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@xxxxxxxxxx>
Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
---
Fixes CVE-2017-0627.
v2: Combination of v1 with the fix suggested by Richard Simmons
Perform validation after uvc_ctrl_fill_xu_info()
Take into account that ctrl->info.size is in bytes
Also validate mapping->size
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 c2ee6e39fd0c..d3e3164f43fd 100644
--- a/drivers/media/usb/uvc/uvc_ctrl.c
+++ b/drivers/media/usb/uvc/uvc_ctrl.c
@@ -2002,6 +2002,13 @@ int uvc_ctrl_add_mapping(struct uvc_video_chain *chain,
goto done;
}
+ /* validate that the user provided bit-size and offset is valid */
+ 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', "
--
2.7.4
