From 84811412464d66fcf73661a279aa1d7985166495 Mon Sep 17 00:00:00 2001 From: Prashant Malani Date: Wed, 20 Nov 2019 11:40:21 -0800 Subject: [PATCH] r8152: Re-order napi_disable in rtl8152_close Both rtl_work_func_t() and rtl8152_close() call napi_disable(). Since the two calls aren't protected by a lock, if the close function starts executing before the work function, we can get into a situation where the napi_disable() function is called twice in succession (first by rtl8152_close(), then by set_carrier()). In such a situation, the second call would loop indefinitely, since rtl8152_close() doesn't call napi_enable() to clear the NAPI_STATE_SCHED bit. The rtl8152_close() function in turn issues a cancel_delayed_work_sync(), and so it would wait indefinitely for the rtl_work_func_t() to complete. Since rtl8152_close() is called by a process holding rtnl_lock() which is requested by other processes, this eventually leads to a system deadlock and crash. Re-order the napi_disable() call to occur after the work function disabling and urb cancellation calls are issued. Change-Id: I6ef0b703fc214998a037a68f722f784e1d07815e Reported-by: http://crbug.com/1017928 Signed-off-by: Prashant Malani Signed-off-by: David S. Miller --- drivers/net/usb/r8152.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c index d4a95b5..4d34c01 100644 --- a/drivers/net/usb/r8152.c +++ b/drivers/net/usb/r8152.c @@ -4283,10 +4283,10 @@ static int rtl8152_close(struct net_device *netdev) unregister_pm_notifier(&tp->pm_notifier); #endif tasklet_disable(&tp->tx_tl); - napi_disable(&tp->napi); clear_bit(WORK_ENABLE, &tp->flags); usb_kill_urb(tp->intr_urb); cancel_delayed_work_sync(&tp->schedule); + napi_disable(&tp->napi); netif_stop_queue(netdev); res = usb_autopm_get_interface(tp->intf); -- 2.7.4