Re: [PATCH v3 1/2] HID: sensor: custom: Fix use-after-free in enable_sensor

[srinivas pandruvada <srinivas.pandruvada@linux.intel.com>]

On Tue, 2026-07-07 at 15:15 +0800, Haoxiang Li wrote:
> enable_sensor_store() can call set_power_report_state(), which
> dereferences sensor_inst->power_state and sensor_inst->report_state.
> These pointers refer to entries in sensor_inst->fields.
> 
> Create the field attributes before exposing the enable_sensor sysfs
> attribute, so enable_sensor cannot be accessed before the state it
> depends on has been initialized.
> 
> On remove, delete enable_sensor before freeing the field attributes,
> so a concurrent sysfs write cannot dereference freed memory through
> power_state or report_state.
> 
> Reported-by: Sashiko AI Review <sashiko-bot@kernel.org>
> Link:
> https://sashiko.dev/#/patchset/20260623021950.1736413-1-haoxiang_li2024@163.com?part=1
> Fixes: 4a7de0519df5 ("HID: sensor: Custom and Generic sensor
> support")
> Cc: stable@vger.kernel.org
> Signed-off-by: Haoxiang Li <haoxiang_li2024@163.com>

Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

> ---
>  drivers/hid/hid-sensor-custom.c | 17 +++++++++--------
>  1 file changed, 9 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/hid/hid-sensor-custom.c b/drivers/hid/hid-
> sensor-custom.c
> index afffea894021..6b0da2e0e1c9 100644
> --- a/drivers/hid/hid-sensor-custom.c
> +++ b/drivers/hid/hid-sensor-custom.c
> @@ -1005,26 +1005,26 @@ static int hid_sensor_custom_probe(struct
> platform_device *pdev)
>  		return ret;
>  	}
>  
> -	ret = sysfs_create_group(&sensor_inst->pdev->dev.kobj,
> -				 &enable_sensor_attr_group);
> +	ret = hid_sensor_custom_add_attributes(sensor_inst);
>  	if (ret)
>  		goto err_remove_callback;
>  
> -	ret = hid_sensor_custom_add_attributes(sensor_inst);
> +	ret = sysfs_create_group(&sensor_inst->pdev->dev.kobj,
> +				 &enable_sensor_attr_group);
>  	if (ret)
> -		goto err_remove_group;
> +		goto err_remove_attributes;
>  
>  	ret = hid_sensor_custom_dev_if_add(sensor_inst);
>  	if (ret)
> -		goto err_remove_attributes;
> +		goto err_remove_group;
>  
>  	return 0;
>  
> -err_remove_attributes:
> -	hid_sensor_custom_remove_attributes(sensor_inst);
>  err_remove_group:
>  	sysfs_remove_group(&sensor_inst->pdev->dev.kobj,
>  			   &enable_sensor_attr_group);
> +err_remove_attributes:
> +	hid_sensor_custom_remove_attributes(sensor_inst);
>  err_remove_callback:
>  	sensor_hub_remove_callback(hsdev, hsdev->usage);
>  
> @@ -1042,9 +1042,10 @@ static void hid_sensor_custom_remove(struct
> platform_device *pdev)
>  	}
>  
>  	hid_sensor_custom_dev_if_remove(sensor_inst);
> -	hid_sensor_custom_remove_attributes(sensor_inst);
> +	/* Remove enable_sensor first as it uses fields via
> power_state/report_state. */
>  	sysfs_remove_group(&sensor_inst->pdev->dev.kobj,
>  			   &enable_sensor_attr_group);
> +	hid_sensor_custom_remove_attributes(sensor_inst);
>  	sensor_hub_remove_callback(hsdev, hsdev->usage);
>  }
>