Re: [PATCH v2 2/2] iio: imu: inv_mpu6050: validate ACPI object types in asus_acpi_get_sensor_info()

[Jonathan Cameron <jic23@kernel.org>]

On Mon, 26 Oct 2026 14:20:39 +0000
Tristan Madani <tristmd@gmail.com> wrote:

> From: Tristan Madani <tristan@talencesecurity.com>
> 
> asus_acpi_get_sensor_info() iterates through a nested ACPI package
> structure without checking types at either level.  The outer object
> returned by acpi_evaluate_object() and each inner element must be
> validated as ACPI_TYPE_PACKAGE before accessing their package.count
> and package.elements members.
> 
> Use acpi_evaluate_object_typed() to validate the outer object type
> at evaluation time.  Add a type check for each inner element before
> accessing its package contents.  Also replace kfree() with
> ACPI_FREE() for the ACPI-allocated buffer.
> 
> Fixes: a35c5d1aa96a ("iio: imu: inv_mpu6050: Create mux clients for ACPI")
> Cc: stable@vger.kernel.org
> Signed-off-by: Tristan Madani <tristan@talencesecurity.com>
> ---
>  drivers/iio/imu/inv_mpu6050/inv_mpu_acpi.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_acpi.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_acpi.c
> index 460792ed27e031..e5ffa0d5f6b1a2 100644
> --- a/drivers/iio/imu/inv_mpu6050/inv_mpu_acpi.c
> +++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_acpi.c
> @@ -52,7 +52,8 @@ static int asus_acpi_get_sensor_info(struct acpi_device *adev,
>  	union acpi_object *cpm;
>  	int ret;
>  
> -	status = acpi_evaluate_object(adev->handle, "CNF0", NULL, &buffer);
> +	status = acpi_evaluate_object_typed(adev->handle, "CNF0", NULL,
> +						&buffer, ACPI_TYPE_PACKAGE);
Same as previous wrt to indent.  In the kernel style guide
this is only there implicitly in examples, but it is definitely
preferred choice for IIO and I don't recall seeing anywhere in
the kernel where this wasn't an acceptable choice.

Jonathan


>  	if (ACPI_FAILURE(status))
>  		return -ENODEV;
>  
> @@ -62,6 +63,8 @@ static int asus_acpi_get_sensor_info(struct acpi_device *adev,
>  		int j;
>  
>  		elem = &cpm->package.elements[i];
> +		if (elem->type != ACPI_TYPE_PACKAGE)
> +			continue;
>  		for (j = 0; j < elem->package.count; ++j) {
>  			union acpi_object *sub_elem;
>  
> @@ -78,7 +81,7 @@ static int asus_acpi_get_sensor_info(struct acpi_device *adev,
>  		}
>  	}
>  	ret = cpm->package.count;
> -	kfree(buffer.pointer);
> +	ACPI_FREE(buffer.pointer);
>  
>  	return ret;
>  }