Due to a change in the authentication proxies used in the RSP deployments, the /oauth2 link previously used for logout from the Portal application is no longer valid.

Update the Portal application to change the default link to the current spec: /logout.  

While performing this modification, check for any other vestiges of the old system.

Meanwhile, since the link was already designed to be capable of being overridden at run time, Russ Allbery will modify the RSP deployments to add this override as a quick fix.