xfrm: check for a vaild skb in xfrm_policy_queue_process
We might dreference a NULL pointer if the hold_queue is empty,
so add a check to avoid this.
Bug was introduced with git commit a0073fe18 ("xfrm: Add a state
resolution packet queue")
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 5f9be97..76e1873 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -1772,6 +1772,10 @@
spin_lock(&pq->hold_queue.lock);
skb = skb_peek(&pq->hold_queue);
+ if (!skb) {
+ spin_unlock(&pq->hold_queue.lock);
+ goto out;
+ }
dst = skb_dst(skb);
sk = skb->sk;
xfrm_decode_session(skb, &fl, dst->ops->family);