diff options
Diffstat (limited to 'debian/patches/features/all/lockdown/efi-lock-down-the-kernel-if-booted-in-secure-boot-mo.patch')
| -rw-r--r-- | debian/patches/features/all/lockdown/efi-lock-down-the-kernel-if-booted-in-secure-boot-mo.patch | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/debian/patches/features/all/lockdown/efi-lock-down-the-kernel-if-booted-in-secure-boot-mo.patch b/debian/patches/features/all/lockdown/efi-lock-down-the-kernel-if-booted-in-secure-boot-mo.patch new file mode 100644 index 000000000..627e37154 --- /dev/null +++ b/debian/patches/features/all/lockdown/efi-lock-down-the-kernel-if-booted-in-secure-boot-mo.patch @@ -0,0 +1,127 @@ +From: Ben Hutchings <ben@decadent.org.uk> +Date: Tue, 10 Sep 2019 11:54:28 +0100 +Subject: efi: Lock down the kernel if booted in secure boot mode + +Based on an earlier patch by David Howells, who wrote the following +description: + +> UEFI Secure Boot provides a mechanism for ensuring that the firmware will +> only load signed bootloaders and kernels. Certain use cases may also +> require that all kernel modules also be signed. Add a configuration option +> that to lock down the kernel - which includes requiring validly signed +> modules - if the kernel is secure-booted. + +Signed-off-by: Ben Hutchings <ben@decadent.org.uk> +--- + arch/x86/kernel/setup.c | 4 ++-- + drivers/firmware/efi/secureboot.c | 3 +++ + include/linux/security.h | 6 ++++++ + security/lockdown/Kconfig | 15 +++++++++++++++ + security/lockdown/lockdown.c | 2 +- + 5 files changed, 27 insertions(+), 3 deletions(-) + +Index: debian-kernel/arch/x86/kernel/setup.c +=================================================================== +--- debian-kernel.orig/arch/x86/kernel/setup.c ++++ debian-kernel/arch/x86/kernel/setup.c +@@ -979,6 +979,8 @@ void __init setup_arch(char **cmdline_p) + if (efi_enabled(EFI_BOOT)) + efi_init(); + ++ efi_set_secure_boot(boot_params.secure_boot); ++ + dmi_setup(); + + /* +@@ -1130,8 +1132,6 @@ void __init setup_arch(char **cmdline_p) + /* Allocate bigger log buffer */ + setup_log_buf(1); + +- efi_set_secure_boot(boot_params.secure_boot); +- + reserve_initrd(); + + acpi_table_upgrade(); +Index: debian-kernel/drivers/firmware/efi/secureboot.c +=================================================================== +--- debian-kernel.orig/drivers/firmware/efi/secureboot.c ++++ debian-kernel/drivers/firmware/efi/secureboot.c +@@ -15,6 +15,7 @@ + #include <linux/efi.h> + #include <linux/kernel.h> + #include <linux/printk.h> ++#include <linux/security.h> + + /* + * Decide what to do when UEFI secure boot mode is enabled. +@@ -28,6 +29,10 @@ void __init efi_set_secure_boot(enum efi + break; + case efi_secureboot_mode_enabled: + set_bit(EFI_SECURE_BOOT, &efi.flags); ++#ifdef CONFIG_LOCK_DOWN_IN_EFI_SECURE_BOOT ++ lock_kernel_down("EFI Secure Boot", ++ LOCKDOWN_INTEGRITY_MAX); ++#endif + pr_info("Secure boot enabled\n"); + break; + default: +Index: debian-kernel/include/linux/security.h +=================================================================== +--- debian-kernel.orig/include/linux/security.h ++++ debian-kernel/include/linux/security.h +@@ -451,6 +451,7 @@ int security_inode_notifysecctx(struct i + int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen); + int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen); + int security_locked_down(enum lockdown_reason what); ++int lock_kernel_down(const char *where, enum lockdown_reason level); + #else /* CONFIG_SECURITY */ + + static inline int call_blocking_lsm_notifier(enum lsm_event event, void *data) +@@ -1291,6 +1292,11 @@ static inline int security_locked_down(e + { + return 0; + } ++static inline int ++lock_kernel_down(const char *where, enum lockdown_reason level) ++{ ++ return -EOPNOTSUPP; ++} + #endif /* CONFIG_SECURITY */ + + #if defined(CONFIG_SECURITY) && defined(CONFIG_WATCH_QUEUE) +Index: debian-kernel/security/lockdown/Kconfig +=================================================================== +--- debian-kernel.orig/security/lockdown/Kconfig ++++ debian-kernel/security/lockdown/Kconfig +@@ -45,3 +45,18 @@ config LOCK_DOWN_KERNEL_FORCE_CONFIDENTI + disabled. + + endchoice ++ ++config LOCK_DOWN_IN_EFI_SECURE_BOOT ++ bool "Lock down the kernel in EFI Secure Boot mode" ++ default n ++ depends on SECURITY_LOCKDOWN_LSM ++ depends on EFI ++ select SECURITY_LOCKDOWN_LSM_EARLY ++ help ++ UEFI Secure Boot provides a mechanism for ensuring that the firmware ++ will only load signed bootloaders and kernels. Secure boot mode may ++ be determined from EFI variables provided by the system firmware if ++ not indicated by the boot parameters. ++ ++ Enabling this option results in kernel lockdown being ++ triggered in confidentiality mode if EFI Secure Boot is set. +Index: debian-kernel/security/lockdown/lockdown.c +=================================================================== +--- debian-kernel.orig/security/lockdown/lockdown.c ++++ debian-kernel/security/lockdown/lockdown.c +@@ -23,7 +23,7 @@ static const enum lockdown_reason lockdo + /* + * Put the kernel into lock-down mode. + */ +-static int lock_kernel_down(const char *where, enum lockdown_reason level) ++int lock_kernel_down(const char *where, enum lockdown_reason level) + { + if (kernel_locked_down >= level) + return -EPERM; |