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/cred.h> 80 #include <linux/rculist.h> 81 #include <linux/user_namespace.h> 82 83 #include "include/apparmor.h" 84 #include "include/capability.h" 85 #include "include/context.h" 86 #include "include/file.h" 87 #include "include/ipc.h" 88 #include "include/match.h" 89 #include "include/path.h" 90 #include "include/policy.h" 91 #include "include/policy_ns.h" 92 #include "include/policy_unpack.h" 93 #include "include/resource.h" 94 95 int unprivileged_userns_apparmor_policy = 1; 96 97 const char *const aa_profile_mode_names[] = { 98 "enforce", 99 "complain", 100 "kill", 101 "unconfined", 102 }; 103 104 /* requires profile list write lock held */ 105 void __aa_update_proxy(struct aa_profile *orig, struct aa_profile *new) 106 { 107 struct aa_profile *tmp; 108 109 tmp = rcu_dereference_protected(orig->proxy->profile, 110 mutex_is_locked(&orig->ns->lock)); 111 rcu_assign_pointer(orig->proxy->profile, aa_get_profile(new)); 112 orig->flags |= PFLAG_STALE; 113 aa_put_profile(tmp); 114 } 115 116 /** 117 * __list_add_profile - add a profile to a list 118 * @list: list to add it to (NOT NULL) 119 * @profile: the profile to add (NOT NULL) 120 * 121 * refcount @profile, should be put by __list_remove_profile 122 * 123 * Requires: namespace lock be held, or list not be shared 124 */ 125 static void __list_add_profile(struct list_head *list, 126 struct aa_profile *profile) 127 { 128 list_add_rcu(&profile->base.list, list); 129 /* get list reference */ 130 aa_get_profile(profile); 131 } 132 133 /** 134 * __list_remove_profile - remove a profile from the list it is on 135 * @profile: the profile to remove (NOT NULL) 136 * 137 * remove a profile from the list, warning generally removal should 138 * be done with __replace_profile as most profile removals are 139 * replacements to the unconfined profile. 140 * 141 * put @profile list refcount 142 * 143 * Requires: namespace lock be held, or list not have been live 144 */ 145 static void __list_remove_profile(struct aa_profile *profile) 146 { 147 list_del_rcu(&profile->base.list); 148 aa_put_profile(profile); 149 } 150 151 /** 152 * __remove_profile - remove old profile, and children 153 * @profile: profile to be replaced (NOT NULL) 154 * 155 * Requires: namespace list lock be held, or list not be shared 156 */ 157 static void __remove_profile(struct aa_profile *profile) 158 { 159 /* release any children lists first */ 160 __aa_profile_list_release(&profile->base.profiles); 161 /* released by free_profile */ 162 __aa_update_proxy(profile, profile->ns->unconfined); 163 __aa_fs_profile_rmdir(profile); 164 __list_remove_profile(profile); 165 } 166 167 /** 168 * __aa_profile_list_release - remove all profiles on the list and put refs 169 * @head: list of profiles (NOT NULL) 170 * 171 * Requires: namespace lock be held 172 */ 173 void __aa_profile_list_release(struct list_head *head) 174 { 175 struct aa_profile *profile, *tmp; 176 list_for_each_entry_safe(profile, tmp, head, base.list) 177 __remove_profile(profile); 178 } 179 180 181 static void free_proxy(struct aa_proxy *p) 182 { 183 if (p) { 184 /* r->profile will not be updated any more as r is dead */ 185 aa_put_profile(rcu_dereference_protected(p->profile, true)); 186 kzfree(p); 187 } 188 } 189 190 191 void aa_free_proxy_kref(struct kref *kref) 192 { 193 struct aa_proxy *p = container_of(kref, struct aa_proxy, count); 194 195 free_proxy(p); 196 } 197 198 /** 199 * aa_free_data - free a data blob 200 * @ptr: data to free 201 * @arg: unused 202 */ 203 static void aa_free_data(void *ptr, void *arg) 204 { 205 struct aa_data *data = ptr; 206 207 kzfree(data->data); 208 kzfree(data->key); 209 kzfree(data); 210 } 211 212 /** 213 * aa_free_profile - free a profile 214 * @profile: the profile to free (MAYBE NULL) 215 * 216 * Free a profile, its hats and null_profile. All references to the profile, 217 * its hats and null_profile must have been put. 218 * 219 * If the profile was referenced from a task context, free_profile() will 220 * be called from an rcu callback routine, so we must not sleep here. 221 */ 222 void aa_free_profile(struct aa_profile *profile) 223 { 224 struct rhashtable *rht; 225 226 AA_DEBUG("%s(%p)\n", __func__, profile); 227 228 if (!profile) 229 return; 230 231 /* free children profiles */ 232 aa_policy_destroy(&profile->base); 233 aa_put_profile(rcu_access_pointer(profile->parent)); 234 235 aa_put_ns(profile->ns); 236 kzfree(profile->rename); 237 238 aa_free_file_rules(&profile->file); 239 aa_free_cap_rules(&profile->caps); 240 aa_free_rlimit_rules(&profile->rlimits); 241 242 kzfree(profile->dirname); 243 aa_put_dfa(profile->xmatch); 244 aa_put_dfa(profile->policy.dfa); 245 aa_put_proxy(profile->proxy); 246 247 if (profile->data) { 248 rht = profile->data; 249 profile->data = NULL; 250 rhashtable_free_and_destroy(rht, aa_free_data, NULL); 251 kzfree(rht); 252 } 253 254 kzfree(profile->hash); 255 aa_put_loaddata(profile->rawdata); 256 kzfree(profile); 257 } 258 259 /** 260 * aa_free_profile_rcu - free aa_profile by rcu (called by aa_free_profile_kref) 261 * @head: rcu_head callback for freeing of a profile (NOT NULL) 262 */ 263 static void aa_free_profile_rcu(struct rcu_head *head) 264 { 265 struct aa_profile *p = container_of(head, struct aa_profile, rcu); 266 if (p->flags & PFLAG_NS_COUNT) 267 aa_free_ns(p->ns); 268 else 269 aa_free_profile(p); 270 } 271 272 /** 273 * aa_free_profile_kref - free aa_profile by kref (called by aa_put_profile) 274 * @kr: kref callback for freeing of a profile (NOT NULL) 275 */ 276 void aa_free_profile_kref(struct kref *kref) 277 { 278 struct aa_profile *p = container_of(kref, struct aa_profile, count); 279 call_rcu(&p->rcu, aa_free_profile_rcu); 280 } 281 282 /** 283 * aa_alloc_profile - allocate, initialize and return a new profile 284 * @hname: name of the profile (NOT NULL) 285 * @gfp: allocation type 286 * 287 * Returns: refcount profile or NULL on failure 288 */ 289 struct aa_profile *aa_alloc_profile(const char *hname, gfp_t gfp) 290 { 291 struct aa_profile *profile; 292 293 /* freed by free_profile - usually through aa_put_profile */ 294 profile = kzalloc(sizeof(*profile), gfp); 295 if (!profile) 296 return NULL; 297 298 profile->proxy = kzalloc(sizeof(struct aa_proxy), gfp); 299 if (!profile->proxy) 300 goto fail; 301 kref_init(&profile->proxy->count); 302 303 if (!aa_policy_init(&profile->base, NULL, hname, gfp)) 304 goto fail; 305 kref_init(&profile->count); 306 307 /* refcount released by caller */ 308 return profile; 309 310 fail: 311 kzfree(profile->proxy); 312 kzfree(profile); 313 314 return NULL; 315 } 316 317 /** 318 * aa_new_null_profile - create or find a null-X learning profile 319 * @parent: profile that caused this profile to be created (NOT NULL) 320 * @hat: true if the null- learning profile is a hat 321 * @base: name to base the null profile off of 322 * @gfp: type of allocation 323 * 324 * Find/Create a null- complain mode profile used in learning mode. The 325 * name of the profile is unique and follows the format of parent//null-XXX. 326 * where XXX is based on the @name or if that fails or is not supplied 327 * a unique number 328 * 329 * null profiles are added to the profile list but the list does not 330 * hold a count on them so that they are automatically released when 331 * not in use. 332 * 333 * Returns: new refcounted profile else NULL on failure 334 */ 335 struct aa_profile *aa_new_null_profile(struct aa_profile *parent, bool hat, 336 const char *base, gfp_t gfp) 337 { 338 struct aa_profile *profile; 339 char *name; 340 341 AA_BUG(!parent); 342 343 if (base) { 344 name = kmalloc(strlen(parent->base.hname) + 8 + strlen(base), 345 gfp); 346 if (name) { 347 sprintf(name, "%s//null-%s", parent->base.hname, base); 348 goto name; 349 } 350 /* fall through to try shorter uniq */ 351 } 352 353 name = kmalloc(strlen(parent->base.hname) + 2 + 7 + 8, gfp); 354 if (!name) 355 return NULL; 356 sprintf(name, "%s//null-%x", parent->base.hname, 357 atomic_inc_return(&parent->ns->uniq_null)); 358 359 name: 360 /* lookup to see if this is a dup creation */ 361 profile = aa_find_child(parent, basename(name)); 362 if (profile) 363 goto out; 364 365 profile = aa_alloc_profile(name, gfp); 366 if (!profile) 367 goto fail; 368 369 profile->mode = APPARMOR_COMPLAIN; 370 profile->flags |= PFLAG_NULL; 371 if (hat) 372 profile->flags |= PFLAG_HAT; 373 profile->path_flags = parent->path_flags; 374 375 /* released on free_profile */ 376 rcu_assign_pointer(profile->parent, aa_get_profile(parent)); 377 profile->ns = aa_get_ns(parent->ns); 378 profile->file.dfa = aa_get_dfa(nulldfa); 379 profile->policy.dfa = aa_get_dfa(nulldfa); 380 381 mutex_lock(&profile->ns->lock); 382 __list_add_profile(&parent->base.profiles, profile); 383 mutex_unlock(&profile->ns->lock); 384 385 /* refcount released by caller */ 386 out: 387 kfree(name); 388 389 return profile; 390 391 fail: 392 kfree(name); 393 aa_free_profile(profile); 394 return NULL; 395 } 396 397 /* TODO: profile accounting - setup in remove */ 398 399 /** 400 * __find_child - find a profile on @head list with a name matching @name 401 * @head: list to search (NOT NULL) 402 * @name: name of profile (NOT NULL) 403 * 404 * Requires: rcu_read_lock be held 405 * 406 * Returns: unrefcounted profile ptr, or NULL if not found 407 */ 408 static struct aa_profile *__find_child(struct list_head *head, const char *name) 409 { 410 return (struct aa_profile *)__policy_find(head, name); 411 } 412 413 /** 414 * __strn_find_child - find a profile on @head list using substring of @name 415 * @head: list to search (NOT NULL) 416 * @name: name of profile (NOT NULL) 417 * @len: length of @name substring to match 418 * 419 * Requires: rcu_read_lock be held 420 * 421 * Returns: unrefcounted profile ptr, or NULL if not found 422 */ 423 static struct aa_profile *__strn_find_child(struct list_head *head, 424 const char *name, int len) 425 { 426 return (struct aa_profile *)__policy_strn_find(head, name, len); 427 } 428 429 /** 430 * aa_find_child - find a profile by @name in @parent 431 * @parent: profile to search (NOT NULL) 432 * @name: profile name to search for (NOT NULL) 433 * 434 * Returns: a refcounted profile or NULL if not found 435 */ 436 struct aa_profile *aa_find_child(struct aa_profile *parent, const char *name) 437 { 438 struct aa_profile *profile; 439 440 rcu_read_lock(); 441 do { 442 profile = __find_child(&parent->base.profiles, name); 443 } while (profile && !aa_get_profile_not0(profile)); 444 rcu_read_unlock(); 445 446 /* refcount released by caller */ 447 return profile; 448 } 449 450 /** 451 * __lookup_parent - lookup the parent of a profile of name @hname 452 * @ns: namespace to lookup profile in (NOT NULL) 453 * @hname: hierarchical profile name to find parent of (NOT NULL) 454 * 455 * Lookups up the parent of a fully qualified profile name, the profile 456 * that matches hname does not need to exist, in general this 457 * is used to load a new profile. 458 * 459 * Requires: rcu_read_lock be held 460 * 461 * Returns: unrefcounted policy or NULL if not found 462 */ 463 static struct aa_policy *__lookup_parent(struct aa_ns *ns, 464 const char *hname) 465 { 466 struct aa_policy *policy; 467 struct aa_profile *profile = NULL; 468 char *split; 469 470 policy = &ns->base; 471 472 for (split = strstr(hname, "//"); split;) { 473 profile = __strn_find_child(&policy->profiles, hname, 474 split - hname); 475 if (!profile) 476 return NULL; 477 policy = &profile->base; 478 hname = split + 2; 479 split = strstr(hname, "//"); 480 } 481 if (!profile) 482 return &ns->base; 483 return &profile->base; 484 } 485 486 /** 487 * __lookupn_profile - lookup the profile matching @hname 488 * @base: base list to start looking up profile name from (NOT NULL) 489 * @hname: hierarchical profile name (NOT NULL) 490 * @n: length of @hname 491 * 492 * Requires: rcu_read_lock be held 493 * 494 * Returns: unrefcounted profile pointer or NULL if not found 495 * 496 * Do a relative name lookup, recursing through profile tree. 497 */ 498 static struct aa_profile *__lookupn_profile(struct aa_policy *base, 499 const char *hname, size_t n) 500 { 501 struct aa_profile *profile = NULL; 502 const char *split; 503 504 for (split = strnstr(hname, "//", n); split; 505 split = strnstr(hname, "//", n)) { 506 profile = __strn_find_child(&base->profiles, hname, 507 split - hname); 508 if (!profile) 509 return NULL; 510 511 base = &profile->base; 512 n -= split + 2 - hname; 513 hname = split + 2; 514 } 515 516 if (n) 517 return __strn_find_child(&base->profiles, hname, n); 518 return NULL; 519 } 520 521 static struct aa_profile *__lookup_profile(struct aa_policy *base, 522 const char *hname) 523 { 524 return __lookupn_profile(base, hname, strlen(hname)); 525 } 526 527 /** 528 * aa_lookup_profile - find a profile by its full or partial name 529 * @ns: the namespace to start from (NOT NULL) 530 * @hname: name to do lookup on. Does not contain namespace prefix (NOT NULL) 531 * @n: size of @hname 532 * 533 * Returns: refcounted profile or NULL if not found 534 */ 535 struct aa_profile *aa_lookupn_profile(struct aa_ns *ns, const char *hname, 536 size_t n) 537 { 538 struct aa_profile *profile; 539 540 rcu_read_lock(); 541 do { 542 profile = __lookupn_profile(&ns->base, hname, n); 543 } while (profile && !aa_get_profile_not0(profile)); 544 rcu_read_unlock(); 545 546 /* the unconfined profile is not in the regular profile list */ 547 if (!profile && strncmp(hname, "unconfined", n) == 0) 548 profile = aa_get_newest_profile(ns->unconfined); 549 550 /* refcount released by caller */ 551 return profile; 552 } 553 554 struct aa_profile *aa_lookup_profile(struct aa_ns *ns, const char *hname) 555 { 556 return aa_lookupn_profile(ns, hname, strlen(hname)); 557 } 558 559 struct aa_profile *aa_fqlookupn_profile(struct aa_profile *base, 560 const char *fqname, size_t n) 561 { 562 struct aa_profile *profile; 563 struct aa_ns *ns; 564 const char *name, *ns_name; 565 size_t ns_len; 566 567 name = aa_splitn_fqname(fqname, n, &ns_name, &ns_len); 568 if (ns_name) { 569 ns = aa_findn_ns(base->ns, ns_name, ns_len); 570 if (!ns) 571 return NULL; 572 } else 573 ns = aa_get_ns(base->ns); 574 575 if (name) 576 profile = aa_lookupn_profile(ns, name, n - (name - fqname)); 577 else if (ns) 578 /* default profile for ns, currently unconfined */ 579 profile = aa_get_newest_profile(ns->unconfined); 580 else 581 profile = NULL; 582 aa_put_ns(ns); 583 584 return profile; 585 } 586 587 /** 588 * replacement_allowed - test to see if replacement is allowed 589 * @profile: profile to test if it can be replaced (MAYBE NULL) 590 * @noreplace: true if replacement shouldn't be allowed but addition is okay 591 * @info: Returns - info about why replacement failed (NOT NULL) 592 * 593 * Returns: %0 if replacement allowed else error code 594 */ 595 static int replacement_allowed(struct aa_profile *profile, int noreplace, 596 const char **info) 597 { 598 if (profile) { 599 if (profile->flags & PFLAG_IMMUTABLE) { 600 *info = "cannot replace immutible profile"; 601 return -EPERM; 602 } else if (noreplace) { 603 *info = "profile already exists"; 604 return -EEXIST; 605 } 606 } 607 return 0; 608 } 609 610 /* audit callback for net specific fields */ 611 static void audit_cb(struct audit_buffer *ab, void *va) 612 { 613 struct common_audit_data *sa = va; 614 615 if (aad(sa)->iface.ns) { 616 audit_log_format(ab, " ns="); 617 audit_log_untrustedstring(ab, aad(sa)->iface.ns); 618 } 619 } 620 621 /** 622 * aa_audit_policy - Do auditing of policy changes 623 * @profile: profile to check if it can manage policy 624 * @op: policy operation being performed 625 * @gfp: memory allocation flags 626 * @nsname: name of the ns being manipulated (MAY BE NULL) 627 * @name: name of profile being manipulated (NOT NULL) 628 * @info: any extra information to be audited (MAYBE NULL) 629 * @error: error code 630 * 631 * Returns: the error to be returned after audit is done 632 */ 633 static int audit_policy(struct aa_profile *profile, const char *op, 634 const char *nsname, const char *name, 635 const char *info, int error) 636 { 637 DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, op); 638 639 aad(&sa)->iface.ns = nsname; 640 aad(&sa)->name = name; 641 aad(&sa)->info = info; 642 aad(&sa)->error = error; 643 644 return aa_audit(AUDIT_APPARMOR_STATUS, profile, &sa, audit_cb); 645 } 646 647 /** 648 * policy_view_capable - check if viewing policy in at @ns is allowed 649 * ns: namespace being viewed by current task (may be NULL) 650 * Returns: true if viewing policy is allowed 651 * 652 * If @ns is NULL then the namespace being viewed is assumed to be the 653 * tasks current namespace. 654 */ 655 bool policy_view_capable(struct aa_ns *ns) 656 { 657 struct user_namespace *user_ns = current_user_ns(); 658 struct aa_ns *view_ns = aa_get_current_ns(); 659 bool root_in_user_ns = uid_eq(current_euid(), make_kuid(user_ns, 0)) || 660 in_egroup_p(make_kgid(user_ns, 0)); 661 bool response = false; 662 if (!ns) 663 ns = view_ns; 664 665 if (root_in_user_ns && aa_ns_visible(view_ns, ns, true) && 666 (user_ns == &init_user_ns || 667 (unprivileged_userns_apparmor_policy != 0 && 668 user_ns->level == view_ns->level))) 669 response = true; 670 aa_put_ns(view_ns); 671 672 return response; 673 } 674 675 bool policy_admin_capable(struct aa_ns *ns) 676 { 677 struct user_namespace *user_ns = current_user_ns(); 678 bool capable = ns_capable(user_ns, CAP_MAC_ADMIN); 679 680 AA_DEBUG("cap_mac_admin? %d\n", capable); 681 AA_DEBUG("policy locked? %d\n", aa_g_lock_policy); 682 683 return policy_view_capable(ns) && capable && !aa_g_lock_policy; 684 } 685 686 /** 687 * aa_may_manage_policy - can the current task manage policy 688 * @profile: profile to check if it can manage policy 689 * @op: the policy manipulation operation being done 690 * 691 * Returns: 0 if the task is allowed to manipulate policy else error 692 */ 693 int aa_may_manage_policy(struct aa_profile *profile, struct aa_ns *ns, 694 const char *op) 695 { 696 /* check if loading policy is locked out */ 697 if (aa_g_lock_policy) 698 return audit_policy(profile, op, NULL, NULL, 699 "policy_locked", -EACCES); 700 701 if (!policy_admin_capable(ns)) 702 return audit_policy(profile, op, NULL, NULL, 703 "not policy admin", -EACCES); 704 705 /* TODO: add fine grained mediation of policy loads */ 706 return 0; 707 } 708 709 static struct aa_profile *__list_lookup_parent(struct list_head *lh, 710 struct aa_profile *profile) 711 { 712 const char *base = basename(profile->base.hname); 713 long len = base - profile->base.hname; 714 struct aa_load_ent *ent; 715 716 /* parent won't have trailing // so remove from len */ 717 if (len <= 2) 718 return NULL; 719 len -= 2; 720 721 list_for_each_entry(ent, lh, list) { 722 if (ent->new == profile) 723 continue; 724 if (strncmp(ent->new->base.hname, profile->base.hname, len) == 725 0 && ent->new->base.hname[len] == 0) 726 return ent->new; 727 } 728 729 return NULL; 730 } 731 732 /** 733 * __replace_profile - replace @old with @new on a list 734 * @old: profile to be replaced (NOT NULL) 735 * @new: profile to replace @old with (NOT NULL) 736 * @share_proxy: transfer @old->proxy to @new 737 * 738 * Will duplicate and refcount elements that @new inherits from @old 739 * and will inherit @old children. 740 * 741 * refcount @new for list, put @old list refcount 742 * 743 * Requires: namespace list lock be held, or list not be shared 744 */ 745 static void __replace_profile(struct aa_profile *old, struct aa_profile *new, 746 bool share_proxy) 747 { 748 struct aa_profile *child, *tmp; 749 750 if (!list_empty(&old->base.profiles)) { 751 LIST_HEAD(lh); 752 list_splice_init_rcu(&old->base.profiles, &lh, synchronize_rcu); 753 754 list_for_each_entry_safe(child, tmp, &lh, base.list) { 755 struct aa_profile *p; 756 757 list_del_init(&child->base.list); 758 p = __find_child(&new->base.profiles, child->base.name); 759 if (p) { 760 /* @p replaces @child */ 761 __replace_profile(child, p, share_proxy); 762 continue; 763 } 764 765 /* inherit @child and its children */ 766 /* TODO: update hname of inherited children */ 767 /* list refcount transferred to @new */ 768 p = aa_deref_parent(child); 769 rcu_assign_pointer(child->parent, aa_get_profile(new)); 770 list_add_rcu(&child->base.list, &new->base.profiles); 771 aa_put_profile(p); 772 } 773 } 774 775 if (!rcu_access_pointer(new->parent)) { 776 struct aa_profile *parent = aa_deref_parent(old); 777 rcu_assign_pointer(new->parent, aa_get_profile(parent)); 778 } 779 __aa_update_proxy(old, new); 780 if (share_proxy) { 781 aa_put_proxy(new->proxy); 782 new->proxy = aa_get_proxy(old->proxy); 783 } else if (!rcu_access_pointer(new->proxy->profile)) 784 /* aafs interface uses proxy */ 785 rcu_assign_pointer(new->proxy->profile, 786 aa_get_profile(new)); 787 __aa_fs_profile_migrate_dents(old, new); 788 789 if (list_empty(&new->base.list)) { 790 /* new is not on a list already */ 791 list_replace_rcu(&old->base.list, &new->base.list); 792 aa_get_profile(new); 793 aa_put_profile(old); 794 } else 795 __list_remove_profile(old); 796 } 797 798 /** 799 * __lookup_replace - lookup replacement information for a profile 800 * @ns - namespace the lookup occurs in 801 * @hname - name of profile to lookup 802 * @noreplace - true if not replacing an existing profile 803 * @p - Returns: profile to be replaced 804 * @info - Returns: info string on why lookup failed 805 * 806 * Returns: profile to replace (no ref) on success else ptr error 807 */ 808 static int __lookup_replace(struct aa_ns *ns, const char *hname, 809 bool noreplace, struct aa_profile **p, 810 const char **info) 811 { 812 *p = aa_get_profile(__lookup_profile(&ns->base, hname)); 813 if (*p) { 814 int error = replacement_allowed(*p, noreplace, info); 815 if (error) { 816 *info = "profile can not be replaced"; 817 return error; 818 } 819 } 820 821 return 0; 822 } 823 824 /** 825 * aa_replace_profiles - replace profile(s) on the profile list 826 * @view: namespace load is viewed from 827 * @label: label that is attempting to load/replace policy 828 * @noreplace: true if only doing addition, no replacement allowed 829 * @udata: serialized data stream (NOT NULL) 830 * 831 * unpack and replace a profile on the profile list and uses of that profile 832 * by any aa_task_ctx. If the profile does not exist on the profile list 833 * it is added. 834 * 835 * Returns: size of data consumed else error code on failure. 836 */ 837 ssize_t aa_replace_profiles(struct aa_ns *view, struct aa_profile *profile, 838 bool noreplace, struct aa_loaddata *udata) 839 { 840 const char *ns_name, *info = NULL; 841 struct aa_ns *ns = NULL; 842 struct aa_load_ent *ent, *tmp; 843 const char *op = OP_PROF_REPL; 844 ssize_t count, error; 845 LIST_HEAD(lh); 846 847 /* released below */ 848 error = aa_unpack(udata, &lh, &ns_name); 849 if (error) 850 goto out; 851 852 /* ensure that profiles are all for the same ns 853 * TODO: update locking to remove this constaint. All profiles in 854 * the load set must succeed as a set or the load will 855 * fail. Sort ent list and take ns locks in hierarchy order 856 */ 857 count = 0; 858 list_for_each_entry(ent, &lh, list) { 859 if (ns_name) { 860 if (ent->ns_name && 861 strcmp(ent->ns_name, ns_name) != 0) { 862 info = "policy load has mixed namespaces"; 863 error = -EACCES; 864 goto fail; 865 } 866 } else if (ent->ns_name) { 867 if (count) { 868 info = "policy load has mixed namespaces"; 869 error = -EACCES; 870 goto fail; 871 } 872 ns_name = ent->ns_name; 873 } else 874 count++; 875 } 876 if (ns_name) { 877 ns = aa_prepare_ns(view, ns_name); 878 if (IS_ERR(ns)) { 879 op = OP_PROF_LOAD; 880 info = "failed to prepare namespace"; 881 error = PTR_ERR(ns); 882 ns = NULL; 883 ent = NULL; 884 goto fail; 885 } 886 } else 887 ns = aa_get_ns(view); 888 889 mutex_lock(&ns->lock); 890 /* setup parent and ns info */ 891 list_for_each_entry(ent, &lh, list) { 892 struct aa_policy *policy; 893 ent->new->rawdata = aa_get_loaddata(udata); 894 error = __lookup_replace(ns, ent->new->base.hname, noreplace, 895 &ent->old, &info); 896 if (error) 897 goto fail_lock; 898 899 if (ent->new->rename) { 900 error = __lookup_replace(ns, ent->new->rename, 901 noreplace, &ent->rename, 902 &info); 903 if (error) 904 goto fail_lock; 905 } 906 907 /* released when @new is freed */ 908 ent->new->ns = aa_get_ns(ns); 909 910 if (ent->old || ent->rename) 911 continue; 912 913 /* no ref on policy only use inside lock */ 914 policy = __lookup_parent(ns, ent->new->base.hname); 915 if (!policy) { 916 struct aa_profile *p; 917 p = __list_lookup_parent(&lh, ent->new); 918 if (!p) { 919 error = -ENOENT; 920 info = "parent does not exist"; 921 goto fail_lock; 922 } 923 rcu_assign_pointer(ent->new->parent, aa_get_profile(p)); 924 } else if (policy != &ns->base) { 925 /* released on profile replacement or free_profile */ 926 struct aa_profile *p = (struct aa_profile *) policy; 927 rcu_assign_pointer(ent->new->parent, aa_get_profile(p)); 928 } 929 } 930 931 /* create new fs entries for introspection if needed */ 932 list_for_each_entry(ent, &lh, list) { 933 if (ent->old) { 934 /* inherit old interface files */ 935 936 /* if (ent->rename) 937 TODO: support rename */ 938 /* } else if (ent->rename) { 939 TODO: support rename */ 940 } else { 941 struct dentry *parent; 942 if (rcu_access_pointer(ent->new->parent)) { 943 struct aa_profile *p; 944 p = aa_deref_parent(ent->new); 945 parent = prof_child_dir(p); 946 } else 947 parent = ns_subprofs_dir(ent->new->ns); 948 error = __aa_fs_profile_mkdir(ent->new, parent); 949 } 950 951 if (error) { 952 info = "failed to create "; 953 goto fail_lock; 954 } 955 } 956 957 /* Done with checks that may fail - do actual replacement */ 958 list_for_each_entry_safe(ent, tmp, &lh, list) { 959 list_del_init(&ent->list); 960 op = (!ent->old && !ent->rename) ? OP_PROF_LOAD : OP_PROF_REPL; 961 962 audit_policy(profile, op, NULL, ent->new->base.hname, 963 NULL, error); 964 965 if (ent->old) { 966 __replace_profile(ent->old, ent->new, 1); 967 if (ent->rename) { 968 /* aafs interface uses proxy */ 969 struct aa_proxy *r = ent->new->proxy; 970 rcu_assign_pointer(r->profile, 971 aa_get_profile(ent->new)); 972 __replace_profile(ent->rename, ent->new, 0); 973 } 974 } else if (ent->rename) { 975 /* aafs interface uses proxy */ 976 rcu_assign_pointer(ent->new->proxy->profile, 977 aa_get_profile(ent->new)); 978 __replace_profile(ent->rename, ent->new, 0); 979 } else if (ent->new->parent) { 980 struct aa_profile *parent, *newest; 981 parent = aa_deref_parent(ent->new); 982 newest = aa_get_newest_profile(parent); 983 984 /* parent replaced in this atomic set? */ 985 if (newest != parent) { 986 aa_get_profile(newest); 987 rcu_assign_pointer(ent->new->parent, newest); 988 aa_put_profile(parent); 989 } 990 /* aafs interface uses proxy */ 991 rcu_assign_pointer(ent->new->proxy->profile, 992 aa_get_profile(ent->new)); 993 __list_add_profile(&newest->base.profiles, ent->new); 994 aa_put_profile(newest); 995 } else { 996 /* aafs interface uses proxy */ 997 rcu_assign_pointer(ent->new->proxy->profile, 998 aa_get_profile(ent->new)); 999 __list_add_profile(&ns->base.profiles, ent->new); 1000 } 1001 aa_load_ent_free(ent); 1002 } 1003 mutex_unlock(&ns->lock); 1004 1005 out: 1006 aa_put_ns(ns); 1007 1008 if (error) 1009 return error; 1010 return udata->size; 1011 1012 fail_lock: 1013 mutex_unlock(&ns->lock); 1014 1015 /* audit cause of failure */ 1016 op = (!ent->old) ? OP_PROF_LOAD : OP_PROF_REPL; 1017 fail: 1018 audit_policy(profile, op, ns_name, ent ? ent->new->base.hname : NULL, 1019 info, error); 1020 /* audit status that rest of profiles in the atomic set failed too */ 1021 info = "valid profile in failed atomic policy load"; 1022 list_for_each_entry(tmp, &lh, list) { 1023 if (tmp == ent) { 1024 info = "unchecked profile in failed atomic policy load"; 1025 /* skip entry that caused failure */ 1026 continue; 1027 } 1028 op = (!tmp->old) ? OP_PROF_LOAD : OP_PROF_REPL; 1029 audit_policy(profile, op, ns_name, 1030 tmp->new->base.hname, info, error); 1031 } 1032 list_for_each_entry_safe(ent, tmp, &lh, list) { 1033 list_del_init(&ent->list); 1034 aa_load_ent_free(ent); 1035 } 1036 1037 goto out; 1038 } 1039 1040 /** 1041 * aa_remove_profiles - remove profile(s) from the system 1042 * @view: namespace the remove is being done from 1043 * @subj: profile attempting to remove policy 1044 * @fqname: name of the profile or namespace to remove (NOT NULL) 1045 * @size: size of the name 1046 * 1047 * Remove a profile or sub namespace from the current namespace, so that 1048 * they can not be found anymore and mark them as replaced by unconfined 1049 * 1050 * NOTE: removing confinement does not restore rlimits to preconfinemnet values 1051 * 1052 * Returns: size of data consume else error code if fails 1053 */ 1054 ssize_t aa_remove_profiles(struct aa_ns *view, struct aa_profile *subj, 1055 char *fqname, size_t size) 1056 { 1057 struct aa_ns *root = NULL, *ns = NULL; 1058 struct aa_profile *profile = NULL; 1059 const char *name = fqname, *info = NULL; 1060 char *ns_name = NULL; 1061 ssize_t error = 0; 1062 1063 if (*fqname == 0) { 1064 info = "no profile specified"; 1065 error = -ENOENT; 1066 goto fail; 1067 } 1068 1069 root = view; 1070 1071 if (fqname[0] == ':') { 1072 name = aa_split_fqname(fqname, &ns_name); 1073 /* released below */ 1074 ns = aa_find_ns(root, ns_name); 1075 if (!ns) { 1076 info = "namespace does not exist"; 1077 error = -ENOENT; 1078 goto fail; 1079 } 1080 } else 1081 /* released below */ 1082 ns = aa_get_ns(root); 1083 1084 if (!name) { 1085 /* remove namespace - can only happen if fqname[0] == ':' */ 1086 mutex_lock(&ns->parent->lock); 1087 __aa_remove_ns(ns); 1088 mutex_unlock(&ns->parent->lock); 1089 } else { 1090 /* remove profile */ 1091 mutex_lock(&ns->lock); 1092 profile = aa_get_profile(__lookup_profile(&ns->base, name)); 1093 if (!profile) { 1094 error = -ENOENT; 1095 info = "profile does not exist"; 1096 goto fail_ns_lock; 1097 } 1098 name = profile->base.hname; 1099 __remove_profile(profile); 1100 mutex_unlock(&ns->lock); 1101 } 1102 1103 /* don't fail removal if audit fails */ 1104 (void) audit_policy(subj, OP_PROF_RM, ns_name, name, info, 1105 error); 1106 aa_put_ns(ns); 1107 aa_put_profile(profile); 1108 return size; 1109 1110 fail_ns_lock: 1111 mutex_unlock(&ns->lock); 1112 aa_put_ns(ns); 1113 1114 fail: 1115 (void) audit_policy(subj, OP_PROF_RM, ns_name, name, info, 1116 error); 1117 return error; 1118 } 1119