Circular reference causes allowed memory exhausted error, how to remove the circular reference

Question

I am pretty sure I have a circular reference, but I do not know howto solve it.

I have a trait like this:

trait UseCaseValidatableTrait
{
    protected function validateParams(array $rules, array $messages = [])
    {
        // ... do smtg
    }

    private function _handle(
        callable $fn,
        array $rules = [],
        array $messages = []
    ): ?JsonResponse
    {
        try {
            $this->validateParams(
                count($rules) ? $rules : ($this->rules ?? []),
                $messages
            );

            return $fn(); // <-- here I call function passed
        } catch (Exception $e) {
            return new JsonResponse([
                'message' => $e->getMessage()
            ], 500);
        }
    }
}

And I have the class that uses it like this:

class MyCase implements UseCaseInterface
{
    use UseCaseValidatableTrait;

    public function handle(): JsonResponse
    {
        return $this->_handle(function () {
            // I do something, here, and sometimes I get error for too much memory consumption

            return new JsonResponse([]);
        });
    }
}

Sometimes, for some use cases, I get error:

Allowed memory size of 134217728 bytes exhausted