Il 06/10/25 11:39, Johan Hovold ha scritto:
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 80805b62ea5b ("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: 1f403699c40f ("drm/mediatek: Fix device/node reference count leaks in mtk_drm_get_all_drm_priv") Reported-by: Sjoerd Simons sjoerd@collabora.com Link: https://lore.kernel.org/r/20251003-mtk-drm-refcount-v1-1-3b3f2813b0db@collab... 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
Heh, nice!
Reviewed-by: AngeloGioacchino Del Regno angelogioacchino.delregno@collabora.com