2023-01-06 08:20:34

by Miaoqian Lin

Subject: [PATCH] media: platform: Fix refcount leak in probe and remove function

rcar_fcp_get() take reference, which should be balanced with
rcar_fcp_put(). Add missing rcar_fcp_put() in fdp1_remove and
the error paths of fdp1_probe() to fix this.

Fixes: 4710b752e029 ("[media] v4l: Add Renesas R-Car FDP1 Driver")
Signed-off-by: Miaoqian Lin <[email protected]>
---
I take commit Fixes: 7113469dafc2 ("media: vsp1: Fix an error handling
path in the probe function") for reference.
---
drivers/media/platform/renesas/rcar_fdp1.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/media/platform/renesas/rcar_fdp1.c b/drivers/media/platform/renesas/rcar_fdp1.c
index 37ecf489d112..ed97bb161743 100644
--- a/drivers/media/platform/renesas/rcar_fdp1.c
+++ b/drivers/media/platform/renesas/rcar_fdp1.c
@@ -2313,8 +2313,10 @@ static int fdp1_probe(struct platform_device *pdev)

/* Determine our clock rate */
clk = clk_get(&pdev->dev, NULL);
- if (IS_ERR(clk))
- return PTR_ERR(clk);
+ if (IS_ERR(clk)) {
+ ret = PTR_ERR(clk);
+ goto put_dev;
+ }

fdp1->clk_rate = clk_get_rate(clk);
clk_put(clk);
@@ -2323,7 +2325,7 @@ static int fdp1_probe(struct platform_device *pdev)
ret = v4l2_device_register(&pdev->dev, &fdp1->v4l2_dev);
if (ret) {
v4l2_err(&fdp1->v4l2_dev, "Failed to register video device\n");
- return ret;
+ goto put_dev;
}

/* M2M registration */
@@ -2393,6 +2395,8 @@ static int fdp1_probe(struct platform_device *pdev)
unreg_dev:
v4l2_device_unregister(&fdp1->v4l2_dev);

+put_dev:
+ rcar_fcp_put(fdp1->fcp);
return ret;
}

@@ -2400,6 +2404,7 @@ static int fdp1_remove(struct platform_device *pdev)
{
struct fdp1_dev *fdp1 = platform_get_drvdata(pdev);

+ rcar_fcp_put(fdp1->fcp);
v4l2_m2m_release(fdp1->m2m_dev);
video_unregister_device(&fdp1->vfd);
v4l2_device_unregister(&fdp1->v4l2_dev);
--
2.25.1

2023-01-06 14:16:15

by Laurent Pinchart

Subject: Re: [PATCH] media: platform: Fix refcount leak in probe and remove function

Hello Miaoqian,

Thank you for the patch.

On Fri, Jan 06, 2023 at 11:58:09AM +0400, Miaoqian Lin wrote:
> rcar_fcp_get() take reference, which should be balanced with
> rcar_fcp_put(). Add missing rcar_fcp_put() in fdp1_remove and
> the error paths of fdp1_probe() to fix this.
>
> Fixes: 4710b752e029 ("[media] v4l: Add Renesas R-Car FDP1 Driver")
> Signed-off-by: Miaoqian Lin <[email protected]>
> ---
> I take commit Fixes: 7113469dafc2 ("media: vsp1: Fix an error handling
> path in the probe function") for reference.
> ---
> drivers/media/platform/renesas/rcar_fdp1.c | 11 ++++++++---
> 1 file changed, 8 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/media/platform/renesas/rcar_fdp1.c b/drivers/media/platform/renesas/rcar_fdp1.c
> index 37ecf489d112..ed97bb161743 100644
> --- a/drivers/media/platform/renesas/rcar_fdp1.c
> +++ b/drivers/media/platform/renesas/rcar_fdp1.c
> @@ -2313,8 +2313,10 @@ static int fdp1_probe(struct platform_device *pdev)
>
> /* Determine our clock rate */
> clk = clk_get(&pdev->dev, NULL);
> - if (IS_ERR(clk))
> - return PTR_ERR(clk);
> + if (IS_ERR(clk)) {
> + ret = PTR_ERR(clk);
> + goto put_dev;
> + }
>
> fdp1->clk_rate = clk_get_rate(clk);
> clk_put(clk);
> @@ -2323,7 +2325,7 @@ static int fdp1_probe(struct platform_device *pdev)
> ret = v4l2_device_register(&pdev->dev, &fdp1->v4l2_dev);
> if (ret) {
> v4l2_err(&fdp1->v4l2_dev, "Failed to register video device\n");
> - return ret;
> + goto put_dev;
> }
>
> /* M2M registration */
> @@ -2393,6 +2395,8 @@ static int fdp1_probe(struct platform_device *pdev)
> unreg_dev:
> v4l2_device_unregister(&fdp1->v4l2_dev);
>
> +put_dev:
> + rcar_fcp_put(fdp1->fcp);
> return ret;
> }
>
> @@ -2400,6 +2404,7 @@ static int fdp1_remove(struct platform_device *pdev)
> {
> struct fdp1_dev *fdp1 = platform_get_drvdata(pdev);
>
> + rcar_fcp_put(fdp1->fcp);

I would move it at the end, after unregistering the V4L2 device, as here
we may still be using the fcp.

Apart from that, the patch looks good to me.

Reviewed-by: Laurent Pinchart <[email protected]>

No need to send a v2, I'll make this small change in my tree.

> v4l2_m2m_release(fdp1->m2m_dev);
> video_unregister_device(&fdp1->vfd);
> v4l2_device_unregister(&fdp1->v4l2_dev);

--
Regards,

Laurent Pinchart