From 15ac0595018f5fdfbec2a23574b81a01c73ee5e1 Mon Sep 17 00:00:00 2001
From: Guenter Roeck <linux@roeck-us.net>
Date: Tue, 8 Aug 2017 08:56:21 -0400
Subject: [PATCH] media: uvcvideo: Prevent heap overflow when accessing mapped
controls
commit 7e09f7d5c790278ab98e5f2c22307ebe8ad6e8ba upstream.
The size of uvc_control_mapping is user controlled leading to a
potential heap overflow in the uvc driver. This adds a check to verify
the user provided size fits within the bounds of the defined buffer
size.
Originally-from: Richard Simmons <rssimmo@amazon.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/media/usb/uvc/uvc_ctrl.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
index 3e59b288b8a89..618e4e2b42077 100644
--- a/drivers/media/usb/uvc/uvc_ctrl.c
+++ b/drivers/media/usb/uvc/uvc_ctrl.c
@@ -2001,6 +2001,13 @@ int uvc_ctrl_add_mapping(struct uvc_video_chain *chain,
goto done;
}
+ /* Validate the user-provided bit-size and offset */
+ if (mapping->size > 32 ||
+ mapping->offset + mapping->size > ctrl->info.size * 8) {
+ ret = -EINVAL;
+ goto done;
+ }
+
list_for_each_entry(map, &ctrl->info.mappings, list) {
if (mapping->id == map->id) {
uvc_trace(UVC_TRACE_CONTROL, "Can't add mapping '%s', "