video: mb862xxfb: prevent divide by zero bug

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

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Anatolij Gustschin <agust@denx.de>
Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>

diff --git a/drivers/video/mb862xx/mb862xxfbdrv.c b/drivers/video/mb862xx/mb862xxfbdrv.c
index 00ce1f34b4965aa1d20f9bc33c709046551f2eca..57d940be5f3d7eaa25b2358c83e169947a779bdf 100644 (file)
--- 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,