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 21 struct aa_ns; 22 23 #define LOCAL_VEC_ENTRIES 8 24 #define DEFINE_VEC(T, V) \ 25 struct aa_ ## T *(_ ## V ## _localtmp)[LOCAL_VEC_ENTRIES]; \ 26 struct aa_ ## T **(V) 27 28 #define vec_setup(T, V, N, GFP) \ 29 ({ \ 30 if ((N) <= LOCAL_VEC_ENTRIES) { \ 31 typeof(N) i; \ 32 (V) = (_ ## V ## _localtmp); \ 33 for (i = 0; i < (N); i++) \ 34 (V)[i] = NULL; \ 35 } else \ 36 (V) = kzalloc(sizeof(struct aa_ ## T *) * (N), (GFP)); \ 37 (V) ? 0 : -ENOMEM; \ 38 }) 39 40 #define vec_cleanup(T, V, N) \ 41 do { \ 42 int i; \ 43 for (i = 0; i < (N); i++) { \ 44 if (!IS_ERR_OR_NULL((V)[i])) \ 45 aa_put_ ## T((V)[i]); \ 46 } \ 47 if ((V) != _ ## V ## _localtmp) \ 48 kfree(V); \ 49 } while (0) 50 51 #define vec_last(VEC, SIZE) ((VEC)[(SIZE) - 1]) 52 #define vec_ns(VEC, SIZE) (vec_last((VEC), (SIZE))->ns) 53 #define vec_labelset(VEC, SIZE) (&vec_ns((VEC), (SIZE))->labels) 54 #define cleanup_domain_vec(V, L) cleanup_label_vec((V), (L)->size) 55 56 struct aa_profile; 57 #define VEC_FLAG_TERMINATE 1 58 int aa_vec_unique(struct aa_profile **vec, int n, int flags); 59 struct aa_label *aa_vec_find_or_create_label(struct aa_profile **vec, int len, 60 gfp_t gfp); 61 #define aa_sort_and_merge_vec(N, V) \ 62 aa_sort_and_merge_profiles((N), (struct aa_profile **)(V)) 63 64 65 /* struct aa_labelset - set of labels for a namespace 66 * 67 * Labels are reference counted; aa_labelset does not contribute to label 68 * reference counts. Once a label's last refcount is put it is removed from 69 * the set. 70 */ 71 struct aa_labelset { 72 rwlock_t lock; 73 74 struct rb_root root; 75 }; 76 77 #define __labelset_for_each(LS, N) \ 78 for ((N) = rb_first(&(LS)->root); (N); (N) = rb_next(N)) 79 80 enum label_flags { 81 FLAG_HAT = 1, /* profile is a hat */ 82 FLAG_UNCONFINED = 2, /* label unconfined only if all */ 83 FLAG_NULL = 4, /* profile is null learning profile */ 84 FLAG_IX_ON_NAME_ERROR = 8, /* fallback to ix on name lookup fail */ 85 FLAG_IMMUTIBLE = 0x10, /* don't allow changes/replacement */ 86 FLAG_USER_DEFINED = 0x20, /* user based profile - lower privs */ 87 FLAG_NO_LIST_REF = 0x40, /* list doesn't keep profile ref */ 88 FLAG_NS_COUNT = 0x80, /* carries NS ref count */ 89 FLAG_IN_TREE = 0x100, /* label is in tree */ 90 FLAG_PROFILE = 0x200, /* label is a profile */ 91 FLAG_EXPLICIT = 0x400, /* explicit static label */ 92 FLAG_STALE = 0x800, /* replaced/removed */ 93 FLAG_RENAMED = 0x1000, /* label has renaming in it */ 94 FLAG_REVOKED = 0x2000, /* label has revocation in it */ 95 96 /* These flags must correspond with PATH_flags */ 97 /* TODO: add new path flags */ 98 }; 99 100 struct aa_label; 101 struct aa_proxy { 102 struct kref count; 103 struct aa_label __rcu *label; 104 }; 105 106 struct label_it { 107 int i, j; 108 }; 109 110 /* struct aa_label - lazy labeling struct 111 * @count: ref count of active users 112 * @node: rbtree position 113 * @rcu: rcu callback struct 114 * @proxy: is set to the label that replaced this label 115 * @hname: text representation of the label (MAYBE_NULL) 116 * @flags: stale and other flags - values may change under label set lock 117 * @secid: secid that references this label 118 * @size: number of entries in @ent[] 119 * @ent: set of profiles for label, actual size determined by @size 120 */ 121 struct aa_label { 122 struct kref count; 123 struct rb_node node; 124 struct rcu_head rcu; 125 struct aa_proxy *proxy; 126 __counted char *hname; 127 long flags; 128 u32 secid; 129 int size; 130 struct aa_profile *vec[]; 131 }; 132 133 #define last_error(E, FN) \ 134 do { \ 135 int __subE = (FN); \ 136 if (__subE) \ 137 (E) = __subE; \ 138 } while (0) 139 140 #define label_isprofile(X) ((X)->flags & FLAG_PROFILE) 141 #define label_unconfined(X) ((X)->flags & FLAG_UNCONFINED) 142 #define unconfined(X) label_unconfined(X) 143 #define label_is_stale(X) ((X)->flags & FLAG_STALE) 144 #define __label_make_stale(X) ((X)->flags |= FLAG_STALE) 145 #define labels_ns(X) (vec_ns(&((X)->vec[0]), (X)->size)) 146 #define labels_set(X) (&labels_ns(X)->labels) 147 #define labels_view(X) labels_ns(X) 148 #define labels_profile(X) ((X)->vec[(X)->size - 1]) 149 150 151 int aa_label_next_confined(struct aa_label *l, int i); 152 153 /* for each profile in a label */ 154 #define label_for_each(I, L, P) \ 155 for ((I).i = 0; ((P) = (L)->vec[(I).i]); ++((I).i)) 156 157 /* assumes break/goto ended label_for_each */ 158 #define label_for_each_cont(I, L, P) \ 159 for (++((I).i); ((P) = (L)->vec[(I).i]); ++((I).i)) 160 161 #define next_comb(I, L1, L2) \ 162 do { \ 163 (I).j++; \ 164 if ((I).j >= (L2)->size) { \ 165 (I).i++; \ 166 (I).j = 0; \ 167 } \ 168 } while (0) 169 170 171 /* for each combination of P1 in L1, and P2 in L2 */ 172 #define label_for_each_comb(I, L1, L2, P1, P2) \ 173 for ((I).i = (I).j = 0; \ 174 ((P1) = (L1)->vec[(I).i]) && ((P2) = (L2)->vec[(I).j]); \ 175 (I) = next_comb(I, L1, L2)) 176 177 #define fn_for_each_comb(L1, L2, P1, P2, FN) \ 178 ({ \ 179 struct label_it i; \ 180 int __E = 0; \ 181 label_for_each_comb(i, (L1), (L2), (P1), (P2)) { \ 182 last_error(__E, (FN)); \ 183 } \ 184 __E; \ 185 }) 186 187 /* for each profile that is enforcing confinement in a label */ 188 #define label_for_each_confined(I, L, P) \ 189 for ((I).i = aa_label_next_confined((L), 0); \ 190 ((P) = (L)->vec[(I).i]); \ 191 (I).i = aa_label_next_confined((L), (I).i + 1)) 192 193 #define label_for_each_in_merge(I, A, B, P) \ 194 for ((I).i = (I).j = 0; \ 195 ((P) = aa_label_next_in_merge(&(I), (A), (B))); \ 196 ) 197 198 #define label_for_each_not_in_set(I, SET, SUB, P) \ 199 for ((I).i = (I).j = 0; \ 200 ((P) = __aa_label_next_not_in_set(&(I), (SET), (SUB))); \ 201 ) 202 203 #define next_in_ns(i, NS, L) \ 204 ({ \ 205 typeof(i) ___i = (i); \ 206 while ((L)->vec[___i] && (L)->vec[___i]->ns != (NS)) \ 207 (___i)++; \ 208 (___i); \ 209 }) 210 211 #define label_for_each_in_ns(I, NS, L, P) \ 212 for ((I).i = next_in_ns(0, (NS), (L)); \ 213 ((P) = (L)->vec[(I).i]); \ 214 (I).i = next_in_ns((I).i + 1, (NS), (L))) 215 216 #define fn_for_each_in_ns(L, P, FN) \ 217 ({ \ 218 struct label_it __i; \ 219 struct aa_ns *__ns = labels_ns(L); \ 220 int __E = 0; \ 221 label_for_each_in_ns(__i, __ns, (L), (P)) { \ 222 last_error(__E, (FN)); \ 223 } \ 224 __E; \ 225 }) 226 227 228 #define fn_for_each_XXX(L, P, FN, ...) \ 229 ({ \ 230 struct label_it i; \ 231 int __E = 0; \ 232 label_for_each ## __VA_ARGS__(i, (L), (P)) { \ 233 last_error(__E, (FN)); \ 234 } \ 235 __E; \ 236 }) 237 238 #define fn_for_each(L, P, FN) fn_for_each_XXX(L, P, FN) 239 #define fn_for_each_confined(L, P, FN) fn_for_each_XXX(L, P, FN, _confined) 240 241 #define fn_for_each2_XXX(L1, L2, P, FN, ...) \ 242 ({ \ 243 struct label_it i; \ 244 int __E = 0; \ 245 label_for_each ## __VA_ARGS__(i, (L1), (L2), (P)) { \ 246 last_error(__E, (FN)); \ 247 } \ 248 __E; \ 249 }) 250 251 #define fn_for_each_in_merge(L1, L2, P, FN) \ 252 fn_for_each2_XXX((L1), (L2), P, FN, _in_merge) 253 #define fn_for_each_not_in_set(L1, L2, P, FN) \ 254 fn_for_each2_XXX((L1), (L2), P, FN, _not_in_set) 255 256 #define LABEL_MEDIATES(L, C) \ 257 ({ \ 258 struct aa_profile *profile; \ 259 struct label_it i; \ 260 int ret = 0; \ 261 label_for_each(i, (L), profile) { \ 262 if (PROFILE_MEDIATES(profile, (C))) { \ 263 ret = 1; \ 264 break; \ 265 } \ 266 } \ 267 ret; \ 268 }) 269 270 271 void aa_labelset_destroy(struct aa_labelset *ls); 272 void aa_labelset_init(struct aa_labelset *ls); 273 void __aa_labelset_update_subtree(struct aa_ns *ns); 274 275 void aa_label_destroy(struct aa_label *label); 276 void aa_label_free(struct aa_label *label); 277 void aa_label_kref(struct kref *kref); 278 bool aa_label_init(struct aa_label *label, int size, gfp_t gfp); 279 struct aa_label *aa_label_alloc(int size, struct aa_proxy *proxy, gfp_t gfp); 280 281 bool aa_label_is_subset(struct aa_label *set, struct aa_label *sub); 282 bool aa_label_is_unconfined_subset(struct aa_label *set, struct aa_label *sub); 283 struct aa_profile *__aa_label_next_not_in_set(struct label_it *I, 284 struct aa_label *set, 285 struct aa_label *sub); 286 bool aa_label_remove(struct aa_label *label); 287 struct aa_label *aa_label_insert(struct aa_labelset *ls, struct aa_label *l); 288 bool aa_label_replace(struct aa_label *old, struct aa_label *new); 289 bool aa_label_make_newest(struct aa_labelset *ls, struct aa_label *old, 290 struct aa_label *new); 291 292 struct aa_label *aa_label_find(struct aa_label *l); 293 294 struct aa_profile *aa_label_next_in_merge(struct label_it *I, 295 struct aa_label *a, 296 struct aa_label *b); 297 struct aa_label *aa_label_find_merge(struct aa_label *a, struct aa_label *b); 298 struct aa_label *aa_label_merge(struct aa_label *a, struct aa_label *b, 299 gfp_t gfp); 300 301 302 bool aa_update_label_name(struct aa_ns *ns, struct aa_label *label, gfp_t gfp); 303 304 #define FLAGS_NONE 0 305 #define FLAG_SHOW_MODE 1 306 #define FLAG_VIEW_SUBNS 2 307 #define FLAG_HIDDEN_UNCONFINED 4 308 #define FLAG_ABS_ROOT 8 309 int aa_label_snxprint(char *str, size_t size, struct aa_ns *view, 310 struct aa_label *label, int flags); 311 int aa_label_asxprint(char **strp, struct aa_ns *ns, struct aa_label *label, 312 int flags, gfp_t gfp); 313 int aa_label_acntsxprint(char __counted **strp, struct aa_ns *ns, 314 struct aa_label *label, int flags, gfp_t gfp); 315 void aa_label_xaudit(struct audit_buffer *ab, struct aa_ns *ns, 316 struct aa_label *label, int flags, gfp_t gfp); 317 void aa_label_seq_xprint(struct seq_file *f, struct aa_ns *ns, 318 struct aa_label *label, int flags, gfp_t gfp); 319 void aa_label_xprintk(struct aa_ns *ns, struct aa_label *label, int flags, 320 gfp_t gfp); 321 void aa_label_audit(struct audit_buffer *ab, struct aa_label *label, gfp_t gfp); 322 void aa_label_seq_print(struct seq_file *f, struct aa_label *label, gfp_t gfp); 323 void aa_label_printk(struct aa_label *label, gfp_t gfp); 324 325 struct aa_label *aa_label_strn_parse(struct aa_label *base, const char *str, 326 size_t n, gfp_t gfp, bool create, 327 bool force_stack); 328 struct aa_label *aa_label_parse(struct aa_label *base, const char *str, 329 gfp_t gfp, bool create, bool force_stack); 330 331 static inline const char *aa_label_strn_split(const char *str, int n) 332 { 333 const char *pos; 334 unsigned int state; 335 336 state = aa_dfa_matchn_until(stacksplitdfa, DFA_START, str, n, &pos); 337 if (!ACCEPT_TABLE(stacksplitdfa)[state]) 338 return NULL; 339 340 return pos - 3; 341 } 342 343 static inline const char *aa_label_str_split(const char *str) 344 { 345 const char *pos; 346 unsigned int state; 347 348 state = aa_dfa_match_until(stacksplitdfa, DFA_START, str, &pos); 349 if (!ACCEPT_TABLE(stacksplitdfa)[state]) 350 return NULL; 351 352 return pos - 3; 353 } 354 355 356 357 struct aa_perms; 358 int aa_label_match(struct aa_profile *profile, struct aa_label *label, 359 unsigned int state, bool subns, u32 request, 360 struct aa_perms *perms); 361 362 363 /** 364 * __aa_get_label - get a reference count to uncounted label reference 365 * @l: reference to get a count on 366 * 367 * Returns: pointer to reference OR NULL if race is lost and reference is 368 * being repeated. 369 * Requires: lock held, and the return code MUST be checked 370 */ 371 static inline struct aa_label *__aa_get_label(struct aa_label *l) 372 { 373 if (l && kref_get_unless_zero(&l->count)) 374 return l; 375 376 return NULL; 377 } 378 379 static inline struct aa_label *aa_get_label(struct aa_label *l) 380 { 381 if (l) 382 kref_get(&(l->count)); 383 384 return l; 385 } 386 387 388 /** 389 * aa_get_label_rcu - increment refcount on a label that can be replaced 390 * @l: pointer to label that can be replaced (NOT NULL) 391 * 392 * Returns: pointer to a refcounted label. 393 * else NULL if no label 394 */ 395 static inline struct aa_label *aa_get_label_rcu(struct aa_label __rcu **l) 396 { 397 struct aa_label *c; 398 399 rcu_read_lock(); 400 do { 401 c = rcu_dereference(*l); 402 } while (c && !kref_get_unless_zero(&c->count)); 403 rcu_read_unlock(); 404 405 return c; 406 } 407 408 /** 409 * aa_get_newest_label - find the newest version of @l 410 * @l: the label to check for newer versions of 411 * 412 * Returns: refcounted newest version of @l taking into account 413 * replacement, renames and removals 414 * return @l. 415 */ 416 static inline struct aa_label *aa_get_newest_label(struct aa_label *l) 417 { 418 if (!l) 419 return NULL; 420 421 if (label_is_stale(l)) { 422 struct aa_label *tmp; 423 424 AA_BUG(!l->proxy); 425 AA_BUG(!l->proxy->label); 426 /* BUG: only way this can happen is @l ref count and its 427 * replacement count have gone to 0 and are on their way 428 * to destruction. ie. we have a refcounting error 429 */ 430 tmp = aa_get_label_rcu(&l->proxy->label); 431 AA_BUG(!tmp); 432 433 return tmp; 434 } 435 436 return aa_get_label(l); 437 } 438 439 static inline void aa_put_label(struct aa_label *l) 440 { 441 if (l) 442 kref_put(&l->count, aa_label_kref); 443 } 444 445 446 struct aa_proxy *aa_alloc_proxy(struct aa_label *l, gfp_t gfp); 447 void aa_proxy_kref(struct kref *kref); 448 449 static inline struct aa_proxy *aa_get_proxy(struct aa_proxy *proxy) 450 { 451 if (proxy) 452 kref_get(&(proxy->count)); 453 454 return proxy; 455 } 456 457 static inline void aa_put_proxy(struct aa_proxy *proxy) 458 { 459 if (proxy) 460 kref_put(&proxy->count, aa_proxy_kref); 461 } 462 463 void __aa_proxy_redirect(struct aa_label *orig, struct aa_label *new); 464 465 #endif /* __AA_LABEL_H */ 466