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media: platform: mtk-mdp3: fix device leaks at probe

PATCH In review Johan Hovold 2 participants 2 messages Sep 24, 2025 – Sep 25, 2025

Subsystems (3)
Stable branch Media (V4L/DVB) Arm MediaTek
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Johan Hovold

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#0 lore raw

PATCH 1/1 media: platform: mtk-mdp3: fix device leaks at probe

Make sure to drop the references taken when looking up the subsys devices during probe on probe failure (e.g. probe deferral) and on driver unbind.

Similarly, drop the SCP device reference after retrieving its platform data during probe to avoid leaking it.

Note that holding a reference to a device does not prevent its driver data from going away.

Fixes 61890ccaefaf ("media: platform: mtk-mdp3: add MediaTek MDP3 driver")
Cc [email protected] # 6.1
Cc Moudy Ho <[email protected]>
Signed-off-by Johan Hovold <[email protected]>
---
 .../media/platform/mediatek/mdp3/mtk-mdp3-core.c   | 14 ++++++++++++++
 1 file changed, 14 insertions(+)
drivers/media/platform/mediatek/mdp3/mtk-mdp3-core.c +14 -0
index 8de2c8e4d333..fc117a6a822c 100644
@@ -157,10 +157,18 @@ void mdp_video_device_release(struct video_device *vdev)
 	kfree(mdp);
 }
 
+static void mdp_put_device(void *_dev)
+{
+	struct device *dev = _dev;
+
+	put_device(dev);
+}
+
 static int mdp_mm_subsys_deploy(struct mdp_dev *mdp, enum mdp_infra_id id)
 {
 	struct platform_device *mm_pdev = NULL;
 	struct device **dev;
+	int ret;
 	int i;
 
 	if (!mdp)

@@ -194,6 +202,11 @@ static int mdp_mm_subsys_deploy(struct mdp_dev *mdp, enum mdp_infra_id id)
 		if (WARN_ON(!mm_pdev))
 			return -ENODEV;
 
+		ret = devm_add_action_or_reset(&mdp->pdev->dev, mdp_put_device,
+					       &mm_pdev->dev);
+		if (ret)
+			return ret;
+
 		*dev = &mm_pdev->dev;
 	}
 

@@ -279,6 +292,7 @@ static int mdp_probe(struct platform_device *pdev)
 			goto err_destroy_clock_wq;
 		}
 		mdp->scp = platform_get_drvdata(mm_pdev);
+		put_device(&mm_pdev->dev);
 	}
 
 	mdp->rproc_handle = scp_get_rproc(mdp->scp);
Signature · 1 line
2.49.1
maintainer Reviewed-by on v1 1/1
#1 lore raw

Il 24/09/25 16:39, Johan Hovold ha scritto:

Quoted 7 lines

Make sure to drop the references taken when looking up the subsys devices during probe on probe failure (e.g. probe deferral) and on driver unbind.

Similarly, drop the SCP device reference after retrieving its platform data during probe to avoid leaking it.

Quoted 7 lines

Note that holding a reference to a device does not prevent its driver data from going away.

Fixes 61890ccaefaf ("media: platform: mtk-mdp3: add MediaTek MDP3 driver")
Cc [email protected] # 6.1
Cc Moudy Ho <[email protected]>
Signed-off-by Johan Hovold <[email protected]>
Reviewed-by AngeloGioacchino Del Regno <[email protected]>