From 3671e6728f796dee5c557f0782725eeb6a9ad721 Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov <vkuznets@redhat.com> Date: Thu, 11 May 2017 13:58:06 +0200 Subject: [PATCH] xen-netfront: avoid crashing on resume after a failure in talk_to_netback() commit d86b5672b1adb98b4cdd6fbf0224bbfb03db6e2e upstream. Unavoidable crashes in netfront_resume() and netback_changed() after a previous fail in talk_to_netback() (e.g. when we fail to read MAC from xenstore) were discovered. The failure path in talk_to_netback() does unregister/free for netdev but we don't reset drvdata and we try accessing it after resume. Fix the bug by removing the whole xen device completely with device_unregister(), this guarantees we won't have any calls into netfront after a failure. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Cc: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/net/xen-netfront.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c index 265e2095f8d99..8d498a997e251 100644 --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -1958,8 +1958,7 @@ static int talk_to_netback(struct xenbus_device *dev, xennet_disconnect_backend(info); xennet_destroy_queues(info); out: - unregister_netdev(info->netdev); - xennet_free_netdev(info->netdev); + device_unregister(&dev->dev); return err; }