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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> | |
95fff33b | 5 | * James Morris <jmorris@redhat.com> |
1da177e4 LT |
6 | * |
7 | * Update: KaiGai, Kohei <kaigai@ak.jp.nec.com> | |
95fff33b | 8 | * Replaced the avc_lock spinlock by RCU. |
1da177e4 LT |
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, | |
95fff33b | 14 | * as published by the Free Software Foundation. |
1da177e4 LT |
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 | 46 | |
95fff33b | 47 | #define TB_(s) static const char *s[] = { |
1da177e4 LT |
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 | |
95fff33b | 75 | #define avc_cache_stats_incr(field) \ |
1da177e4 LT |
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; | |
95fff33b | 95 | struct rcu_head rhead; |
1da177e4 LT |
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, | |
95fff33b EP |
108 | u16 tclass, u32 perms, |
109 | u32 *out_retained); | |
1da177e4 LT |
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 | ||
95fff33b | 205 | rc = security_sid_to_context(ssid, &scontext, &scontext_len); |
1da177e4 LT |
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 | } | |
a764ae4b SS |
220 | |
221 | BUG_ON(tclass >= ARRAY_SIZE(class_to_string) || !class_to_string[tclass]); | |
1da177e4 LT |
222 | audit_log_format(ab, " tclass=%s", class_to_string[tclass]); |
223 | } | |
224 | ||
225 | /** | |
226 | * avc_init - Initialize the AVC. | |
227 | * | |
228 | * Initialize the access vector cache. | |
229 | */ | |
230 | void __init avc_init(void) | |
231 | { | |
232 | int i; | |
233 | ||
234 | for (i = 0; i < AVC_CACHE_SLOTS; i++) { | |
235 | INIT_LIST_HEAD(&avc_cache.slots[i]); | |
236 | spin_lock_init(&avc_cache.slots_lock[i]); | |
237 | } | |
238 | atomic_set(&avc_cache.active_nodes, 0); | |
239 | atomic_set(&avc_cache.lru_hint, 0); | |
240 | ||
241 | avc_node_cachep = kmem_cache_create("avc_node", sizeof(struct avc_node), | |
20c2df83 | 242 | 0, SLAB_PANIC, NULL); |
1da177e4 | 243 | |
9ad9ad38 | 244 | audit_log(current->audit_context, GFP_KERNEL, AUDIT_KERNEL, "AVC INITIALIZED\n"); |
1da177e4 LT |
245 | } |
246 | ||
247 | int avc_get_hash_stats(char *page) | |
248 | { | |
249 | int i, chain_len, max_chain_len, slots_used; | |
250 | struct avc_node *node; | |
251 | ||
252 | rcu_read_lock(); | |
253 | ||
254 | slots_used = 0; | |
255 | max_chain_len = 0; | |
256 | for (i = 0; i < AVC_CACHE_SLOTS; i++) { | |
257 | if (!list_empty(&avc_cache.slots[i])) { | |
258 | slots_used++; | |
259 | chain_len = 0; | |
260 | list_for_each_entry_rcu(node, &avc_cache.slots[i], list) | |
261 | chain_len++; | |
262 | if (chain_len > max_chain_len) | |
263 | max_chain_len = chain_len; | |
264 | } | |
265 | } | |
266 | ||
267 | rcu_read_unlock(); | |
268 | ||
269 | return scnprintf(page, PAGE_SIZE, "entries: %d\nbuckets used: %d/%d\n" | |
270 | "longest chain: %d\n", | |
271 | atomic_read(&avc_cache.active_nodes), | |
272 | slots_used, AVC_CACHE_SLOTS, max_chain_len); | |
273 | } | |
274 | ||
275 | static void avc_node_free(struct rcu_head *rhead) | |
276 | { | |
277 | struct avc_node *node = container_of(rhead, struct avc_node, rhead); | |
278 | kmem_cache_free(avc_node_cachep, node); | |
279 | avc_cache_stats_incr(frees); | |
280 | } | |
281 | ||
282 | static void avc_node_delete(struct avc_node *node) | |
283 | { | |
284 | list_del_rcu(&node->list); | |
285 | call_rcu(&node->rhead, avc_node_free); | |
286 | atomic_dec(&avc_cache.active_nodes); | |
287 | } | |
288 | ||
289 | static void avc_node_kill(struct avc_node *node) | |
290 | { | |
291 | kmem_cache_free(avc_node_cachep, node); | |
292 | avc_cache_stats_incr(frees); | |
293 | atomic_dec(&avc_cache.active_nodes); | |
294 | } | |
295 | ||
296 | static void avc_node_replace(struct avc_node *new, struct avc_node *old) | |
297 | { | |
298 | list_replace_rcu(&old->list, &new->list); | |
299 | call_rcu(&old->rhead, avc_node_free); | |
300 | atomic_dec(&avc_cache.active_nodes); | |
301 | } | |
302 | ||
303 | static inline int avc_reclaim_node(void) | |
304 | { | |
305 | struct avc_node *node; | |
306 | int hvalue, try, ecx; | |
307 | unsigned long flags; | |
308 | ||
95fff33b | 309 | for (try = 0, ecx = 0; try < AVC_CACHE_SLOTS; try++) { |
1da177e4 LT |
310 | hvalue = atomic_inc_return(&avc_cache.lru_hint) & (AVC_CACHE_SLOTS - 1); |
311 | ||
312 | if (!spin_trylock_irqsave(&avc_cache.slots_lock[hvalue], flags)) | |
313 | continue; | |
314 | ||
61844250 | 315 | rcu_read_lock(); |
1da177e4 LT |
316 | list_for_each_entry(node, &avc_cache.slots[hvalue], list) { |
317 | if (atomic_dec_and_test(&node->ae.used)) { | |
318 | /* Recently Unused */ | |
319 | avc_node_delete(node); | |
320 | avc_cache_stats_incr(reclaims); | |
321 | ecx++; | |
322 | if (ecx >= AVC_CACHE_RECLAIM) { | |
61844250 | 323 | rcu_read_unlock(); |
1da177e4 LT |
324 | spin_unlock_irqrestore(&avc_cache.slots_lock[hvalue], flags); |
325 | goto out; | |
326 | } | |
327 | } | |
328 | } | |
61844250 | 329 | rcu_read_unlock(); |
1da177e4 LT |
330 | spin_unlock_irqrestore(&avc_cache.slots_lock[hvalue], flags); |
331 | } | |
332 | out: | |
333 | return ecx; | |
334 | } | |
335 | ||
336 | static struct avc_node *avc_alloc_node(void) | |
337 | { | |
338 | struct avc_node *node; | |
339 | ||
c3762229 | 340 | node = kmem_cache_zalloc(avc_node_cachep, GFP_ATOMIC); |
1da177e4 LT |
341 | if (!node) |
342 | goto out; | |
343 | ||
1da177e4 LT |
344 | INIT_RCU_HEAD(&node->rhead); |
345 | INIT_LIST_HEAD(&node->list); | |
346 | atomic_set(&node->ae.used, 1); | |
347 | avc_cache_stats_incr(allocations); | |
348 | ||
349 | if (atomic_inc_return(&avc_cache.active_nodes) > avc_cache_threshold) | |
350 | avc_reclaim_node(); | |
351 | ||
352 | out: | |
353 | return node; | |
354 | } | |
355 | ||
356 | static void avc_node_populate(struct avc_node *node, u32 ssid, u32 tsid, u16 tclass, struct avc_entry *ae) | |
357 | { | |
358 | node->ae.ssid = ssid; | |
359 | node->ae.tsid = tsid; | |
360 | node->ae.tclass = tclass; | |
361 | memcpy(&node->ae.avd, &ae->avd, sizeof(node->ae.avd)); | |
362 | } | |
363 | ||
364 | static inline struct avc_node *avc_search_node(u32 ssid, u32 tsid, u16 tclass) | |
365 | { | |
366 | struct avc_node *node, *ret = NULL; | |
367 | int hvalue; | |
368 | ||
369 | hvalue = avc_hash(ssid, tsid, tclass); | |
370 | list_for_each_entry_rcu(node, &avc_cache.slots[hvalue], list) { | |
371 | if (ssid == node->ae.ssid && | |
372 | tclass == node->ae.tclass && | |
373 | tsid == node->ae.tsid) { | |
374 | ret = node; | |
375 | break; | |
376 | } | |
377 | } | |
378 | ||
379 | if (ret == NULL) { | |
380 | /* cache miss */ | |
381 | goto out; | |
382 | } | |
383 | ||
384 | /* cache hit */ | |
385 | if (atomic_read(&ret->ae.used) != 1) | |
386 | atomic_set(&ret->ae.used, 1); | |
387 | out: | |
388 | return ret; | |
389 | } | |
390 | ||
391 | /** | |
392 | * avc_lookup - Look up an AVC entry. | |
393 | * @ssid: source security identifier | |
394 | * @tsid: target security identifier | |
395 | * @tclass: target security class | |
396 | * @requested: requested permissions, interpreted based on @tclass | |
397 | * | |
398 | * Look up an AVC entry that is valid for the | |
399 | * @requested permissions between the SID pair | |
400 | * (@ssid, @tsid), interpreting the permissions | |
401 | * based on @tclass. If a valid AVC entry exists, | |
402 | * then this function return the avc_node. | |
403 | * Otherwise, this function returns NULL. | |
404 | */ | |
405 | static struct avc_node *avc_lookup(u32 ssid, u32 tsid, u16 tclass, u32 requested) | |
406 | { | |
407 | struct avc_node *node; | |
408 | ||
409 | avc_cache_stats_incr(lookups); | |
410 | node = avc_search_node(ssid, tsid, tclass); | |
411 | ||
412 | if (node && ((node->ae.avd.decided & requested) == requested)) { | |
413 | avc_cache_stats_incr(hits); | |
414 | goto out; | |
415 | } | |
416 | ||
417 | node = NULL; | |
418 | avc_cache_stats_incr(misses); | |
419 | out: | |
420 | return node; | |
421 | } | |
422 | ||
423 | static int avc_latest_notif_update(int seqno, int is_insert) | |
424 | { | |
425 | int ret = 0; | |
426 | static DEFINE_SPINLOCK(notif_lock); | |
427 | unsigned long flag; | |
428 | ||
429 | spin_lock_irqsave(¬if_lock, flag); | |
430 | if (is_insert) { | |
431 | if (seqno < avc_cache.latest_notif) { | |
744ba35e | 432 | printk(KERN_WARNING "SELinux: avc: seqno %d < latest_notif %d\n", |
1da177e4 LT |
433 | seqno, avc_cache.latest_notif); |
434 | ret = -EAGAIN; | |
435 | } | |
436 | } else { | |
437 | if (seqno > avc_cache.latest_notif) | |
438 | avc_cache.latest_notif = seqno; | |
439 | } | |
440 | spin_unlock_irqrestore(¬if_lock, flag); | |
441 | ||
442 | return ret; | |
443 | } | |
444 | ||
445 | /** | |
446 | * avc_insert - Insert an AVC entry. | |
447 | * @ssid: source security identifier | |
448 | * @tsid: target security identifier | |
449 | * @tclass: target security class | |
450 | * @ae: AVC entry | |
451 | * | |
452 | * Insert an AVC entry for the SID pair | |
453 | * (@ssid, @tsid) and class @tclass. | |
454 | * The access vectors and the sequence number are | |
455 | * normally provided by the security server in | |
456 | * response to a security_compute_av() call. If the | |
457 | * sequence number @ae->avd.seqno is not less than the latest | |
458 | * revocation notification, then the function copies | |
459 | * the access vectors into a cache entry, returns | |
460 | * avc_node inserted. Otherwise, this function returns NULL. | |
461 | */ | |
462 | static struct avc_node *avc_insert(u32 ssid, u32 tsid, u16 tclass, struct avc_entry *ae) | |
463 | { | |
464 | struct avc_node *pos, *node = NULL; | |
465 | int hvalue; | |
466 | unsigned long flag; | |
467 | ||
468 | if (avc_latest_notif_update(ae->avd.seqno, 1)) | |
469 | goto out; | |
470 | ||
471 | node = avc_alloc_node(); | |
472 | if (node) { | |
473 | hvalue = avc_hash(ssid, tsid, tclass); | |
474 | avc_node_populate(node, ssid, tsid, tclass, ae); | |
475 | ||
476 | spin_lock_irqsave(&avc_cache.slots_lock[hvalue], flag); | |
477 | list_for_each_entry(pos, &avc_cache.slots[hvalue], list) { | |
478 | if (pos->ae.ssid == ssid && | |
479 | pos->ae.tsid == tsid && | |
480 | pos->ae.tclass == tclass) { | |
95fff33b | 481 | avc_node_replace(node, pos); |
1da177e4 LT |
482 | goto found; |
483 | } | |
484 | } | |
485 | list_add_rcu(&node->list, &avc_cache.slots[hvalue]); | |
486 | found: | |
487 | spin_unlock_irqrestore(&avc_cache.slots_lock[hvalue], flag); | |
488 | } | |
489 | out: | |
490 | return node; | |
491 | } | |
492 | ||
493 | static inline void avc_print_ipv6_addr(struct audit_buffer *ab, | |
b5bf6c55 | 494 | struct in6_addr *addr, __be16 port, |
1da177e4 LT |
495 | char *name1, char *name2) |
496 | { | |
497 | if (!ipv6_addr_any(addr)) | |
46b86a2d | 498 | audit_log_format(ab, " %s=" NIP6_FMT, name1, NIP6(*addr)); |
1da177e4 LT |
499 | if (port) |
500 | audit_log_format(ab, " %s=%d", name2, ntohs(port)); | |
501 | } | |
502 | ||
87fcd70d | 503 | static inline void avc_print_ipv4_addr(struct audit_buffer *ab, __be32 addr, |
b5bf6c55 | 504 | __be16 port, char *name1, char *name2) |
1da177e4 LT |
505 | { |
506 | if (addr) | |
46b86a2d | 507 | audit_log_format(ab, " %s=" NIPQUAD_FMT, name1, NIPQUAD(addr)); |
1da177e4 LT |
508 | if (port) |
509 | audit_log_format(ab, " %s=%d", name2, ntohs(port)); | |
510 | } | |
511 | ||
512 | /** | |
513 | * avc_audit - Audit the granting or denial of permissions. | |
514 | * @ssid: source security identifier | |
515 | * @tsid: target security identifier | |
516 | * @tclass: target security class | |
517 | * @requested: requested permissions | |
518 | * @avd: access vector decisions | |
519 | * @result: result from avc_has_perm_noaudit | |
520 | * @a: auxiliary audit data | |
521 | * | |
522 | * Audit the granting or denial of permissions in accordance | |
523 | * with the policy. This function is typically called by | |
524 | * avc_has_perm() after a permission check, but can also be | |
525 | * called directly by callers who use avc_has_perm_noaudit() | |
526 | * in order to separate the permission check from the auditing. | |
527 | * For example, this separation is useful when the permission check must | |
528 | * be performed under a lock, to allow the lock to be released | |
529 | * before calling the auditing code. | |
530 | */ | |
531 | void avc_audit(u32 ssid, u32 tsid, | |
95fff33b EP |
532 | u16 tclass, u32 requested, |
533 | struct av_decision *avd, int result, struct avc_audit_data *a) | |
1da177e4 | 534 | { |
cd77b821 | 535 | struct task_struct *tsk = current; |
1da177e4 LT |
536 | struct inode *inode = NULL; |
537 | u32 denied, audited; | |
538 | struct audit_buffer *ab; | |
539 | ||
540 | denied = requested & ~avd->allowed; | |
541 | if (denied) { | |
542 | audited = denied; | |
543 | if (!(audited & avd->auditdeny)) | |
544 | return; | |
545 | } else if (result) { | |
546 | audited = denied = requested; | |
95fff33b | 547 | } else { |
1da177e4 LT |
548 | audited = requested; |
549 | if (!(audited & avd->auditallow)) | |
550 | return; | |
551 | } | |
552 | ||
9ad9ad38 | 553 | ab = audit_log_start(current->audit_context, GFP_ATOMIC, AUDIT_AVC); |
1da177e4 LT |
554 | if (!ab) |
555 | return; /* audit_panic has been called */ | |
556 | audit_log_format(ab, "avc: %s ", denied ? "denied" : "granted"); | |
95fff33b | 557 | avc_dump_av(ab, tclass, audited); |
1da177e4 | 558 | audit_log_format(ab, " for "); |
cd77b821 DW |
559 | if (a && a->tsk) |
560 | tsk = a->tsk; | |
7b5d781c | 561 | if (tsk && tsk->pid) { |
cd77b821 DW |
562 | audit_log_format(ab, " pid=%d comm=", tsk->pid); |
563 | audit_log_untrustedstring(ab, tsk->comm); | |
564 | } | |
1da177e4 LT |
565 | if (a) { |
566 | switch (a->type) { | |
567 | case AVC_AUDIT_DATA_IPC: | |
568 | audit_log_format(ab, " key=%d", a->u.ipc_id); | |
569 | break; | |
570 | case AVC_AUDIT_DATA_CAP: | |
571 | audit_log_format(ab, " capability=%d", a->u.cap); | |
572 | break; | |
573 | case AVC_AUDIT_DATA_FS: | |
44707fdf JB |
574 | if (a->u.fs.path.dentry) { |
575 | struct dentry *dentry = a->u.fs.path.dentry; | |
576 | if (a->u.fs.path.mnt) { | |
577 | audit_log_d_path(ab, "path=", | |
578 | &a->u.fs.path); | |
4259fa01 AV |
579 | } else { |
580 | audit_log_format(ab, " name="); | |
581 | audit_log_untrustedstring(ab, dentry->d_name.name); | |
582 | } | |
1da177e4 LT |
583 | inode = dentry->d_inode; |
584 | } else if (a->u.fs.inode) { | |
585 | struct dentry *dentry; | |
586 | inode = a->u.fs.inode; | |
587 | dentry = d_find_alias(inode); | |
588 | if (dentry) { | |
37ca5389 SS |
589 | audit_log_format(ab, " name="); |
590 | audit_log_untrustedstring(ab, dentry->d_name.name); | |
1da177e4 LT |
591 | dput(dentry); |
592 | } | |
593 | } | |
594 | if (inode) | |
13bddc2e | 595 | audit_log_format(ab, " dev=%s ino=%lu", |
1da177e4 LT |
596 | inode->i_sb->s_id, |
597 | inode->i_ino); | |
598 | break; | |
599 | case AVC_AUDIT_DATA_NET: | |
600 | if (a->u.net.sk) { | |
601 | struct sock *sk = a->u.net.sk; | |
602 | struct unix_sock *u; | |
603 | int len = 0; | |
604 | char *p = NULL; | |
605 | ||
606 | switch (sk->sk_family) { | |
607 | case AF_INET: { | |
608 | struct inet_sock *inet = inet_sk(sk); | |
609 | ||
610 | avc_print_ipv4_addr(ab, inet->rcv_saddr, | |
611 | inet->sport, | |
612 | "laddr", "lport"); | |
613 | avc_print_ipv4_addr(ab, inet->daddr, | |
614 | inet->dport, | |
615 | "faddr", "fport"); | |
616 | break; | |
617 | } | |
618 | case AF_INET6: { | |
619 | struct inet_sock *inet = inet_sk(sk); | |
620 | struct ipv6_pinfo *inet6 = inet6_sk(sk); | |
621 | ||
622 | avc_print_ipv6_addr(ab, &inet6->rcv_saddr, | |
623 | inet->sport, | |
624 | "laddr", "lport"); | |
625 | avc_print_ipv6_addr(ab, &inet6->daddr, | |
626 | inet->dport, | |
627 | "faddr", "fport"); | |
628 | break; | |
629 | } | |
630 | case AF_UNIX: | |
631 | u = unix_sk(sk); | |
632 | if (u->dentry) { | |
44707fdf JB |
633 | struct path path = { |
634 | .dentry = u->dentry, | |
635 | .mnt = u->mnt | |
636 | }; | |
4259fa01 | 637 | audit_log_d_path(ab, "path=", |
44707fdf | 638 | &path); |
1da177e4 LT |
639 | break; |
640 | } | |
641 | if (!u->addr) | |
642 | break; | |
643 | len = u->addr->len-sizeof(short); | |
644 | p = &u->addr->name->sun_path[0]; | |
37ca5389 | 645 | audit_log_format(ab, " path="); |
1da177e4 | 646 | if (*p) |
37ca5389 | 647 | audit_log_untrustedstring(ab, p); |
1da177e4 | 648 | else |
b556f8ad | 649 | audit_log_n_hex(ab, p, len); |
1da177e4 LT |
650 | break; |
651 | } | |
652 | } | |
95fff33b | 653 | |
1da177e4 LT |
654 | switch (a->u.net.family) { |
655 | case AF_INET: | |
656 | avc_print_ipv4_addr(ab, a->u.net.v4info.saddr, | |
657 | a->u.net.sport, | |
658 | "saddr", "src"); | |
659 | avc_print_ipv4_addr(ab, a->u.net.v4info.daddr, | |
660 | a->u.net.dport, | |
661 | "daddr", "dest"); | |
662 | break; | |
663 | case AF_INET6: | |
664 | avc_print_ipv6_addr(ab, &a->u.net.v6info.saddr, | |
665 | a->u.net.sport, | |
666 | "saddr", "src"); | |
667 | avc_print_ipv6_addr(ab, &a->u.net.v6info.daddr, | |
668 | a->u.net.dport, | |
669 | "daddr", "dest"); | |
670 | break; | |
671 | } | |
da5645a2 PM |
672 | if (a->u.net.netif > 0) { |
673 | struct net_device *dev; | |
674 | ||
675 | /* NOTE: we always use init's namespace */ | |
676 | dev = dev_get_by_index(&init_net, | |
677 | a->u.net.netif); | |
678 | if (dev) { | |
679 | audit_log_format(ab, " netif=%s", | |
680 | dev->name); | |
681 | dev_put(dev); | |
682 | } | |
683 | } | |
1da177e4 LT |
684 | break; |
685 | } | |
686 | } | |
687 | audit_log_format(ab, " "); | |
688 | avc_dump_query(ab, ssid, tsid, tclass); | |
689 | audit_log_end(ab); | |
690 | } | |
691 | ||
692 | /** | |
693 | * avc_add_callback - Register a callback for security events. | |
694 | * @callback: callback function | |
695 | * @events: security events | |
696 | * @ssid: source security identifier or %SECSID_WILD | |
697 | * @tsid: target security identifier or %SECSID_WILD | |
698 | * @tclass: target security class | |
699 | * @perms: permissions | |
700 | * | |
701 | * Register a callback function for events in the set @events | |
702 | * related to the SID pair (@ssid, @tsid) and | |
703 | * and the permissions @perms, interpreting | |
704 | * @perms based on @tclass. Returns %0 on success or | |
705 | * -%ENOMEM if insufficient memory exists to add the callback. | |
706 | */ | |
707 | int avc_add_callback(int (*callback)(u32 event, u32 ssid, u32 tsid, | |
95fff33b EP |
708 | u16 tclass, u32 perms, |
709 | u32 *out_retained), | |
710 | u32 events, u32 ssid, u32 tsid, | |
711 | u16 tclass, u32 perms) | |
1da177e4 LT |
712 | { |
713 | struct avc_callback_node *c; | |
714 | int rc = 0; | |
715 | ||
716 | c = kmalloc(sizeof(*c), GFP_ATOMIC); | |
717 | if (!c) { | |
718 | rc = -ENOMEM; | |
719 | goto out; | |
720 | } | |
721 | ||
722 | c->callback = callback; | |
723 | c->events = events; | |
724 | c->ssid = ssid; | |
725 | c->tsid = tsid; | |
726 | c->perms = perms; | |
727 | c->next = avc_callbacks; | |
728 | avc_callbacks = c; | |
729 | out: | |
730 | return rc; | |
731 | } | |
732 | ||
733 | static inline int avc_sidcmp(u32 x, u32 y) | |
734 | { | |
735 | return (x == y || x == SECSID_WILD || y == SECSID_WILD); | |
736 | } | |
737 | ||
738 | /** | |
739 | * avc_update_node Update an AVC entry | |
740 | * @event : Updating event | |
741 | * @perms : Permission mask bits | |
742 | * @ssid,@tsid,@tclass : identifier of an AVC entry | |
743 | * | |
744 | * if a valid AVC entry doesn't exist,this function returns -ENOENT. | |
745 | * if kmalloc() called internal returns NULL, this function returns -ENOMEM. | |
746 | * otherwise, this function update the AVC entry. The original AVC-entry object | |
747 | * will release later by RCU. | |
748 | */ | |
749 | static int avc_update_node(u32 event, u32 perms, u32 ssid, u32 tsid, u16 tclass) | |
750 | { | |
751 | int hvalue, rc = 0; | |
752 | unsigned long flag; | |
753 | struct avc_node *pos, *node, *orig = NULL; | |
754 | ||
755 | node = avc_alloc_node(); | |
756 | if (!node) { | |
757 | rc = -ENOMEM; | |
758 | goto out; | |
759 | } | |
760 | ||
761 | /* Lock the target slot */ | |
762 | hvalue = avc_hash(ssid, tsid, tclass); | |
763 | spin_lock_irqsave(&avc_cache.slots_lock[hvalue], flag); | |
764 | ||
95fff33b EP |
765 | list_for_each_entry(pos, &avc_cache.slots[hvalue], list) { |
766 | if (ssid == pos->ae.ssid && | |
767 | tsid == pos->ae.tsid && | |
768 | tclass == pos->ae.tclass){ | |
1da177e4 LT |
769 | orig = pos; |
770 | break; | |
771 | } | |
772 | } | |
773 | ||
774 | if (!orig) { | |
775 | rc = -ENOENT; | |
776 | avc_node_kill(node); | |
777 | goto out_unlock; | |
778 | } | |
779 | ||
780 | /* | |
781 | * Copy and replace original node. | |
782 | */ | |
783 | ||
784 | avc_node_populate(node, ssid, tsid, tclass, &orig->ae); | |
785 | ||
786 | switch (event) { | |
787 | case AVC_CALLBACK_GRANT: | |
788 | node->ae.avd.allowed |= perms; | |
789 | break; | |
790 | case AVC_CALLBACK_TRY_REVOKE: | |
791 | case AVC_CALLBACK_REVOKE: | |
792 | node->ae.avd.allowed &= ~perms; | |
793 | break; | |
794 | case AVC_CALLBACK_AUDITALLOW_ENABLE: | |
795 | node->ae.avd.auditallow |= perms; | |
796 | break; | |
797 | case AVC_CALLBACK_AUDITALLOW_DISABLE: | |
798 | node->ae.avd.auditallow &= ~perms; | |
799 | break; | |
800 | case AVC_CALLBACK_AUDITDENY_ENABLE: | |
801 | node->ae.avd.auditdeny |= perms; | |
802 | break; | |
803 | case AVC_CALLBACK_AUDITDENY_DISABLE: | |
804 | node->ae.avd.auditdeny &= ~perms; | |
805 | break; | |
806 | } | |
807 | avc_node_replace(node, orig); | |
808 | out_unlock: | |
809 | spin_unlock_irqrestore(&avc_cache.slots_lock[hvalue], flag); | |
810 | out: | |
811 | return rc; | |
812 | } | |
813 | ||
814 | /** | |
815 | * avc_ss_reset - Flush the cache and revalidate migrated permissions. | |
816 | * @seqno: policy sequence number | |
817 | */ | |
818 | int avc_ss_reset(u32 seqno) | |
819 | { | |
820 | struct avc_callback_node *c; | |
376bd9cb | 821 | int i, rc = 0, tmprc; |
1da177e4 LT |
822 | unsigned long flag; |
823 | struct avc_node *node; | |
824 | ||
825 | for (i = 0; i < AVC_CACHE_SLOTS; i++) { | |
826 | spin_lock_irqsave(&avc_cache.slots_lock[i], flag); | |
61844250 PM |
827 | /* |
828 | * With preemptable RCU, the outer spinlock does not | |
829 | * prevent RCU grace periods from ending. | |
830 | */ | |
831 | rcu_read_lock(); | |
1da177e4 LT |
832 | list_for_each_entry(node, &avc_cache.slots[i], list) |
833 | avc_node_delete(node); | |
61844250 | 834 | rcu_read_unlock(); |
1da177e4 LT |
835 | spin_unlock_irqrestore(&avc_cache.slots_lock[i], flag); |
836 | } | |
837 | ||
838 | for (c = avc_callbacks; c; c = c->next) { | |
839 | if (c->events & AVC_CALLBACK_RESET) { | |
376bd9cb | 840 | tmprc = c->callback(AVC_CALLBACK_RESET, |
95fff33b | 841 | 0, 0, 0, 0, NULL); |
376bd9cb DG |
842 | /* save the first error encountered for the return |
843 | value and continue processing the callbacks */ | |
844 | if (!rc) | |
845 | rc = tmprc; | |
1da177e4 LT |
846 | } |
847 | } | |
848 | ||
849 | avc_latest_notif_update(seqno, 0); | |
1da177e4 LT |
850 | return rc; |
851 | } | |
852 | ||
853 | /** | |
854 | * avc_has_perm_noaudit - Check permissions but perform no auditing. | |
855 | * @ssid: source security identifier | |
856 | * @tsid: target security identifier | |
857 | * @tclass: target security class | |
858 | * @requested: requested permissions, interpreted based on @tclass | |
2c3c05db | 859 | * @flags: AVC_STRICT or 0 |
1da177e4 LT |
860 | * @avd: access vector decisions |
861 | * | |
862 | * Check the AVC to determine whether the @requested permissions are granted | |
863 | * for the SID pair (@ssid, @tsid), interpreting the permissions | |
864 | * based on @tclass, and call the security server on a cache miss to obtain | |
865 | * a new decision and add it to the cache. Return a copy of the decisions | |
866 | * in @avd. Return %0 if all @requested permissions are granted, | |
867 | * -%EACCES if any permissions are denied, or another -errno upon | |
868 | * other errors. This function is typically called by avc_has_perm(), | |
869 | * but may also be called directly to separate permission checking from | |
870 | * auditing, e.g. in cases where a lock must be held for the check but | |
871 | * should be released for the auditing. | |
872 | */ | |
873 | int avc_has_perm_noaudit(u32 ssid, u32 tsid, | |
2c3c05db SS |
874 | u16 tclass, u32 requested, |
875 | unsigned flags, | |
876 | struct av_decision *avd) | |
1da177e4 LT |
877 | { |
878 | struct avc_node *node; | |
879 | struct avc_entry entry, *p_ae; | |
880 | int rc = 0; | |
881 | u32 denied; | |
882 | ||
eda4f69c EP |
883 | BUG_ON(!requested); |
884 | ||
1da177e4 LT |
885 | rcu_read_lock(); |
886 | ||
887 | node = avc_lookup(ssid, tsid, tclass, requested); | |
888 | if (!node) { | |
889 | rcu_read_unlock(); | |
95fff33b | 890 | rc = security_compute_av(ssid, tsid, tclass, requested, &entry.avd); |
1da177e4 LT |
891 | if (rc) |
892 | goto out; | |
893 | rcu_read_lock(); | |
95fff33b | 894 | node = avc_insert(ssid, tsid, tclass, &entry); |
1da177e4 LT |
895 | } |
896 | ||
897 | p_ae = node ? &node->ae : &entry; | |
898 | ||
899 | if (avd) | |
900 | memcpy(avd, &p_ae->avd, sizeof(*avd)); | |
901 | ||
902 | denied = requested & ~(p_ae->avd.allowed); | |
903 | ||
eda4f69c | 904 | if (denied) { |
64dbf074 | 905 | if (flags & AVC_STRICT) |
1da177e4 | 906 | rc = -EACCES; |
64dbf074 EP |
907 | else if (!selinux_enforcing || security_permissive_sid(ssid)) |
908 | avc_update_node(AVC_CALLBACK_GRANT, requested, ssid, | |
909 | tsid, tclass); | |
1da177e4 | 910 | else |
64dbf074 | 911 | rc = -EACCES; |
1da177e4 LT |
912 | } |
913 | ||
914 | rcu_read_unlock(); | |
915 | out: | |
916 | return rc; | |
917 | } | |
918 | ||
919 | /** | |
920 | * avc_has_perm - Check permissions and perform any appropriate auditing. | |
921 | * @ssid: source security identifier | |
922 | * @tsid: target security identifier | |
923 | * @tclass: target security class | |
924 | * @requested: requested permissions, interpreted based on @tclass | |
925 | * @auditdata: auxiliary audit data | |
926 | * | |
927 | * Check the AVC to determine whether the @requested permissions are granted | |
928 | * for the SID pair (@ssid, @tsid), interpreting the permissions | |
929 | * based on @tclass, and call the security server on a cache miss to obtain | |
930 | * a new decision and add it to the cache. Audit the granting or denial of | |
931 | * permissions in accordance with the policy. Return %0 if all @requested | |
932 | * permissions are granted, -%EACCES if any permissions are denied, or | |
933 | * another -errno upon other errors. | |
934 | */ | |
935 | int avc_has_perm(u32 ssid, u32 tsid, u16 tclass, | |
95fff33b | 936 | u32 requested, struct avc_audit_data *auditdata) |
1da177e4 LT |
937 | { |
938 | struct av_decision avd; | |
939 | int rc; | |
940 | ||
2c3c05db | 941 | rc = avc_has_perm_noaudit(ssid, tsid, tclass, requested, 0, &avd); |
1da177e4 LT |
942 | avc_audit(ssid, tsid, tclass, requested, &avd, rc, auditdata); |
943 | return rc; | |
944 | } | |
788e7dd4 YN |
945 | |
946 | u32 avc_policy_seqno(void) | |
947 | { | |
948 | return avc_cache.latest_notif; | |
949 | } |