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| author | AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> | 2024-11-12 11:50:30 +0100 |
|---|---|---|
| committer | Chun-Kuang Hu <chunkuang.hu@kernel.org> | 2025-01-04 12:15:19 +0000 |
| commit | f563dd9ca6cb6ed52c5fb6e4285d1ef26cfa7e8a (patch) | |
| tree | 03cf2c4149a92c0c901aa7f5286e484db1d8d52e | |
| parent | 522908140645865dc3e2fac70fd3b28834dfa7be (diff) | |
| download | lwn-f563dd9ca6cb6ed52c5fb6e4285d1ef26cfa7e8a.tar.gz lwn-f563dd9ca6cb6ed52c5fb6e4285d1ef26cfa7e8a.zip | |
drm/mediatek: Initialize pointer in mtk_drm_of_ddp_path_build_one()
The struct device_node *next pointer is not initialized, and it is
used in an error path in which it may have never been modified by
function mtk_drm_of_get_ddp_ep_cid().
Since the error path is relying on that pointer being NULL for the
OVL Adaptor and/or invalid component check and since said pointer
is being used in prints for %pOF, in the case that it points to a
bogus address, the print may cause a KP.
To resolve that, initialize the *next pointer to NULL before usage.
Fixes: 4c932840db1d ("drm/mediatek: Implement OF graphs support for display paths")
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/dri-devel/633f3c6d-d09f-447c-95f1-dfb4114c50e6@stanley.mountain/
Signed-off-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/20241112105030.93337-1-angelogioacchino.delregno@collabora.com/
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
| -rw-r--r-- | drivers/gpu/drm/mediatek/mtk_drm_drv.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c b/drivers/gpu/drm/mediatek/mtk_drm_drv.c index f0f3d545ff19..c86decee6ec9 100644 --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c @@ -905,7 +905,7 @@ static int mtk_drm_of_ddp_path_build_one(struct device *dev, enum mtk_crtc_path const unsigned int **out_path, unsigned int *out_path_len) { - struct device_node *next, *prev, *vdo = dev->parent->of_node; + struct device_node *next = NULL, *prev, *vdo = dev->parent->of_node; unsigned int temp_path[DDP_COMPONENT_DRM_ID_MAX] = { 0 }; unsigned int *final_ddp_path; unsigned short int idx = 0; |