From: Stephen Smalley <sds@tycho.nsa.gov>
Date: Wed, 9 Jan 2019 15:55:10 +0000 (-0500)
Subject: selinux: fix GPF on invalid policy
X-Git-Tag: v3.18.133~24
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=f643372c915bbb9d11787b785890642fce3c1ab2;p=profile%2Fwearable%2Fplatform%2Fkernel%2Flinux-3.18-exynos7270.git

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>
---

diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c
index bc2a586..0b31d61 100644
--- a/security/selinux/ss/policydb.c
+++ b/security/selinux/ss/policydb.c
@@ -717,7 +717,8 @@ 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);