1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Landlock LSM - Credential hooks
4 *
5 * Copyright �� 2017-2020 Micka��l Sala��n <mic@digikod.net>
6 * Copyright �� 2018-2020 ANSSI
7 */
8
9#include <linux/cred.h>
10#include <linux/lsm_hooks.h>
11
12#include "common.h"
13#include "cred.h"
14#include "ruleset.h"
15#include "setup.h"
16
17static int hook_cred_prepare(struct cred *const new,
18			     const struct cred *const old, const gfp_t gfp)
19{
20	struct landlock_ruleset *const old_dom = landlock_cred(old)->domain;
21
22	if (old_dom) {
23		landlock_get_ruleset(old_dom);
24		landlock_cred(new)->domain = old_dom;
25	}
26	return 0;
27}
28
29static void hook_cred_free(struct cred *const cred)
30{
31	struct landlock_ruleset *const dom = landlock_cred(cred)->domain;
32
33	if (dom)
34		landlock_put_ruleset_deferred(dom);
35}
36
37static struct security_hook_list landlock_hooks[] __ro_after_init = {
38	LSM_HOOK_INIT(cred_prepare, hook_cred_prepare),
39	LSM_HOOK_INIT(cred_free, hook_cred_free),
40};
41
42__init void landlock_add_cred_hooks(void)
43{
44	security_add_hooks(landlock_hooks, ARRAY_SIZE(landlock_hooks),
45			   &landlock_lsmid);
46}
47