]> git.proxmox.com Git - mirror_ubuntu-hirsute-kernel.git/blame - security/selinux/hooks.c
selinux: sparse fix: fix several warnings in the security server cod
[mirror_ubuntu-hirsute-kernel.git] / security / selinux / hooks.c
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 30#include <linux/errno.h>
0b24dcb7 31#include <linux/ext2_fs.h>
1da177e4
LT
32#include <linux/sched.h>
33#include <linux/security.h>
34#include <linux/xattr.h>
35#include <linux/capability.h>
36#include <linux/unistd.h>
37#include <linux/mm.h>
38#include <linux/mman.h>
39#include <linux/slab.h>
40#include <linux/pagemap.h>
0b24dcb7 41#include <linux/proc_fs.h>
1da177e4 42#include <linux/swap.h>
1da177e4
LT
43#include <linux/spinlock.h>
44#include <linux/syscalls.h>
2a7dba39 45#include <linux/dcache.h>
1da177e4 46#include <linux/file.h>
9f3acc31 47#include <linux/fdtable.h>
1da177e4
LT
48#include <linux/namei.h>
49#include <linux/mount.h>
1da177e4
LT
50#include <linux/netfilter_ipv4.h>
51#include <linux/netfilter_ipv6.h>
52#include <linux/tty.h>
53#include <net/icmp.h>
227b60f5 54#include <net/ip.h> /* for local_port_range[] */
1da177e4 55#include <net/tcp.h> /* struct or_callable used in sock_rcv_skb */
220deb96 56#include <net/net_namespace.h>
d621d35e 57#include <net/netlabel.h>
f5269710 58#include <linux/uaccess.h>
1da177e4 59#include <asm/ioctls.h>
60063497 60#include <linux/atomic.h>
1da177e4
LT
61#include <linux/bitops.h>
62#include <linux/interrupt.h>
63#include <linux/netdevice.h> /* for network interface checks */
64#include <linux/netlink.h>
65#include <linux/tcp.h>
66#include <linux/udp.h>
2ee92d46 67#include <linux/dccp.h>
1da177e4
LT
68#include <linux/quota.h>
69#include <linux/un.h> /* for Unix socket types */
70#include <net/af_unix.h> /* for Unix socket types */
71#include <linux/parser.h>
72#include <linux/nfs_mount.h>
73#include <net/ipv6.h>
74#include <linux/hugetlb.h>
75#include <linux/personality.h>
1da177e4 76#include <linux/audit.h>
6931dfc9 77#include <linux/string.h>
877ce7c1 78#include <linux/selinux.h>
23970741 79#include <linux/mutex.h>
f06febc9 80#include <linux/posix-timers.h>
00234592 81#include <linux/syslog.h>
3486740a 82#include <linux/user_namespace.h>
1da177e4
LT
83
84#include "avc.h"
85#include "objsec.h"
86#include "netif.h"
224dfbd8 87#include "netnode.h"
3e112172 88#include "netport.h"
d28d1e08 89#include "xfrm.h"
c60475bf 90#include "netlabel.h"
9d57a7f9 91#include "audit.h"
2653812e 92#include "avc_ss.h"
1da177e4 93
11689d47 94#define NUM_SEL_MNT_OPTS 5
c9180a57 95
20510f2f 96extern struct security_operations *security_ops;
1da177e4 97
d621d35e 98/* SECMARK reference count */
b46610ca 99static atomic_t selinux_secmark_refcount = ATOMIC_INIT(0);
d621d35e 100
1da177e4 101#ifdef CONFIG_SECURITY_SELINUX_DEVELOP
828dfe1d 102int selinux_enforcing;
1da177e4
LT
103
104static int __init enforcing_setup(char *str)
105{
f5269710
EP
106 unsigned long enforcing;
107 if (!strict_strtoul(str, 0, &enforcing))
108 selinux_enforcing = enforcing ? 1 : 0;
1da177e4
LT
109 return 1;
110}
111__setup("enforcing=", enforcing_setup);
112#endif
113
114#ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM
115int selinux_enabled = CONFIG_SECURITY_SELINUX_BOOTPARAM_VALUE;
116
117static int __init selinux_enabled_setup(char *str)
118{
f5269710
EP
119 unsigned long enabled;
120 if (!strict_strtoul(str, 0, &enabled))
121 selinux_enabled = enabled ? 1 : 0;
1da177e4
LT
122 return 1;
123}
124__setup("selinux=", selinux_enabled_setup);
30d55280
SS
125#else
126int selinux_enabled = 1;
1da177e4
LT
127#endif
128
e18b890b 129static struct kmem_cache *sel_inode_cache;
7cae7e26 130
d621d35e
PM
131/**
132 * selinux_secmark_enabled - Check to see if SECMARK is currently enabled
133 *
134 * Description:
135 * This function checks the SECMARK reference counter to see if any SECMARK
136 * targets are currently configured, if the reference counter is greater than
137 * zero SECMARK is considered to be enabled. Returns true (1) if SECMARK is
138 * enabled, false (0) if SECMARK is disabled.
139 *
140 */
141static int selinux_secmark_enabled(void)
142{
143 return (atomic_read(&selinux_secmark_refcount) > 0);
144}
145
d84f4f99
DH
146/*
147 * initialise the security for the init task
148 */
149static void cred_init_security(void)
1da177e4 150{
3b11a1de 151 struct cred *cred = (struct cred *) current->real_cred;
1da177e4
LT
152 struct task_security_struct *tsec;
153
89d155ef 154 tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL);
1da177e4 155 if (!tsec)
d84f4f99 156 panic("SELinux: Failed to initialize initial task.\n");
1da177e4 157
d84f4f99 158 tsec->osid = tsec->sid = SECINITSID_KERNEL;
f1752eec 159 cred->security = tsec;
1da177e4
LT
160}
161
88e67f3b
DH
162/*
163 * get the security ID of a set of credentials
164 */
165static inline u32 cred_sid(const struct cred *cred)
166{
167 const struct task_security_struct *tsec;
168
169 tsec = cred->security;
170 return tsec->sid;
171}
172
275bb41e 173/*
3b11a1de 174 * get the objective security ID of a task
275bb41e
DH
175 */
176static inline u32 task_sid(const struct task_struct *task)
177{
275bb41e
DH
178 u32 sid;
179
180 rcu_read_lock();
88e67f3b 181 sid = cred_sid(__task_cred(task));
275bb41e
DH
182 rcu_read_unlock();
183 return sid;
184}
185
186/*
3b11a1de 187 * get the subjective security ID of the current task
275bb41e
DH
188 */
189static inline u32 current_sid(void)
190{
5fb49870 191 const struct task_security_struct *tsec = current_security();
275bb41e
DH
192
193 return tsec->sid;
194}
195
88e67f3b
DH
196/* Allocate and free functions for each kind of security blob. */
197
1da177e4
LT
198static int inode_alloc_security(struct inode *inode)
199{
1da177e4 200 struct inode_security_struct *isec;
275bb41e 201 u32 sid = current_sid();
1da177e4 202
a02fe132 203 isec = kmem_cache_zalloc(sel_inode_cache, GFP_NOFS);
1da177e4
LT
204 if (!isec)
205 return -ENOMEM;
206
23970741 207 mutex_init(&isec->lock);
1da177e4 208 INIT_LIST_HEAD(&isec->list);
1da177e4
LT
209 isec->inode = inode;
210 isec->sid = SECINITSID_UNLABELED;
211 isec->sclass = SECCLASS_FILE;
275bb41e 212 isec->task_sid = sid;
1da177e4
LT
213 inode->i_security = isec;
214
215 return 0;
216}
217
218static void inode_free_security(struct inode *inode)
219{
220 struct inode_security_struct *isec = inode->i_security;
221 struct superblock_security_struct *sbsec = inode->i_sb->s_security;
222
1da177e4
LT
223 spin_lock(&sbsec->isec_lock);
224 if (!list_empty(&isec->list))
225 list_del_init(&isec->list);
226 spin_unlock(&sbsec->isec_lock);
227
228 inode->i_security = NULL;
7cae7e26 229 kmem_cache_free(sel_inode_cache, isec);
1da177e4
LT
230}
231
232static int file_alloc_security(struct file *file)
233{
1da177e4 234 struct file_security_struct *fsec;
275bb41e 235 u32 sid = current_sid();
1da177e4 236
26d2a4be 237 fsec = kzalloc(sizeof(struct file_security_struct), GFP_KERNEL);
1da177e4
LT
238 if (!fsec)
239 return -ENOMEM;
240
275bb41e
DH
241 fsec->sid = sid;
242 fsec->fown_sid = sid;
1da177e4
LT
243 file->f_security = fsec;
244
245 return 0;
246}
247
248static void file_free_security(struct file *file)
249{
250 struct file_security_struct *fsec = file->f_security;
1da177e4
LT
251 file->f_security = NULL;
252 kfree(fsec);
253}
254
255static int superblock_alloc_security(struct super_block *sb)
256{
257 struct superblock_security_struct *sbsec;
258
89d155ef 259 sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL);
1da177e4
LT
260 if (!sbsec)
261 return -ENOMEM;
262
bc7e982b 263 mutex_init(&sbsec->lock);
1da177e4
LT
264 INIT_LIST_HEAD(&sbsec->isec_head);
265 spin_lock_init(&sbsec->isec_lock);
1da177e4
LT
266 sbsec->sb = sb;
267 sbsec->sid = SECINITSID_UNLABELED;
268 sbsec->def_sid = SECINITSID_FILE;
c312feb2 269 sbsec->mntpoint_sid = SECINITSID_UNLABELED;
1da177e4
LT
270 sb->s_security = sbsec;
271
272 return 0;
273}
274
275static void superblock_free_security(struct super_block *sb)
276{
277 struct superblock_security_struct *sbsec = sb->s_security;
1da177e4
LT
278 sb->s_security = NULL;
279 kfree(sbsec);
280}
281
1da177e4
LT
282/* The file system's label must be initialized prior to use. */
283
634a539e 284static const char *labeling_behaviors[6] = {
1da177e4
LT
285 "uses xattr",
286 "uses transition SIDs",
287 "uses task SIDs",
288 "uses genfs_contexts",
289 "not configured for labeling",
290 "uses mountpoint labeling",
291};
292
293static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry);
294
295static inline int inode_doinit(struct inode *inode)
296{
297 return inode_doinit_with_dentry(inode, NULL);
298}
299
300enum {
31e87930 301 Opt_error = -1,
1da177e4
LT
302 Opt_context = 1,
303 Opt_fscontext = 2,
c9180a57
EP
304 Opt_defcontext = 3,
305 Opt_rootcontext = 4,
11689d47 306 Opt_labelsupport = 5,
1da177e4
LT
307};
308
a447c093 309static const match_table_t tokens = {
832cbd9a
EP
310 {Opt_context, CONTEXT_STR "%s"},
311 {Opt_fscontext, FSCONTEXT_STR "%s"},
312 {Opt_defcontext, DEFCONTEXT_STR "%s"},
313 {Opt_rootcontext, ROOTCONTEXT_STR "%s"},
11689d47 314 {Opt_labelsupport, LABELSUPP_STR},
31e87930 315 {Opt_error, NULL},
1da177e4
LT
316};
317
318#define SEL_MOUNT_FAIL_MSG "SELinux: duplicate or incompatible mount options\n"
319
c312feb2
EP
320static int may_context_mount_sb_relabel(u32 sid,
321 struct superblock_security_struct *sbsec,
275bb41e 322 const struct cred *cred)
c312feb2 323{
275bb41e 324 const struct task_security_struct *tsec = cred->security;
c312feb2
EP
325 int rc;
326
327 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
328 FILESYSTEM__RELABELFROM, NULL);
329 if (rc)
330 return rc;
331
332 rc = avc_has_perm(tsec->sid, sid, SECCLASS_FILESYSTEM,
333 FILESYSTEM__RELABELTO, NULL);
334 return rc;
335}
336
0808925e
EP
337static int may_context_mount_inode_relabel(u32 sid,
338 struct superblock_security_struct *sbsec,
275bb41e 339 const struct cred *cred)
0808925e 340{
275bb41e 341 const struct task_security_struct *tsec = cred->security;
0808925e
EP
342 int rc;
343 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
344 FILESYSTEM__RELABELFROM, NULL);
345 if (rc)
346 return rc;
347
348 rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM,
349 FILESYSTEM__ASSOCIATE, NULL);
350 return rc;
351}
352
c9180a57 353static int sb_finish_set_opts(struct super_block *sb)
1da177e4 354{
1da177e4 355 struct superblock_security_struct *sbsec = sb->s_security;
c9180a57
EP
356 struct dentry *root = sb->s_root;
357 struct inode *root_inode = root->d_inode;
358 int rc = 0;
1da177e4 359
c9180a57
EP
360 if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
361 /* Make sure that the xattr handler exists and that no
362 error other than -ENODATA is returned by getxattr on
363 the root directory. -ENODATA is ok, as this may be
364 the first boot of the SELinux kernel before we have
365 assigned xattr values to the filesystem. */
366 if (!root_inode->i_op->getxattr) {
367 printk(KERN_WARNING "SELinux: (dev %s, type %s) has no "
368 "xattr support\n", sb->s_id, sb->s_type->name);
369 rc = -EOPNOTSUPP;
370 goto out;
371 }
372 rc = root_inode->i_op->getxattr(root, XATTR_NAME_SELINUX, NULL, 0);
373 if (rc < 0 && rc != -ENODATA) {
374 if (rc == -EOPNOTSUPP)
375 printk(KERN_WARNING "SELinux: (dev %s, type "
376 "%s) has no security xattr handler\n",
377 sb->s_id, sb->s_type->name);
378 else
379 printk(KERN_WARNING "SELinux: (dev %s, type "
380 "%s) getxattr errno %d\n", sb->s_id,
381 sb->s_type->name, -rc);
382 goto out;
383 }
384 }
1da177e4 385
11689d47 386 sbsec->flags |= (SE_SBINITIALIZED | SE_SBLABELSUPP);
1da177e4 387
c9180a57
EP
388 if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors))
389 printk(KERN_ERR "SELinux: initialized (dev %s, type %s), unknown behavior\n",
390 sb->s_id, sb->s_type->name);
391 else
392 printk(KERN_DEBUG "SELinux: initialized (dev %s, type %s), %s\n",
393 sb->s_id, sb->s_type->name,
394 labeling_behaviors[sbsec->behavior-1]);
1da177e4 395
11689d47
DQ
396 if (sbsec->behavior == SECURITY_FS_USE_GENFS ||
397 sbsec->behavior == SECURITY_FS_USE_MNTPOINT ||
398 sbsec->behavior == SECURITY_FS_USE_NONE ||
399 sbsec->behavior > ARRAY_SIZE(labeling_behaviors))
400 sbsec->flags &= ~SE_SBLABELSUPP;
401
ddd29ec6
DQ
402 /* Special handling for sysfs. Is genfs but also has setxattr handler*/
403 if (strncmp(sb->s_type->name, "sysfs", sizeof("sysfs")) == 0)
404 sbsec->flags |= SE_SBLABELSUPP;
405
c9180a57
EP
406 /* Initialize the root inode. */
407 rc = inode_doinit_with_dentry(root_inode, root);
1da177e4 408
c9180a57
EP
409 /* Initialize any other inodes associated with the superblock, e.g.
410 inodes created prior to initial policy load or inodes created
411 during get_sb by a pseudo filesystem that directly
412 populates itself. */
413 spin_lock(&sbsec->isec_lock);
414next_inode:
415 if (!list_empty(&sbsec->isec_head)) {
416 struct inode_security_struct *isec =
417 list_entry(sbsec->isec_head.next,
418 struct inode_security_struct, list);
419 struct inode *inode = isec->inode;
420 spin_unlock(&sbsec->isec_lock);
421 inode = igrab(inode);
422 if (inode) {
423 if (!IS_PRIVATE(inode))
424 inode_doinit(inode);
425 iput(inode);
426 }
427 spin_lock(&sbsec->isec_lock);
428 list_del_init(&isec->list);
429 goto next_inode;
430 }
431 spin_unlock(&sbsec->isec_lock);
432out:
433 return rc;
434}
1da177e4 435
c9180a57
EP
436/*
437 * This function should allow an FS to ask what it's mount security
438 * options were so it can use those later for submounts, displaying
439 * mount options, or whatever.
440 */
441static int selinux_get_mnt_opts(const struct super_block *sb,
e0007529 442 struct security_mnt_opts *opts)
c9180a57
EP
443{
444 int rc = 0, i;
445 struct superblock_security_struct *sbsec = sb->s_security;
446 char *context = NULL;
447 u32 len;
448 char tmp;
1da177e4 449
e0007529 450 security_init_mnt_opts(opts);
1da177e4 451
0d90a7ec 452 if (!(sbsec->flags & SE_SBINITIALIZED))
c9180a57 453 return -EINVAL;
1da177e4 454
c9180a57
EP
455 if (!ss_initialized)
456 return -EINVAL;
1da177e4 457
0d90a7ec 458 tmp = sbsec->flags & SE_MNTMASK;
c9180a57
EP
459 /* count the number of mount options for this sb */
460 for (i = 0; i < 8; i++) {
461 if (tmp & 0x01)
e0007529 462 opts->num_mnt_opts++;
c9180a57
EP
463 tmp >>= 1;
464 }
11689d47
DQ
465 /* Check if the Label support flag is set */
466 if (sbsec->flags & SE_SBLABELSUPP)
467 opts->num_mnt_opts++;
1da177e4 468
e0007529
EP
469 opts->mnt_opts = kcalloc(opts->num_mnt_opts, sizeof(char *), GFP_ATOMIC);
470 if (!opts->mnt_opts) {
c9180a57
EP
471 rc = -ENOMEM;
472 goto out_free;
473 }
1da177e4 474
e0007529
EP
475 opts->mnt_opts_flags = kcalloc(opts->num_mnt_opts, sizeof(int), GFP_ATOMIC);
476 if (!opts->mnt_opts_flags) {
c9180a57
EP
477 rc = -ENOMEM;
478 goto out_free;
479 }
1da177e4 480
c9180a57
EP
481 i = 0;
482 if (sbsec->flags & FSCONTEXT_MNT) {
483 rc = security_sid_to_context(sbsec->sid, &context, &len);
484 if (rc)
485 goto out_free;
e0007529
EP
486 opts->mnt_opts[i] = context;
487 opts->mnt_opts_flags[i++] = FSCONTEXT_MNT;
c9180a57
EP
488 }
489 if (sbsec->flags & CONTEXT_MNT) {
490 rc = security_sid_to_context(sbsec->mntpoint_sid, &context, &len);
491 if (rc)
492 goto out_free;
e0007529
EP
493 opts->mnt_opts[i] = context;
494 opts->mnt_opts_flags[i++] = CONTEXT_MNT;
c9180a57
EP
495 }
496 if (sbsec->flags & DEFCONTEXT_MNT) {
497 rc = security_sid_to_context(sbsec->def_sid, &context, &len);
498 if (rc)
499 goto out_free;
e0007529
EP
500 opts->mnt_opts[i] = context;
501 opts->mnt_opts_flags[i++] = DEFCONTEXT_MNT;
c9180a57
EP
502 }
503 if (sbsec->flags & ROOTCONTEXT_MNT) {
504 struct inode *root = sbsec->sb->s_root->d_inode;
505 struct inode_security_struct *isec = root->i_security;
0808925e 506
c9180a57
EP
507 rc = security_sid_to_context(isec->sid, &context, &len);
508 if (rc)
509 goto out_free;
e0007529
EP
510 opts->mnt_opts[i] = context;
511 opts->mnt_opts_flags[i++] = ROOTCONTEXT_MNT;
c9180a57 512 }
11689d47
DQ
513 if (sbsec->flags & SE_SBLABELSUPP) {
514 opts->mnt_opts[i] = NULL;
515 opts->mnt_opts_flags[i++] = SE_SBLABELSUPP;
516 }
1da177e4 517
e0007529 518 BUG_ON(i != opts->num_mnt_opts);
1da177e4 519
c9180a57
EP
520 return 0;
521
522out_free:
e0007529 523 security_free_mnt_opts(opts);
c9180a57
EP
524 return rc;
525}
1da177e4 526
c9180a57
EP
527static int bad_option(struct superblock_security_struct *sbsec, char flag,
528 u32 old_sid, u32 new_sid)
529{
0d90a7ec
DQ
530 char mnt_flags = sbsec->flags & SE_MNTMASK;
531
c9180a57 532 /* check if the old mount command had the same options */
0d90a7ec 533 if (sbsec->flags & SE_SBINITIALIZED)
c9180a57
EP
534 if (!(sbsec->flags & flag) ||
535 (old_sid != new_sid))
536 return 1;
537
538 /* check if we were passed the same options twice,
539 * aka someone passed context=a,context=b
540 */
0d90a7ec
DQ
541 if (!(sbsec->flags & SE_SBINITIALIZED))
542 if (mnt_flags & flag)
c9180a57
EP
543 return 1;
544 return 0;
545}
e0007529 546
c9180a57
EP
547/*
548 * Allow filesystems with binary mount data to explicitly set mount point
549 * labeling information.
550 */
e0007529
EP
551static int selinux_set_mnt_opts(struct super_block *sb,
552 struct security_mnt_opts *opts)
c9180a57 553{
275bb41e 554 const struct cred *cred = current_cred();
c9180a57 555 int rc = 0, i;
c9180a57
EP
556 struct superblock_security_struct *sbsec = sb->s_security;
557 const char *name = sb->s_type->name;
089be43e
JM
558 struct inode *inode = sbsec->sb->s_root->d_inode;
559 struct inode_security_struct *root_isec = inode->i_security;
c9180a57
EP
560 u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0;
561 u32 defcontext_sid = 0;
e0007529
EP
562 char **mount_options = opts->mnt_opts;
563 int *flags = opts->mnt_opts_flags;
564 int num_opts = opts->num_mnt_opts;
c9180a57
EP
565
566 mutex_lock(&sbsec->lock);
567
568 if (!ss_initialized) {
569 if (!num_opts) {
570 /* Defer initialization until selinux_complete_init,
571 after the initial policy is loaded and the security
572 server is ready to handle calls. */
c9180a57
EP
573 goto out;
574 }
575 rc = -EINVAL;
744ba35e
EP
576 printk(KERN_WARNING "SELinux: Unable to set superblock options "
577 "before the security server is initialized\n");
1da177e4 578 goto out;
c9180a57 579 }
1da177e4 580
e0007529
EP
581 /*
582 * Binary mount data FS will come through this function twice. Once
583 * from an explicit call and once from the generic calls from the vfs.
584 * Since the generic VFS calls will not contain any security mount data
585 * we need to skip the double mount verification.
586 *
587 * This does open a hole in which we will not notice if the first
588 * mount using this sb set explict options and a second mount using
589 * this sb does not set any security options. (The first options
590 * will be used for both mounts)
591 */
0d90a7ec 592 if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
e0007529 593 && (num_opts == 0))
f5269710 594 goto out;
e0007529 595
c9180a57
EP
596 /*
597 * parse the mount options, check if they are valid sids.
598 * also check if someone is trying to mount the same sb more
599 * than once with different security options.
600 */
601 for (i = 0; i < num_opts; i++) {
602 u32 sid;
11689d47
DQ
603
604 if (flags[i] == SE_SBLABELSUPP)
605 continue;
c9180a57
EP
606 rc = security_context_to_sid(mount_options[i],
607 strlen(mount_options[i]), &sid);
1da177e4
LT
608 if (rc) {
609 printk(KERN_WARNING "SELinux: security_context_to_sid"
610 "(%s) failed for (dev %s, type %s) errno=%d\n",
c9180a57
EP
611 mount_options[i], sb->s_id, name, rc);
612 goto out;
613 }
614 switch (flags[i]) {
615 case FSCONTEXT_MNT:
616 fscontext_sid = sid;
617
618 if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid,
619 fscontext_sid))
620 goto out_double_mount;
621
622 sbsec->flags |= FSCONTEXT_MNT;
623 break;
624 case CONTEXT_MNT:
625 context_sid = sid;
626
627 if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid,
628 context_sid))
629 goto out_double_mount;
630
631 sbsec->flags |= CONTEXT_MNT;
632 break;
633 case ROOTCONTEXT_MNT:
634 rootcontext_sid = sid;
635
636 if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid,
637 rootcontext_sid))
638 goto out_double_mount;
639
640 sbsec->flags |= ROOTCONTEXT_MNT;
641
642 break;
643 case DEFCONTEXT_MNT:
644 defcontext_sid = sid;
645
646 if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid,
647 defcontext_sid))
648 goto out_double_mount;
649
650 sbsec->flags |= DEFCONTEXT_MNT;
651
652 break;
653 default:
654 rc = -EINVAL;
655 goto out;
1da177e4 656 }
c9180a57
EP
657 }
658
0d90a7ec 659 if (sbsec->flags & SE_SBINITIALIZED) {
c9180a57 660 /* previously mounted with options, but not on this attempt? */
0d90a7ec 661 if ((sbsec->flags & SE_MNTMASK) && !num_opts)
c9180a57
EP
662 goto out_double_mount;
663 rc = 0;
664 goto out;
665 }
666
089be43e 667 if (strcmp(sb->s_type->name, "proc") == 0)
0d90a7ec 668 sbsec->flags |= SE_SBPROC;
c9180a57
EP
669
670 /* Determine the labeling behavior to use for this filesystem type. */
0d90a7ec 671 rc = security_fs_use((sbsec->flags & SE_SBPROC) ? "proc" : sb->s_type->name, &sbsec->behavior, &sbsec->sid);
c9180a57
EP
672 if (rc) {
673 printk(KERN_WARNING "%s: security_fs_use(%s) returned %d\n",
089be43e 674 __func__, sb->s_type->name, rc);
c9180a57
EP
675 goto out;
676 }
1da177e4 677
c9180a57
EP
678 /* sets the context of the superblock for the fs being mounted. */
679 if (fscontext_sid) {
275bb41e 680 rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred);
1da177e4 681 if (rc)
c9180a57 682 goto out;
1da177e4 683
c9180a57 684 sbsec->sid = fscontext_sid;
c312feb2
EP
685 }
686
687 /*
688 * Switch to using mount point labeling behavior.
689 * sets the label used on all file below the mountpoint, and will set
690 * the superblock context if not already set.
691 */
c9180a57
EP
692 if (context_sid) {
693 if (!fscontext_sid) {
275bb41e
DH
694 rc = may_context_mount_sb_relabel(context_sid, sbsec,
695 cred);
b04ea3ce 696 if (rc)
c9180a57
EP
697 goto out;
698 sbsec->sid = context_sid;
b04ea3ce 699 } else {
275bb41e
DH
700 rc = may_context_mount_inode_relabel(context_sid, sbsec,
701 cred);
b04ea3ce 702 if (rc)
c9180a57 703 goto out;
b04ea3ce 704 }
c9180a57
EP
705 if (!rootcontext_sid)
706 rootcontext_sid = context_sid;
1da177e4 707
c9180a57 708 sbsec->mntpoint_sid = context_sid;
c312feb2 709 sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
1da177e4
LT
710 }
711
c9180a57 712 if (rootcontext_sid) {
275bb41e
DH
713 rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec,
714 cred);
0808925e 715 if (rc)
c9180a57 716 goto out;
0808925e 717
c9180a57
EP
718 root_isec->sid = rootcontext_sid;
719 root_isec->initialized = 1;
0808925e
EP
720 }
721
c9180a57
EP
722 if (defcontext_sid) {
723 if (sbsec->behavior != SECURITY_FS_USE_XATTR) {
724 rc = -EINVAL;
725 printk(KERN_WARNING "SELinux: defcontext option is "
726 "invalid for this filesystem type\n");
727 goto out;
1da177e4
LT
728 }
729
c9180a57
EP
730 if (defcontext_sid != sbsec->def_sid) {
731 rc = may_context_mount_inode_relabel(defcontext_sid,
275bb41e 732 sbsec, cred);
c9180a57
EP
733 if (rc)
734 goto out;
735 }
1da177e4 736
c9180a57 737 sbsec->def_sid = defcontext_sid;
1da177e4
LT
738 }
739
c9180a57 740 rc = sb_finish_set_opts(sb);
1da177e4 741out:
c9180a57 742 mutex_unlock(&sbsec->lock);
1da177e4 743 return rc;
c9180a57
EP
744out_double_mount:
745 rc = -EINVAL;
746 printk(KERN_WARNING "SELinux: mount invalid. Same superblock, different "
747 "security settings for (dev %s, type %s)\n", sb->s_id, name);
748 goto out;
1da177e4
LT
749}
750
c9180a57
EP
751static void selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
752 struct super_block *newsb)
1da177e4 753{
c9180a57
EP
754 const struct superblock_security_struct *oldsbsec = oldsb->s_security;
755 struct superblock_security_struct *newsbsec = newsb->s_security;
1da177e4 756
c9180a57
EP
757 int set_fscontext = (oldsbsec->flags & FSCONTEXT_MNT);
758 int set_context = (oldsbsec->flags & CONTEXT_MNT);
759 int set_rootcontext = (oldsbsec->flags & ROOTCONTEXT_MNT);
1da177e4 760
0f5e6420
EP
761 /*
762 * if the parent was able to be mounted it clearly had no special lsm
e8c26255 763 * mount options. thus we can safely deal with this superblock later
0f5e6420 764 */
e8c26255 765 if (!ss_initialized)
0f5e6420 766 return;
c9180a57 767
c9180a57 768 /* how can we clone if the old one wasn't set up?? */
0d90a7ec 769 BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED));
c9180a57 770
5a552617 771 /* if fs is reusing a sb, just let its options stand... */
0d90a7ec 772 if (newsbsec->flags & SE_SBINITIALIZED)
5a552617
EP
773 return;
774
c9180a57
EP
775 mutex_lock(&newsbsec->lock);
776
777 newsbsec->flags = oldsbsec->flags;
778
779 newsbsec->sid = oldsbsec->sid;
780 newsbsec->def_sid = oldsbsec->def_sid;
781 newsbsec->behavior = oldsbsec->behavior;
782
783 if (set_context) {
784 u32 sid = oldsbsec->mntpoint_sid;
785
786 if (!set_fscontext)
787 newsbsec->sid = sid;
788 if (!set_rootcontext) {
789 struct inode *newinode = newsb->s_root->d_inode;
790 struct inode_security_struct *newisec = newinode->i_security;
791 newisec->sid = sid;
792 }
793 newsbsec->mntpoint_sid = sid;
1da177e4 794 }
c9180a57
EP
795 if (set_rootcontext) {
796 const struct inode *oldinode = oldsb->s_root->d_inode;
797 const struct inode_security_struct *oldisec = oldinode->i_security;
798 struct inode *newinode = newsb->s_root->d_inode;
799 struct inode_security_struct *newisec = newinode->i_security;
1da177e4 800
c9180a57 801 newisec->sid = oldisec->sid;
1da177e4
LT
802 }
803
c9180a57
EP
804 sb_finish_set_opts(newsb);
805 mutex_unlock(&newsbsec->lock);
806}
807
2e1479d9
AB
808static int selinux_parse_opts_str(char *options,
809 struct security_mnt_opts *opts)
c9180a57 810{
e0007529 811 char *p;
c9180a57
EP
812 char *context = NULL, *defcontext = NULL;
813 char *fscontext = NULL, *rootcontext = NULL;
e0007529 814 int rc, num_mnt_opts = 0;
1da177e4 815
e0007529 816 opts->num_mnt_opts = 0;
1da177e4 817
c9180a57
EP
818 /* Standard string-based options. */
819 while ((p = strsep(&options, "|")) != NULL) {
820 int token;
821 substring_t args[MAX_OPT_ARGS];
1da177e4 822
c9180a57
EP
823 if (!*p)
824 continue;
1da177e4 825
c9180a57 826 token = match_token(p, tokens, args);
1da177e4 827
c9180a57
EP
828 switch (token) {
829 case Opt_context:
830 if (context || defcontext) {
831 rc = -EINVAL;
832 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
833 goto out_err;
834 }
835 context = match_strdup(&args[0]);
836 if (!context) {
837 rc = -ENOMEM;
838 goto out_err;
839 }
840 break;
841
842 case Opt_fscontext:
843 if (fscontext) {
844 rc = -EINVAL;
845 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
846 goto out_err;
847 }
848 fscontext = match_strdup(&args[0]);
849 if (!fscontext) {
850 rc = -ENOMEM;
851 goto out_err;
852 }
853 break;
854
855 case Opt_rootcontext:
856 if (rootcontext) {
857 rc = -EINVAL;
858 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
859 goto out_err;
860 }
861 rootcontext = match_strdup(&args[0]);
862 if (!rootcontext) {
863 rc = -ENOMEM;
864 goto out_err;
865 }
866 break;
867
868 case Opt_defcontext:
869 if (context || defcontext) {
870 rc = -EINVAL;
871 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
872 goto out_err;
873 }
874 defcontext = match_strdup(&args[0]);
875 if (!defcontext) {
876 rc = -ENOMEM;
877 goto out_err;
878 }
879 break;
11689d47
DQ
880 case Opt_labelsupport:
881 break;
c9180a57
EP
882 default:
883 rc = -EINVAL;
884 printk(KERN_WARNING "SELinux: unknown mount option\n");
885 goto out_err;
1da177e4 886
1da177e4 887 }
1da177e4 888 }
c9180a57 889
e0007529
EP
890 rc = -ENOMEM;
891 opts->mnt_opts = kcalloc(NUM_SEL_MNT_OPTS, sizeof(char *), GFP_ATOMIC);
892 if (!opts->mnt_opts)
893 goto out_err;
894
895 opts->mnt_opts_flags = kcalloc(NUM_SEL_MNT_OPTS, sizeof(int), GFP_ATOMIC);
896 if (!opts->mnt_opts_flags) {
897 kfree(opts->mnt_opts);
898 goto out_err;
899 }
900
c9180a57 901 if (fscontext) {
e0007529
EP
902 opts->mnt_opts[num_mnt_opts] = fscontext;
903 opts->mnt_opts_flags[num_mnt_opts++] = FSCONTEXT_MNT;
c9180a57
EP
904 }
905 if (context) {
e0007529
EP
906 opts->mnt_opts[num_mnt_opts] = context;
907 opts->mnt_opts_flags[num_mnt_opts++] = CONTEXT_MNT;
c9180a57
EP
908 }
909 if (rootcontext) {
e0007529
EP
910 opts->mnt_opts[num_mnt_opts] = rootcontext;
911 opts->mnt_opts_flags[num_mnt_opts++] = ROOTCONTEXT_MNT;
c9180a57
EP
912 }
913 if (defcontext) {
e0007529
EP
914 opts->mnt_opts[num_mnt_opts] = defcontext;
915 opts->mnt_opts_flags[num_mnt_opts++] = DEFCONTEXT_MNT;
c9180a57
EP
916 }
917
e0007529
EP
918 opts->num_mnt_opts = num_mnt_opts;
919 return 0;
920
c9180a57
EP
921out_err:
922 kfree(context);
923 kfree(defcontext);
924 kfree(fscontext);
925 kfree(rootcontext);
1da177e4
LT
926 return rc;
927}
e0007529
EP
928/*
929 * string mount options parsing and call set the sbsec
930 */
931static int superblock_doinit(struct super_block *sb, void *data)
932{
933 int rc = 0;
934 char *options = data;
935 struct security_mnt_opts opts;
936
937 security_init_mnt_opts(&opts);
938
939 if (!data)
940 goto out;
941
942 BUG_ON(sb->s_type->fs_flags & FS_BINARY_MOUNTDATA);
943
944 rc = selinux_parse_opts_str(options, &opts);
945 if (rc)
946 goto out_err;
947
948out:
949 rc = selinux_set_mnt_opts(sb, &opts);
950
951out_err:
952 security_free_mnt_opts(&opts);
953 return rc;
954}
1da177e4 955
3583a711
AB
956static void selinux_write_opts(struct seq_file *m,
957 struct security_mnt_opts *opts)
2069f457
EP
958{
959 int i;
960 char *prefix;
961
962 for (i = 0; i < opts->num_mnt_opts; i++) {
11689d47
DQ
963 char *has_comma;
964
965 if (opts->mnt_opts[i])
966 has_comma = strchr(opts->mnt_opts[i], ',');
967 else
968 has_comma = NULL;
2069f457
EP
969
970 switch (opts->mnt_opts_flags[i]) {
971 case CONTEXT_MNT:
972 prefix = CONTEXT_STR;
973 break;
974 case FSCONTEXT_MNT:
975 prefix = FSCONTEXT_STR;
976 break;
977 case ROOTCONTEXT_MNT:
978 prefix = ROOTCONTEXT_STR;
979 break;
980 case DEFCONTEXT_MNT:
981 prefix = DEFCONTEXT_STR;
982 break;
11689d47
DQ
983 case SE_SBLABELSUPP:
984 seq_putc(m, ',');
985 seq_puts(m, LABELSUPP_STR);
986 continue;
2069f457
EP
987 default:
988 BUG();
a35c6c83 989 return;
2069f457
EP
990 };
991 /* we need a comma before each option */
992 seq_putc(m, ',');
993 seq_puts(m, prefix);
994 if (has_comma)
995 seq_putc(m, '\"');
996 seq_puts(m, opts->mnt_opts[i]);
997 if (has_comma)
998 seq_putc(m, '\"');
999 }
1000}
1001
1002static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb)
1003{
1004 struct security_mnt_opts opts;
1005 int rc;
1006
1007 rc = selinux_get_mnt_opts(sb, &opts);
383795c2
EP
1008 if (rc) {
1009 /* before policy load we may get EINVAL, don't show anything */
1010 if (rc == -EINVAL)
1011 rc = 0;
2069f457 1012 return rc;
383795c2 1013 }
2069f457
EP
1014
1015 selinux_write_opts(m, &opts);
1016
1017 security_free_mnt_opts(&opts);
1018
1019 return rc;
1020}
1021
1da177e4
LT
1022static inline u16 inode_mode_to_security_class(umode_t mode)
1023{
1024 switch (mode & S_IFMT) {
1025 case S_IFSOCK:
1026 return SECCLASS_SOCK_FILE;
1027 case S_IFLNK:
1028 return SECCLASS_LNK_FILE;
1029 case S_IFREG:
1030 return SECCLASS_FILE;
1031 case S_IFBLK:
1032 return SECCLASS_BLK_FILE;
1033 case S_IFDIR:
1034 return SECCLASS_DIR;
1035 case S_IFCHR:
1036 return SECCLASS_CHR_FILE;
1037 case S_IFIFO:
1038 return SECCLASS_FIFO_FILE;
1039
1040 }
1041
1042 return SECCLASS_FILE;
1043}
1044
13402580
JM
1045static inline int default_protocol_stream(int protocol)
1046{
1047 return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP);
1048}
1049
1050static inline int default_protocol_dgram(int protocol)
1051{
1052 return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP);
1053}
1054
1da177e4
LT
1055static inline u16 socket_type_to_security_class(int family, int type, int protocol)
1056{
1057 switch (family) {
1058 case PF_UNIX:
1059 switch (type) {
1060 case SOCK_STREAM:
1061 case SOCK_SEQPACKET:
1062 return SECCLASS_UNIX_STREAM_SOCKET;
1063 case SOCK_DGRAM:
1064 return SECCLASS_UNIX_DGRAM_SOCKET;
1065 }
1066 break;
1067 case PF_INET:
1068 case PF_INET6:
1069 switch (type) {
1070 case SOCK_STREAM:
13402580
JM
1071 if (default_protocol_stream(protocol))
1072 return SECCLASS_TCP_SOCKET;
1073 else
1074 return SECCLASS_RAWIP_SOCKET;
1da177e4 1075 case SOCK_DGRAM:
13402580
JM
1076 if (default_protocol_dgram(protocol))
1077 return SECCLASS_UDP_SOCKET;
1078 else
1079 return SECCLASS_RAWIP_SOCKET;
2ee92d46
JM
1080 case SOCK_DCCP:
1081 return SECCLASS_DCCP_SOCKET;
13402580 1082 default:
1da177e4
LT
1083 return SECCLASS_RAWIP_SOCKET;
1084 }
1085 break;
1086 case PF_NETLINK:
1087 switch (protocol) {
1088 case NETLINK_ROUTE:
1089 return SECCLASS_NETLINK_ROUTE_SOCKET;
1090 case NETLINK_FIREWALL:
1091 return SECCLASS_NETLINK_FIREWALL_SOCKET;
216efaaa 1092 case NETLINK_INET_DIAG:
1da177e4
LT
1093 return SECCLASS_NETLINK_TCPDIAG_SOCKET;
1094 case NETLINK_NFLOG:
1095 return SECCLASS_NETLINK_NFLOG_SOCKET;
1096 case NETLINK_XFRM:
1097 return SECCLASS_NETLINK_XFRM_SOCKET;
1098 case NETLINK_SELINUX:
1099 return SECCLASS_NETLINK_SELINUX_SOCKET;
1100 case NETLINK_AUDIT:
1101 return SECCLASS_NETLINK_AUDIT_SOCKET;
1102 case NETLINK_IP6_FW:
1103 return SECCLASS_NETLINK_IP6FW_SOCKET;
1104 case NETLINK_DNRTMSG:
1105 return SECCLASS_NETLINK_DNRT_SOCKET;
0c9b7942
JM
1106 case NETLINK_KOBJECT_UEVENT:
1107 return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET;
1da177e4
LT
1108 default:
1109 return SECCLASS_NETLINK_SOCKET;
1110 }
1111 case PF_PACKET:
1112 return SECCLASS_PACKET_SOCKET;
1113 case PF_KEY:
1114 return SECCLASS_KEY_SOCKET;
3e3ff15e
CP
1115 case PF_APPLETALK:
1116 return SECCLASS_APPLETALK_SOCKET;
1da177e4
LT
1117 }
1118
1119 return SECCLASS_SOCKET;
1120}
1121
1122#ifdef CONFIG_PROC_FS
8e6c9693 1123static int selinux_proc_get_sid(struct dentry *dentry,
1da177e4
LT
1124 u16 tclass,
1125 u32 *sid)
1126{
8e6c9693
LAG
1127 int rc;
1128 char *buffer, *path;
1da177e4 1129
828dfe1d 1130 buffer = (char *)__get_free_page(GFP_KERNEL);
1da177e4
LT
1131 if (!buffer)
1132 return -ENOMEM;
1133
8e6c9693
LAG
1134 path = dentry_path_raw(dentry, buffer, PAGE_SIZE);
1135 if (IS_ERR(path))
1136 rc = PTR_ERR(path);
1137 else {
1138 /* each process gets a /proc/PID/ entry. Strip off the
1139 * PID part to get a valid selinux labeling.
1140 * e.g. /proc/1/net/rpc/nfs -> /net/rpc/nfs */
1141 while (path[1] >= '0' && path[1] <= '9') {
1142 path[1] = '/';
1143 path++;
1144 }
1145 rc = security_genfs_sid("proc", path, tclass, sid);
1da177e4 1146 }
1da177e4
LT
1147 free_page((unsigned long)buffer);
1148 return rc;
1149}
1150#else
8e6c9693 1151static int selinux_proc_get_sid(struct dentry *dentry,
1da177e4
LT
1152 u16 tclass,
1153 u32 *sid)
1154{
1155 return -EINVAL;
1156}
1157#endif
1158
1159/* The inode's security attributes must be initialized before first use. */
1160static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry)
1161{
1162 struct superblock_security_struct *sbsec = NULL;
1163 struct inode_security_struct *isec = inode->i_security;
1164 u32 sid;
1165 struct dentry *dentry;
1166#define INITCONTEXTLEN 255
1167 char *context = NULL;
1168 unsigned len = 0;
1169 int rc = 0;
1da177e4
LT
1170
1171 if (isec->initialized)
1172 goto out;
1173
23970741 1174 mutex_lock(&isec->lock);
1da177e4 1175 if (isec->initialized)
23970741 1176 goto out_unlock;
1da177e4
LT
1177
1178 sbsec = inode->i_sb->s_security;
0d90a7ec 1179 if (!(sbsec->flags & SE_SBINITIALIZED)) {
1da177e4
LT
1180 /* Defer initialization until selinux_complete_init,
1181 after the initial policy is loaded and the security
1182 server is ready to handle calls. */
1183 spin_lock(&sbsec->isec_lock);
1184 if (list_empty(&isec->list))
1185 list_add(&isec->list, &sbsec->isec_head);
1186 spin_unlock(&sbsec->isec_lock);
23970741 1187 goto out_unlock;
1da177e4
LT
1188 }
1189
1190 switch (sbsec->behavior) {
1191 case SECURITY_FS_USE_XATTR:
1192 if (!inode->i_op->getxattr) {
1193 isec->sid = sbsec->def_sid;
1194 break;
1195 }
1196
1197 /* Need a dentry, since the xattr API requires one.
1198 Life would be simpler if we could just pass the inode. */
1199 if (opt_dentry) {
1200 /* Called from d_instantiate or d_splice_alias. */
1201 dentry = dget(opt_dentry);
1202 } else {
1203 /* Called from selinux_complete_init, try to find a dentry. */
1204 dentry = d_find_alias(inode);
1205 }
1206 if (!dentry) {
df7f54c0
EP
1207 /*
1208 * this is can be hit on boot when a file is accessed
1209 * before the policy is loaded. When we load policy we
1210 * may find inodes that have no dentry on the
1211 * sbsec->isec_head list. No reason to complain as these
1212 * will get fixed up the next time we go through
1213 * inode_doinit with a dentry, before these inodes could
1214 * be used again by userspace.
1215 */
23970741 1216 goto out_unlock;
1da177e4
LT
1217 }
1218
1219 len = INITCONTEXTLEN;
4cb912f1 1220 context = kmalloc(len+1, GFP_NOFS);
1da177e4
LT
1221 if (!context) {
1222 rc = -ENOMEM;
1223 dput(dentry);
23970741 1224 goto out_unlock;
1da177e4 1225 }
4cb912f1 1226 context[len] = '\0';
1da177e4
LT
1227 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
1228 context, len);
1229 if (rc == -ERANGE) {
314dabb8
JM
1230 kfree(context);
1231
1da177e4
LT
1232 /* Need a larger buffer. Query for the right size. */
1233 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
1234 NULL, 0);
1235 if (rc < 0) {
1236 dput(dentry);
23970741 1237 goto out_unlock;
1da177e4 1238 }
1da177e4 1239 len = rc;
4cb912f1 1240 context = kmalloc(len+1, GFP_NOFS);
1da177e4
LT
1241 if (!context) {
1242 rc = -ENOMEM;
1243 dput(dentry);
23970741 1244 goto out_unlock;
1da177e4 1245 }
4cb912f1 1246 context[len] = '\0';
1da177e4
LT
1247 rc = inode->i_op->getxattr(dentry,
1248 XATTR_NAME_SELINUX,
1249 context, len);
1250 }
1251 dput(dentry);
1252 if (rc < 0) {
1253 if (rc != -ENODATA) {
744ba35e 1254 printk(KERN_WARNING "SELinux: %s: getxattr returned "
dd6f953a 1255 "%d for dev=%s ino=%ld\n", __func__,
1da177e4
LT
1256 -rc, inode->i_sb->s_id, inode->i_ino);
1257 kfree(context);
23970741 1258 goto out_unlock;
1da177e4
LT
1259 }
1260 /* Map ENODATA to the default file SID */
1261 sid = sbsec->def_sid;
1262 rc = 0;
1263 } else {
f5c1d5b2 1264 rc = security_context_to_sid_default(context, rc, &sid,
869ab514
SS
1265 sbsec->def_sid,
1266 GFP_NOFS);
1da177e4 1267 if (rc) {
4ba0a8ad
EP
1268 char *dev = inode->i_sb->s_id;
1269 unsigned long ino = inode->i_ino;
1270
1271 if (rc == -EINVAL) {
1272 if (printk_ratelimit())
1273 printk(KERN_NOTICE "SELinux: inode=%lu on dev=%s was found to have an invalid "
1274 "context=%s. This indicates you may need to relabel the inode or the "
1275 "filesystem in question.\n", ino, dev, context);
1276 } else {
1277 printk(KERN_WARNING "SELinux: %s: context_to_sid(%s) "
1278 "returned %d for dev=%s ino=%ld\n",
1279 __func__, context, -rc, dev, ino);
1280 }
1da177e4
LT
1281 kfree(context);
1282 /* Leave with the unlabeled SID */
1283 rc = 0;
1284 break;
1285 }
1286 }
1287 kfree(context);
1288 isec->sid = sid;
1289 break;
1290 case SECURITY_FS_USE_TASK:
1291 isec->sid = isec->task_sid;
1292 break;
1293 case SECURITY_FS_USE_TRANS:
1294 /* Default to the fs SID. */
1295 isec->sid = sbsec->sid;
1296
1297 /* Try to obtain a transition SID. */
1298 isec->sclass = inode_mode_to_security_class(inode->i_mode);
652bb9b0
EP
1299 rc = security_transition_sid(isec->task_sid, sbsec->sid,
1300 isec->sclass, NULL, &sid);
1da177e4 1301 if (rc)
23970741 1302 goto out_unlock;
1da177e4
LT
1303 isec->sid = sid;
1304 break;
c312feb2
EP
1305 case SECURITY_FS_USE_MNTPOINT:
1306 isec->sid = sbsec->mntpoint_sid;
1307 break;
1da177e4 1308 default:
c312feb2 1309 /* Default to the fs superblock SID. */
1da177e4
LT
1310 isec->sid = sbsec->sid;
1311
0d90a7ec 1312 if ((sbsec->flags & SE_SBPROC) && !S_ISLNK(inode->i_mode)) {
8e6c9693 1313 if (opt_dentry) {
1da177e4 1314 isec->sclass = inode_mode_to_security_class(inode->i_mode);
8e6c9693 1315 rc = selinux_proc_get_sid(opt_dentry,
1da177e4
LT
1316 isec->sclass,
1317 &sid);
1318 if (rc)
23970741 1319 goto out_unlock;
1da177e4
LT
1320 isec->sid = sid;
1321 }
1322 }
1323 break;
1324 }
1325
1326 isec->initialized = 1;
1327
23970741
EP
1328out_unlock:
1329 mutex_unlock(&isec->lock);
1da177e4
LT
1330out:
1331 if (isec->sclass == SECCLASS_FILE)
1332 isec->sclass = inode_mode_to_security_class(inode->i_mode);
1da177e4
LT
1333 return rc;
1334}
1335
1336/* Convert a Linux signal to an access vector. */
1337static inline u32 signal_to_av(int sig)
1338{
1339 u32 perm = 0;
1340
1341 switch (sig) {
1342 case SIGCHLD:
1343 /* Commonly granted from child to parent. */
1344 perm = PROCESS__SIGCHLD;
1345 break;
1346 case SIGKILL:
1347 /* Cannot be caught or ignored */
1348 perm = PROCESS__SIGKILL;
1349 break;
1350 case SIGSTOP:
1351 /* Cannot be caught or ignored */
1352 perm = PROCESS__SIGSTOP;
1353 break;
1354 default:
1355 /* All other signals. */
1356 perm = PROCESS__SIGNAL;
1357 break;
1358 }
1359
1360 return perm;
1361}
1362
d84f4f99
DH
1363/*
1364 * Check permission between a pair of credentials
1365 * fork check, ptrace check, etc.
1366 */
1367static int cred_has_perm(const struct cred *actor,
1368 const struct cred *target,
1369 u32 perms)
1370{
1371 u32 asid = cred_sid(actor), tsid = cred_sid(target);
1372
1373 return avc_has_perm(asid, tsid, SECCLASS_PROCESS, perms, NULL);
1374}
1375
275bb41e 1376/*
88e67f3b 1377 * Check permission between a pair of tasks, e.g. signal checks,
275bb41e
DH
1378 * fork check, ptrace check, etc.
1379 * tsk1 is the actor and tsk2 is the target
3b11a1de 1380 * - this uses the default subjective creds of tsk1
275bb41e
DH
1381 */
1382static int task_has_perm(const struct task_struct *tsk1,
1383 const struct task_struct *tsk2,
1da177e4
LT
1384 u32 perms)
1385{
275bb41e
DH
1386 const struct task_security_struct *__tsec1, *__tsec2;
1387 u32 sid1, sid2;
1da177e4 1388
275bb41e
DH
1389 rcu_read_lock();
1390 __tsec1 = __task_cred(tsk1)->security; sid1 = __tsec1->sid;
1391 __tsec2 = __task_cred(tsk2)->security; sid2 = __tsec2->sid;
1392 rcu_read_unlock();
1393 return avc_has_perm(sid1, sid2, SECCLASS_PROCESS, perms, NULL);
1da177e4
LT
1394}
1395
3b11a1de
DH
1396/*
1397 * Check permission between current and another task, e.g. signal checks,
1398 * fork check, ptrace check, etc.
1399 * current is the actor and tsk2 is the target
1400 * - this uses current's subjective creds
1401 */
1402static int current_has_perm(const struct task_struct *tsk,
1403 u32 perms)
1404{
1405 u32 sid, tsid;
1406
1407 sid = current_sid();
1408 tsid = task_sid(tsk);
1409 return avc_has_perm(sid, tsid, SECCLASS_PROCESS, perms, NULL);
1410}
1411
b68e418c
SS
1412#if CAP_LAST_CAP > 63
1413#error Fix SELinux to handle capabilities > 63.
1414#endif
1415
1da177e4
LT
1416/* Check whether a task is allowed to use a capability. */
1417static int task_has_capability(struct task_struct *tsk,
3699c53c 1418 const struct cred *cred,
06112163 1419 int cap, int audit)
1da177e4 1420{
2bf49690 1421 struct common_audit_data ad;
06112163 1422 struct av_decision avd;
b68e418c 1423 u16 sclass;
3699c53c 1424 u32 sid = cred_sid(cred);
b68e418c 1425 u32 av = CAP_TO_MASK(cap);
06112163 1426 int rc;
1da177e4 1427
2bf49690 1428 COMMON_AUDIT_DATA_INIT(&ad, CAP);
1da177e4
LT
1429 ad.tsk = tsk;
1430 ad.u.cap = cap;
1431
b68e418c
SS
1432 switch (CAP_TO_INDEX(cap)) {
1433 case 0:
1434 sclass = SECCLASS_CAPABILITY;
1435 break;
1436 case 1:
1437 sclass = SECCLASS_CAPABILITY2;
1438 break;
1439 default:
1440 printk(KERN_ERR
1441 "SELinux: out of range capability %d\n", cap);
1442 BUG();
a35c6c83 1443 return -EINVAL;
b68e418c 1444 }
06112163 1445
275bb41e 1446 rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd);
9ade0cf4
EP
1447 if (audit == SECURITY_CAP_AUDIT) {
1448 int rc2 = avc_audit(sid, sid, sclass, av, &avd, rc, &ad, 0);
1449 if (rc2)
1450 return rc2;
1451 }
06112163 1452 return rc;
1da177e4
LT
1453}
1454
1455/* Check whether a task is allowed to use a system operation. */
1456static int task_has_system(struct task_struct *tsk,
1457 u32 perms)
1458{
275bb41e 1459 u32 sid = task_sid(tsk);
1da177e4 1460
275bb41e 1461 return avc_has_perm(sid, SECINITSID_KERNEL,
1da177e4
LT
1462 SECCLASS_SYSTEM, perms, NULL);
1463}
1464
1465/* Check whether a task has a particular permission to an inode.
1466 The 'adp' parameter is optional and allows other audit
1467 data to be passed (e.g. the dentry). */
88e67f3b 1468static int inode_has_perm(const struct cred *cred,
1da177e4
LT
1469 struct inode *inode,
1470 u32 perms,
9ade0cf4
EP
1471 struct common_audit_data *adp,
1472 unsigned flags)
1da177e4 1473{
1da177e4 1474 struct inode_security_struct *isec;
275bb41e 1475 u32 sid;
1da177e4 1476
e0e81739
DH
1477 validate_creds(cred);
1478
828dfe1d 1479 if (unlikely(IS_PRIVATE(inode)))
bbaca6c2
SS
1480 return 0;
1481
88e67f3b 1482 sid = cred_sid(cred);
1da177e4
LT
1483 isec = inode->i_security;
1484
9ade0cf4 1485 return avc_has_perm_flags(sid, isec->sid, isec->sclass, perms, adp, flags);
1da177e4
LT
1486}
1487
95f4efb2
LT
1488static int inode_has_perm_noadp(const struct cred *cred,
1489 struct inode *inode,
1490 u32 perms,
1491 unsigned flags)
1492{
1493 struct common_audit_data ad;
1494
1495 COMMON_AUDIT_DATA_INIT(&ad, INODE);
1496 ad.u.inode = inode;
1497 return inode_has_perm(cred, inode, perms, &ad, flags);
1498}
1499
1da177e4
LT
1500/* Same as inode_has_perm, but pass explicit audit data containing
1501 the dentry to help the auditing code to more easily generate the
1502 pathname if needed. */
88e67f3b 1503static inline int dentry_has_perm(const struct cred *cred,
1da177e4
LT
1504 struct dentry *dentry,
1505 u32 av)
1506{
1507 struct inode *inode = dentry->d_inode;
2bf49690 1508 struct common_audit_data ad;
88e67f3b 1509
2875fa00
EP
1510 COMMON_AUDIT_DATA_INIT(&ad, DENTRY);
1511 ad.u.dentry = dentry;
1512 return inode_has_perm(cred, inode, av, &ad, 0);
1513}
1514
1515/* Same as inode_has_perm, but pass explicit audit data containing
1516 the path to help the auditing code to more easily generate the
1517 pathname if needed. */
1518static inline int path_has_perm(const struct cred *cred,
1519 struct path *path,
1520 u32 av)
1521{
1522 struct inode *inode = path->dentry->d_inode;
1523 struct common_audit_data ad;
1524
f48b7399 1525 COMMON_AUDIT_DATA_INIT(&ad, PATH);
2875fa00 1526 ad.u.path = *path;
9ade0cf4 1527 return inode_has_perm(cred, inode, av, &ad, 0);
1da177e4
LT
1528}
1529
1530/* Check whether a task can use an open file descriptor to
1531 access an inode in a given way. Check access to the
1532 descriptor itself, and then use dentry_has_perm to
1533 check a particular permission to the file.
1534 Access to the descriptor is implicitly granted if it
1535 has the same SID as the process. If av is zero, then
1536 access to the file is not checked, e.g. for cases
1537 where only the descriptor is affected like seek. */
88e67f3b
DH
1538static int file_has_perm(const struct cred *cred,
1539 struct file *file,
1540 u32 av)
1da177e4 1541{
1da177e4 1542 struct file_security_struct *fsec = file->f_security;
44707fdf 1543 struct inode *inode = file->f_path.dentry->d_inode;
2bf49690 1544 struct common_audit_data ad;
88e67f3b 1545 u32 sid = cred_sid(cred);
1da177e4
LT
1546 int rc;
1547
f48b7399
EP
1548 COMMON_AUDIT_DATA_INIT(&ad, PATH);
1549 ad.u.path = file->f_path;
1da177e4 1550
275bb41e
DH
1551 if (sid != fsec->sid) {
1552 rc = avc_has_perm(sid, fsec->sid,
1da177e4
LT
1553 SECCLASS_FD,
1554 FD__USE,
1555 &ad);
1556 if (rc)
88e67f3b 1557 goto out;
1da177e4
LT
1558 }
1559
1560 /* av is zero if only checking access to the descriptor. */
88e67f3b 1561 rc = 0;
1da177e4 1562 if (av)
9ade0cf4 1563 rc = inode_has_perm(cred, inode, av, &ad, 0);
1da177e4 1564
88e67f3b
DH
1565out:
1566 return rc;
1da177e4
LT
1567}
1568
1569/* Check whether a task can create a file. */
1570static int may_create(struct inode *dir,
1571 struct dentry *dentry,
1572 u16 tclass)
1573{
5fb49870 1574 const struct task_security_struct *tsec = current_security();
1da177e4
LT
1575 struct inode_security_struct *dsec;
1576 struct superblock_security_struct *sbsec;
275bb41e 1577 u32 sid, newsid;
2bf49690 1578 struct common_audit_data ad;
1da177e4
LT
1579 int rc;
1580
1da177e4
LT
1581 dsec = dir->i_security;
1582 sbsec = dir->i_sb->s_security;
1583
275bb41e
DH
1584 sid = tsec->sid;
1585 newsid = tsec->create_sid;
1586
a269434d
EP
1587 COMMON_AUDIT_DATA_INIT(&ad, DENTRY);
1588 ad.u.dentry = dentry;
1da177e4 1589
275bb41e 1590 rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR,
1da177e4
LT
1591 DIR__ADD_NAME | DIR__SEARCH,
1592 &ad);
1593 if (rc)
1594 return rc;
1595
cd89596f 1596 if (!newsid || !(sbsec->flags & SE_SBLABELSUPP)) {
cb1e922f
EP
1597 rc = security_transition_sid(sid, dsec->sid, tclass,
1598 &dentry->d_name, &newsid);
1da177e4
LT
1599 if (rc)
1600 return rc;
1601 }
1602
275bb41e 1603 rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad);
1da177e4
LT
1604 if (rc)
1605 return rc;
1606
1607 return avc_has_perm(newsid, sbsec->sid,
1608 SECCLASS_FILESYSTEM,
1609 FILESYSTEM__ASSOCIATE, &ad);
1610}
1611
4eb582cf
ML
1612/* Check whether a task can create a key. */
1613static int may_create_key(u32 ksid,
1614 struct task_struct *ctx)
1615{
275bb41e 1616 u32 sid = task_sid(ctx);
4eb582cf 1617
275bb41e 1618 return avc_has_perm(sid, ksid, SECCLASS_KEY, KEY__CREATE, NULL);
4eb582cf
ML
1619}
1620
828dfe1d
EP
1621#define MAY_LINK 0
1622#define MAY_UNLINK 1
1623#define MAY_RMDIR 2
1da177e4
LT
1624
1625/* Check whether a task can link, unlink, or rmdir a file/directory. */
1626static int may_link(struct inode *dir,
1627 struct dentry *dentry,
1628 int kind)
1629
1630{
1da177e4 1631 struct inode_security_struct *dsec, *isec;
2bf49690 1632 struct common_audit_data ad;
275bb41e 1633 u32 sid = current_sid();
1da177e4
LT
1634 u32 av;
1635 int rc;
1636
1da177e4
LT
1637 dsec = dir->i_security;
1638 isec = dentry->d_inode->i_security;
1639
a269434d
EP
1640 COMMON_AUDIT_DATA_INIT(&ad, DENTRY);
1641 ad.u.dentry = dentry;
1da177e4
LT
1642
1643 av = DIR__SEARCH;
1644 av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
275bb41e 1645 rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, av, &ad);
1da177e4
LT
1646 if (rc)
1647 return rc;
1648
1649 switch (kind) {
1650 case MAY_LINK:
1651 av = FILE__LINK;
1652 break;
1653 case MAY_UNLINK:
1654 av = FILE__UNLINK;
1655 break;
1656 case MAY_RMDIR:
1657 av = DIR__RMDIR;
1658 break;
1659 default:
744ba35e
EP
1660 printk(KERN_WARNING "SELinux: %s: unrecognized kind %d\n",
1661 __func__, kind);
1da177e4
LT
1662 return 0;
1663 }
1664
275bb41e 1665 rc = avc_has_perm(sid, isec->sid, isec->sclass, av, &ad);
1da177e4
LT
1666 return rc;
1667}
1668
1669static inline int may_rename(struct inode *old_dir,
1670 struct dentry *old_dentry,
1671 struct inode *new_dir,
1672 struct dentry *new_dentry)
1673{
1da177e4 1674 struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec;
2bf49690 1675 struct common_audit_data ad;
275bb41e 1676 u32 sid = current_sid();
1da177e4
LT
1677 u32 av;
1678 int old_is_dir, new_is_dir;
1679 int rc;
1680
1da177e4
LT
1681 old_dsec = old_dir->i_security;
1682 old_isec = old_dentry->d_inode->i_security;
1683 old_is_dir = S_ISDIR(old_dentry->d_inode->i_mode);
1684 new_dsec = new_dir->i_security;
1685
a269434d 1686 COMMON_AUDIT_DATA_INIT(&ad, DENTRY);
1da177e4 1687
a269434d 1688 ad.u.dentry = old_dentry;
275bb41e 1689 rc = avc_has_perm(sid, old_dsec->sid, SECCLASS_DIR,
1da177e4
LT
1690 DIR__REMOVE_NAME | DIR__SEARCH, &ad);
1691 if (rc)
1692 return rc;
275bb41e 1693 rc = avc_has_perm(sid, old_isec->sid,
1da177e4
LT
1694 old_isec->sclass, FILE__RENAME, &ad);
1695 if (rc)
1696 return rc;
1697 if (old_is_dir && new_dir != old_dir) {
275bb41e 1698 rc = avc_has_perm(sid, old_isec->sid,
1da177e4
LT
1699 old_isec->sclass, DIR__REPARENT, &ad);
1700 if (rc)
1701 return rc;
1702 }
1703
a269434d 1704 ad.u.dentry = new_dentry;
1da177e4
LT
1705 av = DIR__ADD_NAME | DIR__SEARCH;
1706 if (new_dentry->d_inode)
1707 av |= DIR__REMOVE_NAME;
275bb41e 1708 rc = avc_has_perm(sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
1da177e4
LT
1709 if (rc)
1710 return rc;
1711 if (new_dentry->d_inode) {
1712 new_isec = new_dentry->d_inode->i_security;
1713 new_is_dir = S_ISDIR(new_dentry->d_inode->i_mode);
275bb41e 1714 rc = avc_has_perm(sid, new_isec->sid,
1da177e4
LT
1715 new_isec->sclass,
1716 (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad);
1717 if (rc)
1718 return rc;
1719 }
1720
1721 return 0;
1722}
1723
1724/* Check whether a task can perform a filesystem operation. */
88e67f3b 1725static int superblock_has_perm(const struct cred *cred,
1da177e4
LT
1726 struct super_block *sb,
1727 u32 perms,
2bf49690 1728 struct common_audit_data *ad)
1da177e4 1729{
1da177e4 1730 struct superblock_security_struct *sbsec;
88e67f3b 1731 u32 sid = cred_sid(cred);
1da177e4 1732
1da177e4 1733 sbsec = sb->s_security;
275bb41e 1734 return avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad);
1da177e4
LT
1735}
1736
1737/* Convert a Linux mode and permission mask to an access vector. */
1738static inline u32 file_mask_to_av(int mode, int mask)
1739{
1740 u32 av = 0;
1741
1742 if ((mode & S_IFMT) != S_IFDIR) {
1743 if (mask & MAY_EXEC)
1744 av |= FILE__EXECUTE;
1745 if (mask & MAY_READ)
1746 av |= FILE__READ;
1747
1748 if (mask & MAY_APPEND)
1749 av |= FILE__APPEND;
1750 else if (mask & MAY_WRITE)
1751 av |= FILE__WRITE;
1752
1753 } else {
1754 if (mask & MAY_EXEC)
1755 av |= DIR__SEARCH;
1756 if (mask & MAY_WRITE)
1757 av |= DIR__WRITE;
1758 if (mask & MAY_READ)
1759 av |= DIR__READ;
1760 }
1761
1762 return av;
1763}
1764
8b6a5a37
EP
1765/* Convert a Linux file to an access vector. */
1766static inline u32 file_to_av(struct file *file)
1767{
1768 u32 av = 0;
1769
1770 if (file->f_mode & FMODE_READ)
1771 av |= FILE__READ;
1772 if (file->f_mode & FMODE_WRITE) {
1773 if (file->f_flags & O_APPEND)
1774 av |= FILE__APPEND;
1775 else
1776 av |= FILE__WRITE;
1777 }
1778 if (!av) {
1779 /*
1780 * Special file opened with flags 3 for ioctl-only use.
1781 */
1782 av = FILE__IOCTL;
1783 }
1784
1785 return av;
1786}
1787
b0c636b9 1788/*
8b6a5a37 1789 * Convert a file to an access vector and include the correct open
b0c636b9
EP
1790 * open permission.
1791 */
8b6a5a37 1792static inline u32 open_file_to_av(struct file *file)
b0c636b9 1793{
8b6a5a37 1794 u32 av = file_to_av(file);
b0c636b9 1795
49b7b8de
EP
1796 if (selinux_policycap_openperm)
1797 av |= FILE__OPEN;
1798
b0c636b9
EP
1799 return av;
1800}
1801
1da177e4
LT
1802/* Hook functions begin here. */
1803
9e48858f 1804static int selinux_ptrace_access_check(struct task_struct *child,
5cd9c58f 1805 unsigned int mode)
1da177e4 1806{
1da177e4
LT
1807 int rc;
1808
9e48858f 1809 rc = cap_ptrace_access_check(child, mode);
1da177e4
LT
1810 if (rc)
1811 return rc;
1812
006ebb40 1813 if (mode == PTRACE_MODE_READ) {
275bb41e
DH
1814 u32 sid = current_sid();
1815 u32 csid = task_sid(child);
1816 return avc_has_perm(sid, csid, SECCLASS_FILE, FILE__READ, NULL);
006ebb40
SS
1817 }
1818
3b11a1de 1819 return current_has_perm(child, PROCESS__PTRACE);
5cd9c58f
DH
1820}
1821
1822static int selinux_ptrace_traceme(struct task_struct *parent)
1823{
1824 int rc;
1825
200ac532 1826 rc = cap_ptrace_traceme(parent);
5cd9c58f
DH
1827 if (rc)
1828 return rc;
1829
1830 return task_has_perm(parent, current, PROCESS__PTRACE);
1da177e4
LT
1831}
1832
1833static int selinux_capget(struct task_struct *target, kernel_cap_t *effective,
828dfe1d 1834 kernel_cap_t *inheritable, kernel_cap_t *permitted)
1da177e4
LT
1835{
1836 int error;
1837
3b11a1de 1838 error = current_has_perm(target, PROCESS__GETCAP);
1da177e4
LT
1839 if (error)
1840 return error;
1841
200ac532 1842 return cap_capget(target, effective, inheritable, permitted);
1da177e4
LT
1843}
1844
d84f4f99
DH
1845static int selinux_capset(struct cred *new, const struct cred *old,
1846 const kernel_cap_t *effective,
1847 const kernel_cap_t *inheritable,
1848 const kernel_cap_t *permitted)
1da177e4
LT
1849{
1850 int error;
1851
200ac532 1852 error = cap_capset(new, old,
d84f4f99 1853 effective, inheritable, permitted);
1da177e4
LT
1854 if (error)
1855 return error;
1856
d84f4f99 1857 return cred_has_perm(old, new, PROCESS__SETCAP);
1da177e4
LT
1858}
1859
5626d3e8
JM
1860/*
1861 * (This comment used to live with the selinux_task_setuid hook,
1862 * which was removed).
1863 *
1864 * Since setuid only affects the current process, and since the SELinux
1865 * controls are not based on the Linux identity attributes, SELinux does not
1866 * need to control this operation. However, SELinux does control the use of
1867 * the CAP_SETUID and CAP_SETGID capabilities using the capable hook.
1868 */
1869
3699c53c 1870static int selinux_capable(struct task_struct *tsk, const struct cred *cred,
3486740a 1871 struct user_namespace *ns, int cap, int audit)
1da177e4
LT
1872{
1873 int rc;
1874
3486740a 1875 rc = cap_capable(tsk, cred, ns, cap, audit);
1da177e4
LT
1876 if (rc)
1877 return rc;
1878
3699c53c 1879 return task_has_capability(tsk, cred, cap, audit);
1da177e4
LT
1880}
1881
1da177e4
LT
1882static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb)
1883{
88e67f3b 1884 const struct cred *cred = current_cred();
1da177e4
LT
1885 int rc = 0;
1886
1887 if (!sb)
1888 return 0;
1889
1890 switch (cmds) {
828dfe1d
EP
1891 case Q_SYNC:
1892 case Q_QUOTAON:
1893 case Q_QUOTAOFF:
1894 case Q_SETINFO:
1895 case Q_SETQUOTA:
88e67f3b 1896 rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAMOD, NULL);
828dfe1d
EP
1897 break;
1898 case Q_GETFMT:
1899 case Q_GETINFO:
1900 case Q_GETQUOTA:
88e67f3b 1901 rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAGET, NULL);
828dfe1d
EP
1902 break;
1903 default:
1904 rc = 0; /* let the kernel handle invalid cmds */
1905 break;
1da177e4
LT
1906 }
1907 return rc;
1908}
1909
1910static int selinux_quota_on(struct dentry *dentry)
1911{
88e67f3b
DH
1912 const struct cred *cred = current_cred();
1913
2875fa00 1914 return dentry_has_perm(cred, dentry, FILE__QUOTAON);
1da177e4
LT
1915}
1916
12b3052c 1917static int selinux_syslog(int type)
1da177e4
LT
1918{
1919 int rc;
1920
1da177e4 1921 switch (type) {
d78ca3cd
KC
1922 case SYSLOG_ACTION_READ_ALL: /* Read last kernel messages */
1923 case SYSLOG_ACTION_SIZE_BUFFER: /* Return size of the log buffer */
828dfe1d
EP
1924 rc = task_has_system(current, SYSTEM__SYSLOG_READ);
1925 break;
d78ca3cd
KC
1926 case SYSLOG_ACTION_CONSOLE_OFF: /* Disable logging to console */
1927 case SYSLOG_ACTION_CONSOLE_ON: /* Enable logging to console */
1928 /* Set level of messages printed to console */
1929 case SYSLOG_ACTION_CONSOLE_LEVEL:
828dfe1d
EP
1930 rc = task_has_system(current, SYSTEM__SYSLOG_CONSOLE);
1931 break;
d78ca3cd
KC
1932 case SYSLOG_ACTION_CLOSE: /* Close log */
1933 case SYSLOG_ACTION_OPEN: /* Open log */
1934 case SYSLOG_ACTION_READ: /* Read from log */
1935 case SYSLOG_ACTION_READ_CLEAR: /* Read/clear last kernel messages */
1936 case SYSLOG_ACTION_CLEAR: /* Clear ring buffer */
828dfe1d
EP
1937 default:
1938 rc = task_has_system(current, SYSTEM__SYSLOG_MOD);
1939 break;
1da177e4
LT
1940 }
1941 return rc;
1942}
1943
1944/*
1945 * Check that a process has enough memory to allocate a new virtual
1946 * mapping. 0 means there is enough memory for the allocation to
1947 * succeed and -ENOMEM implies there is not.
1948 *
1da177e4
LT
1949 * Do not audit the selinux permission check, as this is applied to all
1950 * processes that allocate mappings.
1951 */
34b4e4aa 1952static int selinux_vm_enough_memory(struct mm_struct *mm, long pages)
1da177e4
LT
1953{
1954 int rc, cap_sys_admin = 0;
1da177e4 1955
3486740a
SH
1956 rc = selinux_capable(current, current_cred(),
1957 &init_user_ns, CAP_SYS_ADMIN,
3699c53c 1958 SECURITY_CAP_NOAUDIT);
1da177e4
LT
1959 if (rc == 0)
1960 cap_sys_admin = 1;
1961
34b4e4aa 1962 return __vm_enough_memory(mm, pages, cap_sys_admin);
1da177e4
LT
1963}
1964
1965/* binprm security operations */
1966
a6f76f23 1967static int selinux_bprm_set_creds(struct linux_binprm *bprm)
1da177e4 1968{
a6f76f23
DH
1969 const struct task_security_struct *old_tsec;
1970 struct task_security_struct *new_tsec;
1da177e4 1971 struct inode_security_struct *isec;
2bf49690 1972 struct common_audit_data ad;
a6f76f23 1973 struct inode *inode = bprm->file->f_path.dentry->d_inode;
1da177e4
LT
1974 int rc;
1975
200ac532 1976 rc = cap_bprm_set_creds(bprm);
1da177e4
LT
1977 if (rc)
1978 return rc;
1979
a6f76f23
DH
1980 /* SELinux context only depends on initial program or script and not
1981 * the script interpreter */
1982 if (bprm->cred_prepared)
1da177e4
LT
1983 return 0;
1984
a6f76f23
DH
1985 old_tsec = current_security();
1986 new_tsec = bprm->cred->security;
1da177e4
LT
1987 isec = inode->i_security;
1988
1989 /* Default to the current task SID. */
a6f76f23
DH
1990 new_tsec->sid = old_tsec->sid;
1991 new_tsec->osid = old_tsec->sid;
1da177e4 1992
28eba5bf 1993 /* Reset fs, key, and sock SIDs on execve. */
a6f76f23
DH
1994 new_tsec->create_sid = 0;
1995 new_tsec->keycreate_sid = 0;
1996 new_tsec->sockcreate_sid = 0;
1da177e4 1997
a6f76f23
DH
1998 if (old_tsec->exec_sid) {
1999 new_tsec->sid = old_tsec->exec_sid;
1da177e4 2000 /* Reset exec SID on execve. */
a6f76f23 2001 new_tsec->exec_sid = 0;
1da177e4
LT
2002 } else {
2003 /* Check for a default transition on this program. */
a6f76f23 2004 rc = security_transition_sid(old_tsec->sid, isec->sid,
652bb9b0
EP
2005 SECCLASS_PROCESS, NULL,
2006 &new_tsec->sid);
1da177e4
LT
2007 if (rc)
2008 return rc;
2009 }
2010
f48b7399
EP
2011 COMMON_AUDIT_DATA_INIT(&ad, PATH);
2012 ad.u.path = bprm->file->f_path;
1da177e4 2013
3d5ff529 2014 if (bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID)
a6f76f23 2015 new_tsec->sid = old_tsec->sid;
1da177e4 2016
a6f76f23
DH
2017 if (new_tsec->sid == old_tsec->sid) {
2018 rc = avc_has_perm(old_tsec->sid, isec->sid,
1da177e4
LT
2019 SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
2020 if (rc)
2021 return rc;
2022 } else {
2023 /* Check permissions for the transition. */
a6f76f23 2024 rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
1da177e4
LT
2025 SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
2026 if (rc)
2027 return rc;
2028
a6f76f23 2029 rc = avc_has_perm(new_tsec->sid, isec->sid,
1da177e4
LT
2030 SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
2031 if (rc)
2032 return rc;
2033
a6f76f23
DH
2034 /* Check for shared state */
2035 if (bprm->unsafe & LSM_UNSAFE_SHARE) {
2036 rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2037 SECCLASS_PROCESS, PROCESS__SHARE,
2038 NULL);
2039 if (rc)
2040 return -EPERM;
2041 }
2042
2043 /* Make sure that anyone attempting to ptrace over a task that
2044 * changes its SID has the appropriate permit */
2045 if (bprm->unsafe &
2046 (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) {
2047 struct task_struct *tracer;
2048 struct task_security_struct *sec;
2049 u32 ptsid = 0;
2050
2051 rcu_read_lock();
06d98473 2052 tracer = ptrace_parent(current);
a6f76f23
DH
2053 if (likely(tracer != NULL)) {
2054 sec = __task_cred(tracer)->security;
2055 ptsid = sec->sid;
2056 }
2057 rcu_read_unlock();
2058
2059 if (ptsid != 0) {
2060 rc = avc_has_perm(ptsid, new_tsec->sid,
2061 SECCLASS_PROCESS,
2062 PROCESS__PTRACE, NULL);
2063 if (rc)
2064 return -EPERM;
2065 }
2066 }
1da177e4 2067
a6f76f23
DH
2068 /* Clear any possibly unsafe personality bits on exec: */
2069 bprm->per_clear |= PER_CLEAR_ON_SETID;
1da177e4
LT
2070 }
2071
1da177e4
LT
2072 return 0;
2073}
2074
828dfe1d 2075static int selinux_bprm_secureexec(struct linux_binprm *bprm)
1da177e4 2076{
5fb49870 2077 const struct task_security_struct *tsec = current_security();
275bb41e 2078 u32 sid, osid;
1da177e4
LT
2079 int atsecure = 0;
2080
275bb41e
DH
2081 sid = tsec->sid;
2082 osid = tsec->osid;
2083
2084 if (osid != sid) {
1da177e4
LT
2085 /* Enable secure mode for SIDs transitions unless
2086 the noatsecure permission is granted between
2087 the two SIDs, i.e. ahp returns 0. */
275bb41e 2088 atsecure = avc_has_perm(osid, sid,
a6f76f23
DH
2089 SECCLASS_PROCESS,
2090 PROCESS__NOATSECURE, NULL);
1da177e4
LT
2091 }
2092
200ac532 2093 return (atsecure || cap_bprm_secureexec(bprm));
1da177e4
LT
2094}
2095
1da177e4 2096/* Derived from fs/exec.c:flush_old_files. */
745ca247
DH
2097static inline void flush_unauthorized_files(const struct cred *cred,
2098 struct files_struct *files)
1da177e4 2099{
2bf49690 2100 struct common_audit_data ad;
1da177e4 2101 struct file *file, *devnull = NULL;
b20c8122 2102 struct tty_struct *tty;
badf1662 2103 struct fdtable *fdt;
1da177e4 2104 long j = -1;
24ec839c 2105 int drop_tty = 0;
1da177e4 2106
24ec839c 2107 tty = get_current_tty();
1da177e4 2108 if (tty) {
ee2ffa0d 2109 spin_lock(&tty_files_lock);
37dd0bd0 2110 if (!list_empty(&tty->tty_files)) {
d996b62a 2111 struct tty_file_private *file_priv;
37dd0bd0
EP
2112 struct inode *inode;
2113
1da177e4
LT
2114 /* Revalidate access to controlling tty.
2115 Use inode_has_perm on the tty inode directly rather
2116 than using file_has_perm, as this particular open
2117 file may belong to another process and we are only
2118 interested in the inode-based check here. */
d996b62a
NP
2119 file_priv = list_first_entry(&tty->tty_files,
2120 struct tty_file_private, list);
2121 file = file_priv->file;
37dd0bd0 2122 inode = file->f_path.dentry->d_inode;
95f4efb2
LT
2123 if (inode_has_perm_noadp(cred, inode,
2124 FILE__READ | FILE__WRITE, 0)) {
24ec839c 2125 drop_tty = 1;
1da177e4
LT
2126 }
2127 }
ee2ffa0d 2128 spin_unlock(&tty_files_lock);
452a00d2 2129 tty_kref_put(tty);
1da177e4 2130 }
98a27ba4
EB
2131 /* Reset controlling tty. */
2132 if (drop_tty)
2133 no_tty();
1da177e4
LT
2134
2135 /* Revalidate access to inherited open files. */
2136
f48b7399 2137 COMMON_AUDIT_DATA_INIT(&ad, INODE);
1da177e4
LT
2138
2139 spin_lock(&files->file_lock);
2140 for (;;) {
2141 unsigned long set, i;
2142 int fd;
2143
2144 j++;
2145 i = j * __NFDBITS;
badf1662 2146 fdt = files_fdtable(files);
bbea9f69 2147 if (i >= fdt->max_fds)
1da177e4 2148 break;
badf1662 2149 set = fdt->open_fds->fds_bits[j];
1da177e4
LT
2150 if (!set)
2151 continue;
2152 spin_unlock(&files->file_lock);
828dfe1d 2153 for ( ; set ; i++, set >>= 1) {
1da177e4
LT
2154 if (set & 1) {
2155 file = fget(i);
2156 if (!file)
2157 continue;
88e67f3b 2158 if (file_has_perm(cred,
1da177e4
LT
2159 file,
2160 file_to_av(file))) {
2161 sys_close(i);
2162 fd = get_unused_fd();
2163 if (fd != i) {
2164 if (fd >= 0)
2165 put_unused_fd(fd);
2166 fput(file);
2167 continue;
2168 }
2169 if (devnull) {
095975da 2170 get_file(devnull);
1da177e4 2171 } else {
745ca247
DH
2172 devnull = dentry_open(
2173 dget(selinux_null),
2174 mntget(selinuxfs_mount),
2175 O_RDWR, cred);
fc5d81e6
AM
2176 if (IS_ERR(devnull)) {
2177 devnull = NULL;
1da177e4
LT
2178 put_unused_fd(fd);
2179 fput(file);
2180 continue;
2181 }
2182 }
2183 fd_install(fd, devnull);
2184 }
2185 fput(file);
2186 }
2187 }
2188 spin_lock(&files->file_lock);
2189
2190 }
2191 spin_unlock(&files->file_lock);
2192}
2193
a6f76f23
DH
2194/*
2195 * Prepare a process for imminent new credential changes due to exec
2196 */
2197static void selinux_bprm_committing_creds(struct linux_binprm *bprm)
1da177e4 2198{
a6f76f23
DH
2199 struct task_security_struct *new_tsec;
2200 struct rlimit *rlim, *initrlim;
2201 int rc, i;
d84f4f99 2202
a6f76f23
DH
2203 new_tsec = bprm->cred->security;
2204 if (new_tsec->sid == new_tsec->osid)
2205 return;
1da177e4 2206
a6f76f23
DH
2207 /* Close files for which the new task SID is not authorized. */
2208 flush_unauthorized_files(bprm->cred, current->files);
0356357c 2209
a6f76f23
DH
2210 /* Always clear parent death signal on SID transitions. */
2211 current->pdeath_signal = 0;
0356357c 2212
a6f76f23
DH
2213 /* Check whether the new SID can inherit resource limits from the old
2214 * SID. If not, reset all soft limits to the lower of the current
2215 * task's hard limit and the init task's soft limit.
2216 *
2217 * Note that the setting of hard limits (even to lower them) can be
2218 * controlled by the setrlimit check. The inclusion of the init task's
2219 * soft limit into the computation is to avoid resetting soft limits
2220 * higher than the default soft limit for cases where the default is
2221 * lower than the hard limit, e.g. RLIMIT_CORE or RLIMIT_STACK.
2222 */
2223 rc = avc_has_perm(new_tsec->osid, new_tsec->sid, SECCLASS_PROCESS,
2224 PROCESS__RLIMITINH, NULL);
2225 if (rc) {
eb2d55a3
ON
2226 /* protect against do_prlimit() */
2227 task_lock(current);
a6f76f23
DH
2228 for (i = 0; i < RLIM_NLIMITS; i++) {
2229 rlim = current->signal->rlim + i;
2230 initrlim = init_task.signal->rlim + i;
2231 rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur);
1da177e4 2232 }
eb2d55a3
ON
2233 task_unlock(current);
2234 update_rlimit_cpu(current, rlimit(RLIMIT_CPU));
1da177e4
LT
2235 }
2236}
2237
2238/*
a6f76f23
DH
2239 * Clean up the process immediately after the installation of new credentials
2240 * due to exec
1da177e4 2241 */
a6f76f23 2242static void selinux_bprm_committed_creds(struct linux_binprm *bprm)
1da177e4 2243{
a6f76f23 2244 const struct task_security_struct *tsec = current_security();
1da177e4 2245 struct itimerval itimer;
a6f76f23 2246 u32 osid, sid;
1da177e4
LT
2247 int rc, i;
2248
a6f76f23
DH
2249 osid = tsec->osid;
2250 sid = tsec->sid;
2251
2252 if (sid == osid)
1da177e4
LT
2253 return;
2254
a6f76f23
DH
2255 /* Check whether the new SID can inherit signal state from the old SID.
2256 * If not, clear itimers to avoid subsequent signal generation and
2257 * flush and unblock signals.
2258 *
2259 * This must occur _after_ the task SID has been updated so that any
2260 * kill done after the flush will be checked against the new SID.
2261 */
2262 rc = avc_has_perm(osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL);
1da177e4
LT
2263 if (rc) {
2264 memset(&itimer, 0, sizeof itimer);
2265 for (i = 0; i < 3; i++)
2266 do_setitimer(i, &itimer, NULL);
1da177e4 2267 spin_lock_irq(&current->sighand->siglock);
3bcac026
DH
2268 if (!(current->signal->flags & SIGNAL_GROUP_EXIT)) {
2269 __flush_signals(current);
2270 flush_signal_handlers(current, 1);
2271 sigemptyset(&current->blocked);
2272 }
1da177e4
LT
2273 spin_unlock_irq(&current->sighand->siglock);
2274 }
2275
a6f76f23
DH
2276 /* Wake up the parent if it is waiting so that it can recheck
2277 * wait permission to the new task SID. */
ecd6de3c 2278 read_lock(&tasklist_lock);
0b7570e7 2279 __wake_up_parent(current, current->real_parent);
ecd6de3c 2280 read_unlock(&tasklist_lock);
1da177e4
LT
2281}
2282
2283/* superblock security operations */
2284
2285static int selinux_sb_alloc_security(struct super_block *sb)
2286{
2287 return superblock_alloc_security(sb);
2288}
2289
2290static void selinux_sb_free_security(struct super_block *sb)
2291{
2292 superblock_free_security(sb);
2293}
2294
2295static inline int match_prefix(char *prefix, int plen, char *option, int olen)
2296{
2297 if (plen > olen)
2298 return 0;
2299
2300 return !memcmp(prefix, option, plen);
2301}
2302
2303static inline int selinux_option(char *option, int len)
2304{
832cbd9a
EP
2305 return (match_prefix(CONTEXT_STR, sizeof(CONTEXT_STR)-1, option, len) ||
2306 match_prefix(FSCONTEXT_STR, sizeof(FSCONTEXT_STR)-1, option, len) ||
2307 match_prefix(DEFCONTEXT_STR, sizeof(DEFCONTEXT_STR)-1, option, len) ||
11689d47
DQ
2308 match_prefix(ROOTCONTEXT_STR, sizeof(ROOTCONTEXT_STR)-1, option, len) ||
2309 match_prefix(LABELSUPP_STR, sizeof(LABELSUPP_STR)-1, option, len));
1da177e4
LT
2310}
2311
2312static inline void take_option(char **to, char *from, int *first, int len)
2313{
2314 if (!*first) {
2315 **to = ',';
2316 *to += 1;
3528a953 2317 } else
1da177e4
LT
2318 *first = 0;
2319 memcpy(*to, from, len);
2320 *to += len;
2321}
2322
828dfe1d
EP
2323static inline void take_selinux_option(char **to, char *from, int *first,
2324 int len)
3528a953
CO
2325{
2326 int current_size = 0;
2327
2328 if (!*first) {
2329 **to = '|';
2330 *to += 1;
828dfe1d 2331 } else
3528a953
CO
2332 *first = 0;
2333
2334 while (current_size < len) {
2335 if (*from != '"') {
2336 **to = *from;
2337 *to += 1;
2338 }
2339 from += 1;
2340 current_size += 1;
2341 }
2342}
2343
e0007529 2344static int selinux_sb_copy_data(char *orig, char *copy)
1da177e4
LT
2345{
2346 int fnosec, fsec, rc = 0;
2347 char *in_save, *in_curr, *in_end;
2348 char *sec_curr, *nosec_save, *nosec;
3528a953 2349 int open_quote = 0;
1da177e4
LT
2350
2351 in_curr = orig;
2352 sec_curr = copy;
2353
1da177e4
LT
2354 nosec = (char *)get_zeroed_page(GFP_KERNEL);
2355 if (!nosec) {
2356 rc = -ENOMEM;
2357 goto out;
2358 }
2359
2360 nosec_save = nosec;
2361 fnosec = fsec = 1;
2362 in_save = in_end = orig;
2363
2364 do {
3528a953
CO
2365 if (*in_end == '"')
2366 open_quote = !open_quote;
2367 if ((*in_end == ',' && open_quote == 0) ||
2368 *in_end == '\0') {
1da177e4
LT
2369 int len = in_end - in_curr;
2370
2371 if (selinux_option(in_curr, len))
3528a953 2372 take_selinux_option(&sec_curr, in_curr, &fsec, len);
1da177e4
LT
2373 else
2374 take_option(&nosec, in_curr, &fnosec, len);
2375
2376 in_curr = in_end + 1;
2377 }
2378 } while (*in_end++);
2379
6931dfc9 2380 strcpy(in_save, nosec_save);
da3caa20 2381 free_page((unsigned long)nosec_save);
1da177e4
LT
2382out:
2383 return rc;
2384}
2385
026eb167
EP
2386static int selinux_sb_remount(struct super_block *sb, void *data)
2387{
2388 int rc, i, *flags;
2389 struct security_mnt_opts opts;
2390 char *secdata, **mount_options;
2391 struct superblock_security_struct *sbsec = sb->s_security;
2392
2393 if (!(sbsec->flags & SE_SBINITIALIZED))
2394 return 0;
2395
2396 if (!data)
2397 return 0;
2398
2399 if (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
2400 return 0;
2401
2402 security_init_mnt_opts(&opts);
2403 secdata = alloc_secdata();
2404 if (!secdata)
2405 return -ENOMEM;
2406 rc = selinux_sb_copy_data(data, secdata);
2407 if (rc)
2408 goto out_free_secdata;
2409
2410 rc = selinux_parse_opts_str(secdata, &opts);
2411 if (rc)
2412 goto out_free_secdata;
2413
2414 mount_options = opts.mnt_opts;
2415 flags = opts.mnt_opts_flags;
2416
2417 for (i = 0; i < opts.num_mnt_opts; i++) {
2418 u32 sid;
2419 size_t len;
2420
2421 if (flags[i] == SE_SBLABELSUPP)
2422 continue;
2423 len = strlen(mount_options[i]);
2424 rc = security_context_to_sid(mount_options[i], len, &sid);
2425 if (rc) {
2426 printk(KERN_WARNING "SELinux: security_context_to_sid"
2427 "(%s) failed for (dev %s, type %s) errno=%d\n",
2428 mount_options[i], sb->s_id, sb->s_type->name, rc);
2429 goto out_free_opts;
2430 }
2431 rc = -EINVAL;
2432 switch (flags[i]) {
2433 case FSCONTEXT_MNT:
2434 if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, sid))
2435 goto out_bad_option;
2436 break;
2437 case CONTEXT_MNT:
2438 if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, sid))
2439 goto out_bad_option;
2440 break;
2441 case ROOTCONTEXT_MNT: {
2442 struct inode_security_struct *root_isec;
2443 root_isec = sb->s_root->d_inode->i_security;
2444
2445 if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, sid))
2446 goto out_bad_option;
2447 break;
2448 }
2449 case DEFCONTEXT_MNT:
2450 if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, sid))
2451 goto out_bad_option;
2452 break;
2453 default:
2454 goto out_free_opts;
2455 }
2456 }
2457
2458 rc = 0;
2459out_free_opts:
2460 security_free_mnt_opts(&opts);
2461out_free_secdata:
2462 free_secdata(secdata);
2463 return rc;
2464out_bad_option:
2465 printk(KERN_WARNING "SELinux: unable to change security options "
2466 "during remount (dev %s, type=%s)\n", sb->s_id,
2467 sb->s_type->name);
2468 goto out_free_opts;
2469}
2470
12204e24 2471static int selinux_sb_kern_mount(struct super_block *sb, int flags, void *data)
1da177e4 2472{
88e67f3b 2473 const struct cred *cred = current_cred();
2bf49690 2474 struct common_audit_data ad;
1da177e4
LT
2475 int rc;
2476
2477 rc = superblock_doinit(sb, data);
2478 if (rc)
2479 return rc;
2480
74192246
JM
2481 /* Allow all mounts performed by the kernel */
2482 if (flags & MS_KERNMOUNT)
2483 return 0;
2484
a269434d
EP
2485 COMMON_AUDIT_DATA_INIT(&ad, DENTRY);
2486 ad.u.dentry = sb->s_root;
88e67f3b 2487 return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad);
1da177e4
LT
2488}
2489
726c3342 2490static int selinux_sb_statfs(struct dentry *dentry)
1da177e4 2491{
88e67f3b 2492 const struct cred *cred = current_cred();
2bf49690 2493 struct common_audit_data ad;
1da177e4 2494
a269434d
EP
2495 COMMON_AUDIT_DATA_INIT(&ad, DENTRY);
2496 ad.u.dentry = dentry->d_sb->s_root;
88e67f3b 2497 return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad);
1da177e4
LT
2498}
2499
828dfe1d 2500static int selinux_mount(char *dev_name,
b5266eb4 2501 struct path *path,
828dfe1d
EP
2502 char *type,
2503 unsigned long flags,
2504 void *data)
1da177e4 2505{
88e67f3b 2506 const struct cred *cred = current_cred();
1da177e4
LT
2507
2508 if (flags & MS_REMOUNT)
88e67f3b 2509 return superblock_has_perm(cred, path->mnt->mnt_sb,
828dfe1d 2510 FILESYSTEM__REMOUNT, NULL);
1da177e4 2511 else
2875fa00 2512 return path_has_perm(cred, path, FILE__MOUNTON);
1da177e4
LT
2513}
2514
2515static int selinux_umount(struct vfsmount *mnt, int flags)
2516{
88e67f3b 2517 const struct cred *cred = current_cred();
1da177e4 2518
88e67f3b 2519 return superblock_has_perm(cred, mnt->mnt_sb,
828dfe1d 2520 FILESYSTEM__UNMOUNT, NULL);
1da177e4
LT
2521}
2522
2523/* inode security operations */
2524
2525static int selinux_inode_alloc_security(struct inode *inode)
2526{
2527 return inode_alloc_security(inode);
2528}
2529
2530static void selinux_inode_free_security(struct inode *inode)
2531{
2532 inode_free_security(inode);
2533}
2534
5e41ff9e 2535static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
2a7dba39
EP
2536 const struct qstr *qstr, char **name,
2537 void **value, size_t *len)
5e41ff9e 2538{
5fb49870 2539 const struct task_security_struct *tsec = current_security();
5e41ff9e
SS
2540 struct inode_security_struct *dsec;
2541 struct superblock_security_struct *sbsec;
275bb41e 2542 u32 sid, newsid, clen;
5e41ff9e 2543 int rc;
570bc1c2 2544 char *namep = NULL, *context;
5e41ff9e 2545
5e41ff9e
SS
2546 dsec = dir->i_security;
2547 sbsec = dir->i_sb->s_security;
5e41ff9e 2548
275bb41e
DH
2549 sid = tsec->sid;
2550 newsid = tsec->create_sid;
2551
415103f9
EP
2552 if ((sbsec->flags & SE_SBINITIALIZED) &&
2553 (sbsec->behavior == SECURITY_FS_USE_MNTPOINT))
2554 newsid = sbsec->mntpoint_sid;
2555 else if (!newsid || !(sbsec->flags & SE_SBLABELSUPP)) {
275bb41e 2556 rc = security_transition_sid(sid, dsec->sid,
5e41ff9e 2557 inode_mode_to_security_class(inode->i_mode),
652bb9b0 2558 qstr, &newsid);
5e41ff9e
SS
2559 if (rc) {
2560 printk(KERN_WARNING "%s: "
2561 "security_transition_sid failed, rc=%d (dev=%s "
2562 "ino=%ld)\n",
dd6f953a 2563 __func__,
5e41ff9e
SS
2564 -rc, inode->i_sb->s_id, inode->i_ino);
2565 return rc;
2566 }
2567 }
2568
296fddf7 2569 /* Possibly defer initialization to selinux_complete_init. */
0d90a7ec 2570 if (sbsec->flags & SE_SBINITIALIZED) {
296fddf7
EP
2571 struct inode_security_struct *isec = inode->i_security;
2572 isec->sclass = inode_mode_to_security_class(inode->i_mode);
2573 isec->sid = newsid;
2574 isec->initialized = 1;
2575 }
5e41ff9e 2576
cd89596f 2577 if (!ss_initialized || !(sbsec->flags & SE_SBLABELSUPP))
25a74f3b
SS
2578 return -EOPNOTSUPP;
2579
570bc1c2 2580 if (name) {
a02fe132 2581 namep = kstrdup(XATTR_SELINUX_SUFFIX, GFP_NOFS);
570bc1c2
SS
2582 if (!namep)
2583 return -ENOMEM;
2584 *name = namep;
2585 }
5e41ff9e 2586
570bc1c2 2587 if (value && len) {
12b29f34 2588 rc = security_sid_to_context_force(newsid, &context, &clen);
570bc1c2
SS
2589 if (rc) {
2590 kfree(namep);
2591 return rc;
2592 }
2593 *value = context;
2594 *len = clen;
5e41ff9e 2595 }
5e41ff9e 2596
5e41ff9e
SS
2597 return 0;
2598}
2599
1da177e4
LT
2600static int selinux_inode_create(struct inode *dir, struct dentry *dentry, int mask)
2601{
2602 return may_create(dir, dentry, SECCLASS_FILE);
2603}
2604
1da177e4
LT
2605static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
2606{
1da177e4
LT
2607 return may_link(dir, old_dentry, MAY_LINK);
2608}
2609
1da177e4
LT
2610static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry)
2611{
1da177e4
LT
2612 return may_link(dir, dentry, MAY_UNLINK);
2613}
2614
2615static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name)
2616{
2617 return may_create(dir, dentry, SECCLASS_LNK_FILE);
2618}
2619
1da177e4
LT
2620static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, int mask)
2621{
2622 return may_create(dir, dentry, SECCLASS_DIR);
2623}
2624
1da177e4
LT
2625static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry)
2626{
2627 return may_link(dir, dentry, MAY_RMDIR);
2628}
2629
2630static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
2631{
1da177e4
LT
2632 return may_create(dir, dentry, inode_mode_to_security_class(mode));
2633}
2634
1da177e4 2635static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
828dfe1d 2636 struct inode *new_inode, struct dentry *new_dentry)
1da177e4
LT
2637{
2638 return may_rename(old_inode, old_dentry, new_inode, new_dentry);
2639}
2640
1da177e4
LT
2641static int selinux_inode_readlink(struct dentry *dentry)
2642{
88e67f3b
DH
2643 const struct cred *cred = current_cred();
2644
2875fa00 2645 return dentry_has_perm(cred, dentry, FILE__READ);
1da177e4
LT
2646}
2647
2648static int selinux_inode_follow_link(struct dentry *dentry, struct nameidata *nameidata)
2649{
88e67f3b 2650 const struct cred *cred = current_cred();
1da177e4 2651
2875fa00 2652 return dentry_has_perm(cred, dentry, FILE__READ);
1da177e4
LT
2653}
2654
e74f71eb 2655static int selinux_inode_permission(struct inode *inode, int mask)
1da177e4 2656{
88e67f3b 2657 const struct cred *cred = current_cred();
b782e0a6
EP
2658 struct common_audit_data ad;
2659 u32 perms;
2660 bool from_access;
cf1dd1da 2661 unsigned flags = mask & MAY_NOT_BLOCK;
1da177e4 2662
b782e0a6 2663 from_access = mask & MAY_ACCESS;
d09ca739
EP
2664 mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
2665
b782e0a6
EP
2666 /* No permission to check. Existence test. */
2667 if (!mask)
1da177e4 2668 return 0;
1da177e4 2669
f48b7399
EP
2670 COMMON_AUDIT_DATA_INIT(&ad, INODE);
2671 ad.u.inode = inode;
b782e0a6
EP
2672
2673 if (from_access)
2674 ad.selinux_audit_data.auditdeny |= FILE__AUDIT_ACCESS;
2675
2676 perms = file_mask_to_av(inode->i_mode, mask);
2677
9ade0cf4 2678 return inode_has_perm(cred, inode, perms, &ad, flags);
1da177e4
LT
2679}
2680
2681static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
2682{
88e67f3b 2683 const struct cred *cred = current_cred();
bc6a6008 2684 unsigned int ia_valid = iattr->ia_valid;
1da177e4 2685
bc6a6008
AW
2686 /* ATTR_FORCE is just used for ATTR_KILL_S[UG]ID. */
2687 if (ia_valid & ATTR_FORCE) {
2688 ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE |
2689 ATTR_FORCE);
2690 if (!ia_valid)
2691 return 0;
2692 }
1da177e4 2693
bc6a6008
AW
2694 if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
2695 ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET))
2875fa00 2696 return dentry_has_perm(cred, dentry, FILE__SETATTR);
1da177e4 2697
2875fa00 2698 return dentry_has_perm(cred, dentry, FILE__WRITE);
1da177e4
LT
2699}
2700
2701static int selinux_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
2702{
88e67f3b 2703 const struct cred *cred = current_cred();
2875fa00
EP
2704 struct path path;
2705
2706 path.dentry = dentry;
2707 path.mnt = mnt;
88e67f3b 2708
2875fa00 2709 return path_has_perm(cred, &path, FILE__GETATTR);
1da177e4
LT
2710}
2711
8f0cfa52 2712static int selinux_inode_setotherxattr(struct dentry *dentry, const char *name)
b5376771 2713{
88e67f3b
DH
2714 const struct cred *cred = current_cred();
2715
b5376771
SH
2716 if (!strncmp(name, XATTR_SECURITY_PREFIX,
2717 sizeof XATTR_SECURITY_PREFIX - 1)) {
2718 if (!strcmp(name, XATTR_NAME_CAPS)) {
2719 if (!capable(CAP_SETFCAP))
2720 return -EPERM;
2721 } else if (!capable(CAP_SYS_ADMIN)) {
2722 /* A different attribute in the security namespace.
2723 Restrict to administrator. */
2724 return -EPERM;
2725 }
2726 }
2727
2728 /* Not an attribute we recognize, so just check the
2729 ordinary setattr permission. */
2875fa00 2730 return dentry_has_perm(cred, dentry, FILE__SETATTR);
b5376771
SH
2731}
2732
8f0cfa52
DH
2733static int selinux_inode_setxattr(struct dentry *dentry, const char *name,
2734 const void *value, size_t size, int flags)
1da177e4 2735{
1da177e4
LT
2736 struct inode *inode = dentry->d_inode;
2737 struct inode_security_struct *isec = inode->i_security;
2738 struct superblock_security_struct *sbsec;
2bf49690 2739 struct common_audit_data ad;
275bb41e 2740 u32 newsid, sid = current_sid();
1da177e4
LT
2741 int rc = 0;
2742
b5376771
SH
2743 if (strcmp(name, XATTR_NAME_SELINUX))
2744 return selinux_inode_setotherxattr(dentry, name);
1da177e4
LT
2745
2746 sbsec = inode->i_sb->s_security;
cd89596f 2747 if (!(sbsec->flags & SE_SBLABELSUPP))
1da177e4
LT
2748 return -EOPNOTSUPP;
2749
2e149670 2750 if (!inode_owner_or_capable(inode))
1da177e4
LT
2751 return -EPERM;
2752
a269434d
EP
2753 COMMON_AUDIT_DATA_INIT(&ad, DENTRY);
2754 ad.u.dentry = dentry;
1da177e4 2755
275bb41e 2756 rc = avc_has_perm(sid, isec->sid, isec->sclass,
1da177e4
LT
2757 FILE__RELABELFROM, &ad);
2758 if (rc)
2759 return rc;
2760
2761 rc = security_context_to_sid(value, size, &newsid);
12b29f34
SS
2762 if (rc == -EINVAL) {
2763 if (!capable(CAP_MAC_ADMIN))
2764 return rc;
2765 rc = security_context_to_sid_force(value, size, &newsid);
2766 }
1da177e4
LT
2767 if (rc)
2768 return rc;
2769
275bb41e 2770 rc = avc_has_perm(sid, newsid, isec->sclass,
1da177e4
LT
2771 FILE__RELABELTO, &ad);
2772 if (rc)
2773 return rc;
2774
275bb41e 2775 rc = security_validate_transition(isec->sid, newsid, sid,
828dfe1d 2776 isec->sclass);
1da177e4
LT
2777 if (rc)
2778 return rc;
2779
2780 return avc_has_perm(newsid,
2781 sbsec->sid,
2782 SECCLASS_FILESYSTEM,
2783 FILESYSTEM__ASSOCIATE,
2784 &ad);
2785}
2786
8f0cfa52 2787static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name,
f5269710 2788 const void *value, size_t size,
8f0cfa52 2789 int flags)
1da177e4
LT
2790{
2791 struct inode *inode = dentry->d_inode;
2792 struct inode_security_struct *isec = inode->i_security;
2793 u32 newsid;
2794 int rc;
2795
2796 if (strcmp(name, XATTR_NAME_SELINUX)) {
2797 /* Not an attribute we recognize, so nothing to do. */
2798 return;
2799 }
2800
12b29f34 2801 rc = security_context_to_sid_force(value, size, &newsid);
1da177e4 2802 if (rc) {
12b29f34
SS
2803 printk(KERN_ERR "SELinux: unable to map context to SID"
2804 "for (%s, %lu), rc=%d\n",
2805 inode->i_sb->s_id, inode->i_ino, -rc);
1da177e4
LT
2806 return;
2807 }
2808
2809 isec->sid = newsid;
2810 return;
2811}
2812
8f0cfa52 2813static int selinux_inode_getxattr(struct dentry *dentry, const char *name)
1da177e4 2814{
88e67f3b
DH
2815 const struct cred *cred = current_cred();
2816
2875fa00 2817 return dentry_has_perm(cred, dentry, FILE__GETATTR);
1da177e4
LT
2818}
2819
828dfe1d 2820static int selinux_inode_listxattr(struct dentry *dentry)
1da177e4 2821{
88e67f3b
DH
2822 const struct cred *cred = current_cred();
2823
2875fa00 2824 return dentry_has_perm(cred, dentry, FILE__GETATTR);
1da177e4
LT
2825}
2826
8f0cfa52 2827static int selinux_inode_removexattr(struct dentry *dentry, const char *name)
1da177e4 2828{
b5376771
SH
2829 if (strcmp(name, XATTR_NAME_SELINUX))
2830 return selinux_inode_setotherxattr(dentry, name);
1da177e4
LT
2831
2832 /* No one is allowed to remove a SELinux security label.
2833 You can change the label, but all data must be labeled. */
2834 return -EACCES;
2835}
2836
d381d8a9 2837/*
abc69bb6 2838 * Copy the inode security context value to the user.
d381d8a9
JM
2839 *
2840 * Permission check is handled by selinux_inode_getxattr hook.
2841 */
42492594 2842static int selinux_inode_getsecurity(const struct inode *inode, const char *name, void **buffer, bool alloc)
1da177e4 2843{
42492594
DQ
2844 u32 size;
2845 int error;
2846 char *context = NULL;
1da177e4 2847 struct inode_security_struct *isec = inode->i_security;
d381d8a9 2848
8c8570fb
DK
2849 if (strcmp(name, XATTR_SELINUX_SUFFIX))
2850 return -EOPNOTSUPP;
d381d8a9 2851
abc69bb6
SS
2852 /*
2853 * If the caller has CAP_MAC_ADMIN, then get the raw context
2854 * value even if it is not defined by current policy; otherwise,
2855 * use the in-core value under current policy.
2856 * Use the non-auditing forms of the permission checks since
2857 * getxattr may be called by unprivileged processes commonly
2858 * and lack of permission just means that we fall back to the
2859 * in-core context value, not a denial.
2860 */
3486740a
SH
2861 error = selinux_capable(current, current_cred(),
2862 &init_user_ns, CAP_MAC_ADMIN,
3699c53c 2863 SECURITY_CAP_NOAUDIT);
abc69bb6
SS
2864 if (!error)
2865 error = security_sid_to_context_force(isec->sid, &context,
2866 &size);
2867 else
2868 error = security_sid_to_context(isec->sid, &context, &size);
42492594
DQ
2869 if (error)
2870 return error;
2871 error = size;
2872 if (alloc) {
2873 *buffer = context;
2874 goto out_nofree;
2875 }
2876 kfree(context);
2877out_nofree:
2878 return error;
1da177e4
LT
2879}
2880
2881static int selinux_inode_setsecurity(struct inode *inode, const char *name,
828dfe1d 2882 const void *value, size_t size, int flags)
1da177e4
LT
2883{
2884 struct inode_security_struct *isec = inode->i_security;
2885 u32 newsid;
2886 int rc;
2887
2888 if (strcmp(name, XATTR_SELINUX_SUFFIX))
2889 return -EOPNOTSUPP;
2890
2891 if (!value || !size)
2892 return -EACCES;
2893
828dfe1d 2894 rc = security_context_to_sid((void *)value, size, &newsid);
1da177e4
LT
2895 if (rc)
2896 return rc;
2897
2898 isec->sid = newsid;
ddd29ec6 2899 isec->initialized = 1;
1da177e4
LT
2900 return 0;
2901}
2902
2903static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
2904{
2905 const int len = sizeof(XATTR_NAME_SELINUX);
2906 if (buffer && len <= buffer_size)
2907 memcpy(buffer, XATTR_NAME_SELINUX, len);
2908 return len;
2909}
2910
713a04ae
AD
2911static void selinux_inode_getsecid(const struct inode *inode, u32 *secid)
2912{
2913 struct inode_security_struct *isec = inode->i_security;
2914 *secid = isec->sid;
2915}
2916
1da177e4
LT
2917/* file security operations */
2918
788e7dd4 2919static int selinux_revalidate_file_permission(struct file *file, int mask)
1da177e4 2920{
88e67f3b 2921 const struct cred *cred = current_cred();
3d5ff529 2922 struct inode *inode = file->f_path.dentry->d_inode;
1da177e4 2923
1da177e4
LT
2924 /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */
2925 if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE))
2926 mask |= MAY_APPEND;
2927
389fb800
PM
2928 return file_has_perm(cred, file,
2929 file_mask_to_av(inode->i_mode, mask));
1da177e4
LT
2930}
2931
788e7dd4
YN
2932static int selinux_file_permission(struct file *file, int mask)
2933{
20dda18b
SS
2934 struct inode *inode = file->f_path.dentry->d_inode;
2935 struct file_security_struct *fsec = file->f_security;
2936 struct inode_security_struct *isec = inode->i_security;
2937 u32 sid = current_sid();
2938
389fb800 2939 if (!mask)
788e7dd4
YN
2940 /* No permission to check. Existence test. */
2941 return 0;
788e7dd4 2942
20dda18b
SS
2943 if (sid == fsec->sid && fsec->isid == isec->sid &&
2944 fsec->pseqno == avc_policy_seqno())
2945 /* No change since dentry_open check. */
2946 return 0;
2947
788e7dd4
YN
2948 return selinux_revalidate_file_permission(file, mask);
2949}
2950
1da177e4
LT
2951static int selinux_file_alloc_security(struct file *file)
2952{
2953 return file_alloc_security(file);
2954}
2955
2956static void selinux_file_free_security(struct file *file)
2957{
2958 file_free_security(file);
2959}
2960
2961static int selinux_file_ioctl(struct file *file, unsigned int cmd,
2962 unsigned long arg)
2963{
88e67f3b 2964 const struct cred *cred = current_cred();
0b24dcb7 2965 int error = 0;
1da177e4 2966
0b24dcb7
EP
2967 switch (cmd) {
2968 case FIONREAD:
2969 /* fall through */
2970 case FIBMAP:
2971 /* fall through */
2972 case FIGETBSZ:
2973 /* fall through */
2974 case EXT2_IOC_GETFLAGS:
2975 /* fall through */
2976 case EXT2_IOC_GETVERSION:
2977 error = file_has_perm(cred, file, FILE__GETATTR);
2978 break;
1da177e4 2979
0b24dcb7
EP
2980 case EXT2_IOC_SETFLAGS:
2981 /* fall through */
2982 case EXT2_IOC_SETVERSION:
2983 error = file_has_perm(cred, file, FILE__SETATTR);
2984 break;
2985
2986 /* sys_ioctl() checks */
2987 case FIONBIO:
2988 /* fall through */
2989 case FIOASYNC:
2990 error = file_has_perm(cred, file, 0);
2991 break;
1da177e4 2992
0b24dcb7
EP
2993 case KDSKBENT:
2994 case KDSKBSENT:
2995 error = task_has_capability(current, cred, CAP_SYS_TTY_CONFIG,
3486740a 2996 SECURITY_CAP_AUDIT);
0b24dcb7
EP
2997 break;
2998
2999 /* default case assumes that the command will go
3000 * to the file's ioctl() function.
3001 */
3002 default:
3003 error = file_has_perm(cred, file, FILE__IOCTL);
3004 }
3005 return error;
1da177e4
LT
3006}
3007
fcaaade1
SS
3008static int default_noexec;
3009
1da177e4
LT
3010static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
3011{
88e67f3b 3012 const struct cred *cred = current_cred();
d84f4f99 3013 int rc = 0;
88e67f3b 3014
fcaaade1
SS
3015 if (default_noexec &&
3016 (prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) {
1da177e4
LT
3017 /*
3018 * We are making executable an anonymous mapping or a
3019 * private file mapping that will also be writable.
3020 * This has an additional check.
3021 */
d84f4f99 3022 rc = cred_has_perm(cred, cred, PROCESS__EXECMEM);
1da177e4 3023 if (rc)
d84f4f99 3024 goto error;
1da177e4 3025 }
1da177e4
LT
3026
3027 if (file) {
3028 /* read access is always possible with a mapping */
3029 u32 av = FILE__READ;
3030
3031 /* write access only matters if the mapping is shared */
3032 if (shared && (prot & PROT_WRITE))
3033 av |= FILE__WRITE;
3034
3035 if (prot & PROT_EXEC)
3036 av |= FILE__EXECUTE;
3037
88e67f3b 3038 return file_has_perm(cred, file, av);
1da177e4 3039 }
d84f4f99
DH
3040
3041error:
3042 return rc;
1da177e4
LT
3043}
3044
3045static int selinux_file_mmap(struct file *file, unsigned long reqprot,
ed032189
EP
3046 unsigned long prot, unsigned long flags,
3047 unsigned long addr, unsigned long addr_only)
1da177e4 3048{
ed032189 3049 int rc = 0;
275bb41e 3050 u32 sid = current_sid();
1da177e4 3051
84336d1a
EP
3052 /*
3053 * notice that we are intentionally putting the SELinux check before
3054 * the secondary cap_file_mmap check. This is such a likely attempt
3055 * at bad behaviour/exploit that we always want to get the AVC, even
3056 * if DAC would have also denied the operation.
3057 */
a2551df7 3058 if (addr < CONFIG_LSM_MMAP_MIN_ADDR) {
ed032189
EP
3059 rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT,
3060 MEMPROTECT__MMAP_ZERO, NULL);
84336d1a
EP
3061 if (rc)
3062 return rc;
3063 }
3064
3065 /* do DAC check on address space usage */
3066 rc = cap_file_mmap(file, reqprot, prot, flags, addr, addr_only);
ed032189 3067 if (rc || addr_only)
1da177e4
LT
3068 return rc;
3069
3070 if (selinux_checkreqprot)
3071 prot = reqprot;
3072
3073 return file_map_prot_check(file, prot,
3074 (flags & MAP_TYPE) == MAP_SHARED);
3075}
3076
3077static int selinux_file_mprotect(struct vm_area_struct *vma,
3078 unsigned long reqprot,
3079 unsigned long prot)
3080{
88e67f3b 3081 const struct cred *cred = current_cred();
1da177e4
LT
3082
3083 if (selinux_checkreqprot)
3084 prot = reqprot;
3085
fcaaade1
SS
3086 if (default_noexec &&
3087 (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
d541bbee 3088 int rc = 0;
db4c9641
SS
3089 if (vma->vm_start >= vma->vm_mm->start_brk &&
3090 vma->vm_end <= vma->vm_mm->brk) {
d84f4f99 3091 rc = cred_has_perm(cred, cred, PROCESS__EXECHEAP);
db4c9641
SS
3092 } else if (!vma->vm_file &&
3093 vma->vm_start <= vma->vm_mm->start_stack &&
3094 vma->vm_end >= vma->vm_mm->start_stack) {
3b11a1de 3095 rc = current_has_perm(current, PROCESS__EXECSTACK);
db4c9641
SS
3096 } else if (vma->vm_file && vma->anon_vma) {
3097 /*
3098 * We are making executable a file mapping that has
3099 * had some COW done. Since pages might have been
3100 * written, check ability to execute the possibly
3101 * modified content. This typically should only
3102 * occur for text relocations.
3103 */
d84f4f99 3104 rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD);
db4c9641 3105 }