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 175e4dc..c483de5 100644
--- a/security/selinux/ss/policydb.c
+++ b/security/selinux/ss/policydb.c
@@ -726,7 +726,8 @@ 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);