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References: <20220126014853.2915981-1-jiasheng@iscas.ac.cn>
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From:   "Rafael J. Wysocki" <rafael@kernel.org>
Date:   Fri, 4 Feb 2022 18:58:07 +0100
Message-ID: <CAJZ5v0igZFKcPojJyLkcn=aTVhyznENwLEbfzK7XvrrVrGu_vg@mail.gmail.com>
Subject: Re: [PATCH v3] thermal/int340x_thermal: Check for null pointer after
 calling kmemdup
To:     Jiasheng Jiang <jiasheng@iscas.ac.cn>
Cc:     "Rafael J. Wysocki" <rafael@kernel.org>,
        Daniel Lezcano <daniel.lezcano@linaro.org>,
        "Zhang, Rui" <rui.zhang@intel.com>,
        Amit Kucheria <amitk@kernel.org>,
        Linux PM <linux-pm@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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On Wed, Jan 26, 2022 at 2:49 AM Jiasheng Jiang <jiasheng@iscas.ac.cn> wrote:
>
> As the potential failure of the allocation, kmemdup() may return NULL
> pointer.
> Then the 'bin_attr_data_vault.private' will be NULL pointer but the
> 'bin_attr_data_vault.size' is not 0.
> Therefore, it should be better to check the return value of kmemdup() to
> avoid the wrong size.
> And since the error handling process is simple, it may not use the
> 'goto' to simplify the code.
>
> Fixes: 0ba13c763aac ("thermal/int340x_thermal: Export GDDV")
> Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
> ---
> Changelog
>
> v1 -> v2
>
> * Change 1. Use out_kfree to simplify the code.
>
> v2 -> v3
>
> * Change 1. Revert the code to v1 and refine the commit message.
> ---
>  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 8502b7d8df89..52ac3ee54309 100644
> --- a/drivers/thermal/intel/int340x_thermal/int3400_thermal.c
> +++ b/drivers/thermal/intel/int340x_thermal/int3400_thermal.c
> @@ -464,6 +464,11 @@ 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;
> +       }
> +
>         bin_attr_data_vault.private = priv->data_vault;
>         bin_attr_data_vault.size = obj->package.elements[0].buffer.length;
>         kfree(buffer.pointer);
> --

Applied as 5.18 material with some edits in the subject and changelog, thanks!