[dovecot/core] c67082: login proxy: Hanging outgoing SSL connections caus...

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/dovecot/core
  Commit: c67082dca6eda730c2bb07cdef242b1b8ee09929
      https://github.com/dovecot/core/commit/c67082dca6eda730c2bb07cdef242b1b8ee09929
  Author: Timo Sirainen <timo.sirainen at dovecot.fi>
  Date:   2016-10-20 (Thu, 20 Oct 2016)

  Changed paths:
    M src/login-common/login-proxy.c

  Log Message:
  -----------
  login proxy: Hanging outgoing SSL connections caused using already-freed memory

This mainly happened when login proxy closed the connection due to connect
timeout. The ssl-proxy still had a reference and existed for a longer time.
If SSL handshake still succeeded afterwards, it now called
login_proxy_ssl_handshaked(), which accessed the already-freed proxy and
likely crashed.

Fixed the ssl-client proxy code specifically. Alternatively ssl_proxy_free()
could be calling ssl_proxy_destroy() always, but since ssl-server side of
the code seems to have been working fine, I don't want to accidentally
break it.