Always getting redirected to /login

I have created a custom login-page for login purpose while learning spring security. The problem is that even after inserting correct username and password I am getting redirected to /app/login. Following are those file-content

spring-security.xml

<security:http auto-config="true" use-expressions="true">
 <security:intercept-url pattern="/app/login" access="permitAll" />
 <security:intercept-url pattern="/app/**" access="hasRole('ROLE_USER')" />
 <security:form-login login-page="/app/login" default-target-url="/app/base/" authentication-failure-url="/app/login" />
 <security:logout logout-success-url="/app/logout" />
</security:http>
<security:authentication-manager>
 <security:authentication-provider>
  <security:user-service>
   <security:user name="pallav" password="jha" authorities="ROLE_USER" />
  </security:user-service>
 </security:authentication-provider>
</security:authentication-manager>