Re: [PATCH] media: uvcvideo: Fix buffer overflow in uvc_mapping_get_menu_value()

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

On Fri, Sep 18, 2026 at 03:20:25PM +0300, Dan Carpenter wrote:
> The "idx" value is a user controlled u32 so we have to bounds check it
> before calling test_bit() to avoid reading beyond the end of the bitmap.
> 
> Fixes: 4e15c535659b ("media: uvcvideo: Support any size for mapping get/set")
> Signed-off-by: Dan Carpenter <error27@gmail.com>

What's the status of this patch ? The issue is a false positive, do you
still think there's value in this redundant test ?

> ---
>  drivers/media/usb/uvc/uvc_ctrl.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
> index 3ca108b83f1d..f157ed99be4e 100644
> --- a/drivers/media/usb/uvc/uvc_ctrl.c
> +++ b/drivers/media/usb/uvc/uvc_ctrl.c
> @@ -538,7 +538,7 @@ static void uvc_mapping_set_s32(struct uvc_control_mapping *mapping,
>  static int uvc_mapping_get_menu_value(const struct uvc_control_mapping *mapping,
>  				      u32 idx)
>  {
> -	if (!test_bit(idx, &mapping->menu_mask))
> +	if (idx >= BITS_PER_LONG || !test_bit(idx, &mapping->menu_mask))
>  		return -EINVAL;
>  
>  	if (mapping->menu_mapping)

-- 
Regards,

Laurent Pinchart