(ITS#6478) slapd crashes with segfault

[wolfgang.hummel@hp.com]

Full_Name: Wolfgang Hummel
Version: 2.4.21
OS: RedHat Linux 5.1
URL: ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (15.203.233.80)


OpenLdap crashes occasionally with a segfault error, e.g.
[root@ts2mstsv010 Ldap]# dmesg|grep slapd
slapd[8783]: segfault at 00000000000000f0 rip 0000000000459b72 rsp
000000004286e990 error 4
[root@ts2mstsv010 Ldap]#
After the crash, stale lock files exist, slapd_db_recover has to be run
The server is HP D380 G5 with Intel Quadcore CPU @ 2 GHz
32 GB memory
OS is Linux Redhat 64bit 5.1
Oracle Berkeley DB is 4.7 
The server has 5 DBs. The whole setup has a second master in identical config
with multi-master replication and 2 slaves.
The 2 main DBs have 30 Mio. entries each, the other dbs are very small.