Johan Hovold 926d002e6d drm/mediatek: Fix device use-after-free on unbind
A recent change fixed device reference leaks when looking up drm
platform device driver data during bind() but failed to remove a partial
fix which had been added by commit 80805b62ea ("drm/mediatek: Fix
kobject put for component sub-drivers").

This results in a reference imbalance on component bind() failures and
on unbind() which could lead to a user-after-free.

Make sure to only drop the references after retrieving the driver data
by effectively reverting the previous partial fix.

Note that holding a reference to a device does not prevent its driver
data from going away so there is no point in keeping the reference.

Fixes: 1f403699c4 ("drm/mediatek: Fix device/node reference count leaks in mtk_drm_get_all_drm_priv")
Reported-by: Sjoerd Simons <sjoerd@collabora.com>
Closes: https://lore.kernel.org/r/20251003-mtk-drm-refcount-v1-1-3b3f2813b0db@collabora.com
Cc: stable@vger.kernel.org
Cc: Ma Ke <make24@iscas.ac.cn>
Cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Sjoerd Simons <sjoerd@collabora.com>
Tested-by: Sjoerd Simons <sjoerd@collabora.com>
Tested-by: Ritesh Raj Sarraf <ritesh.sarraf@collabora.com>
Reviewed-by: CK Hu <ck.hu@mediatek.com>
Link: https://patchwork.kernel.org/project/dri-devel/patch/20251006093937.27869-1-johan@kernel.org/
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
2025-10-28 14:56:16 +00:00
2022-09-28 09:02:20 +02:00
2025-02-19 14:53:27 -07:00
2025-10-12 13:42:36 -07:00
2024-03-18 03:36:32 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
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In order to build the documentation, use ``make htmldocs`` or
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There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
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