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// SPDX-License-Identifier: GPL-2.0-only
/*
* Landlock - Credential hooks
*
* Copyright © 2017-2020 Mickaël Salaün <mic@digikod.net>
* Copyright © 2018-2020 ANSSI
* Copyright © 2024-2025 Microsoft Corporation
*/
#include <linux/binfmts.h>
#include <linux/cred.h>
#include <linux/lsm_hooks.h>
#include "common.h"
#include "cred.h"
#include "ruleset.h"
#include "setup.h"
static void hook_cred_transfer(struct cred *const new,
const struct cred *const old)
{
const struct landlock_cred_security *const old_llcred =
landlock_cred(old);
if (old_llcred->domain) {
landlock_get_ruleset(old_llcred->domain);
*landlock_cred(new) = *old_llcred;
}
}
static int hook_cred_prepare(struct cred *const new,
const struct cred *const old, const gfp_t gfp)
{
hook_cred_transfer(new, old);
return 0;
}
static void hook_cred_free(struct cred *const cred)
{
struct landlock_ruleset *const dom = landlock_cred(cred)->domain;
if (dom)
landlock_put_ruleset_deferred(dom);
}
#ifdef CONFIG_AUDIT
static int hook_bprm_creds_for_exec(struct linux_binprm *const bprm)
{
/* Resets for each execution. */
landlock_cred(bprm->cred)->domain_exec = 0;
return 0;
}
#endif /* CONFIG_AUDIT */
static struct security_hook_list landlock_hooks[] __ro_after_init = {
LSM_HOOK_INIT(cred_prepare, hook_cred_prepare),
LSM_HOOK_INIT(cred_transfer, hook_cred_transfer),
LSM_HOOK_INIT(cred_free, hook_cred_free),
#ifdef CONFIG_AUDIT
LSM_HOOK_INIT(bprm_creds_for_exec, hook_bprm_creds_for_exec),
#endif /* CONFIG_AUDIT */
};
__init void landlock_add_cred_hooks(void)
{
security_add_hooks(landlock_hooks, ARRAY_SIZE(landlock_hooks),
&landlock_lsmid);
}
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