Commit 14bd99c8 authored by Kees Cook's avatar Kees Cook
Browse files

LSM: Separate idea of "major" LSM from "exclusive" LSM 



In order to both support old "security=" Legacy Major LSM selection, and
handling real exclusivity, this creates LSM_FLAG_EXCLUSIVE and updates
the selection logic to handle them.

Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Reviewed-by: default avatarCasey Schaufler <casey@schaufler-ca.com>
parent 7e611486

include/linux/lsm_hooks.h

+1 −0
Original line number Diff line number Diff line
@@ -2043,6 +2043,7 @@ extern void security_add_hooks(struct security_hook_list *hooks, int count, 
				char *lsm);



#define LSM_FLAG_LEGACY_MAJOR	BIT(0)

#define LSM_FLAG_EXCLUSIVE	BIT(1)



struct lsm_info {

	const char *name;	/* Required. */

security/apparmor/lsm.c

+1 −1
Original line number Diff line number Diff line
@@ -1723,7 +1723,7 @@ static int __init apparmor_init(void) 


DEFINE_LSM(apparmor) = {

	.name = "apparmor",

	.flags = LSM_FLAG_LEGACY_MAJOR,

	.flags = LSM_FLAG_LEGACY_MAJOR | LSM_FLAG_EXCLUSIVE,

	.enabled = &apparmor_enabled,

	.init = apparmor_init,

};

security/security.c

+12 −0
Original line number Diff line number Diff line
@@ -49,6 +49,7 @@ static __initconst const char * const builtin_lsm_order = CONFIG_LSM; 


/* Ordered list of LSMs to initialize. */

static __initdata struct lsm_info **ordered_lsms;

static __initdata struct lsm_info *exclusive;



static __initdata bool debug;

#define init_debug(...)						\
@@ -129,6 +130,12 @@ static bool __init lsm_allowed(struct lsm_info *lsm) 
	if (!is_enabled(lsm))

		return false;



	/* Not allowed if another exclusive LSM already initialized. */

	if ((lsm->flags & LSM_FLAG_EXCLUSIVE) && exclusive) {

		init_debug("exclusive disabled: %s\n", lsm->name);

		return false;

	}



	return true;

}
@@ -144,6 +151,11 @@ static void __init maybe_initialize_lsm(struct lsm_info *lsm) 
	if (enabled) {

		int ret;



		if ((lsm->flags & LSM_FLAG_EXCLUSIVE) && !exclusive) {

			exclusive = lsm;

			init_debug("exclusive chosen: %s\n", lsm->name);

		}



		init_debug("initializing %s\n", lsm->name);

		ret = lsm->init();

		WARN(ret, "%s failed to initialize: %d\n", lsm->name, ret);

security/selinux/hooks.c

+1 −1
Original line number Diff line number Diff line
@@ -6989,7 +6989,7 @@ void selinux_complete_init(void) 
   all processes and objects when they are created. */

DEFINE_LSM(selinux) = {

	.name = "selinux",

	.flags = LSM_FLAG_LEGACY_MAJOR,

	.flags = LSM_FLAG_LEGACY_MAJOR | LSM_FLAG_EXCLUSIVE,

	.enabled = &selinux_enabled,

	.init = selinux_init,

};

security/smack/smack_lsm.c

+1 −1
Original line number Diff line number Diff line
@@ -4809,6 +4809,6 @@ static __init int smack_init(void) 
 */

DEFINE_LSM(smack) = {

	.name = "smack",

	.flags = LSM_FLAG_LEGACY_MAJOR,

	.flags = LSM_FLAG_LEGACY_MAJOR | LSM_FLAG_EXCLUSIVE,

	.init = smack_init,

};