| Message ID | 20180625072627.9109-1-jslaby@suse.cz |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
| Series | [1/1] r8152: napi hangup fix after disconnect | expand |
From: Jiri Slaby <jslaby@suse.cz> Date: Mon, 25 Jun 2018 09:26:27 +0200 > When unplugging an r8152 adapter while the interface is UP, the NIC > becomes unusable. usb->disconnect (aka rtl8152_disconnect) deletes > napi. Then, rtl8152_disconnect calls unregister_netdev and that invokes > netdev->ndo_stop (aka rtl8152_close). rtl8152_close tries to > napi_disable, but the napi is already deleted by disconnect above. So > the first while loop in napi_disable never finishes. This results in > complete deadlock of the network layer as there is rtnl_mutex held by > unregister_netdev. > > So avoid the call to napi_disable in rtl8152_close when the device is > already gone. > > The other calls to usb_kill_urb, cancel_delayed_work_sync, > netif_stop_queue etc. seem to be fine. The urb and netdev is not > destroyed yet. > > Signed-off-by: Jiri Slaby <jslaby@suse.cz> Applied, thank you.
diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c index c08c0d633407..1fd165090163 100644 --- a/drivers/net/usb/r8152.c +++ b/drivers/net/usb/r8152.c @@ -3964,7 +3964,8 @@ static int rtl8152_close(struct net_device *netdev) #ifdef CONFIG_PM_SLEEP unregister_pm_notifier(&tp->pm_notifier); #endif - napi_disable(&tp->napi); + if (!test_bit(RTL8152_UNPLUG, &tp->flags)) + napi_disable(&tp->napi); clear_bit(WORK_ENABLE, &tp->flags); usb_kill_urb(tp->intr_urb); cancel_delayed_work_sync(&tp->schedule);
When unplugging an r8152 adapter while the interface is UP, the NIC becomes unusable. usb->disconnect (aka rtl8152_disconnect) deletes napi. Then, rtl8152_disconnect calls unregister_netdev and that invokes netdev->ndo_stop (aka rtl8152_close). rtl8152_close tries to napi_disable, but the napi is already deleted by disconnect above. So the first while loop in napi_disable never finishes. This results in complete deadlock of the network layer as there is rtnl_mutex held by unregister_netdev. So avoid the call to napi_disable in rtl8152_close when the device is already gone. The other calls to usb_kill_urb, cancel_delayed_work_sync, netif_stop_queue etc. seem to be fine. The urb and netdev is not destroyed yet. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: linux-usb@vger.kernel.org Cc: netdev@vger.kernel.org --- drivers/net/usb/r8152.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)