[PATCH v3] thermal/int340x_thermal: Check for null pointer after calling kmemdup

[PATCH v3] thermal/int340x_thermal: Check for null pointer after calling kmemdup

[Jiasheng Jiang]

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);
-- 
2.25.1

Re: [PATCH v3] thermal/int340x_thermal: Check for null pointer after calling kmemdup

[Rafael J. Wysocki]

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!