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authorJohan Hovold <johan@kernel.org>2021-10-26 11:55:11 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-01-20 09:19:18 +0100
commit8716657b1b4bbeac238505442c234c8f346ae55a (patch)
tree285382fc8e62f4633041502689af402be2e77c4e /drivers
parent70ae85ca124e8b1df39a3e67ef6d7fc3a42140d2 (diff)
media: uvcvideo: fix division by zero at stream start
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@vger.kernel.org # 2.6.26 Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/media/usb/uvc/uvc_video.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
index 96b85d66e7a8..fe58723fc5ac 100644
--- a/drivers/media/usb/uvc/uvc_video.c
+++ b/drivers/media/usb/uvc/uvc_video.c
@@ -1915,6 +1915,10 @@ 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);
}