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
  80#include "include/apparmor.h"
  81#include "include/capability.h"
  82#include "include/context.h"
  83#include "include/file.h"
  84#include "include/ipc.h"
  85#include "include/match.h"
  86#include "include/path.h"
  87#include "include/policy.h"
  88#include "include/policy_unpack.h"
  89#include "include/resource.h"
  90
  91
  92/* root profile namespace */
  93struct aa_namespace *root_ns;
  94
  95const char *const aa_profile_mode_names[] = {
  96	"enforce",
  97	"complain",
  98	"kill",
  99	"unconfined",
 100};
 101
 102/**
 103 * hname_tail - find the last component of an hname
 104 * @name: hname to find the base profile name component of  (NOT NULL)
 105 *
 106 * Returns: the tail (base profile name) name component of an hname
 107 */
 108static const char *hname_tail(const char *hname)
 109{
 110	char *split;
 111	hname = strim((char *)hname);
 112	for (split = strstr(hname, "//"); split; split = strstr(hname, "//"))
 113		hname = split + 2;
 114
 115	return hname;
 116}
 117
 118/**
 119 * policy_init - initialize a policy structure
 120 * @policy: policy to initialize  (NOT NULL)
 121 * @prefix: prefix name if any is required.  (MAYBE NULL)
 122 * @name: name of the policy, init will make a copy of it  (NOT NULL)
 123 *
 124 * Note: this fn creates a copy of strings passed in
 125 *
 126 * Returns: true if policy init successful
 127 */
 128static bool policy_init(struct aa_policy *policy, const char *prefix,
 129			const char *name)
 130{
 131	/* freed by policy_free */
 132	if (prefix) {
 133		policy->hname = kmalloc(strlen(prefix) + strlen(name) + 3,
 134					GFP_KERNEL);
 135		if (policy->hname)
 136			sprintf(policy->hname, "%s//%s", prefix, name);
 137	} else
 138		policy->hname = kstrdup(name, GFP_KERNEL);
 139	if (!policy->hname)
 140		return 0;
 141	/* base.name is a substring of fqname */
 142	policy->name = (char *)hname_tail(policy->hname);
 143	INIT_LIST_HEAD(&policy->list);
 144	INIT_LIST_HEAD(&policy->profiles);
 145
 146	return 1;
 147}
 148
 149/**
 150 * policy_destroy - free the elements referenced by @policy
 151 * @policy: policy that is to have its elements freed  (NOT NULL)
 152 */
 153static void policy_destroy(struct aa_policy *policy)
 154{
 155	/* still contains profiles -- invalid */
 156	if (on_list_rcu(&policy->profiles)) {
 157		AA_ERROR("%s: internal error, "
 158			 "policy '%s' still contains profiles\n",
 159			 __func__, policy->name);
 160		BUG();
 161	}
 162	if (on_list_rcu(&policy->list)) {
 163		AA_ERROR("%s: internal error, policy '%s' still on list\n",
 164			 __func__, policy->name);
 165		BUG();
 166	}
 167
 168	/* don't free name as its a subset of hname */
 169	kzfree(policy->hname);
 170}
 171
 172/**
 173 * __policy_find - find a policy by @name on a policy list
 174 * @head: list to search  (NOT NULL)
 175 * @name: name to search for  (NOT NULL)
 176 *
 177 * Requires: rcu_read_lock be held
 178 *
 179 * Returns: unrefcounted policy that match @name or NULL if not found
 180 */
 181static struct aa_policy *__policy_find(struct list_head *head, const char *name)
 182{
 183	struct aa_policy *policy;
 184
 185	list_for_each_entry_rcu(policy, head, list) {
 186		if (!strcmp(policy->name, name))
 187			return policy;
 188	}
 189	return NULL;
 190}
 191
 192/**
 193 * __policy_strn_find - find a policy that's name matches @len chars of @str
 194 * @head: list to search  (NOT NULL)
 195 * @str: string to search for  (NOT NULL)
 196 * @len: length of match required
 197 *
 198 * Requires: rcu_read_lock be held
 199 *
 200 * Returns: unrefcounted policy that match @str or NULL if not found
 201 *
 202 * if @len == strlen(@strlen) then this is equiv to __policy_find
 203 * other wise it allows searching for policy by a partial match of name
 204 */
 205static struct aa_policy *__policy_strn_find(struct list_head *head,
 206					    const char *str, int len)
 207{
 208	struct aa_policy *policy;
 209
 210	list_for_each_entry_rcu(policy, head, list) {
 211		if (aa_strneq(policy->name, str, len))
 212			return policy;
 213	}
 214
 215	return NULL;
 216}
 217
 218/*
 219 * Routines for AppArmor namespaces
 220 */
 221
 222static const char *hidden_ns_name = "---";
 223/**
 224 * aa_ns_visible - test if @view is visible from @curr
 225 * @curr: namespace to treat as the parent (NOT NULL)
 226 * @view:  namespace to test if visible from @curr (NOT NULL)
 227 *
 228 * Returns: true if @view is visible from @curr else false
 229 */
 230bool aa_ns_visible(struct aa_namespace *curr, struct aa_namespace *view)
 231{
 232	if (curr == view)
 233		return true;
 234
 235	for ( ; view; view = view->parent) {
 236		if (view->parent == curr)
 237			return true;
 238	}
 239	return false;
 240}
 241
 242/**
 243 * aa_na_name - Find the ns name to display for @view from @curr
 244 * @curr - current namespace (NOT NULL)
 245 * @view - namespace attempting to view (NOT NULL)
 246 *
 247 * Returns: name of @view visible from @curr
 248 */
 249const char *aa_ns_name(struct aa_namespace *curr, struct aa_namespace *view)
 250{
 251	/* if view == curr then the namespace name isn't displayed */
 252	if (curr == view)
 253		return "";
 254
 255	if (aa_ns_visible(curr, view)) {
 256		/* at this point if a ns is visible it is in a view ns
 257		 * thus the curr ns.hname is a prefix of its name.
 258		 * Only output the virtualized portion of the name
 259		 * Add + 2 to skip over // separating curr hname prefix
 260		 * from the visible tail of the views hname
 261		 */
 262		return view->base.hname + strlen(curr->base.hname) + 2;
 263	} else
 264		return hidden_ns_name;
 265}
 266
 267/**
 268 * alloc_namespace - allocate, initialize and return a new namespace
 269 * @prefix: parent namespace name (MAYBE NULL)
 270 * @name: a preallocated name  (NOT NULL)
 271 *
 272 * Returns: refcounted namespace or NULL on failure.
 273 */
 274static struct aa_namespace *alloc_namespace(const char *prefix,
 275					    const char *name)
 276{
 277	struct aa_namespace *ns;
 278
 279	ns = kzalloc(sizeof(*ns), GFP_KERNEL);
 280	AA_DEBUG("%s(%p)\n", __func__, ns);
 281	if (!ns)
 282		return NULL;
 283	if (!policy_init(&ns->base, prefix, name))
 284		goto fail_ns;
 285
 286	INIT_LIST_HEAD(&ns->sub_ns);
 287	mutex_init(&ns->lock);
 288
 289	/* released by free_namespace */
 290	ns->unconfined = aa_alloc_profile("unconfined");
 291	if (!ns->unconfined)
 292		goto fail_unconfined;
 293
 294	ns->unconfined->flags = PFLAG_IX_ON_NAME_ERROR |
 295		PFLAG_IMMUTABLE | PFLAG_NS_COUNT;
 296	ns->unconfined->mode = APPARMOR_UNCONFINED;
 297
 298	/* ns and ns->unconfined share ns->unconfined refcount */
 299	ns->unconfined->ns = ns;
 300
 301	atomic_set(&ns->uniq_null, 0);
 302
 303	return ns;
 304
 305fail_unconfined:
 306	kzfree(ns->base.hname);
 307fail_ns:
 308	kzfree(ns);
 309	return NULL;
 310}
 311
 312/**
 313 * free_namespace - free a profile namespace
 314 * @ns: the namespace to free  (MAYBE NULL)
 315 *
 316 * Requires: All references to the namespace must have been put, if the
 317 *           namespace was referenced by a profile confining a task,
 318 */
 319static void free_namespace(struct aa_namespace *ns)
 320{
 321	if (!ns)
 322		return;
 323
 324	policy_destroy(&ns->base);
 325	aa_put_namespace(ns->parent);
 326
 327	ns->unconfined->ns = NULL;
 328	aa_free_profile(ns->unconfined);
 329	kzfree(ns);
 330}
 331
 332/**
 333 * __aa_find_namespace - find a namespace on a list by @name
 334 * @head: list to search for namespace on  (NOT NULL)
 335 * @name: name of namespace to look for  (NOT NULL)
 336 *
 337 * Returns: unrefcounted namespace
 338 *
 339 * Requires: rcu_read_lock be held
 340 */
 341static struct aa_namespace *__aa_find_namespace(struct list_head *head,
 342						const char *name)
 343{
 344	return (struct aa_namespace *)__policy_find(head, name);
 345}
 346
 347/**
 348 * aa_find_namespace  -  look up a profile namespace on the namespace list
 349 * @root: namespace to search in  (NOT NULL)
 350 * @name: name of namespace to find  (NOT NULL)
 351 *
 352 * Returns: a refcounted namespace on the list, or NULL if no namespace
 353 *          called @name exists.
 354 *
 355 * refcount released by caller
 356 */
 357struct aa_namespace *aa_find_namespace(struct aa_namespace *root,
 358				       const char *name)
 359{
 360	struct aa_namespace *ns = NULL;
 361
 362	rcu_read_lock();
 363	ns = aa_get_namespace(__aa_find_namespace(&root->sub_ns, name));
 364	rcu_read_unlock();
 365
 366	return ns;
 367}
 368
 369/**
 370 * aa_prepare_namespace - find an existing or create a new namespace of @name
 371 * @name: the namespace to find or add  (MAYBE NULL)
 372 *
 373 * Returns: refcounted namespace or NULL if failed to create one
 374 */
 375static struct aa_namespace *aa_prepare_namespace(const char *name)
 376{
 377	struct aa_namespace *ns, *root;
 378
 379	root = aa_current_profile()->ns;
 380
 381	mutex_lock(&root->lock);
 382
 383	/* if name isn't specified the profile is loaded to the current ns */
 384	if (!name) {
 385		/* released by caller */
 386		ns = aa_get_namespace(root);
 387		goto out;
 388	}
 389
 390	/* try and find the specified ns and if it doesn't exist create it */
 391	/* released by caller */
 392	ns = aa_get_namespace(__aa_find_namespace(&root->sub_ns, name));
 393	if (!ns) {
 394		ns = alloc_namespace(root->base.hname, name);
 395		if (!ns)
 396			goto out;
 397		if (__aa_fs_namespace_mkdir(ns, ns_subns_dir(root), name)) {
 398			AA_ERROR("Failed to create interface for ns %s\n",
 399				 ns->base.name);
 400			free_namespace(ns);
 401			ns = NULL;
 402			goto out;
 403		}
 404		ns->parent = aa_get_namespace(root);
 405		list_add_rcu(&ns->base.list, &root->sub_ns);
 406		/* add list ref */
 407		aa_get_namespace(ns);
 408	}
 409out:
 410	mutex_unlock(&root->lock);
 411
 412	/* return ref */
 413	return ns;
 414}
 415
 416/**
 417 * __list_add_profile - add a profile to a list
 418 * @list: list to add it to  (NOT NULL)
 419 * @profile: the profile to add  (NOT NULL)
 420 *
 421 * refcount @profile, should be put by __list_remove_profile
 422 *
 423 * Requires: namespace lock be held, or list not be shared
 424 */
 425static void __list_add_profile(struct list_head *list,
 426			       struct aa_profile *profile)
 427{
 428	list_add_rcu(&profile->base.list, list);
 429	/* get list reference */
 430	aa_get_profile(profile);
 431}
 432
 433/**
 434 * __list_remove_profile - remove a profile from the list it is on
 435 * @profile: the profile to remove  (NOT NULL)
 436 *
 437 * remove a profile from the list, warning generally removal should
 438 * be done with __replace_profile as most profile removals are
 439 * replacements to the unconfined profile.
 440 *
 441 * put @profile list refcount
 442 *
 443 * Requires: namespace lock be held, or list not have been live
 444 */
 445static void __list_remove_profile(struct aa_profile *profile)
 446{
 447	list_del_rcu(&profile->base.list);
 448	aa_put_profile(profile);
 449}
 450
 451static void __profile_list_release(struct list_head *head);
 452
 453/**
 454 * __remove_profile - remove old profile, and children
 455 * @profile: profile to be replaced  (NOT NULL)
 456 *
 457 * Requires: namespace list lock be held, or list not be shared
 458 */
 459static void __remove_profile(struct aa_profile *profile)
 460{
 461	/* release any children lists first */
 462	__profile_list_release(&profile->base.profiles);
 463	/* released by free_profile */
 464	__aa_update_replacedby(profile, profile->ns->unconfined);
 465	__aa_fs_profile_rmdir(profile);
 466	__list_remove_profile(profile);
 467}
 468
 469/**
 470 * __profile_list_release - remove all profiles on the list and put refs
 471 * @head: list of profiles  (NOT NULL)
 472 *
 473 * Requires: namespace lock be held
 474 */
 475static void __profile_list_release(struct list_head *head)
 476{
 477	struct aa_profile *profile, *tmp;
 478	list_for_each_entry_safe(profile, tmp, head, base.list)
 479		__remove_profile(profile);
 480}
 481
 482static void __ns_list_release(struct list_head *head);
 483
 484/**
 485 * destroy_namespace - remove everything contained by @ns
 486 * @ns: namespace to have it contents removed  (NOT NULL)
 487 */
 488static void destroy_namespace(struct aa_namespace *ns)
 489{
 490	if (!ns)
 491		return;
 492
 493	mutex_lock(&ns->lock);
 494	/* release all profiles in this namespace */
 495	__profile_list_release(&ns->base.profiles);
 496
 497	/* release all sub namespaces */
 498	__ns_list_release(&ns->sub_ns);
 499
 500	if (ns->parent)
 501		__aa_update_replacedby(ns->unconfined, ns->parent->unconfined);
 502	__aa_fs_namespace_rmdir(ns);
 503	mutex_unlock(&ns->lock);
 504}
 505
 506/**
 507 * __remove_namespace - remove a namespace and all its children
 508 * @ns: namespace to be removed  (NOT NULL)
 509 *
 510 * Requires: ns->parent->lock be held and ns removed from parent.
 511 */
 512static void __remove_namespace(struct aa_namespace *ns)
 513{
 514	/* remove ns from namespace list */
 515	list_del_rcu(&ns->base.list);
 516	destroy_namespace(ns);
 517	aa_put_namespace(ns);
 518}
 519
 520/**
 521 * __ns_list_release - remove all profile namespaces on the list put refs
 522 * @head: list of profile namespaces  (NOT NULL)
 523 *
 524 * Requires: namespace lock be held
 525 */
 526static void __ns_list_release(struct list_head *head)
 527{
 528	struct aa_namespace *ns, *tmp;
 529	list_for_each_entry_safe(ns, tmp, head, base.list)
 530		__remove_namespace(ns);
 531
 532}
 533
 534/**
 535 * aa_alloc_root_ns - allocate the root profile namespace
 536 *
 537 * Returns: %0 on success else error
 538 *
 539 */
 540int __init aa_alloc_root_ns(void)
 541{
 542	/* released by aa_free_root_ns - used as list ref*/
 543	root_ns = alloc_namespace(NULL, "root");
 544	if (!root_ns)
 545		return -ENOMEM;
 546
 547	return 0;
 548}
 549
 550 /**
 551  * aa_free_root_ns - free the root profile namespace
 552  */
 553void __init aa_free_root_ns(void)
 554 {
 555	 struct aa_namespace *ns = root_ns;
 556	 root_ns = NULL;
 557
 558	 destroy_namespace(ns);
 559	 aa_put_namespace(ns);
 560}
 561
 562
 563static void free_replacedby(struct aa_replacedby *r)
 564{
 565	if (r) {
 566		/* r->profile will not be updated any more as r is dead */
 567		aa_put_profile(rcu_dereference_protected(r->profile, true));
 568		kzfree(r);
 569	}
 570}
 571
 572
 573void aa_free_replacedby_kref(struct kref *kref)
 574{
 575	struct aa_replacedby *r = container_of(kref, struct aa_replacedby,
 576					       count);
 577	free_replacedby(r);
 578}
 579
 580/**
 581 * aa_free_profile - free a profile
 582 * @profile: the profile to free  (MAYBE NULL)
 583 *
 584 * Free a profile, its hats and null_profile. All references to the profile,
 585 * its hats and null_profile must have been put.
 586 *
 587 * If the profile was referenced from a task context, free_profile() will
 588 * be called from an rcu callback routine, so we must not sleep here.
 589 */
 590void aa_free_profile(struct aa_profile *profile)
 591{
 592	AA_DEBUG("%s(%p)\n", __func__, profile);
 593
 594	if (!profile)
 595		return;
 596
 597	/* free children profiles */
 598	policy_destroy(&profile->base);
 599	aa_put_profile(rcu_access_pointer(profile->parent));
 600
 601	aa_put_namespace(profile->ns);
 602	kzfree(profile->rename);
 603
 604	aa_free_file_rules(&profile->file);
 605	aa_free_cap_rules(&profile->caps);
 606	aa_free_rlimit_rules(&profile->rlimits);
 607
 608	kzfree(profile->dirname);
 609	aa_put_dfa(profile->xmatch);
 610	aa_put_dfa(profile->policy.dfa);
 611	aa_put_replacedby(profile->replacedby);
 612
 613	kzfree(profile->hash);
 614	kzfree(profile);
 615}
 616
 617/**
 618 * aa_free_profile_rcu - free aa_profile by rcu (called by aa_free_profile_kref)
 619 * @head: rcu_head callback for freeing of a profile  (NOT NULL)
 620 */
 621static void aa_free_profile_rcu(struct rcu_head *head)
 622{
 623	struct aa_profile *p = container_of(head, struct aa_profile, rcu);
 624	if (p->flags & PFLAG_NS_COUNT)
 625		free_namespace(p->ns);
 626	else
 627		aa_free_profile(p);
 628}
 629
 630/**
 631 * aa_free_profile_kref - free aa_profile by kref (called by aa_put_profile)
 632 * @kr: kref callback for freeing of a profile  (NOT NULL)
 633 */
 634void aa_free_profile_kref(struct kref *kref)
 635{
 636	struct aa_profile *p = container_of(kref, struct aa_profile, count);
 637	call_rcu(&p->rcu, aa_free_profile_rcu);
 638}
 639
 640/**
 641 * aa_alloc_profile - allocate, initialize and return a new profile
 642 * @hname: name of the profile  (NOT NULL)
 643 *
 644 * Returns: refcount profile or NULL on failure
 645 */
 646struct aa_profile *aa_alloc_profile(const char *hname)
 647{
 648	struct aa_profile *profile;
 649
 650	/* freed by free_profile - usually through aa_put_profile */
 651	profile = kzalloc(sizeof(*profile), GFP_KERNEL);
 652	if (!profile)
 653		return NULL;
 654
 655	profile->replacedby = kzalloc(sizeof(struct aa_replacedby), GFP_KERNEL);
 656	if (!profile->replacedby)
 657		goto fail;
 658	kref_init(&profile->replacedby->count);
 659
 660	if (!policy_init(&profile->base, NULL, hname))
 661		goto fail;
 662	kref_init(&profile->count);
 663
 664	/* refcount released by caller */
 665	return profile;
 666
 667fail:
 668	kzfree(profile->replacedby);
 669	kzfree(profile);
 670
 671	return NULL;
 672}
 673
 674/**
 675 * aa_new_null_profile - create a new null-X learning profile
 676 * @parent: profile that caused this profile to be created (NOT NULL)
 677 * @hat: true if the null- learning profile is a hat
 678 *
 679 * Create a null- complain mode profile used in learning mode.  The name of
 680 * the profile is unique and follows the format of parent//null-<uniq>.
 681 *
 682 * null profiles are added to the profile list but the list does not
 683 * hold a count on them so that they are automatically released when
 684 * not in use.
 685 *
 686 * Returns: new refcounted profile else NULL on failure
 687 */
 688struct aa_profile *aa_new_null_profile(struct aa_profile *parent, int hat)
 689{
 690	struct aa_profile *profile = NULL;
 691	char *name;
 692	int uniq = atomic_inc_return(&parent->ns->uniq_null);
 693
 694	/* freed below */
 695	name = kmalloc(strlen(parent->base.hname) + 2 + 7 + 8, GFP_KERNEL);
 696	if (!name)
 697		goto fail;
 698	sprintf(name, "%s//null-%x", parent->base.hname, uniq);
 699
 700	profile = aa_alloc_profile(name);
 701	kfree(name);
 702	if (!profile)
 703		goto fail;
 704
 705	profile->mode = APPARMOR_COMPLAIN;
 706	profile->flags = PFLAG_NULL;
 707	if (hat)
 708		profile->flags |= PFLAG_HAT;
 709
 710	/* released on free_profile */
 711	rcu_assign_pointer(profile->parent, aa_get_profile(parent));
 712	profile->ns = aa_get_namespace(parent->ns);
 713
 714	mutex_lock(&profile->ns->lock);
 715	__list_add_profile(&parent->base.profiles, profile);
 716	mutex_unlock(&profile->ns->lock);
 717
 718	/* refcount released by caller */
 719	return profile;
 720
 721fail:
 722	return NULL;
 723}
 724
 725/* TODO: profile accounting - setup in remove */
 726
 727/**
 728 * __find_child - find a profile on @head list with a name matching @name
 729 * @head: list to search  (NOT NULL)
 730 * @name: name of profile (NOT NULL)
 731 *
 732 * Requires: rcu_read_lock be held
 733 *
 734 * Returns: unrefcounted profile ptr, or NULL if not found
 735 */
 736static struct aa_profile *__find_child(struct list_head *head, const char *name)
 737{
 738	return (struct aa_profile *)__policy_find(head, name);
 739}
 740
 741/**
 742 * __strn_find_child - find a profile on @head list using substring of @name
 743 * @head: list to search  (NOT NULL)
 744 * @name: name of profile (NOT NULL)
 745 * @len: length of @name substring to match
 746 *
 747 * Requires: rcu_read_lock be held
 748 *
 749 * Returns: unrefcounted profile ptr, or NULL if not found
 750 */
 751static struct aa_profile *__strn_find_child(struct list_head *head,
 752					    const char *name, int len)
 753{
 754	return (struct aa_profile *)__policy_strn_find(head, name, len);
 755}
 756
 757/**
 758 * aa_find_child - find a profile by @name in @parent
 759 * @parent: profile to search  (NOT NULL)
 760 * @name: profile name to search for  (NOT NULL)
 761 *
 762 * Returns: a refcounted profile or NULL if not found
 763 */
 764struct aa_profile *aa_find_child(struct aa_profile *parent, const char *name)
 765{
 766	struct aa_profile *profile;
 767
 768	rcu_read_lock();
 769	profile = aa_get_profile(__find_child(&parent->base.profiles, name));
 
 
 770	rcu_read_unlock();
 771
 772	/* refcount released by caller */
 773	return profile;
 774}
 775
 776/**
 777 * __lookup_parent - lookup the parent of a profile of name @hname
 778 * @ns: namespace to lookup profile in  (NOT NULL)
 779 * @hname: hierarchical profile name to find parent of  (NOT NULL)
 780 *
 781 * Lookups up the parent of a fully qualified profile name, the profile
 782 * that matches hname does not need to exist, in general this
 783 * is used to load a new profile.
 784 *
 785 * Requires: rcu_read_lock be held
 786 *
 787 * Returns: unrefcounted policy or NULL if not found
 788 */
 789static struct aa_policy *__lookup_parent(struct aa_namespace *ns,
 790					 const char *hname)
 791{
 792	struct aa_policy *policy;
 793	struct aa_profile *profile = NULL;
 794	char *split;
 795
 796	policy = &ns->base;
 797
 798	for (split = strstr(hname, "//"); split;) {
 799		profile = __strn_find_child(&policy->profiles, hname,
 800					    split - hname);
 801		if (!profile)
 802			return NULL;
 803		policy = &profile->base;
 804		hname = split + 2;
 805		split = strstr(hname, "//");
 806	}
 807	if (!profile)
 808		return &ns->base;
 809	return &profile->base;
 810}
 811
 812/**
 813 * __lookup_profile - lookup the profile matching @hname
 814 * @base: base list to start looking up profile name from  (NOT NULL)
 815 * @hname: hierarchical profile name  (NOT NULL)
 816 *
 817 * Requires: rcu_read_lock be held
 818 *
 819 * Returns: unrefcounted profile pointer or NULL if not found
 820 *
 821 * Do a relative name lookup, recursing through profile tree.
 822 */
 823static struct aa_profile *__lookup_profile(struct aa_policy *base,
 824					   const char *hname)
 825{
 826	struct aa_profile *profile = NULL;
 827	char *split;
 828
 829	for (split = strstr(hname, "//"); split;) {
 830		profile = __strn_find_child(&base->profiles, hname,
 831					    split - hname);
 832		if (!profile)
 833			return NULL;
 834
 835		base = &profile->base;
 836		hname = split + 2;
 837		split = strstr(hname, "//");
 838	}
 839
 840	profile = __find_child(&base->profiles, hname);
 841
 842	return profile;
 843}
 844
 845/**
 846 * aa_lookup_profile - find a profile by its full or partial name
 847 * @ns: the namespace to start from (NOT NULL)
 848 * @hname: name to do lookup on.  Does not contain namespace prefix (NOT NULL)
 849 *
 850 * Returns: refcounted profile or NULL if not found
 851 */
 852struct aa_profile *aa_lookup_profile(struct aa_namespace *ns, const char *hname)
 853{
 854	struct aa_profile *profile;
 855
 856	rcu_read_lock();
 857	do {
 858		profile = __lookup_profile(&ns->base, hname);
 859	} while (profile && !aa_get_profile_not0(profile));
 860	rcu_read_unlock();
 861
 862	/* the unconfined profile is not in the regular profile list */
 863	if (!profile && strcmp(hname, "unconfined") == 0)
 864		profile = aa_get_newest_profile(ns->unconfined);
 865
 866	/* refcount released by caller */
 867	return profile;
 868}
 869
 870/**
 871 * replacement_allowed - test to see if replacement is allowed
 872 * @profile: profile to test if it can be replaced  (MAYBE NULL)
 873 * @noreplace: true if replacement shouldn't be allowed but addition is okay
 874 * @info: Returns - info about why replacement failed (NOT NULL)
 875 *
 876 * Returns: %0 if replacement allowed else error code
 877 */
 878static int replacement_allowed(struct aa_profile *profile, int noreplace,
 879			       const char **info)
 880{
 881	if (profile) {
 882		if (profile->flags & PFLAG_IMMUTABLE) {
 883			*info = "cannot replace immutible profile";
 884			return -EPERM;
 885		} else if (noreplace) {
 886			*info = "profile already exists";
 887			return -EEXIST;
 888		}
 889	}
 890	return 0;
 891}
 892
 893/**
 894 * aa_audit_policy - Do auditing of policy changes
 895 * @op: policy operation being performed
 896 * @gfp: memory allocation flags
 897 * @name: name of profile being manipulated (NOT NULL)
 898 * @info: any extra information to be audited (MAYBE NULL)
 899 * @error: error code
 900 *
 901 * Returns: the error to be returned after audit is done
 902 */
 903static int audit_policy(int op, gfp_t gfp, const char *name, const char *info,
 904			int error)
 905{
 906	struct common_audit_data sa;
 907	struct apparmor_audit_data aad = {0,};
 908	sa.type = LSM_AUDIT_DATA_NONE;
 909	sa.aad = &aad;
 910	aad.op = op;
 911	aad.name = name;
 912	aad.info = info;
 913	aad.error = error;
 914
 915	return aa_audit(AUDIT_APPARMOR_STATUS, __aa_current_profile(), gfp,
 916			&sa, NULL);
 917}
 918
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 919/**
 920 * aa_may_manage_policy - can the current task manage policy
 921 * @op: the policy manipulation operation being done
 922 *
 923 * Returns: true if the task is allowed to manipulate policy
 924 */
 925bool aa_may_manage_policy(int op)
 926{
 927	/* check if loading policy is locked out */
 928	if (aa_g_lock_policy) {
 929		audit_policy(op, GFP_KERNEL, NULL, "policy_locked", -EACCES);
 930		return 0;
 931	}
 932
 933	if (!capable(CAP_MAC_ADMIN)) {
 934		audit_policy(op, GFP_KERNEL, NULL, "not policy admin", -EACCES);
 935		return 0;
 936	}
 937
 938	return 1;
 939}
 940
 941static struct aa_profile *__list_lookup_parent(struct list_head *lh,
 942					       struct aa_profile *profile)
 943{
 944	const char *base = hname_tail(profile->base.hname);
 945	long len = base - profile->base.hname;
 946	struct aa_load_ent *ent;
 947
 948	/* parent won't have trailing // so remove from len */
 949	if (len <= 2)
 950		return NULL;
 951	len -= 2;
 952
 953	list_for_each_entry(ent, lh, list) {
 954		if (ent->new == profile)
 955			continue;
 956		if (strncmp(ent->new->base.hname, profile->base.hname, len) ==
 957		    0 && ent->new->base.hname[len] == 0)
 958			return ent->new;
 959	}
 960
 961	return NULL;
 962}
 963
 964/**
 965 * __replace_profile - replace @old with @new on a list
 966 * @old: profile to be replaced  (NOT NULL)
 967 * @new: profile to replace @old with  (NOT NULL)
 968 * @share_replacedby: transfer @old->replacedby to @new
 969 *
 970 * Will duplicate and refcount elements that @new inherits from @old
 971 * and will inherit @old children.
 972 *
 973 * refcount @new for list, put @old list refcount
 974 *
 975 * Requires: namespace list lock be held, or list not be shared
 976 */
 977static void __replace_profile(struct aa_profile *old, struct aa_profile *new,
 978			      bool share_replacedby)
 979{
 980	struct aa_profile *child, *tmp;
 981
 982	if (!list_empty(&old->base.profiles)) {
 983		LIST_HEAD(lh);
 984		list_splice_init_rcu(&old->base.profiles, &lh, synchronize_rcu);
 985
 986		list_for_each_entry_safe(child, tmp, &lh, base.list) {
 987			struct aa_profile *p;
 988
 989			list_del_init(&child->base.list);
 990			p = __find_child(&new->base.profiles, child->base.name);
 991			if (p) {
 992				/* @p replaces @child  */
 993				__replace_profile(child, p, share_replacedby);
 994				continue;
 995			}
 996
 997			/* inherit @child and its children */
 998			/* TODO: update hname of inherited children */
 999			/* list refcount transferred to @new */
1000			p = aa_deref_parent(child);
1001			rcu_assign_pointer(child->parent, aa_get_profile(new));
1002			list_add_rcu(&child->base.list, &new->base.profiles);
1003			aa_put_profile(p);
1004		}
1005	}
1006
1007	if (!rcu_access_pointer(new->parent)) {
1008		struct aa_profile *parent = aa_deref_parent(old);
1009		rcu_assign_pointer(new->parent, aa_get_profile(parent));
1010	}
1011	__aa_update_replacedby(old, new);
1012	if (share_replacedby) {
1013		aa_put_replacedby(new->replacedby);
1014		new->replacedby = aa_get_replacedby(old->replacedby);
1015	} else if (!rcu_access_pointer(new->replacedby->profile))
1016		/* aafs interface uses replacedby */
1017		rcu_assign_pointer(new->replacedby->profile,
1018				   aa_get_profile(new));
1019	__aa_fs_profile_migrate_dents(old, new);
1020
1021	if (list_empty(&new->base.list)) {
1022		/* new is not on a list already */
1023		list_replace_rcu(&old->base.list, &new->base.list);
1024		aa_get_profile(new);
1025		aa_put_profile(old);
1026	} else
1027		__list_remove_profile(old);
1028}
1029
1030/**
1031 * __lookup_replace - lookup replacement information for a profile
1032 * @ns - namespace the lookup occurs in
1033 * @hname - name of profile to lookup
1034 * @noreplace - true if not replacing an existing profile
1035 * @p - Returns: profile to be replaced
1036 * @info - Returns: info string on why lookup failed
1037 *
1038 * Returns: profile to replace (no ref) on success else ptr error
1039 */
1040static int __lookup_replace(struct aa_namespace *ns, const char *hname,
1041			    bool noreplace, struct aa_profile **p,
1042			    const char **info)
1043{
1044	*p = aa_get_profile(__lookup_profile(&ns->base, hname));
1045	if (*p) {
1046		int error = replacement_allowed(*p, noreplace, info);
1047		if (error) {
1048			*info = "profile can not be replaced";
1049			return error;
1050		}
1051	}
1052
1053	return 0;
1054}
1055
1056/**
1057 * aa_replace_profiles - replace profile(s) on the profile list
1058 * @udata: serialized data stream  (NOT NULL)
1059 * @size: size of the serialized data stream
1060 * @noreplace: true if only doing addition, no replacement allowed
1061 *
1062 * unpack and replace a profile on the profile list and uses of that profile
1063 * by any aa_task_cxt.  If the profile does not exist on the profile list
1064 * it is added.
1065 *
1066 * Returns: size of data consumed else error code on failure.
1067 */
1068ssize_t aa_replace_profiles(void *udata, size_t size, bool noreplace)
1069{
1070	const char *ns_name, *name = NULL, *info = NULL;
1071	struct aa_namespace *ns = NULL;
1072	struct aa_load_ent *ent, *tmp;
1073	int op = OP_PROF_REPL;
1074	ssize_t error;
1075	LIST_HEAD(lh);
1076
1077	/* released below */
1078	error = aa_unpack(udata, size, &lh, &ns_name);
1079	if (error)
1080		goto out;
1081
1082	/* released below */
1083	ns = aa_prepare_namespace(ns_name);
1084	if (!ns) {
1085		info = "failed to prepare namespace";
1086		error = -ENOMEM;
1087		name = ns_name;
1088		goto fail;
1089	}
1090
1091	mutex_lock(&ns->lock);
1092	/* setup parent and ns info */
1093	list_for_each_entry(ent, &lh, list) {
1094		struct aa_policy *policy;
1095
1096		name = ent->new->base.hname;
1097		error = __lookup_replace(ns, ent->new->base.hname, noreplace,
1098					 &ent->old, &info);
1099		if (error)
1100			goto fail_lock;
1101
1102		if (ent->new->rename) {
1103			error = __lookup_replace(ns, ent->new->rename,
1104						 noreplace, &ent->rename,
1105						 &info);
1106			if (error)
1107				goto fail_lock;
1108		}
1109
1110		/* released when @new is freed */
1111		ent->new->ns = aa_get_namespace(ns);
1112
1113		if (ent->old || ent->rename)
1114			continue;
1115
1116		/* no ref on policy only use inside lock */
1117		policy = __lookup_parent(ns, ent->new->base.hname);
1118		if (!policy) {
1119			struct aa_profile *p;
1120			p = __list_lookup_parent(&lh, ent->new);
1121			if (!p) {
1122				error = -ENOENT;
1123				info = "parent does not exist";
1124				name = ent->new->base.hname;
1125				goto fail_lock;
1126			}
1127			rcu_assign_pointer(ent->new->parent, aa_get_profile(p));
1128		} else if (policy != &ns->base) {
1129			/* released on profile replacement or free_profile */
1130			struct aa_profile *p = (struct aa_profile *) policy;
1131			rcu_assign_pointer(ent->new->parent, aa_get_profile(p));
1132		}
1133	}
1134
1135	/* create new fs entries for introspection if needed */
1136	list_for_each_entry(ent, &lh, list) {
1137		if (ent->old) {
1138			/* inherit old interface files */
1139
1140			/* if (ent->rename)
1141				TODO: support rename */
1142		/* } else if (ent->rename) {
1143			TODO: support rename */
1144		} else {
1145			struct dentry *parent;
1146			if (rcu_access_pointer(ent->new->parent)) {
1147				struct aa_profile *p;
1148				p = aa_deref_parent(ent->new);
1149				parent = prof_child_dir(p);
1150			} else
1151				parent = ns_subprofs_dir(ent->new->ns);
1152			error = __aa_fs_profile_mkdir(ent->new, parent);
1153		}
1154
1155		if (error) {
1156			info = "failed to create ";
1157			goto fail_lock;
1158		}
1159	}
1160
1161	/* Done with checks that may fail - do actual replacement */
1162	list_for_each_entry_safe(ent, tmp, &lh, list) {
1163		list_del_init(&ent->list);
1164		op = (!ent->old && !ent->rename) ? OP_PROF_LOAD : OP_PROF_REPL;
1165
1166		audit_policy(op, GFP_ATOMIC, ent->new->base.name, NULL, error);
1167
1168		if (ent->old) {
1169			__replace_profile(ent->old, ent->new, 1);
1170			if (ent->rename) {
1171				/* aafs interface uses replacedby */
1172				struct aa_replacedby *r = ent->new->replacedby;
1173				rcu_assign_pointer(r->profile,
1174						   aa_get_profile(ent->new));
1175				__replace_profile(ent->rename, ent->new, 0);
1176			}
1177		} else if (ent->rename) {
1178			/* aafs interface uses replacedby */
1179			rcu_assign_pointer(ent->new->replacedby->profile,
1180					   aa_get_profile(ent->new));
1181			__replace_profile(ent->rename, ent->new, 0);
1182		} else if (ent->new->parent) {
1183			struct aa_profile *parent, *newest;
1184			parent = aa_deref_parent(ent->new);
1185			newest = aa_get_newest_profile(parent);
1186
1187			/* parent replaced in this atomic set? */
1188			if (newest != parent) {
1189				aa_get_profile(newest);
1190				aa_put_profile(parent);
1191				rcu_assign_pointer(ent->new->parent, newest);
1192			} else
1193				aa_put_profile(newest);
1194			/* aafs interface uses replacedby */
1195			rcu_assign_pointer(ent->new->replacedby->profile,
1196					   aa_get_profile(ent->new));
1197			__list_add_profile(&parent->base.profiles, ent->new);
 
1198		} else {
1199			/* aafs interface uses replacedby */
1200			rcu_assign_pointer(ent->new->replacedby->profile,
1201					   aa_get_profile(ent->new));
1202			__list_add_profile(&ns->base.profiles, ent->new);
1203		}
1204		aa_load_ent_free(ent);
1205	}
1206	mutex_unlock(&ns->lock);
1207
1208out:
1209	aa_put_namespace(ns);
1210
1211	if (error)
1212		return error;
1213	return size;
1214
1215fail_lock:
1216	mutex_unlock(&ns->lock);
1217fail:
1218	error = audit_policy(op, GFP_KERNEL, name, info, error);
1219
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1220	list_for_each_entry_safe(ent, tmp, &lh, list) {
1221		list_del_init(&ent->list);
1222		aa_load_ent_free(ent);
1223	}
1224
1225	goto out;
1226}
1227
1228/**
1229 * aa_remove_profiles - remove profile(s) from the system
1230 * @fqname: name of the profile or namespace to remove  (NOT NULL)
1231 * @size: size of the name
1232 *
1233 * Remove a profile or sub namespace from the current namespace, so that
1234 * they can not be found anymore and mark them as replaced by unconfined
1235 *
1236 * NOTE: removing confinement does not restore rlimits to preconfinemnet values
1237 *
1238 * Returns: size of data consume else error code if fails
1239 */
1240ssize_t aa_remove_profiles(char *fqname, size_t size)
1241{
1242	struct aa_namespace *root, *ns = NULL;
1243	struct aa_profile *profile = NULL;
1244	const char *name = fqname, *info = NULL;
1245	ssize_t error = 0;
1246
1247	if (*fqname == 0) {
1248		info = "no profile specified";
1249		error = -ENOENT;
1250		goto fail;
1251	}
1252
1253	root = aa_current_profile()->ns;
1254
1255	if (fqname[0] == ':') {
1256		char *ns_name;
1257		name = aa_split_fqname(fqname, &ns_name);
1258		/* released below */
1259		ns = aa_find_namespace(root, ns_name);
1260		if (!ns) {
1261			info = "namespace does not exist";
1262			error = -ENOENT;
1263			goto fail;
1264		}
1265	} else
1266		/* released below */
1267		ns = aa_get_namespace(root);
1268
1269	if (!name) {
1270		/* remove namespace - can only happen if fqname[0] == ':' */
1271		mutex_lock(&ns->parent->lock);
1272		__remove_namespace(ns);
1273		mutex_unlock(&ns->parent->lock);
1274	} else {
1275		/* remove profile */
1276		mutex_lock(&ns->lock);
1277		profile = aa_get_profile(__lookup_profile(&ns->base, name));
1278		if (!profile) {
1279			error = -ENOENT;
1280			info = "profile does not exist";
1281			goto fail_ns_lock;
1282		}
1283		name = profile->base.hname;
1284		__remove_profile(profile);
1285		mutex_unlock(&ns->lock);
1286	}
1287
1288	/* don't fail removal if audit fails */
1289	(void) audit_policy(OP_PROF_RM, GFP_KERNEL, name, info, error);
1290	aa_put_namespace(ns);
1291	aa_put_profile(profile);
1292	return size;
1293
1294fail_ns_lock:
1295	mutex_unlock(&ns->lock);
1296	aa_put_namespace(ns);
1297
1298fail:
1299	(void) audit_policy(OP_PROF_RM, GFP_KERNEL, name, info, error);
1300	return error;
1301}