Bug#680363: cyrus-imapd-2.2: imapd gets mad falling into endless loop

[Kiss Gabor (Bitman)]

I could create a core dump. Stack trace:

(gdb) bt
#0  0xb76f5424 in __kernel_vsyscall ()
#1  0xb71b096b in poll () from /lib/i686/cmov/libc.so.6
#2  0xb4ce4444 in ldap_int_select () from /usr/lib/libldap_r-2.4.so.2
#3  0xb4ccddbb in ldap_result () from /usr/lib/libldap_r-2.4.so.2
#4  0xb4b1191e in ?? () from /lib/libnss_ldap.so.2
#5  0xb4b11c38 in ?? () from /lib/libnss_ldap.so.2
#6  0xb4b14625 in _nss_ldap_endgrent () from /lib/libnss_ldap.so.2
#7  0xb71cf9ed in ?? () from /lib/i686/cmov/libc.so.6
#8  0xb7186d4d in endgrent () from /lib/i686/cmov/libc.so.6
#9  0x0809e55c in mynewstate (identifier=<value optimized out>) at auth_unix.c:261
#10 0x0809e104 in auth_newstate (identifier=0x8696111 "foobar") at auth.c:113
#11 0x080870a6 in mysasl_proxy_policy (conn=0x8695400, context=0x812e6a8, requested_user=0x8695d10 "foobar", rlen=6, auth_identity=0x8696111 "foobar", alen=6, def_realm=0x0, urlen=0, propctx=0x88762b8) at global.c:546
#12 0x0805c375 in imapd_proxy_policy (conn=0x8695400, context=0x812e6a8, requested_user=0x8695d10 "foobar", rlen=6, auth_identity=0x8696111 "foobar", alen=6, def_realm=0x0, urlen=0, propctx=0x88762b8) at imapd.c:371
#13 0xb76e0728 in ?? () from /usr/lib/libsasl2.so.2
#14 0xb76e132d in sasl_checkpass () from /usr/lib/libsasl2.so.2
#15 0x0805bb3d in cmd_login (tag=0x0, user=0x86c4478 "foobar") at imapd.c:1785
#16 0x0806071d in cmdloop () at imapd.c:1183
#17 0x08062da8 in service_main (argc=2, argv=0x8690008, envp=0xbfd243a0) at imapd.c:691
#18 0x0804dc61 in main (argc=2, argv=0xbfd24394, envp=0xbfd243a0) at service.c:533
(gdb) in imapd.c

The bug may be in libldap-2.4-2 or libnss-ldap packages too...
Could you give me some hints? What should I check, recompile, sniff,
debug, peek, poke ... etc?
Thanks.

Gabor