| 1 | // SPDX-License-Identifier: GPL-2.0-only |
|---|---|
| 2 | /* |
| 3 | * Landlock LSM - Credential hooks |
| 4 | * |
| 5 | * Copyright © 2017-2020 Mickaël Salaün <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 | |
| 17 | static 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(cred: old)->domain; |
| 21 | |
| 22 | if (old_dom) { |
| 23 | landlock_get_ruleset(ruleset: old_dom); |
| 24 | landlock_cred(cred: new)->domain = old_dom; |
| 25 | } |
| 26 | return 0; |
| 27 | } |
| 28 | |
| 29 | static 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(ruleset: dom); |
| 35 | } |
| 36 | |
| 37 | static 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(hooks: landlock_hooks, ARRAY_SIZE(landlock_hooks), |
| 45 | lsmid: &landlock_lsmid); |
| 46 | } |
| 47 |