385975dca5
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>
47 lines
1.0 KiB
C
47 lines
1.0 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Landlock LSM - Credential hooks
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*
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* Copyright © 2017-2020 Mickaël Salaün <mic@digikod.net>
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* Copyright © 2018-2020 ANSSI
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*/
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#include <linux/cred.h>
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#include <linux/lsm_hooks.h>
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#include "common.h"
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#include "cred.h"
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#include "ruleset.h"
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#include "setup.h"
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static int hook_cred_prepare(struct cred *const new,
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const struct cred *const old, const gfp_t gfp)
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{
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struct landlock_ruleset *const old_dom = landlock_cred(old)->domain;
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if (old_dom) {
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landlock_get_ruleset(old_dom);
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landlock_cred(new)->domain = old_dom;
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}
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return 0;
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}
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static void hook_cred_free(struct cred *const cred)
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{
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struct landlock_ruleset *const dom = landlock_cred(cred)->domain;
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if (dom)
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landlock_put_ruleset_deferred(dom);
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}
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static struct security_hook_list landlock_hooks[] __lsm_ro_after_init = {
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LSM_HOOK_INIT(cred_prepare, hook_cred_prepare),
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LSM_HOOK_INIT(cred_free, hook_cred_free),
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};
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__init void landlock_add_cred_hooks(void)
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{
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security_add_hooks(landlock_hooks, ARRAY_SIZE(landlock_hooks),
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LANDLOCK_NAME);
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}
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