virtio-net: serialize tx routine during reset

[ Upstream commit 713a98d90c5ea072c1bb00ef40617aee2cef2232 ]

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 <jpmenil@gmail.com>
Tested-by: Jean-Philippe Menil <jpmenil@gmail.com>
Fixes commit f600b6905015 ("virtio_net: Add XDP support")
Cc: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Robert McCabe <robert.mccabe@rockwellcollins.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index d9d8f4f43f9027bb409b35ac06c35f743f22a53b..7e171d7aed661397503a139767bb1f7bf5b7bd91 100644 (file)
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -1709,6 +1709,7 @@ static void virtnet_freeze_down(struct virtio_device *vdev)
        flush_work(&vi->config_work);
 
        netif_device_detach(vi->dev);
+       netif_tx_disable(vi->dev);
        cancel_delayed_work_sync(&vi->refill);
 
        if (netif_running(vi->dev)) {