[Acked] [CVE-2017-0627][Trusty][SRU][PATCH 1/1] media: uvcvideo: Prevent heap overflow when accessing mapped controls

[Andy Whitcroft]

On Tue, May 08, 2018 at 03:57:47PM +0800, Po-Hsu Lin wrote:
> From: Guenter Roeck <linux at roeck-us.net>
> 
> CVE-2017-0627
> 
> The size of uvc_control_mapping is user controlled leading to a
> potential heap overflow in the uvc driver. This adds a check to verify
> the user provided size fits within the bounds of the defined buffer
> size.
> 
> Originally-from: Richard Simmons <rssimmo at amazon.com>
> 
> Cc: stable at vger.kernel.org
> Signed-off-by: Guenter Roeck <linux at roeck-us.net>
> Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> Signed-off-by: Hans Verkuil <hans.verkuil at cisco.com>
> Signed-off-by: Mauro Carvalho Chehab <mchehab at s-opensource.com>
> (cherry picked from commit 7e09f7d5c790278ab98e5f2c22307ebe8ad6e8ba)
> Signed-off-by: Po-Hsu Lin <po-hsu.lin at canonical.com>
> ---
>  drivers/media/usb/uvc/uvc_ctrl.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
> index 0eb82106..f1c1467 100644
> --- a/drivers/media/usb/uvc/uvc_ctrl.c
> +++ b/drivers/media/usb/uvc/uvc_ctrl.c
> @@ -1949,6 +1949,13 @@ int uvc_ctrl_add_mapping(struct uvc_video_chain *chain,
>  		goto done;
>  	}
>  
> +	/* Validate the user-provided bit-size and offset */
> +	if (mapping->size > 32 ||
> +	    mapping->offset + mapping->size > ctrl->info.size * 8) {
> +		ret = -EINVAL;
> +		goto done;
> +	}
> +
>  	list_for_each_entry(map, &ctrl->info.mappings, list) {
>  		if (mapping->id == map->id) {
>  			uvc_trace(UVC_TRACE_CONTROL, "Can't add mapping '%s', "
> -- 
> 2.7.4

Clean cherry-pick, looks to do what is claimed.

Acked-by: Andy Whitcroft <apw at canonical.com>

-apw