Erro 500 - Ao tentar deslogar

Galera estou encontrando erro ao tentar deslogar, segue minhas classes FazTudo Filtro de auditoria e logout.

HTTP Status 500 -

type Exception report

message

description The server encountered an internal error that prevented it from fulfilling this request.

exception

javax.servlet.ServletException
    br.com.alura.gerenciador.web.FazTudo.service(FazTudo.java:36)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    br.com.alura.gerenciador.web.FiltroDeAuditoria.doFilter(FiltroDeAuditoria.java:36)
note The full stack trace of the root cause is available in the Apache Tomcat/7.0.67 logs.

Minha Classe fazTudo

package br.com.alura.gerenciador.web;

import java.io.IOException;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@WebServlet(urlPatterns = "/fazTudo")
public class FazTudo extends HttpServlet {
    /**
     * 
     */
    private static final long serialVersionUID = 6626322586019870362L;

    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        String tarefa = req.getParameter("tarefa");
        if (tarefa == null)
            throw new IllegalArgumentException("Você esqueceu de passar a tarefa");

        tarefa = "br.com.alura.gerenciador.web" + tarefa;
        try {

            Class<?> tipo = Class.forName(tarefa);
            Tarefa instancia = (Tarefa) tipo.newInstance();
            String pagina = instancia.executa(req, resp);

            RequestDispatcher requestDispatcher = req.getRequestDispatcher(pagina);
            requestDispatcher.forward(req, resp);
        } catch (ClassNotFoundException | InstantiationException | IllegalAccessException e) {
            throw new ServletException();
        }
    }
}

Filtro de Auditoria

package br.com.alura.gerenciador.web;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import br.com.alura.gerenciador.Usuario;

@WebFilter(urlPatterns = "/*")
public class FiltroDeAuditoria implements Filter {

    @Override
    public void destroy() {
    }

    @Override
    public void init(FilterConfig arg0) throws ServletException {
    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
            throws IOException, ServletException {
        HttpServletRequest req = (HttpServletRequest) request;
        String uri = req.getRequestURI();
        String usuario = getUsuario(req);

        System.out.println("Usuario: " + usuario + "\nAcessando a URI: " + req.getRequestURI());
        chain.doFilter(request, response);

    }

    private String getUsuario(HttpServletRequest req) {

        Usuario usuario = (Usuario) req.getSession().getAttribute("usuario.logado");
        if (usuario == null) {
            return "<deslogado>";
        }

        return usuario.getEmail();
    }

}

Classe Logout

package br.com.alura.gerenciador.web;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

public class Logout implements Tarefa {

    @Override
    public String executa(HttpServletRequest request, HttpServletResponse response) {

        HttpSession session = request.getSession();
        session.removeAttribute("usuarioLogado");

        return "/WEB-INF/paginas/logout.html";

    }

}