releases/4.9.52/media-uvcvideo-prevent-heap-overflow-when-accessing-mapped-controls.patch

   1 From 7e09f7d5c790278ab98e5f2c22307ebe8ad6e8ba Mon Sep 17 00:00:00 2001
   2 From: Guenter Roeck <linux@roeck-us.net>
   3 Date: Tue, 8 Aug 2017 08:56:21 -0400
   4 Subject: media: uvcvideo: Prevent heap overflow when accessing mapped controls
   5
   6 From: Guenter Roeck <linux@roeck-us.net>
   7
   8 commit 7e09f7d5c790278ab98e5f2c22307ebe8ad6e8ba upstream.
   9
  10 The size of uvc_control_mapping is user controlled leading to a
  11 potential heap overflow in the uvc driver. This adds a check to verify
  12 the user provided size fits within the bounds of the defined buffer
  13 size.
  14
  15 Originally-from: Richard Simmons <rssimmo@amazon.com>
  16
  17 Signed-off-by: Guenter Roeck <linux@roeck-us.net>
  18 Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
  19 Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
  20 Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
  21 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  22
  23 ---
  24  drivers/media/usb/uvc/uvc_ctrl.c |    7 +++++++
  25  1 file changed, 7 insertions(+)
  26
  27 --- a/drivers/media/usb/uvc/uvc_ctrl.c
  28 +++ b/drivers/media/usb/uvc/uvc_ctrl.c
  29 @@ -2002,6 +2002,13 @@ int uvc_ctrl_add_mapping(struct uvc_vide
  30                 goto done;
  31         }
  32
  33 +       /* Validate the user-provided bit-size and offset */
  34 +       if (mapping->size > 32 ||
  35 +           mapping->offset + mapping->size > ctrl->info.size * 8) {
  36 +               ret = -EINVAL;
  37 +               goto done;
  38 +       }
  39 +
  40         list_for_each_entry(map, &ctrl->info.mappings, list) {
  41                 if (mapping->id == map->id) {
  42                         uvc_trace(UVC_TRACE_CONTROL, "Can't add mapping '%s', "