[PATCH] drm/meson: Fix refcount bugs in meson_vpu_has_available_connectors()

[PATCH] drm/meson: Fix refcount bugs in meson_vpu_has_available_connectors()

[Liang He]

In this function, there are two refcount leak bugs:
(1) when breaking out of for_each_endpoint_of_node(), we need call
the of_node_put() for the 'ep';
(2) we should call of_node_put() for the reference returned by
of_graph_get_remote_port() when it is not used anymore.

Fixes: bbbe775ec5b5 ("drm: Add support for Amlogic Meson Graphic Controller")
Signed-off-by: Liang He <windhl@126.com>
Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
---
 drivers/gpu/drm/meson/meson_drv.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/meson/meson_drv.c b/drivers/gpu/drm/meson/meson_drv.c
index 1b70938cfd2c..bd4ca11d3ff5 100644
--- a/drivers/gpu/drm/meson/meson_drv.c
+++ b/drivers/gpu/drm/meson/meson_drv.c
@@ -115,8 +115,11 @@ static bool meson_vpu_has_available_connectors(struct device *dev)
 	for_each_endpoint_of_node(dev->of_node, ep) {
 		/* If the endpoint node exists, consider it enabled */
 		remote = of_graph_get_remote_port(ep);
-		if (remote)
+		if (remote) {
+			of_node_put(remote);
+			of_node_put(ep);
 			return true;
+		}
 	}
 
 	return false;
-- 
2.25.1


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Re: [PATCH] drm/meson: Fix refcount bugs in meson_vpu_has_available_connectors()

[Neil Armstrong]

On 26/07/2022 03:07, Liang He wrote:
> In this function, there are two refcount leak bugs:
> (1) when breaking out of for_each_endpoint_of_node(), we need call
> the of_node_put() for the 'ep';
> (2) we should call of_node_put() for the reference returned by
> of_graph_get_remote_port() when it is not used anymore.
> 
> Fixes: bbbe775ec5b5 ("drm: Add support for Amlogic Meson Graphic Controller")
> Signed-off-by: Liang He <windhl@126.com>
> Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
> ---
>   drivers/gpu/drm/meson/meson_drv.c | 5 ++++-
>   1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/meson/meson_drv.c b/drivers/gpu/drm/meson/meson_drv.c
> index 1b70938cfd2c..bd4ca11d3ff5 100644
> --- a/drivers/gpu/drm/meson/meson_drv.c
> +++ b/drivers/gpu/drm/meson/meson_drv.c
> @@ -115,8 +115,11 @@ static bool meson_vpu_has_available_connectors(struct device *dev)
>   	for_each_endpoint_of_node(dev->of_node, ep) {
>   		/* If the endpoint node exists, consider it enabled */
>   		remote = of_graph_get_remote_port(ep);
> -		if (remote)
> +		if (remote) {
> +			of_node_put(remote);
> +			of_node_put(ep);
>   			return true;
> +		}
>   	}
>   
>   	return false;

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

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Re: [PATCH] drm/meson: Fix refcount bugs in meson_vpu_has_available_connectors()

[Neil Armstrong]

Hi,

On Tue, 26 Jul 2022 09:07:22 +0800, Liang He wrote:
> In this function, there are two refcount leak bugs:
> (1) when breaking out of for_each_endpoint_of_node(), we need call
> the of_node_put() for the 'ep';
> (2) we should call of_node_put() for the reference returned by
> of_graph_get_remote_port() when it is not used anymore.
> 
> 
> [...]

Thanks, Applied to https://anongit.freedesktop.org/git/drm/drm-misc.git (drm-misc-fixes)

[1/1] drm/meson: Fix refcount bugs in meson_vpu_has_available_connectors()
      https://cgit.freedesktop.org/drm/drm-misc/commit/?id=91b3c8dbe898df158fd2a84675f3a284ff6666f7

-- 
Neil

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