From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933310Ab0GAVTY (ORCPT ); Thu, 1 Jul 2010 17:19:24 -0400 Received: from kroah.org ([198.145.64.141]:33207 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933131Ab0GAVPO (ORCPT ); Thu, 1 Jul 2010 17:15:14 -0400 X-Mailbox-Line: From gregkh@clark.site Thu Jul 1 10:43:01 2010 Message-Id: <20100701174301.482848572@clark.site> User-Agent: quilt/0.48-10.1 Date: Thu, 01 Jul 2010 10:44:27 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Laurent Pinchart , Mauro Carvalho Chehab Subject: [177/200] V4L/DVB: uvcvideo: Prevent division by 0 when control step value is 0 In-Reply-To: <20100701175201.GA2149@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.34-stable review patch. If anyone has any objections, please let me know. ------------------ From: Laurent Pinchart commit cf7a50eeb6f462a0b7d1619fcb27a727a2981769 upstream. The control step values reported by the device are used as a divisor unchecked, which can result in a division by zero. Check the step value and make it 1 when null. Signed-off-by: Laurent Pinchart Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Greg Kroah-Hartman --- drivers/media/video/uvc/uvc_ctrl.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/media/video/uvc/uvc_ctrl.c +++ b/drivers/media/video/uvc/uvc_ctrl.c @@ -1047,6 +1047,8 @@ int uvc_ctrl_set(struct uvc_video_chain uvc_ctrl_data(ctrl, UVC_CTRL_DATA_MAX)); step = mapping->get(mapping, UVC_GET_RES, uvc_ctrl_data(ctrl, UVC_CTRL_DATA_RES)); + if (step == 0) + step = 1; xctrl->value = min + (xctrl->value - min + step/2) / step * step; xctrl->value = clamp(xctrl->value, min, max);