2017-06-30 16:22:07

by Guenter Roeck

Subject: [PATCH v2] [media] uvcvideo: Prevent heap overflow in uvc driver

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 <[email protected]>
Signed-off-by: Guenter Roeck <[email protected]>
---
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

2017-07-06 18:39:39

by Guenter Roeck

Subject: Re: [PATCH v2] [media] uvcvideo: Prevent heap overflow in uvc driver

On Fri, Jun 30, 2017 at 09:21:56AM -0700, Guenter Roeck wrote:
> 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 <[email protected]>
> Signed-off-by: Guenter Roeck <[email protected]>

Any comments ?

Thanks,
Guenter

> ---
> 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
>

2017-07-11 16:47:22

by Guenter Roeck

Subject: Re: [PATCH v2] [media] uvcvideo: Prevent heap overflow in uvc driver

Any comments / feedback ?

Thanks,
Guenter

On Fri, Jun 30, 2017 at 09:21:56AM -0700, Guenter Roeck wrote:
> 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 <[email protected]>
> Signed-off-by: Guenter Roeck <[email protected]>
> ---
> 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
>

2017-07-12 00:58:15

by Laurent Pinchart

Subject: Re: [PATCH v2] [media] uvcvideo: Prevent heap overflow in uvc driver

Hi Guenter,

Thank you for the patch and sorry for the late reply.

On Friday 30 Jun 2017 09:21:56 Guenter Roeck wrote:
> 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 <[email protected]>
> Signed-off-by: Guenter Roeck <[email protected]>

This looks good to me.

Reviewed-by: Laurent Pinchart <[email protected]>

and taken in my tree for v4.14 with a Cc: [email protected] tag to get it
backported to stable kernels.

> ---
> 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',
"

--
Regards,

Laurent Pinchart