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f1bd9041 JJ |
1 | /* |
2 | * AppArmor security module | |
3 | * | |
4 | * This file contains AppArmor label definitions | |
5 | * | |
6 | * Copyright 2017 Canonical Ltd. | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or | |
9 | * modify it under the terms of the GNU General Public License as | |
10 | * published by the Free Software Foundation, version 2 of the | |
11 | * License. | |
12 | */ | |
13 | ||
14 | #include <linux/audit.h> | |
15 | #include <linux/seq_file.h> | |
16 | #include <linux/sort.h> | |
17 | ||
18 | #include "include/apparmor.h" | |
19 | #include "include/context.h" | |
20 | #include "include/label.h" | |
21 | #include "include/policy.h" | |
22 | #include "include/secid.h" | |
23 | ||
24 | ||
25 | /* | |
26 | * the aa_label represents the set of profiles confining an object | |
27 | * | |
28 | * Labels maintain a reference count to the set of pointers they reference | |
29 | * Labels are ref counted by | |
30 | * tasks and object via the security field/security context off the field | |
31 | * code - will take a ref count on a label if it needs the label | |
32 | * beyond what is possible with an rcu_read_lock. | |
33 | * profiles - each profile is a label | |
34 | * secids - a pinned secid will keep a refcount of the label it is | |
35 | * referencing | |
36 | * objects - inode, files, sockets, ... | |
37 | * | |
38 | * Labels are not ref counted by the label set, so they maybe removed and | |
39 | * freed when no longer in use. | |
40 | * | |
41 | */ | |
42 | ||
43 | #define PROXY_POISON 97 | |
44 | #define LABEL_POISON 100 | |
45 | ||
46 | static void free_proxy(struct aa_proxy *proxy) | |
47 | { | |
48 | if (proxy) { | |
49 | /* p->label will not updated any more as p is dead */ | |
50 | aa_put_label(rcu_dereference_protected(proxy->label, true)); | |
51 | memset(proxy, 0, sizeof(*proxy)); | |
bc4d82fb | 52 | RCU_INIT_POINTER(proxy->label, (struct aa_label *)PROXY_POISON); |
f1bd9041 JJ |
53 | kfree(proxy); |
54 | } | |
55 | } | |
56 | ||
57 | void aa_proxy_kref(struct kref *kref) | |
58 | { | |
59 | struct aa_proxy *proxy = container_of(kref, struct aa_proxy, count); | |
60 | ||
61 | free_proxy(proxy); | |
62 | } | |
63 | ||
64 | struct aa_proxy *aa_alloc_proxy(struct aa_label *label, gfp_t gfp) | |
65 | { | |
66 | struct aa_proxy *new; | |
67 | ||
68 | new = kzalloc(sizeof(struct aa_proxy), gfp); | |
69 | if (new) { | |
70 | kref_init(&new->count); | |
71 | rcu_assign_pointer(new->label, aa_get_label(label)); | |
72 | } | |
73 | return new; | |
74 | } | |
75 | ||
76 | /* requires profile list write lock held */ | |
77 | void __aa_proxy_redirect(struct aa_label *orig, struct aa_label *new) | |
78 | { | |
79 | struct aa_label *tmp; | |
80 | ||
81 | AA_BUG(!orig); | |
82 | AA_BUG(!new); | |
83 | AA_BUG(!write_is_locked(&labels_set(orig)->lock)); | |
84 | ||
85 | tmp = rcu_dereference_protected(orig->proxy->label, | |
86 | &labels_ns(orig)->lock); | |
87 | rcu_assign_pointer(orig->proxy->label, aa_get_label(new)); | |
88 | orig->flags |= FLAG_STALE; | |
89 | aa_put_label(tmp); | |
90 | } | |
91 | ||
92 | static void __proxy_share(struct aa_label *old, struct aa_label *new) | |
93 | { | |
94 | struct aa_proxy *proxy = new->proxy; | |
95 | ||
96 | new->proxy = aa_get_proxy(old->proxy); | |
97 | __aa_proxy_redirect(old, new); | |
98 | aa_put_proxy(proxy); | |
99 | } | |
100 | ||
101 | ||
102 | /** | |
103 | * ns_cmp - compare ns for label set ordering | |
104 | * @a: ns to compare (NOT NULL) | |
105 | * @b: ns to compare (NOT NULL) | |
106 | * | |
107 | * Returns: <0 if a < b | |
108 | * ==0 if a == b | |
109 | * >0 if a > b | |
110 | */ | |
111 | static int ns_cmp(struct aa_ns *a, struct aa_ns *b) | |
112 | { | |
113 | int res; | |
114 | ||
115 | AA_BUG(!a); | |
116 | AA_BUG(!b); | |
117 | AA_BUG(!a->base.hname); | |
118 | AA_BUG(!b->base.hname); | |
119 | ||
120 | if (a == b) | |
121 | return 0; | |
122 | ||
123 | res = a->level - b->level; | |
124 | if (res) | |
125 | return res; | |
126 | ||
127 | return strcmp(a->base.hname, b->base.hname); | |
128 | } | |
129 | ||
130 | /** | |
131 | * profile_cmp - profile comparision for set ordering | |
132 | * @a: profile to compare (NOT NULL) | |
133 | * @b: profile to compare (NOT NULL) | |
134 | * | |
135 | * Returns: <0 if a < b | |
136 | * ==0 if a == b | |
137 | * >0 if a > b | |
138 | */ | |
139 | static int profile_cmp(struct aa_profile *a, struct aa_profile *b) | |
140 | { | |
141 | int res; | |
142 | ||
143 | AA_BUG(!a); | |
144 | AA_BUG(!b); | |
145 | AA_BUG(!a->ns); | |
146 | AA_BUG(!b->ns); | |
147 | AA_BUG(!a->base.hname); | |
148 | AA_BUG(!b->base.hname); | |
149 | ||
150 | if (a == b || a->base.hname == b->base.hname) | |
151 | return 0; | |
152 | res = ns_cmp(a->ns, b->ns); | |
153 | if (res) | |
154 | return res; | |
155 | ||
156 | return strcmp(a->base.hname, b->base.hname); | |
157 | } | |
158 | ||
159 | /** | |
160 | * vec_cmp - label comparision for set ordering | |
161 | * @a: label to compare (NOT NULL) | |
162 | * @vec: vector of profiles to compare (NOT NULL) | |
163 | * @n: length of @vec | |
164 | * | |
165 | * Returns: <0 if a < vec | |
166 | * ==0 if a == vec | |
167 | * >0 if a > vec | |
168 | */ | |
169 | static int vec_cmp(struct aa_profile **a, int an, struct aa_profile **b, int bn) | |
170 | { | |
171 | int i; | |
172 | ||
173 | AA_BUG(!a); | |
174 | AA_BUG(!*a); | |
175 | AA_BUG(!b); | |
176 | AA_BUG(!*b); | |
177 | AA_BUG(an <= 0); | |
178 | AA_BUG(bn <= 0); | |
179 | ||
180 | for (i = 0; i < an && i < bn; i++) { | |
181 | int res = profile_cmp(a[i], b[i]); | |
182 | ||
183 | if (res != 0) | |
184 | return res; | |
185 | } | |
186 | ||
187 | return an - bn; | |
188 | } | |
189 | ||
190 | static bool vec_is_stale(struct aa_profile **vec, int n) | |
191 | { | |
192 | int i; | |
193 | ||
194 | AA_BUG(!vec); | |
195 | ||
196 | for (i = 0; i < n; i++) { | |
197 | if (profile_is_stale(vec[i])) | |
198 | return true; | |
199 | } | |
200 | ||
201 | return false; | |
202 | } | |
203 | ||
204 | static bool vec_unconfined(struct aa_profile **vec, int n) | |
205 | { | |
206 | int i; | |
207 | ||
208 | AA_BUG(!vec); | |
209 | ||
210 | for (i = 0; i < n; i++) { | |
211 | if (!profile_unconfined(vec[i])) | |
212 | return false; | |
213 | } | |
214 | ||
215 | return true; | |
216 | } | |
217 | ||
218 | static int sort_cmp(const void *a, const void *b) | |
219 | { | |
220 | return profile_cmp(*(struct aa_profile **)a, *(struct aa_profile **)b); | |
221 | } | |
222 | ||
223 | /* | |
224 | * assumes vec is sorted | |
225 | * Assumes @vec has null terminator at vec[n], and will null terminate | |
226 | * vec[n - dups] | |
227 | */ | |
228 | static inline int unique(struct aa_profile **vec, int n) | |
229 | { | |
230 | int i, pos, dups = 0; | |
231 | ||
232 | AA_BUG(n < 1); | |
233 | AA_BUG(!vec); | |
234 | ||
235 | pos = 0; | |
236 | for (i = 1; i < n; i++) { | |
237 | int res = profile_cmp(vec[pos], vec[i]); | |
238 | ||
239 | AA_BUG(res > 0, "vec not sorted"); | |
240 | if (res == 0) { | |
241 | /* drop duplicate */ | |
242 | aa_put_profile(vec[i]); | |
243 | dups++; | |
244 | continue; | |
245 | } | |
246 | pos++; | |
247 | if (dups) | |
248 | vec[pos] = vec[i]; | |
249 | } | |
250 | ||
251 | AA_BUG(dups < 0); | |
252 | ||
253 | return dups; | |
254 | } | |
255 | ||
256 | /** | |
257 | * aa_vec_unique - canonical sort and unique a list of profiles | |
258 | * @n: number of refcounted profiles in the list (@n > 0) | |
259 | * @vec: list of profiles to sort and merge | |
260 | * | |
261 | * Returns: the number of duplicates eliminated == references put | |
262 | * | |
263 | * If @flags & VEC_FLAG_TERMINATE @vec has null terminator at vec[n], and will | |
264 | * null terminate vec[n - dups] | |
265 | */ | |
266 | int aa_vec_unique(struct aa_profile **vec, int n, int flags) | |
267 | { | |
268 | int i, dups = 0; | |
269 | ||
270 | AA_BUG(n < 1); | |
271 | AA_BUG(!vec); | |
272 | ||
273 | /* vecs are usually small and inorder, have a fallback for larger */ | |
274 | if (n > 8) { | |
275 | sort(vec, n, sizeof(struct aa_profile *), sort_cmp, NULL); | |
276 | dups = unique(vec, n); | |
277 | goto out; | |
278 | } | |
279 | ||
280 | /* insertion sort + unique in one */ | |
281 | for (i = 1; i < n; i++) { | |
282 | struct aa_profile *tmp = vec[i]; | |
283 | int pos, j; | |
284 | ||
285 | for (pos = i - 1 - dups; pos >= 0; pos--) { | |
286 | int res = profile_cmp(vec[pos], tmp); | |
287 | ||
288 | if (res == 0) { | |
289 | /* drop duplicate entry */ | |
290 | aa_put_profile(tmp); | |
291 | dups++; | |
292 | goto continue_outer; | |
293 | } else if (res < 0) | |
294 | break; | |
295 | } | |
296 | /* pos is at entry < tmp, or index -1. Set to insert pos */ | |
297 | pos++; | |
298 | ||
299 | for (j = i - dups; j > pos; j--) | |
300 | vec[j] = vec[j - 1]; | |
301 | vec[pos] = tmp; | |
302 | continue_outer: | |
303 | ; | |
304 | } | |
305 | ||
306 | AA_BUG(dups < 0); | |
307 | ||
308 | out: | |
309 | if (flags & VEC_FLAG_TERMINATE) | |
310 | vec[n - dups] = NULL; | |
311 | ||
312 | return dups; | |
313 | } | |
314 | ||
315 | ||
316 | static void label_destroy(struct aa_label *label) | |
317 | { | |
318 | struct aa_label *tmp; | |
319 | ||
320 | AA_BUG(!label); | |
321 | ||
322 | if (!label_isprofile(label)) { | |
323 | struct aa_profile *profile; | |
324 | struct label_it i; | |
325 | ||
326 | aa_put_str(label->hname); | |
327 | ||
328 | label_for_each(i, label, profile) { | |
329 | aa_put_profile(profile); | |
330 | label->vec[i.i] = (struct aa_profile *) | |
331 | (LABEL_POISON + (long) i.i); | |
332 | } | |
333 | } | |
334 | ||
335 | if (rcu_dereference_protected(label->proxy->label, true) == label) | |
336 | rcu_assign_pointer(label->proxy->label, NULL); | |
337 | ||
338 | aa_free_secid(label->secid); | |
339 | ||
340 | tmp = rcu_dereference_protected(label->proxy->label, true); | |
341 | if (tmp == label) | |
342 | rcu_assign_pointer(label->proxy->label, NULL); | |
343 | ||
344 | aa_put_proxy(label->proxy); | |
345 | label->proxy = (struct aa_proxy *) PROXY_POISON + 1; | |
346 | } | |
347 | ||
348 | void aa_label_free(struct aa_label *label) | |
349 | { | |
350 | if (!label) | |
351 | return; | |
352 | ||
353 | label_destroy(label); | |
354 | kfree(label); | |
355 | } | |
356 | ||
357 | static void label_free_switch(struct aa_label *label) | |
358 | { | |
359 | if (label->flags & FLAG_NS_COUNT) | |
360 | aa_free_ns(labels_ns(label)); | |
361 | else if (label_isprofile(label)) | |
362 | aa_free_profile(labels_profile(label)); | |
363 | else | |
364 | aa_label_free(label); | |
365 | } | |
366 | ||
367 | static void label_free_rcu(struct rcu_head *head) | |
368 | { | |
369 | struct aa_label *label = container_of(head, struct aa_label, rcu); | |
370 | ||
371 | if (label->flags & FLAG_IN_TREE) | |
372 | (void) aa_label_remove(label); | |
373 | label_free_switch(label); | |
374 | } | |
375 | ||
376 | void aa_label_kref(struct kref *kref) | |
377 | { | |
378 | struct aa_label *label = container_of(kref, struct aa_label, count); | |
379 | struct aa_ns *ns = labels_ns(label); | |
380 | ||
381 | if (!ns) { | |
382 | /* never live, no rcu callback needed, just using the fn */ | |
383 | label_free_switch(label); | |
384 | return; | |
385 | } | |
386 | /* TODO: update labels_profile macro so it works here */ | |
387 | AA_BUG(label_isprofile(label) && | |
388 | on_list_rcu(&label->vec[0]->base.profiles)); | |
389 | AA_BUG(label_isprofile(label) && | |
390 | on_list_rcu(&label->vec[0]->base.list)); | |
391 | ||
392 | /* TODO: if compound label and not stale add to reclaim cache */ | |
393 | call_rcu(&label->rcu, label_free_rcu); | |
394 | } | |
395 | ||
396 | static void label_free_or_put_new(struct aa_label *label, struct aa_label *new) | |
397 | { | |
398 | if (label != new) | |
399 | /* need to free directly to break circular ref with proxy */ | |
400 | aa_label_free(new); | |
401 | else | |
402 | aa_put_label(new); | |
403 | } | |
404 | ||
405 | bool aa_label_init(struct aa_label *label, int size) | |
406 | { | |
407 | AA_BUG(!label); | |
408 | AA_BUG(size < 1); | |
409 | ||
410 | label->secid = aa_alloc_secid(); | |
411 | if (label->secid == AA_SECID_INVALID) | |
412 | return false; | |
413 | ||
414 | label->size = size; /* doesn't include null */ | |
415 | label->vec[size] = NULL; /* null terminate */ | |
416 | kref_init(&label->count); | |
417 | RB_CLEAR_NODE(&label->node); | |
418 | ||
419 | return true; | |
420 | } | |
421 | ||
422 | /** | |
423 | * aa_label_alloc - allocate a label with a profile vector of @size length | |
424 | * @size: size of profile vector in the label | |
425 | * @proxy: proxy to use OR null if to allocate a new one | |
426 | * @gfp: memory allocation type | |
427 | * | |
428 | * Returns: new label | |
429 | * else NULL if failed | |
430 | */ | |
431 | struct aa_label *aa_label_alloc(int size, struct aa_proxy *proxy, gfp_t gfp) | |
432 | { | |
433 | struct aa_label *new; | |
434 | ||
435 | AA_BUG(size < 1); | |
436 | ||
437 | /* + 1 for null terminator entry on vec */ | |
438 | new = kzalloc(sizeof(*new) + sizeof(struct aa_profile *) * (size + 1), | |
439 | gfp); | |
440 | AA_DEBUG("%s (%p)\n", __func__, new); | |
441 | if (!new) | |
442 | goto fail; | |
443 | ||
444 | if (!aa_label_init(new, size)) | |
445 | goto fail; | |
446 | ||
447 | if (!proxy) { | |
448 | proxy = aa_alloc_proxy(new, gfp); | |
449 | if (!proxy) | |
450 | goto fail; | |
451 | } else | |
452 | aa_get_proxy(proxy); | |
453 | /* just set new's proxy, don't redirect proxy here if it was passed in*/ | |
454 | new->proxy = proxy; | |
455 | ||
456 | return new; | |
457 | ||
458 | fail: | |
459 | kfree(new); | |
460 | ||
461 | return NULL; | |
462 | } | |
463 | ||
464 | ||
465 | /** | |
466 | * label_cmp - label comparision for set ordering | |
467 | * @a: label to compare (NOT NULL) | |
468 | * @b: label to compare (NOT NULL) | |
469 | * | |
470 | * Returns: <0 if a < b | |
471 | * ==0 if a == b | |
472 | * >0 if a > b | |
473 | */ | |
474 | static int label_cmp(struct aa_label *a, struct aa_label *b) | |
475 | { | |
476 | AA_BUG(!b); | |
477 | ||
478 | if (a == b) | |
479 | return 0; | |
480 | ||
481 | return vec_cmp(a->vec, a->size, b->vec, b->size); | |
482 | } | |
483 | ||
484 | /* helper fn for label_for_each_confined */ | |
485 | int aa_label_next_confined(struct aa_label *label, int i) | |
486 | { | |
487 | AA_BUG(!label); | |
488 | AA_BUG(i < 0); | |
489 | ||
490 | for (; i < label->size; i++) { | |
491 | if (!profile_unconfined(label->vec[i])) | |
492 | return i; | |
493 | } | |
494 | ||
495 | return i; | |
496 | } | |
497 | ||
498 | /** | |
499 | * aa_label_next_not_in_set - return the next profile of @sub not in @set | |
500 | * @I: label iterator | |
501 | * @set: label to test against | |
502 | * @sub: label to if is subset of @set | |
503 | * | |
504 | * Returns: profile in @sub that is not in @set, with iterator set pos after | |
505 | * else NULL if @sub is a subset of @set | |
506 | */ | |
507 | struct aa_profile *__aa_label_next_not_in_set(struct label_it *I, | |
508 | struct aa_label *set, | |
509 | struct aa_label *sub) | |
510 | { | |
511 | AA_BUG(!set); | |
512 | AA_BUG(!I); | |
513 | AA_BUG(I->i < 0); | |
514 | AA_BUG(I->i > set->size); | |
515 | AA_BUG(!sub); | |
516 | AA_BUG(I->j < 0); | |
517 | AA_BUG(I->j > sub->size); | |
518 | ||
519 | while (I->j < sub->size && I->i < set->size) { | |
520 | int res = profile_cmp(sub->vec[I->j], set->vec[I->i]); | |
521 | ||
522 | if (res == 0) { | |
523 | (I->j)++; | |
524 | (I->i)++; | |
525 | } else if (res > 0) | |
526 | (I->i)++; | |
527 | else | |
528 | return sub->vec[(I->j)++]; | |
529 | } | |
530 | ||
531 | if (I->j < sub->size) | |
532 | return sub->vec[(I->j)++]; | |
533 | ||
534 | return NULL; | |
535 | } | |
536 | ||
537 | /** | |
538 | * aa_label_is_subset - test if @sub is a subset of @set | |
539 | * @set: label to test against | |
540 | * @sub: label to test if is subset of @set | |
541 | * | |
542 | * Returns: true if @sub is subset of @set | |
543 | * else false | |
544 | */ | |
545 | bool aa_label_is_subset(struct aa_label *set, struct aa_label *sub) | |
546 | { | |
547 | struct label_it i = { }; | |
548 | ||
549 | AA_BUG(!set); | |
550 | AA_BUG(!sub); | |
551 | ||
552 | if (sub == set) | |
553 | return true; | |
554 | ||
555 | return __aa_label_next_not_in_set(&i, set, sub) == NULL; | |
556 | } | |
557 | ||
558 | ||
559 | ||
560 | /** | |
561 | * __label_remove - remove @label from the label set | |
562 | * @l: label to remove | |
563 | * @new: label to redirect to | |
564 | * | |
565 | * Requires: labels_set(@label)->lock write_lock | |
566 | * Returns: true if the label was in the tree and removed | |
567 | */ | |
568 | static bool __label_remove(struct aa_label *label, struct aa_label *new) | |
569 | { | |
570 | struct aa_labelset *ls = labels_set(label); | |
571 | ||
572 | AA_BUG(!ls); | |
573 | AA_BUG(!label); | |
574 | AA_BUG(!write_is_locked(&ls->lock)); | |
575 | ||
576 | if (new) | |
577 | __aa_proxy_redirect(label, new); | |
578 | ||
579 | if (!label_is_stale(label)) | |
580 | __label_make_stale(label); | |
581 | ||
582 | if (label->flags & FLAG_IN_TREE) { | |
583 | rb_erase(&label->node, &ls->root); | |
584 | label->flags &= ~FLAG_IN_TREE; | |
585 | return true; | |
586 | } | |
587 | ||
588 | return false; | |
589 | } | |
590 | ||
591 | /** | |
592 | * __label_replace - replace @old with @new in label set | |
593 | * @old: label to remove from label set | |
594 | * @new: label to replace @old with | |
595 | * | |
596 | * Requires: labels_set(@old)->lock write_lock | |
597 | * valid ref count be held on @new | |
598 | * Returns: true if @old was in set and replaced by @new | |
599 | * | |
600 | * Note: current implementation requires label set be order in such a way | |
601 | * that @new directly replaces @old position in the set (ie. | |
602 | * using pointer comparison of the label address would not work) | |
603 | */ | |
604 | static bool __label_replace(struct aa_label *old, struct aa_label *new) | |
605 | { | |
606 | struct aa_labelset *ls = labels_set(old); | |
607 | ||
608 | AA_BUG(!ls); | |
609 | AA_BUG(!old); | |
610 | AA_BUG(!new); | |
611 | AA_BUG(!write_is_locked(&ls->lock)); | |
612 | AA_BUG(new->flags & FLAG_IN_TREE); | |
613 | ||
614 | if (!label_is_stale(old)) | |
615 | __label_make_stale(old); | |
616 | ||
617 | if (old->flags & FLAG_IN_TREE) { | |
618 | rb_replace_node(&old->node, &new->node, &ls->root); | |
619 | old->flags &= ~FLAG_IN_TREE; | |
620 | new->flags |= FLAG_IN_TREE; | |
621 | return true; | |
622 | } | |
623 | ||
624 | return false; | |
625 | } | |
626 | ||
627 | /** | |
628 | * __label_insert - attempt to insert @l into a label set | |
629 | * @ls: set of labels to insert @l into (NOT NULL) | |
630 | * @label: new label to insert (NOT NULL) | |
631 | * @replace: whether insertion should replace existing entry that is not stale | |
632 | * | |
633 | * Requires: @ls->lock | |
634 | * caller to hold a valid ref on l | |
635 | * if @replace is true l has a preallocated proxy associated | |
636 | * Returns: @l if successful in inserting @l - with additional refcount | |
637 | * else ref counted equivalent label that is already in the set, | |
638 | * the else condition only happens if @replace is false | |
639 | */ | |
640 | static struct aa_label *__label_insert(struct aa_labelset *ls, | |
641 | struct aa_label *label, bool replace) | |
642 | { | |
643 | struct rb_node **new, *parent = NULL; | |
644 | ||
645 | AA_BUG(!ls); | |
646 | AA_BUG(!label); | |
647 | AA_BUG(labels_set(label) != ls); | |
648 | AA_BUG(!write_is_locked(&ls->lock)); | |
649 | AA_BUG(label->flags & FLAG_IN_TREE); | |
650 | ||
651 | /* Figure out where to put new node */ | |
652 | new = &ls->root.rb_node; | |
653 | while (*new) { | |
654 | struct aa_label *this = rb_entry(*new, struct aa_label, node); | |
655 | int result = label_cmp(label, this); | |
656 | ||
657 | parent = *new; | |
658 | if (result == 0) { | |
659 | /* !__aa_get_label means queued for destruction, | |
660 | * so replace in place, however the label has | |
661 | * died before the replacement so do not share | |
662 | * the proxy | |
663 | */ | |
664 | if (!replace && !label_is_stale(this)) { | |
665 | if (__aa_get_label(this)) | |
666 | return this; | |
667 | } else | |
668 | __proxy_share(this, label); | |
669 | AA_BUG(!__label_replace(this, label)); | |
670 | return aa_get_label(label); | |
671 | } else if (result < 0) | |
672 | new = &((*new)->rb_left); | |
673 | else /* (result > 0) */ | |
674 | new = &((*new)->rb_right); | |
675 | } | |
676 | ||
677 | /* Add new node and rebalance tree. */ | |
678 | rb_link_node(&label->node, parent, new); | |
679 | rb_insert_color(&label->node, &ls->root); | |
680 | label->flags |= FLAG_IN_TREE; | |
681 | ||
682 | return aa_get_label(label); | |
683 | } | |
684 | ||
685 | /** | |
686 | * __vec_find - find label that matches @vec in label set | |
687 | * @vec: vec of profiles to find matching label for (NOT NULL) | |
688 | * @n: length of @vec | |
689 | * | |
690 | * Requires: @vec_labelset(vec) lock held | |
691 | * caller to hold a valid ref on l | |
692 | * | |
693 | * Returns: ref counted @label if matching label is in tree | |
694 | * ref counted label that is equiv to @l in tree | |
695 | * else NULL if @vec equiv is not in tree | |
696 | */ | |
697 | static struct aa_label *__vec_find(struct aa_profile **vec, int n) | |
698 | { | |
699 | struct rb_node *node; | |
700 | ||
701 | AA_BUG(!vec); | |
702 | AA_BUG(!*vec); | |
703 | AA_BUG(n <= 0); | |
704 | ||
705 | node = vec_labelset(vec, n)->root.rb_node; | |
706 | while (node) { | |
707 | struct aa_label *this = rb_entry(node, struct aa_label, node); | |
708 | int result = vec_cmp(this->vec, this->size, vec, n); | |
709 | ||
710 | if (result > 0) | |
711 | node = node->rb_left; | |
712 | else if (result < 0) | |
713 | node = node->rb_right; | |
714 | else | |
715 | return __aa_get_label(this); | |
716 | } | |
717 | ||
718 | return NULL; | |
719 | } | |
720 | ||
721 | /** | |
722 | * __label_find - find label @label in label set | |
723 | * @label: label to find (NOT NULL) | |
724 | * | |
725 | * Requires: labels_set(@label)->lock held | |
726 | * caller to hold a valid ref on l | |
727 | * | |
728 | * Returns: ref counted @label if @label is in tree OR | |
729 | * ref counted label that is equiv to @label in tree | |
730 | * else NULL if @label or equiv is not in tree | |
731 | */ | |
732 | static struct aa_label *__label_find(struct aa_label *label) | |
733 | { | |
734 | AA_BUG(!label); | |
735 | ||
736 | return __vec_find(label->vec, label->size); | |
737 | } | |
738 | ||
739 | ||
740 | /** | |
741 | * aa_label_remove - remove a label from the labelset | |
742 | * @label: label to remove | |
743 | * | |
744 | * Returns: true if @label was removed from the tree | |
745 | * else @label was not in tree so it could not be removed | |
746 | */ | |
747 | bool aa_label_remove(struct aa_label *label) | |
748 | { | |
749 | struct aa_labelset *ls = labels_set(label); | |
750 | unsigned long flags; | |
751 | bool res; | |
752 | ||
753 | AA_BUG(!ls); | |
754 | ||
755 | write_lock_irqsave(&ls->lock, flags); | |
756 | res = __label_remove(label, ns_unconfined(labels_ns(label))); | |
757 | write_unlock_irqrestore(&ls->lock, flags); | |
758 | ||
759 | return res; | |
760 | } | |
761 | ||
762 | /** | |
763 | * aa_label_replace - replace a label @old with a new version @new | |
764 | * @old: label to replace | |
765 | * @new: label replacing @old | |
766 | * | |
767 | * Returns: true if @old was in tree and replaced | |
768 | * else @old was not in tree, and @new was not inserted | |
769 | */ | |
770 | bool aa_label_replace(struct aa_label *old, struct aa_label *new) | |
771 | { | |
772 | unsigned long flags; | |
773 | bool res; | |
774 | ||
775 | if (name_is_shared(old, new) && labels_ns(old) == labels_ns(new)) { | |
776 | write_lock_irqsave(&labels_set(old)->lock, flags); | |
777 | if (old->proxy != new->proxy) | |
778 | __proxy_share(old, new); | |
779 | else | |
780 | __aa_proxy_redirect(old, new); | |
781 | res = __label_replace(old, new); | |
782 | write_unlock_irqrestore(&labels_set(old)->lock, flags); | |
783 | } else { | |
784 | struct aa_label *l; | |
785 | struct aa_labelset *ls = labels_set(old); | |
786 | ||
787 | write_lock_irqsave(&ls->lock, flags); | |
788 | res = __label_remove(old, new); | |
789 | if (labels_ns(old) != labels_ns(new)) { | |
790 | write_unlock_irqrestore(&ls->lock, flags); | |
791 | ls = labels_set(new); | |
792 | write_lock_irqsave(&ls->lock, flags); | |
793 | } | |
794 | l = __label_insert(ls, new, true); | |
795 | res = (l == new); | |
796 | write_unlock_irqrestore(&ls->lock, flags); | |
797 | aa_put_label(l); | |
798 | } | |
799 | ||
800 | return res; | |
801 | } | |
802 | ||
803 | /** | |
804 | * vec_find - find label @l in label set | |
805 | * @vec: array of profiles to find equiv label for (NOT NULL) | |
806 | * @n: length of @vec | |
807 | * | |
808 | * Returns: refcounted label if @vec equiv is in tree | |
809 | * else NULL if @vec equiv is not in tree | |
810 | */ | |
811 | static struct aa_label *vec_find(struct aa_profile **vec, int n) | |
812 | { | |
813 | struct aa_labelset *ls; | |
814 | struct aa_label *label; | |
815 | unsigned long flags; | |
816 | ||
817 | AA_BUG(!vec); | |
818 | AA_BUG(!*vec); | |
819 | AA_BUG(n <= 0); | |
820 | ||
821 | ls = vec_labelset(vec, n); | |
822 | read_lock_irqsave(&ls->lock, flags); | |
823 | label = __vec_find(vec, n); | |
824 | read_unlock_irqrestore(&ls->lock, flags); | |
825 | ||
826 | return label; | |
827 | } | |
828 | ||
829 | /* requires sort and merge done first */ | |
830 | static struct aa_label *vec_create_and_insert_label(struct aa_profile **vec, | |
831 | int len, gfp_t gfp) | |
832 | { | |
833 | struct aa_label *label = NULL; | |
834 | struct aa_labelset *ls; | |
835 | unsigned long flags; | |
836 | struct aa_label *new; | |
837 | int i; | |
838 | ||
839 | AA_BUG(!vec); | |
840 | ||
841 | if (len == 1) | |
842 | return aa_get_label(&vec[0]->label); | |
843 | ||
844 | ls = labels_set(&vec[len - 1]->label); | |
845 | ||
846 | /* TODO: enable when read side is lockless | |
847 | * check if label exists before taking locks | |
848 | */ | |
849 | new = aa_label_alloc(len, NULL, gfp); | |
850 | if (!new) | |
851 | return NULL; | |
852 | ||
853 | for (i = 0; i < len; i++) | |
854 | new->vec[i] = aa_get_profile(vec[i]); | |
855 | ||
856 | write_lock_irqsave(&ls->lock, flags); | |
857 | label = __label_insert(ls, new, false); | |
858 | write_unlock_irqrestore(&ls->lock, flags); | |
859 | label_free_or_put_new(label, new); | |
860 | ||
861 | return label; | |
862 | } | |
863 | ||
864 | struct aa_label *aa_vec_find_or_create_label(struct aa_profile **vec, int len, | |
865 | gfp_t gfp) | |
866 | { | |
867 | struct aa_label *label = vec_find(vec, len); | |
868 | ||
869 | if (label) | |
870 | return label; | |
871 | ||
872 | return vec_create_and_insert_label(vec, len, gfp); | |
873 | } | |
874 | ||
875 | /** | |
876 | * aa_label_find - find label @label in label set | |
877 | * @label: label to find (NOT NULL) | |
878 | * | |
879 | * Requires: caller to hold a valid ref on l | |
880 | * | |
881 | * Returns: refcounted @label if @label is in tree | |
882 | * refcounted label that is equiv to @label in tree | |
883 | * else NULL if @label or equiv is not in tree | |
884 | */ | |
885 | struct aa_label *aa_label_find(struct aa_label *label) | |
886 | { | |
887 | AA_BUG(!label); | |
888 | ||
889 | return vec_find(label->vec, label->size); | |
890 | } | |
891 | ||
892 | ||
893 | /** | |
894 | * aa_label_insert - insert label @label into @ls or return existing label | |
895 | * @ls - labelset to insert @label into | |
896 | * @label - label to insert | |
897 | * | |
898 | * Requires: caller to hold a valid ref on @label | |
899 | * | |
900 | * Returns: ref counted @label if successful in inserting @label | |
901 | * else ref counted equivalent label that is already in the set | |
902 | */ | |
903 | struct aa_label *aa_label_insert(struct aa_labelset *ls, struct aa_label *label) | |
904 | { | |
905 | struct aa_label *l; | |
906 | unsigned long flags; | |
907 | ||
908 | AA_BUG(!ls); | |
909 | AA_BUG(!label); | |
910 | ||
911 | /* check if label exists before taking lock */ | |
912 | if (!label_is_stale(label)) { | |
913 | read_lock_irqsave(&ls->lock, flags); | |
914 | l = __label_find(label); | |
915 | read_unlock_irqrestore(&ls->lock, flags); | |
916 | if (l) | |
917 | return l; | |
918 | } | |
919 | ||
920 | write_lock_irqsave(&ls->lock, flags); | |
921 | l = __label_insert(ls, label, false); | |
922 | write_unlock_irqrestore(&ls->lock, flags); | |
923 | ||
924 | return l; | |
925 | } | |
926 | ||
927 | ||
928 | /** | |
929 | * aa_label_next_in_merge - find the next profile when merging @a and @b | |
930 | * @I: label iterator | |
931 | * @a: label to merge | |
932 | * @b: label to merge | |
933 | * | |
934 | * Returns: next profile | |
935 | * else null if no more profiles | |
936 | */ | |
937 | struct aa_profile *aa_label_next_in_merge(struct label_it *I, | |
938 | struct aa_label *a, | |
939 | struct aa_label *b) | |
940 | { | |
941 | AA_BUG(!a); | |
942 | AA_BUG(!b); | |
943 | AA_BUG(!I); | |
944 | AA_BUG(I->i < 0); | |
945 | AA_BUG(I->i > a->size); | |
946 | AA_BUG(I->j < 0); | |
947 | AA_BUG(I->j > b->size); | |
948 | ||
949 | if (I->i < a->size) { | |
950 | if (I->j < b->size) { | |
951 | int res = profile_cmp(a->vec[I->i], b->vec[I->j]); | |
952 | ||
953 | if (res > 0) | |
954 | return b->vec[(I->j)++]; | |
955 | if (res == 0) | |
956 | (I->j)++; | |
957 | } | |
958 | ||
959 | return a->vec[(I->i)++]; | |
960 | } | |
961 | ||
962 | if (I->j < b->size) | |
963 | return b->vec[(I->j)++]; | |
964 | ||
965 | return NULL; | |
966 | } | |
967 | ||
968 | /** | |
969 | * label_merge_cmp - cmp of @a merging with @b against @z for set ordering | |
970 | * @a: label to merge then compare (NOT NULL) | |
971 | * @b: label to merge then compare (NOT NULL) | |
972 | * @z: label to compare merge against (NOT NULL) | |
973 | * | |
974 | * Assumes: using the most recent versions of @a, @b, and @z | |
975 | * | |
976 | * Returns: <0 if a < b | |
977 | * ==0 if a == b | |
978 | * >0 if a > b | |
979 | */ | |
980 | static int label_merge_cmp(struct aa_label *a, struct aa_label *b, | |
981 | struct aa_label *z) | |
982 | { | |
983 | struct aa_profile *p = NULL; | |
984 | struct label_it i = { }; | |
985 | int k; | |
986 | ||
987 | AA_BUG(!a); | |
988 | AA_BUG(!b); | |
989 | AA_BUG(!z); | |
990 | ||
991 | for (k = 0; | |
992 | k < z->size && (p = aa_label_next_in_merge(&i, a, b)); | |
993 | k++) { | |
994 | int res = profile_cmp(p, z->vec[k]); | |
995 | ||
996 | if (res != 0) | |
997 | return res; | |
998 | } | |
999 | ||
1000 | if (p) | |
1001 | return 1; | |
1002 | else if (k < z->size) | |
1003 | return -1; | |
1004 | return 0; | |
1005 | } | |
1006 | ||
1007 | /** | |
1008 | * label_merge_insert - create a new label by merging @a and @b | |
1009 | * @new: preallocated label to merge into (NOT NULL) | |
1010 | * @a: label to merge with @b (NOT NULL) | |
1011 | * @b: label to merge with @a (NOT NULL) | |
1012 | * | |
1013 | * Requires: preallocated proxy | |
1014 | * | |
1015 | * Returns: ref counted label either @new if merge is unique | |
1016 | * @a if @b is a subset of @a | |
1017 | * @b if @a is a subset of @b | |
1018 | * | |
1019 | * NOTE: will not use @new if the merge results in @new == @a or @b | |
1020 | * | |
1021 | * Must be used within labelset write lock to avoid racing with | |
1022 | * setting labels stale. | |
1023 | */ | |
1024 | static struct aa_label *label_merge_insert(struct aa_label *new, | |
1025 | struct aa_label *a, | |
1026 | struct aa_label *b) | |
1027 | { | |
1028 | struct aa_label *label; | |
1029 | struct aa_labelset *ls; | |
1030 | struct aa_profile *next; | |
1031 | struct label_it i; | |
1032 | unsigned long flags; | |
1033 | int k = 0, invcount = 0; | |
1034 | bool stale = false; | |
1035 | ||
1036 | AA_BUG(!a); | |
1037 | AA_BUG(a->size < 0); | |
1038 | AA_BUG(!b); | |
1039 | AA_BUG(b->size < 0); | |
1040 | AA_BUG(!new); | |
1041 | AA_BUG(new->size < a->size + b->size); | |
1042 | ||
1043 | label_for_each_in_merge(i, a, b, next) { | |
1044 | AA_BUG(!next); | |
1045 | if (profile_is_stale(next)) { | |
1046 | new->vec[k] = aa_get_newest_profile(next); | |
1047 | AA_BUG(!new->vec[k]->label.proxy); | |
1048 | AA_BUG(!new->vec[k]->label.proxy->label); | |
1049 | if (next->label.proxy != new->vec[k]->label.proxy) | |
1050 | invcount++; | |
1051 | k++; | |
1052 | stale = true; | |
1053 | } else | |
1054 | new->vec[k++] = aa_get_profile(next); | |
1055 | } | |
1056 | /* set to actual size which is <= allocated len */ | |
1057 | new->size = k; | |
1058 | new->vec[k] = NULL; | |
1059 | ||
1060 | if (invcount) { | |
1061 | new->size -= aa_vec_unique(&new->vec[0], new->size, | |
1062 | VEC_FLAG_TERMINATE); | |
1063 | /* TODO: deal with reference labels */ | |
1064 | if (new->size == 1) { | |
1065 | label = aa_get_label(&new->vec[0]->label); | |
1066 | return label; | |
1067 | } | |
1068 | } else if (!stale) { | |
1069 | /* | |
1070 | * merge could be same as a || b, note: it is not possible | |
1071 | * for new->size == a->size == b->size unless a == b | |
1072 | */ | |
1073 | if (k == a->size) | |
1074 | return aa_get_label(a); | |
1075 | else if (k == b->size) | |
1076 | return aa_get_label(b); | |
1077 | } | |
1078 | if (vec_unconfined(new->vec, new->size)) | |
1079 | new->flags |= FLAG_UNCONFINED; | |
1080 | ls = labels_set(new); | |
1081 | write_lock_irqsave(&ls->lock, flags); | |
1082 | label = __label_insert(labels_set(new), new, false); | |
1083 | write_unlock_irqrestore(&ls->lock, flags); | |
1084 | ||
1085 | return label; | |
1086 | } | |
1087 | ||
1088 | /** | |
1089 | * labelset_of_merge - find which labelset a merged label should be inserted | |
1090 | * @a: label to merge and insert | |
1091 | * @b: label to merge and insert | |
1092 | * | |
1093 | * Returns: labelset that the merged label should be inserted into | |
1094 | */ | |
1095 | static struct aa_labelset *labelset_of_merge(struct aa_label *a, | |
1096 | struct aa_label *b) | |
1097 | { | |
1098 | struct aa_ns *nsa = labels_ns(a); | |
1099 | struct aa_ns *nsb = labels_ns(b); | |
1100 | ||
1101 | if (ns_cmp(nsa, nsb) <= 0) | |
1102 | return &nsa->labels; | |
1103 | return &nsb->labels; | |
1104 | } | |
1105 | ||
1106 | /** | |
1107 | * __label_find_merge - find label that is equiv to merge of @a and @b | |
1108 | * @ls: set of labels to search (NOT NULL) | |
1109 | * @a: label to merge with @b (NOT NULL) | |
1110 | * @b: label to merge with @a (NOT NULL) | |
1111 | * | |
1112 | * Requires: ls->lock read_lock held | |
1113 | * | |
1114 | * Returns: ref counted label that is equiv to merge of @a and @b | |
1115 | * else NULL if merge of @a and @b is not in set | |
1116 | */ | |
1117 | static struct aa_label *__label_find_merge(struct aa_labelset *ls, | |
1118 | struct aa_label *a, | |
1119 | struct aa_label *b) | |
1120 | { | |
1121 | struct rb_node *node; | |
1122 | ||
1123 | AA_BUG(!ls); | |
1124 | AA_BUG(!a); | |
1125 | AA_BUG(!b); | |
1126 | ||
1127 | if (a == b) | |
1128 | return __label_find(a); | |
1129 | ||
1130 | node = ls->root.rb_node; | |
1131 | while (node) { | |
1132 | struct aa_label *this = container_of(node, struct aa_label, | |
1133 | node); | |
1134 | int result = label_merge_cmp(a, b, this); | |
1135 | ||
1136 | if (result < 0) | |
1137 | node = node->rb_left; | |
1138 | else if (result > 0) | |
1139 | node = node->rb_right; | |
1140 | else | |
1141 | return __aa_get_label(this); | |
1142 | } | |
1143 | ||
1144 | return NULL; | |
1145 | } | |
1146 | ||
1147 | ||
1148 | /** | |
1149 | * aa_label_find_merge - find label that is equiv to merge of @a and @b | |
1150 | * @a: label to merge with @b (NOT NULL) | |
1151 | * @b: label to merge with @a (NOT NULL) | |
1152 | * | |
1153 | * Requires: labels be fully constructed with a valid ns | |
1154 | * | |
1155 | * Returns: ref counted label that is equiv to merge of @a and @b | |
1156 | * else NULL if merge of @a and @b is not in set | |
1157 | */ | |
1158 | struct aa_label *aa_label_find_merge(struct aa_label *a, struct aa_label *b) | |
1159 | { | |
1160 | struct aa_labelset *ls; | |
1161 | struct aa_label *label, *ar = NULL, *br = NULL; | |
1162 | unsigned long flags; | |
1163 | ||
1164 | AA_BUG(!a); | |
1165 | AA_BUG(!b); | |
1166 | ||
1167 | if (label_is_stale(a)) | |
1168 | a = ar = aa_get_newest_label(a); | |
1169 | if (label_is_stale(b)) | |
1170 | b = br = aa_get_newest_label(b); | |
1171 | ls = labelset_of_merge(a, b); | |
1172 | read_lock_irqsave(&ls->lock, flags); | |
1173 | label = __label_find_merge(ls, a, b); | |
1174 | read_unlock_irqrestore(&ls->lock, flags); | |
1175 | aa_put_label(ar); | |
1176 | aa_put_label(br); | |
1177 | ||
1178 | return label; | |
1179 | } | |
1180 | ||
1181 | /** | |
1182 | * aa_label_merge - attempt to insert new merged label of @a and @b | |
1183 | * @ls: set of labels to insert label into (NOT NULL) | |
1184 | * @a: label to merge with @b (NOT NULL) | |
1185 | * @b: label to merge with @a (NOT NULL) | |
1186 | * @gfp: memory allocation type | |
1187 | * | |
1188 | * Requires: caller to hold valid refs on @a and @b | |
1189 | * labels be fully constructed with a valid ns | |
1190 | * | |
1191 | * Returns: ref counted new label if successful in inserting merge of a & b | |
1192 | * else ref counted equivalent label that is already in the set. | |
1193 | * else NULL if could not create label (-ENOMEM) | |
1194 | */ | |
1195 | struct aa_label *aa_label_merge(struct aa_label *a, struct aa_label *b, | |
1196 | gfp_t gfp) | |
1197 | { | |
1198 | struct aa_label *label = NULL; | |
1199 | ||
1200 | AA_BUG(!a); | |
1201 | AA_BUG(!b); | |
1202 | ||
1203 | if (a == b) | |
1204 | return aa_get_newest_label(a); | |
1205 | ||
1206 | /* TODO: enable when read side is lockless | |
1207 | * check if label exists before taking locks | |
1208 | if (!label_is_stale(a) && !label_is_stale(b)) | |
1209 | label = aa_label_find_merge(a, b); | |
1210 | */ | |
1211 | ||
1212 | if (!label) { | |
1213 | struct aa_label *new; | |
1214 | ||
1215 | a = aa_get_newest_label(a); | |
1216 | b = aa_get_newest_label(b); | |
1217 | ||
1218 | /* could use label_merge_len(a, b), but requires double | |
1219 | * comparison for small savings | |
1220 | */ | |
1221 | new = aa_label_alloc(a->size + b->size, NULL, gfp); | |
1222 | if (!new) | |
1223 | goto out; | |
1224 | ||
1225 | label = label_merge_insert(new, a, b); | |
1226 | label_free_or_put_new(label, new); | |
1227 | out: | |
1228 | aa_put_label(a); | |
1229 | aa_put_label(b); | |
1230 | } | |
1231 | ||
1232 | return label; | |
1233 | } | |
1234 | ||
1235 | static inline bool label_is_visible(struct aa_profile *profile, | |
1236 | struct aa_label *label) | |
1237 | { | |
1238 | return aa_ns_visible(profile->ns, labels_ns(label), true); | |
1239 | } | |
1240 | ||
1241 | /* match a profile and its associated ns component if needed | |
1242 | * Assumes visibility test has already been done. | |
1243 | * If a subns profile is not to be matched should be prescreened with | |
1244 | * visibility test. | |
1245 | */ | |
1246 | static inline unsigned int match_component(struct aa_profile *profile, | |
1247 | struct aa_profile *tp, | |
1248 | unsigned int state) | |
1249 | { | |
1250 | const char *ns_name; | |
1251 | ||
1252 | if (profile->ns == tp->ns) | |
1253 | return aa_dfa_match(profile->policy.dfa, state, tp->base.hname); | |
1254 | ||
1255 | /* try matching with namespace name and then profile */ | |
1256 | ns_name = aa_ns_name(profile->ns, tp->ns, true); | |
1257 | state = aa_dfa_match_len(profile->policy.dfa, state, ":", 1); | |
1258 | state = aa_dfa_match(profile->policy.dfa, state, ns_name); | |
1259 | state = aa_dfa_match_len(profile->policy.dfa, state, ":", 1); | |
1260 | return aa_dfa_match(profile->policy.dfa, state, tp->base.hname); | |
1261 | } | |
1262 | ||
1263 | /** | |
1264 | * label_compound_match - find perms for full compound label | |
1265 | * @profile: profile to find perms for | |
1266 | * @label: label to check access permissions for | |
1267 | * @start: state to start match in | |
1268 | * @subns: whether to do permission checks on components in a subns | |
1269 | * @request: permissions to request | |
1270 | * @perms: perms struct to set | |
1271 | * | |
1272 | * Returns: 0 on success else ERROR | |
1273 | * | |
1274 | * For the label A//&B//&C this does the perm match for A//&B//&C | |
1275 | * @perms should be preinitialized with allperms OR a previous permission | |
1276 | * check to be stacked. | |
1277 | */ | |
1278 | static int label_compound_match(struct aa_profile *profile, | |
1279 | struct aa_label *label, | |
1280 | unsigned int state, bool subns, u32 request, | |
1281 | struct aa_perms *perms) | |
1282 | { | |
1283 | struct aa_profile *tp; | |
1284 | struct label_it i; | |
1285 | ||
1286 | /* find first subcomponent that is visible */ | |
1287 | label_for_each(i, label, tp) { | |
1288 | if (!aa_ns_visible(profile->ns, tp->ns, subns)) | |
1289 | continue; | |
1290 | state = match_component(profile, tp, state); | |
1291 | if (!state) | |
1292 | goto fail; | |
1293 | goto next; | |
1294 | } | |
1295 | ||
1296 | /* no component visible */ | |
1297 | *perms = allperms; | |
1298 | return 0; | |
1299 | ||
1300 | next: | |
1301 | label_for_each_cont(i, label, tp) { | |
1302 | if (!aa_ns_visible(profile->ns, tp->ns, subns)) | |
1303 | continue; | |
1304 | state = aa_dfa_match(profile->policy.dfa, state, "//&"); | |
1305 | state = match_component(profile, tp, state); | |
1306 | if (!state) | |
1307 | goto fail; | |
1308 | } | |
1309 | aa_compute_perms(profile->policy.dfa, state, perms); | |
1310 | aa_apply_modes_to_perms(profile, perms); | |
1311 | if ((perms->allow & request) != request) | |
1312 | return -EACCES; | |
1313 | ||
1314 | return 0; | |
1315 | ||
1316 | fail: | |
1317 | *perms = nullperms; | |
1318 | return state; | |
1319 | } | |
1320 | ||
1321 | /** | |
1322 | * label_components_match - find perms for all subcomponents of a label | |
1323 | * @profile: profile to find perms for | |
1324 | * @label: label to check access permissions for | |
1325 | * @start: state to start match in | |
1326 | * @subns: whether to do permission checks on components in a subns | |
1327 | * @request: permissions to request | |
1328 | * @perms: an initialized perms struct to add accumulation to | |
1329 | * | |
1330 | * Returns: 0 on success else ERROR | |
1331 | * | |
1332 | * For the label A//&B//&C this does the perm match for each of A and B and C | |
1333 | * @perms should be preinitialized with allperms OR a previous permission | |
1334 | * check to be stacked. | |
1335 | */ | |
1336 | static int label_components_match(struct aa_profile *profile, | |
1337 | struct aa_label *label, unsigned int start, | |
1338 | bool subns, u32 request, | |
1339 | struct aa_perms *perms) | |
1340 | { | |
1341 | struct aa_profile *tp; | |
1342 | struct label_it i; | |
1343 | struct aa_perms tmp; | |
1344 | unsigned int state = 0; | |
1345 | ||
1346 | /* find first subcomponent to test */ | |
1347 | label_for_each(i, label, tp) { | |
1348 | if (!aa_ns_visible(profile->ns, tp->ns, subns)) | |
1349 | continue; | |
1350 | state = match_component(profile, tp, start); | |
1351 | if (!state) | |
1352 | goto fail; | |
1353 | goto next; | |
1354 | } | |
1355 | ||
1356 | /* no subcomponents visible - no change in perms */ | |
1357 | return 0; | |
1358 | ||
1359 | next: | |
1360 | aa_compute_perms(profile->policy.dfa, state, &tmp); | |
1361 | aa_apply_modes_to_perms(profile, &tmp); | |
1362 | aa_perms_accum(perms, &tmp); | |
1363 | label_for_each_cont(i, label, tp) { | |
1364 | if (!aa_ns_visible(profile->ns, tp->ns, subns)) | |
1365 | continue; | |
1366 | state = match_component(profile, tp, start); | |
1367 | if (!state) | |
1368 | goto fail; | |
1369 | aa_compute_perms(profile->policy.dfa, state, &tmp); | |
1370 | aa_apply_modes_to_perms(profile, &tmp); | |
1371 | aa_perms_accum(perms, &tmp); | |
1372 | } | |
1373 | ||
1374 | if ((perms->allow & request) != request) | |
1375 | return -EACCES; | |
1376 | ||
1377 | return 0; | |
1378 | ||
1379 | fail: | |
1380 | *perms = nullperms; | |
1381 | return -EACCES; | |
1382 | } | |
1383 | ||
1384 | /** | |
1385 | * aa_label_match - do a multi-component label match | |
1386 | * @profile: profile to match against (NOT NULL) | |
1387 | * @label: label to match (NOT NULL) | |
1388 | * @state: state to start in | |
1389 | * @subns: whether to match subns components | |
1390 | * @request: permission request | |
1391 | * @perms: Returns computed perms (NOT NULL) | |
1392 | * | |
1393 | * Returns: the state the match finished in, may be the none matching state | |
1394 | */ | |
1395 | int aa_label_match(struct aa_profile *profile, struct aa_label *label, | |
1396 | unsigned int state, bool subns, u32 request, | |
1397 | struct aa_perms *perms) | |
1398 | { | |
1399 | int error = label_compound_match(profile, label, state, subns, request, | |
1400 | perms); | |
1401 | if (!error) | |
1402 | return error; | |
1403 | ||
1404 | *perms = allperms; | |
1405 | return label_components_match(profile, label, state, subns, request, | |
1406 | perms); | |
1407 | } | |
1408 | ||
1409 | ||
1410 | /** | |
1411 | * aa_update_label_name - update a label to have a stored name | |
1412 | * @ns: ns being viewed from (NOT NULL) | |
1413 | * @label: label to update (NOT NULL) | |
1414 | * @gfp: type of memory allocation | |
1415 | * | |
1416 | * Requires: labels_set(label) not locked in caller | |
1417 | * | |
1418 | * note: only updates the label name if it does not have a name already | |
1419 | * and if it is in the labelset | |
1420 | */ | |
1421 | bool aa_update_label_name(struct aa_ns *ns, struct aa_label *label, gfp_t gfp) | |
1422 | { | |
1423 | struct aa_labelset *ls; | |
1424 | unsigned long flags; | |
1425 | char __counted *name; | |
1426 | bool res = false; | |
1427 | ||
1428 | AA_BUG(!ns); | |
1429 | AA_BUG(!label); | |
1430 | ||
1431 | if (label->hname || labels_ns(label) != ns) | |
1432 | return res; | |
1433 | ||
1434 | if (aa_label_acntsxprint(&name, ns, label, FLAGS_NONE, gfp) == -1) | |
1435 | return res; | |
1436 | ||
1437 | ls = labels_set(label); | |
1438 | write_lock_irqsave(&ls->lock, flags); | |
1439 | if (!label->hname && label->flags & FLAG_IN_TREE) { | |
1440 | label->hname = name; | |
1441 | res = true; | |
1442 | } else | |
1443 | aa_put_str(name); | |
1444 | write_unlock_irqrestore(&ls->lock, flags); | |
1445 | ||
1446 | return res; | |
1447 | } | |
1448 | ||
1449 | /* | |
1450 | * cached label name is present and visible | |
1451 | * @label->hname only exists if label is namespace hierachical | |
1452 | */ | |
f872af75 JJ |
1453 | static inline bool use_label_hname(struct aa_ns *ns, struct aa_label *label, |
1454 | int flags) | |
f1bd9041 | 1455 | { |
f872af75 JJ |
1456 | if (label->hname && (!ns || labels_ns(label) == ns) && |
1457 | !(flags & ~FLAG_SHOW_MODE)) | |
f1bd9041 JJ |
1458 | return true; |
1459 | ||
1460 | return false; | |
1461 | } | |
1462 | ||
1463 | /* helper macro for snprint routines */ | |
1464 | #define update_for_len(total, len, size, str) \ | |
1465 | do { \ | |
1466 | AA_BUG(len < 0); \ | |
1467 | total += len; \ | |
1468 | len = min(len, size); \ | |
1469 | size -= len; \ | |
1470 | str += len; \ | |
1471 | } while (0) | |
1472 | ||
1473 | /** | |
1474 | * aa_profile_snxprint - print a profile name to a buffer | |
1475 | * @str: buffer to write to. (MAY BE NULL if @size == 0) | |
1476 | * @size: size of buffer | |
1477 | * @view: namespace profile is being viewed from | |
1478 | * @profile: profile to view (NOT NULL) | |
1479 | * @flags: whether to include the mode string | |
1480 | * @prev_ns: last ns printed when used in compound print | |
1481 | * | |
1482 | * Returns: size of name written or would be written if larger than | |
1483 | * available buffer | |
1484 | * | |
1485 | * Note: will not print anything if the profile is not visible | |
1486 | */ | |
1487 | static int aa_profile_snxprint(char *str, size_t size, struct aa_ns *view, | |
1488 | struct aa_profile *profile, int flags, | |
1489 | struct aa_ns **prev_ns) | |
1490 | { | |
1491 | const char *ns_name = NULL; | |
1492 | ||
1493 | AA_BUG(!str && size != 0); | |
1494 | AA_BUG(!profile); | |
1495 | ||
1496 | if (!view) | |
1497 | view = profiles_ns(profile); | |
1498 | ||
1499 | if (view != profile->ns && | |
c5561700 | 1500 | (!prev_ns || (*prev_ns != profile->ns))) { |
f1bd9041 JJ |
1501 | if (prev_ns) |
1502 | *prev_ns = profile->ns; | |
1503 | ns_name = aa_ns_name(view, profile->ns, | |
1504 | flags & FLAG_VIEW_SUBNS); | |
1505 | if (ns_name == aa_hidden_ns_name) { | |
1506 | if (flags & FLAG_HIDDEN_UNCONFINED) | |
1507 | return snprintf(str, size, "%s", "unconfined"); | |
1508 | return snprintf(str, size, "%s", ns_name); | |
1509 | } | |
1510 | } | |
1511 | ||
1512 | if ((flags & FLAG_SHOW_MODE) && profile != profile->ns->unconfined) { | |
1513 | const char *modestr = aa_profile_mode_names[profile->mode]; | |
1514 | ||
1515 | if (ns_name) | |
1516 | return snprintf(str, size, ":%s:%s (%s)", ns_name, | |
1517 | profile->base.hname, modestr); | |
1518 | return snprintf(str, size, "%s (%s)", profile->base.hname, | |
1519 | modestr); | |
1520 | } | |
1521 | ||
1522 | if (ns_name) | |
1523 | return snprintf(str, size, ":%s:%s", ns_name, | |
1524 | profile->base.hname); | |
1525 | return snprintf(str, size, "%s", profile->base.hname); | |
1526 | } | |
1527 | ||
1528 | static const char *label_modename(struct aa_ns *ns, struct aa_label *label, | |
1529 | int flags) | |
1530 | { | |
1531 | struct aa_profile *profile; | |
1532 | struct label_it i; | |
1533 | int mode = -1, count = 0; | |
1534 | ||
1535 | label_for_each(i, label, profile) { | |
1536 | if (aa_ns_visible(ns, profile->ns, flags & FLAG_VIEW_SUBNS)) { | |
1537 | if (profile->mode == APPARMOR_UNCONFINED) | |
1538 | /* special case unconfined so stacks with | |
1539 | * unconfined don't report as mixed. ie. | |
1540 | * profile_foo//&:ns1:unconfined (mixed) | |
1541 | */ | |
1542 | continue; | |
1543 | count++; | |
1544 | if (mode == -1) | |
1545 | mode = profile->mode; | |
1546 | else if (mode != profile->mode) | |
1547 | return "mixed"; | |
1548 | } | |
1549 | } | |
1550 | ||
1551 | if (count == 0) | |
1552 | return "-"; | |
1553 | if (mode == -1) | |
1554 | /* everything was unconfined */ | |
1555 | mode = APPARMOR_UNCONFINED; | |
1556 | ||
1557 | return aa_profile_mode_names[mode]; | |
1558 | } | |
1559 | ||
1560 | /* if any visible label is not unconfined the display_mode returns true */ | |
1561 | static inline bool display_mode(struct aa_ns *ns, struct aa_label *label, | |
1562 | int flags) | |
1563 | { | |
1564 | if ((flags & FLAG_SHOW_MODE)) { | |
1565 | struct aa_profile *profile; | |
1566 | struct label_it i; | |
1567 | ||
1568 | label_for_each(i, label, profile) { | |
1569 | if (aa_ns_visible(ns, profile->ns, | |
1570 | flags & FLAG_VIEW_SUBNS) && | |
1571 | profile != profile->ns->unconfined) | |
1572 | return true; | |
1573 | } | |
1574 | /* only ns->unconfined in set of profiles in ns */ | |
1575 | return false; | |
1576 | } | |
1577 | ||
1578 | return false; | |
1579 | } | |
1580 | ||
1581 | /** | |
1582 | * aa_label_snxprint - print a label name to a string buffer | |
1583 | * @str: buffer to write to. (MAY BE NULL if @size == 0) | |
1584 | * @size: size of buffer | |
1585 | * @ns: namespace profile is being viewed from | |
1586 | * @label: label to view (NOT NULL) | |
1587 | * @flags: whether to include the mode string | |
1588 | * | |
1589 | * Returns: size of name written or would be written if larger than | |
1590 | * available buffer | |
1591 | * | |
1592 | * Note: labels do not have to be strictly hierarchical to the ns as | |
1593 | * objects may be shared across different namespaces and thus | |
1594 | * pickup labeling from each ns. If a particular part of the | |
1595 | * label is not visible it will just be excluded. And if none | |
1596 | * of the label is visible "---" will be used. | |
1597 | */ | |
1598 | int aa_label_snxprint(char *str, size_t size, struct aa_ns *ns, | |
1599 | struct aa_label *label, int flags) | |
1600 | { | |
1601 | struct aa_profile *profile; | |
1602 | struct aa_ns *prev_ns = NULL; | |
1603 | struct label_it i; | |
1604 | int count = 0, total = 0; | |
1605 | size_t len; | |
1606 | ||
1607 | AA_BUG(!str && size != 0); | |
1608 | AA_BUG(!label); | |
1609 | ||
26b78995 JJ |
1610 | if (flags & FLAG_ABS_ROOT) { |
1611 | ns = root_ns; | |
1612 | len = snprintf(str, size, "="); | |
1613 | update_for_len(total, len, size, str); | |
1614 | } else if (!ns) { | |
f1bd9041 | 1615 | ns = labels_ns(label); |
26b78995 | 1616 | } |
f1bd9041 JJ |
1617 | |
1618 | label_for_each(i, label, profile) { | |
1619 | if (aa_ns_visible(ns, profile->ns, flags & FLAG_VIEW_SUBNS)) { | |
1620 | if (count > 0) { | |
1621 | len = snprintf(str, size, "//&"); | |
1622 | update_for_len(total, len, size, str); | |
1623 | } | |
1624 | len = aa_profile_snxprint(str, size, ns, profile, | |
1625 | flags & FLAG_VIEW_SUBNS, | |
1626 | &prev_ns); | |
1627 | update_for_len(total, len, size, str); | |
1628 | count++; | |
1629 | } | |
1630 | } | |
1631 | ||
1632 | if (count == 0) { | |
1633 | if (flags & FLAG_HIDDEN_UNCONFINED) | |
1634 | return snprintf(str, size, "%s", "unconfined"); | |
1635 | return snprintf(str, size, "%s", aa_hidden_ns_name); | |
1636 | } | |
1637 | ||
1638 | /* count == 1 && ... is for backwards compat where the mode | |
1639 | * is not displayed for 'unconfined' in the current ns | |
1640 | */ | |
1641 | if (display_mode(ns, label, flags)) { | |
1642 | len = snprintf(str, size, " (%s)", | |
1643 | label_modename(ns, label, flags)); | |
1644 | update_for_len(total, len, size, str); | |
1645 | } | |
1646 | ||
1647 | return total; | |
1648 | } | |
1649 | #undef update_for_len | |
1650 | ||
1651 | /** | |
1652 | * aa_label_asxprint - allocate a string buffer and print label into it | |
1653 | * @strp: Returns - the allocated buffer with the label name. (NOT NULL) | |
1654 | * @ns: namespace profile is being viewed from | |
1655 | * @label: label to view (NOT NULL) | |
1656 | * @flags: flags controlling what label info is printed | |
1657 | * @gfp: kernel memory allocation type | |
1658 | * | |
1659 | * Returns: size of name written or would be written if larger than | |
1660 | * available buffer | |
1661 | */ | |
1662 | int aa_label_asxprint(char **strp, struct aa_ns *ns, struct aa_label *label, | |
1663 | int flags, gfp_t gfp) | |
1664 | { | |
1665 | int size; | |
1666 | ||
1667 | AA_BUG(!strp); | |
1668 | AA_BUG(!label); | |
1669 | ||
1670 | size = aa_label_snxprint(NULL, 0, ns, label, flags); | |
1671 | if (size < 0) | |
1672 | return size; | |
1673 | ||
1674 | *strp = kmalloc(size + 1, gfp); | |
1675 | if (!*strp) | |
1676 | return -ENOMEM; | |
1677 | return aa_label_snxprint(*strp, size + 1, ns, label, flags); | |
1678 | } | |
1679 | ||
1680 | /** | |
1681 | * aa_label_acntsxprint - allocate a __counted string buffer and print label | |
1682 | * @strp: buffer to write to. (MAY BE NULL if @size == 0) | |
1683 | * @ns: namespace profile is being viewed from | |
1684 | * @label: label to view (NOT NULL) | |
1685 | * @flags: flags controlling what label info is printed | |
1686 | * @gfp: kernel memory allocation type | |
1687 | * | |
1688 | * Returns: size of name written or would be written if larger than | |
1689 | * available buffer | |
1690 | */ | |
1691 | int aa_label_acntsxprint(char __counted **strp, struct aa_ns *ns, | |
1692 | struct aa_label *label, int flags, gfp_t gfp) | |
1693 | { | |
1694 | int size; | |
1695 | ||
1696 | AA_BUG(!strp); | |
1697 | AA_BUG(!label); | |
1698 | ||
1699 | size = aa_label_snxprint(NULL, 0, ns, label, flags); | |
1700 | if (size < 0) | |
1701 | return size; | |
1702 | ||
1703 | *strp = aa_str_alloc(size + 1, gfp); | |
1704 | if (!*strp) | |
1705 | return -ENOMEM; | |
1706 | return aa_label_snxprint(*strp, size + 1, ns, label, flags); | |
1707 | } | |
1708 | ||
1709 | ||
1710 | void aa_label_xaudit(struct audit_buffer *ab, struct aa_ns *ns, | |
1711 | struct aa_label *label, int flags, gfp_t gfp) | |
1712 | { | |
1713 | const char *str; | |
1714 | char *name = NULL; | |
1715 | int len; | |
1716 | ||
1717 | AA_BUG(!ab); | |
1718 | AA_BUG(!label); | |
1719 | ||
f872af75 JJ |
1720 | if (!use_label_hname(ns, label, flags) || |
1721 | display_mode(ns, label, flags)) { | |
f1bd9041 JJ |
1722 | len = aa_label_asxprint(&name, ns, label, flags, gfp); |
1723 | if (len == -1) { | |
1724 | AA_DEBUG("label print error"); | |
1725 | return; | |
1726 | } | |
1727 | str = name; | |
1728 | } else { | |
1729 | str = (char *) label->hname; | |
1730 | len = strlen(str); | |
1731 | } | |
1732 | if (audit_string_contains_control(str, len)) | |
1733 | audit_log_n_hex(ab, str, len); | |
1734 | else | |
1735 | audit_log_n_string(ab, str, len); | |
1736 | ||
1737 | kfree(name); | |
1738 | } | |
1739 | ||
1740 | void aa_label_seq_xprint(struct seq_file *f, struct aa_ns *ns, | |
1741 | struct aa_label *label, int flags, gfp_t gfp) | |
1742 | { | |
1743 | AA_BUG(!f); | |
1744 | AA_BUG(!label); | |
1745 | ||
f872af75 | 1746 | if (!use_label_hname(ns, label, flags)) { |
f1bd9041 JJ |
1747 | char *str; |
1748 | int len; | |
1749 | ||
1750 | len = aa_label_asxprint(&str, ns, label, flags, gfp); | |
1751 | if (len == -1) { | |
1752 | AA_DEBUG("label print error"); | |
1753 | return; | |
1754 | } | |
1755 | seq_printf(f, "%s", str); | |
1756 | kfree(str); | |
1757 | } else if (display_mode(ns, label, flags)) | |
1758 | seq_printf(f, "%s (%s)", label->hname, | |
1759 | label_modename(ns, label, flags)); | |
1760 | else | |
1761 | seq_printf(f, "%s", label->hname); | |
1762 | } | |
1763 | ||
1764 | void aa_label_xprintk(struct aa_ns *ns, struct aa_label *label, int flags, | |
1765 | gfp_t gfp) | |
1766 | { | |
1767 | AA_BUG(!label); | |
1768 | ||
f872af75 | 1769 | if (!use_label_hname(ns, label, flags)) { |
f1bd9041 JJ |
1770 | char *str; |
1771 | int len; | |
1772 | ||
1773 | len = aa_label_asxprint(&str, ns, label, flags, gfp); | |
1774 | if (len == -1) { | |
1775 | AA_DEBUG("label print error"); | |
1776 | return; | |
1777 | } | |
1778 | pr_info("%s", str); | |
1779 | kfree(str); | |
1780 | } else if (display_mode(ns, label, flags)) | |
1781 | pr_info("%s (%s)", label->hname, | |
1782 | label_modename(ns, label, flags)); | |
1783 | else | |
1784 | pr_info("%s", label->hname); | |
1785 | } | |
1786 | ||
1787 | void aa_label_audit(struct audit_buffer *ab, struct aa_label *label, gfp_t gfp) | |
1788 | { | |
1789 | struct aa_ns *ns = aa_get_current_ns(); | |
1790 | ||
1791 | aa_label_xaudit(ab, ns, label, FLAG_VIEW_SUBNS, gfp); | |
1792 | aa_put_ns(ns); | |
1793 | } | |
1794 | ||
1795 | void aa_label_seq_print(struct seq_file *f, struct aa_label *label, gfp_t gfp) | |
1796 | { | |
1797 | struct aa_ns *ns = aa_get_current_ns(); | |
1798 | ||
1799 | aa_label_seq_xprint(f, ns, label, FLAG_VIEW_SUBNS, gfp); | |
1800 | aa_put_ns(ns); | |
1801 | } | |
1802 | ||
1803 | void aa_label_printk(struct aa_label *label, gfp_t gfp) | |
1804 | { | |
1805 | struct aa_ns *ns = aa_get_current_ns(); | |
1806 | ||
1807 | aa_label_xprintk(ns, label, FLAG_VIEW_SUBNS, gfp); | |
1808 | aa_put_ns(ns); | |
1809 | } | |
1810 | ||
1811 | static int label_count_str_entries(const char *str) | |
1812 | { | |
1813 | const char *split; | |
1814 | int count = 1; | |
1815 | ||
1816 | AA_BUG(!str); | |
1817 | ||
1818 | for (split = strstr(str, "//&"); split; split = strstr(str, "//&")) { | |
1819 | count++; | |
1820 | str = split + 3; | |
1821 | } | |
1822 | ||
1823 | return count; | |
1824 | } | |
1825 | ||
1826 | /* | |
1827 | * ensure stacks with components like | |
1828 | * :ns:A//&B | |
1829 | * have :ns: applied to both 'A' and 'B' by making the lookup relative | |
1830 | * to the base if the lookup specifies an ns, else making the stacked lookup | |
1831 | * relative to the last embedded ns in the string. | |
1832 | */ | |
1833 | static struct aa_profile *fqlookupn_profile(struct aa_label *base, | |
1834 | struct aa_label *currentbase, | |
1835 | const char *str, size_t n) | |
1836 | { | |
1837 | const char *first = skipn_spaces(str, n); | |
1838 | ||
1839 | if (first && *first == ':') | |
1840 | return aa_fqlookupn_profile(base, str, n); | |
1841 | ||
1842 | return aa_fqlookupn_profile(currentbase, str, n); | |
1843 | } | |
1844 | ||
1845 | /** | |
1846 | * aa_label_parse - parse, validate and convert a text string to a label | |
1847 | * @base: base label to use for lookups (NOT NULL) | |
1848 | * @str: null terminated text string (NOT NULL) | |
1849 | * @gfp: allocation type | |
1850 | * @create: true if should create compound labels if they don't exist | |
1851 | * @force_stack: true if should stack even if no leading & | |
1852 | * | |
1853 | * Returns: the matching refcounted label if present | |
1854 | * else ERRPTR | |
1855 | */ | |
1856 | struct aa_label *aa_label_parse(struct aa_label *base, const char *str, | |
1857 | gfp_t gfp, bool create, bool force_stack) | |
1858 | { | |
1859 | DEFINE_VEC(profile, vec); | |
1860 | struct aa_label *label, *currbase = base; | |
1861 | int i, len, stack = 0, error; | |
1862 | char *split; | |
1863 | ||
1864 | AA_BUG(!base); | |
1865 | AA_BUG(!str); | |
1866 | ||
1867 | str = skip_spaces(str); | |
1868 | len = label_count_str_entries(str); | |
1869 | if (*str == '&' || force_stack) { | |
1870 | /* stack on top of base */ | |
1871 | stack = base->size; | |
1872 | len += stack; | |
1873 | if (*str == '&') | |
1874 | str++; | |
1875 | } | |
26b78995 JJ |
1876 | if (*str == '=') |
1877 | base = &root_ns->unconfined->label; | |
1878 | ||
f1bd9041 JJ |
1879 | error = vec_setup(profile, vec, len, gfp); |
1880 | if (error) | |
1881 | return ERR_PTR(error); | |
1882 | ||
1883 | for (i = 0; i < stack; i++) | |
1884 | vec[i] = aa_get_profile(base->vec[i]); | |
1885 | ||
1886 | for (split = strstr(str, "//&"), i = stack; split && i < len; i++) { | |
1887 | vec[i] = fqlookupn_profile(base, currbase, str, split - str); | |
1888 | if (!vec[i]) | |
1889 | goto fail; | |
1890 | /* | |
1891 | * if component specified a new ns it becomes the new base | |
1892 | * so that subsequent lookups are relative to it | |
1893 | */ | |
1894 | if (vec[i]->ns != labels_ns(currbase)) | |
1895 | currbase = &vec[i]->label; | |
1896 | str = split + 3; | |
1897 | split = strstr(str, "//&"); | |
1898 | } | |
1899 | /* last element doesn't have a split */ | |
1900 | if (i < len) { | |
1901 | vec[i] = fqlookupn_profile(base, currbase, str, strlen(str)); | |
1902 | if (!vec[i]) | |
1903 | goto fail; | |
1904 | } | |
1905 | if (len == 1) | |
1906 | /* no need to free vec as len < LOCAL_VEC_ENTRIES */ | |
1907 | return &vec[0]->label; | |
1908 | ||
1909 | len -= aa_vec_unique(vec, len, VEC_FLAG_TERMINATE); | |
1910 | /* TODO: deal with reference labels */ | |
1911 | if (len == 1) { | |
1912 | label = aa_get_label(&vec[0]->label); | |
1913 | goto out; | |
1914 | } | |
1915 | ||
1916 | if (create) | |
1917 | label = aa_vec_find_or_create_label(vec, len, gfp); | |
1918 | else | |
1919 | label = vec_find(vec, len); | |
1920 | if (!label) | |
1921 | goto fail; | |
1922 | ||
1923 | out: | |
1924 | /* use adjusted len from after vec_unique, not original */ | |
1925 | vec_cleanup(profile, vec, len); | |
1926 | return label; | |
1927 | ||
1928 | fail: | |
1929 | label = ERR_PTR(-ENOENT); | |
1930 | goto out; | |
1931 | } | |
1932 | ||
1933 | ||
1934 | /** | |
1935 | * aa_labelset_destroy - remove all labels from the label set | |
1936 | * @ls: label set to cleanup (NOT NULL) | |
1937 | * | |
1938 | * Labels that are removed from the set may still exist beyond the set | |
1939 | * being destroyed depending on their reference counting | |
1940 | */ | |
1941 | void aa_labelset_destroy(struct aa_labelset *ls) | |
1942 | { | |
1943 | struct rb_node *node; | |
1944 | unsigned long flags; | |
1945 | ||
1946 | AA_BUG(!ls); | |
1947 | ||
1948 | write_lock_irqsave(&ls->lock, flags); | |
1949 | for (node = rb_first(&ls->root); node; node = rb_first(&ls->root)) { | |
1950 | struct aa_label *this = rb_entry(node, struct aa_label, node); | |
1951 | ||
1952 | if (labels_ns(this) != root_ns) | |
1953 | __label_remove(this, | |
1954 | ns_unconfined(labels_ns(this)->parent)); | |
1955 | else | |
1956 | __label_remove(this, NULL); | |
1957 | } | |
1958 | write_unlock_irqrestore(&ls->lock, flags); | |
1959 | } | |
1960 | ||
1961 | /* | |
1962 | * @ls: labelset to init (NOT NULL) | |
1963 | */ | |
1964 | void aa_labelset_init(struct aa_labelset *ls) | |
1965 | { | |
1966 | AA_BUG(!ls); | |
1967 | ||
1968 | rwlock_init(&ls->lock); | |
1969 | ls->root = RB_ROOT; | |
1970 | } | |
1971 | ||
1972 | static struct aa_label *labelset_next_stale(struct aa_labelset *ls) | |
1973 | { | |
1974 | struct aa_label *label; | |
1975 | struct rb_node *node; | |
1976 | unsigned long flags; | |
1977 | ||
1978 | AA_BUG(!ls); | |
1979 | ||
1980 | read_lock_irqsave(&ls->lock, flags); | |
1981 | ||
1982 | __labelset_for_each(ls, node) { | |
1983 | label = rb_entry(node, struct aa_label, node); | |
1984 | if ((label_is_stale(label) || | |
1985 | vec_is_stale(label->vec, label->size)) && | |
1986 | __aa_get_label(label)) | |
1987 | goto out; | |
1988 | ||
1989 | } | |
1990 | label = NULL; | |
1991 | ||
1992 | out: | |
1993 | read_unlock_irqrestore(&ls->lock, flags); | |
1994 | ||
1995 | return label; | |
1996 | } | |
1997 | ||
1998 | /** | |
1999 | * __label_update - insert updated version of @label into labelset | |
2000 | * @label - the label to update/repace | |
2001 | * | |
2002 | * Returns: new label that is up to date | |
2003 | * else NULL on failure | |
2004 | * | |
2005 | * Requires: @ns lock be held | |
2006 | * | |
2007 | * Note: worst case is the stale @label does not get updated and has | |
2008 | * to be updated at a later time. | |
2009 | */ | |
2010 | static struct aa_label *__label_update(struct aa_label *label) | |
2011 | { | |
2012 | struct aa_label *new, *tmp; | |
2013 | struct aa_labelset *ls; | |
2014 | unsigned long flags; | |
2015 | int i, invcount = 0; | |
2016 | ||
2017 | AA_BUG(!label); | |
2018 | AA_BUG(!mutex_is_locked(&labels_ns(label)->lock)); | |
2019 | ||
2020 | new = aa_label_alloc(label->size, label->proxy, GFP_KERNEL); | |
2021 | if (!new) | |
2022 | return NULL; | |
2023 | ||
2024 | /* | |
2025 | * while holding the ns_lock will stop profile replacement, removal, | |
2026 | * and label updates, label merging and removal can be occurring | |
2027 | */ | |
2028 | ls = labels_set(label); | |
2029 | write_lock_irqsave(&ls->lock, flags); | |
2030 | for (i = 0; i < label->size; i++) { | |
2031 | AA_BUG(!label->vec[i]); | |
2032 | new->vec[i] = aa_get_newest_profile(label->vec[i]); | |
2033 | AA_BUG(!new->vec[i]); | |
2034 | AA_BUG(!new->vec[i]->label.proxy); | |
2035 | AA_BUG(!new->vec[i]->label.proxy->label); | |
2036 | if (new->vec[i]->label.proxy != label->vec[i]->label.proxy) | |
2037 | invcount++; | |
2038 | } | |
2039 | ||
2040 | /* updated stale label by being removed/renamed from labelset */ | |
2041 | if (invcount) { | |
2042 | new->size -= aa_vec_unique(&new->vec[0], new->size, | |
2043 | VEC_FLAG_TERMINATE); | |
2044 | /* TODO: deal with reference labels */ | |
2045 | if (new->size == 1) { | |
2046 | tmp = aa_get_label(&new->vec[0]->label); | |
2047 | AA_BUG(tmp == label); | |
2048 | goto remove; | |
2049 | } | |
2050 | if (labels_set(label) != labels_set(new)) { | |
2051 | write_unlock_irqrestore(&ls->lock, flags); | |
2052 | tmp = aa_label_insert(labels_set(new), new); | |
2053 | write_lock_irqsave(&ls->lock, flags); | |
2054 | goto remove; | |
2055 | } | |
2056 | } else | |
2057 | AA_BUG(labels_ns(label) != labels_ns(new)); | |
2058 | ||
2059 | tmp = __label_insert(labels_set(label), new, true); | |
2060 | remove: | |
2061 | /* ensure label is removed, and redirected correctly */ | |
2062 | __label_remove(label, tmp); | |
2063 | write_unlock_irqrestore(&ls->lock, flags); | |
2064 | label_free_or_put_new(tmp, new); | |
2065 | ||
2066 | return tmp; | |
2067 | } | |
2068 | ||
2069 | /** | |
2070 | * __labelset_update - update labels in @ns | |
2071 | * @ns: namespace to update labels in (NOT NULL) | |
2072 | * | |
2073 | * Requires: @ns lock be held | |
2074 | * | |
2075 | * Walk the labelset ensuring that all labels are up to date and valid | |
2076 | * Any label that has a stale component is marked stale and replaced and | |
2077 | * by an updated version. | |
2078 | * | |
2079 | * If failures happen due to memory pressures then stale labels will | |
2080 | * be left in place until the next pass. | |
2081 | */ | |
2082 | static void __labelset_update(struct aa_ns *ns) | |
2083 | { | |
2084 | struct aa_label *label; | |
2085 | ||
2086 | AA_BUG(!ns); | |
2087 | AA_BUG(!mutex_is_locked(&ns->lock)); | |
2088 | ||
2089 | do { | |
2090 | label = labelset_next_stale(&ns->labels); | |
2091 | if (label) { | |
2092 | struct aa_label *l = __label_update(label); | |
2093 | ||
2094 | aa_put_label(l); | |
2095 | aa_put_label(label); | |
2096 | } | |
2097 | } while (label); | |
2098 | } | |
2099 | ||
2100 | /** | |
2101 | * __aa_labelset_udate_subtree - update all labels with a stale component | |
2102 | * @ns: ns to start update at (NOT NULL) | |
2103 | * | |
2104 | * Requires: @ns lock be held | |
2105 | * | |
2106 | * Invalidates labels based on @p in @ns and any children namespaces. | |
2107 | */ | |
2108 | void __aa_labelset_update_subtree(struct aa_ns *ns) | |
2109 | { | |
2110 | struct aa_ns *child; | |
2111 | ||
2112 | AA_BUG(!ns); | |
2113 | AA_BUG(!mutex_is_locked(&ns->lock)); | |
2114 | ||
2115 | __labelset_update(ns); | |
2116 | ||
2117 | list_for_each_entry(child, &ns->sub_ns, base.list) { | |
2118 | mutex_lock(&child->lock); | |
2119 | __aa_labelset_update_subtree(child); | |
2120 | mutex_unlock(&child->lock); | |
2121 | } | |
2122 | } |