| Message ID | 20170511115806.25322-1-vkuznets@redhat.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
From: Vitaly Kuznetsov <vkuznets@redhat.com> Date: Thu, 11 May 2017 13:58:06 +0200 > 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> > --- > Changes since v1: instead of cleaning drvdata and checking for it in > netfront_resume() and netback_changed() remove the device completely with > device_unregister() [David Miller] This looks a lot better, applied, thanks!
diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c index 6ffc482..7b61adb 100644 --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -1934,8 +1934,7 @@ 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; }
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> --- Changes since v1: instead of cleaning drvdata and checking for it in netfront_resume() and netback_changed() remove the device completely with device_unregister() [David Miller] --- drivers/net/xen-netfront.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)