media: uvcvideo: Skip parsing frames of type UVC_VS_UNDEFINED in uvc_parse_format

commit ecf2b43018da9579842c774b7f35dbe11b5c38dd upstream.

This can lead to out of bounds writes since frames of this type were not
taken into account when calculating the size of the frames buffer in
uvc_parse_streaming.

Fixes: c0efd232929c ("V4L/DVB (8145a): USB Video Class driver")
Signed-off-by: Benoit Sevens <bsevens@google.com>
Cc: stable@vger.kernel.org
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
index cfbc7595cd0b8716fb9e1cab32ca5c55b44b36a2..519fd648f26cbe9e5c1df7f5c47d9ca69879872d 100644 (file)
--- a/drivers/media/usb/uvc/uvc_driver.c
+++ b/drivers/media/usb/uvc/uvc_driver.c
@@ -661,7 +661,7 @@ static int uvc_parse_format(struct uvc_device *dev,
        /* Parse the frame descriptors. Only uncompressed, MJPEG and frame
         * based formats have frame descriptors.
         */
-       while (buflen > 2 && buffer[1] == USB_DT_CS_INTERFACE &&
+       while (ftype && buflen > 2 && buffer[1] == USB_DT_CS_INTERFACE &&
               buffer[2] == ftype) {
                frame = &format->frame[format->nframes];
                if (ftype != UVC_VS_FRAME_FRAME_BASED)