net: ignore packet size greater than INT_MAX

There should not be a reason for passing a packet size greater than
INT_MAX. It's usually a hint of bug somewhere, so ignore packet size
greater than INT_MAX in qemu_deliver_packet_iov()

CC: qemu-stable@nongnu.org
Reported-by: NDaniel Shapira <daniel@twistlock.com>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NJason Wang <jasowang@redhat.com>
(cherry picked from commit 1592a994)
Signed-off-by: NMichael Roth <mdroth@linux.vnet.ibm.com>

net/net.c

@@ -712,10 +712,15 @@ ssize_t qemu_deliver_packet_iov(NetClientState *sender,
                                 void *opaque)
 {
     NetClientState *nc = opaque;
+    size_t size = iov_size(iov, iovcnt);
     int ret;
 
+    if (size > INT_MAX) {
+        return size;
+    }
+
     if (nc->link_down) {
-        return iov_size(iov, iovcnt);
+        return size;
     }
 
     if (nc->receive_disabled) {