Messages in this thread | | | Subject | Re: [PATCH] media: uvcvideo: fix division by zero at stream start | From | Kieran Bingham <> | Date | Tue, 26 Oct 2021 11:55:05 +0100 |
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Quoting Johan Hovold (2021-10-26 10:55:11) > Add the missing bulk-endpoint max-packet sanity check to probe() to > avoid division by zero in uvc_alloc_urb_buffers() in case a malicious > device has broken descriptors (or when doing descriptor fuzz testing). > > Note that USB core will reject URBs submitted for endpoints with zero > wMaxPacketSize but that drivers doing packet-size calculations still > need to handle this (cf. commit 2548288b4fb0 ("USB: Fix: Don't skip > endpoint descriptors with maxpacket=0")). > > Fixes: c0efd232929c ("V4L/DVB (8145a): USB Video Class driver") > Cc: stable@vger.kernel.org # 2.6.26 > Signed-off-by: Johan Hovold <johan@kernel.org> > --- > drivers/media/usb/uvc/uvc_video.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c > index e16464606b14..85ac5c1081b6 100644 > --- a/drivers/media/usb/uvc/uvc_video.c > +++ b/drivers/media/usb/uvc/uvc_video.c > @@ -1958,6 +1958,10 @@ static int uvc_video_start_transfer(struct uvc_streaming *stream, > if (ep == NULL) > return -EIO; > > + /* Reject broken descriptors. */ > + if (usb_endpoint_maxp(&ep->desc) == 0) > + return -EIO;
Is there any value in identifying this with a specific return code like -ENODATA?
But either way, this seems sane.
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> + > ret = uvc_init_video_bulk(stream, ep, gfp_flags); > } > > -- > 2.32.0 >
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