From: Jason Wang <jasowang@redhat.com>
Date: Wed, 28 Jun 2017 09:51:03 +0800

We don't hold any tx lock when trying to disable TX during reset, this
would lead a use after free since ndo_start_xmit() tries to access
the virtqueue which has already been freed. Fix this by using
netif_tx_disable() before freeing the vqs, this could make sure no tx
after vq freeing.

Reported-by: Jean-Philippe Menil <redacted>
Tested-by: Jean-Philippe Menil <redacted>
Fixes commit f600b6905015 ("virtio_net: Add XDP support")
Cc: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>

Applied and queued up for -stable.