Merge branch 'xen-netfront-xsa-403-follow-on'

Jan Beulich says:

====================
xen-netfront: XSA-403 follow-on

While investigating the XSA, I did notice a few more things. The two
patches aren't really dependent on one another.

1: remove leftover call to xennet_tx_buf_gc()
2: re-order error checks in xennet_get_responses()
====================

Link: https://lore.kernel.org/r/7fca0e44-43b5-8448-3653-249d117dc084@suse.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>

drivers/net/xen-netfront.c

@@ -1043,16 +1043,6 @@ static int xennet_get_responses(struct netfront_queue *queue,
 	}
 
 	for (;;) {
-		if (unlikely(rx->status < 0 ||
-			     rx->offset + rx->status > XEN_PAGE_SIZE)) {
-			if (net_ratelimit())
-				dev_warn(dev, "rx->offset: %u, size: %d\n",
-					 rx->offset, rx->status);
-			xennet_move_rx_slot(queue, skb, ref);
-			err = -EINVAL;
-			goto next;
-		}
-
 		/*
 		 * This definitely indicates a bug, either in this driver or in
 		 * the backend driver. In future this should flag the bad
@@ -1066,6 +1056,16 @@ static int xennet_get_responses(struct netfront_queue *queue,
 			goto next;
 		}
 
+		if (unlikely(rx->status < 0 ||
+			     rx->offset + rx->status > XEN_PAGE_SIZE)) {
+			if (net_ratelimit())
+				dev_warn(dev, "rx->offset: %u, size: %d\n",
+					 rx->offset, rx->status);
+			xennet_move_rx_slot(queue, skb, ref);
+			err = -EINVAL;
+			goto next;
+		}
+
 		if (!gnttab_end_foreign_access_ref(ref)) {
 			dev_alert(dev,
 				  "Grant still in use by backend domain\n");
@@ -2464,10 +2464,6 @@ static int xennet_connect(struct net_device *dev)
 		if (queue->tx_irq != queue->rx_irq)
 			notify_remote_via_irq(queue->rx_irq);
 
-		spin_lock_irq(&queue->tx_lock);
-		xennet_tx_buf_gc(queue);
-		spin_unlock_irq(&queue->tx_lock);
-
 		spin_lock_bh(&queue->rx_lock);
 		xennet_alloc_rx_buffers(queue);
 		spin_unlock_bh(&queue->rx_lock);