On Tue, Oct 26, 2021 at 11:55:05AM +0100, Kieran Bingham wrote:
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?
Going one step further, wouldn't it be better to fail probe() for those devices ?
But either way, this seems sane.
Reviewed-by: Kieran Bingham kieran.bingham+renesas@ideasonboard.com
ret = uvc_init_video_bulk(stream, ep, gfp_flags); }