| // 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_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; |
| |