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[net-next-2.6.git] / security / selinux / hooks.c
CommitLineData
1da177e4
LT		 1/*
2 * NSA Security-Enhanced Linux (SELinux) security module
3 *
4 * This file contains the SELinux hook function implementations.
5 *
6 * Authors: Stephen Smalley, <sds@epoch.ncsc.mil>
7 * Chris Vance, <cvance@nai.com>
8 * Wayne Salamon, <wsalamon@nai.com>
9 * James Morris <jmorris@redhat.com>
10 *
11 * Copyright (C) 2001,2002 Networks Associates Technology, Inc.
12 * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
13 * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
14 * <dgoeddel@trustedcs.com>
7420ed23
VY		 15 * Copyright (C) 2006 Hewlett-Packard Development Company, L.P.
16 * Paul Moore, <paul.moore@hp.com>
1da177e4
LT		 17 *
18 * This program is free software; you can redistribute it and/or modify
19 * it under the terms of the GNU General Public License version 2,
20 * as published by the Free Software Foundation.
21 */
22
1da177e4
LT		 23#include <linux/module.h>
24#include <linux/init.h>
25#include <linux/kernel.h>
26#include <linux/ptrace.h>
27#include <linux/errno.h>
28#include <linux/sched.h>
29#include <linux/security.h>
30#include <linux/xattr.h>
31#include <linux/capability.h>
32#include <linux/unistd.h>
33#include <linux/mm.h>
34#include <linux/mman.h>
35#include <linux/slab.h>
36#include <linux/pagemap.h>
37#include <linux/swap.h>
38#include <linux/smp_lock.h>
39#include <linux/spinlock.h>
40#include <linux/syscalls.h>
41#include <linux/file.h>
42#include <linux/namei.h>
43#include <linux/mount.h>
44#include <linux/ext2_fs.h>
45#include <linux/proc_fs.h>
46#include <linux/kd.h>
47#include <linux/netfilter_ipv4.h>
48#include <linux/netfilter_ipv6.h>
49#include <linux/tty.h>
50#include <net/icmp.h>
51#include <net/ip.h> /* for sysctl_local_port_range[] */
52#include <net/tcp.h> /* struct or_callable used in sock_rcv_skb */
53#include <asm/uaccess.h>
1da177e4
LT		 54#include <asm/ioctls.h>
55#include <linux/bitops.h>
56#include <linux/interrupt.h>
57#include <linux/netdevice.h> /* for network interface checks */
58#include <linux/netlink.h>
59#include <linux/tcp.h>
60#include <linux/udp.h>
2ee92d46 61#include <linux/dccp.h>
1da177e4
LT		 62#include <linux/quota.h>
63#include <linux/un.h> /* for Unix socket types */
64#include <net/af_unix.h> /* for Unix socket types */
65#include <linux/parser.h>
66#include <linux/nfs_mount.h>
67#include <net/ipv6.h>
68#include <linux/hugetlb.h>
69#include <linux/personality.h>
70#include <linux/sysctl.h>
71#include <linux/audit.h>
6931dfc9 72#include <linux/string.h>
877ce7c1 73#include <linux/selinux.h>
23970741 74#include <linux/mutex.h>
1da177e4
LT		 75
76#include "avc.h"
77#include "objsec.h"
78#include "netif.h"
d28d1e08 79#include "xfrm.h"
7420ed23 80#include "selinux_netlabel.h"
1da177e4
LT		 81
82#define XATTR_SELINUX_SUFFIX "selinux"
83#define XATTR_NAME_SELINUX XATTR_SECURITY_PREFIX XATTR_SELINUX_SUFFIX
84
85extern unsigned int policydb_loaded_version;
86extern int selinux_nlmsg_lookup(u16 sclass, u16 nlmsg_type, u32 *perm);
4e5ab4cb 87extern int selinux_compat_net;
1da177e4
LT		 88
89#ifdef CONFIG_SECURITY_SELINUX_DEVELOP
90int selinux_enforcing = 0;
91
92static int __init enforcing_setup(char *str)
93{
94 selinux_enforcing = simple_strtol(str,NULL,0);
95 return 1;
96}
97__setup("enforcing=", enforcing_setup);
98#endif
99
100#ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM
101int selinux_enabled = CONFIG_SECURITY_SELINUX_BOOTPARAM_VALUE;
102
103static int __init selinux_enabled_setup(char *str)
104{
105 selinux_enabled = simple_strtol(str, NULL, 0);
106 return 1;
107}
108__setup("selinux=", selinux_enabled_setup);
30d55280
SS		 109#else
110int selinux_enabled = 1;
1da177e4
LT		 111#endif
112
113/* Original (dummy) security module. */
114static struct security_operations *original_ops = NULL;
115
116/* Minimal support for a secondary security module,
117 just to allow the use of the dummy or capability modules.
118 The owlsm module can alternatively be used as a secondary
119 module as long as CONFIG_OWLSM_FD is not enabled. */
120static struct security_operations *secondary_ops = NULL;
121
122/* Lists of inode and superblock security structures initialized
123 before the policy was loaded. */
124static LIST_HEAD(superblock_security_head);
125static DEFINE_SPINLOCK(sb_security_lock);
126
e18b890b 127static struct kmem_cache *sel_inode_cache;
7cae7e26 128
8c8570fb
DK		 129/* Return security context for a given sid or just the context
130 length if the buffer is null or length is 0 */
131static int selinux_getsecurity(u32 sid, void *buffer, size_t size)
132{
133 char *context;
134 unsigned len;
135 int rc;
136
137 rc = security_sid_to_context(sid, &context, &len);
138 if (rc)
139 return rc;
140
141 if (!buffer || !size)
142 goto getsecurity_exit;
143
144 if (size < len) {
145 len = -ERANGE;
146 goto getsecurity_exit;
147 }
148 memcpy(buffer, context, len);
149
150getsecurity_exit:
151 kfree(context);
152 return len;
153}
154
1da177e4
LT		 155/* Allocate and free functions for each kind of security blob. */
156
157static int task_alloc_security(struct task_struct *task)
158{
159 struct task_security_struct *tsec;
160
89d155ef 161 tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL);
1da177e4
LT		 162 if (!tsec)
163 return -ENOMEM;
164
1da177e4
LT		 165 tsec->task = task;
166 tsec->osid = tsec->sid = tsec->ptrace_sid = SECINITSID_UNLABELED;
167 task->security = tsec;
168
169 return 0;
170}
171
172static void task_free_security(struct task_struct *task)
173{
174 struct task_security_struct *tsec = task->security;
1da177e4
LT		 175 task->security = NULL;
176 kfree(tsec);
177}
178
179static int inode_alloc_security(struct inode *inode)
180{
181 struct task_security_struct *tsec = current->security;
182 struct inode_security_struct *isec;
183
c3762229 184 isec = kmem_cache_zalloc(sel_inode_cache, GFP_KERNEL);
1da177e4
LT		 185 if (!isec)
186 return -ENOMEM;
187
23970741 188 mutex_init(&isec->lock);
1da177e4 189 INIT_LIST_HEAD(&isec->list);
1da177e4
LT		 190 isec->inode = inode;
191 isec->sid = SECINITSID_UNLABELED;
192 isec->sclass = SECCLASS_FILE;
9ac49d22 193 isec->task_sid = tsec->sid;
1da177e4
LT		 194 inode->i_security = isec;
195
196 return 0;
197}
198
199static void inode_free_security(struct inode *inode)
200{
201 struct inode_security_struct *isec = inode->i_security;
202 struct superblock_security_struct *sbsec = inode->i_sb->s_security;
203
1da177e4
LT		 204 spin_lock(&sbsec->isec_lock);
205 if (!list_empty(&isec->list))
206 list_del_init(&isec->list);
207 spin_unlock(&sbsec->isec_lock);
208
209 inode->i_security = NULL;
7cae7e26 210 kmem_cache_free(sel_inode_cache, isec);
1da177e4
LT		 211}
212
213static int file_alloc_security(struct file *file)
214{
215 struct task_security_struct *tsec = current->security;
216 struct file_security_struct *fsec;
217
26d2a4be 218 fsec = kzalloc(sizeof(struct file_security_struct), GFP_KERNEL);
1da177e4
LT		 219 if (!fsec)
220 return -ENOMEM;
221
1da177e4 222 fsec->file = file;
9ac49d22
SS		 223 fsec->sid = tsec->sid;
224 fsec->fown_sid = tsec->sid;
1da177e4
LT		 225 file->f_security = fsec;
226
227 return 0;
228}
229
230static void file_free_security(struct file *file)
231{
232 struct file_security_struct *fsec = file->f_security;
1da177e4
LT		 233 file->f_security = NULL;
234 kfree(fsec);
235}
236
237static int superblock_alloc_security(struct super_block *sb)
238{
239 struct superblock_security_struct *sbsec;
240
89d155ef 241 sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL);
1da177e4
LT		 242 if (!sbsec)
243 return -ENOMEM;
244
bc7e982b 245 mutex_init(&sbsec->lock);
1da177e4
LT		 246 INIT_LIST_HEAD(&sbsec->list);
247 INIT_LIST_HEAD(&sbsec->isec_head);
248 spin_lock_init(&sbsec->isec_lock);
1da177e4
LT		 249 sbsec->sb = sb;
250 sbsec->sid = SECINITSID_UNLABELED;
251 sbsec->def_sid = SECINITSID_FILE;
c312feb2 252 sbsec->mntpoint_sid = SECINITSID_UNLABELED;
1da177e4
LT		 253 sb->s_security = sbsec;
254
255 return 0;
256}
257
258static void superblock_free_security(struct super_block *sb)
259{
260 struct superblock_security_struct *sbsec = sb->s_security;
261
1da177e4
LT		 262 spin_lock(&sb_security_lock);
263 if (!list_empty(&sbsec->list))
264 list_del_init(&sbsec->list);
265 spin_unlock(&sb_security_lock);
266
267 sb->s_security = NULL;
268 kfree(sbsec);
269}
270
7d877f3b 271static int sk_alloc_security(struct sock *sk, int family, gfp_t priority)
1da177e4
LT		 272{
273 struct sk_security_struct *ssec;
274
89d155ef 275 ssec = kzalloc(sizeof(*ssec), priority);
1da177e4
LT		 276 if (!ssec)
277 return -ENOMEM;
278
1da177e4
LT		 279 ssec->sk = sk;
280 ssec->peer_sid = SECINITSID_UNLABELED;
892c141e 281 ssec->sid = SECINITSID_UNLABELED;
1da177e4
LT		 282 sk->sk_security = ssec;
283
99f59ed0
PM		 284 selinux_netlbl_sk_security_init(ssec, family);
285
1da177e4
LT		 286 return 0;
287}
288
289static void sk_free_security(struct sock *sk)
290{
291 struct sk_security_struct *ssec = sk->sk_security;
292
1da177e4
LT		 293 sk->sk_security = NULL;
294 kfree(ssec);
295}
1da177e4
LT		 296
297/* The security server must be initialized before
298 any labeling or access decisions can be provided. */
299extern int ss_initialized;
300
301/* The file system's label must be initialized prior to use. */
302
303static char *labeling_behaviors[6] = {
304 "uses xattr",
305 "uses transition SIDs",
306 "uses task SIDs",
307 "uses genfs_contexts",
308 "not configured for labeling",
309 "uses mountpoint labeling",
310};
311
312static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry);
313
314static inline int inode_doinit(struct inode *inode)
315{
316 return inode_doinit_with_dentry(inode, NULL);
317}
318
319enum {
320 Opt_context = 1,
321 Opt_fscontext = 2,
322 Opt_defcontext = 4,
0808925e 323 Opt_rootcontext = 8,
1da177e4
LT		 324};
325
326static match_table_t tokens = {
327 {Opt_context, "context=%s"},
328 {Opt_fscontext, "fscontext=%s"},
329 {Opt_defcontext, "defcontext=%s"},
0808925e 330 {Opt_rootcontext, "rootcontext=%s"},
1da177e4
LT		 331};
332
333#define SEL_MOUNT_FAIL_MSG "SELinux: duplicate or incompatible mount options\n"
334
c312feb2
EP		 335static int may_context_mount_sb_relabel(u32 sid,
336 struct superblock_security_struct *sbsec,
337 struct task_security_struct *tsec)
338{
339 int rc;
340
341 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
342 FILESYSTEM__RELABELFROM, NULL);
343 if (rc)
344 return rc;
345
346 rc = avc_has_perm(tsec->sid, sid, SECCLASS_FILESYSTEM,
347 FILESYSTEM__RELABELTO, NULL);
348 return rc;
349}
350
0808925e
EP		 351static int may_context_mount_inode_relabel(u32 sid,
352 struct superblock_security_struct *sbsec,
353 struct task_security_struct *tsec)
354{
355 int rc;
356 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
357 FILESYSTEM__RELABELFROM, NULL);
358 if (rc)
359 return rc;
360
361 rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM,
362 FILESYSTEM__ASSOCIATE, NULL);
363 return rc;
364}
365
1da177e4
LT		 366static int try_context_mount(struct super_block *sb, void *data)
367{
368 char *context = NULL, *defcontext = NULL;
0808925e 369 char *fscontext = NULL, *rootcontext = NULL;
1da177e4
LT		 370 const char *name;
371 u32 sid;
372 int alloc = 0, rc = 0, seen = 0;
373 struct task_security_struct *tsec = current->security;
374 struct superblock_security_struct *sbsec = sb->s_security;
375
376 if (!data)
377 goto out;
378
379 name = sb->s_type->name;
380
381 if (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA) {
382
383 /* NFS we understand. */
384 if (!strcmp(name, "nfs")) {
385 struct nfs_mount_data *d = data;
386
387 if (d->version < NFS_MOUNT_VERSION)
388 goto out;
389
390 if (d->context[0]) {
391 context = d->context;
392 seen |= Opt_context;
393 }
394 } else
395 goto out;
396
397 } else {
398 /* Standard string-based options. */
399 char *p, *options = data;
400
3528a953 401 while ((p = strsep(&options, "|")) != NULL) {
1da177e4
LT		 402 int token;
403 substring_t args[MAX_OPT_ARGS];
404
405 if (!*p)
406 continue;
407
408 token = match_token(p, tokens, args);
409
410 switch (token) {
411 case Opt_context:
c312feb2 412 if (seen & (Opt_context|Opt_defcontext)) {
1da177e4
LT		 413 rc = -EINVAL;
414 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
415 goto out_free;
416 }
417 context = match_strdup(&args[0]);
418 if (!context) {
419 rc = -ENOMEM;
420 goto out_free;
421 }
422 if (!alloc)
423 alloc = 1;
424 seen |= Opt_context;
425 break;
426
427 case Opt_fscontext:
c312feb2 428 if (seen & Opt_fscontext) {
1da177e4
LT		 429 rc = -EINVAL;
430 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
431 goto out_free;
432 }
c312feb2
EP		 433 fscontext = match_strdup(&args[0]);
434 if (!fscontext) {
1da177e4
LT		 435 rc = -ENOMEM;
436 goto out_free;
437 }
438 if (!alloc)
439 alloc = 1;
440 seen |= Opt_fscontext;
441 break;
442
0808925e
EP		 443 case Opt_rootcontext:
444 if (seen & Opt_rootcontext) {
445 rc = -EINVAL;
446 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
447 goto out_free;
448 }
449 rootcontext = match_strdup(&args[0]);
450 if (!rootcontext) {
451 rc = -ENOMEM;
452 goto out_free;
453 }
454 if (!alloc)
455 alloc = 1;
456 seen |= Opt_rootcontext;
457 break;
458
1da177e4
LT		 459 case Opt_defcontext:
460 if (sbsec->behavior != SECURITY_FS_USE_XATTR) {
461 rc = -EINVAL;
462 printk(KERN_WARNING "SELinux: "
463 "defcontext option is invalid "
464 "for this filesystem type\n");
465 goto out_free;
466 }
467 if (seen & (Opt_context|Opt_defcontext)) {
468 rc = -EINVAL;
469 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
470 goto out_free;
471 }
472 defcontext = match_strdup(&args[0]);
473 if (!defcontext) {
474 rc = -ENOMEM;
475 goto out_free;
476 }
477 if (!alloc)
478 alloc = 1;
479 seen |= Opt_defcontext;
480 break;
481
482 default:
483 rc = -EINVAL;
484 printk(KERN_WARNING "SELinux: unknown mount "
485 "option\n");
486 goto out_free;
487
488 }
489 }
490 }
491
492 if (!seen)
493 goto out;
494
c312feb2
EP		 495 /* sets the context of the superblock for the fs being mounted. */
496 if (fscontext) {
497 rc = security_context_to_sid(fscontext, strlen(fscontext), &sid);
1da177e4
LT		 498 if (rc) {
499 printk(KERN_WARNING "SELinux: security_context_to_sid"
500 "(%s) failed for (dev %s, type %s) errno=%d\n",
c312feb2 501 fscontext, sb->s_id, name, rc);
1da177e4
LT		 502 goto out_free;
503 }
504
c312feb2 505 rc = may_context_mount_sb_relabel(sid, sbsec, tsec);
1da177e4
LT		 506 if (rc)
507 goto out_free;
508
c312feb2
EP		 509 sbsec->sid = sid;
510 }
511
512 /*
513 * Switch to using mount point labeling behavior.
514 * sets the label used on all file below the mountpoint, and will set
515 * the superblock context if not already set.
516 */
517 if (context) {
518 rc = security_context_to_sid(context, strlen(context), &sid);
519 if (rc) {
520 printk(KERN_WARNING "SELinux: security_context_to_sid"
521 "(%s) failed for (dev %s, type %s) errno=%d\n",
522 context, sb->s_id, name, rc);
523 goto out_free;
524 }
525
b04ea3ce
EP		 526 if (!fscontext) {
527 rc = may_context_mount_sb_relabel(sid, sbsec, tsec);
528 if (rc)
529 goto out_free;
c312feb2 530 sbsec->sid = sid;
b04ea3ce
EP		 531 } else {
532 rc = may_context_mount_inode_relabel(sid, sbsec, tsec);
533 if (rc)
534 goto out_free;
535 }
c312feb2 536 sbsec->mntpoint_sid = sid;
1da177e4 537
c312feb2 538 sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
1da177e4
LT		 539 }
540
0808925e
EP		 541 if (rootcontext) {
542 struct inode *inode = sb->s_root->d_inode;
543 struct inode_security_struct *isec = inode->i_security;
544 rc = security_context_to_sid(rootcontext, strlen(rootcontext), &sid);
545 if (rc) {
546 printk(KERN_WARNING "SELinux: security_context_to_sid"
547 "(%s) failed for (dev %s, type %s) errno=%d\n",
548 rootcontext, sb->s_id, name, rc);
549 goto out_free;
550 }
551
552 rc = may_context_mount_inode_relabel(sid, sbsec, tsec);
553 if (rc)
554 goto out_free;
555
556 isec->sid = sid;
557 isec->initialized = 1;
558 }
559
1da177e4
LT		 560 if (defcontext) {
561 rc = security_context_to_sid(defcontext, strlen(defcontext), &sid);
562 if (rc) {
563 printk(KERN_WARNING "SELinux: security_context_to_sid"
564 "(%s) failed for (dev %s, type %s) errno=%d\n",
565 defcontext, sb->s_id, name, rc);
566 goto out_free;
567 }
568
569 if (sid == sbsec->def_sid)
570 goto out_free;
571
0808925e 572 rc = may_context_mount_inode_relabel(sid, sbsec, tsec);
1da177e4
LT		 573 if (rc)
574 goto out_free;
575
576 sbsec->def_sid = sid;
577 }
578
579out_free:
580 if (alloc) {
581 kfree(context);
582 kfree(defcontext);
c312feb2 583 kfree(fscontext);
0808925e 584 kfree(rootcontext);
1da177e4
LT		 585 }
586out:
587 return rc;
588}
589
590static int superblock_doinit(struct super_block *sb, void *data)
591{
592 struct superblock_security_struct *sbsec = sb->s_security;
593 struct dentry *root = sb->s_root;
594 struct inode *inode = root->d_inode;
595 int rc = 0;
596
bc7e982b 597 mutex_lock(&sbsec->lock);
1da177e4
LT		 598 if (sbsec->initialized)
599 goto out;
600
601 if (!ss_initialized) {
602 /* Defer initialization until selinux_complete_init,
603 after the initial policy is loaded and the security
604 server is ready to handle calls. */
605 spin_lock(&sb_security_lock);
606 if (list_empty(&sbsec->list))
607 list_add(&sbsec->list, &superblock_security_head);
608 spin_unlock(&sb_security_lock);
609 goto out;
610 }
611
612 /* Determine the labeling behavior to use for this filesystem type. */
613 rc = security_fs_use(sb->s_type->name, &sbsec->behavior, &sbsec->sid);
614 if (rc) {
615 printk(KERN_WARNING "%s: security_fs_use(%s) returned %d\n",
616 __FUNCTION__, sb->s_type->name, rc);
617 goto out;
618 }
619
620 rc = try_context_mount(sb, data);
621 if (rc)
622 goto out;
623
624 if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
625 /* Make sure that the xattr handler exists and that no
626 error other than -ENODATA is returned by getxattr on
627 the root directory. -ENODATA is ok, as this may be
628 the first boot of the SELinux kernel before we have
629 assigned xattr values to the filesystem. */
630 if (!inode->i_op->getxattr) {
631 printk(KERN_WARNING "SELinux: (dev %s, type %s) has no "
632 "xattr support\n", sb->s_id, sb->s_type->name);
633 rc = -EOPNOTSUPP;
634 goto out;
635 }
636 rc = inode->i_op->getxattr(root, XATTR_NAME_SELINUX, NULL, 0);
637 if (rc < 0 && rc != -ENODATA) {
638 if (rc == -EOPNOTSUPP)
639 printk(KERN_WARNING "SELinux: (dev %s, type "
640 "%s) has no security xattr handler\n",
641 sb->s_id, sb->s_type->name);
642 else
643 printk(KERN_WARNING "SELinux: (dev %s, type "
644 "%s) getxattr errno %d\n", sb->s_id,
645 sb->s_type->name, -rc);
646 goto out;
647 }
648 }
649
650 if (strcmp(sb->s_type->name, "proc") == 0)
651 sbsec->proc = 1;
652
653 sbsec->initialized = 1;
654
655 if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors)) {
656 printk(KERN_INFO "SELinux: initialized (dev %s, type %s), unknown behavior\n",
657 sb->s_id, sb->s_type->name);
658 }
659 else {
660 printk(KERN_INFO "SELinux: initialized (dev %s, type %s), %s\n",
661 sb->s_id, sb->s_type->name,
662 labeling_behaviors[sbsec->behavior-1]);
663 }
664
665 /* Initialize the root inode. */
666 rc = inode_doinit_with_dentry(sb->s_root->d_inode, sb->s_root);
667
668 /* Initialize any other inodes associated with the superblock, e.g.
669 inodes created prior to initial policy load or inodes created
670 during get_sb by a pseudo filesystem that directly
671 populates itself. */
672 spin_lock(&sbsec->isec_lock);
673next_inode:
674 if (!list_empty(&sbsec->isec_head)) {
675 struct inode_security_struct *isec =
676 list_entry(sbsec->isec_head.next,
677 struct inode_security_struct, list);
678 struct inode *inode = isec->inode;
679 spin_unlock(&sbsec->isec_lock);
680 inode = igrab(inode);
681 if (inode) {
682 if (!IS_PRIVATE (inode))
683 inode_doinit(inode);
684 iput(inode);
685 }
686 spin_lock(&sbsec->isec_lock);
687 list_del_init(&isec->list);
688 goto next_inode;
689 }
690 spin_unlock(&sbsec->isec_lock);
691out:
bc7e982b 692 mutex_unlock(&sbsec->lock);
1da177e4
LT		 693 return rc;
694}
695
696static inline u16 inode_mode_to_security_class(umode_t mode)
697{
698 switch (mode & S_IFMT) {
699 case S_IFSOCK:
700 return SECCLASS_SOCK_FILE;
701 case S_IFLNK:
702 return SECCLASS_LNK_FILE;
703 case S_IFREG:
704 return SECCLASS_FILE;
705 case S_IFBLK:
706 return SECCLASS_BLK_FILE;
707 case S_IFDIR:
708 return SECCLASS_DIR;
709 case S_IFCHR:
710 return SECCLASS_CHR_FILE;
711 case S_IFIFO:
712 return SECCLASS_FIFO_FILE;
713
714 }
715
716 return SECCLASS_FILE;
717}
718
13402580
JM		 719static inline int default_protocol_stream(int protocol)
720{
721 return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP);
722}
723
724static inline int default_protocol_dgram(int protocol)
725{
726 return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP);
727}
728
1da177e4
LT		 729static inline u16 socket_type_to_security_class(int family, int type, int protocol)
730{
731 switch (family) {
732 case PF_UNIX:
733 switch (type) {
734 case SOCK_STREAM:
735 case SOCK_SEQPACKET:
736 return SECCLASS_UNIX_STREAM_SOCKET;
737 case SOCK_DGRAM:
738 return SECCLASS_UNIX_DGRAM_SOCKET;
739 }
740 break;
741 case PF_INET:
742 case PF_INET6:
743 switch (type) {
744 case SOCK_STREAM:
13402580
JM		 745 if (default_protocol_stream(protocol))
746 return SECCLASS_TCP_SOCKET;
747 else
748 return SECCLASS_RAWIP_SOCKET;
1da177e4 749 case SOCK_DGRAM:
13402580
JM		 750 if (default_protocol_dgram(protocol))
751 return SECCLASS_UDP_SOCKET;
752 else
753 return SECCLASS_RAWIP_SOCKET;
2ee92d46
JM		 754 case SOCK_DCCP:
755 return SECCLASS_DCCP_SOCKET;
13402580 756 default:
1da177e4
LT		 757 return SECCLASS_RAWIP_SOCKET;
758 }
759 break;
760 case PF_NETLINK:
761 switch (protocol) {
762 case NETLINK_ROUTE:
763 return SECCLASS_NETLINK_ROUTE_SOCKET;
764 case NETLINK_FIREWALL:
765 return SECCLASS_NETLINK_FIREWALL_SOCKET;
216efaaa 766 case NETLINK_INET_DIAG:
1da177e4
LT		 767 return SECCLASS_NETLINK_TCPDIAG_SOCKET;
768 case NETLINK_NFLOG:
769 return SECCLASS_NETLINK_NFLOG_SOCKET;
770 case NETLINK_XFRM:
771 return SECCLASS_NETLINK_XFRM_SOCKET;
772 case NETLINK_SELINUX:
773 return SECCLASS_NETLINK_SELINUX_SOCKET;
774 case NETLINK_AUDIT:
775 return SECCLASS_NETLINK_AUDIT_SOCKET;
776 case NETLINK_IP6_FW:
777 return SECCLASS_NETLINK_IP6FW_SOCKET;
778 case NETLINK_DNRTMSG:
779 return SECCLASS_NETLINK_DNRT_SOCKET;
0c9b7942
JM		 780 case NETLINK_KOBJECT_UEVENT:
781 return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET;
1da177e4
LT		 782 default:
783 return SECCLASS_NETLINK_SOCKET;
784 }
785 case PF_PACKET:
786 return SECCLASS_PACKET_SOCKET;
787 case PF_KEY:
788 return SECCLASS_KEY_SOCKET;
3e3ff15e
CP		 789 case PF_APPLETALK:
790 return SECCLASS_APPLETALK_SOCKET;
1da177e4
LT		 791 }
792
793 return SECCLASS_SOCKET;
794}
795
796#ifdef CONFIG_PROC_FS
797static int selinux_proc_get_sid(struct proc_dir_entry *de,
798 u16 tclass,
799 u32 *sid)
800{
801 int buflen, rc;
802 char *buffer, *path, *end;
803
804 buffer = (char*)__get_free_page(GFP_KERNEL);
805 if (!buffer)
806 return -ENOMEM;
807
808 buflen = PAGE_SIZE;
809 end = buffer+buflen;
810 *--end = '\0';
811 buflen--;
812 path = end-1;
813 *path = '/';
814 while (de && de != de->parent) {
815 buflen -= de->namelen + 1;
816 if (buflen < 0)
817 break;
818 end -= de->namelen;
819 memcpy(end, de->name, de->namelen);
820 *--end = '/';
821 path = end;
822 de = de->parent;
823 }
824 rc = security_genfs_sid("proc", path, tclass, sid);
825 free_page((unsigned long)buffer);
826 return rc;
827}
828#else
829static int selinux_proc_get_sid(struct proc_dir_entry *de,
830 u16 tclass,
831 u32 *sid)
832{
833 return -EINVAL;
834}
835#endif
836
837/* The inode's security attributes must be initialized before first use. */
838static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry)
839{
840 struct superblock_security_struct *sbsec = NULL;
841 struct inode_security_struct *isec = inode->i_security;
842 u32 sid;
843 struct dentry *dentry;
844#define INITCONTEXTLEN 255
845 char *context = NULL;
846 unsigned len = 0;
847 int rc = 0;
1da177e4
LT		 848
849 if (isec->initialized)
850 goto out;
851
23970741 852 mutex_lock(&isec->lock);
1da177e4 853 if (isec->initialized)
23970741 854 goto out_unlock;
1da177e4
LT		 855
856 sbsec = inode->i_sb->s_security;
857 if (!sbsec->initialized) {
858 /* Defer initialization until selinux_complete_init,
859 after the initial policy is loaded and the security
860 server is ready to handle calls. */
861 spin_lock(&sbsec->isec_lock);
862 if (list_empty(&isec->list))
863 list_add(&isec->list, &sbsec->isec_head);
864 spin_unlock(&sbsec->isec_lock);
23970741 865 goto out_unlock;
1da177e4
LT		 866 }
867
868 switch (sbsec->behavior) {
869 case SECURITY_FS_USE_XATTR:
870 if (!inode->i_op->getxattr) {
871 isec->sid = sbsec->def_sid;
872 break;
873 }
874
875 /* Need a dentry, since the xattr API requires one.
876 Life would be simpler if we could just pass the inode. */
877 if (opt_dentry) {
878 /* Called from d_instantiate or d_splice_alias. */
879 dentry = dget(opt_dentry);
880 } else {
881 /* Called from selinux_complete_init, try to find a dentry. */
882 dentry = d_find_alias(inode);
883 }
884 if (!dentry) {
885 printk(KERN_WARNING "%s: no dentry for dev=%s "
886 "ino=%ld\n", __FUNCTION__, inode->i_sb->s_id,
887 inode->i_ino);
23970741 888 goto out_unlock;
1da177e4
LT		 889 }
890
891 len = INITCONTEXTLEN;
892 context = kmalloc(len, GFP_KERNEL);
893 if (!context) {
894 rc = -ENOMEM;
895 dput(dentry);
23970741 896 goto out_unlock;
1da177e4
LT		 897 }
898 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
899 context, len);
900 if (rc == -ERANGE) {
901 /* Need a larger buffer. Query for the right size. */
902 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
903 NULL, 0);
904 if (rc < 0) {
905 dput(dentry);
23970741 906 goto out_unlock;
1da177e4
LT		 907 }
908 kfree(context);
909 len = rc;
910 context = kmalloc(len, GFP_KERNEL);
911 if (!context) {
912 rc = -ENOMEM;
913 dput(dentry);
23970741 914 goto out_unlock;
1da177e4
LT		 915 }
916 rc = inode->i_op->getxattr(dentry,
917 XATTR_NAME_SELINUX,
918 context, len);
919 }
920 dput(dentry);
921 if (rc < 0) {
922 if (rc != -ENODATA) {
923 printk(KERN_WARNING "%s: getxattr returned "
924 "%d for dev=%s ino=%ld\n", __FUNCTION__,
925 -rc, inode->i_sb->s_id, inode->i_ino);
926 kfree(context);
23970741 927 goto out_unlock;
1da177e4
LT		 928 }
929 /* Map ENODATA to the default file SID */
930 sid = sbsec->def_sid;
931 rc = 0;
932 } else {
f5c1d5b2
JM		 933 rc = security_context_to_sid_default(context, rc, &sid,
934 sbsec->def_sid);
1da177e4
LT		 935 if (rc) {
936 printk(KERN_WARNING "%s: context_to_sid(%s) "
937 "returned %d for dev=%s ino=%ld\n",
938 __FUNCTION__, context, -rc,
939 inode->i_sb->s_id, inode->i_ino);
940 kfree(context);
941 /* Leave with the unlabeled SID */
942 rc = 0;
943 break;
944 }
945 }
946 kfree(context);
947 isec->sid = sid;
948 break;
949 case SECURITY_FS_USE_TASK:
950 isec->sid = isec->task_sid;
951 break;
952 case SECURITY_FS_USE_TRANS:
953 /* Default to the fs SID. */
954 isec->sid = sbsec->sid;
955
956 /* Try to obtain a transition SID. */
957 isec->sclass = inode_mode_to_security_class(inode->i_mode);
958 rc = security_transition_sid(isec->task_sid,
959 sbsec->sid,
960 isec->sclass,
961 &sid);
962 if (rc)
23970741 963 goto out_unlock;
1da177e4
LT		 964 isec->sid = sid;
965 break;
c312feb2
EP		 966 case SECURITY_FS_USE_MNTPOINT:
967 isec->sid = sbsec->mntpoint_sid;
968 break;
1da177e4 969 default:
c312feb2 970 /* Default to the fs superblock SID. */
1da177e4
LT		 971 isec->sid = sbsec->sid;
972
973 if (sbsec->proc) {
974 struct proc_inode *proci = PROC_I(inode);
975 if (proci->pde) {
976 isec->sclass = inode_mode_to_security_class(inode->i_mode);
977 rc = selinux_proc_get_sid(proci->pde,
978 isec->sclass,
979 &sid);
980 if (rc)
23970741 981 goto out_unlock;
1da177e4
LT		 982 isec->sid = sid;
983 }
984 }
985 break;
986 }
987
988 isec->initialized = 1;
989
23970741
EP		 990out_unlock:
991 mutex_unlock(&isec->lock);
1da177e4
LT		 992out:
993 if (isec->sclass == SECCLASS_FILE)
994 isec->sclass = inode_mode_to_security_class(inode->i_mode);
1da177e4
LT		 995 return rc;
996}
997
998/* Convert a Linux signal to an access vector. */
999static inline u32 signal_to_av(int sig)
1000{
1001 u32 perm = 0;
1002
1003 switch (sig) {
1004 case SIGCHLD:
1005 /* Commonly granted from child to parent. */
1006 perm = PROCESS__SIGCHLD;
1007 break;
1008 case SIGKILL:
1009 /* Cannot be caught or ignored */
1010 perm = PROCESS__SIGKILL;
1011 break;
1012 case SIGSTOP:
1013 /* Cannot be caught or ignored */
1014 perm = PROCESS__SIGSTOP;
1015 break;
1016 default:
1017 /* All other signals. */
1018 perm = PROCESS__SIGNAL;
1019 break;
1020 }
1021
1022 return perm;
1023}
1024
1025/* Check permission betweeen a pair of tasks, e.g. signal checks,
1026 fork check, ptrace check, etc. */
1027static int task_has_perm(struct task_struct *tsk1,
1028 struct task_struct *tsk2,
1029 u32 perms)
1030{
1031 struct task_security_struct *tsec1, *tsec2;
1032
1033 tsec1 = tsk1->security;
1034 tsec2 = tsk2->security;
1035 return avc_has_perm(tsec1->sid, tsec2->sid,
1036 SECCLASS_PROCESS, perms, NULL);
1037}
1038
1039/* Check whether a task is allowed to use a capability. */
1040static int task_has_capability(struct task_struct *tsk,
1041 int cap)
1042{
1043 struct task_security_struct *tsec;
1044 struct avc_audit_data ad;
1045
1046 tsec = tsk->security;
1047
1048 AVC_AUDIT_DATA_INIT(&ad,CAP);
1049 ad.tsk = tsk;
1050 ad.u.cap = cap;
1051
1052 return avc_has_perm(tsec->sid, tsec->sid,
1053 SECCLASS_CAPABILITY, CAP_TO_MASK(cap), &ad);
1054}
1055
1056/* Check whether a task is allowed to use a system operation. */
1057static int task_has_system(struct task_struct *tsk,
1058 u32 perms)
1059{
1060 struct task_security_struct *tsec;
1061
1062 tsec = tsk->security;
1063
1064 return avc_has_perm(tsec->sid, SECINITSID_KERNEL,
1065 SECCLASS_SYSTEM, perms, NULL);
1066}
1067
1068/* Check whether a task has a particular permission to an inode.
1069 The 'adp' parameter is optional and allows other audit
1070 data to be passed (e.g. the dentry). */
1071static int inode_has_perm(struct task_struct *tsk,
1072 struct inode *inode,
1073 u32 perms,
1074 struct avc_audit_data *adp)
1075{
1076 struct task_security_struct *tsec;
1077 struct inode_security_struct *isec;
1078 struct avc_audit_data ad;
1079
1080 tsec = tsk->security;
1081 isec = inode->i_security;
1082
1083 if (!adp) {
1084 adp = &ad;
1085 AVC_AUDIT_DATA_INIT(&ad, FS);
1086 ad.u.fs.inode = inode;
1087 }
1088
1089 return avc_has_perm(tsec->sid, isec->sid, isec->sclass, perms, adp);
1090}
1091
1092/* Same as inode_has_perm, but pass explicit audit data containing
1093 the dentry to help the auditing code to more easily generate the
1094 pathname if needed. */
1095static inline int dentry_has_perm(struct task_struct *tsk,
1096 struct vfsmount *mnt,
1097 struct dentry *dentry,
1098 u32 av)
1099{
1100 struct inode *inode = dentry->d_inode;
1101 struct avc_audit_data ad;
1102 AVC_AUDIT_DATA_INIT(&ad,FS);
1103 ad.u.fs.mnt = mnt;
1104 ad.u.fs.dentry = dentry;
1105 return inode_has_perm(tsk, inode, av, &ad);
1106}
1107
1108/* Check whether a task can use an open file descriptor to
1109 access an inode in a given way. Check access to the
1110 descriptor itself, and then use dentry_has_perm to
1111 check a particular permission to the file.
1112 Access to the descriptor is implicitly granted if it
1113 has the same SID as the process. If av is zero, then
1114 access to the file is not checked, e.g. for cases
1115 where only the descriptor is affected like seek. */
858119e1 1116static int file_has_perm(struct task_struct *tsk,
1da177e4
LT		 1117 struct file *file,
1118 u32 av)
1119{
1120 struct task_security_struct *tsec = tsk->security;
1121 struct file_security_struct *fsec = file->f_security;
3d5ff529
JS		 1122 struct vfsmount *mnt = file->f_path.mnt;
1123 struct dentry *dentry = file->f_path.dentry;
1da177e4
LT		 1124 struct inode *inode = dentry->d_inode;
1125 struct avc_audit_data ad;
1126 int rc;
1127
1128 AVC_AUDIT_DATA_INIT(&ad, FS);
1129 ad.u.fs.mnt = mnt;
1130 ad.u.fs.dentry = dentry;
1131
1132 if (tsec->sid != fsec->sid) {
1133 rc = avc_has_perm(tsec->sid, fsec->sid,
1134 SECCLASS_FD,
1135 FD__USE,
1136 &ad);
1137 if (rc)
1138 return rc;
1139 }
1140
1141 /* av is zero if only checking access to the descriptor. */
1142 if (av)
1143 return inode_has_perm(tsk, inode, av, &ad);
1144
1145 return 0;
1146}
1147
1148/* Check whether a task can create a file. */
1149static int may_create(struct inode *dir,
1150 struct dentry *dentry,
1151 u16 tclass)
1152{
1153 struct task_security_struct *tsec;
1154 struct inode_security_struct *dsec;
1155 struct superblock_security_struct *sbsec;
1156 u32 newsid;
1157 struct avc_audit_data ad;
1158 int rc;
1159
1160 tsec = current->security;
1161 dsec = dir->i_security;
1162 sbsec = dir->i_sb->s_security;
1163
1164 AVC_AUDIT_DATA_INIT(&ad, FS);
1165 ad.u.fs.dentry = dentry;
1166
1167 rc = avc_has_perm(tsec->sid, dsec->sid, SECCLASS_DIR,
1168 DIR__ADD_NAME | DIR__SEARCH,
1169 &ad);
1170 if (rc)
1171 return rc;
1172
1173 if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
1174 newsid = tsec->create_sid;
1175 } else {
1176 rc = security_transition_sid(tsec->sid, dsec->sid, tclass,
1177 &newsid);
1178 if (rc)
1179 return rc;
1180 }
1181
1182 rc = avc_has_perm(tsec->sid, newsid, tclass, FILE__CREATE, &ad);
1183 if (rc)
1184 return rc;
1185
1186 return avc_has_perm(newsid, sbsec->sid,
1187 SECCLASS_FILESYSTEM,
1188 FILESYSTEM__ASSOCIATE, &ad);
1189}
1190
4eb582cf
ML		 1191/* Check whether a task can create a key. */
1192static int may_create_key(u32 ksid,
1193 struct task_struct *ctx)
1194{
1195 struct task_security_struct *tsec;
1196
1197 tsec = ctx->security;
1198
1199 return avc_has_perm(tsec->sid, ksid, SECCLASS_KEY, KEY__CREATE, NULL);
1200}
1201
1da177e4
LT		 1202#define MAY_LINK 0
1203#define MAY_UNLINK 1
1204#define MAY_RMDIR 2
1205
1206/* Check whether a task can link, unlink, or rmdir a file/directory. */
1207static int may_link(struct inode *dir,
1208 struct dentry *dentry,
1209 int kind)
1210
1211{
1212 struct task_security_struct *tsec;
1213 struct inode_security_struct *dsec, *isec;
1214 struct avc_audit_data ad;
1215 u32 av;
1216 int rc;
1217
1218 tsec = current->security;
1219 dsec = dir->i_security;
1220 isec = dentry->d_inode->i_security;
1221
1222 AVC_AUDIT_DATA_INIT(&ad, FS);
1223 ad.u.fs.dentry = dentry;
1224
1225 av = DIR__SEARCH;
1226 av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
1227 rc = avc_has_perm(tsec->sid, dsec->sid, SECCLASS_DIR, av, &ad);
1228 if (rc)
1229 return rc;
1230
1231 switch (kind) {
1232 case MAY_LINK:
1233 av = FILE__LINK;
1234 break;
1235 case MAY_UNLINK:
1236 av = FILE__UNLINK;
1237 break;
1238 case MAY_RMDIR:
1239 av = DIR__RMDIR;
1240 break;
1241 default:
1242 printk(KERN_WARNING "may_link: unrecognized kind %d\n", kind);
1243 return 0;
1244 }
1245
1246 rc = avc_has_perm(tsec->sid, isec->sid, isec->sclass, av, &ad);
1247 return rc;
1248}
1249
1250static inline int may_rename(struct inode *old_dir,
1251 struct dentry *old_dentry,
1252 struct inode *new_dir,
1253 struct dentry *new_dentry)
1254{
1255 struct task_security_struct *tsec;
1256 struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec;
1257 struct avc_audit_data ad;
1258 u32 av;
1259 int old_is_dir, new_is_dir;
1260 int rc;
1261
1262 tsec = current->security;
1263 old_dsec = old_dir->i_security;
1264 old_isec = old_dentry->d_inode->i_security;
1265 old_is_dir = S_ISDIR(old_dentry->d_inode->i_mode);
1266 new_dsec = new_dir->i_security;
1267
1268 AVC_AUDIT_DATA_INIT(&ad, FS);
1269
1270 ad.u.fs.dentry = old_dentry;
1271 rc = avc_has_perm(tsec->sid, old_dsec->sid, SECCLASS_DIR,
1272 DIR__REMOVE_NAME | DIR__SEARCH, &ad);
1273 if (rc)
1274 return rc;
1275 rc = avc_has_perm(tsec->sid, old_isec->sid,
1276 old_isec->sclass, FILE__RENAME, &ad);
1277 if (rc)
1278 return rc;
1279 if (old_is_dir && new_dir != old_dir) {
1280 rc = avc_has_perm(tsec->sid, old_isec->sid,
1281 old_isec->sclass, DIR__REPARENT, &ad);
1282 if (rc)
1283 return rc;
1284 }
1285
1286 ad.u.fs.dentry = new_dentry;
1287 av = DIR__ADD_NAME | DIR__SEARCH;
1288 if (new_dentry->d_inode)
1289 av |= DIR__REMOVE_NAME;
1290 rc = avc_has_perm(tsec->sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
1291 if (rc)
1292 return rc;
1293 if (new_dentry->d_inode) {
1294 new_isec = new_dentry->d_inode->i_security;
1295 new_is_dir = S_ISDIR(new_dentry->d_inode->i_mode);
1296 rc = avc_has_perm(tsec->sid, new_isec->sid,
1297 new_isec->sclass,
1298 (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad);
1299 if (rc)
1300 return rc;
1301 }
1302
1303 return 0;
1304}
1305
1306/* Check whether a task can perform a filesystem operation. */
1307static int superblock_has_perm(struct task_struct *tsk,
1308 struct super_block *sb,
1309 u32 perms,
1310 struct avc_audit_data *ad)
1311{
1312 struct task_security_struct *tsec;
1313 struct superblock_security_struct *sbsec;
1314
1315 tsec = tsk->security;
1316 sbsec = sb->s_security;
1317 return avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
1318 perms, ad);
1319}
1320
1321/* Convert a Linux mode and permission mask to an access vector. */
1322static inline u32 file_mask_to_av(int mode, int mask)
1323{
1324 u32 av = 0;
1325
1326 if ((mode & S_IFMT) != S_IFDIR) {
1327 if (mask & MAY_EXEC)
1328 av |= FILE__EXECUTE;
1329 if (mask & MAY_READ)
1330 av |= FILE__READ;
1331
1332 if (mask & MAY_APPEND)
1333 av |= FILE__APPEND;
1334 else if (mask & MAY_WRITE)
1335 av |= FILE__WRITE;
1336
1337 } else {
1338 if (mask & MAY_EXEC)
1339 av |= DIR__SEARCH;
1340 if (mask & MAY_WRITE)
1341 av |= DIR__WRITE;
1342 if (mask & MAY_READ)
1343 av |= DIR__READ;
1344 }
1345
1346 return av;
1347}
1348
1349/* Convert a Linux file to an access vector. */
1350static inline u32 file_to_av(struct file *file)
1351{
1352 u32 av = 0;
1353
1354 if (file->f_mode & FMODE_READ)
1355 av |= FILE__READ;
1356 if (file->f_mode & FMODE_WRITE) {
1357 if (file->f_flags & O_APPEND)
1358 av |= FILE__APPEND;
1359 else
1360 av |= FILE__WRITE;
1361 }
1362
1363 return av;
1364}
1365
1da177e4
LT		 1366/* Hook functions begin here. */
1367
1368static int selinux_ptrace(struct task_struct *parent, struct task_struct *child)
1369{
1370 struct task_security_struct *psec = parent->security;
1371 struct task_security_struct *csec = child->security;
1372 int rc;
1373
1374 rc = secondary_ops->ptrace(parent,child);
1375 if (rc)
1376 return rc;
1377
1378 rc = task_has_perm(parent, child, PROCESS__PTRACE);
1379 /* Save the SID of the tracing process for later use in apply_creds. */
341c2d80 1380 if (!(child->ptrace & PT_PTRACED) && !rc)
1da177e4
LT		 1381 csec->ptrace_sid = psec->sid;
1382 return rc;
1383}
1384
1385static int selinux_capget(struct task_struct *target, kernel_cap_t *effective,
1386 kernel_cap_t *inheritable, kernel_cap_t *permitted)
1387{
1388 int error;
1389
1390 error = task_has_perm(current, target, PROCESS__GETCAP);
1391 if (error)
1392 return error;
1393
1394 return secondary_ops->capget(target, effective, inheritable, permitted);
1395}
1396
1397static int selinux_capset_check(struct task_struct *target, kernel_cap_t *effective,
1398 kernel_cap_t *inheritable, kernel_cap_t *permitted)
1399{
1400 int error;
1401
1402 error = secondary_ops->capset_check(target, effective, inheritable, permitted);
1403 if (error)
1404 return error;
1405
1406 return task_has_perm(current, target, PROCESS__SETCAP);
1407}
1408
1409static void selinux_capset_set(struct task_struct *target, kernel_cap_t *effective,
1410 kernel_cap_t *inheritable, kernel_cap_t *permitted)
1411{
1412 secondary_ops->capset_set(target, effective, inheritable, permitted);
1413}
1414
1415static int selinux_capable(struct task_struct *tsk, int cap)
1416{
1417 int rc;
1418
1419 rc = secondary_ops->capable(tsk, cap);
1420 if (rc)
1421 return rc;
1422
1423 return task_has_capability(tsk,cap);
1424}
1425
1426static int selinux_sysctl(ctl_table *table, int op)
1427{
1428 int error = 0;
1429 u32 av;
1430 struct task_security_struct *tsec;
1431 u32 tsid;
1432 int rc;
1433
1434 rc = secondary_ops->sysctl(table, op);
1435 if (rc)
1436 return rc;
1437
1438 tsec = current->security;
1439
1440 rc = selinux_proc_get_sid(table->de, (op == 001) ?
1441 SECCLASS_DIR : SECCLASS_FILE, &tsid);
1442 if (rc) {
1443 /* Default to the well-defined sysctl SID. */
1444 tsid = SECINITSID_SYSCTL;
1445 }
1446
1447 /* The op values are "defined" in sysctl.c, thereby creating
1448 * a bad coupling between this module and sysctl.c */
1449 if(op == 001) {
1450 error = avc_has_perm(tsec->sid, tsid,
1451 SECCLASS_DIR, DIR__SEARCH, NULL);
1452 } else {
1453 av = 0;
1454 if (op & 004)
1455 av |= FILE__READ;
1456 if (op & 002)
1457 av |= FILE__WRITE;
1458 if (av)
1459 error = avc_has_perm(tsec->sid, tsid,
1460 SECCLASS_FILE, av, NULL);
1461 }
1462
1463 return error;
1464}
1465
1466static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb)
1467{
1468 int rc = 0;
1469
1470 if (!sb)
1471 return 0;
1472
1473 switch (cmds) {
1474 case Q_SYNC:
1475 case Q_QUOTAON:
1476 case Q_QUOTAOFF:
1477 case Q_SETINFO:
1478 case Q_SETQUOTA:
1479 rc = superblock_has_perm(current,
1480 sb,
1481 FILESYSTEM__QUOTAMOD, NULL);
1482 break;
1483 case Q_GETFMT:
1484 case Q_GETINFO:
1485 case Q_GETQUOTA:
1486 rc = superblock_has_perm(current,
1487 sb,
1488 FILESYSTEM__QUOTAGET, NULL);
1489 break;
1490 default:
1491 rc = 0; /* let the kernel handle invalid cmds */
1492 break;
1493 }
1494 return rc;
1495}
1496
1497static int selinux_quota_on(struct dentry *dentry)
1498{
1499 return dentry_has_perm(current, NULL, dentry, FILE__QUOTAON);
1500}
1501
1502static int selinux_syslog(int type)
1503{
1504 int rc;
1505
1506 rc = secondary_ops->syslog(type);
1507 if (rc)
1508 return rc;
1509
1510 switch (type) {
1511 case 3: /* Read last kernel messages */
1512 case 10: /* Return size of the log buffer */
1513 rc = task_has_system(current, SYSTEM__SYSLOG_READ);
1514 break;
1515 case 6: /* Disable logging to console */
1516 case 7: /* Enable logging to console */
1517 case 8: /* Set level of messages printed to console */
1518 rc = task_has_system(current, SYSTEM__SYSLOG_CONSOLE);
1519 break;
1520 case 0: /* Close log */
1521 case 1: /* Open log */
1522 case 2: /* Read from log */
1523 case 4: /* Read/clear last kernel messages */
1524 case 5: /* Clear ring buffer */
1525 default:
1526 rc = task_has_system(current, SYSTEM__SYSLOG_MOD);
1527 break;
1528 }
1529 return rc;
1530}
1531
1532/*
1533 * Check that a process has enough memory to allocate a new virtual
1534 * mapping. 0 means there is enough memory for the allocation to
1535 * succeed and -ENOMEM implies there is not.
1536 *
1537 * Note that secondary_ops->capable and task_has_perm_noaudit return 0
1538 * if the capability is granted, but __vm_enough_memory requires 1 if
1539 * the capability is granted.
1540 *
1541 * Do not audit the selinux permission check, as this is applied to all
1542 * processes that allocate mappings.
1543 */
1544static int selinux_vm_enough_memory(long pages)
1545{
1546 int rc, cap_sys_admin = 0;
1547 struct task_security_struct *tsec = current->security;
1548
1549 rc = secondary_ops->capable(current, CAP_SYS_ADMIN);
1550 if (rc == 0)
1551 rc = avc_has_perm_noaudit(tsec->sid, tsec->sid,
1552 SECCLASS_CAPABILITY,
1553 CAP_TO_MASK(CAP_SYS_ADMIN),
1554 NULL);
1555
1556 if (rc == 0)
1557 cap_sys_admin = 1;
1558
1559 return __vm_enough_memory(pages, cap_sys_admin);
1560}
1561
1562/* binprm security operations */
1563
1564static int selinux_bprm_alloc_security(struct linux_binprm *bprm)
1565{
1566 struct bprm_security_struct *bsec;
1567
89d155ef 1568 bsec = kzalloc(sizeof(struct bprm_security_struct), GFP_KERNEL);
1da177e4
LT		 1569 if (!bsec)
1570 return -ENOMEM;
1571
1da177e4
LT		 1572 bsec->bprm = bprm;
1573 bsec->sid = SECINITSID_UNLABELED;
1574 bsec->set = 0;
1575
1576 bprm->security = bsec;
1577 return 0;
1578}
1579
1580static int selinux_bprm_set_security(struct linux_binprm *bprm)
1581{
1582 struct task_security_struct *tsec;
3d5ff529 1583 struct inode *inode = bprm->file->f_path.dentry->d_inode;
1da177e4
LT		 1584 struct inode_security_struct *isec;
1585 struct bprm_security_struct *bsec;
1586 u32 newsid;
1587 struct avc_audit_data ad;
1588 int rc;
1589
1590 rc = secondary_ops->bprm_set_security(bprm);
1591 if (rc)
1592 return rc;
1593
1594 bsec = bprm->security;
1595
1596 if (bsec->set)
1597 return 0;
1598
1599 tsec = current->security;
1600 isec = inode->i_security;
1601
1602 /* Default to the current task SID. */
1603 bsec->sid = tsec->sid;
1604
28eba5bf 1605 /* Reset fs, key, and sock SIDs on execve. */
1da177e4 1606 tsec->create_sid = 0;
28eba5bf 1607 tsec->keycreate_sid = 0;
42c3e03e 1608 tsec->sockcreate_sid = 0;
1da177e4
LT		 1609
1610 if (tsec->exec_sid) {
1611 newsid = tsec->exec_sid;
1612 /* Reset exec SID on execve. */
1613 tsec->exec_sid = 0;
1614 } else {
1615 /* Check for a default transition on this program. */
1616 rc = security_transition_sid(tsec->sid, isec->sid,
1617 SECCLASS_PROCESS, &newsid);
1618 if (rc)
1619 return rc;
1620 }
1621
1622 AVC_AUDIT_DATA_INIT(&ad, FS);
3d5ff529
JS		 1623 ad.u.fs.mnt = bprm->file->f_path.mnt;
1624 ad.u.fs.dentry = bprm->file->f_path.dentry;
1da177e4 1625
3d5ff529 1626 if (bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID)
1da177e4
LT		 1627 newsid = tsec->sid;
1628
1629 if (tsec->sid == newsid) {
1630 rc = avc_has_perm(tsec->sid, isec->sid,
1631 SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
1632 if (rc)
1633 return rc;
1634 } else {
1635 /* Check permissions for the transition. */
1636 rc = avc_has_perm(tsec->sid, newsid,
1637 SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
1638 if (rc)
1639 return rc;
1640
1641 rc = avc_has_perm(newsid, isec->sid,
1642 SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
1643 if (rc)
1644 return rc;
1645
1646 /* Clear any possibly unsafe personality bits on exec: */
1647 current->personality &= ~PER_CLEAR_ON_SETID;
1648
1649 /* Set the security field to the new SID. */
1650 bsec->sid = newsid;
1651 }
1652
1653 bsec->set = 1;
1654 return 0;
1655}
1656
1657static int selinux_bprm_check_security (struct linux_binprm *bprm)
1658{
1659 return secondary_ops->bprm_check_security(bprm);
1660}
1661
1662
1663static int selinux_bprm_secureexec (struct linux_binprm *bprm)
1664{
1665 struct task_security_struct *tsec = current->security;
1666 int atsecure = 0;
1667
1668 if (tsec->osid != tsec->sid) {
1669 /* Enable secure mode for SIDs transitions unless
1670 the noatsecure permission is granted between
1671 the two SIDs, i.e. ahp returns 0. */
1672 atsecure = avc_has_perm(tsec->osid, tsec->sid,
1673 SECCLASS_PROCESS,
1674 PROCESS__NOATSECURE, NULL);
1675 }
1676
1677 return (atsecure || secondary_ops->bprm_secureexec(bprm));
1678}
1679
1680static void selinux_bprm_free_security(struct linux_binprm *bprm)
1681{
9a5f04bf 1682 kfree(bprm->security);
1da177e4 1683 bprm->security = NULL;
1da177e4
LT		 1684}
1685
1686extern struct vfsmount *selinuxfs_mount;
1687extern struct dentry *selinux_null;
1688
1689/* Derived from fs/exec.c:flush_old_files. */
1690static inline void flush_unauthorized_files(struct files_struct * files)
1691{
1692 struct avc_audit_data ad;
1693 struct file *file, *devnull = NULL;
b20c8122 1694 struct tty_struct *tty;
badf1662 1695 struct fdtable *fdt;
1da177e4 1696 long j = -1;
24ec839c 1697 int drop_tty = 0;
1da177e4 1698
b20c8122 1699 mutex_lock(&tty_mutex);
24ec839c 1700 tty = get_current_tty();
1da177e4
LT		 1701 if (tty) {
1702 file_list_lock();
2f512016 1703 file = list_entry(tty->tty_files.next, typeof(*file), f_u.fu_list);
1da177e4
LT		 1704 if (file) {
1705 /* Revalidate access to controlling tty.
1706 Use inode_has_perm on the tty inode directly rather
1707 than using file_has_perm, as this particular open
1708 file may belong to another process and we are only
1709 interested in the inode-based check here. */
3d5ff529 1710 struct inode *inode = file->f_path.dentry->d_inode;
1da177e4
LT		 1711 if (inode_has_perm(current, inode,
1712 FILE__READ | FILE__WRITE, NULL)) {
24ec839c 1713 drop_tty = 1;
1da177e4
LT		 1714 }
1715 }
1716 file_list_unlock();
24ec839c
PZ		 1717
1718 /* Reset controlling tty. */
1719 if (drop_tty)
1720 proc_set_tty(current, NULL);
1da177e4 1721 }
b20c8122 1722 mutex_unlock(&tty_mutex);
1da177e4
LT		 1723
1724 /* Revalidate access to inherited open files. */
1725
1726 AVC_AUDIT_DATA_INIT(&ad,FS);
1727
1728 spin_lock(&files->file_lock);
1729 for (;;) {
1730 unsigned long set, i;
1731 int fd;
1732
1733 j++;
1734 i = j * __NFDBITS;
badf1662 1735 fdt = files_fdtable(files);
bbea9f69 1736 if (i >= fdt->max_fds)
1da177e4 1737 break;
badf1662 1738 set = fdt->open_fds->fds_bits[j];
1da177e4
LT		 1739 if (!set)
1740 continue;
1741 spin_unlock(&files->file_lock);
1742 for ( ; set ; i++,set >>= 1) {
1743 if (set & 1) {
1744 file = fget(i);
1745 if (!file)
1746 continue;
1747 if (file_has_perm(current,
1748 file,
1749 file_to_av(file))) {
1750 sys_close(i);
1751 fd = get_unused_fd();
1752 if (fd != i) {
1753 if (fd >= 0)
1754 put_unused_fd(fd);
1755 fput(file);
1756 continue;
1757 }
1758 if (devnull) {
095975da 1759 get_file(devnull);
1da177e4
LT		 1760 } else {
1761 devnull = dentry_open(dget(selinux_null), mntget(selinuxfs_mount), O_RDWR);
fc5d81e6
AM		 1762 if (IS_ERR(devnull)) {
1763 devnull = NULL;
1da177e4
LT		 1764 put_unused_fd(fd);
1765 fput(file);
1766 continue;
1767 }
1768 }
1769 fd_install(fd, devnull);
1770 }
1771 fput(file);
1772 }
1773 }
1774 spin_lock(&files->file_lock);
1775
1776 }
1777 spin_unlock(&files->file_lock);
1778}
1779
1780static void selinux_bprm_apply_creds(struct linux_binprm *bprm, int unsafe)
1781{
1782 struct task_security_struct *tsec;
1783 struct bprm_security_struct *bsec;
1784 u32 sid;
1785 int rc;
1786
1787 secondary_ops->bprm_apply_creds(bprm, unsafe);
1788
1789 tsec = current->security;
1790
1791 bsec = bprm->security;
1792 sid = bsec->sid;
1793
1794 tsec->osid = tsec->sid;
1795 bsec->unsafe = 0;
1796 if (tsec->sid != sid) {
1797 /* Check for shared state. If not ok, leave SID
1798 unchanged and kill. */
1799 if (unsafe & LSM_UNSAFE_SHARE) {
1800 rc = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
1801 PROCESS__SHARE, NULL);
1802 if (rc) {
1803 bsec->unsafe = 1;
1804 return;
1805 }
1806 }
1807
1808 /* Check for ptracing, and update the task SID if ok.
1809 Otherwise, leave SID unchanged and kill. */
1810 if (unsafe & (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) {
1811 rc = avc_has_perm(tsec->ptrace_sid, sid,
1812 SECCLASS_PROCESS, PROCESS__PTRACE,
1813 NULL);
1814 if (rc) {
1815 bsec->unsafe = 1;
1816 return;
1817 }
1818 }
1819 tsec->sid = sid;
1820 }
1821}
1822
1823/*
1824 * called after apply_creds without the task lock held
1825 */
1826static void selinux_bprm_post_apply_creds(struct linux_binprm *bprm)
1827{
1828 struct task_security_struct *tsec;
1829 struct rlimit *rlim, *initrlim;
1830 struct itimerval itimer;
1831 struct bprm_security_struct *bsec;
1832 int rc, i;
1833
1834 tsec = current->security;
1835 bsec = bprm->security;
1836
1837 if (bsec->unsafe) {
1838 force_sig_specific(SIGKILL, current);
1839 return;
1840 }
1841 if (tsec->osid == tsec->sid)
1842 return;
1843
1844 /* Close files for which the new task SID is not authorized. */
1845 flush_unauthorized_files(current->files);
1846
1847 /* Check whether the new SID can inherit signal state
1848 from the old SID. If not, clear itimers to avoid
1849 subsequent signal generation and flush and unblock
1850 signals. This must occur _after_ the task SID has
1851 been updated so that any kill done after the flush
1852 will be checked against the new SID. */
1853 rc = avc_has_perm(tsec->osid, tsec->sid, SECCLASS_PROCESS,
1854 PROCESS__SIGINH, NULL);
1855 if (rc) {
1856 memset(&itimer, 0, sizeof itimer);
1857 for (i = 0; i < 3; i++)
1858 do_setitimer(i, &itimer, NULL);
1859 flush_signals(current);
1860 spin_lock_irq(&current->sighand->siglock);
1861 flush_signal_handlers(current, 1);
1862 sigemptyset(&current->blocked);
1863 recalc_sigpending();
1864 spin_unlock_irq(&current->sighand->siglock);
1865 }
1866
1867 /* Check whether the new SID can inherit resource limits
1868 from the old SID. If not, reset all soft limits to
1869 the lower of the current task's hard limit and the init
1870 task's soft limit. Note that the setting of hard limits
1871 (even to lower them) can be controlled by the setrlimit
1872 check. The inclusion of the init task's soft limit into
1873 the computation is to avoid resetting soft limits higher
1874 than the default soft limit for cases where the default
1875 is lower than the hard limit, e.g. RLIMIT_CORE or
1876 RLIMIT_STACK.*/
1877 rc = avc_has_perm(tsec->osid, tsec->sid, SECCLASS_PROCESS,
1878 PROCESS__RLIMITINH, NULL);
1879 if (rc) {
1880 for (i = 0; i < RLIM_NLIMITS; i++) {
1881 rlim = current->signal->rlim + i;
1882 initrlim = init_task.signal->rlim+i;
1883 rlim->rlim_cur = min(rlim->rlim_max,initrlim->rlim_cur);
1884 }
1885 if (current->signal->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY) {
1886 /*
1887 * This will cause RLIMIT_CPU calculations
1888 * to be refigured.
1889 */
1890 current->it_prof_expires = jiffies_to_cputime(1);
1891 }
1892 }
1893
1894 /* Wake up the parent if it is waiting so that it can
1895 recheck wait permission to the new task SID. */
1896 wake_up_interruptible(&current->parent->signal->wait_chldexit);
1897}
1898
1899/* superblock security operations */
1900
1901static int selinux_sb_alloc_security(struct super_block *sb)
1902{
1903 return superblock_alloc_security(sb);
1904}
1905
1906static void selinux_sb_free_security(struct super_block *sb)
1907{
1908 superblock_free_security(sb);
1909}
1910
1911static inline int match_prefix(char *prefix, int plen, char *option, int olen)
1912{
1913 if (plen > olen)
1914 return 0;
1915
1916 return !memcmp(prefix, option, plen);
1917}
1918
1919static inline int selinux_option(char *option, int len)
1920{
1921 return (match_prefix("context=", sizeof("context=")-1, option, len) ||
1922 match_prefix("fscontext=", sizeof("fscontext=")-1, option, len) ||
0808925e
EP		 1923 match_prefix("defcontext=", sizeof("defcontext=")-1, option, len) ||
1924 match_prefix("rootcontext=", sizeof("rootcontext=")-1, option, len));
1da177e4
LT		 1925}
1926
1927static inline void take_option(char **to, char *from, int *first, int len)
1928{
1929 if (!*first) {
1930 **to = ',';
1931 *to += 1;
3528a953 1932 } else
1da177e4
LT		 1933 *first = 0;
1934 memcpy(*to, from, len);
1935 *to += len;
1936}
1937
3528a953
CO		 1938static inline void take_selinux_option(char **to, char *from, int *first,
1939 int len)
1940{
1941 int current_size = 0;
1942
1943 if (!*first) {
1944 **to = '|';
1945 *to += 1;
1946 }
1947 else
1948 *first = 0;
1949
1950 while (current_size < len) {
1951 if (*from != '"') {
1952 **to = *from;
1953 *to += 1;
1954 }
1955 from += 1;
1956 current_size += 1;
1957 }
1958}
1959
1da177e4
LT		 1960static int selinux_sb_copy_data(struct file_system_type *type, void *orig, void *copy)
1961{
1962 int fnosec, fsec, rc = 0;
1963 char *in_save, *in_curr, *in_end;
1964 char *sec_curr, *nosec_save, *nosec;
3528a953 1965 int open_quote = 0;
1da177e4
LT		 1966
1967 in_curr = orig;
1968 sec_curr = copy;
1969
1970 /* Binary mount data: just copy */
1971 if (type->fs_flags & FS_BINARY_MOUNTDATA) {
1972 copy_page(sec_curr, in_curr);
1973 goto out;
1974 }
1975
1976 nosec = (char *)get_zeroed_page(GFP_KERNEL);
1977 if (!nosec) {
1978 rc = -ENOMEM;
1979 goto out;
1980 }
1981
1982 nosec_save = nosec;
1983 fnosec = fsec = 1;
1984 in_save = in_end = orig;
1985
1986 do {
3528a953
CO		 1987 if (*in_end == '"')
1988 open_quote = !open_quote;
1989 if ((*in_end == ',' && open_quote == 0) ||
1990 *in_end == '\0') {
1da177e4
LT		 1991 int len = in_end - in_curr;
1992
1993 if (selinux_option(in_curr, len))
3528a953 1994 take_selinux_option(&sec_curr, in_curr, &fsec, len);
1da177e4
LT		 1995 else
1996 take_option(&nosec, in_curr, &fnosec, len);
1997
1998 in_curr = in_end + 1;
1999 }
2000 } while (*in_end++);
2001
6931dfc9 2002 strcpy(in_save, nosec_save);
da3caa20 2003 free_page((unsigned long)nosec_save);
1da177e4
LT		 2004out:
2005 return rc;
2006}
2007
2008static int selinux_sb_kern_mount(struct super_block *sb, void *data)
2009{
2010 struct avc_audit_data ad;
2011 int rc;
2012
2013 rc = superblock_doinit(sb, data);
2014 if (rc)
2015 return rc;
2016
2017 AVC_AUDIT_DATA_INIT(&ad,FS);
2018 ad.u.fs.dentry = sb->s_root;
2019 return superblock_has_perm(current, sb, FILESYSTEM__MOUNT, &ad);
2020}
2021
726c3342 2022static int selinux_sb_statfs(struct dentry *dentry)
1da177e4
LT		 2023{
2024 struct avc_audit_data ad;
2025
2026 AVC_AUDIT_DATA_INIT(&ad,FS);
726c3342
DH		 2027 ad.u.fs.dentry = dentry->d_sb->s_root;
2028 return superblock_has_perm(current, dentry->d_sb, FILESYSTEM__GETATTR, &ad);
1da177e4
LT		 2029}
2030
2031static int selinux_mount(char * dev_name,
2032 struct nameidata *nd,
2033 char * type,
2034 unsigned long flags,
2035 void * data)
2036{
2037 int rc;
2038
2039 rc = secondary_ops->sb_mount(dev_name, nd, type, flags, data);
2040 if (rc)
2041 return rc;
2042
2043 if (flags & MS_REMOUNT)
2044 return superblock_has_perm(current, nd->mnt->mnt_sb,
2045 FILESYSTEM__REMOUNT, NULL);
2046 else
2047 return dentry_has_perm(current, nd->mnt, nd->dentry,
2048 FILE__MOUNTON);
2049}
2050
2051static int selinux_umount(struct vfsmount *mnt, int flags)
2052{
2053 int rc;
2054
2055 rc = secondary_ops->sb_umount(mnt, flags);
2056 if (rc)
2057 return rc;
2058
2059 return superblock_has_perm(current,mnt->mnt_sb,
2060 FILESYSTEM__UNMOUNT,NULL);
2061}
2062
2063/* inode security operations */
2064
2065static int selinux_inode_alloc_security(struct inode *inode)
2066{
2067 return inode_alloc_security(inode);
2068}
2069
2070static void selinux_inode_free_security(struct inode *inode)
2071{
2072 inode_free_security(inode);
2073}
2074
5e41ff9e
SS		 2075static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
2076 char **name, void **value,
2077 size_t *len)
2078{
2079 struct task_security_struct *tsec;
2080 struct inode_security_struct *dsec;
2081 struct superblock_security_struct *sbsec;
570bc1c2 2082 u32 newsid, clen;
5e41ff9e 2083 int rc;
570bc1c2 2084 char *namep = NULL, *context;
5e41ff9e
SS		 2085
2086 tsec = current->security;
2087 dsec = dir->i_security;
2088 sbsec = dir->i_sb->s_security;
5e41ff9e
SS		 2089
2090 if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
2091 newsid = tsec->create_sid;
2092 } else {
2093 rc = security_transition_sid(tsec->sid, dsec->sid,
2094 inode_mode_to_security_class(inode->i_mode),
2095 &newsid);
2096 if (rc) {
2097 printk(KERN_WARNING "%s: "
2098 "security_transition_sid failed, rc=%d (dev=%s "
2099 "ino=%ld)\n",
2100 __FUNCTION__,
2101 -rc, inode->i_sb->s_id, inode->i_ino);
2102 return rc;
2103 }
2104 }
2105
296fddf7
EP		 2106 /* Possibly defer initialization to selinux_complete_init. */
2107 if (sbsec->initialized) {
2108 struct inode_security_struct *isec = inode->i_security;
2109 isec->sclass = inode_mode_to_security_class(inode->i_mode);
2110 isec->sid = newsid;
2111 isec->initialized = 1;
2112 }
5e41ff9e 2113
8aad3875 2114 if (!ss_initialized || sbsec->behavior == SECURITY_FS_USE_MNTPOINT)
25a74f3b
SS		 2115 return -EOPNOTSUPP;
2116
570bc1c2
SS		 2117 if (name) {
2118 namep = kstrdup(XATTR_SELINUX_SUFFIX, GFP_KERNEL);
2119 if (!namep)
2120 return -ENOMEM;
2121 *name = namep;
2122 }
5e41ff9e 2123
570bc1c2
SS		 2124 if (value && len) {
2125 rc = security_sid_to_context(newsid, &context, &clen);
2126 if (rc) {
2127 kfree(namep);
2128 return rc;
2129 }
2130 *value = context;
2131 *len = clen;
5e41ff9e 2132 }
5e41ff9e 2133
5e41ff9e
SS		 2134 return 0;
2135}
2136
1da177e4
LT		 2137static int selinux_inode_create(struct inode *dir, struct dentry *dentry, int mask)
2138{
2139 return may_create(dir, dentry, SECCLASS_FILE);
2140}
2141
1da177e4
LT		 2142static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
2143{
2144 int rc;
2145
2146 rc = secondary_ops->inode_link(old_dentry,dir,new_dentry);
2147 if (rc)
2148 return rc;
2149 return may_link(dir, old_dentry, MAY_LINK);
2150}
2151
1da177e4
LT		 2152static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry)
2153{
2154 int rc;
2155
2156 rc = secondary_ops->inode_unlink(dir, dentry);
2157 if (rc)
2158 return rc;
2159 return may_link(dir, dentry, MAY_UNLINK);
2160}
2161
2162static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name)
2163{
2164 return may_create(dir, dentry, SECCLASS_LNK_FILE);
2165}
2166
1da177e4
LT		 2167static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, int mask)
2168{
2169 return may_create(dir, dentry, SECCLASS_DIR);
2170}
2171
1da177e4
LT		 2172static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry)
2173{
2174 return may_link(dir, dentry, MAY_RMDIR);
2175}
2176
2177static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
2178{
2179 int rc;
2180
2181 rc = secondary_ops->inode_mknod(dir, dentry, mode, dev);
2182 if (rc)
2183 return rc;
2184
2185 return may_create(dir, dentry, inode_mode_to_security_class(mode));
2186}
2187
1da177e4
LT		 2188static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
2189 struct inode *new_inode, struct dentry *new_dentry)
2190{
2191 return may_rename(old_inode, old_dentry, new_inode, new_dentry);
2192}
2193
1da177e4
LT		 2194static int selinux_inode_readlink(struct dentry *dentry)
2195{
2196 return dentry_has_perm(current, NULL, dentry, FILE__READ);
2197}
2198
2199static int selinux_inode_follow_link(struct dentry *dentry, struct nameidata *nameidata)
2200{
2201 int rc;
2202
2203 rc = secondary_ops->inode_follow_link(dentry,nameidata);
2204 if (rc)
2205 return rc;
2206 return dentry_has_perm(current, NULL, dentry, FILE__READ);
2207}
2208
2209static int selinux_inode_permission(struct inode *inode, int mask,
2210 struct nameidata *nd)
2211{
2212 int rc;
2213
2214 rc = secondary_ops->inode_permission(inode, mask, nd);
2215 if (rc)
2216 return rc;
2217
2218 if (!mask) {
2219 /* No permission to check. Existence test. */
2220 return 0;
2221 }
2222
2223 return inode_has_perm(current, inode,
2224 file_mask_to_av(inode->i_mode, mask), NULL);
2225}
2226
2227static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
2228{
2229 int rc;
2230
2231 rc = secondary_ops->inode_setattr(dentry, iattr);
2232 if (rc)
2233 return rc;
2234
2235 if (iattr->ia_valid & ATTR_FORCE)
2236 return 0;
2237
2238 if (iattr->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
2239 ATTR_ATIME_SET | ATTR_MTIME_SET))
2240 return dentry_has_perm(current, NULL, dentry, FILE__SETATTR);
2241
2242 return dentry_has_perm(current, NULL, dentry, FILE__WRITE);
2243}
2244
2245static int selinux_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
2246{
2247 return dentry_has_perm(current, mnt, dentry, FILE__GETATTR);
2248}
2249
2250static int selinux_inode_setxattr(struct dentry *dentry, char *name, void *value, size_t size, int flags)
2251{
2252 struct task_security_struct *tsec = current->security;
2253 struct inode *inode = dentry->d_inode;
2254 struct inode_security_struct *isec = inode->i_security;
2255 struct superblock_security_struct *sbsec;
2256 struct avc_audit_data ad;
2257 u32 newsid;
2258 int rc = 0;
2259
2260 if (strcmp(name, XATTR_NAME_SELINUX)) {
2261 if (!strncmp(name, XATTR_SECURITY_PREFIX,
2262 sizeof XATTR_SECURITY_PREFIX - 1) &&
2263 !capable(CAP_SYS_ADMIN)) {
2264 /* A different attribute in the security namespace.
2265 Restrict to administrator. */
2266 return -EPERM;
2267 }
2268
2269 /* Not an attribute we recognize, so just check the
2270 ordinary setattr permission. */
2271 return dentry_has_perm(current, NULL, dentry, FILE__SETATTR);
2272 }
2273
2274 sbsec = inode->i_sb->s_security;
2275 if (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)
2276 return -EOPNOTSUPP;
2277
2278 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
2279 return -EPERM;
2280
2281 AVC_AUDIT_DATA_INIT(&ad,FS);
2282 ad.u.fs.dentry = dentry;
2283
2284 rc = avc_has_perm(tsec->sid, isec->sid, isec->sclass,
2285 FILE__RELABELFROM, &ad);
2286 if (rc)
2287 return rc;
2288
2289 rc = security_context_to_sid(value, size, &newsid);
2290 if (rc)
2291 return rc;
2292
2293 rc = avc_has_perm(tsec->sid, newsid, isec->sclass,
2294 FILE__RELABELTO, &ad);
2295 if (rc)
2296 return rc;
2297
2298 rc = security_validate_transition(isec->sid, newsid, tsec->sid,
2299 isec->sclass);
2300 if (rc)
2301 return rc;
2302
2303 return avc_has_perm(newsid,
2304 sbsec->sid,
2305 SECCLASS_FILESYSTEM,
2306 FILESYSTEM__ASSOCIATE,
2307 &ad);
2308}
2309
2310static void selinux_inode_post_setxattr(struct dentry *dentry, char *name,
2311 void *value, size_t size, int flags)
2312{
2313 struct inode *inode = dentry->d_inode;
2314 struct inode_security_struct *isec = inode->i_security;
2315 u32 newsid;
2316 int rc;
2317
2318 if (strcmp(name, XATTR_NAME_SELINUX)) {
2319 /* Not an attribute we recognize, so nothing to do. */
2320 return;
2321 }
2322
2323 rc = security_context_to_sid(value, size, &newsid);
2324 if (rc) {
2325 printk(KERN_WARNING "%s: unable to obtain SID for context "
2326 "%s, rc=%d\n", __FUNCTION__, (char*)value, -rc);
2327 return;
2328 }
2329
2330 isec->sid = newsid;
2331 return;
2332}
2333
2334static int selinux_inode_getxattr (struct dentry *dentry, char *name)
2335{
1da177e4
LT		 2336 return dentry_has_perm(current, NULL, dentry, FILE__GETATTR);
2337}
2338
2339static int selinux_inode_listxattr (struct dentry *dentry)
2340{
2341 return dentry_has_perm(current, NULL, dentry, FILE__GETATTR);
2342}
2343
2344static int selinux_inode_removexattr (struct dentry *dentry, char *name)
2345{
2346 if (strcmp(name, XATTR_NAME_SELINUX)) {
2347 if (!strncmp(name, XATTR_SECURITY_PREFIX,
2348 sizeof XATTR_SECURITY_PREFIX - 1) &&
2349 !capable(CAP_SYS_ADMIN)) {
2350 /* A different attribute in the security namespace.
2351 Restrict to administrator. */
2352 return -EPERM;
2353 }
2354
2355 /* Not an attribute we recognize, so just check the
2356 ordinary setattr permission. Might want a separate
2357 permission for removexattr. */
2358 return dentry_has_perm(current, NULL, dentry, FILE__SETATTR);
2359 }
2360
2361 /* No one is allowed to remove a SELinux security label.
2362 You can change the label, but all data must be labeled. */
2363 return -EACCES;
2364}
2365
8c8570fb
DK		 2366static const char *selinux_inode_xattr_getsuffix(void)
2367{
2368 return XATTR_SELINUX_SUFFIX;
2369}
2370
d381d8a9
JM		 2371/*
2372 * Copy the in-core inode security context value to the user. If the
2373 * getxattr() prior to this succeeded, check to see if we need to
2374 * canonicalize the value to be finally returned to the user.
2375 *
2376 * Permission check is handled by selinux_inode_getxattr hook.
2377 */
7306a0b9 2378static int selinux_inode_getsecurity(const struct inode *inode, const char *name, void *buffer, size_t size, int err)
1da177e4
LT		 2379{
2380 struct inode_security_struct *isec = inode->i_security;
d381d8a9 2381
8c8570fb
DK		 2382 if (strcmp(name, XATTR_SELINUX_SUFFIX))
2383 return -EOPNOTSUPP;
d381d8a9 2384
8c8570fb 2385 return selinux_getsecurity(isec->sid, buffer, size);
1da177e4
LT		 2386}
2387
2388static int selinux_inode_setsecurity(struct inode *inode, const char *name,
2389 const void *value, size_t size, int flags)
2390{
2391 struct inode_security_struct *isec = inode->i_security;
2392 u32 newsid;
2393 int rc;
2394
2395 if (strcmp(name, XATTR_SELINUX_SUFFIX))
2396 return -EOPNOTSUPP;
2397
2398 if (!value || !size)
2399 return -EACCES;
2400
2401 rc = security_context_to_sid((void*)value, size, &newsid);
2402 if (rc)
2403 return rc;
2404
2405 isec->sid = newsid;
2406 return 0;
2407}
2408
2409static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
2410{
2411 const int len = sizeof(XATTR_NAME_SELINUX);
2412 if (buffer && len <= buffer_size)
2413 memcpy(buffer, XATTR_NAME_SELINUX, len);
2414 return len;
2415}
2416
2417/* file security operations */
2418
2419static int selinux_file_permission(struct file *file, int mask)
2420{
7420ed23 2421 int rc;
3d5ff529 2422 struct inode *inode = file->f_path.dentry->d_inode;
1da177e4
LT		 2423
2424 if (!mask) {
2425 /* No permission to check. Existence test. */
2426 return 0;
2427 }
2428
2429 /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */
2430 if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE))
2431 mask |= MAY_APPEND;
2432
7420ed23
VY		 2433 rc = file_has_perm(current, file,
2434 file_mask_to_av(inode->i_mode, mask));
2435 if (rc)
2436 return rc;
2437
2438 return selinux_netlbl_inode_permission(inode, mask);
1da177e4
LT		 2439}
2440
2441static int selinux_file_alloc_security(struct file *file)
2442{
2443 return file_alloc_security(file);
2444}
2445
2446static void selinux_file_free_security(struct file *file)
2447{
2448 file_free_security(file);
2449}
2450
2451static int selinux_file_ioctl(struct file *file, unsigned int cmd,
2452 unsigned long arg)
2453{
2454 int error = 0;
2455
2456 switch (cmd) {
2457 case FIONREAD:
2458 /* fall through */
2459 case FIBMAP:
2460 /* fall through */
2461 case FIGETBSZ:
2462 /* fall through */
2463 case EXT2_IOC_GETFLAGS:
2464 /* fall through */
2465 case EXT2_IOC_GETVERSION:
2466 error = file_has_perm(current, file, FILE__GETATTR);
2467 break;
2468
2469 case EXT2_IOC_SETFLAGS:
2470 /* fall through */
2471 case EXT2_IOC_SETVERSION:
2472 error = file_has_perm(current, file, FILE__SETATTR);
2473 break;
2474
2475 /* sys_ioctl() checks */
2476 case FIONBIO:
2477 /* fall through */
2478 case FIOASYNC:
2479 error = file_has_perm(current, file, 0);
2480 break;
2481
2482 case KDSKBENT:
2483 case KDSKBSENT:
2484 error = task_has_capability(current,CAP_SYS_TTY_CONFIG);
2485 break;
2486
2487 /* default case assumes that the command will go
2488 * to the file's ioctl() function.
2489 */
2490 default:
2491 error = file_has_perm(current, file, FILE__IOCTL);
2492
2493 }
2494 return error;
2495}
2496
2497static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
2498{
2499#ifndef CONFIG_PPC32
2500 if ((prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) {
2501 /*
2502 * We are making executable an anonymous mapping or a
2503 * private file mapping that will also be writable.
2504 * This has an additional check.
2505 */
2506 int rc = task_has_perm(current, current, PROCESS__EXECMEM);
2507 if (rc)
2508 return rc;
2509 }
2510#endif
2511
2512 if (file) {
2513 /* read access is always possible with a mapping */
2514 u32 av = FILE__READ;
2515
2516 /* write access only matters if the mapping is shared */
2517 if (shared && (prot & PROT_WRITE))
2518 av |= FILE__WRITE;
2519
2520 if (prot & PROT_EXEC)
2521 av |= FILE__EXECUTE;
2522
2523 return file_has_perm(current, file, av);
2524 }
2525 return 0;
2526}
2527
2528static int selinux_file_mmap(struct file *file, unsigned long reqprot,
2529 unsigned long prot, unsigned long flags)
2530{
2531 int rc;
2532
2533 rc = secondary_ops->file_mmap(file, reqprot, prot, flags);
2534 if (rc)
2535 return rc;
2536
2537 if (selinux_checkreqprot)
2538 prot = reqprot;
2539
2540 return file_map_prot_check(file, prot,
2541 (flags & MAP_TYPE) == MAP_SHARED);
2542}
2543
2544static int selinux_file_mprotect(struct vm_area_struct *vma,
2545 unsigned long reqprot,
2546 unsigned long prot)
2547{
2548 int rc;
2549
2550 rc = secondary_ops->file_mprotect(vma, reqprot, prot);
2551 if (rc)
2552 return rc;
2553
2554 if (selinux_checkreqprot)
2555 prot = reqprot;
2556
2557#ifndef CONFIG_PPC32
db4c9641
SS		 2558 if ((prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
2559 rc = 0;
2560 if (vma->vm_start >= vma->vm_mm->start_brk &&
2561 vma->vm_end <= vma->vm_mm->brk) {
2562 rc = task_has_perm(current, current,
2563 PROCESS__EXECHEAP);
2564 } else if (!vma->vm_file &&
2565 vma->vm_start <= vma->vm_mm->start_stack &&
2566 vma->vm_end >= vma->vm_mm->start_stack) {
2567 rc = task_has_perm(current, current, PROCESS__EXECSTACK);
2568 } else if (vma->vm_file && vma->anon_vma) {
2569 /*
2570 * We are making executable a file mapping that has
2571 * had some COW done. Since pages might have been
2572 * written, check ability to execute the possibly
2573 * modified content. This typically should only
2574 * occur for text relocations.
2575 */
2576 rc = file_has_perm(current, vma->vm_file,
2577 FILE__EXECMOD);
2578 }