6.6-stable review patch. If anyone has any objections, please let me know.
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From: Johan Hovold johan@kernel.org
commit 4de37a48b6b58faaded9eb765047cf0d8785ea18 upstream.
The for_each_child_of_node() helper drops the reference it takes to each node as it iterates over children and an explicit of_node_put() is only needed when exiting the loop early.
Drop the recently introduced bogus additional reference count decrement at each iteration that could potentially lead to a use-after-free.
Fixes: 1f403699c40f ("drm/mediatek: Fix device/node reference count leaks in mtk_drm_get_all_drm_priv") Cc: Ma Ke make24@iscas.ac.cn Cc: stable@vger.kernel.org Signed-off-by: Johan Hovold johan@kernel.org Reviewed-by: CK Hu ck.hu@mediatek.com Reviewed-by: AngeloGioacchino Del Regno angelogioacchino.delregno@collabora.com Link: https://patchwork.kernel.org/project/dri-devel/patch/20250829090345.21075-2-... Signed-off-by: Chun-Kuang Hu chunkuang.hu@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpu/drm/mediatek/mtk_drm_drv.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-)
--- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c @@ -365,11 +365,11 @@ static bool mtk_drm_get_all_drm_priv(str
of_id = of_match_node(mtk_drm_of_ids, node); if (!of_id) - goto next_put_node; + continue;
pdev = of_find_device_by_node(node); if (!pdev) - goto next_put_node; + continue;
drm_dev = device_find_child(&pdev->dev, NULL, mtk_drm_match); if (!drm_dev) @@ -395,11 +395,10 @@ next_put_device_drm_dev: next_put_device_pdev_dev: put_device(&pdev->dev);
-next_put_node: - of_node_put(node); - - if (cnt == MAX_CRTC) + if (cnt == MAX_CRTC) { + of_node_put(node); break; + } }
if (drm_priv->data->mmsys_dev_num == cnt) {