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Date:   Fri, 29 Mar 2019 11:02:02 +0100
From:   Ludovic Desroches <ludovic.desroches@microchip.com>
To:     Peng Hao <peng.hao2@zte.com.cn>
CC:     <nicolas.ferre@microchip.com>, <alexandre.belloni@bootlin.com>,
        <linux-kernel@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH]  arm/mach-at91/pm : fix possible object reference leak
Message-ID: <20190329100202.rupu5xo2prxlcafa@M43218.corp.atmel.com>
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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 <peng.hao2@zte.com.cn>
> ---
>  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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