Re: [PATCH] uvcvideo: Also validate buffers in BULK mode
From: Laurent Pinchart
Date: Tue Jun 05 2018 - 04:52:14 EST
Hi Nicolas,
Thank you for the patch.
On Tuesday, 5 June 2018 03:24:15 EEST Nicolas Dufresne wrote:
> Just like for ISOC, validate the decoded BULK buffer size when possible.
> This avoids sending corrupted or partial buffers to userspace, which may
> lead to application crash or run-time failure.
>
> Signed-off-by: Nicolas Dufresne <nicolas.dufresne@xxxxxxxxxxxxx>
> ---
> drivers/media/usb/uvc/uvc_video.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/media/usb/uvc/uvc_video.c
> b/drivers/media/usb/uvc/uvc_video.c index aa0082fe5833..46df4d01e31b 100644
> --- a/drivers/media/usb/uvc/uvc_video.c
> +++ b/drivers/media/usb/uvc/uvc_video.c
> @@ -1307,8 +1307,10 @@ static void uvc_video_decode_bulk(struct urb *urb,
> struct uvc_streaming *stream, if (stream->bulk.header_size == 0 &&
> !stream->bulk.skip_payload) { do {
> ret = uvc_video_decode_start(stream, buf, mem, len);
> - if (ret == -EAGAIN)
> + if (ret == -EAGAIN) {
> + uvc_video_validate_buffer(stream, buf);
> uvc_video_next_buffers(stream, &buf, &meta_buf);
Wouldn't it be simpler to move the uvc_video_validate_buffer() call to
uvc_video_next_buffers() ?
> + }
> } while (ret == -EAGAIN);
>
> /* If an error occurred skip the rest of the payload. */
> @@ -1342,8 +1344,10 @@ static void uvc_video_decode_bulk(struct urb *urb,
> struct uvc_streaming *stream, if (!stream->bulk.skip_payload && buf !=
> NULL) {
> uvc_video_decode_end(stream, buf, stream->bulk.header,
> stream->bulk.payload_size);
> - if (buf->state == UVC_BUF_STATE_READY)
> + if (buf->state == UVC_BUF_STATE_READY) {
> + uvc_video_validate_buffer(stream, buf);
> uvc_video_next_buffers(stream, &buf, &meta_buf);
> + }
> }
>
> stream->bulk.header_size = 0;
--
Regards,
Laurent Pinchart