[PATCH 4.19 54/77] USB: yurex: fix control-URB timeout handling

[Greg Kroah-Hartman]

From: Johan Hovold <johan@xxxxxxxxxx>

commit 372c93131998c0622304bed118322d2a04489e63 upstream.

Make sure to always cancel the control URB in write() so that it can be
reused after a timeout or spurious CMD_ACK.

Currently any further write requests after a timeout would fail after
triggering a WARN() in usb_submit_urb() when attempting to submit the
already active URB.

Reported-by: syzbot+e87ebe0f7913f71f2ea5@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: 6bc235a2e24a ("USB: add driver for Meywa-Denki & Kayac YUREX")
Cc: stable <stable@xxxxxxxxxxxxxxx>     # 2.6.37
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/usb/misc/yurex.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/usb/misc/yurex.c
+++ b/drivers/usb/misc/yurex.c
@@ -497,6 +497,9 @@ static ssize_t yurex_write(struct file *
 		timeout = schedule_timeout(YUREX_WRITE_TIMEOUT);
 	finish_wait(&dev->waitq, &wait);
 
+	/* make sure URB is idle after timeout or (spurious) CMD_ACK */
+	usb_kill_urb(dev->cntl_urb);
+
 	mutex_unlock(&dev->io_mutex);
 
 	if (retval < 0) {