4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Jiri Slaby jslaby@suse.cz
[ 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@suse.cz Cc: linux-usb@vger.kernel.org Cc: netdev@vger.kernel.org Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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 @@ -3327,7 +3327,8 @@ 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);