linux-kernel - Re: [PATCH] thermal/int340x_thermal: Check for null pointer after calling kmemdup

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Date:   Fri, 7 Jan 2022 13:05:17 +0100
From:   Daniel Lezcano <daniel.lezcano@...aro.org>
To:     Jiasheng Jiang <jiasheng@...as.ac.cn>, rui.zhang@...el.com,
        amitk@...nel.org
Cc:     linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] thermal/int340x_thermal: Check for null pointer after
 calling kmemdup

On 05/01/2022 07:56, Jiasheng Jiang wrote:
> As the possible failure of the allocation, kmemdup() may return NULL
> pointer.
> Therefore, it should be better to check the return value of kmemdup().
> If fails, just free 'buffer.pointer' and directly return is enough, same
> as the way that 'obj' fails above.
> 
> Fixes: 0ba13c763aac ("thermal/int340x_thermal: Export GDDV")
> Signed-off-by: Jiasheng Jiang <jiasheng@...as.ac.cn>
> ---
>  drivers/thermal/intel/int340x_thermal/int3400_thermal.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/thermal/intel/int340x_thermal/int3400_thermal.c b/drivers/thermal/intel/int340x_thermal/int3400_thermal.c
> index 823354a1a91a..999b5682c28a 100644
> --- a/drivers/thermal/intel/int340x_thermal/int3400_thermal.c
> +++ b/drivers/thermal/intel/int340x_thermal/int3400_thermal.c
> @@ -462,6 +462,11 @@ static void int3400_setup_gddv(struct int3400_thermal_priv *priv)
>  	priv->data_vault = kmemdup(obj->package.elements[0].buffer.pointer,
>  				   obj->package.elements[0].buffer.length,
>  				   GFP_KERNEL);
> +	if (!priv->data_vault) {
> +		kfree(buffer.pointer);
> +		return;
> +	}
> +

There is another kfree on error before

Please replace those by a goto out_kfree;

>  	bin_attr_data_vault.private = priv->data_vault;
>  	bin_attr_data_vault.size = obj->package.elements[0].buffer.length;

out_kfree;
>  	kfree(buffer.pointer);
> 

Why there is no error code returned to the caller?

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