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