Spring Security session after login not working properly

i've created a simple login with spring boot and spring security and i'm having a few issues with the fact that if a user logs in it works fine but if the user goes to the same login page again he isn't redirected to the home page and the session exists:( how should i deal with this? do i need to specific the form login page in security config?

Security Config Class:

@Configuration
@EnableWebSecurity
public class WebSecurityConfig extends WebSecurityConfigurerAdapter {

    @Bean
    public BCryptPasswordEncoder bCryptPasswordEncoder() {
        return new BCryptPasswordEncoder();
    }

    @Override
    public void configure(HttpSecurity http) throws Exception {
        http.authorizeRequests()
                .antMatchers("/showReg", "/", "/registerUser","/login")
                .permitAll().antMatchers("/displayUpload","home.html").hasRole("USER").anyRequest().authenticated();
    }

    @Bean(name = BeanIds.AUTHENTICATION_MANAGER)
    @Override
    public AuthenticationManager authenticationManagerBean() throws Exception {
        return super.authenticationManagerBean();
    }

}

Login POST Controller:

@RequestMapping(value = "/login", method = RequestMethod.POST)
public String login(@RequestParam("email") String email, @RequestParam("password") String password, Model model) {
    try {
        boolean loginResponse = securityService.login(email, password);
        if (loginResponse) {
            User user = userRepository.findByEmail(email);
            return "home";
        } else {
            model.addAttribute("msg", "Invalid username or password.Please try again!");
        }
    } catch (Exception e) {
        model.addAttribute("msg", "Invalid username or password.Please try again!");
        e.printStackTrace();
    }
    return "login";
}

@RequestMapping(value = "/", method = RequestMethod.GET)
public String getLogin() {
    return "login";
}