virtio_net: stricter short buffer length checks

Our buffer length check is not strict enough for mergeable
buffers: buffer can still be shorter that header + address
by 2 bytes.

Fix that up.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Jason Wang <jasowang@redhat.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 516f2cb034b5..098f4432afa1 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -437,7 +437,7 @@ static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq,
         struct sk_buff *skb;
         struct virtio_net_hdr_mrg_rxbuf *hdr;
 
-        if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) {
+        if (unlikely(len < vi->hdr_len + ETH_HLEN)) {
                 pr_debug("%s: short packet %i\n", dev->name, len);
                 dev->stats.rx_length_errors++;
                 if (vi->mergeable_rx_bufs) {