can: kvaser_usb: check number of channels returned by HW

It is needed to check the number of channels returned by the HW because it
cannot be greater than MAX_NET_DEVICES otherwise it will crash.
Signed-off-by: NOlivier Sobrie <olivier@sobrie.be>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/usb/kvaser_usb.c

@@ -473,6 +473,8 @@ static int kvaser_usb_get_card_info(struct kvaser_usb *dev)
 		return err;
 
 	dev->nchannels = msg.u.cardinfo.nchannels;
+	if (dev->nchannels > MAX_NET_DEVICES)
+		return -EINVAL;
 
 	return 0;
 }