policy.c 30.4 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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/**
 * aa_free_data - free a data blob
 * @ptr: data to free
 * @arg: unused
 */
static void aa_free_data(void *ptr, void *arg)
{
	struct aa_data *data = ptr;

	kzfree(data->data);
	kzfree(data->key);
	kzfree(data);
}

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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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{
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	struct rhashtable *rht;

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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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	if (profile->data) {
		rht = profile->data;
		profile->data = NULL;
		rhashtable_free_and_destroy(rht, aa_free_data, NULL);
		kzfree(rht);
	}

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	kzfree(profile->hash);
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	aa_put_loaddata(profile->rawdata);
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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;
}

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/* audit callback for net specific fields */
static void audit_cb(struct audit_buffer *ab, void *va)
{
	struct common_audit_data *sa = va;

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	if (aad(sa)->iface.ns) {
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		audit_log_format(ab, " ns=");
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		audit_log_untrustedstring(ab, aad(sa)->iface.ns);
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	}
}

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/**
 * 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
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 * @nsname: name of the ns being manipulated (MAY BE NULL)
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 * @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, const char *op,
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			const char *nsname, const char *name,
			const char *info, int error)
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{
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	DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, op);

	aad(&sa)->iface.ns = nsname;
	aad(&sa)->name = name;
	aad(&sa)->info = info;
	aad(&sa)->error = error;

	return aa_audit(AUDIT_APPARMOR_STATUS, profile, &sa, audit_cb);
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John Johansen 已提交
643 644
}

645 646 647 648 649 650 651 652 653
/**
 * 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)
654 655
{
	struct user_namespace *user_ns = current_user_ns();
656 657 658
	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));
659
	bool response = false;
660 661
	if (!ns)
		ns = view_ns;
662

663 664 665 666
	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)))
667
		response = true;
668
	aa_put_ns(view_ns);
669 670 671 672

	return response;
}

673
bool policy_admin_capable(struct aa_ns *ns)
674
{
675 676 677 678 679 680 681
	struct user_namespace *user_ns = current_user_ns();
	bool capable = ns_capable(user_ns, CAP_MAC_ADMIN);

	AA_DEBUG("cap_mac_admin? %d\n", capable);
	AA_DEBUG("policy locked? %d\n", aa_g_lock_policy);

	return policy_view_capable(ns) && capable && !aa_g_lock_policy;
682 683
}

J
John Johansen 已提交
684 685
/**
 * aa_may_manage_policy - can the current task manage policy
686
 * @profile: profile to check if it can manage policy
J
John Johansen 已提交
687 688
 * @op: the policy manipulation operation being done
 *
689
 * Returns: 0 if the task is allowed to manipulate policy else error
J
John Johansen 已提交
690
 */
691 692
int aa_may_manage_policy(struct aa_profile *profile, struct aa_ns *ns,
			 const char *op)
J
John Johansen 已提交
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);
J
John Johansen 已提交
698

699
	if (!policy_admin_capable(ns))
700
		return audit_policy(profile, op, NULL, NULL,
701
				    "not policy admin", -EACCES);
J
John Johansen 已提交
702

703 704
	/* TODO: add fine grained mediation of policy loads */
	return 0;
J
John Johansen 已提交
705 706
}

707 708 709
static struct aa_profile *__list_lookup_parent(struct list_head *lh,
					       struct aa_profile *profile)
{
710
	const char *base = basename(profile->base.hname);
711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733
	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)
734
 * @share_proxy: transfer @old->proxy to @new
735 736 737 738 739 740 741 742
 *
 * 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
 */
743
static void __replace_profile(struct aa_profile *old, struct aa_profile *new,
744
			      bool share_proxy)
745 746 747 748 749
{
	struct aa_profile *child, *tmp;

	if (!list_empty(&old->base.profiles)) {
		LIST_HEAD(lh);
750
		list_splice_init_rcu(&old->base.profiles, &lh, synchronize_rcu);
751 752 753 754 755 756 757 758

		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  */
759
				__replace_profile(child, p, share_proxy);
760 761 762 763 764 765
				continue;
			}

			/* inherit @child and its children */
			/* TODO: update hname of inherited children */
			/* list refcount transferred to @new */
766
			p = aa_deref_parent(child);
767 768 769
			rcu_assign_pointer(child->parent, aa_get_profile(new));
			list_add_rcu(&child->base.list, &new->base.profiles);
			aa_put_profile(p);
770 771 772
		}
	}

773
	if (!rcu_access_pointer(new->parent)) {
774
		struct aa_profile *parent = aa_deref_parent(old);
775 776
		rcu_assign_pointer(new->parent, aa_get_profile(parent));
	}
777 778 779 780 781 782 783
	__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,
784 785
				   aa_get_profile(new));
	__aa_fs_profile_migrate_dents(old, new);
786 787 788

	if (list_empty(&new->base.list)) {
		/* new is not on a list already */
789
		list_replace_rcu(&old->base.list, &new->base.list);
790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805
		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
 */
806
static int __lookup_replace(struct aa_ns *ns, const char *hname,
807 808 809 810 811 812 813 814 815 816 817 818 819 820 821
			    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
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
J
John Johansen 已提交
826
 * @noreplace: true if only doing addition, no replacement allowed
827
 * @udata: serialized data stream  (NOT NULL)
J
John Johansen 已提交
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
J
John Johansen 已提交
831 832 833 834
 * it is added.
 *
 * Returns: size of data consumed else error code on failure.
 */
835 836
ssize_t aa_replace_profiles(struct aa_ns *view, struct aa_profile *profile,
			    bool noreplace, struct aa_loaddata *udata)
J
John Johansen 已提交
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);
J
John Johansen 已提交
844 845

	/* released below */
846
	error = aa_unpack(udata, &lh, &ns_name);
847 848
	if (error)
		goto out;
J
John Johansen 已提交
849

850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872
	/* ensure that profiles are all for the same ns
	 * TODO: update locking to remove this constaint. All profiles in
	 *       the load set must succeed as a set or the load will
	 *       fail. Sort ent list and take ns locks in hierarchy order
	 */
	count = 0;
	list_for_each_entry(ent, &lh, list) {
		if (ns_name) {
			if (ent->ns_name &&
			    strcmp(ent->ns_name, ns_name) != 0) {
				info = "policy load has mixed namespaces";
				error = -EACCES;
				goto fail;
			}
		} else if (ent->ns_name) {
			if (count) {
				info = "policy load has mixed namespaces";
				error = -EACCES;
				goto fail;
			}
			ns_name = ent->ns_name;
		} else
			count++;
J
John Johansen 已提交
873
	}
874 875 876 877 878 879 880 881 882 883
	if (ns_name) {
		ns = aa_prepare_ns(view, ns_name);
		if (IS_ERR(ns)) {
			info = "failed to prepare namespace";
			error = PTR_ERR(ns);
			ns = NULL;
			goto fail;
		}
	} else
		ns = aa_get_ns(view);
J
John Johansen 已提交
884

885
	mutex_lock(&ns->lock);
886 887 888
	/* setup parent and ns info */
	list_for_each_entry(ent, &lh, list) {
		struct aa_policy *policy;
889
		ent->new->rawdata = aa_get_loaddata(udata);
890 891 892 893 894 895 896 897 898 899 900
		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
901 902
		}

903
		/* released when @new is freed */
904
		ent->new->ns = aa_get_ns(ns);
905 906 907 908 909 910 911 912 913 914 915 916 917 918

		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;
			}
919 920
			rcu_assign_pointer(ent->new->parent, aa_get_profile(p));
		} else if (policy != &ns->base) {
921
			/* released on profile replacement or free_profile */
922 923 924
			struct aa_profile *p = (struct aa_profile *) policy;
			rcu_assign_pointer(ent->new->parent, aa_get_profile(p));
		}
925
	}
J
John Johansen 已提交
926

927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953
	/* 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 */
954 955 956 957
	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;

958 959
		audit_policy(profile, op, NULL, ent->new->base.hname,
			     NULL, error);
960 961

		if (ent->old) {
962
			__replace_profile(ent->old, ent->new, 1);
963
			if (ent->rename) {
964 965
				/* aafs interface uses proxy */
				struct aa_proxy *r = ent->new->proxy;
966 967
				rcu_assign_pointer(r->profile,
						   aa_get_profile(ent->new));
968
				__replace_profile(ent->rename, ent->new, 0);
969
			}
970
		} else if (ent->rename) {
971 972
			/* aafs interface uses proxy */
			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? */
981 982 983
			if (newest != parent) {
				aa_get_profile(newest);
				rcu_assign_pointer(ent->new->parent, newest);
984
				aa_put_profile(parent);
985
			}
986 987
			/* aafs interface uses proxy */
			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 {
992 993
			/* aafs interface uses proxy */
			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);
J
John Johansen 已提交
998
	}
999
	mutex_unlock(&ns->lock);
J
John Johansen 已提交
1000 1001

out:
1002
	aa_put_ns(ns);
1003

J
John Johansen 已提交
1004 1005
	if (error)
		return error;
1006
	return udata->size;
J
John Johansen 已提交
1007

1008
fail_lock:
1009
	mutex_unlock(&ns->lock);
1010

1011 1012
	/* audit cause of failure */
	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 1017 1018 1019 1020 1021 1022 1023 1024
	/* 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;
1025
		audit_policy(profile, op, ns_name,
1026
			     tmp->new->base.hname, info, error);
1027
	}
1028 1029 1030 1031 1032
	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
1033 1034 1035 1036 1037
	goto out;
}

/**
 * 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
J
John Johansen 已提交
1040 1041 1042 1043 1044 1045 1046 1047 1048 1049
 * @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
 */
1050 1051
ssize_t aa_remove_profiles(struct aa_ns *view, struct aa_profile *subj,
			   char *fqname, size_t size)
J
John Johansen 已提交
1052
{
1053
	struct aa_ns *root = NULL, *ns = NULL;
J
John Johansen 已提交
1054 1055
	struct aa_profile *profile = NULL;
	const char *name = fqname, *info = NULL;
1056
	char *ns_name = NULL;
J
John Johansen 已提交
1057 1058 1059 1060 1061 1062 1063 1064
	ssize_t error = 0;

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

1065
	root = view;
J
John Johansen 已提交
1066 1067 1068

	if (fqname[0] == ':') {
		name = aa_split_fqname(fqname, &ns_name);
1069
		/* released below */
1070
		ns = aa_find_ns(root, ns_name);
1071 1072 1073 1074
		if (!ns) {
			info = "namespace does not exist";
			error = -ENOENT;
			goto fail;
J
John Johansen 已提交
1075 1076 1077
		}
	} else
		/* released below */
1078
		ns = aa_get_ns(root);
J
John Johansen 已提交
1079 1080 1081

	if (!name) {
		/* 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);
J
John Johansen 已提交
1085 1086
	} else {
		/* remove profile */
1087
		mutex_lock(&ns->lock);
J
John Johansen 已提交
1088 1089 1090 1091 1092 1093 1094 1095
		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);
1096
		mutex_unlock(&ns->lock);
J
John Johansen 已提交
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);
J
John Johansen 已提交
1103 1104 1105 1106
	aa_put_profile(profile);
	return size;

fail_ns_lock:
1107
	mutex_unlock(&ns->lock);
1108
	aa_put_ns(ns);
J
John Johansen 已提交
1109 1110

fail:
1111
	(void) audit_policy(subj, OP_PROF_RM, ns_name, name, info,
1112
			    error);
J
John Johansen 已提交
1113 1114
	return error;
}