From b2c80e29e49939ec982681a87284f7330bea60af Mon Sep 17 00:00:00 2001
From: Stephen Smalley <sds@tycho.nsa.gov>
Date: Wed, 9 Jan 2019 10:55:10 -0500
Subject: [PATCH] selinux: fix GPF on invalid policy

commit 5b0e7310a2a33c06edc7eb81ffc521af9b2c5610 upstream.

levdatum->level can be NULL if we encounter an error while loading
the policy during sens_read prior to initializing it.  Make sure
sens_destroy handles that case correctly.

Reported-by: syzbot+6664500f0f18f07a5c0e@syzkaller.appspotmail.com
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 security/selinux/ss/policydb.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c
index ca2c6f47d905..b83ac8fae320 100644
--- a/security/selinux/ss/policydb.c
+++ b/security/selinux/ss/policydb.c
@@ -722,7 +722,8 @@ static int sens_destroy(void *key, void *datum, void *p)
 	kfree(key);
 	if (datum) {
 		levdatum = datum;
-		ebitmap_destroy(&levdatum->level->cat);
+		if (levdatum->level)
+			ebitmap_destroy(&levdatum->level->cat);
 		kfree(levdatum->level);
 	}
 	kfree(datum);