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SELinux: rename dentry_open to file_open
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CommitLineData
1da177e4
LT
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@epoch.ncsc.mil>
828dfe1d
EP
7 * Chris Vance, <cvance@nai.com>
8 * Wayne Salamon, <wsalamon@nai.com>
9 * James Morris <jmorris@redhat.com>
1da177e4
LT
10 *
11 * Copyright (C) 2001,2002 Networks Associates Technology, Inc.
2069f457
EP
12 * Copyright (C) 2003-2008 Red Hat, Inc., James Morris <jmorris@redhat.com>
13 * Eric Paris <eparis@redhat.com>
1da177e4 14 * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
828dfe1d 15 * <dgoeddel@trustedcs.com>
ed6d76e4 16 * Copyright (C) 2006, 2007, 2009 Hewlett-Packard Development Company, L.P.
82c21bfa 17 * Paul Moore <paul@paul-moore.com>
788e7dd4 18 * Copyright (C) 2007 Hitachi Software Engineering Co., Ltd.
828dfe1d 19 * Yuichi Nakamura <ynakam@hitachisoft.jp>
1da177e4
LT
20 *
21 * This program is free software; you can redistribute it and/or modify
22 * it under the terms of the GNU General Public License version 2,
828dfe1d 23 * as published by the Free Software Foundation.
1da177e4
LT
24 */
25
1da177e4 26#include <linux/init.h>
0b24dcb7 27#include <linux/kd.h>
1da177e4 28#include <linux/kernel.h>
0d094efe 29#include <linux/tracehook.h>
1da177e4
LT
30#include <linux/errno.h>
31#include <linux/sched.h>
32#include <linux/security.h>
33#include <linux/xattr.h>
34#include <linux/capability.h>
35#include <linux/unistd.h>
36#include <linux/mm.h>
37#include <linux/mman.h>
38#include <linux/slab.h>
39#include <linux/pagemap.h>
0b24dcb7 40#include <linux/proc_fs.h>
1da177e4 41#include <linux/swap.h>
1da177e4
LT
42#include <linux/spinlock.h>
43#include <linux/syscalls.h>
2a7dba39 44#include <linux/dcache.h>
1da177e4 45#include <linux/file.h>
9f3acc31 46#include <linux/fdtable.h>
1da177e4
LT
47#include <linux/namei.h>
48#include <linux/mount.h>
1da177e4
LT
49#include <linux/netfilter_ipv4.h>
50#include <linux/netfilter_ipv6.h>
51#include <linux/tty.h>
52#include <net/icmp.h>
227b60f5 53#include <net/ip.h> /* for local_port_range[] */
1da177e4 54#include <net/tcp.h> /* struct or_callable used in sock_rcv_skb */
220deb96 55#include <net/net_namespace.h>
d621d35e 56#include <net/netlabel.h>
f5269710 57#include <linux/uaccess.h>
1da177e4 58#include <asm/ioctls.h>
60063497 59#include <linux/atomic.h>
1da177e4
LT
60#include <linux/bitops.h>
61#include <linux/interrupt.h>
62#include <linux/netdevice.h> /* for network interface checks */
63#include <linux/netlink.h>
64#include <linux/tcp.h>
65#include <linux/udp.h>
2ee92d46 66#include <linux/dccp.h>
1da177e4
LT
67#include <linux/quota.h>
68#include <linux/un.h> /* for Unix socket types */
69#include <net/af_unix.h> /* for Unix socket types */
70#include <linux/parser.h>
71#include <linux/nfs_mount.h>
72#include <net/ipv6.h>
73#include <linux/hugetlb.h>
74#include <linux/personality.h>
1da177e4 75#include <linux/audit.h>
6931dfc9 76#include <linux/string.h>
877ce7c1 77#include <linux/selinux.h>
23970741 78#include <linux/mutex.h>
f06febc9 79#include <linux/posix-timers.h>
00234592 80#include <linux/syslog.h>
3486740a 81#include <linux/user_namespace.h>
44fc7ea0 82#include <linux/export.h>
40401530
AV
83#include <linux/msg.h>
84#include <linux/shm.h>
1da177e4
LT
85
86#include "avc.h"
87#include "objsec.h"
88#include "netif.h"
224dfbd8 89#include "netnode.h"
3e112172 90#include "netport.h"
d28d1e08 91#include "xfrm.h"
c60475bf 92#include "netlabel.h"
9d57a7f9 93#include "audit.h"
7b98a585 94#include "avc_ss.h"
1da177e4 95
11689d47 96#define NUM_SEL_MNT_OPTS 5
c9180a57 97
20510f2f 98extern struct security_operations *security_ops;
1da177e4 99
d621d35e 100/* SECMARK reference count */
56a4ca99 101static atomic_t selinux_secmark_refcount = ATOMIC_INIT(0);
d621d35e 102
1da177e4 103#ifdef CONFIG_SECURITY_SELINUX_DEVELOP
828dfe1d 104int selinux_enforcing;
1da177e4
LT
105
106static int __init enforcing_setup(char *str)
107{
f5269710
EP
108 unsigned long enforcing;
109 if (!strict_strtoul(str, 0, &enforcing))
110 selinux_enforcing = enforcing ? 1 : 0;
1da177e4
LT
111 return 1;
112}
113__setup("enforcing=", enforcing_setup);
114#endif
115
116#ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM
117int selinux_enabled = CONFIG_SECURITY_SELINUX_BOOTPARAM_VALUE;
118
119static int __init selinux_enabled_setup(char *str)
120{
f5269710
EP
121 unsigned long enabled;
122 if (!strict_strtoul(str, 0, &enabled))
123 selinux_enabled = enabled ? 1 : 0;
1da177e4
LT
124 return 1;
125}
126__setup("selinux=", selinux_enabled_setup);
30d55280
SS
127#else
128int selinux_enabled = 1;
1da177e4
LT
129#endif
130
e18b890b 131static struct kmem_cache *sel_inode_cache;
7cae7e26 132
d621d35e
PM
133/**
134 * selinux_secmark_enabled - Check to see if SECMARK is currently enabled
135 *
136 * Description:
137 * This function checks the SECMARK reference counter to see if any SECMARK
138 * targets are currently configured, if the reference counter is greater than
139 * zero SECMARK is considered to be enabled. Returns true (1) if SECMARK is
140 * enabled, false (0) if SECMARK is disabled.
141 *
142 */
143static int selinux_secmark_enabled(void)
144{
145 return (atomic_read(&selinux_secmark_refcount) > 0);
146}
147
d84f4f99
DH
148/*
149 * initialise the security for the init task
150 */
151static void cred_init_security(void)
1da177e4 152{
3b11a1de 153 struct cred *cred = (struct cred *) current->real_cred;
1da177e4
LT
154 struct task_security_struct *tsec;
155
89d155ef 156 tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL);
1da177e4 157 if (!tsec)
d84f4f99 158 panic("SELinux: Failed to initialize initial task.\n");
1da177e4 159
d84f4f99 160 tsec->osid = tsec->sid = SECINITSID_KERNEL;
f1752eec 161 cred->security = tsec;
1da177e4
LT
162}
163
88e67f3b
DH
164/*
165 * get the security ID of a set of credentials
166 */
167static inline u32 cred_sid(const struct cred *cred)
168{
169 const struct task_security_struct *tsec;
170
171 tsec = cred->security;
172 return tsec->sid;
173}
174
275bb41e 175/*
3b11a1de 176 * get the objective security ID of a task
275bb41e
DH
177 */
178static inline u32 task_sid(const struct task_struct *task)
179{
275bb41e
DH
180 u32 sid;
181
182 rcu_read_lock();
88e67f3b 183 sid = cred_sid(__task_cred(task));
275bb41e
DH
184 rcu_read_unlock();
185 return sid;
186}
187
188/*
3b11a1de 189 * get the subjective security ID of the current task
275bb41e
DH
190 */
191static inline u32 current_sid(void)
192{
5fb49870 193 const struct task_security_struct *tsec = current_security();
275bb41e
DH
194
195 return tsec->sid;
196}
197
88e67f3b
DH
198/* Allocate and free functions for each kind of security blob. */
199
1da177e4
LT
200static int inode_alloc_security(struct inode *inode)
201{
1da177e4 202 struct inode_security_struct *isec;
275bb41e 203 u32 sid = current_sid();
1da177e4 204
a02fe132 205 isec = kmem_cache_zalloc(sel_inode_cache, GFP_NOFS);
1da177e4
LT
206 if (!isec)
207 return -ENOMEM;
208
23970741 209 mutex_init(&isec->lock);
1da177e4 210 INIT_LIST_HEAD(&isec->list);
1da177e4
LT
211 isec->inode = inode;
212 isec->sid = SECINITSID_UNLABELED;
213 isec->sclass = SECCLASS_FILE;
275bb41e 214 isec->task_sid = sid;
1da177e4
LT
215 inode->i_security = isec;
216
217 return 0;
218}
219
220static void inode_free_security(struct inode *inode)
221{
222 struct inode_security_struct *isec = inode->i_security;
223 struct superblock_security_struct *sbsec = inode->i_sb->s_security;
224
1da177e4
LT
225 spin_lock(&sbsec->isec_lock);
226 if (!list_empty(&isec->list))
227 list_del_init(&isec->list);
228 spin_unlock(&sbsec->isec_lock);
229
230 inode->i_security = NULL;
7cae7e26 231 kmem_cache_free(sel_inode_cache, isec);
1da177e4
LT
232}
233
234static int file_alloc_security(struct file *file)
235{
1da177e4 236 struct file_security_struct *fsec;
275bb41e 237 u32 sid = current_sid();
1da177e4 238
26d2a4be 239 fsec = kzalloc(sizeof(struct file_security_struct), GFP_KERNEL);
1da177e4
LT
240 if (!fsec)
241 return -ENOMEM;
242
275bb41e
DH
243 fsec->sid = sid;
244 fsec->fown_sid = sid;
1da177e4
LT
245 file->f_security = fsec;
246
247 return 0;
248}
249
250static void file_free_security(struct file *file)
251{
252 struct file_security_struct *fsec = file->f_security;
1da177e4
LT
253 file->f_security = NULL;
254 kfree(fsec);
255}
256
257static int superblock_alloc_security(struct super_block *sb)
258{
259 struct superblock_security_struct *sbsec;
260
89d155ef 261 sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL);
1da177e4
LT
262 if (!sbsec)
263 return -ENOMEM;
264
bc7e982b 265 mutex_init(&sbsec->lock);
1da177e4
LT
266 INIT_LIST_HEAD(&sbsec->isec_head);
267 spin_lock_init(&sbsec->isec_lock);
1da177e4
LT
268 sbsec->sb = sb;
269 sbsec->sid = SECINITSID_UNLABELED;
270 sbsec->def_sid = SECINITSID_FILE;
c312feb2 271 sbsec->mntpoint_sid = SECINITSID_UNLABELED;
1da177e4
LT
272 sb->s_security = sbsec;
273
274 return 0;
275}
276
277static void superblock_free_security(struct super_block *sb)
278{
279 struct superblock_security_struct *sbsec = sb->s_security;
1da177e4
LT
280 sb->s_security = NULL;
281 kfree(sbsec);
282}
283
1da177e4
LT
284/* The file system's label must be initialized prior to use. */
285
634a539e 286static const char *labeling_behaviors[6] = {
1da177e4
LT
287 "uses xattr",
288 "uses transition SIDs",
289 "uses task SIDs",
290 "uses genfs_contexts",
291 "not configured for labeling",
292 "uses mountpoint labeling",
293};
294
295static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry);
296
297static inline int inode_doinit(struct inode *inode)
298{
299 return inode_doinit_with_dentry(inode, NULL);
300}
301
302enum {
31e87930 303 Opt_error = -1,
1da177e4
LT
304 Opt_context = 1,
305 Opt_fscontext = 2,
c9180a57
EP
306 Opt_defcontext = 3,
307 Opt_rootcontext = 4,
11689d47 308 Opt_labelsupport = 5,
1da177e4
LT
309};
310
a447c093 311static const match_table_t tokens = {
832cbd9a
EP
312 {Opt_context, CONTEXT_STR "%s"},
313 {Opt_fscontext, FSCONTEXT_STR "%s"},
314 {Opt_defcontext, DEFCONTEXT_STR "%s"},
315 {Opt_rootcontext, ROOTCONTEXT_STR "%s"},
11689d47 316 {Opt_labelsupport, LABELSUPP_STR},
31e87930 317 {Opt_error, NULL},
1da177e4
LT
318};
319
320#define SEL_MOUNT_FAIL_MSG "SELinux: duplicate or incompatible mount options\n"
321
c312feb2
EP
322static int may_context_mount_sb_relabel(u32 sid,
323 struct superblock_security_struct *sbsec,
275bb41e 324 const struct cred *cred)
c312feb2 325{
275bb41e 326 const struct task_security_struct *tsec = cred->security;
c312feb2
EP
327 int rc;
328
329 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
330 FILESYSTEM__RELABELFROM, NULL);
331 if (rc)
332 return rc;
333
334 rc = avc_has_perm(tsec->sid, sid, SECCLASS_FILESYSTEM,
335 FILESYSTEM__RELABELTO, NULL);
336 return rc;
337}
338
0808925e
EP
339static int may_context_mount_inode_relabel(u32 sid,
340 struct superblock_security_struct *sbsec,
275bb41e 341 const struct cred *cred)
0808925e 342{
275bb41e 343 const struct task_security_struct *tsec = cred->security;
0808925e
EP
344 int rc;
345 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
346 FILESYSTEM__RELABELFROM, NULL);
347 if (rc)
348 return rc;
349
350 rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM,
351 FILESYSTEM__ASSOCIATE, NULL);
352 return rc;
353}
354
c9180a57 355static int sb_finish_set_opts(struct super_block *sb)
1da177e4 356{
1da177e4 357 struct superblock_security_struct *sbsec = sb->s_security;
c9180a57
EP
358 struct dentry *root = sb->s_root;
359 struct inode *root_inode = root->d_inode;
360 int rc = 0;
1da177e4 361
c9180a57
EP
362 if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
363 /* Make sure that the xattr handler exists and that no
364 error other than -ENODATA is returned by getxattr on
365 the root directory. -ENODATA is ok, as this may be
366 the first boot of the SELinux kernel before we have
367 assigned xattr values to the filesystem. */
368 if (!root_inode->i_op->getxattr) {
369 printk(KERN_WARNING "SELinux: (dev %s, type %s) has no "
370 "xattr support\n", sb->s_id, sb->s_type->name);
371 rc = -EOPNOTSUPP;
372 goto out;
373 }
374 rc = root_inode->i_op->getxattr(root, XATTR_NAME_SELINUX, NULL, 0);
375 if (rc < 0 && rc != -ENODATA) {
376 if (rc == -EOPNOTSUPP)
377 printk(KERN_WARNING "SELinux: (dev %s, type "
378 "%s) has no security xattr handler\n",
379 sb->s_id, sb->s_type->name);
380 else
381 printk(KERN_WARNING "SELinux: (dev %s, type "
382 "%s) getxattr errno %d\n", sb->s_id,
383 sb->s_type->name, -rc);
384 goto out;
385 }
386 }
1da177e4 387
11689d47 388 sbsec->flags |= (SE_SBINITIALIZED | SE_SBLABELSUPP);
1da177e4 389
c9180a57
EP
390 if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors))
391 printk(KERN_ERR "SELinux: initialized (dev %s, type %s), unknown behavior\n",
392 sb->s_id, sb->s_type->name);
393 else
394 printk(KERN_DEBUG "SELinux: initialized (dev %s, type %s), %s\n",
395 sb->s_id, sb->s_type->name,
396 labeling_behaviors[sbsec->behavior-1]);
1da177e4 397
11689d47
DQ
398 if (sbsec->behavior == SECURITY_FS_USE_GENFS ||
399 sbsec->behavior == SECURITY_FS_USE_MNTPOINT ||
400 sbsec->behavior == SECURITY_FS_USE_NONE ||
401 sbsec->behavior > ARRAY_SIZE(labeling_behaviors))
402 sbsec->flags &= ~SE_SBLABELSUPP;
403
ddd29ec6
DQ
404 /* Special handling for sysfs. Is genfs but also has setxattr handler*/
405 if (strncmp(sb->s_type->name, "sysfs", sizeof("sysfs")) == 0)
406 sbsec->flags |= SE_SBLABELSUPP;
407
c9180a57
EP
408 /* Initialize the root inode. */
409 rc = inode_doinit_with_dentry(root_inode, root);
1da177e4 410
c9180a57
EP
411 /* Initialize any other inodes associated with the superblock, e.g.
412 inodes created prior to initial policy load or inodes created
413 during get_sb by a pseudo filesystem that directly
414 populates itself. */
415 spin_lock(&sbsec->isec_lock);
416next_inode:
417 if (!list_empty(&sbsec->isec_head)) {
418 struct inode_security_struct *isec =
419 list_entry(sbsec->isec_head.next,
420 struct inode_security_struct, list);
421 struct inode *inode = isec->inode;
422 spin_unlock(&sbsec->isec_lock);
423 inode = igrab(inode);
424 if (inode) {
425 if (!IS_PRIVATE(inode))
426 inode_doinit(inode);
427 iput(inode);
428 }
429 spin_lock(&sbsec->isec_lock);
430 list_del_init(&isec->list);
431 goto next_inode;
432 }
433 spin_unlock(&sbsec->isec_lock);
434out:
435 return rc;
436}
1da177e4 437
c9180a57
EP
438/*
439 * This function should allow an FS to ask what it's mount security
440 * options were so it can use those later for submounts, displaying
441 * mount options, or whatever.
442 */
443static int selinux_get_mnt_opts(const struct super_block *sb,
e0007529 444 struct security_mnt_opts *opts)
c9180a57
EP
445{
446 int rc = 0, i;
447 struct superblock_security_struct *sbsec = sb->s_security;
448 char *context = NULL;
449 u32 len;
450 char tmp;
1da177e4 451
e0007529 452 security_init_mnt_opts(opts);
1da177e4 453
0d90a7ec 454 if (!(sbsec->flags & SE_SBINITIALIZED))
c9180a57 455 return -EINVAL;
1da177e4 456
c9180a57
EP
457 if (!ss_initialized)
458 return -EINVAL;
1da177e4 459
0d90a7ec 460 tmp = sbsec->flags & SE_MNTMASK;
c9180a57
EP
461 /* count the number of mount options for this sb */
462 for (i = 0; i < 8; i++) {
463 if (tmp & 0x01)
e0007529 464 opts->num_mnt_opts++;
c9180a57
EP
465 tmp >>= 1;
466 }
11689d47
DQ
467 /* Check if the Label support flag is set */
468 if (sbsec->flags & SE_SBLABELSUPP)
469 opts->num_mnt_opts++;
1da177e4 470
e0007529
EP
471 opts->mnt_opts = kcalloc(opts->num_mnt_opts, sizeof(char *), GFP_ATOMIC);
472 if (!opts->mnt_opts) {
c9180a57
EP
473 rc = -ENOMEM;
474 goto out_free;
475 }
1da177e4 476
e0007529
EP
477 opts->mnt_opts_flags = kcalloc(opts->num_mnt_opts, sizeof(int), GFP_ATOMIC);
478 if (!opts->mnt_opts_flags) {
c9180a57
EP
479 rc = -ENOMEM;
480 goto out_free;
481 }
1da177e4 482
c9180a57
EP
483 i = 0;
484 if (sbsec->flags & FSCONTEXT_MNT) {
485 rc = security_sid_to_context(sbsec->sid, &context, &len);
486 if (rc)
487 goto out_free;
e0007529
EP
488 opts->mnt_opts[i] = context;
489 opts->mnt_opts_flags[i++] = FSCONTEXT_MNT;
c9180a57
EP
490 }
491 if (sbsec->flags & CONTEXT_MNT) {
492 rc = security_sid_to_context(sbsec->mntpoint_sid, &context, &len);
493 if (rc)
494 goto out_free;
e0007529
EP
495 opts->mnt_opts[i] = context;
496 opts->mnt_opts_flags[i++] = CONTEXT_MNT;
c9180a57
EP
497 }
498 if (sbsec->flags & DEFCONTEXT_MNT) {
499 rc = security_sid_to_context(sbsec->def_sid, &context, &len);
500 if (rc)
501 goto out_free;
e0007529
EP
502 opts->mnt_opts[i] = context;
503 opts->mnt_opts_flags[i++] = DEFCONTEXT_MNT;
c9180a57
EP
504 }
505 if (sbsec->flags & ROOTCONTEXT_MNT) {
506 struct inode *root = sbsec->sb->s_root->d_inode;
507 struct inode_security_struct *isec = root->i_security;
0808925e 508
c9180a57
EP
509 rc = security_sid_to_context(isec->sid, &context, &len);
510 if (rc)
511 goto out_free;
e0007529
EP
512 opts->mnt_opts[i] = context;
513 opts->mnt_opts_flags[i++] = ROOTCONTEXT_MNT;
c9180a57 514 }
11689d47
DQ
515 if (sbsec->flags & SE_SBLABELSUPP) {
516 opts->mnt_opts[i] = NULL;
517 opts->mnt_opts_flags[i++] = SE_SBLABELSUPP;
518 }
1da177e4 519
e0007529 520 BUG_ON(i != opts->num_mnt_opts);
1da177e4 521
c9180a57
EP
522 return 0;
523
524out_free:
e0007529 525 security_free_mnt_opts(opts);
c9180a57
EP
526 return rc;
527}
1da177e4 528
c9180a57
EP
529static int bad_option(struct superblock_security_struct *sbsec, char flag,
530 u32 old_sid, u32 new_sid)
531{
0d90a7ec
DQ
532 char mnt_flags = sbsec->flags & SE_MNTMASK;
533
c9180a57 534 /* check if the old mount command had the same options */
0d90a7ec 535 if (sbsec->flags & SE_SBINITIALIZED)
c9180a57
EP
536 if (!(sbsec->flags & flag) ||
537 (old_sid != new_sid))
538 return 1;
539
540 /* check if we were passed the same options twice,
541 * aka someone passed context=a,context=b
542 */
0d90a7ec
DQ
543 if (!(sbsec->flags & SE_SBINITIALIZED))
544 if (mnt_flags & flag)
c9180a57
EP
545 return 1;
546 return 0;
547}
e0007529 548
c9180a57
EP
549/*
550 * Allow filesystems with binary mount data to explicitly set mount point
551 * labeling information.
552 */
e0007529
EP
553static int selinux_set_mnt_opts(struct super_block *sb,
554 struct security_mnt_opts *opts)
c9180a57 555{
275bb41e 556 const struct cred *cred = current_cred();
c9180a57 557 int rc = 0, i;
c9180a57
EP
558 struct superblock_security_struct *sbsec = sb->s_security;
559 const char *name = sb->s_type->name;
089be43e
JM
560 struct inode *inode = sbsec->sb->s_root->d_inode;
561 struct inode_security_struct *root_isec = inode->i_security;
c9180a57
EP
562 u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0;
563 u32 defcontext_sid = 0;
e0007529
EP
564 char **mount_options = opts->mnt_opts;
565 int *flags = opts->mnt_opts_flags;
566 int num_opts = opts->num_mnt_opts;
c9180a57
EP
567
568 mutex_lock(&sbsec->lock);
569
570 if (!ss_initialized) {
571 if (!num_opts) {
572 /* Defer initialization until selinux_complete_init,
573 after the initial policy is loaded and the security
574 server is ready to handle calls. */
c9180a57
EP
575 goto out;
576 }
577 rc = -EINVAL;
744ba35e
EP
578 printk(KERN_WARNING "SELinux: Unable to set superblock options "
579 "before the security server is initialized\n");
1da177e4 580 goto out;
c9180a57 581 }
1da177e4 582
e0007529
EP
583 /*
584 * Binary mount data FS will come through this function twice. Once
585 * from an explicit call and once from the generic calls from the vfs.
586 * Since the generic VFS calls will not contain any security mount data
587 * we need to skip the double mount verification.
588 *
589 * This does open a hole in which we will not notice if the first
590 * mount using this sb set explict options and a second mount using
591 * this sb does not set any security options. (The first options
592 * will be used for both mounts)
593 */
0d90a7ec 594 if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
e0007529 595 && (num_opts == 0))
f5269710 596 goto out;
e0007529 597
c9180a57
EP
598 /*
599 * parse the mount options, check if they are valid sids.
600 * also check if someone is trying to mount the same sb more
601 * than once with different security options.
602 */
603 for (i = 0; i < num_opts; i++) {
604 u32 sid;
11689d47
DQ
605
606 if (flags[i] == SE_SBLABELSUPP)
607 continue;
c9180a57
EP
608 rc = security_context_to_sid(mount_options[i],
609 strlen(mount_options[i]), &sid);
1da177e4
LT
610 if (rc) {
611 printk(KERN_WARNING "SELinux: security_context_to_sid"
612 "(%s) failed for (dev %s, type %s) errno=%d\n",
c9180a57
EP
613 mount_options[i], sb->s_id, name, rc);
614 goto out;
615 }
616 switch (flags[i]) {
617 case FSCONTEXT_MNT:
618 fscontext_sid = sid;
619
620 if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid,
621 fscontext_sid))
622 goto out_double_mount;
623
624 sbsec->flags |= FSCONTEXT_MNT;
625 break;
626 case CONTEXT_MNT:
627 context_sid = sid;
628
629 if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid,
630 context_sid))
631 goto out_double_mount;
632
633 sbsec->flags |= CONTEXT_MNT;
634 break;
635 case ROOTCONTEXT_MNT:
636 rootcontext_sid = sid;
637
638 if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid,
639 rootcontext_sid))
640 goto out_double_mount;
641
642 sbsec->flags |= ROOTCONTEXT_MNT;
643
644 break;
645 case DEFCONTEXT_MNT:
646 defcontext_sid = sid;
647
648 if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid,
649 defcontext_sid))
650 goto out_double_mount;
651
652 sbsec->flags |= DEFCONTEXT_MNT;
653
654 break;
655 default:
656 rc = -EINVAL;
657 goto out;
1da177e4 658 }
c9180a57
EP
659 }
660
0d90a7ec 661 if (sbsec->flags & SE_SBINITIALIZED) {
c9180a57 662 /* previously mounted with options, but not on this attempt? */
0d90a7ec 663 if ((sbsec->flags & SE_MNTMASK) && !num_opts)
c9180a57
EP
664 goto out_double_mount;
665 rc = 0;
666 goto out;
667 }
668
089be43e 669 if (strcmp(sb->s_type->name, "proc") == 0)
0d90a7ec 670 sbsec->flags |= SE_SBPROC;
c9180a57
EP
671
672 /* Determine the labeling behavior to use for this filesystem type. */
0d90a7ec 673 rc = security_fs_use((sbsec->flags & SE_SBPROC) ? "proc" : sb->s_type->name, &sbsec->behavior, &sbsec->sid);
c9180a57
EP
674 if (rc) {
675 printk(KERN_WARNING "%s: security_fs_use(%s) returned %d\n",
089be43e 676 __func__, sb->s_type->name, rc);
c9180a57
EP
677 goto out;
678 }
1da177e4 679
c9180a57
EP
680 /* sets the context of the superblock for the fs being mounted. */
681 if (fscontext_sid) {
275bb41e 682 rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred);
1da177e4 683 if (rc)
c9180a57 684 goto out;
1da177e4 685
c9180a57 686 sbsec->sid = fscontext_sid;
c312feb2
EP
687 }
688
689 /*
690 * Switch to using mount point labeling behavior.
691 * sets the label used on all file below the mountpoint, and will set
692 * the superblock context if not already set.
693 */
c9180a57
EP
694 if (context_sid) {
695 if (!fscontext_sid) {
275bb41e
DH
696 rc = may_context_mount_sb_relabel(context_sid, sbsec,
697 cred);
b04ea3ce 698 if (rc)
c9180a57
EP
699 goto out;
700 sbsec->sid = context_sid;
b04ea3ce 701 } else {
275bb41e
DH
702 rc = may_context_mount_inode_relabel(context_sid, sbsec,
703 cred);
b04ea3ce 704 if (rc)
c9180a57 705 goto out;
b04ea3ce 706 }
c9180a57
EP
707 if (!rootcontext_sid)
708 rootcontext_sid = context_sid;
1da177e4 709
c9180a57 710 sbsec->mntpoint_sid = context_sid;
c312feb2 711 sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
1da177e4
LT
712 }
713
c9180a57 714 if (rootcontext_sid) {
275bb41e
DH
715 rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec,
716 cred);
0808925e 717 if (rc)
c9180a57 718 goto out;
0808925e 719
c9180a57
EP
720 root_isec->sid = rootcontext_sid;
721 root_isec->initialized = 1;
0808925e
EP
722 }
723
c9180a57
EP
724 if (defcontext_sid) {
725 if (sbsec->behavior != SECURITY_FS_USE_XATTR) {
726 rc = -EINVAL;
727 printk(KERN_WARNING "SELinux: defcontext option is "
728 "invalid for this filesystem type\n");
729 goto out;
1da177e4
LT
730 }
731
c9180a57
EP
732 if (defcontext_sid != sbsec->def_sid) {
733 rc = may_context_mount_inode_relabel(defcontext_sid,
275bb41e 734 sbsec, cred);
c9180a57
EP
735 if (rc)
736 goto out;
737 }
1da177e4 738
c9180a57 739 sbsec->def_sid = defcontext_sid;
1da177e4
LT
740 }
741
c9180a57 742 rc = sb_finish_set_opts(sb);
1da177e4 743out:
c9180a57 744 mutex_unlock(&sbsec->lock);
1da177e4 745 return rc;
c9180a57
EP
746out_double_mount:
747 rc = -EINVAL;
748 printk(KERN_WARNING "SELinux: mount invalid. Same superblock, different "
749 "security settings for (dev %s, type %s)\n", sb->s_id, name);
750 goto out;
1da177e4
LT
751}
752
c9180a57
EP
753static void selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
754 struct super_block *newsb)
1da177e4 755{
c9180a57
EP
756 const struct superblock_security_struct *oldsbsec = oldsb->s_security;
757 struct superblock_security_struct *newsbsec = newsb->s_security;
1da177e4 758
c9180a57
EP
759 int set_fscontext = (oldsbsec->flags & FSCONTEXT_MNT);
760 int set_context = (oldsbsec->flags & CONTEXT_MNT);
761 int set_rootcontext = (oldsbsec->flags & ROOTCONTEXT_MNT);
1da177e4 762
0f5e6420
EP
763 /*
764 * if the parent was able to be mounted it clearly had no special lsm
e8c26255 765 * mount options. thus we can safely deal with this superblock later
0f5e6420 766 */
e8c26255 767 if (!ss_initialized)
0f5e6420 768 return;
c9180a57 769
c9180a57 770 /* how can we clone if the old one wasn't set up?? */
0d90a7ec 771 BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED));
c9180a57 772
5a552617 773 /* if fs is reusing a sb, just let its options stand... */
0d90a7ec 774 if (newsbsec->flags & SE_SBINITIALIZED)
5a552617
EP
775 return;
776
c9180a57
EP
777 mutex_lock(&newsbsec->lock);
778
779 newsbsec->flags = oldsbsec->flags;
780
781 newsbsec->sid = oldsbsec->sid;
782 newsbsec->def_sid = oldsbsec->def_sid;
783 newsbsec->behavior = oldsbsec->behavior;
784
785 if (set_context) {
786 u32 sid = oldsbsec->mntpoint_sid;
787
788 if (!set_fscontext)
789 newsbsec->sid = sid;
790 if (!set_rootcontext) {
791 struct inode *newinode = newsb->s_root->d_inode;
792 struct inode_security_struct *newisec = newinode->i_security;
793 newisec->sid = sid;
794 }
795 newsbsec->mntpoint_sid = sid;
1da177e4 796 }
c9180a57
EP
797 if (set_rootcontext) {
798 const struct inode *oldinode = oldsb->s_root->d_inode;
799 const struct inode_security_struct *oldisec = oldinode->i_security;
800 struct inode *newinode = newsb->s_root->d_inode;
801 struct inode_security_struct *newisec = newinode->i_security;
1da177e4 802
c9180a57 803 newisec->sid = oldisec->sid;
1da177e4
LT
804 }
805
c9180a57
EP
806 sb_finish_set_opts(newsb);
807 mutex_unlock(&newsbsec->lock);
808}
809
2e1479d9
AB
810static int selinux_parse_opts_str(char *options,
811 struct security_mnt_opts *opts)
c9180a57 812{
e0007529 813 char *p;
c9180a57
EP
814 char *context = NULL, *defcontext = NULL;
815 char *fscontext = NULL, *rootcontext = NULL;
e0007529 816 int rc, num_mnt_opts = 0;
1da177e4 817
e0007529 818 opts->num_mnt_opts = 0;
1da177e4 819
c9180a57
EP
820 /* Standard string-based options. */
821 while ((p = strsep(&options, "|")) != NULL) {
822 int token;
823 substring_t args[MAX_OPT_ARGS];
1da177e4 824
c9180a57
EP
825 if (!*p)
826 continue;
1da177e4 827
c9180a57 828 token = match_token(p, tokens, args);
1da177e4 829
c9180a57
EP
830 switch (token) {
831 case Opt_context:
832 if (context || defcontext) {
833 rc = -EINVAL;
834 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
835 goto out_err;
836 }
837 context = match_strdup(&args[0]);
838 if (!context) {
839 rc = -ENOMEM;
840 goto out_err;
841 }
842 break;
843
844 case Opt_fscontext:
845 if (fscontext) {
846 rc = -EINVAL;
847 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
848 goto out_err;
849 }
850 fscontext = match_strdup(&args[0]);
851 if (!fscontext) {
852 rc = -ENOMEM;
853 goto out_err;
854 }
855 break;
856
857 case Opt_rootcontext:
858 if (rootcontext) {
859 rc = -EINVAL;
860 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
861 goto out_err;
862 }
863 rootcontext = match_strdup(&args[0]);
864 if (!rootcontext) {
865 rc = -ENOMEM;
866 goto out_err;
867 }
868 break;
869
870 case Opt_defcontext:
871 if (context || defcontext) {
872 rc = -EINVAL;
873 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
874 goto out_err;
875 }
876 defcontext = match_strdup(&args[0]);
877 if (!defcontext) {
878 rc = -ENOMEM;
879 goto out_err;
880 }
881 break;
11689d47
DQ
882 case Opt_labelsupport:
883 break;
c9180a57
EP
884 default:
885 rc = -EINVAL;
886 printk(KERN_WARNING "SELinux: unknown mount option\n");
887 goto out_err;
1da177e4 888
1da177e4 889 }
1da177e4 890 }
c9180a57 891
e0007529
EP
892 rc = -ENOMEM;
893 opts->mnt_opts = kcalloc(NUM_SEL_MNT_OPTS, sizeof(char *), GFP_ATOMIC);
894 if (!opts->mnt_opts)
895 goto out_err;
896
897 opts->mnt_opts_flags = kcalloc(NUM_SEL_MNT_OPTS, sizeof(int), GFP_ATOMIC);
898 if (!opts->mnt_opts_flags) {
899 kfree(opts->mnt_opts);
900 goto out_err;
901 }
902
c9180a57 903 if (fscontext) {
e0007529
EP
904 opts->mnt_opts[num_mnt_opts] = fscontext;
905 opts->mnt_opts_flags[num_mnt_opts++] = FSCONTEXT_MNT;
c9180a57
EP
906 }
907 if (context) {
e0007529
EP
908 opts->mnt_opts[num_mnt_opts] = context;
909 opts->mnt_opts_flags[num_mnt_opts++] = CONTEXT_MNT;
c9180a57
EP
910 }
911 if (rootcontext) {
e0007529
EP
912 opts->mnt_opts[num_mnt_opts] = rootcontext;
913 opts->mnt_opts_flags[num_mnt_opts++] = ROOTCONTEXT_MNT;
c9180a57
EP
914 }
915 if (defcontext) {
e0007529
EP
916 opts->mnt_opts[num_mnt_opts] = defcontext;
917 opts->mnt_opts_flags[num_mnt_opts++] = DEFCONTEXT_MNT;
c9180a57
EP
918 }
919
e0007529
EP
920 opts->num_mnt_opts = num_mnt_opts;
921 return 0;
922
c9180a57
EP
923out_err:
924 kfree(context);
925 kfree(defcontext);
926 kfree(fscontext);
927 kfree(rootcontext);
1da177e4
LT
928 return rc;
929}
e0007529
EP
930/*
931 * string mount options parsing and call set the sbsec
932 */
933static int superblock_doinit(struct super_block *sb, void *data)
934{
935 int rc = 0;
936 char *options = data;
937 struct security_mnt_opts opts;
938
939 security_init_mnt_opts(&opts);
940
941 if (!data)
942 goto out;
943
944 BUG_ON(sb->s_type->fs_flags & FS_BINARY_MOUNTDATA);
945
946 rc = selinux_parse_opts_str(options, &opts);
947 if (rc)
948 goto out_err;
949
950out:
951 rc = selinux_set_mnt_opts(sb, &opts);
952
953out_err:
954 security_free_mnt_opts(&opts);
955 return rc;
956}
1da177e4 957
3583a711
AB
958static void selinux_write_opts(struct seq_file *m,
959 struct security_mnt_opts *opts)
2069f457
EP
960{
961 int i;
962 char *prefix;
963
964 for (i = 0; i < opts->num_mnt_opts; i++) {
11689d47
DQ
965 char *has_comma;
966
967 if (opts->mnt_opts[i])
968 has_comma = strchr(opts->mnt_opts[i], ',');
969 else
970 has_comma = NULL;
2069f457
EP
971
972 switch (opts->mnt_opts_flags[i]) {
973 case CONTEXT_MNT:
974 prefix = CONTEXT_STR;
975 break;
976 case FSCONTEXT_MNT:
977 prefix = FSCONTEXT_STR;
978 break;
979 case ROOTCONTEXT_MNT:
980 prefix = ROOTCONTEXT_STR;
981 break;
982 case DEFCONTEXT_MNT:
983 prefix = DEFCONTEXT_STR;
984 break;
11689d47
DQ
985 case SE_SBLABELSUPP:
986 seq_putc(m, ',');
987 seq_puts(m, LABELSUPP_STR);
988 continue;
2069f457
EP
989 default:
990 BUG();
a35c6c83 991 return;
2069f457
EP
992 };
993 /* we need a comma before each option */
994 seq_putc(m, ',');
995 seq_puts(m, prefix);
996 if (has_comma)
997 seq_putc(m, '\"');
998 seq_puts(m, opts->mnt_opts[i]);
999 if (has_comma)
1000 seq_putc(m, '\"');
1001 }
1002}
1003
1004static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb)
1005{
1006 struct security_mnt_opts opts;
1007 int rc;
1008
1009 rc = selinux_get_mnt_opts(sb, &opts);
383795c2
EP
1010 if (rc) {
1011 /* before policy load we may get EINVAL, don't show anything */
1012 if (rc == -EINVAL)
1013 rc = 0;
2069f457 1014 return rc;
383795c2 1015 }
2069f457
EP
1016
1017 selinux_write_opts(m, &opts);
1018
1019 security_free_mnt_opts(&opts);
1020
1021 return rc;
1022}
1023
1da177e4
LT
1024static inline u16 inode_mode_to_security_class(umode_t mode)
1025{
1026 switch (mode & S_IFMT) {
1027 case S_IFSOCK:
1028 return SECCLASS_SOCK_FILE;
1029 case S_IFLNK:
1030 return SECCLASS_LNK_FILE;
1031 case S_IFREG:
1032 return SECCLASS_FILE;
1033 case S_IFBLK:
1034 return SECCLASS_BLK_FILE;
1035 case S_IFDIR:
1036 return SECCLASS_DIR;
1037 case S_IFCHR:
1038 return SECCLASS_CHR_FILE;
1039 case S_IFIFO:
1040 return SECCLASS_FIFO_FILE;
1041
1042 }
1043
1044 return SECCLASS_FILE;
1045}
1046
13402580
JM
1047static inline int default_protocol_stream(int protocol)
1048{
1049 return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP);
1050}
1051
1052static inline int default_protocol_dgram(int protocol)
1053{
1054 return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP);
1055}
1056
1da177e4
LT
1057static inline u16 socket_type_to_security_class(int family, int type, int protocol)
1058{
1059 switch (family) {
1060 case PF_UNIX:
1061 switch (type) {
1062 case SOCK_STREAM:
1063 case SOCK_SEQPACKET:
1064 return SECCLASS_UNIX_STREAM_SOCKET;
1065 case SOCK_DGRAM:
1066 return SECCLASS_UNIX_DGRAM_SOCKET;
1067 }
1068 break;
1069 case PF_INET:
1070 case PF_INET6:
1071 switch (type) {
1072 case SOCK_STREAM:
13402580
JM
1073 if (default_protocol_stream(protocol))
1074 return SECCLASS_TCP_SOCKET;
1075 else
1076 return SECCLASS_RAWIP_SOCKET;
1da177e4 1077 case SOCK_DGRAM:
13402580
JM
1078 if (default_protocol_dgram(protocol))
1079 return SECCLASS_UDP_SOCKET;
1080 else
1081 return SECCLASS_RAWIP_SOCKET;
2ee92d46
JM
1082 case SOCK_DCCP:
1083 return SECCLASS_DCCP_SOCKET;
13402580 1084 default:
1da177e4
LT
1085 return SECCLASS_RAWIP_SOCKET;
1086 }
1087 break;
1088 case PF_NETLINK:
1089 switch (protocol) {
1090 case NETLINK_ROUTE:
1091 return SECCLASS_NETLINK_ROUTE_SOCKET;
1092 case NETLINK_FIREWALL:
1093 return SECCLASS_NETLINK_FIREWALL_SOCKET;
7f1fb60c 1094 case NETLINK_SOCK_DIAG:
1da177e4
LT
1095 return SECCLASS_NETLINK_TCPDIAG_SOCKET;
1096 case NETLINK_NFLOG:
1097 return SECCLASS_NETLINK_NFLOG_SOCKET;
1098 case NETLINK_XFRM:
1099 return SECCLASS_NETLINK_XFRM_SOCKET;
1100 case NETLINK_SELINUX:
1101 return SECCLASS_NETLINK_SELINUX_SOCKET;
1102 case NETLINK_AUDIT:
1103 return SECCLASS_NETLINK_AUDIT_SOCKET;
1104 case NETLINK_IP6_FW:
1105 return SECCLASS_NETLINK_IP6FW_SOCKET;
1106 case NETLINK_DNRTMSG:
1107 return SECCLASS_NETLINK_DNRT_SOCKET;
0c9b7942
JM
1108 case NETLINK_KOBJECT_UEVENT:
1109 return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET;
1da177e4
LT
1110 default:
1111 return SECCLASS_NETLINK_SOCKET;
1112 }
1113 case PF_PACKET:
1114 return SECCLASS_PACKET_SOCKET;
1115 case PF_KEY:
1116 return SECCLASS_KEY_SOCKET;
3e3ff15e
CP
1117 case PF_APPLETALK:
1118 return SECCLASS_APPLETALK_SOCKET;
1da177e4
LT
1119 }
1120
1121 return SECCLASS_SOCKET;
1122}
1123
1124#ifdef CONFIG_PROC_FS
8e6c9693 1125static int selinux_proc_get_sid(struct dentry *dentry,
1da177e4
LT
1126 u16 tclass,
1127 u32 *sid)
1128{
8e6c9693
LAG
1129 int rc;
1130 char *buffer, *path;
1da177e4 1131
828dfe1d 1132 buffer = (char *)__get_free_page(GFP_KERNEL);
1da177e4
LT
1133 if (!buffer)
1134 return -ENOMEM;
1135
8e6c9693
LAG
1136 path = dentry_path_raw(dentry, buffer, PAGE_SIZE);
1137 if (IS_ERR(path))
1138 rc = PTR_ERR(path);
1139 else {
1140 /* each process gets a /proc/PID/ entry. Strip off the
1141 * PID part to get a valid selinux labeling.
1142 * e.g. /proc/1/net/rpc/nfs -> /net/rpc/nfs */
1143 while (path[1] >= '0' && path[1] <= '9') {
1144 path[1] = '/';
1145 path++;
1146 }
1147 rc = security_genfs_sid("proc", path, tclass, sid);
1da177e4 1148 }
1da177e4
LT
1149 free_page((unsigned long)buffer);
1150 return rc;
1151}
1152#else
8e6c9693 1153static int selinux_proc_get_sid(struct dentry *dentry,
1da177e4
LT
1154 u16 tclass,
1155 u32 *sid)
1156{
1157 return -EINVAL;
1158}
1159#endif
1160
1161/* The inode's security attributes must be initialized before first use. */
1162static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry)
1163{
1164 struct superblock_security_struct *sbsec = NULL;
1165 struct inode_security_struct *isec = inode->i_security;
1166 u32 sid;
1167 struct dentry *dentry;
1168#define INITCONTEXTLEN 255
1169 char *context = NULL;
1170 unsigned len = 0;
1171 int rc = 0;
1da177e4
LT
1172
1173 if (isec->initialized)
1174 goto out;
1175
23970741 1176 mutex_lock(&isec->lock);
1da177e4 1177 if (isec->initialized)
23970741 1178 goto out_unlock;
1da177e4
LT
1179
1180 sbsec = inode->i_sb->s_security;
0d90a7ec 1181 if (!(sbsec->flags & SE_SBINITIALIZED)) {
1da177e4
LT
1182 /* Defer initialization until selinux_complete_init,
1183 after the initial policy is loaded and the security
1184 server is ready to handle calls. */
1185 spin_lock(&sbsec->isec_lock);
1186 if (list_empty(&isec->list))
1187 list_add(&isec->list, &sbsec->isec_head);
1188 spin_unlock(&sbsec->isec_lock);
23970741 1189 goto out_unlock;
1da177e4
LT
1190 }
1191
1192 switch (sbsec->behavior) {
1193 case SECURITY_FS_USE_XATTR:
1194 if (!inode->i_op->getxattr) {
1195 isec->sid = sbsec->def_sid;
1196 break;
1197 }
1198
1199 /* Need a dentry, since the xattr API requires one.
1200 Life would be simpler if we could just pass the inode. */
1201 if (opt_dentry) {
1202 /* Called from d_instantiate or d_splice_alias. */
1203 dentry = dget(opt_dentry);
1204 } else {
1205 /* Called from selinux_complete_init, try to find a dentry. */
1206 dentry = d_find_alias(inode);
1207 }
1208 if (!dentry) {
df7f54c0
EP
1209 /*
1210 * this is can be hit on boot when a file is accessed
1211 * before the policy is loaded. When we load policy we
1212 * may find inodes that have no dentry on the
1213 * sbsec->isec_head list. No reason to complain as these
1214 * will get fixed up the next time we go through
1215 * inode_doinit with a dentry, before these inodes could
1216 * be used again by userspace.
1217 */
23970741 1218 goto out_unlock;
1da177e4
LT
1219 }
1220
1221 len = INITCONTEXTLEN;
4cb912f1 1222 context = kmalloc(len+1, GFP_NOFS);
1da177e4
LT
1223 if (!context) {
1224 rc = -ENOMEM;
1225 dput(dentry);
23970741 1226 goto out_unlock;
1da177e4 1227 }
4cb912f1 1228 context[len] = '\0';
1da177e4
LT
1229 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
1230 context, len);
1231 if (rc == -ERANGE) {
314dabb8
JM
1232 kfree(context);
1233
1da177e4
LT
1234 /* Need a larger buffer. Query for the right size. */
1235 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
1236 NULL, 0);
1237 if (rc < 0) {
1238 dput(dentry);
23970741 1239 goto out_unlock;
1da177e4 1240 }
1da177e4 1241 len = rc;
4cb912f1 1242 context = kmalloc(len+1, GFP_NOFS);
1da177e4
LT
1243 if (!context) {
1244 rc = -ENOMEM;
1245 dput(dentry);
23970741 1246 goto out_unlock;
1da177e4 1247 }
4cb912f1 1248 context[len] = '\0';
1da177e4
LT
1249 rc = inode->i_op->getxattr(dentry,
1250 XATTR_NAME_SELINUX,
1251 context, len);
1252 }
1253 dput(dentry);
1254 if (rc < 0) {
1255 if (rc != -ENODATA) {
744ba35e 1256 printk(KERN_WARNING "SELinux: %s: getxattr returned "
dd6f953a 1257 "%d for dev=%s ino=%ld\n", __func__,
1da177e4
LT
1258 -rc, inode->i_sb->s_id, inode->i_ino);
1259 kfree(context);
23970741 1260 goto out_unlock;
1da177e4
LT
1261 }
1262 /* Map ENODATA to the default file SID */
1263 sid = sbsec->def_sid;
1264 rc = 0;
1265 } else {
f5c1d5b2 1266 rc = security_context_to_sid_default(context, rc, &sid,
869ab514
SS
1267 sbsec->def_sid,
1268 GFP_NOFS);
1da177e4 1269 if (rc) {
4ba0a8ad
EP
1270 char *dev = inode->i_sb->s_id;
1271 unsigned long ino = inode->i_ino;
1272
1273 if (rc == -EINVAL) {
1274 if (printk_ratelimit())
1275 printk(KERN_NOTICE "SELinux: inode=%lu on dev=%s was found to have an invalid "
1276 "context=%s. This indicates you may need to relabel the inode or the "
1277 "filesystem in question.\n", ino, dev, context);
1278 } else {
1279 printk(KERN_WARNING "SELinux: %s: context_to_sid(%s) "
1280 "returned %d for dev=%s ino=%ld\n",
1281 __func__, context, -rc, dev, ino);
1282 }
1da177e4
LT
1283 kfree(context);
1284 /* Leave with the unlabeled SID */
1285 rc = 0;
1286 break;
1287 }
1288 }
1289 kfree(context);
1290 isec->sid = sid;
1291 break;
1292 case SECURITY_FS_USE_TASK:
1293 isec->sid = isec->task_sid;
1294 break;
1295 case SECURITY_FS_USE_TRANS:
1296 /* Default to the fs SID. */
1297 isec->sid = sbsec->sid;
1298
1299 /* Try to obtain a transition SID. */
1300 isec->sclass = inode_mode_to_security_class(inode->i_mode);
652bb9b0
EP
1301 rc = security_transition_sid(isec->task_sid, sbsec->sid,
1302 isec->sclass, NULL, &sid);
1da177e4 1303 if (rc)
23970741 1304 goto out_unlock;
1da177e4
LT
1305 isec->sid = sid;
1306 break;
c312feb2
EP
1307 case SECURITY_FS_USE_MNTPOINT:
1308 isec->sid = sbsec->mntpoint_sid;
1309 break;
1da177e4 1310 default:
c312feb2 1311 /* Default to the fs superblock SID. */
1da177e4
LT
1312 isec->sid = sbsec->sid;
1313
0d90a7ec 1314 if ((sbsec->flags & SE_SBPROC) && !S_ISLNK(inode->i_mode)) {
8e6c9693 1315 if (opt_dentry) {
1da177e4 1316 isec->sclass = inode_mode_to_security_class(inode->i_mode);
8e6c9693 1317 rc = selinux_proc_get_sid(opt_dentry,
1da177e4
LT
1318 isec->sclass,
1319 &sid);
1320 if (rc)
23970741 1321 goto out_unlock;
1da177e4
LT
1322 isec->sid = sid;
1323 }
1324 }
1325 break;
1326 }
1327
1328 isec->initialized = 1;
1329
23970741
EP
1330out_unlock:
1331 mutex_unlock(&isec->lock);
1da177e4
LT
1332out:
1333 if (isec->sclass == SECCLASS_FILE)
1334 isec->sclass = inode_mode_to_security_class(inode->i_mode);
1da177e4
LT
1335 return rc;
1336}
1337
1338/* Convert a Linux signal to an access vector. */
1339static inline u32 signal_to_av(int sig)
1340{
1341 u32 perm = 0;
1342
1343 switch (sig) {
1344 case SIGCHLD:
1345 /* Commonly granted from child to parent. */
1346 perm = PROCESS__SIGCHLD;
1347 break;
1348 case SIGKILL:
1349 /* Cannot be caught or ignored */
1350 perm = PROCESS__SIGKILL;
1351 break;
1352 case SIGSTOP:
1353 /* Cannot be caught or ignored */
1354 perm = PROCESS__SIGSTOP;
1355 break;
1356 default:
1357 /* All other signals. */
1358 perm = PROCESS__SIGNAL;
1359 break;
1360 }
1361
1362 return perm;
1363}
1364
d84f4f99
DH
1365/*
1366 * Check permission between a pair of credentials
1367 * fork check, ptrace check, etc.
1368 */
1369static int cred_has_perm(const struct cred *actor,
1370 const struct cred *target,
1371 u32 perms)
1372{
1373 u32 asid = cred_sid(actor), tsid = cred_sid(target);
1374
1375 return avc_has_perm(asid, tsid, SECCLASS_PROCESS, perms, NULL);
1376}
1377
275bb41e 1378/*
88e67f3b 1379 * Check permission between a pair of tasks, e.g. signal checks,
275bb41e
DH
1380 * fork check, ptrace check, etc.
1381 * tsk1 is the actor and tsk2 is the target
3b11a1de 1382 * - this uses the default subjective creds of tsk1
275bb41e
DH
1383 */
1384static int task_has_perm(const struct task_struct *tsk1,
1385 const struct task_struct *tsk2,
1da177e4
LT
1386 u32 perms)
1387{
275bb41e
DH
1388 const struct task_security_struct *__tsec1, *__tsec2;
1389 u32 sid1, sid2;
1da177e4 1390
275bb41e
DH
1391 rcu_read_lock();
1392 __tsec1 = __task_cred(tsk1)->security; sid1 = __tsec1->sid;
1393 __tsec2 = __task_cred(tsk2)->security; sid2 = __tsec2->sid;
1394 rcu_read_unlock();
1395 return avc_has_perm(sid1, sid2, SECCLASS_PROCESS, perms, NULL);
1da177e4
LT
1396}
1397
3b11a1de
DH
1398/*
1399 * Check permission between current and another task, e.g. signal checks,
1400 * fork check, ptrace check, etc.
1401 * current is the actor and tsk2 is the target
1402 * - this uses current's subjective creds
1403 */
1404static int current_has_perm(const struct task_struct *tsk,
1405 u32 perms)
1406{
1407 u32 sid, tsid;
1408
1409 sid = current_sid();
1410 tsid = task_sid(tsk);
1411 return avc_has_perm(sid, tsid, SECCLASS_PROCESS, perms, NULL);
1412}
1413
b68e418c
SS
1414#if CAP_LAST_CAP > 63
1415#error Fix SELinux to handle capabilities > 63.
1416#endif
1417
1da177e4 1418/* Check whether a task is allowed to use a capability. */
6a9de491 1419static int cred_has_capability(const struct cred *cred,
06112163 1420 int cap, int audit)
1da177e4 1421{
2bf49690 1422 struct common_audit_data ad;
3b3b0e4f 1423 struct selinux_audit_data sad = {0,};
06112163 1424 struct av_decision avd;
b68e418c 1425 u16 sclass;
3699c53c 1426 u32 sid = cred_sid(cred);
b68e418c 1427 u32 av = CAP_TO_MASK(cap);
06112163 1428 int rc;
1da177e4 1429
2bf49690 1430 COMMON_AUDIT_DATA_INIT(&ad, CAP);
3b3b0e4f 1431 ad.selinux_audit_data = &sad;
6a9de491 1432 ad.tsk = current;
1da177e4
LT
1433 ad.u.cap = cap;
1434
b68e418c
SS
1435 switch (CAP_TO_INDEX(cap)) {
1436 case 0:
1437 sclass = SECCLASS_CAPABILITY;
1438 break;
1439 case 1:
1440 sclass = SECCLASS_CAPABILITY2;
1441 break;
1442 default:
1443 printk(KERN_ERR
1444 "SELinux: out of range capability %d\n", cap);
1445 BUG();
a35c6c83 1446 return -EINVAL;
b68e418c 1447 }
06112163 1448
275bb41e 1449 rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd);
9ade0cf4
EP
1450 if (audit == SECURITY_CAP_AUDIT) {
1451 int rc2 = avc_audit(sid, sid, sclass, av, &avd, rc, &ad, 0);
1452 if (rc2)
1453 return rc2;
1454 }
06112163 1455 return rc;
1da177e4
LT
1456}
1457
1458/* Check whether a task is allowed to use a system operation. */
1459static int task_has_system(struct task_struct *tsk,
1460 u32 perms)
1461{
275bb41e 1462 u32 sid = task_sid(tsk);
1da177e4 1463
275bb41e 1464 return avc_has_perm(sid, SECINITSID_KERNEL,
1da177e4
LT
1465 SECCLASS_SYSTEM, perms, NULL);
1466}
1467
1468/* Check whether a task has a particular permission to an inode.
1469 The 'adp' parameter is optional and allows other audit
1470 data to be passed (e.g. the dentry). */
88e67f3b 1471static int inode_has_perm(const struct cred *cred,
1da177e4
LT
1472 struct inode *inode,
1473 u32 perms,
9ade0cf4
EP
1474 struct common_audit_data *adp,
1475 unsigned flags)
1da177e4 1476{
1da177e4 1477 struct inode_security_struct *isec;
275bb41e 1478 u32 sid;
1da177e4 1479
e0e81739
DH
1480 validate_creds(cred);
1481
828dfe1d 1482 if (unlikely(IS_PRIVATE(inode)))
bbaca6c2
SS
1483 return 0;
1484
88e67f3b 1485 sid = cred_sid(cred);
1da177e4
LT
1486 isec = inode->i_security;
1487
9ade0cf4 1488 return avc_has_perm_flags(sid, isec->sid, isec->sclass, perms, adp, flags);
1da177e4
LT
1489}
1490
95f4efb2
LT
1491static int inode_has_perm_noadp(const struct cred *cred,
1492 struct inode *inode,
1493 u32 perms,
1494 unsigned flags)
1495{
1496 struct common_audit_data ad;
3b3b0e4f 1497 struct selinux_audit_data sad = {0,};
95f4efb2
LT
1498
1499 COMMON_AUDIT_DATA_INIT(&ad, INODE);
1500 ad.u.inode = inode;
3b3b0e4f 1501 ad.selinux_audit_data = &sad;
95f4efb2
LT
1502 return inode_has_perm(cred, inode, perms, &ad, flags);
1503}
1504
1da177e4
LT
1505/* Same as inode_has_perm, but pass explicit audit data containing
1506 the dentry to help the auditing code to more easily generate the
1507 pathname if needed. */
88e67f3b 1508static inline int dentry_has_perm(const struct cred *cred,
1da177e4
LT
1509 struct dentry *dentry,
1510 u32 av)
1511{
1512 struct inode *inode = dentry->d_inode;
2bf49690 1513 struct common_audit_data ad;
3b3b0e4f 1514 struct selinux_audit_data sad = {0,};
88e67f3b 1515
2875fa00
EP
1516 COMMON_AUDIT_DATA_INIT(&ad, DENTRY);
1517 ad.u.dentry = dentry;
3b3b0e4f 1518 ad.selinux_audit_data = &sad;
2875fa00
EP
1519 return inode_has_perm(cred, inode, av, &ad, 0);
1520}
1521
1522/* Same as inode_has_perm, but pass explicit audit data containing
1523 the path to help the auditing code to more easily generate the
1524 pathname if needed. */
1525static inline int path_has_perm(const struct cred *cred,
1526 struct path *path,
1527 u32 av)
1528{
1529 struct inode *inode = path->dentry->d_inode;
1530 struct common_audit_data ad;
3b3b0e4f 1531 struct selinux_audit_data sad = {0,};
2875fa00 1532
f48b7399 1533 COMMON_AUDIT_DATA_INIT(&ad, PATH);
2875fa00 1534 ad.u.path = *path;
3b3b0e4f 1535 ad.selinux_audit_data = &sad;
9ade0cf4 1536 return inode_has_perm(cred, inode, av, &ad, 0);
1da177e4
LT
1537}
1538
1539/* Check whether a task can use an open file descriptor to
1540 access an inode in a given way. Check access to the
1541 descriptor itself, and then use dentry_has_perm to
1542 check a particular permission to the file.
1543 Access to the descriptor is implicitly granted if it
1544 has the same SID as the process. If av is zero, then
1545 access to the file is not checked, e.g. for cases
1546 where only the descriptor is affected like seek. */
88e67f3b
DH
1547static int file_has_perm(const struct cred *cred,
1548 struct file *file,
1549 u32 av)
1da177e4 1550{
1da177e4 1551 struct file_security_struct *fsec = file->f_security;
44707fdf 1552 struct inode *inode = file->f_path.dentry->d_inode;
2bf49690 1553 struct common_audit_data ad;
3b3b0e4f 1554 struct selinux_audit_data sad = {0,};
88e67f3b 1555 u32 sid = cred_sid(cred);
1da177e4
LT
1556 int rc;
1557
f48b7399
EP
1558 COMMON_AUDIT_DATA_INIT(&ad, PATH);
1559 ad.u.path = file->f_path;
3b3b0e4f 1560 ad.selinux_audit_data = &sad;
1da177e4 1561
275bb41e
DH
1562 if (sid != fsec->sid) {
1563 rc = avc_has_perm(sid, fsec->sid,
1da177e4
LT
1564 SECCLASS_FD,
1565 FD__USE,
1566 &ad);
1567 if (rc)
88e67f3b 1568 goto out;
1da177e4
LT
1569 }
1570
1571 /* av is zero if only checking access to the descriptor. */
88e67f3b 1572 rc = 0;
1da177e4 1573 if (av)
9ade0cf4 1574 rc = inode_has_perm(cred, inode, av, &ad, 0);
1da177e4 1575
88e67f3b
DH
1576out:
1577 return rc;
1da177e4
LT
1578}
1579
1580/* Check whether a task can create a file. */
1581static int may_create(struct inode *dir,
1582 struct dentry *dentry,
1583 u16 tclass)
1584{
5fb49870 1585 const struct task_security_struct *tsec = current_security();
1da177e4
LT
1586 struct inode_security_struct *dsec;
1587 struct superblock_security_struct *sbsec;
275bb41e 1588 u32 sid, newsid;
2bf49690 1589 struct common_audit_data ad;
3b3b0e4f 1590 struct selinux_audit_data sad = {0,};
1da177e4
LT
1591 int rc;
1592
1da177e4
LT
1593 dsec = dir->i_security;
1594 sbsec = dir->i_sb->s_security;
1595
275bb41e
DH
1596 sid = tsec->sid;
1597 newsid = tsec->create_sid;
1598
a269434d
EP
1599 COMMON_AUDIT_DATA_INIT(&ad, DENTRY);
1600 ad.u.dentry = dentry;
3b3b0e4f 1601 ad.selinux_audit_data = &sad;
1da177e4 1602
275bb41e 1603 rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR,
1da177e4
LT
1604 DIR__ADD_NAME | DIR__SEARCH,
1605 &ad);
1606 if (rc)
1607 return rc;
1608
cd89596f 1609 if (!newsid || !(sbsec->flags & SE_SBLABELSUPP)) {
cb1e922f
EP
1610 rc = security_transition_sid(sid, dsec->sid, tclass,
1611 &dentry->d_name, &newsid);
1da177e4
LT
1612 if (rc)
1613 return rc;
1614 }
1615
275bb41e 1616 rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad);
1da177e4
LT
1617 if (rc)
1618 return rc;
1619
1620 return avc_has_perm(newsid, sbsec->sid,
1621 SECCLASS_FILESYSTEM,
1622 FILESYSTEM__ASSOCIATE, &ad);
1623}
1624
4eb582cf
ML
1625/* Check whether a task can create a key. */
1626static int may_create_key(u32 ksid,
1627 struct task_struct *ctx)
1628{
275bb41e 1629 u32 sid = task_sid(ctx);
4eb582cf 1630
275bb41e 1631 return avc_has_perm(sid, ksid, SECCLASS_KEY, KEY__CREATE, NULL);
4eb582cf
ML
1632}
1633
828dfe1d
EP
1634#define MAY_LINK 0
1635#define MAY_UNLINK 1
1636#define MAY_RMDIR 2
1da177e4
LT
1637
1638/* Check whether a task can link, unlink, or rmdir a file/directory. */
1639static int may_link(struct inode *dir,
1640 struct dentry *dentry,
1641 int kind)
1642
1643{
1da177e4 1644 struct inode_security_struct *dsec, *isec;
2bf49690 1645 struct common_audit_data ad;
3b3b0e4f 1646 struct selinux_audit_data sad = {0,};
275bb41e 1647 u32 sid = current_sid();
1da177e4
LT
1648 u32 av;
1649 int rc;
1650
1da177e4
LT
1651 dsec = dir->i_security;
1652 isec = dentry->d_inode->i_security;
1653
a269434d
EP
1654 COMMON_AUDIT_DATA_INIT(&ad, DENTRY);
1655 ad.u.dentry = dentry;
3b3b0e4f 1656 ad.selinux_audit_data = &sad;
1da177e4
LT
1657
1658 av = DIR__SEARCH;
1659 av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
275bb41e 1660 rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, av, &ad);
1da177e4
LT
1661 if (rc)
1662 return rc;
1663
1664 switch (kind) {
1665 case MAY_LINK:
1666 av = FILE__LINK;
1667 break;
1668 case MAY_UNLINK:
1669 av = FILE__UNLINK;
1670 break;
1671 case MAY_RMDIR:
1672 av = DIR__RMDIR;
1673 break;
1674 default:
744ba35e
EP
1675 printk(KERN_WARNING "SELinux: %s: unrecognized kind %d\n",
1676 __func__, kind);
1da177e4
LT
1677 return 0;
1678 }
1679
275bb41e 1680 rc = avc_has_perm(sid, isec->sid, isec->sclass, av, &ad);
1da177e4
LT
1681 return rc;
1682}
1683
1684static inline int may_rename(struct inode *old_dir,
1685 struct dentry *old_dentry,
1686 struct inode *new_dir,
1687 struct dentry *new_dentry)
1688{
1da177e4 1689 struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec;
2bf49690 1690 struct common_audit_data ad;
3b3b0e4f 1691 struct selinux_audit_data sad = {0,};
275bb41e 1692 u32 sid = current_sid();
1da177e4
LT
1693 u32 av;
1694 int old_is_dir, new_is_dir;
1695 int rc;
1696
1da177e4
LT
1697 old_dsec = old_dir->i_security;
1698 old_isec = old_dentry->d_inode->i_security;
1699 old_is_dir = S_ISDIR(old_dentry->d_inode->i_mode);
1700 new_dsec = new_dir->i_security;
1701
a269434d 1702 COMMON_AUDIT_DATA_INIT(&ad, DENTRY);
3b3b0e4f 1703 ad.selinux_audit_data = &sad;
1da177e4 1704
a269434d 1705 ad.u.dentry = old_dentry;
275bb41e 1706 rc = avc_has_perm(sid, old_dsec->sid, SECCLASS_DIR,
1da177e4
LT
1707 DIR__REMOVE_NAME | DIR__SEARCH, &ad);
1708 if (rc)
1709 return rc;
275bb41e 1710 rc = avc_has_perm(sid, old_isec->sid,
1da177e4
LT
1711 old_isec->sclass, FILE__RENAME, &ad);
1712 if (rc)
1713 return rc;
1714 if (old_is_dir && new_dir != old_dir) {
275bb41e 1715 rc = avc_has_perm(sid, old_isec->sid,
1da177e4
LT
1716 old_isec->sclass, DIR__REPARENT, &ad);
1717 if (rc)
1718 return rc;
1719 }
1720
a269434d 1721 ad.u.dentry = new_dentry;
1da177e4
LT
1722 av = DIR__ADD_NAME | DIR__SEARCH;
1723 if (new_dentry->d_inode)
1724 av |= DIR__REMOVE_NAME;
275bb41e 1725 rc = avc_has_perm(sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
1da177e4
LT
1726 if (rc)
1727 return rc;
1728 if (new_dentry->d_inode) {
1729 new_isec = new_dentry->d_inode->i_security;
1730 new_is_dir = S_ISDIR(new_dentry->d_inode->i_mode);
275bb41e 1731 rc = avc_has_perm(sid, new_isec->sid,
1da177e4
LT
1732 new_isec->sclass,
1733 (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad);
1734 if (rc)
1735 return rc;
1736 }
1737
1738 return 0;
1739}
1740
1741/* Check whether a task can perform a filesystem operation. */
88e67f3b 1742static int superblock_has_perm(const struct cred *cred,
1da177e4
LT
1743 struct super_block *sb,
1744 u32 perms,
2bf49690 1745 struct common_audit_data *ad)
1da177e4 1746{
1da177e4 1747 struct superblock_security_struct *sbsec;
88e67f3b 1748 u32 sid = cred_sid(cred);
1da177e4 1749
1da177e4 1750 sbsec = sb->s_security;
275bb41e 1751 return avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad);
1da177e4
LT
1752}
1753
1754/* Convert a Linux mode and permission mask to an access vector. */
1755static inline u32 file_mask_to_av(int mode, int mask)
1756{
1757 u32 av = 0;
1758
dba19c60 1759 if (!S_ISDIR(mode)) {
1da177e4
LT
1760 if (mask & MAY_EXEC)
1761 av |= FILE__EXECUTE;
1762 if (mask & MAY_READ)
1763 av |= FILE__READ;
1764
1765 if (mask & MAY_APPEND)
1766 av |= FILE__APPEND;
1767 else if (mask & MAY_WRITE)
1768 av |= FILE__WRITE;
1769
1770 } else {
1771 if (mask & MAY_EXEC)
1772 av |= DIR__SEARCH;
1773 if (mask & MAY_WRITE)
1774 av |= DIR__WRITE;
1775 if (mask & MAY_READ)
1776 av |= DIR__READ;
1777 }
1778
1779 return av;
1780}
1781
8b6a5a37
EP
1782/* Convert a Linux file to an access vector. */
1783static inline u32 file_to_av(struct file *file)
1784{
1785 u32 av = 0;
1786
1787 if (file->f_mode & FMODE_READ)
1788 av |= FILE__READ;
1789 if (file->f_mode & FMODE_WRITE) {
1790 if (file->f_flags & O_APPEND)
1791 av |= FILE__APPEND;
1792 else
1793 av |= FILE__WRITE;
1794 }
1795 if (!av) {
1796 /*
1797 * Special file opened with flags 3 for ioctl-only use.
1798 */
1799 av = FILE__IOCTL;
1800 }
1801
1802 return av;
1803}
1804
b0c636b9 1805/*
8b6a5a37 1806 * Convert a file to an access vector and include the correct open
b0c636b9
EP
1807 * open permission.
1808 */
8b6a5a37 1809static inline u32 open_file_to_av(struct file *file)
b0c636b9 1810{
8b6a5a37 1811 u32 av = file_to_av(file);
b0c636b9 1812
49b7b8de
EP
1813 if (selinux_policycap_openperm)
1814 av |= FILE__OPEN;
1815
b0c636b9
EP
1816 return av;
1817}
1818
1da177e4
LT
1819/* Hook functions begin here. */
1820
9e48858f 1821static int selinux_ptrace_access_check(struct task_struct *child,
5cd9c58f 1822 unsigned int mode)
1da177e4 1823{
1da177e4
LT
1824 int rc;
1825
9e48858f 1826 rc = cap_ptrace_access_check(child, mode);
1da177e4
LT
1827 if (rc)
1828 return rc;
1829
69f594a3 1830 if (mode & PTRACE_MODE_READ) {
275bb41e
DH
1831 u32 sid = current_sid();
1832 u32 csid = task_sid(child);
1833 return avc_has_perm(sid, csid, SECCLASS_FILE, FILE__READ, NULL);
006ebb40
SS
1834 }
1835
3b11a1de 1836 return current_has_perm(child, PROCESS__PTRACE);
5cd9c58f
DH
1837}
1838
1839static int selinux_ptrace_traceme(struct task_struct *parent)
1840{
1841 int rc;
1842
200ac532 1843 rc = cap_ptrace_traceme(parent);
5cd9c58f
DH
1844 if (rc)
1845 return rc;
1846
1847 return task_has_perm(parent, current, PROCESS__PTRACE);
1da177e4
LT
1848}
1849
1850static int selinux_capget(struct task_struct *target, kernel_cap_t *effective,
828dfe1d 1851 kernel_cap_t *inheritable, kernel_cap_t *permitted)
1da177e4
LT
1852{
1853 int error;
1854
3b11a1de 1855 error = current_has_perm(target, PROCESS__GETCAP);
1da177e4
LT
1856 if (error)
1857 return error;
1858
200ac532 1859 return cap_capget(target, effective, inheritable, permitted);
1da177e4
LT
1860}
1861
d84f4f99
DH
1862static int selinux_capset(struct cred *new, const struct cred *old,
1863 const kernel_cap_t *effective,
1864 const kernel_cap_t *inheritable,
1865 const kernel_cap_t *permitted)
1da177e4
LT
1866{
1867 int error;
1868
200ac532 1869 error = cap_capset(new, old,
d84f4f99 1870 effective, inheritable, permitted);
1da177e4
LT
1871 if (error)
1872 return error;
1873
d84f4f99 1874 return cred_has_perm(old, new, PROCESS__SETCAP);
1da177e4
LT
1875}
1876
5626d3e8
JM
1877/*
1878 * (This comment used to live with the selinux_task_setuid hook,
1879 * which was removed).
1880 *
1881 * Since setuid only affects the current process, and since the SELinux
1882 * controls are not based on the Linux identity attributes, SELinux does not
1883 * need to control this operation. However, SELinux does control the use of
1884 * the CAP_SETUID and CAP_SETGID capabilities using the capable hook.
1885 */
1886
6a9de491
EP
1887static int selinux_capable(const struct cred *cred, struct user_namespace *ns,
1888 int cap, int audit)
1da177e4
LT
1889{
1890 int rc;
1891
6a9de491 1892 rc = cap_capable(cred, ns, cap, audit);
1da177e4
LT
1893 if (rc)
1894 return rc;
1895
6a9de491 1896 return cred_has_capability(cred, cap, audit);
1da177e4
LT
1897}
1898
1da177e4
LT
1899static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb)
1900{
88e67f3b 1901 const struct cred *cred = current_cred();
1da177e4
LT
1902 int rc = 0;
1903
1904 if (!sb)
1905 return 0;
1906
1907 switch (cmds) {
828dfe1d
EP
1908 case Q_SYNC:
1909 case Q_QUOTAON:
1910 case Q_QUOTAOFF:
1911 case Q_SETINFO:
1912 case Q_SETQUOTA:
88e67f3b 1913 rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAMOD, NULL);
828dfe1d
EP
1914 break;
1915 case Q_GETFMT:
1916 case Q_GETINFO:
1917 case Q_GETQUOTA:
88e67f3b 1918 rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAGET, NULL);
828dfe1d
EP
1919 break;
1920 default:
1921 rc = 0; /* let the kernel handle invalid cmds */
1922 break;
1da177e4
LT
1923 }
1924 return rc;
1925}
1926
1927static int selinux_quota_on(struct dentry *dentry)
1928{
88e67f3b
DH
1929 const struct cred *cred = current_cred();
1930
2875fa00 1931 return dentry_has_perm(cred, dentry, FILE__QUOTAON);
1da177e4
LT
1932}
1933
12b3052c 1934static int selinux_syslog(int type)
1da177e4
LT
1935{
1936 int rc;
1937
1da177e4 1938 switch (type) {
d78ca3cd
KC
1939 case SYSLOG_ACTION_READ_ALL: /* Read last kernel messages */
1940 case SYSLOG_ACTION_SIZE_BUFFER: /* Return size of the log buffer */
828dfe1d
EP
1941 rc = task_has_system(current, SYSTEM__SYSLOG_READ);
1942 break;
d78ca3cd
KC
1943 case SYSLOG_ACTION_CONSOLE_OFF: /* Disable logging to console */
1944 case SYSLOG_ACTION_CONSOLE_ON: /* Enable logging to console */
1945 /* Set level of messages printed to console */
1946 case SYSLOG_ACTION_CONSOLE_LEVEL:
828dfe1d
EP
1947 rc = task_has_system(current, SYSTEM__SYSLOG_CONSOLE);
1948 break;
d78ca3cd
KC
1949 case SYSLOG_ACTION_CLOSE: /* Close log */
1950 case SYSLOG_ACTION_OPEN: /* Open log */
1951 case SYSLOG_ACTION_READ: /* Read from log */
1952 case SYSLOG_ACTION_READ_CLEAR: /* Read/clear last kernel messages */
1953 case SYSLOG_ACTION_CLEAR: /* Clear ring buffer */
828dfe1d
EP
1954 default:
1955 rc = task_has_system(current, SYSTEM__SYSLOG_MOD);
1956 break;
1da177e4
LT
1957 }
1958 return rc;
1959}
1960
1961/*
1962 * Check that a process has enough memory to allocate a new virtual
1963 * mapping. 0 means there is enough memory for the allocation to
1964 * succeed and -ENOMEM implies there is not.
1965 *
1da177e4
LT
1966 * Do not audit the selinux permission check, as this is applied to all
1967 * processes that allocate mappings.
1968 */
34b4e4aa 1969static int selinux_vm_enough_memory(struct mm_struct *mm, long pages)
1da177e4
LT
1970{
1971 int rc, cap_sys_admin = 0;
1da177e4 1972
6a9de491 1973 rc = selinux_capable(current_cred(), &init_user_ns, CAP_SYS_ADMIN,
3699c53c 1974 SECURITY_CAP_NOAUDIT);
1da177e4
LT
1975 if (rc == 0)
1976 cap_sys_admin = 1;
1977
34b4e4aa 1978 return __vm_enough_memory(mm, pages, cap_sys_admin);
1da177e4
LT
1979}
1980
1981/* binprm security operations */
1982
a6f76f23 1983static int selinux_bprm_set_creds(struct linux_binprm *bprm)
1da177e4 1984{
a6f76f23
DH
1985 const struct task_security_struct *old_tsec;
1986 struct task_security_struct *new_tsec;
1da177e4 1987 struct inode_security_struct *isec;
2bf49690 1988 struct common_audit_data ad;
3b3b0e4f 1989 struct selinux_audit_data sad = {0,};
a6f76f23 1990 struct inode *inode = bprm->file->f_path.dentry->d_inode;
1da177e4
LT
1991 int rc;
1992
200ac532 1993 rc = cap_bprm_set_creds(bprm);
1da177e4
LT
1994 if (rc)
1995 return rc;
1996
a6f76f23
DH
1997 /* SELinux context only depends on initial program or script and not
1998 * the script interpreter */
1999 if (bprm->cred_prepared)
1da177e4
LT
2000 return 0;
2001
a6f76f23
DH
2002 old_tsec = current_security();
2003 new_tsec = bprm->cred->security;
1da177e4
LT
2004 isec = inode->i_security;
2005
2006 /* Default to the current task SID. */
a6f76f23
DH
2007 new_tsec->sid = old_tsec->sid;
2008 new_tsec->osid = old_tsec->sid;
1da177e4 2009
28eba5bf 2010 /* Reset fs, key, and sock SIDs on execve. */
a6f76f23
DH
2011 new_tsec->create_sid = 0;
2012 new_tsec->keycreate_sid = 0;
2013 new_tsec->sockcreate_sid = 0;
1da177e4 2014
a6f76f23
DH
2015 if (old_tsec->exec_sid) {
2016 new_tsec->sid = old_tsec->exec_sid;
1da177e4 2017 /* Reset exec SID on execve. */
a6f76f23 2018 new_tsec->exec_sid = 0;
1da177e4
LT
2019 } else {
2020 /* Check for a default transition on this program. */
a6f76f23 2021 rc = security_transition_sid(old_tsec->sid, isec->sid,
652bb9b0
EP
2022 SECCLASS_PROCESS, NULL,
2023 &new_tsec->sid);
1da177e4
LT
2024 if (rc)
2025 return rc;
2026 }
2027
f48b7399 2028 COMMON_AUDIT_DATA_INIT(&ad, PATH);
3b3b0e4f 2029 ad.selinux_audit_data = &sad;
f48b7399 2030 ad.u.path = bprm->file->f_path;
1da177e4 2031
3d5ff529 2032 if (bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID)
a6f76f23 2033 new_tsec->sid = old_tsec->sid;
1da177e4 2034
a6f76f23
DH
2035 if (new_tsec->sid == old_tsec->sid) {
2036 rc = avc_has_perm(old_tsec->sid, isec->sid,
1da177e4
LT
2037 SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
2038 if (rc)
2039 return rc;
2040 } else {
2041 /* Check permissions for the transition. */
a6f76f23 2042 rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
1da177e4
LT
2043 SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
2044 if (rc)
2045 return rc;
2046
a6f76f23 2047 rc = avc_has_perm(new_tsec->sid, isec->sid,
1da177e4
LT
2048 SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
2049 if (rc)
2050 return rc;
2051
a6f76f23
DH
2052 /* Check for shared state */
2053 if (bprm->unsafe & LSM_UNSAFE_SHARE) {
2054 rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2055 SECCLASS_PROCESS, PROCESS__SHARE,
2056 NULL);
2057 if (rc)
2058 return -EPERM;
2059 }
2060
2061 /* Make sure that anyone attempting to ptrace over a task that
2062 * changes its SID has the appropriate permit */
2063 if (bprm->unsafe &
2064 (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) {
2065 struct task_struct *tracer;
2066 struct task_security_struct *sec;
2067 u32 ptsid = 0;
2068
2069 rcu_read_lock();
06d98473 2070 tracer = ptrace_parent(current);
a6f76f23
DH
2071 if (likely(tracer != NULL)) {
2072 sec = __task_cred(tracer)->security;
2073 ptsid = sec->sid;
2074 }
2075 rcu_read_unlock();
2076
2077 if (ptsid != 0) {
2078 rc = avc_has_perm(ptsid, new_tsec->sid,
2079 SECCLASS_PROCESS,
2080 PROCESS__PTRACE, NULL);
2081 if (rc)
2082 return -EPERM;
2083 }
2084 }
1da177e4 2085
a6f76f23
DH
2086 /* Clear any possibly unsafe personality bits on exec: */
2087 bprm->per_clear |= PER_CLEAR_ON_SETID;
1da177e4
LT
2088 }
2089
1da177e4
LT
2090 return 0;
2091}
2092
828dfe1d 2093static int selinux_bprm_secureexec(struct linux_binprm *bprm)
1da177e4 2094{
5fb49870 2095 const struct task_security_struct *tsec = current_security();
275bb41e 2096 u32 sid, osid;
1da177e4
LT
2097 int atsecure = 0;
2098
275bb41e
DH
2099 sid = tsec->sid;
2100 osid = tsec->osid;
2101
2102 if (osid != sid) {
1da177e4
LT
2103 /* Enable secure mode for SIDs transitions unless
2104 the noatsecure permission is granted between
2105 the two SIDs, i.e. ahp returns 0. */
275bb41e 2106 atsecure = avc_has_perm(osid, sid,
a6f76f23
DH
2107 SECCLASS_PROCESS,
2108 PROCESS__NOATSECURE, NULL);
1da177e4
LT
2109 }
2110
200ac532 2111 return (atsecure || cap_bprm_secureexec(bprm));
1da177e4
LT
2112}
2113
1da177e4 2114/* Derived from fs/exec.c:flush_old_files. */
745ca247
DH
2115static inline void flush_unauthorized_files(const struct cred *cred,
2116 struct files_struct *files)
1da177e4 2117{
2bf49690 2118 struct common_audit_data ad;
3b3b0e4f 2119 struct selinux_audit_data sad = {0,};
1da177e4 2120 struct file *file, *devnull = NULL;
b20c8122 2121 struct tty_struct *tty;
badf1662 2122 struct fdtable *fdt;
1da177e4 2123 long j = -1;
24ec839c 2124 int drop_tty = 0;
1da177e4 2125
24ec839c 2126 tty = get_current_tty();
1da177e4 2127 if (tty) {
ee2ffa0d 2128 spin_lock(&tty_files_lock);
37dd0bd0 2129 if (!list_empty(&tty->tty_files)) {
d996b62a 2130 struct tty_file_private *file_priv;
37dd0bd0
EP
2131 struct inode *inode;
2132
1da177e4
LT
2133 /* Revalidate access to controlling tty.
2134 Use inode_has_perm on the tty inode directly rather
2135 than using file_has_perm, as this particular open
2136 file may belong to another process and we are only
2137 interested in the inode-based check here. */
d996b62a
NP
2138 file_priv = list_first_entry(&tty->tty_files,
2139 struct tty_file_private, list);
2140 file = file_priv->file;
37dd0bd0 2141 inode = file->f_path.dentry->d_inode;
95f4efb2
LT
2142 if (inode_has_perm_noadp(cred, inode,
2143 FILE__READ | FILE__WRITE, 0)) {
24ec839c 2144 drop_tty = 1;
1da177e4
LT
2145 }
2146 }
ee2ffa0d 2147 spin_unlock(&tty_files_lock);
452a00d2 2148 tty_kref_put(tty);
1da177e4 2149 }
98a27ba4
EB
2150 /* Reset controlling tty. */
2151 if (drop_tty)
2152 no_tty();
1da177e4
LT
2153
2154 /* Revalidate access to inherited open files. */
2155
f48b7399 2156 COMMON_AUDIT_DATA_INIT(&ad, INODE);
3b3b0e4f 2157 ad.selinux_audit_data = &sad;
1da177e4
LT
2158
2159 spin_lock(&files->file_lock);
2160 for (;;) {
2161 unsigned long set, i;
2162 int fd;
2163
2164 j++;
2165 i = j * __NFDBITS;
badf1662 2166 fdt = files_fdtable(files);
bbea9f69 2167 if (i >= fdt->max_fds)
1da177e4 2168 break;
1fd36adc 2169 set = fdt->open_fds[j];
1da177e4
LT
2170 if (!set)
2171 continue;
2172 spin_unlock(&files->file_lock);
828dfe1d 2173 for ( ; set ; i++, set >>= 1) {
1da177e4
LT
2174 if (set & 1) {
2175 file = fget(i);
2176 if (!file)
2177 continue;
88e67f3b 2178 if (file_has_perm(cred,
1da177e4
LT
2179 file,
2180 file_to_av(file))) {
2181 sys_close(i);
2182 fd = get_unused_fd();
2183 if (fd != i) {
2184 if (fd >= 0)
2185 put_unused_fd(fd);
2186 fput(file);
2187 continue;
2188 }
2189 if (devnull) {
095975da 2190 get_file(devnull);
1da177e4 2191 } else {
745ca247
DH
2192 devnull = dentry_open(
2193 dget(selinux_null),
2194 mntget(selinuxfs_mount),
2195 O_RDWR, cred);
fc5d81e6
AM
2196 if (IS_ERR(devnull)) {
2197 devnull = NULL;
1da177e4
LT
2198 put_unused_fd(fd);
2199 fput(file);
2200 continue;
2201 }
2202 }
2203 fd_install(fd, devnull);
2204 }
2205 fput(file);
2206 }
2207 }
2208 spin_lock(&files->file_lock);
2209
2210 }
2211 spin_unlock(&files->file_lock);
2212}
2213
a6f76f23
DH
2214/*
2215 * Prepare a process for imminent new credential changes due to exec
2216 */
2217static void selinux_bprm_committing_creds(struct linux_binprm *bprm)
1da177e4 2218{
a6f76f23
DH
2219 struct task_security_struct *new_tsec;
2220 struct rlimit *rlim, *initrlim;
2221 int rc, i;
d84f4f99 2222
a6f76f23
DH
2223 new_tsec = bprm->cred->security;
2224 if (new_tsec->sid == new_tsec->osid)
2225 return;
1da177e4 2226
a6f76f23
DH
2227 /* Close files for which the new task SID is not authorized. */
2228 flush_unauthorized_files(bprm->cred, current->files);
0356357c 2229
a6f76f23
DH
2230 /* Always clear parent death signal on SID transitions. */
2231 current->pdeath_signal = 0;
0356357c 2232
a6f76f23
DH
2233 /* Check whether the new SID can inherit resource limits from the old
2234 * SID. If not, reset all soft limits to the lower of the current
2235 * task's hard limit and the init task's soft limit.
2236 *
2237 * Note that the setting of hard limits (even to lower them) can be
2238 * controlled by the setrlimit check. The inclusion of the init task's
2239 * soft limit into the computation is to avoid resetting soft limits
2240 * higher than the default soft limit for cases where the default is
2241 * lower than the hard limit, e.g. RLIMIT_CORE or RLIMIT_STACK.
2242 */
2243 rc = avc_has_perm(new_tsec->osid, new_tsec->sid, SECCLASS_PROCESS,
2244 PROCESS__RLIMITINH, NULL);
2245 if (rc) {
eb2d55a3
ON
2246 /* protect against do_prlimit() */
2247 task_lock(current);
a6f76f23
DH
2248 for (i = 0; i < RLIM_NLIMITS; i++) {
2249 rlim = current->signal->rlim + i;
2250 initrlim = init_task.signal->rlim + i;
2251 rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur);
1da177e4 2252 }
eb2d55a3
ON
2253 task_unlock(current);
2254 update_rlimit_cpu(current, rlimit(RLIMIT_CPU));
1da177e4
LT
2255 }
2256}
2257
2258/*
a6f76f23
DH
2259 * Clean up the process immediately after the installation of new credentials
2260 * due to exec
1da177e4 2261 */
a6f76f23 2262static void selinux_bprm_committed_creds(struct linux_binprm *bprm)
1da177e4 2263{
a6f76f23 2264 const struct task_security_struct *tsec = current_security();
1da177e4 2265 struct itimerval itimer;
a6f76f23 2266 u32 osid, sid;
1da177e4
LT
2267 int rc, i;
2268
a6f76f23
DH
2269 osid = tsec->osid;
2270 sid = tsec->sid;
2271
2272 if (sid == osid)
1da177e4
LT
2273 return;
2274
a6f76f23
DH
2275 /* Check whether the new SID can inherit signal state from the old SID.
2276 * If not, clear itimers to avoid subsequent signal generation and
2277 * flush and unblock signals.
2278 *
2279 * This must occur _after_ the task SID has been updated so that any
2280 * kill done after the flush will be checked against the new SID.
2281 */
2282 rc = avc_has_perm(osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL);
1da177e4
LT
2283 if (rc) {
2284 memset(&itimer, 0, sizeof itimer);
2285 for (i = 0; i < 3; i++)
2286 do_setitimer(i, &itimer, NULL);
1da177e4 2287 spin_lock_irq(&current->sighand->siglock);
3bcac026
DH
2288 if (!(current->signal->flags & SIGNAL_GROUP_EXIT)) {
2289 __flush_signals(current);
2290 flush_signal_handlers(current, 1);
2291 sigemptyset(&current->blocked);
2292 }
1da177e4
LT
2293 spin_unlock_irq(&current->sighand->siglock);
2294 }
2295
a6f76f23
DH
2296 /* Wake up the parent if it is waiting so that it can recheck
2297 * wait permission to the new task SID. */
ecd6de3c 2298 read_lock(&tasklist_lock);
0b7570e7 2299 __wake_up_parent(current, current->real_parent);
ecd6de3c 2300 read_unlock(&tasklist_lock);
1da177e4
LT
2301}
2302
2303/* superblock security operations */
2304
2305static int selinux_sb_alloc_security(struct super_block *sb)
2306{
2307 return superblock_alloc_security(sb);
2308}
2309
2310static void selinux_sb_free_security(struct super_block *sb)
2311{
2312 superblock_free_security(sb);
2313}
2314
2315static inline int match_prefix(char *prefix, int plen, char *option, int olen)
2316{
2317 if (plen > olen)
2318 return 0;
2319
2320 return !memcmp(prefix, option, plen);
2321}
2322
2323static inline int selinux_option(char *option, int len)
2324{
832cbd9a
EP
2325 return (match_prefix(CONTEXT_STR, sizeof(CONTEXT_STR)-1, option, len) ||
2326 match_prefix(FSCONTEXT_STR, sizeof(FSCONTEXT_STR)-1, option, len) ||
2327 match_prefix(DEFCONTEXT_STR, sizeof(DEFCONTEXT_STR)-1, option, len) ||
11689d47
DQ
2328 match_prefix(ROOTCONTEXT_STR, sizeof(ROOTCONTEXT_STR)-1, option, len) ||
2329 match_prefix(LABELSUPP_STR, sizeof(LABELSUPP_STR)-1, option, len));
1da177e4
LT
2330}
2331
2332static inline void take_option(char **to, char *from, int *first, int len)
2333{
2334 if (!*first) {
2335 **to = ',';
2336 *to += 1;
3528a953 2337 } else
1da177e4
LT
2338 *first = 0;
2339 memcpy(*to, from, len);
2340 *to += len;
2341}
2342
828dfe1d
EP
2343static inline void take_selinux_option(char **to, char *from, int *first,
2344 int len)
3528a953
CO
2345{
2346 int current_size = 0;
2347
2348 if (!*first) {
2349 **to = '|';
2350 *to += 1;
828dfe1d 2351 } else
3528a953
CO
2352 *first = 0;
2353
2354 while (current_size < len) {
2355 if (*from != '"') {
2356 **to = *from;
2357 *to += 1;
2358 }
2359 from += 1;
2360 current_size += 1;
2361 }
2362}
2363
e0007529 2364static int selinux_sb_copy_data(char *orig, char *copy)
1da177e4
LT
2365{
2366 int fnosec, fsec, rc = 0;
2367 char *in_save, *in_curr, *in_end;
2368 char *sec_curr, *nosec_save, *nosec;
3528a953 2369 int open_quote = 0;
1da177e4
LT
2370
2371 in_curr = orig;
2372 sec_curr = copy;
2373
1da177e4
LT
2374 nosec = (char *)get_zeroed_page(GFP_KERNEL);
2375 if (!nosec) {
2376 rc = -ENOMEM;
2377 goto out;
2378 }
2379
2380 nosec_save = nosec;
2381 fnosec = fsec = 1;
2382 in_save = in_end = orig;
2383
2384 do {
3528a953
CO
2385 if (*in_end == '"')
2386 open_quote = !open_quote;
2387 if ((*in_end == ',' && open_quote == 0) ||
2388 *in_end == '\0') {
1da177e4
LT
2389 int len = in_end - in_curr;
2390
2391 if (selinux_option(in_curr, len))
3528a953 2392 take_selinux_option(&sec_curr, in_curr, &fsec, len);
1da177e4
LT
2393 else
2394 take_option(&nosec, in_curr, &fnosec, len);
2395
2396 in_curr = in_end + 1;
2397 }
2398 } while (*in_end++);
2399
6931dfc9 2400 strcpy(in_save, nosec_save);
da3caa20 2401 free_page((unsigned long)nosec_save);
1da177e4
LT
2402out:
2403 return rc;
2404}
2405
026eb167
EP
2406static int selinux_sb_remount(struct super_block *sb, void *data)
2407{
2408 int rc, i, *flags;
2409 struct security_mnt_opts opts;
2410 char *secdata, **mount_options;
2411 struct superblock_security_struct *sbsec = sb->s_security;
2412
2413 if (!(sbsec->flags & SE_SBINITIALIZED))
2414 return 0;
2415
2416 if (!data)
2417 return 0;
2418
2419 if (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
2420 return 0;
2421
2422 security_init_mnt_opts(&opts);
2423 secdata = alloc_secdata();
2424 if (!secdata)
2425 return -ENOMEM;
2426 rc = selinux_sb_copy_data(data, secdata);
2427 if (rc)
2428 goto out_free_secdata;
2429
2430 rc = selinux_parse_opts_str(secdata, &opts);
2431 if (rc)
2432 goto out_free_secdata;
2433
2434 mount_options = opts.mnt_opts;
2435 flags = opts.mnt_opts_flags;
2436
2437 for (i = 0; i < opts.num_mnt_opts; i++) {
2438 u32 sid;
2439 size_t len;
2440
2441 if (flags[i] == SE_SBLABELSUPP)
2442 continue;
2443 len = strlen(mount_options[i]);
2444 rc = security_context_to_sid(mount_options[i], len, &sid);
2445 if (rc) {
2446 printk(KERN_WARNING "SELinux: security_context_to_sid"
2447 "(%s) failed for (dev %s, type %s) errno=%d\n",
2448 mount_options[i], sb->s_id, sb->s_type->name, rc);
2449 goto out_free_opts;
2450 }
2451 rc = -EINVAL;
2452 switch (flags[i]) {
2453 case FSCONTEXT_MNT:
2454 if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, sid))
2455 goto out_bad_option;
2456 break;
2457 case CONTEXT_MNT:
2458 if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, sid))
2459 goto out_bad_option;
2460 break;
2461 case ROOTCONTEXT_MNT: {
2462 struct inode_security_struct *root_isec;
2463 root_isec = sb->s_root->d_inode->i_security;
2464
2465 if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, sid))
2466 goto out_bad_option;
2467 break;
2468 }
2469 case DEFCONTEXT_MNT:
2470 if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, sid))
2471 goto out_bad_option;
2472 break;
2473 default:
2474 goto out_free_opts;
2475 }
2476 }
2477
2478 rc = 0;
2479out_free_opts:
2480 security_free_mnt_opts(&opts);
2481out_free_secdata:
2482 free_secdata(secdata);
2483 return rc;
2484out_bad_option:
2485 printk(KERN_WARNING "SELinux: unable to change security options "
2486 "during remount (dev %s, type=%s)\n", sb->s_id,
2487 sb->s_type->name);
2488 goto out_free_opts;
2489}
2490
12204e24 2491static int selinux_sb_kern_mount(struct super_block *sb, int flags, void *data)
1da177e4 2492{
88e67f3b 2493 const struct cred *cred = current_cred();
2bf49690 2494 struct common_audit_data ad;
3b3b0e4f 2495 struct selinux_audit_data sad = {0,};
1da177e4
LT
2496 int rc;
2497
2498 rc = superblock_doinit(sb, data);
2499 if (rc)
2500 return rc;
2501
74192246
JM
2502 /* Allow all mounts performed by the kernel */
2503 if (flags & MS_KERNMOUNT)
2504 return 0;
2505
a269434d 2506 COMMON_AUDIT_DATA_INIT(&ad, DENTRY);
3b3b0e4f 2507 ad.selinux_audit_data = &sad;
a269434d 2508 ad.u.dentry = sb->s_root;
88e67f3b 2509 return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad);
1da177e4
LT
2510}
2511
726c3342 2512static int selinux_sb_statfs(struct dentry *dentry)
1da177e4 2513{
88e67f3b 2514 const struct cred *cred = current_cred();
2bf49690 2515 struct common_audit_data ad;
3b3b0e4f 2516 struct selinux_audit_data sad = {0,};
1da177e4 2517
a269434d 2518 COMMON_AUDIT_DATA_INIT(&ad, DENTRY);
3b3b0e4f 2519 ad.selinux_audit_data = &sad;
a269434d 2520 ad.u.dentry = dentry->d_sb->s_root;
88e67f3b 2521 return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad);
1da177e4
LT
2522}
2523
828dfe1d 2524static int selinux_mount(char *dev_name,
b5266eb4 2525 struct path *path,
828dfe1d
EP
2526 char *type,
2527 unsigned long flags,
2528 void *data)
1da177e4 2529{
88e67f3b 2530 const struct cred *cred = current_cred();
1da177e4
LT
2531
2532 if (flags & MS_REMOUNT)
d8c9584e 2533 return superblock_has_perm(cred, path->dentry->d_sb,
828dfe1d 2534 FILESYSTEM__REMOUNT, NULL);
1da177e4 2535 else
2875fa00 2536 return path_has_perm(cred, path, FILE__MOUNTON);
1da177e4
LT
2537}
2538
2539static int selinux_umount(struct vfsmount *mnt, int flags)
2540{
88e67f3b 2541 const struct cred *cred = current_cred();
1da177e4 2542
88e67f3b 2543 return superblock_has_perm(cred, mnt->mnt_sb,
828dfe1d 2544 FILESYSTEM__UNMOUNT, NULL);
1da177e4
LT
2545}
2546
2547/* inode security operations */
2548
2549static int selinux_inode_alloc_security(struct inode *inode)
2550{
2551 return inode_alloc_security(inode);
2552}
2553
2554static void selinux_inode_free_security(struct inode *inode)
2555{
2556 inode_free_security(inode);
2557}
2558
5e41ff9e 2559static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
2a7dba39
EP
2560 const struct qstr *qstr, char **name,
2561 void **value, size_t *len)
5e41ff9e 2562{
5fb49870 2563 const struct task_security_struct *tsec = current_security();
5e41ff9e
SS
2564 struct inode_security_struct *dsec;
2565 struct superblock_security_struct *sbsec;
275bb41e 2566 u32 sid, newsid, clen;
5e41ff9e 2567 int rc;
570bc1c2 2568 char *namep = NULL, *context;
5e41ff9e 2569
5e41ff9e
SS
2570 dsec = dir->i_security;
2571 sbsec = dir->i_sb->s_security;
5e41ff9e 2572
275bb41e
DH
2573 sid = tsec->sid;
2574 newsid = tsec->create_sid;
2575
415103f9
EP
2576 if ((sbsec->flags & SE_SBINITIALIZED) &&
2577 (sbsec->behavior == SECURITY_FS_USE_MNTPOINT))
2578 newsid = sbsec->mntpoint_sid;
2579 else if (!newsid || !(sbsec->flags & SE_SBLABELSUPP)) {
275bb41e 2580 rc = security_transition_sid(sid, dsec->sid,
5e41ff9e 2581 inode_mode_to_security_class(inode->i_mode),
652bb9b0 2582 qstr, &newsid);
5e41ff9e
SS
2583 if (rc) {
2584 printk(KERN_WARNING "%s: "
2585 "security_transition_sid failed, rc=%d (dev=%s "
2586 "ino=%ld)\n",
dd6f953a 2587 __func__,
5e41ff9e
SS
2588 -rc, inode->i_sb->s_id, inode->i_ino);
2589 return rc;
2590 }
2591 }
2592
296fddf7 2593 /* Possibly defer initialization to selinux_complete_init. */
0d90a7ec 2594 if (sbsec->flags & SE_SBINITIALIZED) {
296fddf7
EP
2595 struct inode_security_struct *isec = inode->i_security;
2596 isec->sclass = inode_mode_to_security_class(inode->i_mode);
2597 isec->sid = newsid;
2598 isec->initialized = 1;
2599 }
5e41ff9e 2600
cd89596f 2601 if (!ss_initialized || !(sbsec->flags & SE_SBLABELSUPP))
25a74f3b
SS
2602 return -EOPNOTSUPP;
2603
570bc1c2 2604 if (name) {
a02fe132 2605 namep = kstrdup(XATTR_SELINUX_SUFFIX, GFP_NOFS);
570bc1c2
SS
2606 if (!namep)
2607 return -ENOMEM;
2608 *name = namep;
2609 }
5e41ff9e 2610
570bc1c2 2611 if (value && len) {
12b29f34 2612 rc = security_sid_to_context_force(newsid, &context, &clen);
570bc1c2
SS
2613 if (rc) {
2614 kfree(namep);
2615 return rc;
2616 }
2617 *value = context;
2618 *len = clen;
5e41ff9e 2619 }
5e41ff9e 2620
5e41ff9e
SS
2621 return 0;
2622}
2623
4acdaf27 2624static int selinux_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode)
1da177e4
LT
2625{
2626 return may_create(dir, dentry, SECCLASS_FILE);
2627}
2628
1da177e4
LT
2629static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
2630{
1da177e4
LT
2631 return may_link(dir, old_dentry, MAY_LINK);
2632}
2633
1da177e4
LT
2634static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry)
2635{
1da177e4
LT
2636 return may_link(dir, dentry, MAY_UNLINK);
2637}
2638
2639static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name)
2640{
2641 return may_create(dir, dentry, SECCLASS_LNK_FILE);
2642}
2643
18bb1db3 2644static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, umode_t mask)
1da177e4
LT
2645{
2646 return may_create(dir, dentry, SECCLASS_DIR);
2647}
2648
1da177e4
LT
2649static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry)
2650{
2651 return may_link(dir, dentry, MAY_RMDIR);
2652}
2653
1a67aafb 2654static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
1da177e4 2655{
1da177e4
LT
2656 return may_create(dir, dentry, inode_mode_to_security_class(mode));
2657}
2658
1da177e4 2659static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
828dfe1d 2660 struct inode *new_inode, struct dentry *new_dentry)
1da177e4
LT
2661{
2662 return may_rename(old_inode, old_dentry, new_inode, new_dentry);
2663}
2664
1da177e4
LT
2665static int selinux_inode_readlink(struct dentry *dentry)
2666{
88e67f3b
DH
2667 const struct cred *cred = current_cred();
2668
2875fa00 2669 return dentry_has_perm(cred, dentry, FILE__READ);
1da177e4
LT
2670}
2671
2672static int selinux_inode_follow_link(struct dentry *dentry, struct nameidata *nameidata)
2673{
88e67f3b 2674 const struct cred *cred = current_cred();
1da177e4 2675
2875fa00 2676 return dentry_has_perm(cred, dentry, FILE__READ);
1da177e4
LT
2677}
2678
e74f71eb 2679static int selinux_inode_permission(struct inode *inode, int mask)
1da177e4 2680{
88e67f3b 2681 const struct cred *cred = current_cred();
b782e0a6 2682 struct common_audit_data ad;
3b3b0e4f 2683 struct selinux_audit_data sad = {0,};
b782e0a6
EP
2684 u32 perms;
2685 bool from_access;
cf1dd1da 2686 unsigned flags = mask & MAY_NOT_BLOCK;
1da177e4 2687
b782e0a6 2688 from_access = mask & MAY_ACCESS;
d09ca739
EP
2689 mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
2690
b782e0a6
EP
2691 /* No permission to check. Existence test. */
2692 if (!mask)
1da177e4 2693 return 0;
1da177e4 2694
f48b7399 2695 COMMON_AUDIT_DATA_INIT(&ad, INODE);
3b3b0e4f 2696 ad.selinux_audit_data = &sad;
f48b7399 2697 ad.u.inode = inode;
b782e0a6
EP
2698
2699 if (from_access)
3b3b0e4f 2700 ad.selinux_audit_data->auditdeny |= FILE__AUDIT_ACCESS;
b782e0a6
EP
2701
2702 perms = file_mask_to_av(inode->i_mode, mask);
2703
9ade0cf4 2704 return inode_has_perm(cred, inode, perms, &ad, flags);
1da177e4
LT
2705}
2706
2707static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
2708{
88e67f3b 2709 const struct cred *cred = current_cred();
bc6a6008 2710 unsigned int ia_valid = iattr->ia_valid;
95dbf739 2711 __u32 av = FILE__WRITE;
1da177e4 2712
bc6a6008
AW
2713 /* ATTR_FORCE is just used for ATTR_KILL_S[UG]ID. */
2714 if (ia_valid & ATTR_FORCE) {
2715 ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE |
2716 ATTR_FORCE);
2717 if (!ia_valid)
2718 return 0;
2719 }
1da177e4 2720
bc6a6008
AW
2721 if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
2722 ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET))
2875fa00 2723 return dentry_has_perm(cred, dentry, FILE__SETATTR);
1da177e4 2724
95dbf739
EP
2725 if (ia_valid & ATTR_SIZE)
2726 av |= FILE__OPEN;
2727
2728 return dentry_has_perm(cred, dentry, av);
1da177e4
LT
2729}
2730
2731static int selinux_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
2732{
88e67f3b 2733 const struct cred *cred = current_cred();
2875fa00
EP
2734 struct path path;
2735
2736 path.dentry = dentry;
2737 path.mnt = mnt;
88e67f3b 2738
2875fa00 2739 return path_has_perm(cred, &path, FILE__GETATTR);
1da177e4
LT
2740}
2741
8f0cfa52 2742static int selinux_inode_setotherxattr(struct dentry *dentry, const char *name)
b5376771 2743{
88e67f3b
DH
2744 const struct cred *cred = current_cred();
2745
b5376771
SH
2746 if (!strncmp(name, XATTR_SECURITY_PREFIX,
2747 sizeof XATTR_SECURITY_PREFIX - 1)) {
2748 if (!strcmp(name, XATTR_NAME_CAPS)) {
2749 if (!capable(CAP_SETFCAP))
2750 return -EPERM;
2751 } else if (!capable(CAP_SYS_ADMIN)) {
2752 /* A different attribute in the security namespace.
2753 Restrict to administrator. */
2754 return -EPERM;
2755 }
2756 }
2757
2758 /* Not an attribute we recognize, so just check the
2759 ordinary setattr permission. */
2875fa00 2760 return dentry_has_perm(cred, dentry, FILE__SETATTR);
b5376771
SH
2761}
2762
8f0cfa52
DH
2763static int selinux_inode_setxattr(struct dentry *dentry, const char *name,
2764 const void *value, size_t size, int flags)
1da177e4 2765{
1da177e4
LT
2766 struct inode *inode = dentry->d_inode;
2767 struct inode_security_struct *isec = inode->i_security;
2768 struct superblock_security_struct *sbsec;
2bf49690 2769 struct common_audit_data ad;
3b3b0e4f 2770 struct selinux_audit_data sad = {0,};
275bb41e 2771 u32 newsid, sid = current_sid();
1da177e4
LT
2772 int rc = 0;
2773
b5376771
SH
2774 if (strcmp(name, XATTR_NAME_SELINUX))
2775 return selinux_inode_setotherxattr(dentry, name);
1da177e4
LT
2776
2777 sbsec = inode->i_sb->s_security;
cd89596f 2778 if (!(sbsec->flags & SE_SBLABELSUPP))
1da177e4
LT
2779 return -EOPNOTSUPP;
2780
2e149670 2781 if (!inode_owner_or_capable(inode))
1da177e4
LT
2782 return -EPERM;
2783
a269434d 2784 COMMON_AUDIT_DATA_INIT(&ad, DENTRY);
3b3b0e4f 2785 ad.selinux_audit_data = &sad;
a269434d 2786 ad.u.dentry = dentry;
1da177e4 2787
275bb41e 2788 rc = avc_has_perm(sid, isec->sid, isec->sclass,
1da177e4
LT
2789 FILE__RELABELFROM, &ad);
2790 if (rc)
2791 return rc;
2792
2793 rc = security_context_to_sid(value, size, &newsid);
12b29f34
SS
2794 if (rc == -EINVAL) {
2795 if (!capable(CAP_MAC_ADMIN))
2796 return rc;
2797 rc = security_context_to_sid_force(value, size, &newsid);
2798 }
1da177e4
LT
2799 if (rc)
2800 return rc;
2801
275bb41e 2802 rc = avc_has_perm(sid, newsid, isec->sclass,
1da177e4
LT
2803 FILE__RELABELTO, &ad);
2804 if (rc)
2805 return rc;
2806
275bb41e 2807 rc = security_validate_transition(isec->sid, newsid, sid,
828dfe1d 2808 isec->sclass);
1da177e4
LT
2809 if (rc)
2810 return rc;
2811
2812 return avc_has_perm(newsid,
2813 sbsec->sid,
2814 SECCLASS_FILESYSTEM,
2815 FILESYSTEM__ASSOCIATE,
2816 &ad);
2817}
2818
8f0cfa52 2819static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name,
f5269710 2820 const void *value, size_t size,
8f0cfa52 2821 int flags)
1da177e4
LT
2822{
2823 struct inode *inode = dentry->d_inode;
2824 struct inode_security_struct *isec = inode->i_security;
2825 u32 newsid;
2826 int rc;
2827
2828 if (strcmp(name, XATTR_NAME_SELINUX)) {
2829 /* Not an attribute we recognize, so nothing to do. */
2830 return;
2831 }
2832
12b29f34 2833 rc = security_context_to_sid_force(value, size, &newsid);
1da177e4 2834 if (rc) {
12b29f34
SS
2835 printk(KERN_ERR "SELinux: unable to map context to SID"
2836 "for (%s, %lu), rc=%d\n",
2837 inode->i_sb->s_id, inode->i_ino, -rc);
1da177e4
LT
2838 return;
2839 }
2840
2841 isec->sid = newsid;
2842 return;
2843}
2844
8f0cfa52 2845static int selinux_inode_getxattr(struct dentry *dentry, const char *name)
1da177e4 2846{
88e67f3b
DH
2847 const struct cred *cred = current_cred();
2848
2875fa00 2849 return dentry_has_perm(cred, dentry, FILE__GETATTR);
1da177e4
LT
2850}
2851
828dfe1d 2852static int selinux_inode_listxattr(struct dentry *dentry)
1da177e4 2853{
88e67f3b
DH
2854 const struct cred *cred = current_cred();
2855
2875fa00 2856 return dentry_has_perm(cred, dentry, FILE__GETATTR);
1da177e4
LT
2857}
2858
8f0cfa52 2859static int selinux_inode_removexattr(struct dentry *dentry, const char *name)
1da177e4 2860{
b5376771
SH
2861 if (strcmp(name, XATTR_NAME_SELINUX))
2862 return selinux_inode_setotherxattr(dentry, name);
1da177e4
LT
2863
2864 /* No one is allowed to remove a SELinux security label.
2865 You can change the label, but all data must be labeled. */
2866 return -EACCES;
2867}
2868
d381d8a9 2869/*
abc69bb6 2870 * Copy the inode security context value to the user.
d381d8a9
JM
2871 *
2872 * Permission check is handled by selinux_inode_getxattr hook.
2873 */
42492594 2874static int selinux_inode_getsecurity(const struct inode *inode, const char *name, void **buffer, bool alloc)
1da177e4 2875{
42492594
DQ
2876 u32 size;
2877 int error;
2878 char *context = NULL;
1da177e4 2879 struct inode_security_struct *isec = inode->i_security;
d381d8a9 2880
8c8570fb
DK
2881 if (strcmp(name, XATTR_SELINUX_SUFFIX))
2882 return -EOPNOTSUPP;
d381d8a9 2883
abc69bb6
SS
2884 /*
2885 * If the caller has CAP_MAC_ADMIN, then get the raw context
2886 * value even if it is not defined by current policy; otherwise,
2887 * use the in-core value under current policy.
2888 * Use the non-auditing forms of the permission checks since
2889 * getxattr may be called by unprivileged processes commonly
2890 * and lack of permission just means that we fall back to the
2891 * in-core context value, not a denial.
2892 */
6a9de491 2893 error = selinux_capable(current_cred(), &init_user_ns, CAP_MAC_ADMIN,
3699c53c 2894 SECURITY_CAP_NOAUDIT);
abc69bb6
SS
2895 if (!error)
2896 error = security_sid_to_context_force(isec->sid, &context,
2897 &size);
2898 else
2899 error = security_sid_to_context(isec->sid, &context, &size);
42492594
DQ
2900 if (error)
2901 return error;
2902 error = size;
2903 if (alloc) {
2904 *buffer = context;
2905 goto out_nofree;
2906 }
2907 kfree(context);
2908out_nofree:
2909 return error;
1da177e4
LT
2910}
2911
2912static int selinux_inode_setsecurity(struct inode *inode, const char *name,
828dfe1d 2913 const void *value, size_t size, int flags)
1da177e4
LT
2914{
2915 struct inode_security_struct *isec = inode->i_security;
2916 u32 newsid;
2917 int rc;
2918
2919 if (strcmp(name, XATTR_SELINUX_SUFFIX))
2920 return -EOPNOTSUPP;
2921
2922 if (!value || !size)
2923 return -EACCES;
2924
828dfe1d 2925 rc = security_context_to_sid((void *)value, size, &newsid);
1da177e4
LT
2926 if (rc)
2927 return rc;
2928
2929 isec->sid = newsid;
ddd29ec6 2930 isec->initialized = 1;
1da177e4
LT
2931 return 0;
2932}
2933
2934static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
2935{
2936 const int len = sizeof(XATTR_NAME_SELINUX);
2937 if (buffer && len <= buffer_size)
2938 memcpy(buffer, XATTR_NAME_SELINUX, len);
2939 return len;
2940}
2941
713a04ae
AD
2942static void selinux_inode_getsecid(const struct inode *inode, u32 *secid)
2943{
2944 struct inode_security_struct *isec = inode->i_security;
2945 *secid = isec->sid;
2946}
2947
1da177e4
LT
2948/* file security operations */
2949
788e7dd4 2950static int selinux_revalidate_file_permission(struct file *file, int mask)
1da177e4 2951{
88e67f3b 2952 const struct cred *cred = current_cred();
3d5ff529 2953 struct inode *inode = file->f_path.dentry->d_inode;
1da177e4 2954
1da177e4
LT
2955 /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */
2956 if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE))
2957 mask |= MAY_APPEND;
2958
389fb800
PM
2959 return file_has_perm(cred, file,
2960 file_mask_to_av(inode->i_mode, mask));
1da177e4
LT
2961}
2962
788e7dd4
YN
2963static int selinux_file_permission(struct file *file, int mask)
2964{
20dda18b
SS
2965 struct inode *inode = file->f_path.dentry->d_inode;
2966 struct file_security_struct *fsec = file->f_security;
2967 struct inode_security_struct *isec = inode->i_security;
2968 u32 sid = current_sid();
2969
389fb800 2970 if (!mask)
788e7dd4
YN
2971 /* No permission to check. Existence test. */
2972 return 0;
788e7dd4 2973
20dda18b
SS
2974 if (sid == fsec->sid && fsec->isid == isec->sid &&
2975 fsec->pseqno == avc_policy_seqno())
83d49856 2976 /* No change since file_open check. */
20dda18b
SS
2977 return 0;
2978
788e7dd4
YN
2979 return selinux_revalidate_file_permission(file, mask);
2980}
2981
1da177e4
LT
2982static int selinux_file_alloc_security(struct file *file)
2983{
2984 return file_alloc_security(file);
2985}
2986
2987static void selinux_file_free_security(struct file *file)
2988{
2989 file_free_security(file);
2990}
2991
2992static int selinux_file_ioctl(struct file *file, unsigned int cmd,
2993 unsigned long arg)
2994{
88e67f3b 2995 const struct cred *cred = current_cred();
0b24dcb7 2996 int error = 0;
1da177e4 2997
0b24dcb7
EP
2998 switch (cmd) {
2999 case FIONREAD:
3000 /* fall through */
3001 case FIBMAP:
3002 /* fall through */
3003 case FIGETBSZ:
3004 /* fall through */
2f99c369 3005 case FS_IOC_GETFLAGS:
0b24dcb7 3006 /* fall through */
2f99c369 3007 case FS_IOC_GETVERSION:
0b24dcb7
EP
3008 error = file_has_perm(cred, file, FILE__GETATTR);
3009 break;
1da177e4 3010
2f99c369 3011 case FS_IOC_SETFLAGS:
0b24dcb7 3012 /* fall through */
2f99c369 3013 case FS_IOC_SETVERSION:
0b24dcb7
EP
3014 error = file_has_perm(cred, file, FILE__SETATTR);
3015 break;
3016
3017 /* sys_ioctl() checks */
3018 case FIONBIO:
3019 /* fall through */
3020 case FIOASYNC:
3021 error = file_has_perm(cred, file, 0);
3022 break;
1da177e4 3023
0b24dcb7
EP
3024 case KDSKBENT:
3025 case KDSKBSENT:
6a9de491
EP
3026 error = cred_has_capability(cred, CAP_SYS_TTY_CONFIG,
3027 SECURITY_CAP_AUDIT);
0b24dcb7
EP
3028 break;
3029
3030 /* default case assumes that the command will go
3031 * to the file's ioctl() function.
3032 */
3033 default:
3034 error = file_has_perm(cred, file, FILE__IOCTL);
3035 }
3036 return error;
1da177e4
LT
3037}
3038
fcaaade1
SS
3039static int default_noexec;
3040
1da177e4
LT
3041static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
3042{
88e67f3b 3043 const struct cred *cred = current_cred();
d84f4f99 3044 int rc = 0;
88e67f3b 3045
fcaaade1
SS
3046 if (default_noexec &&
3047 (prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) {
1da177e4
LT
3048 /*
3049 * We are making executable an anonymous mapping or a
3050 * private file mapping that will also be writable.
3051 * This has an additional check.
3052 */
d84f4f99 3053 rc = cred_has_perm(cred, cred, PROCESS__EXECMEM);
1da177e4 3054 if (rc)
d84f4f99 3055 goto error;
1da177e4 3056 }
1da177e4
LT
3057
3058 if (file) {
3059 /* read access is always possible with a mapping */
3060 u32 av = FILE__READ;
3061
3062 /* write access only matters if the mapping is shared */
3063 if (shared && (prot & PROT_WRITE))
3064 av |= FILE__WRITE;
3065
3066 if (prot & PROT_EXEC)
3067 av |= FILE__EXECUTE;
3068
88e67f3b 3069 return file_has_perm(cred, file, av);
1da177e4 3070 }
d84f4f99
DH
3071
3072error:
3073 return rc;
1da177e4
LT
3074}
3075
3076static int selinux_file_mmap(struct file *file, unsigned long reqprot,
ed032189
EP
3077 unsigned long prot, unsigned long flags,
3078 unsigned long addr, unsigned long addr_only)
1da177e4 3079{
ed032189 3080 int rc = 0;
275bb41e 3081 u32 sid = current_sid();
1da177e4 3082
84336d1a
EP
3083 /*
3084 * notice that we are intentionally putting the SELinux check before
3085 * the secondary cap_file_mmap check. This is such a likely attempt
3086 * at bad behaviour/exploit that we always want to get the AVC, even
3087 * if DAC would have also denied the operation.
3088 */
a2551df7 3089 if (addr < CONFIG_LSM_MMAP_MIN_ADDR) {
ed032189
EP
3090 rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT,
3091 MEMPROTECT__MMAP_ZERO, NULL);
84336d1a
EP
3092 if (rc)
3093 return rc;
3094 }
3095
3096 /* do DAC check on address space usage */
3097 rc = cap_file_mmap(file, reqprot, prot, flags, addr, addr_only);
ed032189 3098 if (rc || addr_only)
1da177e4
LT
3099 return rc;
3100
3101 if (selinux_checkreqprot)
3102 prot = reqprot;
3103
3104 return file_map_prot_check(file, prot,
3105 (flags & MAP_TYPE) == MAP_SHARED);
3106}
3107
3108static int selinux_file_mprotect(struct vm_area_struct *vma,
3109 unsigned long reqprot,
3110 unsigned long prot)
3111{
88e67f3b 3112 const struct cred *cred = current_cred();
1da177e4
LT
3113
3114 if (selinux_checkreqprot)
3115 prot = reqprot;
3116
fcaaade1
SS
3117 if (default_noexec &&
3118 (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
d541bbee 3119 int rc = 0;
db4c9641
SS
3120 if (vma->vm_start >= vma->vm_mm->start_brk &&
3121 vma->vm_end <= vma->vm_mm->brk) {
d84f4f99 3122 rc = cred_has_perm(cred, cred, PROCESS__EXECHEAP);
db4c9641
SS
3123 } else if (!vma->vm_file &&
3124 vma->vm_start <= vma->vm_mm->start_stack &&
3125 vma->vm_end >= vma->vm_mm->start_stack) {
3b11a1de 3126 rc = current_has_perm(current, PROCESS__EXECSTACK);
db4c9641
SS
3127 } else if (vma->vm_file && vma->anon_vma) {
3128 /*
3129 * We are making executable a file mapping that has
3130 * had some COW done. Since pages might have been
3131 * written, check ability to execute the possibly
3132 * modified content. This typically should only
3133 * occur for text relocations.
3134 */
d84f4f99 3135 rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD);
db4c9641 3136 }