[PATCH 4.14 39/57] USB: yurex: fix control-URB timeout handling

Greg Kroah-Hartman
2021-01-11T14:00:12Z

From: Johan Hovold <johan@kernel.org>

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@syzkaller.appspotmail.com
Fixes: 6bc235a2e24a ("USB: add driver for Meywa-Denki & Kayac YUREX")
Cc: stable <stable@vger.kernel.org> # 2.6.37
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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

--- a/drivers/usb/misc/yurex.c
+++ b/drivers/usb/misc/yurex.c
@@ -501,6 +501,9 @@ 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) {