Subject: [PATCH 09/30] virtio-net: serialize tx routine during reset

From: Jason Wang <[email-masked]>
Date: Wed, 28 Jun 2017 09:51:03 +0800

[ 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 <[email-masked]>
Tested-by: Jean-Philippe Menil <[email-masked]>
Fixes commit f600b6905015 ("virtio_net: Add XDP support")
Cc: John Fastabend <[email-masked]>
Signed-off-by: Jason Wang <[email-masked]>
Acked-by: Michael S. Tsirkin <[email-masked]>
Acked-by: Robert McCabe <[email-masked]>
Signed-off-by: David S. Miller <[email-masked]>
---
 drivers/net/virtio_net.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index d9d8f4f43f90..7e171d7aed66 100644
--- 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)) {
-- 
2.13.0