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

From: Robert Foss
Date: Mon Aug 08 2022 - 05:34:17 EST


On Wed, 27 Jul 2022 at 09:31, Zeng Jingxiang <zengjx95@xxxxxxxxx> wrote:
>
> From: Zeng Jingxiang <linuszeng@xxxxxxxxxxx>
>
> 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 <linuszeng@xxxxxxxxxxx>
> ---
> 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.