policy.c 30.5 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/cred.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);
J
John Johansen 已提交
644 645
}

646 647 648 649 650 651 652 653 654
/**
 * 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)
655 656
{
	struct user_namespace *user_ns = current_user_ns();
657 658 659
	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));
660
	bool response = false;
661 662
	if (!ns)
		ns = view_ns;
663

664 665 666 667
	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)))
668
		response = true;
669
	aa_put_ns(view_ns);
670 671 672 673

	return response;
}

674
bool policy_admin_capable(struct aa_ns *ns)
675
{
676 677 678 679 680 681 682
	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;
683 684
}

J
John Johansen 已提交
685 686
/**
 * aa_may_manage_policy - can the current task manage policy
687
 * @profile: profile to check if it can manage policy
J
John Johansen 已提交
688 689
 * @op: the policy manipulation operation being done
 *
690
 * Returns: 0 if the task is allowed to manipulate policy else error
J
John Johansen 已提交
691
 */
692 693
int aa_may_manage_policy(struct aa_profile *profile, struct aa_ns *ns,
			 const char *op)
J
John Johansen 已提交
694 695
{
	/* check if loading policy is locked out */
696
	if (aa_g_lock_policy)
697
		return audit_policy(profile, op, NULL, NULL,
698
			     "policy_locked", -EACCES);
J
John Johansen 已提交
699

700
	if (!policy_admin_capable(ns))
701
		return audit_policy(profile, op, NULL, NULL,
702
				    "not policy admin", -EACCES);
J
John Johansen 已提交
703

704 705
	/* TODO: add fine grained mediation of policy loads */
	return 0;
J
John Johansen 已提交
706 707
}

708 709 710
static struct aa_profile *__list_lookup_parent(struct list_head *lh,
					       struct aa_profile *profile)
{
711
	const char *base = basename(profile->base.hname);
712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734
	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)
735
 * @share_proxy: transfer @old->proxy to @new
736 737 738 739 740 741 742 743
 *
 * 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
 */
744
static void __replace_profile(struct aa_profile *old, struct aa_profile *new,
745
			      bool share_proxy)
746 747 748 749 750
{
	struct aa_profile *child, *tmp;

	if (!list_empty(&old->base.profiles)) {
		LIST_HEAD(lh);
751
		list_splice_init_rcu(&old->base.profiles, &lh, synchronize_rcu);
752 753 754 755 756 757 758 759

		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  */
760
				__replace_profile(child, p, share_proxy);
761 762 763 764 765 766
				continue;
			}

			/* inherit @child and its children */
			/* TODO: update hname of inherited children */
			/* list refcount transferred to @new */
767
			p = aa_deref_parent(child);
768 769 770
			rcu_assign_pointer(child->parent, aa_get_profile(new));
			list_add_rcu(&child->base.list, &new->base.profiles);
			aa_put_profile(p);
771 772 773
		}
	}

774
	if (!rcu_access_pointer(new->parent)) {
775
		struct aa_profile *parent = aa_deref_parent(old);
776 777
		rcu_assign_pointer(new->parent, aa_get_profile(parent));
	}
778 779 780 781 782 783 784
	__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,
785 786
				   aa_get_profile(new));
	__aa_fs_profile_migrate_dents(old, new);
787 788 789

	if (list_empty(&new->base.list)) {
		/* new is not on a list already */
790
		list_replace_rcu(&old->base.list, &new->base.list);
791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806
		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
 */
807
static int __lookup_replace(struct aa_ns *ns, const char *hname,
808 809 810 811 812 813 814 815 816 817 818 819 820 821 822
			    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
823 824
/**
 * aa_replace_profiles - replace profile(s) on the profile list
825
 * @view: namespace load is viewed from
826
 * @label: label that is attempting to load/replace policy
J
John Johansen 已提交
827
 * @noreplace: true if only doing addition, no replacement allowed
828
 * @udata: serialized data stream  (NOT NULL)
J
John Johansen 已提交
829 830
 *
 * unpack and replace a profile on the profile list and uses of that profile
831
 * by any aa_task_ctx.  If the profile does not exist on the profile list
J
John Johansen 已提交
832 833 834 835
 * it is added.
 *
 * Returns: size of data consumed else error code on failure.
 */
836 837
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
838
{
839
	const char *ns_name, *info = NULL;
840
	struct aa_ns *ns = NULL;
841
	struct aa_load_ent *ent, *tmp;
842
	const char *op = OP_PROF_REPL;
843
	ssize_t count, error;
844
	LIST_HEAD(lh);
J
John Johansen 已提交
845 846

	/* released below */
847
	error = aa_unpack(udata, &lh, &ns_name);
848 849
	if (error)
		goto out;
J
John Johansen 已提交
850

851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873
	/* 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
874
	}
875 876 877 878 879 880 881 882 883 884
	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
885

886
	mutex_lock(&ns->lock);
887 888 889
	/* setup parent and ns info */
	list_for_each_entry(ent, &lh, list) {
		struct aa_policy *policy;
890
		ent->new->rawdata = aa_get_loaddata(udata);
891 892 893 894 895 896 897 898 899 900 901
		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
902 903
		}

904
		/* released when @new is freed */
905
		ent->new->ns = aa_get_ns(ns);
906 907 908 909 910 911 912 913 914 915 916 917 918 919

		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;
			}
920 921
			rcu_assign_pointer(ent->new->parent, aa_get_profile(p));
		} else if (policy != &ns->base) {
922
			/* released on profile replacement or free_profile */
923 924 925
			struct aa_profile *p = (struct aa_profile *) policy;
			rcu_assign_pointer(ent->new->parent, aa_get_profile(p));
		}
926
	}
J
John Johansen 已提交
927

928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954
	/* 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 */
955 956 957 958
	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;

959 960
		audit_policy(profile, op, NULL, ent->new->base.hname,
			     NULL, error);
961 962

		if (ent->old) {
963
			__replace_profile(ent->old, ent->new, 1);
964
			if (ent->rename) {
965 966
				/* aafs interface uses proxy */
				struct aa_proxy *r = ent->new->proxy;
967 968
				rcu_assign_pointer(r->profile,
						   aa_get_profile(ent->new));
969
				__replace_profile(ent->rename, ent->new, 0);
970
			}
971
		} else if (ent->rename) {
972 973
			/* aafs interface uses proxy */
			rcu_assign_pointer(ent->new->proxy->profile,
974
					   aa_get_profile(ent->new));
975
			__replace_profile(ent->rename, ent->new, 0);
976
		} else if (ent->new->parent) {
977
			struct aa_profile *parent, *newest;
978
			parent = aa_deref_parent(ent->new);
979
			newest = aa_get_newest_profile(parent);
980

981
			/* parent replaced in this atomic set? */
982 983 984
			if (newest != parent) {
				aa_get_profile(newest);
				rcu_assign_pointer(ent->new->parent, newest);
985
				aa_put_profile(parent);
986
			}
987 988
			/* aafs interface uses proxy */
			rcu_assign_pointer(ent->new->proxy->profile,
989
					   aa_get_profile(ent->new));
990
			__list_add_profile(&newest->base.profiles, ent->new);
991
			aa_put_profile(newest);
992
		} else {
993 994
			/* aafs interface uses proxy */
			rcu_assign_pointer(ent->new->proxy->profile,
995
					   aa_get_profile(ent->new));
996
			__list_add_profile(&ns->base.profiles, ent->new);
997
		}
998
		aa_load_ent_free(ent);
J
John Johansen 已提交
999
	}
1000
	mutex_unlock(&ns->lock);
J
John Johansen 已提交
1001 1002

out:
1003
	aa_put_ns(ns);
1004

J
John Johansen 已提交
1005 1006
	if (error)
		return error;
1007
	return udata->size;
J
John Johansen 已提交
1008

1009
fail_lock:
1010
	mutex_unlock(&ns->lock);
1011

1012 1013
	/* audit cause of failure */
	op = (!ent->old) ? OP_PROF_LOAD : OP_PROF_REPL;
1014
fail:
1015
	audit_policy(profile, op, ns_name, ent->new->base.hname,
1016
		     info, error);
1017 1018 1019 1020 1021 1022 1023 1024 1025
	/* 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;
1026
		audit_policy(profile, op, ns_name,
1027
			     tmp->new->base.hname, info, error);
1028
	}
1029 1030 1031 1032 1033
	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
1034 1035 1036 1037 1038
	goto out;
}

/**
 * aa_remove_profiles - remove profile(s) from the system
1039
 * @view: namespace the remove is being done from
1040
 * @subj: profile attempting to remove policy
J
John Johansen 已提交
1041 1042 1043 1044 1045 1046 1047 1048 1049 1050
 * @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
 */
1051 1052
ssize_t aa_remove_profiles(struct aa_ns *view, struct aa_profile *subj,
			   char *fqname, size_t size)
J
John Johansen 已提交
1053
{
1054
	struct aa_ns *root = NULL, *ns = NULL;
J
John Johansen 已提交
1055 1056
	struct aa_profile *profile = NULL;
	const char *name = fqname, *info = NULL;
1057
	char *ns_name = NULL;
J
John Johansen 已提交
1058 1059 1060 1061 1062 1063 1064 1065
	ssize_t error = 0;

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

1066
	root = view;
J
John Johansen 已提交
1067 1068 1069

	if (fqname[0] == ':') {
		name = aa_split_fqname(fqname, &ns_name);
1070
		/* released below */
1071
		ns = aa_find_ns(root, ns_name);
1072 1073 1074 1075
		if (!ns) {
			info = "namespace does not exist";
			error = -ENOENT;
			goto fail;
J
John Johansen 已提交
1076 1077 1078
		}
	} else
		/* released below */
1079
		ns = aa_get_ns(root);
J
John Johansen 已提交
1080 1081 1082

	if (!name) {
		/* remove namespace - can only happen if fqname[0] == ':' */
1083
		mutex_lock(&ns->parent->lock);
1084
		__aa_remove_ns(ns);
1085
		mutex_unlock(&ns->parent->lock);
J
John Johansen 已提交
1086 1087
	} else {
		/* remove profile */
1088
		mutex_lock(&ns->lock);
J
John Johansen 已提交
1089 1090 1091 1092 1093 1094 1095 1096
		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);
1097
		mutex_unlock(&ns->lock);
J
John Johansen 已提交
1098 1099 1100
	}

	/* don't fail removal if audit fails */
1101
	(void) audit_policy(subj, OP_PROF_RM, ns_name, name, info,
1102
			    error);
1103
	aa_put_ns(ns);
J
John Johansen 已提交
1104 1105 1106 1107
	aa_put_profile(profile);
	return size;

fail_ns_lock:
1108
	mutex_unlock(&ns->lock);
1109
	aa_put_ns(ns);
J
John Johansen 已提交
1110 1111

fail:
1112
	(void) audit_policy(subj, OP_PROF_RM, ns_name, name, info,
1113
			    error);
J
John Johansen 已提交
1114 1115
	return error;
}