[PATCH] USB: yurex: fix control-URB timeout handling

From: Johan Hovold
Date: Mon Dec 14 2020 - 05:45:58 EST


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

diff --git a/drivers/usb/misc/yurex.c b/drivers/usb/misc/yurex.c
index 73ebfa6e9715..c640f98d20c5 100644
--- a/drivers/usb/misc/yurex.c
+++ b/drivers/usb/misc/yurex.c
@@ -496,6 +496,9 @@ static ssize_t yurex_write(struct file *file, const char __user *user_buffer,
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) {
--
2.26.2