Creds: creds->security can be NULL is selinux is disabled

__validate_process_creds should check if selinux is actually enabled before
running tests on the selinux portion of the credentials struct.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>

1 files changed, 8 insertions, 5 deletions

diff --git a/include/linux/cred.h b/include/linux/cred.h
index 24520a539c6f..fb371601a3b4 100644
--- a/include/linux/cred.h
+++ b/include/linux/cred.h
@@ -15,6 +15,7 @@
 #include <linux/capability.h>
 #include <linux/init.h>
 #include <linux/key.h>
+#include <linux/selinux.h>
 #include <asm/atomic.h>
 
 struct user_struct;
@@ -182,11 +183,13 @@ static inline bool creds_are_invalid(const struct cred *cred)
         if (atomic_read(&cred->usage) < atomic_read(&cred->subscribers))
                 return true;
 #ifdef CONFIG_SECURITY_SELINUX
-        if ((unsigned long) cred->security < PAGE_SIZE)
-                return true;
-        if ((*(u32*)cred->security & 0xffffff00) ==
-            (POISON_FREE << 24 | POISON_FREE << 16 | POISON_FREE << 8))
-                return true;
+        if (selinux_is_enabled()) {
+                if ((unsigned long) cred->security < PAGE_SIZE)
+                        return true;
+                if ((*(u32 *)cred->security & 0xffffff00) ==
+                    (POISON_FREE << 24 | POISON_FREE << 16 | POISON_FREE << 8))
+                        return true;
+        }
 #endif
         return false;
 }