[PATCH 4.16 44/48] virtio-net: correctly redirect linearized packet

From: Greg Kroah-Hartman
Date: Sat Jun 09 2018 - 11:34:19 EST

4.16-stable review patch. If anyone has any objections, please let me know.


From: Jason Wang <jasowang@xxxxxxxxxx>

[ Upstream commit 6890418bbb780f0ee9cf124055afa79777f1b4f1 ]

After a linearized packet was redirected by XDP, we should not go for
the err path which will try to pop buffers for the next packet and
increase the drop counter. Fixing this by just drop the page refcnt
for the original page.

Fixes: 186b3c998c50 ("virtio-net: support XDP_REDIRECT")
Reported-by: David Ahern <dsahern@xxxxxxxxx>
Tested-by: David Ahern <dsahern@xxxxxxxxx>
Acked-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
drivers/net/virtio_net.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -786,7 +786,7 @@ static struct sk_buff *receive_mergeable
*xdp_xmit = true;
if (unlikely(xdp_page != page))
- goto err_xdp;
+ put_page(page);
goto xdp_xmit;