This is a note to let you know that I've just added the patch titled media: uvcvideo: fix division by zero at stream start to the 4.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: media-uvcvideo-fix-division-by-zero-at-stream-start.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 8aa637bf6d70d2fb2ad4d708d8b9dd02b1c095df Mon Sep 17 00:00:00 2001 From: Johan Hovold <johan@xxxxxxxxxx> Date: Tue, 26 Oct 2021 11:55:11 +0200 Subject: media: uvcvideo: fix division by zero at stream start From: Johan Hovold <johan@xxxxxxxxxx> commit 8aa637bf6d70d2fb2ad4d708d8b9dd02b1c095df upstream. Add the missing bulk-endpoint max-packet sanity check to uvc_video_start_transfer() 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@xxxxxxxxxxxxxxx # 2.6.26 Signed-off-by: Johan Hovold <johan@xxxxxxxxxx> Reviewed-by: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx> Signed-off-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/media/usb/uvc/uvc_video.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/drivers/media/usb/uvc/uvc_video.c +++ b/drivers/media/usb/uvc/uvc_video.c @@ -1854,6 +1854,10 @@ static int uvc_init_video(struct uvc_str 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); } Patches currently in stable-queue which might be from johan@xxxxxxxxxx are queue-4.19/bluetooth-bfusb-fix-division-by-zero-in-send-path.patch queue-4.19/media-uvcvideo-fix-division-by-zero-at-stream-start.patch