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From: "Nícolas F. R. A. Prado" <nfraprado@collabora.com>
To: Chun-Kuang Hu <chunkuang.hu@kernel.org>
Cc: kernel@collabora.com,
	"AngeloGioacchino Del Regno"
	<angelogioacchino.delregno@collabora.com>,
	"Nancy . Lin" <nancy.lin@mediatek.com>,
	"Nícolas F. R. A. Prado" <nfraprado@collabora.com>,
	"Daniel Vetter" <daniel@ffwll.ch>,
	"David Airlie" <airlied@gmail.com>,
	"Matthias Brugger" <matthias.bgg@gmail.com>,
	"Philipp Zabel" <p.zabel@pengutronix.de>,
	dri-devel@lists.freedesktop.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, linux-mediatek@lists.infradead.org
Subject: [PATCH] drm/mediatek: Clean dangling pointer on bind error path
Date: Mon, 21 Nov 2022 17:37:17 -0500	[thread overview]
Message-ID: <20221121223717.3429913-1-nfraprado@collabora.com> (raw)

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.

Signed-off-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>

---

 drivers/gpu/drm/mediatek/mtk_drm_drv.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
index 39a42dc8fb85..a21ff1b3258c 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
@@ -514,6 +514,7 @@ 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;
 }
-- 
2.38.1


WARNING: multiple messages have this Message-ID (diff)
From: "Nícolas F. R. A. Prado" <nfraprado@collabora.com>
To: Chun-Kuang Hu <chunkuang.hu@kernel.org>
Cc: "Nícolas F. R. A. Prado" <nfraprado@collabora.com>,
	linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
	"Nancy . Lin" <nancy.lin@mediatek.com>,
	linux-mediatek@lists.infradead.org,
	"Matthias Brugger" <matthias.bgg@gmail.com>,
	kernel@collabora.com, linux-arm-kernel@lists.infradead.org,
	"AngeloGioacchino Del Regno"
	<angelogioacchino.delregno@collabora.com>
Subject: [PATCH] drm/mediatek: Clean dangling pointer on bind error path
Date: Mon, 21 Nov 2022 17:37:17 -0500	[thread overview]
Message-ID: <20221121223717.3429913-1-nfraprado@collabora.com> (raw)

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.

Signed-off-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>

---

 drivers/gpu/drm/mediatek/mtk_drm_drv.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
index 39a42dc8fb85..a21ff1b3258c 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
@@ -514,6 +514,7 @@ 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;
 }
-- 
2.38.1


WARNING: multiple messages have this Message-ID (diff)
From: "Nícolas F. R. A. Prado" <nfraprado@collabora.com>
To: Chun-Kuang Hu <chunkuang.hu@kernel.org>
Cc: kernel@collabora.com,
	"AngeloGioacchino Del Regno"
	<angelogioacchino.delregno@collabora.com>,
	"Nancy . Lin" <nancy.lin@mediatek.com>,
	"Nícolas F. R. A. Prado" <nfraprado@collabora.com>,
	"Daniel Vetter" <daniel@ffwll.ch>,
	"David Airlie" <airlied@gmail.com>,
	"Matthias Brugger" <matthias.bgg@gmail.com>,
	"Philipp Zabel" <p.zabel@pengutronix.de>,
	dri-devel@lists.freedesktop.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, linux-mediatek@lists.infradead.org
Subject: [PATCH] drm/mediatek: Clean dangling pointer on bind error path
Date: Mon, 21 Nov 2022 17:37:17 -0500	[thread overview]
Message-ID: <20221121223717.3429913-1-nfraprado@collabora.com> (raw)

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.

Signed-off-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>

---

 drivers/gpu/drm/mediatek/mtk_drm_drv.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
index 39a42dc8fb85..a21ff1b3258c 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
@@ -514,6 +514,7 @@ 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;
 }
-- 
2.38.1


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linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

             reply	other threads:[~2022-11-21 22:37 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-11-21 22:37 Nícolas F. R. A. Prado [this message]
2022-11-21 22:37 ` [PATCH] drm/mediatek: Clean dangling pointer on bind error path Nícolas F. R. A. Prado
2022-11-21 22:37 ` Nícolas F. R. A. Prado
2022-11-22  9:12 ` AngeloGioacchino Del Regno
2022-11-22  9:12   ` AngeloGioacchino Del Regno
2022-11-22  9:12   ` AngeloGioacchino Del Regno

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