From mboxrd@z Thu Jan  1 00:00:00 1970
From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Sat, 18 Aug 2012 15:55:41 +0000
Subject: [patch] video: mb862xxfb: prevent divide by zero bug
Message-Id: <20120818155541.GB22424@elgon.mountain>
List-Id: <linux-fbdev.vger.kernel.org>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
To: Florian Tobias Schandinat <FlorianSchandinat-Mmb7MZpHnFY@public.gmane.org>
Cc: linux-fbdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, H Hartley Sweeten <hsweeten-3FF4nKcrg1dE2c76skzGb0EOCMrvLtNR@public.gmane.org>, devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, kernel-janitors-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Rob Herring <rob.herring-bsGFqQB8/DxBDgjK7y7TUQ@public.gmane.org>, Paul Gortmaker <paul.gortmaker-CWA4WttNNZF54TAoqtyWWQ@public.gmane.org>, Laurent Pinchart <laurent.pinchart-ryLnwIuWjnjg/C1BVhZhaw@public.gmane.org>, David Brown <davidb-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>

Do a sanity check on these before using them as divisors.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

diff --git a/drivers/video/mb862xx/mb862xxfbdrv.c b/drivers/video/mb862xx/mb862xxfbdrv.c
index 00ce1f3..57d940b 100644
--- a/drivers/video/mb862xx/mb862xxfbdrv.c
+++ b/drivers/video/mb862xx/mb862xxfbdrv.c
@@ -328,6 +328,8 @@ static int mb862xxfb_ioctl(struct fb_info *fbi, unsigned int cmd,
 	case MB862XX_L1_SET_CFG:
 		if (copy_from_user(l1_cfg, argp, sizeof(*l1_cfg)))
 			return -EFAULT;
+		if (l1_cfg->dh = 0 || l1_cfg->dw = 0)
+			return -EINVAL;
 		if ((l1_cfg->sw >= l1_cfg->dw) && (l1_cfg->sh >= l1_cfg->dh)) {
 			/* downscaling */
 			outreg(cap, GC_CAP_CSC,