mwifiex: handle race during mwifiex_usb_disconnect

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>
This commit is contained in:
Ganapathi Bhat 2018-05-24 19:18:27 +05:30 committed by Kalle Valo
parent 618fd1ed17
commit b817047ae7
1 changed files with 3 additions and 0 deletions

View File

@ -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,