Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Implementation of the kernel access vector cache (AVC). | |
3 | * | |
4 | * Authors: Stephen Smalley, <sds@epoch.ncsc.mil> | |
5 | * James Morris <jmorris@redhat.com> | |
6 | * | |
7 | * Update: KaiGai, Kohei <kaigai@ak.jp.nec.com> | |
8 | * Replaced the avc_lock spinlock by RCU. | |
9 | * | |
10 | * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com> | |
11 | * | |
12 | * This program is free software; you can redistribute it and/or modify | |
13 | * it under the terms of the GNU General Public License version 2, | |
14 | * as published by the Free Software Foundation. | |
15 | */ | |
16 | #include <linux/types.h> | |
17 | #include <linux/stddef.h> | |
18 | #include <linux/kernel.h> | |
19 | #include <linux/slab.h> | |
20 | #include <linux/fs.h> | |
21 | #include <linux/dcache.h> | |
22 | #include <linux/init.h> | |
23 | #include <linux/skbuff.h> | |
24 | #include <linux/percpu.h> | |
25 | #include <net/sock.h> | |
26 | #include <linux/un.h> | |
27 | #include <net/af_unix.h> | |
28 | #include <linux/ip.h> | |
29 | #include <linux/audit.h> | |
30 | #include <linux/ipv6.h> | |
31 | #include <net/ipv6.h> | |
32 | #include "avc.h" | |
33 | #include "avc_ss.h" | |
34 | ||
5c458998 | 35 | static const struct av_perm_to_string av_perm_to_string[] = { |
1da177e4 LT |
36 | #define S_(c, v, s) { c, v, s }, |
37 | #include "av_perm_to_string.h" | |
38 | #undef S_ | |
39 | }; | |
40 | ||
1da177e4 LT |
41 | static const char *class_to_string[] = { |
42 | #define S_(s) s, | |
43 | #include "class_to_string.h" | |
44 | #undef S_ | |
45 | }; | |
1da177e4 LT |
46 | |
47 | #define TB_(s) static const char * s [] = { | |
48 | #define TE_(s) }; | |
49 | #define S_(s) s, | |
50 | #include "common_perm_to_string.h" | |
51 | #undef TB_ | |
52 | #undef TE_ | |
53 | #undef S_ | |
54 | ||
5c458998 | 55 | static const struct av_inherit av_inherit[] = { |
1da177e4 LT |
56 | #define S_(c, i, b) { c, common_##i##_perm_to_string, b }, |
57 | #include "av_inherit.h" | |
58 | #undef S_ | |
59 | }; | |
60 | ||
5c458998 CS |
61 | const struct selinux_class_perm selinux_class_perm = { |
62 | av_perm_to_string, | |
63 | ARRAY_SIZE(av_perm_to_string), | |
64 | class_to_string, | |
65 | ARRAY_SIZE(class_to_string), | |
66 | av_inherit, | |
67 | ARRAY_SIZE(av_inherit) | |
68 | }; | |
69 | ||
1da177e4 LT |
70 | #define AVC_CACHE_SLOTS 512 |
71 | #define AVC_DEF_CACHE_THRESHOLD 512 | |
72 | #define AVC_CACHE_RECLAIM 16 | |
73 | ||
74 | #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS | |
75 | #define avc_cache_stats_incr(field) \ | |
76 | do { \ | |
77 | per_cpu(avc_cache_stats, get_cpu()).field++; \ | |
78 | put_cpu(); \ | |
79 | } while (0) | |
80 | #else | |
81 | #define avc_cache_stats_incr(field) do {} while (0) | |
82 | #endif | |
83 | ||
84 | struct avc_entry { | |
85 | u32 ssid; | |
86 | u32 tsid; | |
87 | u16 tclass; | |
88 | struct av_decision avd; | |
89 | atomic_t used; /* used recently */ | |
90 | }; | |
91 | ||
92 | struct avc_node { | |
93 | struct avc_entry ae; | |
94 | struct list_head list; | |
95 | struct rcu_head rhead; | |
96 | }; | |
97 | ||
98 | struct avc_cache { | |
99 | struct list_head slots[AVC_CACHE_SLOTS]; | |
100 | spinlock_t slots_lock[AVC_CACHE_SLOTS]; /* lock for writes */ | |
101 | atomic_t lru_hint; /* LRU hint for reclaim scan */ | |
102 | atomic_t active_nodes; | |
103 | u32 latest_notif; /* latest revocation notification */ | |
104 | }; | |
105 | ||
106 | struct avc_callback_node { | |
107 | int (*callback) (u32 event, u32 ssid, u32 tsid, | |
108 | u16 tclass, u32 perms, | |
109 | u32 *out_retained); | |
110 | u32 events; | |
111 | u32 ssid; | |
112 | u32 tsid; | |
113 | u16 tclass; | |
114 | u32 perms; | |
115 | struct avc_callback_node *next; | |
116 | }; | |
117 | ||
118 | /* Exported via selinufs */ | |
119 | unsigned int avc_cache_threshold = AVC_DEF_CACHE_THRESHOLD; | |
120 | ||
121 | #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS | |
122 | DEFINE_PER_CPU(struct avc_cache_stats, avc_cache_stats) = { 0 }; | |
123 | #endif | |
124 | ||
125 | static struct avc_cache avc_cache; | |
126 | static struct avc_callback_node *avc_callbacks; | |
e18b890b | 127 | static struct kmem_cache *avc_node_cachep; |
1da177e4 LT |
128 | |
129 | static inline int avc_hash(u32 ssid, u32 tsid, u16 tclass) | |
130 | { | |
131 | return (ssid ^ (tsid<<2) ^ (tclass<<4)) & (AVC_CACHE_SLOTS - 1); | |
132 | } | |
133 | ||
134 | /** | |
135 | * avc_dump_av - Display an access vector in human-readable form. | |
136 | * @tclass: target security class | |
137 | * @av: access vector | |
138 | */ | |
139 | static void avc_dump_av(struct audit_buffer *ab, u16 tclass, u32 av) | |
140 | { | |
141 | const char **common_pts = NULL; | |
142 | u32 common_base = 0; | |
143 | int i, i2, perm; | |
144 | ||
145 | if (av == 0) { | |
146 | audit_log_format(ab, " null"); | |
147 | return; | |
148 | } | |
149 | ||
150 | for (i = 0; i < ARRAY_SIZE(av_inherit); i++) { | |
151 | if (av_inherit[i].tclass == tclass) { | |
152 | common_pts = av_inherit[i].common_pts; | |
153 | common_base = av_inherit[i].common_base; | |
154 | break; | |
155 | } | |
156 | } | |
157 | ||
158 | audit_log_format(ab, " {"); | |
159 | i = 0; | |
160 | perm = 1; | |
161 | while (perm < common_base) { | |
162 | if (perm & av) { | |
163 | audit_log_format(ab, " %s", common_pts[i]); | |
164 | av &= ~perm; | |
165 | } | |
166 | i++; | |
167 | perm <<= 1; | |
168 | } | |
169 | ||
170 | while (i < sizeof(av) * 8) { | |
171 | if (perm & av) { | |
172 | for (i2 = 0; i2 < ARRAY_SIZE(av_perm_to_string); i2++) { | |
173 | if ((av_perm_to_string[i2].tclass == tclass) && | |
174 | (av_perm_to_string[i2].value == perm)) | |
175 | break; | |
176 | } | |
177 | if (i2 < ARRAY_SIZE(av_perm_to_string)) { | |
178 | audit_log_format(ab, " %s", | |
179 | av_perm_to_string[i2].name); | |
180 | av &= ~perm; | |
181 | } | |
182 | } | |
183 | i++; | |
184 | perm <<= 1; | |
185 | } | |
186 | ||
187 | if (av) | |
188 | audit_log_format(ab, " 0x%x", av); | |
189 | ||
190 | audit_log_format(ab, " }"); | |
191 | } | |
192 | ||
193 | /** | |
194 | * avc_dump_query - Display a SID pair and a class in human-readable form. | |
195 | * @ssid: source security identifier | |
196 | * @tsid: target security identifier | |
197 | * @tclass: target security class | |
198 | */ | |
199 | static void avc_dump_query(struct audit_buffer *ab, u32 ssid, u32 tsid, u16 tclass) | |
200 | { | |
201 | int rc; | |
202 | char *scontext; | |
203 | u32 scontext_len; | |
204 | ||
205 | rc = security_sid_to_context(ssid, &scontext, &scontext_len); | |
206 | if (rc) | |
207 | audit_log_format(ab, "ssid=%d", ssid); | |
208 | else { | |
209 | audit_log_format(ab, "scontext=%s", scontext); | |
210 | kfree(scontext); | |
211 | } | |
212 | ||
213 | rc = security_sid_to_context(tsid, &scontext, &scontext_len); | |
214 | if (rc) | |
215 | audit_log_format(ab, " tsid=%d", tsid); | |
216 | else { | |
217 | audit_log_format(ab, " tcontext=%s", scontext); | |
218 | kfree(scontext); | |
219 | } | |
220 | audit_log_format(ab, " tclass=%s", class_to_string[tclass]); | |
221 | } | |
222 | ||
223 | /** | |
224 | * avc_init - Initialize the AVC. | |
225 | * | |
226 | * Initialize the access vector cache. | |
227 | */ | |
228 | void __init avc_init(void) | |
229 | { | |
230 | int i; | |
231 | ||
232 | for (i = 0; i < AVC_CACHE_SLOTS; i++) { | |
233 | INIT_LIST_HEAD(&avc_cache.slots[i]); | |
234 | spin_lock_init(&avc_cache.slots_lock[i]); | |
235 | } | |
236 | atomic_set(&avc_cache.active_nodes, 0); | |
237 | atomic_set(&avc_cache.lru_hint, 0); | |
238 | ||
239 | avc_node_cachep = kmem_cache_create("avc_node", sizeof(struct avc_node), | |
240 | 0, SLAB_PANIC, NULL, NULL); | |
241 | ||
9ad9ad38 | 242 | audit_log(current->audit_context, GFP_KERNEL, AUDIT_KERNEL, "AVC INITIALIZED\n"); |
1da177e4 LT |
243 | } |
244 | ||
245 | int avc_get_hash_stats(char *page) | |
246 | { | |
247 | int i, chain_len, max_chain_len, slots_used; | |
248 | struct avc_node *node; | |
249 | ||
250 | rcu_read_lock(); | |
251 | ||
252 | slots_used = 0; | |
253 | max_chain_len = 0; | |
254 | for (i = 0; i < AVC_CACHE_SLOTS; i++) { | |
255 | if (!list_empty(&avc_cache.slots[i])) { | |
256 | slots_used++; | |
257 | chain_len = 0; | |
258 | list_for_each_entry_rcu(node, &avc_cache.slots[i], list) | |
259 | chain_len++; | |
260 | if (chain_len > max_chain_len) | |
261 | max_chain_len = chain_len; | |
262 | } | |
263 | } | |
264 | ||
265 | rcu_read_unlock(); | |
266 | ||
267 | return scnprintf(page, PAGE_SIZE, "entries: %d\nbuckets used: %d/%d\n" | |
268 | "longest chain: %d\n", | |
269 | atomic_read(&avc_cache.active_nodes), | |
270 | slots_used, AVC_CACHE_SLOTS, max_chain_len); | |
271 | } | |
272 | ||
273 | static void avc_node_free(struct rcu_head *rhead) | |
274 | { | |
275 | struct avc_node *node = container_of(rhead, struct avc_node, rhead); | |
276 | kmem_cache_free(avc_node_cachep, node); | |
277 | avc_cache_stats_incr(frees); | |
278 | } | |
279 | ||
280 | static void avc_node_delete(struct avc_node *node) | |
281 | { | |
282 | list_del_rcu(&node->list); | |
283 | call_rcu(&node->rhead, avc_node_free); | |
284 | atomic_dec(&avc_cache.active_nodes); | |
285 | } | |
286 | ||
287 | static void avc_node_kill(struct avc_node *node) | |
288 | { | |
289 | kmem_cache_free(avc_node_cachep, node); | |
290 | avc_cache_stats_incr(frees); | |
291 | atomic_dec(&avc_cache.active_nodes); | |
292 | } | |
293 | ||
294 | static void avc_node_replace(struct avc_node *new, struct avc_node *old) | |
295 | { | |
296 | list_replace_rcu(&old->list, &new->list); | |
297 | call_rcu(&old->rhead, avc_node_free); | |
298 | atomic_dec(&avc_cache.active_nodes); | |
299 | } | |
300 | ||
301 | static inline int avc_reclaim_node(void) | |
302 | { | |
303 | struct avc_node *node; | |
304 | int hvalue, try, ecx; | |
305 | unsigned long flags; | |
306 | ||
307 | for (try = 0, ecx = 0; try < AVC_CACHE_SLOTS; try++ ) { | |
308 | hvalue = atomic_inc_return(&avc_cache.lru_hint) & (AVC_CACHE_SLOTS - 1); | |
309 | ||
310 | if (!spin_trylock_irqsave(&avc_cache.slots_lock[hvalue], flags)) | |
311 | continue; | |
312 | ||
313 | list_for_each_entry(node, &avc_cache.slots[hvalue], list) { | |
314 | if (atomic_dec_and_test(&node->ae.used)) { | |
315 | /* Recently Unused */ | |
316 | avc_node_delete(node); | |
317 | avc_cache_stats_incr(reclaims); | |
318 | ecx++; | |
319 | if (ecx >= AVC_CACHE_RECLAIM) { | |
320 | spin_unlock_irqrestore(&avc_cache.slots_lock[hvalue], flags); | |
321 | goto out; | |
322 | } | |
323 | } | |
324 | } | |
325 | spin_unlock_irqrestore(&avc_cache.slots_lock[hvalue], flags); | |
326 | } | |
327 | out: | |
328 | return ecx; | |
329 | } | |
330 | ||
331 | static struct avc_node *avc_alloc_node(void) | |
332 | { | |
333 | struct avc_node *node; | |
334 | ||
54e6ecb2 | 335 | node = kmem_cache_alloc(avc_node_cachep, GFP_ATOMIC); |
1da177e4 LT |
336 | if (!node) |
337 | goto out; | |
338 | ||
339 | memset(node, 0, sizeof(*node)); | |
340 | INIT_RCU_HEAD(&node->rhead); | |
341 | INIT_LIST_HEAD(&node->list); | |
342 | atomic_set(&node->ae.used, 1); | |
343 | avc_cache_stats_incr(allocations); | |
344 | ||
345 | if (atomic_inc_return(&avc_cache.active_nodes) > avc_cache_threshold) | |
346 | avc_reclaim_node(); | |
347 | ||
348 | out: | |
349 | return node; | |
350 | } | |
351 | ||
352 | static void avc_node_populate(struct avc_node *node, u32 ssid, u32 tsid, u16 tclass, struct avc_entry *ae) | |
353 | { | |
354 | node->ae.ssid = ssid; | |
355 | node->ae.tsid = tsid; | |
356 | node->ae.tclass = tclass; | |
357 | memcpy(&node->ae.avd, &ae->avd, sizeof(node->ae.avd)); | |
358 | } | |
359 | ||
360 | static inline struct avc_node *avc_search_node(u32 ssid, u32 tsid, u16 tclass) | |
361 | { | |
362 | struct avc_node *node, *ret = NULL; | |
363 | int hvalue; | |
364 | ||
365 | hvalue = avc_hash(ssid, tsid, tclass); | |
366 | list_for_each_entry_rcu(node, &avc_cache.slots[hvalue], list) { | |
367 | if (ssid == node->ae.ssid && | |
368 | tclass == node->ae.tclass && | |
369 | tsid == node->ae.tsid) { | |
370 | ret = node; | |
371 | break; | |
372 | } | |
373 | } | |
374 | ||
375 | if (ret == NULL) { | |
376 | /* cache miss */ | |
377 | goto out; | |
378 | } | |
379 | ||
380 | /* cache hit */ | |
381 | if (atomic_read(&ret->ae.used) != 1) | |
382 | atomic_set(&ret->ae.used, 1); | |
383 | out: | |
384 | return ret; | |
385 | } | |
386 | ||
387 | /** | |
388 | * avc_lookup - Look up an AVC entry. | |
389 | * @ssid: source security identifier | |
390 | * @tsid: target security identifier | |
391 | * @tclass: target security class | |
392 | * @requested: requested permissions, interpreted based on @tclass | |
393 | * | |
394 | * Look up an AVC entry that is valid for the | |
395 | * @requested permissions between the SID pair | |
396 | * (@ssid, @tsid), interpreting the permissions | |
397 | * based on @tclass. If a valid AVC entry exists, | |
398 | * then this function return the avc_node. | |
399 | * Otherwise, this function returns NULL. | |
400 | */ | |
401 | static struct avc_node *avc_lookup(u32 ssid, u32 tsid, u16 tclass, u32 requested) | |
402 | { | |
403 | struct avc_node *node; | |
404 | ||
405 | avc_cache_stats_incr(lookups); | |
406 | node = avc_search_node(ssid, tsid, tclass); | |
407 | ||
408 | if (node && ((node->ae.avd.decided & requested) == requested)) { | |
409 | avc_cache_stats_incr(hits); | |
410 | goto out; | |
411 | } | |
412 | ||
413 | node = NULL; | |
414 | avc_cache_stats_incr(misses); | |
415 | out: | |
416 | return node; | |
417 | } | |
418 | ||
419 | static int avc_latest_notif_update(int seqno, int is_insert) | |
420 | { | |
421 | int ret = 0; | |
422 | static DEFINE_SPINLOCK(notif_lock); | |
423 | unsigned long flag; | |
424 | ||
425 | spin_lock_irqsave(¬if_lock, flag); | |
426 | if (is_insert) { | |
427 | if (seqno < avc_cache.latest_notif) { | |
428 | printk(KERN_WARNING "avc: seqno %d < latest_notif %d\n", | |
429 | seqno, avc_cache.latest_notif); | |
430 | ret = -EAGAIN; | |
431 | } | |
432 | } else { | |
433 | if (seqno > avc_cache.latest_notif) | |
434 | avc_cache.latest_notif = seqno; | |
435 | } | |
436 | spin_unlock_irqrestore(¬if_lock, flag); | |
437 | ||
438 | return ret; | |
439 | } | |
440 | ||
441 | /** | |
442 | * avc_insert - Insert an AVC entry. | |
443 | * @ssid: source security identifier | |
444 | * @tsid: target security identifier | |
445 | * @tclass: target security class | |
446 | * @ae: AVC entry | |
447 | * | |
448 | * Insert an AVC entry for the SID pair | |
449 | * (@ssid, @tsid) and class @tclass. | |
450 | * The access vectors and the sequence number are | |
451 | * normally provided by the security server in | |
452 | * response to a security_compute_av() call. If the | |
453 | * sequence number @ae->avd.seqno is not less than the latest | |
454 | * revocation notification, then the function copies | |
455 | * the access vectors into a cache entry, returns | |
456 | * avc_node inserted. Otherwise, this function returns NULL. | |
457 | */ | |
458 | static struct avc_node *avc_insert(u32 ssid, u32 tsid, u16 tclass, struct avc_entry *ae) | |
459 | { | |
460 | struct avc_node *pos, *node = NULL; | |
461 | int hvalue; | |
462 | unsigned long flag; | |
463 | ||
464 | if (avc_latest_notif_update(ae->avd.seqno, 1)) | |
465 | goto out; | |
466 | ||
467 | node = avc_alloc_node(); | |
468 | if (node) { | |
469 | hvalue = avc_hash(ssid, tsid, tclass); | |
470 | avc_node_populate(node, ssid, tsid, tclass, ae); | |
471 | ||
472 | spin_lock_irqsave(&avc_cache.slots_lock[hvalue], flag); | |
473 | list_for_each_entry(pos, &avc_cache.slots[hvalue], list) { | |
474 | if (pos->ae.ssid == ssid && | |
475 | pos->ae.tsid == tsid && | |
476 | pos->ae.tclass == tclass) { | |
477 | avc_node_replace(node, pos); | |
478 | goto found; | |
479 | } | |
480 | } | |
481 | list_add_rcu(&node->list, &avc_cache.slots[hvalue]); | |
482 | found: | |
483 | spin_unlock_irqrestore(&avc_cache.slots_lock[hvalue], flag); | |
484 | } | |
485 | out: | |
486 | return node; | |
487 | } | |
488 | ||
489 | static inline void avc_print_ipv6_addr(struct audit_buffer *ab, | |
b5bf6c55 | 490 | struct in6_addr *addr, __be16 port, |
1da177e4 LT |
491 | char *name1, char *name2) |
492 | { | |
493 | if (!ipv6_addr_any(addr)) | |
46b86a2d | 494 | audit_log_format(ab, " %s=" NIP6_FMT, name1, NIP6(*addr)); |
1da177e4 LT |
495 | if (port) |
496 | audit_log_format(ab, " %s=%d", name2, ntohs(port)); | |
497 | } | |
498 | ||
87fcd70d | 499 | static inline void avc_print_ipv4_addr(struct audit_buffer *ab, __be32 addr, |
b5bf6c55 | 500 | __be16 port, char *name1, char *name2) |
1da177e4 LT |
501 | { |
502 | if (addr) | |
46b86a2d | 503 | audit_log_format(ab, " %s=" NIPQUAD_FMT, name1, NIPQUAD(addr)); |
1da177e4 LT |
504 | if (port) |
505 | audit_log_format(ab, " %s=%d", name2, ntohs(port)); | |
506 | } | |
507 | ||
508 | /** | |
509 | * avc_audit - Audit the granting or denial of permissions. | |
510 | * @ssid: source security identifier | |
511 | * @tsid: target security identifier | |
512 | * @tclass: target security class | |
513 | * @requested: requested permissions | |
514 | * @avd: access vector decisions | |
515 | * @result: result from avc_has_perm_noaudit | |
516 | * @a: auxiliary audit data | |
517 | * | |
518 | * Audit the granting or denial of permissions in accordance | |
519 | * with the policy. This function is typically called by | |
520 | * avc_has_perm() after a permission check, but can also be | |
521 | * called directly by callers who use avc_has_perm_noaudit() | |
522 | * in order to separate the permission check from the auditing. | |
523 | * For example, this separation is useful when the permission check must | |
524 | * be performed under a lock, to allow the lock to be released | |
525 | * before calling the auditing code. | |
526 | */ | |
527 | void avc_audit(u32 ssid, u32 tsid, | |
528 | u16 tclass, u32 requested, | |
529 | struct av_decision *avd, int result, struct avc_audit_data *a) | |
530 | { | |
cd77b821 | 531 | struct task_struct *tsk = current; |
1da177e4 LT |
532 | struct inode *inode = NULL; |
533 | u32 denied, audited; | |
534 | struct audit_buffer *ab; | |
535 | ||
536 | denied = requested & ~avd->allowed; | |
537 | if (denied) { | |
538 | audited = denied; | |
539 | if (!(audited & avd->auditdeny)) | |
540 | return; | |
541 | } else if (result) { | |
542 | audited = denied = requested; | |
543 | } else { | |
544 | audited = requested; | |
545 | if (!(audited & avd->auditallow)) | |
546 | return; | |
547 | } | |
548 | ||
9ad9ad38 | 549 | ab = audit_log_start(current->audit_context, GFP_ATOMIC, AUDIT_AVC); |
1da177e4 LT |
550 | if (!ab) |
551 | return; /* audit_panic has been called */ | |
552 | audit_log_format(ab, "avc: %s ", denied ? "denied" : "granted"); | |
553 | avc_dump_av(ab, tclass,audited); | |
554 | audit_log_format(ab, " for "); | |
cd77b821 DW |
555 | if (a && a->tsk) |
556 | tsk = a->tsk; | |
7b5d781c | 557 | if (tsk && tsk->pid) { |
cd77b821 DW |
558 | audit_log_format(ab, " pid=%d comm=", tsk->pid); |
559 | audit_log_untrustedstring(ab, tsk->comm); | |
560 | } | |
1da177e4 LT |
561 | if (a) { |
562 | switch (a->type) { | |
563 | case AVC_AUDIT_DATA_IPC: | |
564 | audit_log_format(ab, " key=%d", a->u.ipc_id); | |
565 | break; | |
566 | case AVC_AUDIT_DATA_CAP: | |
567 | audit_log_format(ab, " capability=%d", a->u.cap); | |
568 | break; | |
569 | case AVC_AUDIT_DATA_FS: | |
570 | if (a->u.fs.dentry) { | |
571 | struct dentry *dentry = a->u.fs.dentry; | |
01116105 SS |
572 | if (a->u.fs.mnt) |
573 | audit_avc_path(dentry, a->u.fs.mnt); | |
37ca5389 SS |
574 | audit_log_format(ab, " name="); |
575 | audit_log_untrustedstring(ab, dentry->d_name.name); | |
1da177e4 LT |
576 | inode = dentry->d_inode; |
577 | } else if (a->u.fs.inode) { | |
578 | struct dentry *dentry; | |
579 | inode = a->u.fs.inode; | |
580 | dentry = d_find_alias(inode); | |
581 | if (dentry) { | |
37ca5389 SS |
582 | audit_log_format(ab, " name="); |
583 | audit_log_untrustedstring(ab, dentry->d_name.name); | |
1da177e4 LT |
584 | dput(dentry); |
585 | } | |
586 | } | |
587 | if (inode) | |
588 | audit_log_format(ab, " dev=%s ino=%ld", | |
589 | inode->i_sb->s_id, | |
590 | inode->i_ino); | |
591 | break; | |
592 | case AVC_AUDIT_DATA_NET: | |
593 | if (a->u.net.sk) { | |
594 | struct sock *sk = a->u.net.sk; | |
595 | struct unix_sock *u; | |
596 | int len = 0; | |
597 | char *p = NULL; | |
598 | ||
599 | switch (sk->sk_family) { | |
600 | case AF_INET: { | |
601 | struct inet_sock *inet = inet_sk(sk); | |
602 | ||
603 | avc_print_ipv4_addr(ab, inet->rcv_saddr, | |
604 | inet->sport, | |
605 | "laddr", "lport"); | |
606 | avc_print_ipv4_addr(ab, inet->daddr, | |
607 | inet->dport, | |
608 | "faddr", "fport"); | |
609 | break; | |
610 | } | |
611 | case AF_INET6: { | |
612 | struct inet_sock *inet = inet_sk(sk); | |
613 | struct ipv6_pinfo *inet6 = inet6_sk(sk); | |
614 | ||
615 | avc_print_ipv6_addr(ab, &inet6->rcv_saddr, | |
616 | inet->sport, | |
617 | "laddr", "lport"); | |
618 | avc_print_ipv6_addr(ab, &inet6->daddr, | |
619 | inet->dport, | |
620 | "faddr", "fport"); | |
621 | break; | |
622 | } | |
623 | case AF_UNIX: | |
624 | u = unix_sk(sk); | |
625 | if (u->dentry) { | |
01116105 | 626 | audit_avc_path(u->dentry, u->mnt); |
37ca5389 SS |
627 | audit_log_format(ab, " name="); |
628 | audit_log_untrustedstring(ab, u->dentry->d_name.name); | |
1da177e4 LT |
629 | break; |
630 | } | |
631 | if (!u->addr) | |
632 | break; | |
633 | len = u->addr->len-sizeof(short); | |
634 | p = &u->addr->name->sun_path[0]; | |
37ca5389 | 635 | audit_log_format(ab, " path="); |
1da177e4 | 636 | if (*p) |
37ca5389 | 637 | audit_log_untrustedstring(ab, p); |
1da177e4 | 638 | else |
37ca5389 | 639 | audit_log_hex(ab, p, len); |
1da177e4 LT |
640 | break; |
641 | } | |
642 | } | |
643 | ||
644 | switch (a->u.net.family) { | |
645 | case AF_INET: | |
646 | avc_print_ipv4_addr(ab, a->u.net.v4info.saddr, | |
647 | a->u.net.sport, | |
648 | "saddr", "src"); | |
649 | avc_print_ipv4_addr(ab, a->u.net.v4info.daddr, | |
650 | a->u.net.dport, | |
651 | "daddr", "dest"); | |
652 | break; | |
653 | case AF_INET6: | |
654 | avc_print_ipv6_addr(ab, &a->u.net.v6info.saddr, | |
655 | a->u.net.sport, | |
656 | "saddr", "src"); | |
657 | avc_print_ipv6_addr(ab, &a->u.net.v6info.daddr, | |
658 | a->u.net.dport, | |
659 | "daddr", "dest"); | |
660 | break; | |
661 | } | |
662 | if (a->u.net.netif) | |
663 | audit_log_format(ab, " netif=%s", | |
664 | a->u.net.netif); | |
665 | break; | |
666 | } | |
667 | } | |
668 | audit_log_format(ab, " "); | |
669 | avc_dump_query(ab, ssid, tsid, tclass); | |
670 | audit_log_end(ab); | |
671 | } | |
672 | ||
673 | /** | |
674 | * avc_add_callback - Register a callback for security events. | |
675 | * @callback: callback function | |
676 | * @events: security events | |
677 | * @ssid: source security identifier or %SECSID_WILD | |
678 | * @tsid: target security identifier or %SECSID_WILD | |
679 | * @tclass: target security class | |
680 | * @perms: permissions | |
681 | * | |
682 | * Register a callback function for events in the set @events | |
683 | * related to the SID pair (@ssid, @tsid) and | |
684 | * and the permissions @perms, interpreting | |
685 | * @perms based on @tclass. Returns %0 on success or | |
686 | * -%ENOMEM if insufficient memory exists to add the callback. | |
687 | */ | |
688 | int avc_add_callback(int (*callback)(u32 event, u32 ssid, u32 tsid, | |
689 | u16 tclass, u32 perms, | |
690 | u32 *out_retained), | |
691 | u32 events, u32 ssid, u32 tsid, | |
692 | u16 tclass, u32 perms) | |
693 | { | |
694 | struct avc_callback_node *c; | |
695 | int rc = 0; | |
696 | ||
697 | c = kmalloc(sizeof(*c), GFP_ATOMIC); | |
698 | if (!c) { | |
699 | rc = -ENOMEM; | |
700 | goto out; | |
701 | } | |
702 | ||
703 | c->callback = callback; | |
704 | c->events = events; | |
705 | c->ssid = ssid; | |
706 | c->tsid = tsid; | |
707 | c->perms = perms; | |
708 | c->next = avc_callbacks; | |
709 | avc_callbacks = c; | |
710 | out: | |
711 | return rc; | |
712 | } | |
713 | ||
714 | static inline int avc_sidcmp(u32 x, u32 y) | |
715 | { | |
716 | return (x == y || x == SECSID_WILD || y == SECSID_WILD); | |
717 | } | |
718 | ||
719 | /** | |
720 | * avc_update_node Update an AVC entry | |
721 | * @event : Updating event | |
722 | * @perms : Permission mask bits | |
723 | * @ssid,@tsid,@tclass : identifier of an AVC entry | |
724 | * | |
725 | * if a valid AVC entry doesn't exist,this function returns -ENOENT. | |
726 | * if kmalloc() called internal returns NULL, this function returns -ENOMEM. | |
727 | * otherwise, this function update the AVC entry. The original AVC-entry object | |
728 | * will release later by RCU. | |
729 | */ | |
730 | static int avc_update_node(u32 event, u32 perms, u32 ssid, u32 tsid, u16 tclass) | |
731 | { | |
732 | int hvalue, rc = 0; | |
733 | unsigned long flag; | |
734 | struct avc_node *pos, *node, *orig = NULL; | |
735 | ||
736 | node = avc_alloc_node(); | |
737 | if (!node) { | |
738 | rc = -ENOMEM; | |
739 | goto out; | |
740 | } | |
741 | ||
742 | /* Lock the target slot */ | |
743 | hvalue = avc_hash(ssid, tsid, tclass); | |
744 | spin_lock_irqsave(&avc_cache.slots_lock[hvalue], flag); | |
745 | ||
746 | list_for_each_entry(pos, &avc_cache.slots[hvalue], list){ | |
747 | if ( ssid==pos->ae.ssid && | |
748 | tsid==pos->ae.tsid && | |
749 | tclass==pos->ae.tclass ){ | |
750 | orig = pos; | |
751 | break; | |
752 | } | |
753 | } | |
754 | ||
755 | if (!orig) { | |
756 | rc = -ENOENT; | |
757 | avc_node_kill(node); | |
758 | goto out_unlock; | |
759 | } | |
760 | ||
761 | /* | |
762 | * Copy and replace original node. | |
763 | */ | |
764 | ||
765 | avc_node_populate(node, ssid, tsid, tclass, &orig->ae); | |
766 | ||
767 | switch (event) { | |
768 | case AVC_CALLBACK_GRANT: | |
769 | node->ae.avd.allowed |= perms; | |
770 | break; | |
771 | case AVC_CALLBACK_TRY_REVOKE: | |
772 | case AVC_CALLBACK_REVOKE: | |
773 | node->ae.avd.allowed &= ~perms; | |
774 | break; | |
775 | case AVC_CALLBACK_AUDITALLOW_ENABLE: | |
776 | node->ae.avd.auditallow |= perms; | |
777 | break; | |
778 | case AVC_CALLBACK_AUDITALLOW_DISABLE: | |
779 | node->ae.avd.auditallow &= ~perms; | |
780 | break; | |
781 | case AVC_CALLBACK_AUDITDENY_ENABLE: | |
782 | node->ae.avd.auditdeny |= perms; | |
783 | break; | |
784 | case AVC_CALLBACK_AUDITDENY_DISABLE: | |
785 | node->ae.avd.auditdeny &= ~perms; | |
786 | break; | |
787 | } | |
788 | avc_node_replace(node, orig); | |
789 | out_unlock: | |
790 | spin_unlock_irqrestore(&avc_cache.slots_lock[hvalue], flag); | |
791 | out: | |
792 | return rc; | |
793 | } | |
794 | ||
795 | /** | |
796 | * avc_ss_reset - Flush the cache and revalidate migrated permissions. | |
797 | * @seqno: policy sequence number | |
798 | */ | |
799 | int avc_ss_reset(u32 seqno) | |
800 | { | |
801 | struct avc_callback_node *c; | |
376bd9cb | 802 | int i, rc = 0, tmprc; |
1da177e4 LT |
803 | unsigned long flag; |
804 | struct avc_node *node; | |
805 | ||
806 | for (i = 0; i < AVC_CACHE_SLOTS; i++) { | |
807 | spin_lock_irqsave(&avc_cache.slots_lock[i], flag); | |
808 | list_for_each_entry(node, &avc_cache.slots[i], list) | |
809 | avc_node_delete(node); | |
810 | spin_unlock_irqrestore(&avc_cache.slots_lock[i], flag); | |
811 | } | |
812 | ||
813 | for (c = avc_callbacks; c; c = c->next) { | |
814 | if (c->events & AVC_CALLBACK_RESET) { | |
376bd9cb DG |
815 | tmprc = c->callback(AVC_CALLBACK_RESET, |
816 | 0, 0, 0, 0, NULL); | |
817 | /* save the first error encountered for the return | |
818 | value and continue processing the callbacks */ | |
819 | if (!rc) | |
820 | rc = tmprc; | |
1da177e4 LT |
821 | } |
822 | } | |
823 | ||
824 | avc_latest_notif_update(seqno, 0); | |
1da177e4 LT |
825 | return rc; |
826 | } | |
827 | ||
828 | /** | |
829 | * avc_has_perm_noaudit - Check permissions but perform no auditing. | |
830 | * @ssid: source security identifier | |
831 | * @tsid: target security identifier | |
832 | * @tclass: target security class | |
833 | * @requested: requested permissions, interpreted based on @tclass | |
834 | * @avd: access vector decisions | |
835 | * | |
836 | * Check the AVC to determine whether the @requested permissions are granted | |
837 | * for the SID pair (@ssid, @tsid), interpreting the permissions | |
838 | * based on @tclass, and call the security server on a cache miss to obtain | |
839 | * a new decision and add it to the cache. Return a copy of the decisions | |
840 | * in @avd. Return %0 if all @requested permissions are granted, | |
841 | * -%EACCES if any permissions are denied, or another -errno upon | |
842 | * other errors. This function is typically called by avc_has_perm(), | |
843 | * but may also be called directly to separate permission checking from | |
844 | * auditing, e.g. in cases where a lock must be held for the check but | |
845 | * should be released for the auditing. | |
846 | */ | |
847 | int avc_has_perm_noaudit(u32 ssid, u32 tsid, | |
848 | u16 tclass, u32 requested, | |
849 | struct av_decision *avd) | |
850 | { | |
851 | struct avc_node *node; | |
852 | struct avc_entry entry, *p_ae; | |
853 | int rc = 0; | |
854 | u32 denied; | |
855 | ||
856 | rcu_read_lock(); | |
857 | ||
858 | node = avc_lookup(ssid, tsid, tclass, requested); | |
859 | if (!node) { | |
860 | rcu_read_unlock(); | |
861 | rc = security_compute_av(ssid,tsid,tclass,requested,&entry.avd); | |
862 | if (rc) | |
863 | goto out; | |
864 | rcu_read_lock(); | |
865 | node = avc_insert(ssid,tsid,tclass,&entry); | |
866 | } | |
867 | ||
868 | p_ae = node ? &node->ae : &entry; | |
869 | ||
870 | if (avd) | |
871 | memcpy(avd, &p_ae->avd, sizeof(*avd)); | |
872 | ||
873 | denied = requested & ~(p_ae->avd.allowed); | |
874 | ||
875 | if (!requested || denied) { | |
876 | if (selinux_enforcing) | |
877 | rc = -EACCES; | |
878 | else | |
879 | if (node) | |
880 | avc_update_node(AVC_CALLBACK_GRANT,requested, | |
881 | ssid,tsid,tclass); | |
882 | } | |
883 | ||
884 | rcu_read_unlock(); | |
885 | out: | |
886 | return rc; | |
887 | } | |
888 | ||
889 | /** | |
890 | * avc_has_perm - Check permissions and perform any appropriate auditing. | |
891 | * @ssid: source security identifier | |
892 | * @tsid: target security identifier | |
893 | * @tclass: target security class | |
894 | * @requested: requested permissions, interpreted based on @tclass | |
895 | * @auditdata: auxiliary audit data | |
896 | * | |
897 | * Check the AVC to determine whether the @requested permissions are granted | |
898 | * for the SID pair (@ssid, @tsid), interpreting the permissions | |
899 | * based on @tclass, and call the security server on a cache miss to obtain | |
900 | * a new decision and add it to the cache. Audit the granting or denial of | |
901 | * permissions in accordance with the policy. Return %0 if all @requested | |
902 | * permissions are granted, -%EACCES if any permissions are denied, or | |
903 | * another -errno upon other errors. | |
904 | */ | |
905 | int avc_has_perm(u32 ssid, u32 tsid, u16 tclass, | |
906 | u32 requested, struct avc_audit_data *auditdata) | |
907 | { | |
908 | struct av_decision avd; | |
909 | int rc; | |
910 | ||
911 | rc = avc_has_perm_noaudit(ssid, tsid, tclass, requested, &avd); | |
912 | avc_audit(ssid, tsid, tclass, requested, &avd, rc, auditdata); | |
913 | return rc; | |
914 | } |