct tomoyo_path_info" structure. + * + * @a: Pointer to "struct tomoyo_path_info". + * @b: Pointer to "struct tomoyo_path_info". + * + * Returns true if @a == @b, false otherwise. + */ +static inline bool tomoyo_pathcmp(const struct tomoyo_path_info *a, + const struct tomoyo_path_info *b) +{ + return a->hash != b->hash || strcmp(a->name, b->name); +} + +/** + * tomoyo_put_name - Drop reference on "struct tomoyo_name". + * + * @name: Pointer to "struct tomoyo_path_info". Maybe NULL. + * + * Returns nothing. + */ +static inline void tomoyo_put_name(const struct tomoyo_path_info *name) +{ + if (name) { + struct tomoyo_name *ptr = + container_of(name, typeof(*ptr), entry); + atomic_dec(&ptr->head.users); + } +} + +/** + * tomoyo_put_condition - Drop reference on "struct tomoyo_condition". + * + * @cond: Pointer to "struct tomoyo_condition". Maybe NULL. + * + * Returns nothing. + */ +static inline void tomoyo_put_condition(struct tomoyo_condition *cond) +{ + if (cond) + atomic_dec(&cond->head.users); +} + +/** + * tomoyo_put_group - Drop reference on "struct tomoyo_group". + * + * @group: Pointer to "struct tomoyo_group". Maybe NULL. + * + * Returns nothing. + */ +static inline void tomoyo_put_group(struct tomoyo_group *group) +{ + if (group) + atomic_dec(&group->head.users); +} + +/** + * tomoyo_task - Get "struct tomoyo_task" for specified thread. + * + * @task - Pointer to "struct task_struct". + * + * Returns pointer to "struct tomoyo_task" for specified thread. + */ +static inline struct tomoyo_task *tomoyo_task(struct task_struct *task) +{ + return task->security + tomoyo_blob_sizes.lbs_task; +} + +/** + * tomoyo_same_name_union - Check for duplicated "struct tomoyo_name_union" entry. + * + * @a: Pointer to "struct tomoyo_name_union". + * @b: Pointer to "struct tomoyo_name_union". + * + * Returns true if @a == @b, false otherwise. + */ +static inline bool tomoyo_same_name_union +(const struct tomoyo_name_union *a, const struct tomoyo_name_union *b) +{ + return a->filename == b->filename && a->group == b->group; +} + +/** + * tomoyo_same_number_union - Check for duplicated "struct tomoyo_number_union" entry. + * + * @a: Pointer to "struct tomoyo_number_union". + * @b: Pointer to "struct tomoyo_number_union". + * + * Returns true if @a == @b, false otherwise. + */ +static inline bool tomoyo_same_number_union +(const struct tomoyo_number_union *a, const struct tomoyo_number_union *b) +{ + return a->values[0] == b->values[0] && a->values[1] == b->values[1] && + a->group == b->group && a->value_type[0] == b->value_type[0] && + a->value_type[1] == b->value_type[1]; +} + +/** + * tomoyo_same_ipaddr_union - Check for duplicated "struct tomoyo_ipaddr_union" entry. + * + * @a: Pointer to "struct tomoyo_ipaddr_union". + * @b: Pointer to "struct tomoyo_ipaddr_union". + * + * Returns true if @a == @b, false otherwise. + */ +static inline bool tomoyo_same_ipaddr_union +(const struct tomoyo_ipaddr_union *a, const struct tomoyo_ipaddr_union *b) +{ + return !memcmp(a->ip, b->ip, sizeof(a->ip)) && a->group == b->group && + a->is_ipv6 == b->is_ipv6; +} + +/** + * tomoyo_current_namespace - Get "struct tomoyo_policy_namespace" for current thread. + * + * Returns pointer to "struct tomoyo_policy_namespace" for current thread. + */ +static inline struct tomoyo_policy_namespace *tomoyo_current_namespace(void) +{ + return tomoyo_domain()->ns; +} + +#if defined(CONFIG_SLOB) + +/** + * tomoyo_round2 - Round up to power of 2 for calculating memory usage. + * + * @size: Size to be rounded up. + * + * Returns @size. + * + * Since SLOB does not round up, this function simply returns @size. + */ +static inline int tomoyo_round2(size_t size) +{ + return size; +} + +#else + +/** + * tomoyo_round2 - Round up to power of 2 for calculating memory usage. + * + * @size: Size to be rounded up. + * + * Returns rounded size. + * + * Strictly speaking, SLAB may be able to allocate (e.g.) 96 bytes instead of + * (e.g.) 128 bytes. + */ +static inline int tomoyo_round2(size_t size) +{ +#if PAGE_SIZE == 4096 + size_t bsize = 32; +#else + size_t bsize = 64; +#endif + if (!size) + return 0; + while (size > bsize) + bsize <<= 1; + return bsize; +} + +#endif + +/** + * list_for_each_cookie - iterate over a list with cookie. + * @pos: the &struct list_head to use as a loop cursor. + * @head: the head for your list. + */ +#define list_for_each_cookie(pos, head) \ + if (!pos) \ + pos = srcu_dereference((head)->next, &tomoyo_ss); \ + for ( ; pos != (head); pos = srcu_dereference(pos->next, &tomoyo_ss)) + +#endif /* !defined(_SECURITY_TOMOYO_COMMON_H) */ diff --git a/security/tomoyo/condition.c b/security/tomoyo/condition.c new file mode 100644 index 000000000..f8bcc083b --- /dev/null +++ b/security/tomoyo/condition.c @@ -0,0 +1,1122 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * security/tomoyo/condition.c + * + * Copyright (C) 2005-2011 NTT DATA CORPORATION + */ + +#include "common.h" +#include <linux/slab.h> + +/* List of "struct tomoyo_condition". */ +LIST_HEAD(tomoyo_condition_list); + +/** + * tomoyo_argv - Check argv[] in "struct linux_binbrm". + * + * @index: Index number of @arg_ptr. + * @arg_ptr: Contents of argv[@index]. + * @argc: Length of @argv. + * @argv: Pointer to "struct tomoyo_argv". + * @checked: Set to true if @argv[@index] was found. + * + * Returns true on success, false otherwise. + */ +static bool tomoyo_argv(const unsigned int index, const char *arg_ptr, + const int argc, const struct tomoyo_argv *argv, + u8 *checked) +{ + int i; + struct tomoyo_path_info arg; + + arg.name = arg_ptr; + for (i = 0; i < argc; argv++, checked++, i++) { + bool result; + + if (index != argv->index) + continue; + *checked = 1; + tomoyo_fill_path_info(&arg); + result = tomoyo_path_matches_pattern(&arg, argv->value); + if (argv->is_not) + result = !result; + if (!result) + return false; + } + return true; +} + +/** + * tomoyo_envp - Check envp[] in "struct linux_binbrm". + * + * @env_name: The name of environment variable. + * @env_value: The value of environment variable. + * @envc: Length of @envp. + * @envp: Pointer to "struct tomoyo_envp". + * @checked: Set to true if @envp[@env_name] was found. + * + * Returns true on success, false otherwise. + */ +static bool tomoyo_envp(const char *env_name, const char *env_value, + const int envc, const struct tomoyo_envp *envp, + u8 *checked) +{ + int i; + struct tomoyo_path_info name; + struct tomoyo_path_info value; + + name.name = env_name; + tomoyo_fill_path_info(&name); + value.name = env_value; + tomoyo_fill_path_info(&value); + for (i = 0; i < envc; envp++, checked++, i++) { + bool result; + + if (!tomoyo_path_matches_pattern(&name, envp->name)) + continue; + *checked = 1; + if (envp->value) { + result = tomoyo_path_matches_pattern(&value, + envp->value); + if (envp->is_not) + result = !result; + } else { + result = true; + if (!envp->is_not) + result = !result; + } + if (!result) + return false; + } + return true; +} + +/** + * tomoyo_scan_bprm - Scan "struct linux_binprm". + * + * @ee: Pointer to "struct tomoyo_execve". + * @argc: Length of @argc. + * @argv: Pointer to "struct tomoyo_argv". + * @envc: Length of @envp. + * @envp: Pointer to "struct tomoyo_envp". + * + * Returns true on success, false otherwise. + */ +static bool tomoyo_scan_bprm(struct tomoyo_execve *ee, + const u16 argc, const struct tomoyo_argv *argv, + const u16 envc, const struct tomoyo_envp *envp) +{ + struct linux_binprm *bprm = ee->bprm; + struct tomoyo_page_dump *dump = &ee->dump; + char *arg_ptr = ee->tmp; + int arg_len = 0; + unsigned long pos = bprm->p; + int offset = pos % PAGE_SIZE; + int argv_count = bprm->argc; + int envp_count = bprm->envc; + bool result = true; + u8 local_checked[32]; + u8 *checked; + + if (argc + envc <= sizeof(local_checked)) { + checked = local_checked; + memset(local_checked, 0, sizeof(local_checked)); + } else { + checked = kzalloc(argc + envc, GFP_NOFS); + if (!checked) + return false; + } + while (argv_count || envp_count) { + if (!tomoyo_dump_page(bprm, pos, dump)) { + result = false; + goto out; + } + pos += PAGE_SIZE - offset; + while (offset < PAGE_SIZE) { + /* Read. */ + const char *kaddr = dump->data; + const unsigned char c = kaddr[offset++]; + + if (c && arg_len < TOMOYO_EXEC_TMPSIZE - 10) { + if (c == '\\') { + arg_ptr[arg_len++] = '\\'; + arg_ptr[arg_len++] = '\\'; + } else if (c > ' ' && c < 127) { + arg_ptr[arg_len++] = c; + } else { + arg_ptr[arg_len++] = '\\'; + arg_ptr[arg_len++] = (c >> 6) + '0'; + arg_ptr[arg_len++] = + ((c >> 3) & 7) + '0'; + arg_ptr[arg_len++] = (c & 7) + '0'; + } + } else { + arg_ptr[arg_len] = '\0'; + } + if (c) + continue; + /* Check. */ + if (argv_count) { + if (!tomoyo_argv(bprm->argc - argv_count, + arg_ptr, argc, argv, + checked)) { + result = false; + break; + } + argv_count--; + } else if (envp_count) { + char *cp = strchr(arg_ptr, '='); + + if (cp) { + *cp = '\0'; + if (!tomoyo_envp(arg_ptr, cp + 1, + envc, envp, + checked + argc)) { + result = false; + break; + } + } + envp_count--; + } else { + break; + } + arg_len = 0; + } + offset = 0; + if (!result) + break; + } +out: + if (result) { + int i; + + /* Check not-yet-checked entries. */ + for (i = 0; i < argc; i++) { + if (checked[i]) + continue; + /* + * Return true only if all unchecked indexes in + * bprm->argv[] are not matched. + */ + if (argv[i].is_not) + continue; + result = false; + break; + } + for (i = 0; i < envc; envp++, i++) { + if (checked[argc + i]) + continue; + /* + * Return true only if all unchecked environ variables + * in bprm->envp[] are either undefined or not matched. + */ + if ((!envp->value && !envp->is_not) || + (envp->value && envp->is_not)) + continue; + result = false; + break; + } + } + if (checked != local_checked) + kfree(checked); + return result; +} + +/** + * tomoyo_scan_exec_realpath - Check "exec.realpath" parameter of "struct tomoyo_condition". + * + * @file: Pointer to "struct file". + * @ptr: Pointer to "struct tomoyo_name_union". + * @match: True if "exec.realpath=", false if "exec.realpath!=". + * + * Returns true on success, false otherwise. + */ +static bool tomoyo_scan_exec_realpath(struct file *file, + const struct tomoyo_name_union *ptr, + const bool match) +{ + bool result; + struct tomoyo_path_info exe; + + if (!file) + return false; + exe.name = tomoyo_realpath_from_path(&file->f_path); + if (!exe.name) + return false; + tomoyo_fill_path_info(&exe); + result = tomoyo_compare_name_union(&exe, ptr); + kfree(exe.name); + return result == match; +} + +/** + * tomoyo_get_dqword - tomoyo_get_name() for a quoted string. + * + * @start: String to save. + * + * Returns pointer to "struct tomoyo_path_info" on success, NULL otherwise. + */ +static const struct tomoyo_path_info *tomoyo_get_dqword(char *start) +{ + char *cp = start + strlen(start) - 1; + + if (cp == start || *start++ != '"' || *cp != '"') + return NULL; + *cp = '\0'; + if (*start && !tomoyo_correct_word(start)) + return NULL; + return tomoyo_get_name(start); +} + +/** + * tomoyo_parse_name_union_quoted - Parse a quoted word. + * + * @param: Pointer to "struct tomoyo_acl_param". + * @ptr: Pointer to "struct tomoyo_name_union". + * + * Returns true on success, false otherwise. + */ +static bool tomoyo_parse_name_union_quoted(struct tomoyo_acl_param *param, + struct tomoyo_name_union *ptr) +{ + char *filename = param->data; + + if (*filename == '@') + return tomoyo_parse_name_union(param, ptr); + ptr->filename = tomoyo_get_dqword(filename); + return ptr->filename != NULL; +} + +/** + * tomoyo_parse_argv - Parse an argv[] condition part. + * + * @left: Lefthand value. + * @right: Righthand value. + * @argv: Pointer to "struct tomoyo_argv". + * + * Returns true on success, false otherwise. + */ +static bool tomoyo_parse_argv(char *left, char *right, + struct tomoyo_argv *argv) +{ + if (tomoyo_parse_ulong(&argv->index, &left) != + TOMOYO_VALUE_TYPE_DECIMAL || *left++ != ']' || *left) + return false; + argv->value = tomoyo_get_dqword(right); + return argv->value != NULL; +} + +/** + * tomoyo_parse_envp - Parse an envp[] condition part. + * + * @left: Lefthand value. + * @right: Righthand value. + * @envp: Pointer to "struct tomoyo_envp". + * + * Returns true on success, false otherwise. + */ +static bool tomoyo_parse_envp(char *left, char *right, + struct tomoyo_envp *envp) +{ + const struct tomoyo_path_info *name; + const struct tomoyo_path_info *value; + char *cp = left + strlen(left) - 1; + + if (*cp-- != ']' || *cp != '"') + goto out; + *cp = '\0'; + if (!tomoyo_correct_word(left)) + goto out; + name = tomoyo_get_name(left); + if (!name) + goto out; + if (!strcmp(right, "NULL")) { + value = NULL; + } else { + value = tomoyo_get_dqword(right); + if (!value) { + tomoyo_put_name(name); + goto out; + } + } + envp->name = name; + envp->value = value; + return true; +out: + return false; +} + +/** + * tomoyo_same_condition - Check for duplicated "struct tomoyo_condition" entry. + * + * @a: Pointer to "struct tomoyo_condition". + * @b: Pointer to "struct tomoyo_condition". + * + * Returns true if @a == @b, false otherwise. + */ +static inline bool tomoyo_same_condition(const struct tomoyo_condition *a, + const struct tomoyo_condition *b) +{ + return a->size == b->size && a->condc == b->condc && + a->numbers_count == b->numbers_count && + a->names_count == b->names_count && + a->argc == b->argc && a->envc == b->envc && + a->grant_log == b->grant_log && a->transit == b->transit && + !memcmp(a + 1, b + 1, a->size - sizeof(*a)); +} + +/** + * tomoyo_condition_type - Get condition type. + * + * @word: Keyword string. + * + * Returns one of values in "enum tomoyo_conditions_index" on success, + * TOMOYO_MAX_CONDITION_KEYWORD otherwise. + */ +static u8 tomoyo_condition_type(const char *word) +{ + u8 i; + + for (i = 0; i < TOMOYO_MAX_CONDITION_KEYWORD; i++) { + if (!strcmp(word, tomoyo_condition_keyword[i])) + break; + } + return i; +} + +/* Define this to enable debug mode. */ +/* #define DEBUG_CONDITION */ + +#ifdef DEBUG_CONDITION +#define dprintk printk +#else +#define dprintk(...) do { } while (0) +#endif + +/** + * tomoyo_commit_condition - Commit "struct tomoyo_condition". + * + * @entry: Pointer to "struct tomoyo_condition". + * + * Returns pointer to "struct tomoyo_condition" on success, NULL otherwise. + * + * This function merges duplicated entries. This function returns NULL if + * @entry is not duplicated but memory quota for policy has exceeded. + */ +static struct tomoyo_condition *tomoyo_commit_condition +(struct tomoyo_condition *entry) +{ + struct tomoyo_condition *ptr; + bool found = false; + + if (mutex_lock_interruptible(&tomoyo_policy_lock)) { + dprintk(KERN_WARNING "%u: %s failed\n", __LINE__, __func__); + ptr = NULL; + found = true; + goto out; + } + list_for_each_entry(ptr, &tomoyo_condition_list, head.list) { + if (!tomoyo_same_condition(ptr, entry) || + atomic_read(&ptr->head.users) == TOMOYO_GC_IN_PROGRESS) + continue; + /* Same entry found. Share this entry. */ + atomic_inc(&ptr->head.users); + found = true; + break; + } + if (!found) { + if (tomoyo_memory_ok(entry)) { + atomic_set(&entry->head.users, 1); + list_add(&entry->head.list, &tomoyo_condition_list); + } else { + found = true; + ptr = NULL; + } + } + mutex_unlock(&tomoyo_policy_lock); +out: + if (found) { + tomoyo_del_condition(&entry->head.list); + kfree(entry); + entry = ptr; + } + return entry; +} + +/** + * tomoyo_get_transit_preference - Parse domain transition preference for execve(). + * + * @param: Pointer to "struct tomoyo_acl_param". + * @e: Pointer to "struct tomoyo_condition". + * + * Returns the condition string part. + */ +static char *tomoyo_get_transit_preference(struct tomoyo_acl_param *param, + struct tomoyo_condition *e) +{ + char * const pos = param->data; + bool flag; + + if (*pos == '<') { + e->transit = tomoyo_get_domainname(param); + goto done; + } + { + char *cp = strchr(pos, ' '); + + if (cp) + *cp = '\0'; + flag = tomoyo_correct_path(pos) || !strcmp(pos, "keep") || + !strcmp(pos, "initialize") || !strcmp(pos, "reset") || + !strcmp(pos, "child") || !strcmp(pos, "parent"); + if (cp) + *cp = ' '; + } + if (!flag) + return pos; + e->transit = tomoyo_get_name(tomoyo_read_token(param)); +done: + if (e->transit) + return param->data; + /* + * Return a bad read-only condition string that will let + * tomoyo_get_condition() return NULL. + */ + return "/"; +} + +/** + * tomoyo_get_condition - Parse condition part. + * + * @param: Pointer to "struct tomoyo_acl_param". + * + * Returns pointer to "struct tomoyo_condition" on success, NULL otherwise. + */ +struct tomoyo_condition *tomoyo_get_condition(struct tomoyo_acl_param *param) +{ + struct tomoyo_condition *entry = NULL; + struct tomoyo_condition_element *condp = NULL; + struct tomoyo_number_union *numbers_p = NULL; + struct tomoyo_name_union *names_p = NULL; + struct tomoyo_argv *argv = NULL; + struct tomoyo_envp *envp = NULL; + struct tomoyo_condition e = { }; + char * const start_of_string = + tomoyo_get_transit_preference(param, &e); + char * const end_of_string = start_of_string + strlen(start_of_string); + char *pos; + +rerun: + pos = start_of_string; + while (1) { + u8 left = -1; + u8 right = -1; + char *left_word = pos; + char *cp; + char *right_word; + bool is_not; + + if (!*left_word) + break; + /* + * Since left-hand condition does not allow use of "path_group" + * or "number_group" and environment variable's names do not + * accept '=', it is guaranteed that the original line consists + * of one or more repetition of $left$operator$right blocks + * where "$left is free from '=' and ' '" and "$operator is + * either '=' or '!='" and "$right is free from ' '". + * Therefore, we can reconstruct the original line at the end + * of dry run even if we overwrite $operator with '\0'. + */ + cp = strchr(pos, ' '); + if (cp) { + *cp = '\0'; /* Will restore later. */ + pos = cp + 1; + } else { + pos = ""; + } + right_word = strchr(left_word, '='); + if (!right_word || right_word == left_word) + goto out; + is_not = *(right_word - 1) == '!'; + if (is_not) + *(right_word++ - 1) = '\0'; /* Will restore later. */ + else if (*(right_word + 1) != '=') + *right_word++ = '\0'; /* Will restore later. */ + else + goto out; + dprintk(KERN_WARNING "%u: <%s>%s=<%s>\n", __LINE__, left_word, + is_not ? "!" : "", right_word); + if (!strcmp(left_word, "grant_log")) { + if (entry) { + if (is_not || + entry->grant_log != TOMOYO_GRANTLOG_AUTO) + goto out; + else if (!strcmp(right_word, "yes")) + entry->grant_log = TOMOYO_GRANTLOG_YES; + else if (!strcmp(right_word, "no")) + entry->grant_log = TOMOYO_GRANTLOG_NO; + else + goto out; + } + continue; + } + if (!strncmp(left_word, "exec.argv[", 10)) { + if (!argv) { + e.argc++; + e.condc++; + } else { + e.argc--; + e.condc--; + left = TOMOYO_ARGV_ENTRY; + argv->is_not = is_not; + if (!tomoyo_parse_argv(left_word + 10, + right_word, argv++)) + goto out; + } + goto store_value; + } + if (!strncmp(left_word, "exec.envp[\"", 11)) { + if (!envp) { + e.envc++; + e.condc++; + } else { + e.envc--; + e.condc--; + left = TOMOYO_ENVP_ENTRY; + envp->is_not = is_not; + if (!tomoyo_parse_envp(left_word + 11, + right_word, envp++)) + goto out; + } + goto store_value; + } + left = tomoyo_condition_type(left_word); + dprintk(KERN_WARNING "%u: <%s> left=%u\n", __LINE__, left_word, + left); + if (left == TOMOYO_MAX_CONDITION_KEYWORD) { + if (!numbers_p) { + e.numbers_count++; + } else { + e.numbers_count--; + left = TOMOYO_NUMBER_UNION; + param->data = left_word; + if (*left_word == '@' || + !tomoyo_parse_number_union(param, + numbers_p++)) + goto out; + } + } + if (!condp) + e.condc++; + else + e.condc--; + if (left == TOMOYO_EXEC_REALPATH || + left == TOMOYO_SYMLINK_TARGET) { + if (!names_p) { + e.names_count++; + } else { + e.names_count--; + right = TOMOYO_NAME_UNION; + param->data = right_word; + if (!tomoyo_parse_name_union_quoted(param, + names_p++)) + goto out; + } + goto store_value; + } + right = tomoyo_condition_type(right_word); + if (right == TOMOYO_MAX_CONDITION_KEYWORD) { + if (!numbers_p) { + e.numbers_count++; + } else { + e.numbers_count--; + right = TOMOYO_NUMBER_UNION; + param->data = right_word; + if (!tomoyo_parse_number_union(param, + numbers_p++)) + goto out; + } + } +store_value: + if (!condp) { + dprintk(KERN_WARNING "%u: dry_run left=%u right=%u match=%u\n", + __LINE__, left, right, !is_not); + continue; + } + condp->left = left; + condp->right = right; + condp->equals = !is_not; + dprintk(KERN_WARNING "%u: left=%u right=%u match=%u\n", + __LINE__, condp->left, condp->right, + condp->equals); + condp++; + } + dprintk(KERN_INFO "%u: cond=%u numbers=%u names=%u ac=%u ec=%u\n", + __LINE__, e.condc, e.numbers_count, e.names_count, e.argc, + e.envc); + if (entry) { + BUG_ON(e.names_count | e.numbers_count | e.argc | e.envc | + e.condc); + return tomoyo_commit_condition(entry); + } + e.size = sizeof(*entry) + + e.condc * sizeof(struct tomoyo_condition_element) + + e.numbers_count * sizeof(struct tomoyo_number_union) + + e.names_count * sizeof(struct tomoyo_name_union) + + e.argc * sizeof(struct tomoyo_argv) + + e.envc * sizeof(struct tomoyo_envp); + entry = kzalloc(e.size, GFP_NOFS); + if (!entry) + goto out2; + *entry = e; + e.transit = NULL; + condp = (struct tomoyo_condition_element *) (entry + 1); + numbers_p = (struct tomoyo_number_union *) (condp + e.condc); + names_p = (struct tomoyo_name_union *) (numbers_p + e.numbers_count); + argv = (struct tomoyo_argv *) (names_p + e.names_count); + envp = (struct tomoyo_envp *) (argv + e.argc); + { + bool flag = false; + + for (pos = start_of_string; pos < end_of_string; pos++) { + if (*pos) + continue; + if (flag) /* Restore " ". */ + *pos = ' '; + else if (*(pos + 1) == '=') /* Restore "!=". */ + *pos = '!'; + else /* Restore "=". */ + *pos = '='; + flag = !flag; + } + } + goto rerun; +out: + dprintk(KERN_WARNING "%u: %s failed\n", __LINE__, __func__); + if (entry) { + tomoyo_del_condition(&entry->head.list); + kfree(entry); + } +out2: + tomoyo_put_name(e.transit); + return NULL; +} + +/** + * tomoyo_get_attributes - Revalidate "struct inode". + * + * @obj: Pointer to "struct tomoyo_obj_info". + * + * Returns nothing. + */ +void tomoyo_get_attributes(struct tomoyo_obj_info *obj) +{ + u8 i; + struct dentry *dentry = NULL; + + for (i = 0; i < TOMOYO_MAX_PATH_STAT; i++) { + struct inode *inode; + + switch (i) { + case TOMOYO_PATH1: + dentry = obj->path1.dentry; + if (!dentry) + continue; + break; + case TOMOYO_PATH2: + dentry = obj->path2.dentry; + if (!dentry) + continue; + break; + default: + if (!dentry) + continue; + dentry = dget_parent(dentry); + break; + } + inode = d_backing_inode(dentry); + if (inode) { + struct tomoyo_mini_stat *stat = &obj->stat[i]; + + stat->uid = inode->i_uid; + stat->gid = inode->i_gid; + stat->ino = inode->i_ino; + stat->mode = inode->i_mode; + stat->dev = inode->i_sb->s_dev; + stat->rdev = inode->i_rdev; + obj->stat_valid[i] = true; + } + if (i & 1) /* TOMOYO_PATH1_PARENT or TOMOYO_PATH2_PARENT */ + dput(dentry); + } +} + +/** + * tomoyo_condition - Check condition part. + * + * @r: Pointer to "struct tomoyo_request_info". + * @cond: Pointer to "struct tomoyo_condition". Maybe NULL. + * + * Returns true on success, false otherwise. + * + * Caller holds tomoyo_read_lock(). + */ +bool tomoyo_condition(struct tomoyo_request_info *r, + const struct tomoyo_condition *cond) +{ + u32 i; + unsigned long min_v[2] = { 0, 0 }; + unsigned long max_v[2] = { 0, 0 }; + const struct tomoyo_condition_element *condp; + const struct tomoyo_number_union *numbers_p; + const struct tomoyo_name_union *names_p; + const struct tomoyo_argv *argv; + const struct tomoyo_envp *envp; + struct tomoyo_obj_info *obj; + u16 condc; + u16 argc; + u16 envc; + struct linux_binprm *bprm = NULL; + + if (!cond) + return true; + condc = cond->condc; + argc = cond->argc; + envc = cond->envc; + obj = r->obj; + if (r->ee) + bprm = r->ee->bprm; + if (!bprm && (argc || envc)) + return false; + condp = (struct tomoyo_condition_element *) (cond + 1); + numbers_p = (const struct tomoyo_number_union *) (condp + condc); + names_p = (const struct tomoyo_name_union *) + (numbers_p + cond->numbers_count); + argv = (const struct tomoyo_argv *) (names_p + cond->names_count); + envp = (const struct tomoyo_envp *) (argv + argc); + for (i = 0; i < condc; i++) { + const bool match = condp->equals; + const u8 left = condp->left; + const u8 right = condp->right; + bool is_bitop[2] = { false, false }; + u8 j; + + condp++; + /* Check argv[] and envp[] later. */ + if (left == TOMOYO_ARGV_ENTRY || left == TOMOYO_ENVP_ENTRY) + continue; + /* Check string expressions. */ + if (right == TOMOYO_NAME_UNION) { + const struct tomoyo_name_union *ptr = names_p++; + struct tomoyo_path_info *symlink; + struct tomoyo_execve *ee; + struct file *file; + + switch (left) { + case TOMOYO_SYMLINK_TARGET: + symlink = obj ? obj->symlink_target : NULL; + if (!symlink || + !tomoyo_compare_name_union(symlink, ptr) + == match) + goto out; + break; + case TOMOYO_EXEC_REALPATH: + ee = r->ee; + file = ee ? ee->bprm->file : NULL; + if (!tomoyo_scan_exec_realpath(file, ptr, + match)) + goto out; + break; + } + continue; + } + /* Check numeric or bit-op expressions. */ + for (j = 0; j < 2; j++) { + const u8 index = j ? right : left; + unsigned long value = 0; + + switch (index) { + case TOMOYO_TASK_UID: + value = from_kuid(&init_user_ns, current_uid()); + break; + case TOMOYO_TASK_EUID: + value = from_kuid(&init_user_ns, current_euid()); + break; + case TOMOYO_TASK_SUID: + value = from_kuid(&init_user_ns, current_suid()); + break; + case TOMOYO_TASK_FSUID: + value = from_kuid(&init_user_ns, current_fsuid()); + break; + case TOMOYO_TASK_GID: + value = from_kgid(&init_user_ns, current_gid()); + break; + case TOMOYO_TASK_EGID: + value = from_kgid(&init_user_ns, current_egid()); + break; + case TOMOYO_TASK_SGID: + value = from_kgid(&init_user_ns, current_sgid()); + break; + case TOMOYO_TASK_FSGID: + value = from_kgid(&init_user_ns, current_fsgid()); + break; + case TOMOYO_TASK_PID: + value = tomoyo_sys_getpid(); + break; + case TOMOYO_TASK_PPID: + value = tomoyo_sys_getppid(); + break; + case TOMOYO_TYPE_IS_SOCKET: + value = S_IFSOCK; + break; + case TOMOYO_TYPE_IS_SYMLINK: + value = S_IFLNK; + break; + case TOMOYO_TYPE_IS_FILE: + value = S_IFREG; + break; + case TOMOYO_TYPE_IS_BLOCK_DEV: + value = S_IFBLK; + break; + case TOMOYO_TYPE_IS_DIRECTORY: + value = S_IFDIR; + break; + case TOMOYO_TYPE_IS_CHAR_DEV: + value = S_IFCHR; + break; + case TOMOYO_TYPE_IS_FIFO: + value = S_IFIFO; + break; + case TOMOYO_MODE_SETUID: + value = S_ISUID; + break; + case TOMOYO_MODE_SETGID: + value = S_ISGID; + break; + case TOMOYO_MODE_STICKY: + value = S_ISVTX; + break; + case TOMOYO_MODE_OWNER_READ: + value = 0400; + break; + case TOMOYO_MODE_OWNER_WRITE: + value = 0200; + break; + case TOMOYO_MODE_OWNER_EXECUTE: + value = 0100; + break; + case TOMOYO_MODE_GROUP_READ: + value = 0040; + break; + case TOMOYO_MODE_GROUP_WRITE: + value = 0020; + break; + case TOMOYO_MODE_GROUP_EXECUTE: + value = 0010; + break; + case TOMOYO_MODE_OTHERS_READ: + value = 0004; + break; + case TOMOYO_MODE_OTHERS_WRITE: + value = 0002; + break; + case TOMOYO_MODE_OTHERS_EXECUTE: + value = 0001; + break; + case TOMOYO_EXEC_ARGC: + if (!bprm) + goto out; + value = bprm->argc; + break; + case TOMOYO_EXEC_ENVC: + if (!bprm) + goto out; + value = bprm->envc; + break; + case TOMOYO_NUMBER_UNION: + /* Fetch values later. */ + break; + default: + if (!obj) + goto out; + if (!obj->validate_done) { + tomoyo_get_attributes(obj); + obj->validate_done = true; + } + { + u8 stat_index; + struct tomoyo_mini_stat *stat; + + switch (index) { + case TOMOYO_PATH1_UID: + case TOMOYO_PATH1_GID: + case TOMOYO_PATH1_INO: + case TOMOYO_PATH1_MAJOR: + case TOMOYO_PATH1_MINOR: + case TOMOYO_PATH1_TYPE: + case TOMOYO_PATH1_DEV_MAJOR: + case TOMOYO_PATH1_DEV_MINOR: + case TOMOYO_PATH1_PERM: + stat_index = TOMOYO_PATH1; + break; + case TOMOYO_PATH2_UID: + case TOMOYO_PATH2_GID: + case TOMOYO_PATH2_INO: + case TOMOYO_PATH2_MAJOR: + case TOMOYO_PATH2_MINOR: + case TOMOYO_PATH2_TYPE: + case TOMOYO_PATH2_DEV_MAJOR: + case TOMOYO_PATH2_DEV_MINOR: + case TOMOYO_PATH2_PERM: + stat_index = TOMOYO_PATH2; + break; + case TOMOYO_PATH1_PARENT_UID: + case TOMOYO_PATH1_PARENT_GID: + case TOMOYO_PATH1_PARENT_INO: + case TOMOYO_PATH1_PARENT_PERM: + stat_index = + TOMOYO_PATH1_PARENT; + break; + case TOMOYO_PATH2_PARENT_UID: + case TOMOYO_PATH2_PARENT_GID: + case TOMOYO_PATH2_PARENT_INO: + case TOMOYO_PATH2_PARENT_PERM: + stat_index = + TOMOYO_PATH2_PARENT; + break; + default: + goto out; + } + if (!obj->stat_valid[stat_index]) + goto out; + stat = &obj->stat[stat_index]; + switch (index) { + case TOMOYO_PATH1_UID: + case TOMOYO_PATH2_UID: + case TOMOYO_PATH1_PARENT_UID: + case TOMOYO_PATH2_PARENT_UID: + value = from_kuid(&init_user_ns, stat->uid); + break; + case TOMOYO_PATH1_GID: + case TOMOYO_PATH2_GID: + case TOMOYO_PATH1_PARENT_GID: + case TOMOYO_PATH2_PARENT_GID: + value = from_kgid(&init_user_ns, stat->gid); + break; + case TOMOYO_PATH1_INO: + case TOMOYO_PATH2_INO: + case TOMOYO_PATH1_PARENT_INO: + case TOMOYO_PATH2_PARENT_INO: + value = stat->ino; + break; + case TOMOYO_PATH1_MAJOR: + case TOMOYO_PATH2_MAJOR: + value = MAJOR(stat->dev); + break; + case TOMOYO_PATH1_MINOR: + case TOMOYO_PATH2_MINOR: + value = MINOR(stat->dev); + break; + case TOMOYO_PATH1_TYPE: + case TOMOYO_PATH2_TYPE: + value = stat->mode & S_IFMT; + break; + case TOMOYO_PATH1_DEV_MAJOR: + case TOMOYO_PATH2_DEV_MAJOR: + value = MAJOR(stat->rdev); + break; + case TOMOYO_PATH1_DEV_MINOR: + case TOMOYO_PATH2_DEV_MINOR: + value = MINOR(stat->rdev); + break; + case TOMOYO_PATH1_PERM: + case TOMOYO_PATH2_PERM: + case TOMOYO_PATH1_PARENT_PERM: + case TOMOYO_PATH2_PARENT_PERM: + value = stat->mode & S_IALLUGO; + break; + } + } + break; + } + max_v[j] = value; + min_v[j] = value; + switch (index) { + case TOMOYO_MODE_SETUID: + case TOMOYO_MODE_SETGID: + case TOMOYO_MODE_STICKY: + case TOMOYO_MODE_OWNER_READ: + case TOMOYO_MODE_OWNER_WRITE: + case TOMOYO_MODE_OWNER_EXECUTE: + case TOMOYO_MODE_GROUP_READ: + case TOMOYO_MODE_GROUP_WRITE: + case TOMOYO_MODE_GROUP_EXECUTE: + case TOMOYO_MODE_OTHERS_READ: + case TOMOYO_MODE_OTHERS_WRITE: + case TOMOYO_MODE_OTHERS_EXECUTE: + is_bitop[j] = true; + } + } + if (left == TOMOYO_NUMBER_UNION) { + /* Fetch values now. */ + const struct tomoyo_number_union *ptr = numbers_p++; + + min_v[0] = ptr->values[0]; + max_v[0] = ptr->values[1]; + } + if (right == TOMOYO_NUMBER_UNION) { + /* Fetch values now. */ + const struct tomoyo_number_union *ptr = numbers_p++; + + if (ptr->group) { + if (tomoyo_number_matches_group(min_v[0], + max_v[0], + ptr->group) + == match) + continue; + } else { + if ((min_v[0] <= ptr->values[1] && + max_v[0] >= ptr->values[0]) == match) + continue; + } + goto out; + } + /* + * Bit operation is valid only when counterpart value + * represents permission. + */ + if (is_bitop[0] && is_bitop[1]) { + goto out; + } else if (is_bitop[0]) { + switch (right) { + case TOMOYO_PATH1_PERM: + case TOMOYO_PATH1_PARENT_PERM: + case TOMOYO_PATH2_PERM: + case TOMOYO_PATH2_PARENT_PERM: + if (!(max_v[0] & max_v[1]) == !match) + continue; + } + goto out; + } else if (is_bitop[1]) { + switch (left) { + case TOMOYO_PATH1_PERM: + case TOMOYO_PATH1_PARENT_PERM: + case TOMOYO_PATH2_PERM: + case TOMOYO_PATH2_PARENT_PERM: + if (!(max_v[0] & max_v[1]) == !match) + continue; + } + goto out; + } + /* Normal value range comparison. */ + if ((min_v[0] <= max_v[1] && max_v[0] >= min_v[1]) == match) + continue; +out: + return false; + } + /* Check argv[] and envp[] now. */ + if (r->ee && (argc || envc)) + return tomoyo_scan_bprm(r->ee, argc, argv, envc, envp); + return true; +} diff --git a/security/tomoyo/domain.c b/security/tomoyo/domain.c new file mode 100644 index 000000000..31af29f66 --- /dev/null +++ b/security/tomoyo/domain.c @@ -0,0 +1,945 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * security/tomoyo/domain.c + * + * Copyright (C) 2005-2011 NTT DATA CORPORATION + */ + +#include "common.h" + +#include <linux/binfmts.h> +#include <linux/slab.h> +#include <linux/rculist.h> + +/* Variables definitions.*/ + +/* The initial domain. */ +struct tomoyo_domain_info tomoyo_kernel_domain; + +/** + * tomoyo_update_policy - Update an entry for exception policy. + * + * @new_entry: Pointer to "struct tomoyo_acl_info". + * @size: Size of @new_entry in bytes. + * @param: Pointer to "struct tomoyo_acl_param". + * @check_duplicate: Callback function to find duplicated entry. + * + * Returns 0 on success, negative value otherwise. + * + * Caller holds tomoyo_read_lock(). + */ +int tomoyo_update_policy(struct tomoyo_acl_head *new_entry, const int size, + struct tomoyo_acl_param *param, + bool (*check_duplicate)(const struct tomoyo_acl_head + *, + const struct tomoyo_acl_head + *)) +{ + int error = param->is_delete ? -ENOENT : -ENOMEM; + struct tomoyo_acl_head *entry; + struct list_head *list = param->list; + + if (mutex_lock_interruptible(&tomoyo_policy_lock)) + return -ENOMEM; + list_for_each_entry_rcu(entry, list, list, + srcu_read_lock_held(&tomoyo_ss)) { + if (entry->is_deleted == TOMOYO_GC_IN_PROGRESS) + continue; + if (!check_duplicate(entry, new_entry)) + continue; + entry->is_deleted = param->is_delete; + error = 0; + break; + } + if (error && !param->is_delete) { + entry = tomoyo_commit_ok(new_entry, size); + if (entry) { + list_add_tail_rcu(&entry->list, list); + error = 0; + } + } + mutex_unlock(&tomoyo_policy_lock); + return error; +} + +/** + * tomoyo_same_acl_head - Check for duplicated "struct tomoyo_acl_info" entry. + * + * @a: Pointer to "struct tomoyo_acl_info". + * @b: Pointer to "struct tomoyo_acl_info". + * + * Returns true if @a == @b, false otherwise. + */ +static inline bool tomoyo_same_acl_head(const struct tomoyo_acl_info *a, + const struct tomoyo_acl_info *b) +{ + return a->type == b->type && a->cond == b->cond; +} + +/** + * tomoyo_update_domain - Update an entry for domain policy. + * + * @new_entry: Pointer to "struct tomoyo_acl_info". + * @size: Size of @new_entry in bytes. + * @param: Pointer to "struct tomoyo_acl_param". + * @check_duplicate: Callback function to find duplicated entry. + * @merge_duplicate: Callback function to merge duplicated entry. + * + * Returns 0 on success, negative value otherwise. + * + * Caller holds tomoyo_read_lock(). + */ +int tomoyo_update_domain(struct tomoyo_acl_info *new_entry, const int size, + struct tomoyo_acl_param *param, + bool (*check_duplicate)(const struct tomoyo_acl_info + *, + const struct tomoyo_acl_info + *), + bool (*merge_duplicate)(struct tomoyo_acl_info *, + struct tomoyo_acl_info *, + const bool)) +{ + const bool is_delete = param->is_delete; + int error = is_delete ? -ENOENT : -ENOMEM; + struct tomoyo_acl_info *entry; + struct list_head * const list = param->list; + + if (param->data[0]) { + new_entry->cond = tomoyo_get_condition(param); + if (!new_entry->cond) + return -EINVAL; + /* + * Domain transition preference is allowed for only + * "file execute" entries. + */ + if (new_entry->cond->transit && + !(new_entry->type == TOMOYO_TYPE_PATH_ACL && + container_of(new_entry, struct tomoyo_path_acl, head) + ->perm == 1 << TOMOYO_TYPE_EXECUTE)) + goto out; + } + if (mutex_lock_interruptible(&tomoyo_policy_lock)) + goto out; + list_for_each_entry_rcu(entry, list, list, + srcu_read_lock_held(&tomoyo_ss)) { + if (entry->is_deleted == TOMOYO_GC_IN_PROGRESS) + continue; + if (!tomoyo_same_acl_head(entry, new_entry) || + !check_duplicate(entry, new_entry)) + continue; + if (merge_duplicate) + entry->is_deleted = merge_duplicate(entry, new_entry, + is_delete); + else + entry->is_deleted = is_delete; + error = 0; + break; + } + if (error && !is_delete) { + entry = tomoyo_commit_ok(new_entry, size); + if (entry) { + list_add_tail_rcu(&entry->list, list); + error = 0; + } + } + mutex_unlock(&tomoyo_policy_lock); +out: + tomoyo_put_condition(new_entry->cond); + return error; +} + +/** + * tomoyo_check_acl - Do permission check. + * + * @r: Pointer to "struct tomoyo_request_info". + * @check_entry: Callback function to check type specific parameters. + * + * Returns 0 on success, negative value otherwise. + * + * Caller holds tomoyo_read_lock(). + */ +void tomoyo_check_acl(struct tomoyo_request_info *r, + bool (*check_entry)(struct tomoyo_request_info *, + const struct tomoyo_acl_info *)) +{ + const struct tomoyo_domain_info *domain = r->domain; + struct tomoyo_acl_info *ptr; + const struct list_head *list = &domain->acl_info_list; + u16 i = 0; + +retry: + list_for_each_entry_rcu(ptr, list, list, + srcu_read_lock_held(&tomoyo_ss)) { + if (ptr->is_deleted || ptr->type != r->param_type) + continue; + if (!check_entry(r, ptr)) + continue; + if (!tomoyo_condition(r, ptr->cond)) + continue; + r->matched_acl = ptr; + r->granted = true; + return; + } + for (; i < TOMOYO_MAX_ACL_GROUPS; i++) { + if (!test_bit(i, domain->group)) + continue; + list = &domain->ns->acl_group[i++]; + goto retry; + } + r->granted = false; +} + +/* The list for "struct tomoyo_domain_info". */ +LIST_HEAD(tomoyo_domain_list); + +/** + * tomoyo_last_word - Get last component of a domainname. + * + * @name: Domainname to check. + * + * Returns the last word of @domainname. + */ +static const char *tomoyo_last_word(const char *name) +{ + const char *cp = strrchr(name, ' '); + + if (cp) + return cp + 1; + return name; +} + +/** + * tomoyo_same_transition_control - Check for duplicated "struct tomoyo_transition_control" entry. + * + * @a: Pointer to "struct tomoyo_acl_head". + * @b: Pointer to "struct tomoyo_acl_head". + * + * Returns true if @a == @b, false otherwise. + */ +static bool tomoyo_same_transition_control(const struct tomoyo_acl_head *a, + const struct tomoyo_acl_head *b) +{ + const struct tomoyo_transition_control *p1 = container_of(a, + typeof(*p1), + head); + const struct tomoyo_transition_control *p2 = container_of(b, + typeof(*p2), + head); + + return p1->type == p2->type && p1->is_last_name == p2->is_last_name + && p1->domainname == p2->domainname + && p1->program == p2->program; +} + +/** + * tomoyo_write_transition_control - Write "struct tomoyo_transition_control" list. + * + * @param: Pointer to "struct tomoyo_acl_param". + * @type: Type of this entry. + * + * Returns 0 on success, negative value otherwise. + */ +int tomoyo_write_transition_control(struct tomoyo_acl_param *param, + const u8 type) +{ + struct tomoyo_transition_control e = { .type = type }; + int error = param->is_delete ? -ENOENT : -ENOMEM; + char *program = param->data; + char *domainname = strstr(program, " from "); + + if (domainname) { + *domainname = '\0'; + domainname += 6; + } else if (type == TOMOYO_TRANSITION_CONTROL_NO_KEEP || + type == TOMOYO_TRANSITION_CONTROL_KEEP) { + domainname = program; + program = NULL; + } + if (program && strcmp(program, "any")) { + if (!tomoyo_correct_path(program)) + return -EINVAL; + e.program = tomoyo_get_name(program); + if (!e.program) + goto out; + } + if (domainname && strcmp(domainname, "any")) { + if (!tomoyo_correct_domain(domainname)) { + if (!tomoyo_correct_path(domainname)) + goto out; + e.is_last_name = true; + } + e.domainname = tomoyo_get_name(domainname); + if (!e.domainname) + goto out; + } + param->list = ¶m->ns->policy_list[TOMOYO_ID_TRANSITION_CONTROL]; + error = tomoyo_update_policy(&e.head, sizeof(e), param, + tomoyo_same_transition_control); +out: + tomoyo_put_name(e.domainname); + tomoyo_put_name(e.program); + return error; +} + +/** + * tomoyo_scan_transition - Try to find specific domain transition type. + * + * @list: Pointer to "struct list_head". + * @domainname: The name of current domain. + * @program: The name of requested program. + * @last_name: The last component of @domainname. + * @type: One of values in "enum tomoyo_transition_type". + * + * Returns true if found one, false otherwise. + * + * Caller holds tomoyo_read_lock(). + */ +static inline bool tomoyo_scan_transition +(const struct list_head *list, const struct tomoyo_path_info *domainname, + const struct tomoyo_path_info *program, const char *last_name, + const enum tomoyo_transition_type type) +{ + const struct tomoyo_transition_control *ptr; + + list_for_each_entry_rcu(ptr, list, head.list, + srcu_read_lock_held(&tomoyo_ss)) { + if (ptr->head.is_deleted || ptr->type != type) + continue; + if (ptr->domainname) { + if (!ptr->is_last_name) { + if (ptr->domainname != domainname) + continue; + } else { + /* + * Use direct strcmp() since this is + * unlikely used. + */ + if (strcmp(ptr->domainname->name, last_name)) + continue; + } + } + if (ptr->program && tomoyo_pathcmp(ptr->program, program)) + continue; + return true; + } + return false; +} + +/** + * tomoyo_transition_type - Get domain transition type. + * + * @ns: Pointer to "struct tomoyo_policy_namespace". + * @domainname: The name of current domain. + * @program: The name of requested program. + * + * Returns TOMOYO_TRANSITION_CONTROL_TRANSIT if executing @program causes + * domain transition across namespaces, TOMOYO_TRANSITION_CONTROL_INITIALIZE if + * executing @program reinitializes domain transition within that namespace, + * TOMOYO_TRANSITION_CONTROL_KEEP if executing @program stays at @domainname , + * others otherwise. + * + * Caller holds tomoyo_read_lock(). + */ +static enum tomoyo_transition_type tomoyo_transition_type +(const struct tomoyo_policy_namespace *ns, + const struct tomoyo_path_info *domainname, + const struct tomoyo_path_info *program) +{ + const char *last_name = tomoyo_last_word(domainname->name); + enum tomoyo_transition_type type = TOMOYO_TRANSITION_CONTROL_NO_RESET; + + while (type < TOMOYO_MAX_TRANSITION_TYPE) { + const struct list_head * const list = + &ns->policy_list[TOMOYO_ID_TRANSITION_CONTROL]; + + if (!tomoyo_scan_transition(list, domainname, program, + last_name, type)) { + type++; + continue; + } + if (type != TOMOYO_TRANSITION_CONTROL_NO_RESET && + type != TOMOYO_TRANSITION_CONTROL_NO_INITIALIZE) + break; + /* + * Do not check for reset_domain if no_reset_domain matched. + * Do not check for initialize_domain if no_initialize_domain + * matched. + */ + type++; + type++; + } + return type; +} + +/** + * tomoyo_same_aggregator - Check for duplicated "struct tomoyo_aggregator" entry. + * + * @a: Pointer to "struct tomoyo_acl_head". + * @b: Pointer to "struct tomoyo_acl_head". + * + * Returns true if @a == @b, false otherwise. + */ +static bool tomoyo_same_aggregator(const struct tomoyo_acl_head *a, + const struct tomoyo_acl_head *b) +{ + const struct tomoyo_aggregator *p1 = container_of(a, typeof(*p1), + head); + const struct tomoyo_aggregator *p2 = container_of(b, typeof(*p2), + head); + + return p1->original_name == p2->original_name && + p1->aggregated_name == p2->aggregated_name; +} + +/** + * tomoyo_write_aggregator - Write "struct tomoyo_aggregator" list. + * + * @param: Pointer to "struct tomoyo_acl_param". + * + * Returns 0 on success, negative value otherwise. + * + * Caller holds tomoyo_read_lock(). + */ +int tomoyo_write_aggregator(struct tomoyo_acl_param *param) +{ + struct tomoyo_aggregator e = { }; + int error = param->is_delete ? -ENOENT : -ENOMEM; + const char *original_name = tomoyo_read_token(param); + const char *aggregated_name = tomoyo_read_token(param); + + if (!tomoyo_correct_word(original_name) || + !tomoyo_correct_path(aggregated_name)) + return -EINVAL; + e.original_name = tomoyo_get_name(original_name); + e.aggregated_name = tomoyo_get_name(aggregated_name); + if (!e.original_name || !e.aggregated_name || + e.aggregated_name->is_patterned) /* No patterns allowed. */ + goto out; + param->list = ¶m->ns->policy_list[TOMOYO_ID_AGGREGATOR]; + error = tomoyo_update_policy(&e.head, sizeof(e), param, + tomoyo_same_aggregator); +out: + tomoyo_put_name(e.original_name); + tomoyo_put_name(e.aggregated_name); + return error; +} + +/** + * tomoyo_find_namespace - Find specified namespace. + * + * @name: Name of namespace to find. + * @len: Length of @name. + * + * Returns pointer to "struct tomoyo_policy_namespace" if found, + * NULL otherwise. + * + * Caller holds tomoyo_read_lock(). + */ +static struct tomoyo_policy_namespace *tomoyo_find_namespace +(const char *name, const unsigned int len) +{ + struct tomoyo_policy_namespace *ns; + + list_for_each_entry(ns, &tomoyo_namespace_list, namespace_list) { + if (strncmp(name, ns->name, len) || + (name[len] && name[len] != ' ')) + continue; + return ns; + } + return NULL; +} + +/** + * tomoyo_assign_namespace - Create a new namespace. + * + * @domainname: Name of namespace to create. + * + * Returns pointer to "struct tomoyo_policy_namespace" on success, + * NULL otherwise. + * + * Caller holds tomoyo_read_lock(). + */ +struct tomoyo_policy_namespace *tomoyo_assign_namespace(const char *domainname) +{ + struct tomoyo_policy_namespace *ptr; + struct tomoyo_policy_namespace *entry; + const char *cp = domainname; + unsigned int len = 0; + + while (*cp && *cp++ != ' ') + len++; + ptr = tomoyo_find_namespace(domainname, len); + if (ptr) + return ptr; + if (len >= TOMOYO_EXEC_TMPSIZE - 10 || !tomoyo_domain_def(domainname)) + return NULL; + entry = kzalloc(sizeof(*entry) + len + 1, GFP_NOFS | __GFP_NOWARN); + if (mutex_lock_interruptible(&tomoyo_policy_lock)) + goto out; + ptr = tomoyo_find_namespace(domainname, len); + if (!ptr && tomoyo_memory_ok(entry)) { + char *name = (char *) (entry + 1); + + ptr = entry; + memmove(name, domainname, len); + name[len] = '\0'; + entry->name = name; + tomoyo_init_policy_namespace(entry); + entry = NULL; + } + mutex_unlock(&tomoyo_policy_lock); +out: + kfree(entry); + return ptr; +} + +/** + * tomoyo_namespace_jump - Check for namespace jump. + * + * @domainname: Name of domain. + * + * Returns true if namespace differs, false otherwise. + */ +static bool tomoyo_namespace_jump(const char *domainname) +{ + const char *namespace = tomoyo_current_namespace()->name; + const int len = strlen(namespace); + + return strncmp(domainname, namespace, len) || + (domainname[len] && domainname[len] != ' '); +} + +/** + * tomoyo_assign_domain - Create a domain or a namespace. + * + * @domainname: The name of domain. + * @transit: True if transit to domain found or created. + * + * Returns pointer to "struct tomoyo_domain_info" on success, NULL otherwise. + * + * Caller holds tomoyo_read_lock(). + */ +struct tomoyo_domain_info *tomoyo_assign_domain(const char *domainname, + const bool transit) +{ + struct tomoyo_domain_info e = { }; + struct tomoyo_domain_info *entry = tomoyo_find_domain(domainname); + bool created = false; + + if (entry) { + if (transit) { + /* + * Since namespace is created at runtime, profiles may + * not be created by the moment the process transits to + * that domain. Do not perform domain transition if + * profile for that domain is not yet created. + */ + if (tomoyo_policy_loaded && + !entry->ns->profile_ptr[entry->profile]) + return NULL; + } + return entry; + } + /* Requested domain does not exist. */ + /* Don't create requested domain if domainname is invalid. */ + if (strlen(domainname) >= TOMOYO_EXEC_TMPSIZE - 10 || + !tomoyo_correct_domain(domainname)) + return NULL; + /* + * Since definition of profiles and acl_groups may differ across + * namespaces, do not inherit "use_profile" and "use_group" settings + * by automatically creating requested domain upon domain transition. + */ + if (transit && tomoyo_namespace_jump(domainname)) + return NULL; + e.ns = tomoyo_assign_namespace(domainname); + if (!e.ns) + return NULL; + /* + * "use_profile" and "use_group" settings for automatically created + * domains are inherited from current domain. These are 0 for manually + * created domains. + */ + if (transit) { + const struct tomoyo_domain_info *domain = tomoyo_domain(); + + e.profile = domain->profile; + memcpy(e.group, domain->group, sizeof(e.group)); + } + e.domainname = tomoyo_get_name(domainname); + if (!e.domainname) + return NULL; + if (mutex_lock_interruptible(&tomoyo_policy_lock)) + goto out; + entry = tomoyo_find_domain(domainname); + if (!entry) { + entry = tomoyo_commit_ok(&e, sizeof(e)); + if (entry) { + INIT_LIST_HEAD(&entry->acl_info_list); + list_add_tail_rcu(&entry->list, &tomoyo_domain_list); + created = true; + } + } + mutex_unlock(&tomoyo_policy_lock); +out: + tomoyo_put_name(e.domainname); + if (entry && transit) { + if (created) { + struct tomoyo_request_info r; + int i; + + tomoyo_init_request_info(&r, entry, + TOMOYO_MAC_FILE_EXECUTE); + r.granted = false; + tomoyo_write_log(&r, "use_profile %u\n", + entry->profile); + for (i = 0; i < TOMOYO_MAX_ACL_GROUPS; i++) + if (test_bit(i, entry->group)) + tomoyo_write_log(&r, "use_group %u\n", + i); + tomoyo_update_stat(TOMOYO_STAT_POLICY_UPDATES); + } + } + return entry; +} + +/** + * tomoyo_environ - Check permission for environment variable names. + * + * @ee: Pointer to "struct tomoyo_execve". + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_environ(struct tomoyo_execve *ee) +{ + struct tomoyo_request_info *r = &ee->r; + struct linux_binprm *bprm = ee->bprm; + /* env_page.data is allocated by tomoyo_dump_page(). */ + struct tomoyo_page_dump env_page = { }; + char *arg_ptr; /* Size is TOMOYO_EXEC_TMPSIZE bytes */ + int arg_len = 0; + unsigned long pos = bprm->p; + int offset = pos % PAGE_SIZE; + int argv_count = bprm->argc; + int envp_count = bprm->envc; + int error = -ENOMEM; + + ee->r.type = TOMOYO_MAC_ENVIRON; + ee->r.profile = r->domain->profile; + ee->r.mode = tomoyo_get_mode(r->domain->ns, ee->r.profile, + TOMOYO_MAC_ENVIRON); + if (!r->mode || !envp_count) + return 0; + arg_ptr = kzalloc(TOMOYO_EXEC_TMPSIZE, GFP_NOFS); + if (!arg_ptr) + goto out; + while (error == -ENOMEM) { + if (!tomoyo_dump_page(bprm, pos, &env_page)) + goto out; + pos += PAGE_SIZE - offset; + /* Read. */ + while (argv_count && offset < PAGE_SIZE) { + if (!env_page.data[offset++]) + argv_count--; + } + if (argv_count) { + offset = 0; + continue; + } + while (offset < PAGE_SIZE) { + const unsigned char c = env_page.data[offset++]; + + if (c && arg_len < TOMOYO_EXEC_TMPSIZE - 10) { + if (c == '=') { + arg_ptr[arg_len++] = '\0'; + } else if (c == '\\') { + arg_ptr[arg_len++] = '\\'; + arg_ptr[arg_len++] = '\\'; + } else if (c > ' ' && c < 127) { + arg_ptr[arg_len++] = c; + } else { + arg_ptr[arg_len++] = '\\'; + arg_ptr[arg_len++] = (c >> 6) + '0'; + arg_ptr[arg_len++] + = ((c >> 3) & 7) + '0'; + arg_ptr[arg_len++] = (c & 7) + '0'; + } + } else { + arg_ptr[arg_len] = '\0'; + } + if (c) + continue; + if (tomoyo_env_perm(r, arg_ptr)) { + error = -EPERM; + break; + } + if (!--envp_count) { + error = 0; + break; + } + arg_len = 0; + } + offset = 0; + } +out: + if (r->mode != TOMOYO_CONFIG_ENFORCING) + error = 0; + kfree(env_page.data); + kfree(arg_ptr); + return error; +} + +/** + * tomoyo_find_next_domain - Find a domain. + * + * @bprm: Pointer to "struct linux_binprm". + * + * Returns 0 on success, negative value otherwise. + * + * Caller holds tomoyo_read_lock(). + */ +int tomoyo_find_next_domain(struct linux_binprm *bprm) +{ + struct tomoyo_domain_info *old_domain = tomoyo_domain(); + struct tomoyo_domain_info *domain = NULL; + const char *original_name = bprm->filename; + int retval = -ENOMEM; + bool reject_on_transition_failure = false; + const struct tomoyo_path_info *candidate; + struct tomoyo_path_info exename; + struct tomoyo_execve *ee = kzalloc(sizeof(*ee), GFP_NOFS); + + if (!ee) + return -ENOMEM; + ee->tmp = kzalloc(TOMOYO_EXEC_TMPSIZE, GFP_NOFS); + if (!ee->tmp) { + kfree(ee); + return -ENOMEM; + } + /* ee->dump->data is allocated by tomoyo_dump_page(). */ + tomoyo_init_request_info(&ee->r, NULL, TOMOYO_MAC_FILE_EXECUTE); + ee->r.ee = ee; + ee->bprm = bprm; + ee->r.obj = &ee->obj; + ee->obj.path1 = bprm->file->f_path; + /* Get symlink's pathname of program. */ + retval = -ENOENT; + exename.name = tomoyo_realpath_nofollow(original_name); + if (!exename.name) + goto out; + tomoyo_fill_path_info(&exename); +retry: + /* Check 'aggregator' directive. */ + { + struct tomoyo_aggregator *ptr; + struct list_head *list = + &old_domain->ns->policy_list[TOMOYO_ID_AGGREGATOR]; + + /* Check 'aggregator' directive. */ + candidate = &exename; + list_for_each_entry_rcu(ptr, list, head.list, + srcu_read_lock_held(&tomoyo_ss)) { + if (ptr->head.is_deleted || + !tomoyo_path_matches_pattern(&exename, + ptr->original_name)) + continue; + candidate = ptr->aggregated_name; + break; + } + } + + /* Check execute permission. */ + retval = tomoyo_execute_permission(&ee->r, candidate); + if (retval == TOMOYO_RETRY_REQUEST) + goto retry; + if (retval < 0) + goto out; + /* + * To be able to specify domainnames with wildcards, use the + * pathname specified in the policy (which may contain + * wildcard) rather than the pathname passed to execve() + * (which never contains wildcard). + */ + if (ee->r.param.path.matched_path) + candidate = ee->r.param.path.matched_path; + + /* + * Check for domain transition preference if "file execute" matched. + * If preference is given, make execve() fail if domain transition + * has failed, for domain transition preference should be used with + * destination domain defined. + */ + if (ee->transition) { + const char *domainname = ee->transition->name; + + reject_on_transition_failure = true; + if (!strcmp(domainname, "keep")) + goto force_keep_domain; + if (!strcmp(domainname, "child")) + goto force_child_domain; + if (!strcmp(domainname, "reset")) + goto force_reset_domain; + if (!strcmp(domainname, "initialize")) + goto force_initialize_domain; + if (!strcmp(domainname, "parent")) { + char *cp; + + strncpy(ee->tmp, old_domain->domainname->name, + TOMOYO_EXEC_TMPSIZE - 1); + cp = strrchr(ee->tmp, ' '); + if (cp) + *cp = '\0'; + } else if (*domainname == '<') + strncpy(ee->tmp, domainname, TOMOYO_EXEC_TMPSIZE - 1); + else + snprintf(ee->tmp, TOMOYO_EXEC_TMPSIZE - 1, "%s %s", + old_domain->domainname->name, domainname); + goto force_jump_domain; + } + /* + * No domain transition preference specified. + * Calculate domain to transit to. + */ + switch (tomoyo_transition_type(old_domain->ns, old_domain->domainname, + candidate)) { + case TOMOYO_TRANSITION_CONTROL_RESET: +force_reset_domain: + /* Transit to the root of specified namespace. */ + snprintf(ee->tmp, TOMOYO_EXEC_TMPSIZE - 1, "<%s>", + candidate->name); + /* + * Make execve() fail if domain transition across namespaces + * has failed. + */ + reject_on_transition_failure = true; + break; + case TOMOYO_TRANSITION_CONTROL_INITIALIZE: +force_initialize_domain: + /* Transit to the child of current namespace's root. */ + snprintf(ee->tmp, TOMOYO_EXEC_TMPSIZE - 1, "%s %s", + old_domain->ns->name, candidate->name); + break; + case TOMOYO_TRANSITION_CONTROL_KEEP: +force_keep_domain: + /* Keep current domain. */ + domain = old_domain; + break; + default: + if (old_domain == &tomoyo_kernel_domain && + !tomoyo_policy_loaded) { + /* + * Needn't to transit from kernel domain before + * starting /sbin/init. But transit from kernel domain + * if executing initializers because they might start + * before /sbin/init. + */ + domain = old_domain; + break; + } +force_child_domain: + /* Normal domain transition. */ + snprintf(ee->tmp, TOMOYO_EXEC_TMPSIZE - 1, "%s %s", + old_domain->domainname->name, candidate->name); + break; + } +force_jump_domain: + if (!domain) + domain = tomoyo_assign_domain(ee->tmp, true); + if (domain) + retval = 0; + else if (reject_on_transition_failure) { + pr_warn("ERROR: Domain '%s' not ready.\n", ee->tmp); + retval = -ENOMEM; + } else if (ee->r.mode == TOMOYO_CONFIG_ENFORCING) + retval = -ENOMEM; + else { + retval = 0; + if (!old_domain->flags[TOMOYO_DIF_TRANSITION_FAILED]) { + old_domain->flags[TOMOYO_DIF_TRANSITION_FAILED] = true; + ee->r.granted = false; + tomoyo_write_log(&ee->r, "%s", tomoyo_dif + [TOMOYO_DIF_TRANSITION_FAILED]); + pr_warn("ERROR: Domain '%s' not defined.\n", ee->tmp); + } + } + out: + if (!domain) + domain = old_domain; + /* Update reference count on "struct tomoyo_domain_info". */ + { + struct tomoyo_task *s = tomoyo_task(current); + + s->old_domain_info = s->domain_info; + s->domain_info = domain; + atomic_inc(&domain->users); + } + kfree(exename.name); + if (!retval) { + ee->r.domain = domain; + retval = tomoyo_environ(ee); + } + kfree(ee->tmp); + kfree(ee->dump.data); + kfree(ee); + return retval; +} + +/** + * tomoyo_dump_page - Dump a page to buffer. + * + * @bprm: Pointer to "struct linux_binprm". + * @pos: Location to dump. + * @dump: Pointer to "struct tomoyo_page_dump". + * + * Returns true on success, false otherwise. + */ +bool tomoyo_dump_page(struct linux_binprm *bprm, unsigned long pos, + struct tomoyo_page_dump *dump) +{ + struct page *page; +#ifdef CONFIG_MMU + int ret; +#endif + + /* dump->data is released by tomoyo_find_next_domain(). */ + if (!dump->data) { + dump->data = kzalloc(PAGE_SIZE, GFP_NOFS); + if (!dump->data) + return false; + } + /* Same with get_arg_page(bprm, pos, 0) in fs/exec.c */ +#ifdef CONFIG_MMU + /* + * This is called at execve() time in order to dig around + * in the argv/environment of the new proceess + * (represented by bprm). + */ + mmap_read_lock(bprm->mm); + ret = get_user_pages_remote(bprm->mm, pos, 1, + FOLL_FORCE, &page, NULL, NULL); + mmap_read_unlock(bprm->mm); + if (ret <= 0) + return false; +#else + page = bprm->page[pos / PAGE_SIZE]; +#endif + if (page != dump->page) { + const unsigned int offset = pos % PAGE_SIZE; + /* + * Maybe kmap()/kunmap() should be used here. + * But remove_arg_zero() uses kmap_atomic()/kunmap_atomic(). + * So do I. + */ + char *kaddr = kmap_atomic(page); + + dump->page = page; + memcpy(dump->data + offset, kaddr + offset, + PAGE_SIZE - offset); + kunmap_atomic(kaddr); + } + /* Same with put_arg_page(page) in fs/exec.c */ +#ifdef CONFIG_MMU + put_page(page); +#endif + return true; +} diff --git a/security/tomoyo/environ.c b/security/tomoyo/environ.c new file mode 100644 index 000000000..7f0a471f1 --- /dev/null +++ b/security/tomoyo/environ.c @@ -0,0 +1,123 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * security/tomoyo/environ.c + * + * Copyright (C) 2005-2011 NTT DATA CORPORATION + */ + +#include "common.h" + +/** + * tomoyo_check_env_acl - Check permission for environment variable's name. + * + * @r: Pointer to "struct tomoyo_request_info". + * @ptr: Pointer to "struct tomoyo_acl_info". + * + * Returns true if granted, false otherwise. + */ +static bool tomoyo_check_env_acl(struct tomoyo_request_info *r, + const struct tomoyo_acl_info *ptr) +{ + const struct tomoyo_env_acl *acl = + container_of(ptr, typeof(*acl), head); + + return tomoyo_path_matches_pattern(r->param.environ.name, acl->env); +} + +/** + * tomoyo_audit_env_log - Audit environment variable name log. + * + * @r: Pointer to "struct tomoyo_request_info". + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_audit_env_log(struct tomoyo_request_info *r) +{ + return tomoyo_supervisor(r, "misc env %s\n", + r->param.environ.name->name); +} + +/** + * tomoyo_env_perm - Check permission for environment variable's name. + * + * @r: Pointer to "struct tomoyo_request_info". + * @env: The name of environment variable. + * + * Returns 0 on success, negative value otherwise. + * + * Caller holds tomoyo_read_lock(). + */ +int tomoyo_env_perm(struct tomoyo_request_info *r, const char *env) +{ + struct tomoyo_path_info environ; + int error; + + if (!env || !*env) + return 0; + environ.name = env; + tomoyo_fill_path_info(&environ); + r->param_type = TOMOYO_TYPE_ENV_ACL; + r->param.environ.name = &environ; + do { + tomoyo_check_acl(r, tomoyo_check_env_acl); + error = tomoyo_audit_env_log(r); + } while (error == TOMOYO_RETRY_REQUEST); + return error; +} + +/** + * tomoyo_same_env_acl - Check for duplicated "struct tomoyo_env_acl" entry. + * + * @a: Pointer to "struct tomoyo_acl_info". + * @b: Pointer to "struct tomoyo_acl_info". + * + * Returns true if @a == @b, false otherwise. + */ +static bool tomoyo_same_env_acl(const struct tomoyo_acl_info *a, + const struct tomoyo_acl_info *b) +{ + const struct tomoyo_env_acl *p1 = container_of(a, typeof(*p1), head); + const struct tomoyo_env_acl *p2 = container_of(b, typeof(*p2), head); + + return p1->env == p2->env; +} + +/** + * tomoyo_write_env - Write "struct tomoyo_env_acl" list. + * + * @param: Pointer to "struct tomoyo_acl_param". + * + * Returns 0 on success, negative value otherwise. + * + * Caller holds tomoyo_read_lock(). + */ +static int tomoyo_write_env(struct tomoyo_acl_param *param) +{ + struct tomoyo_env_acl e = { .head.type = TOMOYO_TYPE_ENV_ACL }; + int error = -ENOMEM; + const char *data = tomoyo_read_token(param); + + if (!tomoyo_correct_word(data) || strchr(data, '=')) + return -EINVAL; + e.env = tomoyo_get_name(data); + if (!e.env) + return error; + error = tomoyo_update_domain(&e.head, sizeof(e), param, + tomoyo_same_env_acl, NULL); + tomoyo_put_name(e.env); + return error; +} + +/** + * tomoyo_write_misc - Update environment variable list. + * + * @param: Pointer to "struct tomoyo_acl_param". + * + * Returns 0 on success, negative value otherwise. + */ +int tomoyo_write_misc(struct tomoyo_acl_param *param) +{ + if (tomoyo_str_starts(¶m->data, "env ")) + return tomoyo_write_env(param); + return -EINVAL; +} diff --git a/security/tomoyo/file.c b/security/tomoyo/file.c new file mode 100644 index 000000000..8f3b90b6e --- /dev/null +++ b/security/tomoyo/file.c @@ -0,0 +1,1045 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * security/tomoyo/file.c + * + * Copyright (C) 2005-2011 NTT DATA CORPORATION + */ + +#include "common.h" +#include <linux/slab.h> + +/* + * Mapping table from "enum tomoyo_path_acl_index" to "enum tomoyo_mac_index". + */ +static const u8 tomoyo_p2mac[TOMOYO_MAX_PATH_OPERATION] = { + [TOMOYO_TYPE_EXECUTE] = TOMOYO_MAC_FILE_EXECUTE, + [TOMOYO_TYPE_READ] = TOMOYO_MAC_FILE_OPEN, + [TOMOYO_TYPE_WRITE] = TOMOYO_MAC_FILE_OPEN, + [TOMOYO_TYPE_APPEND] = TOMOYO_MAC_FILE_OPEN, + [TOMOYO_TYPE_UNLINK] = TOMOYO_MAC_FILE_UNLINK, + [TOMOYO_TYPE_GETATTR] = TOMOYO_MAC_FILE_GETATTR, + [TOMOYO_TYPE_RMDIR] = TOMOYO_MAC_FILE_RMDIR, + [TOMOYO_TYPE_TRUNCATE] = TOMOYO_MAC_FILE_TRUNCATE, + [TOMOYO_TYPE_SYMLINK] = TOMOYO_MAC_FILE_SYMLINK, + [TOMOYO_TYPE_CHROOT] = TOMOYO_MAC_FILE_CHROOT, + [TOMOYO_TYPE_UMOUNT] = TOMOYO_MAC_FILE_UMOUNT, +}; + +/* + * Mapping table from "enum tomoyo_mkdev_acl_index" to "enum tomoyo_mac_index". + */ +const u8 tomoyo_pnnn2mac[TOMOYO_MAX_MKDEV_OPERATION] = { + [TOMOYO_TYPE_MKBLOCK] = TOMOYO_MAC_FILE_MKBLOCK, + [TOMOYO_TYPE_MKCHAR] = TOMOYO_MAC_FILE_MKCHAR, +}; + +/* + * Mapping table from "enum tomoyo_path2_acl_index" to "enum tomoyo_mac_index". + */ +const u8 tomoyo_pp2mac[TOMOYO_MAX_PATH2_OPERATION] = { + [TOMOYO_TYPE_LINK] = TOMOYO_MAC_FILE_LINK, + [TOMOYO_TYPE_RENAME] = TOMOYO_MAC_FILE_RENAME, + [TOMOYO_TYPE_PIVOT_ROOT] = TOMOYO_MAC_FILE_PIVOT_ROOT, +}; + +/* + * Mapping table from "enum tomoyo_path_number_acl_index" to + * "enum tomoyo_mac_index". + */ +const u8 tomoyo_pn2mac[TOMOYO_MAX_PATH_NUMBER_OPERATION] = { + [TOMOYO_TYPE_CREATE] = TOMOYO_MAC_FILE_CREATE, + [TOMOYO_TYPE_MKDIR] = TOMOYO_MAC_FILE_MKDIR, + [TOMOYO_TYPE_MKFIFO] = TOMOYO_MAC_FILE_MKFIFO, + [TOMOYO_TYPE_MKSOCK] = TOMOYO_MAC_FILE_MKSOCK, + [TOMOYO_TYPE_IOCTL] = TOMOYO_MAC_FILE_IOCTL, + [TOMOYO_TYPE_CHMOD] = TOMOYO_MAC_FILE_CHMOD, + [TOMOYO_TYPE_CHOWN] = TOMOYO_MAC_FILE_CHOWN, + [TOMOYO_TYPE_CHGRP] = TOMOYO_MAC_FILE_CHGRP, +}; + +/** + * tomoyo_put_name_union - Drop reference on "struct tomoyo_name_union". + * + * @ptr: Pointer to "struct tomoyo_name_union". + * + * Returns nothing. + */ +void tomoyo_put_name_union(struct tomoyo_name_union *ptr) +{ + tomoyo_put_group(ptr->group); + tomoyo_put_name(ptr->filename); +} + +/** + * tomoyo_compare_name_union - Check whether a name matches "struct tomoyo_name_union" or not. + * + * @name: Pointer to "struct tomoyo_path_info". + * @ptr: Pointer to "struct tomoyo_name_union". + * + * Returns "struct tomoyo_path_info" if @name matches @ptr, NULL otherwise. + */ +const struct tomoyo_path_info * +tomoyo_compare_name_union(const struct tomoyo_path_info *name, + const struct tomoyo_name_union *ptr) +{ + if (ptr->group) + return tomoyo_path_matches_group(name, ptr->group); + if (tomoyo_path_matches_pattern(name, ptr->filename)) + return ptr->filename; + return NULL; +} + +/** + * tomoyo_put_number_union - Drop reference on "struct tomoyo_number_union". + * + * @ptr: Pointer to "struct tomoyo_number_union". + * + * Returns nothing. + */ +void tomoyo_put_number_union(struct tomoyo_number_union *ptr) +{ + tomoyo_put_group(ptr->group); +} + +/** + * tomoyo_compare_number_union - Check whether a value matches "struct tomoyo_number_union" or not. + * + * @value: Number to check. + * @ptr: Pointer to "struct tomoyo_number_union". + * + * Returns true if @value matches @ptr, false otherwise. + */ +bool tomoyo_compare_number_union(const unsigned long value, + const struct tomoyo_number_union *ptr) +{ + if (ptr->group) + return tomoyo_number_matches_group(value, value, ptr->group); + return value >= ptr->values[0] && value <= ptr->values[1]; +} + +/** + * tomoyo_add_slash - Add trailing '/' if needed. + * + * @buf: Pointer to "struct tomoyo_path_info". + * + * Returns nothing. + * + * @buf must be generated by tomoyo_encode() because this function does not + * allocate memory for adding '/'. + */ +static void tomoyo_add_slash(struct tomoyo_path_info *buf) +{ + if (buf->is_dir) + return; + /* + * This is OK because tomoyo_encode() reserves space for appending "/". + */ + strcat((char *) buf->name, "/"); + tomoyo_fill_path_info(buf); +} + +/** + * tomoyo_get_realpath - Get realpath. + * + * @buf: Pointer to "struct tomoyo_path_info". + * @path: Pointer to "struct path". + * + * Returns true on success, false otherwise. + */ +static bool tomoyo_get_realpath(struct tomoyo_path_info *buf, const struct path *path) +{ + buf->name = tomoyo_realpath_from_path(path); + if (buf->name) { + tomoyo_fill_path_info(buf); + return true; + } + return false; +} + +/** + * tomoyo_audit_path_log - Audit path request log. + * + * @r: Pointer to "struct tomoyo_request_info". + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_audit_path_log(struct tomoyo_request_info *r) +{ + return tomoyo_supervisor(r, "file %s %s\n", tomoyo_path_keyword + [r->param.path.operation], + r->param.path.filename->name); +} + +/** + * tomoyo_audit_path2_log - Audit path/path request log. + * + * @r: Pointer to "struct tomoyo_request_info". + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_audit_path2_log(struct tomoyo_request_info *r) +{ + return tomoyo_supervisor(r, "file %s %s %s\n", tomoyo_mac_keywords + [tomoyo_pp2mac[r->param.path2.operation]], + r->param.path2.filename1->name, + r->param.path2.filename2->name); +} + +/** + * tomoyo_audit_mkdev_log - Audit path/number/number/number request log. + * + * @r: Pointer to "struct tomoyo_request_info". + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_audit_mkdev_log(struct tomoyo_request_info *r) +{ + return tomoyo_supervisor(r, "file %s %s 0%o %u %u\n", + tomoyo_mac_keywords + [tomoyo_pnnn2mac[r->param.mkdev.operation]], + r->param.mkdev.filename->name, + r->param.mkdev.mode, r->param.mkdev.major, + r->param.mkdev.minor); +} + +/** + * tomoyo_audit_path_number_log - Audit path/number request log. + * + * @r: Pointer to "struct tomoyo_request_info". + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_audit_path_number_log(struct tomoyo_request_info *r) +{ + const u8 type = r->param.path_number.operation; + u8 radix; + char buffer[64]; + + switch (type) { + case TOMOYO_TYPE_CREATE: + case TOMOYO_TYPE_MKDIR: + case TOMOYO_TYPE_MKFIFO: + case TOMOYO_TYPE_MKSOCK: + case TOMOYO_TYPE_CHMOD: + radix = TOMOYO_VALUE_TYPE_OCTAL; + break; + case TOMOYO_TYPE_IOCTL: + radix = TOMOYO_VALUE_TYPE_HEXADECIMAL; + break; + default: + radix = TOMOYO_VALUE_TYPE_DECIMAL; + break; + } + tomoyo_print_ulong(buffer, sizeof(buffer), r->param.path_number.number, + radix); + return tomoyo_supervisor(r, "file %s %s %s\n", tomoyo_mac_keywords + [tomoyo_pn2mac[type]], + r->param.path_number.filename->name, buffer); +} + +/** + * tomoyo_check_path_acl - Check permission for path operation. + * + * @r: Pointer to "struct tomoyo_request_info". + * @ptr: Pointer to "struct tomoyo_acl_info". + * + * Returns true if granted, false otherwise. + * + * To be able to use wildcard for domain transition, this function sets + * matching entry on success. Since the caller holds tomoyo_read_lock(), + * it is safe to set matching entry. + */ +static bool tomoyo_check_path_acl(struct tomoyo_request_info *r, + const struct tomoyo_acl_info *ptr) +{ + const struct tomoyo_path_acl *acl = container_of(ptr, typeof(*acl), + head); + + if (acl->perm & (1 << r->param.path.operation)) { + r->param.path.matched_path = + tomoyo_compare_name_union(r->param.path.filename, + &acl->name); + return r->param.path.matched_path != NULL; + } + return false; +} + +/** + * tomoyo_check_path_number_acl - Check permission for path number operation. + * + * @r: Pointer to "struct tomoyo_request_info". + * @ptr: Pointer to "struct tomoyo_acl_info". + * + * Returns true if granted, false otherwise. + */ +static bool tomoyo_check_path_number_acl(struct tomoyo_request_info *r, + const struct tomoyo_acl_info *ptr) +{ + const struct tomoyo_path_number_acl *acl = + container_of(ptr, typeof(*acl), head); + + return (acl->perm & (1 << r->param.path_number.operation)) && + tomoyo_compare_number_union(r->param.path_number.number, + &acl->number) && + tomoyo_compare_name_union(r->param.path_number.filename, + &acl->name); +} + +/** + * tomoyo_check_path2_acl - Check permission for path path operation. + * + * @r: Pointer to "struct tomoyo_request_info". + * @ptr: Pointer to "struct tomoyo_acl_info". + * + * Returns true if granted, false otherwise. + */ +static bool tomoyo_check_path2_acl(struct tomoyo_request_info *r, + const struct tomoyo_acl_info *ptr) +{ + const struct tomoyo_path2_acl *acl = + container_of(ptr, typeof(*acl), head); + + return (acl->perm & (1 << r->param.path2.operation)) && + tomoyo_compare_name_union(r->param.path2.filename1, &acl->name1) + && tomoyo_compare_name_union(r->param.path2.filename2, + &acl->name2); +} + +/** + * tomoyo_check_mkdev_acl - Check permission for path number number number operation. + * + * @r: Pointer to "struct tomoyo_request_info". + * @ptr: Pointer to "struct tomoyo_acl_info". + * + * Returns true if granted, false otherwise. + */ +static bool tomoyo_check_mkdev_acl(struct tomoyo_request_info *r, + const struct tomoyo_acl_info *ptr) +{ + const struct tomoyo_mkdev_acl *acl = + container_of(ptr, typeof(*acl), head); + + return (acl->perm & (1 << r->param.mkdev.operation)) && + tomoyo_compare_number_union(r->param.mkdev.mode, + &acl->mode) && + tomoyo_compare_number_union(r->param.mkdev.major, + &acl->major) && + tomoyo_compare_number_union(r->param.mkdev.minor, + &acl->minor) && + tomoyo_compare_name_union(r->param.mkdev.filename, + &acl->name); +} + +/** + * tomoyo_same_path_acl - Check for duplicated "struct tomoyo_path_acl" entry. + * + * @a: Pointer to "struct tomoyo_acl_info". + * @b: Pointer to "struct tomoyo_acl_info". + * + * Returns true if @a == @b except permission bits, false otherwise. + */ +static bool tomoyo_same_path_acl(const struct tomoyo_acl_info *a, + const struct tomoyo_acl_info *b) +{ + const struct tomoyo_path_acl *p1 = container_of(a, typeof(*p1), head); + const struct tomoyo_path_acl *p2 = container_of(b, typeof(*p2), head); + + return tomoyo_same_name_union(&p1->name, &p2->name); +} + +/** + * tomoyo_merge_path_acl - Merge duplicated "struct tomoyo_path_acl" entry. + * + * @a: Pointer to "struct tomoyo_acl_info". + * @b: Pointer to "struct tomoyo_acl_info". + * @is_delete: True for @a &= ~@b, false for @a |= @b. + * + * Returns true if @a is empty, false otherwise. + */ +static bool tomoyo_merge_path_acl(struct tomoyo_acl_info *a, + struct tomoyo_acl_info *b, + const bool is_delete) +{ + u16 * const a_perm = &container_of(a, struct tomoyo_path_acl, head) + ->perm; + u16 perm = READ_ONCE(*a_perm); + const u16 b_perm = container_of(b, struct tomoyo_path_acl, head)->perm; + + if (is_delete) + perm &= ~b_perm; + else + perm |= b_perm; + WRITE_ONCE(*a_perm, perm); + return !perm; +} + +/** + * tomoyo_update_path_acl - Update "struct tomoyo_path_acl" list. + * + * @perm: Permission. + * @param: Pointer to "struct tomoyo_acl_param". + * + * Returns 0 on success, negative value otherwise. + * + * Caller holds tomoyo_read_lock(). + */ +static int tomoyo_update_path_acl(const u16 perm, + struct tomoyo_acl_param *param) +{ + struct tomoyo_path_acl e = { + .head.type = TOMOYO_TYPE_PATH_ACL, + .perm = perm + }; + int error; + + if (!tomoyo_parse_name_union(param, &e.name)) + error = -EINVAL; + else + error = tomoyo_update_domain(&e.head, sizeof(e), param, + tomoyo_same_path_acl, + tomoyo_merge_path_acl); + tomoyo_put_name_union(&e.name); + return error; +} + +/** + * tomoyo_same_mkdev_acl - Check for duplicated "struct tomoyo_mkdev_acl" entry. + * + * @a: Pointer to "struct tomoyo_acl_info". + * @b: Pointer to "struct tomoyo_acl_info". + * + * Returns true if @a == @b except permission bits, false otherwise. + */ +static bool tomoyo_same_mkdev_acl(const struct tomoyo_acl_info *a, + const struct tomoyo_acl_info *b) +{ + const struct tomoyo_mkdev_acl *p1 = container_of(a, typeof(*p1), head); + const struct tomoyo_mkdev_acl *p2 = container_of(b, typeof(*p2), head); + + return tomoyo_same_name_union(&p1->name, &p2->name) && + tomoyo_same_number_union(&p1->mode, &p2->mode) && + tomoyo_same_number_union(&p1->major, &p2->major) && + tomoyo_same_number_union(&p1->minor, &p2->minor); +} + +/** + * tomoyo_merge_mkdev_acl - Merge duplicated "struct tomoyo_mkdev_acl" entry. + * + * @a: Pointer to "struct tomoyo_acl_info". + * @b: Pointer to "struct tomoyo_acl_info". + * @is_delete: True for @a &= ~@b, false for @a |= @b. + * + * Returns true if @a is empty, false otherwise. + */ +static bool tomoyo_merge_mkdev_acl(struct tomoyo_acl_info *a, + struct tomoyo_acl_info *b, + const bool is_delete) +{ + u8 *const a_perm = &container_of(a, struct tomoyo_mkdev_acl, + head)->perm; + u8 perm = READ_ONCE(*a_perm); + const u8 b_perm = container_of(b, struct tomoyo_mkdev_acl, head) + ->perm; + + if (is_delete) + perm &= ~b_perm; + else + perm |= b_perm; + WRITE_ONCE(*a_perm, perm); + return !perm; +} + +/** + * tomoyo_update_mkdev_acl - Update "struct tomoyo_mkdev_acl" list. + * + * @perm: Permission. + * @param: Pointer to "struct tomoyo_acl_param". + * + * Returns 0 on success, negative value otherwise. + * + * Caller holds tomoyo_read_lock(). + */ +static int tomoyo_update_mkdev_acl(const u8 perm, + struct tomoyo_acl_param *param) +{ + struct tomoyo_mkdev_acl e = { + .head.type = TOMOYO_TYPE_MKDEV_ACL, + .perm = perm + }; + int error; + + if (!tomoyo_parse_name_union(param, &e.name) || + !tomoyo_parse_number_union(param, &e.mode) || + !tomoyo_parse_number_union(param, &e.major) || + !tomoyo_parse_number_union(param, &e.minor)) + error = -EINVAL; + else + error = tomoyo_update_domain(&e.head, sizeof(e), param, + tomoyo_same_mkdev_acl, + tomoyo_merge_mkdev_acl); + tomoyo_put_name_union(&e.name); + tomoyo_put_number_union(&e.mode); + tomoyo_put_number_union(&e.major); + tomoyo_put_number_union(&e.minor); + return error; +} + +/** + * tomoyo_same_path2_acl - Check for duplicated "struct tomoyo_path2_acl" entry. + * + * @a: Pointer to "struct tomoyo_acl_info". + * @b: Pointer to "struct tomoyo_acl_info". + * + * Returns true if @a == @b except permission bits, false otherwise. + */ +static bool tomoyo_same_path2_acl(const struct tomoyo_acl_info *a, + const struct tomoyo_acl_info *b) +{ + const struct tomoyo_path2_acl *p1 = container_of(a, typeof(*p1), head); + const struct tomoyo_path2_acl *p2 = container_of(b, typeof(*p2), head); + + return tomoyo_same_name_union(&p1->name1, &p2->name1) && + tomoyo_same_name_union(&p1->name2, &p2->name2); +} + +/** + * tomoyo_merge_path2_acl - Merge duplicated "struct tomoyo_path2_acl" entry. + * + * @a: Pointer to "struct tomoyo_acl_info". + * @b: Pointer to "struct tomoyo_acl_info". + * @is_delete: True for @a &= ~@b, false for @a |= @b. + * + * Returns true if @a is empty, false otherwise. + */ +static bool tomoyo_merge_path2_acl(struct tomoyo_acl_info *a, + struct tomoyo_acl_info *b, + const bool is_delete) +{ + u8 * const a_perm = &container_of(a, struct tomoyo_path2_acl, head) + ->perm; + u8 perm = READ_ONCE(*a_perm); + const u8 b_perm = container_of(b, struct tomoyo_path2_acl, head)->perm; + + if (is_delete) + perm &= ~b_perm; + else + perm |= b_perm; + WRITE_ONCE(*a_perm, perm); + return !perm; +} + +/** + * tomoyo_update_path2_acl - Update "struct tomoyo_path2_acl" list. + * + * @perm: Permission. + * @param: Pointer to "struct tomoyo_acl_param". + * + * Returns 0 on success, negative value otherwise. + * + * Caller holds tomoyo_read_lock(). + */ +static int tomoyo_update_path2_acl(const u8 perm, + struct tomoyo_acl_param *param) +{ + struct tomoyo_path2_acl e = { + .head.type = TOMOYO_TYPE_PATH2_ACL, + .perm = perm + }; + int error; + + if (!tomoyo_parse_name_union(param, &e.name1) || + !tomoyo_parse_name_union(param, &e.name2)) + error = -EINVAL; + else + error = tomoyo_update_domain(&e.head, sizeof(e), param, + tomoyo_same_path2_acl, + tomoyo_merge_path2_acl); + tomoyo_put_name_union(&e.name1); + tomoyo_put_name_union(&e.name2); + return error; +} + +/** + * tomoyo_path_permission - Check permission for single path operation. + * + * @r: Pointer to "struct tomoyo_request_info". + * @operation: Type of operation. + * @filename: Filename to check. + * + * Returns 0 on success, negative value otherwise. + * + * Caller holds tomoyo_read_lock(). + */ +static int tomoyo_path_permission(struct tomoyo_request_info *r, u8 operation, + const struct tomoyo_path_info *filename) +{ + int error; + + r->type = tomoyo_p2mac[operation]; + r->mode = tomoyo_get_mode(r->domain->ns, r->profile, r->type); + if (r->mode == TOMOYO_CONFIG_DISABLED) + return 0; + r->param_type = TOMOYO_TYPE_PATH_ACL; + r->param.path.filename = filename; + r->param.path.operation = operation; + do { + tomoyo_check_acl(r, tomoyo_check_path_acl); + error = tomoyo_audit_path_log(r); + } while (error == TOMOYO_RETRY_REQUEST); + return error; +} + +/** + * tomoyo_execute_permission - Check permission for execute operation. + * + * @r: Pointer to "struct tomoyo_request_info". + * @filename: Filename to check. + * + * Returns 0 on success, negative value otherwise. + * + * Caller holds tomoyo_read_lock(). + */ +int tomoyo_execute_permission(struct tomoyo_request_info *r, + const struct tomoyo_path_info *filename) +{ + /* + * Unlike other permission checks, this check is done regardless of + * profile mode settings in order to check for domain transition + * preference. + */ + r->type = TOMOYO_MAC_FILE_EXECUTE; + r->mode = tomoyo_get_mode(r->domain->ns, r->profile, r->type); + r->param_type = TOMOYO_TYPE_PATH_ACL; + r->param.path.filename = filename; + r->param.path.operation = TOMOYO_TYPE_EXECUTE; + tomoyo_check_acl(r, tomoyo_check_path_acl); + r->ee->transition = r->matched_acl && r->matched_acl->cond ? + r->matched_acl->cond->transit : NULL; + if (r->mode != TOMOYO_CONFIG_DISABLED) + return tomoyo_audit_path_log(r); + return 0; +} + +/** + * tomoyo_same_path_number_acl - Check for duplicated "struct tomoyo_path_number_acl" entry. + * + * @a: Pointer to "struct tomoyo_acl_info". + * @b: Pointer to "struct tomoyo_acl_info". + * + * Returns true if @a == @b except permission bits, false otherwise. + */ +static bool tomoyo_same_path_number_acl(const struct tomoyo_acl_info *a, + const struct tomoyo_acl_info *b) +{ + const struct tomoyo_path_number_acl *p1 = container_of(a, typeof(*p1), + head); + const struct tomoyo_path_number_acl *p2 = container_of(b, typeof(*p2), + head); + + return tomoyo_same_name_union(&p1->name, &p2->name) && + tomoyo_same_number_union(&p1->number, &p2->number); +} + +/** + * tomoyo_merge_path_number_acl - Merge duplicated "struct tomoyo_path_number_acl" entry. + * + * @a: Pointer to "struct tomoyo_acl_info". + * @b: Pointer to "struct tomoyo_acl_info". + * @is_delete: True for @a &= ~@b, false for @a |= @b. + * + * Returns true if @a is empty, false otherwise. + */ +static bool tomoyo_merge_path_number_acl(struct tomoyo_acl_info *a, + struct tomoyo_acl_info *b, + const bool is_delete) +{ + u8 * const a_perm = &container_of(a, struct tomoyo_path_number_acl, + head)->perm; + u8 perm = READ_ONCE(*a_perm); + const u8 b_perm = container_of(b, struct tomoyo_path_number_acl, head) + ->perm; + + if (is_delete) + perm &= ~b_perm; + else + perm |= b_perm; + WRITE_ONCE(*a_perm, perm); + return !perm; +} + +/** + * tomoyo_update_path_number_acl - Update ioctl/chmod/chown/chgrp ACL. + * + * @perm: Permission. + * @param: Pointer to "struct tomoyo_acl_param". + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_update_path_number_acl(const u8 perm, + struct tomoyo_acl_param *param) +{ + struct tomoyo_path_number_acl e = { + .head.type = TOMOYO_TYPE_PATH_NUMBER_ACL, + .perm = perm + }; + int error; + + if (!tomoyo_parse_name_union(param, &e.name) || + !tomoyo_parse_number_union(param, &e.number)) + error = -EINVAL; + else + error = tomoyo_update_domain(&e.head, sizeof(e), param, + tomoyo_same_path_number_acl, + tomoyo_merge_path_number_acl); + tomoyo_put_name_union(&e.name); + tomoyo_put_number_union(&e.number); + return error; +} + +/** + * tomoyo_path_number_perm - Check permission for "create", "mkdir", "mkfifo", "mksock", "ioctl", "chmod", "chown", "chgrp". + * + * @type: Type of operation. + * @path: Pointer to "struct path". + * @number: Number. + * + * Returns 0 on success, negative value otherwise. + */ +int tomoyo_path_number_perm(const u8 type, const struct path *path, + unsigned long number) +{ + struct tomoyo_request_info r; + struct tomoyo_obj_info obj = { + .path1 = { .mnt = path->mnt, .dentry = path->dentry }, + }; + int error = -ENOMEM; + struct tomoyo_path_info buf; + int idx; + + if (tomoyo_init_request_info(&r, NULL, tomoyo_pn2mac[type]) + == TOMOYO_CONFIG_DISABLED) + return 0; + idx = tomoyo_read_lock(); + if (!tomoyo_get_realpath(&buf, path)) + goto out; + r.obj = &obj; + if (type == TOMOYO_TYPE_MKDIR) + tomoyo_add_slash(&buf); + r.param_type = TOMOYO_TYPE_PATH_NUMBER_ACL; + r.param.path_number.operation = type; + r.param.path_number.filename = &buf; + r.param.path_number.number = number; + do { + tomoyo_check_acl(&r, tomoyo_check_path_number_acl); + error = tomoyo_audit_path_number_log(&r); + } while (error == TOMOYO_RETRY_REQUEST); + kfree(buf.name); + out: + tomoyo_read_unlock(idx); + if (r.mode != TOMOYO_CONFIG_ENFORCING) + error = 0; + return error; +} + +/** + * tomoyo_check_open_permission - Check permission for "read" and "write". + * + * @domain: Pointer to "struct tomoyo_domain_info". + * @path: Pointer to "struct path". + * @flag: Flags for open(). + * + * Returns 0 on success, negative value otherwise. + */ +int tomoyo_check_open_permission(struct tomoyo_domain_info *domain, + const struct path *path, const int flag) +{ + const u8 acc_mode = ACC_MODE(flag); + int error = 0; + struct tomoyo_path_info buf; + struct tomoyo_request_info r; + struct tomoyo_obj_info obj = { + .path1 = { .mnt = path->mnt, .dentry = path->dentry }, + }; + int idx; + + buf.name = NULL; + r.mode = TOMOYO_CONFIG_DISABLED; + idx = tomoyo_read_lock(); + if (acc_mode && + tomoyo_init_request_info(&r, domain, TOMOYO_MAC_FILE_OPEN) + != TOMOYO_CONFIG_DISABLED) { + if (!tomoyo_get_realpath(&buf, path)) { + error = -ENOMEM; + goto out; + } + r.obj = &obj; + if (acc_mode & MAY_READ) + error = tomoyo_path_permission(&r, TOMOYO_TYPE_READ, + &buf); + if (!error && (acc_mode & MAY_WRITE)) + error = tomoyo_path_permission(&r, (flag & O_APPEND) ? + TOMOYO_TYPE_APPEND : + TOMOYO_TYPE_WRITE, + &buf); + } + out: + kfree(buf.name); + tomoyo_read_unlock(idx); + if (r.mode != TOMOYO_CONFIG_ENFORCING) + error = 0; + return error; +} + +/** + * tomoyo_path_perm - Check permission for "unlink", "rmdir", "truncate", "symlink", "append", "chroot" and "unmount". + * + * @operation: Type of operation. + * @path: Pointer to "struct path". + * @target: Symlink's target if @operation is TOMOYO_TYPE_SYMLINK, + * NULL otherwise. + * + * Returns 0 on success, negative value otherwise. + */ +int tomoyo_path_perm(const u8 operation, const struct path *path, const char *target) +{ + struct tomoyo_request_info r; + struct tomoyo_obj_info obj = { + .path1 = { .mnt = path->mnt, .dentry = path->dentry }, + }; + int error; + struct tomoyo_path_info buf; + bool is_enforce; + struct tomoyo_path_info symlink_target; + int idx; + + if (tomoyo_init_request_info(&r, NULL, tomoyo_p2mac[operation]) + == TOMOYO_CONFIG_DISABLED) + return 0; + is_enforce = (r.mode == TOMOYO_CONFIG_ENFORCING); + error = -ENOMEM; + buf.name = NULL; + idx = tomoyo_read_lock(); + if (!tomoyo_get_realpath(&buf, path)) + goto out; + r.obj = &obj; + switch (operation) { + case TOMOYO_TYPE_RMDIR: + case TOMOYO_TYPE_CHROOT: + tomoyo_add_slash(&buf); + break; + case TOMOYO_TYPE_SYMLINK: + symlink_target.name = tomoyo_encode(target); + if (!symlink_target.name) + goto out; + tomoyo_fill_path_info(&symlink_target); + obj.symlink_target = &symlink_target; + break; + } + error = tomoyo_path_permission(&r, operation, &buf); + if (operation == TOMOYO_TYPE_SYMLINK) + kfree(symlink_target.name); + out: + kfree(buf.name); + tomoyo_read_unlock(idx); + if (!is_enforce) + error = 0; + return error; +} + +/** + * tomoyo_mkdev_perm - Check permission for "mkblock" and "mkchar". + * + * @operation: Type of operation. (TOMOYO_TYPE_MKCHAR or TOMOYO_TYPE_MKBLOCK) + * @path: Pointer to "struct path". + * @mode: Create mode. + * @dev: Device number. + * + * Returns 0 on success, negative value otherwise. + */ +int tomoyo_mkdev_perm(const u8 operation, const struct path *path, + const unsigned int mode, unsigned int dev) +{ + struct tomoyo_request_info r; + struct tomoyo_obj_info obj = { + .path1 = { .mnt = path->mnt, .dentry = path->dentry }, + }; + int error = -ENOMEM; + struct tomoyo_path_info buf; + int idx; + + if (tomoyo_init_request_info(&r, NULL, tomoyo_pnnn2mac[operation]) + == TOMOYO_CONFIG_DISABLED) + return 0; + idx = tomoyo_read_lock(); + error = -ENOMEM; + if (tomoyo_get_realpath(&buf, path)) { + r.obj = &obj; + dev = new_decode_dev(dev); + r.param_type = TOMOYO_TYPE_MKDEV_ACL; + r.param.mkdev.filename = &buf; + r.param.mkdev.operation = operation; + r.param.mkdev.mode = mode; + r.param.mkdev.major = MAJOR(dev); + r.param.mkdev.minor = MINOR(dev); + tomoyo_check_acl(&r, tomoyo_check_mkdev_acl); + error = tomoyo_audit_mkdev_log(&r); + kfree(buf.name); + } + tomoyo_read_unlock(idx); + if (r.mode != TOMOYO_CONFIG_ENFORCING) + error = 0; + return error; +} + +/** + * tomoyo_path2_perm - Check permission for "rename", "link" and "pivot_root". + * + * @operation: Type of operation. + * @path1: Pointer to "struct path". + * @path2: Pointer to "struct path". + * + * Returns 0 on success, negative value otherwise. + */ +int tomoyo_path2_perm(const u8 operation, const struct path *path1, + const struct path *path2) +{ + int error = -ENOMEM; + struct tomoyo_path_info buf1; + struct tomoyo_path_info buf2; + struct tomoyo_request_info r; + struct tomoyo_obj_info obj = { + .path1 = { .mnt = path1->mnt, .dentry = path1->dentry }, + .path2 = { .mnt = path2->mnt, .dentry = path2->dentry } + }; + int idx; + + if (tomoyo_init_request_info(&r, NULL, tomoyo_pp2mac[operation]) + == TOMOYO_CONFIG_DISABLED) + return 0; + buf1.name = NULL; + buf2.name = NULL; + idx = tomoyo_read_lock(); + if (!tomoyo_get_realpath(&buf1, path1) || + !tomoyo_get_realpath(&buf2, path2)) + goto out; + switch (operation) { + case TOMOYO_TYPE_RENAME: + case TOMOYO_TYPE_LINK: + if (!d_is_dir(path1->dentry)) + break; + fallthrough; + case TOMOYO_TYPE_PIVOT_ROOT: + tomoyo_add_slash(&buf1); + tomoyo_add_slash(&buf2); + break; + } + r.obj = &obj; + r.param_type = TOMOYO_TYPE_PATH2_ACL; + r.param.path2.operation = operation; + r.param.path2.filename1 = &buf1; + r.param.path2.filename2 = &buf2; + do { + tomoyo_check_acl(&r, tomoyo_check_path2_acl); + error = tomoyo_audit_path2_log(&r); + } while (error == TOMOYO_RETRY_REQUEST); + out: + kfree(buf1.name); + kfree(buf2.name); + tomoyo_read_unlock(idx); + if (r.mode != TOMOYO_CONFIG_ENFORCING) + error = 0; + return error; +} + +/** + * tomoyo_same_mount_acl - Check for duplicated "struct tomoyo_mount_acl" entry. + * + * @a: Pointer to "struct tomoyo_acl_info". + * @b: Pointer to "struct tomoyo_acl_info". + * + * Returns true if @a == @b, false otherwise. + */ +static bool tomoyo_same_mount_acl(const struct tomoyo_acl_info *a, + const struct tomoyo_acl_info *b) +{ + const struct tomoyo_mount_acl *p1 = container_of(a, typeof(*p1), head); + const struct tomoyo_mount_acl *p2 = container_of(b, typeof(*p2), head); + + return tomoyo_same_name_union(&p1->dev_name, &p2->dev_name) && + tomoyo_same_name_union(&p1->dir_name, &p2->dir_name) && + tomoyo_same_name_union(&p1->fs_type, &p2->fs_type) && + tomoyo_same_number_union(&p1->flags, &p2->flags); +} + +/** + * tomoyo_update_mount_acl - Write "struct tomoyo_mount_acl" list. + * + * @param: Pointer to "struct tomoyo_acl_param". + * + * Returns 0 on success, negative value otherwise. + * + * Caller holds tomoyo_read_lock(). + */ +static int tomoyo_update_mount_acl(struct tomoyo_acl_param *param) +{ + struct tomoyo_mount_acl e = { .head.type = TOMOYO_TYPE_MOUNT_ACL }; + int error; + + if (!tomoyo_parse_name_union(param, &e.dev_name) || + !tomoyo_parse_name_union(param, &e.dir_name) || + !tomoyo_parse_name_union(param, &e.fs_type) || + !tomoyo_parse_number_union(param, &e.flags)) + error = -EINVAL; + else + error = tomoyo_update_domain(&e.head, sizeof(e), param, + tomoyo_same_mount_acl, NULL); + tomoyo_put_name_union(&e.dev_name); + tomoyo_put_name_union(&e.dir_name); + tomoyo_put_name_union(&e.fs_type); + tomoyo_put_number_union(&e.flags); + return error; +} + +/** + * tomoyo_write_file - Update file related list. + * + * @param: Pointer to "struct tomoyo_acl_param". + * + * Returns 0 on success, negative value otherwise. + * + * Caller holds tomoyo_read_lock(). + */ +int tomoyo_write_file(struct tomoyo_acl_param *param) +{ + u16 perm = 0; + u8 type; + const char *operation = tomoyo_read_token(param); + + for (type = 0; type < TOMOYO_MAX_PATH_OPERATION; type++) + if (tomoyo_permstr(operation, tomoyo_path_keyword[type])) + perm |= 1 << type; + if (perm) + return tomoyo_update_path_acl(perm, param); + for (type = 0; type < TOMOYO_MAX_PATH2_OPERATION; type++) + if (tomoyo_permstr(operation, + tomoyo_mac_keywords[tomoyo_pp2mac[type]])) + perm |= 1 << type; + if (perm) + return tomoyo_update_path2_acl(perm, param); + for (type = 0; type < TOMOYO_MAX_PATH_NUMBER_OPERATION; type++) + if (tomoyo_permstr(operation, + tomoyo_mac_keywords[tomoyo_pn2mac[type]])) + perm |= 1 << type; + if (perm) + return tomoyo_update_path_number_acl(perm, param); + for (type = 0; type < TOMOYO_MAX_MKDEV_OPERATION; type++) + if (tomoyo_permstr(operation, + tomoyo_mac_keywords[tomoyo_pnnn2mac[type]])) + perm |= 1 << type; + if (perm) + return tomoyo_update_mkdev_acl(perm, param); + if (tomoyo_permstr(operation, + tomoyo_mac_keywords[TOMOYO_MAC_FILE_MOUNT])) + return tomoyo_update_mount_acl(param); + return -EINVAL; +} diff --git a/security/tomoyo/gc.c b/security/tomoyo/gc.c new file mode 100644 index 000000000..026e29ea3 --- /dev/null +++ b/security/tomoyo/gc.c @@ -0,0 +1,670 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * security/tomoyo/gc.c + * + * Copyright (C) 2005-2011 NTT DATA CORPORATION + */ + +#include "common.h" +#include <linux/kthread.h> +#include <linux/slab.h> + +/** + * tomoyo_memory_free - Free memory for elements. + * + * @ptr: Pointer to allocated memory. + * + * Returns nothing. + * + * Caller holds tomoyo_policy_lock mutex. + */ +static inline void tomoyo_memory_free(void *ptr) +{ + tomoyo_memory_used[TOMOYO_MEMORY_POLICY] -= ksize(ptr); + kfree(ptr); +} + +/* The list for "struct tomoyo_io_buffer". */ +static LIST_HEAD(tomoyo_io_buffer_list); +/* Lock for protecting tomoyo_io_buffer_list. */ +static DEFINE_SPINLOCK(tomoyo_io_buffer_list_lock); + +/** + * tomoyo_struct_used_by_io_buffer - Check whether the list element is used by /sys/kernel/security/tomoyo/ users or not. + * + * @element: Pointer to "struct list_head". + * + * Returns true if @element is used by /sys/kernel/security/tomoyo/ users, + * false otherwise. + */ +static bool tomoyo_struct_used_by_io_buffer(const struct list_head *element) +{ + struct tomoyo_io_buffer *head; + bool in_use = false; + + spin_lock(&tomoyo_io_buffer_list_lock); + list_for_each_entry(head, &tomoyo_io_buffer_list, list) { + head->users++; + spin_unlock(&tomoyo_io_buffer_list_lock); + mutex_lock(&head->io_sem); + if (head->r.domain == element || head->r.group == element || + head->r.acl == element || &head->w.domain->list == element) + in_use = true; + mutex_unlock(&head->io_sem); + spin_lock(&tomoyo_io_buffer_list_lock); + head->users--; + if (in_use) + break; + } + spin_unlock(&tomoyo_io_buffer_list_lock); + return in_use; +} + +/** + * tomoyo_name_used_by_io_buffer - Check whether the string is used by /sys/kernel/security/tomoyo/ users or not. + * + * @string: String to check. + * + * Returns true if @string is used by /sys/kernel/security/tomoyo/ users, + * false otherwise. + */ +static bool tomoyo_name_used_by_io_buffer(const char *string) +{ + struct tomoyo_io_buffer *head; + const size_t size = strlen(string) + 1; + bool in_use = false; + + spin_lock(&tomoyo_io_buffer_list_lock); + list_for_each_entry(head, &tomoyo_io_buffer_list, list) { + int i; + + head->users++; + spin_unlock(&tomoyo_io_buffer_list_lock); + mutex_lock(&head->io_sem); + for (i = 0; i < TOMOYO_MAX_IO_READ_QUEUE; i++) { + const char *w = head->r.w[i]; + + if (w < string || w > string + size) + continue; + in_use = true; + break; + } + mutex_unlock(&head->io_sem); + spin_lock(&tomoyo_io_buffer_list_lock); + head->users--; + if (in_use) + break; + } + spin_unlock(&tomoyo_io_buffer_list_lock); + return in_use; +} + +/** + * tomoyo_del_transition_control - Delete members in "struct tomoyo_transition_control". + * + * @element: Pointer to "struct list_head". + * + * Returns nothing. + */ +static inline void tomoyo_del_transition_control(struct list_head *element) +{ + struct tomoyo_transition_control *ptr = + container_of(element, typeof(*ptr), head.list); + + tomoyo_put_name(ptr->domainname); + tomoyo_put_name(ptr->program); +} + +/** + * tomoyo_del_aggregator - Delete members in "struct tomoyo_aggregator". + * + * @element: Pointer to "struct list_head". + * + * Returns nothing. + */ +static inline void tomoyo_del_aggregator(struct list_head *element) +{ + struct tomoyo_aggregator *ptr = + container_of(element, typeof(*ptr), head.list); + + tomoyo_put_name(ptr->original_name); + tomoyo_put_name(ptr->aggregated_name); +} + +/** + * tomoyo_del_manager - Delete members in "struct tomoyo_manager". + * + * @element: Pointer to "struct list_head". + * + * Returns nothing. + */ +static inline void tomoyo_del_manager(struct list_head *element) +{ + struct tomoyo_manager *ptr = + container_of(element, typeof(*ptr), head.list); + + tomoyo_put_name(ptr->manager); +} + +/** + * tomoyo_del_acl - Delete members in "struct tomoyo_acl_info". + * + * @element: Pointer to "struct list_head". + * + * Returns nothing. + */ +static void tomoyo_del_acl(struct list_head *element) +{ + struct tomoyo_acl_info *acl = + container_of(element, typeof(*acl), list); + + tomoyo_put_condition(acl->cond); + switch (acl->type) { + case TOMOYO_TYPE_PATH_ACL: + { + struct tomoyo_path_acl *entry + = container_of(acl, typeof(*entry), head); + tomoyo_put_name_union(&entry->name); + } + break; + case TOMOYO_TYPE_PATH2_ACL: + { + struct tomoyo_path2_acl *entry + = container_of(acl, typeof(*entry), head); + tomoyo_put_name_union(&entry->name1); + tomoyo_put_name_union(&entry->name2); + } + break; + case TOMOYO_TYPE_PATH_NUMBER_ACL: + { + struct tomoyo_path_number_acl *entry + = container_of(acl, typeof(*entry), head); + tomoyo_put_name_union(&entry->name); + tomoyo_put_number_union(&entry->number); + } + break; + case TOMOYO_TYPE_MKDEV_ACL: + { + struct tomoyo_mkdev_acl *entry + = container_of(acl, typeof(*entry), head); + tomoyo_put_name_union(&entry->name); + tomoyo_put_number_union(&entry->mode); + tomoyo_put_number_union(&entry->major); + tomoyo_put_number_union(&entry->minor); + } + break; + case TOMOYO_TYPE_MOUNT_ACL: + { + struct tomoyo_mount_acl *entry + = container_of(acl, typeof(*entry), head); + tomoyo_put_name_union(&entry->dev_name); + tomoyo_put_name_union(&entry->dir_name); + tomoyo_put_name_union(&entry->fs_type); + tomoyo_put_number_union(&entry->flags); + } + break; + case TOMOYO_TYPE_ENV_ACL: + { + struct tomoyo_env_acl *entry = + container_of(acl, typeof(*entry), head); + + tomoyo_put_name(entry->env); + } + break; + case TOMOYO_TYPE_INET_ACL: + { + struct tomoyo_inet_acl *entry = + container_of(acl, typeof(*entry), head); + + tomoyo_put_group(entry->address.group); + tomoyo_put_number_union(&entry->port); + } + break; + case TOMOYO_TYPE_UNIX_ACL: + { + struct tomoyo_unix_acl *entry = + container_of(acl, typeof(*entry), head); + + tomoyo_put_name_union(&entry->name); + } + break; + case TOMOYO_TYPE_MANUAL_TASK_ACL: + { + struct tomoyo_task_acl *entry = + container_of(acl, typeof(*entry), head); + + tomoyo_put_name(entry->domainname); + } + break; + } +} + +/** + * tomoyo_del_domain - Delete members in "struct tomoyo_domain_info". + * + * @element: Pointer to "struct list_head". + * + * Returns nothing. + * + * Caller holds tomoyo_policy_lock mutex. + */ +static inline void tomoyo_del_domain(struct list_head *element) +{ + struct tomoyo_domain_info *domain = + container_of(element, typeof(*domain), list); + struct tomoyo_acl_info *acl; + struct tomoyo_acl_info *tmp; + + /* + * Since this domain is referenced from neither + * "struct tomoyo_io_buffer" nor "struct cred"->security, we can delete + * elements without checking for is_deleted flag. + */ + list_for_each_entry_safe(acl, tmp, &domain->acl_info_list, list) { + tomoyo_del_acl(&acl->list); + tomoyo_memory_free(acl); + } + tomoyo_put_name(domain->domainname); +} + +/** + * tomoyo_del_condition - Delete members in "struct tomoyo_condition". + * + * @element: Pointer to "struct list_head". + * + * Returns nothing. + */ +void tomoyo_del_condition(struct list_head *element) +{ + struct tomoyo_condition *cond = container_of(element, typeof(*cond), + head.list); + const u16 condc = cond->condc; + const u16 numbers_count = cond->numbers_count; + const u16 names_count = cond->names_count; + const u16 argc = cond->argc; + const u16 envc = cond->envc; + unsigned int i; + const struct tomoyo_condition_element *condp + = (const struct tomoyo_condition_element *) (cond + 1); + struct tomoyo_number_union *numbers_p + = (struct tomoyo_number_union *) (condp + condc); + struct tomoyo_name_union *names_p + = (struct tomoyo_name_union *) (numbers_p + numbers_count); + const struct tomoyo_argv *argv + = (const struct tomoyo_argv *) (names_p + names_count); + const struct tomoyo_envp *envp + = (const struct tomoyo_envp *) (argv + argc); + + for (i = 0; i < numbers_count; i++) + tomoyo_put_number_union(numbers_p++); + for (i = 0; i < names_count; i++) + tomoyo_put_name_union(names_p++); + for (i = 0; i < argc; argv++, i++) + tomoyo_put_name(argv->value); + for (i = 0; i < envc; envp++, i++) { + tomoyo_put_name(envp->name); + tomoyo_put_name(envp->value); + } +} + +/** + * tomoyo_del_name - Delete members in "struct tomoyo_name". + * + * @element: Pointer to "struct list_head". + * + * Returns nothing. + */ +static inline void tomoyo_del_name(struct list_head *element) +{ + /* Nothing to do. */ +} + +/** + * tomoyo_del_path_group - Delete members in "struct tomoyo_path_group". + * + * @element: Pointer to "struct list_head". + * + * Returns nothing. + */ +static inline void tomoyo_del_path_group(struct list_head *element) +{ + struct tomoyo_path_group *member = + container_of(element, typeof(*member), head.list); + + tomoyo_put_name(member->member_name); +} + +/** + * tomoyo_del_group - Delete "struct tomoyo_group". + * + * @element: Pointer to "struct list_head". + * + * Returns nothing. + */ +static inline void tomoyo_del_group(struct list_head *element) +{ + struct tomoyo_group *group = + container_of(element, typeof(*group), head.list); + + tomoyo_put_name(group->group_name); +} + +/** + * tomoyo_del_address_group - Delete members in "struct tomoyo_address_group". + * + * @element: Pointer to "struct list_head". + * + * Returns nothing. + */ +static inline void tomoyo_del_address_group(struct list_head *element) +{ + /* Nothing to do. */ +} + +/** + * tomoyo_del_number_group - Delete members in "struct tomoyo_number_group". + * + * @element: Pointer to "struct list_head". + * + * Returns nothing. + */ +static inline void tomoyo_del_number_group(struct list_head *element) +{ + /* Nothing to do. */ +} + +/** + * tomoyo_try_to_gc - Try to kfree() an entry. + * + * @type: One of values in "enum tomoyo_policy_id". + * @element: Pointer to "struct list_head". + * + * Returns nothing. + * + * Caller holds tomoyo_policy_lock mutex. + */ +static void tomoyo_try_to_gc(const enum tomoyo_policy_id type, + struct list_head *element) +{ + /* + * __list_del_entry() guarantees that the list element became no longer + * reachable from the list which the element was originally on (e.g. + * tomoyo_domain_list). Also, synchronize_srcu() guarantees that the + * list element became no longer referenced by syscall users. + */ + __list_del_entry(element); + mutex_unlock(&tomoyo_policy_lock); + synchronize_srcu(&tomoyo_ss); + /* + * However, there are two users which may still be using the list + * element. We need to defer until both users forget this element. + * + * Don't kfree() until "struct tomoyo_io_buffer"->r.{domain,group,acl} + * and "struct tomoyo_io_buffer"->w.domain forget this element. + */ + if (tomoyo_struct_used_by_io_buffer(element)) + goto reinject; + switch (type) { + case TOMOYO_ID_TRANSITION_CONTROL: + tomoyo_del_transition_control(element); + break; + case TOMOYO_ID_MANAGER: + tomoyo_del_manager(element); + break; + case TOMOYO_ID_AGGREGATOR: + tomoyo_del_aggregator(element); + break; + case TOMOYO_ID_GROUP: + tomoyo_del_group(element); + break; + case TOMOYO_ID_PATH_GROUP: + tomoyo_del_path_group(element); + break; + case TOMOYO_ID_ADDRESS_GROUP: + tomoyo_del_address_group(element); + break; + case TOMOYO_ID_NUMBER_GROUP: + tomoyo_del_number_group(element); + break; + case TOMOYO_ID_CONDITION: + tomoyo_del_condition(element); + break; + case TOMOYO_ID_NAME: + /* + * Don't kfree() until all "struct tomoyo_io_buffer"->r.w[] + * forget this element. + */ + if (tomoyo_name_used_by_io_buffer + (container_of(element, typeof(struct tomoyo_name), + head.list)->entry.name)) + goto reinject; + tomoyo_del_name(element); + break; + case TOMOYO_ID_ACL: + tomoyo_del_acl(element); + break; + case TOMOYO_ID_DOMAIN: + /* + * Don't kfree() until all "struct cred"->security forget this + * element. + */ + if (atomic_read(&container_of + (element, typeof(struct tomoyo_domain_info), + list)->users)) + goto reinject; + break; + case TOMOYO_MAX_POLICY: + break; + } + mutex_lock(&tomoyo_policy_lock); + if (type == TOMOYO_ID_DOMAIN) + tomoyo_del_domain(element); + tomoyo_memory_free(element); + return; +reinject: + /* + * We can safely reinject this element here because + * (1) Appending list elements and removing list elements are protected + * by tomoyo_policy_lock mutex. + * (2) Only this function removes list elements and this function is + * exclusively executed by tomoyo_gc_mutex mutex. + * are true. + */ + mutex_lock(&tomoyo_policy_lock); + list_add_rcu(element, element->prev); +} + +/** + * tomoyo_collect_member - Delete elements with "struct tomoyo_acl_head". + * + * @id: One of values in "enum tomoyo_policy_id". + * @member_list: Pointer to "struct list_head". + * + * Returns nothing. + */ +static void tomoyo_collect_member(const enum tomoyo_policy_id id, + struct list_head *member_list) +{ + struct tomoyo_acl_head *member; + struct tomoyo_acl_head *tmp; + + list_for_each_entry_safe(member, tmp, member_list, list) { + if (!member->is_deleted) + continue; + member->is_deleted = TOMOYO_GC_IN_PROGRESS; + tomoyo_try_to_gc(id, &member->list); + } +} + +/** + * tomoyo_collect_acl - Delete elements in "struct tomoyo_domain_info". + * + * @list: Pointer to "struct list_head". + * + * Returns nothing. + */ +static void tomoyo_collect_acl(struct list_head *list) +{ + struct tomoyo_acl_info *acl; + struct tomoyo_acl_info *tmp; + + list_for_each_entry_safe(acl, tmp, list, list) { + if (!acl->is_deleted) + continue; + acl->is_deleted = TOMOYO_GC_IN_PROGRESS; + tomoyo_try_to_gc(TOMOYO_ID_ACL, &acl->list); + } +} + +/** + * tomoyo_collect_entry - Try to kfree() deleted elements. + * + * Returns nothing. + */ +static void tomoyo_collect_entry(void) +{ + int i; + enum tomoyo_policy_id id; + struct tomoyo_policy_namespace *ns; + + mutex_lock(&tomoyo_policy_lock); + { + struct tomoyo_domain_info *domain; + struct tomoyo_domain_info *tmp; + + list_for_each_entry_safe(domain, tmp, &tomoyo_domain_list, + list) { + tomoyo_collect_acl(&domain->acl_info_list); + if (!domain->is_deleted || atomic_read(&domain->users)) + continue; + tomoyo_try_to_gc(TOMOYO_ID_DOMAIN, &domain->list); + } + } + list_for_each_entry(ns, &tomoyo_namespace_list, namespace_list) { + for (id = 0; id < TOMOYO_MAX_POLICY; id++) + tomoyo_collect_member(id, &ns->policy_list[id]); + for (i = 0; i < TOMOYO_MAX_ACL_GROUPS; i++) + tomoyo_collect_acl(&ns->acl_group[i]); + } + { + struct tomoyo_shared_acl_head *ptr; + struct tomoyo_shared_acl_head *tmp; + + list_for_each_entry_safe(ptr, tmp, &tomoyo_condition_list, + list) { + if (atomic_read(&ptr->users) > 0) + continue; + atomic_set(&ptr->users, TOMOYO_GC_IN_PROGRESS); + tomoyo_try_to_gc(TOMOYO_ID_CONDITION, &ptr->list); + } + } + list_for_each_entry(ns, &tomoyo_namespace_list, namespace_list) { + for (i = 0; i < TOMOYO_MAX_GROUP; i++) { + struct list_head *list = &ns->group_list[i]; + struct tomoyo_group *group; + struct tomoyo_group *tmp; + + switch (i) { + case 0: + id = TOMOYO_ID_PATH_GROUP; + break; + case 1: + id = TOMOYO_ID_NUMBER_GROUP; + break; + default: + id = TOMOYO_ID_ADDRESS_GROUP; + break; + } + list_for_each_entry_safe(group, tmp, list, head.list) { + tomoyo_collect_member(id, &group->member_list); + if (!list_empty(&group->member_list) || + atomic_read(&group->head.users) > 0) + continue; + atomic_set(&group->head.users, + TOMOYO_GC_IN_PROGRESS); + tomoyo_try_to_gc(TOMOYO_ID_GROUP, + &group->head.list); + } + } + } + for (i = 0; i < TOMOYO_MAX_HASH; i++) { + struct list_head *list = &tomoyo_name_list[i]; + struct tomoyo_shared_acl_head *ptr; + struct tomoyo_shared_acl_head *tmp; + + list_for_each_entry_safe(ptr, tmp, list, list) { + if (atomic_read(&ptr->users) > 0) + continue; + atomic_set(&ptr->users, TOMOYO_GC_IN_PROGRESS); + tomoyo_try_to_gc(TOMOYO_ID_NAME, &ptr->list); + } + } + mutex_unlock(&tomoyo_policy_lock); +} + +/** + * tomoyo_gc_thread - Garbage collector thread function. + * + * @unused: Unused. + * + * Returns 0. + */ +static int tomoyo_gc_thread(void *unused) +{ + /* Garbage collector thread is exclusive. */ + static DEFINE_MUTEX(tomoyo_gc_mutex); + + if (!mutex_trylock(&tomoyo_gc_mutex)) + goto out; + tomoyo_collect_entry(); + { + struct tomoyo_io_buffer *head; + struct tomoyo_io_buffer *tmp; + + spin_lock(&tomoyo_io_buffer_list_lock); + list_for_each_entry_safe(head, tmp, &tomoyo_io_buffer_list, + list) { + if (head->users) + continue; + list_del(&head->list); + kfree(head->read_buf); + kfree(head->write_buf); + kfree(head); + } + spin_unlock(&tomoyo_io_buffer_list_lock); + } + mutex_unlock(&tomoyo_gc_mutex); +out: + /* This acts as do_exit(0). */ + return 0; +} + +/** + * tomoyo_notify_gc - Register/unregister /sys/kernel/security/tomoyo/ users. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * @is_register: True if register, false if unregister. + * + * Returns nothing. + */ +void tomoyo_notify_gc(struct tomoyo_io_buffer *head, const bool is_register) +{ + bool is_write = false; + + spin_lock(&tomoyo_io_buffer_list_lock); + if (is_register) { + head->users = 1; + list_add(&head->list, &tomoyo_io_buffer_list); + } else { + is_write = head->write_buf != NULL; + if (!--head->users) { + list_del(&head->list); + kfree(head->read_buf); + kfree(head->write_buf); + kfree(head); + } + } + spin_unlock(&tomoyo_io_buffer_list_lock); + if (is_write) + kthread_run(tomoyo_gc_thread, NULL, "GC for TOMOYO"); +} diff --git a/security/tomoyo/group.c b/security/tomoyo/group.c new file mode 100644 index 000000000..1cecdd797 --- /dev/null +++ b/security/tomoyo/group.c @@ -0,0 +1,209 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * security/tomoyo/group.c + * + * Copyright (C) 2005-2011 NTT DATA CORPORATION + */ + +#include <linux/slab.h> +#include <linux/rculist.h> + +#include "common.h" + +/** + * tomoyo_same_path_group - Check for duplicated "struct tomoyo_path_group" entry. + * + * @a: Pointer to "struct tomoyo_acl_head". + * @b: Pointer to "struct tomoyo_acl_head". + * + * Returns true if @a == @b, false otherwise. + */ +static bool tomoyo_same_path_group(const struct tomoyo_acl_head *a, + const struct tomoyo_acl_head *b) +{ + return container_of(a, struct tomoyo_path_group, head)->member_name == + container_of(b, struct tomoyo_path_group, head)->member_name; +} + +/** + * tomoyo_same_number_group - Check for duplicated "struct tomoyo_number_group" entry. + * + * @a: Pointer to "struct tomoyo_acl_head". + * @b: Pointer to "struct tomoyo_acl_head". + * + * Returns true if @a == @b, false otherwise. + */ +static bool tomoyo_same_number_group(const struct tomoyo_acl_head *a, + const struct tomoyo_acl_head *b) +{ + return !memcmp(&container_of(a, struct tomoyo_number_group, head) + ->number, + &container_of(b, struct tomoyo_number_group, head) + ->number, + sizeof(container_of(a, struct tomoyo_number_group, head) + ->number)); +} + +/** + * tomoyo_same_address_group - Check for duplicated "struct tomoyo_address_group" entry. + * + * @a: Pointer to "struct tomoyo_acl_head". + * @b: Pointer to "struct tomoyo_acl_head". + * + * Returns true if @a == @b, false otherwise. + */ +static bool tomoyo_same_address_group(const struct tomoyo_acl_head *a, + const struct tomoyo_acl_head *b) +{ + const struct tomoyo_address_group *p1 = container_of(a, typeof(*p1), + head); + const struct tomoyo_address_group *p2 = container_of(b, typeof(*p2), + head); + + return tomoyo_same_ipaddr_union(&p1->address, &p2->address); +} + +/** + * tomoyo_write_group - Write "struct tomoyo_path_group"/"struct tomoyo_number_group"/"struct tomoyo_address_group" list. + * + * @param: Pointer to "struct tomoyo_acl_param". + * @type: Type of this group. + * + * Returns 0 on success, negative value otherwise. + */ +int tomoyo_write_group(struct tomoyo_acl_param *param, const u8 type) +{ + struct tomoyo_group *group = tomoyo_get_group(param, type); + int error = -EINVAL; + + if (!group) + return -ENOMEM; + param->list = &group->member_list; + if (type == TOMOYO_PATH_GROUP) { + struct tomoyo_path_group e = { }; + + e.member_name = tomoyo_get_name(tomoyo_read_token(param)); + if (!e.member_name) { + error = -ENOMEM; + goto out; + } + error = tomoyo_update_policy(&e.head, sizeof(e), param, + tomoyo_same_path_group); + tomoyo_put_name(e.member_name); + } else if (type == TOMOYO_NUMBER_GROUP) { + struct tomoyo_number_group e = { }; + + if (param->data[0] == '@' || + !tomoyo_parse_number_union(param, &e.number)) + goto out; + error = tomoyo_update_policy(&e.head, sizeof(e), param, + tomoyo_same_number_group); + /* + * tomoyo_put_number_union() is not needed because + * param->data[0] != '@'. + */ + } else { + struct tomoyo_address_group e = { }; + + if (param->data[0] == '@' || + !tomoyo_parse_ipaddr_union(param, &e.address)) + goto out; + error = tomoyo_update_policy(&e.head, sizeof(e), param, + tomoyo_same_address_group); + } +out: + tomoyo_put_group(group); + return error; +} + +/** + * tomoyo_path_matches_group - Check whether the given pathname matches members of the given pathname group. + * + * @pathname: The name of pathname. + * @group: Pointer to "struct tomoyo_path_group". + * + * Returns matched member's pathname if @pathname matches pathnames in @group, + * NULL otherwise. + * + * Caller holds tomoyo_read_lock(). + */ +const struct tomoyo_path_info * +tomoyo_path_matches_group(const struct tomoyo_path_info *pathname, + const struct tomoyo_group *group) +{ + struct tomoyo_path_group *member; + + list_for_each_entry_rcu(member, &group->member_list, head.list, + srcu_read_lock_held(&tomoyo_ss)) { + if (member->head.is_deleted) + continue; + if (!tomoyo_path_matches_pattern(pathname, member->member_name)) + continue; + return member->member_name; + } + return NULL; +} + +/** + * tomoyo_number_matches_group - Check whether the given number matches members of the given number group. + * + * @min: Min number. + * @max: Max number. + * @group: Pointer to "struct tomoyo_number_group". + * + * Returns true if @min and @max partially overlaps @group, false otherwise. + * + * Caller holds tomoyo_read_lock(). + */ +bool tomoyo_number_matches_group(const unsigned long min, + const unsigned long max, + const struct tomoyo_group *group) +{ + struct tomoyo_number_group *member; + bool matched = false; + + list_for_each_entry_rcu(member, &group->member_list, head.list, + srcu_read_lock_held(&tomoyo_ss)) { + if (member->head.is_deleted) + continue; + if (min > member->number.values[1] || + max < member->number.values[0]) + continue; + matched = true; + break; + } + return matched; +} + +/** + * tomoyo_address_matches_group - Check whether the given address matches members of the given address group. + * + * @is_ipv6: True if @address is an IPv6 address. + * @address: An IPv4 or IPv6 address. + * @group: Pointer to "struct tomoyo_address_group". + * + * Returns true if @address matches addresses in @group group, false otherwise. + * + * Caller holds tomoyo_read_lock(). + */ +bool tomoyo_address_matches_group(const bool is_ipv6, const __be32 *address, + const struct tomoyo_group *group) +{ + struct tomoyo_address_group *member; + bool matched = false; + const u8 size = is_ipv6 ? 16 : 4; + + list_for_each_entry_rcu(member, &group->member_list, head.list, + srcu_read_lock_held(&tomoyo_ss)) { + if (member->head.is_deleted) + continue; + if (member->address.is_ipv6 != is_ipv6) + continue; + if (memcmp(&member->address.ip[0], address, size) > 0 || + memcmp(address, &member->address.ip[1], size) > 0) + continue; + matched = true; + break; + } + return matched; +} diff --git a/security/tomoyo/load_policy.c b/security/tomoyo/load_policy.c new file mode 100644 index 000000000..363b65be8 --- /dev/null +++ b/security/tomoyo/load_policy.c @@ -0,0 +1,110 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * security/tomoyo/load_policy.c + * + * Copyright (C) 2005-2011 NTT DATA CORPORATION + */ + +#include "common.h" + +#ifndef CONFIG_SECURITY_TOMOYO_OMIT_USERSPACE_LOADER + +/* + * Path to the policy loader. (default = CONFIG_SECURITY_TOMOYO_POLICY_LOADER) + */ +static const char *tomoyo_loader; + +/** + * tomoyo_loader_setup - Set policy loader. + * + * @str: Program to use as a policy loader (e.g. /sbin/tomoyo-init ). + * + * Returns 0. + */ +static int __init tomoyo_loader_setup(char *str) +{ + tomoyo_loader = str; + return 1; +} + +__setup("TOMOYO_loader=", tomoyo_loader_setup); + +/** + * tomoyo_policy_loader_exists - Check whether /sbin/tomoyo-init exists. + * + * Returns true if /sbin/tomoyo-init exists, false otherwise. + */ +static bool tomoyo_policy_loader_exists(void) +{ + struct path path; + + if (!tomoyo_loader) + tomoyo_loader = CONFIG_SECURITY_TOMOYO_POLICY_LOADER; + if (kern_path(tomoyo_loader, LOOKUP_FOLLOW, &path)) { + pr_info("Not activating Mandatory Access Control as %s does not exist.\n", + tomoyo_loader); + return false; + } + path_put(&path); + return true; +} + +/* + * Path to the trigger. (default = CONFIG_SECURITY_TOMOYO_ACTIVATION_TRIGGER) + */ +static const char *tomoyo_trigger; + +/** + * tomoyo_trigger_setup - Set trigger for activation. + * + * @str: Program to use as an activation trigger (e.g. /sbin/init ). + * + * Returns 0. + */ +static int __init tomoyo_trigger_setup(char *str) +{ + tomoyo_trigger = str; + return 1; +} + +__setup("TOMOYO_trigger=", tomoyo_trigger_setup); + +/** + * tomoyo_load_policy - Run external policy loader to load policy. + * + * @filename: The program about to start. + * + * This function checks whether @filename is /sbin/init , and if so + * invoke /sbin/tomoyo-init and wait for the termination of /sbin/tomoyo-init + * and then continues invocation of /sbin/init. + * /sbin/tomoyo-init reads policy files in /etc/tomoyo/ directory and + * writes to /sys/kernel/security/tomoyo/ interfaces. + * + * Returns nothing. + */ +void tomoyo_load_policy(const char *filename) +{ + static bool done; + char *argv[2]; + char *envp[3]; + + if (tomoyo_policy_loaded || done) + return; + if (!tomoyo_trigger) + tomoyo_trigger = CONFIG_SECURITY_TOMOYO_ACTIVATION_TRIGGER; + if (strcmp(filename, tomoyo_trigger)) + return; + if (!tomoyo_policy_loader_exists()) + return; + done = true; + pr_info("Calling %s to load policy. Please wait.\n", tomoyo_loader); + argv[0] = (char *) tomoyo_loader; + argv[1] = NULL; + envp[0] = "HOME=/"; + envp[1] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin"; + envp[2] = NULL; + call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC); + tomoyo_check_profile(); +} + +#endif diff --git a/security/tomoyo/memory.c b/security/tomoyo/memory.c new file mode 100644 index 000000000..1b570bde7 --- /dev/null +++ b/security/tomoyo/memory.c @@ -0,0 +1,207 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * security/tomoyo/memory.c + * + * Copyright (C) 2005-2011 NTT DATA CORPORATION + */ + +#include <linux/hash.h> +#include <linux/slab.h> +#include "common.h" + +/** + * tomoyo_warn_oom - Print out of memory warning message. + * + * @function: Function's name. + */ +void tomoyo_warn_oom(const char *function) +{ + /* Reduce error messages. */ + static pid_t tomoyo_last_pid; + const pid_t pid = current->pid; + + if (tomoyo_last_pid != pid) { + pr_warn("ERROR: Out of memory at %s.\n", function); + tomoyo_last_pid = pid; + } + if (!tomoyo_policy_loaded) + panic("MAC Initialization failed.\n"); +} + +/* Memoy currently used by policy/audit log/query. */ +unsigned int tomoyo_memory_used[TOMOYO_MAX_MEMORY_STAT]; +/* Memory quota for "policy"/"audit log"/"query". */ +unsigned int tomoyo_memory_quota[TOMOYO_MAX_MEMORY_STAT]; + +/** + * tomoyo_memory_ok - Check memory quota. + * + * @ptr: Pointer to allocated memory. + * + * Returns true on success, false otherwise. + * + * Returns true if @ptr is not NULL and quota not exceeded, false otherwise. + * + * Caller holds tomoyo_policy_lock mutex. + */ +bool tomoyo_memory_ok(void *ptr) +{ + if (ptr) { + const size_t s = ksize(ptr); + + tomoyo_memory_used[TOMOYO_MEMORY_POLICY] += s; + if (!tomoyo_memory_quota[TOMOYO_MEMORY_POLICY] || + tomoyo_memory_used[TOMOYO_MEMORY_POLICY] <= + tomoyo_memory_quota[TOMOYO_MEMORY_POLICY]) + return true; + tomoyo_memory_used[TOMOYO_MEMORY_POLICY] -= s; + } + tomoyo_warn_oom(__func__); + return false; +} + +/** + * tomoyo_commit_ok - Check memory quota. + * + * @data: Data to copy from. + * @size: Size in byte. + * + * Returns pointer to allocated memory on success, NULL otherwise. + * @data is zero-cleared on success. + * + * Caller holds tomoyo_policy_lock mutex. + */ +void *tomoyo_commit_ok(void *data, const unsigned int size) +{ + void *ptr = kzalloc(size, GFP_NOFS | __GFP_NOWARN); + + if (tomoyo_memory_ok(ptr)) { + memmove(ptr, data, size); + memset(data, 0, size); + return ptr; + } + kfree(ptr); + return NULL; +} + +/** + * tomoyo_get_group - Allocate memory for "struct tomoyo_path_group"/"struct tomoyo_number_group". + * + * @param: Pointer to "struct tomoyo_acl_param". + * @idx: Index number. + * + * Returns pointer to "struct tomoyo_group" on success, NULL otherwise. + */ +struct tomoyo_group *tomoyo_get_group(struct tomoyo_acl_param *param, + const u8 idx) +{ + struct tomoyo_group e = { }; + struct tomoyo_group *group = NULL; + struct list_head *list; + const char *group_name = tomoyo_read_token(param); + bool found = false; + + if (!tomoyo_correct_word(group_name) || idx >= TOMOYO_MAX_GROUP) + return NULL; + e.group_name = tomoyo_get_name(group_name); + if (!e.group_name) + return NULL; + if (mutex_lock_interruptible(&tomoyo_policy_lock)) + goto out; + list = ¶m->ns->group_list[idx]; + list_for_each_entry(group, list, head.list) { + if (e.group_name != group->group_name || + atomic_read(&group->head.users) == TOMOYO_GC_IN_PROGRESS) + continue; + atomic_inc(&group->head.users); + found = true; + break; + } + if (!found) { + struct tomoyo_group *entry = tomoyo_commit_ok(&e, sizeof(e)); + + if (entry) { + INIT_LIST_HEAD(&entry->member_list); + atomic_set(&entry->head.users, 1); + list_add_tail_rcu(&entry->head.list, list); + group = entry; + found = true; + } + } + mutex_unlock(&tomoyo_policy_lock); +out: + tomoyo_put_name(e.group_name); + return found ? group : NULL; +} + +/* + * tomoyo_name_list is used for holding string data used by TOMOYO. + * Since same string data is likely used for multiple times (e.g. + * "/lib/libc-2.5.so"), TOMOYO shares string data in the form of + * "const struct tomoyo_path_info *". + */ +struct list_head tomoyo_name_list[TOMOYO_MAX_HASH]; + +/** + * tomoyo_get_name - Allocate permanent memory for string data. + * + * @name: The string to store into the permernent memory. + * + * Returns pointer to "struct tomoyo_path_info" on success, NULL otherwise. + */ +const struct tomoyo_path_info *tomoyo_get_name(const char *name) +{ + struct tomoyo_name *ptr; + unsigned int hash; + int len; + struct list_head *head; + + if (!name) + return NULL; + len = strlen(name) + 1; + hash = full_name_hash(NULL, (const unsigned char *) name, len - 1); + head = &tomoyo_name_list[hash_long(hash, TOMOYO_HASH_BITS)]; + if (mutex_lock_interruptible(&tomoyo_policy_lock)) + return NULL; + list_for_each_entry(ptr, head, head.list) { + if (hash != ptr->entry.hash || strcmp(name, ptr->entry.name) || + atomic_read(&ptr->head.users) == TOMOYO_GC_IN_PROGRESS) + continue; + atomic_inc(&ptr->head.users); + goto out; + } + ptr = kzalloc(sizeof(*ptr) + len, GFP_NOFS | __GFP_NOWARN); + if (tomoyo_memory_ok(ptr)) { + ptr->entry.name = ((char *) ptr) + sizeof(*ptr); + memmove((char *) ptr->entry.name, name, len); + atomic_set(&ptr->head.users, 1); + tomoyo_fill_path_info(&ptr->entry); + list_add_tail(&ptr->head.list, head); + } else { + kfree(ptr); + ptr = NULL; + } +out: + mutex_unlock(&tomoyo_policy_lock); + return ptr ? &ptr->entry : NULL; +} + +/* Initial namespace.*/ +struct tomoyo_policy_namespace tomoyo_kernel_namespace; + +/** + * tomoyo_mm_init - Initialize mm related code. + */ +void __init tomoyo_mm_init(void) +{ + int idx; + + for (idx = 0; idx < TOMOYO_MAX_HASH; idx++) + INIT_LIST_HEAD(&tomoyo_name_list[idx]); + tomoyo_kernel_namespace.name = "<kernel>"; + tomoyo_init_policy_namespace(&tomoyo_kernel_namespace); + tomoyo_kernel_domain.ns = &tomoyo_kernel_namespace; + INIT_LIST_HEAD(&tomoyo_kernel_domain.acl_info_list); + tomoyo_kernel_domain.domainname = tomoyo_get_name("<kernel>"); + list_add_tail_rcu(&tomoyo_kernel_domain.list, &tomoyo_domain_list); +} diff --git a/security/tomoyo/mount.c b/security/tomoyo/mount.c new file mode 100644 index 000000000..2755971f5 --- /dev/null +++ b/security/tomoyo/mount.c @@ -0,0 +1,240 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * security/tomoyo/mount.c + * + * Copyright (C) 2005-2011 NTT DATA CORPORATION + */ + +#include <linux/slab.h> +#include <uapi/linux/mount.h> +#include "common.h" + +/* String table for special mount operations. */ +static const char * const tomoyo_mounts[TOMOYO_MAX_SPECIAL_MOUNT] = { + [TOMOYO_MOUNT_BIND] = "--bind", + [TOMOYO_MOUNT_MOVE] = "--move", + [TOMOYO_MOUNT_REMOUNT] = "--remount", + [TOMOYO_MOUNT_MAKE_UNBINDABLE] = "--make-unbindable", + [TOMOYO_MOUNT_MAKE_PRIVATE] = "--make-private", + [TOMOYO_MOUNT_MAKE_SLAVE] = "--make-slave", + [TOMOYO_MOUNT_MAKE_SHARED] = "--make-shared", +}; + +/** + * tomoyo_audit_mount_log - Audit mount log. + * + * @r: Pointer to "struct tomoyo_request_info". + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_audit_mount_log(struct tomoyo_request_info *r) +{ + return tomoyo_supervisor(r, "file mount %s %s %s 0x%lX\n", + r->param.mount.dev->name, + r->param.mount.dir->name, + r->param.mount.type->name, + r->param.mount.flags); +} + +/** + * tomoyo_check_mount_acl - Check permission for path path path number operation. + * + * @r: Pointer to "struct tomoyo_request_info". + * @ptr: Pointer to "struct tomoyo_acl_info". + * + * Returns true if granted, false otherwise. + */ +static bool tomoyo_check_mount_acl(struct tomoyo_request_info *r, + const struct tomoyo_acl_info *ptr) +{ + const struct tomoyo_mount_acl *acl = + container_of(ptr, typeof(*acl), head); + + return tomoyo_compare_number_union(r->param.mount.flags, + &acl->flags) && + tomoyo_compare_name_union(r->param.mount.type, + &acl->fs_type) && + tomoyo_compare_name_union(r->param.mount.dir, + &acl->dir_name) && + (!r->param.mount.need_dev || + tomoyo_compare_name_union(r->param.mount.dev, + &acl->dev_name)); +} + +/** + * tomoyo_mount_acl - Check permission for mount() operation. + * + * @r: Pointer to "struct tomoyo_request_info". + * @dev_name: Name of device file. Maybe NULL. + * @dir: Pointer to "struct path". + * @type: Name of filesystem type. + * @flags: Mount options. + * + * Returns 0 on success, negative value otherwise. + * + * Caller holds tomoyo_read_lock(). + */ +static int tomoyo_mount_acl(struct tomoyo_request_info *r, + const char *dev_name, + const struct path *dir, const char *type, + unsigned long flags) +{ + struct tomoyo_obj_info obj = { }; + struct path path; + struct file_system_type *fstype = NULL; + const char *requested_type = NULL; + const char *requested_dir_name = NULL; + const char *requested_dev_name = NULL; + struct tomoyo_path_info rtype; + struct tomoyo_path_info rdev; + struct tomoyo_path_info rdir; + int need_dev = 0; + int error = -ENOMEM; + + r->obj = &obj; + + /* Get fstype. */ + requested_type = tomoyo_encode(type); + if (!requested_type) + goto out; + rtype.name = requested_type; + tomoyo_fill_path_info(&rtype); + + /* Get mount point. */ + obj.path2 = *dir; + requested_dir_name = tomoyo_realpath_from_path(dir); + if (!requested_dir_name) { + error = -ENOMEM; + goto out; + } + rdir.name = requested_dir_name; + tomoyo_fill_path_info(&rdir); + + /* Compare fs name. */ + if (type == tomoyo_mounts[TOMOYO_MOUNT_REMOUNT]) { + /* dev_name is ignored. */ + } else if (type == tomoyo_mounts[TOMOYO_MOUNT_MAKE_UNBINDABLE] || + type == tomoyo_mounts[TOMOYO_MOUNT_MAKE_PRIVATE] || + type == tomoyo_mounts[TOMOYO_MOUNT_MAKE_SLAVE] || + type == tomoyo_mounts[TOMOYO_MOUNT_MAKE_SHARED]) { + /* dev_name is ignored. */ + } else if (type == tomoyo_mounts[TOMOYO_MOUNT_BIND] || + type == tomoyo_mounts[TOMOYO_MOUNT_MOVE]) { + need_dev = -1; /* dev_name is a directory */ + } else { + fstype = get_fs_type(type); + if (!fstype) { + error = -ENODEV; + goto out; + } + if (fstype->fs_flags & FS_REQUIRES_DEV) + /* dev_name is a block device file. */ + need_dev = 1; + } + if (need_dev) { + /* Get mount point or device file. */ + if (!dev_name || kern_path(dev_name, LOOKUP_FOLLOW, &path)) { + error = -ENOENT; + goto out; + } + obj.path1 = path; + requested_dev_name = tomoyo_realpath_from_path(&path); + if (!requested_dev_name) { + error = -ENOENT; + goto out; + } + } else { + /* Map dev_name to "<NULL>" if no dev_name given. */ + if (!dev_name) + dev_name = "<NULL>"; + requested_dev_name = tomoyo_encode(dev_name); + if (!requested_dev_name) { + error = -ENOMEM; + goto out; + } + } + rdev.name = requested_dev_name; + tomoyo_fill_path_info(&rdev); + r->param_type = TOMOYO_TYPE_MOUNT_ACL; + r->param.mount.need_dev = need_dev; + r->param.mount.dev = &rdev; + r->param.mount.dir = &rdir; + r->param.mount.type = &rtype; + r->param.mount.flags = flags; + do { + tomoyo_check_acl(r, tomoyo_check_mount_acl); + error = tomoyo_audit_mount_log(r); + } while (error == TOMOYO_RETRY_REQUEST); + out: + kfree(requested_dev_name); + kfree(requested_dir_name); + if (fstype) + put_filesystem(fstype); + kfree(requested_type); + /* Drop refcount obtained by kern_path(). */ + if (obj.path1.dentry) + path_put(&obj.path1); + return error; +} + +/** + * tomoyo_mount_permission - Check permission for mount() operation. + * + * @dev_name: Name of device file. Maybe NULL. + * @path: Pointer to "struct path". + * @type: Name of filesystem type. Maybe NULL. + * @flags: Mount options. + * @data_page: Optional data. Maybe NULL. + * + * Returns 0 on success, negative value otherwise. + */ +int tomoyo_mount_permission(const char *dev_name, const struct path *path, + const char *type, unsigned long flags, + void *data_page) +{ + struct tomoyo_request_info r; + int error; + int idx; + + if (tomoyo_init_request_info(&r, NULL, TOMOYO_MAC_FILE_MOUNT) + == TOMOYO_CONFIG_DISABLED) + return 0; + if ((flags & MS_MGC_MSK) == MS_MGC_VAL) + flags &= ~MS_MGC_MSK; + if (flags & MS_REMOUNT) { + type = tomoyo_mounts[TOMOYO_MOUNT_REMOUNT]; + flags &= ~MS_REMOUNT; + } else if (flags & MS_BIND) { + type = tomoyo_mounts[TOMOYO_MOUNT_BIND]; + flags &= ~MS_BIND; + } else if (flags & MS_SHARED) { + if (flags & (MS_PRIVATE | MS_SLAVE | MS_UNBINDABLE)) + return -EINVAL; + type = tomoyo_mounts[TOMOYO_MOUNT_MAKE_SHARED]; + flags &= ~MS_SHARED; + } else if (flags & MS_PRIVATE) { + if (flags & (MS_SHARED | MS_SLAVE | MS_UNBINDABLE)) + return -EINVAL; + type = tomoyo_mounts[TOMOYO_MOUNT_MAKE_PRIVATE]; + flags &= ~MS_PRIVATE; + } else if (flags & MS_SLAVE) { + if (flags & (MS_SHARED | MS_PRIVATE | MS_UNBINDABLE)) + return -EINVAL; + type = tomoyo_mounts[TOMOYO_MOUNT_MAKE_SLAVE]; + flags &= ~MS_SLAVE; + } else if (flags & MS_UNBINDABLE) { + if (flags & (MS_SHARED | MS_PRIVATE | MS_SLAVE)) + return -EINVAL; + type = tomoyo_mounts[TOMOYO_MOUNT_MAKE_UNBINDABLE]; + flags &= ~MS_UNBINDABLE; + } else if (flags & MS_MOVE) { + type = tomoyo_mounts[TOMOYO_MOUNT_MOVE]; + flags &= ~MS_MOVE; + } + if (!type) + type = "<NULL>"; + idx = tomoyo_read_lock(); + error = tomoyo_mount_acl(&r, dev_name, path, type, flags); + tomoyo_read_unlock(idx); + return error; +} diff --git a/security/tomoyo/network.c b/security/tomoyo/network.c new file mode 100644 index 000000000..8dc61335f --- /dev/null +++ b/security/tomoyo/network.c @@ -0,0 +1,777 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * security/tomoyo/network.c + * + * Copyright (C) 2005-2011 NTT DATA CORPORATION + */ + +#include "common.h" +#include <linux/slab.h> + +/* Structure for holding inet domain socket's address. */ +struct tomoyo_inet_addr_info { + __be16 port; /* In network byte order. */ + const __be32 *address; /* In network byte order. */ + bool is_ipv6; +}; + +/* Structure for holding unix domain socket's address. */ +struct tomoyo_unix_addr_info { + u8 *addr; /* This may not be '\0' terminated string. */ + unsigned int addr_len; +}; + +/* Structure for holding socket address. */ +struct tomoyo_addr_info { + u8 protocol; + u8 operation; + struct tomoyo_inet_addr_info inet; + struct tomoyo_unix_addr_info unix0; +}; + +/* String table for socket's protocols. */ +const char * const tomoyo_proto_keyword[TOMOYO_SOCK_MAX] = { + [SOCK_STREAM] = "stream", + [SOCK_DGRAM] = "dgram", + [SOCK_RAW] = "raw", + [SOCK_SEQPACKET] = "seqpacket", + [0] = " ", /* Dummy for avoiding NULL pointer dereference. */ + [4] = " ", /* Dummy for avoiding NULL pointer dereference. */ +}; + +/** + * tomoyo_parse_ipaddr_union - Parse an IP address. + * + * @param: Pointer to "struct tomoyo_acl_param". + * @ptr: Pointer to "struct tomoyo_ipaddr_union". + * + * Returns true on success, false otherwise. + */ +bool tomoyo_parse_ipaddr_union(struct tomoyo_acl_param *param, + struct tomoyo_ipaddr_union *ptr) +{ + u8 * const min = ptr->ip[0].in6_u.u6_addr8; + u8 * const max = ptr->ip[1].in6_u.u6_addr8; + char *address = tomoyo_read_token(param); + const char *end; + + if (!strchr(address, ':') && + in4_pton(address, -1, min, '-', &end) > 0) { + ptr->is_ipv6 = false; + if (!*end) + ptr->ip[1].s6_addr32[0] = ptr->ip[0].s6_addr32[0]; + else if (*end++ != '-' || + in4_pton(end, -1, max, '\0', &end) <= 0 || *end) + return false; + return true; + } + if (in6_pton(address, -1, min, '-', &end) > 0) { + ptr->is_ipv6 = true; + if (!*end) + memmove(max, min, sizeof(u16) * 8); + else if (*end++ != '-' || + in6_pton(end, -1, max, '\0', &end) <= 0 || *end) + return false; + return true; + } + return false; +} + +/** + * tomoyo_print_ipv4 - Print an IPv4 address. + * + * @buffer: Buffer to write to. + * @buffer_len: Size of @buffer. + * @min_ip: Pointer to __be32. + * @max_ip: Pointer to __be32. + * + * Returns nothing. + */ +static void tomoyo_print_ipv4(char *buffer, const unsigned int buffer_len, + const __be32 *min_ip, const __be32 *max_ip) +{ + snprintf(buffer, buffer_len, "%pI4%c%pI4", min_ip, + *min_ip == *max_ip ? '\0' : '-', max_ip); +} + +/** + * tomoyo_print_ipv6 - Print an IPv6 address. + * + * @buffer: Buffer to write to. + * @buffer_len: Size of @buffer. + * @min_ip: Pointer to "struct in6_addr". + * @max_ip: Pointer to "struct in6_addr". + * + * Returns nothing. + */ +static void tomoyo_print_ipv6(char *buffer, const unsigned int buffer_len, + const struct in6_addr *min_ip, + const struct in6_addr *max_ip) +{ + snprintf(buffer, buffer_len, "%pI6c%c%pI6c", min_ip, + !memcmp(min_ip, max_ip, 16) ? '\0' : '-', max_ip); +} + +/** + * tomoyo_print_ip - Print an IP address. + * + * @buf: Buffer to write to. + * @size: Size of @buf. + * @ptr: Pointer to "struct ipaddr_union". + * + * Returns nothing. + */ +void tomoyo_print_ip(char *buf, const unsigned int size, + const struct tomoyo_ipaddr_union *ptr) +{ + if (ptr->is_ipv6) + tomoyo_print_ipv6(buf, size, &ptr->ip[0], &ptr->ip[1]); + else + tomoyo_print_ipv4(buf, size, &ptr->ip[0].s6_addr32[0], + &ptr->ip[1].s6_addr32[0]); +} + +/* + * Mapping table from "enum tomoyo_network_acl_index" to + * "enum tomoyo_mac_index" for inet domain socket. + */ +static const u8 tomoyo_inet2mac +[TOMOYO_SOCK_MAX][TOMOYO_MAX_NETWORK_OPERATION] = { + [SOCK_STREAM] = { + [TOMOYO_NETWORK_BIND] = TOMOYO_MAC_NETWORK_INET_STREAM_BIND, + [TOMOYO_NETWORK_LISTEN] = + TOMOYO_MAC_NETWORK_INET_STREAM_LISTEN, + [TOMOYO_NETWORK_CONNECT] = + TOMOYO_MAC_NETWORK_INET_STREAM_CONNECT, + }, + [SOCK_DGRAM] = { + [TOMOYO_NETWORK_BIND] = TOMOYO_MAC_NETWORK_INET_DGRAM_BIND, + [TOMOYO_NETWORK_SEND] = TOMOYO_MAC_NETWORK_INET_DGRAM_SEND, + }, + [SOCK_RAW] = { + [TOMOYO_NETWORK_BIND] = TOMOYO_MAC_NETWORK_INET_RAW_BIND, + [TOMOYO_NETWORK_SEND] = TOMOYO_MAC_NETWORK_INET_RAW_SEND, + }, +}; + +/* + * Mapping table from "enum tomoyo_network_acl_index" to + * "enum tomoyo_mac_index" for unix domain socket. + */ +static const u8 tomoyo_unix2mac +[TOMOYO_SOCK_MAX][TOMOYO_MAX_NETWORK_OPERATION] = { + [SOCK_STREAM] = { + [TOMOYO_NETWORK_BIND] = TOMOYO_MAC_NETWORK_UNIX_STREAM_BIND, + [TOMOYO_NETWORK_LISTEN] = + TOMOYO_MAC_NETWORK_UNIX_STREAM_LISTEN, + [TOMOYO_NETWORK_CONNECT] = + TOMOYO_MAC_NETWORK_UNIX_STREAM_CONNECT, + }, + [SOCK_DGRAM] = { + [TOMOYO_NETWORK_BIND] = TOMOYO_MAC_NETWORK_UNIX_DGRAM_BIND, + [TOMOYO_NETWORK_SEND] = TOMOYO_MAC_NETWORK_UNIX_DGRAM_SEND, + }, + [SOCK_SEQPACKET] = { + [TOMOYO_NETWORK_BIND] = + TOMOYO_MAC_NETWORK_UNIX_SEQPACKET_BIND, + [TOMOYO_NETWORK_LISTEN] = + TOMOYO_MAC_NETWORK_UNIX_SEQPACKET_LISTEN, + [TOMOYO_NETWORK_CONNECT] = + TOMOYO_MAC_NETWORK_UNIX_SEQPACKET_CONNECT, + }, +}; + +/** + * tomoyo_same_inet_acl - Check for duplicated "struct tomoyo_inet_acl" entry. + * + * @a: Pointer to "struct tomoyo_acl_info". + * @b: Pointer to "struct tomoyo_acl_info". + * + * Returns true if @a == @b except permission bits, false otherwise. + */ +static bool tomoyo_same_inet_acl(const struct tomoyo_acl_info *a, + const struct tomoyo_acl_info *b) +{ + const struct tomoyo_inet_acl *p1 = container_of(a, typeof(*p1), head); + const struct tomoyo_inet_acl *p2 = container_of(b, typeof(*p2), head); + + return p1->protocol == p2->protocol && + tomoyo_same_ipaddr_union(&p1->address, &p2->address) && + tomoyo_same_number_union(&p1->port, &p2->port); +} + +/** + * tomoyo_same_unix_acl - Check for duplicated "struct tomoyo_unix_acl" entry. + * + * @a: Pointer to "struct tomoyo_acl_info". + * @b: Pointer to "struct tomoyo_acl_info". + * + * Returns true if @a == @b except permission bits, false otherwise. + */ +static bool tomoyo_same_unix_acl(const struct tomoyo_acl_info *a, + const struct tomoyo_acl_info *b) +{ + const struct tomoyo_unix_acl *p1 = container_of(a, typeof(*p1), head); + const struct tomoyo_unix_acl *p2 = container_of(b, typeof(*p2), head); + + return p1->protocol == p2->protocol && + tomoyo_same_name_union(&p1->name, &p2->name); +} + +/** + * tomoyo_merge_inet_acl - Merge duplicated "struct tomoyo_inet_acl" entry. + * + * @a: Pointer to "struct tomoyo_acl_info". + * @b: Pointer to "struct tomoyo_acl_info". + * @is_delete: True for @a &= ~@b, false for @a |= @b. + * + * Returns true if @a is empty, false otherwise. + */ +static bool tomoyo_merge_inet_acl(struct tomoyo_acl_info *a, + struct tomoyo_acl_info *b, + const bool is_delete) +{ + u8 * const a_perm = + &container_of(a, struct tomoyo_inet_acl, head)->perm; + u8 perm = READ_ONCE(*a_perm); + const u8 b_perm = container_of(b, struct tomoyo_inet_acl, head)->perm; + + if (is_delete) + perm &= ~b_perm; + else + perm |= b_perm; + WRITE_ONCE(*a_perm, perm); + return !perm; +} + +/** + * tomoyo_merge_unix_acl - Merge duplicated "struct tomoyo_unix_acl" entry. + * + * @a: Pointer to "struct tomoyo_acl_info". + * @b: Pointer to "struct tomoyo_acl_info". + * @is_delete: True for @a &= ~@b, false for @a |= @b. + * + * Returns true if @a is empty, false otherwise. + */ +static bool tomoyo_merge_unix_acl(struct tomoyo_acl_info *a, + struct tomoyo_acl_info *b, + const bool is_delete) +{ + u8 * const a_perm = + &container_of(a, struct tomoyo_unix_acl, head)->perm; + u8 perm = READ_ONCE(*a_perm); + const u8 b_perm = container_of(b, struct tomoyo_unix_acl, head)->perm; + + if (is_delete) + perm &= ~b_perm; + else + perm |= b_perm; + WRITE_ONCE(*a_perm, perm); + return !perm; +} + +/** + * tomoyo_write_inet_network - Write "struct tomoyo_inet_acl" list. + * + * @param: Pointer to "struct tomoyo_acl_param". + * + * Returns 0 on success, negative value otherwise. + * + * Caller holds tomoyo_read_lock(). + */ +int tomoyo_write_inet_network(struct tomoyo_acl_param *param) +{ + struct tomoyo_inet_acl e = { .head.type = TOMOYO_TYPE_INET_ACL }; + int error = -EINVAL; + u8 type; + const char *protocol = tomoyo_read_token(param); + const char *operation = tomoyo_read_token(param); + + for (e.protocol = 0; e.protocol < TOMOYO_SOCK_MAX; e.protocol++) + if (!strcmp(protocol, tomoyo_proto_keyword[e.protocol])) + break; + for (type = 0; type < TOMOYO_MAX_NETWORK_OPERATION; type++) + if (tomoyo_permstr(operation, tomoyo_socket_keyword[type])) + e.perm |= 1 << type; + if (e.protocol == TOMOYO_SOCK_MAX || !e.perm) + return -EINVAL; + if (param->data[0] == '@') { + param->data++; + e.address.group = + tomoyo_get_group(param, TOMOYO_ADDRESS_GROUP); + if (!e.address.group) + return -ENOMEM; + } else { + if (!tomoyo_parse_ipaddr_union(param, &e.address)) + goto out; + } + if (!tomoyo_parse_number_union(param, &e.port) || + e.port.values[1] > 65535) + goto out; + error = tomoyo_update_domain(&e.head, sizeof(e), param, + tomoyo_same_inet_acl, + tomoyo_merge_inet_acl); +out: + tomoyo_put_group(e.address.group); + tomoyo_put_number_union(&e.port); + return error; +} + +/** + * tomoyo_write_unix_network - Write "struct tomoyo_unix_acl" list. + * + * @param: Pointer to "struct tomoyo_acl_param". + * + * Returns 0 on success, negative value otherwise. + */ +int tomoyo_write_unix_network(struct tomoyo_acl_param *param) +{ + struct tomoyo_unix_acl e = { .head.type = TOMOYO_TYPE_UNIX_ACL }; + int error; + u8 type; + const char *protocol = tomoyo_read_token(param); + const char *operation = tomoyo_read_token(param); + + for (e.protocol = 0; e.protocol < TOMOYO_SOCK_MAX; e.protocol++) + if (!strcmp(protocol, tomoyo_proto_keyword[e.protocol])) + break; + for (type = 0; type < TOMOYO_MAX_NETWORK_OPERATION; type++) + if (tomoyo_permstr(operation, tomoyo_socket_keyword[type])) + e.perm |= 1 << type; + if (e.protocol == TOMOYO_SOCK_MAX || !e.perm) + return -EINVAL; + if (!tomoyo_parse_name_union(param, &e.name)) + return -EINVAL; + error = tomoyo_update_domain(&e.head, sizeof(e), param, + tomoyo_same_unix_acl, + tomoyo_merge_unix_acl); + tomoyo_put_name_union(&e.name); + return error; +} + +/** + * tomoyo_audit_net_log - Audit network log. + * + * @r: Pointer to "struct tomoyo_request_info". + * @family: Name of socket family ("inet" or "unix"). + * @protocol: Name of protocol in @family. + * @operation: Name of socket operation. + * @address: Name of address. + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_audit_net_log(struct tomoyo_request_info *r, + const char *family, const u8 protocol, + const u8 operation, const char *address) +{ + return tomoyo_supervisor(r, "network %s %s %s %s\n", family, + tomoyo_proto_keyword[protocol], + tomoyo_socket_keyword[operation], address); +} + +/** + * tomoyo_audit_inet_log - Audit INET network log. + * + * @r: Pointer to "struct tomoyo_request_info". + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_audit_inet_log(struct tomoyo_request_info *r) +{ + char buf[128]; + int len; + const __be32 *address = r->param.inet_network.address; + + if (r->param.inet_network.is_ipv6) + tomoyo_print_ipv6(buf, sizeof(buf), (const struct in6_addr *) + address, (const struct in6_addr *) address); + else + tomoyo_print_ipv4(buf, sizeof(buf), address, address); + len = strlen(buf); + snprintf(buf + len, sizeof(buf) - len, " %u", + r->param.inet_network.port); + return tomoyo_audit_net_log(r, "inet", r->param.inet_network.protocol, + r->param.inet_network.operation, buf); +} + +/** + * tomoyo_audit_unix_log - Audit UNIX network log. + * + * @r: Pointer to "struct tomoyo_request_info". + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_audit_unix_log(struct tomoyo_request_info *r) +{ + return tomoyo_audit_net_log(r, "unix", r->param.unix_network.protocol, + r->param.unix_network.operation, + r->param.unix_network.address->name); +} + +/** + * tomoyo_check_inet_acl - Check permission for inet domain socket operation. + * + * @r: Pointer to "struct tomoyo_request_info". + * @ptr: Pointer to "struct tomoyo_acl_info". + * + * Returns true if granted, false otherwise. + */ +static bool tomoyo_check_inet_acl(struct tomoyo_request_info *r, + const struct tomoyo_acl_info *ptr) +{ + const struct tomoyo_inet_acl *acl = + container_of(ptr, typeof(*acl), head); + const u8 size = r->param.inet_network.is_ipv6 ? 16 : 4; + + if (!(acl->perm & (1 << r->param.inet_network.operation)) || + !tomoyo_compare_number_union(r->param.inet_network.port, + &acl->port)) + return false; + if (acl->address.group) + return tomoyo_address_matches_group + (r->param.inet_network.is_ipv6, + r->param.inet_network.address, acl->address.group); + return acl->address.is_ipv6 == r->param.inet_network.is_ipv6 && + memcmp(&acl->address.ip[0], + r->param.inet_network.address, size) <= 0 && + memcmp(r->param.inet_network.address, + &acl->address.ip[1], size) <= 0; +} + +/** + * tomoyo_check_unix_acl - Check permission for unix domain socket operation. + * + * @r: Pointer to "struct tomoyo_request_info". + * @ptr: Pointer to "struct tomoyo_acl_info". + * + * Returns true if granted, false otherwise. + */ +static bool tomoyo_check_unix_acl(struct tomoyo_request_info *r, + const struct tomoyo_acl_info *ptr) +{ + const struct tomoyo_unix_acl *acl = + container_of(ptr, typeof(*acl), head); + + return (acl->perm & (1 << r->param.unix_network.operation)) && + tomoyo_compare_name_union(r->param.unix_network.address, + &acl->name); +} + +/** + * tomoyo_inet_entry - Check permission for INET network operation. + * + * @address: Pointer to "struct tomoyo_addr_info". + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_inet_entry(const struct tomoyo_addr_info *address) +{ + const int idx = tomoyo_read_lock(); + struct tomoyo_request_info r; + int error = 0; + const u8 type = tomoyo_inet2mac[address->protocol][address->operation]; + + if (type && tomoyo_init_request_info(&r, NULL, type) + != TOMOYO_CONFIG_DISABLED) { + r.param_type = TOMOYO_TYPE_INET_ACL; + r.param.inet_network.protocol = address->protocol; + r.param.inet_network.operation = address->operation; + r.param.inet_network.is_ipv6 = address->inet.is_ipv6; + r.param.inet_network.address = address->inet.address; + r.param.inet_network.port = ntohs(address->inet.port); + do { + tomoyo_check_acl(&r, tomoyo_check_inet_acl); + error = tomoyo_audit_inet_log(&r); + } while (error == TOMOYO_RETRY_REQUEST); + } + tomoyo_read_unlock(idx); + return error; +} + +/** + * tomoyo_check_inet_address - Check permission for inet domain socket's operation. + * + * @addr: Pointer to "struct sockaddr". + * @addr_len: Size of @addr. + * @port: Port number. + * @address: Pointer to "struct tomoyo_addr_info". + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_check_inet_address(const struct sockaddr *addr, + const unsigned int addr_len, + const u16 port, + struct tomoyo_addr_info *address) +{ + struct tomoyo_inet_addr_info *i = &address->inet; + + if (addr_len < offsetofend(struct sockaddr, sa_family)) + return 0; + switch (addr->sa_family) { + case AF_INET6: + if (addr_len < SIN6_LEN_RFC2133) + goto skip; + i->is_ipv6 = true; + i->address = (__be32 *) + ((struct sockaddr_in6 *) addr)->sin6_addr.s6_addr; + i->port = ((struct sockaddr_in6 *) addr)->sin6_port; + break; + case AF_INET: + if (addr_len < sizeof(struct sockaddr_in)) + goto skip; + i->is_ipv6 = false; + i->address = (__be32 *) + &((struct sockaddr_in *) addr)->sin_addr; + i->port = ((struct sockaddr_in *) addr)->sin_port; + break; + default: + goto skip; + } + if (address->protocol == SOCK_RAW) + i->port = htons(port); + return tomoyo_inet_entry(address); +skip: + return 0; +} + +/** + * tomoyo_unix_entry - Check permission for UNIX network operation. + * + * @address: Pointer to "struct tomoyo_addr_info". + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_unix_entry(const struct tomoyo_addr_info *address) +{ + const int idx = tomoyo_read_lock(); + struct tomoyo_request_info r; + int error = 0; + const u8 type = tomoyo_unix2mac[address->protocol][address->operation]; + + if (type && tomoyo_init_request_info(&r, NULL, type) + != TOMOYO_CONFIG_DISABLED) { + char *buf = address->unix0.addr; + int len = address->unix0.addr_len - sizeof(sa_family_t); + + if (len <= 0) { + buf = "anonymous"; + len = 9; + } else if (buf[0]) { + len = strnlen(buf, len); + } + buf = tomoyo_encode2(buf, len); + if (buf) { + struct tomoyo_path_info addr; + + addr.name = buf; + tomoyo_fill_path_info(&addr); + r.param_type = TOMOYO_TYPE_UNIX_ACL; + r.param.unix_network.protocol = address->protocol; + r.param.unix_network.operation = address->operation; + r.param.unix_network.address = &addr; + do { + tomoyo_check_acl(&r, tomoyo_check_unix_acl); + error = tomoyo_audit_unix_log(&r); + } while (error == TOMOYO_RETRY_REQUEST); + kfree(buf); + } else + error = -ENOMEM; + } + tomoyo_read_unlock(idx); + return error; +} + +/** + * tomoyo_check_unix_address - Check permission for unix domain socket's operation. + * + * @addr: Pointer to "struct sockaddr". + * @addr_len: Size of @addr. + * @address: Pointer to "struct tomoyo_addr_info". + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_check_unix_address(struct sockaddr *addr, + const unsigned int addr_len, + struct tomoyo_addr_info *address) +{ + struct tomoyo_unix_addr_info *u = &address->unix0; + + if (addr_len < offsetofend(struct sockaddr, sa_family)) + return 0; + if (addr->sa_family != AF_UNIX) + return 0; + u->addr = ((struct sockaddr_un *) addr)->sun_path; + u->addr_len = addr_len; + return tomoyo_unix_entry(address); +} + +/** + * tomoyo_kernel_service - Check whether I'm kernel service or not. + * + * Returns true if I'm kernel service, false otherwise. + */ +static bool tomoyo_kernel_service(void) +{ + /* Nothing to do if I am a kernel service. */ + return current->flags & PF_KTHREAD; +} + +/** + * tomoyo_sock_family - Get socket's family. + * + * @sk: Pointer to "struct sock". + * + * Returns one of PF_INET, PF_INET6, PF_UNIX or 0. + */ +static u8 tomoyo_sock_family(struct sock *sk) +{ + u8 family; + + if (tomoyo_kernel_service()) + return 0; + family = sk->sk_family; + switch (family) { + case PF_INET: + case PF_INET6: + case PF_UNIX: + return family; + default: + return 0; + } +} + +/** + * tomoyo_socket_listen_permission - Check permission for listening a socket. + * + * @sock: Pointer to "struct socket". + * + * Returns 0 on success, negative value otherwise. + */ +int tomoyo_socket_listen_permission(struct socket *sock) +{ + struct tomoyo_addr_info address; + const u8 family = tomoyo_sock_family(sock->sk); + const unsigned int type = sock->type; + struct sockaddr_storage addr; + int addr_len; + + if (!family || (type != SOCK_STREAM && type != SOCK_SEQPACKET)) + return 0; + { + const int error = sock->ops->getname(sock, (struct sockaddr *) + &addr, 0); + + if (error < 0) + return error; + addr_len = error; + } + address.protocol = type; + address.operation = TOMOYO_NETWORK_LISTEN; + if (family == PF_UNIX) + return tomoyo_check_unix_address((struct sockaddr *) &addr, + addr_len, &address); + return tomoyo_check_inet_address((struct sockaddr *) &addr, addr_len, + 0, &address); +} + +/** + * tomoyo_socket_connect_permission - Check permission for setting the remote address of a socket. + * + * @sock: Pointer to "struct socket". + * @addr: Pointer to "struct sockaddr". + * @addr_len: Size of @addr. + * + * Returns 0 on success, negative value otherwise. + */ +int tomoyo_socket_connect_permission(struct socket *sock, + struct sockaddr *addr, int addr_len) +{ + struct tomoyo_addr_info address; + const u8 family = tomoyo_sock_family(sock->sk); + const unsigned int type = sock->type; + + if (!family) + return 0; + address.protocol = type; + switch (type) { + case SOCK_DGRAM: + case SOCK_RAW: + address.operation = TOMOYO_NETWORK_SEND; + break; + case SOCK_STREAM: + case SOCK_SEQPACKET: + address.operation = TOMOYO_NETWORK_CONNECT; + break; + default: + return 0; + } + if (family == PF_UNIX) + return tomoyo_check_unix_address(addr, addr_len, &address); + return tomoyo_check_inet_address(addr, addr_len, sock->sk->sk_protocol, + &address); +} + +/** + * tomoyo_socket_bind_permission - Check permission for setting the local address of a socket. + * + * @sock: Pointer to "struct socket". + * @addr: Pointer to "struct sockaddr". + * @addr_len: Size of @addr. + * + * Returns 0 on success, negative value otherwise. + */ +int tomoyo_socket_bind_permission(struct socket *sock, struct sockaddr *addr, + int addr_len) +{ + struct tomoyo_addr_info address; + const u8 family = tomoyo_sock_family(sock->sk); + const unsigned int type = sock->type; + + if (!family) + return 0; + switch (type) { + case SOCK_STREAM: + case SOCK_DGRAM: + case SOCK_RAW: + case SOCK_SEQPACKET: + address.protocol = type; + address.operation = TOMOYO_NETWORK_BIND; + break; + default: + return 0; + } + if (family == PF_UNIX) + return tomoyo_check_unix_address(addr, addr_len, &address); + return tomoyo_check_inet_address(addr, addr_len, sock->sk->sk_protocol, + &address); +} + +/** + * tomoyo_socket_sendmsg_permission - Check permission for sending a datagram. + * + * @sock: Pointer to "struct socket". + * @msg: Pointer to "struct msghdr". + * @size: Unused. + * + * Returns 0 on success, negative value otherwise. + */ +int tomoyo_socket_sendmsg_permission(struct socket *sock, struct msghdr *msg, + int size) +{ + struct tomoyo_addr_info address; + const u8 family = tomoyo_sock_family(sock->sk); + const unsigned int type = sock->type; + + if (!msg->msg_name || !family || + (type != SOCK_DGRAM && type != SOCK_RAW)) + return 0; + address.protocol = type; + address.operation = TOMOYO_NETWORK_SEND; + if (family == PF_UNIX) + return tomoyo_check_unix_address((struct sockaddr *) + msg->msg_name, + msg->msg_namelen, &address); + return tomoyo_check_inet_address((struct sockaddr *) msg->msg_name, + msg->msg_namelen, + sock->sk->sk_protocol, &address); +} diff --git a/security/tomoyo/policy/exception_policy.conf.default b/security/tomoyo/policy/exception_policy.conf.default new file mode 100644 index 000000000..2678df496 --- /dev/null +++ b/security/tomoyo/policy/exception_policy.conf.default @@ -0,0 +1,2 @@ +initialize_domain /sbin/modprobe from any +initialize_domain /sbin/hotplug from any diff --git a/security/tomoyo/realpath.c b/security/tomoyo/realpath.c new file mode 100644 index 000000000..1c483ee7f --- /dev/null +++ b/security/tomoyo/realpath.c @@ -0,0 +1,310 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * security/tomoyo/realpath.c + * + * Copyright (C) 2005-2011 NTT DATA CORPORATION + */ + +#include "common.h" +#include <linux/magic.h> +#include <linux/proc_fs.h> + +/** + * tomoyo_encode2 - Encode binary string to ascii string. + * + * @str: String in binary format. + * @str_len: Size of @str in byte. + * + * Returns pointer to @str in ascii format on success, NULL otherwise. + * + * This function uses kzalloc(), so caller must kfree() if this function + * didn't return NULL. + */ +char *tomoyo_encode2(const char *str, int str_len) +{ + int i; + int len = 0; + const char *p = str; + char *cp; + char *cp0; + + if (!p) + return NULL; + for (i = 0; i < str_len; i++) { + const unsigned char c = p[i]; + + if (c == '\\') + len += 2; + else if (c > ' ' && c < 127) + len++; + else + len += 4; + } + len++; + /* Reserve space for appending "/". */ + cp = kzalloc(len + 10, GFP_NOFS); + if (!cp) + return NULL; + cp0 = cp; + p = str; + for (i = 0; i < str_len; i++) { + const unsigned char c = p[i]; + + if (c == '\\') { + *cp++ = '\\'; + *cp++ = '\\'; + } else if (c > ' ' && c < 127) { + *cp++ = c; + } else { + *cp++ = '\\'; + *cp++ = (c >> 6) + '0'; + *cp++ = ((c >> 3) & 7) + '0'; + *cp++ = (c & 7) + '0'; + } + } + return cp0; +} + +/** + * tomoyo_encode - Encode binary string to ascii string. + * + * @str: String in binary format. + * + * Returns pointer to @str in ascii format on success, NULL otherwise. + * + * This function uses kzalloc(), so caller must kfree() if this function + * didn't return NULL. + */ +char *tomoyo_encode(const char *str) +{ + return str ? tomoyo_encode2(str, strlen(str)) : NULL; +} + +/** + * tomoyo_get_absolute_path - Get the path of a dentry but ignores chroot'ed root. + * + * @path: Pointer to "struct path". + * @buffer: Pointer to buffer to return value in. + * @buflen: Sizeof @buffer. + * + * Returns the buffer on success, an error code otherwise. + * + * If dentry is a directory, trailing '/' is appended. + */ +static char *tomoyo_get_absolute_path(const struct path *path, char * const buffer, + const int buflen) +{ + char *pos = ERR_PTR(-ENOMEM); + + if (buflen >= 256) { + /* go to whatever namespace root we are under */ + pos = d_absolute_path(path, buffer, buflen - 1); + if (!IS_ERR(pos) && *pos == '/' && pos[1]) { + struct inode *inode = d_backing_inode(path->dentry); + + if (inode && S_ISDIR(inode->i_mode)) { + buffer[buflen - 2] = '/'; + buffer[buflen - 1] = '\0'; + } + } + } + return pos; +} + +/** + * tomoyo_get_dentry_path - Get the path of a dentry. + * + * @dentry: Pointer to "struct dentry". + * @buffer: Pointer to buffer to return value in. + * @buflen: Sizeof @buffer. + * + * Returns the buffer on success, an error code otherwise. + * + * If dentry is a directory, trailing '/' is appended. + */ +static char *tomoyo_get_dentry_path(struct dentry *dentry, char * const buffer, + const int buflen) +{ + char *pos = ERR_PTR(-ENOMEM); + + if (buflen >= 256) { + pos = dentry_path_raw(dentry, buffer, buflen - 1); + if (!IS_ERR(pos) && *pos == '/' && pos[1]) { + struct inode *inode = d_backing_inode(dentry); + + if (inode && S_ISDIR(inode->i_mode)) { + buffer[buflen - 2] = '/'; + buffer[buflen - 1] = '\0'; + } + } + } + return pos; +} + +/** + * tomoyo_get_local_path - Get the path of a dentry. + * + * @dentry: Pointer to "struct dentry". + * @buffer: Pointer to buffer to return value in. + * @buflen: Sizeof @buffer. + * + * Returns the buffer on success, an error code otherwise. + */ +static char *tomoyo_get_local_path(struct dentry *dentry, char * const buffer, + const int buflen) +{ + struct super_block *sb = dentry->d_sb; + char *pos = tomoyo_get_dentry_path(dentry, buffer, buflen); + + if (IS_ERR(pos)) + return pos; + /* Convert from $PID to self if $PID is current thread. */ + if (sb->s_magic == PROC_SUPER_MAGIC && *pos == '/') { + char *ep; + const pid_t pid = (pid_t) simple_strtoul(pos + 1, &ep, 10); + struct pid_namespace *proc_pidns = proc_pid_ns(sb); + + if (*ep == '/' && pid && pid == + task_tgid_nr_ns(current, proc_pidns)) { + pos = ep - 5; + if (pos < buffer) + goto out; + memmove(pos, "/self", 5); + } + goto prepend_filesystem_name; + } + /* Use filesystem name for unnamed devices. */ + if (!MAJOR(sb->s_dev)) + goto prepend_filesystem_name; + { + struct inode *inode = d_backing_inode(sb->s_root); + + /* + * Use filesystem name if filesystem does not support rename() + * operation. + */ + if (!inode->i_op->rename) + goto prepend_filesystem_name; + } + /* Prepend device name. */ + { + char name[64]; + int name_len; + const dev_t dev = sb->s_dev; + + name[sizeof(name) - 1] = '\0'; + snprintf(name, sizeof(name) - 1, "dev(%u,%u):", MAJOR(dev), + MINOR(dev)); + name_len = strlen(name); + pos -= name_len; + if (pos < buffer) + goto out; + memmove(pos, name, name_len); + return pos; + } + /* Prepend filesystem name. */ +prepend_filesystem_name: + { + const char *name = sb->s_type->name; + const int name_len = strlen(name); + + pos -= name_len + 1; + if (pos < buffer) + goto out; + memmove(pos, name, name_len); + pos[name_len] = ':'; + } + return pos; +out: + return ERR_PTR(-ENOMEM); +} + +/** + * tomoyo_realpath_from_path - Returns realpath(3) of the given pathname but ignores chroot'ed root. + * + * @path: Pointer to "struct path". + * + * Returns the realpath of the given @path on success, NULL otherwise. + * + * If dentry is a directory, trailing '/' is appended. + * Characters out of 0x20 < c < 0x7F range are converted to + * \ooo style octal string. + * Character \ is converted to \\ string. + * + * These functions use kzalloc(), so the caller must call kfree() + * if these functions didn't return NULL. + */ +char *tomoyo_realpath_from_path(const struct path *path) +{ + char *buf = NULL; + char *name = NULL; + unsigned int buf_len = PAGE_SIZE / 2; + struct dentry *dentry = path->dentry; + struct super_block *sb = dentry->d_sb; + + while (1) { + char *pos; + struct inode *inode; + + buf_len <<= 1; + kfree(buf); + buf = kmalloc(buf_len, GFP_NOFS); + if (!buf) + break; + /* To make sure that pos is '\0' terminated. */ + buf[buf_len - 1] = '\0'; + /* For "pipe:[\$]" and "socket:[\$]". */ + if (dentry->d_op && dentry->d_op->d_dname) { + pos = dentry->d_op->d_dname(dentry, buf, buf_len - 1); + goto encode; + } + inode = d_backing_inode(sb->s_root); + /* + * Get local name for filesystems without rename() operation + */ + if ((!inode->i_op->rename && + !(sb->s_type->fs_flags & FS_REQUIRES_DEV))) + pos = tomoyo_get_local_path(path->dentry, buf, + buf_len - 1); + /* Get absolute name for the rest. */ + else { + pos = tomoyo_get_absolute_path(path, buf, buf_len - 1); + /* + * Fall back to local name if absolute name is not + * available. + */ + if (pos == ERR_PTR(-EINVAL)) + pos = tomoyo_get_local_path(path->dentry, buf, + buf_len - 1); + } +encode: + if (IS_ERR(pos)) + continue; + name = tomoyo_encode(pos); + break; + } + kfree(buf); + if (!name) + tomoyo_warn_oom(__func__); + return name; +} + +/** + * tomoyo_realpath_nofollow - Get realpath of a pathname. + * + * @pathname: The pathname to solve. + * + * Returns the realpath of @pathname on success, NULL otherwise. + */ +char *tomoyo_realpath_nofollow(const char *pathname) +{ + struct path path; + + if (pathname && kern_path(pathname, 0, &path) == 0) { + char *buf = tomoyo_realpath_from_path(&path); + + path_put(&path); + return buf; + } + return NULL; +} diff --git a/security/tomoyo/securityfs_if.c b/security/tomoyo/securityfs_if.c new file mode 100644 index 000000000..a27057984 --- /dev/null +++ b/security/tomoyo/securityfs_if.c @@ -0,0 +1,273 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * security/tomoyo/securityfs_if.c + * + * Copyright (C) 2005-2011 NTT DATA CORPORATION + */ + +#include <linux/security.h> +#include "common.h" + +/** + * tomoyo_check_task_acl - Check permission for task operation. + * + * @r: Pointer to "struct tomoyo_request_info". + * @ptr: Pointer to "struct tomoyo_acl_info". + * + * Returns true if granted, false otherwise. + */ +static bool tomoyo_check_task_acl(struct tomoyo_request_info *r, + const struct tomoyo_acl_info *ptr) +{ + const struct tomoyo_task_acl *acl = container_of(ptr, typeof(*acl), + head); + + return !tomoyo_pathcmp(r->param.task.domainname, acl->domainname); +} + +/** + * tomoyo_write_self - write() for /sys/kernel/security/tomoyo/self_domain interface. + * + * @file: Pointer to "struct file". + * @buf: Domainname to transit to. + * @count: Size of @buf. + * @ppos: Unused. + * + * Returns @count on success, negative value otherwise. + * + * If domain transition was permitted but the domain transition failed, this + * function returns error rather than terminating current thread with SIGKILL. + */ +static ssize_t tomoyo_write_self(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + char *data; + int error; + + if (!count || count >= TOMOYO_EXEC_TMPSIZE - 10) + return -ENOMEM; + data = memdup_user_nul(buf, count); + if (IS_ERR(data)) + return PTR_ERR(data); + tomoyo_normalize_line(data); + if (tomoyo_correct_domain(data)) { + const int idx = tomoyo_read_lock(); + struct tomoyo_path_info name; + struct tomoyo_request_info r; + + name.name = data; + tomoyo_fill_path_info(&name); + /* Check "task manual_domain_transition" permission. */ + tomoyo_init_request_info(&r, NULL, TOMOYO_MAC_FILE_EXECUTE); + r.param_type = TOMOYO_TYPE_MANUAL_TASK_ACL; + r.param.task.domainname = &name; + tomoyo_check_acl(&r, tomoyo_check_task_acl); + if (!r.granted) + error = -EPERM; + else { + struct tomoyo_domain_info *new_domain = + tomoyo_assign_domain(data, true); + if (!new_domain) { + error = -ENOENT; + } else { + struct tomoyo_task *s = tomoyo_task(current); + struct tomoyo_domain_info *old_domain = + s->domain_info; + + s->domain_info = new_domain; + atomic_inc(&new_domain->users); + atomic_dec(&old_domain->users); + error = 0; + } + } + tomoyo_read_unlock(idx); + } else + error = -EINVAL; + kfree(data); + return error ? error : count; +} + +/** + * tomoyo_read_self - read() for /sys/kernel/security/tomoyo/self_domain interface. + * + * @file: Pointer to "struct file". + * @buf: Domainname which current thread belongs to. + * @count: Size of @buf. + * @ppos: Bytes read by now. + * + * Returns read size on success, negative value otherwise. + */ +static ssize_t tomoyo_read_self(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + const char *domain = tomoyo_domain()->domainname->name; + loff_t len = strlen(domain); + loff_t pos = *ppos; + + if (pos >= len || !count) + return 0; + len -= pos; + if (count < len) + len = count; + if (copy_to_user(buf, domain + pos, len)) + return -EFAULT; + *ppos += len; + return len; +} + +/* Operations for /sys/kernel/security/tomoyo/self_domain interface. */ +static const struct file_operations tomoyo_self_operations = { + .write = tomoyo_write_self, + .read = tomoyo_read_self, +}; + +/** + * tomoyo_open - open() for /sys/kernel/security/tomoyo/ interface. + * + * @inode: Pointer to "struct inode". + * @file: Pointer to "struct file". + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_open(struct inode *inode, struct file *file) +{ + const u8 key = (uintptr_t) file_inode(file)->i_private; + + return tomoyo_open_control(key, file); +} + +/** + * tomoyo_release - close() for /sys/kernel/security/tomoyo/ interface. + * + * @inode: Pointer to "struct inode". + * @file: Pointer to "struct file". + * + */ +static int tomoyo_release(struct inode *inode, struct file *file) +{ + tomoyo_close_control(file->private_data); + return 0; +} + +/** + * tomoyo_poll - poll() for /sys/kernel/security/tomoyo/ interface. + * + * @file: Pointer to "struct file". + * @wait: Pointer to "poll_table". Maybe NULL. + * + * Returns EPOLLIN | EPOLLRDNORM | EPOLLOUT | EPOLLWRNORM if ready to read/write, + * EPOLLOUT | EPOLLWRNORM otherwise. + */ +static __poll_t tomoyo_poll(struct file *file, poll_table *wait) +{ + return tomoyo_poll_control(file, wait); +} + +/** + * tomoyo_read - read() for /sys/kernel/security/tomoyo/ interface. + * + * @file: Pointer to "struct file". + * @buf: Pointer to buffer. + * @count: Size of @buf. + * @ppos: Unused. + * + * Returns bytes read on success, negative value otherwise. + */ +static ssize_t tomoyo_read(struct file *file, char __user *buf, size_t count, + loff_t *ppos) +{ + return tomoyo_read_control(file->private_data, buf, count); +} + +/** + * tomoyo_write - write() for /sys/kernel/security/tomoyo/ interface. + * + * @file: Pointer to "struct file". + * @buf: Pointer to buffer. + * @count: Size of @buf. + * @ppos: Unused. + * + * Returns @count on success, negative value otherwise. + */ +static ssize_t tomoyo_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + return tomoyo_write_control(file->private_data, buf, count); +} + +/* + * tomoyo_operations is a "struct file_operations" which is used for handling + * /sys/kernel/security/tomoyo/ interface. + * + * Some files under /sys/kernel/security/tomoyo/ directory accept open(O_RDWR). + * See tomoyo_io_buffer for internals. + */ +static const struct file_operations tomoyo_operations = { + .open = tomoyo_open, + .release = tomoyo_release, + .poll = tomoyo_poll, + .read = tomoyo_read, + .write = tomoyo_write, + .llseek = noop_llseek, +}; + +/** + * tomoyo_create_entry - Create interface files under /sys/kernel/security/tomoyo/ directory. + * + * @name: The name of the interface file. + * @mode: The permission of the interface file. + * @parent: The parent directory. + * @key: Type of interface. + * + * Returns nothing. + */ +static void __init tomoyo_create_entry(const char *name, const umode_t mode, + struct dentry *parent, const u8 key) +{ + securityfs_create_file(name, mode, parent, (void *) (uintptr_t) key, + &tomoyo_operations); +} + +/** + * tomoyo_initerface_init - Initialize /sys/kernel/security/tomoyo/ interface. + * + * Returns 0. + */ +static int __init tomoyo_initerface_init(void) +{ + struct tomoyo_domain_info *domain; + struct dentry *tomoyo_dir; + + if (!tomoyo_enabled) + return 0; + domain = tomoyo_domain(); + /* Don't create securityfs entries unless registered. */ + if (domain != &tomoyo_kernel_domain) + return 0; + + tomoyo_dir = securityfs_create_dir("tomoyo", NULL); + tomoyo_create_entry("query", 0600, tomoyo_dir, + TOMOYO_QUERY); + tomoyo_create_entry("domain_policy", 0600, tomoyo_dir, + TOMOYO_DOMAINPOLICY); + tomoyo_create_entry("exception_policy", 0600, tomoyo_dir, + TOMOYO_EXCEPTIONPOLICY); + tomoyo_create_entry("audit", 0400, tomoyo_dir, + TOMOYO_AUDIT); + tomoyo_create_entry(".process_status", 0600, tomoyo_dir, + TOMOYO_PROCESS_STATUS); + tomoyo_create_entry("stat", 0644, tomoyo_dir, + TOMOYO_STAT); + tomoyo_create_entry("profile", 0600, tomoyo_dir, + TOMOYO_PROFILE); + tomoyo_create_entry("manager", 0600, tomoyo_dir, + TOMOYO_MANAGER); + tomoyo_create_entry("version", 0400, tomoyo_dir, + TOMOYO_VERSION); + securityfs_create_file("self_domain", 0666, tomoyo_dir, NULL, + &tomoyo_self_operations); + tomoyo_load_builtin_policy(); + return 0; +} + +fs_initcall(tomoyo_initerface_init); diff --git a/security/tomoyo/tomoyo.c b/security/tomoyo/tomoyo.c new file mode 100644 index 000000000..fb599401b --- /dev/null +++ b/security/tomoyo/tomoyo.c @@ -0,0 +1,602 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * security/tomoyo/tomoyo.c + * + * Copyright (C) 2005-2011 NTT DATA CORPORATION + */ + +#include <linux/lsm_hooks.h> +#include "common.h" + +/** + * tomoyo_domain - Get "struct tomoyo_domain_info" for current thread. + * + * Returns pointer to "struct tomoyo_domain_info" for current thread. + */ +struct tomoyo_domain_info *tomoyo_domain(void) +{ + struct tomoyo_task *s = tomoyo_task(current); + + if (s->old_domain_info && !current->in_execve) { + atomic_dec(&s->old_domain_info->users); + s->old_domain_info = NULL; + } + return s->domain_info; +} + +/** + * tomoyo_cred_prepare - Target for security_prepare_creds(). + * + * @new: Pointer to "struct cred". + * @old: Pointer to "struct cred". + * @gfp: Memory allocation flags. + * + * Returns 0. + */ +static int tomoyo_cred_prepare(struct cred *new, const struct cred *old, + gfp_t gfp) +{ + /* Restore old_domain_info saved by previous execve() request. */ + struct tomoyo_task *s = tomoyo_task(current); + + if (s->old_domain_info && !current->in_execve) { + atomic_dec(&s->domain_info->users); + s->domain_info = s->old_domain_info; + s->old_domain_info = NULL; + } + return 0; +} + +/** + * tomoyo_bprm_committed_creds - Target for security_bprm_committed_creds(). + * + * @bprm: Pointer to "struct linux_binprm". + */ +static void tomoyo_bprm_committed_creds(struct linux_binprm *bprm) +{ + /* Clear old_domain_info saved by execve() request. */ + struct tomoyo_task *s = tomoyo_task(current); + + atomic_dec(&s->old_domain_info->users); + s->old_domain_info = NULL; +} + +#ifndef CONFIG_SECURITY_TOMOYO_OMIT_USERSPACE_LOADER +/** + * tomoyo_bprm_creds_for_exec - Target for security_bprm_creds_for_exec(). + * + * @bprm: Pointer to "struct linux_binprm". + * + * Returns 0. + */ +static int tomoyo_bprm_creds_for_exec(struct linux_binprm *bprm) +{ + /* + * Load policy if /sbin/tomoyo-init exists and /sbin/init is requested + * for the first time. + */ + if (!tomoyo_policy_loaded) + tomoyo_load_policy(bprm->filename); + return 0; +} +#endif + +/** + * tomoyo_bprm_check_security - Target for security_bprm_check(). + * + * @bprm: Pointer to "struct linux_binprm". + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_bprm_check_security(struct linux_binprm *bprm) +{ + struct tomoyo_task *s = tomoyo_task(current); + + /* + * Execute permission is checked against pathname passed to execve() + * using current domain. + */ + if (!s->old_domain_info) { + const int idx = tomoyo_read_lock(); + const int err = tomoyo_find_next_domain(bprm); + + tomoyo_read_unlock(idx); + return err; + } + /* + * Read permission is checked against interpreters using next domain. + */ + return tomoyo_check_open_permission(s->domain_info, + &bprm->file->f_path, O_RDONLY); +} + +/** + * tomoyo_inode_getattr - Target for security_inode_getattr(). + * + * @path: Pointer to "struct path". + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_inode_getattr(const struct path *path) +{ + return tomoyo_path_perm(TOMOYO_TYPE_GETATTR, path, NULL); +} + +/** + * tomoyo_path_truncate - Target for security_path_truncate(). + * + * @path: Pointer to "struct path". + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_path_truncate(const struct path *path) +{ + return tomoyo_path_perm(TOMOYO_TYPE_TRUNCATE, path, NULL); +} + +/** + * tomoyo_path_unlink - Target for security_path_unlink(). + * + * @parent: Pointer to "struct path". + * @dentry: Pointer to "struct dentry". + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_path_unlink(const struct path *parent, struct dentry *dentry) +{ + struct path path = { .mnt = parent->mnt, .dentry = dentry }; + + return tomoyo_path_perm(TOMOYO_TYPE_UNLINK, &path, NULL); +} + +/** + * tomoyo_path_mkdir - Target for security_path_mkdir(). + * + * @parent: Pointer to "struct path". + * @dentry: Pointer to "struct dentry". + * @mode: DAC permission mode. + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_path_mkdir(const struct path *parent, struct dentry *dentry, + umode_t mode) +{ + struct path path = { .mnt = parent->mnt, .dentry = dentry }; + + return tomoyo_path_number_perm(TOMOYO_TYPE_MKDIR, &path, + mode & S_IALLUGO); +} + +/** + * tomoyo_path_rmdir - Target for security_path_rmdir(). + * + * @parent: Pointer to "struct path". + * @dentry: Pointer to "struct dentry". + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_path_rmdir(const struct path *parent, struct dentry *dentry) +{ + struct path path = { .mnt = parent->mnt, .dentry = dentry }; + + return tomoyo_path_perm(TOMOYO_TYPE_RMDIR, &path, NULL); +} + +/** + * tomoyo_path_symlink - Target for security_path_symlink(). + * + * @parent: Pointer to "struct path". + * @dentry: Pointer to "struct dentry". + * @old_name: Symlink's content. + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_path_symlink(const struct path *parent, struct dentry *dentry, + const char *old_name) +{ + struct path path = { .mnt = parent->mnt, .dentry = dentry }; + + return tomoyo_path_perm(TOMOYO_TYPE_SYMLINK, &path, old_name); +} + +/** + * tomoyo_path_mknod - Target for security_path_mknod(). + * + * @parent: Pointer to "struct path". + * @dentry: Pointer to "struct dentry". + * @mode: DAC permission mode. + * @dev: Device attributes. + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_path_mknod(const struct path *parent, struct dentry *dentry, + umode_t mode, unsigned int dev) +{ + struct path path = { .mnt = parent->mnt, .dentry = dentry }; + int type = TOMOYO_TYPE_CREATE; + const unsigned int perm = mode & S_IALLUGO; + + switch (mode & S_IFMT) { + case S_IFCHR: + type = TOMOYO_TYPE_MKCHAR; + break; + case S_IFBLK: + type = TOMOYO_TYPE_MKBLOCK; + break; + default: + goto no_dev; + } + return tomoyo_mkdev_perm(type, &path, perm, dev); + no_dev: + switch (mode & S_IFMT) { + case S_IFIFO: + type = TOMOYO_TYPE_MKFIFO; + break; + case S_IFSOCK: + type = TOMOYO_TYPE_MKSOCK; + break; + } + return tomoyo_path_number_perm(type, &path, perm); +} + +/** + * tomoyo_path_link - Target for security_path_link(). + * + * @old_dentry: Pointer to "struct dentry". + * @new_dir: Pointer to "struct path". + * @new_dentry: Pointer to "struct dentry". + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_path_link(struct dentry *old_dentry, const struct path *new_dir, + struct dentry *new_dentry) +{ + struct path path1 = { .mnt = new_dir->mnt, .dentry = old_dentry }; + struct path path2 = { .mnt = new_dir->mnt, .dentry = new_dentry }; + + return tomoyo_path2_perm(TOMOYO_TYPE_LINK, &path1, &path2); +} + +/** + * tomoyo_path_rename - Target for security_path_rename(). + * + * @old_parent: Pointer to "struct path". + * @old_dentry: Pointer to "struct dentry". + * @new_parent: Pointer to "struct path". + * @new_dentry: Pointer to "struct dentry". + * @flags: Rename options. + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_path_rename(const struct path *old_parent, + struct dentry *old_dentry, + const struct path *new_parent, + struct dentry *new_dentry, + const unsigned int flags) +{ + struct path path1 = { .mnt = old_parent->mnt, .dentry = old_dentry }; + struct path path2 = { .mnt = new_parent->mnt, .dentry = new_dentry }; + + if (flags & RENAME_EXCHANGE) { + const int err = tomoyo_path2_perm(TOMOYO_TYPE_RENAME, &path2, + &path1); + + if (err) + return err; + } + return tomoyo_path2_perm(TOMOYO_TYPE_RENAME, &path1, &path2); +} + +/** + * tomoyo_file_fcntl - Target for security_file_fcntl(). + * + * @file: Pointer to "struct file". + * @cmd: Command for fcntl(). + * @arg: Argument for @cmd. + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_file_fcntl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + if (!(cmd == F_SETFL && ((arg ^ file->f_flags) & O_APPEND))) + return 0; + return tomoyo_check_open_permission(tomoyo_domain(), &file->f_path, + O_WRONLY | (arg & O_APPEND)); +} + +/** + * tomoyo_file_open - Target for security_file_open(). + * + * @f: Pointer to "struct file". + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_file_open(struct file *f) +{ + /* Don't check read permission here if called from execve(). */ + if (current->in_execve) + return 0; + return tomoyo_check_open_permission(tomoyo_domain(), &f->f_path, + f->f_flags); +} + +/** + * tomoyo_file_ioctl - Target for security_file_ioctl(). + * + * @file: Pointer to "struct file". + * @cmd: Command for ioctl(). + * @arg: Argument for @cmd. + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_file_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + return tomoyo_path_number_perm(TOMOYO_TYPE_IOCTL, &file->f_path, cmd); +} + +/** + * tomoyo_path_chmod - Target for security_path_chmod(). + * + * @path: Pointer to "struct path". + * @mode: DAC permission mode. + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_path_chmod(const struct path *path, umode_t mode) +{ + return tomoyo_path_number_perm(TOMOYO_TYPE_CHMOD, path, + mode & S_IALLUGO); +} + +/** + * tomoyo_path_chown - Target for security_path_chown(). + * + * @path: Pointer to "struct path". + * @uid: Owner ID. + * @gid: Group ID. + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_path_chown(const struct path *path, kuid_t uid, kgid_t gid) +{ + int error = 0; + + if (uid_valid(uid)) + error = tomoyo_path_number_perm(TOMOYO_TYPE_CHOWN, path, + from_kuid(&init_user_ns, uid)); + if (!error && gid_valid(gid)) + error = tomoyo_path_number_perm(TOMOYO_TYPE_CHGRP, path, + from_kgid(&init_user_ns, gid)); + return error; +} + +/** + * tomoyo_path_chroot - Target for security_path_chroot(). + * + * @path: Pointer to "struct path". + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_path_chroot(const struct path *path) +{ + return tomoyo_path_perm(TOMOYO_TYPE_CHROOT, path, NULL); +} + +/** + * tomoyo_sb_mount - Target for security_sb_mount(). + * + * @dev_name: Name of device file. Maybe NULL. + * @path: Pointer to "struct path". + * @type: Name of filesystem type. Maybe NULL. + * @flags: Mount options. + * @data: Optional data. Maybe NULL. + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_sb_mount(const char *dev_name, const struct path *path, + const char *type, unsigned long flags, void *data) +{ + return tomoyo_mount_permission(dev_name, path, type, flags, data); +} + +/** + * tomoyo_sb_umount - Target for security_sb_umount(). + * + * @mnt: Pointer to "struct vfsmount". + * @flags: Unmount options. + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_sb_umount(struct vfsmount *mnt, int flags) +{ + struct path path = { .mnt = mnt, .dentry = mnt->mnt_root }; + + return tomoyo_path_perm(TOMOYO_TYPE_UMOUNT, &path, NULL); +} + +/** + * tomoyo_sb_pivotroot - Target for security_sb_pivotroot(). + * + * @old_path: Pointer to "struct path". + * @new_path: Pointer to "struct path". + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_sb_pivotroot(const struct path *old_path, const struct path *new_path) +{ + return tomoyo_path2_perm(TOMOYO_TYPE_PIVOT_ROOT, new_path, old_path); +} + +/** + * tomoyo_socket_listen - Check permission for listen(). + * + * @sock: Pointer to "struct socket". + * @backlog: Backlog parameter. + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_socket_listen(struct socket *sock, int backlog) +{ + return tomoyo_socket_listen_permission(sock); +} + +/** + * tomoyo_socket_connect - Check permission for connect(). + * + * @sock: Pointer to "struct socket". + * @addr: Pointer to "struct sockaddr". + * @addr_len: Size of @addr. + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_socket_connect(struct socket *sock, struct sockaddr *addr, + int addr_len) +{ + return tomoyo_socket_connect_permission(sock, addr, addr_len); +} + +/** + * tomoyo_socket_bind - Check permission for bind(). + * + * @sock: Pointer to "struct socket". + * @addr: Pointer to "struct sockaddr". + * @addr_len: Size of @addr. + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_socket_bind(struct socket *sock, struct sockaddr *addr, + int addr_len) +{ + return tomoyo_socket_bind_permission(sock, addr, addr_len); +} + +/** + * tomoyo_socket_sendmsg - Check permission for sendmsg(). + * + * @sock: Pointer to "struct socket". + * @msg: Pointer to "struct msghdr". + * @size: Size of message. + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_socket_sendmsg(struct socket *sock, struct msghdr *msg, + int size) +{ + return tomoyo_socket_sendmsg_permission(sock, msg, size); +} + +struct lsm_blob_sizes tomoyo_blob_sizes __lsm_ro_after_init = { + .lbs_task = sizeof(struct tomoyo_task), +}; + +/** + * tomoyo_task_alloc - Target for security_task_alloc(). + * + * @task: Pointer to "struct task_struct". + * @clone_flags: clone() flags. + * + * Returns 0. + */ +static int tomoyo_task_alloc(struct task_struct *task, + unsigned long clone_flags) +{ + struct tomoyo_task *old = tomoyo_task(current); + struct tomoyo_task *new = tomoyo_task(task); + + new->domain_info = old->domain_info; + atomic_inc(&new->domain_info->users); + new->old_domain_info = NULL; + return 0; +} + +/** + * tomoyo_task_free - Target for security_task_free(). + * + * @task: Pointer to "struct task_struct". + */ +static void tomoyo_task_free(struct task_struct *task) +{ + struct tomoyo_task *s = tomoyo_task(task); + + if (s->domain_info) { + atomic_dec(&s->domain_info->users); + s->domain_info = NULL; + } + if (s->old_domain_info) { + atomic_dec(&s->old_domain_info->users); + s->old_domain_info = NULL; + } +} + +/* + * tomoyo_security_ops is a "struct security_operations" which is used for + * registering TOMOYO. + */ +static struct security_hook_list tomoyo_hooks[] __lsm_ro_after_init = { + LSM_HOOK_INIT(cred_prepare, tomoyo_cred_prepare), + LSM_HOOK_INIT(bprm_committed_creds, tomoyo_bprm_committed_creds), + LSM_HOOK_INIT(task_alloc, tomoyo_task_alloc), + LSM_HOOK_INIT(task_free, tomoyo_task_free), +#ifndef CONFIG_SECURITY_TOMOYO_OMIT_USERSPACE_LOADER + LSM_HOOK_INIT(bprm_creds_for_exec, tomoyo_bprm_creds_for_exec), +#endif + LSM_HOOK_INIT(bprm_check_security, tomoyo_bprm_check_security), + LSM_HOOK_INIT(file_fcntl, tomoyo_file_fcntl), + LSM_HOOK_INIT(file_open, tomoyo_file_open), + LSM_HOOK_INIT(path_truncate, tomoyo_path_truncate), + LSM_HOOK_INIT(path_unlink, tomoyo_path_unlink), + LSM_HOOK_INIT(path_mkdir, tomoyo_path_mkdir), + LSM_HOOK_INIT(path_rmdir, tomoyo_path_rmdir), + LSM_HOOK_INIT(path_symlink, tomoyo_path_symlink), + LSM_HOOK_INIT(path_mknod, tomoyo_path_mknod), + LSM_HOOK_INIT(path_link, tomoyo_path_link), + LSM_HOOK_INIT(path_rename, tomoyo_path_rename), + LSM_HOOK_INIT(inode_getattr, tomoyo_inode_getattr), + LSM_HOOK_INIT(file_ioctl, tomoyo_file_ioctl), + LSM_HOOK_INIT(file_ioctl_compat, tomoyo_file_ioctl), + LSM_HOOK_INIT(path_chmod, tomoyo_path_chmod), + LSM_HOOK_INIT(path_chown, tomoyo_path_chown), + LSM_HOOK_INIT(path_chroot, tomoyo_path_chroot), + LSM_HOOK_INIT(sb_mount, tomoyo_sb_mount), + LSM_HOOK_INIT(sb_umount, tomoyo_sb_umount), + LSM_HOOK_INIT(sb_pivotroot, tomoyo_sb_pivotroot), + LSM_HOOK_INIT(socket_bind, tomoyo_socket_bind), + LSM_HOOK_INIT(socket_connect, tomoyo_socket_connect), + LSM_HOOK_INIT(socket_listen, tomoyo_socket_listen), + LSM_HOOK_INIT(socket_sendmsg, tomoyo_socket_sendmsg), +}; + +/* Lock for GC. */ +DEFINE_SRCU(tomoyo_ss); + +int tomoyo_enabled __lsm_ro_after_init = 1; + +/** + * tomoyo_init - Register TOMOYO Linux as a LSM module. + * + * Returns 0. + */ +static int __init tomoyo_init(void) +{ + struct tomoyo_task *s = tomoyo_task(current); + + /* register ourselves with the security framework */ + security_add_hooks(tomoyo_hooks, ARRAY_SIZE(tomoyo_hooks), "tomoyo"); + pr_info("TOMOYO Linux initialized\n"); + s->domain_info = &tomoyo_kernel_domain; + atomic_inc(&tomoyo_kernel_domain.users); + s->old_domain_info = NULL; + tomoyo_mm_init(); + + return 0; +} + +DEFINE_LSM(tomoyo) = { + .name = "tomoyo", + .enabled = &tomoyo_enabled, + .flags = LSM_FLAG_LEGACY_MAJOR, + .blobs = &tomoyo_blob_sizes, + .init = tomoyo_init, +}; diff --git a/security/tomoyo/util.c b/security/tomoyo/util.c new file mode 100644 index 000000000..6799b1122 --- /dev/null +++ b/security/tomoyo/util.c @@ -0,0 +1,1106 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * security/tomoyo/util.c + * + * Copyright (C) 2005-2011 NTT DATA CORPORATION + */ + +#include <linux/slab.h> +#include <linux/rculist.h> + +#include "common.h" + +/* Lock for protecting policy. */ +DEFINE_MUTEX(tomoyo_policy_lock); + +/* Has /sbin/init started? */ +bool tomoyo_policy_loaded; + +/* + * Mapping table from "enum tomoyo_mac_index" to + * "enum tomoyo_mac_category_index". + */ +const u8 tomoyo_index2category[TOMOYO_MAX_MAC_INDEX] = { + /* CONFIG::file group */ + [TOMOYO_MAC_FILE_EXECUTE] = TOMOYO_MAC_CATEGORY_FILE, + [TOMOYO_MAC_FILE_OPEN] = TOMOYO_MAC_CATEGORY_FILE, + [TOMOYO_MAC_FILE_CREATE] = TOMOYO_MAC_CATEGORY_FILE, + [TOMOYO_MAC_FILE_UNLINK] = TOMOYO_MAC_CATEGORY_FILE, + [TOMOYO_MAC_FILE_GETATTR] = TOMOYO_MAC_CATEGORY_FILE, + [TOMOYO_MAC_FILE_MKDIR] = TOMOYO_MAC_CATEGORY_FILE, + [TOMOYO_MAC_FILE_RMDIR] = TOMOYO_MAC_CATEGORY_FILE, + [TOMOYO_MAC_FILE_MKFIFO] = TOMOYO_MAC_CATEGORY_FILE, + [TOMOYO_MAC_FILE_MKSOCK] = TOMOYO_MAC_CATEGORY_FILE, + [TOMOYO_MAC_FILE_TRUNCATE] = TOMOYO_MAC_CATEGORY_FILE, + [TOMOYO_MAC_FILE_SYMLINK] = TOMOYO_MAC_CATEGORY_FILE, + [TOMOYO_MAC_FILE_MKBLOCK] = TOMOYO_MAC_CATEGORY_FILE, + [TOMOYO_MAC_FILE_MKCHAR] = TOMOYO_MAC_CATEGORY_FILE, + [TOMOYO_MAC_FILE_LINK] = TOMOYO_MAC_CATEGORY_FILE, + [TOMOYO_MAC_FILE_RENAME] = TOMOYO_MAC_CATEGORY_FILE, + [TOMOYO_MAC_FILE_CHMOD] = TOMOYO_MAC_CATEGORY_FILE, + [TOMOYO_MAC_FILE_CHOWN] = TOMOYO_MAC_CATEGORY_FILE, + [TOMOYO_MAC_FILE_CHGRP] = TOMOYO_MAC_CATEGORY_FILE, + [TOMOYO_MAC_FILE_IOCTL] = TOMOYO_MAC_CATEGORY_FILE, + [TOMOYO_MAC_FILE_CHROOT] = TOMOYO_MAC_CATEGORY_FILE, + [TOMOYO_MAC_FILE_MOUNT] = TOMOYO_MAC_CATEGORY_FILE, + [TOMOYO_MAC_FILE_UMOUNT] = TOMOYO_MAC_CATEGORY_FILE, + [TOMOYO_MAC_FILE_PIVOT_ROOT] = TOMOYO_MAC_CATEGORY_FILE, + /* CONFIG::network group */ + [TOMOYO_MAC_NETWORK_INET_STREAM_BIND] = + TOMOYO_MAC_CATEGORY_NETWORK, + [TOMOYO_MAC_NETWORK_INET_STREAM_LISTEN] = + TOMOYO_MAC_CATEGORY_NETWORK, + [TOMOYO_MAC_NETWORK_INET_STREAM_CONNECT] = + TOMOYO_MAC_CATEGORY_NETWORK, + [TOMOYO_MAC_NETWORK_INET_DGRAM_BIND] = + TOMOYO_MAC_CATEGORY_NETWORK, + [TOMOYO_MAC_NETWORK_INET_DGRAM_SEND] = + TOMOYO_MAC_CATEGORY_NETWORK, + [TOMOYO_MAC_NETWORK_INET_RAW_BIND] = + TOMOYO_MAC_CATEGORY_NETWORK, + [TOMOYO_MAC_NETWORK_INET_RAW_SEND] = + TOMOYO_MAC_CATEGORY_NETWORK, + [TOMOYO_MAC_NETWORK_UNIX_STREAM_BIND] = + TOMOYO_MAC_CATEGORY_NETWORK, + [TOMOYO_MAC_NETWORK_UNIX_STREAM_LISTEN] = + TOMOYO_MAC_CATEGORY_NETWORK, + [TOMOYO_MAC_NETWORK_UNIX_STREAM_CONNECT] = + TOMOYO_MAC_CATEGORY_NETWORK, + [TOMOYO_MAC_NETWORK_UNIX_DGRAM_BIND] = + TOMOYO_MAC_CATEGORY_NETWORK, + [TOMOYO_MAC_NETWORK_UNIX_DGRAM_SEND] = + TOMOYO_MAC_CATEGORY_NETWORK, + [TOMOYO_MAC_NETWORK_UNIX_SEQPACKET_BIND] = + TOMOYO_MAC_CATEGORY_NETWORK, + [TOMOYO_MAC_NETWORK_UNIX_SEQPACKET_LISTEN] = + TOMOYO_MAC_CATEGORY_NETWORK, + [TOMOYO_MAC_NETWORK_UNIX_SEQPACKET_CONNECT] = + TOMOYO_MAC_CATEGORY_NETWORK, + /* CONFIG::misc group */ + [TOMOYO_MAC_ENVIRON] = TOMOYO_MAC_CATEGORY_MISC, +}; + +/** + * tomoyo_convert_time - Convert time_t to YYYY/MM/DD hh/mm/ss. + * + * @time64: Seconds since 1970/01/01 00:00:00. + * @stamp: Pointer to "struct tomoyo_time". + * + * Returns nothing. + */ +void tomoyo_convert_time(time64_t time64, struct tomoyo_time *stamp) +{ + struct tm tm; + + time64_to_tm(time64, 0, &tm); + stamp->sec = tm.tm_sec; + stamp->min = tm.tm_min; + stamp->hour = tm.tm_hour; + stamp->day = tm.tm_mday; + stamp->month = tm.tm_mon + 1; + stamp->year = tm.tm_year + 1900; +} + +/** + * tomoyo_permstr - Find permission keywords. + * + * @string: String representation for permissions in foo/bar/buz format. + * @keyword: Keyword to find from @string/ + * + * Returns true if @keyword was found in @string, false otherwise. + * + * This function assumes that strncmp(w1, w2, strlen(w1)) != 0 if w1 != w2. + */ +bool tomoyo_permstr(const char *string, const char *keyword) +{ + const char *cp = strstr(string, keyword); + + if (cp) + return cp == string || *(cp - 1) == '/'; + return false; +} + +/** + * tomoyo_read_token - Read a word from a line. + * + * @param: Pointer to "struct tomoyo_acl_param". + * + * Returns a word on success, "" otherwise. + * + * To allow the caller to skip NULL check, this function returns "" rather than + * NULL if there is no more words to read. + */ +char *tomoyo_read_token(struct tomoyo_acl_param *param) +{ + char *pos = param->data; + char *del = strchr(pos, ' '); + + if (del) + *del++ = '\0'; + else + del = pos + strlen(pos); + param->data = del; + return pos; +} + +static bool tomoyo_correct_path2(const char *filename, const size_t len); + +/** + * tomoyo_get_domainname - Read a domainname from a line. + * + * @param: Pointer to "struct tomoyo_acl_param". + * + * Returns a domainname on success, NULL otherwise. + */ +const struct tomoyo_path_info *tomoyo_get_domainname +(struct tomoyo_acl_param *param) +{ + char *start = param->data; + char *pos = start; + + while (*pos) { + if (*pos++ != ' ' || + tomoyo_correct_path2(pos, strchrnul(pos, ' ') - pos)) + continue; + *(pos - 1) = '\0'; + break; + } + param->data = pos; + if (tomoyo_correct_domain(start)) + return tomoyo_get_name(start); + return NULL; +} + +/** + * tomoyo_parse_ulong - Parse an "unsigned long" value. + * + * @result: Pointer to "unsigned long". + * @str: Pointer to string to parse. + * + * Returns one of values in "enum tomoyo_value_type". + * + * The @src is updated to point the first character after the value + * on success. + */ +u8 tomoyo_parse_ulong(unsigned long *result, char **str) +{ + const char *cp = *str; + char *ep; + int base = 10; + + if (*cp == '0') { + char c = *(cp + 1); + + if (c == 'x' || c == 'X') { + base = 16; + cp += 2; + } else if (c >= '0' && c <= '7') { + base = 8; + cp++; + } + } + *result = simple_strtoul(cp, &ep, base); + if (cp == ep) + return TOMOYO_VALUE_TYPE_INVALID; + *str = ep; + switch (base) { + case 16: + return TOMOYO_VALUE_TYPE_HEXADECIMAL; + case 8: + return TOMOYO_VALUE_TYPE_OCTAL; + default: + return TOMOYO_VALUE_TYPE_DECIMAL; + } +} + +/** + * tomoyo_print_ulong - Print an "unsigned long" value. + * + * @buffer: Pointer to buffer. + * @buffer_len: Size of @buffer. + * @value: An "unsigned long" value. + * @type: Type of @value. + * + * Returns nothing. + */ +void tomoyo_print_ulong(char *buffer, const int buffer_len, + const unsigned long value, const u8 type) +{ + if (type == TOMOYO_VALUE_TYPE_DECIMAL) + snprintf(buffer, buffer_len, "%lu", value); + else if (type == TOMOYO_VALUE_TYPE_OCTAL) + snprintf(buffer, buffer_len, "0%lo", value); + else if (type == TOMOYO_VALUE_TYPE_HEXADECIMAL) + snprintf(buffer, buffer_len, "0x%lX", value); + else + snprintf(buffer, buffer_len, "type(%u)", type); +} + +/** + * tomoyo_parse_name_union - Parse a tomoyo_name_union. + * + * @param: Pointer to "struct tomoyo_acl_param". + * @ptr: Pointer to "struct tomoyo_name_union". + * + * Returns true on success, false otherwise. + */ +bool tomoyo_parse_name_union(struct tomoyo_acl_param *param, + struct tomoyo_name_union *ptr) +{ + char *filename; + + if (param->data[0] == '@') { + param->data++; + ptr->group = tomoyo_get_group(param, TOMOYO_PATH_GROUP); + return ptr->group != NULL; + } + filename = tomoyo_read_token(param); + if (!tomoyo_correct_word(filename)) + return false; + ptr->filename = tomoyo_get_name(filename); + return ptr->filename != NULL; +} + +/** + * tomoyo_parse_number_union - Parse a tomoyo_number_union. + * + * @param: Pointer to "struct tomoyo_acl_param". + * @ptr: Pointer to "struct tomoyo_number_union". + * + * Returns true on success, false otherwise. + */ +bool tomoyo_parse_number_union(struct tomoyo_acl_param *param, + struct tomoyo_number_union *ptr) +{ + char *data; + u8 type; + unsigned long v; + + memset(ptr, 0, sizeof(*ptr)); + if (param->data[0] == '@') { + param->data++; + ptr->group = tomoyo_get_group(param, TOMOYO_NUMBER_GROUP); + return ptr->group != NULL; + } + data = tomoyo_read_token(param); + type = tomoyo_parse_ulong(&v, &data); + if (type == TOMOYO_VALUE_TYPE_INVALID) + return false; + ptr->values[0] = v; + ptr->value_type[0] = type; + if (!*data) { + ptr->values[1] = v; + ptr->value_type[1] = type; + return true; + } + if (*data++ != '-') + return false; + type = tomoyo_parse_ulong(&v, &data); + if (type == TOMOYO_VALUE_TYPE_INVALID || *data || ptr->values[0] > v) + return false; + ptr->values[1] = v; + ptr->value_type[1] = type; + return true; +} + +/** + * tomoyo_byte_range - Check whether the string is a \ooo style octal value. + * + * @str: Pointer to the string. + * + * Returns true if @str is a \ooo style octal value, false otherwise. + * + * TOMOYO uses \ooo style representation for 0x01 - 0x20 and 0x7F - 0xFF. + * This function verifies that \ooo is in valid range. + */ +static inline bool tomoyo_byte_range(const char *str) +{ + return *str >= '0' && *str++ <= '3' && + *str >= '0' && *str++ <= '7' && + *str >= '0' && *str <= '7'; +} + +/** + * tomoyo_alphabet_char - Check whether the character is an alphabet. + * + * @c: The character to check. + * + * Returns true if @c is an alphabet character, false otherwise. + */ +static inline bool tomoyo_alphabet_char(const char c) +{ + return (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z'); +} + +/** + * tomoyo_make_byte - Make byte value from three octal characters. + * + * @c1: The first character. + * @c2: The second character. + * @c3: The third character. + * + * Returns byte value. + */ +static inline u8 tomoyo_make_byte(const u8 c1, const u8 c2, const u8 c3) +{ + return ((c1 - '0') << 6) + ((c2 - '0') << 3) + (c3 - '0'); +} + +/** + * tomoyo_valid - Check whether the character is a valid char. + * + * @c: The character to check. + * + * Returns true if @c is a valid character, false otherwise. + */ +static inline bool tomoyo_valid(const unsigned char c) +{ + return c > ' ' && c < 127; +} + +/** + * tomoyo_invalid - Check whether the character is an invalid char. + * + * @c: The character to check. + * + * Returns true if @c is an invalid character, false otherwise. + */ +static inline bool tomoyo_invalid(const unsigned char c) +{ + return c && (c <= ' ' || c >= 127); +} + +/** + * tomoyo_str_starts - Check whether the given string starts with the given keyword. + * + * @src: Pointer to pointer to the string. + * @find: Pointer to the keyword. + * + * Returns true if @src starts with @find, false otherwise. + * + * The @src is updated to point the first character after the @find + * if @src starts with @find. + */ +bool tomoyo_str_starts(char **src, const char *find) +{ + const int len = strlen(find); + char *tmp = *src; + + if (strncmp(tmp, find, len)) + return false; + tmp += len; + *src = tmp; + return true; +} + +/** + * tomoyo_normalize_line - Format string. + * + * @buffer: The line to normalize. + * + * Leading and trailing whitespaces are removed. + * Multiple whitespaces are packed into single space. + * + * Returns nothing. + */ +void tomoyo_normalize_line(unsigned char *buffer) +{ + unsigned char *sp = buffer; + unsigned char *dp = buffer; + bool first = true; + + while (tomoyo_invalid(*sp)) + sp++; + while (*sp) { + if (!first) + *dp++ = ' '; + first = false; + while (tomoyo_valid(*sp)) + *dp++ = *sp++; + while (tomoyo_invalid(*sp)) + sp++; + } + *dp = '\0'; +} + +/** + * tomoyo_correct_word2 - Validate a string. + * + * @string: The string to check. Maybe non-'\0'-terminated. + * @len: Length of @string. + * + * Check whether the given string follows the naming rules. + * Returns true if @string follows the naming rules, false otherwise. + */ +static bool tomoyo_correct_word2(const char *string, size_t len) +{ + u8 recursion = 20; + const char *const start = string; + bool in_repetition = false; + + if (!len) + goto out; + while (len--) { + unsigned char c = *string++; + + if (c == '\\') { + if (!len--) + goto out; + c = *string++; + if (c >= '0' && c <= '3') { + unsigned char d; + unsigned char e; + + if (!len-- || !len--) + goto out; + d = *string++; + e = *string++; + if (d < '0' || d > '7' || e < '0' || e > '7') + goto out; + c = tomoyo_make_byte(c, d, e); + if (c <= ' ' || c >= 127) + continue; + goto out; + } + switch (c) { + case '\\': /* "\\" */ + case '+': /* "\+" */ + case '?': /* "\?" */ + case 'x': /* "\x" */ + case 'a': /* "\a" */ + case '-': /* "\-" */ + continue; + } + if (!recursion--) + goto out; + switch (c) { + case '*': /* "\*" */ + case '@': /* "\@" */ + case '$': /* "\$" */ + case 'X': /* "\X" */ + case 'A': /* "\A" */ + continue; + case '{': /* "/\{" */ + if (string - 3 < start || *(string - 3) != '/') + goto out; + in_repetition = true; + continue; + case '}': /* "\}/" */ + if (*string != '/') + goto out; + if (!in_repetition) + goto out; + in_repetition = false; + continue; + } + goto out; + } else if (in_repetition && c == '/') { + goto out; + } else if (c <= ' ' || c >= 127) { + goto out; + } + } + if (in_repetition) + goto out; + return true; + out: + return false; +} + +/** + * tomoyo_correct_word - Validate a string. + * + * @string: The string to check. + * + * Check whether the given string follows the naming rules. + * Returns true if @string follows the naming rules, false otherwise. + */ +bool tomoyo_correct_word(const char *string) +{ + return tomoyo_correct_word2(string, strlen(string)); +} + +/** + * tomoyo_correct_path2 - Check whether the given pathname follows the naming rules. + * + * @filename: The pathname to check. + * @len: Length of @filename. + * + * Returns true if @filename follows the naming rules, false otherwise. + */ +static bool tomoyo_correct_path2(const char *filename, const size_t len) +{ + const char *cp1 = memchr(filename, '/', len); + const char *cp2 = memchr(filename, '.', len); + + return cp1 && (!cp2 || (cp1 < cp2)) && tomoyo_correct_word2(filename, len); +} + +/** + * tomoyo_correct_path - Validate a pathname. + * + * @filename: The pathname to check. + * + * Check whether the given pathname follows the naming rules. + * Returns true if @filename follows the naming rules, false otherwise. + */ +bool tomoyo_correct_path(const char *filename) +{ + return tomoyo_correct_path2(filename, strlen(filename)); +} + +/** + * tomoyo_correct_domain - Check whether the given domainname follows the naming rules. + * + * @domainname: The domainname to check. + * + * Returns true if @domainname follows the naming rules, false otherwise. + */ +bool tomoyo_correct_domain(const unsigned char *domainname) +{ + if (!domainname || !tomoyo_domain_def(domainname)) + return false; + domainname = strchr(domainname, ' '); + if (!domainname++) + return true; + while (1) { + const unsigned char *cp = strchr(domainname, ' '); + + if (!cp) + break; + if (!tomoyo_correct_path2(domainname, cp - domainname)) + return false; + domainname = cp + 1; + } + return tomoyo_correct_path(domainname); +} + +/** + * tomoyo_domain_def - Check whether the given token can be a domainname. + * + * @buffer: The token to check. + * + * Returns true if @buffer possibly be a domainname, false otherwise. + */ +bool tomoyo_domain_def(const unsigned char *buffer) +{ + const unsigned char *cp; + int len; + + if (*buffer != '<') + return false; + cp = strchr(buffer, ' '); + if (!cp) + len = strlen(buffer); + else + len = cp - buffer; + if (buffer[len - 1] != '>' || + !tomoyo_correct_word2(buffer + 1, len - 2)) + return false; + return true; +} + +/** + * tomoyo_find_domain - Find a domain by the given name. + * + * @domainname: The domainname to find. + * + * Returns pointer to "struct tomoyo_domain_info" if found, NULL otherwise. + * + * Caller holds tomoyo_read_lock(). + */ +struct tomoyo_domain_info *tomoyo_find_domain(const char *domainname) +{ + struct tomoyo_domain_info *domain; + struct tomoyo_path_info name; + + name.name = domainname; + tomoyo_fill_path_info(&name); + list_for_each_entry_rcu(domain, &tomoyo_domain_list, list, + srcu_read_lock_held(&tomoyo_ss)) { + if (!domain->is_deleted && + !tomoyo_pathcmp(&name, domain->domainname)) + return domain; + } + return NULL; +} + +/** + * tomoyo_const_part_length - Evaluate the initial length without a pattern in a token. + * + * @filename: The string to evaluate. + * + * Returns the initial length without a pattern in @filename. + */ +static int tomoyo_const_part_length(const char *filename) +{ + char c; + int len = 0; + + if (!filename) + return 0; + while ((c = *filename++) != '\0') { + if (c != '\\') { + len++; + continue; + } + c = *filename++; + switch (c) { + case '\\': /* "\\" */ + len += 2; + continue; + case '0': /* "\ooo" */ + case '1': + case '2': + case '3': + c = *filename++; + if (c < '0' || c > '7') + break; + c = *filename++; + if (c < '0' || c > '7') + break; + len += 4; + continue; + } + break; + } + return len; +} + +/** + * tomoyo_fill_path_info - Fill in "struct tomoyo_path_info" members. + * + * @ptr: Pointer to "struct tomoyo_path_info" to fill in. + * + * The caller sets "struct tomoyo_path_info"->name. + */ +void tomoyo_fill_path_info(struct tomoyo_path_info *ptr) +{ + const char *name = ptr->name; + const int len = strlen(name); + + ptr->const_len = tomoyo_const_part_length(name); + ptr->is_dir = len && (name[len - 1] == '/'); + ptr->is_patterned = (ptr->const_len < len); + ptr->hash = full_name_hash(NULL, name, len); +} + +/** + * tomoyo_file_matches_pattern2 - Pattern matching without '/' character and "\-" pattern. + * + * @filename: The start of string to check. + * @filename_end: The end of string to check. + * @pattern: The start of pattern to compare. + * @pattern_end: The end of pattern to compare. + * + * Returns true if @filename matches @pattern, false otherwise. + */ +static bool tomoyo_file_matches_pattern2(const char *filename, + const char *filename_end, + const char *pattern, + const char *pattern_end) +{ + while (filename < filename_end && pattern < pattern_end) { + char c; + int i; + int j; + + if (*pattern != '\\') { + if (*filename++ != *pattern++) + return false; + continue; + } + c = *filename; + pattern++; + switch (*pattern) { + case '?': + if (c == '/') { + return false; + } else if (c == '\\') { + if (filename[1] == '\\') + filename++; + else if (tomoyo_byte_range(filename + 1)) + filename += 3; + else + return false; + } + break; + case '\\': + if (c != '\\') + return false; + if (*++filename != '\\') + return false; + break; + case '+': + if (!isdigit(c)) + return false; + break; + case 'x': + if (!isxdigit(c)) + return false; + break; + case 'a': + if (!tomoyo_alphabet_char(c)) + return false; + break; + case '0': + case '1': + case '2': + case '3': + if (c == '\\' && tomoyo_byte_range(filename + 1) + && strncmp(filename + 1, pattern, 3) == 0) { + filename += 3; + pattern += 2; + break; + } + return false; /* Not matched. */ + case '*': + case '@': + for (i = 0; i <= filename_end - filename; i++) { + if (tomoyo_file_matches_pattern2( + filename + i, filename_end, + pattern + 1, pattern_end)) + return true; + c = filename[i]; + if (c == '.' && *pattern == '@') + break; + if (c != '\\') + continue; + if (filename[i + 1] == '\\') + i++; + else if (tomoyo_byte_range(filename + i + 1)) + i += 3; + else + break; /* Bad pattern. */ + } + return false; /* Not matched. */ + default: + j = 0; + c = *pattern; + if (c == '$') { + while (isdigit(filename[j])) + j++; + } else if (c == 'X') { + while (isxdigit(filename[j])) + j++; + } else if (c == 'A') { + while (tomoyo_alphabet_char(filename[j])) + j++; + } + for (i = 1; i <= j; i++) { + if (tomoyo_file_matches_pattern2( + filename + i, filename_end, + pattern + 1, pattern_end)) + return true; + } + return false; /* Not matched or bad pattern. */ + } + filename++; + pattern++; + } + while (*pattern == '\\' && + (*(pattern + 1) == '*' || *(pattern + 1) == '@')) + pattern += 2; + return filename == filename_end && pattern == pattern_end; +} + +/** + * tomoyo_file_matches_pattern - Pattern matching without '/' character. + * + * @filename: The start of string to check. + * @filename_end: The end of string to check. + * @pattern: The start of pattern to compare. + * @pattern_end: The end of pattern to compare. + * + * Returns true if @filename matches @pattern, false otherwise. + */ +static bool tomoyo_file_matches_pattern(const char *filename, + const char *filename_end, + const char *pattern, + const char *pattern_end) +{ + const char *pattern_start = pattern; + bool first = true; + bool result; + + while (pattern < pattern_end - 1) { + /* Split at "\-" pattern. */ + if (*pattern++ != '\\' || *pattern++ != '-') + continue; + result = tomoyo_file_matches_pattern2(filename, + filename_end, + pattern_start, + pattern - 2); + if (first) + result = !result; + if (result) + return false; + first = false; + pattern_start = pattern; + } + result = tomoyo_file_matches_pattern2(filename, filename_end, + pattern_start, pattern_end); + return first ? result : !result; +} + +/** + * tomoyo_path_matches_pattern2 - Do pathname pattern matching. + * + * @f: The start of string to check. + * @p: The start of pattern to compare. + * + * Returns true if @f matches @p, false otherwise. + */ +static bool tomoyo_path_matches_pattern2(const char *f, const char *p) +{ + const char *f_delimiter; + const char *p_delimiter; + + while (*f && *p) { + f_delimiter = strchr(f, '/'); + if (!f_delimiter) + f_delimiter = f + strlen(f); + p_delimiter = strchr(p, '/'); + if (!p_delimiter) + p_delimiter = p + strlen(p); + if (*p == '\\' && *(p + 1) == '{') + goto recursive; + if (!tomoyo_file_matches_pattern(f, f_delimiter, p, + p_delimiter)) + return false; + f = f_delimiter; + if (*f) + f++; + p = p_delimiter; + if (*p) + p++; + } + /* Ignore trailing "\*" and "\@" in @pattern. */ + while (*p == '\\' && + (*(p + 1) == '*' || *(p + 1) == '@')) + p += 2; + return !*f && !*p; + recursive: + /* + * The "\{" pattern is permitted only after '/' character. + * This guarantees that below "*(p - 1)" is safe. + * Also, the "\}" pattern is permitted only before '/' character + * so that "\{" + "\}" pair will not break the "\-" operator. + */ + if (*(p - 1) != '/' || p_delimiter <= p + 3 || *p_delimiter != '/' || + *(p_delimiter - 1) != '}' || *(p_delimiter - 2) != '\\') + return false; /* Bad pattern. */ + do { + /* Compare current component with pattern. */ + if (!tomoyo_file_matches_pattern(f, f_delimiter, p + 2, + p_delimiter - 2)) + break; + /* Proceed to next component. */ + f = f_delimiter; + if (!*f) + break; + f++; + /* Continue comparison. */ + if (tomoyo_path_matches_pattern2(f, p_delimiter + 1)) + return true; + f_delimiter = strchr(f, '/'); + } while (f_delimiter); + return false; /* Not matched. */ +} + +/** + * tomoyo_path_matches_pattern - Check whether the given filename matches the given pattern. + * + * @filename: The filename to check. + * @pattern: The pattern to compare. + * + * Returns true if matches, false otherwise. + * + * The following patterns are available. + * \\ \ itself. + * \ooo Octal representation of a byte. + * \* Zero or more repetitions of characters other than '/'. + * \@ Zero or more repetitions of characters other than '/' or '.'. + * \? 1 byte character other than '/'. + * \$ One or more repetitions of decimal digits. + * \+ 1 decimal digit. + * \X One or more repetitions of hexadecimal digits. + * \x 1 hexadecimal digit. + * \A One or more repetitions of alphabet characters. + * \a 1 alphabet character. + * + * \- Subtraction operator. + * + * /\{dir\}/ '/' + 'One or more repetitions of dir/' (e.g. /dir/ /dir/dir/ + * /dir/dir/dir/ ). + */ +bool tomoyo_path_matches_pattern(const struct tomoyo_path_info *filename, + const struct tomoyo_path_info *pattern) +{ + const char *f = filename->name; + const char *p = pattern->name; + const int len = pattern->const_len; + + /* If @pattern doesn't contain pattern, I can use strcmp(). */ + if (!pattern->is_patterned) + return !tomoyo_pathcmp(filename, pattern); + /* Don't compare directory and non-directory. */ + if (filename->is_dir != pattern->is_dir) + return false; + /* Compare the initial length without patterns. */ + if (strncmp(f, p, len)) + return false; + f += len; + p += len; + return tomoyo_path_matches_pattern2(f, p); +} + +/** + * tomoyo_get_exe - Get tomoyo_realpath() of current process. + * + * Returns the tomoyo_realpath() of current process on success, NULL otherwise. + * + * This function uses kzalloc(), so the caller must call kfree() + * if this function didn't return NULL. + */ +const char *tomoyo_get_exe(void) +{ + struct file *exe_file; + const char *cp; + struct mm_struct *mm = current->mm; + + if (!mm) + return NULL; + exe_file = get_mm_exe_file(mm); + if (!exe_file) + return NULL; + + cp = tomoyo_realpath_from_path(&exe_file->f_path); + fput(exe_file); + return cp; +} + +/** + * tomoyo_get_mode - Get MAC mode. + * + * @ns: Pointer to "struct tomoyo_policy_namespace". + * @profile: Profile number. + * @index: Index number of functionality. + * + * Returns mode. + */ +int tomoyo_get_mode(const struct tomoyo_policy_namespace *ns, const u8 profile, + const u8 index) +{ + u8 mode; + struct tomoyo_profile *p; + + if (!tomoyo_policy_loaded) + return TOMOYO_CONFIG_DISABLED; + p = tomoyo_profile(ns, profile); + mode = p->config[index]; + if (mode == TOMOYO_CONFIG_USE_DEFAULT) + mode = p->config[tomoyo_index2category[index] + + TOMOYO_MAX_MAC_INDEX]; + if (mode == TOMOYO_CONFIG_USE_DEFAULT) + mode = p->default_config; + return mode & 3; +} + +/** + * tomoyo_init_request_info - Initialize "struct tomoyo_request_info" members. + * + * @r: Pointer to "struct tomoyo_request_info" to initialize. + * @domain: Pointer to "struct tomoyo_domain_info". NULL for tomoyo_domain(). + * @index: Index number of functionality. + * + * Returns mode. + */ +int tomoyo_init_request_info(struct tomoyo_request_info *r, + struct tomoyo_domain_info *domain, const u8 index) +{ + u8 profile; + + memset(r, 0, sizeof(*r)); + if (!domain) + domain = tomoyo_domain(); + r->domain = domain; + profile = domain->profile; + r->profile = profile; + r->type = index; + r->mode = tomoyo_get_mode(domain->ns, profile, index); + return r->mode; +} + +/** + * tomoyo_domain_quota_is_ok - Check for domain's quota. + * + * @r: Pointer to "struct tomoyo_request_info". + * + * Returns true if the domain is not exceeded quota, false otherwise. + * + * Caller holds tomoyo_read_lock(). + */ +bool tomoyo_domain_quota_is_ok(struct tomoyo_request_info *r) +{ + unsigned int count = 0; + struct tomoyo_domain_info *domain = r->domain; + struct tomoyo_acl_info *ptr; + + if (r->mode != TOMOYO_CONFIG_LEARNING) + return false; + if (!domain) + return true; + if (READ_ONCE(domain->flags[TOMOYO_DIF_QUOTA_WARNED])) + return false; + list_for_each_entry_rcu(ptr, &domain->acl_info_list, list, + srcu_read_lock_held(&tomoyo_ss)) { + u16 perm; + + if (ptr->is_deleted) + continue; + /* + * Reading perm bitmap might race with tomoyo_merge_*() because + * caller does not hold tomoyo_policy_lock mutex. But exceeding + * max_learning_entry parameter by a few entries does not harm. + */ + switch (ptr->type) { + case TOMOYO_TYPE_PATH_ACL: + perm = data_race(container_of(ptr, struct tomoyo_path_acl, head)->perm); + break; + case TOMOYO_TYPE_PATH2_ACL: + perm = data_race(container_of(ptr, struct tomoyo_path2_acl, head)->perm); + break; + case TOMOYO_TYPE_PATH_NUMBER_ACL: + perm = data_race(container_of(ptr, struct tomoyo_path_number_acl, head) + ->perm); + break; + case TOMOYO_TYPE_MKDEV_ACL: + perm = data_race(container_of(ptr, struct tomoyo_mkdev_acl, head)->perm); + break; + case TOMOYO_TYPE_INET_ACL: + perm = data_race(container_of(ptr, struct tomoyo_inet_acl, head)->perm); + break; + case TOMOYO_TYPE_UNIX_ACL: + perm = data_race(container_of(ptr, struct tomoyo_unix_acl, head)->perm); + break; + case TOMOYO_TYPE_MANUAL_TASK_ACL: + perm = 0; + break; + default: + perm = 1; + } + count += hweight16(perm); + } + if (count < tomoyo_profile(domain->ns, domain->profile)-> + pref[TOMOYO_PREF_MAX_LEARNING_ENTRY]) + return true; + WRITE_ONCE(domain->flags[TOMOYO_DIF_QUOTA_WARNED], true); + /* r->granted = false; */ + tomoyo_write_log(r, "%s", tomoyo_dif[TOMOYO_DIF_QUOTA_WARNED]); +#ifndef CONFIG_SECURITY_TOMOYO_INSECURE_BUILTIN_SETTING + pr_warn("WARNING: Domain '%s' has too many ACLs to hold. Stopped learning mode.\n", + domain->domainname->name); +#endif + return false; +} diff --git a/security/yama/Kconfig b/security/yama/Kconfig new file mode 100644 index 000000000..a81030412 --- /dev/null +++ b/security/yama/Kconfig @@ -0,0 +1,14 @@ +# SPDX-License-Identifier: GPL-2.0-only +config SECURITY_YAMA + bool "Yama support" + depends on SECURITY + default n + help + This selects Yama, which extends DAC support with additional + system-wide security settings beyond regular Linux discretionary + access controls. Currently available is ptrace scope restriction. + Like capabilities, this security module stacks with other LSMs. + Further information can be found in + Documentation/admin-guide/LSM/Yama.rst. + + If you are unsure how to answer this question, answer N. diff --git a/security/yama/Makefile b/security/yama/Makefile new file mode 100644 index 000000000..0fa5d0fe2 --- /dev/null +++ b/security/yama/Makefile @@ -0,0 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0-only +obj-$(CONFIG_SECURITY_YAMA) := yama.o + +yama-y := yama_lsm.o diff --git a/security/yama/yama_lsm.c b/security/yama/yama_lsm.c new file mode 100644 index 000000000..06e226166 --- /dev/null +++ b/security/yama/yama_lsm.c @@ -0,0 +1,488 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Yama Linux Security Module + * + * Author: Kees Cook <keescook@chromium.org> + * + * Copyright (C) 2010 Canonical, Ltd. + * Copyright (C) 2011 The Chromium OS Authors. + */ + +#include <linux/lsm_hooks.h> +#include <linux/sysctl.h> +#include <linux/ptrace.h> +#include <linux/prctl.h> +#include <linux/ratelimit.h> +#include <linux/workqueue.h> +#include <linux/string_helpers.h> +#include <linux/task_work.h> +#include <linux/sched.h> +#include <linux/spinlock.h> + +#define YAMA_SCOPE_DISABLED 0 +#define YAMA_SCOPE_RELATIONAL 1 +#define YAMA_SCOPE_CAPABILITY 2 +#define YAMA_SCOPE_NO_ATTACH 3 + +static int ptrace_scope = YAMA_SCOPE_RELATIONAL; + +/* describe a ptrace relationship for potential exception */ +struct ptrace_relation { + struct task_struct *tracer; + struct task_struct *tracee; + bool invalid; + struct list_head node; + struct rcu_head rcu; +}; + +static LIST_HEAD(ptracer_relations); +static DEFINE_SPINLOCK(ptracer_relations_lock); + +static void yama_relation_cleanup(struct work_struct *work); +static DECLARE_WORK(yama_relation_work, yama_relation_cleanup); + +struct access_report_info { + struct callback_head work; + const char *access; + struct task_struct *target; + struct task_struct *agent; +}; + +static void __report_access(struct callback_head *work) +{ + struct access_report_info *info = + container_of(work, struct access_report_info, work); + char *target_cmd, *agent_cmd; + + target_cmd = kstrdup_quotable_cmdline(info->target, GFP_KERNEL); + agent_cmd = kstrdup_quotable_cmdline(info->agent, GFP_KERNEL); + + pr_notice_ratelimited( + "ptrace %s of \"%s\"[%d] was attempted by \"%s\"[%d]\n", + info->access, target_cmd, info->target->pid, agent_cmd, + info->agent->pid); + + kfree(agent_cmd); + kfree(target_cmd); + + put_task_struct(info->agent); + put_task_struct(info->target); + kfree(info); +} + +/* defers execution because cmdline access can sleep */ +static void report_access(const char *access, struct task_struct *target, + struct task_struct *agent) +{ + struct access_report_info *info; + char agent_comm[sizeof(agent->comm)]; + + assert_spin_locked(&target->alloc_lock); /* for target->comm */ + + if (current->flags & PF_KTHREAD) { + /* I don't think kthreads call task_work_run() before exiting. + * Imagine angry ranting about procfs here. + */ + pr_notice_ratelimited( + "ptrace %s of \"%s\"[%d] was attempted by \"%s\"[%d]\n", + access, target->comm, target->pid, + get_task_comm(agent_comm, agent), agent->pid); + return; + } + + info = kmalloc(sizeof(*info), GFP_ATOMIC); + if (!info) + return; + init_task_work(&info->work, __report_access); + get_task_struct(target); + get_task_struct(agent); + info->access = access; + info->target = target; + info->agent = agent; + if (task_work_add(current, &info->work, TWA_RESUME) == 0) + return; /* success */ + + WARN(1, "report_access called from exiting task"); + put_task_struct(target); + put_task_struct(agent); + kfree(info); +} + +/** + * yama_relation_cleanup - remove invalid entries from the relation list + * + */ +static void yama_relation_cleanup(struct work_struct *work) +{ + struct ptrace_relation *relation; + + spin_lock(&ptracer_relations_lock); + rcu_read_lock(); + list_for_each_entry_rcu(relation, &ptracer_relations, node) { + if (relation->invalid) { + list_del_rcu(&relation->node); + kfree_rcu(relation, rcu); + } + } + rcu_read_unlock(); + spin_unlock(&ptracer_relations_lock); +} + +/** + * yama_ptracer_add - add/replace an exception for this tracer/tracee pair + * @tracer: the task_struct of the process doing the ptrace + * @tracee: the task_struct of the process to be ptraced + * + * Each tracee can have, at most, one tracer registered. Each time this + * is called, the prior registered tracer will be replaced for the tracee. + * + * Returns 0 if relationship was added, -ve on error. + */ +static int yama_ptracer_add(struct task_struct *tracer, + struct task_struct *tracee) +{ + struct ptrace_relation *relation, *added; + + added = kmalloc(sizeof(*added), GFP_KERNEL); + if (!added) + return -ENOMEM; + + added->tracee = tracee; + added->tracer = tracer; + added->invalid = false; + + spin_lock(&ptracer_relations_lock); + rcu_read_lock(); + list_for_each_entry_rcu(relation, &ptracer_relations, node) { + if (relation->invalid) + continue; + if (relation->tracee == tracee) { + list_replace_rcu(&relation->node, &added->node); + kfree_rcu(relation, rcu); + goto out; + } + } + + list_add_rcu(&added->node, &ptracer_relations); + +out: + rcu_read_unlock(); + spin_unlock(&ptracer_relations_lock); + return 0; +} + +/** + * yama_ptracer_del - remove exceptions related to the given tasks + * @tracer: remove any relation where tracer task matches + * @tracee: remove any relation where tracee task matches + */ +static void yama_ptracer_del(struct task_struct *tracer, + struct task_struct *tracee) +{ + struct ptrace_relation *relation; + bool marked = false; + + rcu_read_lock(); + list_for_each_entry_rcu(relation, &ptracer_relations, node) { + if (relation->invalid) + continue; + if (relation->tracee == tracee || + (tracer && relation->tracer == tracer)) { + relation->invalid = true; + marked = true; + } + } + rcu_read_unlock(); + + if (marked) + schedule_work(&yama_relation_work); +} + +/** + * yama_task_free - check for task_pid to remove from exception list + * @task: task being removed + */ +static void yama_task_free(struct task_struct *task) +{ + yama_ptracer_del(task, task); +} + +/** + * yama_task_prctl - check for Yama-specific prctl operations + * @option: operation + * @arg2: argument + * @arg3: argument + * @arg4: argument + * @arg5: argument + * + * Return 0 on success, -ve on error. -ENOSYS is returned when Yama + * does not handle the given option. + */ +static int yama_task_prctl(int option, unsigned long arg2, unsigned long arg3, + unsigned long arg4, unsigned long arg5) +{ + int rc = -ENOSYS; + struct task_struct *myself = current; + + switch (option) { + case PR_SET_PTRACER: + /* Since a thread can call prctl(), find the group leader + * before calling _add() or _del() on it, since we want + * process-level granularity of control. The tracer group + * leader checking is handled later when walking the ancestry + * at the time of PTRACE_ATTACH check. + */ + rcu_read_lock(); + if (!thread_group_leader(myself)) + myself = rcu_dereference(myself->group_leader); + get_task_struct(myself); + rcu_read_unlock(); + + if (arg2 == 0) { + yama_ptracer_del(NULL, myself); + rc = 0; + } else if (arg2 == PR_SET_PTRACER_ANY || (int)arg2 == -1) { + rc = yama_ptracer_add(NULL, myself); + } else { + struct task_struct *tracer; + + tracer = find_get_task_by_vpid(arg2); + if (!tracer) { + rc = -EINVAL; + } else { + rc = yama_ptracer_add(tracer, myself); + put_task_struct(tracer); + } + } + + put_task_struct(myself); + break; + } + + return rc; +} + +/** + * task_is_descendant - walk up a process family tree looking for a match + * @parent: the process to compare against while walking up from child + * @child: the process to start from while looking upwards for parent + * + * Returns 1 if child is a descendant of parent, 0 if not. + */ +static int task_is_descendant(struct task_struct *parent, + struct task_struct *child) +{ + int rc = 0; + struct task_struct *walker = child; + + if (!parent || !child) + return 0; + + rcu_read_lock(); + if (!thread_group_leader(parent)) + parent = rcu_dereference(parent->group_leader); + while (walker->pid > 0) { + if (!thread_group_leader(walker)) + walker = rcu_dereference(walker->group_leader); + if (walker == parent) { + rc = 1; + break; + } + walker = rcu_dereference(walker->real_parent); + } + rcu_read_unlock(); + + return rc; +} + +/** + * ptracer_exception_found - tracer registered as exception for this tracee + * @tracer: the task_struct of the process attempting ptrace + * @tracee: the task_struct of the process to be ptraced + * + * Returns 1 if tracer has a ptracer exception ancestor for tracee. + */ +static int ptracer_exception_found(struct task_struct *tracer, + struct task_struct *tracee) +{ + int rc = 0; + struct ptrace_relation *relation; + struct task_struct *parent = NULL; + bool found = false; + + rcu_read_lock(); + + /* + * If there's already an active tracing relationship, then make an + * exception for the sake of other accesses, like process_vm_rw(). + */ + parent = ptrace_parent(tracee); + if (parent != NULL && same_thread_group(parent, tracer)) { + rc = 1; + goto unlock; + } + + /* Look for a PR_SET_PTRACER relationship. */ + if (!thread_group_leader(tracee)) + tracee = rcu_dereference(tracee->group_leader); + list_for_each_entry_rcu(relation, &ptracer_relations, node) { + if (relation->invalid) + continue; + if (relation->tracee == tracee) { + parent = relation->tracer; + found = true; + break; + } + } + + if (found && (parent == NULL || task_is_descendant(parent, tracer))) + rc = 1; + +unlock: + rcu_read_unlock(); + + return rc; +} + +/** + * yama_ptrace_access_check - validate PTRACE_ATTACH calls + * @child: task that current task is attempting to ptrace + * @mode: ptrace attach mode + * + * Returns 0 if following the ptrace is allowed, -ve on error. + */ +static int yama_ptrace_access_check(struct task_struct *child, + unsigned int mode) +{ + int rc = 0; + + /* require ptrace target be a child of ptracer on attach */ + if (mode & PTRACE_MODE_ATTACH) { + switch (ptrace_scope) { + case YAMA_SCOPE_DISABLED: + /* No additional restrictions. */ + break; + case YAMA_SCOPE_RELATIONAL: + rcu_read_lock(); + if (!pid_alive(child)) + rc = -EPERM; + if (!rc && !task_is_descendant(current, child) && + !ptracer_exception_found(current, child) && + !ns_capable(__task_cred(child)->user_ns, CAP_SYS_PTRACE)) + rc = -EPERM; + rcu_read_unlock(); + break; + case YAMA_SCOPE_CAPABILITY: + rcu_read_lock(); + if (!ns_capable(__task_cred(child)->user_ns, CAP_SYS_PTRACE)) + rc = -EPERM; + rcu_read_unlock(); + break; + case YAMA_SCOPE_NO_ATTACH: + default: + rc = -EPERM; + break; + } + } + + if (rc && (mode & PTRACE_MODE_NOAUDIT) == 0) + report_access("attach", child, current); + + return rc; +} + +/** + * yama_ptrace_traceme - validate PTRACE_TRACEME calls + * @parent: task that will become the ptracer of the current task + * + * Returns 0 if following the ptrace is allowed, -ve on error. + */ +static int yama_ptrace_traceme(struct task_struct *parent) +{ + int rc = 0; + + /* Only disallow PTRACE_TRACEME on more aggressive settings. */ + switch (ptrace_scope) { + case YAMA_SCOPE_CAPABILITY: + if (!has_ns_capability(parent, current_user_ns(), CAP_SYS_PTRACE)) + rc = -EPERM; + break; + case YAMA_SCOPE_NO_ATTACH: + rc = -EPERM; + break; + } + + if (rc) { + task_lock(current); + report_access("traceme", current, parent); + task_unlock(current); + } + + return rc; +} + +static struct security_hook_list yama_hooks[] __lsm_ro_after_init = { + LSM_HOOK_INIT(ptrace_access_check, yama_ptrace_access_check), + LSM_HOOK_INIT(ptrace_traceme, yama_ptrace_traceme), + LSM_HOOK_INIT(task_prctl, yama_task_prctl), + LSM_HOOK_INIT(task_free, yama_task_free), +}; + +#ifdef CONFIG_SYSCTL +static int yama_dointvec_minmax(struct ctl_table *table, int write, + void *buffer, size_t *lenp, loff_t *ppos) +{ + struct ctl_table table_copy; + + if (write && !capable(CAP_SYS_PTRACE)) + return -EPERM; + + /* Lock the max value if it ever gets set. */ + table_copy = *table; + if (*(int *)table_copy.data == *(int *)table_copy.extra2) + table_copy.extra1 = table_copy.extra2; + + return proc_dointvec_minmax(&table_copy, write, buffer, lenp, ppos); +} + +static int max_scope = YAMA_SCOPE_NO_ATTACH; + +static struct ctl_path yama_sysctl_path[] = { + { .procname = "kernel", }, + { .procname = "yama", }, + { } +}; + +static struct ctl_table yama_sysctl_table[] = { + { + .procname = "ptrace_scope", + .data = &ptrace_scope, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = yama_dointvec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = &max_scope, + }, + { } +}; +static void __init yama_init_sysctl(void) +{ + if (!register_sysctl_paths(yama_sysctl_path, yama_sysctl_table)) + panic("Yama: sysctl registration failed.\n"); +} +#else +static inline void yama_init_sysctl(void) { } +#endif /* CONFIG_SYSCTL */ + +static int __init yama_init(void) +{ + pr_info("Yama: becoming mindful.\n"); + security_add_hooks(yama_hooks, ARRAY_SIZE(yama_hooks), "yama"); + yama_init_sysctl(); + return 0; +} + +DEFINE_LSM(yama) = { + .name = "yama", + .init = yama_init, +}; |