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 FLAG_DEBUG1 = 0x4000, 96 FLAG_DEBUG2 = 0x8000, 97 98 /* These flags must correspond with PATH_flags */ 99 /* TODO: add new path flags */ 100 }; 101 102 struct aa_label; 103 struct aa_proxy { 104 struct kref count; 105 struct aa_label __rcu *label; 106 }; 107 108 struct label_it { 109 int i, j; 110 }; 111 112 /* struct aa_label - lazy labeling struct 113 * @count: ref count of active users 114 * @node: rbtree position 115 * @rcu: rcu callback struct 116 * @proxy: is set to the label that replaced this label 117 * @hname: text representation of the label (MAYBE_NULL) 118 * @flags: stale and other flags - values may change under label set lock 119 * @secid: secid that references this label 120 * @size: number of entries in @ent[] 121 * @ent: set of profiles for label, actual size determined by @size 122 */ 123 struct aa_label { 124 struct kref count; 125 struct rb_node node; 126 struct rcu_head rcu; 127 struct aa_proxy *proxy; 128 __counted char *hname; 129 long flags; 130 u32 secid; 131 int size; 132 u64 mediates; 133 struct aa_profile *vec[]; 134 }; 135 136 #define last_error(E, FN) \ 137 do { \ 138 int __subE = (FN); \ 139 if (__subE) \ 140 (E) = __subE; \ 141 } while (0) 142 143 #define label_isprofile(X) ((X)->flags & FLAG_PROFILE) 144 #define label_unconfined(X) ((X)->flags & FLAG_UNCONFINED) 145 #define unconfined(X) label_unconfined(X) 146 #define label_is_stale(X) ((X)->flags & FLAG_STALE) 147 #define __label_make_stale(X) ((X)->flags |= FLAG_STALE) 148 #define labels_ns(X) (vec_ns(&((X)->vec[0]), (X)->size)) 149 #define labels_set(X) (&labels_ns(X)->labels) 150 #define labels_view(X) labels_ns(X) 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)) 163 164 165 166 /* for each profile that is enforcing confinement in a label */ 167 #define label_for_each_confined(I, L, P) \ 168 for ((I).i = aa_label_next_confined((L), 0); \ 169 ((P) = (L)->vec[(I).i]); \ 170 (I).i = aa_label_next_confined((L), (I).i + 1)) 171 172 #define label_for_each_in_merge(I, A, B, P) \ 173 for ((I).i = (I).j = 0; \ 174 ((P) = aa_label_next_in_merge(&(I), (A), (B))); \ 175 ) 176 177 #define label_for_each_not_in_set(I, SET, SUB, P) \ 178 for ((I).i = (I).j = 0; \ 179 ((P) = __aa_label_next_not_in_set(&(I), (SET), (SUB))); \ 180 ) 181 182 #define next_in_ns(i, NS, L) \ 183 ({ \ 184 typeof(i) ___i = (i); \ 185 while ((L)->vec[___i] && (L)->vec[___i]->ns != (NS)) \ 186 (___i)++; \ 187 (___i); \ 188 }) 189 190 #define label_for_each_in_ns(I, NS, L, P) \ 191 for ((I).i = next_in_ns(0, (NS), (L)); \ 192 ((P) = (L)->vec[(I).i]); \ 193 (I).i = next_in_ns((I).i + 1, (NS), (L))) 194 195 #define fn_for_each_in_ns(L, P, FN) \ 196 ({ \ 197 struct label_it __i; \ 198 struct aa_ns *__ns = labels_ns(L); \ 199 int __E = 0; \ 200 label_for_each_in_ns(__i, __ns, (L), (P)) { \ 201 last_error(__E, (FN)); \ 202 } \ 203 __E; \ 204 }) 205 206 207 #define fn_for_each_XXX(L, P, FN, ...) \ 208 ({ \ 209 struct label_it i; \ 210 int __E = 0; \ 211 label_for_each ## __VA_ARGS__(i, (L), (P)) { \ 212 last_error(__E, (FN)); \ 213 } \ 214 __E; \ 215 }) 216 217 #define fn_for_each(L, P, FN) fn_for_each_XXX(L, P, FN) 218 #define fn_for_each_confined(L, P, FN) fn_for_each_XXX(L, P, FN, _confined) 219 220 #define fn_for_each2_XXX(L1, L2, P, FN, ...) \ 221 ({ \ 222 struct label_it i; \ 223 int __E = 0; \ 224 label_for_each ## __VA_ARGS__(i, (L1), (L2), (P)) { \ 225 last_error(__E, (FN)); \ 226 } \ 227 __E; \ 228 }) 229 230 #define fn_for_each_in_merge(L1, L2, P, FN) \ 231 fn_for_each2_XXX((L1), (L2), P, FN, _in_merge) 232 #define fn_for_each_not_in_set(L1, L2, P, FN) \ 233 fn_for_each2_XXX((L1), (L2), P, FN, _not_in_set) 234 235 static inline bool label_mediates(struct aa_label *L, unsigned char C) 236 { 237 return (L)->mediates & (((u64) 1) << (C)); 238 } 239 240 static inline bool label_mediates_safe(struct aa_label *L, unsigned char C) 241 { 242 if (C > AA_CLASS_LAST) 243 return false; 244 return label_mediates(L, C); 245 } 246 247 void aa_labelset_destroy(struct aa_labelset *ls); 248 void aa_labelset_init(struct aa_labelset *ls); 249 void __aa_labelset_update_subtree(struct aa_ns *ns); 250 251 void aa_label_destroy(struct aa_label *label); 252 void aa_label_free(struct aa_label *label); 253 void aa_label_kref(struct kref *kref); 254 bool aa_label_init(struct aa_label *label, int size, gfp_t gfp); 255 struct aa_label *aa_label_alloc(int size, struct aa_proxy *proxy, gfp_t gfp); 256 257 bool aa_label_is_subset(struct aa_label *set, struct aa_label *sub); 258 bool aa_label_is_unconfined_subset(struct aa_label *set, struct aa_label *sub); 259 struct aa_profile *__aa_label_next_not_in_set(struct label_it *I, 260 struct aa_label *set, 261 struct aa_label *sub); 262 bool aa_label_remove(struct aa_label *label); 263 struct aa_label *aa_label_insert(struct aa_labelset *ls, struct aa_label *l); 264 bool aa_label_replace(struct aa_label *old, struct aa_label *new); 265 bool aa_label_make_newest(struct aa_labelset *ls, struct aa_label *old, 266 struct aa_label *new); 267 268 struct aa_profile *aa_label_next_in_merge(struct label_it *I, 269 struct aa_label *a, 270 struct aa_label *b); 271 struct aa_label *aa_label_find_merge(struct aa_label *a, struct aa_label *b); 272 struct aa_label *aa_label_merge(struct aa_label *a, struct aa_label *b, 273 gfp_t gfp); 274 275 276 bool aa_update_label_name(struct aa_ns *ns, struct aa_label *label, gfp_t gfp); 277 278 #define FLAGS_NONE 0 279 #define FLAG_SHOW_MODE 1 280 #define FLAG_VIEW_SUBNS 2 281 #define FLAG_HIDDEN_UNCONFINED 4 282 #define FLAG_ABS_ROOT 8 283 int aa_label_snxprint(char *str, size_t size, struct aa_ns *view, 284 struct aa_label *label, int flags); 285 int aa_label_asxprint(char **strp, struct aa_ns *ns, struct aa_label *label, 286 int flags, gfp_t gfp); 287 int aa_label_acntsxprint(char __counted **strp, struct aa_ns *ns, 288 struct aa_label *label, int flags, gfp_t gfp); 289 void aa_label_xaudit(struct audit_buffer *ab, struct aa_ns *ns, 290 struct aa_label *label, int flags, gfp_t gfp); 291 void aa_label_seq_xprint(struct seq_file *f, struct aa_ns *ns, 292 struct aa_label *label, int flags, gfp_t gfp); 293 void aa_label_xprintk(struct aa_ns *ns, struct aa_label *label, int flags, 294 gfp_t gfp); 295 void aa_label_printk(struct aa_label *label, gfp_t gfp); 296 297 struct aa_label *aa_label_strn_parse(struct aa_label *base, const char *str, 298 size_t n, gfp_t gfp, bool create, 299 bool force_stack); 300 struct aa_label *aa_label_parse(struct aa_label *base, const char *str, 301 gfp_t gfp, bool create, bool force_stack); 302 303 static inline const char *aa_label_strn_split(const char *str, int n) 304 { 305 const char *pos; 306 aa_state_t state; 307 308 state = aa_dfa_matchn_until(stacksplitdfa, DFA_START, str, n, &pos); 309 if (!ACCEPT_TABLE(stacksplitdfa)[state]) 310 return NULL; 311 312 return pos - 3; 313 } 314 315 static inline const char *aa_label_str_split(const char *str) 316 { 317 const char *pos; 318 aa_state_t state; 319 320 state = aa_dfa_match_until(stacksplitdfa, DFA_START, str, &pos); 321 if (!ACCEPT_TABLE(stacksplitdfa)[state]) 322 return NULL; 323 324 return pos - 3; 325 } 326 327 328 329 struct aa_perms; 330 struct aa_ruleset; 331 int aa_label_match(struct aa_profile *profile, struct aa_ruleset *rules, 332 struct aa_label *label, aa_state_t state, bool subns, 333 u32 request, struct aa_perms *perms); 334 335 336 /** 337 * __aa_get_label - get a reference count to uncounted label reference 338 * @l: reference to get a count on 339 * 340 * Returns: pointer to reference OR NULL if race is lost and reference is 341 * being repeated. 342 * Requires: lock held, and the return code MUST be checked 343 */ 344 static inline struct aa_label *__aa_get_label(struct aa_label *l) 345 { 346 if (l && kref_get_unless_zero(&l->count)) 347 return l; 348 349 return NULL; 350 } 351 352 static inline struct aa_label *aa_get_label(struct aa_label *l) 353 { 354 if (l) 355 kref_get(&(l->count)); 356 357 return l; 358 } 359 360 361 /** 362 * aa_get_label_rcu - increment refcount on a label that can be replaced 363 * @l: pointer to label that can be replaced (NOT NULL) 364 * 365 * Returns: pointer to a refcounted label. 366 * else NULL if no label 367 */ 368 static inline struct aa_label *aa_get_label_rcu(struct aa_label __rcu **l) 369 { 370 struct aa_label *c; 371 372 rcu_read_lock(); 373 do { 374 c = rcu_dereference(*l); 375 } while (c && !kref_get_unless_zero(&c->count)); 376 rcu_read_unlock(); 377 378 return c; 379 } 380 381 /** 382 * aa_get_newest_label - find the newest version of @l 383 * @l: the label to check for newer versions of 384 * 385 * Returns: refcounted newest version of @l taking into account 386 * replacement, renames and removals 387 * return @l. 388 */ 389 static inline struct aa_label *aa_get_newest_label(struct aa_label *l) 390 { 391 if (!l) 392 return NULL; 393 394 if (label_is_stale(l)) { 395 struct aa_label *tmp; 396 397 AA_BUG(!l->proxy); 398 AA_BUG(!l->proxy->label); 399 /* BUG: only way this can happen is @l ref count and its 400 * replacement count have gone to 0 and are on their way 401 * to destruction. ie. we have a refcounting error 402 */ 403 tmp = aa_get_label_rcu(&l->proxy->label); 404 AA_BUG(!tmp); 405 406 return tmp; 407 } 408 409 return aa_get_label(l); 410 } 411 412 static inline void aa_put_label(struct aa_label *l) 413 { 414 if (l) 415 kref_put(&l->count, aa_label_kref); 416 } 417 418 /* wrapper fn to indicate semantics of the check */ 419 static inline bool __aa_subj_label_is_cached(struct aa_label *subj_label, 420 struct aa_label *obj_label) 421 { 422 return aa_label_is_subset(obj_label, subj_label); 423 } 424 425 426 struct aa_proxy *aa_alloc_proxy(struct aa_label *l, gfp_t gfp); 427 void aa_proxy_kref(struct kref *kref); 428 429 static inline struct aa_proxy *aa_get_proxy(struct aa_proxy *proxy) 430 { 431 if (proxy) 432 kref_get(&(proxy->count)); 433 434 return proxy; 435 } 436 437 static inline void aa_put_proxy(struct aa_proxy *proxy) 438 { 439 if (proxy) 440 kref_put(&proxy->count, aa_proxy_kref); 441 } 442 443 void __aa_proxy_redirect(struct aa_label *orig, struct aa_label *new); 444 445 #endif /* __AA_LABEL_H */ 446