[PATCH 07/18] LSM: Add minor LSM initialization loop

From: Kees Cook
Date: Sat Sep 15 2018 - 20:31:18 EST


Split initialization loop into two phases: "exclusive" LSMs and "minor"
LSMs.

Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
include/linux/lsm_hooks.h | 6 ++++++
security/security.c | 8 +++++---
2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index f8e618e2bdd2..ec3419b9b16f 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -2039,7 +2039,13 @@ extern char *lsm_names;
extern void security_add_hooks(struct security_hook_list *hooks, int count,
char *lsm);

+enum lsm_type {
+ LSM_TYPE_EXCLUSIVE = 0,
+ LSM_TYPE_MINOR,
+};
+
struct lsm_info {
+ enum lsm_type type; /* Optional: default is LSM_TYPE_EXCLUSIVE */
int (*init)(void);
};

diff --git a/security/security.c b/security/security.c
index 74ab98f82d34..da2a923f2609 100644
--- a/security/security.c
+++ b/security/security.c
@@ -43,12 +43,13 @@ char *lsm_names;
static __initdata char chosen_lsm[SECURITY_NAME_MAX + 1] =
CONFIG_DEFAULT_SECURITY;

-static void __init major_lsm_init(void)
+static void __init lsm_init(enum lsm_type type)
{
struct lsm_info *lsm;

for (lsm = __start_lsm_info; lsm < __end_lsm_info; lsm++) {
- lsm->init();
+ if (lsm->type == type)
+ lsm->init();
}
}

@@ -73,11 +74,12 @@ int __init security_init(void)
capability_add_hooks();
yama_add_hooks();
loadpin_add_hooks();
+ lsm_init(LSM_TYPE_MINOR);

/*
* Load all the remaining security modules.
*/
- major_lsm_init();
+ lsm_init(LSM_TYPE_EXCLUSIVE);

return 0;
}
--
2.17.1