2020-12-01 09:30:15

by Qinglang Miao

Subject: [PATCH 4/8] i2c: imx: fix reference leak when pm_runtime_get_sync fails

In i2c_imx_xfer() and i2c_imx_remove(), the pm reference count
is not expected to be incremented on return.

However, pm_runtime_get_sync will increment pm reference count
even failed. Forgetting to putting operation will result in a
reference leak here.

Replace it with pm_runtime_resume_and_get to keep usage
counter balanced.

Fixes: 3a5ee18d2a32 ("i2c: imx: implement master_xfer_atomic callback")
Reported-by: Hulk Robot <[email protected]>
Signed-off-by: Qinglang Miao <[email protected]>
---
drivers/i2c/busses/i2c-imx.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
index c98529c76..93d2069da 100644
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -1008,7 +1008,7 @@ static int i2c_imx_xfer(struct i2c_adapter *adapter,
struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(adapter);
int result;

- result = pm_runtime_get_sync(i2c_imx->adapter.dev.parent);
+ result = pm_runtime_resume_and_get(i2c_imx->adapter.dev.parent);
if (result < 0)
return result;

@@ -1252,7 +1252,7 @@ static int i2c_imx_remove(struct platform_device *pdev)
struct imx_i2c_struct *i2c_imx = platform_get_drvdata(pdev);
int irq, ret;

- ret = pm_runtime_get_sync(&pdev->dev);
+ ret = pm_runtime_resume_and_get(&pdev->dev);
if (ret < 0)
return ret;

--
2.23.0

2020-12-11 13:47:20

by Oleksij Rempel

Subject: Re: [PATCH 4/8] i2c: imx: fix reference leak when pm_runtime_get_sync fails

On Tue, Dec 01, 2020 at 05:31:41PM +0800, Qinglang Miao wrote:
> In i2c_imx_xfer() and i2c_imx_remove(), the pm reference count
> is not expected to be incremented on return.
>
> However, pm_runtime_get_sync will increment pm reference count
> even failed. Forgetting to putting operation will result in a
> reference leak here.
>
> Replace it with pm_runtime_resume_and_get to keep usage
> counter balanced.
>
> Fixes: 3a5ee18d2a32 ("i2c: imx: implement master_xfer_atomic callback")
> Reported-by: Hulk Robot <[email protected]>
> Signed-off-by: Qinglang Miao <[email protected]>

Thank you!

Reviewed-by: Oleksij Rempel <[email protected]>

> ---
> drivers/i2c/busses/i2c-imx.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
> index c98529c76..93d2069da 100644
> --- a/drivers/i2c/busses/i2c-imx.c
> +++ b/drivers/i2c/busses/i2c-imx.c
> @@ -1008,7 +1008,7 @@ static int i2c_imx_xfer(struct i2c_adapter *adapter,
> struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(adapter);
> int result;
>
> - result = pm_runtime_get_sync(i2c_imx->adapter.dev.parent);
> + result = pm_runtime_resume_and_get(i2c_imx->adapter.dev.parent);
> if (result < 0)
> return result;
>
> @@ -1252,7 +1252,7 @@ static int i2c_imx_remove(struct platform_device *pdev)
> struct imx_i2c_struct *i2c_imx = platform_get_drvdata(pdev);
> int irq, ret;
>
> - ret = pm_runtime_get_sync(&pdev->dev);
> + ret = pm_runtime_resume_and_get(&pdev->dev);
> if (ret < 0)
> return ret;
>
> --
> 2.23.0
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> [email protected]
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>

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