LXR linux/security/landlock/cred.c

   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
  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[] __lsm_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_NAME);
  46}
  47