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 this, move mwifiex_usb_free() from mwifiex_usb_disconnect
to mwifiex_unregister_dev(). Function mwifiex_unregister_dev() is
called after flushing the command and RX work queues.
Signed-off-by: Brian Norris <briannorris@xxxxxxxxxxxx>
Signed-off-by: Ganapathi Bhat <gbhat@xxxxxxxxxxx>
---
drivers/net/wireless/marvell/mwifiex/usb.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/net/wireless/marvell/mwifiex/usb.c b/drivers/net/wireless/marvell/mwifiex/usb.c
index bc475b8..88f4c89 100644
--- a/drivers/net/wireless/marvell/mwifiex/usb.c
+++ b/drivers/net/wireless/marvell/mwifiex/usb.c
@@ -644,8 +644,6 @@ static void mwifiex_usb_disconnect(struct usb_interface *intf)
MWIFIEX_FUNC_SHUTDOWN);
}
- mwifiex_usb_free(card);
-
mwifiex_dbg(adapter, FATAL,
"%s: removing card\n", __func__);
mwifiex_remove_card(adapter);
@@ -1353,6 +1351,8 @@ static void mwifiex_unregister_dev(struct mwifiex_adapter *adapter)
{
struct usb_card_rec *card = (struct usb_card_rec *)adapter->card;
+ mwifiex_usb_free(card);
+
mwifiex_usb_cleanup_tx_aggr(adapter);
card->adapter = NULL;
--
1.9.1
