Bluetooth: btsdio: fix use after free bug in btsdio_remove due to unfinished work

In btsdio_probe, &data->work was bound with btsdio_work.In
btsdio_send_frame, it was started by schedule_work.

If we call btsdio_remove with an unfinished job, there may
be a race condition and cause UAF bug on hdev.

Fixes: ddbaf13e ("[Bluetooth] Add generic driver for Bluetooth SDIO devices")
Signed-off-by: Zheng Wang <zyytlz.wz@163.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

drivers/bluetooth/btsdio.c

@@ -354,6 +354,7 @@ static void btsdio_remove(struct sdio_func *func)
 
 	BT_DBG("func %p", func);
 
+	cancel_work_sync(&data->work);
 	if (!data)
 		return;