xref: /openbmc/linux/security/apparmor/policy.c (revision 4e1a33b1)
1 /*
2  * AppArmor security module
3  *
4  * This file contains AppArmor policy manipulation functions
5  *
6  * Copyright (C) 1998-2008 Novell/SUSE
7  * Copyright 2009-2010 Canonical Ltd.
8  *
9  * This program is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU General Public License as
11  * published by the Free Software Foundation, version 2 of the
12  * License.
13  *
14  *
15  * AppArmor policy is based around profiles, which contain the rules a
16  * task is confined by.  Every task in the system has a profile attached
17  * to it determined either by matching "unconfined" tasks against the
18  * visible set of profiles or by following a profiles attachment rules.
19  *
20  * Each profile exists in a profile namespace which is a container of
21  * visible profiles.  Each namespace contains a special "unconfined" profile,
22  * which doesn't enforce any confinement on a task beyond DAC.
23  *
24  * Namespace and profile names can be written together in either
25  * of two syntaxes.
26  *	:namespace:profile - used by kernel interfaces for easy detection
27  *	namespace://profile - used by policy
28  *
29  * Profile names can not start with : or @ or ^ and may not contain \0
30  *
31  * Reserved profile names
32  *	unconfined - special automatically generated unconfined profile
33  *	inherit - special name to indicate profile inheritance
34  *	null-XXXX-YYYY - special automatically generated learning profiles
35  *
36  * Namespace names may not start with / or @ and may not contain \0 or :
37  * Reserved namespace names
38  *	user-XXXX - user defined profiles
39  *
40  * a // in a profile or namespace name indicates a hierarchical name with the
41  * name before the // being the parent and the name after the child.
42  *
43  * Profile and namespace hierarchies serve two different but similar purposes.
44  * The namespace contains the set of visible profiles that are considered
45  * for attachment.  The hierarchy of namespaces allows for virtualizing
46  * the namespace so that for example a chroot can have its own set of profiles
47  * which may define some local user namespaces.
48  * The profile hierarchy severs two distinct purposes,
49  * -  it allows for sub profiles or hats, which allows an application to run
50  *    subprograms under its own profile with different restriction than it
51  *    self, and not have it use the system profile.
52  *    eg. if a mail program starts an editor, the policy might make the
53  *        restrictions tighter on the editor tighter than the mail program,
54  *        and definitely different than general editor restrictions
55  * - it allows for binary hierarchy of profiles, so that execution history
56  *   is preserved.  This feature isn't exploited by AppArmor reference policy
57  *   but is allowed.  NOTE: this is currently suboptimal because profile
58  *   aliasing is not currently implemented so that a profile for each
59  *   level must be defined.
60  *   eg. /bin/bash///bin/ls as a name would indicate /bin/ls was started
61  *       from /bin/bash
62  *
63  *   A profile or namespace name that can contain one or more // separators
64  *   is referred to as an hname (hierarchical).
65  *   eg.  /bin/bash//bin/ls
66  *
67  *   An fqname is a name that may contain both namespace and profile hnames.
68  *   eg. :ns:/bin/bash//bin/ls
69  *
70  * NOTES:
71  *   - locking of profile lists is currently fairly coarse.  All profile
72  *     lists within a namespace use the namespace lock.
73  * FIXME: move profile lists to using rcu_lists
74  */
75 
76 #include <linux/slab.h>
77 #include <linux/spinlock.h>
78 #include <linux/string.h>
79 #include <linux/user_namespace.h>
80 
81 #include "include/apparmor.h"
82 #include "include/capability.h"
83 #include "include/context.h"
84 #include "include/file.h"
85 #include "include/ipc.h"
86 #include "include/match.h"
87 #include "include/path.h"
88 #include "include/policy.h"
89 #include "include/policy_ns.h"
90 #include "include/policy_unpack.h"
91 #include "include/resource.h"
92 
93 int unprivileged_userns_apparmor_policy = 1;
94 
95 const char *const aa_profile_mode_names[] = {
96 	"enforce",
97 	"complain",
98 	"kill",
99 	"unconfined",
100 };
101 
102 /* requires profile list write lock held */
103 void __aa_update_proxy(struct aa_profile *orig, struct aa_profile *new)
104 {
105 	struct aa_profile *tmp;
106 
107 	tmp = rcu_dereference_protected(orig->proxy->profile,
108 					mutex_is_locked(&orig->ns->lock));
109 	rcu_assign_pointer(orig->proxy->profile, aa_get_profile(new));
110 	orig->flags |= PFLAG_STALE;
111 	aa_put_profile(tmp);
112 }
113 
114 /**
115  * __list_add_profile - add a profile to a list
116  * @list: list to add it to  (NOT NULL)
117  * @profile: the profile to add  (NOT NULL)
118  *
119  * refcount @profile, should be put by __list_remove_profile
120  *
121  * Requires: namespace lock be held, or list not be shared
122  */
123 static void __list_add_profile(struct list_head *list,
124 			       struct aa_profile *profile)
125 {
126 	list_add_rcu(&profile->base.list, list);
127 	/* get list reference */
128 	aa_get_profile(profile);
129 }
130 
131 /**
132  * __list_remove_profile - remove a profile from the list it is on
133  * @profile: the profile to remove  (NOT NULL)
134  *
135  * remove a profile from the list, warning generally removal should
136  * be done with __replace_profile as most profile removals are
137  * replacements to the unconfined profile.
138  *
139  * put @profile list refcount
140  *
141  * Requires: namespace lock be held, or list not have been live
142  */
143 static void __list_remove_profile(struct aa_profile *profile)
144 {
145 	list_del_rcu(&profile->base.list);
146 	aa_put_profile(profile);
147 }
148 
149 /**
150  * __remove_profile - remove old profile, and children
151  * @profile: profile to be replaced  (NOT NULL)
152  *
153  * Requires: namespace list lock be held, or list not be shared
154  */
155 static void __remove_profile(struct aa_profile *profile)
156 {
157 	/* release any children lists first */
158 	__aa_profile_list_release(&profile->base.profiles);
159 	/* released by free_profile */
160 	__aa_update_proxy(profile, profile->ns->unconfined);
161 	__aa_fs_profile_rmdir(profile);
162 	__list_remove_profile(profile);
163 }
164 
165 /**
166  * __aa_profile_list_release - remove all profiles on the list and put refs
167  * @head: list of profiles  (NOT NULL)
168  *
169  * Requires: namespace lock be held
170  */
171 void __aa_profile_list_release(struct list_head *head)
172 {
173 	struct aa_profile *profile, *tmp;
174 	list_for_each_entry_safe(profile, tmp, head, base.list)
175 		__remove_profile(profile);
176 }
177 
178 
179 static void free_proxy(struct aa_proxy *p)
180 {
181 	if (p) {
182 		/* r->profile will not be updated any more as r is dead */
183 		aa_put_profile(rcu_dereference_protected(p->profile, true));
184 		kzfree(p);
185 	}
186 }
187 
188 
189 void aa_free_proxy_kref(struct kref *kref)
190 {
191 	struct aa_proxy *p = container_of(kref, struct aa_proxy, count);
192 
193 	free_proxy(p);
194 }
195 
196 /**
197  * aa_free_data - free a data blob
198  * @ptr: data to free
199  * @arg: unused
200  */
201 static void aa_free_data(void *ptr, void *arg)
202 {
203 	struct aa_data *data = ptr;
204 
205 	kzfree(data->data);
206 	kzfree(data->key);
207 	kzfree(data);
208 }
209 
210 /**
211  * aa_free_profile - free a profile
212  * @profile: the profile to free  (MAYBE NULL)
213  *
214  * Free a profile, its hats and null_profile. All references to the profile,
215  * its hats and null_profile must have been put.
216  *
217  * If the profile was referenced from a task context, free_profile() will
218  * be called from an rcu callback routine, so we must not sleep here.
219  */
220 void aa_free_profile(struct aa_profile *profile)
221 {
222 	struct rhashtable *rht;
223 
224 	AA_DEBUG("%s(%p)\n", __func__, profile);
225 
226 	if (!profile)
227 		return;
228 
229 	/* free children profiles */
230 	aa_policy_destroy(&profile->base);
231 	aa_put_profile(rcu_access_pointer(profile->parent));
232 
233 	aa_put_ns(profile->ns);
234 	kzfree(profile->rename);
235 
236 	aa_free_file_rules(&profile->file);
237 	aa_free_cap_rules(&profile->caps);
238 	aa_free_rlimit_rules(&profile->rlimits);
239 
240 	kzfree(profile->dirname);
241 	aa_put_dfa(profile->xmatch);
242 	aa_put_dfa(profile->policy.dfa);
243 	aa_put_proxy(profile->proxy);
244 
245 	if (profile->data) {
246 		rht = profile->data;
247 		profile->data = NULL;
248 		rhashtable_free_and_destroy(rht, aa_free_data, NULL);
249 		kzfree(rht);
250 	}
251 
252 	kzfree(profile->hash);
253 	aa_put_loaddata(profile->rawdata);
254 	kzfree(profile);
255 }
256 
257 /**
258  * aa_free_profile_rcu - free aa_profile by rcu (called by aa_free_profile_kref)
259  * @head: rcu_head callback for freeing of a profile  (NOT NULL)
260  */
261 static void aa_free_profile_rcu(struct rcu_head *head)
262 {
263 	struct aa_profile *p = container_of(head, struct aa_profile, rcu);
264 	if (p->flags & PFLAG_NS_COUNT)
265 		aa_free_ns(p->ns);
266 	else
267 		aa_free_profile(p);
268 }
269 
270 /**
271  * aa_free_profile_kref - free aa_profile by kref (called by aa_put_profile)
272  * @kr: kref callback for freeing of a profile  (NOT NULL)
273  */
274 void aa_free_profile_kref(struct kref *kref)
275 {
276 	struct aa_profile *p = container_of(kref, struct aa_profile, count);
277 	call_rcu(&p->rcu, aa_free_profile_rcu);
278 }
279 
280 /**
281  * aa_alloc_profile - allocate, initialize and return a new profile
282  * @hname: name of the profile  (NOT NULL)
283  * @gfp: allocation type
284  *
285  * Returns: refcount profile or NULL on failure
286  */
287 struct aa_profile *aa_alloc_profile(const char *hname, gfp_t gfp)
288 {
289 	struct aa_profile *profile;
290 
291 	/* freed by free_profile - usually through aa_put_profile */
292 	profile = kzalloc(sizeof(*profile), gfp);
293 	if (!profile)
294 		return NULL;
295 
296 	profile->proxy = kzalloc(sizeof(struct aa_proxy), gfp);
297 	if (!profile->proxy)
298 		goto fail;
299 	kref_init(&profile->proxy->count);
300 
301 	if (!aa_policy_init(&profile->base, NULL, hname, gfp))
302 		goto fail;
303 	kref_init(&profile->count);
304 
305 	/* refcount released by caller */
306 	return profile;
307 
308 fail:
309 	kzfree(profile->proxy);
310 	kzfree(profile);
311 
312 	return NULL;
313 }
314 
315 /**
316  * aa_new_null_profile - create or find a null-X learning profile
317  * @parent: profile that caused this profile to be created (NOT NULL)
318  * @hat: true if the null- learning profile is a hat
319  * @base: name to base the null profile off of
320  * @gfp: type of allocation
321  *
322  * Find/Create a null- complain mode profile used in learning mode.  The
323  * name of the profile is unique and follows the format of parent//null-XXX.
324  * where XXX is based on the @name or if that fails or is not supplied
325  * a unique number
326  *
327  * null profiles are added to the profile list but the list does not
328  * hold a count on them so that they are automatically released when
329  * not in use.
330  *
331  * Returns: new refcounted profile else NULL on failure
332  */
333 struct aa_profile *aa_new_null_profile(struct aa_profile *parent, bool hat,
334 				       const char *base, gfp_t gfp)
335 {
336 	struct aa_profile *profile;
337 	char *name;
338 
339 	AA_BUG(!parent);
340 
341 	if (base) {
342 		name = kmalloc(strlen(parent->base.hname) + 8 + strlen(base),
343 			       gfp);
344 		if (name) {
345 			sprintf(name, "%s//null-%s", parent->base.hname, base);
346 			goto name;
347 		}
348 		/* fall through to try shorter uniq */
349 	}
350 
351 	name = kmalloc(strlen(parent->base.hname) + 2 + 7 + 8, gfp);
352 	if (!name)
353 		return NULL;
354 	sprintf(name, "%s//null-%x", parent->base.hname,
355 		atomic_inc_return(&parent->ns->uniq_null));
356 
357 name:
358 	/* lookup to see if this is a dup creation */
359 	profile = aa_find_child(parent, basename(name));
360 	if (profile)
361 		goto out;
362 
363 	profile = aa_alloc_profile(name, gfp);
364 	if (!profile)
365 		goto fail;
366 
367 	profile->mode = APPARMOR_COMPLAIN;
368 	profile->flags |= PFLAG_NULL;
369 	if (hat)
370 		profile->flags |= PFLAG_HAT;
371 	profile->path_flags = parent->path_flags;
372 
373 	/* released on free_profile */
374 	rcu_assign_pointer(profile->parent, aa_get_profile(parent));
375 	profile->ns = aa_get_ns(parent->ns);
376 	profile->file.dfa = aa_get_dfa(nulldfa);
377 	profile->policy.dfa = aa_get_dfa(nulldfa);
378 
379 	mutex_lock(&profile->ns->lock);
380 	__list_add_profile(&parent->base.profiles, profile);
381 	mutex_unlock(&profile->ns->lock);
382 
383 	/* refcount released by caller */
384 out:
385 	kfree(name);
386 
387 	return profile;
388 
389 fail:
390 	kfree(name);
391 	aa_free_profile(profile);
392 	return NULL;
393 }
394 
395 /* TODO: profile accounting - setup in remove */
396 
397 /**
398  * __find_child - find a profile on @head list with a name matching @name
399  * @head: list to search  (NOT NULL)
400  * @name: name of profile (NOT NULL)
401  *
402  * Requires: rcu_read_lock be held
403  *
404  * Returns: unrefcounted profile ptr, or NULL if not found
405  */
406 static struct aa_profile *__find_child(struct list_head *head, const char *name)
407 {
408 	return (struct aa_profile *)__policy_find(head, name);
409 }
410 
411 /**
412  * __strn_find_child - find a profile on @head list using substring of @name
413  * @head: list to search  (NOT NULL)
414  * @name: name of profile (NOT NULL)
415  * @len: length of @name substring to match
416  *
417  * Requires: rcu_read_lock be held
418  *
419  * Returns: unrefcounted profile ptr, or NULL if not found
420  */
421 static struct aa_profile *__strn_find_child(struct list_head *head,
422 					    const char *name, int len)
423 {
424 	return (struct aa_profile *)__policy_strn_find(head, name, len);
425 }
426 
427 /**
428  * aa_find_child - find a profile by @name in @parent
429  * @parent: profile to search  (NOT NULL)
430  * @name: profile name to search for  (NOT NULL)
431  *
432  * Returns: a refcounted profile or NULL if not found
433  */
434 struct aa_profile *aa_find_child(struct aa_profile *parent, const char *name)
435 {
436 	struct aa_profile *profile;
437 
438 	rcu_read_lock();
439 	do {
440 		profile = __find_child(&parent->base.profiles, name);
441 	} while (profile && !aa_get_profile_not0(profile));
442 	rcu_read_unlock();
443 
444 	/* refcount released by caller */
445 	return profile;
446 }
447 
448 /**
449  * __lookup_parent - lookup the parent of a profile of name @hname
450  * @ns: namespace to lookup profile in  (NOT NULL)
451  * @hname: hierarchical profile name to find parent of  (NOT NULL)
452  *
453  * Lookups up the parent of a fully qualified profile name, the profile
454  * that matches hname does not need to exist, in general this
455  * is used to load a new profile.
456  *
457  * Requires: rcu_read_lock be held
458  *
459  * Returns: unrefcounted policy or NULL if not found
460  */
461 static struct aa_policy *__lookup_parent(struct aa_ns *ns,
462 					 const char *hname)
463 {
464 	struct aa_policy *policy;
465 	struct aa_profile *profile = NULL;
466 	char *split;
467 
468 	policy = &ns->base;
469 
470 	for (split = strstr(hname, "//"); split;) {
471 		profile = __strn_find_child(&policy->profiles, hname,
472 					    split - hname);
473 		if (!profile)
474 			return NULL;
475 		policy = &profile->base;
476 		hname = split + 2;
477 		split = strstr(hname, "//");
478 	}
479 	if (!profile)
480 		return &ns->base;
481 	return &profile->base;
482 }
483 
484 /**
485  * __lookupn_profile - lookup the profile matching @hname
486  * @base: base list to start looking up profile name from  (NOT NULL)
487  * @hname: hierarchical profile name  (NOT NULL)
488  * @n: length of @hname
489  *
490  * Requires: rcu_read_lock be held
491  *
492  * Returns: unrefcounted profile pointer or NULL if not found
493  *
494  * Do a relative name lookup, recursing through profile tree.
495  */
496 static struct aa_profile *__lookupn_profile(struct aa_policy *base,
497 					    const char *hname, size_t n)
498 {
499 	struct aa_profile *profile = NULL;
500 	const char *split;
501 
502 	for (split = strnstr(hname, "//", n); split;
503 	     split = strnstr(hname, "//", n)) {
504 		profile = __strn_find_child(&base->profiles, hname,
505 					    split - hname);
506 		if (!profile)
507 			return NULL;
508 
509 		base = &profile->base;
510 		n -= split + 2 - hname;
511 		hname = split + 2;
512 	}
513 
514 	if (n)
515 		return __strn_find_child(&base->profiles, hname, n);
516 	return NULL;
517 }
518 
519 static struct aa_profile *__lookup_profile(struct aa_policy *base,
520 					   const char *hname)
521 {
522 	return __lookupn_profile(base, hname, strlen(hname));
523 }
524 
525 /**
526  * aa_lookup_profile - find a profile by its full or partial name
527  * @ns: the namespace to start from (NOT NULL)
528  * @hname: name to do lookup on.  Does not contain namespace prefix (NOT NULL)
529  * @n: size of @hname
530  *
531  * Returns: refcounted profile or NULL if not found
532  */
533 struct aa_profile *aa_lookupn_profile(struct aa_ns *ns, const char *hname,
534 				      size_t n)
535 {
536 	struct aa_profile *profile;
537 
538 	rcu_read_lock();
539 	do {
540 		profile = __lookupn_profile(&ns->base, hname, n);
541 	} while (profile && !aa_get_profile_not0(profile));
542 	rcu_read_unlock();
543 
544 	/* the unconfined profile is not in the regular profile list */
545 	if (!profile && strncmp(hname, "unconfined", n) == 0)
546 		profile = aa_get_newest_profile(ns->unconfined);
547 
548 	/* refcount released by caller */
549 	return profile;
550 }
551 
552 struct aa_profile *aa_lookup_profile(struct aa_ns *ns, const char *hname)
553 {
554 	return aa_lookupn_profile(ns, hname, strlen(hname));
555 }
556 
557 struct aa_profile *aa_fqlookupn_profile(struct aa_profile *base,
558 					const char *fqname, size_t n)
559 {
560 	struct aa_profile *profile;
561 	struct aa_ns *ns;
562 	const char *name, *ns_name;
563 	size_t ns_len;
564 
565 	name = aa_splitn_fqname(fqname, n, &ns_name, &ns_len);
566 	if (ns_name) {
567 		ns = aa_findn_ns(base->ns, ns_name, ns_len);
568 		if (!ns)
569 			return NULL;
570 	} else
571 		ns = aa_get_ns(base->ns);
572 
573 	if (name)
574 		profile = aa_lookupn_profile(ns, name, n - (name - fqname));
575 	else if (ns)
576 		/* default profile for ns, currently unconfined */
577 		profile = aa_get_newest_profile(ns->unconfined);
578 	else
579 		profile = NULL;
580 	aa_put_ns(ns);
581 
582 	return profile;
583 }
584 
585 /**
586  * replacement_allowed - test to see if replacement is allowed
587  * @profile: profile to test if it can be replaced  (MAYBE NULL)
588  * @noreplace: true if replacement shouldn't be allowed but addition is okay
589  * @info: Returns - info about why replacement failed (NOT NULL)
590  *
591  * Returns: %0 if replacement allowed else error code
592  */
593 static int replacement_allowed(struct aa_profile *profile, int noreplace,
594 			       const char **info)
595 {
596 	if (profile) {
597 		if (profile->flags & PFLAG_IMMUTABLE) {
598 			*info = "cannot replace immutible profile";
599 			return -EPERM;
600 		} else if (noreplace) {
601 			*info = "profile already exists";
602 			return -EEXIST;
603 		}
604 	}
605 	return 0;
606 }
607 
608 /* audit callback for net specific fields */
609 static void audit_cb(struct audit_buffer *ab, void *va)
610 {
611 	struct common_audit_data *sa = va;
612 
613 	if (aad(sa)->iface.ns) {
614 		audit_log_format(ab, " ns=");
615 		audit_log_untrustedstring(ab, aad(sa)->iface.ns);
616 	}
617 }
618 
619 /**
620  * aa_audit_policy - Do auditing of policy changes
621  * @profile: profile to check if it can manage policy
622  * @op: policy operation being performed
623  * @gfp: memory allocation flags
624  * @nsname: name of the ns being manipulated (MAY BE NULL)
625  * @name: name of profile being manipulated (NOT NULL)
626  * @info: any extra information to be audited (MAYBE NULL)
627  * @error: error code
628  *
629  * Returns: the error to be returned after audit is done
630  */
631 static int audit_policy(struct aa_profile *profile, const char *op,
632 			const char *nsname, const char *name,
633 			const char *info, int error)
634 {
635 	DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, op);
636 
637 	aad(&sa)->iface.ns = nsname;
638 	aad(&sa)->name = name;
639 	aad(&sa)->info = info;
640 	aad(&sa)->error = error;
641 
642 	return aa_audit(AUDIT_APPARMOR_STATUS, profile, &sa, audit_cb);
643 }
644 
645 /**
646  * policy_view_capable - check if viewing policy in at @ns is allowed
647  * ns: namespace being viewed by current task (may be NULL)
648  * Returns: true if viewing policy is allowed
649  *
650  * If @ns is NULL then the namespace being viewed is assumed to be the
651  * tasks current namespace.
652  */
653 bool policy_view_capable(struct aa_ns *ns)
654 {
655 	struct user_namespace *user_ns = current_user_ns();
656 	struct aa_ns *view_ns = aa_get_current_ns();
657 	bool root_in_user_ns = uid_eq(current_euid(), make_kuid(user_ns, 0)) ||
658 			       in_egroup_p(make_kgid(user_ns, 0));
659 	bool response = false;
660 	if (!ns)
661 		ns = view_ns;
662 
663 	if (root_in_user_ns && aa_ns_visible(view_ns, ns, true) &&
664 	    (user_ns == &init_user_ns ||
665 	     (unprivileged_userns_apparmor_policy != 0 &&
666 	      user_ns->level == view_ns->level)))
667 		response = true;
668 	aa_put_ns(view_ns);
669 
670 	return response;
671 }
672 
673 bool policy_admin_capable(struct aa_ns *ns)
674 {
675 	struct user_namespace *user_ns = current_user_ns();
676 	bool capable = ns_capable(user_ns, CAP_MAC_ADMIN);
677 
678 	AA_DEBUG("cap_mac_admin? %d\n", capable);
679 	AA_DEBUG("policy locked? %d\n", aa_g_lock_policy);
680 
681 	return policy_view_capable(ns) && capable && !aa_g_lock_policy;
682 }
683 
684 /**
685  * aa_may_manage_policy - can the current task manage policy
686  * @profile: profile to check if it can manage policy
687  * @op: the policy manipulation operation being done
688  *
689  * Returns: 0 if the task is allowed to manipulate policy else error
690  */
691 int aa_may_manage_policy(struct aa_profile *profile, struct aa_ns *ns,
692 			 const char *op)
693 {
694 	/* check if loading policy is locked out */
695 	if (aa_g_lock_policy)
696 		return audit_policy(profile, op, NULL, NULL,
697 			     "policy_locked", -EACCES);
698 
699 	if (!policy_admin_capable(ns))
700 		return audit_policy(profile, op, NULL, NULL,
701 				    "not policy admin", -EACCES);
702 
703 	/* TODO: add fine grained mediation of policy loads */
704 	return 0;
705 }
706 
707 static struct aa_profile *__list_lookup_parent(struct list_head *lh,
708 					       struct aa_profile *profile)
709 {
710 	const char *base = basename(profile->base.hname);
711 	long len = base - profile->base.hname;
712 	struct aa_load_ent *ent;
713 
714 	/* parent won't have trailing // so remove from len */
715 	if (len <= 2)
716 		return NULL;
717 	len -= 2;
718 
719 	list_for_each_entry(ent, lh, list) {
720 		if (ent->new == profile)
721 			continue;
722 		if (strncmp(ent->new->base.hname, profile->base.hname, len) ==
723 		    0 && ent->new->base.hname[len] == 0)
724 			return ent->new;
725 	}
726 
727 	return NULL;
728 }
729 
730 /**
731  * __replace_profile - replace @old with @new on a list
732  * @old: profile to be replaced  (NOT NULL)
733  * @new: profile to replace @old with  (NOT NULL)
734  * @share_proxy: transfer @old->proxy to @new
735  *
736  * Will duplicate and refcount elements that @new inherits from @old
737  * and will inherit @old children.
738  *
739  * refcount @new for list, put @old list refcount
740  *
741  * Requires: namespace list lock be held, or list not be shared
742  */
743 static void __replace_profile(struct aa_profile *old, struct aa_profile *new,
744 			      bool share_proxy)
745 {
746 	struct aa_profile *child, *tmp;
747 
748 	if (!list_empty(&old->base.profiles)) {
749 		LIST_HEAD(lh);
750 		list_splice_init_rcu(&old->base.profiles, &lh, synchronize_rcu);
751 
752 		list_for_each_entry_safe(child, tmp, &lh, base.list) {
753 			struct aa_profile *p;
754 
755 			list_del_init(&child->base.list);
756 			p = __find_child(&new->base.profiles, child->base.name);
757 			if (p) {
758 				/* @p replaces @child  */
759 				__replace_profile(child, p, share_proxy);
760 				continue;
761 			}
762 
763 			/* inherit @child and its children */
764 			/* TODO: update hname of inherited children */
765 			/* list refcount transferred to @new */
766 			p = aa_deref_parent(child);
767 			rcu_assign_pointer(child->parent, aa_get_profile(new));
768 			list_add_rcu(&child->base.list, &new->base.profiles);
769 			aa_put_profile(p);
770 		}
771 	}
772 
773 	if (!rcu_access_pointer(new->parent)) {
774 		struct aa_profile *parent = aa_deref_parent(old);
775 		rcu_assign_pointer(new->parent, aa_get_profile(parent));
776 	}
777 	__aa_update_proxy(old, new);
778 	if (share_proxy) {
779 		aa_put_proxy(new->proxy);
780 		new->proxy = aa_get_proxy(old->proxy);
781 	} else if (!rcu_access_pointer(new->proxy->profile))
782 		/* aafs interface uses proxy */
783 		rcu_assign_pointer(new->proxy->profile,
784 				   aa_get_profile(new));
785 	__aa_fs_profile_migrate_dents(old, new);
786 
787 	if (list_empty(&new->base.list)) {
788 		/* new is not on a list already */
789 		list_replace_rcu(&old->base.list, &new->base.list);
790 		aa_get_profile(new);
791 		aa_put_profile(old);
792 	} else
793 		__list_remove_profile(old);
794 }
795 
796 /**
797  * __lookup_replace - lookup replacement information for a profile
798  * @ns - namespace the lookup occurs in
799  * @hname - name of profile to lookup
800  * @noreplace - true if not replacing an existing profile
801  * @p - Returns: profile to be replaced
802  * @info - Returns: info string on why lookup failed
803  *
804  * Returns: profile to replace (no ref) on success else ptr error
805  */
806 static int __lookup_replace(struct aa_ns *ns, const char *hname,
807 			    bool noreplace, struct aa_profile **p,
808 			    const char **info)
809 {
810 	*p = aa_get_profile(__lookup_profile(&ns->base, hname));
811 	if (*p) {
812 		int error = replacement_allowed(*p, noreplace, info);
813 		if (error) {
814 			*info = "profile can not be replaced";
815 			return error;
816 		}
817 	}
818 
819 	return 0;
820 }
821 
822 /**
823  * aa_replace_profiles - replace profile(s) on the profile list
824  * @view: namespace load is viewed from
825  * @label: label that is attempting to load/replace policy
826  * @noreplace: true if only doing addition, no replacement allowed
827  * @udata: serialized data stream  (NOT NULL)
828  *
829  * unpack and replace a profile on the profile list and uses of that profile
830  * by any aa_task_ctx.  If the profile does not exist on the profile list
831  * it is added.
832  *
833  * Returns: size of data consumed else error code on failure.
834  */
835 ssize_t aa_replace_profiles(struct aa_ns *view, struct aa_profile *profile,
836 			    bool noreplace, struct aa_loaddata *udata)
837 {
838 	const char *ns_name, *info = NULL;
839 	struct aa_ns *ns = NULL;
840 	struct aa_load_ent *ent, *tmp;
841 	const char *op = OP_PROF_REPL;
842 	ssize_t count, error;
843 	LIST_HEAD(lh);
844 
845 	/* released below */
846 	error = aa_unpack(udata, &lh, &ns_name);
847 	if (error)
848 		goto out;
849 
850 	/* ensure that profiles are all for the same ns
851 	 * TODO: update locking to remove this constaint. All profiles in
852 	 *       the load set must succeed as a set or the load will
853 	 *       fail. Sort ent list and take ns locks in hierarchy order
854 	 */
855 	count = 0;
856 	list_for_each_entry(ent, &lh, list) {
857 		if (ns_name) {
858 			if (ent->ns_name &&
859 			    strcmp(ent->ns_name, ns_name) != 0) {
860 				info = "policy load has mixed namespaces";
861 				error = -EACCES;
862 				goto fail;
863 			}
864 		} else if (ent->ns_name) {
865 			if (count) {
866 				info = "policy load has mixed namespaces";
867 				error = -EACCES;
868 				goto fail;
869 			}
870 			ns_name = ent->ns_name;
871 		} else
872 			count++;
873 	}
874 	if (ns_name) {
875 		ns = aa_prepare_ns(view, ns_name);
876 		if (IS_ERR(ns)) {
877 			info = "failed to prepare namespace";
878 			error = PTR_ERR(ns);
879 			ns = NULL;
880 			goto fail;
881 		}
882 	} else
883 		ns = aa_get_ns(view);
884 
885 	mutex_lock(&ns->lock);
886 	/* setup parent and ns info */
887 	list_for_each_entry(ent, &lh, list) {
888 		struct aa_policy *policy;
889 		ent->new->rawdata = aa_get_loaddata(udata);
890 		error = __lookup_replace(ns, ent->new->base.hname, noreplace,
891 					 &ent->old, &info);
892 		if (error)
893 			goto fail_lock;
894 
895 		if (ent->new->rename) {
896 			error = __lookup_replace(ns, ent->new->rename,
897 						 noreplace, &ent->rename,
898 						 &info);
899 			if (error)
900 				goto fail_lock;
901 		}
902 
903 		/* released when @new is freed */
904 		ent->new->ns = aa_get_ns(ns);
905 
906 		if (ent->old || ent->rename)
907 			continue;
908 
909 		/* no ref on policy only use inside lock */
910 		policy = __lookup_parent(ns, ent->new->base.hname);
911 		if (!policy) {
912 			struct aa_profile *p;
913 			p = __list_lookup_parent(&lh, ent->new);
914 			if (!p) {
915 				error = -ENOENT;
916 				info = "parent does not exist";
917 				goto fail_lock;
918 			}
919 			rcu_assign_pointer(ent->new->parent, aa_get_profile(p));
920 		} else if (policy != &ns->base) {
921 			/* released on profile replacement or free_profile */
922 			struct aa_profile *p = (struct aa_profile *) policy;
923 			rcu_assign_pointer(ent->new->parent, aa_get_profile(p));
924 		}
925 	}
926 
927 	/* create new fs entries for introspection if needed */
928 	list_for_each_entry(ent, &lh, list) {
929 		if (ent->old) {
930 			/* inherit old interface files */
931 
932 			/* if (ent->rename)
933 				TODO: support rename */
934 		/* } else if (ent->rename) {
935 			TODO: support rename */
936 		} else {
937 			struct dentry *parent;
938 			if (rcu_access_pointer(ent->new->parent)) {
939 				struct aa_profile *p;
940 				p = aa_deref_parent(ent->new);
941 				parent = prof_child_dir(p);
942 			} else
943 				parent = ns_subprofs_dir(ent->new->ns);
944 			error = __aa_fs_profile_mkdir(ent->new, parent);
945 		}
946 
947 		if (error) {
948 			info = "failed to create ";
949 			goto fail_lock;
950 		}
951 	}
952 
953 	/* Done with checks that may fail - do actual replacement */
954 	list_for_each_entry_safe(ent, tmp, &lh, list) {
955 		list_del_init(&ent->list);
956 		op = (!ent->old && !ent->rename) ? OP_PROF_LOAD : OP_PROF_REPL;
957 
958 		audit_policy(profile, op, NULL, ent->new->base.hname,
959 			     NULL, error);
960 
961 		if (ent->old) {
962 			__replace_profile(ent->old, ent->new, 1);
963 			if (ent->rename) {
964 				/* aafs interface uses proxy */
965 				struct aa_proxy *r = ent->new->proxy;
966 				rcu_assign_pointer(r->profile,
967 						   aa_get_profile(ent->new));
968 				__replace_profile(ent->rename, ent->new, 0);
969 			}
970 		} else if (ent->rename) {
971 			/* aafs interface uses proxy */
972 			rcu_assign_pointer(ent->new->proxy->profile,
973 					   aa_get_profile(ent->new));
974 			__replace_profile(ent->rename, ent->new, 0);
975 		} else if (ent->new->parent) {
976 			struct aa_profile *parent, *newest;
977 			parent = aa_deref_parent(ent->new);
978 			newest = aa_get_newest_profile(parent);
979 
980 			/* parent replaced in this atomic set? */
981 			if (newest != parent) {
982 				aa_get_profile(newest);
983 				rcu_assign_pointer(ent->new->parent, newest);
984 				aa_put_profile(parent);
985 			}
986 			/* aafs interface uses proxy */
987 			rcu_assign_pointer(ent->new->proxy->profile,
988 					   aa_get_profile(ent->new));
989 			__list_add_profile(&newest->base.profiles, ent->new);
990 			aa_put_profile(newest);
991 		} else {
992 			/* aafs interface uses proxy */
993 			rcu_assign_pointer(ent->new->proxy->profile,
994 					   aa_get_profile(ent->new));
995 			__list_add_profile(&ns->base.profiles, ent->new);
996 		}
997 		aa_load_ent_free(ent);
998 	}
999 	mutex_unlock(&ns->lock);
1000 
1001 out:
1002 	aa_put_ns(ns);
1003 
1004 	if (error)
1005 		return error;
1006 	return udata->size;
1007 
1008 fail_lock:
1009 	mutex_unlock(&ns->lock);
1010 
1011 	/* audit cause of failure */
1012 	op = (!ent->old) ? OP_PROF_LOAD : OP_PROF_REPL;
1013 fail:
1014 	audit_policy(profile, op, ns_name, ent->new->base.hname,
1015 		     info, error);
1016 	/* audit status that rest of profiles in the atomic set failed too */
1017 	info = "valid profile in failed atomic policy load";
1018 	list_for_each_entry(tmp, &lh, list) {
1019 		if (tmp == ent) {
1020 			info = "unchecked profile in failed atomic policy load";
1021 			/* skip entry that caused failure */
1022 			continue;
1023 		}
1024 		op = (!ent->old) ? OP_PROF_LOAD : OP_PROF_REPL;
1025 		audit_policy(profile, op, ns_name,
1026 			     tmp->new->base.hname, info, error);
1027 	}
1028 	list_for_each_entry_safe(ent, tmp, &lh, list) {
1029 		list_del_init(&ent->list);
1030 		aa_load_ent_free(ent);
1031 	}
1032 
1033 	goto out;
1034 }
1035 
1036 /**
1037  * aa_remove_profiles - remove profile(s) from the system
1038  * @view: namespace the remove is being done from
1039  * @subj: profile attempting to remove policy
1040  * @fqname: name of the profile or namespace to remove  (NOT NULL)
1041  * @size: size of the name
1042  *
1043  * Remove a profile or sub namespace from the current namespace, so that
1044  * they can not be found anymore and mark them as replaced by unconfined
1045  *
1046  * NOTE: removing confinement does not restore rlimits to preconfinemnet values
1047  *
1048  * Returns: size of data consume else error code if fails
1049  */
1050 ssize_t aa_remove_profiles(struct aa_ns *view, struct aa_profile *subj,
1051 			   char *fqname, size_t size)
1052 {
1053 	struct aa_ns *root = NULL, *ns = NULL;
1054 	struct aa_profile *profile = NULL;
1055 	const char *name = fqname, *info = NULL;
1056 	char *ns_name = NULL;
1057 	ssize_t error = 0;
1058 
1059 	if (*fqname == 0) {
1060 		info = "no profile specified";
1061 		error = -ENOENT;
1062 		goto fail;
1063 	}
1064 
1065 	root = view;
1066 
1067 	if (fqname[0] == ':') {
1068 		name = aa_split_fqname(fqname, &ns_name);
1069 		/* released below */
1070 		ns = aa_find_ns(root, ns_name);
1071 		if (!ns) {
1072 			info = "namespace does not exist";
1073 			error = -ENOENT;
1074 			goto fail;
1075 		}
1076 	} else
1077 		/* released below */
1078 		ns = aa_get_ns(root);
1079 
1080 	if (!name) {
1081 		/* remove namespace - can only happen if fqname[0] == ':' */
1082 		mutex_lock(&ns->parent->lock);
1083 		__aa_remove_ns(ns);
1084 		mutex_unlock(&ns->parent->lock);
1085 	} else {
1086 		/* remove profile */
1087 		mutex_lock(&ns->lock);
1088 		profile = aa_get_profile(__lookup_profile(&ns->base, name));
1089 		if (!profile) {
1090 			error = -ENOENT;
1091 			info = "profile does not exist";
1092 			goto fail_ns_lock;
1093 		}
1094 		name = profile->base.hname;
1095 		__remove_profile(profile);
1096 		mutex_unlock(&ns->lock);
1097 	}
1098 
1099 	/* don't fail removal if audit fails */
1100 	(void) audit_policy(subj, OP_PROF_RM, ns_name, name, info,
1101 			    error);
1102 	aa_put_ns(ns);
1103 	aa_put_profile(profile);
1104 	return size;
1105 
1106 fail_ns_lock:
1107 	mutex_unlock(&ns->lock);
1108 	aa_put_ns(ns);
1109 
1110 fail:
1111 	(void) audit_policy(subj, OP_PROF_RM, ns_name, name, info,
1112 			    error);
1113 	return error;
1114 }
1115