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 void hook_cred_transfer(struct cred *const new, 18 const struct cred *const old) 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 } 27 28 static int hook_cred_prepare(struct cred *const new, 29 const struct cred *const old, const gfp_t gfp) 30 { 31 hook_cred_transfer(new, old); 32 return 0; 33 } 34 35 static void hook_cred_free(struct cred *const cred) 36 { 37 struct landlock_ruleset *const dom = landlock_cred(cred)->domain; 38 39 if (dom) 40 landlock_put_ruleset_deferred(dom); 41 } 42 43 static struct security_hook_list landlock_hooks[] __ro_after_init = { 44 LSM_HOOK_INIT(cred_prepare, hook_cred_prepare), 45 LSM_HOOK_INIT(cred_transfer, hook_cred_transfer), 46 LSM_HOOK_INIT(cred_free, hook_cred_free), 47 }; 48 49 __init void landlock_add_cred_hooks(void) 50 { 51 security_add_hooks(landlock_hooks, ARRAY_SIZE(landlock_hooks), 52 LANDLOCK_NAME); 53 } 54