From e84f44eb5523401faeb9cc1c97895b68e3cfb78d Mon Sep 17 00:00:00 2001
From: Jimmy Assarsson <jimmyassarsson@gmail.com>
Date: Tue, 21 Nov 2017 08:22:27 +0100
Subject: [PATCH] can: kvaser_usb: Fix comparison bug in kvaser_usb_read_bulk_callback()
Git-commit: e84f44eb5523401faeb9cc1c97895b68e3cfb78d
Patch-mainline: v4.15-rc3
References: bsc#1051510

The conditon in the while-loop becomes true when actual_length is less than
2 (MSG_HEADER_LEN). In best case we end up with a former, already
dispatched msg, that got msg->len greater than actual_length. This will
result in a "Format error" error printout.

Problem seen when unplugging a Kvaser USB device connected to a vbox guest.

Warning: comparison between signed and unsigned integer expressions
[-Wsign-compare]

Signed-off-by: Jimmy Assarsson <jimmyassarsson@gmail.com>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/net/can/usb/kvaser_usb.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/net/can/usb/kvaser_usb.c
+++ b/drivers/net/can/usb/kvaser_usb.c
@@ -1334,7 +1334,7 @@ static void kvaser_usb_read_bulk_callbac
 		goto resubmit_urb;
 	}
 
-	while (pos <= urb->actual_length - MSG_HEADER_LEN) {
+	while (pos <= (int)(urb->actual_length - MSG_HEADER_LEN)) {
 		msg = urb->transfer_buffer + pos;
 
 		/* The Kvaser firmware can only read and write messages that