From: Ganapathi Bhat Date: Thu, 24 May 2018 13:48:27 +0000 (+0530) Subject: mwifiex: handle race during mwifiex_usb_disconnect X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=a7a336ed3d39ecdbe6e202e87e27220afca682e5;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git mwifiex: handle race during mwifiex_usb_disconnect [ Upstream commit b817047ae70c0bd67b677b65d0d69d72cd6e9728 ] 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 Signed-off-by: Kalle Valo Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/net/wireless/marvell/mwifiex/usb.c b/drivers/net/wireless/marvell/mwifiex/usb.c index 73eb0846db21..09185a1f7379 100644 --- a/drivers/net/wireless/marvell/mwifiex/usb.c +++ b/drivers/net/wireless/marvell/mwifiex/usb.c @@ -624,6 +624,9 @@ 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,