2022-07-27 07:48:08

by Zeng Jingxiang

Subject: [PATCH] gpu: lontium-lt9611: Fix NULL pointer dereference in lt9611_connector_init()

From: Zeng Jingxiang <[email protected]>

A NULL check for bridge->encoder shows that it may be NULL, but it
already been dereferenced on all paths leading to the check.
812 if (!bridge->encoder) {

Dereference the pointer bridge->encoder.
810 drm_connector_attach_encoder(&lt9611->connector, bridge->encoder);

Signed-off-by: Zeng Jingxiang <[email protected]>
---
drivers/gpu/drm/bridge/lontium-lt9611.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bridge/lontium-lt9611.c b/drivers/gpu/drm/bridge/lontium-lt9611.c
index 7ef8fe5abc12..81a4751573fa 100644
--- a/drivers/gpu/drm/bridge/lontium-lt9611.c
+++ b/drivers/gpu/drm/bridge/lontium-lt9611.c
@@ -807,13 +807,14 @@ static int lt9611_connector_init(struct drm_bridge *bridge, struct lt9611 *lt961

drm_connector_helper_add(&lt9611->connector,
&lt9611_bridge_connector_helper_funcs);
- drm_connector_attach_encoder(&lt9611->connector, bridge->encoder);

if (!bridge->encoder) {
DRM_ERROR("Parent encoder object not found");
return -ENODEV;
}

+ drm_connector_attach_encoder(&lt9611->connector, bridge->encoder);
+
return 0;
}

--
2.27.0

2022-08-08 09:43:57

by Robert Foss

Subject: Re: [PATCH] gpu: lontium-lt9611: Fix NULL pointer dereference in lt9611_connector_init()

On Wed, 27 Jul 2022 at 09:31, Zeng Jingxiang <[email protected]> wrote:
>
> From: Zeng Jingxiang <[email protected]>
>
> A NULL check for bridge->encoder shows that it may be NULL, but it
> already been dereferenced on all paths leading to the check.
> 812 if (!bridge->encoder) {
>
> Dereference the pointer bridge->encoder.
> 810 drm_connector_attach_encoder(&lt9611->connector, bridge->encoder);
>
> Signed-off-by: Zeng Jingxiang <[email protected]>
> ---
> drivers/gpu/drm/bridge/lontium-lt9611.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/bridge/lontium-lt9611.c b/drivers/gpu/drm/bridge/lontium-lt9611.c
> index 7ef8fe5abc12..81a4751573fa 100644
> --- a/drivers/gpu/drm/bridge/lontium-lt9611.c
> +++ b/drivers/gpu/drm/bridge/lontium-lt9611.c
> @@ -807,13 +807,14 @@ static int lt9611_connector_init(struct drm_bridge *bridge, struct lt9611 *lt961
>
> drm_connector_helper_add(&lt9611->connector,
> &lt9611_bridge_connector_helper_funcs);
> - drm_connector_attach_encoder(&lt9611->connector, bridge->encoder);
>
> if (!bridge->encoder) {
> DRM_ERROR("Parent encoder object not found");
> return -ENODEV;
> }
>
> + drm_connector_attach_encoder(&lt9611->connector, bridge->encoder);
> +
> return 0;
> }
>
> --
> 2.27.0
>

Applied to drm-misc-next.