LSM: Plumb visibility into optional "enabled" state

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 <[email protected]> Reviewed-by: Casey Schaufler <[email protected]> Reviewed-by: John Johansen <[email protected]>
ambv · Jan 8, 2019 · c5459b8 · c5459b8
1 parent 657d910
commit c5459b8
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Showing 3 changed files with 5 additions and 2 deletions.
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
@@ -2047,6 +2047,7 @@ 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
@@ -1333,8 +1333,8 @@ 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)
 {
@@ -1730,5 +1730,6 @@ 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
@@ -7000,6 +7000,7 @@ void selinux_complete_init(void)
 DEFINE_LSM(selinux) = {
 	.name = "selinux",
 	.flags = LSM_FLAG_LEGACY_MAJOR,
+	.enabled = &selinux_enabled,
 	.init = selinux_init,
 };