[PATCH 2/4] media: platform: meson-ao-cec: fix possible object reference leak

[PATCH 2/4] media: platform: meson-ao-cec: fix possible object reference leak

[Wen Yang]

The call to of_parse_phandle() returns a node pointer with refcount
incremented thus it must be explicitly decremented here after the last
usage.
The of_find_device_by_node() takes a reference to the underlying device
structure, we also should release that reference.
This patch fixes those two issues.

Fixes: 7ec2c0f72cb1 ("media: platform: Add Amlogic Meson AO CEC Controller driver")
Signed-off-by: Wen Yang <yellowriver2010@hotmail.com>
---
 drivers/media/platform/meson/ao-cec.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/media/platform/meson/ao-cec.c b/drivers/media/platform/meson/ao-cec.c
index cd4be38..8ba8b46 100644
--- a/drivers/media/platform/meson/ao-cec.c
+++ b/drivers/media/platform/meson/ao-cec.c
@@ -613,18 +613,25 @@ static int meson_ao_cec_probe(struct platform_device *pdev)
 	}
 
 	hdmi_dev = of_find_device_by_node(np);
-	if (hdmi_dev == NULL)
+	if (hdmi_dev == NULL) {
+		of_node_put(np);
 		return -EPROBE_DEFER;
+	}
 
+	of_node_put(np);
 	ao_cec = devm_kzalloc(&pdev->dev, sizeof(*ao_cec), GFP_KERNEL);
-	if (!ao_cec)
+	if (!ao_cec) {
+		put_device(&hdmi_dev->dev);
 		return -ENOMEM;
+	}
 
 	spin_lock_init(&ao_cec->cec_reg_lock);
 
 	ao_cec->notify = cec_notifier_get(&hdmi_dev->dev);
-	if (!ao_cec->notify)
+	if (!ao_cec->notify) {
+		put_device(&hdmi_dev->dev);
 		return -ENOMEM;
+	}
 
 	ao_cec->adap = cec_allocate_adapter(&meson_ao_cec_ops, ao_cec,
 					    "meson_ao_cec",
-- 
2.7.4


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Re: [PATCH 2/4] media: platform: meson-ao-cec: fix possible object reference leak

[Neil Armstrong]

Le 09/02/2019 03:52, Wen Yang a écrit :
> The call to of_parse_phandle() returns a node pointer with refcount
> incremented thus it must be explicitly decremented here after the last
> usage.
> The of_find_device_by_node() takes a reference to the underlying device
> structure, we also should release that reference.
> This patch fixes those two issues.
> 
> Fixes: 7ec2c0f72cb1 ("media: platform: Add Amlogic Meson AO CEC Controller driver")
> Signed-off-by: Wen Yang <yellowriver2010@hotmail.com>
> ---
>  drivers/media/platform/meson/ao-cec.c | 13 ++++++++++---
>  1 file changed, 10 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/media/platform/meson/ao-cec.c b/drivers/media/platform/meson/ao-cec.c
> index cd4be38..8ba8b46 100644
> --- a/drivers/media/platform/meson/ao-cec.c
> +++ b/drivers/media/platform/meson/ao-cec.c
> @@ -613,18 +613,25 @@ static int meson_ao_cec_probe(struct platform_device *pdev)
>  	}
>  
>  	hdmi_dev = of_find_device_by_node(np);
> -	if (hdmi_dev == NULL)
> +	if (hdmi_dev == NULL) {
> +		of_node_put(np);
>  		return -EPROBE_DEFER;
> +	}
>  
> +	of_node_put(np);
>  	ao_cec = devm_kzalloc(&pdev->dev, sizeof(*ao_cec), GFP_KERNEL);
> -	if (!ao_cec)
> +	if (!ao_cec) {
> +		put_device(&hdmi_dev->dev);
>  		return -ENOMEM;
> +	}
>  
>  	spin_lock_init(&ao_cec->cec_reg_lock);
>  
>  	ao_cec->notify = cec_notifier_get(&hdmi_dev->dev);
> -	if (!ao_cec->notify)
> +	if (!ao_cec->notify) {
> +		put_device(&hdmi_dev->dev);
>  		return -ENOMEM;
> +	}
>  
>  	ao_cec->adap = cec_allocate_adapter(&meson_ao_cec_ops, ao_cec,
>  					    "meson_ao_cec",
> 

Acked-by: Neil Armstrong <narmstrong@baylibre.com>

Thanks for the fix !

Neil

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