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#include "include/sid.h"
  91
  92
  93/* root profile namespace */
  94struct aa_namespace *root_ns;
  95
  96const char *profile_mode_names[] = {
  97	"enforce",
  98	"complain",
  99	"kill",
 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	kref_init(&policy->count);
 146
 147	return 1;
 148}
 149
 150/**
 151 * policy_destroy - free the elements referenced by @policy
 152 * @policy: policy that is to have its elements freed  (NOT NULL)
 153 */
 154static void policy_destroy(struct aa_policy *policy)
 155{
 156	/* still contains profiles -- invalid */
 157	if (!list_empty(&policy->profiles)) {
 158		AA_ERROR("%s: internal error, "
 159			 "policy '%s' still contains profiles\n",
 160			 __func__, policy->name);
 161		BUG();
 162	}
 163	if (!list_empty(&policy->list)) {
 164		AA_ERROR("%s: internal error, policy '%s' still on list\n",
 165			 __func__, policy->name);
 166		BUG();
 167	}
 168
 169	/* don't free name as its a subset of hname */
 170	kzfree(policy->hname);
 171}
 172
 173/**
 174 * __policy_find - find a policy by @name on a policy list
 175 * @head: list to search  (NOT NULL)
 176 * @name: name to search for  (NOT NULL)
 177 *
 178 * Requires: correct locks for the @head list be held
 179 *
 180 * Returns: unrefcounted policy that match @name or NULL if not found
 181 */
 182static struct aa_policy *__policy_find(struct list_head *head, const char *name)
 183{
 184	struct aa_policy *policy;
 185
 186	list_for_each_entry(policy, head, list) {
 187		if (!strcmp(policy->name, name))
 188			return policy;
 189	}
 190	return NULL;
 191}
 192
 193/**
 194 * __policy_strn_find - find a policy that's name matches @len chars of @str
 195 * @head: list to search  (NOT NULL)
 196 * @str: string to search for  (NOT NULL)
 197 * @len: length of match required
 198 *
 199 * Requires: correct locks for the @head list be held
 200 *
 201 * Returns: unrefcounted policy that match @str or NULL if not found
 202 *
 203 * if @len == strlen(@strlen) then this is equiv to __policy_find
 204 * other wise it allows searching for policy by a partial match of name
 205 */
 206static struct aa_policy *__policy_strn_find(struct list_head *head,
 207					    const char *str, int len)
 208{
 209	struct aa_policy *policy;
 210
 211	list_for_each_entry(policy, head, list) {
 212		if (aa_strneq(policy->name, str, len))
 213			return policy;
 214	}
 215
 216	return NULL;
 217}
 218
 219/*
 220 * Routines for AppArmor namespaces
 221 */
 222
 223static const char *hidden_ns_name = "---";
 224/**
 225 * aa_ns_visible - test if @view is visible from @curr
 226 * @curr: namespace to treat as the parent (NOT NULL)
 227 * @view:  namespace to test if visible from @curr (NOT NULL)
 228 *
 229 * Returns: true if @view is visible from @curr else false
 230 */
 231bool aa_ns_visible(struct aa_namespace *curr, struct aa_namespace *view)
 232{
 233	if (curr == view)
 234		return true;
 235
 236	for ( ; view; view = view->parent) {
 237		if (view->parent == curr)
 238			return true;
 239	}
 240	return false;
 241}
 242
 243/**
 244 * aa_na_name - Find the ns name to display for @view from @curr
 245 * @curr - current namespace (NOT NULL)
 246 * @view - namespace attempting to view (NOT NULL)
 247 *
 248 * Returns: name of @view visible from @curr
 249 */
 250const char *aa_ns_name(struct aa_namespace *curr, struct aa_namespace *view)
 251{
 252	/* if view == curr then the namespace name isn't displayed */
 253	if (curr == view)
 254		return "";
 255
 256	if (aa_ns_visible(curr, view)) {
 257		/* at this point if a ns is visible it is in a view ns
 258		 * thus the curr ns.hname is a prefix of its name.
 259		 * Only output the virtualized portion of the name
 260		 * Add + 2 to skip over // separating curr hname prefix
 261		 * from the visible tail of the views hname
 262		 */
 263		return view->base.hname + strlen(curr->base.hname) + 2;
 264	} else
 265		return hidden_ns_name;
 266}
 267
 268/**
 269 * alloc_namespace - allocate, initialize and return a new namespace
 270 * @prefix: parent namespace name (MAYBE NULL)
 271 * @name: a preallocated name  (NOT NULL)
 272 *
 273 * Returns: refcounted namespace or NULL on failure.
 274 */
 275static struct aa_namespace *alloc_namespace(const char *prefix,
 276					    const char *name)
 277{
 278	struct aa_namespace *ns;
 279
 280	ns = kzalloc(sizeof(*ns), GFP_KERNEL);
 281	AA_DEBUG("%s(%p)\n", __func__, ns);
 282	if (!ns)
 283		return NULL;
 284	if (!policy_init(&ns->base, prefix, name))
 285		goto fail_ns;
 286
 287	INIT_LIST_HEAD(&ns->sub_ns);
 288	rwlock_init(&ns->lock);
 289
 290	/* released by free_namespace */
 291	ns->unconfined = aa_alloc_profile("unconfined");
 292	if (!ns->unconfined)
 293		goto fail_unconfined;
 294
 295	ns->unconfined->sid = aa_alloc_sid();
 296	ns->unconfined->flags = PFLAG_UNCONFINED | PFLAG_IX_ON_NAME_ERROR |
 297	    PFLAG_IMMUTABLE;
 298
 299	/*
 300	 * released by free_namespace, however __remove_namespace breaks
 301	 * the cyclic references (ns->unconfined, and unconfined->ns) and
 302	 * replaces with refs to parent namespace unconfined
 303	 */
 304	ns->unconfined->ns = aa_get_namespace(ns);
 305
 306	return ns;
 307
 308fail_unconfined:
 309	kzfree(ns->base.hname);
 310fail_ns:
 311	kzfree(ns);
 312	return NULL;
 313}
 314
 315/**
 316 * free_namespace - free a profile namespace
 317 * @ns: the namespace to free  (MAYBE NULL)
 318 *
 319 * Requires: All references to the namespace must have been put, if the
 320 *           namespace was referenced by a profile confining a task,
 321 */
 322static void free_namespace(struct aa_namespace *ns)
 323{
 324	if (!ns)
 325		return;
 326
 327	policy_destroy(&ns->base);
 328	aa_put_namespace(ns->parent);
 329
 330	if (ns->unconfined && ns->unconfined->ns == ns)
 331		ns->unconfined->ns = NULL;
 332
 333	aa_put_profile(ns->unconfined);
 334	kzfree(ns);
 335}
 336
 337/**
 338 * aa_free_namespace_kref - free aa_namespace by kref (see aa_put_namespace)
 339 * @kr: kref callback for freeing of a namespace  (NOT NULL)
 340 */
 341void aa_free_namespace_kref(struct kref *kref)
 342{
 343	free_namespace(container_of(kref, struct aa_namespace, base.count));
 344}
 345
 346/**
 347 * __aa_find_namespace - find a namespace on a list by @name
 348 * @head: list to search for namespace on  (NOT NULL)
 349 * @name: name of namespace to look for  (NOT NULL)
 350 *
 351 * Returns: unrefcounted namespace
 352 *
 353 * Requires: ns lock be held
 354 */
 355static struct aa_namespace *__aa_find_namespace(struct list_head *head,
 356						const char *name)
 357{
 358	return (struct aa_namespace *)__policy_find(head, name);
 359}
 360
 361/**
 362 * aa_find_namespace  -  look up a profile namespace on the namespace list
 363 * @root: namespace to search in  (NOT NULL)
 364 * @name: name of namespace to find  (NOT NULL)
 365 *
 366 * Returns: a refcounted namespace on the list, or NULL if no namespace
 367 *          called @name exists.
 368 *
 369 * refcount released by caller
 370 */
 371struct aa_namespace *aa_find_namespace(struct aa_namespace *root,
 372				       const char *name)
 373{
 374	struct aa_namespace *ns = NULL;
 375
 376	read_lock(&root->lock);
 377	ns = aa_get_namespace(__aa_find_namespace(&root->sub_ns, name));
 378	read_unlock(&root->lock);
 379
 380	return ns;
 381}
 382
 383/**
 384 * aa_prepare_namespace - find an existing or create a new namespace of @name
 385 * @name: the namespace to find or add  (MAYBE NULL)
 386 *
 387 * Returns: refcounted namespace or NULL if failed to create one
 388 */
 389static struct aa_namespace *aa_prepare_namespace(const char *name)
 390{
 391	struct aa_namespace *ns, *root;
 392
 393	root = aa_current_profile()->ns;
 394
 395	write_lock(&root->lock);
 396
 397	/* if name isn't specified the profile is loaded to the current ns */
 398	if (!name) {
 399		/* released by caller */
 400		ns = aa_get_namespace(root);
 401		goto out;
 402	}
 403
 404	/* try and find the specified ns and if it doesn't exist create it */
 405	/* released by caller */
 406	ns = aa_get_namespace(__aa_find_namespace(&root->sub_ns, name));
 407	if (!ns) {
 408		/* namespace not found */
 409		struct aa_namespace *new_ns;
 410		write_unlock(&root->lock);
 411		new_ns = alloc_namespace(root->base.hname, name);
 412		if (!new_ns)
 413			return NULL;
 414		write_lock(&root->lock);
 415		/* test for race when new_ns was allocated */
 416		ns = __aa_find_namespace(&root->sub_ns, name);
 417		if (!ns) {
 418			/* add parent ref */
 419			new_ns->parent = aa_get_namespace(root);
 420
 421			list_add(&new_ns->base.list, &root->sub_ns);
 422			/* add list ref */
 423			ns = aa_get_namespace(new_ns);
 424		} else {
 425			/* raced so free the new one */
 426			free_namespace(new_ns);
 427			/* get reference on namespace */
 428			aa_get_namespace(ns);
 429		}
 430	}
 431out:
 432	write_unlock(&root->lock);
 433
 434	/* return ref */
 435	return ns;
 436}
 437
 438/**
 439 * __list_add_profile - add a profile to a list
 440 * @list: list to add it to  (NOT NULL)
 441 * @profile: the profile to add  (NOT NULL)
 442 *
 443 * refcount @profile, should be put by __list_remove_profile
 444 *
 445 * Requires: namespace lock be held, or list not be shared
 446 */
 447static void __list_add_profile(struct list_head *list,
 448			       struct aa_profile *profile)
 449{
 450	list_add(&profile->base.list, list);
 451	/* get list reference */
 452	aa_get_profile(profile);
 453}
 454
 455/**
 456 * __list_remove_profile - remove a profile from the list it is on
 457 * @profile: the profile to remove  (NOT NULL)
 458 *
 459 * remove a profile from the list, warning generally removal should
 460 * be done with __replace_profile as most profile removals are
 461 * replacements to the unconfined profile.
 462 *
 463 * put @profile list refcount
 464 *
 465 * Requires: namespace lock be held, or list not have been live
 466 */
 467static void __list_remove_profile(struct aa_profile *profile)
 468{
 469	list_del_init(&profile->base.list);
 470	if (!(profile->flags & PFLAG_NO_LIST_REF))
 471		/* release list reference */
 472		aa_put_profile(profile);
 473}
 474
 475/**
 476 * __replace_profile - replace @old with @new on a list
 477 * @old: profile to be replaced  (NOT NULL)
 478 * @new: profile to replace @old with  (NOT NULL)
 479 *
 480 * Will duplicate and refcount elements that @new inherits from @old
 481 * and will inherit @old children.
 482 *
 483 * refcount @new for list, put @old list refcount
 484 *
 485 * Requires: namespace list lock be held, or list not be shared
 486 */
 487static void __replace_profile(struct aa_profile *old, struct aa_profile *new)
 488{
 489	struct aa_policy *policy;
 490	struct aa_profile *child, *tmp;
 491
 492	if (old->parent)
 493		policy = &old->parent->base;
 494	else
 495		policy = &old->ns->base;
 496
 497	/* released when @new is freed */
 498	new->parent = aa_get_profile(old->parent);
 499	new->ns = aa_get_namespace(old->ns);
 500	new->sid = old->sid;
 501	__list_add_profile(&policy->profiles, new);
 502	/* inherit children */
 503	list_for_each_entry_safe(child, tmp, &old->base.profiles, base.list) {
 504		aa_put_profile(child->parent);
 505		child->parent = aa_get_profile(new);
 506		/* list refcount transferred to @new*/
 507		list_move(&child->base.list, &new->base.profiles);
 508	}
 509
 510	/* released by free_profile */
 511	old->replacedby = aa_get_profile(new);
 512	__list_remove_profile(old);
 513}
 514
 515static void __profile_list_release(struct list_head *head);
 516
 517/**
 518 * __remove_profile - remove old profile, and children
 519 * @profile: profile to be replaced  (NOT NULL)
 520 *
 521 * Requires: namespace list lock be held, or list not be shared
 522 */
 523static void __remove_profile(struct aa_profile *profile)
 524{
 525	/* release any children lists first */
 526	__profile_list_release(&profile->base.profiles);
 527	/* released by free_profile */
 528	profile->replacedby = aa_get_profile(profile->ns->unconfined);
 529	__list_remove_profile(profile);
 530}
 531
 532/**
 533 * __profile_list_release - remove all profiles on the list and put refs
 534 * @head: list of profiles  (NOT NULL)
 535 *
 536 * Requires: namespace lock be held
 537 */
 538static void __profile_list_release(struct list_head *head)
 539{
 540	struct aa_profile *profile, *tmp;
 541	list_for_each_entry_safe(profile, tmp, head, base.list)
 542		__remove_profile(profile);
 543}
 544
 545static void __ns_list_release(struct list_head *head);
 546
 547/**
 548 * destroy_namespace - remove everything contained by @ns
 549 * @ns: namespace to have it contents removed  (NOT NULL)
 550 */
 551static void destroy_namespace(struct aa_namespace *ns)
 552{
 553	if (!ns)
 554		return;
 555
 556	write_lock(&ns->lock);
 557	/* release all profiles in this namespace */
 558	__profile_list_release(&ns->base.profiles);
 559
 560	/* release all sub namespaces */
 561	__ns_list_release(&ns->sub_ns);
 562
 563	write_unlock(&ns->lock);
 564}
 565
 566/**
 567 * __remove_namespace - remove a namespace and all its children
 568 * @ns: namespace to be removed  (NOT NULL)
 569 *
 570 * Requires: ns->parent->lock be held and ns removed from parent.
 571 */
 572static void __remove_namespace(struct aa_namespace *ns)
 573{
 574	struct aa_profile *unconfined = ns->unconfined;
 575
 576	/* remove ns from namespace list */
 577	list_del_init(&ns->base.list);
 578
 579	/*
 580	 * break the ns, unconfined profile cyclic reference and forward
 581	 * all new unconfined profiles requests to the parent namespace
 582	 * This will result in all confined tasks that have a profile
 583	 * being removed, inheriting the parent->unconfined profile.
 584	 */
 585	if (ns->parent)
 586		ns->unconfined = aa_get_profile(ns->parent->unconfined);
 587
 588	destroy_namespace(ns);
 589
 590	/* release original ns->unconfined ref */
 591	aa_put_profile(unconfined);
 592	/* release ns->base.list ref, from removal above */
 593	aa_put_namespace(ns);
 594}
 595
 596/**
 597 * __ns_list_release - remove all profile namespaces on the list put refs
 598 * @head: list of profile namespaces  (NOT NULL)
 599 *
 600 * Requires: namespace lock be held
 601 */
 602static void __ns_list_release(struct list_head *head)
 603{
 604	struct aa_namespace *ns, *tmp;
 605	list_for_each_entry_safe(ns, tmp, head, base.list)
 606		__remove_namespace(ns);
 607
 608}
 609
 610/**
 611 * aa_alloc_root_ns - allocate the root profile namespace
 612 *
 613 * Returns: %0 on success else error
 614 *
 615 */
 616int __init aa_alloc_root_ns(void)
 617{
 618	/* released by aa_free_root_ns - used as list ref*/
 619	root_ns = alloc_namespace(NULL, "root");
 620	if (!root_ns)
 621		return -ENOMEM;
 622
 623	return 0;
 624}
 625
 626 /**
 627  * aa_free_root_ns - free the root profile namespace
 628  */
 629void __init aa_free_root_ns(void)
 630 {
 631	 struct aa_namespace *ns = root_ns;
 632	 root_ns = NULL;
 633
 634	 destroy_namespace(ns);
 635	 aa_put_namespace(ns);
 636}
 637
 638/**
 639 * aa_alloc_profile - allocate, initialize and return a new profile
 640 * @hname: name of the profile  (NOT NULL)
 641 *
 642 * Returns: refcount profile or NULL on failure
 643 */
 644struct aa_profile *aa_alloc_profile(const char *hname)
 645{
 646	struct aa_profile *profile;
 647
 648	/* freed by free_profile - usually through aa_put_profile */
 649	profile = kzalloc(sizeof(*profile), GFP_KERNEL);
 650	if (!profile)
 651		return NULL;
 652
 653	if (!policy_init(&profile->base, NULL, hname)) {
 654		kzfree(profile);
 655		return NULL;
 656	}
 657
 658	/* refcount released by caller */
 659	return profile;
 660}
 661
 662/**
 663 * aa_new_null_profile - create a new null-X learning profile
 664 * @parent: profile that caused this profile to be created (NOT NULL)
 665 * @hat: true if the null- learning profile is a hat
 666 *
 667 * Create a null- complain mode profile used in learning mode.  The name of
 668 * the profile is unique and follows the format of parent//null-sid.
 669 *
 670 * null profiles are added to the profile list but the list does not
 671 * hold a count on them so that they are automatically released when
 672 * not in use.
 673 *
 674 * Returns: new refcounted profile else NULL on failure
 675 */
 676struct aa_profile *aa_new_null_profile(struct aa_profile *parent, int hat)
 677{
 678	struct aa_profile *profile = NULL;
 679	char *name;
 680	u32 sid = aa_alloc_sid();
 681
 682	/* freed below */
 683	name = kmalloc(strlen(parent->base.hname) + 2 + 7 + 8, GFP_KERNEL);
 684	if (!name)
 685		goto fail;
 686	sprintf(name, "%s//null-%x", parent->base.hname, sid);
 687
 688	profile = aa_alloc_profile(name);
 689	kfree(name);
 690	if (!profile)
 691		goto fail;
 692
 693	profile->sid = sid;
 694	profile->mode = APPARMOR_COMPLAIN;
 695	profile->flags = PFLAG_NULL;
 696	if (hat)
 697		profile->flags |= PFLAG_HAT;
 698
 699	/* released on free_profile */
 700	profile->parent = aa_get_profile(parent);
 701	profile->ns = aa_get_namespace(parent->ns);
 702
 703	write_lock(&profile->ns->lock);
 704	__list_add_profile(&parent->base.profiles, profile);
 705	write_unlock(&profile->ns->lock);
 706
 707	/* refcount released by caller */
 708	return profile;
 709
 710fail:
 711	aa_free_sid(sid);
 712	return NULL;
 713}
 714
 715/**
 716 * free_profile - free a profile
 717 * @profile: the profile to free  (MAYBE NULL)
 718 *
 719 * Free a profile, its hats and null_profile. All references to the profile,
 720 * its hats and null_profile must have been put.
 721 *
 722 * If the profile was referenced from a task context, free_profile() will
 723 * be called from an rcu callback routine, so we must not sleep here.
 724 */
 725static void free_profile(struct aa_profile *profile)
 726{
 727	AA_DEBUG("%s(%p)\n", __func__, profile);
 728
 729	if (!profile)
 730		return;
 731
 732	if (!list_empty(&profile->base.list)) {
 733		AA_ERROR("%s: internal error, "
 734			 "profile '%s' still on ns list\n",
 735			 __func__, profile->base.name);
 736		BUG();
 737	}
 738
 739	/* free children profiles */
 740	policy_destroy(&profile->base);
 741	aa_put_profile(profile->parent);
 742
 743	aa_put_namespace(profile->ns);
 744	kzfree(profile->rename);
 745
 746	aa_free_file_rules(&profile->file);
 747	aa_free_cap_rules(&profile->caps);
 748	aa_free_rlimit_rules(&profile->rlimits);
 749
 750	aa_free_sid(profile->sid);
 751	aa_put_dfa(profile->xmatch);
 
 752
 753	aa_put_profile(profile->replacedby);
 754
 755	kzfree(profile);
 756}
 757
 758/**
 759 * aa_free_profile_kref - free aa_profile by kref (called by aa_put_profile)
 760 * @kr: kref callback for freeing of a profile  (NOT NULL)
 761 */
 762void aa_free_profile_kref(struct kref *kref)
 763{
 764	struct aa_profile *p = container_of(kref, struct aa_profile,
 765					    base.count);
 766
 767	free_profile(p);
 768}
 769
 770/* TODO: profile accounting - setup in remove */
 771
 772/**
 773 * __find_child - find a profile on @head list with a name matching @name
 774 * @head: list to search  (NOT NULL)
 775 * @name: name of profile (NOT NULL)
 776 *
 777 * Requires: ns lock protecting list be held
 778 *
 779 * Returns: unrefcounted profile ptr, or NULL if not found
 780 */
 781static struct aa_profile *__find_child(struct list_head *head, const char *name)
 782{
 783	return (struct aa_profile *)__policy_find(head, name);
 784}
 785
 786/**
 787 * __strn_find_child - find a profile on @head list using substring of @name
 788 * @head: list to search  (NOT NULL)
 789 * @name: name of profile (NOT NULL)
 790 * @len: length of @name substring to match
 791 *
 792 * Requires: ns lock protecting list be held
 793 *
 794 * Returns: unrefcounted profile ptr, or NULL if not found
 795 */
 796static struct aa_profile *__strn_find_child(struct list_head *head,
 797					    const char *name, int len)
 798{
 799	return (struct aa_profile *)__policy_strn_find(head, name, len);
 800}
 801
 802/**
 803 * aa_find_child - find a profile by @name in @parent
 804 * @parent: profile to search  (NOT NULL)
 805 * @name: profile name to search for  (NOT NULL)
 806 *
 807 * Returns: a refcounted profile or NULL if not found
 808 */
 809struct aa_profile *aa_find_child(struct aa_profile *parent, const char *name)
 810{
 811	struct aa_profile *profile;
 812
 813	read_lock(&parent->ns->lock);
 814	profile = aa_get_profile(__find_child(&parent->base.profiles, name));
 815	read_unlock(&parent->ns->lock);
 816
 817	/* refcount released by caller */
 818	return profile;
 819}
 820
 821/**
 822 * __lookup_parent - lookup the parent of a profile of name @hname
 823 * @ns: namespace to lookup profile in  (NOT NULL)
 824 * @hname: hierarchical profile name to find parent of  (NOT NULL)
 825 *
 826 * Lookups up the parent of a fully qualified profile name, the profile
 827 * that matches hname does not need to exist, in general this
 828 * is used to load a new profile.
 829 *
 830 * Requires: ns->lock be held
 831 *
 832 * Returns: unrefcounted policy or NULL if not found
 833 */
 834static struct aa_policy *__lookup_parent(struct aa_namespace *ns,
 835					 const char *hname)
 836{
 837	struct aa_policy *policy;
 838	struct aa_profile *profile = NULL;
 839	char *split;
 840
 841	policy = &ns->base;
 842
 843	for (split = strstr(hname, "//"); split;) {
 844		profile = __strn_find_child(&policy->profiles, hname,
 845					    split - hname);
 846		if (!profile)
 847			return NULL;
 848		policy = &profile->base;
 849		hname = split + 2;
 850		split = strstr(hname, "//");
 851	}
 852	if (!profile)
 853		return &ns->base;
 854	return &profile->base;
 855}
 856
 857/**
 858 * __lookup_profile - lookup the profile matching @hname
 859 * @base: base list to start looking up profile name from  (NOT NULL)
 860 * @hname: hierarchical profile name  (NOT NULL)
 861 *
 862 * Requires: ns->lock be held
 863 *
 864 * Returns: unrefcounted profile pointer or NULL if not found
 865 *
 866 * Do a relative name lookup, recursing through profile tree.
 867 */
 868static struct aa_profile *__lookup_profile(struct aa_policy *base,
 869					   const char *hname)
 870{
 871	struct aa_profile *profile = NULL;
 872	char *split;
 873
 874	for (split = strstr(hname, "//"); split;) {
 875		profile = __strn_find_child(&base->profiles, hname,
 876					    split - hname);
 877		if (!profile)
 878			return NULL;
 879
 880		base = &profile->base;
 881		hname = split + 2;
 882		split = strstr(hname, "//");
 883	}
 884
 885	profile = __find_child(&base->profiles, hname);
 886
 887	return profile;
 888}
 889
 890/**
 891 * aa_lookup_profile - find a profile by its full or partial name
 892 * @ns: the namespace to start from (NOT NULL)
 893 * @hname: name to do lookup on.  Does not contain namespace prefix (NOT NULL)
 894 *
 895 * Returns: refcounted profile or NULL if not found
 896 */
 897struct aa_profile *aa_lookup_profile(struct aa_namespace *ns, const char *hname)
 898{
 899	struct aa_profile *profile;
 900
 901	read_lock(&ns->lock);
 902	profile = aa_get_profile(__lookup_profile(&ns->base, hname));
 903	read_unlock(&ns->lock);
 904
 
 
 
 
 905	/* refcount released by caller */
 906	return profile;
 907}
 908
 909/**
 910 * replacement_allowed - test to see if replacement is allowed
 911 * @profile: profile to test if it can be replaced  (MAYBE NULL)
 912 * @noreplace: true if replacement shouldn't be allowed but addition is okay
 913 * @info: Returns - info about why replacement failed (NOT NULL)
 914 *
 915 * Returns: %0 if replacement allowed else error code
 916 */
 917static int replacement_allowed(struct aa_profile *profile, int noreplace,
 918			       const char **info)
 919{
 920	if (profile) {
 921		if (profile->flags & PFLAG_IMMUTABLE) {
 922			*info = "cannot replace immutible profile";
 923			return -EPERM;
 924		} else if (noreplace) {
 925			*info = "profile already exists";
 926			return -EEXIST;
 927		}
 928	}
 929	return 0;
 930}
 931
 932/**
 933 * __add_new_profile - simple wrapper around __list_add_profile
 934 * @ns: namespace that profile is being added to  (NOT NULL)
 935 * @policy: the policy container to add the profile to  (NOT NULL)
 936 * @profile: profile to add  (NOT NULL)
 937 *
 938 * add a profile to a list and do other required basic allocations
 939 */
 940static void __add_new_profile(struct aa_namespace *ns, struct aa_policy *policy,
 941			      struct aa_profile *profile)
 942{
 943	if (policy != &ns->base)
 944		/* released on profile replacement or free_profile */
 945		profile->parent = aa_get_profile((struct aa_profile *) policy);
 946	__list_add_profile(&policy->profiles, profile);
 947	/* released on free_profile */
 948	profile->sid = aa_alloc_sid();
 949	profile->ns = aa_get_namespace(ns);
 950}
 951
 952/**
 953 * aa_audit_policy - Do auditing of policy changes
 954 * @op: policy operation being performed
 955 * @gfp: memory allocation flags
 956 * @name: name of profile being manipulated (NOT NULL)
 957 * @info: any extra information to be audited (MAYBE NULL)
 958 * @error: error code
 959 *
 960 * Returns: the error to be returned after audit is done
 961 */
 962static int audit_policy(int op, gfp_t gfp, const char *name, const char *info,
 963			int error)
 964{
 965	struct common_audit_data sa;
 966	COMMON_AUDIT_DATA_INIT(&sa, NONE);
 967	sa.aad.op = op;
 968	sa.aad.name = name;
 969	sa.aad.info = info;
 970	sa.aad.error = error;
 
 
 971
 972	return aa_audit(AUDIT_APPARMOR_STATUS, __aa_current_profile(), gfp,
 973			&sa, NULL);
 974}
 975
 976/**
 977 * aa_may_manage_policy - can the current task manage policy
 978 * @op: the policy manipulation operation being done
 979 *
 980 * Returns: true if the task is allowed to manipulate policy
 981 */
 982bool aa_may_manage_policy(int op)
 983{
 984	/* check if loading policy is locked out */
 985	if (aa_g_lock_policy) {
 986		audit_policy(op, GFP_KERNEL, NULL, "policy_locked", -EACCES);
 987		return 0;
 988	}
 989
 990	if (!capable(CAP_MAC_ADMIN)) {
 991		audit_policy(op, GFP_KERNEL, NULL, "not policy admin", -EACCES);
 992		return 0;
 993	}
 994
 995	return 1;
 996}
 997
 998/**
 999 * aa_replace_profiles - replace profile(s) on the profile list
1000 * @udata: serialized data stream  (NOT NULL)
1001 * @size: size of the serialized data stream
1002 * @noreplace: true if only doing addition, no replacement allowed
1003 *
1004 * unpack and replace a profile on the profile list and uses of that profile
1005 * by any aa_task_cxt.  If the profile does not exist on the profile list
1006 * it is added.
1007 *
1008 * Returns: size of data consumed else error code on failure.
1009 */
1010ssize_t aa_replace_profiles(void *udata, size_t size, bool noreplace)
1011{
1012	struct aa_policy *policy;
1013	struct aa_profile *old_profile = NULL, *new_profile = NULL;
1014	struct aa_profile *rename_profile = NULL;
1015	struct aa_namespace *ns = NULL;
1016	const char *ns_name, *name = NULL, *info = NULL;
1017	int op = OP_PROF_REPL;
1018	ssize_t error;
1019
1020	/* released below */
1021	new_profile = aa_unpack(udata, size, &ns_name);
1022	if (IS_ERR(new_profile)) {
1023		error = PTR_ERR(new_profile);
1024		new_profile = NULL;
1025		goto fail;
1026	}
1027
1028	/* released below */
1029	ns = aa_prepare_namespace(ns_name);
1030	if (!ns) {
1031		info = "failed to prepare namespace";
1032		error = -ENOMEM;
1033		name = ns_name;
1034		goto fail;
1035	}
1036
1037	name = new_profile->base.hname;
1038
1039	write_lock(&ns->lock);
1040	/* no ref on policy only use inside lock */
1041	policy = __lookup_parent(ns, new_profile->base.hname);
1042
1043	if (!policy) {
1044		info = "parent does not exist";
1045		error = -ENOENT;
1046		goto audit;
1047	}
1048
1049	old_profile = __find_child(&policy->profiles, new_profile->base.name);
1050	/* released below */
1051	aa_get_profile(old_profile);
1052
1053	if (new_profile->rename) {
1054		rename_profile = __lookup_profile(&ns->base,
1055						  new_profile->rename);
1056		/* released below */
1057		aa_get_profile(rename_profile);
1058
1059		if (!rename_profile) {
1060			info = "profile to rename does not exist";
1061			name = new_profile->rename;
1062			error = -ENOENT;
1063			goto audit;
1064		}
1065	}
1066
1067	error = replacement_allowed(old_profile, noreplace, &info);
1068	if (error)
1069		goto audit;
1070
1071	error = replacement_allowed(rename_profile, noreplace, &info);
1072	if (error)
1073		goto audit;
1074
1075audit:
1076	if (!old_profile && !rename_profile)
1077		op = OP_PROF_LOAD;
1078
1079	error = audit_policy(op, GFP_ATOMIC, name, info, error);
1080
1081	if (!error) {
1082		if (rename_profile)
1083			__replace_profile(rename_profile, new_profile);
1084		if (old_profile) {
1085			/* when there are both rename and old profiles
1086			 * inherit old profiles sid
1087			 */
1088			if (rename_profile)
1089				aa_free_sid(new_profile->sid);
1090			__replace_profile(old_profile, new_profile);
1091		}
1092		if (!(old_profile || rename_profile))
1093			__add_new_profile(ns, policy, new_profile);
1094	}
1095	write_unlock(&ns->lock);
1096
1097out:
1098	aa_put_namespace(ns);
1099	aa_put_profile(rename_profile);
1100	aa_put_profile(old_profile);
1101	aa_put_profile(new_profile);
1102	if (error)
1103		return error;
1104	return size;
1105
1106fail:
1107	error = audit_policy(op, GFP_KERNEL, name, info, error);
1108	goto out;
1109}
1110
1111/**
1112 * aa_remove_profiles - remove profile(s) from the system
1113 * @fqname: name of the profile or namespace to remove  (NOT NULL)
1114 * @size: size of the name
1115 *
1116 * Remove a profile or sub namespace from the current namespace, so that
1117 * they can not be found anymore and mark them as replaced by unconfined
1118 *
1119 * NOTE: removing confinement does not restore rlimits to preconfinemnet values
1120 *
1121 * Returns: size of data consume else error code if fails
1122 */
1123ssize_t aa_remove_profiles(char *fqname, size_t size)
1124{
1125	struct aa_namespace *root, *ns = NULL;
1126	struct aa_profile *profile = NULL;
1127	const char *name = fqname, *info = NULL;
1128	ssize_t error = 0;
1129
1130	if (*fqname == 0) {
1131		info = "no profile specified";
1132		error = -ENOENT;
1133		goto fail;
1134	}
1135
1136	root = aa_current_profile()->ns;
1137
1138	if (fqname[0] == ':') {
1139		char *ns_name;
1140		name = aa_split_fqname(fqname, &ns_name);
1141		if (ns_name) {
1142			/* released below */
1143			ns = aa_find_namespace(root, ns_name);
1144			if (!ns) {
1145				info = "namespace does not exist";
1146				error = -ENOENT;
1147				goto fail;
1148			}
1149		}
1150	} else
1151		/* released below */
1152		ns = aa_get_namespace(root);
1153
1154	if (!name) {
1155		/* remove namespace - can only happen if fqname[0] == ':' */
1156		write_lock(&ns->parent->lock);
1157		__remove_namespace(ns);
1158		write_unlock(&ns->parent->lock);
1159	} else {
1160		/* remove profile */
1161		write_lock(&ns->lock);
1162		profile = aa_get_profile(__lookup_profile(&ns->base, name));
1163		if (!profile) {
1164			error = -ENOENT;
1165			info = "profile does not exist";
1166			goto fail_ns_lock;
1167		}
1168		name = profile->base.hname;
1169		__remove_profile(profile);
1170		write_unlock(&ns->lock);
1171	}
1172
1173	/* don't fail removal if audit fails */
1174	(void) audit_policy(OP_PROF_RM, GFP_KERNEL, name, info, error);
1175	aa_put_namespace(ns);
1176	aa_put_profile(profile);
1177	return size;
1178
1179fail_ns_lock:
1180	write_unlock(&ns->lock);
1181	aa_put_namespace(ns);
1182
1183fail:
1184	(void) audit_policy(OP_PROF_RM, GFP_KERNEL, name, info, error);
1185	return error;
1186}