Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
MIME-Version: 1.0
References: <20220808132158.24099-1-jlee@suse.com>
In-Reply-To: <20220808132158.24099-1-jlee@suse.com>
From:   "Rafael J. Wysocki" <rafael@kernel.org>
Date:   Tue, 23 Aug 2022 19:53:18 +0200
Message-ID: <CAJZ5v0ig8mkNSrwsUhNVVGeBgB9TMmTDZQQmf_tCV4oJ85VPRA@mail.gmail.com>
Subject: Re: [PATCH] thermal/int340x_thermal: handle data_vault when the value
 is ZERO_SIZE_PTR
To:     "Lee, Chun-Yi" <joeyli.kernel@gmail.com>
Cc:     "Rafael J . Wysocki" <rafael@kernel.org>,
        Daniel Lezcano <daniel.lezcano@linaro.org>,
        Amit Kucheria <amitk@kernel.org>,
        Zhang Rui <rui.zhang@intel.com>,
        Linux PM <linux-pm@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        "Lee, Chun-Yi" <jlee@suse.com>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Mon, Aug 8, 2022 at 3:22 PM Lee, Chun-Yi <joeyli.kernel@gmail.com> wrote:
>
> In some case, the GDDV returns a package with a buffer which has
> zero length. It causes that kmemdup() returns ZERO_SIZE_PTR (0x10).
>
> Then the data_vault_read() got NULL point dereference problem when
> accessing the 0x10 value in data_vault.
>
> [   71.024560] BUG: kernel NULL pointer dereference, address:
> 0000000000000010
>
> This patch uses ZERO_OR_NULL_PTR() for checking ZERO_SIZE_PTR or
> NULL value in data_vault.
>
> Signed-off-by: "Lee, Chun-Yi" <jlee@suse.com>

Applied as 6.0-rc material, thanks!

> ---
>  drivers/thermal/intel/int340x_thermal/int3400_thermal.c | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/thermal/intel/int340x_thermal/int3400_thermal.c b/drivers/thermal/intel/int340x_thermal/int3400_thermal.c
> index 80d4e0676083..365489bf4b8c 100644
> --- a/drivers/thermal/intel/int340x_thermal/int3400_thermal.c
> +++ b/drivers/thermal/intel/int340x_thermal/int3400_thermal.c
> @@ -527,7 +527,7 @@ 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)
> +       if (ZERO_OR_NULL_PTR(priv->data_vault))
>                 goto out_free;
>
>         bin_attr_data_vault.private = priv->data_vault;
> @@ -597,7 +597,7 @@ static int int3400_thermal_probe(struct platform_device *pdev)
>                         goto free_imok;
>         }
>
> -       if (priv->data_vault) {
> +       if (!ZERO_OR_NULL_PTR(priv->data_vault)) {
>                 result = sysfs_create_group(&pdev->dev.kobj,
>                                             &data_attribute_group);
>                 if (result)
> @@ -615,7 +615,8 @@ static int int3400_thermal_probe(struct platform_device *pdev)
>  free_sysfs:
>         cleanup_odvp(priv);
>         if (priv->data_vault) {
> -               sysfs_remove_group(&pdev->dev.kobj, &data_attribute_group);
> +               if (!ZERO_OR_NULL_PTR(priv->data_vault))
> +                       sysfs_remove_group(&pdev->dev.kobj, &data_attribute_group);
>                 kfree(priv->data_vault);
>         }
>  free_uuid:
> @@ -647,7 +648,7 @@ static int int3400_thermal_remove(struct platform_device *pdev)
>         if (!priv->rel_misc_dev_res)
>                 acpi_thermal_rel_misc_device_remove(priv->adev->handle);
>
> -       if (priv->data_vault)
> +       if (!ZERO_OR_NULL_PTR(priv->data_vault))
>                 sysfs_remove_group(&pdev->dev.kobj, &data_attribute_group);
>         sysfs_remove_group(&pdev->dev.kobj, &uuid_attribute_group);
>         sysfs_remove_group(&pdev->dev.kobj, &imok_attribute_group);
> --
> 2.26.2
>