Commit | Line | Data |
---|---|---|
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; | |
1da177e4 LT |
91 | }; |
92 | ||
93 | struct avc_node { | |
94 | struct avc_entry ae; | |
edf3d1ae | 95 | struct list_head list; /* anchored in avc_cache->slots[i] */ |
95fff33b | 96 | struct rcu_head rhead; |
1da177e4 LT |
97 | }; |
98 | ||
99 | struct avc_cache { | |
edf3d1ae | 100 | struct list_head slots[AVC_CACHE_SLOTS]; /* head for avc_node->list */ |
1da177e4 LT |
101 | spinlock_t slots_lock[AVC_CACHE_SLOTS]; /* lock for writes */ |
102 | atomic_t lru_hint; /* LRU hint for reclaim scan */ | |
103 | atomic_t active_nodes; | |
104 | u32 latest_notif; /* latest revocation notification */ | |
105 | }; | |
106 | ||
107 | struct avc_callback_node { | |
108 | int (*callback) (u32 event, u32 ssid, u32 tsid, | |
95fff33b EP |
109 | u16 tclass, u32 perms, |
110 | u32 *out_retained); | |
1da177e4 LT |
111 | u32 events; |
112 | u32 ssid; | |
113 | u32 tsid; | |
114 | u16 tclass; | |
115 | u32 perms; | |
116 | struct avc_callback_node *next; | |
117 | }; | |
118 | ||
119 | /* Exported via selinufs */ | |
120 | unsigned int avc_cache_threshold = AVC_DEF_CACHE_THRESHOLD; | |
121 | ||
122 | #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS | |
123 | DEFINE_PER_CPU(struct avc_cache_stats, avc_cache_stats) = { 0 }; | |
124 | #endif | |
125 | ||
126 | static struct avc_cache avc_cache; | |
127 | static struct avc_callback_node *avc_callbacks; | |
e18b890b | 128 | static struct kmem_cache *avc_node_cachep; |
1da177e4 LT |
129 | |
130 | static inline int avc_hash(u32 ssid, u32 tsid, u16 tclass) | |
131 | { | |
132 | return (ssid ^ (tsid<<2) ^ (tclass<<4)) & (AVC_CACHE_SLOTS - 1); | |
133 | } | |
134 | ||
135 | /** | |
136 | * avc_dump_av - Display an access vector in human-readable form. | |
137 | * @tclass: target security class | |
138 | * @av: access vector | |
139 | */ | |
d9250dea | 140 | void avc_dump_av(struct audit_buffer *ab, u16 tclass, u32 av) |
1da177e4 LT |
141 | { |
142 | const char **common_pts = NULL; | |
143 | u32 common_base = 0; | |
144 | int i, i2, perm; | |
145 | ||
146 | if (av == 0) { | |
147 | audit_log_format(ab, " null"); | |
148 | return; | |
149 | } | |
150 | ||
151 | for (i = 0; i < ARRAY_SIZE(av_inherit); i++) { | |
152 | if (av_inherit[i].tclass == tclass) { | |
153 | common_pts = av_inherit[i].common_pts; | |
154 | common_base = av_inherit[i].common_base; | |
155 | break; | |
156 | } | |
157 | } | |
158 | ||
159 | audit_log_format(ab, " {"); | |
160 | i = 0; | |
161 | perm = 1; | |
162 | while (perm < common_base) { | |
163 | if (perm & av) { | |
164 | audit_log_format(ab, " %s", common_pts[i]); | |
165 | av &= ~perm; | |
166 | } | |
167 | i++; | |
168 | perm <<= 1; | |
169 | } | |
170 | ||
171 | while (i < sizeof(av) * 8) { | |
172 | if (perm & av) { | |
173 | for (i2 = 0; i2 < ARRAY_SIZE(av_perm_to_string); i2++) { | |
174 | if ((av_perm_to_string[i2].tclass == tclass) && | |
175 | (av_perm_to_string[i2].value == perm)) | |
176 | break; | |
177 | } | |
178 | if (i2 < ARRAY_SIZE(av_perm_to_string)) { | |
179 | audit_log_format(ab, " %s", | |
180 | av_perm_to_string[i2].name); | |
181 | av &= ~perm; | |
182 | } | |
183 | } | |
184 | i++; | |
185 | perm <<= 1; | |
186 | } | |
187 | ||
188 | if (av) | |
189 | audit_log_format(ab, " 0x%x", av); | |
190 | ||
191 | audit_log_format(ab, " }"); | |
192 | } | |
193 | ||
194 | /** | |
195 | * avc_dump_query - Display a SID pair and a class in human-readable form. | |
196 | * @ssid: source security identifier | |
197 | * @tsid: target security identifier | |
198 | * @tclass: target security class | |
199 | */ | |
200 | static void avc_dump_query(struct audit_buffer *ab, u32 ssid, u32 tsid, u16 tclass) | |
201 | { | |
202 | int rc; | |
203 | char *scontext; | |
204 | u32 scontext_len; | |
205 | ||
95fff33b | 206 | rc = security_sid_to_context(ssid, &scontext, &scontext_len); |
1da177e4 LT |
207 | if (rc) |
208 | audit_log_format(ab, "ssid=%d", ssid); | |
209 | else { | |
210 | audit_log_format(ab, "scontext=%s", scontext); | |
211 | kfree(scontext); | |
212 | } | |
213 | ||
214 | rc = security_sid_to_context(tsid, &scontext, &scontext_len); | |
215 | if (rc) | |
216 | audit_log_format(ab, " tsid=%d", tsid); | |
217 | else { | |
218 | audit_log_format(ab, " tcontext=%s", scontext); | |
219 | kfree(scontext); | |
220 | } | |
a764ae4b SS |
221 | |
222 | BUG_ON(tclass >= ARRAY_SIZE(class_to_string) || !class_to_string[tclass]); | |
1da177e4 LT |
223 | audit_log_format(ab, " tclass=%s", class_to_string[tclass]); |
224 | } | |
225 | ||
226 | /** | |
227 | * avc_init - Initialize the AVC. | |
228 | * | |
229 | * Initialize the access vector cache. | |
230 | */ | |
231 | void __init avc_init(void) | |
232 | { | |
233 | int i; | |
234 | ||
235 | for (i = 0; i < AVC_CACHE_SLOTS; i++) { | |
236 | INIT_LIST_HEAD(&avc_cache.slots[i]); | |
237 | spin_lock_init(&avc_cache.slots_lock[i]); | |
238 | } | |
239 | atomic_set(&avc_cache.active_nodes, 0); | |
240 | atomic_set(&avc_cache.lru_hint, 0); | |
241 | ||
242 | avc_node_cachep = kmem_cache_create("avc_node", sizeof(struct avc_node), | |
20c2df83 | 243 | 0, SLAB_PANIC, NULL); |
1da177e4 | 244 | |
9ad9ad38 | 245 | audit_log(current->audit_context, GFP_KERNEL, AUDIT_KERNEL, "AVC INITIALIZED\n"); |
1da177e4 LT |
246 | } |
247 | ||
248 | int avc_get_hash_stats(char *page) | |
249 | { | |
250 | int i, chain_len, max_chain_len, slots_used; | |
251 | struct avc_node *node; | |
edf3d1ae | 252 | struct list_head *head; |
1da177e4 LT |
253 | |
254 | rcu_read_lock(); | |
255 | ||
256 | slots_used = 0; | |
257 | max_chain_len = 0; | |
258 | for (i = 0; i < AVC_CACHE_SLOTS; i++) { | |
edf3d1ae EP |
259 | head = &avc_cache.slots[i]; |
260 | if (!list_empty(head)) { | |
1da177e4 LT |
261 | slots_used++; |
262 | chain_len = 0; | |
edf3d1ae | 263 | list_for_each_entry_rcu(node, head, list) |
1da177e4 LT |
264 | chain_len++; |
265 | if (chain_len > max_chain_len) | |
266 | max_chain_len = chain_len; | |
267 | } | |
268 | } | |
269 | ||
270 | rcu_read_unlock(); | |
271 | ||
272 | return scnprintf(page, PAGE_SIZE, "entries: %d\nbuckets used: %d/%d\n" | |
273 | "longest chain: %d\n", | |
274 | atomic_read(&avc_cache.active_nodes), | |
275 | slots_used, AVC_CACHE_SLOTS, max_chain_len); | |
276 | } | |
277 | ||
278 | static void avc_node_free(struct rcu_head *rhead) | |
279 | { | |
280 | struct avc_node *node = container_of(rhead, struct avc_node, rhead); | |
281 | kmem_cache_free(avc_node_cachep, node); | |
282 | avc_cache_stats_incr(frees); | |
283 | } | |
284 | ||
285 | static void avc_node_delete(struct avc_node *node) | |
286 | { | |
287 | list_del_rcu(&node->list); | |
288 | call_rcu(&node->rhead, avc_node_free); | |
289 | atomic_dec(&avc_cache.active_nodes); | |
290 | } | |
291 | ||
292 | static void avc_node_kill(struct avc_node *node) | |
293 | { | |
294 | kmem_cache_free(avc_node_cachep, node); | |
295 | avc_cache_stats_incr(frees); | |
296 | atomic_dec(&avc_cache.active_nodes); | |
297 | } | |
298 | ||
299 | static void avc_node_replace(struct avc_node *new, struct avc_node *old) | |
300 | { | |
301 | list_replace_rcu(&old->list, &new->list); | |
302 | call_rcu(&old->rhead, avc_node_free); | |
303 | atomic_dec(&avc_cache.active_nodes); | |
304 | } | |
305 | ||
306 | static inline int avc_reclaim_node(void) | |
307 | { | |
308 | struct avc_node *node; | |
309 | int hvalue, try, ecx; | |
310 | unsigned long flags; | |
edf3d1ae EP |
311 | struct list_head *head; |
312 | spinlock_t *lock; | |
1da177e4 | 313 | |
95fff33b | 314 | for (try = 0, ecx = 0; try < AVC_CACHE_SLOTS; try++) { |
1da177e4 | 315 | hvalue = atomic_inc_return(&avc_cache.lru_hint) & (AVC_CACHE_SLOTS - 1); |
edf3d1ae EP |
316 | head = &avc_cache.slots[hvalue]; |
317 | lock = &avc_cache.slots_lock[hvalue]; | |
1da177e4 | 318 | |
edf3d1ae | 319 | if (!spin_trylock_irqsave(lock, flags)) |
1da177e4 LT |
320 | continue; |
321 | ||
61844250 | 322 | rcu_read_lock(); |
edf3d1ae | 323 | list_for_each_entry(node, head, list) { |
906d27d9 EP |
324 | avc_node_delete(node); |
325 | avc_cache_stats_incr(reclaims); | |
326 | ecx++; | |
327 | if (ecx >= AVC_CACHE_RECLAIM) { | |
328 | rcu_read_unlock(); | |
edf3d1ae | 329 | spin_unlock_irqrestore(lock, flags); |
906d27d9 | 330 | goto out; |
1da177e4 LT |
331 | } |
332 | } | |
61844250 | 333 | rcu_read_unlock(); |
edf3d1ae | 334 | spin_unlock_irqrestore(lock, flags); |
1da177e4 LT |
335 | } |
336 | out: | |
337 | return ecx; | |
338 | } | |
339 | ||
340 | static struct avc_node *avc_alloc_node(void) | |
341 | { | |
342 | struct avc_node *node; | |
343 | ||
c3762229 | 344 | node = kmem_cache_zalloc(avc_node_cachep, GFP_ATOMIC); |
1da177e4 LT |
345 | if (!node) |
346 | goto out; | |
347 | ||
1da177e4 LT |
348 | INIT_RCU_HEAD(&node->rhead); |
349 | INIT_LIST_HEAD(&node->list); | |
1da177e4 LT |
350 | avc_cache_stats_incr(allocations); |
351 | ||
352 | if (atomic_inc_return(&avc_cache.active_nodes) > avc_cache_threshold) | |
353 | avc_reclaim_node(); | |
354 | ||
355 | out: | |
356 | return node; | |
357 | } | |
358 | ||
21193dcd | 359 | static void avc_node_populate(struct avc_node *node, u32 ssid, u32 tsid, u16 tclass, struct av_decision *avd) |
1da177e4 LT |
360 | { |
361 | node->ae.ssid = ssid; | |
362 | node->ae.tsid = tsid; | |
363 | node->ae.tclass = tclass; | |
21193dcd | 364 | memcpy(&node->ae.avd, avd, sizeof(node->ae.avd)); |
1da177e4 LT |
365 | } |
366 | ||
367 | static inline struct avc_node *avc_search_node(u32 ssid, u32 tsid, u16 tclass) | |
368 | { | |
369 | struct avc_node *node, *ret = NULL; | |
370 | int hvalue; | |
edf3d1ae | 371 | struct list_head *head; |
1da177e4 LT |
372 | |
373 | hvalue = avc_hash(ssid, tsid, tclass); | |
edf3d1ae EP |
374 | head = &avc_cache.slots[hvalue]; |
375 | list_for_each_entry_rcu(node, head, list) { | |
1da177e4 LT |
376 | if (ssid == node->ae.ssid && |
377 | tclass == node->ae.tclass && | |
378 | tsid == node->ae.tsid) { | |
379 | ret = node; | |
380 | break; | |
381 | } | |
382 | } | |
383 | ||
1da177e4 LT |
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 | |
1da177e4 LT |
392 | * |
393 | * Look up an AVC entry that is valid for the | |
1da177e4 LT |
394 | * (@ssid, @tsid), interpreting the permissions |
395 | * based on @tclass. If a valid AVC entry exists, | |
396 | * then this function return the avc_node. | |
397 | * Otherwise, this function returns NULL. | |
398 | */ | |
f1c6381a | 399 | static struct avc_node *avc_lookup(u32 ssid, u32 tsid, u16 tclass) |
1da177e4 LT |
400 | { |
401 | struct avc_node *node; | |
402 | ||
403 | avc_cache_stats_incr(lookups); | |
404 | node = avc_search_node(ssid, tsid, tclass); | |
405 | ||
f1c6381a | 406 | if (node) |
1da177e4 | 407 | avc_cache_stats_incr(hits); |
f1c6381a EP |
408 | else |
409 | avc_cache_stats_incr(misses); | |
1da177e4 | 410 | |
1da177e4 LT |
411 | return node; |
412 | } | |
413 | ||
414 | static int avc_latest_notif_update(int seqno, int is_insert) | |
415 | { | |
416 | int ret = 0; | |
417 | static DEFINE_SPINLOCK(notif_lock); | |
418 | unsigned long flag; | |
419 | ||
420 | spin_lock_irqsave(¬if_lock, flag); | |
421 | if (is_insert) { | |
422 | if (seqno < avc_cache.latest_notif) { | |
744ba35e | 423 | printk(KERN_WARNING "SELinux: avc: seqno %d < latest_notif %d\n", |
1da177e4 LT |
424 | seqno, avc_cache.latest_notif); |
425 | ret = -EAGAIN; | |
426 | } | |
427 | } else { | |
428 | if (seqno > avc_cache.latest_notif) | |
429 | avc_cache.latest_notif = seqno; | |
430 | } | |
431 | spin_unlock_irqrestore(¬if_lock, flag); | |
432 | ||
433 | return ret; | |
434 | } | |
435 | ||
436 | /** | |
437 | * avc_insert - Insert an AVC entry. | |
438 | * @ssid: source security identifier | |
439 | * @tsid: target security identifier | |
440 | * @tclass: target security class | |
21193dcd | 441 | * @avd: resulting av decision |
1da177e4 LT |
442 | * |
443 | * Insert an AVC entry for the SID pair | |
444 | * (@ssid, @tsid) and class @tclass. | |
445 | * The access vectors and the sequence number are | |
446 | * normally provided by the security server in | |
447 | * response to a security_compute_av() call. If the | |
21193dcd | 448 | * sequence number @avd->seqno is not less than the latest |
1da177e4 LT |
449 | * revocation notification, then the function copies |
450 | * the access vectors into a cache entry, returns | |
451 | * avc_node inserted. Otherwise, this function returns NULL. | |
452 | */ | |
21193dcd | 453 | static struct avc_node *avc_insert(u32 ssid, u32 tsid, u16 tclass, struct av_decision *avd) |
1da177e4 LT |
454 | { |
455 | struct avc_node *pos, *node = NULL; | |
456 | int hvalue; | |
457 | unsigned long flag; | |
458 | ||
21193dcd | 459 | if (avc_latest_notif_update(avd->seqno, 1)) |
1da177e4 LT |
460 | goto out; |
461 | ||
462 | node = avc_alloc_node(); | |
463 | if (node) { | |
edf3d1ae EP |
464 | struct list_head *head; |
465 | spinlock_t *lock; | |
466 | ||
1da177e4 | 467 | hvalue = avc_hash(ssid, tsid, tclass); |
21193dcd | 468 | avc_node_populate(node, ssid, tsid, tclass, avd); |
1da177e4 | 469 | |
edf3d1ae EP |
470 | head = &avc_cache.slots[hvalue]; |
471 | lock = &avc_cache.slots_lock[hvalue]; | |
472 | ||
473 | spin_lock_irqsave(lock, flag); | |
474 | list_for_each_entry(pos, head, list) { | |
1da177e4 LT |
475 | if (pos->ae.ssid == ssid && |
476 | pos->ae.tsid == tsid && | |
477 | pos->ae.tclass == tclass) { | |
95fff33b | 478 | avc_node_replace(node, pos); |
1da177e4 LT |
479 | goto found; |
480 | } | |
481 | } | |
edf3d1ae | 482 | list_add_rcu(&node->list, head); |
1da177e4 | 483 | found: |
edf3d1ae | 484 | spin_unlock_irqrestore(lock, flag); |
1da177e4 LT |
485 | } |
486 | out: | |
487 | return node; | |
488 | } | |
489 | ||
490 | static inline void avc_print_ipv6_addr(struct audit_buffer *ab, | |
b5bf6c55 | 491 | struct in6_addr *addr, __be16 port, |
1da177e4 LT |
492 | char *name1, char *name2) |
493 | { | |
494 | if (!ipv6_addr_any(addr)) | |
5b095d98 | 495 | audit_log_format(ab, " %s=%pI6", name1, addr); |
1da177e4 LT |
496 | if (port) |
497 | audit_log_format(ab, " %s=%d", name2, ntohs(port)); | |
498 | } | |
499 | ||
87fcd70d | 500 | static inline void avc_print_ipv4_addr(struct audit_buffer *ab, __be32 addr, |
b5bf6c55 | 501 | __be16 port, char *name1, char *name2) |
1da177e4 LT |
502 | { |
503 | if (addr) | |
3685f25d | 504 | audit_log_format(ab, " %s=%pI4", name1, &addr); |
1da177e4 LT |
505 | if (port) |
506 | audit_log_format(ab, " %s=%d", name2, ntohs(port)); | |
507 | } | |
508 | ||
509 | /** | |
510 | * avc_audit - Audit the granting or denial of permissions. | |
511 | * @ssid: source security identifier | |
512 | * @tsid: target security identifier | |
513 | * @tclass: target security class | |
514 | * @requested: requested permissions | |
515 | * @avd: access vector decisions | |
516 | * @result: result from avc_has_perm_noaudit | |
517 | * @a: auxiliary audit data | |
518 | * | |
519 | * Audit the granting or denial of permissions in accordance | |
520 | * with the policy. This function is typically called by | |
521 | * avc_has_perm() after a permission check, but can also be | |
522 | * called directly by callers who use avc_has_perm_noaudit() | |
523 | * in order to separate the permission check from the auditing. | |
524 | * For example, this separation is useful when the permission check must | |
525 | * be performed under a lock, to allow the lock to be released | |
526 | * before calling the auditing code. | |
527 | */ | |
528 | void avc_audit(u32 ssid, u32 tsid, | |
95fff33b EP |
529 | u16 tclass, u32 requested, |
530 | struct av_decision *avd, int result, struct avc_audit_data *a) | |
1da177e4 | 531 | { |
cd77b821 | 532 | struct task_struct *tsk = current; |
1da177e4 LT |
533 | struct inode *inode = NULL; |
534 | u32 denied, audited; | |
535 | struct audit_buffer *ab; | |
536 | ||
537 | denied = requested & ~avd->allowed; | |
538 | if (denied) { | |
539 | audited = denied; | |
540 | if (!(audited & avd->auditdeny)) | |
541 | return; | |
542 | } else if (result) { | |
543 | audited = denied = requested; | |
95fff33b | 544 | } else { |
1da177e4 LT |
545 | audited = requested; |
546 | if (!(audited & avd->auditallow)) | |
547 | return; | |
548 | } | |
549 | ||
9ad9ad38 | 550 | ab = audit_log_start(current->audit_context, GFP_ATOMIC, AUDIT_AVC); |
1da177e4 LT |
551 | if (!ab) |
552 | return; /* audit_panic has been called */ | |
553 | audit_log_format(ab, "avc: %s ", denied ? "denied" : "granted"); | |
95fff33b | 554 | avc_dump_av(ab, tclass, audited); |
1da177e4 | 555 | audit_log_format(ab, " for "); |
cd77b821 DW |
556 | if (a && a->tsk) |
557 | tsk = a->tsk; | |
7b5d781c | 558 | if (tsk && tsk->pid) { |
cd77b821 DW |
559 | audit_log_format(ab, " pid=%d comm=", tsk->pid); |
560 | audit_log_untrustedstring(ab, tsk->comm); | |
561 | } | |
1da177e4 LT |
562 | if (a) { |
563 | switch (a->type) { | |
564 | case AVC_AUDIT_DATA_IPC: | |
565 | audit_log_format(ab, " key=%d", a->u.ipc_id); | |
566 | break; | |
567 | case AVC_AUDIT_DATA_CAP: | |
568 | audit_log_format(ab, " capability=%d", a->u.cap); | |
569 | break; | |
570 | case AVC_AUDIT_DATA_FS: | |
44707fdf JB |
571 | if (a->u.fs.path.dentry) { |
572 | struct dentry *dentry = a->u.fs.path.dentry; | |
573 | if (a->u.fs.path.mnt) { | |
574 | audit_log_d_path(ab, "path=", | |
575 | &a->u.fs.path); | |
4259fa01 AV |
576 | } else { |
577 | audit_log_format(ab, " name="); | |
578 | audit_log_untrustedstring(ab, dentry->d_name.name); | |
579 | } | |
1da177e4 LT |
580 | inode = dentry->d_inode; |
581 | } else if (a->u.fs.inode) { | |
582 | struct dentry *dentry; | |
583 | inode = a->u.fs.inode; | |
584 | dentry = d_find_alias(inode); | |
585 | if (dentry) { | |
37ca5389 SS |
586 | audit_log_format(ab, " name="); |
587 | audit_log_untrustedstring(ab, dentry->d_name.name); | |
1da177e4 LT |
588 | dput(dentry); |
589 | } | |
590 | } | |
591 | if (inode) | |
13bddc2e | 592 | audit_log_format(ab, " dev=%s ino=%lu", |
1da177e4 LT |
593 | inode->i_sb->s_id, |
594 | inode->i_ino); | |
595 | break; | |
596 | case AVC_AUDIT_DATA_NET: | |
597 | if (a->u.net.sk) { | |
598 | struct sock *sk = a->u.net.sk; | |
599 | struct unix_sock *u; | |
600 | int len = 0; | |
601 | char *p = NULL; | |
602 | ||
603 | switch (sk->sk_family) { | |
604 | case AF_INET: { | |
605 | struct inet_sock *inet = inet_sk(sk); | |
606 | ||
607 | avc_print_ipv4_addr(ab, inet->rcv_saddr, | |
608 | inet->sport, | |
609 | "laddr", "lport"); | |
610 | avc_print_ipv4_addr(ab, inet->daddr, | |
611 | inet->dport, | |
612 | "faddr", "fport"); | |
613 | break; | |
614 | } | |
615 | case AF_INET6: { | |
616 | struct inet_sock *inet = inet_sk(sk); | |
617 | struct ipv6_pinfo *inet6 = inet6_sk(sk); | |
618 | ||
619 | avc_print_ipv6_addr(ab, &inet6->rcv_saddr, | |
620 | inet->sport, | |
621 | "laddr", "lport"); | |
622 | avc_print_ipv6_addr(ab, &inet6->daddr, | |
623 | inet->dport, | |
624 | "faddr", "fport"); | |
625 | break; | |
626 | } | |
627 | case AF_UNIX: | |
628 | u = unix_sk(sk); | |
629 | if (u->dentry) { | |
44707fdf JB |
630 | struct path path = { |
631 | .dentry = u->dentry, | |
632 | .mnt = u->mnt | |
633 | }; | |
4259fa01 | 634 | audit_log_d_path(ab, "path=", |
44707fdf | 635 | &path); |
1da177e4 LT |
636 | break; |
637 | } | |
638 | if (!u->addr) | |
639 | break; | |
640 | len = u->addr->len-sizeof(short); | |
641 | p = &u->addr->name->sun_path[0]; | |
37ca5389 | 642 | audit_log_format(ab, " path="); |
1da177e4 | 643 | if (*p) |
37ca5389 | 644 | audit_log_untrustedstring(ab, p); |
1da177e4 | 645 | else |
b556f8ad | 646 | audit_log_n_hex(ab, p, len); |
1da177e4 LT |
647 | break; |
648 | } | |
649 | } | |
95fff33b | 650 | |
1da177e4 LT |
651 | switch (a->u.net.family) { |
652 | case AF_INET: | |
653 | avc_print_ipv4_addr(ab, a->u.net.v4info.saddr, | |
654 | a->u.net.sport, | |
655 | "saddr", "src"); | |
656 | avc_print_ipv4_addr(ab, a->u.net.v4info.daddr, | |
657 | a->u.net.dport, | |
658 | "daddr", "dest"); | |
659 | break; | |
660 | case AF_INET6: | |
661 | avc_print_ipv6_addr(ab, &a->u.net.v6info.saddr, | |
662 | a->u.net.sport, | |
663 | "saddr", "src"); | |
664 | avc_print_ipv6_addr(ab, &a->u.net.v6info.daddr, | |
665 | a->u.net.dport, | |
666 | "daddr", "dest"); | |
667 | break; | |
668 | } | |
da5645a2 PM |
669 | if (a->u.net.netif > 0) { |
670 | struct net_device *dev; | |
671 | ||
672 | /* NOTE: we always use init's namespace */ | |
673 | dev = dev_get_by_index(&init_net, | |
674 | a->u.net.netif); | |
675 | if (dev) { | |
676 | audit_log_format(ab, " netif=%s", | |
677 | dev->name); | |
678 | dev_put(dev); | |
679 | } | |
680 | } | |
1da177e4 LT |
681 | break; |
682 | } | |
683 | } | |
684 | audit_log_format(ab, " "); | |
685 | avc_dump_query(ab, ssid, tsid, tclass); | |
686 | audit_log_end(ab); | |
687 | } | |
688 | ||
689 | /** | |
690 | * avc_add_callback - Register a callback for security events. | |
691 | * @callback: callback function | |
692 | * @events: security events | |
693 | * @ssid: source security identifier or %SECSID_WILD | |
694 | * @tsid: target security identifier or %SECSID_WILD | |
695 | * @tclass: target security class | |
696 | * @perms: permissions | |
697 | * | |
698 | * Register a callback function for events in the set @events | |
699 | * related to the SID pair (@ssid, @tsid) and | |
700 | * and the permissions @perms, interpreting | |
701 | * @perms based on @tclass. Returns %0 on success or | |
702 | * -%ENOMEM if insufficient memory exists to add the callback. | |
703 | */ | |
704 | int avc_add_callback(int (*callback)(u32 event, u32 ssid, u32 tsid, | |
95fff33b EP |
705 | u16 tclass, u32 perms, |
706 | u32 *out_retained), | |
707 | u32 events, u32 ssid, u32 tsid, | |
708 | u16 tclass, u32 perms) | |
1da177e4 LT |
709 | { |
710 | struct avc_callback_node *c; | |
711 | int rc = 0; | |
712 | ||
713 | c = kmalloc(sizeof(*c), GFP_ATOMIC); | |
714 | if (!c) { | |
715 | rc = -ENOMEM; | |
716 | goto out; | |
717 | } | |
718 | ||
719 | c->callback = callback; | |
720 | c->events = events; | |
721 | c->ssid = ssid; | |
722 | c->tsid = tsid; | |
723 | c->perms = perms; | |
724 | c->next = avc_callbacks; | |
725 | avc_callbacks = c; | |
726 | out: | |
727 | return rc; | |
728 | } | |
729 | ||
730 | static inline int avc_sidcmp(u32 x, u32 y) | |
731 | { | |
732 | return (x == y || x == SECSID_WILD || y == SECSID_WILD); | |
733 | } | |
734 | ||
735 | /** | |
736 | * avc_update_node Update an AVC entry | |
737 | * @event : Updating event | |
738 | * @perms : Permission mask bits | |
739 | * @ssid,@tsid,@tclass : identifier of an AVC entry | |
a5dda683 | 740 | * @seqno : sequence number when decision was made |
1da177e4 LT |
741 | * |
742 | * if a valid AVC entry doesn't exist,this function returns -ENOENT. | |
743 | * if kmalloc() called internal returns NULL, this function returns -ENOMEM. | |
744 | * otherwise, this function update the AVC entry. The original AVC-entry object | |
745 | * will release later by RCU. | |
746 | */ | |
a5dda683 EP |
747 | static int avc_update_node(u32 event, u32 perms, u32 ssid, u32 tsid, u16 tclass, |
748 | u32 seqno) | |
1da177e4 LT |
749 | { |
750 | int hvalue, rc = 0; | |
751 | unsigned long flag; | |
752 | struct avc_node *pos, *node, *orig = NULL; | |
edf3d1ae EP |
753 | struct list_head *head; |
754 | spinlock_t *lock; | |
1da177e4 LT |
755 | |
756 | node = avc_alloc_node(); | |
757 | if (!node) { | |
758 | rc = -ENOMEM; | |
759 | goto out; | |
760 | } | |
761 | ||
762 | /* Lock the target slot */ | |
763 | hvalue = avc_hash(ssid, tsid, tclass); | |
1da177e4 | 764 | |
edf3d1ae EP |
765 | head = &avc_cache.slots[hvalue]; |
766 | lock = &avc_cache.slots_lock[hvalue]; | |
767 | ||
768 | spin_lock_irqsave(lock, flag); | |
769 | ||
770 | list_for_each_entry(pos, head, list) { | |
95fff33b EP |
771 | if (ssid == pos->ae.ssid && |
772 | tsid == pos->ae.tsid && | |
a5dda683 EP |
773 | tclass == pos->ae.tclass && |
774 | seqno == pos->ae.avd.seqno){ | |
1da177e4 LT |
775 | orig = pos; |
776 | break; | |
777 | } | |
778 | } | |
779 | ||
780 | if (!orig) { | |
781 | rc = -ENOENT; | |
782 | avc_node_kill(node); | |
783 | goto out_unlock; | |
784 | } | |
785 | ||
786 | /* | |
787 | * Copy and replace original node. | |
788 | */ | |
789 | ||
21193dcd | 790 | avc_node_populate(node, ssid, tsid, tclass, &orig->ae.avd); |
1da177e4 LT |
791 | |
792 | switch (event) { | |
793 | case AVC_CALLBACK_GRANT: | |
794 | node->ae.avd.allowed |= perms; | |
795 | break; | |
796 | case AVC_CALLBACK_TRY_REVOKE: | |
797 | case AVC_CALLBACK_REVOKE: | |
798 | node->ae.avd.allowed &= ~perms; | |
799 | break; | |
800 | case AVC_CALLBACK_AUDITALLOW_ENABLE: | |
801 | node->ae.avd.auditallow |= perms; | |
802 | break; | |
803 | case AVC_CALLBACK_AUDITALLOW_DISABLE: | |
804 | node->ae.avd.auditallow &= ~perms; | |
805 | break; | |
806 | case AVC_CALLBACK_AUDITDENY_ENABLE: | |
807 | node->ae.avd.auditdeny |= perms; | |
808 | break; | |
809 | case AVC_CALLBACK_AUDITDENY_DISABLE: | |
810 | node->ae.avd.auditdeny &= ~perms; | |
811 | break; | |
812 | } | |
813 | avc_node_replace(node, orig); | |
814 | out_unlock: | |
edf3d1ae | 815 | spin_unlock_irqrestore(lock, flag); |
1da177e4 LT |
816 | out: |
817 | return rc; | |
818 | } | |
819 | ||
820 | /** | |
821 | * avc_ss_reset - Flush the cache and revalidate migrated permissions. | |
822 | * @seqno: policy sequence number | |
823 | */ | |
824 | int avc_ss_reset(u32 seqno) | |
825 | { | |
826 | struct avc_callback_node *c; | |
376bd9cb | 827 | int i, rc = 0, tmprc; |
1da177e4 LT |
828 | unsigned long flag; |
829 | struct avc_node *node; | |
edf3d1ae EP |
830 | struct list_head *head; |
831 | spinlock_t *lock; | |
1da177e4 LT |
832 | |
833 | for (i = 0; i < AVC_CACHE_SLOTS; i++) { | |
edf3d1ae EP |
834 | head = &avc_cache.slots[i]; |
835 | lock = &avc_cache.slots_lock[i]; | |
836 | ||
837 | spin_lock_irqsave(lock, flag); | |
61844250 PM |
838 | /* |
839 | * With preemptable RCU, the outer spinlock does not | |
840 | * prevent RCU grace periods from ending. | |
841 | */ | |
842 | rcu_read_lock(); | |
edf3d1ae | 843 | list_for_each_entry(node, head, list) |
1da177e4 | 844 | avc_node_delete(node); |
61844250 | 845 | rcu_read_unlock(); |
edf3d1ae | 846 | spin_unlock_irqrestore(lock, flag); |
1da177e4 LT |
847 | } |
848 | ||
849 | for (c = avc_callbacks; c; c = c->next) { | |
850 | if (c->events & AVC_CALLBACK_RESET) { | |
376bd9cb | 851 | tmprc = c->callback(AVC_CALLBACK_RESET, |
95fff33b | 852 | 0, 0, 0, 0, NULL); |
376bd9cb DG |
853 | /* save the first error encountered for the return |
854 | value and continue processing the callbacks */ | |
855 | if (!rc) | |
856 | rc = tmprc; | |
1da177e4 LT |
857 | } |
858 | } | |
859 | ||
860 | avc_latest_notif_update(seqno, 0); | |
1da177e4 LT |
861 | return rc; |
862 | } | |
863 | ||
864 | /** | |
865 | * avc_has_perm_noaudit - Check permissions but perform no auditing. | |
866 | * @ssid: source security identifier | |
867 | * @tsid: target security identifier | |
868 | * @tclass: target security class | |
869 | * @requested: requested permissions, interpreted based on @tclass | |
2c3c05db | 870 | * @flags: AVC_STRICT or 0 |
1da177e4 LT |
871 | * @avd: access vector decisions |
872 | * | |
873 | * Check the AVC to determine whether the @requested permissions are granted | |
874 | * for the SID pair (@ssid, @tsid), interpreting the permissions | |
875 | * based on @tclass, and call the security server on a cache miss to obtain | |
876 | * a new decision and add it to the cache. Return a copy of the decisions | |
877 | * in @avd. Return %0 if all @requested permissions are granted, | |
878 | * -%EACCES if any permissions are denied, or another -errno upon | |
879 | * other errors. This function is typically called by avc_has_perm(), | |
880 | * but may also be called directly to separate permission checking from | |
881 | * auditing, e.g. in cases where a lock must be held for the check but | |
882 | * should be released for the auditing. | |
883 | */ | |
884 | int avc_has_perm_noaudit(u32 ssid, u32 tsid, | |
2c3c05db SS |
885 | u16 tclass, u32 requested, |
886 | unsigned flags, | |
21193dcd | 887 | struct av_decision *in_avd) |
1da177e4 LT |
888 | { |
889 | struct avc_node *node; | |
21193dcd | 890 | struct av_decision avd_entry, *avd; |
1da177e4 LT |
891 | int rc = 0; |
892 | u32 denied; | |
893 | ||
eda4f69c EP |
894 | BUG_ON(!requested); |
895 | ||
1da177e4 LT |
896 | rcu_read_lock(); |
897 | ||
f1c6381a | 898 | node = avc_lookup(ssid, tsid, tclass); |
1da177e4 LT |
899 | if (!node) { |
900 | rcu_read_unlock(); | |
21193dcd EP |
901 | |
902 | if (in_avd) | |
903 | avd = in_avd; | |
904 | else | |
905 | avd = &avd_entry; | |
906 | ||
907 | rc = security_compute_av(ssid, tsid, tclass, requested, avd); | |
1da177e4 LT |
908 | if (rc) |
909 | goto out; | |
910 | rcu_read_lock(); | |
21193dcd EP |
911 | node = avc_insert(ssid, tsid, tclass, avd); |
912 | } else { | |
913 | if (in_avd) | |
914 | memcpy(in_avd, &node->ae.avd, sizeof(*in_avd)); | |
915 | avd = &node->ae.avd; | |
1da177e4 LT |
916 | } |
917 | ||
21193dcd | 918 | denied = requested & ~(avd->allowed); |
1da177e4 | 919 | |
eda4f69c | 920 | if (denied) { |
64dbf074 | 921 | if (flags & AVC_STRICT) |
1da177e4 | 922 | rc = -EACCES; |
64dbf074 EP |
923 | else if (!selinux_enforcing || security_permissive_sid(ssid)) |
924 | avc_update_node(AVC_CALLBACK_GRANT, requested, ssid, | |
21193dcd | 925 | tsid, tclass, avd->seqno); |
1da177e4 | 926 | else |
64dbf074 | 927 | rc = -EACCES; |
1da177e4 LT |
928 | } |
929 | ||
930 | rcu_read_unlock(); | |
931 | out: | |
932 | return rc; | |
933 | } | |
934 | ||
935 | /** | |
936 | * avc_has_perm - Check permissions and perform any appropriate auditing. | |
937 | * @ssid: source security identifier | |
938 | * @tsid: target security identifier | |
939 | * @tclass: target security class | |
940 | * @requested: requested permissions, interpreted based on @tclass | |
941 | * @auditdata: auxiliary audit data | |
942 | * | |
943 | * Check the AVC to determine whether the @requested permissions are granted | |
944 | * for the SID pair (@ssid, @tsid), interpreting the permissions | |
945 | * based on @tclass, and call the security server on a cache miss to obtain | |
946 | * a new decision and add it to the cache. Audit the granting or denial of | |
947 | * permissions in accordance with the policy. Return %0 if all @requested | |
948 | * permissions are granted, -%EACCES if any permissions are denied, or | |
949 | * another -errno upon other errors. | |
950 | */ | |
951 | int avc_has_perm(u32 ssid, u32 tsid, u16 tclass, | |
95fff33b | 952 | u32 requested, struct avc_audit_data *auditdata) |
1da177e4 LT |
953 | { |
954 | struct av_decision avd; | |
955 | int rc; | |
956 | ||
2c3c05db | 957 | rc = avc_has_perm_noaudit(ssid, tsid, tclass, requested, 0, &avd); |
1da177e4 LT |
958 | avc_audit(ssid, tsid, tclass, requested, &avd, rc, auditdata); |
959 | return rc; | |
960 | } | |
788e7dd4 YN |
961 | |
962 | u32 avc_policy_seqno(void) | |
963 | { | |
964 | return avc_cache.latest_notif; | |
965 | } |