[PATCH] selinux: fix GPF on invalid policy

[Stephen Smalley]

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@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Stephen Smalley <sds@xxxxxxxxxxxxx>
---
 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 a50d625e7946..c1c31e33657a 100644
--- a/security/selinux/ss/policydb.c
+++ b/security/selinux/ss/policydb.c
@@ -732,7 +732,8 @@ 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);
-- 
2.20.1

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