linux/security/landlock/cred.c
Mickaël Salaün 385975dca5 landlock: Set up the security framework and manage credentials
Process's credentials point to a Landlock domain, which is underneath
implemented with a ruleset.  In the following commits, this domain is
used to check and enforce the ptrace and filesystem security policies.
A domain is inherited from a parent to its child the same way a thread
inherits a seccomp policy.

Cc: James Morris <jmorris@namei.org>
Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com>
Reviewed-by: Jann Horn <jannh@google.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210422154123.13086-4-mic@digikod.net
Signed-off-by: James Morris <jamorris@linux.microsoft.com>
2021-04-22 12:22:10 -07:00

47 lines
1.0 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Landlock LSM - Credential hooks
*
* Copyright © 2017-2020 Mickaël Salaün <mic@digikod.net>
* Copyright © 2018-2020 ANSSI
*/
#include <linux/cred.h>
#include <linux/lsm_hooks.h>
#include "common.h"
#include "cred.h"
#include "ruleset.h"
#include "setup.h"
static int hook_cred_prepare(struct cred *const new,
const struct cred *const old, const gfp_t gfp)
{
struct landlock_ruleset *const old_dom = landlock_cred(old)->domain;
if (old_dom) {
landlock_get_ruleset(old_dom);
landlock_cred(new)->domain = old_dom;
}
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);
}
static struct security_hook_list landlock_hooks[] __lsm_ro_after_init = {
LSM_HOOK_INIT(cred_prepare, hook_cred_prepare),
LSM_HOOK_INIT(cred_free, hook_cred_free),
};
__init void landlock_add_cred_hooks(void)
{
security_add_hooks(landlock_hooks, ARRAY_SIZE(landlock_hooks),
LANDLOCK_NAME);
}