From 7926b6255a515056262fdc48977926810c839f61 Mon Sep 17 00:00:00 2001
From: "Jason-JH.Lin" <jason-jh.lin@mediatek.com>
Date: Fri, 14 Jul 2023 17:49:08 +0800
Subject: drm/mediatek: Fix dereference before null check
Git-commit: ed6adfb7d4b5cb912c763f87dfedc1d41d3c4a49
Patch-mainline: v6.6-rc1
References: jsc#PED-3527 jsc#PED-5475 jsc#PED-6068 jsc#PED-6070 jsc#PED-6116 jsc#PED-6120 jsc#PED-5065 jsc#PED-5477 jsc#PED-5511 jsc#PED-6041 jsc#PED-6069 jsc#PED-6071
Null-checking state suggests that it may be null, but it has already
been dereferenced on drm_atomic_get_new_plane_state(state, plane).
The parameter state will never be NULL currently, so just remove the
state is NULL flow in this function.
Fixes: 5ddb0bd4ddc3 ("drm/atomic: Pass the full state to planes async atomic check and update")
Signed-off-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: CK Hu <ck.hu@mediatek.com>
Reviewed-by: Alexandre Mergnat <amergnat@baylibre.com>
Link: https://patchwork.kernel.org/project/dri-devel/patch/20230714094908.13087-5-jason-jh.lin@mediatek.com/
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/mediatek/mtk_drm_plane.c | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_plane.c b/drivers/gpu/drm/mediatek/mtk_drm_plane.c
index 31f9420aff6f..db2f70ae060d 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_plane.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_plane.c
@@ -122,11 +122,7 @@ static int mtk_plane_atomic_async_check(struct drm_plane *plane,
if (ret)
return ret;
- if (state)
- crtc_state = drm_atomic_get_existing_crtc_state(state,
- new_plane_state->crtc);
- else /* Special case for asynchronous cursor updates. */
- crtc_state = new_plane_state->crtc->state;
+ crtc_state = drm_atomic_get_existing_crtc_state(state, new_plane_state->crtc);
return drm_atomic_helper_check_plane_state(plane->state, crtc_state,
DRM_PLANE_NO_SCALING,
--
2.43.0