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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * AppArmor security module
4 *
5 * This file contains AppArmor label definitions
6 *
7 * Copyright 2017 Canonical Ltd.
8 */
9
10#include <linux/audit.h>
11#include <linux/seq_file.h>
12#include <linux/sort.h>
13
14#include "include/apparmor.h"
15#include "include/cred.h"
16#include "include/label.h"
17#include "include/policy.h"
18#include "include/secid.h"
19
20
21/*
22 * the aa_label represents the set of profiles confining an object
23 *
24 * Labels maintain a reference count to the set of pointers they reference
25 * Labels are ref counted by
26 * tasks and object via the security field/security context off the field
27 * code - will take a ref count on a label if it needs the label
28 * beyond what is possible with an rcu_read_lock.
29 * profiles - each profile is a label
30 * secids - a pinned secid will keep a refcount of the label it is
31 * referencing
32 * objects - inode, files, sockets, ...
33 *
34 * Labels are not ref counted by the label set, so they maybe removed and
35 * freed when no longer in use.
36 *
37 */
38
39#define PROXY_POISON 97
40#define LABEL_POISON 100
41
42static void free_proxy(struct aa_proxy *proxy)
43{
44 if (proxy) {
45 /* p->label will not updated any more as p is dead */
46 aa_put_label(rcu_dereference_protected(proxy->label, true));
47 memset(proxy, 0, sizeof(*proxy));
48 RCU_INIT_POINTER(proxy->label, (struct aa_label *)PROXY_POISON);
49 kfree(proxy);
50 }
51}
52
53void aa_proxy_kref(struct kref *kref)
54{
55 struct aa_proxy *proxy = container_of(kref, struct aa_proxy, count);
56
57 free_proxy(proxy);
58}
59
60struct aa_proxy *aa_alloc_proxy(struct aa_label *label, gfp_t gfp)
61{
62 struct aa_proxy *new;
63
64 new = kzalloc(sizeof(struct aa_proxy), gfp);
65 if (new) {
66 kref_init(&new->count);
67 rcu_assign_pointer(new->label, aa_get_label(label));
68 }
69 return new;
70}
71
72/* requires profile list write lock held */
73void __aa_proxy_redirect(struct aa_label *orig, struct aa_label *new)
74{
75 struct aa_label *tmp;
76
77 AA_BUG(!orig);
78 AA_BUG(!new);
79 lockdep_assert_held_write(&labels_set(orig)->lock);
80
81 tmp = rcu_dereference_protected(orig->proxy->label,
82 &labels_ns(orig)->lock);
83 rcu_assign_pointer(orig->proxy->label, aa_get_label(new));
84 orig->flags |= FLAG_STALE;
85 aa_put_label(tmp);
86}
87
88static void __proxy_share(struct aa_label *old, struct aa_label *new)
89{
90 struct aa_proxy *proxy = new->proxy;
91
92 new->proxy = aa_get_proxy(old->proxy);
93 __aa_proxy_redirect(old, new);
94 aa_put_proxy(proxy);
95}
96
97
98/**
99 * ns_cmp - compare ns for label set ordering
100 * @a: ns to compare (NOT NULL)
101 * @b: ns to compare (NOT NULL)
102 *
103 * Returns: <0 if a < b
104 * ==0 if a == b
105 * >0 if a > b
106 */
107static int ns_cmp(struct aa_ns *a, struct aa_ns *b)
108{
109 int res;
110
111 AA_BUG(!a);
112 AA_BUG(!b);
113 AA_BUG(!a->base.hname);
114 AA_BUG(!b->base.hname);
115
116 if (a == b)
117 return 0;
118
119 res = a->level - b->level;
120 if (res)
121 return res;
122
123 return strcmp(a->base.hname, b->base.hname);
124}
125
126/**
127 * profile_cmp - profile comparison for set ordering
128 * @a: profile to compare (NOT NULL)
129 * @b: profile to compare (NOT NULL)
130 *
131 * Returns: <0 if a < b
132 * ==0 if a == b
133 * >0 if a > b
134 */
135static int profile_cmp(struct aa_profile *a, struct aa_profile *b)
136{
137 int res;
138
139 AA_BUG(!a);
140 AA_BUG(!b);
141 AA_BUG(!a->ns);
142 AA_BUG(!b->ns);
143 AA_BUG(!a->base.hname);
144 AA_BUG(!b->base.hname);
145
146 if (a == b || a->base.hname == b->base.hname)
147 return 0;
148 res = ns_cmp(a->ns, b->ns);
149 if (res)
150 return res;
151
152 return strcmp(a->base.hname, b->base.hname);
153}
154
155/**
156 * vec_cmp - label comparison for set ordering
157 * @a: label to compare (NOT NULL)
158 * @vec: vector of profiles to compare (NOT NULL)
159 * @n: length of @vec
160 *
161 * Returns: <0 if a < vec
162 * ==0 if a == vec
163 * >0 if a > vec
164 */
165static int vec_cmp(struct aa_profile **a, int an, struct aa_profile **b, int bn)
166{
167 int i;
168
169 AA_BUG(!a);
170 AA_BUG(!*a);
171 AA_BUG(!b);
172 AA_BUG(!*b);
173 AA_BUG(an <= 0);
174 AA_BUG(bn <= 0);
175
176 for (i = 0; i < an && i < bn; i++) {
177 int res = profile_cmp(a[i], b[i]);
178
179 if (res != 0)
180 return res;
181 }
182
183 return an - bn;
184}
185
186static bool vec_is_stale(struct aa_profile **vec, int n)
187{
188 int i;
189
190 AA_BUG(!vec);
191
192 for (i = 0; i < n; i++) {
193 if (profile_is_stale(vec[i]))
194 return true;
195 }
196
197 return false;
198}
199
200static long accum_vec_flags(struct aa_profile **vec, int n)
201{
202 long u = FLAG_UNCONFINED;
203 int i;
204
205 AA_BUG(!vec);
206
207 for (i = 0; i < n; i++) {
208 u |= vec[i]->label.flags & (FLAG_DEBUG1 | FLAG_DEBUG2 |
209 FLAG_STALE);
210 if (!(u & vec[i]->label.flags & FLAG_UNCONFINED))
211 u &= ~FLAG_UNCONFINED;
212 }
213
214 return u;
215}
216
217static int sort_cmp(const void *a, const void *b)
218{
219 return profile_cmp(*(struct aa_profile **)a, *(struct aa_profile **)b);
220}
221
222/*
223 * assumes vec is sorted
224 * Assumes @vec has null terminator at vec[n], and will null terminate
225 * vec[n - dups]
226 */
227static inline int unique(struct aa_profile **vec, int n)
228{
229 int i, pos, dups = 0;
230
231 AA_BUG(n < 1);
232 AA_BUG(!vec);
233
234 pos = 0;
235 for (i = 1; i < n; i++) {
236 int res = profile_cmp(vec[pos], vec[i]);
237
238 AA_BUG(res > 0, "vec not sorted");
239 if (res == 0) {
240 /* drop duplicate */
241 aa_put_profile(vec[i]);
242 dups++;
243 continue;
244 }
245 pos++;
246 if (dups)
247 vec[pos] = vec[i];
248 }
249
250 AA_BUG(dups < 0);
251
252 return dups;
253}
254
255/**
256 * aa_vec_unique - canonical sort and unique a list of profiles
257 * @n: number of refcounted profiles in the list (@n > 0)
258 * @vec: list of profiles to sort and merge
259 *
260 * Returns: the number of duplicates eliminated == references put
261 *
262 * If @flags & VEC_FLAG_TERMINATE @vec has null terminator at vec[n], and will
263 * null terminate vec[n - dups]
264 */
265int aa_vec_unique(struct aa_profile **vec, int n, int flags)
266{
267 int i, dups = 0;
268
269 AA_BUG(n < 1);
270 AA_BUG(!vec);
271
272 /* vecs are usually small and inorder, have a fallback for larger */
273 if (n > 8) {
274 sort(vec, n, sizeof(struct aa_profile *), sort_cmp, NULL);
275 dups = unique(vec, n);
276 goto out;
277 }
278
279 /* insertion sort + unique in one */
280 for (i = 1; i < n; i++) {
281 struct aa_profile *tmp = vec[i];
282 int pos, j;
283
284 for (pos = i - 1 - dups; pos >= 0; pos--) {
285 int res = profile_cmp(vec[pos], tmp);
286
287 if (res == 0) {
288 /* drop duplicate entry */
289 aa_put_profile(tmp);
290 dups++;
291 goto continue_outer;
292 } else if (res < 0)
293 break;
294 }
295 /* pos is at entry < tmp, or index -1. Set to insert pos */
296 pos++;
297
298 for (j = i - dups; j > pos; j--)
299 vec[j] = vec[j - 1];
300 vec[pos] = tmp;
301continue_outer:
302 ;
303 }
304
305 AA_BUG(dups < 0);
306
307out:
308 if (flags & VEC_FLAG_TERMINATE)
309 vec[n - dups] = NULL;
310
311 return dups;
312}
313
314
315void aa_label_destroy(struct aa_label *label)
316{
317 AA_BUG(!label);
318
319 if (!label_isprofile(label)) {
320 struct aa_profile *profile;
321 struct label_it i;
322
323 aa_put_str(label->hname);
324
325 label_for_each(i, label, profile) {
326 aa_put_profile(profile);
327 label->vec[i.i] = (struct aa_profile *)
328 (LABEL_POISON + (long) i.i);
329 }
330 }
331
332 if (label->proxy) {
333 if (rcu_dereference_protected(label->proxy->label, true) == label)
334 rcu_assign_pointer(label->proxy->label, NULL);
335 aa_put_proxy(label->proxy);
336 }
337 aa_free_secid(label->secid);
338
339 label->proxy = (struct aa_proxy *) PROXY_POISON + 1;
340}
341
342void aa_label_free(struct aa_label *label)
343{
344 if (!label)
345 return;
346
347 aa_label_destroy(label);
348 kfree(label);
349}
350
351static void label_free_switch(struct aa_label *label)
352{
353 if (label->flags & FLAG_NS_COUNT)
354 aa_free_ns(labels_ns(label));
355 else if (label_isprofile(label))
356 aa_free_profile(labels_profile(label));
357 else
358 aa_label_free(label);
359}
360
361static void label_free_rcu(struct rcu_head *head)
362{
363 struct aa_label *label = container_of(head, struct aa_label, rcu);
364
365 if (label->flags & FLAG_IN_TREE)
366 (void) aa_label_remove(label);
367 label_free_switch(label);
368}
369
370void aa_label_kref(struct kref *kref)
371{
372 struct aa_label *label = container_of(kref, struct aa_label, count);
373 struct aa_ns *ns = labels_ns(label);
374
375 if (!ns) {
376 /* never live, no rcu callback needed, just using the fn */
377 label_free_switch(label);
378 return;
379 }
380 /* TODO: update labels_profile macro so it works here */
381 AA_BUG(label_isprofile(label) &&
382 on_list_rcu(&label->vec[0]->base.profiles));
383 AA_BUG(label_isprofile(label) &&
384 on_list_rcu(&label->vec[0]->base.list));
385
386 /* TODO: if compound label and not stale add to reclaim cache */
387 call_rcu(&label->rcu, label_free_rcu);
388}
389
390static void label_free_or_put_new(struct aa_label *label, struct aa_label *new)
391{
392 if (label != new)
393 /* need to free directly to break circular ref with proxy */
394 aa_label_free(new);
395 else
396 aa_put_label(new);
397}
398
399bool aa_label_init(struct aa_label *label, int size, gfp_t gfp)
400{
401 AA_BUG(!label);
402 AA_BUG(size < 1);
403
404 if (aa_alloc_secid(label, gfp) < 0)
405 return false;
406
407 label->size = size; /* doesn't include null */
408 label->vec[size] = NULL; /* null terminate */
409 kref_init(&label->count);
410 RB_CLEAR_NODE(&label->node);
411
412 return true;
413}
414
415/**
416 * aa_label_alloc - allocate a label with a profile vector of @size length
417 * @size: size of profile vector in the label
418 * @proxy: proxy to use OR null if to allocate a new one
419 * @gfp: memory allocation type
420 *
421 * Returns: new label
422 * else NULL if failed
423 */
424struct aa_label *aa_label_alloc(int size, struct aa_proxy *proxy, gfp_t gfp)
425{
426 struct aa_label *new;
427
428 AA_BUG(size < 1);
429
430 /* + 1 for null terminator entry on vec */
431 new = kzalloc(struct_size(new, vec, size + 1), gfp);
432 AA_DEBUG("%s (%p)\n", __func__, new);
433 if (!new)
434 goto fail;
435
436 if (!aa_label_init(new, size, gfp))
437 goto fail;
438
439 if (!proxy) {
440 proxy = aa_alloc_proxy(new, gfp);
441 if (!proxy)
442 goto fail;
443 } else
444 aa_get_proxy(proxy);
445 /* just set new's proxy, don't redirect proxy here if it was passed in*/
446 new->proxy = proxy;
447
448 return new;
449
450fail:
451 kfree(new);
452
453 return NULL;
454}
455
456
457/**
458 * label_cmp - label comparison for set ordering
459 * @a: label to compare (NOT NULL)
460 * @b: label to compare (NOT NULL)
461 *
462 * Returns: <0 if a < b
463 * ==0 if a == b
464 * >0 if a > b
465 */
466static int label_cmp(struct aa_label *a, struct aa_label *b)
467{
468 AA_BUG(!b);
469
470 if (a == b)
471 return 0;
472
473 return vec_cmp(a->vec, a->size, b->vec, b->size);
474}
475
476/* helper fn for label_for_each_confined */
477int aa_label_next_confined(struct aa_label *label, int i)
478{
479 AA_BUG(!label);
480 AA_BUG(i < 0);
481
482 for (; i < label->size; i++) {
483 if (!profile_unconfined(label->vec[i]))
484 return i;
485 }
486
487 return i;
488}
489
490/**
491 * __aa_label_next_not_in_set - return the next profile of @sub not in @set
492 * @I: label iterator
493 * @set: label to test against
494 * @sub: label to if is subset of @set
495 *
496 * Returns: profile in @sub that is not in @set, with iterator set pos after
497 * else NULL if @sub is a subset of @set
498 */
499struct aa_profile *__aa_label_next_not_in_set(struct label_it *I,
500 struct aa_label *set,
501 struct aa_label *sub)
502{
503 AA_BUG(!set);
504 AA_BUG(!I);
505 AA_BUG(I->i < 0);
506 AA_BUG(I->i > set->size);
507 AA_BUG(!sub);
508 AA_BUG(I->j < 0);
509 AA_BUG(I->j > sub->size);
510
511 while (I->j < sub->size && I->i < set->size) {
512 int res = profile_cmp(sub->vec[I->j], set->vec[I->i]);
513
514 if (res == 0) {
515 (I->j)++;
516 (I->i)++;
517 } else if (res > 0)
518 (I->i)++;
519 else
520 return sub->vec[(I->j)++];
521 }
522
523 if (I->j < sub->size)
524 return sub->vec[(I->j)++];
525
526 return NULL;
527}
528
529/**
530 * aa_label_is_subset - test if @sub is a subset of @set
531 * @set: label to test against
532 * @sub: label to test if is subset of @set
533 *
534 * Returns: true if @sub is subset of @set
535 * else false
536 */
537bool aa_label_is_subset(struct aa_label *set, struct aa_label *sub)
538{
539 struct label_it i = { };
540
541 AA_BUG(!set);
542 AA_BUG(!sub);
543
544 if (sub == set)
545 return true;
546
547 return __aa_label_next_not_in_set(&i, set, sub) == NULL;
548}
549
550/**
551 * aa_label_is_unconfined_subset - test if @sub is a subset of @set
552 * @set: label to test against
553 * @sub: label to test if is subset of @set
554 *
555 * This checks for subset but taking into account unconfined. IF
556 * @sub contains an unconfined profile that does not have a matching
557 * unconfined in @set then this will not cause the test to fail.
558 * Conversely we don't care about an unconfined in @set that is not in
559 * @sub
560 *
561 * Returns: true if @sub is special_subset of @set
562 * else false
563 */
564bool aa_label_is_unconfined_subset(struct aa_label *set, struct aa_label *sub)
565{
566 struct label_it i = { };
567 struct aa_profile *p;
568
569 AA_BUG(!set);
570 AA_BUG(!sub);
571
572 if (sub == set)
573 return true;
574
575 do {
576 p = __aa_label_next_not_in_set(&i, set, sub);
577 if (p && !profile_unconfined(p))
578 break;
579 } while (p);
580
581 return p == NULL;
582}
583
584
585/**
586 * __label_remove - remove @label from the label set
587 * @l: label to remove
588 * @new: label to redirect to
589 *
590 * Requires: labels_set(@label)->lock write_lock
591 * Returns: true if the label was in the tree and removed
592 */
593static bool __label_remove(struct aa_label *label, struct aa_label *new)
594{
595 struct aa_labelset *ls = labels_set(label);
596
597 AA_BUG(!ls);
598 AA_BUG(!label);
599 lockdep_assert_held_write(&ls->lock);
600
601 if (new)
602 __aa_proxy_redirect(label, new);
603
604 if (!label_is_stale(label))
605 __label_make_stale(label);
606
607 if (label->flags & FLAG_IN_TREE) {
608 rb_erase(&label->node, &ls->root);
609 label->flags &= ~FLAG_IN_TREE;
610 return true;
611 }
612
613 return false;
614}
615
616/**
617 * __label_replace - replace @old with @new in label set
618 * @old: label to remove from label set
619 * @new: label to replace @old with
620 *
621 * Requires: labels_set(@old)->lock write_lock
622 * valid ref count be held on @new
623 * Returns: true if @old was in set and replaced by @new
624 *
625 * Note: current implementation requires label set be order in such a way
626 * that @new directly replaces @old position in the set (ie.
627 * using pointer comparison of the label address would not work)
628 */
629static bool __label_replace(struct aa_label *old, struct aa_label *new)
630{
631 struct aa_labelset *ls = labels_set(old);
632
633 AA_BUG(!ls);
634 AA_BUG(!old);
635 AA_BUG(!new);
636 lockdep_assert_held_write(&ls->lock);
637 AA_BUG(new->flags & FLAG_IN_TREE);
638
639 if (!label_is_stale(old))
640 __label_make_stale(old);
641
642 if (old->flags & FLAG_IN_TREE) {
643 rb_replace_node(&old->node, &new->node, &ls->root);
644 old->flags &= ~FLAG_IN_TREE;
645 new->flags |= FLAG_IN_TREE;
646 return true;
647 }
648
649 return false;
650}
651
652/**
653 * __label_insert - attempt to insert @l into a label set
654 * @ls: set of labels to insert @l into (NOT NULL)
655 * @label: new label to insert (NOT NULL)
656 * @replace: whether insertion should replace existing entry that is not stale
657 *
658 * Requires: @ls->lock
659 * caller to hold a valid ref on l
660 * if @replace is true l has a preallocated proxy associated
661 * Returns: @l if successful in inserting @l - with additional refcount
662 * else ref counted equivalent label that is already in the set,
663 * the else condition only happens if @replace is false
664 */
665static struct aa_label *__label_insert(struct aa_labelset *ls,
666 struct aa_label *label, bool replace)
667{
668 struct rb_node **new, *parent = NULL;
669
670 AA_BUG(!ls);
671 AA_BUG(!label);
672 AA_BUG(labels_set(label) != ls);
673 lockdep_assert_held_write(&ls->lock);
674 AA_BUG(label->flags & FLAG_IN_TREE);
675
676 /* Figure out where to put new node */
677 new = &ls->root.rb_node;
678 while (*new) {
679 struct aa_label *this = rb_entry(*new, struct aa_label, node);
680 int result = label_cmp(label, this);
681
682 parent = *new;
683 if (result == 0) {
684 /* !__aa_get_label means queued for destruction,
685 * so replace in place, however the label has
686 * died before the replacement so do not share
687 * the proxy
688 */
689 if (!replace && !label_is_stale(this)) {
690 if (__aa_get_label(this))
691 return this;
692 } else
693 __proxy_share(this, label);
694 AA_BUG(!__label_replace(this, label));
695 return aa_get_label(label);
696 } else if (result < 0)
697 new = &((*new)->rb_left);
698 else /* (result > 0) */
699 new = &((*new)->rb_right);
700 }
701
702 /* Add new node and rebalance tree. */
703 rb_link_node(&label->node, parent, new);
704 rb_insert_color(&label->node, &ls->root);
705 label->flags |= FLAG_IN_TREE;
706
707 return aa_get_label(label);
708}
709
710/**
711 * __vec_find - find label that matches @vec in label set
712 * @vec: vec of profiles to find matching label for (NOT NULL)
713 * @n: length of @vec
714 *
715 * Requires: @vec_labelset(vec) lock held
716 * caller to hold a valid ref on l
717 *
718 * Returns: ref counted @label if matching label is in tree
719 * ref counted label that is equiv to @l in tree
720 * else NULL if @vec equiv is not in tree
721 */
722static struct aa_label *__vec_find(struct aa_profile **vec, int n)
723{
724 struct rb_node *node;
725
726 AA_BUG(!vec);
727 AA_BUG(!*vec);
728 AA_BUG(n <= 0);
729
730 node = vec_labelset(vec, n)->root.rb_node;
731 while (node) {
732 struct aa_label *this = rb_entry(node, struct aa_label, node);
733 int result = vec_cmp(this->vec, this->size, vec, n);
734
735 if (result > 0)
736 node = node->rb_left;
737 else if (result < 0)
738 node = node->rb_right;
739 else
740 return __aa_get_label(this);
741 }
742
743 return NULL;
744}
745
746/**
747 * __label_find - find label @label in label set
748 * @label: label to find (NOT NULL)
749 *
750 * Requires: labels_set(@label)->lock held
751 * caller to hold a valid ref on l
752 *
753 * Returns: ref counted @label if @label is in tree OR
754 * ref counted label that is equiv to @label in tree
755 * else NULL if @label or equiv is not in tree
756 */
757static struct aa_label *__label_find(struct aa_label *label)
758{
759 AA_BUG(!label);
760
761 return __vec_find(label->vec, label->size);
762}
763
764
765/**
766 * aa_label_remove - remove a label from the labelset
767 * @label: label to remove
768 *
769 * Returns: true if @label was removed from the tree
770 * else @label was not in tree so it could not be removed
771 */
772bool aa_label_remove(struct aa_label *label)
773{
774 struct aa_labelset *ls = labels_set(label);
775 unsigned long flags;
776 bool res;
777
778 AA_BUG(!ls);
779
780 write_lock_irqsave(&ls->lock, flags);
781 res = __label_remove(label, ns_unconfined(labels_ns(label)));
782 write_unlock_irqrestore(&ls->lock, flags);
783
784 return res;
785}
786
787/**
788 * aa_label_replace - replace a label @old with a new version @new
789 * @old: label to replace
790 * @new: label replacing @old
791 *
792 * Returns: true if @old was in tree and replaced
793 * else @old was not in tree, and @new was not inserted
794 */
795bool aa_label_replace(struct aa_label *old, struct aa_label *new)
796{
797 unsigned long flags;
798 bool res;
799
800 if (name_is_shared(old, new) && labels_ns(old) == labels_ns(new)) {
801 write_lock_irqsave(&labels_set(old)->lock, flags);
802 if (old->proxy != new->proxy)
803 __proxy_share(old, new);
804 else
805 __aa_proxy_redirect(old, new);
806 res = __label_replace(old, new);
807 write_unlock_irqrestore(&labels_set(old)->lock, flags);
808 } else {
809 struct aa_label *l;
810 struct aa_labelset *ls = labels_set(old);
811
812 write_lock_irqsave(&ls->lock, flags);
813 res = __label_remove(old, new);
814 if (labels_ns(old) != labels_ns(new)) {
815 write_unlock_irqrestore(&ls->lock, flags);
816 ls = labels_set(new);
817 write_lock_irqsave(&ls->lock, flags);
818 }
819 l = __label_insert(ls, new, true);
820 res = (l == new);
821 write_unlock_irqrestore(&ls->lock, flags);
822 aa_put_label(l);
823 }
824
825 return res;
826}
827
828/**
829 * vec_find - find label @l in label set
830 * @vec: array of profiles to find equiv label for (NOT NULL)
831 * @n: length of @vec
832 *
833 * Returns: refcounted label if @vec equiv is in tree
834 * else NULL if @vec equiv is not in tree
835 */
836static struct aa_label *vec_find(struct aa_profile **vec, int n)
837{
838 struct aa_labelset *ls;
839 struct aa_label *label;
840 unsigned long flags;
841
842 AA_BUG(!vec);
843 AA_BUG(!*vec);
844 AA_BUG(n <= 0);
845
846 ls = vec_labelset(vec, n);
847 read_lock_irqsave(&ls->lock, flags);
848 label = __vec_find(vec, n);
849 read_unlock_irqrestore(&ls->lock, flags);
850
851 return label;
852}
853
854/* requires sort and merge done first */
855static struct aa_label *vec_create_and_insert_label(struct aa_profile **vec,
856 int len, gfp_t gfp)
857{
858 struct aa_label *label = NULL;
859 struct aa_labelset *ls;
860 unsigned long flags;
861 struct aa_label *new;
862 int i;
863
864 AA_BUG(!vec);
865
866 if (len == 1)
867 return aa_get_label(&vec[0]->label);
868
869 ls = labels_set(&vec[len - 1]->label);
870
871 /* TODO: enable when read side is lockless
872 * check if label exists before taking locks
873 */
874 new = aa_label_alloc(len, NULL, gfp);
875 if (!new)
876 return NULL;
877
878 for (i = 0; i < len; i++)
879 new->vec[i] = aa_get_profile(vec[i]);
880
881 write_lock_irqsave(&ls->lock, flags);
882 label = __label_insert(ls, new, false);
883 write_unlock_irqrestore(&ls->lock, flags);
884 label_free_or_put_new(label, new);
885
886 return label;
887}
888
889struct aa_label *aa_vec_find_or_create_label(struct aa_profile **vec, int len,
890 gfp_t gfp)
891{
892 struct aa_label *label = vec_find(vec, len);
893
894 if (label)
895 return label;
896
897 return vec_create_and_insert_label(vec, len, gfp);
898}
899
900/**
901 * aa_label_find - find label @label in label set
902 * @label: label to find (NOT NULL)
903 *
904 * Requires: caller to hold a valid ref on l
905 *
906 * Returns: refcounted @label if @label is in tree
907 * refcounted label that is equiv to @label in tree
908 * else NULL if @label or equiv is not in tree
909 */
910struct aa_label *aa_label_find(struct aa_label *label)
911{
912 AA_BUG(!label);
913
914 return vec_find(label->vec, label->size);
915}
916
917
918/**
919 * aa_label_insert - insert label @label into @ls or return existing label
920 * @ls - labelset to insert @label into
921 * @label - label to insert
922 *
923 * Requires: caller to hold a valid ref on @label
924 *
925 * Returns: ref counted @label if successful in inserting @label
926 * else ref counted equivalent label that is already in the set
927 */
928struct aa_label *aa_label_insert(struct aa_labelset *ls, struct aa_label *label)
929{
930 struct aa_label *l;
931 unsigned long flags;
932
933 AA_BUG(!ls);
934 AA_BUG(!label);
935
936 /* check if label exists before taking lock */
937 if (!label_is_stale(label)) {
938 read_lock_irqsave(&ls->lock, flags);
939 l = __label_find(label);
940 read_unlock_irqrestore(&ls->lock, flags);
941 if (l)
942 return l;
943 }
944
945 write_lock_irqsave(&ls->lock, flags);
946 l = __label_insert(ls, label, false);
947 write_unlock_irqrestore(&ls->lock, flags);
948
949 return l;
950}
951
952
953/**
954 * aa_label_next_in_merge - find the next profile when merging @a and @b
955 * @I: label iterator
956 * @a: label to merge
957 * @b: label to merge
958 *
959 * Returns: next profile
960 * else null if no more profiles
961 */
962struct aa_profile *aa_label_next_in_merge(struct label_it *I,
963 struct aa_label *a,
964 struct aa_label *b)
965{
966 AA_BUG(!a);
967 AA_BUG(!b);
968 AA_BUG(!I);
969 AA_BUG(I->i < 0);
970 AA_BUG(I->i > a->size);
971 AA_BUG(I->j < 0);
972 AA_BUG(I->j > b->size);
973
974 if (I->i < a->size) {
975 if (I->j < b->size) {
976 int res = profile_cmp(a->vec[I->i], b->vec[I->j]);
977
978 if (res > 0)
979 return b->vec[(I->j)++];
980 if (res == 0)
981 (I->j)++;
982 }
983
984 return a->vec[(I->i)++];
985 }
986
987 if (I->j < b->size)
988 return b->vec[(I->j)++];
989
990 return NULL;
991}
992
993/**
994 * label_merge_cmp - cmp of @a merging with @b against @z for set ordering
995 * @a: label to merge then compare (NOT NULL)
996 * @b: label to merge then compare (NOT NULL)
997 * @z: label to compare merge against (NOT NULL)
998 *
999 * Assumes: using the most recent versions of @a, @b, and @z
1000 *
1001 * Returns: <0 if a < b
1002 * ==0 if a == b
1003 * >0 if a > b
1004 */
1005static int label_merge_cmp(struct aa_label *a, struct aa_label *b,
1006 struct aa_label *z)
1007{
1008 struct aa_profile *p = NULL;
1009 struct label_it i = { };
1010 int k;
1011
1012 AA_BUG(!a);
1013 AA_BUG(!b);
1014 AA_BUG(!z);
1015
1016 for (k = 0;
1017 k < z->size && (p = aa_label_next_in_merge(&i, a, b));
1018 k++) {
1019 int res = profile_cmp(p, z->vec[k]);
1020
1021 if (res != 0)
1022 return res;
1023 }
1024
1025 if (p)
1026 return 1;
1027 else if (k < z->size)
1028 return -1;
1029 return 0;
1030}
1031
1032/**
1033 * label_merge_insert - create a new label by merging @a and @b
1034 * @new: preallocated label to merge into (NOT NULL)
1035 * @a: label to merge with @b (NOT NULL)
1036 * @b: label to merge with @a (NOT NULL)
1037 *
1038 * Requires: preallocated proxy
1039 *
1040 * Returns: ref counted label either @new if merge is unique
1041 * @a if @b is a subset of @a
1042 * @b if @a is a subset of @b
1043 *
1044 * NOTE: will not use @new if the merge results in @new == @a or @b
1045 *
1046 * Must be used within labelset write lock to avoid racing with
1047 * setting labels stale.
1048 */
1049static struct aa_label *label_merge_insert(struct aa_label *new,
1050 struct aa_label *a,
1051 struct aa_label *b)
1052{
1053 struct aa_label *label;
1054 struct aa_labelset *ls;
1055 struct aa_profile *next;
1056 struct label_it i;
1057 unsigned long flags;
1058 int k = 0, invcount = 0;
1059 bool stale = false;
1060
1061 AA_BUG(!a);
1062 AA_BUG(a->size < 0);
1063 AA_BUG(!b);
1064 AA_BUG(b->size < 0);
1065 AA_BUG(!new);
1066 AA_BUG(new->size < a->size + b->size);
1067
1068 label_for_each_in_merge(i, a, b, next) {
1069 AA_BUG(!next);
1070 if (profile_is_stale(next)) {
1071 new->vec[k] = aa_get_newest_profile(next);
1072 AA_BUG(!new->vec[k]->label.proxy);
1073 AA_BUG(!new->vec[k]->label.proxy->label);
1074 if (next->label.proxy != new->vec[k]->label.proxy)
1075 invcount++;
1076 k++;
1077 stale = true;
1078 } else
1079 new->vec[k++] = aa_get_profile(next);
1080 }
1081 /* set to actual size which is <= allocated len */
1082 new->size = k;
1083 new->vec[k] = NULL;
1084
1085 if (invcount) {
1086 new->size -= aa_vec_unique(&new->vec[0], new->size,
1087 VEC_FLAG_TERMINATE);
1088 /* TODO: deal with reference labels */
1089 if (new->size == 1) {
1090 label = aa_get_label(&new->vec[0]->label);
1091 return label;
1092 }
1093 } else if (!stale) {
1094 /*
1095 * merge could be same as a || b, note: it is not possible
1096 * for new->size == a->size == b->size unless a == b
1097 */
1098 if (k == a->size)
1099 return aa_get_label(a);
1100 else if (k == b->size)
1101 return aa_get_label(b);
1102 }
1103 new->flags |= accum_vec_flags(new->vec, new->size);
1104 ls = labels_set(new);
1105 write_lock_irqsave(&ls->lock, flags);
1106 label = __label_insert(labels_set(new), new, false);
1107 write_unlock_irqrestore(&ls->lock, flags);
1108
1109 return label;
1110}
1111
1112/**
1113 * labelset_of_merge - find which labelset a merged label should be inserted
1114 * @a: label to merge and insert
1115 * @b: label to merge and insert
1116 *
1117 * Returns: labelset that the merged label should be inserted into
1118 */
1119static struct aa_labelset *labelset_of_merge(struct aa_label *a,
1120 struct aa_label *b)
1121{
1122 struct aa_ns *nsa = labels_ns(a);
1123 struct aa_ns *nsb = labels_ns(b);
1124
1125 if (ns_cmp(nsa, nsb) <= 0)
1126 return &nsa->labels;
1127 return &nsb->labels;
1128}
1129
1130/**
1131 * __label_find_merge - find label that is equiv to merge of @a and @b
1132 * @ls: set of labels to search (NOT NULL)
1133 * @a: label to merge with @b (NOT NULL)
1134 * @b: label to merge with @a (NOT NULL)
1135 *
1136 * Requires: ls->lock read_lock held
1137 *
1138 * Returns: ref counted label that is equiv to merge of @a and @b
1139 * else NULL if merge of @a and @b is not in set
1140 */
1141static struct aa_label *__label_find_merge(struct aa_labelset *ls,
1142 struct aa_label *a,
1143 struct aa_label *b)
1144{
1145 struct rb_node *node;
1146
1147 AA_BUG(!ls);
1148 AA_BUG(!a);
1149 AA_BUG(!b);
1150
1151 if (a == b)
1152 return __label_find(a);
1153
1154 node = ls->root.rb_node;
1155 while (node) {
1156 struct aa_label *this = container_of(node, struct aa_label,
1157 node);
1158 int result = label_merge_cmp(a, b, this);
1159
1160 if (result < 0)
1161 node = node->rb_left;
1162 else if (result > 0)
1163 node = node->rb_right;
1164 else
1165 return __aa_get_label(this);
1166 }
1167
1168 return NULL;
1169}
1170
1171
1172/**
1173 * aa_label_find_merge - find label that is equiv to merge of @a and @b
1174 * @a: label to merge with @b (NOT NULL)
1175 * @b: label to merge with @a (NOT NULL)
1176 *
1177 * Requires: labels be fully constructed with a valid ns
1178 *
1179 * Returns: ref counted label that is equiv to merge of @a and @b
1180 * else NULL if merge of @a and @b is not in set
1181 */
1182struct aa_label *aa_label_find_merge(struct aa_label *a, struct aa_label *b)
1183{
1184 struct aa_labelset *ls;
1185 struct aa_label *label, *ar = NULL, *br = NULL;
1186 unsigned long flags;
1187
1188 AA_BUG(!a);
1189 AA_BUG(!b);
1190
1191 if (label_is_stale(a))
1192 a = ar = aa_get_newest_label(a);
1193 if (label_is_stale(b))
1194 b = br = aa_get_newest_label(b);
1195 ls = labelset_of_merge(a, b);
1196 read_lock_irqsave(&ls->lock, flags);
1197 label = __label_find_merge(ls, a, b);
1198 read_unlock_irqrestore(&ls->lock, flags);
1199 aa_put_label(ar);
1200 aa_put_label(br);
1201
1202 return label;
1203}
1204
1205/**
1206 * aa_label_merge - attempt to insert new merged label of @a and @b
1207 * @ls: set of labels to insert label into (NOT NULL)
1208 * @a: label to merge with @b (NOT NULL)
1209 * @b: label to merge with @a (NOT NULL)
1210 * @gfp: memory allocation type
1211 *
1212 * Requires: caller to hold valid refs on @a and @b
1213 * labels be fully constructed with a valid ns
1214 *
1215 * Returns: ref counted new label if successful in inserting merge of a & b
1216 * else ref counted equivalent label that is already in the set.
1217 * else NULL if could not create label (-ENOMEM)
1218 */
1219struct aa_label *aa_label_merge(struct aa_label *a, struct aa_label *b,
1220 gfp_t gfp)
1221{
1222 struct aa_label *label = NULL;
1223
1224 AA_BUG(!a);
1225 AA_BUG(!b);
1226
1227 if (a == b)
1228 return aa_get_newest_label(a);
1229
1230 /* TODO: enable when read side is lockless
1231 * check if label exists before taking locks
1232 if (!label_is_stale(a) && !label_is_stale(b))
1233 label = aa_label_find_merge(a, b);
1234 */
1235
1236 if (!label) {
1237 struct aa_label *new;
1238
1239 a = aa_get_newest_label(a);
1240 b = aa_get_newest_label(b);
1241
1242 /* could use label_merge_len(a, b), but requires double
1243 * comparison for small savings
1244 */
1245 new = aa_label_alloc(a->size + b->size, NULL, gfp);
1246 if (!new)
1247 goto out;
1248
1249 label = label_merge_insert(new, a, b);
1250 label_free_or_put_new(label, new);
1251out:
1252 aa_put_label(a);
1253 aa_put_label(b);
1254 }
1255
1256 return label;
1257}
1258
1259/* match a profile and its associated ns component if needed
1260 * Assumes visibility test has already been done.
1261 * If a subns profile is not to be matched should be prescreened with
1262 * visibility test.
1263 */
1264static inline aa_state_t match_component(struct aa_profile *profile,
1265 struct aa_ruleset *rules,
1266 struct aa_profile *tp,
1267 aa_state_t state)
1268{
1269 const char *ns_name;
1270
1271 if (profile->ns == tp->ns)
1272 return aa_dfa_match(rules->policy.dfa, state, tp->base.hname);
1273
1274 /* try matching with namespace name and then profile */
1275 ns_name = aa_ns_name(profile->ns, tp->ns, true);
1276 state = aa_dfa_match_len(rules->policy.dfa, state, ":", 1);
1277 state = aa_dfa_match(rules->policy.dfa, state, ns_name);
1278 state = aa_dfa_match_len(rules->policy.dfa, state, ":", 1);
1279 return aa_dfa_match(rules->policy.dfa, state, tp->base.hname);
1280}
1281
1282/**
1283 * label_compound_match - find perms for full compound label
1284 * @profile: profile to find perms for
1285 * @label: label to check access permissions for
1286 * @start: state to start match in
1287 * @subns: whether to do permission checks on components in a subns
1288 * @request: permissions to request
1289 * @perms: perms struct to set
1290 *
1291 * Returns: 0 on success else ERROR
1292 *
1293 * For the label A//&B//&C this does the perm match for A//&B//&C
1294 * @perms should be preinitialized with allperms OR a previous permission
1295 * check to be stacked.
1296 */
1297static int label_compound_match(struct aa_profile *profile,
1298 struct aa_ruleset *rules,
1299 struct aa_label *label,
1300 aa_state_t state, bool subns, u32 request,
1301 struct aa_perms *perms)
1302{
1303 struct aa_profile *tp;
1304 struct label_it i;
1305
1306 /* find first subcomponent that is visible */
1307 label_for_each(i, label, tp) {
1308 if (!aa_ns_visible(profile->ns, tp->ns, subns))
1309 continue;
1310 state = match_component(profile, rules, tp, state);
1311 if (!state)
1312 goto fail;
1313 goto next;
1314 }
1315
1316 /* no component visible */
1317 *perms = allperms;
1318 return 0;
1319
1320next:
1321 label_for_each_cont(i, label, tp) {
1322 if (!aa_ns_visible(profile->ns, tp->ns, subns))
1323 continue;
1324 state = aa_dfa_match(rules->policy.dfa, state, "//&");
1325 state = match_component(profile, rules, tp, state);
1326 if (!state)
1327 goto fail;
1328 }
1329 *perms = *aa_lookup_perms(&rules->policy, state);
1330 aa_apply_modes_to_perms(profile, perms);
1331 if ((perms->allow & request) != request)
1332 return -EACCES;
1333
1334 return 0;
1335
1336fail:
1337 *perms = nullperms;
1338 return state;
1339}
1340
1341/**
1342 * label_components_match - find perms for all subcomponents of a label
1343 * @profile: profile to find perms for
1344 * @rules: ruleset to search
1345 * @label: label to check access permissions for
1346 * @start: state to start match in
1347 * @subns: whether to do permission checks on components in a subns
1348 * @request: permissions to request
1349 * @perms: an initialized perms struct to add accumulation to
1350 *
1351 * Returns: 0 on success else ERROR
1352 *
1353 * For the label A//&B//&C this does the perm match for each of A and B and C
1354 * @perms should be preinitialized with allperms OR a previous permission
1355 * check to be stacked.
1356 */
1357static int label_components_match(struct aa_profile *profile,
1358 struct aa_ruleset *rules,
1359 struct aa_label *label, aa_state_t start,
1360 bool subns, u32 request,
1361 struct aa_perms *perms)
1362{
1363 struct aa_profile *tp;
1364 struct label_it i;
1365 struct aa_perms tmp;
1366 aa_state_t state = 0;
1367
1368 /* find first subcomponent to test */
1369 label_for_each(i, label, tp) {
1370 if (!aa_ns_visible(profile->ns, tp->ns, subns))
1371 continue;
1372 state = match_component(profile, rules, tp, start);
1373 if (!state)
1374 goto fail;
1375 goto next;
1376 }
1377
1378 /* no subcomponents visible - no change in perms */
1379 return 0;
1380
1381next:
1382 tmp = *aa_lookup_perms(&rules->policy, state);
1383 aa_apply_modes_to_perms(profile, &tmp);
1384 aa_perms_accum(perms, &tmp);
1385 label_for_each_cont(i, label, tp) {
1386 if (!aa_ns_visible(profile->ns, tp->ns, subns))
1387 continue;
1388 state = match_component(profile, rules, tp, start);
1389 if (!state)
1390 goto fail;
1391 tmp = *aa_lookup_perms(&rules->policy, state);
1392 aa_apply_modes_to_perms(profile, &tmp);
1393 aa_perms_accum(perms, &tmp);
1394 }
1395
1396 if ((perms->allow & request) != request)
1397 return -EACCES;
1398
1399 return 0;
1400
1401fail:
1402 *perms = nullperms;
1403 return -EACCES;
1404}
1405
1406/**
1407 * aa_label_match - do a multi-component label match
1408 * @profile: profile to match against (NOT NULL)
1409 * @rules: ruleset to search
1410 * @label: label to match (NOT NULL)
1411 * @state: state to start in
1412 * @subns: whether to match subns components
1413 * @request: permission request
1414 * @perms: Returns computed perms (NOT NULL)
1415 *
1416 * Returns: the state the match finished in, may be the none matching state
1417 */
1418int aa_label_match(struct aa_profile *profile, struct aa_ruleset *rules,
1419 struct aa_label *label, aa_state_t state, bool subns,
1420 u32 request, struct aa_perms *perms)
1421{
1422 int error = label_compound_match(profile, rules, label, state, subns,
1423 request, perms);
1424 if (!error)
1425 return error;
1426
1427 *perms = allperms;
1428 return label_components_match(profile, rules, label, state, subns,
1429 request, perms);
1430}
1431
1432
1433/**
1434 * aa_update_label_name - update a label to have a stored name
1435 * @ns: ns being viewed from (NOT NULL)
1436 * @label: label to update (NOT NULL)
1437 * @gfp: type of memory allocation
1438 *
1439 * Requires: labels_set(label) not locked in caller
1440 *
1441 * note: only updates the label name if it does not have a name already
1442 * and if it is in the labelset
1443 */
1444bool aa_update_label_name(struct aa_ns *ns, struct aa_label *label, gfp_t gfp)
1445{
1446 struct aa_labelset *ls;
1447 unsigned long flags;
1448 char __counted *name;
1449 bool res = false;
1450
1451 AA_BUG(!ns);
1452 AA_BUG(!label);
1453
1454 if (label->hname || labels_ns(label) != ns)
1455 return res;
1456
1457 if (aa_label_acntsxprint(&name, ns, label, FLAGS_NONE, gfp) < 0)
1458 return res;
1459
1460 ls = labels_set(label);
1461 write_lock_irqsave(&ls->lock, flags);
1462 if (!label->hname && label->flags & FLAG_IN_TREE) {
1463 label->hname = name;
1464 res = true;
1465 } else
1466 aa_put_str(name);
1467 write_unlock_irqrestore(&ls->lock, flags);
1468
1469 return res;
1470}
1471
1472/*
1473 * cached label name is present and visible
1474 * @label->hname only exists if label is namespace hierachical
1475 */
1476static inline bool use_label_hname(struct aa_ns *ns, struct aa_label *label,
1477 int flags)
1478{
1479 if (label->hname && (!ns || labels_ns(label) == ns) &&
1480 !(flags & ~FLAG_SHOW_MODE))
1481 return true;
1482
1483 return false;
1484}
1485
1486/* helper macro for snprint routines */
1487#define update_for_len(total, len, size, str) \
1488do { \
1489 size_t ulen = len; \
1490 \
1491 AA_BUG(len < 0); \
1492 total += ulen; \
1493 ulen = min(ulen, size); \
1494 size -= ulen; \
1495 str += ulen; \
1496} while (0)
1497
1498/**
1499 * aa_profile_snxprint - print a profile name to a buffer
1500 * @str: buffer to write to. (MAY BE NULL if @size == 0)
1501 * @size: size of buffer
1502 * @view: namespace profile is being viewed from
1503 * @profile: profile to view (NOT NULL)
1504 * @flags: whether to include the mode string
1505 * @prev_ns: last ns printed when used in compound print
1506 *
1507 * Returns: size of name written or would be written if larger than
1508 * available buffer
1509 *
1510 * Note: will not print anything if the profile is not visible
1511 */
1512static int aa_profile_snxprint(char *str, size_t size, struct aa_ns *view,
1513 struct aa_profile *profile, int flags,
1514 struct aa_ns **prev_ns)
1515{
1516 const char *ns_name = NULL;
1517
1518 AA_BUG(!str && size != 0);
1519 AA_BUG(!profile);
1520
1521 if (!view)
1522 view = profiles_ns(profile);
1523
1524 if (view != profile->ns &&
1525 (!prev_ns || (*prev_ns != profile->ns))) {
1526 if (prev_ns)
1527 *prev_ns = profile->ns;
1528 ns_name = aa_ns_name(view, profile->ns,
1529 flags & FLAG_VIEW_SUBNS);
1530 if (ns_name == aa_hidden_ns_name) {
1531 if (flags & FLAG_HIDDEN_UNCONFINED)
1532 return snprintf(str, size, "%s", "unconfined");
1533 return snprintf(str, size, "%s", ns_name);
1534 }
1535 }
1536
1537 if ((flags & FLAG_SHOW_MODE) && profile != profile->ns->unconfined) {
1538 const char *modestr = aa_profile_mode_names[profile->mode];
1539
1540 if (ns_name)
1541 return snprintf(str, size, ":%s:%s (%s)", ns_name,
1542 profile->base.hname, modestr);
1543 return snprintf(str, size, "%s (%s)", profile->base.hname,
1544 modestr);
1545 }
1546
1547 if (ns_name)
1548 return snprintf(str, size, ":%s:%s", ns_name,
1549 profile->base.hname);
1550 return snprintf(str, size, "%s", profile->base.hname);
1551}
1552
1553static const char *label_modename(struct aa_ns *ns, struct aa_label *label,
1554 int flags)
1555{
1556 struct aa_profile *profile;
1557 struct label_it i;
1558 int mode = -1, count = 0;
1559
1560 label_for_each(i, label, profile) {
1561 if (aa_ns_visible(ns, profile->ns, flags & FLAG_VIEW_SUBNS)) {
1562 count++;
1563 if (profile == profile->ns->unconfined)
1564 /* special case unconfined so stacks with
1565 * unconfined don't report as mixed. ie.
1566 * profile_foo//&:ns1:unconfined (mixed)
1567 */
1568 continue;
1569 if (mode == -1)
1570 mode = profile->mode;
1571 else if (mode != profile->mode)
1572 return "mixed";
1573 }
1574 }
1575
1576 if (count == 0)
1577 return "-";
1578 if (mode == -1)
1579 /* everything was unconfined */
1580 mode = APPARMOR_UNCONFINED;
1581
1582 return aa_profile_mode_names[mode];
1583}
1584
1585/* if any visible label is not unconfined the display_mode returns true */
1586static inline bool display_mode(struct aa_ns *ns, struct aa_label *label,
1587 int flags)
1588{
1589 if ((flags & FLAG_SHOW_MODE)) {
1590 struct aa_profile *profile;
1591 struct label_it i;
1592
1593 label_for_each(i, label, profile) {
1594 if (aa_ns_visible(ns, profile->ns,
1595 flags & FLAG_VIEW_SUBNS) &&
1596 profile != profile->ns->unconfined)
1597 return true;
1598 }
1599 /* only ns->unconfined in set of profiles in ns */
1600 return false;
1601 }
1602
1603 return false;
1604}
1605
1606/**
1607 * aa_label_snxprint - print a label name to a string buffer
1608 * @str: buffer to write to. (MAY BE NULL if @size == 0)
1609 * @size: size of buffer
1610 * @ns: namespace profile is being viewed from
1611 * @label: label to view (NOT NULL)
1612 * @flags: whether to include the mode string
1613 *
1614 * Returns: size of name written or would be written if larger than
1615 * available buffer
1616 *
1617 * Note: labels do not have to be strictly hierarchical to the ns as
1618 * objects may be shared across different namespaces and thus
1619 * pickup labeling from each ns. If a particular part of the
1620 * label is not visible it will just be excluded. And if none
1621 * of the label is visible "---" will be used.
1622 */
1623int aa_label_snxprint(char *str, size_t size, struct aa_ns *ns,
1624 struct aa_label *label, int flags)
1625{
1626 struct aa_profile *profile;
1627 struct aa_ns *prev_ns = NULL;
1628 struct label_it i;
1629 int count = 0, total = 0;
1630 ssize_t len;
1631
1632 AA_BUG(!str && size != 0);
1633 AA_BUG(!label);
1634
1635 if (AA_DEBUG_LABEL && (flags & FLAG_ABS_ROOT)) {
1636 ns = root_ns;
1637 len = snprintf(str, size, "_");
1638 update_for_len(total, len, size, str);
1639 } else if (!ns) {
1640 ns = labels_ns(label);
1641 }
1642
1643 label_for_each(i, label, profile) {
1644 if (aa_ns_visible(ns, profile->ns, flags & FLAG_VIEW_SUBNS)) {
1645 if (count > 0) {
1646 len = snprintf(str, size, "//&");
1647 update_for_len(total, len, size, str);
1648 }
1649 len = aa_profile_snxprint(str, size, ns, profile,
1650 flags & FLAG_VIEW_SUBNS,
1651 &prev_ns);
1652 update_for_len(total, len, size, str);
1653 count++;
1654 }
1655 }
1656
1657 if (count == 0) {
1658 if (flags & FLAG_HIDDEN_UNCONFINED)
1659 return snprintf(str, size, "%s", "unconfined");
1660 return snprintf(str, size, "%s", aa_hidden_ns_name);
1661 }
1662
1663 /* count == 1 && ... is for backwards compat where the mode
1664 * is not displayed for 'unconfined' in the current ns
1665 */
1666 if (display_mode(ns, label, flags)) {
1667 len = snprintf(str, size, " (%s)",
1668 label_modename(ns, label, flags));
1669 update_for_len(total, len, size, str);
1670 }
1671
1672 return total;
1673}
1674#undef update_for_len
1675
1676/**
1677 * aa_label_asxprint - allocate a string buffer and print label into it
1678 * @strp: Returns - the allocated buffer with the label name. (NOT NULL)
1679 * @ns: namespace profile is being viewed from
1680 * @label: label to view (NOT NULL)
1681 * @flags: flags controlling what label info is printed
1682 * @gfp: kernel memory allocation type
1683 *
1684 * Returns: size of name written or would be written if larger than
1685 * available buffer
1686 */
1687int aa_label_asxprint(char **strp, struct aa_ns *ns, struct aa_label *label,
1688 int flags, gfp_t gfp)
1689{
1690 int size;
1691
1692 AA_BUG(!strp);
1693 AA_BUG(!label);
1694
1695 size = aa_label_snxprint(NULL, 0, ns, label, flags);
1696 if (size < 0)
1697 return size;
1698
1699 *strp = kmalloc(size + 1, gfp);
1700 if (!*strp)
1701 return -ENOMEM;
1702 return aa_label_snxprint(*strp, size + 1, ns, label, flags);
1703}
1704
1705/**
1706 * aa_label_acntsxprint - allocate a __counted string buffer and print label
1707 * @strp: buffer to write to.
1708 * @ns: namespace profile is being viewed from
1709 * @label: label to view (NOT NULL)
1710 * @flags: flags controlling what label info is printed
1711 * @gfp: kernel memory allocation type
1712 *
1713 * Returns: size of name written or would be written if larger than
1714 * available buffer
1715 */
1716int aa_label_acntsxprint(char __counted **strp, struct aa_ns *ns,
1717 struct aa_label *label, int flags, gfp_t gfp)
1718{
1719 int size;
1720
1721 AA_BUG(!strp);
1722 AA_BUG(!label);
1723
1724 size = aa_label_snxprint(NULL, 0, ns, label, flags);
1725 if (size < 0)
1726 return size;
1727
1728 *strp = aa_str_alloc(size + 1, gfp);
1729 if (!*strp)
1730 return -ENOMEM;
1731 return aa_label_snxprint(*strp, size + 1, ns, label, flags);
1732}
1733
1734
1735void aa_label_xaudit(struct audit_buffer *ab, struct aa_ns *ns,
1736 struct aa_label *label, int flags, gfp_t gfp)
1737{
1738 const char *str;
1739 char *name = NULL;
1740 int len;
1741
1742 AA_BUG(!ab);
1743 AA_BUG(!label);
1744
1745 if (!use_label_hname(ns, label, flags) ||
1746 display_mode(ns, label, flags)) {
1747 len = aa_label_asxprint(&name, ns, label, flags, gfp);
1748 if (len < 0) {
1749 AA_DEBUG("label print error");
1750 return;
1751 }
1752 str = name;
1753 } else {
1754 str = (char *) label->hname;
1755 len = strlen(str);
1756 }
1757 if (audit_string_contains_control(str, len))
1758 audit_log_n_hex(ab, str, len);
1759 else
1760 audit_log_n_string(ab, str, len);
1761
1762 kfree(name);
1763}
1764
1765void aa_label_seq_xprint(struct seq_file *f, struct aa_ns *ns,
1766 struct aa_label *label, int flags, gfp_t gfp)
1767{
1768 AA_BUG(!f);
1769 AA_BUG(!label);
1770
1771 if (!use_label_hname(ns, label, flags)) {
1772 char *str;
1773 int len;
1774
1775 len = aa_label_asxprint(&str, ns, label, flags, gfp);
1776 if (len < 0) {
1777 AA_DEBUG("label print error");
1778 return;
1779 }
1780 seq_puts(f, str);
1781 kfree(str);
1782 } else if (display_mode(ns, label, flags))
1783 seq_printf(f, "%s (%s)", label->hname,
1784 label_modename(ns, label, flags));
1785 else
1786 seq_puts(f, label->hname);
1787}
1788
1789void aa_label_xprintk(struct aa_ns *ns, struct aa_label *label, int flags,
1790 gfp_t gfp)
1791{
1792 AA_BUG(!label);
1793
1794 if (!use_label_hname(ns, label, flags)) {
1795 char *str;
1796 int len;
1797
1798 len = aa_label_asxprint(&str, ns, label, flags, gfp);
1799 if (len < 0) {
1800 AA_DEBUG("label print error");
1801 return;
1802 }
1803 pr_info("%s", str);
1804 kfree(str);
1805 } else if (display_mode(ns, label, flags))
1806 pr_info("%s (%s)", label->hname,
1807 label_modename(ns, label, flags));
1808 else
1809 pr_info("%s", label->hname);
1810}
1811
1812void aa_label_audit(struct audit_buffer *ab, struct aa_label *label, gfp_t gfp)
1813{
1814 struct aa_ns *ns = aa_get_current_ns();
1815
1816 aa_label_xaudit(ab, ns, label, FLAG_VIEW_SUBNS, gfp);
1817 aa_put_ns(ns);
1818}
1819
1820void aa_label_seq_print(struct seq_file *f, struct aa_label *label, gfp_t gfp)
1821{
1822 struct aa_ns *ns = aa_get_current_ns();
1823
1824 aa_label_seq_xprint(f, ns, label, FLAG_VIEW_SUBNS, gfp);
1825 aa_put_ns(ns);
1826}
1827
1828void aa_label_printk(struct aa_label *label, gfp_t gfp)
1829{
1830 struct aa_ns *ns = aa_get_current_ns();
1831
1832 aa_label_xprintk(ns, label, FLAG_VIEW_SUBNS, gfp);
1833 aa_put_ns(ns);
1834}
1835
1836static int label_count_strn_entries(const char *str, size_t n)
1837{
1838 const char *end = str + n;
1839 const char *split;
1840 int count = 1;
1841
1842 AA_BUG(!str);
1843
1844 for (split = aa_label_strn_split(str, end - str);
1845 split;
1846 split = aa_label_strn_split(str, end - str)) {
1847 count++;
1848 str = split + 3;
1849 }
1850
1851 return count;
1852}
1853
1854/*
1855 * ensure stacks with components like
1856 * :ns:A//&B
1857 * have :ns: applied to both 'A' and 'B' by making the lookup relative
1858 * to the base if the lookup specifies an ns, else making the stacked lookup
1859 * relative to the last embedded ns in the string.
1860 */
1861static struct aa_profile *fqlookupn_profile(struct aa_label *base,
1862 struct aa_label *currentbase,
1863 const char *str, size_t n)
1864{
1865 const char *first = skipn_spaces(str, n);
1866
1867 if (first && *first == ':')
1868 return aa_fqlookupn_profile(base, str, n);
1869
1870 return aa_fqlookupn_profile(currentbase, str, n);
1871}
1872
1873/**
1874 * aa_label_strn_parse - parse, validate and convert a text string to a label
1875 * @base: base label to use for lookups (NOT NULL)
1876 * @str: null terminated text string (NOT NULL)
1877 * @n: length of str to parse, will stop at \0 if encountered before n
1878 * @gfp: allocation type
1879 * @create: true if should create compound labels if they don't exist
1880 * @force_stack: true if should stack even if no leading &
1881 *
1882 * Returns: the matching refcounted label if present
1883 * else ERRPTR
1884 */
1885struct aa_label *aa_label_strn_parse(struct aa_label *base, const char *str,
1886 size_t n, gfp_t gfp, bool create,
1887 bool force_stack)
1888{
1889 DEFINE_VEC(profile, vec);
1890 struct aa_label *label, *currbase = base;
1891 int i, len, stack = 0, error;
1892 const char *end = str + n;
1893 const char *split;
1894
1895 AA_BUG(!base);
1896 AA_BUG(!str);
1897
1898 str = skipn_spaces(str, n);
1899 if (str == NULL || (AA_DEBUG_LABEL && *str == '_' &&
1900 base != &root_ns->unconfined->label))
1901 return ERR_PTR(-EINVAL);
1902
1903 len = label_count_strn_entries(str, end - str);
1904 if (*str == '&' || force_stack) {
1905 /* stack on top of base */
1906 stack = base->size;
1907 len += stack;
1908 if (*str == '&')
1909 str++;
1910 }
1911
1912 error = vec_setup(profile, vec, len, gfp);
1913 if (error)
1914 return ERR_PTR(error);
1915
1916 for (i = 0; i < stack; i++)
1917 vec[i] = aa_get_profile(base->vec[i]);
1918
1919 for (split = aa_label_strn_split(str, end - str), i = stack;
1920 split && i < len; i++) {
1921 vec[i] = fqlookupn_profile(base, currbase, str, split - str);
1922 if (!vec[i])
1923 goto fail;
1924 /*
1925 * if component specified a new ns it becomes the new base
1926 * so that subsequent lookups are relative to it
1927 */
1928 if (vec[i]->ns != labels_ns(currbase))
1929 currbase = &vec[i]->label;
1930 str = split + 3;
1931 split = aa_label_strn_split(str, end - str);
1932 }
1933 /* last element doesn't have a split */
1934 if (i < len) {
1935 vec[i] = fqlookupn_profile(base, currbase, str, end - str);
1936 if (!vec[i])
1937 goto fail;
1938 }
1939 if (len == 1)
1940 /* no need to free vec as len < LOCAL_VEC_ENTRIES */
1941 return &vec[0]->label;
1942
1943 len -= aa_vec_unique(vec, len, VEC_FLAG_TERMINATE);
1944 /* TODO: deal with reference labels */
1945 if (len == 1) {
1946 label = aa_get_label(&vec[0]->label);
1947 goto out;
1948 }
1949
1950 if (create)
1951 label = aa_vec_find_or_create_label(vec, len, gfp);
1952 else
1953 label = vec_find(vec, len);
1954 if (!label)
1955 goto fail;
1956
1957out:
1958 /* use adjusted len from after vec_unique, not original */
1959 vec_cleanup(profile, vec, len);
1960 return label;
1961
1962fail:
1963 label = ERR_PTR(-ENOENT);
1964 goto out;
1965}
1966
1967struct aa_label *aa_label_parse(struct aa_label *base, const char *str,
1968 gfp_t gfp, bool create, bool force_stack)
1969{
1970 return aa_label_strn_parse(base, str, strlen(str), gfp, create,
1971 force_stack);
1972}
1973
1974/**
1975 * aa_labelset_destroy - remove all labels from the label set
1976 * @ls: label set to cleanup (NOT NULL)
1977 *
1978 * Labels that are removed from the set may still exist beyond the set
1979 * being destroyed depending on their reference counting
1980 */
1981void aa_labelset_destroy(struct aa_labelset *ls)
1982{
1983 struct rb_node *node;
1984 unsigned long flags;
1985
1986 AA_BUG(!ls);
1987
1988 write_lock_irqsave(&ls->lock, flags);
1989 for (node = rb_first(&ls->root); node; node = rb_first(&ls->root)) {
1990 struct aa_label *this = rb_entry(node, struct aa_label, node);
1991
1992 if (labels_ns(this) != root_ns)
1993 __label_remove(this,
1994 ns_unconfined(labels_ns(this)->parent));
1995 else
1996 __label_remove(this, NULL);
1997 }
1998 write_unlock_irqrestore(&ls->lock, flags);
1999}
2000
2001/*
2002 * @ls: labelset to init (NOT NULL)
2003 */
2004void aa_labelset_init(struct aa_labelset *ls)
2005{
2006 AA_BUG(!ls);
2007
2008 rwlock_init(&ls->lock);
2009 ls->root = RB_ROOT;
2010}
2011
2012static struct aa_label *labelset_next_stale(struct aa_labelset *ls)
2013{
2014 struct aa_label *label;
2015 struct rb_node *node;
2016 unsigned long flags;
2017
2018 AA_BUG(!ls);
2019
2020 read_lock_irqsave(&ls->lock, flags);
2021
2022 __labelset_for_each(ls, node) {
2023 label = rb_entry(node, struct aa_label, node);
2024 if ((label_is_stale(label) ||
2025 vec_is_stale(label->vec, label->size)) &&
2026 __aa_get_label(label))
2027 goto out;
2028
2029 }
2030 label = NULL;
2031
2032out:
2033 read_unlock_irqrestore(&ls->lock, flags);
2034
2035 return label;
2036}
2037
2038/**
2039 * __label_update - insert updated version of @label into labelset
2040 * @label - the label to update/replace
2041 *
2042 * Returns: new label that is up to date
2043 * else NULL on failure
2044 *
2045 * Requires: @ns lock be held
2046 *
2047 * Note: worst case is the stale @label does not get updated and has
2048 * to be updated at a later time.
2049 */
2050static struct aa_label *__label_update(struct aa_label *label)
2051{
2052 struct aa_label *new, *tmp;
2053 struct aa_labelset *ls;
2054 unsigned long flags;
2055 int i, invcount = 0;
2056
2057 AA_BUG(!label);
2058 AA_BUG(!mutex_is_locked(&labels_ns(label)->lock));
2059
2060 new = aa_label_alloc(label->size, label->proxy, GFP_KERNEL);
2061 if (!new)
2062 return NULL;
2063
2064 /*
2065 * while holding the ns_lock will stop profile replacement, removal,
2066 * and label updates, label merging and removal can be occurring
2067 */
2068 ls = labels_set(label);
2069 write_lock_irqsave(&ls->lock, flags);
2070 for (i = 0; i < label->size; i++) {
2071 AA_BUG(!label->vec[i]);
2072 new->vec[i] = aa_get_newest_profile(label->vec[i]);
2073 AA_BUG(!new->vec[i]);
2074 AA_BUG(!new->vec[i]->label.proxy);
2075 AA_BUG(!new->vec[i]->label.proxy->label);
2076 if (new->vec[i]->label.proxy != label->vec[i]->label.proxy)
2077 invcount++;
2078 }
2079
2080 /* updated stale label by being removed/renamed from labelset */
2081 if (invcount) {
2082 new->size -= aa_vec_unique(&new->vec[0], new->size,
2083 VEC_FLAG_TERMINATE);
2084 /* TODO: deal with reference labels */
2085 if (new->size == 1) {
2086 tmp = aa_get_label(&new->vec[0]->label);
2087 AA_BUG(tmp == label);
2088 goto remove;
2089 }
2090 if (labels_set(label) != labels_set(new)) {
2091 write_unlock_irqrestore(&ls->lock, flags);
2092 tmp = aa_label_insert(labels_set(new), new);
2093 write_lock_irqsave(&ls->lock, flags);
2094 goto remove;
2095 }
2096 } else
2097 AA_BUG(labels_ns(label) != labels_ns(new));
2098
2099 tmp = __label_insert(labels_set(label), new, true);
2100remove:
2101 /* ensure label is removed, and redirected correctly */
2102 __label_remove(label, tmp);
2103 write_unlock_irqrestore(&ls->lock, flags);
2104 label_free_or_put_new(tmp, new);
2105
2106 return tmp;
2107}
2108
2109/**
2110 * __labelset_update - update labels in @ns
2111 * @ns: namespace to update labels in (NOT NULL)
2112 *
2113 * Requires: @ns lock be held
2114 *
2115 * Walk the labelset ensuring that all labels are up to date and valid
2116 * Any label that has a stale component is marked stale and replaced and
2117 * by an updated version.
2118 *
2119 * If failures happen due to memory pressures then stale labels will
2120 * be left in place until the next pass.
2121 */
2122static void __labelset_update(struct aa_ns *ns)
2123{
2124 struct aa_label *label;
2125
2126 AA_BUG(!ns);
2127 AA_BUG(!mutex_is_locked(&ns->lock));
2128
2129 do {
2130 label = labelset_next_stale(&ns->labels);
2131 if (label) {
2132 struct aa_label *l = __label_update(label);
2133
2134 aa_put_label(l);
2135 aa_put_label(label);
2136 }
2137 } while (label);
2138}
2139
2140/**
2141 * __aa_labelset_update_subtree - update all labels with a stale component
2142 * @ns: ns to start update at (NOT NULL)
2143 *
2144 * Requires: @ns lock be held
2145 *
2146 * Invalidates labels based on @p in @ns and any children namespaces.
2147 */
2148void __aa_labelset_update_subtree(struct aa_ns *ns)
2149{
2150 struct aa_ns *child;
2151
2152 AA_BUG(!ns);
2153 AA_BUG(!mutex_is_locked(&ns->lock));
2154
2155 __labelset_update(ns);
2156
2157 list_for_each_entry(child, &ns->sub_ns, base.list) {
2158 mutex_lock_nested(&child->lock, child->level);
2159 __aa_labelset_update_subtree(child);
2160 mutex_unlock(&child->lock);
2161 }
2162}