RDMA/cxgb4: Drop peer_abort when no endpoint found

Log a warning and drop the abort message.  Otherwise we will do a
bogus wake_up() and crash.
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>

drivers/infiniband/hw/cxgb4/cm.c

@@ -2656,6 +2656,12 @@ static int peer_abort_intr(struct c4iw_dev *dev, struct sk_buff *skb)
 	unsigned int tid = GET_TID(req);
 
 	ep = lookup_tid(t, tid);
+	if (!ep) {
+		printk(KERN_WARNING MOD
+		       "Abort on non-existent endpoint, tid %d\n", tid);
+		kfree_skb(skb);
+		return 0;
+	}
 	if (is_neg_adv_abort(req->status)) {
 		PDBG("%s neg_adv_abort ep %p tid %u\n", __func__, ep,
 		     ep->hwtid);