4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jiri Slaby <jslaby@xxxxxxx> [ Upstream commit 0ee1f4734967af8321ecebaf9c74221ace34f2d5 ] 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@xxxxxxx> Cc: linux-usb@xxxxxxxxxxxxxxx Cc: netdev@xxxxxxxxxxxxxxx Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/usb/r8152.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/net/usb/r8152.c +++ b/drivers/net/usb/r8152.c @@ -3139,7 +3139,8 @@ static int rtl8152_close(struct net_devi #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);
