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 void aa_labelset_destroy(struct aa_labelset *ls); 81 void aa_labelset_init(struct aa_labelset *ls); 82 83 84 enum label_flags { 85 FLAG_HAT = 1, /* profile is a hat */ 86 FLAG_UNCONFINED = 2, /* label unconfined only if all */ 87 FLAG_NULL = 4, /* profile is null learning profile */ 88 FLAG_IX_ON_NAME_ERROR = 8, /* fallback to ix on name lookup fail */ 89 FLAG_IMMUTIBLE = 0x10, /* don't allow changes/replacement */ 90 FLAG_USER_DEFINED = 0x20, /* user based profile - lower privs */ 91 FLAG_NO_LIST_REF = 0x40, /* list doesn't keep profile ref */ 92 FLAG_NS_COUNT = 0x80, /* carries NS ref count */ 93 FLAG_IN_TREE = 0x100, /* label is in tree */ 94 FLAG_PROFILE = 0x200, /* label is a profile */ 95 FLAG_EXPLICIT = 0x400, /* explicit static label */ 96 FLAG_STALE = 0x800, /* replaced/removed */ 97 FLAG_RENAMED = 0x1000, /* label has renaming in it */ 98 FLAG_REVOKED = 0x2000, /* label has revocation in it */ 99 100 /* These flags must correspond with PATH_flags */ 101 /* TODO: add new path flags */ 102 }; 103 104 struct aa_label; 105 struct aa_proxy { 106 struct kref count; 107 struct aa_label __rcu *label; 108 }; 109 110 struct label_it { 111 int i, j; 112 }; 113 114 /* struct aa_label - lazy labeling struct 115 * @count: ref count of active users 116 * @node: rbtree position 117 * @rcu: rcu callback struct 118 * @proxy: is set to the label that replaced this label 119 * @hname: text representation of the label (MAYBE_NULL) 120 * @flags: stale and other flags - values may change under label set lock 121 * @secid: secid that references this label 122 * @size: number of entries in @ent[] 123 * @ent: set of profiles for label, actual size determined by @size 124 */ 125 struct aa_label { 126 struct kref count; 127 struct rb_node node; 128 struct rcu_head rcu; 129 struct aa_proxy *proxy; 130 __counted char *hname; 131 long flags; 132 u32 secid; 133 int size; 134 struct aa_profile *vec[]; 135 }; 136 137 #define last_error(E, FN) \ 138 do { \ 139 int __subE = (FN); \ 140 if (__subE) \ 141 (E) = __subE; \ 142 } while (0) 143 144 #define label_isprofile(X) ((X)->flags & FLAG_PROFILE) 145 #define label_unconfined(X) ((X)->flags & FLAG_UNCONFINED) 146 #define unconfined(X) label_unconfined(X) 147 #define label_is_stale(X) ((X)->flags & FLAG_STALE) 148 #define __label_make_stale(X) ((X)->flags |= FLAG_STALE) 149 #define labels_ns(X) (vec_ns(&((X)->vec[0]), (X)->size)) 150 #define labels_set(X) (&labels_ns(X)->labels) 151 #define labels_profile(X) ((X)->vec[(X)->size - 1]) 152 153 154 int aa_label_next_confined(struct aa_label *l, int i); 155 156 /* for each profile in a label */ 157 #define label_for_each(I, L, P) \ 158 for ((I).i = 0; ((P) = (L)->vec[(I).i]); ++((I).i)) 159 160 /* assumes break/goto ended label_for_each */ 161 #define label_for_each_cont(I, L, P) \ 162 for (++((I).i); ((P) = (L)->vec[(I).i]); ++((I).i)) 163 164 #define next_comb(I, L1, L2) \ 165 do { \ 166 (I).j++; \ 167 if ((I).j >= (L2)->size) { \ 168 (I).i++; \ 169 (I).j = 0; \ 170 } \ 171 } while (0) 172 173 174 /* for each combination of P1 in L1, and P2 in L2 */ 175 #define label_for_each_comb(I, L1, L2, P1, P2) \ 176 for ((I).i = (I).j = 0; \ 177 ((P1) = (L1)->vec[(I).i]) && ((P2) = (L2)->vec[(I).j]); \ 178 (I) = next_comb(I, L1, L2)) 179 180 #define fn_for_each_comb(L1, L2, P1, P2, FN) \ 181 ({ \ 182 struct label_it i; \ 183 int __E = 0; \ 184 label_for_each_comb(i, (L1), (L2), (P1), (P2)) { \ 185 last_error(__E, (FN)); \ 186 } \ 187 __E; \ 188 }) 189 190 /* for each profile that is enforcing confinement in a label */ 191 #define label_for_each_confined(I, L, P) \ 192 for ((I).i = aa_label_next_confined((L), 0); \ 193 ((P) = (L)->vec[(I).i]); \ 194 (I).i = aa_label_next_confined((L), (I).i + 1)) 195 196 #define label_for_each_in_merge(I, A, B, P) \ 197 for ((I).i = (I).j = 0; \ 198 ((P) = aa_label_next_in_merge(&(I), (A), (B))); \ 199 ) 200 201 #define label_for_each_not_in_set(I, SET, SUB, P) \ 202 for ((I).i = (I).j = 0; \ 203 ((P) = __aa_label_next_not_in_set(&(I), (SET), (SUB))); \ 204 ) 205 206 #define next_in_ns(i, NS, L) \ 207 ({ \ 208 typeof(i) ___i = (i); \ 209 while ((L)->vec[___i] && (L)->vec[___i]->ns != (NS)) \ 210 (___i)++; \ 211 (___i); \ 212 }) 213 214 #define label_for_each_in_ns(I, NS, L, P) \ 215 for ((I).i = next_in_ns(0, (NS), (L)); \ 216 ((P) = (L)->vec[(I).i]); \ 217 (I).i = next_in_ns((I).i + 1, (NS), (L))) 218 219 #define fn_for_each_in_ns(L, P, FN) \ 220 ({ \ 221 struct label_it __i; \ 222 struct aa_ns *__ns = labels_ns(L); \ 223 int __E = 0; \ 224 label_for_each_in_ns(__i, __ns, (L), (P)) { \ 225 last_error(__E, (FN)); \ 226 } \ 227 __E; \ 228 }) 229 230 231 #define fn_for_each_XXX(L, P, FN, ...) \ 232 ({ \ 233 struct label_it i; \ 234 int __E = 0; \ 235 label_for_each ## __VA_ARGS__(i, (L), (P)) { \ 236 last_error(__E, (FN)); \ 237 } \ 238 __E; \ 239 }) 240 241 #define fn_for_each(L, P, FN) fn_for_each_XXX(L, P, FN) 242 #define fn_for_each_confined(L, P, FN) fn_for_each_XXX(L, P, FN, _confined) 243 244 #define fn_for_each2_XXX(L1, L2, P, FN, ...) \ 245 ({ \ 246 struct label_it i; \ 247 int __E = 0; \ 248 label_for_each ## __VA_ARGS__(i, (L1), (L2), (P)) { \ 249 last_error(__E, (FN)); \ 250 } \ 251 __E; \ 252 }) 253 254 #define fn_for_each_in_merge(L1, L2, P, FN) \ 255 fn_for_each2_XXX((L1), (L2), P, FN, _in_merge) 256 #define fn_for_each_not_in_set(L1, L2, P, FN) \ 257 fn_for_each2_XXX((L1), (L2), P, FN, _not_in_set) 258 259 #define LABEL_MEDIATES(L, C) \ 260 ({ \ 261 struct aa_profile *profile; \ 262 struct label_it i; \ 263 int ret = 0; \ 264 label_for_each(i, (L), profile) { \ 265 if (PROFILE_MEDIATES(profile, (C))) { \ 266 ret = 1; \ 267 break; \ 268 } \ 269 } \ 270 ret; \ 271 }) 272 273 274 void aa_labelset_destroy(struct aa_labelset *ls); 275 void aa_labelset_init(struct aa_labelset *ls); 276 void __aa_labelset_update_subtree(struct aa_ns *ns); 277 278 void aa_label_free(struct aa_label *label); 279 void aa_label_kref(struct kref *kref); 280 bool aa_label_init(struct aa_label *label, int size, gfp_t gfp); 281 struct aa_label *aa_label_alloc(int size, struct aa_proxy *proxy, gfp_t gfp); 282 283 bool aa_label_is_subset(struct aa_label *set, struct aa_label *sub); 284 struct aa_profile *__aa_label_next_not_in_set(struct label_it *I, 285 struct aa_label *set, 286 struct aa_label *sub); 287 bool aa_label_remove(struct aa_label *label); 288 struct aa_label *aa_label_insert(struct aa_labelset *ls, struct aa_label *l); 289 bool aa_label_replace(struct aa_label *old, struct aa_label *new); 290 bool aa_label_make_newest(struct aa_labelset *ls, struct aa_label *old, 291 struct aa_label *new); 292 293 struct aa_label *aa_label_find(struct aa_label *l); 294 295 struct aa_profile *aa_label_next_in_merge(struct label_it *I, 296 struct aa_label *a, 297 struct aa_label *b); 298 struct aa_label *aa_label_find_merge(struct aa_label *a, struct aa_label *b); 299 struct aa_label *aa_label_merge(struct aa_label *a, struct aa_label *b, 300 gfp_t gfp); 301 302 303 bool aa_update_label_name(struct aa_ns *ns, struct aa_label *label, gfp_t gfp); 304 305 #define FLAGS_NONE 0 306 #define FLAG_SHOW_MODE 1 307 #define FLAG_VIEW_SUBNS 2 308 #define FLAG_HIDDEN_UNCONFINED 4 309 #define FLAG_ABS_ROOT 8 310 int aa_label_snxprint(char *str, size_t size, struct aa_ns *view, 311 struct aa_label *label, int flags); 312 int aa_label_asxprint(char **strp, struct aa_ns *ns, struct aa_label *label, 313 int flags, gfp_t gfp); 314 int aa_label_acntsxprint(char __counted **strp, struct aa_ns *ns, 315 struct aa_label *label, int flags, gfp_t gfp); 316 void aa_label_xaudit(struct audit_buffer *ab, struct aa_ns *ns, 317 struct aa_label *label, int flags, gfp_t gfp); 318 void aa_label_seq_xprint(struct seq_file *f, struct aa_ns *ns, 319 struct aa_label *label, int flags, gfp_t gfp); 320 void aa_label_xprintk(struct aa_ns *ns, struct aa_label *label, int flags, 321 gfp_t gfp); 322 void aa_label_audit(struct audit_buffer *ab, struct aa_label *label, gfp_t gfp); 323 void aa_label_seq_print(struct seq_file *f, struct aa_label *label, gfp_t gfp); 324 void aa_label_printk(struct aa_label *label, gfp_t gfp); 325 326 struct aa_label *aa_label_strn_parse(struct aa_label *base, const char *str, 327 size_t n, gfp_t gfp, bool create, 328 bool force_stack); 329 struct aa_label *aa_label_parse(struct aa_label *base, const char *str, 330 gfp_t gfp, bool create, bool force_stack); 331 332 static inline const char *aa_label_strn_split(const char *str, int n) 333 { 334 const char *pos; 335 unsigned int state; 336 337 state = aa_dfa_matchn_until(stacksplitdfa, DFA_START, str, n, &pos); 338 if (!ACCEPT_TABLE(stacksplitdfa)[state]) 339 return NULL; 340 341 return pos - 3; 342 } 343 344 static inline const char *aa_label_str_split(const char *str) 345 { 346 const char *pos; 347 unsigned int state; 348 349 state = aa_dfa_match_until(stacksplitdfa, DFA_START, str, &pos); 350 if (!ACCEPT_TABLE(stacksplitdfa)[state]) 351 return NULL; 352 353 return pos - 3; 354 } 355 356 357 358 struct aa_perms; 359 int aa_label_match(struct aa_profile *profile, struct aa_label *label, 360 unsigned int state, bool subns, u32 request, 361 struct aa_perms *perms); 362 363 364 /** 365 * __aa_get_label - get a reference count to uncounted label reference 366 * @l: reference to get a count on 367 * 368 * Returns: pointer to reference OR NULL if race is lost and reference is 369 * being repeated. 370 * Requires: lock held, and the return code MUST be checked 371 */ 372 static inline struct aa_label *__aa_get_label(struct aa_label *l) 373 { 374 if (l && kref_get_unless_zero(&l->count)) 375 return l; 376 377 return NULL; 378 } 379 380 static inline struct aa_label *aa_get_label(struct aa_label *l) 381 { 382 if (l) 383 kref_get(&(l->count)); 384 385 return l; 386 } 387 388 389 /** 390 * aa_get_label_rcu - increment refcount on a label that can be replaced 391 * @l: pointer to label that can be replaced (NOT NULL) 392 * 393 * Returns: pointer to a refcounted label. 394 * else NULL if no label 395 */ 396 static inline struct aa_label *aa_get_label_rcu(struct aa_label __rcu **l) 397 { 398 struct aa_label *c; 399 400 rcu_read_lock(); 401 do { 402 c = rcu_dereference(*l); 403 } while (c && !kref_get_unless_zero(&c->count)); 404 rcu_read_unlock(); 405 406 return c; 407 } 408 409 /** 410 * aa_get_newest_label - find the newest version of @l 411 * @l: the label to check for newer versions of 412 * 413 * Returns: refcounted newest version of @l taking into account 414 * replacement, renames and removals 415 * return @l. 416 */ 417 static inline struct aa_label *aa_get_newest_label(struct aa_label *l) 418 { 419 if (!l) 420 return NULL; 421 422 if (label_is_stale(l)) { 423 struct aa_label *tmp; 424 425 AA_BUG(!l->proxy); 426 AA_BUG(!l->proxy->label); 427 /* BUG: only way this can happen is @l ref count and its 428 * replacement count have gone to 0 and are on their way 429 * to destruction. ie. we have a refcounting error 430 */ 431 tmp = aa_get_label_rcu(&l->proxy->label); 432 AA_BUG(!tmp); 433 434 return tmp; 435 } 436 437 return aa_get_label(l); 438 } 439 440 static inline void aa_put_label(struct aa_label *l) 441 { 442 if (l) 443 kref_put(&l->count, aa_label_kref); 444 } 445 446 447 struct aa_proxy *aa_alloc_proxy(struct aa_label *l, gfp_t gfp); 448 void aa_proxy_kref(struct kref *kref); 449 450 static inline struct aa_proxy *aa_get_proxy(struct aa_proxy *proxy) 451 { 452 if (proxy) 453 kref_get(&(proxy->count)); 454 455 return proxy; 456 } 457 458 static inline void aa_put_proxy(struct aa_proxy *proxy) 459 { 460 if (proxy) 461 kref_put(&proxy->count, aa_proxy_kref); 462 } 463 464 void __aa_proxy_redirect(struct aa_label *orig, struct aa_label *new); 465 466 #endif /* __AA_LABEL_H */ 467