4.9-stable review patch. If anyone has any objections, please let me know.
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From: Jason A. Donenfeld Jason@zx2c4.com
commit e2fcad58fd230f635a74e4e983c6f4ea893642d2 upstream.
Signed-off-by: Jason A. Donenfeld Jason@zx2c4.com Reviewed-by: Sergei Shtylyov sergei.shtylyov@cogentembedded.com Cc: "Michael S. Tsirkin" mst@redhat.com Cc: Jason Wang jasowang@redhat.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Nathan Chancellor natechancellor@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/net/virtio_net.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
--- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -831,7 +831,7 @@ static int xmit_skb(struct send_queue *s struct virtio_net_hdr_mrg_rxbuf *hdr; const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest; struct virtnet_info *vi = sq->vq->vdev->priv; - unsigned num_sg; + int num_sg; unsigned hdr_len = vi->hdr_len; bool can_push;
@@ -858,11 +858,16 @@ static int xmit_skb(struct send_queue *s if (can_push) { __skb_push(skb, hdr_len); num_sg = skb_to_sgvec(skb, sq->sg, 0, skb->len); + if (unlikely(num_sg < 0)) + return num_sg; /* Pull header back to avoid skew in tx bytes calculations. */ __skb_pull(skb, hdr_len); } else { sg_set_buf(sq->sg, hdr, hdr_len); - num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len) + 1; + num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len); + if (unlikely(num_sg < 0)) + return num_sg; + num_sg++; } return virtqueue_add_outbuf(sq->vq, sq->sg, num_sg, skb, GFP_ATOMIC); }