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
@@ -1915,6 +1915,10 @@ static int uvc_video_start_transfer(stru
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);
}
