Commit 96eca8c9 authored by Dan Carpenter's avatar Dan Carpenter Committed by Guenter Roeck
Browse files

hwmon: (acpi_power_meter) clean up freeing code 



This code works okay but Smatch flagged it as a double free.  I've
changed three things to make it more clear.  1)  Remove the call to
free_capabilities() in acpi_power_meter_add().  This call is a no-op
because the capabilities have not been allocated yet.  2)  Set "*str" to
NULL in free_capabilities() so that way the function can be called twice
in a row without leading to a double free.  3)  Call free_capabilities()
in read_capabilities() instead of open coding the free.

Signed-off-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20201007075148.GB2529578@mwanda


Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent bce776f1

drivers/hwmon/acpi_power_meter.c

+4 −5
Original line number Diff line number Diff line
@@ -725,8 +725,10 @@ static void free_capabilities(struct acpi_power_meter_resource *resource) 
	int i;



	str = &resource->model_number;

	for (i = 0; i < 3; i++, str++)

	for (i = 0; i < 3; i++, str++) {

		kfree(*str);

		*str = NULL;

	}

}



static int read_capabilities(struct acpi_power_meter_resource *resource)
@@ -801,9 +803,7 @@ static int read_capabilities(struct acpi_power_meter_resource *resource) 
	dev_info(&resource->acpi_dev->dev, "Found ACPI power meter.\n");

	goto end;

error:

	str = &resource->model_number;

	for (i = 0; i < 3; i++, str++)

		kfree(*str);

	free_capabilities(resource);

end:

	kfree(buffer.pointer);

	return res;
@@ -874,7 +874,6 @@ static int acpi_power_meter_add(struct acpi_device *device) 
	strcpy(acpi_device_class(device), ACPI_POWER_METER_CLASS);

	device->driver_data = resource;



	free_capabilities(resource);

	res = read_capabilities(resource);

	if (res)

		goto exit_free;