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 --- drivers/gpu/drm/mediatek/mtk_drm_drv.c | 11 +++++------ 1 file 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 34131ae2c207..3b02ed0a16da 100644 --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c @@ -388,11 +388,11 @@ 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) @@ -418,11 +418,10 @@ static bool mtk_drm_get_all_drm_priv(struct device *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) {
On Fri, 2025-08-29 at 11:03 +0200, Johan Hovold wrote:
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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.
Reviewed-by: CK Hu ck.hu@mediatek.com
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
drivers/gpu/drm/mediatek/mtk_drm_drv.c | 11 +++++------ 1 file 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 34131ae2c207..3b02ed0a16da 100644 --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c @@ -388,11 +388,11 @@ 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)@@ -418,11 +418,10 @@ static bool mtk_drm_get_all_drm_priv(struct device *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) {-- 2.49.1
linux-stable-mirror@lists.linaro.org
-
CK Hu (胡俊光) -
Johan Hovold