virtio-net: correctly transmit XDP buff after linearizing

BugLink: http://bugs.launchpad.net/bugs/1789666
[ Upstream commit 5d458a13dd59d04b4d6658a6d5b94d42732b15ae ]

We should not go for the error path after successfully transmitting a
XDP buffer after linearizing. Since the error path may try to pop and
drop next packet and increase the drop counters. Fixing this by simply
drop the refcnt of original page and go for xmit path.

Fixes: 72979a6c3590 ("virtio_net: xdp, add slowpath case for non contiguous buffers")
Cc: John Fastabend <john.fastabend@gmail.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index bbb744570153c8c01c8d0eed11668dd4d4d90798..199eb5312a3585184c863ca8c9ec4f113a8b03c8 100644 (file)
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -725,7 +725,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
                        else
                                *xdp_xmit = true;
                        if (unlikely(xdp_page != page))
-                               goto err_xdp;
+                               put_page(page);
                        rcu_read_unlock();
                        goto xdp_xmit;
                case XDP_REDIRECT: