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 <gbhat@xxxxxxxxxxx> --- 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