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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[] = { |
76f7ba35 EP |
56 | #define S_(c, i, b) { .tclass = c,\ |
57 | .common_pts = common_##i##_perm_to_string,\ | |
58 | .common_base = b }, | |
1da177e4 LT |
59 | #include "av_inherit.h" |
60 | #undef S_ | |
61 | }; | |
62 | ||
5c458998 | 63 | const struct selinux_class_perm selinux_class_perm = { |
76f7ba35 EP |
64 | .av_perm_to_string = av_perm_to_string, |
65 | .av_pts_len = ARRAY_SIZE(av_perm_to_string), | |
66 | .class_to_string = class_to_string, | |
67 | .cts_len = ARRAY_SIZE(class_to_string), | |
68 | .av_inherit = av_inherit, | |
69 | .av_inherit_len = ARRAY_SIZE(av_inherit) | |
5c458998 CS |
70 | }; |
71 | ||
1da177e4 LT |
72 | #define AVC_CACHE_SLOTS 512 |
73 | #define AVC_DEF_CACHE_THRESHOLD 512 | |
74 | #define AVC_CACHE_RECLAIM 16 | |
75 | ||
76 | #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS | |
95fff33b | 77 | #define avc_cache_stats_incr(field) \ |
1da177e4 LT |
78 | do { \ |
79 | per_cpu(avc_cache_stats, get_cpu()).field++; \ | |
80 | put_cpu(); \ | |
81 | } while (0) | |
82 | #else | |
83 | #define avc_cache_stats_incr(field) do {} while (0) | |
84 | #endif | |
85 | ||
86 | struct avc_entry { | |
87 | u32 ssid; | |
88 | u32 tsid; | |
89 | u16 tclass; | |
90 | struct av_decision avd; | |
91 | atomic_t used; /* used recently */ | |
92 | }; | |
93 | ||
94 | struct avc_node { | |
95 | struct avc_entry ae; | |
96 | struct list_head list; | |
95fff33b | 97 | struct rcu_head rhead; |
1da177e4 LT |
98 | }; |
99 | ||
100 | struct avc_cache { | |
101 | struct list_head slots[AVC_CACHE_SLOTS]; | |
102 | spinlock_t slots_lock[AVC_CACHE_SLOTS]; /* lock for writes */ | |
103 | atomic_t lru_hint; /* LRU hint for reclaim scan */ | |
104 | atomic_t active_nodes; | |
105 | u32 latest_notif; /* latest revocation notification */ | |
106 | }; | |
107 | ||
108 | struct avc_callback_node { | |
109 | int (*callback) (u32 event, u32 ssid, u32 tsid, | |
95fff33b EP |
110 | u16 tclass, u32 perms, |
111 | u32 *out_retained); | |
1da177e4 LT |
112 | u32 events; |
113 | u32 ssid; | |
114 | u32 tsid; | |
115 | u16 tclass; | |
116 | u32 perms; | |
117 | struct avc_callback_node *next; | |
118 | }; | |
119 | ||
120 | /* Exported via selinufs */ | |
121 | unsigned int avc_cache_threshold = AVC_DEF_CACHE_THRESHOLD; | |
122 | ||
123 | #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS | |
124 | DEFINE_PER_CPU(struct avc_cache_stats, avc_cache_stats) = { 0 }; | |
125 | #endif | |
126 | ||
127 | static struct avc_cache avc_cache; | |
128 | static struct avc_callback_node *avc_callbacks; | |
e18b890b | 129 | static struct kmem_cache *avc_node_cachep; |
1da177e4 LT |
130 | |
131 | static inline int avc_hash(u32 ssid, u32 tsid, u16 tclass) | |
132 | { | |
133 | return (ssid ^ (tsid<<2) ^ (tclass<<4)) & (AVC_CACHE_SLOTS - 1); | |
134 | } | |
135 | ||
136 | /** | |
137 | * avc_dump_av - Display an access vector in human-readable form. | |
138 | * @tclass: target security class | |
139 | * @av: access vector | |
140 | */ | |
d9250dea | 141 | void avc_dump_av(struct audit_buffer *ab, u16 tclass, u32 av) |
1da177e4 LT |
142 | { |
143 | const char **common_pts = NULL; | |
144 | u32 common_base = 0; | |
145 | int i, i2, perm; | |
146 | ||
147 | if (av == 0) { | |
148 | audit_log_format(ab, " null"); | |
149 | return; | |
150 | } | |
151 | ||
152 | for (i = 0; i < ARRAY_SIZE(av_inherit); i++) { | |
153 | if (av_inherit[i].tclass == tclass) { | |
154 | common_pts = av_inherit[i].common_pts; | |
155 | common_base = av_inherit[i].common_base; | |
156 | break; | |
157 | } | |
158 | } | |
159 | ||
160 | audit_log_format(ab, " {"); | |
161 | i = 0; | |
162 | perm = 1; | |
163 | while (perm < common_base) { | |
164 | if (perm & av) { | |
165 | audit_log_format(ab, " %s", common_pts[i]); | |
166 | av &= ~perm; | |
167 | } | |
168 | i++; | |
169 | perm <<= 1; | |
170 | } | |
171 | ||
172 | while (i < sizeof(av) * 8) { | |
173 | if (perm & av) { | |
174 | for (i2 = 0; i2 < ARRAY_SIZE(av_perm_to_string); i2++) { | |
175 | if ((av_perm_to_string[i2].tclass == tclass) && | |
176 | (av_perm_to_string[i2].value == perm)) | |
177 | break; | |
178 | } | |
179 | if (i2 < ARRAY_SIZE(av_perm_to_string)) { | |
180 | audit_log_format(ab, " %s", | |
181 | av_perm_to_string[i2].name); | |
182 | av &= ~perm; | |
183 | } | |
184 | } | |
185 | i++; | |
186 | perm <<= 1; | |
187 | } | |
188 | ||
189 | if (av) | |
190 | audit_log_format(ab, " 0x%x", av); | |
191 | ||
192 | audit_log_format(ab, " }"); | |
193 | } | |
194 | ||
195 | /** | |
196 | * avc_dump_query - Display a SID pair and a class in human-readable form. | |
197 | * @ssid: source security identifier | |
198 | * @tsid: target security identifier | |
199 | * @tclass: target security class | |
200 | */ | |
201 | static void avc_dump_query(struct audit_buffer *ab, u32 ssid, u32 tsid, u16 tclass) | |
202 | { | |
203 | int rc; | |
204 | char *scontext; | |
205 | u32 scontext_len; | |
206 | ||
95fff33b | 207 | rc = security_sid_to_context(ssid, &scontext, &scontext_len); |
1da177e4 LT |
208 | if (rc) |
209 | audit_log_format(ab, "ssid=%d", ssid); | |
210 | else { | |
211 | audit_log_format(ab, "scontext=%s", scontext); | |
212 | kfree(scontext); | |
213 | } | |
214 | ||
215 | rc = security_sid_to_context(tsid, &scontext, &scontext_len); | |
216 | if (rc) | |
217 | audit_log_format(ab, " tsid=%d", tsid); | |
218 | else { | |
219 | audit_log_format(ab, " tcontext=%s", scontext); | |
220 | kfree(scontext); | |
221 | } | |
a764ae4b SS |
222 | |
223 | BUG_ON(tclass >= ARRAY_SIZE(class_to_string) || !class_to_string[tclass]); | |
1da177e4 LT |
224 | audit_log_format(ab, " tclass=%s", class_to_string[tclass]); |
225 | } | |
226 | ||
227 | /** | |
228 | * avc_init - Initialize the AVC. | |
229 | * | |
230 | * Initialize the access vector cache. | |
231 | */ | |
232 | void __init avc_init(void) | |
233 | { | |
234 | int i; | |
235 | ||
236 | for (i = 0; i < AVC_CACHE_SLOTS; i++) { | |
237 | INIT_LIST_HEAD(&avc_cache.slots[i]); | |
238 | spin_lock_init(&avc_cache.slots_lock[i]); | |
239 | } | |
240 | atomic_set(&avc_cache.active_nodes, 0); | |
241 | atomic_set(&avc_cache.lru_hint, 0); | |
242 | ||
243 | avc_node_cachep = kmem_cache_create("avc_node", sizeof(struct avc_node), | |
20c2df83 | 244 | 0, SLAB_PANIC, NULL); |
1da177e4 | 245 | |
9ad9ad38 | 246 | audit_log(current->audit_context, GFP_KERNEL, AUDIT_KERNEL, "AVC INITIALIZED\n"); |
1da177e4 LT |
247 | } |
248 | ||
249 | int avc_get_hash_stats(char *page) | |
250 | { | |
251 | int i, chain_len, max_chain_len, slots_used; | |
252 | struct avc_node *node; | |
253 | ||
254 | rcu_read_lock(); | |
255 | ||
256 | slots_used = 0; | |
257 | max_chain_len = 0; | |
258 | for (i = 0; i < AVC_CACHE_SLOTS; i++) { | |
259 | if (!list_empty(&avc_cache.slots[i])) { | |
260 | slots_used++; | |
261 | chain_len = 0; | |
262 | list_for_each_entry_rcu(node, &avc_cache.slots[i], list) | |
263 | chain_len++; | |
264 | if (chain_len > max_chain_len) | |
265 | max_chain_len = chain_len; | |
266 | } | |
267 | } | |
268 | ||
269 | rcu_read_unlock(); | |
270 | ||
271 | return scnprintf(page, PAGE_SIZE, "entries: %d\nbuckets used: %d/%d\n" | |
272 | "longest chain: %d\n", | |
273 | atomic_read(&avc_cache.active_nodes), | |
274 | slots_used, AVC_CACHE_SLOTS, max_chain_len); | |
275 | } | |
276 | ||
277 | static void avc_node_free(struct rcu_head *rhead) | |
278 | { | |
279 | struct avc_node *node = container_of(rhead, struct avc_node, rhead); | |
280 | kmem_cache_free(avc_node_cachep, node); | |
281 | avc_cache_stats_incr(frees); | |
282 | } | |
283 | ||
284 | static void avc_node_delete(struct avc_node *node) | |
285 | { | |
286 | list_del_rcu(&node->list); | |
287 | call_rcu(&node->rhead, avc_node_free); | |
288 | atomic_dec(&avc_cache.active_nodes); | |
289 | } | |
290 | ||
291 | static void avc_node_kill(struct avc_node *node) | |
292 | { | |
293 | kmem_cache_free(avc_node_cachep, node); | |
294 | avc_cache_stats_incr(frees); | |
295 | atomic_dec(&avc_cache.active_nodes); | |
296 | } | |
297 | ||
298 | static void avc_node_replace(struct avc_node *new, struct avc_node *old) | |
299 | { | |
300 | list_replace_rcu(&old->list, &new->list); | |
301 | call_rcu(&old->rhead, avc_node_free); | |
302 | atomic_dec(&avc_cache.active_nodes); | |
303 | } | |
304 | ||
305 | static inline int avc_reclaim_node(void) | |
306 | { | |
307 | struct avc_node *node; | |
308 | int hvalue, try, ecx; | |
309 | unsigned long flags; | |
310 | ||
95fff33b | 311 | for (try = 0, ecx = 0; try < AVC_CACHE_SLOTS; try++) { |
1da177e4 LT |
312 | hvalue = atomic_inc_return(&avc_cache.lru_hint) & (AVC_CACHE_SLOTS - 1); |
313 | ||
314 | if (!spin_trylock_irqsave(&avc_cache.slots_lock[hvalue], flags)) | |
315 | continue; | |
316 | ||
61844250 | 317 | rcu_read_lock(); |
1da177e4 LT |
318 | list_for_each_entry(node, &avc_cache.slots[hvalue], list) { |
319 | if (atomic_dec_and_test(&node->ae.used)) { | |
320 | /* Recently Unused */ | |
321 | avc_node_delete(node); | |
322 | avc_cache_stats_incr(reclaims); | |
323 | ecx++; | |
324 | if (ecx >= AVC_CACHE_RECLAIM) { | |
61844250 | 325 | rcu_read_unlock(); |
1da177e4 LT |
326 | spin_unlock_irqrestore(&avc_cache.slots_lock[hvalue], flags); |
327 | goto out; | |
328 | } | |
329 | } | |
330 | } | |
61844250 | 331 | rcu_read_unlock(); |
1da177e4 LT |
332 | spin_unlock_irqrestore(&avc_cache.slots_lock[hvalue], flags); |
333 | } | |
334 | out: | |
335 | return ecx; | |
336 | } | |
337 | ||
338 | static struct avc_node *avc_alloc_node(void) | |
339 | { | |
340 | struct avc_node *node; | |
341 | ||
c3762229 | 342 | node = kmem_cache_zalloc(avc_node_cachep, GFP_ATOMIC); |
1da177e4 LT |
343 | if (!node) |
344 | goto out; | |
345 | ||
1da177e4 LT |
346 | INIT_RCU_HEAD(&node->rhead); |
347 | INIT_LIST_HEAD(&node->list); | |
348 | atomic_set(&node->ae.used, 1); | |
349 | avc_cache_stats_incr(allocations); | |
350 | ||
351 | if (atomic_inc_return(&avc_cache.active_nodes) > avc_cache_threshold) | |
352 | avc_reclaim_node(); | |
353 | ||
354 | out: | |
355 | return node; | |
356 | } | |
357 | ||
358 | static void avc_node_populate(struct avc_node *node, u32 ssid, u32 tsid, u16 tclass, struct avc_entry *ae) | |
359 | { | |
360 | node->ae.ssid = ssid; | |
361 | node->ae.tsid = tsid; | |
362 | node->ae.tclass = tclass; | |
363 | memcpy(&node->ae.avd, &ae->avd, sizeof(node->ae.avd)); | |
364 | } | |
365 | ||
366 | static inline struct avc_node *avc_search_node(u32 ssid, u32 tsid, u16 tclass) | |
367 | { | |
368 | struct avc_node *node, *ret = NULL; | |
369 | int hvalue; | |
370 | ||
371 | hvalue = avc_hash(ssid, tsid, tclass); | |
372 | list_for_each_entry_rcu(node, &avc_cache.slots[hvalue], list) { | |
373 | if (ssid == node->ae.ssid && | |
374 | tclass == node->ae.tclass && | |
375 | tsid == node->ae.tsid) { | |
376 | ret = node; | |
377 | break; | |
378 | } | |
379 | } | |
380 | ||
381 | if (ret == NULL) { | |
382 | /* cache miss */ | |
383 | goto out; | |
384 | } | |
385 | ||
386 | /* cache hit */ | |
387 | if (atomic_read(&ret->ae.used) != 1) | |
388 | atomic_set(&ret->ae.used, 1); | |
389 | out: | |
390 | return ret; | |
391 | } | |
392 | ||
393 | /** | |
394 | * avc_lookup - Look up an AVC entry. | |
395 | * @ssid: source security identifier | |
396 | * @tsid: target security identifier | |
397 | * @tclass: target security class | |
398 | * @requested: requested permissions, interpreted based on @tclass | |
399 | * | |
400 | * Look up an AVC entry that is valid for the | |
401 | * @requested permissions between the SID pair | |
402 | * (@ssid, @tsid), interpreting the permissions | |
403 | * based on @tclass. If a valid AVC entry exists, | |
404 | * then this function return the avc_node. | |
405 | * Otherwise, this function returns NULL. | |
406 | */ | |
407 | static struct avc_node *avc_lookup(u32 ssid, u32 tsid, u16 tclass, u32 requested) | |
408 | { | |
409 | struct avc_node *node; | |
410 | ||
411 | avc_cache_stats_incr(lookups); | |
412 | node = avc_search_node(ssid, tsid, tclass); | |
413 | ||
414 | if (node && ((node->ae.avd.decided & requested) == requested)) { | |
415 | avc_cache_stats_incr(hits); | |
416 | goto out; | |
417 | } | |
418 | ||
419 | node = NULL; | |
420 | avc_cache_stats_incr(misses); | |
421 | out: | |
422 | return node; | |
423 | } | |
424 | ||
425 | static int avc_latest_notif_update(int seqno, int is_insert) | |
426 | { | |
427 | int ret = 0; | |
428 | static DEFINE_SPINLOCK(notif_lock); | |
429 | unsigned long flag; | |
430 | ||
431 | spin_lock_irqsave(¬if_lock, flag); | |
432 | if (is_insert) { | |
433 | if (seqno < avc_cache.latest_notif) { | |
744ba35e | 434 | printk(KERN_WARNING "SELinux: avc: seqno %d < latest_notif %d\n", |
1da177e4 LT |
435 | seqno, avc_cache.latest_notif); |
436 | ret = -EAGAIN; | |
437 | } | |
438 | } else { | |
439 | if (seqno > avc_cache.latest_notif) | |
440 | avc_cache.latest_notif = seqno; | |
441 | } | |
442 | spin_unlock_irqrestore(¬if_lock, flag); | |
443 | ||
444 | return ret; | |
445 | } | |
446 | ||
447 | /** | |
448 | * avc_insert - Insert an AVC entry. | |
449 | * @ssid: source security identifier | |
450 | * @tsid: target security identifier | |
451 | * @tclass: target security class | |
452 | * @ae: AVC entry | |
453 | * | |
454 | * Insert an AVC entry for the SID pair | |
455 | * (@ssid, @tsid) and class @tclass. | |
456 | * The access vectors and the sequence number are | |
457 | * normally provided by the security server in | |
458 | * response to a security_compute_av() call. If the | |
459 | * sequence number @ae->avd.seqno is not less than the latest | |
460 | * revocation notification, then the function copies | |
461 | * the access vectors into a cache entry, returns | |
462 | * avc_node inserted. Otherwise, this function returns NULL. | |
463 | */ | |
464 | static struct avc_node *avc_insert(u32 ssid, u32 tsid, u16 tclass, struct avc_entry *ae) | |
465 | { | |
466 | struct avc_node *pos, *node = NULL; | |
467 | int hvalue; | |
468 | unsigned long flag; | |
469 | ||
470 | if (avc_latest_notif_update(ae->avd.seqno, 1)) | |
471 | goto out; | |
472 | ||
473 | node = avc_alloc_node(); | |
474 | if (node) { | |
475 | hvalue = avc_hash(ssid, tsid, tclass); | |
476 | avc_node_populate(node, ssid, tsid, tclass, ae); | |
477 | ||
478 | spin_lock_irqsave(&avc_cache.slots_lock[hvalue], flag); | |
479 | list_for_each_entry(pos, &avc_cache.slots[hvalue], list) { | |
480 | if (pos->ae.ssid == ssid && | |
481 | pos->ae.tsid == tsid && | |
482 | pos->ae.tclass == tclass) { | |
95fff33b | 483 | avc_node_replace(node, pos); |
1da177e4 LT |
484 | goto found; |
485 | } | |
486 | } | |
487 | list_add_rcu(&node->list, &avc_cache.slots[hvalue]); | |
488 | found: | |
489 | spin_unlock_irqrestore(&avc_cache.slots_lock[hvalue], flag); | |
490 | } | |
491 | out: | |
492 | return node; | |
493 | } | |
494 | ||
495 | static inline void avc_print_ipv6_addr(struct audit_buffer *ab, | |
b5bf6c55 | 496 | struct in6_addr *addr, __be16 port, |
1da177e4 LT |
497 | char *name1, char *name2) |
498 | { | |
499 | if (!ipv6_addr_any(addr)) | |
5b095d98 | 500 | audit_log_format(ab, " %s=%pI6", name1, addr); |
1da177e4 LT |
501 | if (port) |
502 | audit_log_format(ab, " %s=%d", name2, ntohs(port)); | |
503 | } | |
504 | ||
87fcd70d | 505 | static inline void avc_print_ipv4_addr(struct audit_buffer *ab, __be32 addr, |
b5bf6c55 | 506 | __be16 port, char *name1, char *name2) |
1da177e4 LT |
507 | { |
508 | if (addr) | |
3685f25d | 509 | audit_log_format(ab, " %s=%pI4", name1, &addr); |
1da177e4 LT |
510 | if (port) |
511 | audit_log_format(ab, " %s=%d", name2, ntohs(port)); | |
512 | } | |
513 | ||
514 | /** | |
515 | * avc_audit - Audit the granting or denial of permissions. | |
516 | * @ssid: source security identifier | |
517 | * @tsid: target security identifier | |
518 | * @tclass: target security class | |
519 | * @requested: requested permissions | |
520 | * @avd: access vector decisions | |
521 | * @result: result from avc_has_perm_noaudit | |
522 | * @a: auxiliary audit data | |
523 | * | |
524 | * Audit the granting or denial of permissions in accordance | |
525 | * with the policy. This function is typically called by | |
526 | * avc_has_perm() after a permission check, but can also be | |
527 | * called directly by callers who use avc_has_perm_noaudit() | |
528 | * in order to separate the permission check from the auditing. | |
529 | * For example, this separation is useful when the permission check must | |
530 | * be performed under a lock, to allow the lock to be released | |
531 | * before calling the auditing code. | |
532 | */ | |
533 | void avc_audit(u32 ssid, u32 tsid, | |
95fff33b EP |
534 | u16 tclass, u32 requested, |
535 | struct av_decision *avd, int result, struct avc_audit_data *a) | |
1da177e4 | 536 | { |
cd77b821 | 537 | struct task_struct *tsk = current; |
1da177e4 LT |
538 | struct inode *inode = NULL; |
539 | u32 denied, audited; | |
540 | struct audit_buffer *ab; | |
541 | ||
542 | denied = requested & ~avd->allowed; | |
543 | if (denied) { | |
544 | audited = denied; | |
545 | if (!(audited & avd->auditdeny)) | |
546 | return; | |
547 | } else if (result) { | |
548 | audited = denied = requested; | |
95fff33b | 549 | } else { |
1da177e4 LT |
550 | audited = requested; |
551 | if (!(audited & avd->auditallow)) | |
552 | return; | |
553 | } | |
554 | ||
9ad9ad38 | 555 | ab = audit_log_start(current->audit_context, GFP_ATOMIC, AUDIT_AVC); |
1da177e4 LT |
556 | if (!ab) |
557 | return; /* audit_panic has been called */ | |
558 | audit_log_format(ab, "avc: %s ", denied ? "denied" : "granted"); | |
95fff33b | 559 | avc_dump_av(ab, tclass, audited); |
1da177e4 | 560 | audit_log_format(ab, " for "); |
cd77b821 DW |
561 | if (a && a->tsk) |
562 | tsk = a->tsk; | |
7b5d781c | 563 | if (tsk && tsk->pid) { |
cd77b821 DW |
564 | audit_log_format(ab, " pid=%d comm=", tsk->pid); |
565 | audit_log_untrustedstring(ab, tsk->comm); | |
566 | } | |
1da177e4 LT |
567 | if (a) { |
568 | switch (a->type) { | |
569 | case AVC_AUDIT_DATA_IPC: | |
570 | audit_log_format(ab, " key=%d", a->u.ipc_id); | |
571 | break; | |
572 | case AVC_AUDIT_DATA_CAP: | |
573 | audit_log_format(ab, " capability=%d", a->u.cap); | |
574 | break; | |
575 | case AVC_AUDIT_DATA_FS: | |
44707fdf JB |
576 | if (a->u.fs.path.dentry) { |
577 | struct dentry *dentry = a->u.fs.path.dentry; | |
578 | if (a->u.fs.path.mnt) { | |
579 | audit_log_d_path(ab, "path=", | |
580 | &a->u.fs.path); | |
4259fa01 AV |
581 | } else { |
582 | audit_log_format(ab, " name="); | |
583 | audit_log_untrustedstring(ab, dentry->d_name.name); | |
584 | } | |
1da177e4 LT |
585 | inode = dentry->d_inode; |
586 | } else if (a->u.fs.inode) { | |
587 | struct dentry *dentry; | |
588 | inode = a->u.fs.inode; | |
589 | dentry = d_find_alias(inode); | |
590 | if (dentry) { | |
37ca5389 SS |
591 | audit_log_format(ab, " name="); |
592 | audit_log_untrustedstring(ab, dentry->d_name.name); | |
1da177e4 LT |
593 | dput(dentry); |
594 | } | |
595 | } | |
596 | if (inode) | |
13bddc2e | 597 | audit_log_format(ab, " dev=%s ino=%lu", |
1da177e4 LT |
598 | inode->i_sb->s_id, |
599 | inode->i_ino); | |
600 | break; | |
601 | case AVC_AUDIT_DATA_NET: | |
602 | if (a->u.net.sk) { | |
603 | struct sock *sk = a->u.net.sk; | |
604 | struct unix_sock *u; | |
605 | int len = 0; | |
606 | char *p = NULL; | |
607 | ||
608 | switch (sk->sk_family) { | |
609 | case AF_INET: { | |
610 | struct inet_sock *inet = inet_sk(sk); | |
611 | ||
612 | avc_print_ipv4_addr(ab, inet->rcv_saddr, | |
613 | inet->sport, | |
614 | "laddr", "lport"); | |
615 | avc_print_ipv4_addr(ab, inet->daddr, | |
616 | inet->dport, | |
617 | "faddr", "fport"); | |
618 | break; | |
619 | } | |
620 | case AF_INET6: { | |
621 | struct inet_sock *inet = inet_sk(sk); | |
622 | struct ipv6_pinfo *inet6 = inet6_sk(sk); | |
623 | ||
624 | avc_print_ipv6_addr(ab, &inet6->rcv_saddr, | |
625 | inet->sport, | |
626 | "laddr", "lport"); | |
627 | avc_print_ipv6_addr(ab, &inet6->daddr, | |
628 | inet->dport, | |
629 | "faddr", "fport"); | |
630 | break; | |
631 | } | |
632 | case AF_UNIX: | |
633 | u = unix_sk(sk); | |
634 | if (u->dentry) { | |
44707fdf JB |
635 | struct path path = { |
636 | .dentry = u->dentry, | |
637 | .mnt = u->mnt | |
638 | }; | |
4259fa01 | 639 | audit_log_d_path(ab, "path=", |
44707fdf | 640 | &path); |
1da177e4 LT |
641 | break; |
642 | } | |
643 | if (!u->addr) | |
644 | break; | |
645 | len = u->addr->len-sizeof(short); | |
646 | p = &u->addr->name->sun_path[0]; | |
37ca5389 | 647 | audit_log_format(ab, " path="); |
1da177e4 | 648 | if (*p) |
37ca5389 | 649 | audit_log_untrustedstring(ab, p); |
1da177e4 | 650 | else |
b556f8ad | 651 | audit_log_n_hex(ab, p, len); |
1da177e4 LT |
652 | break; |
653 | } | |
654 | } | |
95fff33b | 655 | |
1da177e4 LT |
656 | switch (a->u.net.family) { |
657 | case AF_INET: | |
658 | avc_print_ipv4_addr(ab, a->u.net.v4info.saddr, | |
659 | a->u.net.sport, | |
660 | "saddr", "src"); | |
661 | avc_print_ipv4_addr(ab, a->u.net.v4info.daddr, | |
662 | a->u.net.dport, | |
663 | "daddr", "dest"); | |
664 | break; | |
665 | case AF_INET6: | |
666 | avc_print_ipv6_addr(ab, &a->u.net.v6info.saddr, | |
667 | a->u.net.sport, | |
668 | "saddr", "src"); | |
669 | avc_print_ipv6_addr(ab, &a->u.net.v6info.daddr, | |
670 | a->u.net.dport, | |
671 | "daddr", "dest"); | |
672 | break; | |
673 | } | |
da5645a2 PM |
674 | if (a->u.net.netif > 0) { |
675 | struct net_device *dev; | |
676 | ||
677 | /* NOTE: we always use init's namespace */ | |
678 | dev = dev_get_by_index(&init_net, | |
679 | a->u.net.netif); | |
680 | if (dev) { | |
681 | audit_log_format(ab, " netif=%s", | |
682 | dev->name); | |
683 | dev_put(dev); | |
684 | } | |
685 | } | |
1da177e4 LT |
686 | break; |
687 | } | |
688 | } | |
689 | audit_log_format(ab, " "); | |
690 | avc_dump_query(ab, ssid, tsid, tclass); | |
691 | audit_log_end(ab); | |
692 | } | |
693 | ||
694 | /** | |
695 | * avc_add_callback - Register a callback for security events. | |
696 | * @callback: callback function | |
697 | * @events: security events | |
698 | * @ssid: source security identifier or %SECSID_WILD | |
699 | * @tsid: target security identifier or %SECSID_WILD | |
700 | * @tclass: target security class | |
701 | * @perms: permissions | |
702 | * | |
703 | * Register a callback function for events in the set @events | |
704 | * related to the SID pair (@ssid, @tsid) and | |
705 | * and the permissions @perms, interpreting | |
706 | * @perms based on @tclass. Returns %0 on success or | |
707 | * -%ENOMEM if insufficient memory exists to add the callback. | |
708 | */ | |
709 | int avc_add_callback(int (*callback)(u32 event, u32 ssid, u32 tsid, | |
95fff33b EP |
710 | u16 tclass, u32 perms, |
711 | u32 *out_retained), | |
712 | u32 events, u32 ssid, u32 tsid, | |
713 | u16 tclass, u32 perms) | |
1da177e4 LT |
714 | { |
715 | struct avc_callback_node *c; | |
716 | int rc = 0; | |
717 | ||
718 | c = kmalloc(sizeof(*c), GFP_ATOMIC); | |
719 | if (!c) { | |
720 | rc = -ENOMEM; | |
721 | goto out; | |
722 | } | |
723 | ||
724 | c->callback = callback; | |
725 | c->events = events; | |
726 | c->ssid = ssid; | |
727 | c->tsid = tsid; | |
728 | c->perms = perms; | |
729 | c->next = avc_callbacks; | |
730 | avc_callbacks = c; | |
731 | out: | |
732 | return rc; | |
733 | } | |
734 | ||
735 | static inline int avc_sidcmp(u32 x, u32 y) | |
736 | { | |
737 | return (x == y || x == SECSID_WILD || y == SECSID_WILD); | |
738 | } | |
739 | ||
740 | /** | |
741 | * avc_update_node Update an AVC entry | |
742 | * @event : Updating event | |
743 | * @perms : Permission mask bits | |
744 | * @ssid,@tsid,@tclass : identifier of an AVC entry | |
a5dda683 | 745 | * @seqno : sequence number when decision was made |
1da177e4 LT |
746 | * |
747 | * if a valid AVC entry doesn't exist,this function returns -ENOENT. | |
748 | * if kmalloc() called internal returns NULL, this function returns -ENOMEM. | |
749 | * otherwise, this function update the AVC entry. The original AVC-entry object | |
750 | * will release later by RCU. | |
751 | */ | |
a5dda683 EP |
752 | static int avc_update_node(u32 event, u32 perms, u32 ssid, u32 tsid, u16 tclass, |
753 | u32 seqno) | |
1da177e4 LT |
754 | { |
755 | int hvalue, rc = 0; | |
756 | unsigned long flag; | |
757 | struct avc_node *pos, *node, *orig = NULL; | |
758 | ||
759 | node = avc_alloc_node(); | |
760 | if (!node) { | |
761 | rc = -ENOMEM; | |
762 | goto out; | |
763 | } | |
764 | ||
765 | /* Lock the target slot */ | |
766 | hvalue = avc_hash(ssid, tsid, tclass); | |
767 | spin_lock_irqsave(&avc_cache.slots_lock[hvalue], flag); | |
768 | ||
95fff33b EP |
769 | list_for_each_entry(pos, &avc_cache.slots[hvalue], list) { |
770 | if (ssid == pos->ae.ssid && | |
771 | tsid == pos->ae.tsid && | |
a5dda683 EP |
772 | tclass == pos->ae.tclass && |
773 | seqno == pos->ae.avd.seqno){ | |
1da177e4 LT |
774 | orig = pos; |
775 | break; | |
776 | } | |
777 | } | |
778 | ||
779 | if (!orig) { | |
780 | rc = -ENOENT; | |
781 | avc_node_kill(node); | |
782 | goto out_unlock; | |
783 | } | |
784 | ||
785 | /* | |
786 | * Copy and replace original node. | |
787 | */ | |
788 | ||
789 | avc_node_populate(node, ssid, tsid, tclass, &orig->ae); | |
790 | ||
791 | switch (event) { | |
792 | case AVC_CALLBACK_GRANT: | |
793 | node->ae.avd.allowed |= perms; | |
794 | break; | |
795 | case AVC_CALLBACK_TRY_REVOKE: | |
796 | case AVC_CALLBACK_REVOKE: | |
797 | node->ae.avd.allowed &= ~perms; | |
798 | break; | |
799 | case AVC_CALLBACK_AUDITALLOW_ENABLE: | |
800 | node->ae.avd.auditallow |= perms; | |
801 | break; | |
802 | case AVC_CALLBACK_AUDITALLOW_DISABLE: | |
803 | node->ae.avd.auditallow &= ~perms; | |
804 | break; | |
805 | case AVC_CALLBACK_AUDITDENY_ENABLE: | |
806 | node->ae.avd.auditdeny |= perms; | |
807 | break; | |
808 | case AVC_CALLBACK_AUDITDENY_DISABLE: | |
809 | node->ae.avd.auditdeny &= ~perms; | |
810 | break; | |
811 | } | |
812 | avc_node_replace(node, orig); | |
813 | out_unlock: | |
814 | spin_unlock_irqrestore(&avc_cache.slots_lock[hvalue], flag); | |
815 | out: | |
816 | return rc; | |
817 | } | |
818 | ||
819 | /** | |
820 | * avc_ss_reset - Flush the cache and revalidate migrated permissions. | |
821 | * @seqno: policy sequence number | |
822 | */ | |
823 | int avc_ss_reset(u32 seqno) | |
824 | { | |
825 | struct avc_callback_node *c; | |
376bd9cb | 826 | int i, rc = 0, tmprc; |
1da177e4 LT |
827 | unsigned long flag; |
828 | struct avc_node *node; | |
829 | ||
830 | for (i = 0; i < AVC_CACHE_SLOTS; i++) { | |
831 | spin_lock_irqsave(&avc_cache.slots_lock[i], flag); | |
61844250 PM |
832 | /* |
833 | * With preemptable RCU, the outer spinlock does not | |
834 | * prevent RCU grace periods from ending. | |
835 | */ | |
836 | rcu_read_lock(); | |
1da177e4 LT |
837 | list_for_each_entry(node, &avc_cache.slots[i], list) |
838 | avc_node_delete(node); | |
61844250 | 839 | rcu_read_unlock(); |
1da177e4 LT |
840 | spin_unlock_irqrestore(&avc_cache.slots_lock[i], flag); |
841 | } | |
842 | ||
843 | for (c = avc_callbacks; c; c = c->next) { | |
844 | if (c->events & AVC_CALLBACK_RESET) { | |
376bd9cb | 845 | tmprc = c->callback(AVC_CALLBACK_RESET, |
95fff33b | 846 | 0, 0, 0, 0, NULL); |
376bd9cb DG |
847 | /* save the first error encountered for the return |
848 | value and continue processing the callbacks */ | |
849 | if (!rc) | |
850 | rc = tmprc; | |
1da177e4 LT |
851 | } |
852 | } | |
853 | ||
854 | avc_latest_notif_update(seqno, 0); | |
1da177e4 LT |
855 | return rc; |
856 | } | |
857 | ||
858 | /** | |
859 | * avc_has_perm_noaudit - Check permissions but perform no auditing. | |
860 | * @ssid: source security identifier | |
861 | * @tsid: target security identifier | |
862 | * @tclass: target security class | |
863 | * @requested: requested permissions, interpreted based on @tclass | |
2c3c05db | 864 | * @flags: AVC_STRICT or 0 |
1da177e4 LT |
865 | * @avd: access vector decisions |
866 | * | |
867 | * Check the AVC to determine whether the @requested permissions are granted | |
868 | * for the SID pair (@ssid, @tsid), interpreting the permissions | |
869 | * based on @tclass, and call the security server on a cache miss to obtain | |
870 | * a new decision and add it to the cache. Return a copy of the decisions | |
871 | * in @avd. Return %0 if all @requested permissions are granted, | |
872 | * -%EACCES if any permissions are denied, or another -errno upon | |
873 | * other errors. This function is typically called by avc_has_perm(), | |
874 | * but may also be called directly to separate permission checking from | |
875 | * auditing, e.g. in cases where a lock must be held for the check but | |
876 | * should be released for the auditing. | |
877 | */ | |
878 | int avc_has_perm_noaudit(u32 ssid, u32 tsid, | |
2c3c05db SS |
879 | u16 tclass, u32 requested, |
880 | unsigned flags, | |
881 | struct av_decision *avd) | |
1da177e4 LT |
882 | { |
883 | struct avc_node *node; | |
884 | struct avc_entry entry, *p_ae; | |
885 | int rc = 0; | |
886 | u32 denied; | |
887 | ||
eda4f69c EP |
888 | BUG_ON(!requested); |
889 | ||
1da177e4 LT |
890 | rcu_read_lock(); |
891 | ||
892 | node = avc_lookup(ssid, tsid, tclass, requested); | |
893 | if (!node) { | |
894 | rcu_read_unlock(); | |
95fff33b | 895 | rc = security_compute_av(ssid, tsid, tclass, requested, &entry.avd); |
1da177e4 LT |
896 | if (rc) |
897 | goto out; | |
898 | rcu_read_lock(); | |
95fff33b | 899 | node = avc_insert(ssid, tsid, tclass, &entry); |
1da177e4 LT |
900 | } |
901 | ||
902 | p_ae = node ? &node->ae : &entry; | |
903 | ||
904 | if (avd) | |
905 | memcpy(avd, &p_ae->avd, sizeof(*avd)); | |
906 | ||
907 | denied = requested & ~(p_ae->avd.allowed); | |
908 | ||
eda4f69c | 909 | if (denied) { |
64dbf074 | 910 | if (flags & AVC_STRICT) |
1da177e4 | 911 | rc = -EACCES; |
64dbf074 EP |
912 | else if (!selinux_enforcing || security_permissive_sid(ssid)) |
913 | avc_update_node(AVC_CALLBACK_GRANT, requested, ssid, | |
a5dda683 | 914 | tsid, tclass, p_ae->avd.seqno); |
1da177e4 | 915 | else |
64dbf074 | 916 | rc = -EACCES; |
1da177e4 LT |
917 | } |
918 | ||
919 | rcu_read_unlock(); | |
920 | out: | |
921 | return rc; | |
922 | } | |
923 | ||
924 | /** | |
925 | * avc_has_perm - Check permissions and perform any appropriate auditing. | |
926 | * @ssid: source security identifier | |
927 | * @tsid: target security identifier | |
928 | * @tclass: target security class | |
929 | * @requested: requested permissions, interpreted based on @tclass | |
930 | * @auditdata: auxiliary audit data | |
931 | * | |
932 | * Check the AVC to determine whether the @requested permissions are granted | |
933 | * for the SID pair (@ssid, @tsid), interpreting the permissions | |
934 | * based on @tclass, and call the security server on a cache miss to obtain | |
935 | * a new decision and add it to the cache. Audit the granting or denial of | |
936 | * permissions in accordance with the policy. Return %0 if all @requested | |
937 | * permissions are granted, -%EACCES if any permissions are denied, or | |
938 | * another -errno upon other errors. | |
939 | */ | |
940 | int avc_has_perm(u32 ssid, u32 tsid, u16 tclass, | |
95fff33b | 941 | u32 requested, struct avc_audit_data *auditdata) |
1da177e4 LT |
942 | { |
943 | struct av_decision avd; | |
944 | int rc; | |
945 | ||
2c3c05db | 946 | rc = avc_has_perm_noaudit(ssid, tsid, tclass, requested, 0, &avd); |
1da177e4 LT |
947 | avc_audit(ssid, tsid, tclass, requested, &avd, rc, auditdata); |
948 | return rc; | |
949 | } | |
788e7dd4 YN |
950 | |
951 | u32 avc_policy_seqno(void) | |
952 | { | |
953 | return avc_cache.latest_notif; | |
954 | } |