Return-path: Received: from mx0a-0016f401.pphosted.com ([67.231.148.174]:40236 "EHLO mx0b-0016f401.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S966066AbeEXNse (ORCPT ); Thu, 24 May 2018 09:48:34 -0400 From: Ganapathi Bhat To: CC: Brian Norris , Cathy Luo , Xinming Hu , Zhiyuan Yang , James Cao , Mangesh Malusare , Ganapathi Bhat Subject: [PATCH] mwifiex: handle race during mwifiex_usb_disconnect Date: Thu, 24 May 2018 19:18:27 +0530 Message-ID: <1527169707-27317-1-git-send-email-gbhat@marvell.com> (sfid-20180524_154953_907328_1211896F) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-wireless-owner@vger.kernel.org List-ID: Race condition is observed during rmmod of mwifiex_usb: 1. The rmmod thread will call mwifiex_usb_disconnect(), download SHUTDOWN command and do wait_event_interruptible_timeout(), waiting for response. 2. The main thread will handle the response and will do a wake_up_interruptible(), unblocking rmmod thread. 3. On getting unblocked, rmmod thread will make rx_cmd.urb = NULL in mwifiex_usb_free(). 4. The main thread will try to resubmit rx_cmd.urb in mwifiex_usb_submit_rx_urb(), which is NULL. To fix, wait for main thread to complete before calling mwifiex_usb_free(). Signed-off-by: Ganapathi Bhat --- drivers/net/wireless/marvell/mwifiex/usb.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/net/wireless/marvell/mwifiex/usb.c b/drivers/net/wireless/marvell/mwifiex/usb.c index bc475b8..6e3cf98 100644 --- a/drivers/net/wireless/marvell/mwifiex/usb.c +++ b/drivers/net/wireless/marvell/mwifiex/usb.c @@ -644,6 +644,9 @@ static void mwifiex_usb_disconnect(struct usb_interface *intf) MWIFIEX_FUNC_SHUTDOWN); } + if (adapter->workqueue) + flush_workqueue(adapter->workqueue); + mwifiex_usb_free(card); mwifiex_dbg(adapter, FATAL, -- 1.9.1