2019-02-13 09:41:29

by Peng Hao

Subject: [PATCH] arm/mach-at91/pm : fix possible object reference leak

of_find_device_by_node() takes a reference to the struct device
when it finds a match via get_device. When returning error we should
call put_device.

Signed-off-by: Peng Hao <[email protected]>
---
arch/arm/mach-at91/pm.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/arch/arm/mach-at91/pm.c b/arch/arm/mach-at91/pm.c
index 51e808a..70fadb7 100644
--- a/arch/arm/mach-at91/pm.c
+++ b/arch/arm/mach-at91/pm.c
@@ -621,6 +621,7 @@ static int __init at91_pm_backup_init(void)

securam_fail:
iounmap(pm_data.sfrbu);
+ put_device(&pdev->dev);
pm_data.sfrbu = NULL;
return ret;
}
--
1.8.3.1

2019-03-29 10:04:00

by Ludovic Desroches

Subject: Re: [PATCH] arm/mach-at91/pm : fix possible object reference leak

Hi,

On Wed, Feb 13, 2019 at 10:55:46PM +0800, Peng Hao wrote:
> of_find_device_by_node() takes a reference to the struct device
> when it finds a match via get_device. When returning error we should
> call put_device.
>
> Signed-off-by: Peng Hao <[email protected]>
> ---
> arch/arm/mach-at91/pm.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/arch/arm/mach-at91/pm.c b/arch/arm/mach-at91/pm.c
> index 51e808a..70fadb7 100644
> --- a/arch/arm/mach-at91/pm.c
> +++ b/arch/arm/mach-at91/pm.c
> @@ -621,6 +621,7 @@ static int __init at91_pm_backup_init(void)
>
> securam_fail:
> iounmap(pm_data.sfrbu);
> + put_device(&pdev->dev);

Fixed in this way, in some cases (as there are goto securam_fail before calling
of_find_device_by_node), we may decrement a reference which has not been
incremented. Is it safe?

Regards

Ludovic

> pm_data.sfrbu = NULL;
> return ret;
> }
> --
> 1.8.3.1
>
>
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