(ITS#6058) slapcat aborts on a double free

[luca@OpenLDAP.org]

Full_Name: Luca Scamoni
Version: 2.4.16
OS: Linux
URL: ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (82.63.140.131)


Slapcat on a slapd instance using rwm overlay, aborts with:
*** glibc detected *** free(): invalid pointer: 0x09ed06e3 ***

To simulate it's enough a slapd.conf containing something like

# Load dynamic backend modules:
modulepath      /usr/local/openldap/sbin
moduleload      back_hdb.la
moduleload      rwm.la

database        hdb
suffix          "dc=example,dc=com"
rootdn          "cn=Manager,dc=example,dc=com"
rootpw          secret
directory       /usr/local/openldap/var/data
index           objectClass             eq
index           entryCSN,entryUUID      eq

overlay         rwm

Simple database:

dn: dc=example,dc=com
objectClass: dcObject
objectClass: organization
dc: example
o: example.com