diff options
Diffstat (limited to '')
| -rw-r--r-- | security/selinux/hooks.c | 7570 |
1 files changed, 7570 insertions, 0 deletions
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 |