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authorJohan Hovold <johan@kernel.org>2021-10-26 12:55:11 +0300
committerMauro Carvalho Chehab <mchehab+huawei@kernel.org>2021-12-07 13:29:53 +0300
commit8aa637bf6d70d2fb2ad4d708d8b9dd02b1c095df (patch)
treecc4aff579a56eed0474a4b7b8b9ced311d4e9b20 /drivers/media
parent4b065060555b14c7a9b86c013a1c9bee8e8b6fbd (diff)
downloadlinux-8aa637bf6d70d2fb2ad4d708d8b9dd02b1c095df.tar.xz
media: uvcvideo: fix division by zero at stream start
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>
Diffstat (limited to 'drivers/media')
-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 9f37eaf28ce7..1b4cc934109e 100644
--- a/drivers/media/usb/uvc/uvc_video.c
+++ b/drivers/media/usb/uvc/uvc_video.c
@@ -1963,6 +1963,10 @@ 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);
}