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[NETLINK]: Add "groups" argument to netlink_kernel_create
[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;
662 case NETLINK_TCPDIAG:
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;
1277 u32 newsid;
1278 char *context;
1279 unsigned int len;
1280 int rc;
1281
1282 tsec = current->security;
1283 dsec = dir->i_security;
1284 sbsec = dir->i_sb->s_security;
1285
1286 inode = dentry->d_inode;
1287 if (!inode) {
1288 /* Some file system types (e.g. NFS) may not instantiate
1289 a dentry for all create operations (e.g. symlink),
1290 so we have to check to see if the inode is non-NULL. */
1291 printk(KERN_WARNING "post_create: no inode, dir (dev=%s, "
1292 "ino=%ld)\n", dir->i_sb->s_id, dir->i_ino);
1293 return 0;
1294 }
1295
1296 if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
1297 newsid = tsec->create_sid;
1298 } else {
1299 rc = security_transition_sid(tsec->sid, dsec->sid,
1300 inode_mode_to_security_class(inode->i_mode),
1301 &newsid);
1302 if (rc) {
1303 printk(KERN_WARNING "post_create: "
1304 "security_transition_sid failed, rc=%d (dev=%s "
1305 "ino=%ld)\n",
1306 -rc, inode->i_sb->s_id, inode->i_ino);
1307 return rc;
1308 }
1309 }
1310
1311 rc = inode_security_set_sid(inode, newsid);
1312 if (rc) {
1313 printk(KERN_WARNING "post_create: inode_security_set_sid "
1314 "failed, rc=%d (dev=%s ino=%ld)\n",
1315 -rc, inode->i_sb->s_id, inode->i_ino);
1316 return rc;
1317 }
1318
1319 if (sbsec->behavior == SECURITY_FS_USE_XATTR &&
1320 inode->i_op->setxattr) {
1321 /* Use extended attributes. */
1322 rc = security_sid_to_context(newsid, &context, &len);
1323 if (rc) {
1324 printk(KERN_WARNING "post_create: sid_to_context "
1325 "failed, rc=%d (dev=%s ino=%ld)\n",
1326 -rc, inode->i_sb->s_id, inode->i_ino);
1327 return rc;
1328 }
1329 down(&inode->i_sem);
1330 rc = inode->i_op->setxattr(dentry,
1331 XATTR_NAME_SELINUX,
1332 context, len, 0);
1333 up(&inode->i_sem);
1334 kfree(context);
1335 if (rc < 0) {
1336 printk(KERN_WARNING "post_create: setxattr failed, "
1337 "rc=%d (dev=%s ino=%ld)\n",
1338 -rc, inode->i_sb->s_id, inode->i_ino);
1339 return rc;
1340 }
1341 }
1342
1343 return 0;
1344}
1345
1346
1347/* Hook functions begin here. */
1348
1349static int selinux_ptrace(struct task_struct *parent, struct task_struct *child)
1350{
1351 struct task_security_struct *psec = parent->security;
1352 struct task_security_struct *csec = child->security;
1353 int rc;
1354
1355 rc = secondary_ops->ptrace(parent,child);
1356 if (rc)
1357 return rc;
1358
1359 rc = task_has_perm(parent, child, PROCESS__PTRACE);
1360 /* Save the SID of the tracing process for later use in apply_creds. */
1361 if (!rc)
1362 csec->ptrace_sid = psec->sid;
1363 return rc;
1364}
1365
1366static int selinux_capget(struct task_struct *target, kernel_cap_t *effective,
1367 kernel_cap_t *inheritable, kernel_cap_t *permitted)
1368{
1369 int error;
1370
1371 error = task_has_perm(current, target, PROCESS__GETCAP);
1372 if (error)
1373 return error;
1374
1375 return secondary_ops->capget(target, effective, inheritable, permitted);
1376}
1377
1378static int selinux_capset_check(struct task_struct *target, kernel_cap_t *effective,
1379 kernel_cap_t *inheritable, kernel_cap_t *permitted)
1380{
1381 int error;
1382
1383 error = secondary_ops->capset_check(target, effective, inheritable, permitted);
1384 if (error)
1385 return error;
1386
1387 return task_has_perm(current, target, PROCESS__SETCAP);
1388}
1389
1390static void selinux_capset_set(struct task_struct *target, kernel_cap_t *effective,
1391 kernel_cap_t *inheritable, kernel_cap_t *permitted)
1392{
1393 secondary_ops->capset_set(target, effective, inheritable, permitted);
1394}
1395
1396static int selinux_capable(struct task_struct *tsk, int cap)
1397{
1398 int rc;
1399
1400 rc = secondary_ops->capable(tsk, cap);
1401 if (rc)
1402 return rc;
1403
1404 return task_has_capability(tsk,cap);
1405}
1406
1407static int selinux_sysctl(ctl_table *table, int op)
1408{
1409 int error = 0;
1410 u32 av;
1411 struct task_security_struct *tsec;
1412 u32 tsid;
1413 int rc;
1414
1415 rc = secondary_ops->sysctl(table, op);
1416 if (rc)
1417 return rc;
1418
1419 tsec = current->security;
1420
1421 rc = selinux_proc_get_sid(table->de, (op == 001) ?
1422 SECCLASS_DIR : SECCLASS_FILE, &tsid);
1423 if (rc) {
1424 /* Default to the well-defined sysctl SID. */
1425 tsid = SECINITSID_SYSCTL;
1426 }
1427
1428 /* The op values are "defined" in sysctl.c, thereby creating
1429 * a bad coupling between this module and sysctl.c */
1430 if(op == 001) {
1431 error = avc_has_perm(tsec->sid, tsid,
1432 SECCLASS_DIR, DIR__SEARCH, NULL);
1433 } else {
1434 av = 0;
1435 if (op & 004)
1436 av |= FILE__READ;
1437 if (op & 002)
1438 av |= FILE__WRITE;
1439 if (av)
1440 error = avc_has_perm(tsec->sid, tsid,
1441 SECCLASS_FILE, av, NULL);
1442 }
1443
1444 return error;
1445}
1446
1447static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb)
1448{
1449 int rc = 0;
1450
1451 if (!sb)
1452 return 0;
1453
1454 switch (cmds) {
1455 case Q_SYNC:
1456 case Q_QUOTAON:
1457 case Q_QUOTAOFF:
1458 case Q_SETINFO:
1459 case Q_SETQUOTA:
1460 rc = superblock_has_perm(current,
1461 sb,
1462 FILESYSTEM__QUOTAMOD, NULL);
1463 break;
1464 case Q_GETFMT:
1465 case Q_GETINFO:
1466 case Q_GETQUOTA:
1467 rc = superblock_has_perm(current,
1468 sb,
1469 FILESYSTEM__QUOTAGET, NULL);
1470 break;
1471 default:
1472 rc = 0; /* let the kernel handle invalid cmds */
1473 break;
1474 }
1475 return rc;
1476}
1477
1478static int selinux_quota_on(struct dentry *dentry)
1479{
1480 return dentry_has_perm(current, NULL, dentry, FILE__QUOTAON);
1481}
1482
1483static int selinux_syslog(int type)
1484{
1485 int rc;
1486
1487 rc = secondary_ops->syslog(type);
1488 if (rc)
1489 return rc;
1490
1491 switch (type) {
1492 case 3: /* Read last kernel messages */
1493 case 10: /* Return size of the log buffer */
1494 rc = task_has_system(current, SYSTEM__SYSLOG_READ);
1495 break;
1496 case 6: /* Disable logging to console */
1497 case 7: /* Enable logging to console */
1498 case 8: /* Set level of messages printed to console */
1499 rc = task_has_system(current, SYSTEM__SYSLOG_CONSOLE);
1500 break;
1501 case 0: /* Close log */
1502 case 1: /* Open log */
1503 case 2: /* Read from log */
1504 case 4: /* Read/clear last kernel messages */
1505 case 5: /* Clear ring buffer */
1506 default:
1507 rc = task_has_system(current, SYSTEM__SYSLOG_MOD);
1508 break;
1509 }
1510 return rc;
1511}
1512
1513/*
1514 * Check that a process has enough memory to allocate a new virtual
1515 * mapping. 0 means there is enough memory for the allocation to
1516 * succeed and -ENOMEM implies there is not.
1517 *
1518 * Note that secondary_ops->capable and task_has_perm_noaudit return 0
1519 * if the capability is granted, but __vm_enough_memory requires 1 if
1520 * the capability is granted.
1521 *
1522 * Do not audit the selinux permission check, as this is applied to all
1523 * processes that allocate mappings.
1524 */
1525static int selinux_vm_enough_memory(long pages)
1526{
1527 int rc, cap_sys_admin = 0;
1528 struct task_security_struct *tsec = current->security;
1529
1530 rc = secondary_ops->capable(current, CAP_SYS_ADMIN);
1531 if (rc == 0)
1532 rc = avc_has_perm_noaudit(tsec->sid, tsec->sid,
1533 SECCLASS_CAPABILITY,
1534 CAP_TO_MASK(CAP_SYS_ADMIN),
1535 NULL);
1536
1537 if (rc == 0)
1538 cap_sys_admin = 1;
1539
1540 return __vm_enough_memory(pages, cap_sys_admin);
1541}
1542
1543/* binprm security operations */
1544
1545static int selinux_bprm_alloc_security(struct linux_binprm *bprm)
1546{
1547 struct bprm_security_struct *bsec;
1548
1549 bsec = kmalloc(sizeof(struct bprm_security_struct), GFP_KERNEL);
1550 if (!bsec)
1551 return -ENOMEM;
1552
1553 memset(bsec, 0, sizeof *bsec);
1554 bsec->magic = SELINUX_MAGIC;
1555 bsec->bprm = bprm;
1556 bsec->sid = SECINITSID_UNLABELED;
1557 bsec->set = 0;
1558
1559 bprm->security = bsec;
1560 return 0;
1561}
1562
1563static int selinux_bprm_set_security(struct linux_binprm *bprm)
1564{
1565 struct task_security_struct *tsec;
1566 struct inode *inode = bprm->file->f_dentry->d_inode;
1567 struct inode_security_struct *isec;
1568 struct bprm_security_struct *bsec;
1569 u32 newsid;
1570 struct avc_audit_data ad;
1571 int rc;
1572
1573 rc = secondary_ops->bprm_set_security(bprm);
1574 if (rc)
1575 return rc;
1576
1577 bsec = bprm->security;
1578
1579 if (bsec->set)
1580 return 0;
1581
1582 tsec = current->security;
1583 isec = inode->i_security;
1584
1585 /* Default to the current task SID. */
1586 bsec->sid = tsec->sid;
1587
1588 /* Reset create SID on execve. */
1589 tsec->create_sid = 0;
1590
1591 if (tsec->exec_sid) {
1592 newsid = tsec->exec_sid;
1593 /* Reset exec SID on execve. */
1594 tsec->exec_sid = 0;
1595 } else {
1596 /* Check for a default transition on this program. */
1597 rc = security_transition_sid(tsec->sid, isec->sid,
1598 SECCLASS_PROCESS, &newsid);
1599 if (rc)
1600 return rc;
1601 }
1602
1603 AVC_AUDIT_DATA_INIT(&ad, FS);
1604 ad.u.fs.mnt = bprm->file->f_vfsmnt;
1605 ad.u.fs.dentry = bprm->file->f_dentry;
1606
1607 if (bprm->file->f_vfsmnt->mnt_flags & MNT_NOSUID)
1608 newsid = tsec->sid;
1609
1610 if (tsec->sid == newsid) {
1611 rc = avc_has_perm(tsec->sid, isec->sid,
1612 SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
1613 if (rc)
1614 return rc;
1615 } else {
1616 /* Check permissions for the transition. */
1617 rc = avc_has_perm(tsec->sid, newsid,
1618 SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
1619 if (rc)
1620 return rc;
1621
1622 rc = avc_has_perm(newsid, isec->sid,
1623 SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
1624 if (rc)
1625 return rc;
1626
1627 /* Clear any possibly unsafe personality bits on exec: */
1628 current->personality &= ~PER_CLEAR_ON_SETID;
1629
1630 /* Set the security field to the new SID. */
1631 bsec->sid = newsid;
1632 }
1633
1634 bsec->set = 1;
1635 return 0;
1636}
1637
1638static int selinux_bprm_check_security (struct linux_binprm *bprm)
1639{
1640 return secondary_ops->bprm_check_security(bprm);
1641}
1642
1643
1644static int selinux_bprm_secureexec (struct linux_binprm *bprm)
1645{
1646 struct task_security_struct *tsec = current->security;
1647 int atsecure = 0;
1648
1649 if (tsec->osid != tsec->sid) {
1650 /* Enable secure mode for SIDs transitions unless
1651 the noatsecure permission is granted between
1652 the two SIDs, i.e. ahp returns 0. */
1653 atsecure = avc_has_perm(tsec->osid, tsec->sid,
1654 SECCLASS_PROCESS,
1655 PROCESS__NOATSECURE, NULL);
1656 }
1657
1658 return (atsecure || secondary_ops->bprm_secureexec(bprm));
1659}
1660
1661static void selinux_bprm_free_security(struct linux_binprm *bprm)
1662{
9a5f04bf 1663 kfree(bprm->security);
1da177e4 1664 bprm->security = NULL;
1da177e4
LT		 1665}
1666
1667extern struct vfsmount *selinuxfs_mount;
1668extern struct dentry *selinux_null;
1669
1670/* Derived from fs/exec.c:flush_old_files. */
1671static inline void flush_unauthorized_files(struct files_struct * files)
1672{
1673 struct avc_audit_data ad;
1674 struct file *file, *devnull = NULL;
1675 struct tty_struct *tty = current->signal->tty;
1676 long j = -1;
1677
1678 if (tty) {
1679 file_list_lock();
1680 file = list_entry(tty->tty_files.next, typeof(*file), f_list);
1681 if (file) {
1682 /* Revalidate access to controlling tty.
1683 Use inode_has_perm on the tty inode directly rather
1684 than using file_has_perm, as this particular open
1685 file may belong to another process and we are only
1686 interested in the inode-based check here. */
1687 struct inode *inode = file->f_dentry->d_inode;
1688 if (inode_has_perm(current, inode,
1689 FILE__READ | FILE__WRITE, NULL)) {
1690 /* Reset controlling tty. */
1691 current->signal->tty = NULL;
1692 current->signal->tty_old_pgrp = 0;
1693 }
1694 }
1695 file_list_unlock();
1696 }
1697
1698 /* Revalidate access to inherited open files. */
1699
1700 AVC_AUDIT_DATA_INIT(&ad,FS);
1701
1702 spin_lock(&files->file_lock);
1703 for (;;) {
1704 unsigned long set, i;
1705 int fd;
1706
1707 j++;
1708 i = j * __NFDBITS;
1709 if (i >= files->max_fds || i >= files->max_fdset)
1710 break;
1711 set = files->open_fds->fds_bits[j];
1712 if (!set)
1713 continue;
1714 spin_unlock(&files->file_lock);
1715 for ( ; set ; i++,set >>= 1) {
1716 if (set & 1) {
1717 file = fget(i);
1718 if (!file)
1719 continue;
1720 if (file_has_perm(current,
1721 file,
1722 file_to_av(file))) {
1723 sys_close(i);
1724 fd = get_unused_fd();
1725 if (fd != i) {
1726 if (fd >= 0)
1727 put_unused_fd(fd);
1728 fput(file);
1729 continue;
1730 }
1731 if (devnull) {
1732 atomic_inc(&devnull->f_count);
1733 } else {
1734 devnull = dentry_open(dget(selinux_null), mntget(selinuxfs_mount), O_RDWR);
1735 if (!devnull) {
1736 put_unused_fd(fd);
1737 fput(file);
1738 continue;
1739 }
1740 }
1741 fd_install(fd, devnull);
1742 }
1743 fput(file);
1744 }
1745 }
1746 spin_lock(&files->file_lock);
1747
1748 }
1749 spin_unlock(&files->file_lock);
1750}
1751
1752static void selinux_bprm_apply_creds(struct linux_binprm *bprm, int unsafe)
1753{
1754 struct task_security_struct *tsec;
1755 struct bprm_security_struct *bsec;
1756 u32 sid;
1757 int rc;
1758
1759 secondary_ops->bprm_apply_creds(bprm, unsafe);
1760
1761 tsec = current->security;
1762
1763 bsec = bprm->security;
1764 sid = bsec->sid;
1765
1766 tsec->osid = tsec->sid;
1767 bsec->unsafe = 0;
1768 if (tsec->sid != sid) {
1769 /* Check for shared state. If not ok, leave SID
1770 unchanged and kill. */
1771 if (unsafe & LSM_UNSAFE_SHARE) {
1772 rc = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
1773 PROCESS__SHARE, NULL);
1774 if (rc) {
1775 bsec->unsafe = 1;
1776 return;
1777 }
1778 }
1779
1780 /* Check for ptracing, and update the task SID if ok.
1781 Otherwise, leave SID unchanged and kill. */
1782 if (unsafe & (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) {
1783 rc = avc_has_perm(tsec->ptrace_sid, sid,
1784 SECCLASS_PROCESS, PROCESS__PTRACE,
1785 NULL);
1786 if (rc) {
1787 bsec->unsafe = 1;
1788 return;
1789 }
1790 }
1791 tsec->sid = sid;
1792 }
1793}
1794
1795/*
1796 * called after apply_creds without the task lock held
1797 */
1798static void selinux_bprm_post_apply_creds(struct linux_binprm *bprm)
1799{
1800 struct task_security_struct *tsec;
1801 struct rlimit *rlim, *initrlim;
1802 struct itimerval itimer;
1803 struct bprm_security_struct *bsec;
1804 int rc, i;
1805
1806 tsec = current->security;
1807 bsec = bprm->security;
1808
1809 if (bsec->unsafe) {
1810 force_sig_specific(SIGKILL, current);
1811 return;
1812 }
1813 if (tsec->osid == tsec->sid)
1814 return;
1815
1816 /* Close files for which the new task SID is not authorized. */
1817 flush_unauthorized_files(current->files);
1818
1819 /* Check whether the new SID can inherit signal state
1820 from the old SID. If not, clear itimers to avoid
1821 subsequent signal generation and flush and unblock
1822 signals. This must occur _after_ the task SID has
1823 been updated so that any kill done after the flush
1824 will be checked against the new SID. */
1825 rc = avc_has_perm(tsec->osid, tsec->sid, SECCLASS_PROCESS,
1826 PROCESS__SIGINH, NULL);
1827 if (rc) {
1828 memset(&itimer, 0, sizeof itimer);
1829 for (i = 0; i < 3; i++)
1830 do_setitimer(i, &itimer, NULL);
1831 flush_signals(current);
1832 spin_lock_irq(&current->sighand->siglock);
1833 flush_signal_handlers(current, 1);
1834 sigemptyset(&current->blocked);
1835 recalc_sigpending();
1836 spin_unlock_irq(&current->sighand->siglock);
1837 }
1838
1839 /* Check whether the new SID can inherit resource limits
1840 from the old SID. If not, reset all soft limits to
1841 the lower of the current task's hard limit and the init
1842 task's soft limit. Note that the setting of hard limits
1843 (even to lower them) can be controlled by the setrlimit
1844 check. The inclusion of the init task's soft limit into
1845 the computation is to avoid resetting soft limits higher
1846 than the default soft limit for cases where the default
1847 is lower than the hard limit, e.g. RLIMIT_CORE or
1848 RLIMIT_STACK.*/
1849 rc = avc_has_perm(tsec->osid, tsec->sid, SECCLASS_PROCESS,
1850 PROCESS__RLIMITINH, NULL);
1851 if (rc) {
1852 for (i = 0; i < RLIM_NLIMITS; i++) {
1853 rlim = current->signal->rlim + i;
1854 initrlim = init_task.signal->rlim+i;
1855 rlim->rlim_cur = min(rlim->rlim_max,initrlim->rlim_cur);
1856 }
1857 if (current->signal->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY) {
1858 /*
1859 * This will cause RLIMIT_CPU calculations
1860 * to be refigured.
1861 */
1862 current->it_prof_expires = jiffies_to_cputime(1);
1863 }
1864 }
1865
1866 /* Wake up the parent if it is waiting so that it can
1867 recheck wait permission to the new task SID. */
1868 wake_up_interruptible(&current->parent->signal->wait_chldexit);
1869}
1870
1871/* superblock security operations */
1872
1873static int selinux_sb_alloc_security(struct super_block *sb)
1874{
1875 return superblock_alloc_security(sb);
1876}
1877
1878static void selinux_sb_free_security(struct super_block *sb)
1879{
1880 superblock_free_security(sb);
1881}
1882
1883static inline int match_prefix(char *prefix, int plen, char *option, int olen)
1884{
1885 if (plen > olen)
1886 return 0;
1887
1888 return !memcmp(prefix, option, plen);
1889}
1890
1891static inline int selinux_option(char *option, int len)
1892{
1893 return (match_prefix("context=", sizeof("context=")-1, option, len) ||
1894 match_prefix("fscontext=", sizeof("fscontext=")-1, option, len) ||
1895 match_prefix("defcontext=", sizeof("defcontext=")-1, option, len));
1896}
1897
1898static inline void take_option(char **to, char *from, int *first, int len)
1899{
1900 if (!*first) {
1901 **to = ',';
1902 *to += 1;
1903 }
1904 else
1905 *first = 0;
1906 memcpy(*to, from, len);
1907 *to += len;
1908}
1909
1910static int selinux_sb_copy_data(struct file_system_type *type, void *orig, void *copy)
1911{
1912 int fnosec, fsec, rc = 0;
1913 char *in_save, *in_curr, *in_end;
1914 char *sec_curr, *nosec_save, *nosec;
1915
1916 in_curr = orig;
1917 sec_curr = copy;
1918
1919 /* Binary mount data: just copy */
1920 if (type->fs_flags & FS_BINARY_MOUNTDATA) {
1921 copy_page(sec_curr, in_curr);
1922 goto out;
1923 }
1924
1925 nosec = (char *)get_zeroed_page(GFP_KERNEL);
1926 if (!nosec) {
1927 rc = -ENOMEM;
1928 goto out;
1929 }
1930
1931 nosec_save = nosec;
1932 fnosec = fsec = 1;
1933 in_save = in_end = orig;
1934
1935 do {
1936 if (*in_end == ',' || *in_end == '\0') {
1937 int len = in_end - in_curr;
1938
1939 if (selinux_option(in_curr, len))
1940 take_option(&sec_curr, in_curr, &fsec, len);
1941 else
1942 take_option(&nosec, in_curr, &fnosec, len);
1943
1944 in_curr = in_end + 1;
1945 }
1946 } while (*in_end++);
1947
6931dfc9 1948 strcpy(in_save, nosec_save);
da3caa20 1949 free_page((unsigned long)nosec_save);
1da177e4
LT		 1950out:
1951 return rc;
1952}
1953
1954static int selinux_sb_kern_mount(struct super_block *sb, void *data)
1955{
1956 struct avc_audit_data ad;
1957 int rc;
1958
1959 rc = superblock_doinit(sb, data);
1960 if (rc)
1961 return rc;
1962
1963 AVC_AUDIT_DATA_INIT(&ad,FS);
1964 ad.u.fs.dentry = sb->s_root;
1965 return superblock_has_perm(current, sb, FILESYSTEM__MOUNT, &ad);
1966}
1967
1968static int selinux_sb_statfs(struct super_block *sb)
1969{
1970 struct avc_audit_data ad;
1971
1972 AVC_AUDIT_DATA_INIT(&ad,FS);
1973 ad.u.fs.dentry = sb->s_root;
1974 return superblock_has_perm(current, sb, FILESYSTEM__GETATTR, &ad);
1975}
1976
1977static int selinux_mount(char * dev_name,
1978 struct nameidata *nd,
1979 char * type,
1980 unsigned long flags,
1981 void * data)
1982{
1983 int rc;
1984
1985 rc = secondary_ops->sb_mount(dev_name, nd, type, flags, data);
1986 if (rc)
1987 return rc;
1988
1989 if (flags & MS_REMOUNT)
1990 return superblock_has_perm(current, nd->mnt->mnt_sb,
1991 FILESYSTEM__REMOUNT, NULL);
1992 else
1993 return dentry_has_perm(current, nd->mnt, nd->dentry,
1994 FILE__MOUNTON);
1995}
1996
1997static int selinux_umount(struct vfsmount *mnt, int flags)
1998{
1999 int rc;
2000
2001 rc = secondary_ops->sb_umount(mnt, flags);
2002 if (rc)
2003 return rc;
2004
2005 return superblock_has_perm(current,mnt->mnt_sb,
2006 FILESYSTEM__UNMOUNT,NULL);
2007}
2008
2009/* inode security operations */
2010
2011static int selinux_inode_alloc_security(struct inode *inode)
2012{
2013 return inode_alloc_security(inode);
2014}
2015
2016static void selinux_inode_free_security(struct inode *inode)
2017{
2018 inode_free_security(inode);
2019}
2020
2021static int selinux_inode_create(struct inode *dir, struct dentry *dentry, int mask)
2022{
2023 return may_create(dir, dentry, SECCLASS_FILE);
2024}
2025
2026static void selinux_inode_post_create(struct inode *dir, struct dentry *dentry, int mask)
2027{
2028 post_create(dir, dentry);
2029}
2030
2031static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
2032{
2033 int rc;
2034
2035 rc = secondary_ops->inode_link(old_dentry,dir,new_dentry);
2036 if (rc)
2037 return rc;
2038 return may_link(dir, old_dentry, MAY_LINK);
2039}
2040
2041static void selinux_inode_post_link(struct dentry *old_dentry, struct inode *inode, struct dentry *new_dentry)
2042{
2043 return;
2044}
2045
2046static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry)
2047{
2048 int rc;
2049
2050 rc = secondary_ops->inode_unlink(dir, dentry);
2051 if (rc)
2052 return rc;
2053 return may_link(dir, dentry, MAY_UNLINK);
2054}
2055
2056static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name)
2057{
2058 return may_create(dir, dentry, SECCLASS_LNK_FILE);
2059}
2060
2061static void selinux_inode_post_symlink(struct inode *dir, struct dentry *dentry, const char *name)
2062{
2063 post_create(dir, dentry);
2064}
2065
2066static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, int mask)
2067{
2068 return may_create(dir, dentry, SECCLASS_DIR);
2069}
2070
2071static void selinux_inode_post_mkdir(struct inode *dir, struct dentry *dentry, int mask)
2072{
2073 post_create(dir, dentry);
2074}
2075
2076static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry)
2077{
2078 return may_link(dir, dentry, MAY_RMDIR);
2079}
2080
2081static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
2082{
2083 int rc;
2084
2085 rc = secondary_ops->inode_mknod(dir, dentry, mode, dev);
2086 if (rc)
2087 return rc;
2088
2089 return may_create(dir, dentry, inode_mode_to_security_class(mode));
2090}
2091
2092static void selinux_inode_post_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
2093{
2094 post_create(dir, dentry);
2095}
2096
2097static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
2098 struct inode *new_inode, struct dentry *new_dentry)
2099{
2100 return may_rename(old_inode, old_dentry, new_inode, new_dentry);
2101}
2102
2103static void selinux_inode_post_rename(struct inode *old_inode, struct dentry *old_dentry,
2104 struct inode *new_inode, struct dentry *new_dentry)
2105{
2106 return;
2107}
2108
2109static int selinux_inode_readlink(struct dentry *dentry)
2110{
2111 return dentry_has_perm(current, NULL, dentry, FILE__READ);
2112}
2113
2114static int selinux_inode_follow_link(struct dentry *dentry, struct nameidata *nameidata)
2115{
2116 int rc;
2117
2118 rc = secondary_ops->inode_follow_link(dentry,nameidata);
2119 if (rc)
2120 return rc;
2121 return dentry_has_perm(current, NULL, dentry, FILE__READ);
2122}
2123
2124static int selinux_inode_permission(struct inode *inode, int mask,
2125 struct nameidata *nd)
2126{
2127 int rc;
2128
2129 rc = secondary_ops->inode_permission(inode, mask, nd);
2130 if (rc)
2131 return rc;
2132
2133 if (!mask) {
2134 /* No permission to check. Existence test. */
2135 return 0;
2136 }
2137
2138 return inode_has_perm(current, inode,
2139 file_mask_to_av(inode->i_mode, mask), NULL);
2140}
2141
2142static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
2143{
2144 int rc;
2145
2146 rc = secondary_ops->inode_setattr(dentry, iattr);
2147 if (rc)
2148 return rc;
2149
2150 if (iattr->ia_valid & ATTR_FORCE)
2151 return 0;
2152
2153 if (iattr->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
2154 ATTR_ATIME_SET | ATTR_MTIME_SET))
2155 return dentry_has_perm(current, NULL, dentry, FILE__SETATTR);
2156
2157 return dentry_has_perm(current, NULL, dentry, FILE__WRITE);
2158}
2159
2160static int selinux_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
2161{
2162 return dentry_has_perm(current, mnt, dentry, FILE__GETATTR);
2163}
2164
2165static int selinux_inode_setxattr(struct dentry *dentry, char *name, void *value, size_t size, int flags)
2166{
2167 struct task_security_struct *tsec = current->security;
2168 struct inode *inode = dentry->d_inode;
2169 struct inode_security_struct *isec = inode->i_security;
2170 struct superblock_security_struct *sbsec;
2171 struct avc_audit_data ad;
2172 u32 newsid;
2173 int rc = 0;
2174
2175 if (strcmp(name, XATTR_NAME_SELINUX)) {
2176 if (!strncmp(name, XATTR_SECURITY_PREFIX,
2177 sizeof XATTR_SECURITY_PREFIX - 1) &&
2178 !capable(CAP_SYS_ADMIN)) {
2179 /* A different attribute in the security namespace.
2180 Restrict to administrator. */
2181 return -EPERM;
2182 }
2183
2184 /* Not an attribute we recognize, so just check the
2185 ordinary setattr permission. */
2186 return dentry_has_perm(current, NULL, dentry, FILE__SETATTR);
2187 }
2188
2189 sbsec = inode->i_sb->s_security;
2190 if (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)
2191 return -EOPNOTSUPP;
2192
2193 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
2194 return -EPERM;
2195
2196 AVC_AUDIT_DATA_INIT(&ad,FS);
2197 ad.u.fs.dentry = dentry;
2198
2199 rc = avc_has_perm(tsec->sid, isec->sid, isec->sclass,
2200 FILE__RELABELFROM, &ad);
2201 if (rc)
2202 return rc;
2203
2204 rc = security_context_to_sid(value, size, &newsid);
2205 if (rc)
2206 return rc;
2207
2208 rc = avc_has_perm(tsec->sid, newsid, isec->sclass,
2209 FILE__RELABELTO, &ad);
2210 if (rc)
2211 return rc;
2212
2213 rc = security_validate_transition(isec->sid, newsid, tsec->sid,
2214 isec->sclass);
2215 if (rc)
2216 return rc;
2217
2218 return avc_has_perm(newsid,
2219 sbsec->sid,
2220 SECCLASS_FILESYSTEM,
2221 FILESYSTEM__ASSOCIATE,
2222 &ad);
2223}
2224
2225static void selinux_inode_post_setxattr(struct dentry *dentry, char *name,
2226 void *value, size_t size, int flags)
2227{
2228 struct inode *inode = dentry->d_inode;
2229 struct inode_security_struct *isec = inode->i_security;
2230 u32 newsid;
2231 int rc;
2232
2233 if (strcmp(name, XATTR_NAME_SELINUX)) {
2234 /* Not an attribute we recognize, so nothing to do. */
2235 return;
2236 }
2237
2238 rc = security_context_to_sid(value, size, &newsid);
2239 if (rc) {
2240 printk(KERN_WARNING "%s: unable to obtain SID for context "
2241 "%s, rc=%d\n", __FUNCTION__, (char*)value, -rc);
2242 return;
2243 }
2244
2245 isec->sid = newsid;
2246 return;
2247}
2248
2249static int selinux_inode_getxattr (struct dentry *dentry, char *name)
2250{
2251 struct inode *inode = dentry->d_inode;
2252 struct superblock_security_struct *sbsec = inode->i_sb->s_security;
2253
2254 if (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)
2255 return -EOPNOTSUPP;
2256
2257 return dentry_has_perm(current, NULL, dentry, FILE__GETATTR);
2258}
2259
2260static int selinux_inode_listxattr (struct dentry *dentry)
2261{
2262 return dentry_has_perm(current, NULL, dentry, FILE__GETATTR);
2263}
2264
2265static int selinux_inode_removexattr (struct dentry *dentry, char *name)
2266{
2267 if (strcmp(name, XATTR_NAME_SELINUX)) {
2268 if (!strncmp(name, XATTR_SECURITY_PREFIX,
2269 sizeof XATTR_SECURITY_PREFIX - 1) &&
2270 !capable(CAP_SYS_ADMIN)) {
2271 /* A different attribute in the security namespace.
2272 Restrict to administrator. */
2273 return -EPERM;
2274 }
2275
2276 /* Not an attribute we recognize, so just check the
2277 ordinary setattr permission. Might want a separate
2278 permission for removexattr. */
2279 return dentry_has_perm(current, NULL, dentry, FILE__SETATTR);
2280 }
2281
2282 /* No one is allowed to remove a SELinux security label.
2283 You can change the label, but all data must be labeled. */
2284 return -EACCES;
2285}
2286
2287static int selinux_inode_getsecurity(struct inode *inode, const char *name, void *buffer, size_t size)
2288{
2289 struct inode_security_struct *isec = inode->i_security;
2290 char *context;
2291 unsigned len;
2292 int rc;
2293
2294 /* Permission check handled by selinux_inode_getxattr hook.*/
2295
2296 if (strcmp(name, XATTR_SELINUX_SUFFIX))
2297 return -EOPNOTSUPP;
2298
2299 rc = security_sid_to_context(isec->sid, &context, &len);
2300 if (rc)
2301 return rc;
2302
2303 if (!buffer || !size) {
2304 kfree(context);
2305 return len;
2306 }
2307 if (size < len) {
2308 kfree(context);
2309 return -ERANGE;
2310 }
2311 memcpy(buffer, context, len);
2312 kfree(context);
2313 return len;
2314}
2315
2316static int selinux_inode_setsecurity(struct inode *inode, const char *name,
2317 const void *value, size_t size, int flags)
2318{
2319 struct inode_security_struct *isec = inode->i_security;
2320 u32 newsid;
2321 int rc;
2322
2323 if (strcmp(name, XATTR_SELINUX_SUFFIX))
2324 return -EOPNOTSUPP;
2325
2326 if (!value || !size)
2327 return -EACCES;
2328
2329 rc = security_context_to_sid((void*)value, size, &newsid);
2330 if (rc)
2331 return rc;
2332
2333 isec->sid = newsid;
2334 return 0;
2335}
2336
2337static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
2338{
2339 const int len = sizeof(XATTR_NAME_SELINUX);
2340 if (buffer && len <= buffer_size)
2341 memcpy(buffer, XATTR_NAME_SELINUX, len);
2342 return len;
2343}
2344
2345/* file security operations */
2346
2347static int selinux_file_permission(struct file *file, int mask)
2348{
2349 struct inode *inode = file->f_dentry->d_inode;
2350
2351 if (!mask) {
2352 /* No permission to check. Existence test. */
2353 return 0;
2354 }
2355
2356 /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */
2357 if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE))
2358 mask |= MAY_APPEND;
2359
2360 return file_has_perm(current, file,
2361 file_mask_to_av(inode->i_mode, mask));
2362}
2363
2364static int selinux_file_alloc_security(struct file *file)
2365{
2366 return file_alloc_security(file);
2367}
2368
2369static void selinux_file_free_security(struct file *file)
2370{
2371 file_free_security(file);
2372}
2373
2374static int selinux_file_ioctl(struct file *file, unsigned int cmd,
2375 unsigned long arg)
2376{
2377 int error = 0;
2378
2379 switch (cmd) {
2380 case FIONREAD:
2381 /* fall through */
2382 case FIBMAP:
2383 /* fall through */
2384 case FIGETBSZ:
2385 /* fall through */
2386 case EXT2_IOC_GETFLAGS:
2387 /* fall through */
2388 case EXT2_IOC_GETVERSION:
2389 error = file_has_perm(current, file, FILE__GETATTR);
2390 break;
2391
2392 case EXT2_IOC_SETFLAGS:
2393 /* fall through */
2394 case EXT2_IOC_SETVERSION:
2395 error = file_has_perm(current, file, FILE__SETATTR);
2396 break;
2397
2398 /* sys_ioctl() checks */
2399 case FIONBIO:
2400 /* fall through */
2401 case FIOASYNC:
2402 error = file_has_perm(current, file, 0);
2403 break;
2404
2405 case KDSKBENT:
2406 case KDSKBSENT:
2407 error = task_has_capability(current,CAP_SYS_TTY_CONFIG);
2408 break;
2409
2410 /* default case assumes that the command will go
2411 * to the file's ioctl() function.
2412 */
2413 default:
2414 error = file_has_perm(current, file, FILE__IOCTL);
2415
2416 }
2417 return error;
2418}
2419
2420static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
2421{
2422#ifndef CONFIG_PPC32
2423 if ((prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) {
2424 /*
2425 * We are making executable an anonymous mapping or a
2426 * private file mapping that will also be writable.
2427 * This has an additional check.
2428 */
2429 int rc = task_has_perm(current, current, PROCESS__EXECMEM);
2430 if (rc)
2431 return rc;
2432 }
2433#endif
2434
2435 if (file) {
2436 /* read access is always possible with a mapping */
2437 u32 av = FILE__READ;
2438
2439 /* write access only matters if the mapping is shared */
2440 if (shared && (prot & PROT_WRITE))
2441 av |= FILE__WRITE;
2442
2443 if (prot & PROT_EXEC)
2444 av |= FILE__EXECUTE;
2445
2446 return file_has_perm(current, file, av);
2447 }
2448 return 0;
2449}
2450
2451static int selinux_file_mmap(struct file *file, unsigned long reqprot,
2452 unsigned long prot, unsigned long flags)
2453{
2454 int rc;
2455
2456 rc = secondary_ops->file_mmap(file, reqprot, prot, flags);
2457 if (rc)
2458 return rc;
2459
2460 if (selinux_checkreqprot)
2461 prot = reqprot;
2462
2463 return file_map_prot_check(file, prot,
2464 (flags & MAP_TYPE) == MAP_SHARED);
2465}
2466
2467static int selinux_file_mprotect(struct vm_area_struct *vma,
2468 unsigned long reqprot,
2469 unsigned long prot)
2470{
2471 int rc;
2472
2473 rc = secondary_ops->file_mprotect(vma, reqprot, prot);
2474 if (rc)
2475 return rc;
2476
2477 if (selinux_checkreqprot)
2478 prot = reqprot;
2479
2480#ifndef CONFIG_PPC32