# Re: \[patch\] video: mb862xxfb: prevent divide by zero bug

- List: linux-fbdev
- 1 message, 1 author
- Page: https://ratatoskr.run/linux-fbdev/2012/08/8062314/t

## Re: \[patch\] video: mb862xxfb: prevent divide by zero bug

- From: Anatolij Gustschin \<hidden\>
- Date: 2012-08-18 18:35:07 
- Message: https://ratatoskr.run/linux-fbdev/2012/08/8062314.md

```text
On Sat, 18 Aug 2012 18:55:41 +0300
Dan Carpenter [ref] wrote:

> Do a sanity check on these before using them as divisors.
> 
> Signed-off-by: Dan Carpenter <redacted>

Acked-by: Anatolij Gustschin <agust@denx.de>

> 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,

Thanks,

Anatolij
```