openldap 2.4.7 Segfault when deleting olcAccess parameter from cn=config

[Faraz Khan <faraz.khan@emergen.biz>]

When trying to delete a single olcAccess attribute from cn=config the  
openldap server crashes. The client library (php) returns error code  
-1 (cant contact LDAP Server) and the openldap server crashes.

The delete operation is:

dn: olcDatabase={2}bdb,cn=config
changetype: modify
delete: olcAccess
olcAccess: 2


This behavior is not consistent. Sometimes the server crashes while  
sometimes it will report back :

modifying entry "olcDatabase={2}bdb,cn=config"
ldap_modify: No such attribute (16)

It might continue to say Error 19 for a while (3-4 times) and on the  
5th time the operation completes successfully. However, the dn at this  
time seems to contain NO entries. After this slapd crashes. Restarting  
will show that the operation was never ACTUALLY completed. The  
segfault trace is:


ber_dump: buf=0x82c1ef0 ptr=0x82c1ef3 end=0x82c1f2c len=57
  0000:  66 37 04 1c 6f 6c 63 64  61 74 61 62 61 73 65 3d   f7..olcdatabase=
  0010:  7b 32 7d 62 64 62 2c 63  6e 3d 63 6f 6e 66 69 67   {2}bdb,cn=config
  0020:  30 17 30 15 0a 01 01 30  10 04 09 6f 6c 63 61 63   0.0....0...olcac
  0030:  63 65 73 73 31 03 04 01  32                        cess1...2
conn=0 op=3 do_modify: dn (olcdatabase={2}bdb,cn=config)
ber_scanf fmt ({e{m[W]}}) ber:
ber_dump: buf=0x82c1ef0 ptr=0x82c1f15 end=0x82c1f2c len=23
  0000:  30 15 0a 01 01 30 10 04  09 6f 6c 63 61 63 63 65   0....0...olcacce
  0010:  73 73 31 03 04 01 32                               ss1...2
> > > dnPrettyNormal: <olcdatabase={2}bdb,cn=config>
=> ldap_bv2dn(olcdatabase={2}bdb,cn=config,0)
<= ldap_bv2dn(olcdatabase={2}bdb,cn=config)=0
=> ldap_dn2bv(272)
<= ldap_dn2bv(olcDatabase={2}bdb,cn=config)=0
=> ldap_dn2bv(272)
<= ldap_dn2bv(olcDatabase={2}bdb,cn=config)=0
<<< dnPrettyNormal: <olcDatabase={2}bdb,cn=config>,  
<olcDatabase={2}bdb,cn=config>
conn=0 op=3 modifications:
        delete: olcaccess
                one value, length 1
conn=0 op=3 MOD dn="olcDatabase={2}bdb,cn=config"
conn=0 op=3 MOD attr=olcaccess
<= acl_access_allowed: granted to database root
Segmentation fault



--
Faraz R Khan
Chief Architect
Emergen Consulting Pvt Ltd
www.emergen.biz