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