Red Hat IdM (IPA) server's LDAP service down with ns-slapd segfault after upgrade from RHEL 6.5 to RHEL 6.6

Issue

After upgrading from RHEL6.5 to RHEL6.6, the Red Hat IdM (IPA)'s LDAP service fails with following system log messages:

Oct 20 17:05:29 ipaserver1 kernel: ns-slapd[7119] general protection ip:7fb13bb6da23 sp:7fb1157f5f60 error:0 in libslapd.so.0.0.0[7fb13baef000+fd000]

Or

Oct 20 18:20:06 ipaserver1 kernel: ns-slapd[8496]: segfault at 0 ip 00007f49dc219572 sp 00007f49baff1f20 error 4 in libslapd.so.0.0.0[7f49dc1d4000+fd000]

There are no related errors in the embedded LDAP srever ( /var/log/dirsrv/slapd-ipaserver1/errors). The LDAP service comes up and seems to be available to login via kinit and via the web interface for a short while, then the ns-slapd process dies and leaves the pid file.