2022-03-25 17:28:36

by Ricardo Ribalda

[permalink] [raw]
Subject: Re: [PATCH v2] media: uvc_video: fix bit overflow in uvc_probe_video

On Fri, 25 Mar 2022 at 16:34, Hangyu Hua <[email protected]> wrote:
>
> probe->dwMaxPayloadTransferSize is a 32bit value, but bandwidth is 16bit. This
> may lead to a bit overflow.
>
> Fix this by using probe->dwMaxPayloadTransferSize directly.
>
> Signed-off-by: Hangyu Hua <[email protected]>
Reviewed-by: Ricardo Ribalda <[email protected]>
> ---
>
> v2:
> Use probe->dwMaxPayloadTransferSize directly instead of changing temporary
> variable.
>
> drivers/media/usb/uvc/uvc_video.c | 4 +---
> 1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
> index 1b4cc934109e..e016f88bdf96 100644
> --- a/drivers/media/usb/uvc/uvc_video.c
> +++ b/drivers/media/usb/uvc/uvc_video.c
> @@ -383,7 +383,6 @@ int uvc_probe_video(struct uvc_streaming *stream,
> struct uvc_streaming_control *probe)
> {
> struct uvc_streaming_control probe_min, probe_max;
> - u16 bandwidth;
> unsigned int i;
> int ret;
>
> @@ -421,8 +420,7 @@ int uvc_probe_video(struct uvc_streaming *stream,
> if (stream->intf->num_altsetting == 1)
> break;
>
> - bandwidth = probe->dwMaxPayloadTransferSize;
> - if (bandwidth <= stream->maxpsize)
> + if (probe->dwMaxPayloadTransferSize <= stream->maxpsize)
> break;
>
> if (stream->dev->quirks & UVC_QUIRK_PROBE_MINMAX) {
> --
> 2.25.1
>


--
Ricardo Ribalda