net/rpmsg: add support for new rpmsg sockets
[rpmsg/rpmsg.git] / security / selinux / hooks.c
1 /*
2  *  NSA Security-Enhanced Linux (SELinux) security module
3  *
4  *  This file contains the SELinux hook function implementations.
5  *
6  *  Authors:  Stephen Smalley, <sds@tycho.nsa.gov>
7  *            Chris Vance, <cvance@nai.com>
8  *            Wayne Salamon, <wsalamon@nai.com>
9  *            James Morris <jmorris@redhat.com>
10  *
11  *  Copyright (C) 2001,2002 Networks Associates Technology, Inc.
12  *  Copyright (C) 2003-2008 Red Hat, Inc., James Morris <jmorris@redhat.com>
13  *                                         Eric Paris <eparis@redhat.com>
14  *  Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
15  *                          <dgoeddel@trustedcs.com>
16  *  Copyright (C) 2006, 2007, 2009 Hewlett-Packard Development Company, L.P.
17  *      Paul Moore <paul@paul-moore.com>
18  *  Copyright (C) 2007 Hitachi Software Engineering Co., Ltd.
19  *                     Yuichi Nakamura <ynakam@hitachisoft.jp>
20  *  Copyright (C) 2016 Mellanox Technologies
21  *
22  *      This program is free software; you can redistribute it and/or modify
23  *      it under the terms of the GNU General Public License version 2,
24  *      as published by the Free Software Foundation.
25  */
27 #include <linux/init.h>
28 #include <linux/kd.h>
29 #include <linux/kernel.h>
30 #include <linux/tracehook.h>
31 #include <linux/errno.h>
32 #include <linux/sched/signal.h>
33 #include <linux/sched/task.h>
34 #include <linux/lsm_hooks.h>
35 #include <linux/xattr.h>
36 #include <linux/capability.h>
37 #include <linux/unistd.h>
38 #include <linux/mm.h>
39 #include <linux/mman.h>
40 #include <linux/slab.h>
41 #include <linux/pagemap.h>
42 #include <linux/proc_fs.h>
43 #include <linux/swap.h>
44 #include <linux/spinlock.h>
45 #include <linux/syscalls.h>
46 #include <linux/dcache.h>
47 #include <linux/file.h>
48 #include <linux/fdtable.h>
49 #include <linux/namei.h>
50 #include <linux/mount.h>
51 #include <linux/netfilter_ipv4.h>
52 #include <linux/netfilter_ipv6.h>
53 #include <linux/tty.h>
54 #include <net/icmp.h>
55 #include <net/ip.h>             /* for local_port_range[] */
56 #include <net/tcp.h>            /* struct or_callable used in sock_rcv_skb */
57 #include <net/inet_connection_sock.h>
58 #include <net/net_namespace.h>
59 #include <net/netlabel.h>
60 #include <linux/uaccess.h>
61 #include <asm/ioctls.h>
62 #include <linux/atomic.h>
63 #include <linux/bitops.h>
64 #include <linux/interrupt.h>
65 #include <linux/netdevice.h>    /* for network interface checks */
66 #include <net/netlink.h>
67 #include <linux/tcp.h>
68 #include <linux/udp.h>
69 #include <linux/dccp.h>
70 #include <linux/sctp.h>
71 #include <net/sctp/structs.h>
72 #include <linux/quota.h>
73 #include <linux/un.h>           /* for Unix socket types */
74 #include <net/af_unix.h>        /* for Unix socket types */
75 #include <linux/parser.h>
76 #include <linux/nfs_mount.h>
77 #include <net/ipv6.h>
78 #include <linux/hugetlb.h>
79 #include <linux/personality.h>
80 #include <linux/audit.h>
81 #include <linux/string.h>
82 #include <linux/selinux.h>
83 #include <linux/mutex.h>
84 #include <linux/posix-timers.h>
85 #include <linux/syslog.h>
86 #include <linux/user_namespace.h>
87 #include <linux/export.h>
88 #include <linux/msg.h>
89 #include <linux/shm.h>
90 #include <linux/bpf.h>
92 #include "avc.h"
93 #include "objsec.h"
94 #include "netif.h"
95 #include "netnode.h"
96 #include "netport.h"
97 #include "ibpkey.h"
98 #include "xfrm.h"
99 #include "netlabel.h"
100 #include "audit.h"
101 #include "avc_ss.h"
103 struct selinux_state selinux_state;
105 /* SECMARK reference count */
106 static atomic_t selinux_secmark_refcount = ATOMIC_INIT(0);
108 #ifdef CONFIG_SECURITY_SELINUX_DEVELOP
109 static int selinux_enforcing_boot;
111 static int __init enforcing_setup(char *str)
113         unsigned long enforcing;
114         if (!kstrtoul(str, 0, &enforcing))
115                 selinux_enforcing_boot = enforcing ? 1 : 0;
116         return 1;
118 __setup("enforcing=", enforcing_setup);
119 #else
120 #define selinux_enforcing_boot 1
121 #endif
123 #ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM
124 int selinux_enabled = CONFIG_SECURITY_SELINUX_BOOTPARAM_VALUE;
126 static int __init selinux_enabled_setup(char *str)
128         unsigned long enabled;
129         if (!kstrtoul(str, 0, &enabled))
130                 selinux_enabled = enabled ? 1 : 0;
131         return 1;
133 __setup("selinux=", selinux_enabled_setup);
134 #else
135 int selinux_enabled = 1;
136 #endif
138 static unsigned int selinux_checkreqprot_boot =
139         CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE;
141 static int __init checkreqprot_setup(char *str)
143         unsigned long checkreqprot;
145         if (!kstrtoul(str, 0, &checkreqprot))
146                 selinux_checkreqprot_boot = checkreqprot ? 1 : 0;
147         return 1;
149 __setup("checkreqprot=", checkreqprot_setup);
151 static struct kmem_cache *sel_inode_cache;
152 static struct kmem_cache *file_security_cache;
154 /**
155  * selinux_secmark_enabled - Check to see if SECMARK is currently enabled
156  *
157  * Description:
158  * This function checks the SECMARK reference counter to see if any SECMARK
159  * targets are currently configured, if the reference counter is greater than
160  * zero SECMARK is considered to be enabled.  Returns true (1) if SECMARK is
161  * enabled, false (0) if SECMARK is disabled.  If the always_check_network
162  * policy capability is enabled, SECMARK is always considered enabled.
163  *
164  */
165 static int selinux_secmark_enabled(void)
167         return (selinux_policycap_alwaysnetwork() ||
168                 atomic_read(&selinux_secmark_refcount));
171 /**
172  * selinux_peerlbl_enabled - Check to see if peer labeling is currently enabled
173  *
174  * Description:
175  * This function checks if NetLabel or labeled IPSEC is enabled.  Returns true
176  * (1) if any are enabled or false (0) if neither are enabled.  If the
177  * always_check_network policy capability is enabled, peer labeling
178  * is always considered enabled.
179  *
180  */
181 static int selinux_peerlbl_enabled(void)
183         return (selinux_policycap_alwaysnetwork() ||
184                 netlbl_enabled() || selinux_xfrm_enabled());
187 static int selinux_netcache_avc_callback(u32 event)
189         if (event == AVC_CALLBACK_RESET) {
190                 sel_netif_flush();
191                 sel_netnode_flush();
192                 sel_netport_flush();
193                 synchronize_net();
194         }
195         return 0;
198 static int selinux_lsm_notifier_avc_callback(u32 event)
200         if (event == AVC_CALLBACK_RESET) {
201                 sel_ib_pkey_flush();
202                 call_lsm_notifier(LSM_POLICY_CHANGE, NULL);
203         }
205         return 0;
208 /*
209  * initialise the security for the init task
210  */
211 static void cred_init_security(void)
213         struct cred *cred = (struct cred *) current->real_cred;
214         struct task_security_struct *tsec;
216         tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL);
217         if (!tsec)
218                 panic("SELinux:  Failed to initialize initial task.\n");
220         tsec->osid = tsec->sid = SECINITSID_KERNEL;
221         cred->security = tsec;
224 /*
225  * get the security ID of a set of credentials
226  */
227 static inline u32 cred_sid(const struct cred *cred)
229         const struct task_security_struct *tsec;
231         tsec = cred->security;
232         return tsec->sid;
235 /*
236  * get the objective security ID of a task
237  */
238 static inline u32 task_sid(const struct task_struct *task)
240         u32 sid;
242         rcu_read_lock();
243         sid = cred_sid(__task_cred(task));
244         rcu_read_unlock();
245         return sid;
248 /* Allocate and free functions for each kind of security blob. */
250 static int inode_alloc_security(struct inode *inode)
252         struct inode_security_struct *isec;
253         u32 sid = current_sid();
255         isec = kmem_cache_zalloc(sel_inode_cache, GFP_NOFS);
256         if (!isec)
257                 return -ENOMEM;
259         spin_lock_init(&isec->lock);
260         INIT_LIST_HEAD(&isec->list);
261         isec->inode = inode;
262         isec->sid = SECINITSID_UNLABELED;
263         isec->sclass = SECCLASS_FILE;
264         isec->task_sid = sid;
265         isec->initialized = LABEL_INVALID;
266         inode->i_security = isec;
268         return 0;
271 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry);
273 /*
274  * Try reloading inode security labels that have been marked as invalid.  The
275  * @may_sleep parameter indicates when sleeping and thus reloading labels is
276  * allowed; when set to false, returns -ECHILD when the label is
277  * invalid.  The @dentry parameter should be set to a dentry of the inode.
278  */
279 static int __inode_security_revalidate(struct inode *inode,
280                                        struct dentry *dentry,
281                                        bool may_sleep)
283         struct inode_security_struct *isec = inode->i_security;
285         might_sleep_if(may_sleep);
287         if (selinux_state.initialized &&
288             isec->initialized != LABEL_INITIALIZED) {
289                 if (!may_sleep)
290                         return -ECHILD;
292                 /*
293                  * Try reloading the inode security label.  This will fail if
294                  * @opt_dentry is NULL and no dentry for this inode can be
295                  * found; in that case, continue using the old label.
296                  */
297                 inode_doinit_with_dentry(inode, dentry);
298         }
299         return 0;
302 static struct inode_security_struct *inode_security_novalidate(struct inode *inode)
304         return inode->i_security;
307 static struct inode_security_struct *inode_security_rcu(struct inode *inode, bool rcu)
309         int error;
311         error = __inode_security_revalidate(inode, NULL, !rcu);
312         if (error)
313                 return ERR_PTR(error);
314         return inode->i_security;
317 /*
318  * Get the security label of an inode.
319  */
320 static struct inode_security_struct *inode_security(struct inode *inode)
322         __inode_security_revalidate(inode, NULL, true);
323         return inode->i_security;
326 static struct inode_security_struct *backing_inode_security_novalidate(struct dentry *dentry)
328         struct inode *inode = d_backing_inode(dentry);
330         return inode->i_security;
333 /*
334  * Get the security label of a dentry's backing inode.
335  */
336 static struct inode_security_struct *backing_inode_security(struct dentry *dentry)
338         struct inode *inode = d_backing_inode(dentry);
340         __inode_security_revalidate(inode, dentry, true);
341         return inode->i_security;
344 static void inode_free_rcu(struct rcu_head *head)
346         struct inode_security_struct *isec;
348         isec = container_of(head, struct inode_security_struct, rcu);
349         kmem_cache_free(sel_inode_cache, isec);
352 static void inode_free_security(struct inode *inode)
354         struct inode_security_struct *isec = inode->i_security;
355         struct superblock_security_struct *sbsec = inode->i_sb->s_security;
357         /*
358          * As not all inode security structures are in a list, we check for
359          * empty list outside of the lock to make sure that we won't waste
360          * time taking a lock doing nothing.
361          *
362          * The list_del_init() function can be safely called more than once.
363          * It should not be possible for this function to be called with
364          * concurrent list_add(), but for better safety against future changes
365          * in the code, we use list_empty_careful() here.
366          */
367         if (!list_empty_careful(&isec->list)) {
368                 spin_lock(&sbsec->isec_lock);
369                 list_del_init(&isec->list);
370                 spin_unlock(&sbsec->isec_lock);
371         }
373         /*
374          * The inode may still be referenced in a path walk and
375          * a call to selinux_inode_permission() can be made
376          * after inode_free_security() is called. Ideally, the VFS
377          * wouldn't do this, but fixing that is a much harder
378          * job. For now, simply free the i_security via RCU, and
379          * leave the current inode->i_security pointer intact.
380          * The inode will be freed after the RCU grace period too.
381          */
382         call_rcu(&isec->rcu, inode_free_rcu);
385 static int file_alloc_security(struct file *file)
387         struct file_security_struct *fsec;
388         u32 sid = current_sid();
390         fsec = kmem_cache_zalloc(file_security_cache, GFP_KERNEL);
391         if (!fsec)
392                 return -ENOMEM;
394         fsec->sid = sid;
395         fsec->fown_sid = sid;
396         file->f_security = fsec;
398         return 0;
401 static void file_free_security(struct file *file)
403         struct file_security_struct *fsec = file->f_security;
404         file->f_security = NULL;
405         kmem_cache_free(file_security_cache, fsec);
408 static int superblock_alloc_security(struct super_block *sb)
410         struct superblock_security_struct *sbsec;
412         sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL);
413         if (!sbsec)
414                 return -ENOMEM;
416         mutex_init(&sbsec->lock);
417         INIT_LIST_HEAD(&sbsec->isec_head);
418         spin_lock_init(&sbsec->isec_lock);
419         sbsec->sb = sb;
420         sbsec->sid = SECINITSID_UNLABELED;
421         sbsec->def_sid = SECINITSID_FILE;
422         sbsec->mntpoint_sid = SECINITSID_UNLABELED;
423         sb->s_security = sbsec;
425         return 0;
428 static void superblock_free_security(struct super_block *sb)
430         struct superblock_security_struct *sbsec = sb->s_security;
431         sb->s_security = NULL;
432         kfree(sbsec);
435 static inline int inode_doinit(struct inode *inode)
437         return inode_doinit_with_dentry(inode, NULL);
440 enum {
441         Opt_error = -1,
442         Opt_context = 1,
443         Opt_fscontext = 2,
444         Opt_defcontext = 3,
445         Opt_rootcontext = 4,
446         Opt_labelsupport = 5,
447         Opt_nextmntopt = 6,
448 };
450 #define NUM_SEL_MNT_OPTS        (Opt_nextmntopt - 1)
452 static const match_table_t tokens = {
453         {Opt_context, CONTEXT_STR "%s"},
454         {Opt_fscontext, FSCONTEXT_STR "%s"},
455         {Opt_defcontext, DEFCONTEXT_STR "%s"},
456         {Opt_rootcontext, ROOTCONTEXT_STR "%s"},
457         {Opt_labelsupport, LABELSUPP_STR},
458         {Opt_error, NULL},
459 };
461 #define SEL_MOUNT_FAIL_MSG "SELinux:  duplicate or incompatible mount options\n"
463 static int may_context_mount_sb_relabel(u32 sid,
464                         struct superblock_security_struct *sbsec,
465                         const struct cred *cred)
467         const struct task_security_struct *tsec = cred->security;
468         int rc;
470         rc = avc_has_perm(&selinux_state,
471                           tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
472                           FILESYSTEM__RELABELFROM, NULL);
473         if (rc)
474                 return rc;
476         rc = avc_has_perm(&selinux_state,
477                           tsec->sid, sid, SECCLASS_FILESYSTEM,
478                           FILESYSTEM__RELABELTO, NULL);
479         return rc;
482 static int may_context_mount_inode_relabel(u32 sid,
483                         struct superblock_security_struct *sbsec,
484                         const struct cred *cred)
486         const struct task_security_struct *tsec = cred->security;
487         int rc;
488         rc = avc_has_perm(&selinux_state,
489                           tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
490                           FILESYSTEM__RELABELFROM, NULL);
491         if (rc)
492                 return rc;
494         rc = avc_has_perm(&selinux_state,
495                           sid, sbsec->sid, SECCLASS_FILESYSTEM,
496                           FILESYSTEM__ASSOCIATE, NULL);
497         return rc;
500 static int selinux_is_sblabel_mnt(struct super_block *sb)
502         struct superblock_security_struct *sbsec = sb->s_security;
504         return sbsec->behavior == SECURITY_FS_USE_XATTR ||
505                 sbsec->behavior == SECURITY_FS_USE_TRANS ||
506                 sbsec->behavior == SECURITY_FS_USE_TASK ||
507                 sbsec->behavior == SECURITY_FS_USE_NATIVE ||
508                 /* Special handling. Genfs but also in-core setxattr handler */
509                 !strcmp(sb->s_type->name, "sysfs") ||
510                 !strcmp(sb->s_type->name, "pstore") ||
511                 !strcmp(sb->s_type->name, "debugfs") ||
512                 !strcmp(sb->s_type->name, "tracefs") ||
513                 !strcmp(sb->s_type->name, "rootfs") ||
514                 (selinux_policycap_cgroupseclabel() &&
515                  (!strcmp(sb->s_type->name, "cgroup") ||
516                   !strcmp(sb->s_type->name, "cgroup2")));
519 static int sb_finish_set_opts(struct super_block *sb)
521         struct superblock_security_struct *sbsec = sb->s_security;
522         struct dentry *root = sb->s_root;
523         struct inode *root_inode = d_backing_inode(root);
524         int rc = 0;
526         if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
527                 /* Make sure that the xattr handler exists and that no
528                    error other than -ENODATA is returned by getxattr on
529                    the root directory.  -ENODATA is ok, as this may be
530                    the first boot of the SELinux kernel before we have
531                    assigned xattr values to the filesystem. */
532                 if (!(root_inode->i_opflags & IOP_XATTR)) {
533                         pr_warn("SELinux: (dev %s, type %s) has no "
534                                "xattr support\n", sb->s_id, sb->s_type->name);
535                         rc = -EOPNOTSUPP;
536                         goto out;
537                 }
539                 rc = __vfs_getxattr(root, root_inode, XATTR_NAME_SELINUX, NULL, 0);
540                 if (rc < 0 && rc != -ENODATA) {
541                         if (rc == -EOPNOTSUPP)
542                                 pr_warn("SELinux: (dev %s, type "
543                                        "%s) has no security xattr handler\n",
544                                        sb->s_id, sb->s_type->name);
545                         else
546                                 pr_warn("SELinux: (dev %s, type "
547                                        "%s) getxattr errno %d\n", sb->s_id,
548                                        sb->s_type->name, -rc);
549                         goto out;
550                 }
551         }
553         sbsec->flags |= SE_SBINITIALIZED;
555         /*
556          * Explicitly set or clear SBLABEL_MNT.  It's not sufficient to simply
557          * leave the flag untouched because sb_clone_mnt_opts might be handing
558          * us a superblock that needs the flag to be cleared.
559          */
560         if (selinux_is_sblabel_mnt(sb))
561                 sbsec->flags |= SBLABEL_MNT;
562         else
563                 sbsec->flags &= ~SBLABEL_MNT;
565         /* Initialize the root inode. */
566         rc = inode_doinit_with_dentry(root_inode, root);
568         /* Initialize any other inodes associated with the superblock, e.g.
569            inodes created prior to initial policy load or inodes created
570            during get_sb by a pseudo filesystem that directly
571            populates itself. */
572         spin_lock(&sbsec->isec_lock);
573 next_inode:
574         if (!list_empty(&sbsec->isec_head)) {
575                 struct inode_security_struct *isec =
576                                 list_entry(sbsec->isec_head.next,
577                                            struct inode_security_struct, list);
578                 struct inode *inode = isec->inode;
579                 list_del_init(&isec->list);
580                 spin_unlock(&sbsec->isec_lock);
581                 inode = igrab(inode);
582                 if (inode) {
583                         if (!IS_PRIVATE(inode))
584                                 inode_doinit(inode);
585                         iput(inode);
586                 }
587                 spin_lock(&sbsec->isec_lock);
588                 goto next_inode;
589         }
590         spin_unlock(&sbsec->isec_lock);
591 out:
592         return rc;
595 /*
596  * This function should allow an FS to ask what it's mount security
597  * options were so it can use those later for submounts, displaying
598  * mount options, or whatever.
599  */
600 static int selinux_get_mnt_opts(const struct super_block *sb,
601                                 struct security_mnt_opts *opts)
603         int rc = 0, i;
604         struct superblock_security_struct *sbsec = sb->s_security;
605         char *context = NULL;
606         u32 len;
607         char tmp;
609         security_init_mnt_opts(opts);
611         if (!(sbsec->flags & SE_SBINITIALIZED))
612                 return -EINVAL;
614         if (!selinux_state.initialized)
615                 return -EINVAL;
617         /* make sure we always check enough bits to cover the mask */
618         BUILD_BUG_ON(SE_MNTMASK >= (1 << NUM_SEL_MNT_OPTS));
620         tmp = sbsec->flags & SE_MNTMASK;
621         /* count the number of mount options for this sb */
622         for (i = 0; i < NUM_SEL_MNT_OPTS; i++) {
623                 if (tmp & 0x01)
624                         opts->num_mnt_opts++;
625                 tmp >>= 1;
626         }
627         /* Check if the Label support flag is set */
628         if (sbsec->flags & SBLABEL_MNT)
629                 opts->num_mnt_opts++;
631         opts->mnt_opts = kcalloc(opts->num_mnt_opts, sizeof(char *), GFP_ATOMIC);
632         if (!opts->mnt_opts) {
633                 rc = -ENOMEM;
634                 goto out_free;
635         }
637         opts->mnt_opts_flags = kcalloc(opts->num_mnt_opts, sizeof(int), GFP_ATOMIC);
638         if (!opts->mnt_opts_flags) {
639                 rc = -ENOMEM;
640                 goto out_free;
641         }
643         i = 0;
644         if (sbsec->flags & FSCONTEXT_MNT) {
645                 rc = security_sid_to_context(&selinux_state, sbsec->sid,
646                                              &context, &len);
647                 if (rc)
648                         goto out_free;
649                 opts->mnt_opts[i] = context;
650                 opts->mnt_opts_flags[i++] = FSCONTEXT_MNT;
651         }
652         if (sbsec->flags & CONTEXT_MNT) {
653                 rc = security_sid_to_context(&selinux_state,
654                                              sbsec->mntpoint_sid,
655                                              &context, &len);
656                 if (rc)
657                         goto out_free;
658                 opts->mnt_opts[i] = context;
659                 opts->mnt_opts_flags[i++] = CONTEXT_MNT;
660         }
661         if (sbsec->flags & DEFCONTEXT_MNT) {
662                 rc = security_sid_to_context(&selinux_state, sbsec->def_sid,
663                                              &context, &len);
664                 if (rc)
665                         goto out_free;
666                 opts->mnt_opts[i] = context;
667                 opts->mnt_opts_flags[i++] = DEFCONTEXT_MNT;
668         }
669         if (sbsec->flags & ROOTCONTEXT_MNT) {
670                 struct dentry *root = sbsec->sb->s_root;
671                 struct inode_security_struct *isec = backing_inode_security(root);
673                 rc = security_sid_to_context(&selinux_state, isec->sid,
674                                              &context, &len);
675                 if (rc)
676                         goto out_free;
677                 opts->mnt_opts[i] = context;
678                 opts->mnt_opts_flags[i++] = ROOTCONTEXT_MNT;
679         }
680         if (sbsec->flags & SBLABEL_MNT) {
681                 opts->mnt_opts[i] = NULL;
682                 opts->mnt_opts_flags[i++] = SBLABEL_MNT;
683         }
685         BUG_ON(i != opts->num_mnt_opts);
687         return 0;
689 out_free:
690         security_free_mnt_opts(opts);
691         return rc;
694 static int bad_option(struct superblock_security_struct *sbsec, char flag,
695                       u32 old_sid, u32 new_sid)
697         char mnt_flags = sbsec->flags & SE_MNTMASK;
699         /* check if the old mount command had the same options */
700         if (sbsec->flags & SE_SBINITIALIZED)
701                 if (!(sbsec->flags & flag) ||
702                     (old_sid != new_sid))
703                         return 1;
705         /* check if we were passed the same options twice,
706          * aka someone passed context=a,context=b
707          */
708         if (!(sbsec->flags & SE_SBINITIALIZED))
709                 if (mnt_flags & flag)
710                         return 1;
711         return 0;
714 /*
715  * Allow filesystems with binary mount data to explicitly set mount point
716  * labeling information.
717  */
718 static int selinux_set_mnt_opts(struct super_block *sb,
719                                 struct security_mnt_opts *opts,
720                                 unsigned long kern_flags,
721                                 unsigned long *set_kern_flags)
723         const struct cred *cred = current_cred();
724         int rc = 0, i;
725         struct superblock_security_struct *sbsec = sb->s_security;
726         const char *name = sb->s_type->name;
727         struct dentry *root = sbsec->sb->s_root;
728         struct inode_security_struct *root_isec;
729         u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0;
730         u32 defcontext_sid = 0;
731         char **mount_options = opts->mnt_opts;
732         int *flags = opts->mnt_opts_flags;
733         int num_opts = opts->num_mnt_opts;
735         mutex_lock(&sbsec->lock);
737         if (!selinux_state.initialized) {
738                 if (!num_opts) {
739                         /* Defer initialization until selinux_complete_init,
740                            after the initial policy is loaded and the security
741                            server is ready to handle calls. */
742                         goto out;
743                 }
744                 rc = -EINVAL;
745                 pr_warn("SELinux: Unable to set superblock options "
746                         "before the security server is initialized\n");
747                 goto out;
748         }
749         if (kern_flags && !set_kern_flags) {
750                 /* Specifying internal flags without providing a place to
751                  * place the results is not allowed */
752                 rc = -EINVAL;
753                 goto out;
754         }
756         /*
757          * Binary mount data FS will come through this function twice.  Once
758          * from an explicit call and once from the generic calls from the vfs.
759          * Since the generic VFS calls will not contain any security mount data
760          * we need to skip the double mount verification.
761          *
762          * This does open a hole in which we will not notice if the first
763          * mount using this sb set explict options and a second mount using
764          * this sb does not set any security options.  (The first options
765          * will be used for both mounts)
766          */
767         if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
768             && (num_opts == 0))
769                 goto out;
771         root_isec = backing_inode_security_novalidate(root);
773         /*
774          * parse the mount options, check if they are valid sids.
775          * also check if someone is trying to mount the same sb more
776          * than once with different security options.
777          */
778         for (i = 0; i < num_opts; i++) {
779                 u32 sid;
781                 if (flags[i] == SBLABEL_MNT)
782                         continue;
783                 rc = security_context_str_to_sid(&selinux_state,
784                                                  mount_options[i], &sid,
785                                                  GFP_KERNEL);
786                 if (rc) {
787                         pr_warn("SELinux: security_context_str_to_sid"
788                                "(%s) failed for (dev %s, type %s) errno=%d\n",
789                                mount_options[i], sb->s_id, name, rc);
790                         goto out;
791                 }
792                 switch (flags[i]) {
793                 case FSCONTEXT_MNT:
794                         fscontext_sid = sid;
796                         if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid,
797                                         fscontext_sid))
798                                 goto out_double_mount;
800                         sbsec->flags |= FSCONTEXT_MNT;
801                         break;
802                 case CONTEXT_MNT:
803                         context_sid = sid;
805                         if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid,
806                                         context_sid))
807                                 goto out_double_mount;
809                         sbsec->flags |= CONTEXT_MNT;
810                         break;
811                 case ROOTCONTEXT_MNT:
812                         rootcontext_sid = sid;
814                         if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid,
815                                         rootcontext_sid))
816                                 goto out_double_mount;
818                         sbsec->flags |= ROOTCONTEXT_MNT;
820                         break;
821                 case DEFCONTEXT_MNT:
822                         defcontext_sid = sid;
824                         if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid,
825                                         defcontext_sid))
826                                 goto out_double_mount;
828                         sbsec->flags |= DEFCONTEXT_MNT;
830                         break;
831                 default:
832                         rc = -EINVAL;
833                         goto out;
834                 }
835         }
837         if (sbsec->flags & SE_SBINITIALIZED) {
838                 /* previously mounted with options, but not on this attempt? */
839                 if ((sbsec->flags & SE_MNTMASK) && !num_opts)
840                         goto out_double_mount;
841                 rc = 0;
842                 goto out;
843         }
845         if (strcmp(sb->s_type->name, "proc") == 0)
846                 sbsec->flags |= SE_SBPROC | SE_SBGENFS;
848         if (!strcmp(sb->s_type->name, "debugfs") ||
849             !strcmp(sb->s_type->name, "tracefs") ||
850             !strcmp(sb->s_type->name, "sysfs") ||
851             !strcmp(sb->s_type->name, "pstore") ||
852             !strcmp(sb->s_type->name, "cgroup") ||
853             !strcmp(sb->s_type->name, "cgroup2"))
854                 sbsec->flags |= SE_SBGENFS;
856         if (!sbsec->behavior) {
857                 /*
858                  * Determine the labeling behavior to use for this
859                  * filesystem type.
860                  */
861                 rc = security_fs_use(&selinux_state, sb);
862                 if (rc) {
863                         pr_warn("%s: security_fs_use(%s) returned %d\n",
864                                         __func__, sb->s_type->name, rc);
865                         goto out;
866                 }
867         }
869         /*
870          * If this is a user namespace mount and the filesystem type is not
871          * explicitly whitelisted, then no contexts are allowed on the command
872          * line and security labels must be ignored.
873          */
874         if (sb->s_user_ns != &init_user_ns &&
875             strcmp(sb->s_type->name, "tmpfs") &&
876             strcmp(sb->s_type->name, "ramfs") &&
877             strcmp(sb->s_type->name, "devpts")) {
878                 if (context_sid || fscontext_sid || rootcontext_sid ||
879                     defcontext_sid) {
880                         rc = -EACCES;
881                         goto out;
882                 }
883                 if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
884                         sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
885                         rc = security_transition_sid(&selinux_state,
886                                                      current_sid(),
887                                                      current_sid(),
888                                                      SECCLASS_FILE, NULL,
889                                                      &sbsec->mntpoint_sid);
890                         if (rc)
891                                 goto out;
892                 }
893                 goto out_set_opts;
894         }
896         /* sets the context of the superblock for the fs being mounted. */
897         if (fscontext_sid) {
898                 rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred);
899                 if (rc)
900                         goto out;
902                 sbsec->sid = fscontext_sid;
903         }
905         /*
906          * Switch to using mount point labeling behavior.
907          * sets the label used on all file below the mountpoint, and will set
908          * the superblock context if not already set.
909          */
910         if (kern_flags & SECURITY_LSM_NATIVE_LABELS && !context_sid) {
911                 sbsec->behavior = SECURITY_FS_USE_NATIVE;
912                 *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
913         }
915         if (context_sid) {
916                 if (!fscontext_sid) {
917                         rc = may_context_mount_sb_relabel(context_sid, sbsec,
918                                                           cred);
919                         if (rc)
920                                 goto out;
921                         sbsec->sid = context_sid;
922                 } else {
923                         rc = may_context_mount_inode_relabel(context_sid, sbsec,
924                                                              cred);
925                         if (rc)
926                                 goto out;
927                 }
928                 if (!rootcontext_sid)
929                         rootcontext_sid = context_sid;
931                 sbsec->mntpoint_sid = context_sid;
932                 sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
933         }
935         if (rootcontext_sid) {
936                 rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec,
937                                                      cred);
938                 if (rc)
939                         goto out;
941                 root_isec->sid = rootcontext_sid;
942                 root_isec->initialized = LABEL_INITIALIZED;
943         }
945         if (defcontext_sid) {
946                 if (sbsec->behavior != SECURITY_FS_USE_XATTR &&
947                         sbsec->behavior != SECURITY_FS_USE_NATIVE) {
948                         rc = -EINVAL;
949                         pr_warn("SELinux: defcontext option is "
950                                "invalid for this filesystem type\n");
951                         goto out;
952                 }
954                 if (defcontext_sid != sbsec->def_sid) {
955                         rc = may_context_mount_inode_relabel(defcontext_sid,
956                                                              sbsec, cred);
957                         if (rc)
958                                 goto out;
959                 }
961                 sbsec->def_sid = defcontext_sid;
962         }
964 out_set_opts:
965         rc = sb_finish_set_opts(sb);
966 out:
967         mutex_unlock(&sbsec->lock);
968         return rc;
969 out_double_mount:
970         rc = -EINVAL;
971         pr_warn("SELinux: mount invalid.  Same superblock, different "
972                "security settings for (dev %s, type %s)\n", sb->s_id, name);
973         goto out;
976 static int selinux_cmp_sb_context(const struct super_block *oldsb,
977                                     const struct super_block *newsb)
979         struct superblock_security_struct *old = oldsb->s_security;
980         struct superblock_security_struct *new = newsb->s_security;
981         char oldflags = old->flags & SE_MNTMASK;
982         char newflags = new->flags & SE_MNTMASK;
984         if (oldflags != newflags)
985                 goto mismatch;
986         if ((oldflags & FSCONTEXT_MNT) && old->sid != new->sid)
987                 goto mismatch;
988         if ((oldflags & CONTEXT_MNT) && old->mntpoint_sid != new->mntpoint_sid)
989                 goto mismatch;
990         if ((oldflags & DEFCONTEXT_MNT) && old->def_sid != new->def_sid)
991                 goto mismatch;
992         if (oldflags & ROOTCONTEXT_MNT) {
993                 struct inode_security_struct *oldroot = backing_inode_security(oldsb->s_root);
994                 struct inode_security_struct *newroot = backing_inode_security(newsb->s_root);
995                 if (oldroot->sid != newroot->sid)
996                         goto mismatch;
997         }
998         return 0;
999 mismatch:
1000         pr_warn("SELinux: mount invalid.  Same superblock, "
1001                             "different security settings for (dev %s, "
1002                             "type %s)\n", newsb->s_id, newsb->s_type->name);
1003         return -EBUSY;
1006 static int selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
1007                                         struct super_block *newsb,
1008                                         unsigned long kern_flags,
1009                                         unsigned long *set_kern_flags)
1011         int rc = 0;
1012         const struct superblock_security_struct *oldsbsec = oldsb->s_security;
1013         struct superblock_security_struct *newsbsec = newsb->s_security;
1015         int set_fscontext =     (oldsbsec->flags & FSCONTEXT_MNT);
1016         int set_context =       (oldsbsec->flags & CONTEXT_MNT);
1017         int set_rootcontext =   (oldsbsec->flags & ROOTCONTEXT_MNT);
1019         /*
1020          * if the parent was able to be mounted it clearly had no special lsm
1021          * mount options.  thus we can safely deal with this superblock later
1022          */
1023         if (!selinux_state.initialized)
1024                 return 0;
1026         /*
1027          * Specifying internal flags without providing a place to
1028          * place the results is not allowed.
1029          */
1030         if (kern_flags && !set_kern_flags)
1031                 return -EINVAL;
1033         /* how can we clone if the old one wasn't set up?? */
1034         BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED));
1036         /* if fs is reusing a sb, make sure that the contexts match */
1037         if (newsbsec->flags & SE_SBINITIALIZED)
1038                 return selinux_cmp_sb_context(oldsb, newsb);
1040         mutex_lock(&newsbsec->lock);
1042         newsbsec->flags = oldsbsec->flags;
1044         newsbsec->sid = oldsbsec->sid;
1045         newsbsec->def_sid = oldsbsec->def_sid;
1046         newsbsec->behavior = oldsbsec->behavior;
1048         if (newsbsec->behavior == SECURITY_FS_USE_NATIVE &&
1049                 !(kern_flags & SECURITY_LSM_NATIVE_LABELS) && !set_context) {
1050                 rc = security_fs_use(&selinux_state, newsb);
1051                 if (rc)
1052                         goto out;
1053         }
1055         if (kern_flags & SECURITY_LSM_NATIVE_LABELS && !set_context) {
1056                 newsbsec->behavior = SECURITY_FS_USE_NATIVE;
1057                 *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
1058         }
1060         if (set_context) {
1061                 u32 sid = oldsbsec->mntpoint_sid;
1063                 if (!set_fscontext)
1064                         newsbsec->sid = sid;
1065                 if (!set_rootcontext) {
1066                         struct inode_security_struct *newisec = backing_inode_security(newsb->s_root);
1067                         newisec->sid = sid;
1068                 }
1069                 newsbsec->mntpoint_sid = sid;
1070         }
1071         if (set_rootcontext) {
1072                 const struct inode_security_struct *oldisec = backing_inode_security(oldsb->s_root);
1073                 struct inode_security_struct *newisec = backing_inode_security(newsb->s_root);
1075                 newisec->sid = oldisec->sid;
1076         }
1078         sb_finish_set_opts(newsb);
1079 out:
1080         mutex_unlock(&newsbsec->lock);
1081         return rc;
1084 static int selinux_parse_opts_str(char *options,
1085                                   struct security_mnt_opts *opts)
1087         char *p;
1088         char *context = NULL, *defcontext = NULL;
1089         char *fscontext = NULL, *rootcontext = NULL;
1090         int rc, num_mnt_opts = 0;
1092         opts->num_mnt_opts = 0;
1094         /* Standard string-based options. */
1095         while ((p = strsep(&options, "|")) != NULL) {
1096                 int token;
1097                 substring_t args[MAX_OPT_ARGS];
1099                 if (!*p)
1100                         continue;
1102                 token = match_token(p, tokens, args);
1104                 switch (token) {
1105                 case Opt_context:
1106                         if (context || defcontext) {
1107                                 rc = -EINVAL;
1108                                 pr_warn(SEL_MOUNT_FAIL_MSG);
1109                                 goto out_err;
1110                         }
1111                         context = match_strdup(&args[0]);
1112                         if (!context) {
1113                                 rc = -ENOMEM;
1114                                 goto out_err;
1115                         }
1116                         break;
1118                 case Opt_fscontext:
1119                         if (fscontext) {
1120                                 rc = -EINVAL;
1121                                 pr_warn(SEL_MOUNT_FAIL_MSG);
1122                                 goto out_err;
1123                         }
1124                         fscontext = match_strdup(&args[0]);
1125                         if (!fscontext) {
1126                                 rc = -ENOMEM;
1127                                 goto out_err;
1128                         }
1129                         break;
1131                 case Opt_rootcontext:
1132                         if (rootcontext) {
1133                                 rc = -EINVAL;
1134                                 pr_warn(SEL_MOUNT_FAIL_MSG);
1135                                 goto out_err;
1136                         }
1137                         rootcontext = match_strdup(&args[0]);
1138                         if (!rootcontext) {
1139                                 rc = -ENOMEM;
1140                                 goto out_err;
1141                         }
1142                         break;
1144                 case Opt_defcontext:
1145                         if (context || defcontext) {
1146                                 rc = -EINVAL;
1147                                 pr_warn(SEL_MOUNT_FAIL_MSG);
1148                                 goto out_err;
1149                         }
1150                         defcontext = match_strdup(&args[0]);
1151                         if (!defcontext) {
1152                                 rc = -ENOMEM;
1153                                 goto out_err;
1154                         }
1155                         break;
1156                 case Opt_labelsupport:
1157                         break;
1158                 default:
1159                         rc = -EINVAL;
1160                         pr_warn("SELinux:  unknown mount option\n");
1161                         goto out_err;
1163                 }
1164         }
1166         rc = -ENOMEM;
1167         opts->mnt_opts = kcalloc(NUM_SEL_MNT_OPTS, sizeof(char *), GFP_KERNEL);
1168         if (!opts->mnt_opts)
1169                 goto out_err;
1171         opts->mnt_opts_flags = kcalloc(NUM_SEL_MNT_OPTS, sizeof(int),
1172                                        GFP_KERNEL);
1173         if (!opts->mnt_opts_flags)
1174                 goto out_err;
1176         if (fscontext) {
1177                 opts->mnt_opts[num_mnt_opts] = fscontext;
1178                 opts->mnt_opts_flags[num_mnt_opts++] = FSCONTEXT_MNT;
1179         }
1180         if (context) {
1181                 opts->mnt_opts[num_mnt_opts] = context;
1182                 opts->mnt_opts_flags[num_mnt_opts++] = CONTEXT_MNT;
1183         }
1184         if (rootcontext) {
1185                 opts->mnt_opts[num_mnt_opts] = rootcontext;
1186                 opts->mnt_opts_flags[num_mnt_opts++] = ROOTCONTEXT_MNT;
1187         }
1188         if (defcontext) {
1189                 opts->mnt_opts[num_mnt_opts] = defcontext;
1190                 opts->mnt_opts_flags[num_mnt_opts++] = DEFCONTEXT_MNT;
1191         }
1193         opts->num_mnt_opts = num_mnt_opts;
1194         return 0;
1196 out_err:
1197         security_free_mnt_opts(opts);
1198         kfree(context);
1199         kfree(defcontext);
1200         kfree(fscontext);
1201         kfree(rootcontext);
1202         return rc;
1204 /*
1205  * string mount options parsing and call set the sbsec
1206  */
1207 static int superblock_doinit(struct super_block *sb, void *data)
1209         int rc = 0;
1210         char *options = data;
1211         struct security_mnt_opts opts;
1213         security_init_mnt_opts(&opts);
1215         if (!data)
1216                 goto out;
1218         BUG_ON(sb->s_type->fs_flags & FS_BINARY_MOUNTDATA);
1220         rc = selinux_parse_opts_str(options, &opts);
1221         if (rc)
1222                 goto out_err;
1224 out:
1225         rc = selinux_set_mnt_opts(sb, &opts, 0, NULL);
1227 out_err:
1228         security_free_mnt_opts(&opts);
1229         return rc;
1232 static void selinux_write_opts(struct seq_file *m,
1233                                struct security_mnt_opts *opts)
1235         int i;
1236         char *prefix;
1238         for (i = 0; i < opts->num_mnt_opts; i++) {
1239                 char *has_comma;
1241                 if (opts->mnt_opts[i])
1242                         has_comma = strchr(opts->mnt_opts[i], ',');
1243                 else
1244                         has_comma = NULL;
1246                 switch (opts->mnt_opts_flags[i]) {
1247                 case CONTEXT_MNT:
1248                         prefix = CONTEXT_STR;
1249                         break;
1250                 case FSCONTEXT_MNT:
1251                         prefix = FSCONTEXT_STR;
1252                         break;
1253                 case ROOTCONTEXT_MNT:
1254                         prefix = ROOTCONTEXT_STR;
1255                         break;
1256                 case DEFCONTEXT_MNT:
1257                         prefix = DEFCONTEXT_STR;
1258                         break;
1259                 case SBLABEL_MNT:
1260                         seq_putc(m, ',');
1261                         seq_puts(m, LABELSUPP_STR);
1262                         continue;
1263                 default:
1264                         BUG();
1265                         return;
1266                 };
1267                 /* we need a comma before each option */
1268                 seq_putc(m, ',');
1269                 seq_puts(m, prefix);
1270                 if (has_comma)
1271                         seq_putc(m, '\"');
1272                 seq_escape(m, opts->mnt_opts[i], "\"\n\\");
1273                 if (has_comma)
1274                         seq_putc(m, '\"');
1275         }
1278 static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb)
1280         struct security_mnt_opts opts;
1281         int rc;
1283         rc = selinux_get_mnt_opts(sb, &opts);
1284         if (rc) {
1285                 /* before policy load we may get EINVAL, don't show anything */
1286                 if (rc == -EINVAL)
1287                         rc = 0;
1288                 return rc;
1289         }
1291         selinux_write_opts(m, &opts);
1293         security_free_mnt_opts(&opts);
1295         return rc;
1298 static inline u16 inode_mode_to_security_class(umode_t mode)
1300         switch (mode & S_IFMT) {
1301         case S_IFSOCK:
1302                 return SECCLASS_SOCK_FILE;
1303         case S_IFLNK:
1304                 return SECCLASS_LNK_FILE;
1305         case S_IFREG:
1306                 return SECCLASS_FILE;
1307         case S_IFBLK:
1308                 return SECCLASS_BLK_FILE;
1309         case S_IFDIR:
1310                 return SECCLASS_DIR;
1311         case S_IFCHR:
1312                 return SECCLASS_CHR_FILE;
1313         case S_IFIFO:
1314                 return SECCLASS_FIFO_FILE;
1316         }
1318         return SECCLASS_FILE;
1321 static inline int default_protocol_stream(int protocol)
1323         return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP);
1326 static inline int default_protocol_dgram(int protocol)
1328         return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP);
1331 static inline u16 socket_type_to_security_class(int family, int type, int protocol)
1333         int extsockclass = selinux_policycap_extsockclass();
1335         switch (family) {
1336         case PF_UNIX:
1337                 switch (type) {
1338                 case SOCK_STREAM:
1339                 case SOCK_SEQPACKET:
1340                         return SECCLASS_UNIX_STREAM_SOCKET;
1341                 case SOCK_DGRAM:
1342                 case SOCK_RAW:
1343                         return SECCLASS_UNIX_DGRAM_SOCKET;
1344                 }
1345                 break;
1346         case PF_INET:
1347         case PF_INET6:
1348                 switch (type) {
1349                 case SOCK_STREAM:
1350                 case SOCK_SEQPACKET:
1351                         if (default_protocol_stream(protocol))
1352                                 return SECCLASS_TCP_SOCKET;
1353                         else if (extsockclass && protocol == IPPROTO_SCTP)
1354                                 return SECCLASS_SCTP_SOCKET;
1355                         else
1356                                 return SECCLASS_RAWIP_SOCKET;
1357                 case SOCK_DGRAM:
1358                         if (default_protocol_dgram(protocol))
1359                                 return SECCLASS_UDP_SOCKET;
1360                         else if (extsockclass && (protocol == IPPROTO_ICMP ||
1361                                                   protocol == IPPROTO_ICMPV6))
1362                                 return SECCLASS_ICMP_SOCKET;
1363                         else
1364                                 return SECCLASS_RAWIP_SOCKET;
1365                 case SOCK_DCCP:
1366                         return SECCLASS_DCCP_SOCKET;
1367                 default:
1368                         return SECCLASS_RAWIP_SOCKET;
1369                 }
1370                 break;
1371         case PF_NETLINK:
1372                 switch (protocol) {
1373                 case NETLINK_ROUTE:
1374                         return SECCLASS_NETLINK_ROUTE_SOCKET;
1375                 case NETLINK_SOCK_DIAG:
1376                         return SECCLASS_NETLINK_TCPDIAG_SOCKET;
1377                 case NETLINK_NFLOG:
1378                         return SECCLASS_NETLINK_NFLOG_SOCKET;
1379                 case NETLINK_XFRM:
1380                         return SECCLASS_NETLINK_XFRM_SOCKET;
1381                 case NETLINK_SELINUX:
1382                         return SECCLASS_NETLINK_SELINUX_SOCKET;
1383                 case NETLINK_ISCSI:
1384                         return SECCLASS_NETLINK_ISCSI_SOCKET;
1385                 case NETLINK_AUDIT:
1386                         return SECCLASS_NETLINK_AUDIT_SOCKET;
1387                 case NETLINK_FIB_LOOKUP:
1388                         return SECCLASS_NETLINK_FIB_LOOKUP_SOCKET;
1389                 case NETLINK_CONNECTOR:
1390                         return SECCLASS_NETLINK_CONNECTOR_SOCKET;
1391                 case NETLINK_NETFILTER:
1392                         return SECCLASS_NETLINK_NETFILTER_SOCKET;
1393                 case NETLINK_DNRTMSG:
1394                         return SECCLASS_NETLINK_DNRT_SOCKET;
1395                 case NETLINK_KOBJECT_UEVENT:
1396                         return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET;
1397                 case NETLINK_GENERIC:
1398                         return SECCLASS_NETLINK_GENERIC_SOCKET;
1399                 case NETLINK_SCSITRANSPORT:
1400                         return SECCLASS_NETLINK_SCSITRANSPORT_SOCKET;
1401                 case NETLINK_RDMA:
1402                         return SECCLASS_NETLINK_RDMA_SOCKET;
1403                 case NETLINK_CRYPTO:
1404                         return SECCLASS_NETLINK_CRYPTO_SOCKET;
1405                 default:
1406                         return SECCLASS_NETLINK_SOCKET;
1407                 }
1408         case PF_PACKET:
1409                 return SECCLASS_PACKET_SOCKET;
1410         case PF_KEY:
1411                 return SECCLASS_KEY_SOCKET;
1412         case PF_APPLETALK:
1413                 return SECCLASS_APPLETALK_SOCKET;
1414         }
1416         if (extsockclass) {
1417                 switch (family) {
1418                 case PF_AX25:
1419                         return SECCLASS_AX25_SOCKET;
1420                 case PF_IPX:
1421                         return SECCLASS_IPX_SOCKET;
1422                 case PF_NETROM:
1423                         return SECCLASS_NETROM_SOCKET;
1424                 case PF_ATMPVC:
1425                         return SECCLASS_ATMPVC_SOCKET;
1426                 case PF_X25:
1427                         return SECCLASS_X25_SOCKET;
1428                 case PF_ROSE:
1429                         return SECCLASS_ROSE_SOCKET;
1430                 case PF_DECnet:
1431                         return SECCLASS_DECNET_SOCKET;
1432                 case PF_ATMSVC:
1433                         return SECCLASS_ATMSVC_SOCKET;
1434                 case PF_RDS:
1435                         return SECCLASS_RDS_SOCKET;
1436                 case PF_IRDA:
1437                         return SECCLASS_IRDA_SOCKET;
1438                 case PF_PPPOX:
1439                         return SECCLASS_PPPOX_SOCKET;
1440                 case PF_LLC:
1441                         return SECCLASS_LLC_SOCKET;
1442                 case PF_CAN:
1443                         return SECCLASS_CAN_SOCKET;
1444                 case PF_TIPC:
1445                         return SECCLASS_TIPC_SOCKET;
1446                 case PF_BLUETOOTH:
1447                         return SECCLASS_BLUETOOTH_SOCKET;
1448                 case PF_IUCV:
1449                         return SECCLASS_IUCV_SOCKET;
1450                 case PF_RXRPC:
1451                         return SECCLASS_RXRPC_SOCKET;
1452                 case PF_ISDN:
1453                         return SECCLASS_ISDN_SOCKET;
1454                 case PF_PHONET:
1455                         return SECCLASS_PHONET_SOCKET;
1456                 case PF_IEEE802154:
1457                         return SECCLASS_IEEE802154_SOCKET;
1458                 case PF_CAIF:
1459                         return SECCLASS_CAIF_SOCKET;
1460                 case PF_ALG:
1461                         return SECCLASS_ALG_SOCKET;
1462                 case PF_NFC:
1463                         return SECCLASS_NFC_SOCKET;
1464                 case PF_VSOCK:
1465                         return SECCLASS_VSOCK_SOCKET;
1466                 case PF_KCM:
1467                         return SECCLASS_KCM_SOCKET;
1468                 case PF_QIPCRTR:
1469                         return SECCLASS_QIPCRTR_SOCKET;
1470                 case PF_SMC:
1471                         return SECCLASS_SMC_SOCKET;
1472                 case PF_XDP:
1473                         return SECCLASS_XDP_SOCKET;
1474                 case PF_RPMSG:
1475                         return SECCLASS_RPMSG_SOCKET;
1476 #if PF_MAX > 46
1477 #error New address family defined, please update this function.
1478 #endif
1479                 }
1480         }
1482         return SECCLASS_SOCKET;
1485 static int selinux_genfs_get_sid(struct dentry *dentry,
1486                                  u16 tclass,
1487                                  u16 flags,
1488                                  u32 *sid)
1490         int rc;
1491         struct super_block *sb = dentry->d_sb;
1492         char *buffer, *path;
1494         buffer = (char *)__get_free_page(GFP_KERNEL);
1495         if (!buffer)
1496                 return -ENOMEM;
1498         path = dentry_path_raw(dentry, buffer, PAGE_SIZE);
1499         if (IS_ERR(path))
1500                 rc = PTR_ERR(path);
1501         else {
1502                 if (flags & SE_SBPROC) {
1503                         /* each process gets a /proc/PID/ entry. Strip off the
1504                          * PID part to get a valid selinux labeling.
1505                          * e.g. /proc/1/net/rpc/nfs -> /net/rpc/nfs */
1506                         while (path[1] >= '0' && path[1] <= '9') {
1507                                 path[1] = '/';
1508                                 path++;
1509                         }
1510                 }
1511                 rc = security_genfs_sid(&selinux_state, sb->s_type->name,
1512                                         path, tclass, sid);
1513         }
1514         free_page((unsigned long)buffer);
1515         return rc;
1518 /* The inode's security attributes must be initialized before first use. */
1519 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry)
1521         struct superblock_security_struct *sbsec = NULL;
1522         struct inode_security_struct *isec = inode->i_security;
1523         u32 task_sid, sid = 0;
1524         u16 sclass;
1525         struct dentry *dentry;
1526 #define INITCONTEXTLEN 255
1527         char *context = NULL;
1528         unsigned len = 0;
1529         int rc = 0;
1531         if (isec->initialized == LABEL_INITIALIZED)
1532                 return 0;
1534         spin_lock(&isec->lock);
1535         if (isec->initialized == LABEL_INITIALIZED)
1536                 goto out_unlock;
1538         if (isec->sclass == SECCLASS_FILE)
1539                 isec->sclass = inode_mode_to_security_class(inode->i_mode);
1541         sbsec = inode->i_sb->s_security;
1542         if (!(sbsec->flags & SE_SBINITIALIZED)) {
1543                 /* Defer initialization until selinux_complete_init,
1544                    after the initial policy is loaded and the security
1545                    server is ready to handle calls. */
1546                 spin_lock(&sbsec->isec_lock);
1547                 if (list_empty(&isec->list))
1548                         list_add(&isec->list, &sbsec->isec_head);
1549                 spin_unlock(&sbsec->isec_lock);
1550                 goto out_unlock;
1551         }
1553         sclass = isec->sclass;
1554         task_sid = isec->task_sid;
1555         sid = isec->sid;
1556         isec->initialized = LABEL_PENDING;
1557         spin_unlock(&isec->lock);
1559         switch (sbsec->behavior) {
1560         case SECURITY_FS_USE_NATIVE:
1561                 break;
1562         case SECURITY_FS_USE_XATTR:
1563                 if (!(inode->i_opflags & IOP_XATTR)) {
1564                         sid = sbsec->def_sid;
1565                         break;
1566                 }
1567                 /* Need a dentry, since the xattr API requires one.
1568                    Life would be simpler if we could just pass the inode. */
1569                 if (opt_dentry) {
1570                         /* Called from d_instantiate or d_splice_alias. */
1571                         dentry = dget(opt_dentry);
1572                 } else {
1573                         /*
1574                          * Called from selinux_complete_init, try to find a dentry.
1575                          * Some filesystems really want a connected one, so try
1576                          * that first.  We could split SECURITY_FS_USE_XATTR in
1577                          * two, depending upon that...
1578                          */
1579                         dentry = d_find_alias(inode);
1580                         if (!dentry)
1581                                 dentry = d_find_any_alias(inode);
1582                 }
1583                 if (!dentry) {
1584                         /*
1585                          * this is can be hit on boot when a file is accessed
1586                          * before the policy is loaded.  When we load policy we
1587                          * may find inodes that have no dentry on the
1588                          * sbsec->isec_head list.  No reason to complain as these
1589                          * will get fixed up the next time we go through
1590                          * inode_doinit with a dentry, before these inodes could
1591                          * be used again by userspace.
1592                          */
1593                         goto out;
1594                 }
1596                 len = INITCONTEXTLEN;
1597                 context = kmalloc(len+1, GFP_NOFS);
1598                 if (!context) {
1599                         rc = -ENOMEM;
1600                         dput(dentry);
1601                         goto out;
1602                 }
1603                 context[len] = '\0';
1604                 rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, context, len);
1605                 if (rc == -ERANGE) {
1606                         kfree(context);
1608                         /* Need a larger buffer.  Query for the right size. */
1609                         rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, NULL, 0);
1610                         if (rc < 0) {
1611                                 dput(dentry);
1612                                 goto out;
1613                         }
1614                         len = rc;
1615                         context = kmalloc(len+1, GFP_NOFS);
1616                         if (!context) {
1617                                 rc = -ENOMEM;
1618                                 dput(dentry);
1619                                 goto out;
1620                         }
1621                         context[len] = '\0';
1622                         rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, context, len);
1623                 }
1624                 dput(dentry);
1625                 if (rc < 0) {
1626                         if (rc != -ENODATA) {
1627                                 pr_warn("SELinux: %s:  getxattr returned "
1628                                        "%d for dev=%s ino=%ld\n", __func__,
1629                                        -rc, inode->i_sb->s_id, inode->i_ino);
1630                                 kfree(context);
1631                                 goto out;
1632                         }
1633                         /* Map ENODATA to the default file SID */
1634                         sid = sbsec->def_sid;
1635                         rc = 0;
1636                 } else {
1637                         rc = security_context_to_sid_default(&selinux_state,
1638                                                              context, rc, &sid,
1639                                                              sbsec->def_sid,
1640                                                              GFP_NOFS);
1641                         if (rc) {
1642                                 char *dev = inode->i_sb->s_id;
1643                                 unsigned long ino = inode->i_ino;
1645                                 if (rc == -EINVAL) {
1646                                         if (printk_ratelimit())
1647                                                 pr_notice("SELinux: inode=%lu on dev=%s was found to have an invalid "
1648                                                         "context=%s.  This indicates you may need to relabel the inode or the "
1649                                                         "filesystem in question.\n", ino, dev, context);
1650                                 } else {
1651                                         pr_warn("SELinux: %s:  context_to_sid(%s) "
1652                                                "returned %d for dev=%s ino=%ld\n",
1653                                                __func__, context, -rc, dev, ino);
1654                                 }
1655                                 kfree(context);
1656                                 /* Leave with the unlabeled SID */
1657                                 rc = 0;
1658                                 break;
1659                         }
1660                 }
1661                 kfree(context);
1662                 break;
1663         case SECURITY_FS_USE_TASK:
1664                 sid = task_sid;
1665                 break;
1666         case SECURITY_FS_USE_TRANS:
1667                 /* Default to the fs SID. */
1668                 sid = sbsec->sid;
1670                 /* Try to obtain a transition SID. */
1671                 rc = security_transition_sid(&selinux_state, task_sid, sid,
1672                                              sclass, NULL, &sid);
1673                 if (rc)
1674                         goto out;
1675                 break;
1676         case SECURITY_FS_USE_MNTPOINT:
1677                 sid = sbsec->mntpoint_sid;
1678                 break;
1679         default:
1680                 /* Default to the fs superblock SID. */
1681                 sid = sbsec->sid;
1683                 if ((sbsec->flags & SE_SBGENFS) && !S_ISLNK(inode->i_mode)) {
1684                         /* We must have a dentry to determine the label on
1685                          * procfs inodes */
1686                         if (opt_dentry) {
1687                                 /* Called from d_instantiate or
1688                                  * d_splice_alias. */
1689                                 dentry = dget(opt_dentry);
1690                         } else {
1691                                 /* Called from selinux_complete_init, try to
1692                                  * find a dentry.  Some filesystems really want
1693                                  * a connected one, so try that first.
1694                                  */
1695                                 dentry = d_find_alias(inode);
1696                                 if (!dentry)
1697                                         dentry = d_find_any_alias(inode);
1698                         }
1699                         /*
1700                          * This can be hit on boot when a file is accessed
1701                          * before the policy is loaded.  When we load policy we
1702                          * may find inodes that have no dentry on the
1703                          * sbsec->isec_head list.  No reason to complain as
1704                          * these will get fixed up the next time we go through
1705                          * inode_doinit() with a dentry, before these inodes
1706                          * could be used again by userspace.
1707                          */
1708                         if (!dentry)
1709                                 goto out;
1710                         rc = selinux_genfs_get_sid(dentry, sclass,
1711                                                    sbsec->flags, &sid);
1712                         dput(dentry);
1713                         if (rc)
1714                                 goto out;
1715                 }
1716                 break;
1717         }
1719 out:
1720         spin_lock(&isec->lock);
1721         if (isec->initialized == LABEL_PENDING) {
1722                 if (!sid || rc) {
1723                         isec->initialized = LABEL_INVALID;
1724                         goto out_unlock;
1725                 }
1727                 isec->initialized = LABEL_INITIALIZED;
1728                 isec->sid = sid;
1729         }
1731 out_unlock:
1732         spin_unlock(&isec->lock);
1733         return rc;
1736 /* Convert a Linux signal to an access vector. */
1737 static inline u32 signal_to_av(int sig)
1739         u32 perm = 0;
1741         switch (sig) {
1742         case SIGCHLD:
1743                 /* Commonly granted from child to parent. */
1744                 perm = PROCESS__SIGCHLD;
1745                 break;
1746         case SIGKILL:
1747                 /* Cannot be caught or ignored */
1748                 perm = PROCESS__SIGKILL;
1749                 break;
1750         case SIGSTOP:
1751                 /* Cannot be caught or ignored */
1752                 perm = PROCESS__SIGSTOP;
1753                 break;
1754         default:
1755                 /* All other signals. */
1756                 perm = PROCESS__SIGNAL;
1757                 break;
1758         }
1760         return perm;
1763 #if CAP_LAST_CAP > 63
1764 #error Fix SELinux to handle capabilities > 63.
1765 #endif
1767 /* Check whether a task is allowed to use a capability. */
1768 static int cred_has_capability(const struct cred *cred,
1769                                int cap, int audit, bool initns)
1771         struct common_audit_data ad;
1772         struct av_decision avd;
1773         u16 sclass;
1774         u32 sid = cred_sid(cred);
1775         u32 av = CAP_TO_MASK(cap);
1776         int rc;
1778         ad.type = LSM_AUDIT_DATA_CAP;
1779         ad.u.cap = cap;
1781         switch (CAP_TO_INDEX(cap)) {
1782         case 0:
1783                 sclass = initns ? SECCLASS_CAPABILITY : SECCLASS_CAP_USERNS;
1784                 break;
1785         case 1:
1786                 sclass = initns ? SECCLASS_CAPABILITY2 : SECCLASS_CAP2_USERNS;
1787                 break;
1788         default:
1789                 pr_err("SELinux:  out of range capability %d\n", cap);
1790                 BUG();
1791                 return -EINVAL;
1792         }
1794         rc = avc_has_perm_noaudit(&selinux_state,
1795                                   sid, sid, sclass, av, 0, &avd);
1796         if (audit == SECURITY_CAP_AUDIT) {
1797                 int rc2 = avc_audit(&selinux_state,
1798                                     sid, sid, sclass, av, &avd, rc, &ad, 0);
1799                 if (rc2)
1800                         return rc2;
1801         }
1802         return rc;
1805 /* Check whether a task has a particular permission to an inode.
1806    The 'adp' parameter is optional and allows other audit
1807    data to be passed (e.g. the dentry). */
1808 static int inode_has_perm(const struct cred *cred,
1809                           struct inode *inode,
1810                           u32 perms,
1811                           struct common_audit_data *adp)
1813         struct inode_security_struct *isec;
1814         u32 sid;
1816         validate_creds(cred);
1818         if (unlikely(IS_PRIVATE(inode)))
1819                 return 0;
1821         sid = cred_sid(cred);
1822         isec = inode->i_security;
1824         return avc_has_perm(&selinux_state,
1825                             sid, isec->sid, isec->sclass, perms, adp);
1828 /* Same as inode_has_perm, but pass explicit audit data containing
1829    the dentry to help the auditing code to more easily generate the
1830    pathname if needed. */
1831 static inline int dentry_has_perm(const struct cred *cred,
1832                                   struct dentry *dentry,
1833                                   u32 av)
1835         struct inode *inode = d_backing_inode(dentry);
1836         struct common_audit_data ad;
1838         ad.type = LSM_AUDIT_DATA_DENTRY;
1839         ad.u.dentry = dentry;
1840         __inode_security_revalidate(inode, dentry, true);
1841         return inode_has_perm(cred, inode, av, &ad);
1844 /* Same as inode_has_perm, but pass explicit audit data containing
1845    the path to help the auditing code to more easily generate the
1846    pathname if needed. */
1847 static inline int path_has_perm(const struct cred *cred,
1848                                 const struct path *path,
1849                                 u32 av)
1851         struct inode *inode = d_backing_inode(path->dentry);
1852         struct common_audit_data ad;
1854         ad.type = LSM_AUDIT_DATA_PATH;
1855         ad.u.path = *path;
1856         __inode_security_revalidate(inode, path->dentry, true);
1857         return inode_has_perm(cred, inode, av, &ad);
1860 /* Same as path_has_perm, but uses the inode from the file struct. */
1861 static inline int file_path_has_perm(const struct cred *cred,
1862                                      struct file *file,
1863                                      u32 av)
1865         struct common_audit_data ad;
1867         ad.type = LSM_AUDIT_DATA_FILE;
1868         ad.u.file = file;
1869         return inode_has_perm(cred, file_inode(file), av, &ad);
1872 #ifdef CONFIG_BPF_SYSCALL
1873 static int bpf_fd_pass(struct file *file, u32 sid);
1874 #endif
1876 /* Check whether a task can use an open file descriptor to
1877    access an inode in a given way.  Check access to the
1878    descriptor itself, and then use dentry_has_perm to
1879    check a particular permission to the file.
1880    Access to the descriptor is implicitly granted if it
1881    has the same SID as the process.  If av is zero, then
1882    access to the file is not checked, e.g. for cases
1883    where only the descriptor is affected like seek. */
1884 static int file_has_perm(const struct cred *cred,
1885                          struct file *file,
1886                          u32 av)
1888         struct file_security_struct *fsec = file->f_security;
1889         struct inode *inode = file_inode(file);
1890         struct common_audit_data ad;
1891         u32 sid = cred_sid(cred);
1892         int rc;
1894         ad.type = LSM_AUDIT_DATA_FILE;
1895         ad.u.file = file;
1897         if (sid != fsec->sid) {
1898                 rc = avc_has_perm(&selinux_state,
1899                                   sid, fsec->sid,
1900                                   SECCLASS_FD,
1901                                   FD__USE,
1902                                   &ad);
1903                 if (rc)
1904                         goto out;
1905         }
1907 #ifdef CONFIG_BPF_SYSCALL
1908         rc = bpf_fd_pass(file, cred_sid(cred));
1909         if (rc)
1910                 return rc;
1911 #endif
1913         /* av is zero if only checking access to the descriptor. */
1914         rc = 0;
1915         if (av)
1916                 rc = inode_has_perm(cred, inode, av, &ad);
1918 out:
1919         return rc;
1922 /*
1923  * Determine the label for an inode that might be unioned.
1924  */
1925 static int
1926 selinux_determine_inode_label(const struct task_security_struct *tsec,
1927                                  struct inode *dir,
1928                                  const struct qstr *name, u16 tclass,
1929                                  u32 *_new_isid)
1931         const struct superblock_security_struct *sbsec = dir->i_sb->s_security;
1933         if ((sbsec->flags & SE_SBINITIALIZED) &&
1934             (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)) {
1935                 *_new_isid = sbsec->mntpoint_sid;
1936         } else if ((sbsec->flags & SBLABEL_MNT) &&
1937                    tsec->create_sid) {
1938                 *_new_isid = tsec->create_sid;
1939         } else {
1940                 const struct inode_security_struct *dsec = inode_security(dir);
1941                 return security_transition_sid(&selinux_state, tsec->sid,
1942                                                dsec->sid, tclass,
1943                                                name, _new_isid);
1944         }
1946         return 0;
1949 /* Check whether a task can create a file. */
1950 static int may_create(struct inode *dir,
1951                       struct dentry *dentry,
1952                       u16 tclass)
1954         const struct task_security_struct *tsec = current_security();
1955         struct inode_security_struct *dsec;
1956         struct superblock_security_struct *sbsec;
1957         u32 sid, newsid;
1958         struct common_audit_data ad;
1959         int rc;
1961         dsec = inode_security(dir);
1962         sbsec = dir->i_sb->s_security;
1964         sid = tsec->sid;
1966         ad.type = LSM_AUDIT_DATA_DENTRY;
1967         ad.u.dentry = dentry;
1969         rc = avc_has_perm(&selinux_state,
1970                           sid, dsec->sid, SECCLASS_DIR,
1971                           DIR__ADD_NAME | DIR__SEARCH,
1972                           &ad);
1973         if (rc)
1974                 return rc;
1976         rc = selinux_determine_inode_label(current_security(), dir,
1977                                            &dentry->d_name, tclass, &newsid);
1978         if (rc)
1979                 return rc;
1981         rc = avc_has_perm(&selinux_state,
1982                           sid, newsid, tclass, FILE__CREATE, &ad);
1983         if (rc)
1984                 return rc;
1986         return avc_has_perm(&selinux_state,
1987                             newsid, sbsec->sid,
1988                             SECCLASS_FILESYSTEM,
1989                             FILESYSTEM__ASSOCIATE, &ad);
1992 #define MAY_LINK        0
1993 #define MAY_UNLINK      1
1994 #define MAY_RMDIR       2
1996 /* Check whether a task can link, unlink, or rmdir a file/directory. */
1997 static int may_link(struct inode *dir,
1998                     struct dentry *dentry,
1999                     int kind)
2002         struct inode_security_struct *dsec, *isec;
2003         struct common_audit_data ad;
2004         u32 sid = current_sid();
2005         u32 av;
2006         int rc;
2008         dsec = inode_security(dir);
2009         isec = backing_inode_security(dentry);
2011         ad.type = LSM_AUDIT_DATA_DENTRY;
2012         ad.u.dentry = dentry;
2014         av = DIR__SEARCH;
2015         av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
2016         rc = avc_has_perm(&selinux_state,
2017                           sid, dsec->sid, SECCLASS_DIR, av, &ad);
2018         if (rc)
2019                 return rc;
2021         switch (kind) {
2022         case MAY_LINK:
2023                 av = FILE__LINK;
2024                 break;
2025         case MAY_UNLINK:
2026                 av = FILE__UNLINK;
2027                 break;
2028         case MAY_RMDIR:
2029                 av = DIR__RMDIR;
2030                 break;
2031         default:
2032                 pr_warn("SELinux: %s:  unrecognized kind %d\n",
2033                         __func__, kind);
2034                 return 0;
2035         }
2037         rc = avc_has_perm(&selinux_state,
2038                           sid, isec->sid, isec->sclass, av, &ad);
2039         return rc;
2042 static inline int may_rename(struct inode *old_dir,
2043                              struct dentry *old_dentry,
2044                              struct inode *new_dir,
2045                              struct dentry *new_dentry)
2047         struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec;
2048         struct common_audit_data ad;
2049         u32 sid = current_sid();
2050         u32 av;
2051         int old_is_dir, new_is_dir;
2052         int rc;
2054         old_dsec = inode_security(old_dir);
2055         old_isec = backing_inode_security(old_dentry);
2056         old_is_dir = d_is_dir(old_dentry);
2057         new_dsec = inode_security(new_dir);
2059         ad.type = LSM_AUDIT_DATA_DENTRY;
2061         ad.u.dentry = old_dentry;
2062         rc = avc_has_perm(&selinux_state,
2063                           sid, old_dsec->sid, SECCLASS_DIR,
2064                           DIR__REMOVE_NAME | DIR__SEARCH, &ad);
2065         if (rc)
2066                 return rc;
2067         rc = avc_has_perm(&selinux_state,
2068                           sid, old_isec->sid,
2069                           old_isec->sclass, FILE__RENAME, &ad);
2070         if (rc)
2071                 return rc;
2072         if (old_is_dir && new_dir != old_dir) {
2073                 rc = avc_has_perm(&selinux_state,
2074                                   sid, old_isec->sid,
2075                                   old_isec->sclass, DIR__REPARENT, &ad);
2076                 if (rc)
2077                         return rc;
2078         }
2080         ad.u.dentry = new_dentry;
2081         av = DIR__ADD_NAME | DIR__SEARCH;
2082         if (d_is_positive(new_dentry))
2083                 av |= DIR__REMOVE_NAME;
2084         rc = avc_has_perm(&selinux_state,
2085                           sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
2086         if (rc)
2087                 return rc;
2088         if (d_is_positive(new_dentry)) {
2089                 new_isec = backing_inode_security(new_dentry);
2090                 new_is_dir = d_is_dir(new_dentry);
2091                 rc = avc_has_perm(&selinux_state,
2092                                   sid, new_isec->sid,
2093                                   new_isec->sclass,
2094                                   (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad);
2095                 if (rc)
2096                         return rc;
2097         }
2099         return 0;
2102 /* Check whether a task can perform a filesystem operation. */
2103 static int superblock_has_perm(const struct cred *cred,
2104                                struct super_block *sb,
2105                                u32 perms,
2106                                struct common_audit_data *ad)
2108         struct superblock_security_struct *sbsec;
2109         u32 sid = cred_sid(cred);
2111         sbsec = sb->s_security;
2112         return avc_has_perm(&selinux_state,
2113                             sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad);
2116 /* Convert a Linux mode and permission mask to an access vector. */
2117 static inline u32 file_mask_to_av(int mode, int mask)
2119         u32 av = 0;
2121         if (!S_ISDIR(mode)) {
2122                 if (mask & MAY_EXEC)
2123                         av |= FILE__EXECUTE;
2124                 if (mask & MAY_READ)
2125                         av |= FILE__READ;
2127                 if (mask & MAY_APPEND)
2128                         av |= FILE__APPEND;
2129                 else if (mask & MAY_WRITE)
2130                         av |= FILE__WRITE;
2132         } else {
2133                 if (mask & MAY_EXEC)
2134                         av |= DIR__SEARCH;
2135                 if (mask & MAY_WRITE)
2136                         av |= DIR__WRITE;
2137                 if (mask & MAY_READ)
2138                         av |= DIR__READ;
2139         }
2141         return av;
2144 /* Convert a Linux file to an access vector. */
2145 static inline u32 file_to_av(struct file *file)
2147         u32 av = 0;
2149         if (file->f_mode & FMODE_READ)
2150                 av |= FILE__READ;
2151         if (file->f_mode & FMODE_WRITE) {
2152                 if (file->f_flags & O_APPEND)
2153                         av |= FILE__APPEND;
2154                 else
2155                         av |= FILE__WRITE;
2156         }
2157         if (!av) {
2158                 /*
2159                  * Special file opened with flags 3 for ioctl-only use.
2160                  */
2161                 av = FILE__IOCTL;
2162         }
2164         return av;
2167 /*
2168  * Convert a file to an access vector and include the correct open
2169  * open permission.
2170  */
2171 static inline u32 open_file_to_av(struct file *file)
2173         u32 av = file_to_av(file);
2174         struct inode *inode = file_inode(file);
2176         if (selinux_policycap_openperm() &&
2177             inode->i_sb->s_magic != SOCKFS_MAGIC)
2178                 av |= FILE__OPEN;
2180         return av;
2183 /* Hook functions begin here. */
2185 static int selinux_binder_set_context_mgr(struct task_struct *mgr)
2187         u32 mysid = current_sid();
2188         u32 mgrsid = task_sid(mgr);
2190         return avc_has_perm(&selinux_state,
2191                             mysid, mgrsid, SECCLASS_BINDER,
2192                             BINDER__SET_CONTEXT_MGR, NULL);
2195 static int selinux_binder_transaction(struct task_struct *from,
2196                                       struct task_struct *to)
2198         u32 mysid = current_sid();
2199         u32 fromsid = task_sid(from);
2200         u32 tosid = task_sid(to);
2201         int rc;
2203         if (mysid != fromsid) {
2204                 rc = avc_has_perm(&selinux_state,
2205                                   mysid, fromsid, SECCLASS_BINDER,
2206                                   BINDER__IMPERSONATE, NULL);
2207                 if (rc)
2208                         return rc;
2209         }
2211         return avc_has_perm(&selinux_state,
2212                             fromsid, tosid, SECCLASS_BINDER, BINDER__CALL,
2213                             NULL);
2216 static int selinux_binder_transfer_binder(struct task_struct *from,
2217                                           struct task_struct *to)
2219         u32 fromsid = task_sid(from);
2220         u32 tosid = task_sid(to);
2222         return avc_has_perm(&selinux_state,
2223                             fromsid, tosid, SECCLASS_BINDER, BINDER__TRANSFER,
2224                             NULL);
2227 static int selinux_binder_transfer_file(struct task_struct *from,
2228                                         struct task_struct *to,
2229                                         struct file *file)
2231         u32 sid = task_sid(to);
2232         struct file_security_struct *fsec = file->f_security;
2233         struct dentry *dentry = file->f_path.dentry;
2234         struct inode_security_struct *isec;
2235         struct common_audit_data ad;
2236         int rc;
2238         ad.type = LSM_AUDIT_DATA_PATH;
2239         ad.u.path = file->f_path;
2241         if (sid != fsec->sid) {
2242                 rc = avc_has_perm(&selinux_state,
2243                                   sid, fsec->sid,
2244                                   SECCLASS_FD,
2245                                   FD__USE,
2246                                   &ad);
2247                 if (rc)
2248                         return rc;
2249         }
2251 #ifdef CONFIG_BPF_SYSCALL
2252         rc = bpf_fd_pass(file, sid);
2253         if (rc)
2254                 return rc;
2255 #endif
2257         if (unlikely(IS_PRIVATE(d_backing_inode(dentry))))
2258                 return 0;
2260         isec = backing_inode_security(dentry);
2261         return avc_has_perm(&selinux_state,
2262                             sid, isec->sid, isec->sclass, file_to_av(file),
2263                             &ad);
2266 static int selinux_ptrace_access_check(struct task_struct *child,
2267                                      unsigned int mode)
2269         u32 sid = current_sid();
2270         u32 csid = task_sid(child);
2272         if (mode & PTRACE_MODE_READ)
2273                 return avc_has_perm(&selinux_state,
2274                                     sid, csid, SECCLASS_FILE, FILE__READ, NULL);
2276         return avc_has_perm(&selinux_state,
2277                             sid, csid, SECCLASS_PROCESS, PROCESS__PTRACE, NULL);
2280 static int selinux_ptrace_traceme(struct task_struct *parent)
2282         return avc_has_perm(&selinux_state,
2283                             task_sid(parent), current_sid(), SECCLASS_PROCESS,
2284                             PROCESS__PTRACE, NULL);
2287 static int selinux_capget(struct task_struct *target, kernel_cap_t *effective,
2288                           kernel_cap_t *inheritable, kernel_cap_t *permitted)
2290         return avc_has_perm(&selinux_state,
2291                             current_sid(), task_sid(target), SECCLASS_PROCESS,
2292                             PROCESS__GETCAP, NULL);
2295 static int selinux_capset(struct cred *new, const struct cred *old,
2296                           const kernel_cap_t *effective,
2297                           const kernel_cap_t *inheritable,
2298                           const kernel_cap_t *permitted)
2300         return avc_has_perm(&selinux_state,
2301                             cred_sid(old), cred_sid(new), SECCLASS_PROCESS,
2302                             PROCESS__SETCAP, NULL);
2305 /*
2306  * (This comment used to live with the selinux_task_setuid hook,
2307  * which was removed).
2308  *
2309  * Since setuid only affects the current process, and since the SELinux
2310  * controls are not based on the Linux identity attributes, SELinux does not
2311  * need to control this operation.  However, SELinux does control the use of
2312  * the CAP_SETUID and CAP_SETGID capabilities using the capable hook.
2313  */
2315 static int selinux_capable(const struct cred *cred, struct user_namespace *ns,
2316                            int cap, int audit)
2318         return cred_has_capability(cred, cap, audit, ns == &init_user_ns);
2321 static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb)
2323         const struct cred *cred = current_cred();
2324         int rc = 0;
2326         if (!sb)
2327                 return 0;
2329         switch (cmds) {
2330         case Q_SYNC:
2331         case Q_QUOTAON:
2332         case Q_QUOTAOFF:
2333         case Q_SETINFO:
2334         case Q_SETQUOTA:
2335                 rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAMOD, NULL);
2336                 break;
2337         case Q_GETFMT:
2338         case Q_GETINFO:
2339         case Q_GETQUOTA:
2340                 rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAGET, NULL);
2341                 break;
2342         default:
2343                 rc = 0;  /* let the kernel handle invalid cmds */
2344                 break;
2345         }
2346         return rc;
2349 static int selinux_quota_on(struct dentry *dentry)
2351         const struct cred *cred = current_cred();
2353         return dentry_has_perm(cred, dentry, FILE__QUOTAON);
2356 static int selinux_syslog(int type)
2358         switch (type) {
2359         case SYSLOG_ACTION_READ_ALL:    /* Read last kernel messages */
2360         case SYSLOG_ACTION_SIZE_BUFFER: /* Return size of the log buffer */
2361                 return avc_has_perm(&selinux_state,
2362                                     current_sid(), SECINITSID_KERNEL,
2363                                     SECCLASS_SYSTEM, SYSTEM__SYSLOG_READ, NULL);
2364         case SYSLOG_ACTION_CONSOLE_OFF: /* Disable logging to console */
2365         case SYSLOG_ACTION_CONSOLE_ON:  /* Enable logging to console */
2366         /* Set level of messages printed to console */
2367         case SYSLOG_ACTION_CONSOLE_LEVEL:
2368                 return avc_has_perm(&selinux_state,
2369                                     current_sid(), SECINITSID_KERNEL,
2370                                     SECCLASS_SYSTEM, SYSTEM__SYSLOG_CONSOLE,
2371                                     NULL);
2372         }
2373         /* All other syslog types */
2374         return avc_has_perm(&selinux_state,
2375                             current_sid(), SECINITSID_KERNEL,
2376                             SECCLASS_SYSTEM, SYSTEM__SYSLOG_MOD, NULL);
2379 /*
2380  * Check that a process has enough memory to allocate a new virtual
2381  * mapping. 0 means there is enough memory for the allocation to
2382  * succeed and -ENOMEM implies there is not.
2383  *
2384  * Do not audit the selinux permission check, as this is applied to all
2385  * processes that allocate mappings.
2386  */
2387 static int selinux_vm_enough_memory(struct mm_struct *mm, long pages)
2389         int rc, cap_sys_admin = 0;
2391         rc = cred_has_capability(current_cred(), CAP_SYS_ADMIN,
2392                                  SECURITY_CAP_NOAUDIT, true);
2393         if (rc == 0)
2394                 cap_sys_admin = 1;
2396         return cap_sys_admin;
2399 /* binprm security operations */
2401 static u32 ptrace_parent_sid(void)
2403         u32 sid = 0;
2404         struct task_struct *tracer;
2406         rcu_read_lock();
2407         tracer = ptrace_parent(current);
2408         if (tracer)
2409                 sid = task_sid(tracer);
2410         rcu_read_unlock();
2412         return sid;
2415 static int check_nnp_nosuid(const struct linux_binprm *bprm,
2416                             const struct task_security_struct *old_tsec,
2417                             const struct task_security_struct *new_tsec)
2419         int nnp = (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS);
2420         int nosuid = !mnt_may_suid(bprm->file->f_path.mnt);
2421         int rc;
2422         u32 av;
2424         if (!nnp && !nosuid)
2425                 return 0; /* neither NNP nor nosuid */
2427         if (new_tsec->sid == old_tsec->sid)
2428                 return 0; /* No change in credentials */
2430         /*
2431          * If the policy enables the nnp_nosuid_transition policy capability,
2432          * then we permit transitions under NNP or nosuid if the
2433          * policy allows the corresponding permission between
2434          * the old and new contexts.
2435          */
2436         if (selinux_policycap_nnp_nosuid_transition()) {
2437                 av = 0;
2438                 if (nnp)
2439                         av |= PROCESS2__NNP_TRANSITION;
2440                 if (nosuid)
2441                         av |= PROCESS2__NOSUID_TRANSITION;
2442                 rc = avc_has_perm(&selinux_state,
2443                                   old_tsec->sid, new_tsec->sid,
2444                                   SECCLASS_PROCESS2, av, NULL);
2445                 if (!rc)
2446                         return 0;
2447         }
2449         /*
2450          * We also permit NNP or nosuid transitions to bounded SIDs,
2451          * i.e. SIDs that are guaranteed to only be allowed a subset
2452          * of the permissions of the current SID.
2453          */
2454         rc = security_bounded_transition(&selinux_state, old_tsec->sid,
2455                                          new_tsec->sid);
2456         if (!rc)
2457                 return 0;
2459         /*
2460          * On failure, preserve the errno values for NNP vs nosuid.
2461          * NNP:  Operation not permitted for caller.
2462          * nosuid:  Permission denied to file.
2463          */
2464         if (nnp)
2465                 return -EPERM;
2466         return -EACCES;
2469 static int selinux_bprm_set_creds(struct linux_binprm *bprm)
2471         const struct task_security_struct *old_tsec;
2472         struct task_security_struct *new_tsec;
2473         struct inode_security_struct *isec;
2474         struct common_audit_data ad;
2475         struct inode *inode = file_inode(bprm->file);
2476         int rc;
2478         /* SELinux context only depends on initial program or script and not
2479          * the script interpreter */
2480         if (bprm->called_set_creds)
2481                 return 0;
2483         old_tsec = current_security();
2484         new_tsec = bprm->cred->security;
2485         isec = inode_security(inode);
2487         /* Default to the current task SID. */
2488         new_tsec->sid = old_tsec->sid;
2489         new_tsec->osid = old_tsec->sid;
2491         /* Reset fs, key, and sock SIDs on execve. */
2492         new_tsec->create_sid = 0;
2493         new_tsec->keycreate_sid = 0;
2494         new_tsec->sockcreate_sid = 0;
2496         if (old_tsec->exec_sid) {
2497                 new_tsec->sid = old_tsec->exec_sid;
2498                 /* Reset exec SID on execve. */
2499                 new_tsec->exec_sid = 0;
2501                 /* Fail on NNP or nosuid if not an allowed transition. */
2502                 rc = check_nnp_nosuid(bprm, old_tsec, new_tsec);
2503                 if (rc)
2504                         return rc;
2505         } else {
2506                 /* Check for a default transition on this program. */
2507                 rc = security_transition_sid(&selinux_state, old_tsec->sid,
2508                                              isec->sid, SECCLASS_PROCESS, NULL,
2509                                              &new_tsec->sid);
2510                 if (rc)
2511                         return rc;
2513                 /*
2514                  * Fallback to old SID on NNP or nosuid if not an allowed
2515                  * transition.
2516                  */
2517                 rc = check_nnp_nosuid(bprm, old_tsec, new_tsec);
2518                 if (rc)
2519                         new_tsec->sid = old_tsec->sid;
2520         }
2522         ad.type = LSM_AUDIT_DATA_FILE;
2523         ad.u.file = bprm->file;
2525         if (new_tsec->sid == old_tsec->sid) {
2526                 rc = avc_has_perm(&selinux_state,
2527                                   old_tsec->sid, isec->sid,
2528                                   SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
2529                 if (rc)
2530                         return rc;
2531         } else {
2532                 /* Check permissions for the transition. */
2533                 rc = avc_has_perm(&selinux_state,
2534                                   old_tsec->sid, new_tsec->sid,
2535                                   SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
2536                 if (rc)
2537                         return rc;
2539                 rc = avc_has_perm(&selinux_state,
2540                                   new_tsec->sid, isec->sid,
2541                                   SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
2542                 if (rc)
2543                         return rc;
2545                 /* Check for shared state */
2546                 if (bprm->unsafe & LSM_UNSAFE_SHARE) {
2547                         rc = avc_has_perm(&selinux_state,
2548                                           old_tsec->sid, new_tsec->sid,
2549                                           SECCLASS_PROCESS, PROCESS__SHARE,
2550                                           NULL);
2551                         if (rc)
2552                                 return -EPERM;
2553                 }
2555                 /* Make sure that anyone attempting to ptrace over a task that
2556                  * changes its SID has the appropriate permit */
2557                 if (bprm->unsafe & LSM_UNSAFE_PTRACE) {
2558                         u32 ptsid = ptrace_parent_sid();
2559                         if (ptsid != 0) {
2560                                 rc = avc_has_perm(&selinux_state,
2561                                                   ptsid, new_tsec->sid,
2562                                                   SECCLASS_PROCESS,
2563                                                   PROCESS__PTRACE, NULL);
2564                                 if (rc)
2565                                         return -EPERM;
2566                         }
2567                 }
2569                 /* Clear any possibly unsafe personality bits on exec: */
2570                 bprm->per_clear |= PER_CLEAR_ON_SETID;
2572                 /* Enable secure mode for SIDs transitions unless
2573                    the noatsecure permission is granted between
2574                    the two SIDs, i.e. ahp returns 0. */
2575                 rc = avc_has_perm(&selinux_state,
2576                                   old_tsec->sid, new_tsec->sid,
2577                                   SECCLASS_PROCESS, PROCESS__NOATSECURE,
2578                                   NULL);
2579                 bprm->secureexec |= !!rc;
2580         }
2582         return 0;
2585 static int match_file(const void *p, struct file *file, unsigned fd)
2587         return file_has_perm(p, file, file_to_av(file)) ? fd + 1 : 0;
2590 /* Derived from fs/exec.c:flush_old_files. */
2591 static inline void flush_unauthorized_files(const struct cred *cred,
2592                                             struct files_struct *files)
2594         struct file *file, *devnull = NULL;
2595         struct tty_struct *tty;
2596         int drop_tty = 0;
2597         unsigned n;
2599         tty = get_current_tty();
2600         if (tty) {
2601                 spin_lock(&tty->files_lock);
2602                 if (!list_empty(&tty->tty_files)) {
2603                         struct tty_file_private *file_priv;
2605                         /* Revalidate access to controlling tty.
2606                            Use file_path_has_perm on the tty path directly
2607                            rather than using file_has_perm, as this particular
2608                            open file may belong to another process and we are
2609                            only interested in the inode-based check here. */
2610                         file_priv = list_first_entry(&tty->tty_files,
2611                                                 struct tty_file_private, list);
2612                         file = file_priv->file;
2613                         if (file_path_has_perm(cred, file, FILE__READ | FILE__WRITE))
2614                                 drop_tty = 1;
2615                 }
2616                 spin_unlock(&tty->files_lock);
2617                 tty_kref_put(tty);
2618         }
2619         /* Reset controlling tty. */
2620         if (drop_tty)
2621                 no_tty();
2623         /* Revalidate access to inherited open files. */
2624         n = iterate_fd(files, 0, match_file, cred);
2625         if (!n) /* none found? */
2626                 return;
2628         devnull = dentry_open(&selinux_null, O_RDWR, cred);
2629         if (IS_ERR(devnull))
2630                 devnull = NULL;
2631         /* replace all the matching ones with this */
2632         do {
2633                 replace_fd(n - 1, devnull, 0);
2634         } while ((n = iterate_fd(files, n, match_file, cred)) != 0);
2635         if (devnull)
2636                 fput(devnull);
2639 /*
2640  * Prepare a process for imminent new credential changes due to exec
2641  */
2642 static void selinux_bprm_committing_creds(struct linux_binprm *bprm)
2644         struct task_security_struct *new_tsec;
2645         struct rlimit *rlim, *initrlim;
2646         int rc, i;
2648         new_tsec = bprm->cred->security;
2649         if (new_tsec->sid == new_tsec->osid)
2650                 return;
2652         /* Close files for which the new task SID is not authorized. */
2653         flush_unauthorized_files(bprm->cred, current->files);
2655         /* Always clear parent death signal on SID transitions. */
2656         current->pdeath_signal = 0;
2658         /* Check whether the new SID can inherit resource limits from the old
2659          * SID.  If not, reset all soft limits to the lower of the current
2660          * task's hard limit and the init task's soft limit.
2661          *
2662          * Note that the setting of hard limits (even to lower them) can be
2663          * controlled by the setrlimit check.  The inclusion of the init task's
2664          * soft limit into the computation is to avoid resetting soft limits
2665          * higher than the default soft limit for cases where the default is
2666          * lower than the hard limit, e.g. RLIMIT_CORE or RLIMIT_STACK.
2667          */
2668         rc = avc_has_perm(&selinux_state,
2669                           new_tsec->osid, new_tsec->sid, SECCLASS_PROCESS,
2670                           PROCESS__RLIMITINH, NULL);
2671         if (rc) {
2672                 /* protect against do_prlimit() */
2673                 task_lock(current);
2674                 for (i = 0; i < RLIM_NLIMITS; i++) {
2675                         rlim = current->signal->rlim + i;
2676                         initrlim = init_task.signal->rlim + i;
2677                         rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur);
2678                 }
2679                 task_unlock(current);
2680                 if (IS_ENABLED(CONFIG_POSIX_TIMERS))
2681                         update_rlimit_cpu(current, rlimit(RLIMIT_CPU));
2682         }
2685 /*
2686  * Clean up the process immediately after the installation of new credentials
2687  * due to exec
2688  */
2689 static void selinux_bprm_committed_creds(struct linux_binprm *bprm)
2691         const struct task_security_struct *tsec = current_security();
2692         struct itimerval itimer;
2693         u32 osid, sid;
2694         int rc, i;
2696         osid = tsec->osid;
2697         sid = tsec->sid;
2699         if (sid == osid)
2700                 return;
2702         /* Check whether the new SID can inherit signal state from the old SID.
2703          * If not, clear itimers to avoid subsequent signal generation and
2704          * flush and unblock signals.
2705          *
2706          * This must occur _after_ the task SID has been updated so that any
2707          * kill done after the flush will be checked against the new SID.
2708          */
2709         rc = avc_has_perm(&selinux_state,
2710                           osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL);
2711         if (rc) {
2712                 if (IS_ENABLED(CONFIG_POSIX_TIMERS)) {
2713                         memset(&itimer, 0, sizeof itimer);
2714                         for (i = 0; i < 3; i++)
2715                                 do_setitimer(i, &itimer, NULL);
2716                 }
2717                 spin_lock_irq(&current->sighand->siglock);
2718                 if (!fatal_signal_pending(current)) {
2719                         flush_sigqueue(&current->pending);
2720                         flush_sigqueue(&current->signal->shared_pending);
2721                         flush_signal_handlers(current, 1);
2722                         sigemptyset(&current->blocked);
2723                         recalc_sigpending();
2724                 }
2725                 spin_unlock_irq(&current->sighand->siglock);
2726         }
2728         /* Wake up the parent if it is waiting so that it can recheck
2729          * wait permission to the new task SID. */
2730         read_lock(&tasklist_lock);
2731         __wake_up_parent(current, current->real_parent);
2732         read_unlock(&tasklist_lock);
2735 /* superblock security operations */
2737 static int selinux_sb_alloc_security(struct super_block *sb)
2739         return superblock_alloc_security(sb);
2742 static void selinux_sb_free_security(struct super_block *sb)
2744         superblock_free_security(sb);
2747 static inline int match_prefix(char *prefix, int plen, char *option, int olen)
2749         if (plen > olen)
2750                 return 0;
2752         return !memcmp(prefix, option, plen);
2755 static inline int selinux_option(char *option, int len)
2757         return (match_prefix(CONTEXT_STR, sizeof(CONTEXT_STR)-1, option, len) ||
2758                 match_prefix(FSCONTEXT_STR, sizeof(FSCONTEXT_STR)-1, option, len) ||
2759                 match_prefix(DEFCONTEXT_STR, sizeof(DEFCONTEXT_STR)-1, option, len) ||
2760                 match_prefix(ROOTCONTEXT_STR, sizeof(ROOTCONTEXT_STR)-1, option, len) ||
2761                 match_prefix(LABELSUPP_STR, sizeof(LABELSUPP_STR)-1, option, len));
2764 static inline void take_option(char **to, char *from, int *first, int len)
2766         if (!*first) {
2767                 **to = ',';
2768                 *to += 1;
2769         } else
2770                 *first = 0;
2771         memcpy(*to, from, len);
2772         *to += len;
2775 static inline void take_selinux_option(char **to, char *from, int *first,
2776                                        int len)
2778         int current_size = 0;
2780         if (!*first) {
2781                 **to = '|';
2782                 *to += 1;
2783         } else
2784                 *first = 0;
2786         while (current_size < len) {
2787                 if (*from != '"') {
2788                         **to = *from;
2789                         *to += 1;
2790                 }
2791                 from += 1;
2792                 current_size += 1;
2793         }
2796 static int selinux_sb_copy_data(char *orig, char *copy)
2798         int fnosec, fsec, rc = 0;
2799         char *in_save, *in_curr, *in_end;
2800         char *sec_curr, *nosec_save, *nosec;
2801         int open_quote = 0;
2803         in_curr = orig;
2804         sec_curr = copy;
2806         nosec = (char *)get_zeroed_page(GFP_KERNEL);
2807         if (!nosec) {
2808                 rc = -ENOMEM;
2809                 goto out;
2810         }
2812         nosec_save = nosec;
2813         fnosec = fsec = 1;
2814         in_save = in_end = orig;
2816         do {
2817                 if (*in_end == '"')
2818                         open_quote = !open_quote;
2819                 if ((*in_end == ',' && open_quote == 0) ||
2820                                 *in_end == '\0') {
2821                         int len = in_end - in_curr;
2823                         if (selinux_option(in_curr, len))
2824                                 take_selinux_option(&sec_curr, in_curr, &fsec, len);
2825                         else
2826                                 take_option(&nosec, in_curr, &fnosec, len);
2828                         in_curr = in_end + 1;
2829                 }
2830         } while (*in_end++);
2832         strcpy(in_save, nosec_save);
2833         free_page((unsigned long)nosec_save);
2834 out:
2835         return rc;
2838 static int selinux_sb_remount(struct super_block *sb, void *data)
2840         int rc, i, *flags;
2841         struct security_mnt_opts opts;
2842         char *secdata, **mount_options;
2843         struct superblock_security_struct *sbsec = sb->s_security;
2845         if (!(sbsec->flags & SE_SBINITIALIZED))
2846                 return 0;
2848         if (!data)
2849                 return 0;
2851         if (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
2852                 return 0;
2854         security_init_mnt_opts(&opts);
2855         secdata = alloc_secdata();
2856         if (!secdata)
2857                 return -ENOMEM;
2858         rc = selinux_sb_copy_data(data, secdata);
2859         if (rc)
2860                 goto out_free_secdata;
2862         rc = selinux_parse_opts_str(secdata, &opts);
2863         if (rc)
2864                 goto out_free_secdata;
2866         mount_options = opts.mnt_opts;
2867         flags = opts.mnt_opts_flags;
2869         for (i = 0; i < opts.num_mnt_opts; i++) {
2870                 u32 sid;
2872                 if (flags[i] == SBLABEL_MNT)
2873                         continue;
2874                 rc = security_context_str_to_sid(&selinux_state,
2875                                                  mount_options[i], &sid,
2876                                                  GFP_KERNEL);
2877                 if (rc) {
2878                         pr_warn("SELinux: security_context_str_to_sid"
2879                                "(%s) failed for (dev %s, type %s) errno=%d\n",
2880                                mount_options[i], sb->s_id, sb->s_type->name, rc);
2881                         goto out_free_opts;
2882                 }
2883                 rc = -EINVAL;
2884                 switch (flags[i]) {
2885                 case FSCONTEXT_MNT:
2886                         if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, sid))
2887                                 goto out_bad_option;
2888                         break;
2889                 case CONTEXT_MNT:
2890                         if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, sid))
2891                                 goto out_bad_option;
2892                         break;
2893                 case ROOTCONTEXT_MNT: {
2894                         struct inode_security_struct *root_isec;
2895                         root_isec = backing_inode_security(sb->s_root);
2897                         if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, sid))
2898                                 goto out_bad_option;
2899                         break;
2900                 }
2901                 case DEFCONTEXT_MNT:
2902                         if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, sid))
2903                                 goto out_bad_option;
2904                         break;
2905                 default:
2906                         goto out_free_opts;
2907                 }
2908         }
2910         rc = 0;
2911 out_free_opts:
2912         security_free_mnt_opts(&opts);
2913 out_free_secdata:
2914         free_secdata(secdata);
2915         return rc;
2916 out_bad_option:
2917         pr_warn("SELinux: unable to change security options "
2918                "during remount (dev %s, type=%s)\n", sb->s_id,
2919                sb->s_type->name);
2920         goto out_free_opts;
2923 static int selinux_sb_kern_mount(struct super_block *sb, int flags, void *data)
2925         const struct cred *cred = current_cred();
2926         struct common_audit_data ad;
2927         int rc;
2929         rc = superblock_doinit(sb, data);
2930         if (rc)
2931                 return rc;
2933         /* Allow all mounts performed by the kernel */
2934         if (flags & MS_KERNMOUNT)
2935                 return 0;
2937         ad.type = LSM_AUDIT_DATA_DENTRY;
2938         ad.u.dentry = sb->s_root;
2939         return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad);
2942 static int selinux_sb_statfs(struct dentry *dentry)
2944         const struct cred *cred = current_cred();
2945         struct common_audit_data ad;
2947         ad.type = LSM_AUDIT_DATA_DENTRY;
2948         ad.u.dentry = dentry->d_sb->s_root;
2949         return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad);
2952 static int selinux_mount(const char *dev_name,
2953                          const struct path *path,
2954                          const char *type,
2955                          unsigned long flags,
2956                          void *data)
2958         const struct cred *cred = current_cred();
2960         if (flags & MS_REMOUNT)
2961                 return superblock_has_perm(cred, path->dentry->d_sb,
2962                                            FILESYSTEM__REMOUNT, NULL);
2963         else
2964                 return path_has_perm(cred, path, FILE__MOUNTON);
2967 static int selinux_umount(struct vfsmount *mnt, int flags)
2969         const struct cred *cred = current_cred();
2971         return superblock_has_perm(cred, mnt->mnt_sb,
2972                                    FILESYSTEM__UNMOUNT, NULL);
2975 /* inode security operations */
2977 static int selinux_inode_alloc_security(struct inode *inode)
2979         return inode_alloc_security(inode);
2982 static void selinux_inode_free_security(struct inode *inode)
2984         inode_free_security(inode);
2987 static int selinux_dentry_init_security(struct dentry *dentry, int mode,
2988                                         const struct qstr *name, void **ctx,
2989                                         u32 *ctxlen)
2991         u32 newsid;
2992         int rc;
2994         rc = selinux_determine_inode_label(current_security(),
2995                                            d_inode(dentry->d_parent), name,
2996                                            inode_mode_to_security_class(mode),
2997                                            &newsid);
2998         if (rc)
2999                 return rc;
3001         return security_sid_to_context(&selinux_state, newsid, (char **)ctx,
3002                                        ctxlen);
3005 static int selinux_dentry_create_files_as(struct dentry *dentry, int mode,
3006                                           struct qstr *name,
3007                                           const struct cred *old,
3008                                           struct cred *new)
3010         u32 newsid;
3011         int rc;
3012         struct task_security_struct *tsec;
3014         rc = selinux_determine_inode_label(old->security,
3015                                            d_inode(dentry->d_parent), name,
3016                                            inode_mode_to_security_class(mode),
3017                                            &newsid);
3018         if (rc)
3019                 return rc;
3021         tsec = new->security;
3022         tsec->create_sid = newsid;
3023         return 0;
3026 static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
3027                                        const struct qstr *qstr,
3028                                        const char **name,
3029                                        void **value, size_t *len)
3031         const struct task_security_struct *tsec = current_security();
3032         struct superblock_security_struct *sbsec;
3033         u32 newsid, clen;
3034         int rc;
3035         char *context;
3037         sbsec = dir->i_sb->s_security;
3039         newsid = tsec->create_sid;
3041         rc = selinux_determine_inode_label(current_security(),
3042                 dir, qstr,
3043                 inode_mode_to_security_class(inode->i_mode),
3044                 &newsid);
3045         if (rc)
3046                 return rc;
3048         /* Possibly defer initialization to selinux_complete_init. */
3049         if (sbsec->flags & SE_SBINITIALIZED) {
3050                 struct inode_security_struct *isec = inode->i_security;
3051                 isec->sclass = inode_mode_to_security_class(inode->i_mode);
3052                 isec->sid = newsid;
3053                 isec->initialized = LABEL_INITIALIZED;
3054         }
3056         if (!selinux_state.initialized || !(sbsec->flags & SBLABEL_MNT))
3057                 return -EOPNOTSUPP;
3059         if (name)
3060                 *name = XATTR_SELINUX_SUFFIX;
3062         if (value && len) {
3063                 rc = security_sid_to_context_force(&selinux_state, newsid,
3064                                                    &context, &clen);
3065                 if (rc)
3066                         return rc;
3067                 *value = context;
3068                 *len = clen;
3069         }
3071         return 0;
3074 static int selinux_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode)
3076         return may_create(dir, dentry, SECCLASS_FILE);
3079 static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
3081         return may_link(dir, old_dentry, MAY_LINK);
3084 static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry)
3086         return may_link(dir, dentry, MAY_UNLINK);
3089 static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name)
3091         return may_create(dir, dentry, SECCLASS_LNK_FILE);
3094 static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, umode_t mask)
3096         return may_create(dir, dentry, SECCLASS_DIR);
3099 static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry)
3101         return may_link(dir, dentry, MAY_RMDIR);
3104 static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
3106         return may_create(dir, dentry, inode_mode_to_security_class(mode));
3109 static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
3110                                 struct inode *new_inode, struct dentry *new_dentry)
3112         return may_rename(old_inode, old_dentry, new_inode, new_dentry);
3115 static int selinux_inode_readlink(struct dentry *dentry)
3117         const struct cred *cred = current_cred();
3119         return dentry_has_perm(cred, dentry, FILE__READ);
3122 static int selinux_inode_follow_link(struct dentry *dentry, struct inode *inode,
3123                                      bool rcu)
3125         const struct cred *cred = current_cred();
3126         struct common_audit_data ad;
3127         struct inode_security_struct *isec;
3128         u32 sid;
3130         validate_creds(cred);
3132         ad.type = LSM_AUDIT_DATA_DENTRY;
3133         ad.u.dentry = dentry;
3134         sid = cred_sid(cred);
3135         isec = inode_security_rcu(inode, rcu);
3136         if (IS_ERR(isec))
3137                 return PTR_ERR(isec);
3139         return avc_has_perm_flags(&selinux_state,
3140                                   sid, isec->sid, isec->sclass, FILE__READ, &ad,
3141                                   rcu ? MAY_NOT_BLOCK : 0);
3144 static noinline int audit_inode_permission(struct inode *inode,
3145                                            u32 perms, u32 audited, u32 denied,
3146                                            int result,
3147                                            unsigned flags)
3149         struct common_audit_data ad;
3150         struct inode_security_struct *isec = inode->i_security;
3151         int rc;
3153         ad.type = LSM_AUDIT_DATA_INODE;
3154         ad.u.inode = inode;
3156         rc = slow_avc_audit(&selinux_state,
3157                             current_sid(), isec->sid, isec->sclass, perms,
3158                             audited, denied, result, &ad, flags);
3159         if (rc)
3160                 return rc;
3161         return 0;
3164 static int selinux_inode_permission(struct inode *inode, int mask)
3166         const struct cred *cred = current_cred();
3167         u32 perms;
3168         bool from_access;
3169         unsigned flags = mask & MAY_NOT_BLOCK;
3170         struct inode_security_struct *isec;
3171         u32 sid;
3172         struct av_decision avd;
3173         int rc, rc2;
3174         u32 audited, denied;
3176         from_access = mask & MAY_ACCESS;
3177         mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
3179         /* No permission to check.  Existence test. */
3180         if (!mask)
3181                 return 0;
3183         validate_creds(cred);
3185         if (unlikely(IS_PRIVATE(inode)))
3186                 return 0;
3188         perms = file_mask_to_av(inode->i_mode, mask);
3190         sid = cred_sid(cred);
3191         isec = inode_security_rcu(inode, flags & MAY_NOT_BLOCK);
3192         if (IS_ERR(isec))
3193                 return PTR_ERR(isec);
3195         rc = avc_has_perm_noaudit(&selinux_state,
3196                                   sid, isec->sid, isec->sclass, perms, 0, &avd);
3197         audited = avc_audit_required(perms, &avd, rc,
3198                                      from_access ? FILE__AUDIT_ACCESS : 0,
3199                                      &denied);
3200         if (likely(!audited))
3201                 return rc;
3203         rc2 = audit_inode_permission(inode, perms, audited, denied, rc, flags);
3204         if (rc2)
3205                 return rc2;
3206         return rc;
3209 static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
3211         const struct cred *cred = current_cred();
3212         struct inode *inode = d_backing_inode(dentry);
3213         unsigned int ia_valid = iattr->ia_valid;
3214         __u32 av = FILE__WRITE;
3216         /* ATTR_FORCE is just used for ATTR_KILL_S[UG]ID. */
3217         if (ia_valid & ATTR_FORCE) {
3218                 ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE |
3219                               ATTR_FORCE);
3220                 if (!ia_valid)
3221                         return 0;
3222         }