policy.c 28.8 KB
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/*
 * AppArmor security module
 *
 * This file contains AppArmor policy manipulation functions
 *
 * Copyright (C) 1998-2008 Novell/SUSE
 * Copyright 2009-2010 Canonical Ltd.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation, version 2 of the
 * License.
 *
 *
 * AppArmor policy is based around profiles, which contain the rules a
 * task is confined by.  Every task in the system has a profile attached
 * to it determined either by matching "unconfined" tasks against the
 * visible set of profiles or by following a profiles attachment rules.
 *
 * Each profile exists in a profile namespace which is a container of
 * visible profiles.  Each namespace contains a special "unconfined" profile,
 * which doesn't enforce any confinement on a task beyond DAC.
 *
 * Namespace and profile names can be written together in either
 * of two syntaxes.
 *	:namespace:profile - used by kernel interfaces for easy detection
 *	namespace://profile - used by policy
 *
 * Profile names can not start with : or @ or ^ and may not contain \0
 *
 * Reserved profile names
 *	unconfined - special automatically generated unconfined profile
 *	inherit - special name to indicate profile inheritance
 *	null-XXXX-YYYY - special automatically generated learning profiles
 *
 * Namespace names may not start with / or @ and may not contain \0 or :
 * Reserved namespace names
 *	user-XXXX - user defined profiles
 *
 * a // in a profile or namespace name indicates a hierarchical name with the
 * name before the // being the parent and the name after the child.
 *
 * Profile and namespace hierarchies serve two different but similar purposes.
 * The namespace contains the set of visible profiles that are considered
 * for attachment.  The hierarchy of namespaces allows for virtualizing
 * the namespace so that for example a chroot can have its own set of profiles
 * which may define some local user namespaces.
 * The profile hierarchy severs two distinct purposes,
 * -  it allows for sub profiles or hats, which allows an application to run
 *    subprograms under its own profile with different restriction than it
 *    self, and not have it use the system profile.
 *    eg. if a mail program starts an editor, the policy might make the
 *        restrictions tighter on the editor tighter than the mail program,
 *        and definitely different than general editor restrictions
 * - it allows for binary hierarchy of profiles, so that execution history
 *   is preserved.  This feature isn't exploited by AppArmor reference policy
 *   but is allowed.  NOTE: this is currently suboptimal because profile
 *   aliasing is not currently implemented so that a profile for each
 *   level must be defined.
 *   eg. /bin/bash///bin/ls as a name would indicate /bin/ls was started
 *       from /bin/bash
 *
 *   A profile or namespace name that can contain one or more // separators
 *   is referred to as an hname (hierarchical).
 *   eg.  /bin/bash//bin/ls
 *
 *   An fqname is a name that may contain both namespace and profile hnames.
 *   eg. :ns:/bin/bash//bin/ls
 *
 * NOTES:
 *   - locking of profile lists is currently fairly coarse.  All profile
 *     lists within a namespace use the namespace lock.
 * FIXME: move profile lists to using rcu_lists
 */

#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/string.h>
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#include <linux/user_namespace.h>
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#include "include/apparmor.h"
#include "include/capability.h"
#include "include/context.h"
#include "include/file.h"
#include "include/ipc.h"
#include "include/match.h"
#include "include/path.h"
#include "include/policy.h"
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#include "include/policy_ns.h"
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#include "include/policy_unpack.h"
#include "include/resource.h"

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int unprivileged_userns_apparmor_policy = 1;
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const char *const aa_profile_mode_names[] = {
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	"enforce",
	"complain",
	"kill",
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	"unconfined",
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};


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/* requires profile list write lock held */
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void __aa_update_proxy(struct aa_profile *orig, struct aa_profile *new)
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{
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	struct aa_profile *tmp;
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	tmp = rcu_dereference_protected(orig->proxy->profile,
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					mutex_is_locked(&orig->ns->lock));
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	rcu_assign_pointer(orig->proxy->profile, aa_get_profile(new));
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	orig->flags |= PFLAG_STALE;
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	aa_put_profile(tmp);
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}

/**
 * __list_add_profile - add a profile to a list
 * @list: list to add it to  (NOT NULL)
 * @profile: the profile to add  (NOT NULL)
 *
 * refcount @profile, should be put by __list_remove_profile
 *
 * Requires: namespace lock be held, or list not be shared
 */
static void __list_add_profile(struct list_head *list,
			       struct aa_profile *profile)
{
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	list_add_rcu(&profile->base.list, list);
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	/* get list reference */
	aa_get_profile(profile);
}

/**
 * __list_remove_profile - remove a profile from the list it is on
 * @profile: the profile to remove  (NOT NULL)
 *
 * remove a profile from the list, warning generally removal should
 * be done with __replace_profile as most profile removals are
 * replacements to the unconfined profile.
 *
 * put @profile list refcount
 *
 * Requires: namespace lock be held, or list not have been live
 */
static void __list_remove_profile(struct aa_profile *profile)
{
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	list_del_rcu(&profile->base.list);
	aa_put_profile(profile);
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}

/**
 * __remove_profile - remove old profile, and children
 * @profile: profile to be replaced  (NOT NULL)
 *
 * Requires: namespace list lock be held, or list not be shared
 */
static void __remove_profile(struct aa_profile *profile)
{
	/* release any children lists first */
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	__aa_profile_list_release(&profile->base.profiles);
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	/* released by free_profile */
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	__aa_update_proxy(profile, profile->ns->unconfined);
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	__aa_fs_profile_rmdir(profile);
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	__list_remove_profile(profile);
}

/**
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 * __aa_profile_list_release - remove all profiles on the list and put refs
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 * @head: list of profiles  (NOT NULL)
 *
 * Requires: namespace lock be held
 */
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void __aa_profile_list_release(struct list_head *head)
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{
	struct aa_profile *profile, *tmp;
	list_for_each_entry_safe(profile, tmp, head, base.list)
		__remove_profile(profile);
}

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static void free_proxy(struct aa_proxy *p)
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{
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	if (p) {
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		/* r->profile will not be updated any more as r is dead */
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		aa_put_profile(rcu_dereference_protected(p->profile, true));
		kzfree(p);
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	}
}


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void aa_free_proxy_kref(struct kref *kref)
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{
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	struct aa_proxy *p = container_of(kref, struct aa_proxy, count);

	free_proxy(p);
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}

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/**
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 * aa_free_profile - free a profile
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 * @profile: the profile to free  (MAYBE NULL)
 *
 * Free a profile, its hats and null_profile. All references to the profile,
 * its hats and null_profile must have been put.
 *
 * If the profile was referenced from a task context, free_profile() will
 * be called from an rcu callback routine, so we must not sleep here.
 */
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void aa_free_profile(struct aa_profile *profile)
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{
	AA_DEBUG("%s(%p)\n", __func__, profile);

	if (!profile)
		return;

	/* free children profiles */
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	aa_policy_destroy(&profile->base);
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	aa_put_profile(rcu_access_pointer(profile->parent));
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	aa_put_ns(profile->ns);
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	kzfree(profile->rename);

	aa_free_file_rules(&profile->file);
	aa_free_cap_rules(&profile->caps);
	aa_free_rlimit_rules(&profile->rlimits);

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	kzfree(profile->dirname);
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	aa_put_dfa(profile->xmatch);
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	aa_put_dfa(profile->policy.dfa);
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	aa_put_proxy(profile->proxy);
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	kzfree(profile->hash);
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	kzfree(profile);
}

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/**
 * aa_free_profile_rcu - free aa_profile by rcu (called by aa_free_profile_kref)
 * @head: rcu_head callback for freeing of a profile  (NOT NULL)
 */
static void aa_free_profile_rcu(struct rcu_head *head)
{
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	struct aa_profile *p = container_of(head, struct aa_profile, rcu);
	if (p->flags & PFLAG_NS_COUNT)
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		aa_free_ns(p->ns);
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	else
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		aa_free_profile(p);
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}

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/**
 * aa_free_profile_kref - free aa_profile by kref (called by aa_put_profile)
 * @kr: kref callback for freeing of a profile  (NOT NULL)
 */
void aa_free_profile_kref(struct kref *kref)
{
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	struct aa_profile *p = container_of(kref, struct aa_profile, count);
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	call_rcu(&p->rcu, aa_free_profile_rcu);
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}

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/**
 * aa_alloc_profile - allocate, initialize and return a new profile
 * @hname: name of the profile  (NOT NULL)
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 * @gfp: allocation type
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 *
 * Returns: refcount profile or NULL on failure
 */
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struct aa_profile *aa_alloc_profile(const char *hname, gfp_t gfp)
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{
	struct aa_profile *profile;

	/* freed by free_profile - usually through aa_put_profile */
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	profile = kzalloc(sizeof(*profile), gfp);
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	if (!profile)
		return NULL;

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	profile->proxy = kzalloc(sizeof(struct aa_proxy), gfp);
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	if (!profile->proxy)
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		goto fail;
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	kref_init(&profile->proxy->count);
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	if (!aa_policy_init(&profile->base, NULL, hname, gfp))
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		goto fail;
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	kref_init(&profile->count);
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	/* refcount released by caller */
	return profile;
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fail:
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	kzfree(profile->proxy);
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	kzfree(profile);

	return NULL;
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}

/**
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 * aa_new_null_profile - create or find a null-X learning profile
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 * @parent: profile that caused this profile to be created (NOT NULL)
 * @hat: true if the null- learning profile is a hat
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 * @base: name to base the null profile off of
 * @gfp: type of allocation
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 *
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 * Find/Create a null- complain mode profile used in learning mode.  The
 * name of the profile is unique and follows the format of parent//null-XXX.
 * where XXX is based on the @name or if that fails or is not supplied
 * a unique number
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 *
 * null profiles are added to the profile list but the list does not
 * hold a count on them so that they are automatically released when
 * not in use.
 *
 * Returns: new refcounted profile else NULL on failure
 */
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struct aa_profile *aa_new_null_profile(struct aa_profile *parent, bool hat,
				       const char *base, gfp_t gfp)
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{
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	struct aa_profile *profile;
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	char *name;

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	AA_BUG(!parent);

	if (base) {
		name = kmalloc(strlen(parent->base.hname) + 8 + strlen(base),
			       gfp);
		if (name) {
			sprintf(name, "%s//null-%s", parent->base.hname, base);
			goto name;
		}
		/* fall through to try shorter uniq */
	}

	name = kmalloc(strlen(parent->base.hname) + 2 + 7 + 8, gfp);
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	if (!name)
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		return NULL;
	sprintf(name, "%s//null-%x", parent->base.hname,
		atomic_inc_return(&parent->ns->uniq_null));
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name:
	/* lookup to see if this is a dup creation */
	profile = aa_find_child(parent, basename(name));
	if (profile)
		goto out;

	profile = aa_alloc_profile(name, gfp);
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	if (!profile)
		goto fail;

	profile->mode = APPARMOR_COMPLAIN;
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	profile->flags |= PFLAG_NULL;
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	if (hat)
		profile->flags |= PFLAG_HAT;
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	profile->path_flags = parent->path_flags;
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	/* released on free_profile */
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	rcu_assign_pointer(profile->parent, aa_get_profile(parent));
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	profile->ns = aa_get_ns(parent->ns);
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	profile->file.dfa = aa_get_dfa(nulldfa);
	profile->policy.dfa = aa_get_dfa(nulldfa);
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	mutex_lock(&profile->ns->lock);
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	__list_add_profile(&parent->base.profiles, profile);
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	mutex_unlock(&profile->ns->lock);
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	/* refcount released by caller */
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out:
	kfree(name);

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	return profile;

fail:
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	kfree(name);
	aa_free_profile(profile);
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	return NULL;
}

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/* TODO: profile accounting - setup in remove */

/**
 * __find_child - find a profile on @head list with a name matching @name
 * @head: list to search  (NOT NULL)
 * @name: name of profile (NOT NULL)
 *
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 * Requires: rcu_read_lock be held
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 *
 * Returns: unrefcounted profile ptr, or NULL if not found
 */
static struct aa_profile *__find_child(struct list_head *head, const char *name)
{
	return (struct aa_profile *)__policy_find(head, name);
}

/**
 * __strn_find_child - find a profile on @head list using substring of @name
 * @head: list to search  (NOT NULL)
 * @name: name of profile (NOT NULL)
 * @len: length of @name substring to match
 *
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 * Requires: rcu_read_lock be held
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 *
 * Returns: unrefcounted profile ptr, or NULL if not found
 */
static struct aa_profile *__strn_find_child(struct list_head *head,
					    const char *name, int len)
{
	return (struct aa_profile *)__policy_strn_find(head, name, len);
}

/**
 * aa_find_child - find a profile by @name in @parent
 * @parent: profile to search  (NOT NULL)
 * @name: profile name to search for  (NOT NULL)
 *
 * Returns: a refcounted profile or NULL if not found
 */
struct aa_profile *aa_find_child(struct aa_profile *parent, const char *name)
{
	struct aa_profile *profile;

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	rcu_read_lock();
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	do {
		profile = __find_child(&parent->base.profiles, name);
	} while (profile && !aa_get_profile_not0(profile));
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	rcu_read_unlock();
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	/* refcount released by caller */
	return profile;
}

/**
 * __lookup_parent - lookup the parent of a profile of name @hname
 * @ns: namespace to lookup profile in  (NOT NULL)
 * @hname: hierarchical profile name to find parent of  (NOT NULL)
 *
 * Lookups up the parent of a fully qualified profile name, the profile
 * that matches hname does not need to exist, in general this
 * is used to load a new profile.
 *
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 * Requires: rcu_read_lock be held
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 *
 * Returns: unrefcounted policy or NULL if not found
 */
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static struct aa_policy *__lookup_parent(struct aa_ns *ns,
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					 const char *hname)
{
	struct aa_policy *policy;
	struct aa_profile *profile = NULL;
	char *split;

	policy = &ns->base;

	for (split = strstr(hname, "//"); split;) {
		profile = __strn_find_child(&policy->profiles, hname,
					    split - hname);
		if (!profile)
			return NULL;
		policy = &profile->base;
		hname = split + 2;
		split = strstr(hname, "//");
	}
	if (!profile)
		return &ns->base;
	return &profile->base;
}

/**
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 * __lookupn_profile - lookup the profile matching @hname
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 * @base: base list to start looking up profile name from  (NOT NULL)
 * @hname: hierarchical profile name  (NOT NULL)
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 * @n: length of @hname
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 *
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 * Requires: rcu_read_lock be held
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 *
 * Returns: unrefcounted profile pointer or NULL if not found
 *
 * Do a relative name lookup, recursing through profile tree.
 */
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static struct aa_profile *__lookupn_profile(struct aa_policy *base,
					    const char *hname, size_t n)
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{
	struct aa_profile *profile = NULL;
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	const char *split;
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	for (split = strnstr(hname, "//", n); split;
	     split = strnstr(hname, "//", n)) {
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		profile = __strn_find_child(&base->profiles, hname,
					    split - hname);
		if (!profile)
			return NULL;

		base = &profile->base;
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		n -= split + 2 - hname;
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		hname = split + 2;
	}

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	if (n)
		return __strn_find_child(&base->profiles, hname, n);
	return NULL;
}
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static struct aa_profile *__lookup_profile(struct aa_policy *base,
					   const char *hname)
{
	return __lookupn_profile(base, hname, strlen(hname));
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}

/**
 * aa_lookup_profile - find a profile by its full or partial name
 * @ns: the namespace to start from (NOT NULL)
 * @hname: name to do lookup on.  Does not contain namespace prefix (NOT NULL)
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 * @n: size of @hname
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 *
 * Returns: refcounted profile or NULL if not found
 */
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struct aa_profile *aa_lookupn_profile(struct aa_ns *ns, const char *hname,
				      size_t n)
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{
	struct aa_profile *profile;

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	rcu_read_lock();
	do {
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		profile = __lookupn_profile(&ns->base, hname, n);
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	} while (profile && !aa_get_profile_not0(profile));
	rcu_read_unlock();
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	/* the unconfined profile is not in the regular profile list */
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	if (!profile && strncmp(hname, "unconfined", n) == 0)
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		profile = aa_get_newest_profile(ns->unconfined);
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	/* refcount released by caller */
	return profile;
}

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struct aa_profile *aa_lookup_profile(struct aa_ns *ns, const char *hname)
{
	return aa_lookupn_profile(ns, hname, strlen(hname));
}
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struct aa_profile *aa_fqlookupn_profile(struct aa_profile *base,
					const char *fqname, size_t n)
{
	struct aa_profile *profile;
	struct aa_ns *ns;
	const char *name, *ns_name;
	size_t ns_len;

	name = aa_splitn_fqname(fqname, n, &ns_name, &ns_len);
	if (ns_name) {
		ns = aa_findn_ns(base->ns, ns_name, ns_len);
		if (!ns)
			return NULL;
	} else
		ns = aa_get_ns(base->ns);

	if (name)
		profile = aa_lookupn_profile(ns, name, n - (name - fqname));
	else if (ns)
		/* default profile for ns, currently unconfined */
		profile = aa_get_newest_profile(ns->unconfined);
	else
		profile = NULL;
	aa_put_ns(ns);

	return profile;
}

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/**
 * replacement_allowed - test to see if replacement is allowed
 * @profile: profile to test if it can be replaced  (MAYBE NULL)
 * @noreplace: true if replacement shouldn't be allowed but addition is okay
 * @info: Returns - info about why replacement failed (NOT NULL)
 *
 * Returns: %0 if replacement allowed else error code
 */
static int replacement_allowed(struct aa_profile *profile, int noreplace,
			       const char **info)
{
	if (profile) {
		if (profile->flags & PFLAG_IMMUTABLE) {
			*info = "cannot replace immutible profile";
			return -EPERM;
		} else if (noreplace) {
			*info = "profile already exists";
			return -EEXIST;
		}
	}
	return 0;
}

/**
 * aa_audit_policy - Do auditing of policy changes
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 * @profile: profile to check if it can manage policy
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 * @op: policy operation being performed
 * @gfp: memory allocation flags
 * @name: name of profile being manipulated (NOT NULL)
 * @info: any extra information to be audited (MAYBE NULL)
 * @error: error code
 *
 * Returns: the error to be returned after audit is done
 */
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static int audit_policy(struct aa_profile *profile, int op, gfp_t gfp,
			const char *name, const char *info, int error)
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{
	struct common_audit_data sa;
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	struct apparmor_audit_data aad = {0,};
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	sa.type = LSM_AUDIT_DATA_NONE;
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	sa.aad = &aad;
	aad.op = op;
	aad.name = name;
	aad.info = info;
	aad.error = error;
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	return aa_audit(AUDIT_APPARMOR_STATUS, profile, gfp,
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			&sa, NULL);
}

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/**
 * policy_view_capable - check if viewing policy in at @ns is allowed
 * ns: namespace being viewed by current task (may be NULL)
 * Returns: true if viewing policy is allowed
 *
 * If @ns is NULL then the namespace being viewed is assumed to be the
 * tasks current namespace.
 */
bool policy_view_capable(struct aa_ns *ns)
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{
	struct user_namespace *user_ns = current_user_ns();
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	struct aa_ns *view_ns = aa_get_current_ns();
	bool root_in_user_ns = uid_eq(current_euid(), make_kuid(user_ns, 0)) ||
			       in_egroup_p(make_kgid(user_ns, 0));
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	bool response = false;
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	if (!ns)
		ns = view_ns;
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	if (root_in_user_ns && aa_ns_visible(view_ns, ns, true) &&
	    (user_ns == &init_user_ns ||
	     (unprivileged_userns_apparmor_policy != 0 &&
	      user_ns->level == view_ns->level)))
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		response = true;
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	aa_put_ns(view_ns);
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	return response;
}

bool policy_admin_capable(void)
{
642
	return policy_view_capable(NULL) && !aa_g_lock_policy;
643 644
}

J
John Johansen 已提交
645 646 647 648 649 650 651 652 653 654
/**
 * aa_may_manage_policy - can the current task manage policy
 * @op: the policy manipulation operation being done
 *
 * Returns: true if the task is allowed to manipulate policy
 */
bool aa_may_manage_policy(int op)
{
	/* check if loading policy is locked out */
	if (aa_g_lock_policy) {
655 656
		audit_policy(__aa_current_profile(), op, GFP_KERNEL, NULL,
			     "policy_locked", -EACCES);
J
John Johansen 已提交
657 658 659
		return 0;
	}

660
	if (!policy_admin_capable()) {
661 662
		audit_policy(__aa_current_profile(), op, GFP_KERNEL, NULL,
			     "not policy admin", -EACCES);
J
John Johansen 已提交
663 664 665 666 667 668
		return 0;
	}

	return 1;
}

669 670 671
static struct aa_profile *__list_lookup_parent(struct list_head *lh,
					       struct aa_profile *profile)
{
672
	const char *base = basename(profile->base.hname);
673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695
	long len = base - profile->base.hname;
	struct aa_load_ent *ent;

	/* parent won't have trailing // so remove from len */
	if (len <= 2)
		return NULL;
	len -= 2;

	list_for_each_entry(ent, lh, list) {
		if (ent->new == profile)
			continue;
		if (strncmp(ent->new->base.hname, profile->base.hname, len) ==
		    0 && ent->new->base.hname[len] == 0)
			return ent->new;
	}

	return NULL;
}

/**
 * __replace_profile - replace @old with @new on a list
 * @old: profile to be replaced  (NOT NULL)
 * @new: profile to replace @old with  (NOT NULL)
696
 * @share_proxy: transfer @old->proxy to @new
697 698 699 700 701 702 703 704
 *
 * Will duplicate and refcount elements that @new inherits from @old
 * and will inherit @old children.
 *
 * refcount @new for list, put @old list refcount
 *
 * Requires: namespace list lock be held, or list not be shared
 */
705
static void __replace_profile(struct aa_profile *old, struct aa_profile *new,
706
			      bool share_proxy)
707 708 709 710 711
{
	struct aa_profile *child, *tmp;

	if (!list_empty(&old->base.profiles)) {
		LIST_HEAD(lh);
712
		list_splice_init_rcu(&old->base.profiles, &lh, synchronize_rcu);
713 714 715 716 717 718 719 720

		list_for_each_entry_safe(child, tmp, &lh, base.list) {
			struct aa_profile *p;

			list_del_init(&child->base.list);
			p = __find_child(&new->base.profiles, child->base.name);
			if (p) {
				/* @p replaces @child  */
721
				__replace_profile(child, p, share_proxy);
722 723 724 725 726 727
				continue;
			}

			/* inherit @child and its children */
			/* TODO: update hname of inherited children */
			/* list refcount transferred to @new */
728
			p = aa_deref_parent(child);
729 730 731
			rcu_assign_pointer(child->parent, aa_get_profile(new));
			list_add_rcu(&child->base.list, &new->base.profiles);
			aa_put_profile(p);
732 733 734
		}
	}

735
	if (!rcu_access_pointer(new->parent)) {
736
		struct aa_profile *parent = aa_deref_parent(old);
737 738
		rcu_assign_pointer(new->parent, aa_get_profile(parent));
	}
739 740 741 742 743 744 745
	__aa_update_proxy(old, new);
	if (share_proxy) {
		aa_put_proxy(new->proxy);
		new->proxy = aa_get_proxy(old->proxy);
	} else if (!rcu_access_pointer(new->proxy->profile))
		/* aafs interface uses proxy */
		rcu_assign_pointer(new->proxy->profile,
746 747
				   aa_get_profile(new));
	__aa_fs_profile_migrate_dents(old, new);
748 749 750

	if (list_empty(&new->base.list)) {
		/* new is not on a list already */
751
		list_replace_rcu(&old->base.list, &new->base.list);
752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767
		aa_get_profile(new);
		aa_put_profile(old);
	} else
		__list_remove_profile(old);
}

/**
 * __lookup_replace - lookup replacement information for a profile
 * @ns - namespace the lookup occurs in
 * @hname - name of profile to lookup
 * @noreplace - true if not replacing an existing profile
 * @p - Returns: profile to be replaced
 * @info - Returns: info string on why lookup failed
 *
 * Returns: profile to replace (no ref) on success else ptr error
 */
768
static int __lookup_replace(struct aa_ns *ns, const char *hname,
769 770 771 772 773 774 775 776 777 778 779 780 781 782 783
			    bool noreplace, struct aa_profile **p,
			    const char **info)
{
	*p = aa_get_profile(__lookup_profile(&ns->base, hname));
	if (*p) {
		int error = replacement_allowed(*p, noreplace, info);
		if (error) {
			*info = "profile can not be replaced";
			return error;
		}
	}

	return 0;
}

J
John Johansen 已提交
784 785
/**
 * aa_replace_profiles - replace profile(s) on the profile list
786
 * @view: namespace load is viewed from
787
 * @profile: profile that is attempting to load/replace policy
J
John Johansen 已提交
788 789 790 791 792 793 794 795 796 797
 * @udata: serialized data stream  (NOT NULL)
 * @size: size of the serialized data stream
 * @noreplace: true if only doing addition, no replacement allowed
 *
 * unpack and replace a profile on the profile list and uses of that profile
 * by any aa_task_cxt.  If the profile does not exist on the profile list
 * it is added.
 *
 * Returns: size of data consumed else error code on failure.
 */
798 799
ssize_t aa_replace_profiles(struct aa_ns *view, void *udata, size_t size,
			    bool noreplace)
J
John Johansen 已提交
800
{
801
	const char *ns_name, *info = NULL;
802
	struct aa_ns *ns = NULL;
803
	struct aa_load_ent *ent, *tmp;
J
John Johansen 已提交
804 805
	int op = OP_PROF_REPL;
	ssize_t error;
806
	LIST_HEAD(lh);
J
John Johansen 已提交
807 808

	/* released below */
809 810 811
	error = aa_unpack(udata, size, &lh, &ns_name);
	if (error)
		goto out;
J
John Johansen 已提交
812 813

	/* released below */
814
	ns = aa_prepare_ns(view, ns_name);
J
John Johansen 已提交
815
	if (!ns) {
816 817
		error = audit_policy(__aa_current_profile(), op, GFP_KERNEL,
				     ns_name,
818 819
				     "failed to prepare namespace", -ENOMEM);
		goto free;
J
John Johansen 已提交
820 821
	}

822
	mutex_lock(&ns->lock);
823 824 825 826 827 828 829 830 831 832 833 834 835 836
	/* setup parent and ns info */
	list_for_each_entry(ent, &lh, list) {
		struct aa_policy *policy;
		error = __lookup_replace(ns, ent->new->base.hname, noreplace,
					 &ent->old, &info);
		if (error)
			goto fail_lock;

		if (ent->new->rename) {
			error = __lookup_replace(ns, ent->new->rename,
						 noreplace, &ent->rename,
						 &info);
			if (error)
				goto fail_lock;
J
John Johansen 已提交
837 838
		}

839
		/* released when @new is freed */
840
		ent->new->ns = aa_get_ns(ns);
841 842 843 844 845 846 847 848 849 850 851 852 853 854

		if (ent->old || ent->rename)
			continue;

		/* no ref on policy only use inside lock */
		policy = __lookup_parent(ns, ent->new->base.hname);
		if (!policy) {
			struct aa_profile *p;
			p = __list_lookup_parent(&lh, ent->new);
			if (!p) {
				error = -ENOENT;
				info = "parent does not exist";
				goto fail_lock;
			}
855 856
			rcu_assign_pointer(ent->new->parent, aa_get_profile(p));
		} else if (policy != &ns->base) {
857
			/* released on profile replacement or free_profile */
858 859 860
			struct aa_profile *p = (struct aa_profile *) policy;
			rcu_assign_pointer(ent->new->parent, aa_get_profile(p));
		}
861
	}
J
John Johansen 已提交
862

863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889
	/* create new fs entries for introspection if needed */
	list_for_each_entry(ent, &lh, list) {
		if (ent->old) {
			/* inherit old interface files */

			/* if (ent->rename)
				TODO: support rename */
		/* } else if (ent->rename) {
			TODO: support rename */
		} else {
			struct dentry *parent;
			if (rcu_access_pointer(ent->new->parent)) {
				struct aa_profile *p;
				p = aa_deref_parent(ent->new);
				parent = prof_child_dir(p);
			} else
				parent = ns_subprofs_dir(ent->new->ns);
			error = __aa_fs_profile_mkdir(ent->new, parent);
		}

		if (error) {
			info = "failed to create ";
			goto fail_lock;
		}
	}

	/* Done with checks that may fail - do actual replacement */
890 891 892 893
	list_for_each_entry_safe(ent, tmp, &lh, list) {
		list_del_init(&ent->list);
		op = (!ent->old && !ent->rename) ? OP_PROF_LOAD : OP_PROF_REPL;

894 895
		audit_policy(__aa_current_profile(), op, GFP_ATOMIC,
			     ent->new->base.hname, NULL, error);
896 897

		if (ent->old) {
898
			__replace_profile(ent->old, ent->new, 1);
899
			if (ent->rename) {
900 901
				/* aafs interface uses proxy */
				struct aa_proxy *r = ent->new->proxy;
902 903
				rcu_assign_pointer(r->profile,
						   aa_get_profile(ent->new));
904
				__replace_profile(ent->rename, ent->new, 0);
905
			}
906
		} else if (ent->rename) {
907 908
			/* aafs interface uses proxy */
			rcu_assign_pointer(ent->new->proxy->profile,
909
					   aa_get_profile(ent->new));
910
			__replace_profile(ent->rename, ent->new, 0);
911
		} else if (ent->new->parent) {
912
			struct aa_profile *parent, *newest;
913
			parent = aa_deref_parent(ent->new);
914
			newest = aa_get_newest_profile(parent);
915

916
			/* parent replaced in this atomic set? */
917 918 919
			if (newest != parent) {
				aa_get_profile(newest);
				rcu_assign_pointer(ent->new->parent, newest);
920
				aa_put_profile(parent);
921
			}
922 923
			/* aafs interface uses proxy */
			rcu_assign_pointer(ent->new->proxy->profile,
924
					   aa_get_profile(ent->new));
925
			__list_add_profile(&newest->base.profiles, ent->new);
926
			aa_put_profile(newest);
927
		} else {
928 929
			/* aafs interface uses proxy */
			rcu_assign_pointer(ent->new->proxy->profile,
930
					   aa_get_profile(ent->new));
931
			__list_add_profile(&ns->base.profiles, ent->new);
932
		}
933
		aa_load_ent_free(ent);
J
John Johansen 已提交
934
	}
935
	mutex_unlock(&ns->lock);
J
John Johansen 已提交
936 937

out:
938
	aa_put_ns(ns);
939

J
John Johansen 已提交
940 941 942 943
	if (error)
		return error;
	return size;

944
fail_lock:
945
	mutex_unlock(&ns->lock);
946

947 948
	/* audit cause of failure */
	op = (!ent->old) ? OP_PROF_LOAD : OP_PROF_REPL;
949 950
	audit_policy(__aa_current_profile(), op, GFP_KERNEL,
		     ent->new->base.hname, info, error);
951 952 953 954 955 956 957 958 959
	/* audit status that rest of profiles in the atomic set failed too */
	info = "valid profile in failed atomic policy load";
	list_for_each_entry(tmp, &lh, list) {
		if (tmp == ent) {
			info = "unchecked profile in failed atomic policy load";
			/* skip entry that caused failure */
			continue;
		}
		op = (!ent->old) ? OP_PROF_LOAD : OP_PROF_REPL;
960 961
		audit_policy(__aa_current_profile(), op, GFP_KERNEL,
			     tmp->new->base.hname, info, error);
962 963
	}
free:
964 965 966 967 968
	list_for_each_entry_safe(ent, tmp, &lh, list) {
		list_del_init(&ent->list);
		aa_load_ent_free(ent);
	}

J
John Johansen 已提交
969 970 971 972 973
	goto out;
}

/**
 * aa_remove_profiles - remove profile(s) from the system
974
 * @view: namespace the remove is being done from
J
John Johansen 已提交
975 976 977 978 979 980 981 982 983 984
 * @fqname: name of the profile or namespace to remove  (NOT NULL)
 * @size: size of the name
 *
 * Remove a profile or sub namespace from the current namespace, so that
 * they can not be found anymore and mark them as replaced by unconfined
 *
 * NOTE: removing confinement does not restore rlimits to preconfinemnet values
 *
 * Returns: size of data consume else error code if fails
 */
985
ssize_t aa_remove_profiles(struct aa_ns *view, char *fqname, size_t size)
J
John Johansen 已提交
986
{
987
	struct aa_ns *root = NULL, *ns = NULL;
J
John Johansen 已提交
988 989 990 991 992 993 994 995 996 997
	struct aa_profile *profile = NULL;
	const char *name = fqname, *info = NULL;
	ssize_t error = 0;

	if (*fqname == 0) {
		info = "no profile specified";
		error = -ENOENT;
		goto fail;
	}

998
	root = view;
J
John Johansen 已提交
999 1000 1001 1002

	if (fqname[0] == ':') {
		char *ns_name;
		name = aa_split_fqname(fqname, &ns_name);
1003
		/* released below */
1004
		ns = aa_find_ns(root, ns_name);
1005 1006 1007 1008
		if (!ns) {
			info = "namespace does not exist";
			error = -ENOENT;
			goto fail;
J
John Johansen 已提交
1009 1010 1011
		}
	} else
		/* released below */
1012
		ns = aa_get_ns(root);
J
John Johansen 已提交
1013 1014 1015

	if (!name) {
		/* remove namespace - can only happen if fqname[0] == ':' */
1016
		mutex_lock(&ns->parent->lock);
1017
		__aa_remove_ns(ns);
1018
		mutex_unlock(&ns->parent->lock);
J
John Johansen 已提交
1019 1020
	} else {
		/* remove profile */
1021
		mutex_lock(&ns->lock);
J
John Johansen 已提交
1022 1023 1024 1025 1026 1027 1028 1029
		profile = aa_get_profile(__lookup_profile(&ns->base, name));
		if (!profile) {
			error = -ENOENT;
			info = "profile does not exist";
			goto fail_ns_lock;
		}
		name = profile->base.hname;
		__remove_profile(profile);
1030
		mutex_unlock(&ns->lock);
J
John Johansen 已提交
1031 1032 1033
	}

	/* don't fail removal if audit fails */
1034 1035
	(void) audit_policy(__aa_current_profile(), OP_PROF_RM, GFP_KERNEL,
			    name, info, error);
1036
	aa_put_ns(ns);
J
John Johansen 已提交
1037 1038 1039 1040
	aa_put_profile(profile);
	return size;

fail_ns_lock:
1041
	mutex_unlock(&ns->lock);
1042
	aa_put_ns(ns);
J
John Johansen 已提交
1043 1044

fail:
1045 1046
	(void) audit_policy(__aa_current_profile(), OP_PROF_RM, GFP_KERNEL,
			    name, info, error);
J
John Johansen 已提交
1047 1048
	return error;
}