SELinux: policy selectable handling of unknown classes and perms

Allow policy to select, in much the same way as it selects MLS support, how
the kernel should handle access decisions which contain either unknown
classes or unknown permissions in known classes.  The three choices for the
policy flags are

0 - Deny unknown security access. (default)
2 - reject loading policy if it does not contain all definitions
4 - allow unknown security access

The policy's choice is exported through 2 booleans in
selinuxfs.  /selinux/deny_unknown and /selinux/reject_unknown.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

1 files changed, 8 insertions, 0 deletions

diff --git a/security/selinux/ss/policydb.h b/security/selinux/ss/policydb.h
index 8319d5ff5944..844d310f4f1b 100644
--- a/security/selinux/ss/policydb.h
+++ b/security/selinux/ss/policydb.h
@@ -242,6 +242,10 @@ struct policydb {
         struct ebitmap *type_attr_map;
 
         unsigned int policyvers;
+
+        unsigned int reject_unknown : 1;
+        unsigned int allow_unknown : 1;
+        u32 *undefined_perms;
 };
 
 extern void policydb_destroy(struct policydb *p);
@@ -253,6 +257,10 @@ extern int policydb_read(struct policydb *p, void *fp);
 
 #define POLICYDB_CONFIG_MLS    1
 
+/* the config flags related to unknown classes/perms are bits 2 and 3 */
+#define REJECT_UNKNOWN  0x00000002
+#define ALLOW_UNKNOWN   0x00000004
+
 #define OBJECT_R "object_r"
 #define OBJECT_R_VAL 1