1 /* 2 * AppArmor security module 3 * 4 * This file contains AppArmor policy manipulation functions 5 * 6 * Copyright (C) 1998-2008 Novell/SUSE 7 * Copyright 2009-2010 Canonical Ltd. 8 * 9 * This program is free software; you can redistribute it and/or 10 * modify it under the terms of the GNU General Public License as 11 * published by the Free Software Foundation, version 2 of the 12 * License. 13 * 14 * 15 * AppArmor policy is based around profiles, which contain the rules a 16 * task is confined by. Every task in the system has a profile attached 17 * to it determined either by matching "unconfined" tasks against the 18 * visible set of profiles or by following a profiles attachment rules. 19 * 20 * Each profile exists in a profile namespace which is a container of 21 * visible profiles. Each namespace contains a special "unconfined" profile, 22 * which doesn't enforce any confinement on a task beyond DAC. 23 * 24 * Namespace and profile names can be written together in either 25 * of two syntaxes. 26 * :namespace:profile - used by kernel interfaces for easy detection 27 * namespace://profile - used by policy 28 * 29 * Profile names can not start with : or @ or ^ and may not contain \0 30 * 31 * Reserved profile names 32 * unconfined - special automatically generated unconfined profile 33 * inherit - special name to indicate profile inheritance 34 * null-XXXX-YYYY - special automatically generated learning profiles 35 * 36 * Namespace names may not start with / or @ and may not contain \0 or : 37 * Reserved namespace names 38 * user-XXXX - user defined profiles 39 * 40 * a // in a profile or namespace name indicates a hierarchical name with the 41 * name before the // being the parent and the name after the child. 42 * 43 * Profile and namespace hierarchies serve two different but similar purposes. 44 * The namespace contains the set of visible profiles that are considered 45 * for attachment. The hierarchy of namespaces allows for virtualizing 46 * the namespace so that for example a chroot can have its own set of profiles 47 * which may define some local user namespaces. 48 * The profile hierarchy severs two distinct purposes, 49 * - it allows for sub profiles or hats, which allows an application to run 50 * subprograms under its own profile with different restriction than it 51 * self, and not have it use the system profile. 52 * eg. if a mail program starts an editor, the policy might make the 53 * restrictions tighter on the editor tighter than the mail program, 54 * and definitely different than general editor restrictions 55 * - it allows for binary hierarchy of profiles, so that execution history 56 * is preserved. This feature isn't exploited by AppArmor reference policy 57 * but is allowed. NOTE: this is currently suboptimal because profile 58 * aliasing is not currently implemented so that a profile for each 59 * level must be defined. 60 * eg. /bin/bash///bin/ls as a name would indicate /bin/ls was started 61 * from /bin/bash 62 * 63 * A profile or namespace name that can contain one or more // separators 64 * is referred to as an hname (hierarchical). 65 * eg. /bin/bash//bin/ls 66 * 67 * An fqname is a name that may contain both namespace and profile hnames. 68 * eg. :ns:/bin/bash//bin/ls 69 * 70 * NOTES: 71 * - locking of profile lists is currently fairly coarse. All profile 72 * lists within a namespace use the namespace lock. 73 * FIXME: move profile lists to using rcu_lists 74 */ 75 76 #include <linux/slab.h> 77 #include <linux/spinlock.h> 78 #include <linux/string.h> 79 #include <linux/user_namespace.h> 80 81 #include "include/apparmor.h" 82 #include "include/capability.h" 83 #include "include/context.h" 84 #include "include/file.h" 85 #include "include/ipc.h" 86 #include "include/match.h" 87 #include "include/path.h" 88 #include "include/policy.h" 89 #include "include/policy_ns.h" 90 #include "include/policy_unpack.h" 91 #include "include/resource.h" 92 93 int unprivileged_userns_apparmor_policy = 1; 94 95 const char *const aa_profile_mode_names[] = { 96 "enforce", 97 "complain", 98 "kill", 99 "unconfined", 100 }; 101 102 /* requires profile list write lock held */ 103 void __aa_update_proxy(struct aa_profile *orig, struct aa_profile *new) 104 { 105 struct aa_profile *tmp; 106 107 tmp = rcu_dereference_protected(orig->proxy->profile, 108 mutex_is_locked(&orig->ns->lock)); 109 rcu_assign_pointer(orig->proxy->profile, aa_get_profile(new)); 110 orig->flags |= PFLAG_STALE; 111 aa_put_profile(tmp); 112 } 113 114 /** 115 * __list_add_profile - add a profile to a list 116 * @list: list to add it to (NOT NULL) 117 * @profile: the profile to add (NOT NULL) 118 * 119 * refcount @profile, should be put by __list_remove_profile 120 * 121 * Requires: namespace lock be held, or list not be shared 122 */ 123 static void __list_add_profile(struct list_head *list, 124 struct aa_profile *profile) 125 { 126 list_add_rcu(&profile->base.list, list); 127 /* get list reference */ 128 aa_get_profile(profile); 129 } 130 131 /** 132 * __list_remove_profile - remove a profile from the list it is on 133 * @profile: the profile to remove (NOT NULL) 134 * 135 * remove a profile from the list, warning generally removal should 136 * be done with __replace_profile as most profile removals are 137 * replacements to the unconfined profile. 138 * 139 * put @profile list refcount 140 * 141 * Requires: namespace lock be held, or list not have been live 142 */ 143 static void __list_remove_profile(struct aa_profile *profile) 144 { 145 list_del_rcu(&profile->base.list); 146 aa_put_profile(profile); 147 } 148 149 /** 150 * __remove_profile - remove old profile, and children 151 * @profile: profile to be replaced (NOT NULL) 152 * 153 * Requires: namespace list lock be held, or list not be shared 154 */ 155 static void __remove_profile(struct aa_profile *profile) 156 { 157 /* release any children lists first */ 158 __aa_profile_list_release(&profile->base.profiles); 159 /* released by free_profile */ 160 __aa_update_proxy(profile, profile->ns->unconfined); 161 __aa_fs_profile_rmdir(profile); 162 __list_remove_profile(profile); 163 } 164 165 /** 166 * __aa_profile_list_release - remove all profiles on the list and put refs 167 * @head: list of profiles (NOT NULL) 168 * 169 * Requires: namespace lock be held 170 */ 171 void __aa_profile_list_release(struct list_head *head) 172 { 173 struct aa_profile *profile, *tmp; 174 list_for_each_entry_safe(profile, tmp, head, base.list) 175 __remove_profile(profile); 176 } 177 178 179 static void free_proxy(struct aa_proxy *p) 180 { 181 if (p) { 182 /* r->profile will not be updated any more as r is dead */ 183 aa_put_profile(rcu_dereference_protected(p->profile, true)); 184 kzfree(p); 185 } 186 } 187 188 189 void aa_free_proxy_kref(struct kref *kref) 190 { 191 struct aa_proxy *p = container_of(kref, struct aa_proxy, count); 192 193 free_proxy(p); 194 } 195 196 /** 197 * aa_free_data - free a data blob 198 * @ptr: data to free 199 * @arg: unused 200 */ 201 static void aa_free_data(void *ptr, void *arg) 202 { 203 struct aa_data *data = ptr; 204 205 kzfree(data->data); 206 kzfree(data->key); 207 kzfree(data); 208 } 209 210 /** 211 * aa_free_profile - free a profile 212 * @profile: the profile to free (MAYBE NULL) 213 * 214 * Free a profile, its hats and null_profile. All references to the profile, 215 * its hats and null_profile must have been put. 216 * 217 * If the profile was referenced from a task context, free_profile() will 218 * be called from an rcu callback routine, so we must not sleep here. 219 */ 220 void aa_free_profile(struct aa_profile *profile) 221 { 222 struct rhashtable *rht; 223 224 AA_DEBUG("%s(%p)\n", __func__, profile); 225 226 if (!profile) 227 return; 228 229 /* free children profiles */ 230 aa_policy_destroy(&profile->base); 231 aa_put_profile(rcu_access_pointer(profile->parent)); 232 233 aa_put_ns(profile->ns); 234 kzfree(profile->rename); 235 236 aa_free_file_rules(&profile->file); 237 aa_free_cap_rules(&profile->caps); 238 aa_free_rlimit_rules(&profile->rlimits); 239 240 kzfree(profile->dirname); 241 aa_put_dfa(profile->xmatch); 242 aa_put_dfa(profile->policy.dfa); 243 aa_put_proxy(profile->proxy); 244 245 if (profile->data) { 246 rht = profile->data; 247 profile->data = NULL; 248 rhashtable_free_and_destroy(rht, aa_free_data, NULL); 249 kzfree(rht); 250 } 251 252 kzfree(profile->hash); 253 aa_put_loaddata(profile->rawdata); 254 kzfree(profile); 255 } 256 257 /** 258 * aa_free_profile_rcu - free aa_profile by rcu (called by aa_free_profile_kref) 259 * @head: rcu_head callback for freeing of a profile (NOT NULL) 260 */ 261 static void aa_free_profile_rcu(struct rcu_head *head) 262 { 263 struct aa_profile *p = container_of(head, struct aa_profile, rcu); 264 if (p->flags & PFLAG_NS_COUNT) 265 aa_free_ns(p->ns); 266 else 267 aa_free_profile(p); 268 } 269 270 /** 271 * aa_free_profile_kref - free aa_profile by kref (called by aa_put_profile) 272 * @kr: kref callback for freeing of a profile (NOT NULL) 273 */ 274 void aa_free_profile_kref(struct kref *kref) 275 { 276 struct aa_profile *p = container_of(kref, struct aa_profile, count); 277 call_rcu(&p->rcu, aa_free_profile_rcu); 278 } 279 280 /** 281 * aa_alloc_profile - allocate, initialize and return a new profile 282 * @hname: name of the profile (NOT NULL) 283 * @gfp: allocation type 284 * 285 * Returns: refcount profile or NULL on failure 286 */ 287 struct aa_profile *aa_alloc_profile(const char *hname, gfp_t gfp) 288 { 289 struct aa_profile *profile; 290 291 /* freed by free_profile - usually through aa_put_profile */ 292 profile = kzalloc(sizeof(*profile), gfp); 293 if (!profile) 294 return NULL; 295 296 profile->proxy = kzalloc(sizeof(struct aa_proxy), gfp); 297 if (!profile->proxy) 298 goto fail; 299 kref_init(&profile->proxy->count); 300 301 if (!aa_policy_init(&profile->base, NULL, hname, gfp)) 302 goto fail; 303 kref_init(&profile->count); 304 305 /* refcount released by caller */ 306 return profile; 307 308 fail: 309 kzfree(profile->proxy); 310 kzfree(profile); 311 312 return NULL; 313 } 314 315 /** 316 * aa_new_null_profile - create or find a null-X learning profile 317 * @parent: profile that caused this profile to be created (NOT NULL) 318 * @hat: true if the null- learning profile is a hat 319 * @base: name to base the null profile off of 320 * @gfp: type of allocation 321 * 322 * Find/Create a null- complain mode profile used in learning mode. The 323 * name of the profile is unique and follows the format of parent//null-XXX. 324 * where XXX is based on the @name or if that fails or is not supplied 325 * a unique number 326 * 327 * null profiles are added to the profile list but the list does not 328 * hold a count on them so that they are automatically released when 329 * not in use. 330 * 331 * Returns: new refcounted profile else NULL on failure 332 */ 333 struct aa_profile *aa_new_null_profile(struct aa_profile *parent, bool hat, 334 const char *base, gfp_t gfp) 335 { 336 struct aa_profile *profile; 337 char *name; 338 339 AA_BUG(!parent); 340 341 if (base) { 342 name = kmalloc(strlen(parent->base.hname) + 8 + strlen(base), 343 gfp); 344 if (name) { 345 sprintf(name, "%s//null-%s", parent->base.hname, base); 346 goto name; 347 } 348 /* fall through to try shorter uniq */ 349 } 350 351 name = kmalloc(strlen(parent->base.hname) + 2 + 7 + 8, gfp); 352 if (!name) 353 return NULL; 354 sprintf(name, "%s//null-%x", parent->base.hname, 355 atomic_inc_return(&parent->ns->uniq_null)); 356 357 name: 358 /* lookup to see if this is a dup creation */ 359 profile = aa_find_child(parent, basename(name)); 360 if (profile) 361 goto out; 362 363 profile = aa_alloc_profile(name, gfp); 364 if (!profile) 365 goto fail; 366 367 profile->mode = APPARMOR_COMPLAIN; 368 profile->flags |= PFLAG_NULL; 369 if (hat) 370 profile->flags |= PFLAG_HAT; 371 profile->path_flags = parent->path_flags; 372 373 /* released on free_profile */ 374 rcu_assign_pointer(profile->parent, aa_get_profile(parent)); 375 profile->ns = aa_get_ns(parent->ns); 376 profile->file.dfa = aa_get_dfa(nulldfa); 377 profile->policy.dfa = aa_get_dfa(nulldfa); 378 379 mutex_lock(&profile->ns->lock); 380 __list_add_profile(&parent->base.profiles, profile); 381 mutex_unlock(&profile->ns->lock); 382 383 /* refcount released by caller */ 384 out: 385 kfree(name); 386 387 return profile; 388 389 fail: 390 kfree(name); 391 aa_free_profile(profile); 392 return NULL; 393 } 394 395 /* TODO: profile accounting - setup in remove */ 396 397 /** 398 * __find_child - find a profile on @head list with a name matching @name 399 * @head: list to search (NOT NULL) 400 * @name: name of profile (NOT NULL) 401 * 402 * Requires: rcu_read_lock be held 403 * 404 * Returns: unrefcounted profile ptr, or NULL if not found 405 */ 406 static struct aa_profile *__find_child(struct list_head *head, const char *name) 407 { 408 return (struct aa_profile *)__policy_find(head, name); 409 } 410 411 /** 412 * __strn_find_child - find a profile on @head list using substring of @name 413 * @head: list to search (NOT NULL) 414 * @name: name of profile (NOT NULL) 415 * @len: length of @name substring to match 416 * 417 * Requires: rcu_read_lock be held 418 * 419 * Returns: unrefcounted profile ptr, or NULL if not found 420 */ 421 static struct aa_profile *__strn_find_child(struct list_head *head, 422 const char *name, int len) 423 { 424 return (struct aa_profile *)__policy_strn_find(head, name, len); 425 } 426 427 /** 428 * aa_find_child - find a profile by @name in @parent 429 * @parent: profile to search (NOT NULL) 430 * @name: profile name to search for (NOT NULL) 431 * 432 * Returns: a refcounted profile or NULL if not found 433 */ 434 struct aa_profile *aa_find_child(struct aa_profile *parent, const char *name) 435 { 436 struct aa_profile *profile; 437 438 rcu_read_lock(); 439 do { 440 profile = __find_child(&parent->base.profiles, name); 441 } while (profile && !aa_get_profile_not0(profile)); 442 rcu_read_unlock(); 443 444 /* refcount released by caller */ 445 return profile; 446 } 447 448 /** 449 * __lookup_parent - lookup the parent of a profile of name @hname 450 * @ns: namespace to lookup profile in (NOT NULL) 451 * @hname: hierarchical profile name to find parent of (NOT NULL) 452 * 453 * Lookups up the parent of a fully qualified profile name, the profile 454 * that matches hname does not need to exist, in general this 455 * is used to load a new profile. 456 * 457 * Requires: rcu_read_lock be held 458 * 459 * Returns: unrefcounted policy or NULL if not found 460 */ 461 static struct aa_policy *__lookup_parent(struct aa_ns *ns, 462 const char *hname) 463 { 464 struct aa_policy *policy; 465 struct aa_profile *profile = NULL; 466 char *split; 467 468 policy = &ns->base; 469 470 for (split = strstr(hname, "//"); split;) { 471 profile = __strn_find_child(&policy->profiles, hname, 472 split - hname); 473 if (!profile) 474 return NULL; 475 policy = &profile->base; 476 hname = split + 2; 477 split = strstr(hname, "//"); 478 } 479 if (!profile) 480 return &ns->base; 481 return &profile->base; 482 } 483 484 /** 485 * __lookupn_profile - lookup the profile matching @hname 486 * @base: base list to start looking up profile name from (NOT NULL) 487 * @hname: hierarchical profile name (NOT NULL) 488 * @n: length of @hname 489 * 490 * Requires: rcu_read_lock be held 491 * 492 * Returns: unrefcounted profile pointer or NULL if not found 493 * 494 * Do a relative name lookup, recursing through profile tree. 495 */ 496 static struct aa_profile *__lookupn_profile(struct aa_policy *base, 497 const char *hname, size_t n) 498 { 499 struct aa_profile *profile = NULL; 500 const char *split; 501 502 for (split = strnstr(hname, "//", n); split; 503 split = strnstr(hname, "//", n)) { 504 profile = __strn_find_child(&base->profiles, hname, 505 split - hname); 506 if (!profile) 507 return NULL; 508 509 base = &profile->base; 510 n -= split + 2 - hname; 511 hname = split + 2; 512 } 513 514 if (n) 515 return __strn_find_child(&base->profiles, hname, n); 516 return NULL; 517 } 518 519 static struct aa_profile *__lookup_profile(struct aa_policy *base, 520 const char *hname) 521 { 522 return __lookupn_profile(base, hname, strlen(hname)); 523 } 524 525 /** 526 * aa_lookup_profile - find a profile by its full or partial name 527 * @ns: the namespace to start from (NOT NULL) 528 * @hname: name to do lookup on. Does not contain namespace prefix (NOT NULL) 529 * @n: size of @hname 530 * 531 * Returns: refcounted profile or NULL if not found 532 */ 533 struct aa_profile *aa_lookupn_profile(struct aa_ns *ns, const char *hname, 534 size_t n) 535 { 536 struct aa_profile *profile; 537 538 rcu_read_lock(); 539 do { 540 profile = __lookupn_profile(&ns->base, hname, n); 541 } while (profile && !aa_get_profile_not0(profile)); 542 rcu_read_unlock(); 543 544 /* the unconfined profile is not in the regular profile list */ 545 if (!profile && strncmp(hname, "unconfined", n) == 0) 546 profile = aa_get_newest_profile(ns->unconfined); 547 548 /* refcount released by caller */ 549 return profile; 550 } 551 552 struct aa_profile *aa_lookup_profile(struct aa_ns *ns, const char *hname) 553 { 554 return aa_lookupn_profile(ns, hname, strlen(hname)); 555 } 556 557 struct aa_profile *aa_fqlookupn_profile(struct aa_profile *base, 558 const char *fqname, size_t n) 559 { 560 struct aa_profile *profile; 561 struct aa_ns *ns; 562 const char *name, *ns_name; 563 size_t ns_len; 564 565 name = aa_splitn_fqname(fqname, n, &ns_name, &ns_len); 566 if (ns_name) { 567 ns = aa_findn_ns(base->ns, ns_name, ns_len); 568 if (!ns) 569 return NULL; 570 } else 571 ns = aa_get_ns(base->ns); 572 573 if (name) 574 profile = aa_lookupn_profile(ns, name, n - (name - fqname)); 575 else if (ns) 576 /* default profile for ns, currently unconfined */ 577 profile = aa_get_newest_profile(ns->unconfined); 578 else 579 profile = NULL; 580 aa_put_ns(ns); 581 582 return profile; 583 } 584 585 /** 586 * replacement_allowed - test to see if replacement is allowed 587 * @profile: profile to test if it can be replaced (MAYBE NULL) 588 * @noreplace: true if replacement shouldn't be allowed but addition is okay 589 * @info: Returns - info about why replacement failed (NOT NULL) 590 * 591 * Returns: %0 if replacement allowed else error code 592 */ 593 static int replacement_allowed(struct aa_profile *profile, int noreplace, 594 const char **info) 595 { 596 if (profile) { 597 if (profile->flags & PFLAG_IMMUTABLE) { 598 *info = "cannot replace immutible profile"; 599 return -EPERM; 600 } else if (noreplace) { 601 *info = "profile already exists"; 602 return -EEXIST; 603 } 604 } 605 return 0; 606 } 607 608 /* audit callback for net specific fields */ 609 static void audit_cb(struct audit_buffer *ab, void *va) 610 { 611 struct common_audit_data *sa = va; 612 613 if (aad(sa)->iface.ns) { 614 audit_log_format(ab, " ns="); 615 audit_log_untrustedstring(ab, aad(sa)->iface.ns); 616 } 617 } 618 619 /** 620 * aa_audit_policy - Do auditing of policy changes 621 * @profile: profile to check if it can manage policy 622 * @op: policy operation being performed 623 * @gfp: memory allocation flags 624 * @nsname: name of the ns being manipulated (MAY BE NULL) 625 * @name: name of profile being manipulated (NOT NULL) 626 * @info: any extra information to be audited (MAYBE NULL) 627 * @error: error code 628 * 629 * Returns: the error to be returned after audit is done 630 */ 631 static int audit_policy(struct aa_profile *profile, const char *op, 632 const char *nsname, const char *name, 633 const char *info, int error) 634 { 635 DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, op); 636 637 aad(&sa)->iface.ns = nsname; 638 aad(&sa)->name = name; 639 aad(&sa)->info = info; 640 aad(&sa)->error = error; 641 642 return aa_audit(AUDIT_APPARMOR_STATUS, profile, &sa, audit_cb); 643 } 644 645 /** 646 * policy_view_capable - check if viewing policy in at @ns is allowed 647 * ns: namespace being viewed by current task (may be NULL) 648 * Returns: true if viewing policy is allowed 649 * 650 * If @ns is NULL then the namespace being viewed is assumed to be the 651 * tasks current namespace. 652 */ 653 bool policy_view_capable(struct aa_ns *ns) 654 { 655 struct user_namespace *user_ns = current_user_ns(); 656 struct aa_ns *view_ns = aa_get_current_ns(); 657 bool root_in_user_ns = uid_eq(current_euid(), make_kuid(user_ns, 0)) || 658 in_egroup_p(make_kgid(user_ns, 0)); 659 bool response = false; 660 if (!ns) 661 ns = view_ns; 662 663 if (root_in_user_ns && aa_ns_visible(view_ns, ns, true) && 664 (user_ns == &init_user_ns || 665 (unprivileged_userns_apparmor_policy != 0 && 666 user_ns->level == view_ns->level))) 667 response = true; 668 aa_put_ns(view_ns); 669 670 return response; 671 } 672 673 bool policy_admin_capable(struct aa_ns *ns) 674 { 675 struct user_namespace *user_ns = current_user_ns(); 676 bool capable = ns_capable(user_ns, CAP_MAC_ADMIN); 677 678 AA_DEBUG("cap_mac_admin? %d\n", capable); 679 AA_DEBUG("policy locked? %d\n", aa_g_lock_policy); 680 681 return policy_view_capable(ns) && capable && !aa_g_lock_policy; 682 } 683 684 /** 685 * aa_may_manage_policy - can the current task manage policy 686 * @profile: profile to check if it can manage policy 687 * @op: the policy manipulation operation being done 688 * 689 * Returns: 0 if the task is allowed to manipulate policy else error 690 */ 691 int aa_may_manage_policy(struct aa_profile *profile, struct aa_ns *ns, 692 const char *op) 693 { 694 /* check if loading policy is locked out */ 695 if (aa_g_lock_policy) 696 return audit_policy(profile, op, NULL, NULL, 697 "policy_locked", -EACCES); 698 699 if (!policy_admin_capable(ns)) 700 return audit_policy(profile, op, NULL, NULL, 701 "not policy admin", -EACCES); 702 703 /* TODO: add fine grained mediation of policy loads */ 704 return 0; 705 } 706 707 static struct aa_profile *__list_lookup_parent(struct list_head *lh, 708 struct aa_profile *profile) 709 { 710 const char *base = basename(profile->base.hname); 711 long len = base - profile->base.hname; 712 struct aa_load_ent *ent; 713 714 /* parent won't have trailing // so remove from len */ 715 if (len <= 2) 716 return NULL; 717 len -= 2; 718 719 list_for_each_entry(ent, lh, list) { 720 if (ent->new == profile) 721 continue; 722 if (strncmp(ent->new->base.hname, profile->base.hname, len) == 723 0 && ent->new->base.hname[len] == 0) 724 return ent->new; 725 } 726 727 return NULL; 728 } 729 730 /** 731 * __replace_profile - replace @old with @new on a list 732 * @old: profile to be replaced (NOT NULL) 733 * @new: profile to replace @old with (NOT NULL) 734 * @share_proxy: transfer @old->proxy to @new 735 * 736 * Will duplicate and refcount elements that @new inherits from @old 737 * and will inherit @old children. 738 * 739 * refcount @new for list, put @old list refcount 740 * 741 * Requires: namespace list lock be held, or list not be shared 742 */ 743 static void __replace_profile(struct aa_profile *old, struct aa_profile *new, 744 bool share_proxy) 745 { 746 struct aa_profile *child, *tmp; 747 748 if (!list_empty(&old->base.profiles)) { 749 LIST_HEAD(lh); 750 list_splice_init_rcu(&old->base.profiles, &lh, synchronize_rcu); 751 752 list_for_each_entry_safe(child, tmp, &lh, base.list) { 753 struct aa_profile *p; 754 755 list_del_init(&child->base.list); 756 p = __find_child(&new->base.profiles, child->base.name); 757 if (p) { 758 /* @p replaces @child */ 759 __replace_profile(child, p, share_proxy); 760 continue; 761 } 762 763 /* inherit @child and its children */ 764 /* TODO: update hname of inherited children */ 765 /* list refcount transferred to @new */ 766 p = aa_deref_parent(child); 767 rcu_assign_pointer(child->parent, aa_get_profile(new)); 768 list_add_rcu(&child->base.list, &new->base.profiles); 769 aa_put_profile(p); 770 } 771 } 772 773 if (!rcu_access_pointer(new->parent)) { 774 struct aa_profile *parent = aa_deref_parent(old); 775 rcu_assign_pointer(new->parent, aa_get_profile(parent)); 776 } 777 __aa_update_proxy(old, new); 778 if (share_proxy) { 779 aa_put_proxy(new->proxy); 780 new->proxy = aa_get_proxy(old->proxy); 781 } else if (!rcu_access_pointer(new->proxy->profile)) 782 /* aafs interface uses proxy */ 783 rcu_assign_pointer(new->proxy->profile, 784 aa_get_profile(new)); 785 __aa_fs_profile_migrate_dents(old, new); 786 787 if (list_empty(&new->base.list)) { 788 /* new is not on a list already */ 789 list_replace_rcu(&old->base.list, &new->base.list); 790 aa_get_profile(new); 791 aa_put_profile(old); 792 } else 793 __list_remove_profile(old); 794 } 795 796 /** 797 * __lookup_replace - lookup replacement information for a profile 798 * @ns - namespace the lookup occurs in 799 * @hname - name of profile to lookup 800 * @noreplace - true if not replacing an existing profile 801 * @p - Returns: profile to be replaced 802 * @info - Returns: info string on why lookup failed 803 * 804 * Returns: profile to replace (no ref) on success else ptr error 805 */ 806 static int __lookup_replace(struct aa_ns *ns, const char *hname, 807 bool noreplace, struct aa_profile **p, 808 const char **info) 809 { 810 *p = aa_get_profile(__lookup_profile(&ns->base, hname)); 811 if (*p) { 812 int error = replacement_allowed(*p, noreplace, info); 813 if (error) { 814 *info = "profile can not be replaced"; 815 return error; 816 } 817 } 818 819 return 0; 820 } 821 822 /** 823 * aa_replace_profiles - replace profile(s) on the profile list 824 * @view: namespace load is viewed from 825 * @label: label that is attempting to load/replace policy 826 * @noreplace: true if only doing addition, no replacement allowed 827 * @udata: serialized data stream (NOT NULL) 828 * 829 * unpack and replace a profile on the profile list and uses of that profile 830 * by any aa_task_ctx. If the profile does not exist on the profile list 831 * it is added. 832 * 833 * Returns: size of data consumed else error code on failure. 834 */ 835 ssize_t aa_replace_profiles(struct aa_ns *view, struct aa_profile *profile, 836 bool noreplace, struct aa_loaddata *udata) 837 { 838 const char *ns_name, *info = NULL; 839 struct aa_ns *ns = NULL; 840 struct aa_load_ent *ent, *tmp; 841 const char *op = OP_PROF_REPL; 842 ssize_t count, error; 843 LIST_HEAD(lh); 844 845 /* released below */ 846 error = aa_unpack(udata, &lh, &ns_name); 847 if (error) 848 goto out; 849 850 /* ensure that profiles are all for the same ns 851 * TODO: update locking to remove this constaint. All profiles in 852 * the load set must succeed as a set or the load will 853 * fail. Sort ent list and take ns locks in hierarchy order 854 */ 855 count = 0; 856 list_for_each_entry(ent, &lh, list) { 857 if (ns_name) { 858 if (ent->ns_name && 859 strcmp(ent->ns_name, ns_name) != 0) { 860 info = "policy load has mixed namespaces"; 861 error = -EACCES; 862 goto fail; 863 } 864 } else if (ent->ns_name) { 865 if (count) { 866 info = "policy load has mixed namespaces"; 867 error = -EACCES; 868 goto fail; 869 } 870 ns_name = ent->ns_name; 871 } else 872 count++; 873 } 874 if (ns_name) { 875 ns = aa_prepare_ns(view, ns_name); 876 if (IS_ERR(ns)) { 877 info = "failed to prepare namespace"; 878 error = PTR_ERR(ns); 879 ns = NULL; 880 goto fail; 881 } 882 } else 883 ns = aa_get_ns(view); 884 885 mutex_lock(&ns->lock); 886 /* setup parent and ns info */ 887 list_for_each_entry(ent, &lh, list) { 888 struct aa_policy *policy; 889 ent->new->rawdata = aa_get_loaddata(udata); 890 error = __lookup_replace(ns, ent->new->base.hname, noreplace, 891 &ent->old, &info); 892 if (error) 893 goto fail_lock; 894 895 if (ent->new->rename) { 896 error = __lookup_replace(ns, ent->new->rename, 897 noreplace, &ent->rename, 898 &info); 899 if (error) 900 goto fail_lock; 901 } 902 903 /* released when @new is freed */ 904 ent->new->ns = aa_get_ns(ns); 905 906 if (ent->old || ent->rename) 907 continue; 908 909 /* no ref on policy only use inside lock */ 910 policy = __lookup_parent(ns, ent->new->base.hname); 911 if (!policy) { 912 struct aa_profile *p; 913 p = __list_lookup_parent(&lh, ent->new); 914 if (!p) { 915 error = -ENOENT; 916 info = "parent does not exist"; 917 goto fail_lock; 918 } 919 rcu_assign_pointer(ent->new->parent, aa_get_profile(p)); 920 } else if (policy != &ns->base) { 921 /* released on profile replacement or free_profile */ 922 struct aa_profile *p = (struct aa_profile *) policy; 923 rcu_assign_pointer(ent->new->parent, aa_get_profile(p)); 924 } 925 } 926 927 /* create new fs entries for introspection if needed */ 928 list_for_each_entry(ent, &lh, list) { 929 if (ent->old) { 930 /* inherit old interface files */ 931 932 /* if (ent->rename) 933 TODO: support rename */ 934 /* } else if (ent->rename) { 935 TODO: support rename */ 936 } else { 937 struct dentry *parent; 938 if (rcu_access_pointer(ent->new->parent)) { 939 struct aa_profile *p; 940 p = aa_deref_parent(ent->new); 941 parent = prof_child_dir(p); 942 } else 943 parent = ns_subprofs_dir(ent->new->ns); 944 error = __aa_fs_profile_mkdir(ent->new, parent); 945 } 946 947 if (error) { 948 info = "failed to create "; 949 goto fail_lock; 950 } 951 } 952 953 /* Done with checks that may fail - do actual replacement */ 954 list_for_each_entry_safe(ent, tmp, &lh, list) { 955 list_del_init(&ent->list); 956 op = (!ent->old && !ent->rename) ? OP_PROF_LOAD : OP_PROF_REPL; 957 958 audit_policy(profile, op, NULL, ent->new->base.hname, 959 NULL, error); 960 961 if (ent->old) { 962 __replace_profile(ent->old, ent->new, 1); 963 if (ent->rename) { 964 /* aafs interface uses proxy */ 965 struct aa_proxy *r = ent->new->proxy; 966 rcu_assign_pointer(r->profile, 967 aa_get_profile(ent->new)); 968 __replace_profile(ent->rename, ent->new, 0); 969 } 970 } else if (ent->rename) { 971 /* aafs interface uses proxy */ 972 rcu_assign_pointer(ent->new->proxy->profile, 973 aa_get_profile(ent->new)); 974 __replace_profile(ent->rename, ent->new, 0); 975 } else if (ent->new->parent) { 976 struct aa_profile *parent, *newest; 977 parent = aa_deref_parent(ent->new); 978 newest = aa_get_newest_profile(parent); 979 980 /* parent replaced in this atomic set? */ 981 if (newest != parent) { 982 aa_get_profile(newest); 983 rcu_assign_pointer(ent->new->parent, newest); 984 aa_put_profile(parent); 985 } 986 /* aafs interface uses proxy */ 987 rcu_assign_pointer(ent->new->proxy->profile, 988 aa_get_profile(ent->new)); 989 __list_add_profile(&newest->base.profiles, ent->new); 990 aa_put_profile(newest); 991 } else { 992 /* aafs interface uses proxy */ 993 rcu_assign_pointer(ent->new->proxy->profile, 994 aa_get_profile(ent->new)); 995 __list_add_profile(&ns->base.profiles, ent->new); 996 } 997 aa_load_ent_free(ent); 998 } 999 mutex_unlock(&ns->lock); 1000 1001 out: 1002 aa_put_ns(ns); 1003 1004 if (error) 1005 return error; 1006 return udata->size; 1007 1008 fail_lock: 1009 mutex_unlock(&ns->lock); 1010 1011 /* audit cause of failure */ 1012 op = (!ent->old) ? OP_PROF_LOAD : OP_PROF_REPL; 1013 fail: 1014 audit_policy(profile, op, ns_name, ent->new->base.hname, 1015 info, error); 1016 /* audit status that rest of profiles in the atomic set failed too */ 1017 info = "valid profile in failed atomic policy load"; 1018 list_for_each_entry(tmp, &lh, list) { 1019 if (tmp == ent) { 1020 info = "unchecked profile in failed atomic policy load"; 1021 /* skip entry that caused failure */ 1022 continue; 1023 } 1024 op = (!ent->old) ? OP_PROF_LOAD : OP_PROF_REPL; 1025 audit_policy(profile, op, ns_name, 1026 tmp->new->base.hname, info, error); 1027 } 1028 list_for_each_entry_safe(ent, tmp, &lh, list) { 1029 list_del_init(&ent->list); 1030 aa_load_ent_free(ent); 1031 } 1032 1033 goto out; 1034 } 1035 1036 /** 1037 * aa_remove_profiles - remove profile(s) from the system 1038 * @view: namespace the remove is being done from 1039 * @subj: profile attempting to remove policy 1040 * @fqname: name of the profile or namespace to remove (NOT NULL) 1041 * @size: size of the name 1042 * 1043 * Remove a profile or sub namespace from the current namespace, so that 1044 * they can not be found anymore and mark them as replaced by unconfined 1045 * 1046 * NOTE: removing confinement does not restore rlimits to preconfinemnet values 1047 * 1048 * Returns: size of data consume else error code if fails 1049 */ 1050 ssize_t aa_remove_profiles(struct aa_ns *view, struct aa_profile *subj, 1051 char *fqname, size_t size) 1052 { 1053 struct aa_ns *root = NULL, *ns = NULL; 1054 struct aa_profile *profile = NULL; 1055 const char *name = fqname, *info = NULL; 1056 char *ns_name = NULL; 1057 ssize_t error = 0; 1058 1059 if (*fqname == 0) { 1060 info = "no profile specified"; 1061 error = -ENOENT; 1062 goto fail; 1063 } 1064 1065 root = view; 1066 1067 if (fqname[0] == ':') { 1068 name = aa_split_fqname(fqname, &ns_name); 1069 /* released below */ 1070 ns = aa_find_ns(root, ns_name); 1071 if (!ns) { 1072 info = "namespace does not exist"; 1073 error = -ENOENT; 1074 goto fail; 1075 } 1076 } else 1077 /* released below */ 1078 ns = aa_get_ns(root); 1079 1080 if (!name) { 1081 /* remove namespace - can only happen if fqname[0] == ':' */ 1082 mutex_lock(&ns->parent->lock); 1083 __aa_remove_ns(ns); 1084 mutex_unlock(&ns->parent->lock); 1085 } else { 1086 /* remove profile */ 1087 mutex_lock(&ns->lock); 1088 profile = aa_get_profile(__lookup_profile(&ns->base, name)); 1089 if (!profile) { 1090 error = -ENOENT; 1091 info = "profile does not exist"; 1092 goto fail_ns_lock; 1093 } 1094 name = profile->base.hname; 1095 __remove_profile(profile); 1096 mutex_unlock(&ns->lock); 1097 } 1098 1099 /* don't fail removal if audit fails */ 1100 (void) audit_policy(subj, OP_PROF_RM, ns_name, name, info, 1101 error); 1102 aa_put_ns(ns); 1103 aa_put_profile(profile); 1104 return size; 1105 1106 fail_ns_lock: 1107 mutex_unlock(&ns->lock); 1108 aa_put_ns(ns); 1109 1110 fail: 1111 (void) audit_policy(subj, OP_PROF_RM, ns_name, name, info, 1112 error); 1113 return error; 1114 } 1115