Config option to set a default LSM
The LSM currently requires setting a kernel parameter at boot to select
a specific LSM. This adds a config option that allows specifying a default
LSM that is used unless overridden with the security= kernel parameter.
If the the config option is not set the current behavior of first LSM
to register is used.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/security/Kconfig b/security/Kconfig
index aeea8c2..95cc089 100644
--- a/security/Kconfig
+++ b/security/Kconfig
@@ -152,5 +152,37 @@
source security/integrity/ima/Kconfig
+choice
+ prompt "Default security module"
+ default DEFAULT_SECURITY_SELINUX if SECURITY_SELINUX
+ default DEFAULT_SECURITY_SMACK if SECURITY_SMACK
+ default DEFAULT_SECURITY_TOMOYO if SECURITY_TOMOYO
+ default DEFAULT_SECURITY_DAC
+
+ help
+ Select the security module that will be used by default if the
+ kernel parameter security= is not specified.
+
+ config DEFAULT_SECURITY_SELINUX
+ bool "SELinux" if SECURITY_SELINUX=y
+
+ config DEFAULT_SECURITY_SMACK
+ bool "Simplified Mandatory Access Control" if SECURITY_SMACK=y
+
+ config DEFAULT_SECURITY_TOMOYO
+ bool "TOMOYO" if SECURITY_TOMOYO=y
+
+ config DEFAULT_SECURITY_DAC
+ bool "Unix Discretionary Access Controls"
+
+endchoice
+
+config DEFAULT_SECURITY
+ string
+ default "selinux" if DEFAULT_SECURITY_SELINUX
+ default "smack" if DEFAULT_SECURITY_SMACK
+ default "tomoyo" if DEFAULT_SECURITY_TOMOYO
+ default "" if DEFAULT_SECURITY_DAC
+
endmenu
diff --git a/security/security.c b/security/security.c
index 684d5ee..aad71b2 100644
--- a/security/security.c
+++ b/security/security.c
@@ -19,7 +19,8 @@
#include <linux/ima.h>
/* Boot-time LSM user choice */
-static __initdata char chosen_lsm[SECURITY_NAME_MAX + 1];
+static __initdata char chosen_lsm[SECURITY_NAME_MAX + 1] =
+ CONFIG_DEFAULT_SECURITY;
/* things that live in capability.c */
extern struct security_operations default_security_ops;
@@ -80,8 +81,10 @@
*
* Return true if:
* -The passed LSM is the one chosen by user at boot time,
- * -or user didn't specify a specific LSM and we're the first to ask
- * for registration permission,
+ * -or the passed LSM is configured as the default and the user did not
+ * choose an alternate LSM at boot time,
+ * -or there is no default LSM set and the user didn't specify a
+ * specific LSM and we're the first to ask for registration permission,
* -or the passed LSM is currently loaded.
* Otherwise, return false.
*/