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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#ifndef __AA_LABEL_H
11#define __AA_LABEL_H
12
13#include <linux/atomic.h>
14#include <linux/audit.h>
15#include <linux/rbtree.h>
16#include <linux/rcupdate.h>
17
18#include "apparmor.h"
19#include "lib.h"
20
21struct aa_ns;
22struct aa_ruleset;
23
24#define LOCAL_VEC_ENTRIES 8
25#define DEFINE_VEC(T, V) \
26 struct aa_ ## T *(_ ## V ## _localtmp)[LOCAL_VEC_ENTRIES + 1]; \
27 struct aa_ ## T **(V)
28
29#define vec_setup(T, V, N, GFP) \
30({ \
31 if ((N) <= LOCAL_VEC_ENTRIES) { \
32 typeof(N) i; \
33 (V) = (_ ## V ## _localtmp); \
34 for (i = 0; i <= (N); i++) \
35 (V)[i] = NULL; \
36 } else \
37 (V) = kzalloc_objs(struct aa_ ## T *, (N) + 1, (GFP)); \
38 (V) ? 0 : -ENOMEM; \
39})
40
41#define vec_cleanup(T, V, N) \
42do { \
43 int i; \
44 for (i = 0; i < (N); i++) { \
45 if (!IS_ERR_OR_NULL((V)[i])) \
46 aa_put_ ## T((V)[i]); \
47 } \
48 if ((V) != _ ## V ## _localtmp) \
49 kfree(V); \
50} while (0)
51
52#define vec_last(VEC, SIZE) ((VEC)[(SIZE) - 1])
53#define vec_ns(VEC, SIZE) (vec_last((VEC), (SIZE))->ns)
54#define vec_labelset(VEC, SIZE) (&vec_ns((VEC), (SIZE))->labels)
55#define cleanup_domain_vec(V, L) cleanup_label_vec((V), (L)->size)
56
57struct aa_profile;
58#define VEC_FLAG_TERMINATE 1
59int aa_vec_unique(struct aa_profile **vec, int n, int flags);
60struct aa_label *aa_vec_find_or_create_label(struct aa_profile **vec, int len,
61 gfp_t gfp);
62#define aa_sort_and_merge_vec(N, V) \
63 aa_sort_and_merge_profiles((N), (struct aa_profile **)(V))
64
65
66/* struct aa_labelset - set of labels for a namespace
67 *
68 * Labels are reference counted; aa_labelset does not contribute to label
69 * reference counts. Once a label's last refcount is put it is removed from
70 * the set.
71 */
72struct aa_labelset {
73 rwlock_t lock;
74
75 struct rb_root root;
76};
77
78#define __labelset_for_each(LS, N) \
79 for ((N) = rb_first(&(LS)->root); (N); (N) = rb_next(N))
80
81enum label_flags {
82 FLAG_HAT = 1, /* profile is a hat */
83 FLAG_UNCONFINED = 2, /* label unconfined only if all */
84 FLAG_NULL = 4, /* profile is null learning profile */
85 FLAG_IX_ON_NAME_ERROR = 8, /* fallback to ix on name lookup fail */
86 FLAG_IMMUTIBLE = 0x10, /* don't allow changes/replacement */
87 FLAG_USER_DEFINED = 0x20, /* user based profile - lower privs */
88 FLAG_NO_LIST_REF = 0x40, /* list doesn't keep profile ref */
89 FLAG_NS_COUNT = 0x80, /* carries NS ref count */
90 FLAG_IN_TREE = 0x100, /* label is in tree */
91 FLAG_PROFILE = 0x200, /* label is a profile */
92 FLAG_EXPLICIT = 0x400, /* explicit static label */
93 FLAG_STALE = 0x800, /* replaced/removed */
94 FLAG_RENAMED = 0x1000, /* label has renaming in it */
95 FLAG_REVOKED = 0x2000, /* label has revocation in it */
96 FLAG_DEBUG1 = 0x4000,
97 FLAG_DEBUG2 = 0x8000,
98
99 /* These flags must correspond with PATH_flags */
100 /* TODO: add new path flags */
101};
102
103struct aa_label;
104struct aa_proxy {
105 struct aa_common_ref count;
106 struct aa_label __rcu *label;
107};
108
109struct label_it {
110 int i, j;
111};
112
113/* struct aa_label_base - base info of label
114 * @count: ref count of active users
115 * @node: rbtree position
116 * @rcu: rcu callback struct
117 * @proxy: is set to the label that replaced this label
118 * @hname: text representation of the label (MAYBE_NULL)
119 * @flags: stale and other flags - values may change under label set lock
120 * @secid: secid that references this label
121 * @size: number of entries in @ent[]
122 * @mediates: bitmask for label_mediates
123 * profile: label vec when embedded in a profile FLAG_PROFILE is set
124 * rules: variable length rules in a profile FLAG_PROFILE is set
125 * vec: vector of profiles comprising the compound label
126 */
127struct aa_label {
128 struct aa_common_ref count;
129 struct rb_node node;
130 struct rcu_head rcu;
131 struct aa_proxy *proxy;
132 __counted char *hname;
133 long flags;
134 u32 secid;
135 int size;
136 u64 mediates;
137 union {
138 struct {
139 /* only used is the label is a profile, size of
140 * rules[] is determined by the profile
141 * profile[1] is poison or null as guard
142 */
143 struct aa_profile *profile[2];
144 DECLARE_FLEX_ARRAY(struct aa_ruleset *, rules);
145 };
146 DECLARE_FLEX_ARRAY(struct aa_profile *, vec);
147 };
148};
149
150#define last_error(E, FN) \
151do { \
152 int __subE = (FN); \
153 if (__subE) \
154 (E) = __subE; \
155} while (0)
156
157#define label_isprofile(X) ((X)->flags & FLAG_PROFILE)
158#define label_unconfined(X) ((X)->flags & FLAG_UNCONFINED)
159#define unconfined(X) label_unconfined(X)
160#define label_is_stale(X) ((X)->flags & FLAG_STALE)
161#define __label_make_stale(X) ((X)->flags |= FLAG_STALE)
162#define labels_ns(X) (vec_ns(&((X)->vec[0]), (X)->size))
163#define labels_set(X) (&labels_ns(X)->labels)
164#define labels_view(X) labels_ns(X)
165#define labels_profile(X) ((X)->vec[(X)->size - 1])
166
167
168int aa_label_next_confined(const struct aa_label *l, int i);
169
170/* for each profile in a label */
171#define label_for_each(I, L, P) \
172 for ((I).i = 0; ((P) = (L)->vec[(I).i]); ++((I).i))
173
174/* assumes break/goto ended label_for_each */
175#define label_for_each_cont(I, L, P) \
176 for (++((I).i); ((P) = (L)->vec[(I).i]); ++((I).i))
177
178
179
180/* for each profile that is enforcing confinement in a label */
181#define label_for_each_confined(I, L, P) \
182 for ((I).i = aa_label_next_confined((L), 0); \
183 ((P) = (L)->vec[(I).i]); \
184 (I).i = aa_label_next_confined((L), (I).i + 1))
185
186#define label_for_each_in_merge(I, A, B, P) \
187 for ((I).i = (I).j = 0; \
188 ((P) = aa_label_next_in_merge(&(I), (A), (B))); \
189 )
190
191#define label_for_each_not_in_set(I, SET, SUB, P) \
192 for ((I).i = (I).j = 0; \
193 ((P) = __aa_label_next_not_in_set(&(I), (SET), (SUB))); \
194 )
195
196#define next_in_ns(i, NS, L) \
197({ \
198 typeof(i) ___i = (i); \
199 while ((L)->vec[___i] && (L)->vec[___i]->ns != (NS)) \
200 (___i)++; \
201 (___i); \
202})
203
204#define label_for_each_in_ns(I, NS, L, P) \
205 for ((I).i = next_in_ns(0, (NS), (L)); \
206 ((P) = (L)->vec[(I).i]); \
207 (I).i = next_in_ns((I).i + 1, (NS), (L)))
208
209#define fn_for_each_in_ns(L, P, FN) \
210({ \
211 struct label_it __i; \
212 struct aa_ns *__ns = labels_ns(L); \
213 int __E = 0; \
214 label_for_each_in_ns(__i, __ns, (L), (P)) { \
215 last_error(__E, (FN)); \
216 } \
217 __E; \
218})
219
220
221#define fn_for_each_XXX(L, P, FN, ...) \
222({ \
223 struct label_it i; \
224 int __E = 0; \
225 label_for_each ## __VA_ARGS__(i, (L), (P)) { \
226 last_error(__E, (FN)); \
227 } \
228 __E; \
229})
230
231#define fn_for_each(L, P, FN) fn_for_each_XXX(L, P, FN)
232#define fn_for_each_confined(L, P, FN) fn_for_each_XXX(L, P, FN, _confined)
233
234#define fn_for_each2_XXX(L1, L2, P, FN, ...) \
235({ \
236 struct label_it i; \
237 int __E = 0; \
238 label_for_each ## __VA_ARGS__(i, (L1), (L2), (P)) { \
239 last_error(__E, (FN)); \
240 } \
241 __E; \
242})
243
244#define fn_for_each_in_merge(L1, L2, P, FN) \
245 fn_for_each2_XXX((L1), (L2), P, FN, _in_merge)
246#define fn_for_each_not_in_set(L1, L2, P, FN) \
247 fn_for_each2_XXX((L1), (L2), P, FN, _not_in_set)
248
249static inline bool label_mediates(const struct aa_label *L, unsigned char C)
250{
251 return (L)->mediates & (((u64) 1) << (C));
252}
253
254static inline bool label_mediates_safe(const struct aa_label *L, unsigned char C)
255{
256 if (C > AA_CLASS_LAST)
257 return false;
258 return label_mediates(L, C);
259}
260
261void aa_labelset_destroy(struct aa_labelset *ls);
262void aa_labelset_init(struct aa_labelset *ls);
263void __aa_labelset_update_subtree(struct aa_ns *ns);
264
265void aa_label_destroy(struct aa_label *label);
266void aa_label_free(struct aa_label *label);
267void aa_label_kref(struct kref *kref);
268bool aa_label_init(struct aa_label *label, int size, gfp_t gfp);
269struct aa_label *aa_label_alloc(int size, struct aa_proxy *proxy, gfp_t gfp);
270
271bool aa_label_is_subset(const struct aa_label *set, const struct aa_label *sub);
272bool aa_label_is_unconfined_subset(const struct aa_label *set,
273 const struct aa_label *sub);
274struct aa_profile *__aa_label_next_not_in_set(struct label_it *I,
275 const struct aa_label *set,
276 const struct aa_label *sub);
277bool aa_label_remove(struct aa_label *label);
278struct aa_label *aa_label_insert(struct aa_labelset *ls, struct aa_label *l);
279bool aa_label_replace(struct aa_label *old, struct aa_label *new);
280bool aa_label_make_newest(struct aa_labelset *ls, struct aa_label *old,
281 struct aa_label *new);
282
283struct aa_profile *aa_label_next_in_merge(struct label_it *I,
284 const struct aa_label *a,
285 const struct aa_label *b);
286struct aa_label *aa_label_find_merge(struct aa_label *a, struct aa_label *b);
287struct aa_label *aa_label_merge(struct aa_label *a, struct aa_label *b,
288 gfp_t gfp);
289
290
291bool aa_update_label_name(struct aa_ns *ns, struct aa_label *label, gfp_t gfp);
292
293#define FLAGS_NONE 0
294#define FLAG_SHOW_MODE 1
295#define FLAG_VIEW_SUBNS 2
296#define FLAG_HIDDEN_UNCONFINED 4
297#define FLAG_ABS_ROOT 8
298int aa_label_snxprint(char *str, size_t size, struct aa_ns *view,
299 struct aa_label *label, int flags);
300int aa_label_asxprint(char **strp, struct aa_ns *ns, struct aa_label *label,
301 int flags, gfp_t gfp);
302int aa_label_acntsxprint(char __counted **strp, struct aa_ns *ns,
303 struct aa_label *label, int flags, gfp_t gfp);
304void aa_label_xaudit(struct audit_buffer *ab, struct aa_ns *ns,
305 struct aa_label *label, int flags, gfp_t gfp);
306void aa_label_seq_xprint(struct seq_file *f, struct aa_ns *ns,
307 struct aa_label *label, int flags, gfp_t gfp);
308void aa_label_xprintk(struct aa_ns *ns, struct aa_label *label, int flags,
309 gfp_t gfp);
310void aa_label_printk(struct aa_label *label, gfp_t gfp);
311
312struct aa_label *aa_label_strn_parse(struct aa_label *base, const char *str,
313 size_t n, gfp_t gfp, bool create,
314 bool force_stack);
315struct aa_label *aa_label_parse(struct aa_label *base, const char *str,
316 gfp_t gfp, bool create, bool force_stack);
317
318static inline const char *aa_label_strn_split(const char *str, int n)
319{
320 const char *pos;
321 aa_state_t state;
322
323 state = aa_dfa_matchn_until(stacksplitdfa, DFA_START, str, n, &pos);
324 if (!ACCEPT_TABLE(stacksplitdfa)[state])
325 return NULL;
326
327 return pos - 3;
328}
329
330static inline const char *aa_label_str_split(const char *str)
331{
332 const char *pos;
333 aa_state_t state;
334
335 state = aa_dfa_match_until(stacksplitdfa, DFA_START, str, &pos);
336 if (!ACCEPT_TABLE(stacksplitdfa)[state])
337 return NULL;
338
339 return pos - 3;
340}
341
342
343
344struct aa_perms;
345struct aa_ruleset;
346int aa_label_match(const struct aa_profile *profile, struct aa_ruleset *rules,
347 struct aa_label *label, aa_state_t state, bool subns,
348 u32 request, struct aa_perms *perms);
349
350
351/**
352 * __aa_get_label - get a reference count to uncounted label reference
353 * @l: reference to get a count on
354 *
355 * Returns: pointer to reference OR NULL if race is lost and reference is
356 * being repeated.
357 * Requires: lock held, and the return code MUST be checked
358 */
359static inline struct aa_label *__aa_get_label(struct aa_label *l)
360{
361 if (l && kref_get_unless_zero(&l->count.count))
362 return l;
363
364 return NULL;
365}
366
367static inline struct aa_label *aa_get_label(struct aa_label *l)
368{
369 if (l)
370 kref_get(&(l->count.count));
371
372 return l;
373}
374
375
376/**
377 * aa_get_label_rcu - increment refcount on a label that can be replaced
378 * @l: pointer to label that can be replaced (NOT NULL)
379 *
380 * Returns: pointer to a refcounted label.
381 * else NULL if no label
382 */
383static inline struct aa_label *aa_get_label_rcu(struct aa_label __rcu **l)
384{
385 struct aa_label *c;
386
387 rcu_read_lock();
388 do {
389 c = rcu_dereference(*l);
390 } while (c && !kref_get_unless_zero(&c->count.count));
391 rcu_read_unlock();
392
393 return c;
394}
395
396/**
397 * aa_get_newest_label - find the newest version of @l
398 * @l: the label to check for newer versions of
399 *
400 * Returns: refcounted newest version of @l taking into account
401 * replacement, renames and removals
402 * return @l.
403 */
404static inline struct aa_label *aa_get_newest_label(struct aa_label *l)
405{
406 if (!l)
407 return NULL;
408
409 if (label_is_stale(l)) {
410 struct aa_label *tmp;
411
412 AA_BUG(!l->proxy);
413 AA_BUG(!l->proxy->label);
414 /* BUG: only way this can happen is @l ref count and its
415 * replacement count have gone to 0 and are on their way
416 * to destruction. ie. we have a refcounting error
417 */
418 tmp = aa_get_label_rcu(&l->proxy->label);
419 AA_BUG(!tmp);
420
421 return tmp;
422 }
423
424 return aa_get_label(l);
425}
426
427/**
428 * aa_get_newest_label_condref - find the newest version of @l
429 * @l: the label to check for newer versions of
430 * @needput: returns whether the reference needs put
431 *
432 * Returns: refcounted newest version of @l taking into account
433 * replacement, renames and removals
434 * return @l.
435 */
436static inline struct aa_label *aa_get_newest_label_condref(struct aa_label *l,
437 bool *needput)
438{
439 if (l && unlikely(label_is_stale(l))) {
440 struct aa_label *tmp;
441
442 AA_BUG(!l->proxy);
443 AA_BUG(!l->proxy->label);
444 /* BUG: only way this can happen is @l ref count and its
445 * replacement count have gone to 0 and are on their way
446 * to destruction. ie. we have a refcounting error
447 */
448 tmp = aa_get_label_rcu(&l->proxy->label);
449 AA_BUG(!tmp);
450
451 *needput = true;
452 return tmp;
453 }
454
455 *needput = false;
456 return l;
457}
458
459static inline void aa_put_label(struct aa_label *l)
460{
461 if (l)
462 kref_put(&l->count.count, aa_label_kref);
463}
464
465/* wrapper fn to indicate semantics of the check */
466static inline bool __aa_subj_label_is_cached(const struct aa_label *subj_label,
467 const struct aa_label *obj_label)
468{
469 return aa_label_is_subset(obj_label, subj_label);
470}
471
472
473struct aa_proxy *aa_alloc_proxy(struct aa_label *l, gfp_t gfp);
474void aa_proxy_kref(struct kref *kref);
475
476static inline struct aa_proxy *aa_get_proxy(struct aa_proxy *proxy)
477{
478 if (proxy)
479 kref_get(&(proxy->count.count));
480
481 return proxy;
482}
483
484static inline void aa_put_proxy(struct aa_proxy *proxy)
485{
486 if (proxy)
487 kref_put(&proxy->count.count, aa_proxy_kref);
488}
489
490void __aa_proxy_redirect(struct aa_label *orig, struct aa_label *new);
491
492#endif /* __AA_LABEL_H */