diff options
| author | Johan Hovold <johan@kernel.org> | 2025-08-29 11:03:44 +0200 |
|---|---|---|
| committer | Chun-Kuang Hu <chunkuang.hu@kernel.org> | 2025-09-10 12:49:37 +0000 |
| commit | 4de37a48b6b58faaded9eb765047cf0d8785ea18 (patch) | |
| tree | 411ce236049188921119666f1ca98fa100edd9a1 | |
| parent | c34414883f773412964404d77cd2fea04c6f7d60 (diff) | |
drm/mediatek: fix potential OF node use-after-free
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-johan@kernel.org/
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
| -rw-r--r-- | drivers/gpu/drm/mediatek/mtk_drm_drv.c | 11 |
1 files changed, 5 insertions, 6 deletions
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c b/drivers/gpu/drm/mediatek/mtk_drm_drv.c index f8a817689e16..76719eb5db09 100644 --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c @@ -387,11 +387,11 @@ static bool mtk_drm_get_all_drm_priv(struct device *dev) 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) @@ -417,11 +417,10 @@ 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) { |