USB: serial: opticon: fix control-message timeouts

BugLink: https://bugs.launchpad.net/bugs/1860681

commit 5e28055f upstream.

The driver was issuing synchronous uninterruptible control requests
without using a timeout. This could lead to the driver hanging
on open() or tiocmset() due to a malfunctioning (or malicious) device
until the device is physically disconnected.

The USB upper limit of five seconds per request should be more than
enough.

Fixes: 309a0579 ("USB: opticon: add rts and cts support")
Cc: stable <stable@vger.kernel.org>     # 2.6.39
Cc: Martin Jansen <martin.jansen@opticon.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Connor Kuehl <connor.kuehl@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

drivers/usb/serial/opticon.c

@@ -116,7 +116,7 @@ static int send_control_msg(struct usb_serial_port *port, u8 requesttype,
 	retval = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
 				requesttype,
 				USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
-				0, 0, buffer, 1, 0);
+				0, 0, buffer, 1, USB_CTRL_SET_TIMEOUT);
 	kfree(buffer);
 
 	if (retval < 0)