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 <gbhat@marvell.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 file changed