root/security/apparmor/policy.c

DEFINITIONS

1. __add_profile
2. __list_remove_profile
3. __remove_profile
4. __aa_profile_list_release
5. aa_free_data
6. aa_free_profile
7. aa_alloc_profile
8. __strn_find_child
9. __find_child
10. aa_find_child
11. __lookup_parent
12. __lookupn_profile
13. __lookup_profile
14. aa_lookupn_profile
15. aa_lookup_profile
16. aa_fqlookupn_profile
17. aa_new_null_profile
18. replacement_allowed
19. audit_cb
20. audit_policy
21. policy_view_capable
22. policy_admin_capable
23. aa_may_manage_policy
24. __list_lookup_parent
25. __replace_profile
26. __lookup_replace
27. share_name
28. update_to_newest_parent
29. aa_replace_profiles
30. aa_remove_profiles

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * AppArmor security module
   4  *
   5  * This file contains AppArmor policy manipulation functions
   6  *
   7  * Copyright (C) 1998-2008 Novell/SUSE
   8  * Copyright 2009-2010 Canonical Ltd.
   9  *
  10  * AppArmor policy is based around profiles, which contain the rules a
  11  * task is confined by.  Every task in the system has a profile attached
  12  * to it determined either by matching "unconfined" tasks against the
  13  * visible set of profiles or by following a profiles attachment rules.
  14  *
  15  * Each profile exists in a profile namespace which is a container of
  16  * visible profiles.  Each namespace contains a special "unconfined" profile,
  17  * which doesn't enforce any confinement on a task beyond DAC.
  18  *
  19  * Namespace and profile names can be written together in either
  20  * of two syntaxes.
  21  *      :namespace:profile - used by kernel interfaces for easy detection
  22  *      namespace://profile - used by policy
  23  *
  24  * Profile names can not start with : or @ or ^ and may not contain \0
  25  *
  26  * Reserved profile names
  27  *      unconfined - special automatically generated unconfined profile
  28  *      inherit - special name to indicate profile inheritance
  29  *      null-XXXX-YYYY - special automatically generated learning profiles
  30  *
  31  * Namespace names may not start with / or @ and may not contain \0 or :
  32  * Reserved namespace names
  33  *      user-XXXX - user defined profiles
  34  *
  35  * a // in a profile or namespace name indicates a hierarchical name with the
  36  * name before the // being the parent and the name after the child.
  37  *
  38  * Profile and namespace hierarchies serve two different but similar purposes.
  39  * The namespace contains the set of visible profiles that are considered
  40  * for attachment.  The hierarchy of namespaces allows for virtualizing
  41  * the namespace so that for example a chroot can have its own set of profiles
  42  * which may define some local user namespaces.
  43  * The profile hierarchy severs two distinct purposes,
  44  * -  it allows for sub profiles or hats, which allows an application to run
  45  *    subprograms under its own profile with different restriction than it
  46  *    self, and not have it use the system profile.
  47  *    eg. if a mail program starts an editor, the policy might make the
  48  *        restrictions tighter on the editor tighter than the mail program,
  49  *        and definitely different than general editor restrictions
  50  * - it allows for binary hierarchy of profiles, so that execution history
  51  *   is preserved.  This feature isn't exploited by AppArmor reference policy
  52  *   but is allowed.  NOTE: this is currently suboptimal because profile
  53  *   aliasing is not currently implemented so that a profile for each
  54  *   level must be defined.
  55  *   eg. /bin/bash///bin/ls as a name would indicate /bin/ls was started
  56  *       from /bin/bash
  57  *
  58  *   A profile or namespace name that can contain one or more // separators
  59  *   is referred to as an hname (hierarchical).
  60  *   eg.  /bin/bash//bin/ls
  61  *
  62  *   An fqname is a name that may contain both namespace and profile hnames.
  63  *   eg. :ns:/bin/bash//bin/ls
  64  *
  65  * NOTES:
  66  *   - locking of profile lists is currently fairly coarse.  All profile
  67  *     lists within a namespace use the namespace lock.
  68  * FIXME: move profile lists to using rcu_lists
  69  */
  70 
  71 #include <linux/slab.h>
  72 #include <linux/spinlock.h>
  73 #include <linux/string.h>
  74 #include <linux/cred.h>
  75 #include <linux/rculist.h>
  76 #include <linux/user_namespace.h>
  77 
  78 #include "include/apparmor.h"
  79 #include "include/capability.h"
  80 #include "include/cred.h"
  81 #include "include/file.h"
  82 #include "include/ipc.h"
  83 #include "include/match.h"
  84 #include "include/path.h"
  85 #include "include/policy.h"
  86 #include "include/policy_ns.h"
  87 #include "include/policy_unpack.h"
  88 #include "include/resource.h"
  89 
  90 int unprivileged_userns_apparmor_policy = 1;
  91 
  92 const char *const aa_profile_mode_names[] = {
  93         "enforce",
  94         "complain",
  95         "kill",
  96         "unconfined",
  97 };
  98 
  99 
 100 /**
 101  * __add_profile - add a profiles to list and label tree
 102  * @list: list to add it to  (NOT NULL)
 103  * @profile: the profile to add  (NOT NULL)
 104  *
 105  * refcount @profile, should be put by __list_remove_profile
 106  *
 107  * Requires: namespace lock be held, or list not be shared
 108  */
 109 static void __add_profile(struct list_head *list, struct aa_profile *profile)
 110 {
 111         struct aa_label *l;
 112 
 113         AA_BUG(!list);
 114         AA_BUG(!profile);
 115         AA_BUG(!profile->ns);
 116         AA_BUG(!mutex_is_locked(&profile->ns->lock));
 117 
 118         list_add_rcu(&profile->base.list, list);
 119         /* get list reference */
 120         aa_get_profile(profile);
 121         l = aa_label_insert(&profile->ns->labels, &profile->label);
 122         AA_BUG(l != &profile->label);
 123         aa_put_label(l);
 124 }
 125 
 126 /**
 127  * __list_remove_profile - remove a profile from the list it is on
 128  * @profile: the profile to remove  (NOT NULL)
 129  *
 130  * remove a profile from the list, warning generally removal should
 131  * be done with __replace_profile as most profile removals are
 132  * replacements to the unconfined profile.
 133  *
 134  * put @profile list refcount
 135  *
 136  * Requires: namespace lock be held, or list not have been live
 137  */
 138 static void __list_remove_profile(struct aa_profile *profile)
 139 {
 140         AA_BUG(!profile);
 141         AA_BUG(!profile->ns);
 142         AA_BUG(!mutex_is_locked(&profile->ns->lock));
 143 
 144         list_del_rcu(&profile->base.list);
 145         aa_put_profile(profile);
 146 }
 147 
 148 /**
 149  * __remove_profile - remove old profile, and children
 150  * @profile: profile to be replaced  (NOT NULL)
 151  *
 152  * Requires: namespace list lock be held, or list not be shared
 153  */
 154 static void __remove_profile(struct aa_profile *profile)
 155 {
 156         AA_BUG(!profile);
 157         AA_BUG(!profile->ns);
 158         AA_BUG(!mutex_is_locked(&profile->ns->lock));
 159 
 160         /* release any children lists first */
 161         __aa_profile_list_release(&profile->base.profiles);
 162         /* released by free_profile */
 163         aa_label_remove(&profile->label);
 164         __aafs_profile_rmdir(profile);
 165         __list_remove_profile(profile);
 166 }
 167 
 168 /**
 169  * __aa_profile_list_release - remove all profiles on the list and put refs
 170  * @head: list of profiles  (NOT NULL)
 171  *
 172  * Requires: namespace lock be held
 173  */
 174 void __aa_profile_list_release(struct list_head *head)
 175 {
 176         struct aa_profile *profile, *tmp;
 177         list_for_each_entry_safe(profile, tmp, head, base.list)
 178                 __remove_profile(profile);
 179 }
 180 
 181 /**
 182  * aa_free_data - free a data blob
 183  * @ptr: data to free
 184  * @arg: unused
 185  */
 186 static void aa_free_data(void *ptr, void *arg)
 187 {
 188         struct aa_data *data = ptr;
 189 
 190         kzfree(data->data);
 191         kzfree(data->key);
 192         kzfree(data);
 193 }
 194 
 195 /**
 196  * aa_free_profile - free a profile
 197  * @profile: the profile to free  (MAYBE NULL)
 198  *
 199  * Free a profile, its hats and null_profile. All references to the profile,
 200  * its hats and null_profile must have been put.
 201  *
 202  * If the profile was referenced from a task context, free_profile() will
 203  * be called from an rcu callback routine, so we must not sleep here.
 204  */
 205 void aa_free_profile(struct aa_profile *profile)
 206 {
 207         struct rhashtable *rht;
 208         int i;
 209 
 210         AA_DEBUG("%s(%p)\n", __func__, profile);
 211 
 212         if (!profile)
 213                 return;
 214 
 215         /* free children profiles */
 216         aa_policy_destroy(&profile->base);
 217         aa_put_profile(rcu_access_pointer(profile->parent));
 218 
 219         aa_put_ns(profile->ns);
 220         kzfree(profile->rename);
 221 
 222         aa_free_file_rules(&profile->file);
 223         aa_free_cap_rules(&profile->caps);
 224         aa_free_rlimit_rules(&profile->rlimits);
 225 
 226         for (i = 0; i < profile->xattr_count; i++)
 227                 kzfree(profile->xattrs[i]);
 228         kzfree(profile->xattrs);
 229         for (i = 0; i < profile->secmark_count; i++)
 230                 kzfree(profile->secmark[i].label);
 231         kzfree(profile->secmark);
 232         kzfree(profile->dirname);
 233         aa_put_dfa(profile->xmatch);
 234         aa_put_dfa(profile->policy.dfa);
 235 
 236         if (profile->data) {
 237                 rht = profile->data;
 238                 profile->data = NULL;
 239                 rhashtable_free_and_destroy(rht, aa_free_data, NULL);
 240                 kzfree(rht);
 241         }
 242 
 243         kzfree(profile->hash);
 244         aa_put_loaddata(profile->rawdata);
 245 
 246         kzfree(profile);
 247 }
 248 
 249 /**
 250  * aa_alloc_profile - allocate, initialize and return a new profile
 251  * @hname: name of the profile  (NOT NULL)
 252  * @gfp: allocation type
 253  *
 254  * Returns: refcount profile or NULL on failure
 255  */
 256 struct aa_profile *aa_alloc_profile(const char *hname, struct aa_proxy *proxy,
 257                                     gfp_t gfp)
 258 {
 259         struct aa_profile *profile;
 260 
 261         /* freed by free_profile - usually through aa_put_profile */
 262         profile = kzalloc(sizeof(*profile) + sizeof(struct aa_profile *) * 2,
 263                           gfp);
 264         if (!profile)
 265                 return NULL;
 266 
 267         if (!aa_policy_init(&profile->base, NULL, hname, gfp))
 268                 goto fail;
 269         if (!aa_label_init(&profile->label, 1, gfp))
 270                 goto fail;
 271 
 272         /* update being set needed by fs interface */
 273         if (!proxy) {
 274                 proxy = aa_alloc_proxy(&profile->label, gfp);
 275                 if (!proxy)
 276                         goto fail;
 277         } else
 278                 aa_get_proxy(proxy);
 279         profile->label.proxy = proxy;
 280 
 281         profile->label.hname = profile->base.hname;
 282         profile->label.flags |= FLAG_PROFILE;
 283         profile->label.vec[0] = profile;
 284 
 285         /* refcount released by caller */
 286         return profile;
 287 
 288 fail:
 289         aa_free_profile(profile);
 290 
 291         return NULL;
 292 }
 293 
 294 /* TODO: profile accounting - setup in remove */
 295 
 296 /**
 297  * __strn_find_child - find a profile on @head list using substring of @name
 298  * @head: list to search  (NOT NULL)
 299  * @name: name of profile (NOT NULL)
 300  * @len: length of @name substring to match
 301  *
 302  * Requires: rcu_read_lock be held
 303  *
 304  * Returns: unrefcounted profile ptr, or NULL if not found
 305  */
 306 static struct aa_profile *__strn_find_child(struct list_head *head,
 307                                             const char *name, int len)
 308 {
 309         return (struct aa_profile *)__policy_strn_find(head, name, len);
 310 }
 311 
 312 /**
 313  * __find_child - find a profile on @head list with a name matching @name
 314  * @head: list to search  (NOT NULL)
 315  * @name: name of profile (NOT NULL)
 316  *
 317  * Requires: rcu_read_lock be held
 318  *
 319  * Returns: unrefcounted profile ptr, or NULL if not found
 320  */
 321 static struct aa_profile *__find_child(struct list_head *head, const char *name)
 322 {
 323         return __strn_find_child(head, name, strlen(name));
 324 }
 325 
 326 /**
 327  * aa_find_child - find a profile by @name in @parent
 328  * @parent: profile to search  (NOT NULL)
 329  * @name: profile name to search for  (NOT NULL)
 330  *
 331  * Returns: a refcounted profile or NULL if not found
 332  */
 333 struct aa_profile *aa_find_child(struct aa_profile *parent, const char *name)
 334 {
 335         struct aa_profile *profile;
 336 
 337         rcu_read_lock();
 338         do {
 339                 profile = __find_child(&parent->base.profiles, name);
 340         } while (profile && !aa_get_profile_not0(profile));
 341         rcu_read_unlock();
 342 
 343         /* refcount released by caller */
 344         return profile;
 345 }
 346 
 347 /**
 348  * __lookup_parent - lookup the parent of a profile of name @hname
 349  * @ns: namespace to lookup profile in  (NOT NULL)
 350  * @hname: hierarchical profile name to find parent of  (NOT NULL)
 351  *
 352  * Lookups up the parent of a fully qualified profile name, the profile
 353  * that matches hname does not need to exist, in general this
 354  * is used to load a new profile.
 355  *
 356  * Requires: rcu_read_lock be held
 357  *
 358  * Returns: unrefcounted policy or NULL if not found
 359  */
 360 static struct aa_policy *__lookup_parent(struct aa_ns *ns,
 361                                          const char *hname)
 362 {
 363         struct aa_policy *policy;
 364         struct aa_profile *profile = NULL;
 365         char *split;
 366 
 367         policy = &ns->base;
 368 
 369         for (split = strstr(hname, "//"); split;) {
 370                 profile = __strn_find_child(&policy->profiles, hname,
 371                                             split - hname);
 372                 if (!profile)
 373                         return NULL;
 374                 policy = &profile->base;
 375                 hname = split + 2;
 376                 split = strstr(hname, "//");
 377         }
 378         if (!profile)
 379                 return &ns->base;
 380         return &profile->base;
 381 }
 382 
 383 /**
 384  * __lookupn_profile - lookup the profile matching @hname
 385  * @base: base list to start looking up profile name from  (NOT NULL)
 386  * @hname: hierarchical profile name  (NOT NULL)
 387  * @n: length of @hname
 388  *
 389  * Requires: rcu_read_lock be held
 390  *
 391  * Returns: unrefcounted profile pointer or NULL if not found
 392  *
 393  * Do a relative name lookup, recursing through profile tree.
 394  */
 395 static struct aa_profile *__lookupn_profile(struct aa_policy *base,
 396                                             const char *hname, size_t n)
 397 {
 398         struct aa_profile *profile = NULL;
 399         const char *split;
 400 
 401         for (split = strnstr(hname, "//", n); split;
 402              split = strnstr(hname, "//", n)) {
 403                 profile = __strn_find_child(&base->profiles, hname,
 404                                             split - hname);
 405                 if (!profile)
 406                         return NULL;
 407 
 408                 base = &profile->base;
 409                 n -= split + 2 - hname;
 410                 hname = split + 2;
 411         }
 412 
 413         if (n)
 414                 return __strn_find_child(&base->profiles, hname, n);
 415         return NULL;
 416 }
 417 
 418 static struct aa_profile *__lookup_profile(struct aa_policy *base,
 419                                            const char *hname)
 420 {
 421         return __lookupn_profile(base, hname, strlen(hname));
 422 }
 423 
 424 /**
 425  * aa_lookup_profile - find a profile by its full or partial name
 426  * @ns: the namespace to start from (NOT NULL)
 427  * @hname: name to do lookup on.  Does not contain namespace prefix (NOT NULL)
 428  * @n: size of @hname
 429  *
 430  * Returns: refcounted profile or NULL if not found
 431  */
 432 struct aa_profile *aa_lookupn_profile(struct aa_ns *ns, const char *hname,
 433                                       size_t n)
 434 {
 435         struct aa_profile *profile;
 436 
 437         rcu_read_lock();
 438         do {
 439                 profile = __lookupn_profile(&ns->base, hname, n);
 440         } while (profile && !aa_get_profile_not0(profile));
 441         rcu_read_unlock();
 442 
 443         /* the unconfined profile is not in the regular profile list */
 444         if (!profile && strncmp(hname, "unconfined", n) == 0)
 445                 profile = aa_get_newest_profile(ns->unconfined);
 446 
 447         /* refcount released by caller */
 448         return profile;
 449 }
 450 
 451 struct aa_profile *aa_lookup_profile(struct aa_ns *ns, const char *hname)
 452 {
 453         return aa_lookupn_profile(ns, hname, strlen(hname));
 454 }
 455 
 456 struct aa_profile *aa_fqlookupn_profile(struct aa_label *base,
 457                                         const char *fqname, size_t n)
 458 {
 459         struct aa_profile *profile;
 460         struct aa_ns *ns;
 461         const char *name, *ns_name;
 462         size_t ns_len;
 463 
 464         name = aa_splitn_fqname(fqname, n, &ns_name, &ns_len);
 465         if (ns_name) {
 466                 ns = aa_lookupn_ns(labels_ns(base), ns_name, ns_len);
 467                 if (!ns)
 468                         return NULL;
 469         } else
 470                 ns = aa_get_ns(labels_ns(base));
 471 
 472         if (name)
 473                 profile = aa_lookupn_profile(ns, name, n - (name - fqname));
 474         else if (ns)
 475                 /* default profile for ns, currently unconfined */
 476                 profile = aa_get_newest_profile(ns->unconfined);
 477         else
 478                 profile = NULL;
 479         aa_put_ns(ns);
 480 
 481         return profile;
 482 }
 483 
 484 /**
 485  * aa_new_null_profile - create or find a null-X learning profile
 486  * @parent: profile that caused this profile to be created (NOT NULL)
 487  * @hat: true if the null- learning profile is a hat
 488  * @base: name to base the null profile off of
 489  * @gfp: type of allocation
 490  *
 491  * Find/Create a null- complain mode profile used in learning mode.  The
 492  * name of the profile is unique and follows the format of parent//null-XXX.
 493  * where XXX is based on the @name or if that fails or is not supplied
 494  * a unique number
 495  *
 496  * null profiles are added to the profile list but the list does not
 497  * hold a count on them so that they are automatically released when
 498  * not in use.
 499  *
 500  * Returns: new refcounted profile else NULL on failure
 501  */
 502 struct aa_profile *aa_new_null_profile(struct aa_profile *parent, bool hat,
 503                                        const char *base, gfp_t gfp)
 504 {
 505         struct aa_profile *p, *profile;
 506         const char *bname;
 507         char *name = NULL;
 508 
 509         AA_BUG(!parent);
 510 
 511         if (base) {
 512                 name = kmalloc(strlen(parent->base.hname) + 8 + strlen(base),
 513                                gfp);
 514                 if (name) {
 515                         sprintf(name, "%s//null-%s", parent->base.hname, base);
 516                         goto name;
 517                 }
 518                 /* fall through to try shorter uniq */
 519         }
 520 
 521         name = kmalloc(strlen(parent->base.hname) + 2 + 7 + 8, gfp);
 522         if (!name)
 523                 return NULL;
 524         sprintf(name, "%s//null-%x", parent->base.hname,
 525                 atomic_inc_return(&parent->ns->uniq_null));
 526 
 527 name:
 528         /* lookup to see if this is a dup creation */
 529         bname = basename(name);
 530         profile = aa_find_child(parent, bname);
 531         if (profile)
 532                 goto out;
 533 
 534         profile = aa_alloc_profile(name, NULL, gfp);
 535         if (!profile)
 536                 goto fail;
 537 
 538         profile->mode = APPARMOR_COMPLAIN;
 539         profile->label.flags |= FLAG_NULL;
 540         if (hat)
 541                 profile->label.flags |= FLAG_HAT;
 542         profile->path_flags = parent->path_flags;
 543 
 544         /* released on free_profile */
 545         rcu_assign_pointer(profile->parent, aa_get_profile(parent));
 546         profile->ns = aa_get_ns(parent->ns);
 547         profile->file.dfa = aa_get_dfa(nulldfa);
 548         profile->policy.dfa = aa_get_dfa(nulldfa);
 549 
 550         mutex_lock_nested(&profile->ns->lock, profile->ns->level);
 551         p = __find_child(&parent->base.profiles, bname);
 552         if (p) {
 553                 aa_free_profile(profile);
 554                 profile = aa_get_profile(p);
 555         } else {
 556                 __add_profile(&parent->base.profiles, profile);
 557         }
 558         mutex_unlock(&profile->ns->lock);
 559 
 560         /* refcount released by caller */
 561 out:
 562         kfree(name);
 563 
 564         return profile;
 565 
 566 fail:
 567         kfree(name);
 568         aa_free_profile(profile);
 569         return NULL;
 570 }
 571 
 572 /**
 573  * replacement_allowed - test to see if replacement is allowed
 574  * @profile: profile to test if it can be replaced  (MAYBE NULL)
 575  * @noreplace: true if replacement shouldn't be allowed but addition is okay
 576  * @info: Returns - info about why replacement failed (NOT NULL)
 577  *
 578  * Returns: %0 if replacement allowed else error code
 579  */
 580 static int replacement_allowed(struct aa_profile *profile, int noreplace,
 581                                const char **info)
 582 {
 583         if (profile) {
 584                 if (profile->label.flags & FLAG_IMMUTIBLE) {
 585                         *info = "cannot replace immutible profile";
 586                         return -EPERM;
 587                 } else if (noreplace) {
 588                         *info = "profile already exists";
 589                         return -EEXIST;
 590                 }
 591         }
 592         return 0;
 593 }
 594 
 595 /* audit callback for net specific fields */
 596 static void audit_cb(struct audit_buffer *ab, void *va)
 597 {
 598         struct common_audit_data *sa = va;
 599 
 600         if (aad(sa)->iface.ns) {
 601                 audit_log_format(ab, " ns=");
 602                 audit_log_untrustedstring(ab, aad(sa)->iface.ns);
 603         }
 604 }
 605 
 606 /**
 607  * audit_policy - Do auditing of policy changes
 608  * @label: label to check if it can manage policy
 609  * @op: policy operation being performed
 610  * @ns_name: name of namespace being manipulated
 611  * @name: name of profile being manipulated (NOT NULL)
 612  * @info: any extra information to be audited (MAYBE NULL)
 613  * @error: error code
 614  *
 615  * Returns: the error to be returned after audit is done
 616  */
 617 static int audit_policy(struct aa_label *label, const char *op,
 618                         const char *ns_name, const char *name,
 619                         const char *info, int error)
 620 {
 621         DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, op);
 622 
 623         aad(&sa)->iface.ns = ns_name;
 624         aad(&sa)->name = name;
 625         aad(&sa)->info = info;
 626         aad(&sa)->error = error;
 627         aad(&sa)->label = label;
 628 
 629         aa_audit_msg(AUDIT_APPARMOR_STATUS, &sa, audit_cb);
 630 
 631         return error;
 632 }
 633 
 634 /**
 635  * policy_view_capable - check if viewing policy in at @ns is allowed
 636  * ns: namespace being viewed by current task (may be NULL)
 637  * Returns: true if viewing policy is allowed
 638  *
 639  * If @ns is NULL then the namespace being viewed is assumed to be the
 640  * tasks current namespace.
 641  */
 642 bool policy_view_capable(struct aa_ns *ns)
 643 {
 644         struct user_namespace *user_ns = current_user_ns();
 645         struct aa_ns *view_ns = aa_get_current_ns();
 646         bool root_in_user_ns = uid_eq(current_euid(), make_kuid(user_ns, 0)) ||
 647                                in_egroup_p(make_kgid(user_ns, 0));
 648         bool response = false;
 649         if (!ns)
 650                 ns = view_ns;
 651 
 652         if (root_in_user_ns && aa_ns_visible(view_ns, ns, true) &&
 653             (user_ns == &init_user_ns ||
 654              (unprivileged_userns_apparmor_policy != 0 &&
 655               user_ns->level == view_ns->level)))
 656                 response = true;
 657         aa_put_ns(view_ns);
 658 
 659         return response;
 660 }
 661 
 662 bool policy_admin_capable(struct aa_ns *ns)
 663 {
 664         struct user_namespace *user_ns = current_user_ns();
 665         bool capable = ns_capable(user_ns, CAP_MAC_ADMIN);
 666 
 667         AA_DEBUG("cap_mac_admin? %d\n", capable);
 668         AA_DEBUG("policy locked? %d\n", aa_g_lock_policy);
 669 
 670         return policy_view_capable(ns) && capable && !aa_g_lock_policy;
 671 }
 672 
 673 /**
 674  * aa_may_manage_policy - can the current task manage policy
 675  * @label: label to check if it can manage policy
 676  * @op: the policy manipulation operation being done
 677  *
 678  * Returns: 0 if the task is allowed to manipulate policy else error
 679  */
 680 int aa_may_manage_policy(struct aa_label *label, struct aa_ns *ns, u32 mask)
 681 {
 682         const char *op;
 683 
 684         if (mask & AA_MAY_REMOVE_POLICY)
 685                 op = OP_PROF_RM;
 686         else if (mask & AA_MAY_REPLACE_POLICY)
 687                 op = OP_PROF_REPL;
 688         else
 689                 op = OP_PROF_LOAD;
 690 
 691         /* check if loading policy is locked out */
 692         if (aa_g_lock_policy)
 693                 return audit_policy(label, op, NULL, NULL, "policy_locked",
 694                                     -EACCES);
 695 
 696         if (!policy_admin_capable(ns))
 697                 return audit_policy(label, op, NULL, NULL, "not policy admin",
 698                                     -EACCES);
 699 
 700         /* TODO: add fine grained mediation of policy loads */
 701         return 0;
 702 }
 703 
 704 static struct aa_profile *__list_lookup_parent(struct list_head *lh,
 705                                                struct aa_profile *profile)
 706 {
 707         const char *base = basename(profile->base.hname);
 708         long len = base - profile->base.hname;
 709         struct aa_load_ent *ent;
 710 
 711         /* parent won't have trailing // so remove from len */
 712         if (len <= 2)
 713                 return NULL;
 714         len -= 2;
 715 
 716         list_for_each_entry(ent, lh, list) {
 717                 if (ent->new == profile)
 718                         continue;
 719                 if (strncmp(ent->new->base.hname, profile->base.hname, len) ==
 720                     0 && ent->new->base.hname[len] == 0)
 721                         return ent->new;
 722         }
 723 
 724         return NULL;
 725 }
 726 
 727 /**
 728  * __replace_profile - replace @old with @new on a list
 729  * @old: profile to be replaced  (NOT NULL)
 730  * @new: profile to replace @old with  (NOT NULL)
 731  * @share_proxy: transfer @old->proxy to @new
 732  *
 733  * Will duplicate and refcount elements that @new inherits from @old
 734  * and will inherit @old children.
 735  *
 736  * refcount @new for list, put @old list refcount
 737  *
 738  * Requires: namespace list lock be held, or list not be shared
 739  */
 740 static void __replace_profile(struct aa_profile *old, struct aa_profile *new)
 741 {
 742         struct aa_profile *child, *tmp;
 743 
 744         if (!list_empty(&old->base.profiles)) {
 745                 LIST_HEAD(lh);
 746                 list_splice_init_rcu(&old->base.profiles, &lh, synchronize_rcu);
 747 
 748                 list_for_each_entry_safe(child, tmp, &lh, base.list) {
 749                         struct aa_profile *p;
 750 
 751                         list_del_init(&child->base.list);
 752                         p = __find_child(&new->base.profiles, child->base.name);
 753                         if (p) {
 754                                 /* @p replaces @child  */
 755                                 __replace_profile(child, p);
 756                                 continue;
 757                         }
 758 
 759                         /* inherit @child and its children */
 760                         /* TODO: update hname of inherited children */
 761                         /* list refcount transferred to @new */
 762                         p = aa_deref_parent(child);
 763                         rcu_assign_pointer(child->parent, aa_get_profile(new));
 764                         list_add_rcu(&child->base.list, &new->base.profiles);
 765                         aa_put_profile(p);
 766                 }
 767         }
 768 
 769         if (!rcu_access_pointer(new->parent)) {
 770                 struct aa_profile *parent = aa_deref_parent(old);
 771                 rcu_assign_pointer(new->parent, aa_get_profile(parent));
 772         }
 773         aa_label_replace(&old->label, &new->label);
 774         /* migrate dents must come after label replacement b/c update */
 775         __aafs_profile_migrate_dents(old, new);
 776 
 777         if (list_empty(&new->base.list)) {
 778                 /* new is not on a list already */
 779                 list_replace_rcu(&old->base.list, &new->base.list);
 780                 aa_get_profile(new);
 781                 aa_put_profile(old);
 782         } else
 783                 __list_remove_profile(old);
 784 }
 785 
 786 /**
 787  * __lookup_replace - lookup replacement information for a profile
 788  * @ns - namespace the lookup occurs in
 789  * @hname - name of profile to lookup
 790  * @noreplace - true if not replacing an existing profile
 791  * @p - Returns: profile to be replaced
 792  * @info - Returns: info string on why lookup failed
 793  *
 794  * Returns: profile to replace (no ref) on success else ptr error
 795  */
 796 static int __lookup_replace(struct aa_ns *ns, const char *hname,
 797                             bool noreplace, struct aa_profile **p,
 798                             const char **info)
 799 {
 800         *p = aa_get_profile(__lookup_profile(&ns->base, hname));
 801         if (*p) {
 802                 int error = replacement_allowed(*p, noreplace, info);
 803                 if (error) {
 804                         *info = "profile can not be replaced";
 805                         return error;
 806                 }
 807         }
 808 
 809         return 0;
 810 }
 811 
 812 static void share_name(struct aa_profile *old, struct aa_profile *new)
 813 {
 814         aa_put_str(new->base.hname);
 815         aa_get_str(old->base.hname);
 816         new->base.hname = old->base.hname;
 817         new->base.name = old->base.name;
 818         new->label.hname = old->label.hname;
 819 }
 820 
 821 /* Update to newest version of parent after previous replacements
 822  * Returns: unrefcount newest version of parent
 823  */
 824 static struct aa_profile *update_to_newest_parent(struct aa_profile *new)
 825 {
 826         struct aa_profile *parent, *newest;
 827 
 828         parent = rcu_dereference_protected(new->parent,
 829                                            mutex_is_locked(&new->ns->lock));
 830         newest = aa_get_newest_profile(parent);
 831 
 832         /* parent replaced in this atomic set? */
 833         if (newest != parent) {
 834                 aa_put_profile(parent);
 835                 rcu_assign_pointer(new->parent, newest);
 836         } else
 837                 aa_put_profile(newest);
 838 
 839         return newest;
 840 }
 841 
 842 /**
 843  * aa_replace_profiles - replace profile(s) on the profile list
 844  * @policy_ns: namespace load is occurring on
 845  * @label: label that is attempting to load/replace policy
 846  * @mask: permission mask
 847  * @udata: serialized data stream  (NOT NULL)
 848  *
 849  * unpack and replace a profile on the profile list and uses of that profile
 850  * by any task creds via invalidating the old version of the profile, which
 851  * tasks will notice to update their own cred.  If the profile does not exist
 852  * on the profile list it is added.
 853  *
 854  * Returns: size of data consumed else error code on failure.
 855  */
 856 ssize_t aa_replace_profiles(struct aa_ns *policy_ns, struct aa_label *label,
 857                             u32 mask, struct aa_loaddata *udata)
 858 {
 859         const char *ns_name, *info = NULL;
 860         struct aa_ns *ns = NULL;
 861         struct aa_load_ent *ent, *tmp;
 862         struct aa_loaddata *rawdata_ent;
 863         const char *op;
 864         ssize_t count, error;
 865         LIST_HEAD(lh);
 866 
 867         op = mask & AA_MAY_REPLACE_POLICY ? OP_PROF_REPL : OP_PROF_LOAD;
 868         aa_get_loaddata(udata);
 869         /* released below */
 870         error = aa_unpack(udata, &lh, &ns_name);
 871         if (error)
 872                 goto out;
 873 
 874         /* ensure that profiles are all for the same ns
 875          * TODO: update locking to remove this constaint. All profiles in
 876          *       the load set must succeed as a set or the load will
 877          *       fail. Sort ent list and take ns locks in hierarchy order
 878          */
 879         count = 0;
 880         list_for_each_entry(ent, &lh, list) {
 881                 if (ns_name) {
 882                         if (ent->ns_name &&
 883                             strcmp(ent->ns_name, ns_name) != 0) {
 884                                 info = "policy load has mixed namespaces";
 885                                 error = -EACCES;
 886                                 goto fail;
 887                         }
 888                 } else if (ent->ns_name) {
 889                         if (count) {
 890                                 info = "policy load has mixed namespaces";
 891                                 error = -EACCES;
 892                                 goto fail;
 893                         }
 894                         ns_name = ent->ns_name;
 895                 } else
 896                         count++;
 897         }
 898         if (ns_name) {
 899                 ns = aa_prepare_ns(policy_ns ? policy_ns : labels_ns(label),
 900                                    ns_name);
 901                 if (IS_ERR(ns)) {
 902                         op = OP_PROF_LOAD;
 903                         info = "failed to prepare namespace";
 904                         error = PTR_ERR(ns);
 905                         ns = NULL;
 906                         ent = NULL;
 907                         goto fail;
 908                 }
 909         } else
 910                 ns = aa_get_ns(policy_ns ? policy_ns : labels_ns(label));
 911 
 912         mutex_lock_nested(&ns->lock, ns->level);
 913         /* check for duplicate rawdata blobs: space and file dedup */
 914         list_for_each_entry(rawdata_ent, &ns->rawdata_list, list) {
 915                 if (aa_rawdata_eq(rawdata_ent, udata)) {
 916                         struct aa_loaddata *tmp;
 917 
 918                         tmp = __aa_get_loaddata(rawdata_ent);
 919                         /* check we didn't fail the race */
 920                         if (tmp) {
 921                                 aa_put_loaddata(udata);
 922                                 udata = tmp;
 923                                 break;
 924                         }
 925                 }
 926         }
 927         /* setup parent and ns info */
 928         list_for_each_entry(ent, &lh, list) {
 929                 struct aa_policy *policy;
 930 
 931                 ent->new->rawdata = aa_get_loaddata(udata);
 932                 error = __lookup_replace(ns, ent->new->base.hname,
 933                                          !(mask & AA_MAY_REPLACE_POLICY),
 934                                          &ent->old, &info);
 935                 if (error)
 936                         goto fail_lock;
 937 
 938                 if (ent->new->rename) {
 939                         error = __lookup_replace(ns, ent->new->rename,
 940                                                 !(mask & AA_MAY_REPLACE_POLICY),
 941                                                 &ent->rename, &info);
 942                         if (error)
 943                                 goto fail_lock;
 944                 }
 945 
 946                 /* released when @new is freed */
 947                 ent->new->ns = aa_get_ns(ns);
 948 
 949                 if (ent->old || ent->rename)
 950                         continue;
 951 
 952                 /* no ref on policy only use inside lock */
 953                 policy = __lookup_parent(ns, ent->new->base.hname);
 954                 if (!policy) {
 955                         struct aa_profile *p;
 956                         p = __list_lookup_parent(&lh, ent->new);
 957                         if (!p) {
 958                                 error = -ENOENT;
 959                                 info = "parent does not exist";
 960                                 goto fail_lock;
 961                         }
 962                         rcu_assign_pointer(ent->new->parent, aa_get_profile(p));
 963                 } else if (policy != &ns->base) {
 964                         /* released on profile replacement or free_profile */
 965                         struct aa_profile *p = (struct aa_profile *) policy;
 966                         rcu_assign_pointer(ent->new->parent, aa_get_profile(p));
 967                 }
 968         }
 969 
 970         /* create new fs entries for introspection if needed */
 971         if (!udata->dents[AAFS_LOADDATA_DIR]) {
 972                 error = __aa_fs_create_rawdata(ns, udata);
 973                 if (error) {
 974                         info = "failed to create raw_data dir and files";
 975                         ent = NULL;
 976                         goto fail_lock;
 977                 }
 978         }
 979         list_for_each_entry(ent, &lh, list) {
 980                 if (!ent->old) {
 981                         struct dentry *parent;
 982                         if (rcu_access_pointer(ent->new->parent)) {
 983                                 struct aa_profile *p;
 984                                 p = aa_deref_parent(ent->new);
 985                                 parent = prof_child_dir(p);
 986                         } else
 987                                 parent = ns_subprofs_dir(ent->new->ns);
 988                         error = __aafs_profile_mkdir(ent->new, parent);
 989                 }
 990 
 991                 if (error) {
 992                         info = "failed to create";
 993                         goto fail_lock;
 994                 }
 995         }
 996 
 997         /* Done with checks that may fail - do actual replacement */
 998         __aa_bump_ns_revision(ns);
 999         __aa_loaddata_update(udata, ns->revision);
1000         list_for_each_entry_safe(ent, tmp, &lh, list) {
1001                 list_del_init(&ent->list);
1002                 op = (!ent->old && !ent->rename) ? OP_PROF_LOAD : OP_PROF_REPL;
1003 
1004                 if (ent->old && ent->old->rawdata == ent->new->rawdata) {
1005                         /* dedup actual profile replacement */
1006                         audit_policy(label, op, ns_name, ent->new->base.hname,
1007                                      "same as current profile, skipping",
1008                                      error);
1009                         /* break refcount cycle with proxy. */
1010                         aa_put_proxy(ent->new->label.proxy);
1011                         ent->new->label.proxy = NULL;
1012                         goto skip;
1013                 }
1014 
1015                 /*
1016                  * TODO: finer dedup based on profile range in data. Load set
1017                  * can differ but profile may remain unchanged
1018                  */
1019                 audit_policy(label, op, ns_name, ent->new->base.hname, NULL,
1020                              error);
1021 
1022                 if (ent->old) {
1023                         share_name(ent->old, ent->new);
1024                         __replace_profile(ent->old, ent->new);
1025                 } else {
1026                         struct list_head *lh;
1027 
1028                         if (rcu_access_pointer(ent->new->parent)) {
1029                                 struct aa_profile *parent;
1030 
1031                                 parent = update_to_newest_parent(ent->new);
1032                                 lh = &parent->base.profiles;
1033                         } else
1034                                 lh = &ns->base.profiles;
1035                         __add_profile(lh, ent->new);
1036                 }
1037         skip:
1038                 aa_load_ent_free(ent);
1039         }
1040         __aa_labelset_update_subtree(ns);
1041         mutex_unlock(&ns->lock);
1042 
1043 out:
1044         aa_put_ns(ns);
1045         aa_put_loaddata(udata);
1046 
1047         if (error)
1048                 return error;
1049         return udata->size;
1050 
1051 fail_lock:
1052         mutex_unlock(&ns->lock);
1053 
1054         /* audit cause of failure */
1055         op = (ent && !ent->old) ? OP_PROF_LOAD : OP_PROF_REPL;
1056 fail:
1057           audit_policy(label, op, ns_name, ent ? ent->new->base.hname : NULL,
1058                        info, error);
1059         /* audit status that rest of profiles in the atomic set failed too */
1060         info = "valid profile in failed atomic policy load";
1061         list_for_each_entry(tmp, &lh, list) {
1062                 if (tmp == ent) {
1063                         info = "unchecked profile in failed atomic policy load";
1064                         /* skip entry that caused failure */
1065                         continue;
1066                 }
1067                 op = (!tmp->old) ? OP_PROF_LOAD : OP_PROF_REPL;
1068                 audit_policy(label, op, ns_name, tmp->new->base.hname, info,
1069                              error);
1070         }
1071         list_for_each_entry_safe(ent, tmp, &lh, list) {
1072                 list_del_init(&ent->list);
1073                 aa_load_ent_free(ent);
1074         }
1075 
1076         goto out;
1077 }
1078 
1079 /**
1080  * aa_remove_profiles - remove profile(s) from the system
1081  * @policy_ns: namespace the remove is being done from
1082  * @subj: label attempting to remove policy
1083  * @fqname: name of the profile or namespace to remove  (NOT NULL)
1084  * @size: size of the name
1085  *
1086  * Remove a profile or sub namespace from the current namespace, so that
1087  * they can not be found anymore and mark them as replaced by unconfined
1088  *
1089  * NOTE: removing confinement does not restore rlimits to preconfinement values
1090  *
1091  * Returns: size of data consume else error code if fails
1092  */
1093 ssize_t aa_remove_profiles(struct aa_ns *policy_ns, struct aa_label *subj,
1094                            char *fqname, size_t size)
1095 {
1096         struct aa_ns *ns = NULL;
1097         struct aa_profile *profile = NULL;
1098         const char *name = fqname, *info = NULL;
1099         const char *ns_name = NULL;
1100         ssize_t error = 0;
1101 
1102         if (*fqname == 0) {
1103                 info = "no profile specified";
1104                 error = -ENOENT;
1105                 goto fail;
1106         }
1107 
1108         if (fqname[0] == ':') {
1109                 size_t ns_len;
1110 
1111                 name = aa_splitn_fqname(fqname, size, &ns_name, &ns_len);
1112                 /* released below */
1113                 ns = aa_lookupn_ns(policy_ns ? policy_ns : labels_ns(subj),
1114                                    ns_name, ns_len);
1115                 if (!ns) {
1116                         info = "namespace does not exist";
1117                         error = -ENOENT;
1118                         goto fail;
1119                 }
1120         } else
1121                 /* released below */
1122                 ns = aa_get_ns(policy_ns ? policy_ns : labels_ns(subj));
1123 
1124         if (!name) {
1125                 /* remove namespace - can only happen if fqname[0] == ':' */
1126                 mutex_lock_nested(&ns->parent->lock, ns->level);
1127                 __aa_bump_ns_revision(ns);
1128                 __aa_remove_ns(ns);
1129                 mutex_unlock(&ns->parent->lock);
1130         } else {
1131                 /* remove profile */
1132                 mutex_lock_nested(&ns->lock, ns->level);
1133                 profile = aa_get_profile(__lookup_profile(&ns->base, name));
1134                 if (!profile) {
1135                         error = -ENOENT;
1136                         info = "profile does not exist";
1137                         goto fail_ns_lock;
1138                 }
1139                 name = profile->base.hname;
1140                 __aa_bump_ns_revision(ns);
1141                 __remove_profile(profile);
1142                 __aa_labelset_update_subtree(ns);
1143                 mutex_unlock(&ns->lock);
1144         }
1145 
1146         /* don't fail removal if audit fails */
1147         (void) audit_policy(subj, OP_PROF_RM, ns_name, name, info,
1148                             error);
1149         aa_put_ns(ns);
1150         aa_put_profile(profile);
1151         return size;
1152 
1153 fail_ns_lock:
1154         mutex_unlock(&ns->lock);
1155         aa_put_ns(ns);
1156 
1157 fail:
1158         (void) audit_policy(subj, OP_PROF_RM, ns_name, name, info,
1159                             error);
1160         return error;
1161 }