Commit 4c73f193 authored Jul 04, 2018 by Dan Carpenter Committed by Greg Kroah-Hartman Jul 17, 2018

USB: serial: ch341: fix type promotion bug in ch341_control_in()



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@oracle.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent f510cc3a

drivers/usb/serial/ch341.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -118,7 +118,7 @@ static int ch341_control_in(struct usb_device *dev,
		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",