Re: [PATCH] char: hw_random: Fix a reference count leak.

From: Lukasz Stelmach
Date: Mon Jun 15 2020 - 09:19:26 EST


It was <2020-06-13 sob 16:41>, when wu000273@xxxxxxx wrote:
> From: Qiushi Wu <wu000273@xxxxxxx>
>
> Calling pm_runtime_get_sync increments the counter even in case of
> failure, causing incorrect ref count if pm_runtime_put_sync is not
> called in error handling paths. Thus replace the jump target
> "err_pm_get" by "err_clock".
>
> Fixes: 6cd225cc5d8a ("hwrng: exynos - add Samsung Exynos True RNG driver")
> Signed-off-by: Qiushi Wu <wu000273@xxxxxxx>
> ---
> drivers/char/hw_random/exynos-trng.c | 4 +---
> 1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/drivers/char/hw_random/exynos-trng.c b/drivers/char/hw_random/exynos-trng.c
> index 8e1fe3f8dd2d..ffa7e0f061f0 100644
> --- a/drivers/char/hw_random/exynos-trng.c
> +++ b/drivers/char/hw_random/exynos-trng.c
> @@ -135,7 +135,7 @@ static int exynos_trng_probe(struct platform_device *pdev)
> ret = pm_runtime_get_sync(&pdev->dev);
> if (ret < 0) {
> dev_err(&pdev->dev, "Could not get runtime PM.\n");
> - goto err_pm_get;
> + goto err_clock;
> }
>
> trng->clk = devm_clk_get(&pdev->dev, "secss");
> @@ -166,8 +166,6 @@ static int exynos_trng_probe(struct platform_device *pdev)
>
> err_clock:
> pm_runtime_put_sync(&pdev->dev);
> -
> -err_pm_get:
> pm_runtime_disable(&pdev->dev);
>
> return ret;

I believe this fix has already been submitted

https://lore.kernel.org/linux-arm-kernel/20200522011659.26727-1-dinghao.liu@xxxxxxxxxx/T/#u

It hasn't been applied though. Anyway, thank you for your work.

Herbert, could you take a look at the Dinghao's patch, please?
--
Åukasz Stelmach
Samsung R&D Institute Poland
Samsung Electronics

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