[PATCH security-next v4 14/32] LSM: Plumb visibility into optional "enabled" state

[Kees Cook]

In preparation for lifting the "is this LSM enabled?" logic out of the
individual LSMs, pass in any special enabled state tracking (as needed
for SELinux, AppArmor, and LoadPin). This should be an "int" to include
handling any future cases where "enabled" is exposed via sysctl which
has no "bool" type.

Signed-off-by: Kees Cook <keescook at chromium.org>
Reviewed-by: Casey Schaufler <casey at schaufler-ca.com>
Reviewed-by: John Johansen <john.johansen at canonical.com>
---
 include/linux/lsm_hooks.h | 1 +
 security/apparmor/lsm.c   | 5 +++--
 security/selinux/hooks.c  | 1 +
 3 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index 531e219a49b9..6ec5a0266f21 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -2044,6 +2044,7 @@ extern void security_add_hooks(struct security_hook_list *hooks, int count,
 struct lsm_info {
 	const char *name;	/* Required. */
 	unsigned long flags;	/* Optional: flags describing LSM */
+	int *enabled;		/* Optional: NULL means enabled. */
 	int (*init)(void);	/* Required. */
 };
 
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index 768cb539fb6c..6ace45704cb6 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -1303,8 +1303,8 @@ bool aa_g_paranoid_load = true;
 module_param_named(paranoid_load, aa_g_paranoid_load, aabool, S_IRUGO);
 
 /* Boot time disable flag */
-static bool apparmor_enabled = CONFIG_SECURITY_APPARMOR_BOOTPARAM_VALUE;
-module_param_named(enabled, apparmor_enabled, bool, S_IRUGO);
+static int apparmor_enabled = CONFIG_SECURITY_APPARMOR_BOOTPARAM_VALUE;
+module_param_named(enabled, apparmor_enabled, int, 0444);
 
 static int __init apparmor_enabled_setup(char *str)
 {
@@ -1609,5 +1609,6 @@ static int __init apparmor_init(void)
 DEFINE_LSM(apparmor) = {
 	.name = "apparmor",
 	.flags = LSM_FLAG_LEGACY_MAJOR,
+	.enabled = &apparmor_enabled,
 	.init = apparmor_init,
 };
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 020886895819..e8da99550b67 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -7205,6 +7205,7 @@ void selinux_complete_init(void)
 DEFINE_LSM(selinux) = {
 	.name = "selinux",
 	.flags = LSM_FLAG_LEGACY_MAJOR,
+	.enabled = &selinux_enabled,
 	.init = selinux_init,
 };
 
-- 
2.17.1