On Fri, Jun 30, 2017 at 09:21:56AM -0700, Guenter Roeck wrote:
> 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@xxxxxxxxxx>
> Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Any comments ?
Thanks,
Guenter
> ---
> Fixes CVE-2017-0627.
>
> v2: Combination of v1 with the fix suggested by Richard Simmons
> Perform validation after uvc_ctrl_fill_xu_info()
> Take into account that ctrl->info.size is in bytes
> Also validate mapping->size
>
> 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 c2ee6e39fd0c..d3e3164f43fd 100644
> --- a/drivers/media/usb/uvc/uvc_ctrl.c
> +++ b/drivers/media/usb/uvc/uvc_ctrl.c
> @@ -2002,6 +2002,13 @@ int uvc_ctrl_add_mapping(struct uvc_video_chain *chain,
> goto done;
> }
>
> + /* validate that the user provided bit-size and offset is valid */
> + 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
>
