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CommitLineData
1da177e4
LT
1/*
2 * NSA Security-Enhanced Linux (SELinux) security module
3 *
4 * This file contains the SELinux hook function implementations.
5 *
6 * Authors: Stephen Smalley, <sds@epoch.ncsc.mil>
828dfe1d
EP
7 * Chris Vance, <cvance@nai.com>
8 * Wayne Salamon, <wsalamon@nai.com>
9 * James Morris <jmorris@redhat.com>
1da177e4
LT
10 *
11 * Copyright (C) 2001,2002 Networks Associates Technology, Inc.
2069f457
EP
12 * Copyright (C) 2003-2008 Red Hat, Inc., James Morris <jmorris@redhat.com>
13 * Eric Paris <eparis@redhat.com>
1da177e4 14 * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
828dfe1d 15 * <dgoeddel@trustedcs.com>
ed6d76e4 16 * Copyright (C) 2006, 2007, 2009 Hewlett-Packard Development Company, L.P.
82c21bfa 17 * Paul Moore <paul@paul-moore.com>
788e7dd4 18 * Copyright (C) 2007 Hitachi Software Engineering Co., Ltd.
828dfe1d 19 * Yuichi Nakamura <ynakam@hitachisoft.jp>
1da177e4
LT
20 *
21 * This program is free software; you can redistribute it and/or modify
22 * it under the terms of the GNU General Public License version 2,
828dfe1d 23 * as published by the Free Software Foundation.
1da177e4
LT
24 */
25
1da177e4 26#include <linux/init.h>
0b24dcb7 27#include <linux/kd.h>
1da177e4 28#include <linux/kernel.h>
0d094efe 29#include <linux/tracehook.h>
1da177e4 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>
44fc7ea0 83#include <linux/export.h>
1da177e4
LT
84
85#include "avc.h"
86#include "objsec.h"
87#include "netif.h"
224dfbd8 88#include "netnode.h"
3e112172 89#include "netport.h"
d28d1e08 90#include "xfrm.h"
c60475bf 91#include "netlabel.h"
9d57a7f9 92#include "audit.h"
7b98a585 93#include "avc_ss.h"
1da177e4 94
11689d47 95#define NUM_SEL_MNT_OPTS 5
c9180a57 96
20510f2f 97extern struct security_operations *security_ops;
1da177e4 98
d621d35e 99/* SECMARK reference count */
56a4ca99 100static atomic_t selinux_secmark_refcount = ATOMIC_INIT(0);
d621d35e 101
1da177e4 102#ifdef CONFIG_SECURITY_SELINUX_DEVELOP
828dfe1d 103int selinux_enforcing;
1da177e4
LT
104
105static int __init enforcing_setup(char *str)
106{
f5269710
EP
107 unsigned long enforcing;
108 if (!strict_strtoul(str, 0, &enforcing))
109 selinux_enforcing = enforcing ? 1 : 0;
1da177e4
LT
110 return 1;
111}
112__setup("enforcing=", enforcing_setup);
113#endif
114
115#ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM
116int selinux_enabled = CONFIG_SECURITY_SELINUX_BOOTPARAM_VALUE;
117
118static int __init selinux_enabled_setup(char *str)
119{
f5269710
EP
120 unsigned long enabled;
121 if (!strict_strtoul(str, 0, &enabled))
122 selinux_enabled = enabled ? 1 : 0;
1da177e4
LT
123 return 1;
124}
125__setup("selinux=", selinux_enabled_setup);
30d55280
SS
126#else
127int selinux_enabled = 1;
1da177e4
LT
128#endif
129
e18b890b 130static struct kmem_cache *sel_inode_cache;
7cae7e26 131
d621d35e
PM
132/**
133 * selinux_secmark_enabled - Check to see if SECMARK is currently enabled
134 *
135 * Description:
136 * This function checks the SECMARK reference counter to see if any SECMARK
137 * targets are currently configured, if the reference counter is greater than
138 * zero SECMARK is considered to be enabled. Returns true (1) if SECMARK is
139 * enabled, false (0) if SECMARK is disabled.
140 *
141 */
142static int selinux_secmark_enabled(void)
143{
144 return (atomic_read(&selinux_secmark_refcount) > 0);
145}
146
d84f4f99
DH
147/*
148 * initialise the security for the init task
149 */
150static void cred_init_security(void)
1da177e4 151{
3b11a1de 152 struct cred *cred = (struct cred *) current->real_cred;
1da177e4
LT
153 struct task_security_struct *tsec;
154
89d155ef 155 tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL);
1da177e4 156 if (!tsec)
d84f4f99 157 panic("SELinux: Failed to initialize initial task.\n");
1da177e4 158
d84f4f99 159 tsec->osid = tsec->sid = SECINITSID_KERNEL;
f1752eec 160 cred->security = tsec;
1da177e4
LT
161}
162
88e67f3b
DH
163/*
164 * get the security ID of a set of credentials
165 */
166static inline u32 cred_sid(const struct cred *cred)
167{
168 const struct task_security_struct *tsec;
169
170 tsec = cred->security;
171 return tsec->sid;
172}
173
275bb41e 174/*
3b11a1de 175 * get the objective security ID of a task
275bb41e
DH
176 */
177static inline u32 task_sid(const struct task_struct *task)
178{
275bb41e
DH
179 u32 sid;
180
181 rcu_read_lock();
88e67f3b 182 sid = cred_sid(__task_cred(task));
275bb41e
DH
183 rcu_read_unlock();
184 return sid;
185}
186
187/*
3b11a1de 188 * get the subjective security ID of the current task
275bb41e
DH
189 */
190static inline u32 current_sid(void)
191{
5fb49870 192 const struct task_security_struct *tsec = current_security();
275bb41e
DH
193
194 return tsec->sid;
195}
196
88e67f3b
DH
197/* Allocate and free functions for each kind of security blob. */
198
1da177e4
LT
199static int inode_alloc_security(struct inode *inode)
200{
1da177e4 201 struct inode_security_struct *isec;
275bb41e 202 u32 sid = current_sid();
1da177e4 203
a02fe132 204 isec = kmem_cache_zalloc(sel_inode_cache, GFP_NOFS);
1da177e4
LT
205 if (!isec)
206 return -ENOMEM;
207
23970741 208 mutex_init(&isec->lock);
1da177e4 209 INIT_LIST_HEAD(&isec->list);
1da177e4
LT
210 isec->inode = inode;
211 isec->sid = SECINITSID_UNLABELED;
212 isec->sclass = SECCLASS_FILE;
275bb41e 213 isec->task_sid = sid;
1da177e4
LT
214 inode->i_security = isec;
215
216 return 0;
217}
218
219static void inode_free_security(struct inode *inode)
220{
221 struct inode_security_struct *isec = inode->i_security;
222 struct superblock_security_struct *sbsec = inode->i_sb->s_security;
223
1da177e4
LT
224 spin_lock(&sbsec->isec_lock);
225 if (!list_empty(&isec->list))
226 list_del_init(&isec->list);
227 spin_unlock(&sbsec->isec_lock);
228
229 inode->i_security = NULL;
7cae7e26 230 kmem_cache_free(sel_inode_cache, isec);
1da177e4
LT
231}
232
233static int file_alloc_security(struct file *file)
234{
1da177e4 235 struct file_security_struct *fsec;
275bb41e 236 u32 sid = current_sid();
1da177e4 237
26d2a4be 238 fsec = kzalloc(sizeof(struct file_security_struct), GFP_KERNEL);
1da177e4
LT
239 if (!fsec)
240 return -ENOMEM;
241
275bb41e
DH
242 fsec->sid = sid;
243 fsec->fown_sid = sid;
1da177e4
LT
244 file->f_security = fsec;
245
246 return 0;
247}
248
249static void file_free_security(struct file *file)
250{
251 struct file_security_struct *fsec = file->f_security;
1da177e4
LT
252 file->f_security = NULL;
253 kfree(fsec);
254}
255
256static int superblock_alloc_security(struct super_block *sb)
257{
258 struct superblock_security_struct *sbsec;
259
89d155ef 260 sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL);
1da177e4
LT
261 if (!sbsec)
262 return -ENOMEM;
263
bc7e982b 264 mutex_init(&sbsec->lock);
1da177e4
LT
265 INIT_LIST_HEAD(&sbsec->isec_head);
266 spin_lock_init(&sbsec->isec_lock);
1da177e4
LT
267 sbsec->sb = sb;
268 sbsec->sid = SECINITSID_UNLABELED;
269 sbsec->def_sid = SECINITSID_FILE;
c312feb2 270 sbsec->mntpoint_sid = SECINITSID_UNLABELED;
1da177e4
LT
271 sb->s_security = sbsec;
272
273 return 0;
274}
275
276static void superblock_free_security(struct super_block *sb)
277{
278 struct superblock_security_struct *sbsec = sb->s_security;
1da177e4
LT
279 sb->s_security = NULL;
280 kfree(sbsec);
281}
282
1da177e4
LT
283/* The file system's label must be initialized prior to use. */
284
634a539e 285static const char *labeling_behaviors[6] = {
1da177e4
LT
286 "uses xattr",
287 "uses transition SIDs",
288 "uses task SIDs",
289 "uses genfs_contexts",
290 "not configured for labeling",
291 "uses mountpoint labeling",
292};
293
294static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry);
295
296static inline int inode_doinit(struct inode *inode)
297{
298 return inode_doinit_with_dentry(inode, NULL);
299}
300
301enum {
31e87930 302 Opt_error = -1,
1da177e4
LT
303 Opt_context = 1,
304 Opt_fscontext = 2,
c9180a57
EP
305 Opt_defcontext = 3,
306 Opt_rootcontext = 4,
11689d47 307 Opt_labelsupport = 5,
1da177e4
LT
308};
309
a447c093 310static const match_table_t tokens = {
832cbd9a
EP
311 {Opt_context, CONTEXT_STR "%s"},
312 {Opt_fscontext, FSCONTEXT_STR "%s"},
313 {Opt_defcontext, DEFCONTEXT_STR "%s"},
314 {Opt_rootcontext, ROOTCONTEXT_STR "%s"},
11689d47 315 {Opt_labelsupport, LABELSUPP_STR},
31e87930 316 {Opt_error, NULL},
1da177e4
LT
317};
318
319#define SEL_MOUNT_FAIL_MSG "SELinux: duplicate or incompatible mount options\n"
320
c312feb2
EP
321static int may_context_mount_sb_relabel(u32 sid,
322 struct superblock_security_struct *sbsec,
275bb41e 323 const struct cred *cred)
c312feb2 324{
275bb41e 325 const struct task_security_struct *tsec = cred->security;
c312feb2
EP
326 int rc;
327
328 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
329 FILESYSTEM__RELABELFROM, NULL);
330 if (rc)
331 return rc;
332
333 rc = avc_has_perm(tsec->sid, sid, SECCLASS_FILESYSTEM,
334 FILESYSTEM__RELABELTO, NULL);
335 return rc;
336}
337
0808925e
EP
338static int may_context_mount_inode_relabel(u32 sid,
339 struct superblock_security_struct *sbsec,
275bb41e 340 const struct cred *cred)
0808925e 341{
275bb41e 342 const struct task_security_struct *tsec = cred->security;
0808925e
EP
343 int rc;
344 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
345 FILESYSTEM__RELABELFROM, NULL);
346 if (rc)
347 return rc;
348
349 rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM,
350 FILESYSTEM__ASSOCIATE, NULL);
351 return rc;
352}
353
c9180a57 354static int sb_finish_set_opts(struct super_block *sb)
1da177e4 355{
1da177e4 356 struct superblock_security_struct *sbsec = sb->s_security;
c9180a57
EP
357 struct dentry *root = sb->s_root;
358 struct inode *root_inode = root->d_inode;
359 int rc = 0;
1da177e4 360
c9180a57
EP
361 if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
362 /* Make sure that the xattr handler exists and that no
363 error other than -ENODATA is returned by getxattr on
364 the root directory. -ENODATA is ok, as this may be
365 the first boot of the SELinux kernel before we have
366 assigned xattr values to the filesystem. */
367 if (!root_inode->i_op->getxattr) {
368 printk(KERN_WARNING "SELinux: (dev %s, type %s) has no "
369 "xattr support\n", sb->s_id, sb->s_type->name);
370 rc = -EOPNOTSUPP;
371 goto out;
372 }
373 rc = root_inode->i_op->getxattr(root, XATTR_NAME_SELINUX, NULL, 0);
374 if (rc < 0 && rc != -ENODATA) {
375 if (rc == -EOPNOTSUPP)
376 printk(KERN_WARNING "SELinux: (dev %s, type "
377 "%s) has no security xattr handler\n",
378 sb->s_id, sb->s_type->name);
379 else
380 printk(KERN_WARNING "SELinux: (dev %s, type "
381 "%s) getxattr errno %d\n", sb->s_id,
382 sb->s_type->name, -rc);
383 goto out;
384 }
385 }
1da177e4 386
11689d47 387 sbsec->flags |= (SE_SBINITIALIZED | SE_SBLABELSUPP);
1da177e4 388
c9180a57
EP
389 if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors))
390 printk(KERN_ERR "SELinux: initialized (dev %s, type %s), unknown behavior\n",
391 sb->s_id, sb->s_type->name);
392 else
393 printk(KERN_DEBUG "SELinux: initialized (dev %s, type %s), %s\n",
394 sb->s_id, sb->s_type->name,
395 labeling_behaviors[sbsec->behavior-1]);
1da177e4 396
11689d47
DQ
397 if (sbsec->behavior == SECURITY_FS_USE_GENFS ||
398 sbsec->behavior == SECURITY_FS_USE_MNTPOINT ||
399 sbsec->behavior == SECURITY_FS_USE_NONE ||
400 sbsec->behavior > ARRAY_SIZE(labeling_behaviors))
401 sbsec->flags &= ~SE_SBLABELSUPP;
402
ddd29ec6
DQ
403 /* Special handling for sysfs. Is genfs but also has setxattr handler*/
404 if (strncmp(sb->s_type->name, "sysfs", sizeof("sysfs")) == 0)
405 sbsec->flags |= SE_SBLABELSUPP;
406
c9180a57
EP
407 /* Initialize the root inode. */
408 rc = inode_doinit_with_dentry(root_inode, root);
1da177e4 409
c9180a57
EP
410 /* Initialize any other inodes associated with the superblock, e.g.
411 inodes created prior to initial policy load or inodes created
412 during get_sb by a pseudo filesystem that directly
413 populates itself. */
414 spin_lock(&sbsec->isec_lock);
415next_inode:
416 if (!list_empty(&sbsec->isec_head)) {
417 struct inode_security_struct *isec =
418 list_entry(sbsec->isec_head.next,
419 struct inode_security_struct, list);
420 struct inode *inode = isec->inode;
421 spin_unlock(&sbsec->isec_lock);
422 inode = igrab(inode);
423 if (inode) {
424 if (!IS_PRIVATE(inode))
425 inode_doinit(inode);
426 iput(inode);
427 }
428 spin_lock(&sbsec->isec_lock);
429 list_del_init(&isec->list);
430 goto next_inode;
431 }
432 spin_unlock(&sbsec->isec_lock);
433out:
434 return rc;
435}
1da177e4 436
c9180a57
EP
437/*
438 * This function should allow an FS to ask what it's mount security
439 * options were so it can use those later for submounts, displaying
440 * mount options, or whatever.
441 */
442static int selinux_get_mnt_opts(const struct super_block *sb,
e0007529 443 struct security_mnt_opts *opts)
c9180a57
EP
444{
445 int rc = 0, i;
446 struct superblock_security_struct *sbsec = sb->s_security;
447 char *context = NULL;
448 u32 len;
449 char tmp;
1da177e4 450
e0007529 451 security_init_mnt_opts(opts);
1da177e4 452
0d90a7ec 453 if (!(sbsec->flags & SE_SBINITIALIZED))
c9180a57 454 return -EINVAL;
1da177e4 455
c9180a57
EP
456 if (!ss_initialized)
457 return -EINVAL;
1da177e4 458
0d90a7ec 459 tmp = sbsec->flags & SE_MNTMASK;
c9180a57
EP
460 /* count the number of mount options for this sb */
461 for (i = 0; i < 8; i++) {
462 if (tmp & 0x01)
e0007529 463 opts->num_mnt_opts++;
c9180a57
EP
464 tmp >>= 1;
465 }
11689d47
DQ
466 /* Check if the Label support flag is set */
467 if (sbsec->flags & SE_SBLABELSUPP)
468 opts->num_mnt_opts++;
1da177e4 469
e0007529
EP
470 opts->mnt_opts = kcalloc(opts->num_mnt_opts, sizeof(char *), GFP_ATOMIC);
471 if (!opts->mnt_opts) {
c9180a57
EP
472 rc = -ENOMEM;
473 goto out_free;
474 }
1da177e4 475
e0007529
EP
476 opts->mnt_opts_flags = kcalloc(opts->num_mnt_opts, sizeof(int), GFP_ATOMIC);
477 if (!opts->mnt_opts_flags) {
c9180a57
EP
478 rc = -ENOMEM;
479 goto out_free;
480 }
1da177e4 481
c9180a57
EP
482 i = 0;
483 if (sbsec->flags & FSCONTEXT_MNT) {
484 rc = security_sid_to_context(sbsec->sid, &context, &len);
485 if (rc)
486 goto out_free;
e0007529
EP
487 opts->mnt_opts[i] = context;
488 opts->mnt_opts_flags[i++] = FSCONTEXT_MNT;
c9180a57
EP
489 }
490 if (sbsec->flags & CONTEXT_MNT) {
491 rc = security_sid_to_context(sbsec->mntpoint_sid, &context, &len);
492 if (rc)
493 goto out_free;
e0007529
EP
494 opts->mnt_opts[i] = context;
495 opts->mnt_opts_flags[i++] = CONTEXT_MNT;
c9180a57
EP
496 }
497 if (sbsec->flags & DEFCONTEXT_MNT) {
498 rc = security_sid_to_context(sbsec->def_sid, &context, &len);
499 if (rc)
500 goto out_free;
e0007529
EP
501 opts->mnt_opts[i] = context;
502 opts->mnt_opts_flags[i++] = DEFCONTEXT_MNT;
c9180a57
EP
503 }
504 if (sbsec->flags & ROOTCONTEXT_MNT) {
505 struct inode *root = sbsec->sb->s_root->d_inode;
506 struct inode_security_struct *isec = root->i_security;
0808925e 507
c9180a57
EP
508 rc = security_sid_to_context(isec->sid, &context, &len);
509 if (rc)
510 goto out_free;
e0007529
EP
511 opts->mnt_opts[i] = context;
512 opts->mnt_opts_flags[i++] = ROOTCONTEXT_MNT;
c9180a57 513 }
11689d47
DQ
514 if (sbsec->flags & SE_SBLABELSUPP) {
515 opts->mnt_opts[i] = NULL;
516 opts->mnt_opts_flags[i++] = SE_SBLABELSUPP;
517 }
1da177e4 518
e0007529 519 BUG_ON(i != opts->num_mnt_opts);
1da177e4 520
c9180a57
EP
521 return 0;
522
523out_free:
e0007529 524 security_free_mnt_opts(opts);
c9180a57
EP
525 return rc;
526}
1da177e4 527
c9180a57
EP
528static int bad_option(struct superblock_security_struct *sbsec, char flag,
529 u32 old_sid, u32 new_sid)
530{
0d90a7ec
DQ
531 char mnt_flags = sbsec->flags & SE_MNTMASK;
532
c9180a57 533 /* check if the old mount command had the same options */
0d90a7ec 534 if (sbsec->flags & SE_SBINITIALIZED)
c9180a57
EP
535 if (!(sbsec->flags & flag) ||
536 (old_sid != new_sid))
537 return 1;
538
539 /* check if we were passed the same options twice,
540 * aka someone passed context=a,context=b
541 */
0d90a7ec
DQ
542 if (!(sbsec->flags & SE_SBINITIALIZED))
543 if (mnt_flags & flag)
c9180a57
EP
544 return 1;
545 return 0;
546}
e0007529 547
c9180a57
EP
548/*
549 * Allow filesystems with binary mount data to explicitly set mount point
550 * labeling information.
551 */
e0007529
EP
552static int selinux_set_mnt_opts(struct super_block *sb,
553 struct security_mnt_opts *opts)
c9180a57 554{
275bb41e 555 const struct cred *cred = current_cred();
c9180a57 556 int rc = 0, i;
c9180a57
EP
557 struct superblock_security_struct *sbsec = sb->s_security;
558 const char *name = sb->s_type->name;
089be43e
JM
559 struct inode *inode = sbsec->sb->s_root->d_inode;
560 struct inode_security_struct *root_isec = inode->i_security;
c9180a57
EP
561 u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0;
562 u32 defcontext_sid = 0;
e0007529
EP
563 char **mount_options = opts->mnt_opts;
564 int *flags = opts->mnt_opts_flags;
565 int num_opts = opts->num_mnt_opts;
c9180a57
EP
566
567 mutex_lock(&sbsec->lock);
568
569 if (!ss_initialized) {
570 if (!num_opts) {
571 /* Defer initialization until selinux_complete_init,
572 after the initial policy is loaded and the security
573 server is ready to handle calls. */
c9180a57
EP
574 goto out;
575 }
576 rc = -EINVAL;
744ba35e
EP
577 printk(KERN_WARNING "SELinux: Unable to set superblock options "
578 "before the security server is initialized\n");
1da177e4 579 goto out;
c9180a57 580 }
1da177e4 581
e0007529
EP
582 /*
583 * Binary mount data FS will come through this function twice. Once
584 * from an explicit call and once from the generic calls from the vfs.
585 * Since the generic VFS calls will not contain any security mount data
586 * we need to skip the double mount verification.
587 *
588 * This does open a hole in which we will not notice if the first
589 * mount using this sb set explict options and a second mount using
590 * this sb does not set any security options. (The first options
591 * will be used for both mounts)
592 */
0d90a7ec 593 if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
e0007529 594 && (num_opts == 0))
f5269710 595 goto out;
e0007529 596
c9180a57
EP
597 /*
598 * parse the mount options, check if they are valid sids.
599 * also check if someone is trying to mount the same sb more
600 * than once with different security options.
601 */
602 for (i = 0; i < num_opts; i++) {
603 u32 sid;
11689d47
DQ
604
605 if (flags[i] == SE_SBLABELSUPP)
606 continue;
c9180a57
EP
607 rc = security_context_to_sid(mount_options[i],
608 strlen(mount_options[i]), &sid);
1da177e4
LT
609 if (rc) {
610 printk(KERN_WARNING "SELinux: security_context_to_sid"
611 "(%s) failed for (dev %s, type %s) errno=%d\n",
c9180a57
EP
612 mount_options[i], sb->s_id, name, rc);
613 goto out;
614 }
615 switch (flags[i]) {
616 case FSCONTEXT_MNT:
617 fscontext_sid = sid;
618
619 if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid,
620 fscontext_sid))
621 goto out_double_mount;
622
623 sbsec->flags |= FSCONTEXT_MNT;
624 break;
625 case CONTEXT_MNT:
626 context_sid = sid;
627
628 if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid,
629 context_sid))
630 goto out_double_mount;
631
632 sbsec->flags |= CONTEXT_MNT;
633 break;
634 case ROOTCONTEXT_MNT:
635 rootcontext_sid = sid;
636
637 if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid,
638 rootcontext_sid))
639 goto out_double_mount;
640
641 sbsec->flags |= ROOTCONTEXT_MNT;
642
643 break;
644 case DEFCONTEXT_MNT:
645 defcontext_sid = sid;
646
647 if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid,
648 defcontext_sid))
649 goto out_double_mount;
650
651 sbsec->flags |= DEFCONTEXT_MNT;
652
653 break;
654 default:
655 rc = -EINVAL;
656 goto out;
1da177e4 657 }
c9180a57
EP
658 }
659
0d90a7ec 660 if (sbsec->flags & SE_SBINITIALIZED) {
c9180a57 661 /* previously mounted with options, but not on this attempt? */
0d90a7ec 662 if ((sbsec->flags & SE_MNTMASK) && !num_opts)
c9180a57
EP
663 goto out_double_mount;
664 rc = 0;
665 goto out;
666 }
667
089be43e 668 if (strcmp(sb->s_type->name, "proc") == 0)
0d90a7ec 669 sbsec->flags |= SE_SBPROC;
c9180a57
EP
670
671 /* Determine the labeling behavior to use for this filesystem type. */
0d90a7ec 672 rc = security_fs_use((sbsec->flags & SE_SBPROC) ? "proc" : sb->s_type->name, &sbsec->behavior, &sbsec->sid);
c9180a57
EP
673 if (rc) {
674 printk(KERN_WARNING "%s: security_fs_use(%s) returned %d\n",
089be43e 675 __func__, sb->s_type->name, rc);
c9180a57
EP
676 goto out;
677 }
1da177e4 678
c9180a57
EP
679 /* sets the context of the superblock for the fs being mounted. */
680 if (fscontext_sid) {
275bb41e 681 rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred);
1da177e4 682 if (rc)
c9180a57 683 goto out;
1da177e4 684
c9180a57 685 sbsec->sid = fscontext_sid;
c312feb2
EP
686 }
687
688 /*
689 * Switch to using mount point labeling behavior.
690 * sets the label used on all file below the mountpoint, and will set
691 * the superblock context if not already set.
692 */
c9180a57
EP
693 if (context_sid) {
694 if (!fscontext_sid) {
275bb41e
DH
695 rc = may_context_mount_sb_relabel(context_sid, sbsec,
696 cred);
b04ea3ce 697 if (rc)
c9180a57
EP
698 goto out;
699 sbsec->sid = context_sid;
b04ea3ce 700 } else {
275bb41e
DH
701 rc = may_context_mount_inode_relabel(context_sid, sbsec,
702 cred);
b04ea3ce 703 if (rc)
c9180a57 704 goto out;
b04ea3ce 705 }
c9180a57
EP
706 if (!rootcontext_sid)
707 rootcontext_sid = context_sid;
1da177e4 708
c9180a57 709 sbsec->mntpoint_sid = context_sid;
c312feb2 710 sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
1da177e4
LT
711 }
712
c9180a57 713 if (rootcontext_sid) {
275bb41e
DH
714 rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec,
715 cred);
0808925e 716 if (rc)
c9180a57 717 goto out;
0808925e 718
c9180a57
EP
719 root_isec->sid = rootcontext_sid;
720 root_isec->initialized = 1;
0808925e
EP
721 }
722
c9180a57
EP
723 if (defcontext_sid) {
724 if (sbsec->behavior != SECURITY_FS_USE_XATTR) {
725 rc = -EINVAL;
726 printk(KERN_WARNING "SELinux: defcontext option is "
727 "invalid for this filesystem type\n");
728 goto out;
1da177e4
LT
729 }
730
c9180a57
EP
731 if (defcontext_sid != sbsec->def_sid) {
732 rc = may_context_mount_inode_relabel(defcontext_sid,
275bb41e 733 sbsec, cred);
c9180a57
EP
734 if (rc)
735 goto out;
736 }
1da177e4 737
c9180a57 738 sbsec->def_sid = defcontext_sid;
1da177e4
LT
739 }
740
c9180a57 741 rc = sb_finish_set_opts(sb);
1da177e4 742out:
c9180a57 743 mutex_unlock(&sbsec->lock);
1da177e4 744 return rc;
c9180a57
EP
745out_double_mount:
746 rc = -EINVAL;
747 printk(KERN_WARNING "SELinux: mount invalid. Same superblock, different "
748 "security settings for (dev %s, type %s)\n", sb->s_id, name);
749 goto out;
1da177e4
LT
750}
751
c9180a57
EP
752static void selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
753 struct super_block *newsb)
1da177e4 754{
c9180a57
EP
755 const struct superblock_security_struct *oldsbsec = oldsb->s_security;
756 struct superblock_security_struct *newsbsec = newsb->s_security;
1da177e4 757
c9180a57
EP
758 int set_fscontext = (oldsbsec->flags & FSCONTEXT_MNT);
759 int set_context = (oldsbsec->flags & CONTEXT_MNT);
760 int set_rootcontext = (oldsbsec->flags & ROOTCONTEXT_MNT);
1da177e4 761
0f5e6420
EP
762 /*
763 * if the parent was able to be mounted it clearly had no special lsm
e8c26255 764 * mount options. thus we can safely deal with this superblock later
0f5e6420 765 */
e8c26255 766 if (!ss_initialized)
0f5e6420 767 return;
c9180a57 768
c9180a57 769 /* how can we clone if the old one wasn't set up?? */
0d90a7ec 770 BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED));
c9180a57 771
5a552617 772 /* if fs is reusing a sb, just let its options stand... */
0d90a7ec 773 if (newsbsec->flags & SE_SBINITIALIZED)
5a552617
EP
774 return;
775
c9180a57
EP
776 mutex_lock(&newsbsec->lock);
777
778 newsbsec->flags = oldsbsec->flags;
779
780 newsbsec->sid = oldsbsec->sid;
781 newsbsec->def_sid = oldsbsec->def_sid;
782 newsbsec->behavior = oldsbsec->behavior;
783
784 if (set_context) {
785 u32 sid = oldsbsec->mntpoint_sid;
786
787 if (!set_fscontext)
788 newsbsec->sid = sid;
789 if (!set_rootcontext) {
790 struct inode *newinode = newsb->s_root->d_inode;
791 struct inode_security_struct *newisec = newinode->i_security;
792 newisec->sid = sid;
793 }
794 newsbsec->mntpoint_sid = sid;
1da177e4 795 }
c9180a57
EP
796 if (set_rootcontext) {
797 const struct inode *oldinode = oldsb->s_root->d_inode;
798 const struct inode_security_struct *oldisec = oldinode->i_security;
799 struct inode *newinode = newsb->s_root->d_inode;
800 struct inode_security_struct *newisec = newinode->i_security;
1da177e4 801
c9180a57 802 newisec->sid = oldisec->sid;
1da177e4
LT
803 }
804
c9180a57
EP
805 sb_finish_set_opts(newsb);
806 mutex_unlock(&newsbsec->lock);
807}
808
2e1479d9
AB
809static int selinux_parse_opts_str(char *options,
810 struct security_mnt_opts *opts)
c9180a57 811{
e0007529 812 char *p;
c9180a57
EP
813 char *context = NULL, *defcontext = NULL;
814 char *fscontext = NULL, *rootcontext = NULL;
e0007529 815 int rc, num_mnt_opts = 0;
1da177e4 816
e0007529 817 opts->num_mnt_opts = 0;
1da177e4 818
c9180a57
EP
819 /* Standard string-based options. */
820 while ((p = strsep(&options, "|")) != NULL) {
821 int token;
822 substring_t args[MAX_OPT_ARGS];
1da177e4 823
c9180a57
EP
824 if (!*p)
825 continue;
1da177e4 826
c9180a57 827 token = match_token(p, tokens, args);
1da177e4 828
c9180a57
EP
829 switch (token) {
830 case Opt_context:
831 if (context || defcontext) {
832 rc = -EINVAL;
833 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
834 goto out_err;
835 }
836 context = match_strdup(&args[0]);
837 if (!context) {
838 rc = -ENOMEM;
839 goto out_err;
840 }
841 break;
842
843 case Opt_fscontext:
844 if (fscontext) {
845 rc = -EINVAL;
846 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
847 goto out_err;
848 }
849 fscontext = match_strdup(&args[0]);
850 if (!fscontext) {
851 rc = -ENOMEM;
852 goto out_err;
853 }
854 break;
855
856 case Opt_rootcontext:
857 if (rootcontext) {
858 rc = -EINVAL;
859 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
860 goto out_err;
861 }
862 rootcontext = match_strdup(&args[0]);
863 if (!rootcontext) {
864 rc = -ENOMEM;
865 goto out_err;
866 }
867 break;
868
869 case Opt_defcontext:
870 if (context || defcontext) {
871 rc = -EINVAL;
872 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
873 goto out_err;
874 }
875 defcontext = match_strdup(&args[0]);
876 if (!defcontext) {
877 rc = -ENOMEM;
878 goto out_err;
879 }
880 break;
11689d47
DQ
881 case Opt_labelsupport:
882 break;
c9180a57
EP
883 default:
884 rc = -EINVAL;
885 printk(KERN_WARNING "SELinux: unknown mount option\n");
886 goto out_err;
1da177e4 887
1da177e4 888 }
1da177e4 889 }
c9180a57 890
e0007529
EP
891 rc = -ENOMEM;
892 opts->mnt_opts = kcalloc(NUM_SEL_MNT_OPTS, sizeof(char *), GFP_ATOMIC);
893 if (!opts->mnt_opts)
894 goto out_err;
895
896 opts->mnt_opts_flags = kcalloc(NUM_SEL_MNT_OPTS, sizeof(int), GFP_ATOMIC);
897 if (!opts->mnt_opts_flags) {
898 kfree(opts->mnt_opts);
899 goto out_err;
900 }
901
c9180a57 902 if (fscontext) {
e0007529
EP
903 opts->mnt_opts[num_mnt_opts] = fscontext;
904 opts->mnt_opts_flags[num_mnt_opts++] = FSCONTEXT_MNT;
c9180a57
EP
905 }
906 if (context) {
e0007529
EP
907 opts->mnt_opts[num_mnt_opts] = context;
908 opts->mnt_opts_flags[num_mnt_opts++] = CONTEXT_MNT;
c9180a57
EP
909 }
910 if (rootcontext) {
e0007529
EP
911 opts->mnt_opts[num_mnt_opts] = rootcontext;
912 opts->mnt_opts_flags[num_mnt_opts++] = ROOTCONTEXT_MNT;
c9180a57
EP
913 }
914 if (defcontext) {
e0007529
EP
915 opts->mnt_opts[num_mnt_opts] = defcontext;
916 opts->mnt_opts_flags[num_mnt_opts++] = DEFCONTEXT_MNT;
c9180a57
EP
917 }
918
e0007529
EP
919 opts->num_mnt_opts = num_mnt_opts;
920 return 0;
921
c9180a57
EP
922out_err:
923 kfree(context);
924 kfree(defcontext);
925 kfree(fscontext);
926 kfree(rootcontext);
1da177e4
LT
927 return rc;
928}
e0007529
EP
929/*
930 * string mount options parsing and call set the sbsec
931 */
932static int superblock_doinit(struct super_block *sb, void *data)
933{
934 int rc = 0;
935 char *options = data;
936 struct security_mnt_opts opts;
937
938 security_init_mnt_opts(&opts);
939
940 if (!data)
941 goto out;
942
943 BUG_ON(sb->s_type->fs_flags & FS_BINARY_MOUNTDATA);
944
945 rc = selinux_parse_opts_str(options, &opts);
946 if (rc)
947 goto out_err;
948
949out:
950 rc = selinux_set_mnt_opts(sb, &opts);
951
952out_err:
953 security_free_mnt_opts(&opts);
954 return rc;
955}
1da177e4 956
3583a711
AB
957static void selinux_write_opts(struct seq_file *m,
958 struct security_mnt_opts *opts)
2069f457
EP
959{
960 int i;
961 char *prefix;
962
963 for (i = 0; i < opts->num_mnt_opts; i++) {
11689d47
DQ
964 char *has_comma;
965
966 if (opts->mnt_opts[i])
967 has_comma = strchr(opts->mnt_opts[i], ',');
968 else
969 has_comma = NULL;
2069f457
EP
970
971 switch (opts->mnt_opts_flags[i]) {
972 case CONTEXT_MNT:
973 prefix = CONTEXT_STR;
974 break;
975 case FSCONTEXT_MNT:
976 prefix = FSCONTEXT_STR;
977 break;
978 case ROOTCONTEXT_MNT:
979 prefix = ROOTCONTEXT_STR;
980 break;
981 case DEFCONTEXT_MNT:
982 prefix = DEFCONTEXT_STR;
983 break;
11689d47
DQ
984 case SE_SBLABELSUPP:
985 seq_putc(m, ',');
986 seq_puts(m, LABELSUPP_STR);
987 continue;
2069f457
EP
988 default:
989 BUG();
a35c6c83 990 return;
2069f457
EP
991 };
992 /* we need a comma before each option */
993 seq_putc(m, ',');
994 seq_puts(m, prefix);
995 if (has_comma)
996 seq_putc(m, '\"');
997 seq_puts(m, opts->mnt_opts[i]);
998 if (has_comma)
999 seq_putc(m, '\"');
1000 }
1001}
1002
1003static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb)
1004{
1005 struct security_mnt_opts opts;
1006 int rc;
1007
1008 rc = selinux_get_mnt_opts(sb, &opts);
383795c2
EP
1009 if (rc) {
1010 /* before policy load we may get EINVAL, don't show anything */
1011 if (rc == -EINVAL)
1012 rc = 0;
2069f457 1013 return rc;
383795c2 1014 }
2069f457
EP
1015
1016 selinux_write_opts(m, &opts);
1017
1018 security_free_mnt_opts(&opts);
1019
1020 return rc;
1021}
1022
1da177e4
LT
1023static inline u16 inode_mode_to_security_class(umode_t mode)
1024{
1025 switch (mode & S_IFMT) {
1026 case S_IFSOCK:
1027 return SECCLASS_SOCK_FILE;
1028 case S_IFLNK:
1029 return SECCLASS_LNK_FILE;
1030 case S_IFREG:
1031 return SECCLASS_FILE;
1032 case S_IFBLK:
1033 return SECCLASS_BLK_FILE;
1034 case S_IFDIR:
1035 return SECCLASS_DIR;
1036 case S_IFCHR:
1037 return SECCLASS_CHR_FILE;
1038 case S_IFIFO:
1039 return SECCLASS_FIFO_FILE;
1040
1041 }
1042
1043 return SECCLASS_FILE;
1044}
1045
13402580
JM
1046static inline int default_protocol_stream(int protocol)
1047{
1048 return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP);
1049}
1050
1051static inline int default_protocol_dgram(int protocol)
1052{
1053 return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP);
1054}
1055
1da177e4
LT
1056static inline u16 socket_type_to_security_class(int family, int type, int protocol)
1057{
1058 switch (family) {
1059 case PF_UNIX:
1060 switch (type) {
1061 case SOCK_STREAM:
1062 case SOCK_SEQPACKET:
1063 return SECCLASS_UNIX_STREAM_SOCKET;
1064 case SOCK_DGRAM:
1065 return SECCLASS_UNIX_DGRAM_SOCKET;
1066 }
1067 break;
1068 case PF_INET:
1069 case PF_INET6:
1070 switch (type) {
1071 case SOCK_STREAM:
13402580
JM
1072 if (default_protocol_stream(protocol))
1073 return SECCLASS_TCP_SOCKET;
1074 else
1075 return SECCLASS_RAWIP_SOCKET;
1da177e4 1076 case SOCK_DGRAM:
13402580
JM
1077 if (default_protocol_dgram(protocol))
1078 return SECCLASS_UDP_SOCKET;
1079 else
1080 return SECCLASS_RAWIP_SOCKET;
2ee92d46
JM
1081 case SOCK_DCCP:
1082 return SECCLASS_DCCP_SOCKET;
13402580 1083 default:
1da177e4
LT
1084 return SECCLASS_RAWIP_SOCKET;
1085 }
1086 break;
1087 case PF_NETLINK:
1088 switch (protocol) {
1089 case NETLINK_ROUTE:
1090 return SECCLASS_NETLINK_ROUTE_SOCKET;
1091 case NETLINK_FIREWALL:
1092 return SECCLASS_NETLINK_FIREWALL_SOCKET;
216efaaa 1093 case NETLINK_INET_DIAG:
1da177e4
LT
1094 return SECCLASS_NETLINK_TCPDIAG_SOCKET;
1095 case NETLINK_NFLOG:
1096 return SECCLASS_NETLINK_NFLOG_SOCKET;
1097 case NETLINK_XFRM:
1098 return SECCLASS_NETLINK_XFRM_SOCKET;
1099 case NETLINK_SELINUX:
1100 return SECCLASS_NETLINK_SELINUX_SOCKET;
1101 case NETLINK_AUDIT:
1102 return SECCLASS_NETLINK_AUDIT_SOCKET;
1103 case NETLINK_IP6_FW:
1104 return SECCLASS_NETLINK_IP6FW_SOCKET;
1105 case NETLINK_DNRTMSG:
1106 return SECCLASS_NETLINK_DNRT_SOCKET;
0c9b7942
JM
1107 case NETLINK_KOBJECT_UEVENT:
1108 return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET;
1da177e4
LT
1109 default:
1110 return SECCLASS_NETLINK_SOCKET;
1111 }
1112 case PF_PACKET:
1113 return SECCLASS_PACKET_SOCKET;
1114 case PF_KEY:
1115 return SECCLASS_KEY_SOCKET;
3e3ff15e
CP
1116 case PF_APPLETALK:
1117 return SECCLASS_APPLETALK_SOCKET;
1da177e4
LT
1118 }
1119
1120 return SECCLASS_SOCKET;
1121}
1122
1123#ifdef CONFIG_PROC_FS
8e6c9693 1124static int selinux_proc_get_sid(struct dentry *dentry,
1da177e4
LT
1125 u16 tclass,
1126 u32 *sid)
1127{
8e6c9693
LAG
1128 int rc;
1129 char *buffer, *path;
1da177e4 1130
828dfe1d 1131 buffer = (char *)__get_free_page(GFP_KERNEL);
1da177e4
LT
1132 if (!buffer)
1133 return -ENOMEM;
1134
8e6c9693
LAG
1135 path = dentry_path_raw(dentry, buffer, PAGE_SIZE);
1136 if (IS_ERR(path))
1137 rc = PTR_ERR(path);
1138 else {
1139 /* each process gets a /proc/PID/ entry. Strip off the
1140 * PID part to get a valid selinux labeling.
1141 * e.g. /proc/1/net/rpc/nfs -> /net/rpc/nfs */
1142 while (path[1] >= '0' && path[1] <= '9') {
1143 path[1] = '/';
1144 path++;
1145 }
1146 rc = security_genfs_sid("proc", path, tclass, sid);
1da177e4 1147 }
1da177e4
LT
1148 free_page((unsigned long)buffer);
1149 return rc;
1150}
1151#else
8e6c9693 1152static int selinux_proc_get_sid(struct dentry *dentry,
1da177e4
LT
1153 u16 tclass,
1154 u32 *sid)
1155{
1156 return -EINVAL;
1157}
1158#endif
1159
1160/* The inode's security attributes must be initialized before first use. */
1161static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry)
1162{
1163 struct superblock_security_struct *sbsec = NULL;
1164 struct inode_security_struct *isec = inode->i_security;
1165 u32 sid;
1166 struct dentry *dentry;
1167#define INITCONTEXTLEN 255
1168 char *context = NULL;
1169 unsigned len = 0;
1170 int rc = 0;
1da177e4
LT
1171
1172 if (isec->initialized)
1173 goto out;
1174
23970741 1175 mutex_lock(&isec->lock);
1da177e4 1176 if (isec->initialized)
23970741 1177 goto out_unlock;
1da177e4
LT
1178
1179 sbsec = inode->i_sb->s_security;
0d90a7ec 1180 if (!(sbsec->flags & SE_SBINITIALIZED)) {
1da177e4
LT
1181 /* Defer initialization until selinux_complete_init,
1182 after the initial policy is loaded and the security
1183 server is ready to handle calls. */
1184 spin_lock(&sbsec->isec_lock);
1185 if (list_empty(&isec->list))
1186 list_add(&isec->list, &sbsec->isec_head);
1187 spin_unlock(&sbsec->isec_lock);
23970741 1188 goto out_unlock;
1da177e4
LT
1189 }
1190
1191 switch (sbsec->behavior) {
1192 case SECURITY_FS_USE_XATTR:
1193 if (!inode->i_op->getxattr) {
1194 isec->sid = sbsec->def_sid;
1195 break;
1196 }
1197
1198 /* Need a dentry, since the xattr API requires one.
1199 Life would be simpler if we could just pass the inode. */
1200 if (opt_dentry) {
1201 /* Called from d_instantiate or d_splice_alias. */
1202 dentry = dget(opt_dentry);
1203 } else {
1204 /* Called from selinux_complete_init, try to find a dentry. */
1205 dentry = d_find_alias(inode);
1206 }
1207 if (!dentry) {
df7f54c0
EP
1208 /*
1209 * this is can be hit on boot when a file is accessed
1210 * before the policy is loaded. When we load policy we
1211 * may find inodes that have no dentry on the
1212 * sbsec->isec_head list. No reason to complain as these
1213 * will get fixed up the next time we go through
1214 * inode_doinit with a dentry, before these inodes could
1215 * be used again by userspace.
1216 */
23970741 1217 goto out_unlock;
1da177e4
LT
1218 }
1219
1220 len = INITCONTEXTLEN;
4cb912f1 1221 context = kmalloc(len+1, GFP_NOFS);
1da177e4
LT
1222 if (!context) {
1223 rc = -ENOMEM;
1224 dput(dentry);
23970741 1225 goto out_unlock;
1da177e4 1226 }
4cb912f1 1227 context[len] = '\0';
1da177e4
LT
1228 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
1229 context, len);
1230 if (rc == -ERANGE) {
314dabb8
JM
1231 kfree(context);
1232
1da177e4
LT
1233 /* Need a larger buffer. Query for the right size. */
1234 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
1235 NULL, 0);
1236 if (rc < 0) {
1237 dput(dentry);
23970741 1238 goto out_unlock;
1da177e4 1239 }
1da177e4 1240 len = rc;
4cb912f1 1241 context = kmalloc(len+1, GFP_NOFS);
1da177e4
LT
1242 if (!context) {
1243 rc = -ENOMEM;
1244 dput(dentry);
23970741 1245 goto out_unlock;
1da177e4 1246 }
4cb912f1 1247 context[len] = '\0';
1da177e4
LT
1248 rc = inode->i_op->getxattr(dentry,
1249 XATTR_NAME_SELINUX,
1250 context, len);
1251 }
1252 dput(dentry);
1253 if (rc < 0) {
1254 if (rc != -ENODATA) {
744ba35e 1255 printk(KERN_WARNING "SELinux: %s: getxattr returned "
dd6f953a 1256 "%d for dev=%s ino=%ld\n", __func__,
1da177e4
LT
1257 -rc, inode->i_sb->s_id, inode->i_ino);
1258 kfree(context);
23970741 1259 goto out_unlock;
1da177e4
LT
1260 }
1261 /* Map ENODATA to the default file SID */
1262 sid = sbsec->def_sid;
1263 rc = 0;
1264 } else {
f5c1d5b2 1265 rc = security_context_to_sid_default(context, rc, &sid,
869ab514
SS
1266 sbsec->def_sid,
1267 GFP_NOFS);
1da177e4 1268 if (rc) {
4ba0a8ad
EP
1269 char *dev = inode->i_sb->s_id;
1270 unsigned long ino = inode->i_ino;
1271
1272 if (rc == -EINVAL) {
1273 if (printk_ratelimit())
1274 printk(KERN_NOTICE "SELinux: inode=%lu on dev=%s was found to have an invalid "
1275 "context=%s. This indicates you may need to relabel the inode or the "
1276 "filesystem in question.\n", ino, dev, context);
1277 } else {
1278 printk(KERN_WARNING "SELinux: %s: context_to_sid(%s) "
1279 "returned %d for dev=%s ino=%ld\n",
1280 __func__, context, -rc, dev, ino);
1281 }
1da177e4
LT
1282 kfree(context);
1283 /* Leave with the unlabeled SID */
1284 rc = 0;
1285 break;
1286 }
1287 }
1288 kfree(context);
1289 isec->sid = sid;
1290 break;
1291 case SECURITY_FS_USE_TASK:
1292 isec->sid = isec->task_sid;
1293 break;
1294 case SECURITY_FS_USE_TRANS:
1295 /* Default to the fs SID. */
1296 isec->sid = sbsec->sid;
1297
1298 /* Try to obtain a transition SID. */
1299 isec->sclass = inode_mode_to_security_class(inode->i_mode);
652bb9b0
EP
1300 rc = security_transition_sid(isec->task_sid, sbsec->sid,
1301 isec->sclass, NULL, &sid);
1da177e4 1302 if (rc)
23970741 1303 goto out_unlock;
1da177e4
LT
1304 isec->sid = sid;
1305 break;
c312feb2
EP
1306 case SECURITY_FS_USE_MNTPOINT:
1307 isec->sid = sbsec->mntpoint_sid;
1308 break;
1da177e4 1309 default:
c312feb2 1310 /* Default to the fs superblock SID. */
1da177e4
LT
1311 isec->sid = sbsec->sid;
1312
0d90a7ec 1313 if ((sbsec->flags & SE_SBPROC) && !S_ISLNK(inode->i_mode)) {
8e6c9693 1314 if (opt_dentry) {
1da177e4 1315 isec->sclass = inode_mode_to_security_class(inode->i_mode);
8e6c9693 1316 rc = selinux_proc_get_sid(opt_dentry,
1da177e4
LT
1317 isec->sclass,
1318 &sid);
1319 if (rc)
23970741 1320 goto out_unlock;
1da177e4
LT
1321 isec->sid = sid;
1322 }
1323 }
1324 break;
1325 }
1326
1327 isec->initialized = 1;
1328
23970741
EP
1329out_unlock:
1330 mutex_unlock(&isec->lock);
1da177e4
LT
1331out:
1332 if (isec->sclass == SECCLASS_FILE)
1333 isec->sclass = inode_mode_to_security_class(inode->i_mode);
1da177e4
LT
1334 return rc;
1335}
1336
1337/* Convert a Linux signal to an access vector. */
1338static inline u32 signal_to_av(int sig)
1339{
1340 u32 perm = 0;
1341
1342 switch (sig) {
1343 case SIGCHLD:
1344 /* Commonly granted from child to parent. */
1345 perm = PROCESS__SIGCHLD;
1346 break;
1347 case SIGKILL:
1348 /* Cannot be caught or ignored */
1349 perm = PROCESS__SIGKILL;
1350 break;
1351 case SIGSTOP:
1352 /* Cannot be caught or ignored */
1353 perm = PROCESS__SIGSTOP;
1354 break;
1355 default:
1356 /* All other signals. */
1357 perm = PROCESS__SIGNAL;
1358 break;
1359 }
1360
1361 return perm;
1362}
1363
d84f4f99
DH
1364/*
1365 * Check permission between a pair of credentials
1366 * fork check, ptrace check, etc.
1367 */
1368static int cred_has_perm(const struct cred *actor,
1369 const struct cred *target,
1370 u32 perms)
1371{
1372 u32 asid = cred_sid(actor), tsid = cred_sid(target);
1373
1374 return avc_has_perm(asid, tsid, SECCLASS_PROCESS, perms, NULL);
1375}
1376
275bb41e 1377/*
88e67f3b 1378 * Check permission between a pair of tasks, e.g. signal checks,
275bb41e
DH
1379 * fork check, ptrace check, etc.
1380 * tsk1 is the actor and tsk2 is the target
3b11a1de 1381 * - this uses the default subjective creds of tsk1
275bb41e
DH
1382 */
1383static int task_has_perm(const struct task_struct *tsk1,
1384 const struct task_struct *tsk2,
1da177e4
LT
1385 u32 perms)
1386{
275bb41e
DH
1387 const struct task_security_struct *__tsec1, *__tsec2;
1388 u32 sid1, sid2;
1da177e4 1389
275bb41e
DH
1390 rcu_read_lock();
1391 __tsec1 = __task_cred(tsk1)->security; sid1 = __tsec1->sid;
1392 __tsec2 = __task_cred(tsk2)->security; sid2 = __tsec2->sid;
1393 rcu_read_unlock();
1394 return avc_has_perm(sid1, sid2, SECCLASS_PROCESS, perms, NULL);
1da177e4
LT
1395}
1396
3b11a1de
DH
1397/*
1398 * Check permission between current and another task, e.g. signal checks,
1399 * fork check, ptrace check, etc.
1400 * current is the actor and tsk2 is the target
1401 * - this uses current's subjective creds
1402 */
1403static int current_has_perm(const struct task_struct *tsk,
1404 u32 perms)
1405{
1406 u32 sid, tsid;
1407
1408 sid = current_sid();
1409 tsid = task_sid(tsk);
1410 return avc_has_perm(sid, tsid, SECCLASS_PROCESS, perms, NULL);
1411}
1412
b68e418c
SS
1413#if CAP_LAST_CAP > 63
1414#error Fix SELinux to handle capabilities > 63.
1415#endif
1416
1da177e4
LT
1417/* Check whether a task is allowed to use a capability. */
1418static int task_has_capability(struct task_struct *tsk,
3699c53c 1419 const struct cred *cred,
06112163 1420 int cap, int audit)
1da177e4 1421{
2bf49690 1422 struct common_audit_data ad;
06112163 1423 struct av_decision avd;
b68e418c 1424 u16 sclass;
3699c53c 1425 u32 sid = cred_sid(cred);
b68e418c 1426 u32 av = CAP_TO_MASK(cap);
06112163 1427 int rc;
1da177e4 1428
2bf49690 1429 COMMON_AUDIT_DATA_INIT(&ad, CAP);
1da177e4
LT
1430 ad.tsk = tsk;
1431 ad.u.cap = cap;
1432
b68e418c
SS
1433 switch (CAP_TO_INDEX(cap)) {
1434 case 0:
1435 sclass = SECCLASS_CAPABILITY;
1436 break;
1437 case 1:
1438 sclass = SECCLASS_CAPABILITY2;
1439 break;
1440 default:
1441 printk(KERN_ERR
1442 "SELinux: out of range capability %d\n", cap);
1443 BUG();
a35c6c83 1444 return -EINVAL;
b68e418c 1445 }
06112163 1446
275bb41e 1447 rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd);
9ade0cf4
EP
1448 if (audit == SECURITY_CAP_AUDIT) {
1449 int rc2 = avc_audit(sid, sid, sclass, av, &avd, rc, &ad, 0);
1450 if (rc2)
1451 return rc2;
1452 }
06112163 1453 return rc;
1da177e4
LT
1454}
1455
1456/* Check whether a task is allowed to use a system operation. */
1457static int task_has_system(struct task_struct *tsk,
1458 u32 perms)
1459{
275bb41e 1460 u32 sid = task_sid(tsk);
1da177e4 1461
275bb41e 1462 return avc_has_perm(sid, SECINITSID_KERNEL,
1da177e4
LT
1463 SECCLASS_SYSTEM, perms, NULL);
1464}
1465
1466/* Check whether a task has a particular permission to an inode.
1467 The 'adp' parameter is optional and allows other audit
1468 data to be passed (e.g. the dentry). */
88e67f3b 1469static int inode_has_perm(const struct cred *cred,
1da177e4
LT
1470 struct inode *inode,
1471 u32 perms,
9ade0cf4
EP
1472 struct common_audit_data *adp,
1473 unsigned flags)
1da177e4 1474{
1da177e4 1475 struct inode_security_struct *isec;
275bb41e 1476 u32 sid;
1da177e4 1477
e0e81739
DH
1478 validate_creds(cred);
1479
828dfe1d 1480 if (unlikely(IS_PRIVATE(inode)))
bbaca6c2
SS
1481 return 0;
1482
88e67f3b 1483 sid = cred_sid(cred);
1da177e4
LT
1484 isec = inode->i_security;
1485
9ade0cf4 1486 return avc_has_perm_flags(sid, isec->sid, isec->sclass, perms, adp, flags);
1da177e4
LT
1487}
1488
95f4efb2
LT
1489static int inode_has_perm_noadp(const struct cred *cred,
1490 struct inode *inode,
1491 u32 perms,
1492 unsigned flags)
1493{
1494 struct common_audit_data ad;
1495
1496 COMMON_AUDIT_DATA_INIT(&ad, INODE);
1497 ad.u.inode = inode;
1498 return inode_has_perm(cred, inode, perms, &ad, flags);
1499}
1500
1da177e4
LT
1501/* Same as inode_has_perm, but pass explicit audit data containing
1502 the dentry to help the auditing code to more easily generate the
1503 pathname if needed. */
88e67f3b 1504static inline int dentry_has_perm(const struct cred *cred,
1da177e4
LT
1505 struct dentry *dentry,
1506 u32 av)
1507{
1508 struct inode *inode = dentry->d_inode;
2bf49690 1509 struct common_audit_data ad;
88e67f3b 1510
2875fa00
EP
1511 COMMON_AUDIT_DATA_INIT(&ad, DENTRY);
1512 ad.u.dentry = dentry;
1513 return inode_has_perm(cred, inode, av, &ad, 0);
1514}
1515
1516/* Same as inode_has_perm, but pass explicit audit data containing
1517 the path to help the auditing code to more easily generate the
1518 pathname if needed. */
1519static inline int path_has_perm(const struct cred *cred,
1520 struct path *path,
1521 u32 av)
1522{
1523 struct inode *inode = path->dentry->d_inode;
1524 struct common_audit_data ad;
1525
f48b7399 1526 COMMON_AUDIT_DATA_INIT(&ad, PATH);
2875fa00 1527 ad.u.path = *path;
9ade0cf4 1528 return inode_has_perm(cred, inode, av, &ad, 0);
1da177e4
LT
1529}
1530
1531/* Check whether a task can use an open file descriptor to
1532 access an inode in a given way. Check access to the
1533 descriptor itself, and then use dentry_has_perm to
1534 check a particular permission to the file.
1535 Access to the descriptor is implicitly granted if it
1536 has the same SID as the process. If av is zero, then
1537 access to the file is not checked, e.g. for cases
1538 where only the descriptor is affected like seek. */
88e67f3b
DH
1539static int file_has_perm(const struct cred *cred,
1540 struct file *file,
1541 u32 av)
1da177e4 1542{
1da177e4 1543 struct file_security_struct *fsec = file->f_security;
44707fdf 1544 struct inode *inode = file->f_path.dentry->d_inode;
2bf49690 1545 struct common_audit_data ad;
88e67f3b 1546 u32 sid = cred_sid(cred);
1da177e4
LT
1547 int rc;
1548
f48b7399
EP
1549 COMMON_AUDIT_DATA_INIT(&ad, PATH);
1550 ad.u.path = file->f_path;
1da177e4 1551
275bb41e
DH
1552 if (sid != fsec->sid) {
1553 rc = avc_has_perm(sid, fsec->sid,
1da177e4
LT
1554 SECCLASS_FD,
1555 FD__USE,
1556 &ad);
1557 if (rc)
88e67f3b 1558 goto out;
1da177e4
LT
1559 }
1560
1561 /* av is zero if only checking access to the descriptor. */
88e67f3b 1562 rc = 0;
1da177e4 1563 if (av)
9ade0cf4 1564 rc = inode_has_perm(cred, inode, av, &ad, 0);
1da177e4 1565
88e67f3b
DH
1566out:
1567 return rc;
1da177e4
LT
1568}
1569
1570/* Check whether a task can create a file. */
1571static int may_create(struct inode *dir,
1572 struct dentry *dentry,
1573 u16 tclass)
1574{
5fb49870 1575 const struct task_security_struct *tsec = current_security();
1da177e4
LT
1576 struct inode_security_struct *dsec;
1577 struct superblock_security_struct *sbsec;
275bb41e 1578 u32 sid, newsid;
2bf49690 1579 struct common_audit_data ad;
1da177e4
LT
1580 int rc;
1581
1da177e4
LT
1582 dsec = dir->i_security;
1583 sbsec = dir->i_sb->s_security;
1584
275bb41e
DH
1585 sid = tsec->sid;
1586 newsid = tsec->create_sid;
1587
a269434d
EP
1588 COMMON_AUDIT_DATA_INIT(&ad, DENTRY);
1589 ad.u.dentry = dentry;
1da177e4 1590
275bb41e 1591 rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR,
1da177e4
LT
1592 DIR__ADD_NAME | DIR__SEARCH,
1593 &ad);
1594 if (rc)
1595 return rc;
1596
cd89596f 1597 if (!newsid || !(sbsec->flags & SE_SBLABELSUPP)) {
cb1e922f
EP
1598 rc = security_transition_sid(sid, dsec->sid, tclass,
1599 &dentry->d_name, &newsid);
1da177e4
LT
1600 if (rc)
1601 return rc;
1602 }
1603
275bb41e 1604 rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad);
1da177e4
LT
1605 if (rc)
1606 return rc;
1607
1608 return avc_has_perm(newsid, sbsec->sid,
1609 SECCLASS_FILESYSTEM,
1610 FILESYSTEM__ASSOCIATE, &ad);
1611}
1612
4eb582cf
ML
1613/* Check whether a task can create a key. */
1614static int may_create_key(u32 ksid,
1615 struct task_struct *ctx)
1616{
275bb41e 1617 u32 sid = task_sid(ctx);
4eb582cf 1618
275bb41e 1619 return avc_has_perm(sid, ksid, SECCLASS_KEY, KEY__CREATE, NULL);
4eb582cf
ML
1620}
1621
828dfe1d
EP
1622#define MAY_LINK 0
1623#define MAY_UNLINK 1
1624#define MAY_RMDIR 2
1da177e4
LT
1625
1626/* Check whether a task can link, unlink, or rmdir a file/directory. */
1627static int may_link(struct inode *dir,
1628 struct dentry *dentry,
1629 int kind)
1630
1631{
1da177e4 1632 struct inode_security_struct *dsec, *isec;
2bf49690 1633 struct common_audit_data ad;
275bb41e 1634 u32 sid = current_sid();
1da177e4
LT
1635 u32 av;
1636 int rc;
1637
1da177e4
LT
1638 dsec = dir->i_security;
1639 isec = dentry->d_inode->i_security;
1640
a269434d
EP
1641 COMMON_AUDIT_DATA_INIT(&ad, DENTRY);
1642 ad.u.dentry = dentry;
1da177e4
LT
1643
1644 av = DIR__SEARCH;
1645 av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
275bb41e 1646 rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, av, &ad);
1da177e4
LT
1647 if (rc)
1648 return rc;
1649
1650 switch (kind) {
1651 case MAY_LINK:
1652 av = FILE__LINK;
1653 break;
1654 case MAY_UNLINK:
1655 av = FILE__UNLINK;
1656 break;
1657 case MAY_RMDIR:
1658 av = DIR__RMDIR;
1659 break;
1660 default:
744ba35e
EP
1661 printk(KERN_WARNING "SELinux: %s: unrecognized kind %d\n",
1662 __func__, kind);
1da177e4
LT
1663 return 0;
1664 }
1665
275bb41e 1666 rc = avc_has_perm(sid, isec->sid, isec->sclass, av, &ad);
1da177e4
LT
1667 return rc;
1668}
1669
1670static inline int may_rename(struct inode *old_dir,
1671 struct dentry *old_dentry,
1672 struct inode *new_dir,
1673 struct dentry *new_dentry)
1674{
1da177e4 1675 struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec;
2bf49690 1676 struct common_audit_data ad;
275bb41e 1677 u32 sid = current_sid();
1da177e4
LT
1678 u32 av;
1679 int old_is_dir, new_is_dir;
1680 int rc;
1681
1da177e4
LT
1682 old_dsec = old_dir->i_security;
1683 old_isec = old_dentry->d_inode->i_security;
1684 old_is_dir = S_ISDIR(old_dentry->d_inode->i_mode);
1685 new_dsec = new_dir->i_security;
1686
a269434d 1687 COMMON_AUDIT_DATA_INIT(&ad, DENTRY);
1da177e4 1688
a269434d 1689 ad.u.dentry = old_dentry;
275bb41e 1690 rc = avc_has_perm(sid, old_dsec->sid, SECCLASS_DIR,
1da177e4
LT
1691 DIR__REMOVE_NAME | DIR__SEARCH, &ad);
1692 if (rc)
1693 return rc;
275bb41e 1694 rc = avc_has_perm(sid, old_isec->sid,
1da177e4
LT
1695 old_isec->sclass, FILE__RENAME, &ad);
1696 if (rc)
1697 return rc;
1698 if (old_is_dir && new_dir != old_dir) {
275bb41e 1699 rc = avc_has_perm(sid, old_isec->sid,
1da177e4
LT
1700 old_isec->sclass, DIR__REPARENT, &ad);
1701 if (rc)
1702 return rc;
1703 }
1704
a269434d 1705 ad.u.dentry = new_dentry;
1da177e4
LT
1706 av = DIR__ADD_NAME | DIR__SEARCH;
1707 if (new_dentry->d_inode)
1708 av |= DIR__REMOVE_NAME;
275bb41e 1709 rc = avc_has_perm(sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
1da177e4
LT
1710 if (rc)
1711 return rc;
1712 if (new_dentry->d_inode) {
1713 new_isec = new_dentry->d_inode->i_security;
1714 new_is_dir = S_ISDIR(new_dentry->d_inode->i_mode);
275bb41e 1715 rc = avc_has_perm(sid, new_isec->sid,
1da177e4
LT
1716 new_isec->sclass,
1717 (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad);
1718 if (rc)
1719 return rc;
1720 }
1721
1722 return 0;
1723}
1724
1725/* Check whether a task can perform a filesystem operation. */
88e67f3b 1726static int superblock_has_perm(const struct cred *cred,
1da177e4
LT
1727 struct super_block *sb,
1728 u32 perms,
2bf49690 1729 struct common_audit_data *ad)
1da177e4 1730{
1da177e4 1731 struct superblock_security_struct *sbsec;
88e67f3b 1732 u32 sid = cred_sid(cred);
1da177e4 1733
1da177e4 1734 sbsec = sb->s_security;
275bb41e 1735 return avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad);
1da177e4
LT
1736}
1737
1738/* Convert a Linux mode and permission mask to an access vector. */
1739static inline u32 file_mask_to_av(int mode, int mask)
1740{
1741 u32 av = 0;
1742
dba19c60 1743 if (!S_ISDIR(mode)) {
1da177e4
LT
1744 if (mask & MAY_EXEC)
1745 av |= FILE__EXECUTE;
1746 if (mask & MAY_READ)
1747 av |= FILE__READ;
1748
1749 if (mask & MAY_APPEND)
1750 av |= FILE__APPEND;
1751 else if (mask & MAY_WRITE)
1752 av |= FILE__WRITE;
1753
1754 } else {
1755 if (mask & MAY_EXEC)
1756 av |= DIR__SEARCH;
1757 if (mask & MAY_WRITE)
1758 av |= DIR__WRITE;
1759 if (mask & MAY_READ)
1760 av |= DIR__READ;
1761 }
1762
1763 return av;
1764}
1765
8b6a5a37
EP
1766/* Convert a Linux file to an access vector. */
1767static inline u32 file_to_av(struct file *file)
1768{
1769 u32 av = 0;
1770
1771 if (file->f_mode & FMODE_READ)
1772 av |= FILE__READ;
1773 if (file->f_mode & FMODE_WRITE) {
1774 if (file->f_flags & O_APPEND)
1775 av |= FILE__APPEND;
1776 else
1777 av |= FILE__WRITE;
1778 }
1779 if (!av) {
1780 /*
1781 * Special file opened with flags 3 for ioctl-only use.
1782 */
1783 av = FILE__IOCTL;
1784 }
1785
1786 return av;
1787}
1788
b0c636b9 1789/*
8b6a5a37 1790 * Convert a file to an access vector and include the correct open
b0c636b9
EP
1791 * open permission.
1792 */
8b6a5a37 1793static inline u32 open_file_to_av(struct file *file)
b0c636b9 1794{
8b6a5a37 1795 u32 av = file_to_av(file);
b0c636b9 1796
49b7b8de
EP
1797 if (selinux_policycap_openperm)
1798 av |= FILE__OPEN;
1799
b0c636b9
EP
1800 return av;
1801}
1802
1da177e4
LT
1803/* Hook functions begin here. */
1804
9e48858f 1805static int selinux_ptrace_access_check(struct task_struct *child,
5cd9c58f 1806 unsigned int mode)
1da177e4 1807{
1da177e4
LT
1808 int rc;
1809
9e48858f 1810 rc = cap_ptrace_access_check(child, mode);
1da177e4
LT
1811 if (rc)
1812 return rc;
1813
006ebb40 1814 if (mode == PTRACE_MODE_READ) {
275bb41e
DH
1815 u32 sid = current_sid();
1816 u32 csid = task_sid(child);
1817 return avc_has_perm(sid, csid, SECCLASS_FILE, FILE__READ, NULL);
006ebb40
SS
1818 }
1819
3b11a1de 1820 return current_has_perm(child, PROCESS__PTRACE);
5cd9c58f
DH
1821}
1822
1823static int selinux_ptrace_traceme(struct task_struct *parent)
1824{
1825 int rc;
1826
200ac532 1827 rc = cap_ptrace_traceme(parent);
5cd9c58f
DH
1828 if (rc)
1829 return rc;
1830
1831 return task_has_perm(parent, current, PROCESS__PTRACE);
1da177e4
LT
1832}
1833
1834static int selinux_capget(struct task_struct *target, kernel_cap_t *effective,
828dfe1d 1835 kernel_cap_t *inheritable, kernel_cap_t *permitted)
1da177e4
LT
1836{
1837 int error;
1838
3b11a1de 1839 error = current_has_perm(target, PROCESS__GETCAP);
1da177e4
LT
1840 if (error)
1841 return error;
1842
200ac532 1843 return cap_capget(target, effective, inheritable, permitted);
1da177e4
LT
1844}
1845
d84f4f99
DH
1846static int selinux_capset(struct cred *new, const struct cred *old,
1847 const kernel_cap_t *effective,
1848 const kernel_cap_t *inheritable,
1849 const kernel_cap_t *permitted)
1da177e4
LT
1850{
1851 int error;
1852
200ac532 1853 error = cap_capset(new, old,
d84f4f99 1854 effective, inheritable, permitted);
1da177e4
LT
1855 if (error)
1856 return error;
1857
d84f4f99 1858 return cred_has_perm(old, new, PROCESS__SETCAP);
1da177e4
LT
1859}
1860
5626d3e8
JM
1861/*
1862 * (This comment used to live with the selinux_task_setuid hook,
1863 * which was removed).
1864 *
1865 * Since setuid only affects the current process, and since the SELinux
1866 * controls are not based on the Linux identity attributes, SELinux does not
1867 * need to control this operation. However, SELinux does control the use of
1868 * the CAP_SETUID and CAP_SETGID capabilities using the capable hook.
1869 */
1870
3699c53c 1871static int selinux_capable(struct task_struct *tsk, const struct cred *cred,
3486740a 1872 struct user_namespace *ns, int cap, int audit)
1da177e4
LT
1873{
1874 int rc;
1875
3486740a 1876 rc = cap_capable(tsk, cred, ns, cap, audit);
1da177e4
LT
1877 if (rc)
1878 return rc;
1879
3699c53c 1880 return task_has_capability(tsk, cred, cap, audit);
1da177e4
LT
1881}
1882
1da177e4
LT
1883static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb)
1884{
88e67f3b 1885 const struct cred *cred = current_cred();
1da177e4
LT
1886 int rc = 0;
1887
1888 if (!sb)
1889 return 0;
1890
1891 switch (cmds) {
828dfe1d
EP
1892 case Q_SYNC:
1893 case Q_QUOTAON:
1894 case Q_QUOTAOFF:
1895 case Q_SETINFO:
1896 case Q_SETQUOTA:
88e67f3b 1897 rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAMOD, NULL);
828dfe1d
EP
1898 break;
1899 case Q_GETFMT:
1900 case Q_GETINFO:
1901 case Q_GETQUOTA:
88e67f3b 1902 rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAGET, NULL);
828dfe1d
EP
1903 break;
1904 default:
1905 rc = 0; /* let the kernel handle invalid cmds */
1906 break;
1da177e4
LT
1907 }
1908 return rc;
1909}
1910
1911static int selinux_quota_on(struct dentry *dentry)
1912{
88e67f3b
DH
1913 const struct cred *cred = current_cred();
1914
2875fa00 1915 return dentry_has_perm(cred, dentry, FILE__QUOTAON);
1da177e4
LT
1916}
1917
12b3052c 1918static int selinux_syslog(int type)
1da177e4
LT
1919{
1920 int rc;
1921
1da177e4 1922 switch (type) {
d78ca3cd
KC
1923 case SYSLOG_ACTION_READ_ALL: /* Read last kernel messages */
1924 case SYSLOG_ACTION_SIZE_BUFFER: /* Return size of the log buffer */
828dfe1d
EP
1925 rc = task_has_system(current, SYSTEM__SYSLOG_READ);
1926 break;
d78ca3cd
KC
1927 case SYSLOG_ACTION_CONSOLE_OFF: /* Disable logging to console */
1928 case SYSLOG_ACTION_CONSOLE_ON: /* Enable logging to console */
1929 /* Set level of messages printed to console */
1930 case SYSLOG_ACTION_CONSOLE_LEVEL:
828dfe1d
EP
1931 rc = task_has_system(current, SYSTEM__SYSLOG_CONSOLE);
1932 break;
d78ca3cd
KC
1933 case SYSLOG_ACTION_CLOSE: /* Close log */
1934 case SYSLOG_ACTION_OPEN: /* Open log */
1935 case SYSLOG_ACTION_READ: /* Read from log */
1936 case SYSLOG_ACTION_READ_CLEAR: /* Read/clear last kernel messages */
1937 case SYSLOG_ACTION_CLEAR: /* Clear ring buffer */
828dfe1d
EP
1938 default:
1939 rc = task_has_system(current, SYSTEM__SYSLOG_MOD);
1940 break;
1da177e4
LT
1941 }
1942 return rc;
1943}
1944
1945/*
1946 * Check that a process has enough memory to allocate a new virtual
1947 * mapping. 0 means there is enough memory for the allocation to
1948 * succeed and -ENOMEM implies there is not.
1949 *
1da177e4
LT
1950 * Do not audit the selinux permission check, as this is applied to all
1951 * processes that allocate mappings.
1952 */
34b4e4aa 1953static int selinux_vm_enough_memory(struct mm_struct *mm, long pages)
1da177e4
LT
1954{
1955 int rc, cap_sys_admin = 0;
1da177e4 1956
3486740a
SH
1957 rc = selinux_capable(current, current_cred(),
1958 &init_user_ns, CAP_SYS_ADMIN,
3699c53c 1959 SECURITY_CAP_NOAUDIT);
1da177e4
LT
1960 if (rc == 0)
1961 cap_sys_admin = 1;
1962
34b4e4aa 1963 return __vm_enough_memory(mm, pages, cap_sys_admin);
1da177e4
LT
1964}
1965
1966/* binprm security operations */
1967
a6f76f23 1968static int selinux_bprm_set_creds(struct linux_binprm *bprm)
1da177e4 1969{
a6f76f23
DH
1970 const struct task_security_struct *old_tsec;
1971 struct task_security_struct *new_tsec;
1da177e4 1972 struct inode_security_struct *isec;
2bf49690 1973 struct common_audit_data ad;
a6f76f23 1974 struct inode *inode = bprm->file->f_path.dentry->d_inode;
1da177e4
LT
1975 int rc;
1976
200ac532 1977 rc = cap_bprm_set_creds(bprm);
1da177e4
LT
1978 if (rc)
1979 return rc;
1980
a6f76f23
DH
1981 /* SELinux context only depends on initial program or script and not
1982 * the script interpreter */
1983 if (bprm->cred_prepared)
1da177e4
LT
1984 return 0;
1985
a6f76f23
DH
1986 old_tsec = current_security();
1987 new_tsec = bprm->cred->security;
1da177e4
LT
1988 isec = inode->i_security;
1989
1990 /* Default to the current task SID. */
a6f76f23
DH
1991 new_tsec->sid = old_tsec->sid;
1992 new_tsec->osid = old_tsec->sid;
1da177e4 1993
28eba5bf 1994 /* Reset fs, key, and sock SIDs on execve. */
a6f76f23
DH
1995 new_tsec->create_sid = 0;
1996 new_tsec->keycreate_sid = 0;
1997 new_tsec->sockcreate_sid = 0;
1da177e4 1998
a6f76f23
DH
1999 if (old_tsec->exec_sid) {
2000 new_tsec->sid = old_tsec->exec_sid;
1da177e4 2001 /* Reset exec SID on execve. */
a6f76f23 2002 new_tsec->exec_sid = 0;
1da177e4
LT
2003 } else {
2004 /* Check for a default transition on this program. */
a6f76f23 2005 rc = security_transition_sid(old_tsec->sid, isec->sid,
652bb9b0
EP
2006 SECCLASS_PROCESS, NULL,
2007 &new_tsec->sid);
1da177e4
LT
2008 if (rc)
2009 return rc;
2010 }
2011
f48b7399
EP
2012 COMMON_AUDIT_DATA_INIT(&ad, PATH);
2013 ad.u.path = bprm->file->f_path;
1da177e4 2014
3d5ff529 2015 if (bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID)
a6f76f23 2016 new_tsec->sid = old_tsec->sid;
1da177e4 2017
a6f76f23
DH
2018 if (new_tsec->sid == old_tsec->sid) {
2019 rc = avc_has_perm(old_tsec->sid, isec->sid,
1da177e4
LT
2020 SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
2021 if (rc)
2022 return rc;
2023 } else {
2024 /* Check permissions for the transition. */
a6f76f23 2025 rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
1da177e4
LT
2026 SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
2027 if (rc)
2028 return rc;
2029
a6f76f23 2030 rc = avc_has_perm(new_tsec->sid, isec->sid,
1da177e4
LT
2031 SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
2032 if (rc)
2033 return rc;
2034
a6f76f23
DH
2035 /* Check for shared state */
2036 if (bprm->unsafe & LSM_UNSAFE_SHARE) {
2037 rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2038 SECCLASS_PROCESS, PROCESS__SHARE,
2039 NULL);
2040 if (rc)
2041 return -EPERM;
2042 }
2043
2044 /* Make sure that anyone attempting to ptrace over a task that
2045 * changes its SID has the appropriate permit */
2046 if (bprm->unsafe &
2047 (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) {
2048 struct task_struct *tracer;
2049 struct task_security_struct *sec;
2050 u32 ptsid = 0;
2051
2052 rcu_read_lock();
06d98473 2053 tracer = ptrace_parent(current);
a6f76f23
DH
2054 if (likely(tracer != NULL)) {
2055 sec = __task_cred(tracer)->security;
2056 ptsid = sec->sid;
2057 }
2058 rcu_read_unlock();
2059
2060 if (ptsid != 0) {
2061 rc = avc_has_perm(ptsid, new_tsec->sid,
2062 SECCLASS_PROCESS,
2063 PROCESS__PTRACE, NULL);
2064 if (rc)
2065 return -EPERM;
2066 }
2067 }
1da177e4 2068
a6f76f23
DH
2069 /* Clear any possibly unsafe personality bits on exec: */
2070 bprm->per_clear |= PER_CLEAR_ON_SETID;
1da177e4
LT
2071 }
2072
1da177e4
LT
2073 return 0;
2074}
2075
828dfe1d 2076static int selinux_bprm_secureexec(struct linux_binprm *bprm)
1da177e4 2077{
5fb49870 2078 const struct task_security_struct *tsec = current_security();
275bb41e 2079 u32 sid, osid;
1da177e4
LT
2080 int atsecure = 0;
2081
275bb41e
DH
2082 sid = tsec->sid;
2083 osid = tsec->osid;
2084
2085 if (osid != sid) {
1da177e4
LT
2086 /* Enable secure mode for SIDs transitions unless
2087 the noatsecure permission is granted between
2088 the two SIDs, i.e. ahp returns 0. */
275bb41e 2089 atsecure = avc_has_perm(osid, sid,
a6f76f23
DH
2090 SECCLASS_PROCESS,
2091 PROCESS__NOATSECURE, NULL);
1da177e4
LT
2092 }
2093
200ac532 2094 return (atsecure || cap_bprm_secureexec(bprm));
1da177e4
LT
2095}
2096
1da177e4 2097/* Derived from fs/exec.c:flush_old_files. */
745ca247
DH
2098static inline void flush_unauthorized_files(const struct cred *cred,
2099 struct files_struct *files)
1da177e4 2100{
2bf49690 2101 struct common_audit_data ad;
1da177e4 2102 struct file *file, *devnull = NULL;
b20c8122 2103 struct tty_struct *tty;
badf1662 2104 struct fdtable *fdt;
1da177e4 2105 long j = -1;
24ec839c 2106 int drop_tty = 0;
1da177e4 2107
24ec839c 2108 tty = get_current_tty();
1da177e4 2109 if (tty) {
ee2ffa0d 2110 spin_lock(&tty_files_lock);
37dd0bd0 2111 if (!list_empty(&tty->tty_files)) {
d996b62a 2112 struct tty_file_private *file_priv;
37dd0bd0
EP
2113 struct inode *inode;
2114
1da177e4
LT
2115 /* Revalidate access to controlling tty.
2116 Use inode_has_perm on the tty inode directly rather
2117 than using file_has_perm, as this particular open
2118 file may belong to another process and we are only
2119 interested in the inode-based check here. */
d996b62a
NP
2120 file_priv = list_first_entry(&tty->tty_files,
2121 struct tty_file_private, list);
2122 file = file_priv->file;
37dd0bd0 2123 inode = file->f_path.dentry->d_inode;
95f4efb2
LT
2124 if (inode_has_perm_noadp(cred, inode,
2125 FILE__READ | FILE__WRITE, 0)) {
24ec839c 2126 drop_tty = 1;
1da177e4
LT
2127 }
2128 }
ee2ffa0d 2129 spin_unlock(&tty_files_lock);
452a00d2 2130 tty_kref_put(tty);
1da177e4 2131 }
98a27ba4
EB
2132 /* Reset controlling tty. */
2133 if (drop_tty)
2134 no_tty();
1da177e4
LT
2135
2136 /* Revalidate access to inherited open files. */
2137
f48b7399 2138 COMMON_AUDIT_DATA_INIT(&ad, INODE);
1da177e4
LT
2139
2140 spin_lock(&files->file_lock);
2141 for (;;) {
2142 unsigned long set, i;
2143 int fd;
2144
2145 j++;
2146 i = j * __NFDBITS;
badf1662 2147 fdt = files_fdtable(files);
bbea9f69 2148 if (i >= fdt->max_fds)
1da177e4 2149 break;
badf1662 2150 set = fdt->open_fds->fds_bits[j];
1da177e4
LT
2151 if (!set)
2152 continue;
2153 spin_unlock(&files->file_lock);
828dfe1d 2154 for ( ; set ; i++, set >>= 1) {
1da177e4
LT
2155 if (set & 1) {
2156 file = fget(i);
2157 if (!file)
2158 continue;
88e67f3b 2159 if (file_has_perm(cred,
1da177e4
LT
2160 file,
2161 file_to_av(file))) {
2162 sys_close(i);
2163 fd = get_unused_fd();
2164 if (fd != i) {
2165 if (fd >= 0)
2166 put_unused_fd(fd);
2167 fput(file);
2168 continue;
2169 }
2170 if (devnull) {
095975da 2171 get_file(devnull);
1da177e4 2172 } else {
745ca247
DH
2173 devnull = dentry_open(
2174 dget(selinux_null),
2175 mntget(selinuxfs_mount),
2176 O_RDWR, cred);
fc5d81e6
AM
2177 if (IS_ERR(devnull)) {
2178 devnull = NULL;
1da177e4
LT
2179 put_unused_fd(fd);
2180 fput(file);
2181 continue;
2182 }
2183 }
2184 fd_install(fd, devnull);
2185 }
2186 fput(file);
2187 }
2188 }
2189 spin_lock(&files->file_lock);
2190
2191 }
2192 spin_unlock(&files->file_lock);
2193}
2194
a6f76f23
DH
2195/*
2196 * Prepare a process for imminent new credential changes due to exec
2197 */
2198static void selinux_bprm_committing_creds(struct linux_binprm *bprm)
1da177e4 2199{
a6f76f23
DH
2200 struct task_security_struct *new_tsec;
2201 struct rlimit *rlim, *initrlim;
2202 int rc, i;
d84f4f99 2203
a6f76f23
DH
2204 new_tsec = bprm->cred->security;
2205 if (new_tsec->sid == new_tsec->osid)
2206 return;
1da177e4 2207
a6f76f23
DH
2208 /* Close files for which the new task SID is not authorized. */
2209 flush_unauthorized_files(bprm->cred, current->files);
0356357c 2210
a6f76f23
DH
2211 /* Always clear parent death signal on SID transitions. */
2212 current->pdeath_signal = 0;
0356357c 2213
a6f76f23
DH
2214 /* Check whether the new SID can inherit resource limits from the old
2215 * SID. If not, reset all soft limits to the lower of the current
2216 * task's hard limit and the init task's soft limit.
2217 *
2218 * Note that the setting of hard limits (even to lower them) can be
2219 * controlled by the setrlimit check. The inclusion of the init task's
2220 * soft limit into the computation is to avoid resetting soft limits
2221 * higher than the default soft limit for cases where the default is
2222 * lower than the hard limit, e.g. RLIMIT_CORE or RLIMIT_STACK.
2223 */
2224 rc = avc_has_perm(new_tsec->osid, new_tsec->sid, SECCLASS_PROCESS,
2225 PROCESS__RLIMITINH, NULL);
2226 if (rc) {
eb2d55a3
ON
2227 /* protect against do_prlimit() */
2228 task_lock(current);
a6f76f23
DH
2229 for (i = 0; i < RLIM_NLIMITS; i++) {
2230 rlim = current->signal->rlim + i;
2231 initrlim = init_task.signal->rlim + i;
2232 rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur);
1da177e4 2233 }
eb2d55a3
ON
2234 task_unlock(current);
2235 update_rlimit_cpu(current, rlimit(RLIMIT_CPU));
1da177e4
LT
2236 }
2237}
2238
2239/*
a6f76f23
DH
2240 * Clean up the process immediately after the installation of new credentials
2241 * due to exec
1da177e4 2242 */
a6f76f23 2243static void selinux_bprm_committed_creds(struct linux_binprm *bprm)
1da177e4 2244{
a6f76f23 2245 const struct task_security_struct *tsec = current_security();
1da177e4 2246 struct itimerval itimer;
a6f76f23 2247 u32 osid, sid;
1da177e4
LT
2248 int rc, i;
2249
a6f76f23
DH
2250 osid = tsec->osid;
2251 sid = tsec->sid;
2252
2253 if (sid == osid)
1da177e4
LT
2254 return;
2255
a6f76f23
DH
2256 /* Check whether the new SID can inherit signal state from the old SID.
2257 * If not, clear itimers to avoid subsequent signal generation and
2258 * flush and unblock signals.
2259 *
2260 * This must occur _after_ the task SID has been updated so that any
2261 * kill done after the flush will be checked against the new SID.
2262 */
2263 rc = avc_has_perm(osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL);
1da177e4
LT
2264 if (rc) {
2265 memset(&itimer, 0, sizeof itimer);
2266 for (i = 0; i < 3; i++)
2267 do_setitimer(i, &itimer, NULL);
1da177e4 2268 spin_lock_irq(&current->sighand->siglock);
3bcac026
DH
2269 if (!(current->signal->flags & SIGNAL_GROUP_EXIT)) {
2270 __flush_signals(current);
2271 flush_signal_handlers(current, 1);
2272 sigemptyset(&current->blocked);
2273 }
1da177e4
LT
2274 spin_unlock_irq(&current->sighand->siglock);
2275 }
2276
a6f76f23
DH
2277 /* Wake up the parent if it is waiting so that it can recheck
2278 * wait permission to the new task SID. */
ecd6de3c 2279 read_lock(&tasklist_lock);
0b7570e7 2280 __wake_up_parent(current, current->real_parent);
ecd6de3c 2281 read_unlock(&tasklist_lock);
1da177e4
LT
2282}
2283
2284/* superblock security operations */
2285
2286static int selinux_sb_alloc_security(struct super_block *sb)
2287{
2288 return superblock_alloc_security(sb);
2289}
2290
2291static void selinux_sb_free_security(struct super_block *sb)
2292{
2293 superblock_free_security(sb);
2294}
2295
2296static inline int match_prefix(char *prefix, int plen, char *option, int olen)
2297{
2298 if (plen > olen)
2299 return 0;
2300
2301 return !memcmp(prefix, option, plen);
2302}
2303
2304static inline int selinux_option(char *option, int len)
2305{
832cbd9a
EP
2306 return (match_prefix(CONTEXT_STR, sizeof(CONTEXT_STR)-1, option, len) ||
2307 match_prefix(FSCONTEXT_STR, sizeof(FSCONTEXT_STR)-1, option, len) ||
2308 match_prefix(DEFCONTEXT_STR, sizeof(DEFCONTEXT_STR)-1, option, len) ||
11689d47
DQ
2309 match_prefix(ROOTCONTEXT_STR, sizeof(ROOTCONTEXT_STR)-1, option, len) ||
2310 match_prefix(LABELSUPP_STR, sizeof(LABELSUPP_STR)-1, option, len));
1da177e4
LT
2311}
2312
2313static inline void take_option(char **to, char *from, int *first, int len)
2314{
2315 if (!*first) {
2316 **to = ',';
2317 *to += 1;
3528a953 2318 } else
1da177e4
LT
2319 *first = 0;
2320 memcpy(*to, from, len);
2321 *to += len;
2322}
2323
828dfe1d
EP
2324static inline void take_selinux_option(char **to, char *from, int *first,
2325 int len)
3528a953
CO
2326{
2327 int current_size = 0;
2328
2329 if (!*first) {
2330 **to = '|';
2331 *to += 1;
828dfe1d 2332 } else
3528a953
CO
2333 *first = 0;
2334
2335 while (current_size < len) {
2336 if (*from != '"') {
2337 **to = *from;
2338 *to += 1;
2339 }
2340 from += 1;
2341 current_size += 1;
2342 }
2343}
2344
e0007529 2345static int selinux_sb_copy_data(char *orig, char *copy)
1da177e4
LT
2346{
2347 int fnosec, fsec, rc = 0;
2348 char *in_save, *in_curr, *in_end;
2349 char *sec_curr, *nosec_save, *nosec;
3528a953 2350 int open_quote = 0;
1da177e4
LT
2351
2352 in_curr = orig;
2353 sec_curr = copy;
2354
1da177e4
LT
2355 nosec = (char *)get_zeroed_page(GFP_KERNEL);
2356 if (!nosec) {
2357 rc = -ENOMEM;
2358 goto out;
2359 }
2360
2361 nosec_save = nosec;
2362 fnosec = fsec = 1;
2363 in_save = in_end = orig;
2364
2365 do {
3528a953
CO
2366 if (*in_end == '"')
2367 open_quote = !open_quote;
2368 if ((*in_end == ',' && open_quote == 0) ||
2369 *in_end == '\0') {
1da177e4
LT
2370 int len = in_end - in_curr;
2371
2372 if (selinux_option(in_curr, len))
3528a953 2373 take_selinux_option(&sec_curr, in_curr, &fsec, len);
1da177e4
LT
2374 else
2375 take_option(&nosec, in_curr, &fnosec, len);
2376
2377 in_curr = in_end + 1;
2378 }
2379 } while (*in_end++);
2380
6931dfc9 2381 strcpy(in_save, nosec_save);
da3caa20 2382 free_page((unsigned long)nosec_save);
1da177e4
LT
2383out:
2384 return rc;
2385}
2386
026eb167
EP
2387static int selinux_sb_remount(struct super_block *sb, void *data)
2388{
2389 int rc, i, *flags;
2390 struct security_mnt_opts opts;
2391 char *secdata, **mount_options;
2392 struct superblock_security_struct *sbsec = sb->s_security;
2393
2394 if (!(sbsec->flags & SE_SBINITIALIZED))
2395 return 0;
2396
2397 if (!data)
2398 return 0;
2399
2400 if (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
2401 return 0;
2402
2403 security_init_mnt_opts(&opts);
2404 secdata = alloc_secdata();
2405 if (!secdata)
2406 return -ENOMEM;
2407 rc = selinux_sb_copy_data(data, secdata);
2408 if (rc)
2409 goto out_free_secdata;
2410
2411 rc = selinux_parse_opts_str(secdata, &opts);
2412 if (rc)
2413 goto out_free_secdata;
2414
2415 mount_options = opts.mnt_opts;
2416 flags = opts.mnt_opts_flags;
2417
2418 for (i = 0; i < opts.num_mnt_opts; i++) {
2419 u32 sid;
2420 size_t len;
2421
2422 if (flags[i] == SE_SBLABELSUPP)
2423 continue;
2424 len = strlen(mount_options[i]);
2425 rc = security_context_to_sid(mount_options[i], len, &sid);
2426 if (rc) {
2427 printk(KERN_WARNING "SELinux: security_context_to_sid"
2428 "(%s) failed for (dev %s, type %s) errno=%d\n",
2429 mount_options[i], sb->s_id, sb->s_type->name, rc);
2430 goto out_free_opts;
2431 }
2432 rc = -EINVAL;
2433 switch (flags[i]) {
2434 case FSCONTEXT_MNT:
2435 if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, sid))
2436 goto out_bad_option;
2437 break;
2438 case CONTEXT_MNT:
2439 if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, sid))
2440 goto out_bad_option;
2441 break;
2442 case ROOTCONTEXT_MNT: {
2443 struct inode_security_struct *root_isec;
2444 root_isec = sb->s_root->d_inode->i_security;
2445
2446 if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, sid))
2447 goto out_bad_option;
2448 break;
2449 }
2450 case DEFCONTEXT_MNT:
2451 if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, sid))
2452 goto out_bad_option;
2453 break;
2454 default:
2455 goto out_free_opts;
2456 }
2457 }
2458
2459 rc = 0;
2460out_free_opts:
2461 security_free_mnt_opts(&opts);
2462out_free_secdata:
2463 free_secdata(secdata);
2464 return rc;
2465out_bad_option:
2466 printk(KERN_WARNING "SELinux: unable to change security options "
2467 "during remount (dev %s, type=%s)\n", sb->s_id,
2468 sb->s_type->name);
2469 goto out_free_opts;
2470}
2471
12204e24 2472static int selinux_sb_kern_mount(struct super_block *sb, int flags, void *data)
1da177e4 2473{
88e67f3b 2474 const struct cred *cred = current_cred();
2bf49690 2475 struct common_audit_data ad;
1da177e4
LT
2476 int rc;
2477
2478 rc = superblock_doinit(sb, data);
2479 if (rc)
2480 return rc;
2481
74192246
JM
2482 /* Allow all mounts performed by the kernel */
2483 if (flags & MS_KERNMOUNT)
2484 return 0;
2485
a269434d
EP
2486 COMMON_AUDIT_DATA_INIT(&ad, DENTRY);
2487 ad.u.dentry = sb->s_root;
88e67f3b 2488 return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad);
1da177e4
LT
2489}
2490
726c3342 2491static int selinux_sb_statfs(struct dentry *dentry)
1da177e4 2492{
88e67f3b 2493 const struct cred *cred = current_cred();
2bf49690 2494 struct common_audit_data ad;
1da177e4 2495
a269434d
EP
2496 COMMON_AUDIT_DATA_INIT(&ad, DENTRY);
2497 ad.u.dentry = dentry->d_sb->s_root;
88e67f3b 2498 return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad);
1da177e4
LT
2499}
2500
828dfe1d 2501static int selinux_mount(char *dev_name,
b5266eb4 2502 struct path *path,
828dfe1d
EP
2503 char *type,
2504 unsigned long flags,
2505 void *data)
1da177e4 2506{
88e67f3b 2507 const struct cred *cred = current_cred();
1da177e4
LT
2508
2509 if (flags & MS_REMOUNT)
88e67f3b 2510 return superblock_has_perm(cred, path->mnt->mnt_sb,
828dfe1d 2511 FILESYSTEM__REMOUNT, NULL);
1da177e4 2512 else
2875fa00 2513 return path_has_perm(cred, path, FILE__MOUNTON);
1da177e4
LT
2514}
2515
2516static int selinux_umount(struct vfsmount *mnt, int flags)
2517{
88e67f3b 2518 const struct cred *cred = current_cred();
1da177e4 2519
88e67f3b 2520 return superblock_has_perm(cred, mnt->mnt_sb,
828dfe1d 2521 FILESYSTEM__UNMOUNT, NULL);
1da177e4
LT
2522}
2523
2524/* inode security operations */
2525
2526static int selinux_inode_alloc_security(struct inode *inode)
2527{
2528 return inode_alloc_security(inode);
2529}
2530
2531static void selinux_inode_free_security(struct inode *inode)
2532{
2533 inode_free_security(inode);
2534}
2535
5e41ff9e 2536static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
2a7dba39
EP
2537 const struct qstr *qstr, char **name,
2538 void **value, size_t *len)
5e41ff9e 2539{
5fb49870 2540 const struct task_security_struct *tsec = current_security();
5e41ff9e
SS
2541 struct inode_security_struct *dsec;
2542 struct superblock_security_struct *sbsec;
275bb41e 2543 u32 sid, newsid, clen;
5e41ff9e 2544 int rc;
570bc1c2 2545 char *namep = NULL, *context;
5e41ff9e 2546
5e41ff9e
SS
2547 dsec = dir->i_security;
2548 sbsec = dir->i_sb->s_security;
5e41ff9e 2549
275bb41e
DH
2550 sid = tsec->sid;
2551 newsid = tsec->create_sid;
2552
415103f9
EP
2553 if ((sbsec->flags & SE_SBINITIALIZED) &&
2554 (sbsec->behavior == SECURITY_FS_USE_MNTPOINT))
2555 newsid = sbsec->mntpoint_sid;
2556 else if (!newsid || !(sbsec->flags & SE_SBLABELSUPP)) {
275bb41e 2557 rc = security_transition_sid(sid, dsec->sid,
5e41ff9e 2558 inode_mode_to_security_class(inode->i_mode),
652bb9b0 2559 qstr, &newsid);
5e41ff9e
SS
2560 if (rc) {
2561 printk(KERN_WARNING "%s: "
2562 "security_transition_sid failed, rc=%d (dev=%s "
2563 "ino=%ld)\n",
dd6f953a 2564 __func__,
5e41ff9e
SS
2565 -rc, inode->i_sb->s_id, inode->i_ino);
2566 return rc;
2567 }
2568 }
2569
296fddf7 2570 /* Possibly defer initialization to selinux_complete_init. */
0d90a7ec 2571 if (sbsec->flags & SE_SBINITIALIZED) {
296fddf7
EP
2572 struct inode_security_struct *isec = inode->i_security;
2573 isec->sclass = inode_mode_to_security_class(inode->i_mode);
2574 isec->sid = newsid;
2575 isec->initialized = 1;
2576 }
5e41ff9e 2577
cd89596f 2578 if (!ss_initialized || !(sbsec->flags & SE_SBLABELSUPP))
25a74f3b
SS
2579 return -EOPNOTSUPP;
2580
570bc1c2 2581 if (name) {
a02fe132 2582 namep = kstrdup(XATTR_SELINUX_SUFFIX, GFP_NOFS);
570bc1c2
SS
2583 if (!namep)
2584 return -ENOMEM;
2585 *name = namep;
2586 }
5e41ff9e 2587
570bc1c2 2588 if (value && len) {
12b29f34 2589 rc = security_sid_to_context_force(newsid, &context, &clen);
570bc1c2
SS
2590 if (rc) {
2591 kfree(namep);
2592 return rc;
2593 }
2594 *value = context;
2595 *len = clen;
5e41ff9e 2596 }
5e41ff9e 2597
5e41ff9e
SS
2598 return 0;
2599}
2600
4acdaf27 2601static int selinux_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode)
1da177e4
LT
2602{
2603 return may_create(dir, dentry, SECCLASS_FILE);
2604}
2605
1da177e4
LT
2606static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
2607{
1da177e4
LT
2608 return may_link(dir, old_dentry, MAY_LINK);
2609}
2610
1da177e4
LT
2611static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry)
2612{
1da177e4
LT
2613 return may_link(dir, dentry, MAY_UNLINK);
2614}
2615
2616static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name)
2617{
2618 return may_create(dir, dentry, SECCLASS_LNK_FILE);
2619}
2620
18bb1db3 2621static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, umode_t mask)
1da177e4
LT
2622{
2623 return may_create(dir, dentry, SECCLASS_DIR);
2624}
2625
1da177e4
LT
2626static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry)
2627{
2628 return may_link(dir, dentry, MAY_RMDIR);
2629}
2630
1a67aafb 2631static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
1da177e4 2632{
1da177e4
LT
2633 return may_create(dir, dentry, inode_mode_to_security_class(mode));
2634}
2635
1da177e4 2636static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
828dfe1d 2637 struct inode *new_inode, struct dentry *new_dentry)
1da177e4
LT
2638{
2639 return may_rename(old_inode, old_dentry, new_inode, new_dentry);
2640}
2641
1da177e4
LT
2642static int selinux_inode_readlink(struct dentry *dentry)
2643{
88e67f3b
DH
2644 const struct cred *cred = current_cred();
2645
2875fa00 2646 return dentry_has_perm(cred, dentry, FILE__READ);
1da177e4
LT
2647}
2648
2649static int selinux_inode_follow_link(struct dentry *dentry, struct nameidata *nameidata)
2650{
88e67f3b 2651 const struct cred *cred = current_cred();
1da177e4 2652
2875fa00 2653 return dentry_has_perm(cred, dentry, FILE__READ);
1da177e4
LT
2654}
2655
e74f71eb 2656static int selinux_inode_permission(struct inode *inode, int mask)
1da177e4 2657{
88e67f3b 2658 const struct cred *cred = current_cred();
b782e0a6
EP
2659 struct common_audit_data ad;
2660 u32 perms;
2661 bool from_access;
cf1dd1da 2662 unsigned flags = mask & MAY_NOT_BLOCK;
1da177e4 2663
b782e0a6 2664 from_access = mask & MAY_ACCESS;
d09ca739
EP
2665 mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
2666
b782e0a6
EP
2667 /* No permission to check. Existence test. */
2668 if (!mask)
1da177e4 2669 return 0;
1da177e4 2670
f48b7399
EP
2671 COMMON_AUDIT_DATA_INIT(&ad, INODE);
2672 ad.u.inode = inode;
b782e0a6
EP
2673
2674 if (from_access)
2675 ad.selinux_audit_data.auditdeny |= FILE__AUDIT_ACCESS;
2676
2677 perms = file_mask_to_av(inode->i_mode, mask);
2678
9ade0cf4 2679 return inode_has_perm(cred, inode, perms, &ad, flags);
1da177e4
LT
2680}
2681
2682static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
2683{
88e67f3b 2684 const struct cred *cred = current_cred();
bc6a6008 2685 unsigned int ia_valid = iattr->ia_valid;
1da177e4 2686
bc6a6008
AW
2687 /* ATTR_FORCE is just used for ATTR_KILL_S[UG]ID. */
2688 if (ia_valid & ATTR_FORCE) {
2689 ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE |
2690 ATTR_FORCE);
2691 if (!ia_valid)
2692 return 0;
2693 }
1da177e4 2694
bc6a6008
AW
2695 if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
2696 ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET))
2875fa00 2697 return dentry_has_perm(cred, dentry, FILE__SETATTR);
1da177e4 2698
2875fa00 2699 return dentry_has_perm(cred, dentry, FILE__WRITE);
1da177e4
LT
2700}
2701
2702static int selinux_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
2703{
88e67f3b 2704 const struct cred *cred = current_cred();
2875fa00
EP
2705 struct path path;
2706
2707 path.dentry = dentry;
2708 path.mnt = mnt;
88e67f3b 2709
2875fa00 2710 return path_has_perm(cred, &path, FILE__GETATTR);
1da177e4
LT
2711}
2712
8f0cfa52 2713static int selinux_inode_setotherxattr(struct dentry *dentry, const char *name)
b5376771 2714{
88e67f3b
DH
2715 const struct cred *cred = current_cred();
2716
b5376771
SH
2717 if (!strncmp(name, XATTR_SECURITY_PREFIX,
2718 sizeof XATTR_SECURITY_PREFIX - 1)) {
2719 if (!strcmp(name, XATTR_NAME_CAPS)) {
2720 if (!capable(CAP_SETFCAP))
2721 return -EPERM;
2722 } else if (!capable(CAP_SYS_ADMIN)) {
2723 /* A different attribute in the security namespace.
2724 Restrict to administrator. */
2725 return -EPERM;
2726 }
2727 }
2728
2729 /* Not an attribute we recognize, so just check the
2730 ordinary setattr permission. */
2875fa00 2731 return dentry_has_perm(cred, dentry, FILE__SETATTR);
b5376771
SH
2732}
2733
8f0cfa52
DH
2734static int selinux_inode_setxattr(struct dentry *dentry, const char *name,
2735 const void *value, size_t size, int flags)
1da177e4 2736{
1da177e4
LT
2737 struct inode *inode = dentry->d_inode;
2738 struct inode_security_struct *isec = inode->i_security;
2739 struct superblock_security_struct *sbsec;
2bf49690 2740 struct common_audit_data ad;
275bb41e 2741 u32 newsid, sid = current_sid();
1da177e4
LT
2742 int rc = 0;
2743
b5376771
SH
2744 if (strcmp(name, XATTR_NAME_SELINUX))
2745 return selinux_inode_setotherxattr(dentry, name);
1da177e4
LT
2746
2747 sbsec = inode->i_sb->s_security;
cd89596f 2748 if (!(sbsec->flags & SE_SBLABELSUPP))
1da177e4
LT
2749 return -EOPNOTSUPP;
2750
2e149670 2751 if (!inode_owner_or_capable(inode))
1da177e4
LT
2752 return -EPERM;
2753
a269434d
EP
2754 COMMON_AUDIT_DATA_INIT(&ad, DENTRY);
2755 ad.u.dentry = dentry;
1da177e4 2756
275bb41e 2757 rc = avc_has_perm(sid, isec->sid, isec->sclass,
1da177e4
LT
2758 FILE__RELABELFROM, &ad);
2759 if (rc)
2760 return rc;
2761
2762 rc = security_context_to_sid(value, size, &newsid);
12b29f34
SS
2763 if (rc == -EINVAL) {
2764 if (!capable(CAP_MAC_ADMIN))
2765 return rc;
2766 rc = security_context_to_sid_force(value, size, &newsid);
2767 }
1da177e4
LT
2768 if (rc)
2769 return rc;
2770
275bb41e 2771 rc = avc_has_perm(sid, newsid, isec->sclass,
1da177e4
LT
2772 FILE__RELABELTO, &ad);
2773 if (rc)
2774 return rc;
2775
275bb41e 2776 rc = security_validate_transition(isec->sid, newsid, sid,
828dfe1d 2777 isec->sclass);
1da177e4
LT
2778 if (rc)
2779 return rc;
2780
2781 return avc_has_perm(newsid,
2782 sbsec->sid,
2783 SECCLASS_FILESYSTEM,
2784 FILESYSTEM__ASSOCIATE,
2785 &ad);
2786}
2787
8f0cfa52 2788static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name,
f5269710 2789 const void *value, size_t size,
8f0cfa52 2790 int flags)
1da177e4
LT
2791{
2792 struct inode *inode = dentry->d_inode;
2793 struct inode_security_struct *isec = inode->i_security;
2794 u32 newsid;
2795 int rc;
2796
2797 if (strcmp(name, XATTR_NAME_SELINUX)) {
2798 /* Not an attribute we recognize, so nothing to do. */
2799 return;
2800 }
2801
12b29f34 2802 rc = security_context_to_sid_force(value, size, &newsid);
1da177e4 2803 if (rc) {
12b29f34
SS
2804 printk(KERN_ERR "SELinux: unable to map context to SID"
2805 "for (%s, %lu), rc=%d\n",
2806 inode->i_sb->s_id, inode->i_ino, -rc);
1da177e4
LT
2807 return;
2808 }
2809
2810 isec->sid = newsid;
2811 return;
2812}
2813
8f0cfa52 2814static int selinux_inode_getxattr(struct dentry *dentry, const char *name)
1da177e4 2815{
88e67f3b
DH
2816 const struct cred *cred = current_cred();
2817
2875fa00 2818 return dentry_has_perm(cred, dentry, FILE__GETATTR);
1da177e4
LT
2819}
2820
828dfe1d 2821static int selinux_inode_listxattr(struct dentry *dentry)
1da177e4 2822{
88e67f3b
DH
2823 const struct cred *cred = current_cred();
2824
2875fa00 2825 return dentry_has_perm(cred, dentry, FILE__GETATTR);
1da177e4
LT
2826}
2827
8f0cfa52 2828static int selinux_inode_removexattr(struct dentry *dentry, const char *name)
1da177e4 2829{
b5376771
SH
2830 if (strcmp(name, XATTR_NAME_SELINUX))
2831 return selinux_inode_setotherxattr(dentry, name);
1da177e4
LT
2832
2833 /* No one is allowed to remove a SELinux security label.
2834 You can change the label, but all data must be labeled. */
2835 return -EACCES;
2836}
2837
d381d8a9 2838/*
abc69bb6 2839 * Copy the inode security context value to the user.
d381d8a9
JM
2840 *
2841 * Permission check is handled by selinux_inode_getxattr hook.
2842 */
42492594 2843static int selinux_inode_getsecurity(const struct inode *inode, const char *name, void **buffer, bool alloc)
1da177e4 2844{
42492594
DQ
2845 u32 size;
2846 int error;
2847 char *context = NULL;
1da177e4 2848 struct inode_security_struct *isec = inode->i_security;
d381d8a9 2849
8c8570fb
DK
2850 if (strcmp(name, XATTR_SELINUX_SUFFIX))
2851 return -EOPNOTSUPP;
d381d8a9 2852
abc69bb6
SS
2853 /*
2854 * If the caller has CAP_MAC_ADMIN, then get the raw context
2855 * value even if it is not defined by current policy; otherwise,
2856 * use the in-core value under current policy.
2857 * Use the non-auditing forms of the permission checks since
2858 * getxattr may be called by unprivileged processes commonly
2859 * and lack of permission just means that we fall back to the
2860 * in-core context value, not a denial.
2861 */
3486740a
SH
2862 error = selinux_capable(current, current_cred(),
2863 &init_user_ns, CAP_MAC_ADMIN,
3699c53c 2864 SECURITY_CAP_NOAUDIT);
abc69bb6
SS
2865 if (!error)
2866 error = security_sid_to_context_force(isec->sid, &context,
2867 &size);
2868 else
2869 error = security_sid_to_context(isec->sid, &context, &size);
42492594
DQ
2870 if (error)
2871 return error;
2872 error = size;
2873 if (alloc) {
2874 *buffer = context;
2875 goto out_nofree;
2876 }
2877 kfree(context);
2878out_nofree:
2879 return error;
1da177e4
LT
2880}
2881
2882static int selinux_inode_setsecurity(struct inode *inode, const char *name,
828dfe1d 2883 const void *value, size_t size, int flags)
1da177e4
LT
2884{
2885 struct inode_security_struct *isec = inode->i_security;
2886 u32 newsid;
2887 int rc;
2888
2889 if (strcmp(name, XATTR_SELINUX_SUFFIX))
2890 return -EOPNOTSUPP;
2891
2892 if (!value || !size)
2893 return -EACCES;
2894
828dfe1d 2895 rc = security_context_to_sid((void *)value, size, &newsid);
1da177e4
LT
2896 if (rc)
2897 return rc;
2898
2899 isec->sid = newsid;
ddd29ec6 2900 isec->initialized = 1;
1da177e4
LT
2901 return 0;
2902}
2903
2904static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
2905{
2906 const int len = sizeof(XATTR_NAME_SELINUX);
2907 if (buffer && len <= buffer_size)
2908 memcpy(buffer, XATTR_NAME_SELINUX, len);
2909 return len;
2910}
2911
713a04ae
AD
2912static void selinux_inode_getsecid(const struct inode *inode, u32 *secid)
2913{
2914 struct inode_security_struct *isec = inode->i_security;
2915 *secid = isec->sid;
2916}
2917
1da177e4
LT
2918/* file security operations */
2919
788e7dd4 2920static int selinux_revalidate_file_permission(struct file *file, int mask)
1da177e4 2921{
88e67f3b 2922 const struct cred *cred = current_cred();
3d5ff529 2923 struct inode *inode = file->f_path.dentry->d_inode;
1da177e4 2924
1da177e4
LT
2925 /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */
2926 if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE))
2927 mask |= MAY_APPEND;
2928
389fb800
PM
2929 return file_has_perm(cred, file,
2930 file_mask_to_av(inode->i_mode, mask));
1da177e4
LT
2931}
2932
788e7dd4
YN
2933static int selinux_file_permission(struct file *file, int mask)
2934{
20dda18b
SS
2935 struct inode *inode = file->f_path.dentry->d_inode;
2936 struct file_security_struct *fsec = file->f_security;
2937 struct inode_security_struct *isec = inode->i_security;
2938 u32 sid = current_sid();
2939
389fb800 2940 if (!mask)
788e7dd4
YN
2941 /* No permission to check. Existence test. */
2942 return 0;
788e7dd4 2943
20dda18b
SS
2944 if (sid == fsec->sid && fsec->isid == isec->sid &&
2945 fsec->pseqno == avc_policy_seqno())
2946 /* No change since dentry_open check. */
2947 return 0;
2948
788e7dd4
YN
2949 return selinux_revalidate_file_permission(file, mask);
2950}
2951
1da177e4
LT
2952static int selinux_file_alloc_security(struct file *file)
2953{
2954 return file_alloc_security(file);
2955}
2956
2957static void selinux_file_free_security(struct file *file)
2958{
2959 file_free_security(file);
2960}
2961
2962static int selinux_file_ioctl(struct file *file, unsigned int cmd,
2963 unsigned long arg)
2964{
88e67f3b 2965 const struct cred *cred = current_cred();
0b24dcb7 2966 int error = 0;
1da177e4 2967
0b24dcb7
EP
2968 switch (cmd) {
2969 case FIONREAD:
2970 /* fall through */
2971 case FIBMAP:
2972 /* fall through */
2973 case FIGETBSZ:
2974 /* fall through */
2975 case EXT2_IOC_GETFLAGS:
2976 /* fall through */
2977 case EXT2_IOC_GETVERSION:
2978 error = file_has_perm(cred, file, FILE__GETATTR);
2979 break;
1da177e4 2980
0b24dcb7
EP
2981 case EXT2_IOC_SETFLAGS:
2982 /* fall through */
2983 case EXT2_IOC_SETVERSION:
2984 error = file_has_perm(cred, file, FILE__SETATTR);
2985 break;
2986
2987 /* sys_ioctl() checks */
2988 case FIONBIO:
2989 /* fall through */
2990 case FIOASYNC:
2991 error = file_has_perm(cred, file, 0);
2992 break;
1da177e4 2993
0b24dcb7
EP
2994 case KDSKBENT:
2995 case KDSKBSENT:
2996 error = task_has_capability(current, cred, CAP_SYS_TTY_CONFIG,
3486740a 2997 SECURITY_CAP_AUDIT);
0b24dcb7
EP
2998 break;
2999
3000 /* default case assumes that the command will go
3001 * to the file's ioctl() function.
3002 */
3003 default:
3004 error = file_has_perm(cred, file, FILE__IOCTL);
3005 }
3006 return error;
1da177e4
LT
3007}
3008
fcaaade1
SS
3009static int default_noexec;
3010
1da177e4
LT
3011static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
3012{
88e67f3b 3013 const struct cred *cred = current_cred();
d84f4f99 3014 int rc = 0;
88e67f3b 3015
fcaaade1
SS
3016 if (default_noexec &&
3017 (prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) {
1da177e4
LT
3018 /*
3019 * We are making executable an anonymous mapping or a
3020 * private file mapping that will also be writable.
3021 * This has an additional check.
3022 */
d84f4f99 3023 rc = cred_has_perm(cred, cred, PROCESS__EXECMEM);
1da177e4 3024 if (rc)
d84f4f99 3025 goto error;
1da177e4 3026 }
1da177e4
LT
3027
3028 if (file) {
3029 /* read access is always possible with a mapping */
3030 u32 av = FILE__READ;
3031
3032 /* write access only matters if the mapping is shared */
3033 if (shared && (prot & PROT_WRITE))
3034 av |= FILE__WRITE;
3035
3036 if (prot & PROT_EXEC)
3037 av |= FILE__EXECUTE;
3038
88e67f3b 3039 return file_has_perm(cred, file, av);
1da177e4 3040 }
d84f4f99
DH
3041
3042error:
3043 return rc;
1da177e4
LT
3044}
3045
3046static int selinux_file_mmap(struct file *file, unsigned long reqprot,
ed032189
EP
3047 unsigned long prot, unsigned long flags,
3048 unsigned long addr, unsigned long addr_only)
1da177e4 3049{
ed032189 3050 int rc = 0;
275bb41e 3051 u32 sid = current_sid();
1da177e4 3052
84336d1a
EP
3053 /*
3054 * notice that we are intentionally putting the SELinux check before
3055 * the secondary cap_file_mmap check. This is such a likely attempt
3056 * at bad behaviour/exploit that we always want to get the AVC, even
3057 * if DAC would have also denied the operation.
3058 */
a2551df7 3059 if (addr < CONFIG_LSM_MMAP_MIN_ADDR) {
ed032189
EP
3060 rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT,
3061 MEMPROTECT__MMAP_ZERO, NULL);
84336d1a
EP
3062 if (rc)
3063 return rc;
3064 }
3065
3066 /* do DAC check on address space usage */
3067 rc = cap_file_mmap(file, reqprot, prot, flags, addr, addr_only);
ed032189 3068 if (rc || addr_only)
1da177e4
LT
3069 return rc;
3070
3071 if (selinux_checkreqprot)
3072 prot = reqprot;
3073
3074 return file_map_prot_check(file, prot,
3075 (flags & MAP_TYPE) == MAP_SHARED);
3076}
3077
3078static int selinux_file_mprotect(struct vm_area_struct *vma,
3079 unsigned long reqprot,
3080 unsigned long prot)
3081{
88e67f3b 3082 const struct cred *cred = current_cred();
1da177e4
LT
3083
3084 if (selinux_checkreqprot)
3085 prot = reqprot;
3086
fcaaade1
SS
3087 if (default_noexec &&
3088 (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
d541bbee 3089 int rc = 0;
db4c9641
SS
3090 if (vma->vm_start >= vma->vm_mm->start_brk &&
3091 vma->vm_end <= vma->vm_mm->brk) {
d84f4f99 3092 rc = cred_has_perm(cred, cred, PROCESS__EXECHEAP);
db4c9641
SS
3093 } else if (!vma->vm_file &&
3094 vma->vm_start <= vma->vm_mm->start_stack &&
3095 vma->vm_end >= vma->vm_mm->start_stack) {
3b11a1de 3096 rc = current_has_perm(current, PROCESS__EXECSTACK);
db4c9641
SS
3097 } else if (vma->vm_file && vma->anon_vma) {
3098 /*
3099 * We are making executable a file mapping that has
3100 * had some COW done. Since pages might have been
3101 * written, check ability to execute the possibly
3102 * modified content. This typically should only
3103 * occur for text relocations.
3104 */
d84f4f99 3105 rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD);
db4c9641 3106 }