[PATCH security-next v3 12/29] LSM: Provide separate ordered initialization

From: Kees Cook
Date: Mon Sep 24 2018 - 20:20:07 EST


This provides a place for ordered LSMs to be initialized, separate from
the "major" LSMs. This is mainly a copy/paste from major_lsm_init() to
ordered_lsm_init(), but it will change drastically in later patches.

What is not obvious in the patch is that this change moves the integrity
LSM from major_lsm_init() into ordered_lsm_init(), since it is not marked
with the LSM_FLAG_LEGACY_MAJOR. As it is the only LSM in the "ordered"
list, there is no reordering yet created.

Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
security/security.c | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)

diff --git a/security/security.c b/security/security.c
index 1f055936a746..a886a978214a 100644
--- a/security/security.c
+++ b/security/security.c
@@ -52,12 +52,30 @@ static bool debug __initdata;
pr_info(__VA_ARGS__); \
} while (0)

+static void __init ordered_lsm_init(void)
+{
+ struct lsm_info *lsm;
+ int ret;
+
+ for (lsm = __start_lsm_info; lsm < __end_lsm_info; lsm++) {
+ if ((lsm->flags & LSM_FLAG_LEGACY_MAJOR) != 0)
+ continue;
+
+ init_debug("initializing %s\n", lsm->name);
+ ret = lsm->init();
+ WARN(ret, "%s failed to initialize: %d\n", lsm->name, ret);
+ }
+}
+
static void __init major_lsm_init(void)
{
struct lsm_info *lsm;
int ret;

for (lsm = __start_lsm_info; lsm < __end_lsm_info; lsm++) {
+ if ((lsm->flags & LSM_FLAG_LEGACY_MAJOR) == 0)
+ continue;
+
init_debug("initializing %s\n", lsm->name);
ret = lsm->init();
WARN(ret, "%s failed to initialize: %d\n", lsm->name, ret);
@@ -87,6 +105,9 @@ int __init security_init(void)
yama_add_hooks();
loadpin_add_hooks();

+ /* Load LSMs in specified order. */
+ ordered_lsm_init();
+
/*
* Load all the remaining security modules.
*/
--
2.17.1