linux-kernel - Re: [PATCH] csky: fix refcount leak in setup

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Date:   Fri, 28 Dec 2018 01:02:08 +0800
From:   Guo Ren <guoren@...nel.org>
To:     Yangtao Li <tiny.windzz@...il.com>
Cc:     arnd@...db.de, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] csky: fix refcount leak in setup_smp()

Hi Li,

On Thu, Dec 27, 2018 at 11:27:11AM -0500, Yangtao Li wrote:
> The of_find_node_by_type() returns a node pointer with refcount
> incremented, but there is the lack of use of the of_node_put() when
> done. Add the missing of_node_put() to release the refcount.
> 
> Signed-off-by: Yangtao Li <tiny.windzz@...il.com>
> ---
>  arch/csky/kernel/smp.c | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/csky/kernel/smp.c b/arch/csky/kernel/smp.c
> index 36ebaf9834e1..adec56df613b 100644
> --- a/arch/csky/kernel/smp.c
> +++ b/arch/csky/kernel/smp.c
> @@ -139,11 +139,17 @@ void __init setup_smp(void)
>  	int cpu;
>  
>  	while ((node = of_find_node_by_type(node, "cpu"))) {
> -		if (!of_device_is_available(node))
> +		if (!of_device_is_available(node)) {
> +			of_node_put(node);
>  			continue;
> +		}
>  
> -		if (of_property_read_u32(node, "reg", &cpu))
> +		if (of_property_read_u32(node, "reg", &cpu)) {
> +			of_node_put(node);
>  			continue;
> +		}
> +
> +		of_node_put(node);
If success, of_node_put ?
>  
>  		if (cpu >= NR_CPUS)
Here need a of_node_put()?
>  			continue;

Can you use for_each_of_cpu_node() for the patch?

Thx
 Guo Ren