// region is valid only for CreateBucketAction.
	var region string
	if action == policy.CreateBucketAction {
		// To extract region from XML in request body, get copy of request body.
		payload, err := io.ReadAll(io.LimitReader(r.Body, maxLocationConstraintSize))
		if err != nil {
			authZLogIf(ctx, err, logger.ErrorKind)
			return ErrMalformedXML
		}

		// Populate payload to extract location constraint.