This is a note to let you know that I've just added the patch titled
drm/mediatek: Clean dangling pointer on bind error path
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-mediatek-clean-dangling-pointer-on-bind-error-pa.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit c7d80df0ebbb6b7d4c5d437cc1cc26e636cd6f2a
Author: Nícolas F. R. A. Prado <nfraprado@xxxxxxxxxxxxx>
Date: Tue Nov 22 09:39:49 2022 -0500
drm/mediatek: Clean dangling pointer on bind error path
[ Upstream commit 36aa8c61af55675ed967900fbe5deb32d776f051 ]
mtk_drm_bind() can fail, in which case drm_dev_put() is called,
destroying the drm_device object. However a pointer to it was still
being held in the private object, and that pointer would be passed along
to DRM in mtk_drm_sys_prepare() if a suspend were triggered at that
point, resulting in a panic. Clean the pointer when destroying the
object in the error path to prevent this from happening.
Fixes: 119f5173628a ("drm/mediatek: Add DRM Driver for Mediatek SoC MT8173.")
Signed-off-by: Nícolas F. R. A. Prado <nfraprado@xxxxxxxxxxxxx>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
Link: https://patchwork.kernel.org/project/linux-mediatek/patch/20221122143949.3493104-1-nfraprado@xxxxxxxxxxxxx/
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
index f98bb2e263723..5569454ad9e40 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
@@ -417,6 +417,7 @@ static int mtk_drm_bind(struct device *dev)
err_deinit:
mtk_drm_kms_deinit(drm);
err_free:
+ private->drm = NULL;
drm_dev_put(drm);
return ret;
}
