[PATCH 4.17 24/67] USB: serial: ch341: fix type promotion bug in ch341_control_in()

[Greg Kroah-Hartman]

4.17-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

commit e33eab9ded328ccc14308afa51b5be7cbe78d30b upstream.

The "r" variable is an int and "bufsize" is an unsigned int so the
comparison is type promoted to unsigned.  If usb_control_msg() returns a
negative that is treated as a high positive value and the error handling
doesn't work.

Fixes: 2d5a9c72d0c4 ("USB: serial: ch341: fix control-message error handling")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Cc: stable <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/usb/serial/ch341.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/usb/serial/ch341.c
+++ b/drivers/usb/serial/ch341.c
@@ -128,7 +128,7 @@ static int ch341_control_in(struct usb_d
 	r = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), request,
 			    USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
 			    value, index, buf, bufsize, DEFAULT_TIMEOUT);
-	if (r < bufsize) {
+	if (r < (int)bufsize) {
 		if (r >= 0) {
 			dev_err(&dev->dev,
 				"short control message received (%d < %u)\n",