1 /* 2 * AppArmor security module 3 * 4 * This file contains AppArmor label definitions 5 * 6 * Copyright 2017 Canonical Ltd. 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License as 10 * published by the Free Software Foundation, version 2 of the 11 * License. 12 */ 13 14 #ifndef __AA_LABEL_H 15 #define __AA_LABEL_H 16 17 #include <linux/atomic.h> 18 #include <linux/audit.h> 19 #include <linux/rbtree.h> 20 #include <linux/rcupdate.h> 21 22 #include "apparmor.h" 23 #include "lib.h" 24 25 struct aa_ns; 26 27 #define LOCAL_VEC_ENTRIES 8 28 #define DEFINE_VEC(T, V) \ 29 struct aa_ ## T *(_ ## V ## _localtmp)[LOCAL_VEC_ENTRIES]; \ 30 struct aa_ ## T **(V) 31 32 #define vec_setup(T, V, N, GFP) \ 33 ({ \ 34 if ((N) <= LOCAL_VEC_ENTRIES) { \ 35 typeof(N) i; \ 36 (V) = (_ ## V ## _localtmp); \ 37 for (i = 0; i < (N); i++) \ 38 (V)[i] = NULL; \ 39 } else \ 40 (V) = kzalloc(sizeof(struct aa_ ## T *) * (N), (GFP)); \ 41 (V) ? 0 : -ENOMEM; \ 42 }) 43 44 #define vec_cleanup(T, V, N) \ 45 do { \ 46 int i; \ 47 for (i = 0; i < (N); i++) { \ 48 if (!IS_ERR_OR_NULL((V)[i])) \ 49 aa_put_ ## T((V)[i]); \ 50 } \ 51 if ((V) != _ ## V ## _localtmp) \ 52 kfree(V); \ 53 } while (0) 54 55 #define vec_last(VEC, SIZE) ((VEC)[(SIZE) - 1]) 56 #define vec_ns(VEC, SIZE) (vec_last((VEC), (SIZE))->ns) 57 #define vec_labelset(VEC, SIZE) (&vec_ns((VEC), (SIZE))->labels) 58 #define cleanup_domain_vec(V, L) cleanup_label_vec((V), (L)->size) 59 60 struct aa_profile; 61 #define VEC_FLAG_TERMINATE 1 62 int aa_vec_unique(struct aa_profile **vec, int n, int flags); 63 struct aa_label *aa_vec_find_or_create_label(struct aa_profile **vec, int len, 64 gfp_t gfp); 65 #define aa_sort_and_merge_vec(N, V) \ 66 aa_sort_and_merge_profiles((N), (struct aa_profile **)(V)) 67 68 69 /* struct aa_labelset - set of labels for a namespace 70 * 71 * Labels are reference counted; aa_labelset does not contribute to label 72 * reference counts. Once a label's last refcount is put it is removed from 73 * the set. 74 */ 75 struct aa_labelset { 76 rwlock_t lock; 77 78 struct rb_root root; 79 }; 80 81 #define __labelset_for_each(LS, N) \ 82 for ((N) = rb_first(&(LS)->root); (N); (N) = rb_next(N)) 83 84 void aa_labelset_destroy(struct aa_labelset *ls); 85 void aa_labelset_init(struct aa_labelset *ls); 86 87 88 enum label_flags { 89 FLAG_HAT = 1, /* profile is a hat */ 90 FLAG_UNCONFINED = 2, /* label unconfined only if all */ 91 FLAG_NULL = 4, /* profile is null learning profile */ 92 FLAG_IX_ON_NAME_ERROR = 8, /* fallback to ix on name lookup fail */ 93 FLAG_IMMUTIBLE = 0x10, /* don't allow changes/replacement */ 94 FLAG_USER_DEFINED = 0x20, /* user based profile - lower privs */ 95 FLAG_NO_LIST_REF = 0x40, /* list doesn't keep profile ref */ 96 FLAG_NS_COUNT = 0x80, /* carries NS ref count */ 97 FLAG_IN_TREE = 0x100, /* label is in tree */ 98 FLAG_PROFILE = 0x200, /* label is a profile */ 99 FLAG_EXPLICIT = 0x400, /* explicit static label */ 100 FLAG_STALE = 0x800, /* replaced/removed */ 101 FLAG_RENAMED = 0x1000, /* label has renaming in it */ 102 FLAG_REVOKED = 0x2000, /* label has revocation in it */ 103 104 /* These flags must correspond with PATH_flags */ 105 /* TODO: add new path flags */ 106 }; 107 108 struct aa_label; 109 struct aa_proxy { 110 struct kref count; 111 struct aa_label __rcu *label; 112 }; 113 114 struct label_it { 115 int i, j; 116 }; 117 118 /* struct aa_label - lazy labeling struct 119 * @count: ref count of active users 120 * @node: rbtree position 121 * @rcu: rcu callback struct 122 * @proxy: is set to the label that replaced this label 123 * @hname: text representation of the label (MAYBE_NULL) 124 * @flags: stale and other flags - values may change under label set lock 125 * @secid: secid that references this label 126 * @size: number of entries in @ent[] 127 * @ent: set of profiles for label, actual size determined by @size 128 */ 129 struct aa_label { 130 struct kref count; 131 struct rb_node node; 132 struct rcu_head rcu; 133 struct aa_proxy *proxy; 134 __counted char *hname; 135 long flags; 136 u32 secid; 137 int size; 138 struct aa_profile *vec[]; 139 }; 140 141 #define last_error(E, FN) \ 142 do { \ 143 int __subE = (FN); \ 144 if (__subE) \ 145 (E) = __subE; \ 146 } while (0) 147 148 #define label_isprofile(X) ((X)->flags & FLAG_PROFILE) 149 #define label_unconfined(X) ((X)->flags & FLAG_UNCONFINED) 150 #define unconfined(X) label_unconfined(X) 151 #define label_is_stale(X) ((X)->flags & FLAG_STALE) 152 #define __label_make_stale(X) ((X)->flags |= FLAG_STALE) 153 #define labels_ns(X) (vec_ns(&((X)->vec[0]), (X)->size)) 154 #define labels_set(X) (&labels_ns(X)->labels) 155 #define labels_profile(X) ((X)->vec[(X)->size - 1]) 156 157 158 int aa_label_next_confined(struct aa_label *l, int i); 159 160 /* for each profile in a label */ 161 #define label_for_each(I, L, P) \ 162 for ((I).i = 0; ((P) = (L)->vec[(I).i]); ++((I).i)) 163 164 /* assumes break/goto ended label_for_each */ 165 #define label_for_each_cont(I, L, P) \ 166 for (++((I).i); ((P) = (L)->vec[(I).i]); ++((I).i)) 167 168 #define next_comb(I, L1, L2) \ 169 do { \ 170 (I).j++; \ 171 if ((I).j >= (L2)->size) { \ 172 (I).i++; \ 173 (I).j = 0; \ 174 } \ 175 } while (0) 176 177 178 /* for each combination of P1 in L1, and P2 in L2 */ 179 #define label_for_each_comb(I, L1, L2, P1, P2) \ 180 for ((I).i = (I).j = 0; \ 181 ((P1) = (L1)->vec[(I).i]) && ((P2) = (L2)->vec[(I).j]); \ 182 (I) = next_comb(I, L1, L2)) 183 184 #define fn_for_each_comb(L1, L2, P1, P2, FN) \ 185 ({ \ 186 struct label_it i; \ 187 int __E = 0; \ 188 label_for_each_comb(i, (L1), (L2), (P1), (P2)) { \ 189 last_error(__E, (FN)); \ 190 } \ 191 __E; \ 192 }) 193 194 /* for each profile that is enforcing confinement in a label */ 195 #define label_for_each_confined(I, L, P) \ 196 for ((I).i = aa_label_next_confined((L), 0); \ 197 ((P) = (L)->vec[(I).i]); \ 198 (I).i = aa_label_next_confined((L), (I).i + 1)) 199 200 #define label_for_each_in_merge(I, A, B, P) \ 201 for ((I).i = (I).j = 0; \ 202 ((P) = aa_label_next_in_merge(&(I), (A), (B))); \ 203 ) 204 205 #define label_for_each_not_in_set(I, SET, SUB, P) \ 206 for ((I).i = (I).j = 0; \ 207 ((P) = __aa_label_next_not_in_set(&(I), (SET), (SUB))); \ 208 ) 209 210 #define next_in_ns(i, NS, L) \ 211 ({ \ 212 typeof(i) ___i = (i); \ 213 while ((L)->vec[___i] && (L)->vec[___i]->ns != (NS)) \ 214 (___i)++; \ 215 (___i); \ 216 }) 217 218 #define label_for_each_in_ns(I, NS, L, P) \ 219 for ((I).i = next_in_ns(0, (NS), (L)); \ 220 ((P) = (L)->vec[(I).i]); \ 221 (I).i = next_in_ns((I).i + 1, (NS), (L))) 222 223 #define fn_for_each_in_ns(L, P, FN) \ 224 ({ \ 225 struct label_it __i; \ 226 struct aa_ns *__ns = labels_ns(L); \ 227 int __E = 0; \ 228 label_for_each_in_ns(__i, __ns, (L), (P)) { \ 229 last_error(__E, (FN)); \ 230 } \ 231 __E; \ 232 }) 233 234 235 #define fn_for_each_XXX(L, P, FN, ...) \ 236 ({ \ 237 struct label_it i; \ 238 int __E = 0; \ 239 label_for_each ## __VA_ARGS__(i, (L), (P)) { \ 240 last_error(__E, (FN)); \ 241 } \ 242 __E; \ 243 }) 244 245 #define fn_for_each(L, P, FN) fn_for_each_XXX(L, P, FN) 246 #define fn_for_each_confined(L, P, FN) fn_for_each_XXX(L, P, FN, _confined) 247 248 #define fn_for_each2_XXX(L1, L2, P, FN, ...) \ 249 ({ \ 250 struct label_it i; \ 251 int __E = 0; \ 252 label_for_each ## __VA_ARGS__(i, (L1), (L2), (P)) { \ 253 last_error(__E, (FN)); \ 254 } \ 255 __E; \ 256 }) 257 258 #define fn_for_each_in_merge(L1, L2, P, FN) \ 259 fn_for_each2_XXX((L1), (L2), P, FN, _in_merge) 260 #define fn_for_each_not_in_set(L1, L2, P, FN) \ 261 fn_for_each2_XXX((L1), (L2), P, FN, _not_in_set) 262 263 #define LABEL_MEDIATES(L, C) \ 264 ({ \ 265 struct aa_profile *profile; \ 266 struct label_it i; \ 267 int ret = 0; \ 268 label_for_each(i, (L), profile) { \ 269 if (PROFILE_MEDIATES(profile, (C))) { \ 270 ret = 1; \ 271 break; \ 272 } \ 273 } \ 274 ret; \ 275 }) 276 277 278 void aa_labelset_destroy(struct aa_labelset *ls); 279 void aa_labelset_init(struct aa_labelset *ls); 280 void __aa_labelset_update_subtree(struct aa_ns *ns); 281 282 void aa_label_free(struct aa_label *label); 283 void aa_label_kref(struct kref *kref); 284 bool aa_label_init(struct aa_label *label, int size); 285 struct aa_label *aa_label_alloc(int size, struct aa_proxy *proxy, gfp_t gfp); 286 287 bool aa_label_is_subset(struct aa_label *set, struct aa_label *sub); 288 struct aa_profile *__aa_label_next_not_in_set(struct label_it *I, 289 struct aa_label *set, 290 struct aa_label *sub); 291 bool aa_label_remove(struct aa_label *label); 292 struct aa_label *aa_label_insert(struct aa_labelset *ls, struct aa_label *l); 293 bool aa_label_replace(struct aa_label *old, struct aa_label *new); 294 bool aa_label_make_newest(struct aa_labelset *ls, struct aa_label *old, 295 struct aa_label *new); 296 297 struct aa_label *aa_label_find(struct aa_label *l); 298 299 struct aa_profile *aa_label_next_in_merge(struct label_it *I, 300 struct aa_label *a, 301 struct aa_label *b); 302 struct aa_label *aa_label_find_merge(struct aa_label *a, struct aa_label *b); 303 struct aa_label *aa_label_merge(struct aa_label *a, struct aa_label *b, 304 gfp_t gfp); 305 306 307 bool aa_update_label_name(struct aa_ns *ns, struct aa_label *label, gfp_t gfp); 308 309 #define FLAGS_NONE 0 310 #define FLAG_SHOW_MODE 1 311 #define FLAG_VIEW_SUBNS 2 312 #define FLAG_HIDDEN_UNCONFINED 4 313 #define FLAG_ABS_ROOT 8 314 int aa_label_snxprint(char *str, size_t size, struct aa_ns *view, 315 struct aa_label *label, int flags); 316 int aa_label_asxprint(char **strp, struct aa_ns *ns, struct aa_label *label, 317 int flags, gfp_t gfp); 318 int aa_label_acntsxprint(char __counted **strp, struct aa_ns *ns, 319 struct aa_label *label, int flags, gfp_t gfp); 320 void aa_label_xaudit(struct audit_buffer *ab, struct aa_ns *ns, 321 struct aa_label *label, int flags, gfp_t gfp); 322 void aa_label_seq_xprint(struct seq_file *f, struct aa_ns *ns, 323 struct aa_label *label, int flags, gfp_t gfp); 324 void aa_label_xprintk(struct aa_ns *ns, struct aa_label *label, int flags, 325 gfp_t gfp); 326 void aa_label_audit(struct audit_buffer *ab, struct aa_label *label, gfp_t gfp); 327 void aa_label_seq_print(struct seq_file *f, struct aa_label *label, gfp_t gfp); 328 void aa_label_printk(struct aa_label *label, gfp_t gfp); 329 330 struct aa_label *aa_label_parse(struct aa_label *base, const char *str, 331 gfp_t gfp, bool create, bool force_stack); 332 333 334 struct aa_perms; 335 int aa_label_match(struct aa_profile *profile, struct aa_label *label, 336 unsigned int state, bool subns, u32 request, 337 struct aa_perms *perms); 338 339 340 /** 341 * __aa_get_label - get a reference count to uncounted label reference 342 * @l: reference to get a count on 343 * 344 * Returns: pointer to reference OR NULL if race is lost and reference is 345 * being repeated. 346 * Requires: lock held, and the return code MUST be checked 347 */ 348 static inline struct aa_label *__aa_get_label(struct aa_label *l) 349 { 350 if (l && kref_get_unless_zero(&l->count)) 351 return l; 352 353 return NULL; 354 } 355 356 static inline struct aa_label *aa_get_label(struct aa_label *l) 357 { 358 if (l) 359 kref_get(&(l->count)); 360 361 return l; 362 } 363 364 365 /** 366 * aa_get_label_rcu - increment refcount on a label that can be replaced 367 * @l: pointer to label that can be replaced (NOT NULL) 368 * 369 * Returns: pointer to a refcounted label. 370 * else NULL if no label 371 */ 372 static inline struct aa_label *aa_get_label_rcu(struct aa_label __rcu **l) 373 { 374 struct aa_label *c; 375 376 rcu_read_lock(); 377 do { 378 c = rcu_dereference(*l); 379 } while (c && !kref_get_unless_zero(&c->count)); 380 rcu_read_unlock(); 381 382 return c; 383 } 384 385 /** 386 * aa_get_newest_label - find the newest version of @l 387 * @l: the label to check for newer versions of 388 * 389 * Returns: refcounted newest version of @l taking into account 390 * replacement, renames and removals 391 * return @l. 392 */ 393 static inline struct aa_label *aa_get_newest_label(struct aa_label *l) 394 { 395 if (!l) 396 return NULL; 397 398 if (label_is_stale(l)) { 399 struct aa_label *tmp; 400 401 AA_BUG(!l->proxy); 402 AA_BUG(!l->proxy->label); 403 /* BUG: only way this can happen is @l ref count and its 404 * replacement count have gone to 0 and are on their way 405 * to destruction. ie. we have a refcounting error 406 */ 407 tmp = aa_get_label_rcu(&l->proxy->label); 408 AA_BUG(!tmp); 409 410 return tmp; 411 } 412 413 return aa_get_label(l); 414 } 415 416 static inline void aa_put_label(struct aa_label *l) 417 { 418 if (l) 419 kref_put(&l->count, aa_label_kref); 420 } 421 422 423 struct aa_proxy *aa_alloc_proxy(struct aa_label *l, gfp_t gfp); 424 void aa_proxy_kref(struct kref *kref); 425 426 static inline struct aa_proxy *aa_get_proxy(struct aa_proxy *proxy) 427 { 428 if (proxy) 429 kref_get(&(proxy->count)); 430 431 return proxy; 432 } 433 434 static inline void aa_put_proxy(struct aa_proxy *proxy) 435 { 436 if (proxy) 437 kref_put(&proxy->count, aa_proxy_kref); 438 } 439 440 void __aa_proxy_redirect(struct aa_label *orig, struct aa_label *new); 441 442 #endif /* __AA_LABEL_H */ 443