Due to legacy reasons, I have to use GET for my LogOutFilter and XML config. The below works. Note I don't recommend working around the csrf protection but I've had to.
This might help others.
<b:bean id="logoutFilter" class="org.springframework.security.web.authentication.logout.LogoutFilter">
<b:constructor-arg name="logoutSuccessUrl" value="/loggedOut" />
<b:constructor-arg name="handlers">
<b:list>
<b:bean class="org.springframework.security.web.authentication.logout.SecurityContextLogoutHandler"/>
</b:list>
</b:constructor-arg>
<b:property name="logoutRequestMatcher">
<b:bean class="org.springframework.security.web.util.matcher.AntPathRequestMatcher">
<b:constructor-arg name="pattern" value="/logout*"/>
<b:constructor-arg name="httpMethod" value="GET"/>
</b:bean>
</b:property>
</b:bean>
Remember to put the custom filter in the element
<custom-filter before="CSRF_FILTER" ref="logoutFilter" />
The key thing here is that you register your own logoutRequestMatcher