]> bbs.cooldavid.org Git - net-next-2.6.git/blame - security/selinux/hooks.c
git://bbs.cooldavid.org / net-next-2.6.git / blame
? search:
summary | shortlog | log | commit | commitdiff | tree
blob | blame (incremental) | history | HEAD
[PATCH] ext3: Enable atomic inode security labeling
[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>
15 *
16 * This program is free software; you can redistribute it and/or modify
17 * it under the terms of the GNU General Public License version 2,
18 * as published by the Free Software Foundation.
19 */
20
21#include <linux/config.h>
22#include <linux/module.h>
23#include <linux/init.h>
24#include <linux/kernel.h>
25#include <linux/ptrace.h>
26#include <linux/errno.h>
27#include <linux/sched.h>
28#include <linux/security.h>
29#include <linux/xattr.h>
30#include <linux/capability.h>
31#include <linux/unistd.h>
32#include <linux/mm.h>
33#include <linux/mman.h>
34#include <linux/slab.h>
35#include <linux/pagemap.h>
36#include <linux/swap.h>
37#include <linux/smp_lock.h>
38#include <linux/spinlock.h>
39#include <linux/syscalls.h>
40#include <linux/file.h>
41#include <linux/namei.h>
42#include <linux/mount.h>
43#include <linux/ext2_fs.h>
44#include <linux/proc_fs.h>
45#include <linux/kd.h>
46#include <linux/netfilter_ipv4.h>
47#include <linux/netfilter_ipv6.h>
48#include <linux/tty.h>
49#include <net/icmp.h>
50#include <net/ip.h> /* for sysctl_local_port_range[] */
51#include <net/tcp.h> /* struct or_callable used in sock_rcv_skb */
52#include <asm/uaccess.h>
53#include <asm/semaphore.h>
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>
61#include <linux/quota.h>
62#include <linux/un.h> /* for Unix socket types */
63#include <net/af_unix.h> /* for Unix socket types */
64#include <linux/parser.h>
65#include <linux/nfs_mount.h>
66#include <net/ipv6.h>
67#include <linux/hugetlb.h>
68#include <linux/personality.h>
69#include <linux/sysctl.h>
70#include <linux/audit.h>
6931dfc9 71#include <linux/string.h>
1da177e4
LT		 72
73#include "avc.h"
74#include "objsec.h"
75#include "netif.h"
76
77#define XATTR_SELINUX_SUFFIX "selinux"
78#define XATTR_NAME_SELINUX XATTR_SECURITY_PREFIX XATTR_SELINUX_SUFFIX
79
80extern unsigned int policydb_loaded_version;
81extern int selinux_nlmsg_lookup(u16 sclass, u16 nlmsg_type, u32 *perm);
82
83#ifdef CONFIG_SECURITY_SELINUX_DEVELOP
84int selinux_enforcing = 0;
85
86static int __init enforcing_setup(char *str)
87{
88 selinux_enforcing = simple_strtol(str,NULL,0);
89 return 1;
90}
91__setup("enforcing=", enforcing_setup);
92#endif
93
94#ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM
95int selinux_enabled = CONFIG_SECURITY_SELINUX_BOOTPARAM_VALUE;
96
97static int __init selinux_enabled_setup(char *str)
98{
99 selinux_enabled = simple_strtol(str, NULL, 0);
100 return 1;
101}
102__setup("selinux=", selinux_enabled_setup);
103#endif
104
105/* Original (dummy) security module. */
106static struct security_operations *original_ops = NULL;
107
108/* Minimal support for a secondary security module,
109 just to allow the use of the dummy or capability modules.
110 The owlsm module can alternatively be used as a secondary
111 module as long as CONFIG_OWLSM_FD is not enabled. */
112static struct security_operations *secondary_ops = NULL;
113
114/* Lists of inode and superblock security structures initialized
115 before the policy was loaded. */
116static LIST_HEAD(superblock_security_head);
117static DEFINE_SPINLOCK(sb_security_lock);
118
119/* Allocate and free functions for each kind of security blob. */
120
121static int task_alloc_security(struct task_struct *task)
122{
123 struct task_security_struct *tsec;
124
125 tsec = kmalloc(sizeof(struct task_security_struct), GFP_KERNEL);
126 if (!tsec)
127 return -ENOMEM;
128
129 memset(tsec, 0, sizeof(struct task_security_struct));
130 tsec->magic = SELINUX_MAGIC;
131 tsec->task = task;
132 tsec->osid = tsec->sid = tsec->ptrace_sid = SECINITSID_UNLABELED;
133 task->security = tsec;
134
135 return 0;
136}
137
138static void task_free_security(struct task_struct *task)
139{
140 struct task_security_struct *tsec = task->security;
141
142 if (!tsec || tsec->magic != SELINUX_MAGIC)
143 return;
144
145 task->security = NULL;
146 kfree(tsec);
147}
148
149static int inode_alloc_security(struct inode *inode)
150{
151 struct task_security_struct *tsec = current->security;
152 struct inode_security_struct *isec;
153
154 isec = kmalloc(sizeof(struct inode_security_struct), GFP_KERNEL);
155 if (!isec)
156 return -ENOMEM;
157
158 memset(isec, 0, sizeof(struct inode_security_struct));
159 init_MUTEX(&isec->sem);
160 INIT_LIST_HEAD(&isec->list);
161 isec->magic = SELINUX_MAGIC;
162 isec->inode = inode;
163 isec->sid = SECINITSID_UNLABELED;
164 isec->sclass = SECCLASS_FILE;
165 if (tsec && tsec->magic == SELINUX_MAGIC)
166 isec->task_sid = tsec->sid;
167 else
168 isec->task_sid = SECINITSID_UNLABELED;
169 inode->i_security = isec;
170
171 return 0;
172}
173
174static void inode_free_security(struct inode *inode)
175{
176 struct inode_security_struct *isec = inode->i_security;
177 struct superblock_security_struct *sbsec = inode->i_sb->s_security;
178
179 if (!isec || isec->magic != SELINUX_MAGIC)
180 return;
181
182 spin_lock(&sbsec->isec_lock);
183 if (!list_empty(&isec->list))
184 list_del_init(&isec->list);
185 spin_unlock(&sbsec->isec_lock);
186
187 inode->i_security = NULL;
188 kfree(isec);
189}
190
191static int file_alloc_security(struct file *file)
192{
193 struct task_security_struct *tsec = current->security;
194 struct file_security_struct *fsec;
195
196 fsec = kmalloc(sizeof(struct file_security_struct), GFP_ATOMIC);
197 if (!fsec)
198 return -ENOMEM;
199
200 memset(fsec, 0, sizeof(struct file_security_struct));
201 fsec->magic = SELINUX_MAGIC;
202 fsec->file = file;
203 if (tsec && tsec->magic == SELINUX_MAGIC) {
204 fsec->sid = tsec->sid;
205 fsec->fown_sid = tsec->sid;
206 } else {
207 fsec->sid = SECINITSID_UNLABELED;
208 fsec->fown_sid = SECINITSID_UNLABELED;
209 }
210 file->f_security = fsec;
211
212 return 0;
213}
214
215static void file_free_security(struct file *file)
216{
217 struct file_security_struct *fsec = file->f_security;
218
219 if (!fsec || fsec->magic != SELINUX_MAGIC)
220 return;
221
222 file->f_security = NULL;
223 kfree(fsec);
224}
225
226static int superblock_alloc_security(struct super_block *sb)
227{
228 struct superblock_security_struct *sbsec;
229
230 sbsec = kmalloc(sizeof(struct superblock_security_struct), GFP_KERNEL);
231 if (!sbsec)
232 return -ENOMEM;
233
234 memset(sbsec, 0, sizeof(struct superblock_security_struct));
235 init_MUTEX(&sbsec->sem);
236 INIT_LIST_HEAD(&sbsec->list);
237 INIT_LIST_HEAD(&sbsec->isec_head);
238 spin_lock_init(&sbsec->isec_lock);
239 sbsec->magic = SELINUX_MAGIC;
240 sbsec->sb = sb;
241 sbsec->sid = SECINITSID_UNLABELED;
242 sbsec->def_sid = SECINITSID_FILE;
243 sb->s_security = sbsec;
244
245 return 0;
246}
247
248static void superblock_free_security(struct super_block *sb)
249{
250 struct superblock_security_struct *sbsec = sb->s_security;
251
252 if (!sbsec || sbsec->magic != SELINUX_MAGIC)
253 return;
254
255 spin_lock(&sb_security_lock);
256 if (!list_empty(&sbsec->list))
257 list_del_init(&sbsec->list);
258 spin_unlock(&sb_security_lock);
259
260 sb->s_security = NULL;
261 kfree(sbsec);
262}
263
264#ifdef CONFIG_SECURITY_NETWORK
265static int sk_alloc_security(struct sock *sk, int family, int priority)
266{
267 struct sk_security_struct *ssec;
268
269 if (family != PF_UNIX)
270 return 0;
271
272 ssec = kmalloc(sizeof(*ssec), priority);
273 if (!ssec)
274 return -ENOMEM;
275
276 memset(ssec, 0, sizeof(*ssec));
277 ssec->magic = SELINUX_MAGIC;
278 ssec->sk = sk;
279 ssec->peer_sid = SECINITSID_UNLABELED;
280 sk->sk_security = ssec;
281
282 return 0;
283}
284
285static void sk_free_security(struct sock *sk)
286{
287 struct sk_security_struct *ssec = sk->sk_security;
288
289 if (sk->sk_family != PF_UNIX || ssec->magic != SELINUX_MAGIC)
290 return;
291
292 sk->sk_security = NULL;
293 kfree(ssec);
294}
295#endif /* CONFIG_SECURITY_NETWORK */
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,
323};
324
325static match_table_t tokens = {
326 {Opt_context, "context=%s"},
327 {Opt_fscontext, "fscontext=%s"},
328 {Opt_defcontext, "defcontext=%s"},
329};
330
331#define SEL_MOUNT_FAIL_MSG "SELinux: duplicate or incompatible mount options\n"
332
333static int try_context_mount(struct super_block *sb, void *data)
334{
335 char *context = NULL, *defcontext = NULL;
336 const char *name;
337 u32 sid;
338 int alloc = 0, rc = 0, seen = 0;
339 struct task_security_struct *tsec = current->security;
340 struct superblock_security_struct *sbsec = sb->s_security;
341
342 if (!data)
343 goto out;
344
345 name = sb->s_type->name;
346
347 if (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA) {
348
349 /* NFS we understand. */
350 if (!strcmp(name, "nfs")) {
351 struct nfs_mount_data *d = data;
352
353 if (d->version < NFS_MOUNT_VERSION)
354 goto out;
355
356 if (d->context[0]) {
357 context = d->context;
358 seen |= Opt_context;
359 }
360 } else
361 goto out;
362
363 } else {
364 /* Standard string-based options. */
365 char *p, *options = data;
366
367 while ((p = strsep(&options, ",")) != NULL) {
368 int token;
369 substring_t args[MAX_OPT_ARGS];
370
371 if (!*p)
372 continue;
373
374 token = match_token(p, tokens, args);
375
376 switch (token) {
377 case Opt_context:
378 if (seen) {
379 rc = -EINVAL;
380 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
381 goto out_free;
382 }
383 context = match_strdup(&args[0]);
384 if (!context) {
385 rc = -ENOMEM;
386 goto out_free;
387 }
388 if (!alloc)
389 alloc = 1;
390 seen |= Opt_context;
391 break;
392
393 case Opt_fscontext:
394 if (seen & (Opt_context|Opt_fscontext)) {
395 rc = -EINVAL;
396 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
397 goto out_free;
398 }
399 context = match_strdup(&args[0]);
400 if (!context) {
401 rc = -ENOMEM;
402 goto out_free;
403 }
404 if (!alloc)
405 alloc = 1;
406 seen |= Opt_fscontext;
407 break;
408
409 case Opt_defcontext:
410 if (sbsec->behavior != SECURITY_FS_USE_XATTR) {
411 rc = -EINVAL;
412 printk(KERN_WARNING "SELinux: "
413 "defcontext option is invalid "
414 "for this filesystem type\n");
415 goto out_free;
416 }
417 if (seen & (Opt_context|Opt_defcontext)) {
418 rc = -EINVAL;
419 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
420 goto out_free;
421 }
422 defcontext = match_strdup(&args[0]);
423 if (!defcontext) {
424 rc = -ENOMEM;
425 goto out_free;
426 }
427 if (!alloc)
428 alloc = 1;
429 seen |= Opt_defcontext;
430 break;
431
432 default:
433 rc = -EINVAL;
434 printk(KERN_WARNING "SELinux: unknown mount "
435 "option\n");
436 goto out_free;
437
438 }
439 }
440 }
441
442 if (!seen)
443 goto out;
444
445 if (context) {
446 rc = security_context_to_sid(context, strlen(context), &sid);
447 if (rc) {
448 printk(KERN_WARNING "SELinux: security_context_to_sid"
449 "(%s) failed for (dev %s, type %s) errno=%d\n",
450 context, sb->s_id, name, rc);
451 goto out_free;
452 }
453
454 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
455 FILESYSTEM__RELABELFROM, NULL);
456 if (rc)
457 goto out_free;
458
459 rc = avc_has_perm(tsec->sid, sid, SECCLASS_FILESYSTEM,
460 FILESYSTEM__RELABELTO, NULL);
461 if (rc)
462 goto out_free;
463
464 sbsec->sid = sid;
465
466 if (seen & Opt_context)
467 sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
468 }
469
470 if (defcontext) {
471 rc = security_context_to_sid(defcontext, strlen(defcontext), &sid);
472 if (rc) {
473 printk(KERN_WARNING "SELinux: security_context_to_sid"
474 "(%s) failed for (dev %s, type %s) errno=%d\n",
475 defcontext, sb->s_id, name, rc);
476 goto out_free;
477 }
478
479 if (sid == sbsec->def_sid)
480 goto out_free;
481
482 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
483 FILESYSTEM__RELABELFROM, NULL);
484 if (rc)
485 goto out_free;
486
487 rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM,
488 FILESYSTEM__ASSOCIATE, NULL);
489 if (rc)
490 goto out_free;
491
492 sbsec->def_sid = sid;
493 }
494
495out_free:
496 if (alloc) {
497 kfree(context);
498 kfree(defcontext);
499 }
500out:
501 return rc;
502}
503
504static int superblock_doinit(struct super_block *sb, void *data)
505{
506 struct superblock_security_struct *sbsec = sb->s_security;
507 struct dentry *root = sb->s_root;
508 struct inode *inode = root->d_inode;
509 int rc = 0;
510
511 down(&sbsec->sem);
512 if (sbsec->initialized)
513 goto out;
514
515 if (!ss_initialized) {
516 /* Defer initialization until selinux_complete_init,
517 after the initial policy is loaded and the security
518 server is ready to handle calls. */
519 spin_lock(&sb_security_lock);
520 if (list_empty(&sbsec->list))
521 list_add(&sbsec->list, &superblock_security_head);
522 spin_unlock(&sb_security_lock);
523 goto out;
524 }
525
526 /* Determine the labeling behavior to use for this filesystem type. */
527 rc = security_fs_use(sb->s_type->name, &sbsec->behavior, &sbsec->sid);
528 if (rc) {
529 printk(KERN_WARNING "%s: security_fs_use(%s) returned %d\n",
530 __FUNCTION__, sb->s_type->name, rc);
531 goto out;
532 }
533
534 rc = try_context_mount(sb, data);
535 if (rc)
536 goto out;
537
538 if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
539 /* Make sure that the xattr handler exists and that no
540 error other than -ENODATA is returned by getxattr on
541 the root directory. -ENODATA is ok, as this may be
542 the first boot of the SELinux kernel before we have
543 assigned xattr values to the filesystem. */
544 if (!inode->i_op->getxattr) {
545 printk(KERN_WARNING "SELinux: (dev %s, type %s) has no "
546 "xattr support\n", sb->s_id, sb->s_type->name);
547 rc = -EOPNOTSUPP;
548 goto out;
549 }
550 rc = inode->i_op->getxattr(root, XATTR_NAME_SELINUX, NULL, 0);
551 if (rc < 0 && rc != -ENODATA) {
552 if (rc == -EOPNOTSUPP)
553 printk(KERN_WARNING "SELinux: (dev %s, type "
554 "%s) has no security xattr handler\n",
555 sb->s_id, sb->s_type->name);
556 else
557 printk(KERN_WARNING "SELinux: (dev %s, type "
558 "%s) getxattr errno %d\n", sb->s_id,
559 sb->s_type->name, -rc);
560 goto out;
561 }
562 }
563
564 if (strcmp(sb->s_type->name, "proc") == 0)
565 sbsec->proc = 1;
566
567 sbsec->initialized = 1;
568
569 if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors)) {
570 printk(KERN_INFO "SELinux: initialized (dev %s, type %s), unknown behavior\n",
571 sb->s_id, sb->s_type->name);
572 }
573 else {
574 printk(KERN_INFO "SELinux: initialized (dev %s, type %s), %s\n",
575 sb->s_id, sb->s_type->name,
576 labeling_behaviors[sbsec->behavior-1]);
577 }
578
579 /* Initialize the root inode. */
580 rc = inode_doinit_with_dentry(sb->s_root->d_inode, sb->s_root);
581
582 /* Initialize any other inodes associated with the superblock, e.g.
583 inodes created prior to initial policy load or inodes created
584 during get_sb by a pseudo filesystem that directly
585 populates itself. */
586 spin_lock(&sbsec->isec_lock);
587next_inode:
588 if (!list_empty(&sbsec->isec_head)) {
589 struct inode_security_struct *isec =
590 list_entry(sbsec->isec_head.next,
591 struct inode_security_struct, list);
592 struct inode *inode = isec->inode;
593 spin_unlock(&sbsec->isec_lock);
594 inode = igrab(inode);
595 if (inode) {
596 if (!IS_PRIVATE (inode))
597 inode_doinit(inode);
598 iput(inode);
599 }
600 spin_lock(&sbsec->isec_lock);
601 list_del_init(&isec->list);
602 goto next_inode;
603 }
604 spin_unlock(&sbsec->isec_lock);
605out:
606 up(&sbsec->sem);
607 return rc;
608}
609
610static inline u16 inode_mode_to_security_class(umode_t mode)
611{
612 switch (mode & S_IFMT) {
613 case S_IFSOCK:
614 return SECCLASS_SOCK_FILE;
615 case S_IFLNK:
616 return SECCLASS_LNK_FILE;
617 case S_IFREG:
618 return SECCLASS_FILE;
619 case S_IFBLK:
620 return SECCLASS_BLK_FILE;
621 case S_IFDIR:
622 return SECCLASS_DIR;
623 case S_IFCHR:
624 return SECCLASS_CHR_FILE;
625 case S_IFIFO:
626 return SECCLASS_FIFO_FILE;
627
628 }
629
630 return SECCLASS_FILE;
631}
632
633static inline u16 socket_type_to_security_class(int family, int type, int protocol)
634{
635 switch (family) {
636 case PF_UNIX:
637 switch (type) {
638 case SOCK_STREAM:
639 case SOCK_SEQPACKET:
640 return SECCLASS_UNIX_STREAM_SOCKET;
641 case SOCK_DGRAM:
642 return SECCLASS_UNIX_DGRAM_SOCKET;
643 }
644 break;
645 case PF_INET:
646 case PF_INET6:
647 switch (type) {
648 case SOCK_STREAM:
649 return SECCLASS_TCP_SOCKET;
650 case SOCK_DGRAM:
651 return SECCLASS_UDP_SOCKET;
652 case SOCK_RAW:
653 return SECCLASS_RAWIP_SOCKET;
654 }
655 break;
656 case PF_NETLINK:
657 switch (protocol) {
658 case NETLINK_ROUTE:
659 return SECCLASS_NETLINK_ROUTE_SOCKET;
660 case NETLINK_FIREWALL:
661 return SECCLASS_NETLINK_FIREWALL_SOCKET;
216efaaa 662 case NETLINK_INET_DIAG:
1da177e4
LT		 663 return SECCLASS_NETLINK_TCPDIAG_SOCKET;
664 case NETLINK_NFLOG:
665 return SECCLASS_NETLINK_NFLOG_SOCKET;
666 case NETLINK_XFRM:
667 return SECCLASS_NETLINK_XFRM_SOCKET;
668 case NETLINK_SELINUX:
669 return SECCLASS_NETLINK_SELINUX_SOCKET;
670 case NETLINK_AUDIT:
671 return SECCLASS_NETLINK_AUDIT_SOCKET;
672 case NETLINK_IP6_FW:
673 return SECCLASS_NETLINK_IP6FW_SOCKET;
674 case NETLINK_DNRTMSG:
675 return SECCLASS_NETLINK_DNRT_SOCKET;
0c9b7942
JM		 676 case NETLINK_KOBJECT_UEVENT:
677 return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET;
1da177e4
LT		 678 default:
679 return SECCLASS_NETLINK_SOCKET;
680 }
681 case PF_PACKET:
682 return SECCLASS_PACKET_SOCKET;
683 case PF_KEY:
684 return SECCLASS_KEY_SOCKET;
685 }
686
687 return SECCLASS_SOCKET;
688}
689
690#ifdef CONFIG_PROC_FS
691static int selinux_proc_get_sid(struct proc_dir_entry *de,
692 u16 tclass,
693 u32 *sid)
694{
695 int buflen, rc;
696 char *buffer, *path, *end;
697
698 buffer = (char*)__get_free_page(GFP_KERNEL);
699 if (!buffer)
700 return -ENOMEM;
701
702 buflen = PAGE_SIZE;
703 end = buffer+buflen;
704 *--end = '\0';
705 buflen--;
706 path = end-1;
707 *path = '/';
708 while (de && de != de->parent) {
709 buflen -= de->namelen + 1;
710 if (buflen < 0)
711 break;
712 end -= de->namelen;
713 memcpy(end, de->name, de->namelen);
714 *--end = '/';
715 path = end;
716 de = de->parent;
717 }
718 rc = security_genfs_sid("proc", path, tclass, sid);
719 free_page((unsigned long)buffer);
720 return rc;
721}
722#else
723static int selinux_proc_get_sid(struct proc_dir_entry *de,
724 u16 tclass,
725 u32 *sid)
726{
727 return -EINVAL;
728}
729#endif
730
731/* The inode's security attributes must be initialized before first use. */
732static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry)
733{
734 struct superblock_security_struct *sbsec = NULL;
735 struct inode_security_struct *isec = inode->i_security;
736 u32 sid;
737 struct dentry *dentry;
738#define INITCONTEXTLEN 255
739 char *context = NULL;
740 unsigned len = 0;
741 int rc = 0;
742 int hold_sem = 0;
743
744 if (isec->initialized)
745 goto out;
746
747 down(&isec->sem);
748 hold_sem = 1;
749 if (isec->initialized)
750 goto out;
751
752 sbsec = inode->i_sb->s_security;
753 if (!sbsec->initialized) {
754 /* Defer initialization until selinux_complete_init,
755 after the initial policy is loaded and the security
756 server is ready to handle calls. */
757 spin_lock(&sbsec->isec_lock);
758 if (list_empty(&isec->list))
759 list_add(&isec->list, &sbsec->isec_head);
760 spin_unlock(&sbsec->isec_lock);
761 goto out;
762 }
763
764 switch (sbsec->behavior) {
765 case SECURITY_FS_USE_XATTR:
766 if (!inode->i_op->getxattr) {
767 isec->sid = sbsec->def_sid;
768 break;
769 }
770
771 /* Need a dentry, since the xattr API requires one.
772 Life would be simpler if we could just pass the inode. */
773 if (opt_dentry) {
774 /* Called from d_instantiate or d_splice_alias. */
775 dentry = dget(opt_dentry);
776 } else {
777 /* Called from selinux_complete_init, try to find a dentry. */
778 dentry = d_find_alias(inode);
779 }
780 if (!dentry) {
781 printk(KERN_WARNING "%s: no dentry for dev=%s "
782 "ino=%ld\n", __FUNCTION__, inode->i_sb->s_id,
783 inode->i_ino);
784 goto out;
785 }
786
787 len = INITCONTEXTLEN;
788 context = kmalloc(len, GFP_KERNEL);
789 if (!context) {
790 rc = -ENOMEM;
791 dput(dentry);
792 goto out;
793 }
794 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
795 context, len);
796 if (rc == -ERANGE) {
797 /* Need a larger buffer. Query for the right size. */
798 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
799 NULL, 0);
800 if (rc < 0) {
801 dput(dentry);
802 goto out;
803 }
804 kfree(context);
805 len = rc;
806 context = kmalloc(len, GFP_KERNEL);
807 if (!context) {
808 rc = -ENOMEM;
809 dput(dentry);
810 goto out;
811 }
812 rc = inode->i_op->getxattr(dentry,
813 XATTR_NAME_SELINUX,
814 context, len);
815 }
816 dput(dentry);
817 if (rc < 0) {
818 if (rc != -ENODATA) {
819 printk(KERN_WARNING "%s: getxattr returned "
820 "%d for dev=%s ino=%ld\n", __FUNCTION__,
821 -rc, inode->i_sb->s_id, inode->i_ino);
822 kfree(context);
823 goto out;
824 }
825 /* Map ENODATA to the default file SID */
826 sid = sbsec->def_sid;
827 rc = 0;
828 } else {
f5c1d5b2
JM		 829 rc = security_context_to_sid_default(context, rc, &sid,
830 sbsec->def_sid);
1da177e4
LT		 831 if (rc) {
832 printk(KERN_WARNING "%s: context_to_sid(%s) "
833 "returned %d for dev=%s ino=%ld\n",
834 __FUNCTION__, context, -rc,
835 inode->i_sb->s_id, inode->i_ino);
836 kfree(context);
837 /* Leave with the unlabeled SID */
838 rc = 0;
839 break;
840 }
841 }
842 kfree(context);
843 isec->sid = sid;
844 break;
845 case SECURITY_FS_USE_TASK:
846 isec->sid = isec->task_sid;
847 break;
848 case SECURITY_FS_USE_TRANS:
849 /* Default to the fs SID. */
850 isec->sid = sbsec->sid;
851
852 /* Try to obtain a transition SID. */
853 isec->sclass = inode_mode_to_security_class(inode->i_mode);
854 rc = security_transition_sid(isec->task_sid,
855 sbsec->sid,
856 isec->sclass,
857 &sid);
858 if (rc)
859 goto out;
860 isec->sid = sid;
861 break;
862 default:
863 /* Default to the fs SID. */
864 isec->sid = sbsec->sid;
865
866 if (sbsec->proc) {
867 struct proc_inode *proci = PROC_I(inode);
868 if (proci->pde) {
869 isec->sclass = inode_mode_to_security_class(inode->i_mode);
870 rc = selinux_proc_get_sid(proci->pde,
871 isec->sclass,
872 &sid);
873 if (rc)
874 goto out;
875 isec->sid = sid;
876 }
877 }
878 break;
879 }
880
881 isec->initialized = 1;
882
883out:
884 if (isec->sclass == SECCLASS_FILE)
885 isec->sclass = inode_mode_to_security_class(inode->i_mode);
886
887 if (hold_sem)
888 up(&isec->sem);
889 return rc;
890}
891
892/* Convert a Linux signal to an access vector. */
893static inline u32 signal_to_av(int sig)
894{
895 u32 perm = 0;
896
897 switch (sig) {
898 case SIGCHLD:
899 /* Commonly granted from child to parent. */
900 perm = PROCESS__SIGCHLD;
901 break;
902 case SIGKILL:
903 /* Cannot be caught or ignored */
904 perm = PROCESS__SIGKILL;
905 break;
906 case SIGSTOP:
907 /* Cannot be caught or ignored */
908 perm = PROCESS__SIGSTOP;
909 break;
910 default:
911 /* All other signals. */
912 perm = PROCESS__SIGNAL;
913 break;
914 }
915
916 return perm;
917}
918
919/* Check permission betweeen a pair of tasks, e.g. signal checks,
920 fork check, ptrace check, etc. */
921static int task_has_perm(struct task_struct *tsk1,
922 struct task_struct *tsk2,
923 u32 perms)
924{
925 struct task_security_struct *tsec1, *tsec2;
926
927 tsec1 = tsk1->security;
928 tsec2 = tsk2->security;
929 return avc_has_perm(tsec1->sid, tsec2->sid,
930 SECCLASS_PROCESS, perms, NULL);
931}
932
933/* Check whether a task is allowed to use a capability. */
934static int task_has_capability(struct task_struct *tsk,
935 int cap)
936{
937 struct task_security_struct *tsec;
938 struct avc_audit_data ad;
939
940 tsec = tsk->security;
941
942 AVC_AUDIT_DATA_INIT(&ad,CAP);
943 ad.tsk = tsk;
944 ad.u.cap = cap;
945
946 return avc_has_perm(tsec->sid, tsec->sid,
947 SECCLASS_CAPABILITY, CAP_TO_MASK(cap), &ad);
948}
949
950/* Check whether a task is allowed to use a system operation. */
951static int task_has_system(struct task_struct *tsk,
952 u32 perms)
953{
954 struct task_security_struct *tsec;
955
956 tsec = tsk->security;
957
958 return avc_has_perm(tsec->sid, SECINITSID_KERNEL,
959 SECCLASS_SYSTEM, perms, NULL);
960}
961
962/* Check whether a task has a particular permission to an inode.
963 The 'adp' parameter is optional and allows other audit
964 data to be passed (e.g. the dentry). */
965static int inode_has_perm(struct task_struct *tsk,
966 struct inode *inode,
967 u32 perms,
968 struct avc_audit_data *adp)
969{
970 struct task_security_struct *tsec;
971 struct inode_security_struct *isec;
972 struct avc_audit_data ad;
973
974 tsec = tsk->security;
975 isec = inode->i_security;
976
977 if (!adp) {
978 adp = &ad;
979 AVC_AUDIT_DATA_INIT(&ad, FS);
980 ad.u.fs.inode = inode;
981 }
982
983 return avc_has_perm(tsec->sid, isec->sid, isec->sclass, perms, adp);
984}
985
986/* Same as inode_has_perm, but pass explicit audit data containing
987 the dentry to help the auditing code to more easily generate the
988 pathname if needed. */
989static inline int dentry_has_perm(struct task_struct *tsk,
990 struct vfsmount *mnt,
991 struct dentry *dentry,
992 u32 av)
993{
994 struct inode *inode = dentry->d_inode;
995 struct avc_audit_data ad;
996 AVC_AUDIT_DATA_INIT(&ad,FS);
997 ad.u.fs.mnt = mnt;
998 ad.u.fs.dentry = dentry;
999 return inode_has_perm(tsk, inode, av, &ad);
1000}
1001
1002/* Check whether a task can use an open file descriptor to
1003 access an inode in a given way. Check access to the
1004 descriptor itself, and then use dentry_has_perm to
1005 check a particular permission to the file.
1006 Access to the descriptor is implicitly granted if it
1007 has the same SID as the process. If av is zero, then
1008 access to the file is not checked, e.g. for cases
1009 where only the descriptor is affected like seek. */
1010static inline int file_has_perm(struct task_struct *tsk,
1011 struct file *file,
1012 u32 av)
1013{
1014 struct task_security_struct *tsec = tsk->security;
1015 struct file_security_struct *fsec = file->f_security;
1016 struct vfsmount *mnt = file->f_vfsmnt;
1017 struct dentry *dentry = file->f_dentry;
1018 struct inode *inode = dentry->d_inode;
1019 struct avc_audit_data ad;
1020 int rc;
1021
1022 AVC_AUDIT_DATA_INIT(&ad, FS);
1023 ad.u.fs.mnt = mnt;
1024 ad.u.fs.dentry = dentry;
1025
1026 if (tsec->sid != fsec->sid) {
1027 rc = avc_has_perm(tsec->sid, fsec->sid,
1028 SECCLASS_FD,
1029 FD__USE,
1030 &ad);
1031 if (rc)
1032 return rc;
1033 }
1034
1035 /* av is zero if only checking access to the descriptor. */
1036 if (av)
1037 return inode_has_perm(tsk, inode, av, &ad);
1038
1039 return 0;
1040}
1041
1042/* Check whether a task can create a file. */
1043static int may_create(struct inode *dir,
1044 struct dentry *dentry,
1045 u16 tclass)
1046{
1047 struct task_security_struct *tsec;
1048 struct inode_security_struct *dsec;
1049 struct superblock_security_struct *sbsec;
1050 u32 newsid;
1051 struct avc_audit_data ad;
1052 int rc;
1053
1054 tsec = current->security;
1055 dsec = dir->i_security;
1056 sbsec = dir->i_sb->s_security;
1057
1058 AVC_AUDIT_DATA_INIT(&ad, FS);
1059 ad.u.fs.dentry = dentry;
1060
1061 rc = avc_has_perm(tsec->sid, dsec->sid, SECCLASS_DIR,
1062 DIR__ADD_NAME | DIR__SEARCH,
1063 &ad);
1064 if (rc)
1065 return rc;
1066
1067 if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
1068 newsid = tsec->create_sid;
1069 } else {
1070 rc = security_transition_sid(tsec->sid, dsec->sid, tclass,
1071 &newsid);
1072 if (rc)
1073 return rc;
1074 }
1075
1076 rc = avc_has_perm(tsec->sid, newsid, tclass, FILE__CREATE, &ad);
1077 if (rc)
1078 return rc;
1079
1080 return avc_has_perm(newsid, sbsec->sid,
1081 SECCLASS_FILESYSTEM,
1082 FILESYSTEM__ASSOCIATE, &ad);
1083}
1084
1085#define MAY_LINK 0
1086#define MAY_UNLINK 1
1087#define MAY_RMDIR 2
1088
1089/* Check whether a task can link, unlink, or rmdir a file/directory. */
1090static int may_link(struct inode *dir,
1091 struct dentry *dentry,
1092 int kind)
1093
1094{
1095 struct task_security_struct *tsec;
1096 struct inode_security_struct *dsec, *isec;
1097 struct avc_audit_data ad;
1098 u32 av;
1099 int rc;
1100
1101 tsec = current->security;
1102 dsec = dir->i_security;
1103 isec = dentry->d_inode->i_security;
1104
1105 AVC_AUDIT_DATA_INIT(&ad, FS);
1106 ad.u.fs.dentry = dentry;
1107
1108 av = DIR__SEARCH;
1109 av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
1110 rc = avc_has_perm(tsec->sid, dsec->sid, SECCLASS_DIR, av, &ad);
1111 if (rc)
1112 return rc;
1113
1114 switch (kind) {
1115 case MAY_LINK:
1116 av = FILE__LINK;
1117 break;
1118 case MAY_UNLINK:
1119 av = FILE__UNLINK;
1120 break;
1121 case MAY_RMDIR:
1122 av = DIR__RMDIR;
1123 break;
1124 default:
1125 printk(KERN_WARNING "may_link: unrecognized kind %d\n", kind);
1126 return 0;
1127 }
1128
1129 rc = avc_has_perm(tsec->sid, isec->sid, isec->sclass, av, &ad);
1130 return rc;
1131}
1132
1133static inline int may_rename(struct inode *old_dir,
1134 struct dentry *old_dentry,
1135 struct inode *new_dir,
1136 struct dentry *new_dentry)
1137{
1138 struct task_security_struct *tsec;
1139 struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec;
1140 struct avc_audit_data ad;
1141 u32 av;
1142 int old_is_dir, new_is_dir;
1143 int rc;
1144
1145 tsec = current->security;
1146 old_dsec = old_dir->i_security;
1147 old_isec = old_dentry->d_inode->i_security;
1148 old_is_dir = S_ISDIR(old_dentry->d_inode->i_mode);
1149 new_dsec = new_dir->i_security;
1150
1151 AVC_AUDIT_DATA_INIT(&ad, FS);
1152
1153 ad.u.fs.dentry = old_dentry;
1154 rc = avc_has_perm(tsec->sid, old_dsec->sid, SECCLASS_DIR,
1155 DIR__REMOVE_NAME | DIR__SEARCH, &ad);
1156 if (rc)
1157 return rc;
1158 rc = avc_has_perm(tsec->sid, old_isec->sid,
1159 old_isec->sclass, FILE__RENAME, &ad);
1160 if (rc)
1161 return rc;
1162 if (old_is_dir && new_dir != old_dir) {
1163 rc = avc_has_perm(tsec->sid, old_isec->sid,
1164 old_isec->sclass, DIR__REPARENT, &ad);
1165 if (rc)
1166 return rc;
1167 }
1168
1169 ad.u.fs.dentry = new_dentry;
1170 av = DIR__ADD_NAME | DIR__SEARCH;
1171 if (new_dentry->d_inode)
1172 av |= DIR__REMOVE_NAME;
1173 rc = avc_has_perm(tsec->sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
1174 if (rc)
1175 return rc;
1176 if (new_dentry->d_inode) {
1177 new_isec = new_dentry->d_inode->i_security;
1178 new_is_dir = S_ISDIR(new_dentry->d_inode->i_mode);
1179 rc = avc_has_perm(tsec->sid, new_isec->sid,
1180 new_isec->sclass,
1181 (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad);
1182 if (rc)
1183 return rc;
1184 }
1185
1186 return 0;
1187}
1188
1189/* Check whether a task can perform a filesystem operation. */
1190static int superblock_has_perm(struct task_struct *tsk,
1191 struct super_block *sb,
1192 u32 perms,
1193 struct avc_audit_data *ad)
1194{
1195 struct task_security_struct *tsec;
1196 struct superblock_security_struct *sbsec;
1197
1198 tsec = tsk->security;
1199 sbsec = sb->s_security;
1200 return avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
1201 perms, ad);
1202}
1203
1204/* Convert a Linux mode and permission mask to an access vector. */
1205static inline u32 file_mask_to_av(int mode, int mask)
1206{
1207 u32 av = 0;
1208
1209 if ((mode & S_IFMT) != S_IFDIR) {
1210 if (mask & MAY_EXEC)
1211 av |= FILE__EXECUTE;
1212 if (mask & MAY_READ)
1213 av |= FILE__READ;
1214
1215 if (mask & MAY_APPEND)
1216 av |= FILE__APPEND;
1217 else if (mask & MAY_WRITE)
1218 av |= FILE__WRITE;
1219
1220 } else {
1221 if (mask & MAY_EXEC)
1222 av |= DIR__SEARCH;
1223 if (mask & MAY_WRITE)
1224 av |= DIR__WRITE;
1225 if (mask & MAY_READ)
1226 av |= DIR__READ;
1227 }
1228
1229 return av;
1230}
1231
1232/* Convert a Linux file to an access vector. */
1233static inline u32 file_to_av(struct file *file)
1234{
1235 u32 av = 0;
1236
1237 if (file->f_mode & FMODE_READ)
1238 av |= FILE__READ;
1239 if (file->f_mode & FMODE_WRITE) {
1240 if (file->f_flags & O_APPEND)
1241 av |= FILE__APPEND;
1242 else
1243 av |= FILE__WRITE;
1244 }
1245
1246 return av;
1247}
1248
1249/* Set an inode's SID to a specified value. */
1250static int inode_security_set_sid(struct inode *inode, u32 sid)
1251{
1252 struct inode_security_struct *isec = inode->i_security;
1253 struct superblock_security_struct *sbsec = inode->i_sb->s_security;
1254
1255 if (!sbsec->initialized) {
1256 /* Defer initialization to selinux_complete_init. */
1257 return 0;
1258 }
1259
1260 down(&isec->sem);
1261 isec->sclass = inode_mode_to_security_class(inode->i_mode);
1262 isec->sid = sid;
1263 isec->initialized = 1;
1264 up(&isec->sem);
1265 return 0;
1266}
1267
1268/* Set the security attributes on a newly created file. */
1269static int post_create(struct inode *dir,
1270 struct dentry *dentry)
1271{
1272
1273 struct task_security_struct *tsec;
1274 struct inode *inode;
1275 struct inode_security_struct *dsec;
1276 struct superblock_security_struct *sbsec;
5e41ff9e 1277 struct inode_security_struct *isec;
1da177e4
LT		 1278 u32 newsid;
1279 char *context;
1280 unsigned int len;
1281 int rc;
1282
1283 tsec = current->security;
1284 dsec = dir->i_security;
1285 sbsec = dir->i_sb->s_security;
1286
1287 inode = dentry->d_inode;
1288 if (!inode) {
1289 /* Some file system types (e.g. NFS) may not instantiate
1290 a dentry for all create operations (e.g. symlink),
1291 so we have to check to see if the inode is non-NULL. */
1292 printk(KERN_WARNING "post_create: no inode, dir (dev=%s, "
1293 "ino=%ld)\n", dir->i_sb->s_id, dir->i_ino);
1294 return 0;
1295 }
1296
5e41ff9e
SS		 1297 isec = inode->i_security;
1298
1299 if (isec->security_attr_init)
1300 return 0;
1301
1da177e4
LT		 1302 if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
1303 newsid = tsec->create_sid;
1304 } else {
1305 rc = security_transition_sid(tsec->sid, dsec->sid,
1306 inode_mode_to_security_class(inode->i_mode),
1307 &newsid);
1308 if (rc) {
1309 printk(KERN_WARNING "post_create: "
1310 "security_transition_sid failed, rc=%d (dev=%s "
1311 "ino=%ld)\n",
1312 -rc, inode->i_sb->s_id, inode->i_ino);
1313 return rc;
1314 }
1315 }
1316
1317 rc = inode_security_set_sid(inode, newsid);
1318 if (rc) {
1319 printk(KERN_WARNING "post_create: inode_security_set_sid "
1320 "failed, rc=%d (dev=%s ino=%ld)\n",
1321 -rc, inode->i_sb->s_id, inode->i_ino);
1322 return rc;
1323 }
1324
1325 if (sbsec->behavior == SECURITY_FS_USE_XATTR &&
1326 inode->i_op->setxattr) {
1327 /* Use extended attributes. */
1328 rc = security_sid_to_context(newsid, &context, &len);
1329 if (rc) {
1330 printk(KERN_WARNING "post_create: sid_to_context "
1331 "failed, rc=%d (dev=%s ino=%ld)\n",
1332 -rc, inode->i_sb->s_id, inode->i_ino);
1333 return rc;
1334 }
1335 down(&inode->i_sem);
1336 rc = inode->i_op->setxattr(dentry,
1337 XATTR_NAME_SELINUX,
1338 context, len, 0);
1339 up(&inode->i_sem);
1340 kfree(context);
1341 if (rc < 0) {
1342 printk(KERN_WARNING "post_create: setxattr failed, "
1343 "rc=%d (dev=%s ino=%ld)\n",
1344 -rc, inode->i_sb->s_id, inode->i_ino);
1345 return rc;
1346 }
1347 }
1348
1349 return 0;
1350}
1351
1352
1353/* Hook functions begin here. */
1354
1355static int selinux_ptrace(struct task_struct *parent, struct task_struct *child)
1356{
1357 struct task_security_struct *psec = parent->security;
1358 struct task_security_struct *csec = child->security;
1359 int rc;
1360
1361 rc = secondary_ops->ptrace(parent,child);
1362 if (rc)
1363 return rc;
1364
1365 rc = task_has_perm(parent, child, PROCESS__PTRACE);
1366 /* Save the SID of the tracing process for later use in apply_creds. */
1367 if (!rc)
1368 csec->ptrace_sid = psec->sid;
1369 return rc;
1370}
1371
1372static int selinux_capget(struct task_struct *target, kernel_cap_t *effective,
1373 kernel_cap_t *inheritable, kernel_cap_t *permitted)
1374{
1375 int error;
1376
1377 error = task_has_perm(current, target, PROCESS__GETCAP);
1378 if (error)
1379 return error;
1380
1381 return secondary_ops->capget(target, effective, inheritable, permitted);
1382}
1383
1384static int selinux_capset_check(struct task_struct *target, kernel_cap_t *effective,
1385 kernel_cap_t *inheritable, kernel_cap_t *permitted)
1386{
1387 int error;
1388
1389 error = secondary_ops->capset_check(target, effective, inheritable, permitted);
1390 if (error)
1391 return error;
1392
1393 return task_has_perm(current, target, PROCESS__SETCAP);
1394}
1395
1396static void selinux_capset_set(struct task_struct *target, kernel_cap_t *effective,
1397 kernel_cap_t *inheritable, kernel_cap_t *permitted)
1398{
1399 secondary_ops->capset_set(target, effective, inheritable, permitted);
1400}
1401
1402static int selinux_capable(struct task_struct *tsk, int cap)
1403{
1404 int rc;
1405
1406 rc = secondary_ops->capable(tsk, cap);
1407 if (rc)
1408 return rc;
1409
1410 return task_has_capability(tsk,cap);
1411}
1412
1413static int selinux_sysctl(ctl_table *table, int op)
1414{
1415 int error = 0;
1416 u32 av;
1417 struct task_security_struct *tsec;
1418 u32 tsid;
1419 int rc;
1420
1421 rc = secondary_ops->sysctl(table, op);
1422 if (rc)
1423 return rc;
1424
1425 tsec = current->security;
1426
1427 rc = selinux_proc_get_sid(table->de, (op == 001) ?
1428 SECCLASS_DIR : SECCLASS_FILE, &tsid);
1429 if (rc) {
1430 /* Default to the well-defined sysctl SID. */
1431 tsid = SECINITSID_SYSCTL;
1432 }
1433
1434 /* The op values are "defined" in sysctl.c, thereby creating
1435 * a bad coupling between this module and sysctl.c */
1436 if(op == 001) {
1437 error = avc_has_perm(tsec->sid, tsid,
1438 SECCLASS_DIR, DIR__SEARCH, NULL);
1439 } else {
1440 av = 0;
1441 if (op & 004)
1442 av |= FILE__READ;
1443 if (op & 002)
1444 av |= FILE__WRITE;
1445 if (av)
1446 error = avc_has_perm(tsec->sid, tsid,
1447 SECCLASS_FILE, av, NULL);
1448 }
1449
1450 return error;
1451}
1452
1453static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb)
1454{
1455 int rc = 0;
1456
1457 if (!sb)
1458 return 0;
1459
1460 switch (cmds) {
1461 case Q_SYNC:
1462 case Q_QUOTAON:
1463 case Q_QUOTAOFF:
1464 case Q_SETINFO:
1465 case Q_SETQUOTA:
1466 rc = superblock_has_perm(current,
1467 sb,
1468 FILESYSTEM__QUOTAMOD, NULL);
1469 break;
1470 case Q_GETFMT:
1471 case Q_GETINFO:
1472 case Q_GETQUOTA:
1473 rc = superblock_has_perm(current,
1474 sb,
1475 FILESYSTEM__QUOTAGET, NULL);
1476 break;
1477 default:
1478 rc = 0; /* let the kernel handle invalid cmds */
1479 break;
1480 }
1481 return rc;
1482}
1483
1484static int selinux_quota_on(struct dentry *dentry)
1485{
1486 return dentry_has_perm(current, NULL, dentry, FILE__QUOTAON);
1487}
1488
1489static int selinux_syslog(int type)
1490{
1491 int rc;
1492
1493 rc = secondary_ops->syslog(type);
1494 if (rc)
1495 return rc;
1496
1497 switch (type) {
1498 case 3: /* Read last kernel messages */
1499 case 10: /* Return size of the log buffer */
1500 rc = task_has_system(current, SYSTEM__SYSLOG_READ);
1501 break;
1502 case 6: /* Disable logging to console */
1503 case 7: /* Enable logging to console */
1504 case 8: /* Set level of messages printed to console */
1505 rc = task_has_system(current, SYSTEM__SYSLOG_CONSOLE);
1506 break;
1507 case 0: /* Close log */
1508 case 1: /* Open log */
1509 case 2: /* Read from log */
1510 case 4: /* Read/clear last kernel messages */
1511 case 5: /* Clear ring buffer */
1512 default:
1513 rc = task_has_system(current, SYSTEM__SYSLOG_MOD);
1514 break;
1515 }
1516 return rc;
1517}
1518
1519/*
1520 * Check that a process has enough memory to allocate a new virtual
1521 * mapping. 0 means there is enough memory for the allocation to
1522 * succeed and -ENOMEM implies there is not.
1523 *
1524 * Note that secondary_ops->capable and task_has_perm_noaudit return 0
1525 * if the capability is granted, but __vm_enough_memory requires 1 if
1526 * the capability is granted.
1527 *
1528 * Do not audit the selinux permission check, as this is applied to all
1529 * processes that allocate mappings.
1530 */
1531static int selinux_vm_enough_memory(long pages)
1532{
1533 int rc, cap_sys_admin = 0;
1534 struct task_security_struct *tsec = current->security;
1535
1536 rc = secondary_ops->capable(current, CAP_SYS_ADMIN);
1537 if (rc == 0)
1538 rc = avc_has_perm_noaudit(tsec->sid, tsec->sid,
1539 SECCLASS_CAPABILITY,
1540 CAP_TO_MASK(CAP_SYS_ADMIN),
1541 NULL);
1542
1543 if (rc == 0)
1544 cap_sys_admin = 1;
1545
1546 return __vm_enough_memory(pages, cap_sys_admin);
1547}
1548
1549/* binprm security operations */
1550
1551static int selinux_bprm_alloc_security(struct linux_binprm *bprm)
1552{
1553 struct bprm_security_struct *bsec;
1554
1555 bsec = kmalloc(sizeof(struct bprm_security_struct), GFP_KERNEL);
1556 if (!bsec)
1557 return -ENOMEM;
1558
1559 memset(bsec, 0, sizeof *bsec);
1560 bsec->magic = SELINUX_MAGIC;
1561 bsec->bprm = bprm;
1562 bsec->sid = SECINITSID_UNLABELED;
1563 bsec->set = 0;
1564
1565 bprm->security = bsec;
1566 return 0;
1567}
1568
1569static int selinux_bprm_set_security(struct linux_binprm *bprm)
1570{
1571 struct task_security_struct *tsec;
1572 struct inode *inode = bprm->file->f_dentry->d_inode;
1573 struct inode_security_struct *isec;
1574 struct bprm_security_struct *bsec;
1575 u32 newsid;
1576 struct avc_audit_data ad;
1577 int rc;
1578
1579 rc = secondary_ops->bprm_set_security(bprm);
1580 if (rc)
1581 return rc;
1582
1583 bsec = bprm->security;
1584
1585 if (bsec->set)
1586 return 0;
1587
1588 tsec = current->security;
1589 isec = inode->i_security;
1590
1591 /* Default to the current task SID. */
1592 bsec->sid = tsec->sid;
1593
1594 /* Reset create SID on execve. */
1595 tsec->create_sid = 0;
1596
1597 if (tsec->exec_sid) {
1598 newsid = tsec->exec_sid;
1599 /* Reset exec SID on execve. */
1600 tsec->exec_sid = 0;
1601 } else {
1602 /* Check for a default transition on this program. */
1603 rc = security_transition_sid(tsec->sid, isec->sid,
1604 SECCLASS_PROCESS, &newsid);
1605 if (rc)
1606 return rc;
1607 }
1608
1609 AVC_AUDIT_DATA_INIT(&ad, FS);
1610 ad.u.fs.mnt = bprm->file->f_vfsmnt;
1611 ad.u.fs.dentry = bprm->file->f_dentry;
1612
1613 if (bprm->file->f_vfsmnt->mnt_flags & MNT_NOSUID)
1614 newsid = tsec->sid;
1615
1616 if (tsec->sid == newsid) {
1617 rc = avc_has_perm(tsec->sid, isec->sid,
1618 SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
1619 if (rc)
1620 return rc;
1621 } else {
1622 /* Check permissions for the transition. */
1623 rc = avc_has_perm(tsec->sid, newsid,
1624 SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
1625 if (rc)
1626 return rc;
1627
1628 rc = avc_has_perm(newsid, isec->sid,
1629 SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
1630 if (rc)
1631 return rc;
1632
1633 /* Clear any possibly unsafe personality bits on exec: */
1634 current->personality &= ~PER_CLEAR_ON_SETID;
1635
1636 /* Set the security field to the new SID. */
1637 bsec->sid = newsid;
1638 }
1639
1640 bsec->set = 1;
1641 return 0;
1642}
1643
1644static int selinux_bprm_check_security (struct linux_binprm *bprm)
1645{
1646 return secondary_ops->bprm_check_security(bprm);
1647}
1648
1649
1650static int selinux_bprm_secureexec (struct linux_binprm *bprm)
1651{
1652 struct task_security_struct *tsec = current->security;
1653 int atsecure = 0;
1654
1655 if (tsec->osid != tsec->sid) {
1656 /* Enable secure mode for SIDs transitions unless
1657 the noatsecure permission is granted between
1658 the two SIDs, i.e. ahp returns 0. */
1659 atsecure = avc_has_perm(tsec->osid, tsec->sid,
1660 SECCLASS_PROCESS,
1661 PROCESS__NOATSECURE, NULL);
1662 }
1663
1664 return (atsecure || secondary_ops->bprm_secureexec(bprm));
1665}
1666
1667static void selinux_bprm_free_security(struct linux_binprm *bprm)
1668{
9a5f04bf 1669 kfree(bprm->security);
1da177e4 1670 bprm->security = NULL;
1da177e4
LT		 1671}
1672
1673extern struct vfsmount *selinuxfs_mount;
1674extern struct dentry *selinux_null;
1675
1676/* Derived from fs/exec.c:flush_old_files. */
1677static inline void flush_unauthorized_files(struct files_struct * files)
1678{
1679 struct avc_audit_data ad;
1680 struct file *file, *devnull = NULL;
1681 struct tty_struct *tty = current->signal->tty;
1682 long j = -1;
1683
1684 if (tty) {
1685 file_list_lock();
1686 file = list_entry(tty->tty_files.next, typeof(*file), f_list);
1687 if (file) {
1688 /* Revalidate access to controlling tty.
1689 Use inode_has_perm on the tty inode directly rather
1690 than using file_has_perm, as this particular open
1691 file may belong to another process and we are only
1692 interested in the inode-based check here. */
1693 struct inode *inode = file->f_dentry->d_inode;
1694 if (inode_has_perm(current, inode,
1695 FILE__READ | FILE__WRITE, NULL)) {
1696 /* Reset controlling tty. */
1697 current->signal->tty = NULL;
1698 current->signal->tty_old_pgrp = 0;
1699 }
1700 }
1701 file_list_unlock();
1702 }
1703
1704 /* Revalidate access to inherited open files. */
1705
1706 AVC_AUDIT_DATA_INIT(&ad,FS);
1707
1708 spin_lock(&files->file_lock);
1709 for (;;) {
1710 unsigned long set, i;
1711 int fd;
1712
1713 j++;
1714 i = j * __NFDBITS;
1715 if (i >= files->max_fds || i >= files->max_fdset)
1716 break;
1717 set = files->open_fds->fds_bits[j];
1718 if (!set)
1719 continue;
1720 spin_unlock(&files->file_lock);
1721 for ( ; set ; i++,set >>= 1) {
1722 if (set & 1) {
1723 file = fget(i);
1724 if (!file)
1725 continue;
1726 if (file_has_perm(current,
1727 file,
1728 file_to_av(file))) {
1729 sys_close(i);
1730 fd = get_unused_fd();
1731 if (fd != i) {
1732 if (fd >= 0)
1733 put_unused_fd(fd);
1734 fput(file);
1735 continue;
1736 }
1737 if (devnull) {
1738 atomic_inc(&devnull->f_count);
1739 } else {
1740 devnull = dentry_open(dget(selinux_null), mntget(selinuxfs_mount), O_RDWR);
1741 if (!devnull) {
1742 put_unused_fd(fd);
1743 fput(file);
1744 continue;
1745 }
1746 }
1747 fd_install(fd, devnull);
1748 }
1749 fput(file);
1750 }
1751 }
1752 spin_lock(&files->file_lock);
1753
1754 }
1755 spin_unlock(&files->file_lock);
1756}
1757
1758static void selinux_bprm_apply_creds(struct linux_binprm *bprm, int unsafe)
1759{
1760 struct task_security_struct *tsec;
1761 struct bprm_security_struct *bsec;
1762 u32 sid;
1763 int rc;
1764
1765 secondary_ops->bprm_apply_creds(bprm, unsafe);
1766
1767 tsec = current->security;
1768
1769 bsec = bprm->security;
1770 sid = bsec->sid;
1771
1772 tsec->osid = tsec->sid;
1773 bsec->unsafe = 0;
1774 if (tsec->sid != sid) {
1775 /* Check for shared state. If not ok, leave SID
1776 unchanged and kill. */
1777 if (unsafe & LSM_UNSAFE_SHARE) {
1778 rc = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
1779 PROCESS__SHARE, NULL);
1780 if (rc) {
1781 bsec->unsafe = 1;
1782 return;
1783 }
1784 }
1785
1786 /* Check for ptracing, and update the task SID if ok.
1787 Otherwise, leave SID unchanged and kill. */
1788 if (unsafe & (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) {
1789 rc = avc_has_perm(tsec->ptrace_sid, sid,
1790 SECCLASS_PROCESS, PROCESS__PTRACE,
1791 NULL);
1792 if (rc) {
1793 bsec->unsafe = 1;
1794 return;
1795 }
1796 }
1797 tsec->sid = sid;
1798 }
1799}
1800
1801/*
1802 * called after apply_creds without the task lock held
1803 */
1804static void selinux_bprm_post_apply_creds(struct linux_binprm *bprm)
1805{
1806 struct task_security_struct *tsec;
1807 struct rlimit *rlim, *initrlim;
1808 struct itimerval itimer;
1809 struct bprm_security_struct *bsec;
1810 int rc, i;
1811
1812 tsec = current->security;
1813 bsec = bprm->security;
1814
1815 if (bsec->unsafe) {
1816 force_sig_specific(SIGKILL, current);
1817 return;
1818 }
1819 if (tsec->osid == tsec->sid)
1820 return;
1821
1822 /* Close files for which the new task SID is not authorized. */
1823 flush_unauthorized_files(current->files);
1824
1825 /* Check whether the new SID can inherit signal state
1826 from the old SID. If not, clear itimers to avoid
1827 subsequent signal generation and flush and unblock
1828 signals. This must occur _after_ the task SID has
1829 been updated so that any kill done after the flush
1830 will be checked against the new SID. */
1831 rc = avc_has_perm(tsec->osid, tsec->sid, SECCLASS_PROCESS,
1832 PROCESS__SIGINH, NULL);
1833 if (rc) {
1834 memset(&itimer, 0, sizeof itimer);
1835 for (i = 0; i < 3; i++)
1836 do_setitimer(i, &itimer, NULL);
1837 flush_signals(current);
1838 spin_lock_irq(&current->sighand->siglock);
1839 flush_signal_handlers(current, 1);
1840 sigemptyset(&current->blocked);
1841 recalc_sigpending();
1842 spin_unlock_irq(&current->sighand->siglock);
1843 }
1844
1845 /* Check whether the new SID can inherit resource limits
1846 from the old SID. If not, reset all soft limits to
1847 the lower of the current task's hard limit and the init
1848 task's soft limit. Note that the setting of hard limits
1849 (even to lower them) can be controlled by the setrlimit
1850 check. The inclusion of the init task's soft limit into
1851 the computation is to avoid resetting soft limits higher
1852 than the default soft limit for cases where the default
1853 is lower than the hard limit, e.g. RLIMIT_CORE or
1854 RLIMIT_STACK.*/
1855 rc = avc_has_perm(tsec->osid, tsec->sid, SECCLASS_PROCESS,
1856 PROCESS__RLIMITINH, NULL);
1857 if (rc) {
1858 for (i = 0; i < RLIM_NLIMITS; i++) {
1859 rlim = current->signal->rlim + i;
1860 initrlim = init_task.signal->rlim+i;
1861 rlim->rlim_cur = min(rlim->rlim_max,initrlim->rlim_cur);
1862 }
1863 if (current->signal->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY) {
1864 /*
1865 * This will cause RLIMIT_CPU calculations
1866 * to be refigured.
1867 */
1868 current->it_prof_expires = jiffies_to_cputime(1);
1869 }
1870 }
1871
1872 /* Wake up the parent if it is waiting so that it can
1873 recheck wait permission to the new task SID. */
1874 wake_up_interruptible(&current->parent->signal->wait_chldexit);
1875}
1876
1877/* superblock security operations */
1878
1879static int selinux_sb_alloc_security(struct super_block *sb)
1880{
1881 return superblock_alloc_security(sb);
1882}
1883
1884static void selinux_sb_free_security(struct super_block *sb)
1885{
1886 superblock_free_security(sb);
1887}
1888
1889static inline int match_prefix(char *prefix, int plen, char *option, int olen)
1890{
1891 if (plen > olen)
1892 return 0;
1893
1894 return !memcmp(prefix, option, plen);
1895}
1896
1897static inline int selinux_option(char *option, int len)
1898{
1899 return (match_prefix("context=", sizeof("context=")-1, option, len) ||
1900 match_prefix("fscontext=", sizeof("fscontext=")-1, option, len) ||
1901 match_prefix("defcontext=", sizeof("defcontext=")-1, option, len));
1902}
1903
1904static inline void take_option(char **to, char *from, int *first, int len)
1905{
1906 if (!*first) {
1907 **to = ',';
1908 *to += 1;
1909 }
1910 else
1911 *first = 0;
1912 memcpy(*to, from, len);
1913 *to += len;
1914}
1915
1916static int selinux_sb_copy_data(struct file_system_type *type, void *orig, void *copy)
1917{
1918 int fnosec, fsec, rc = 0;
1919 char *in_save, *in_curr, *in_end;
1920 char *sec_curr, *nosec_save, *nosec;
1921
1922 in_curr = orig;
1923 sec_curr = copy;
1924
1925 /* Binary mount data: just copy */
1926 if (type->fs_flags & FS_BINARY_MOUNTDATA) {
1927 copy_page(sec_curr, in_curr);
1928 goto out;
1929 }
1930
1931 nosec = (char *)get_zeroed_page(GFP_KERNEL);
1932 if (!nosec) {
1933 rc = -ENOMEM;
1934 goto out;
1935 }
1936
1937 nosec_save = nosec;
1938 fnosec = fsec = 1;
1939 in_save = in_end = orig;
1940
1941 do {
1942 if (*in_end == ',' || *in_end == '\0') {
1943 int len = in_end - in_curr;
1944
1945 if (selinux_option(in_curr, len))
1946 take_option(&sec_curr, in_curr, &fsec, len);
1947 else
1948 take_option(&nosec, in_curr, &fnosec, len);
1949
1950 in_curr = in_end + 1;
1951 }
1952 } while (*in_end++);
1953
6931dfc9 1954 strcpy(in_save, nosec_save);
da3caa20 1955 free_page((unsigned long)nosec_save);
1da177e4
LT		 1956out:
1957 return rc;
1958}
1959
1960static int selinux_sb_kern_mount(struct super_block *sb, void *data)
1961{
1962 struct avc_audit_data ad;
1963 int rc;
1964
1965 rc = superblock_doinit(sb, data);
1966 if (rc)
1967 return rc;
1968
1969 AVC_AUDIT_DATA_INIT(&ad,FS);
1970 ad.u.fs.dentry = sb->s_root;
1971 return superblock_has_perm(current, sb, FILESYSTEM__MOUNT, &ad);
1972}
1973
1974static int selinux_sb_statfs(struct super_block *sb)
1975{
1976 struct avc_audit_data ad;
1977
1978 AVC_AUDIT_DATA_INIT(&ad,FS);
1979 ad.u.fs.dentry = sb->s_root;
1980 return superblock_has_perm(current, sb, FILESYSTEM__GETATTR, &ad);
1981}
1982
1983static int selinux_mount(char * dev_name,
1984 struct nameidata *nd,
1985 char * type,
1986 unsigned long flags,
1987 void * data)
1988{
1989 int rc;
1990
1991 rc = secondary_ops->sb_mount(dev_name, nd, type, flags, data);
1992 if (rc)
1993 return rc;
1994
1995 if (flags & MS_REMOUNT)
1996 return superblock_has_perm(current, nd->mnt->mnt_sb,
1997 FILESYSTEM__REMOUNT, NULL);
1998 else
1999 return dentry_has_perm(current, nd->mnt, nd->dentry,
2000 FILE__MOUNTON);
2001}
2002
2003static int selinux_umount(struct vfsmount *mnt, int flags)
2004{
2005 int rc;
2006
2007 rc = secondary_ops->sb_umount(mnt, flags);
2008 if (rc)
2009 return rc;
2010
2011 return superblock_has_perm(current,mnt->mnt_sb,
2012 FILESYSTEM__UNMOUNT,NULL);
2013}
2014
2015/* inode security operations */
2016
2017static int selinux_inode_alloc_security(struct inode *inode)
2018{
2019 return inode_alloc_security(inode);
2020}
2021
2022static void selinux_inode_free_security(struct inode *inode)
2023{
2024 inode_free_security(inode);
2025}
2026
5e41ff9e
SS		 2027static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
2028 char **name, void **value,
2029 size_t *len)
2030{
2031 struct task_security_struct *tsec;
2032 struct inode_security_struct *dsec;
2033 struct superblock_security_struct *sbsec;
2034 struct inode_security_struct *isec;
2035 u32 newsid;
2036 int rc;
2037 char *namep, *context;
2038
2039 tsec = current->security;
2040 dsec = dir->i_security;
2041 sbsec = dir->i_sb->s_security;
2042 isec = inode->i_security;
2043
2044 if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
2045 newsid = tsec->create_sid;
2046 } else {
2047 rc = security_transition_sid(tsec->sid, dsec->sid,
2048 inode_mode_to_security_class(inode->i_mode),
2049 &newsid);
2050 if (rc) {
2051 printk(KERN_WARNING "%s: "
2052 "security_transition_sid failed, rc=%d (dev=%s "
2053 "ino=%ld)\n",
2054 __FUNCTION__,
2055 -rc, inode->i_sb->s_id, inode->i_ino);
2056 return rc;
2057 }
2058 }
2059
2060 inode_security_set_sid(inode, newsid);
2061
2062 namep = kstrdup(XATTR_SELINUX_SUFFIX, GFP_KERNEL);
2063 if (!namep)
2064 return -ENOMEM;
2065 *name = namep;
2066
2067 rc = security_sid_to_context(newsid, &context, len);
2068 if (rc) {
2069 kfree(namep);
2070 return rc;
2071 }
2072 *value = context;
2073
2074 isec->security_attr_init = 1;
2075
2076 return 0;
2077}
2078
1da177e4
LT		 2079static int selinux_inode_create(struct inode *dir, struct dentry *dentry, int mask)
2080{
2081 return may_create(dir, dentry, SECCLASS_FILE);
2082}
2083
2084static void selinux_inode_post_create(struct inode *dir, struct dentry *dentry, int mask)
2085{
2086 post_create(dir, dentry);
2087}
2088
2089static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
2090{
2091 int rc;
2092
2093 rc = secondary_ops->inode_link(old_dentry,dir,new_dentry);
2094 if (rc)
2095 return rc;
2096 return may_link(dir, old_dentry, MAY_LINK);
2097}
2098
2099static void selinux_inode_post_link(struct dentry *old_dentry, struct inode *inode, struct dentry *new_dentry)
2100{
2101 return;
2102}
2103
2104static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry)
2105{
2106 int rc;
2107
2108 rc = secondary_ops->inode_unlink(dir, dentry);
2109 if (rc)
2110 return rc;
2111 return may_link(dir, dentry, MAY_UNLINK);
2112}
2113
2114static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name)
2115{
2116 return may_create(dir, dentry, SECCLASS_LNK_FILE);
2117}
2118
2119static void selinux_inode_post_symlink(struct inode *dir, struct dentry *dentry, const char *name)
2120{
2121 post_create(dir, dentry);
2122}
2123
2124static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, int mask)
2125{
2126 return may_create(dir, dentry, SECCLASS_DIR);
2127}
2128
2129static void selinux_inode_post_mkdir(struct inode *dir, struct dentry *dentry, int mask)
2130{
2131 post_create(dir, dentry);
2132}
2133
2134static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry)
2135{
2136 return may_link(dir, dentry, MAY_RMDIR);
2137}
2138
2139static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
2140{
2141 int rc;
2142
2143 rc = secondary_ops->inode_mknod(dir, dentry, mode, dev);
2144 if (rc)
2145 return rc;
2146
2147 return may_create(dir, dentry, inode_mode_to_security_class(mode));
2148}
2149
2150static void selinux_inode_post_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
2151{
2152 post_create(dir, dentry);
2153}
2154
2155static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
2156 struct inode *new_inode, struct dentry *new_dentry)
2157{
2158 return may_rename(old_inode, old_dentry, new_inode, new_dentry);
2159}
2160
2161static void selinux_inode_post_rename(struct inode *old_inode, struct dentry *old_dentry,
2162 struct inode *new_inode, struct dentry *new_dentry)
2163{
2164 return;
2165}
2166
2167static int selinux_inode_readlink(struct dentry *dentry)
2168{
2169 return dentry_has_perm(current, NULL, dentry, FILE__READ);
2170}
2171
2172static int selinux_inode_follow_link(struct dentry *dentry, struct nameidata *nameidata)
2173{
2174 int rc;
2175
2176 rc = secondary_ops->inode_follow_link(dentry,nameidata);
2177 if (rc)
2178 return rc;
2179 return dentry_has_perm(current, NULL, dentry, FILE__READ);
2180}
2181
2182static int selinux_inode_permission(struct inode *inode, int mask,
2183 struct nameidata *nd)
2184{
2185 int rc;
2186
2187 rc = secondary_ops->inode_permission(inode, mask, nd);
2188 if (rc)
2189 return rc;
2190
2191 if (!mask) {
2192 /* No permission to check. Existence test. */
2193 return 0;
2194 }
2195
2196 return inode_has_perm(current, inode,
2197 file_mask_to_av(inode->i_mode, mask), NULL);
2198}
2199
2200static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
2201{
2202 int rc;
2203
2204 rc = secondary_ops->inode_setattr(dentry, iattr);
2205 if (rc)
2206 return rc;
2207
2208 if (iattr->ia_valid & ATTR_FORCE)
2209 return 0;
2210
2211 if (iattr->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
2212 ATTR_ATIME_SET | ATTR_MTIME_SET))
2213 return dentry_has_perm(current, NULL, dentry, FILE__SETATTR);
2214
2215 return dentry_has_perm(current, NULL, dentry, FILE__WRITE);
2216}
2217
2218static int selinux_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
2219{
2220 return dentry_has_perm(current, mnt, dentry, FILE__GETATTR);
2221}
2222
2223static int selinux_inode_setxattr(struct dentry *dentry, char *name, void *value, size_t size, int flags)
2224{
2225 struct task_security_struct *tsec = current->security;
2226 struct inode *inode = dentry->d_inode;
2227 struct inode_security_struct *isec = inode->i_security;
2228 struct superblock_security_struct *sbsec;
2229 struct avc_audit_data ad;
2230 u32 newsid;
2231 int rc = 0;
2232
2233 if (strcmp(name, XATTR_NAME_SELINUX)) {
2234 if (!strncmp(name, XATTR_SECURITY_PREFIX,
2235 sizeof XATTR_SECURITY_PREFIX - 1) &&
2236 !capable(CAP_SYS_ADMIN)) {
2237 /* A different attribute in the security namespace.
2238 Restrict to administrator. */
2239 return -EPERM;
2240 }
2241
2242 /* Not an attribute we recognize, so just check the
2243 ordinary setattr permission. */
2244 return dentry_has_perm(current, NULL, dentry, FILE__SETATTR);
2245 }
2246
2247 sbsec = inode->i_sb->s_security;
2248 if (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)
2249 return -EOPNOTSUPP;
2250
2251 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
2252 return -EPERM;
2253
2254 AVC_AUDIT_DATA_INIT(&ad,FS);
2255 ad.u.fs.dentry = dentry;
2256
2257 rc = avc_has_perm(tsec->sid, isec->sid, isec->sclass,
2258 FILE__RELABELFROM, &ad);
2259 if (rc)
2260 return rc;
2261
2262 rc = security_context_to_sid(value, size, &newsid);
2263 if (rc)
2264 return rc;
2265
2266 rc = avc_has_perm(tsec->sid, newsid, isec->sclass,
2267 FILE__RELABELTO, &ad);
2268 if (rc)
2269 return rc;
2270
2271 rc = security_validate_transition(isec->sid, newsid, tsec->sid,
2272 isec->sclass);
2273 if (rc)
2274 return rc;
2275
2276 return avc_has_perm(newsid,
2277 sbsec->sid,
2278 SECCLASS_FILESYSTEM,
2279 FILESYSTEM__ASSOCIATE,
2280 &ad);
2281}
2282
2283static void selinux_inode_post_setxattr(struct dentry *dentry, char *name,
2284 void *value, size_t size, int flags)
2285{
2286 struct inode *inode = dentry->d_inode;
2287 struct inode_security_struct *isec = inode->i_security;
2288 u32 newsid;
2289 int rc;
2290
2291 if (strcmp(name, XATTR_NAME_SELINUX)) {
2292 /* Not an attribute we recognize, so nothing to do. */
2293 return;
2294 }
2295
2296 rc = security_context_to_sid(value, size, &newsid);
2297 if (rc) {
2298 printk(KERN_WARNING "%s: unable to obtain SID for context "
2299 "%s, rc=%d\n", __FUNCTION__, (char*)value, -rc);
2300 return;
2301 }
2302
2303 isec->sid = newsid;
2304 return;
2305}
2306
2307static int selinux_inode_getxattr (struct dentry *dentry, char *name)
2308{
2309 struct inode *inode = dentry->d_inode;
2310 struct superblock_security_struct *sbsec = inode->i_sb->s_security;
2311
2312 if (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)
2313 return -EOPNOTSUPP;
2314
2315 return dentry_has_perm(current, NULL, dentry, FILE__GETATTR);
2316}
2317
2318static int selinux_inode_listxattr (struct dentry *dentry)
2319{
2320 return dentry_has_perm(current, NULL, dentry, FILE__GETATTR);
2321}
2322
2323static int selinux_inode_removexattr (struct dentry *dentry, char *name)
2324{
2325 if (strcmp(name, XATTR_NAME_SELINUX)) {
2326 if (!strncmp(name, XATTR_SECURITY_PREFIX,
2327 sizeof XATTR_SECURITY_PREFIX - 1) &&
2328 !capable(CAP_SYS_ADMIN)) {
2329 /* A different attribute in the security namespace.
2330 Restrict to administrator. */
2331 return -EPERM;
2332 }
2333
2334 /* Not an attribute we recognize, so just check the
2335 ordinary setattr permission. Might want a separate
2336 permission for removexattr. */
2337 return dentry_has_perm(current, NULL, dentry, FILE__SETATTR);
2338 }
2339
2340 /* No one is allowed to remove a SELinux security label.
2341 You can change the label, but all data must be labeled. */
2342 return -EACCES;
2343}
2344
2345static int selinux_inode_getsecurity(struct inode *inode, const char *name, void *buffer, size_t size)
2346{
2347 struct inode_security_struct *isec = inode->i_security;
2348 char *context;
2349 unsigned len;
2350 int rc;
2351
2352 /* Permission check handled by selinux_inode_getxattr hook.*/
2353
2354 if (strcmp(name, XATTR_SELINUX_SUFFIX))
2355 return -EOPNOTSUPP;
2356
2357 rc = security_sid_to_context(isec->sid, &context, &len);
2358 if (rc)
2359 return rc;
2360
2361 if (!buffer || !size) {
2362 kfree(context);
2363 return len;
2364 }
2365 if (size < len) {
2366 kfree(context);
2367 return -ERANGE;
2368 }
2369 memcpy(buffer, context, len);
2370 kfree(context);
2371 return len;
2372}
2373
2374static int selinux_inode_setsecurity(struct inode *inode, const char *name,
2375 const void *value, size_t size, int flags)
2376{
2377 struct inode_security_struct *isec = inode->i_security;
2378 u32 newsid;
2379 int rc;
2380
2381 if (strcmp(name, XATTR_SELINUX_SUFFIX))
2382 return -EOPNOTSUPP;
2383
2384 if (!value || !size)
2385 return -EACCES;
2386
2387 rc = security_context_to_sid((void*)value, size, &newsid);
2388 if (rc)
2389 return rc;
2390
2391 isec->sid = newsid;
2392 return 0;
2393}
2394
2395static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
2396{
2397 const int len = sizeof(XATTR_NAME_SELINUX);
2398 if (buffer && len <= buffer_size)
2399 memcpy(buffer, XATTR_NAME_SELINUX, len);
2400 return len;
2401}
2402
2403/* file security operations */
2404
2405static int selinux_file_permission(struct file *file, int mask)
2406{
2407 struct inode *inode = file->f_dentry->d_inode;
2408
2409 if (!mask) {
2410 /* No permission to check. Existence test. */
2411 return 0;
2412 }
2413
2414 /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */
2415 if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE))
2416 mask |= MAY_APPEND;
2417
2418 return file_has_perm(current, file,
2419 file_mask_to_av(inode->i_mode, mask));
2420}
2421
2422static int selinux_file_alloc_security(struct file *file)
2423{
2424 return file_alloc_security(file);
2425}
2426
2427static void selinux_file_free_security(struct file *file)
2428{
2429 file_free_security(file);
2430}
2431
2432static int selinux_file_ioctl(struct file *file, unsigned int cmd,
2433 unsigned long arg)
2434{
2435 int error = 0;
2436
2437 switch (cmd) {
2438 case FIONREAD:
2439 /* fall through */
2440 case FIBMAP:
2441 /* fall through */
2442 case FIGETBSZ:
2443 /* fall through */
2444 case EXT2_IOC_GETFLAGS:
2445 /* fall through */
2446 case EXT2_IOC_GETVERSION:
2447 error = file_has_perm(current, file, FILE__GETATTR);
2448 break;
2449
2450 case EXT2_IOC_SETFLAGS:
2451 /* fall through */
2452 case EXT2_IOC_SETVERSION:
2453 error = file_has_perm(current, file, FILE__SETATTR);
2454 break;
2455
2456 /* sys_ioctl() checks */
2457 case FIONBIO:
2458 /* fall through */
2459 case FIOASYNC:
2460 error = file_has_perm(current, file, 0);
2461 break;
2462
2463 case KDSKBENT:
2464 case KDSKBSENT:
2465 error = task_has_capability(current,CAP_SYS_TTY_CONFIG);
2466 break;
2467
2468 /* default case assumes that the command will go
2469 * to the file's ioctl() function.
2470 */
2471 default:
2472 error = file_has_perm(current, file, FILE__IOCTL);
2473
2474 }
2475 return error;
2476}
2477
2478static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
2479{
2480#ifndef CONFIG_PPC32
2481 if ((prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) {
2482 /*
2483 * We are making executable an anonymous mapping or a
2484 * private file mapping that will also be writable.
2485 * This has an additional check.
2486 */
2487 int rc = task_has_perm(current, current, PROCESS__EXECMEM);
2488 if (rc)
2489 return rc;
2490 }
2491#endif
2492
2493 if (file) {
2494 /* read access is always possible with a mapping */
2495 u32 av = FILE__READ;
2496
2497 /* write access only matters if the mapping is shared */
2498 if (shared && (prot & PROT_WRITE))
2499 av |= FILE__WRITE;
2500
2501 if (prot & PROT_EXEC)
2502 av |= FILE__EXECUTE;
2503
2504 return file_has_perm(current, file, av);
2505 }
2506 return 0;
2507}
2508
2509static int selinux_file_mmap(struct file *file, unsigned long reqprot,
2510 unsigned long prot, unsigned long flags)
2511{
2512 int rc;
2513
2514 rc = secondary_ops->file_mmap(file, reqprot, prot, flags);
2515 if (rc)
2516 return rc;
2517
2518 if (selinux_checkreqprot)
2519 prot = reqprot;
2520
2521 return file_map_prot_check(file, prot,
2522 (flags & MAP_TYPE) == MAP_SHARED);
2523}
2524
2525static int selinux_file_mprotect(struct vm_area_struct *vma,
2526 unsigned long reqprot,
2527 unsigned long prot)
2528{
2529 int rc;
2530
2531 rc = secondary_ops->file_mprotect(vma, reqprot, prot);
2532 if (rc)
2533 return rc;
2534
2535 if (selinux_checkreqprot)
2536 prot = reqprot;
2537
2538#ifndef CONFIG_PPC32