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; + ret = uvc_init_video_bulk(stream, ep, gfp_flags); }