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openldap client GSSAPI authentication segfaults in fbgsd8-stable i386

Dear all,
I have submitted this email to freebsd-stable mailing list as well, but with no luck until now; so, I decided to share it with this list as well. The email is large, only because I have tested my setup in six different machines, and I explain my results for each one. The problem is more simple; my email subject explains it all. 

So, here is how it goes:
I am facing many instabilities in FBSD8 with openldap-client and sasl authentication (GSSAPI in particular). I have setup an openldap 2.4.1 server with gssapi support (through cyrus-sasl-2.1.23) on a fbsd8-stable amd64 latest sources, in a esxi host. In the same host I have setup two fbsd8-stable i386 clients; one has latest sources, the other one is installed via the iso-image of January's fbsd snapshot; on both systems openldap client and sasl is installed (all ldap/cyrus versions on all hosts mentioned in this email are the same). My laptop has fbsd8-i386 stable (sources 25 January 2010), and on my laptop I have setup an fbsd8-stable i386 (snapshot iso image) on a virtualbox client. Lastly, on the esxi host I have setup another fbsd8-stable amd64 system, to act as an ldap client (latest sources). 

To summarize, and put a label-number on each host, we have:

1 - esxi: fbsd8(latest) amd64 openldap server
2 - esxi: fbsd8(latest) i386 openldap client
3 - esxi: fbsd8(snapshot) i386 openldap client
4 - esxi: fbsd8(latest) amd64 openldap client
5 - laptop: fbsd8(jan 25) i386 openldap client
6 - laptop/vbox: fbsd8(snapshot) i386 openldap client
The openldap server is installed in a jail, and the client is tested in the same jail. 

Kerberos works on all machines (same /etc/krb5.conf), and ldap as well.

In all machines, line 96 of /usr/bin/krb5-config is changed to read:

lib_flags="$lib_flags -lgssapi -lgssapi_spnego -lgssapi_krb5  -lheimntlm"

instead of:
lib_flags="$lib_flags -lgssapi -lheimntlm"
which was the default, since without these lines I couldn't get gssapi authentication to work for cyrus (and spnego). This change was made after recommendations given from freebsd-stable mailing list, and I was very happy to see that after this change the ldap server worked as I expected. 

On all system, cat /usr/local/etc/openldap/ldap.conf:

BASE    dc=ee,dc=auth,dc=gr
URI ldap://ldap.ee.auth.gr
SASL_MECH    GSSAPI
without kiniting in any client I get the following outcomes when I give ldapwhoami (with no arguments): 

1:
SASL/GSSAPI authentication started
ldap_sasl_interactive_bind_s: Local error (-2)
additional info: SASL(-1): generic failure: GSSAPI Error: Miscellaneous failure (see text) (unknown mech-code 2 for mech unknown) 

which is expected.

2:
SASL/GSSAPI authentication started
Segmentation fault: 11 (core dumped)

which is not rational at all

3:
SASL/GSSAPI authentication started
Segmentation fault: 11 (core dumped)

4:
SASL/GSSAPI authentication started
ldap_sasl_interactive_bind_s: Local error (-2)
additional info: SASL(-1): generic failure: GSSAPI Error: Miscellaneous failure (see text) (unknown mech-code 2 for mech unknown) 

which is the same as 1 (as expected)

5:
SASL/GSSAPI authentication started
Segmentation fault: 11 (core dumped)

6:
SASL/GSSAPI authentication started
Segmentation fault: 11 (core dumped)

if I kinit to mamalos, ldapwhoami returns:

1:
SASL/GSSAPI authentication started
SASL username: mamalos@EE.AUTH.GR
SASL SSF: 56
SASL data security layer installed.
dn:uid=mamalos,ou=people,dc=ee,dc=auth,dc=gr

which is super!

2:
SASL/GSSAPI authentication started
Segmentation fault: 11 (core dumped)

which is dramatic.

3:
SASL/GSSAPI authentication started
Segmentation fault: 11 (core dumped)

4:
SASL/GSSAPI authentication started
ldap_sasl_interactive_bind_s: Local error (-2)
additional info: SASL(-1): generic failure: GSSAPI Error: Miscellaneous failure (see text) (unknown mech-code 2529638919 for mech unknown) 

which is very strange, since mech-code seems unnaturally large.

5:
SASL/GSSAPI authentication started
SASL username: mamalos@EE.AUTH.GR
SASL SSF: 56
SASL data security layer installed.
dn:uid=mamalos,ou=people,dc=ee,dc=auth,dc=gr
which is super, but without kinit the same command segfaulted on this machine 

6:
SASL/GSSAPI authentication started
SASL username: mamalos@EE.AUTH.GR
SASL SSF: 56
SASL data security layer installed.
dn:uid=mamalos,ou=people,dc=ee,dc=auth,dc=gr

which is the exact same behavior as 5 above.

All this means that there is no single pattern!!!!!!!

If I gdb ldapwhoami in the clients that segfault, I get:

GNU gdb 6.1.1 [FreeBSD]
Copyright 2004 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are welcome to change it and/or distribute copies of it under certain conditions. 
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for details.
This GDB was configured as "i386-marcel-freebsd"...(no debugging symbols found)... 
(gdb) run -d0
Starting program: /usr/local/bin/ldapwhoami -d0
(no debugging symbols found)...(no debugging symbols found)...(no debugging symbols found)...(no debugging symbols found)...(no debugging symbols found)...(no debugging symbols found)...(no debugging symbols found)...(no debugging symbols found)...(no debugging symbols found)...(no debugging symbols found)...(no debugging symbols found)...(no debugging symbols found)...(no debugging symbols found)...(no debugging symbols found)...(no debugging symbols found)...(no debugging symbols found)...(no debugging symbols found)...(no debugging symbols found)...(no debugging symbols found)...(no debugging symbols found)...(no debugging symbols found)...(no debugging symbols found)...(no debugging symbols found)...(no debugging symbols found)...(no debugging symbols found)...(no debugging symbols found)...(no debugging symbols found)...(no debugging symbols found)...(no debugging symbols found)...SASL/GSSAPI authentication started 

Program received signal SIGSEGV, Segmentation fault.
0x2831e187 in free () from /lib/libc.so.7
(gdb) where
#0  0x2831e187 in free () from /lib/libc.so.7
#1  0x2850fb82 in gss_release_buffer () from /usr/lib/libgssapi.so.10
#2  0x2850f552 in gss_release_name () from /usr/lib/libgssapi.so.10
#3  0x2850bea9 in gss_init_sec_context () from /usr/lib/libgssapi.so.10
#4 0x283f9abf in gssapi_client_mech_step () from /usr/local/lib/sasl2/libgssapiv2.so.2 
#5  0x280e84b1 in sasl_client_step () from /usr/local/lib/libsasl2.so.2
#6  0x28443100 in ?? ()
#7  0x00000000 in ?? ()
#8  0x00000000 in ?? ()
#9  0xbfbfe968 in ?? ()
#10 0xbfbfe954 in ?? ()
#11 0xbfbfe964 in ?? ()
#12 0x28445860 in ?? ()
#13 0x280e83fe in sasl_client_step () from /usr/local/lib/libsasl2.so.2
#14 0xbfbfe8a8 in ?? ()
#15 0x280e9135 in sasl_client_start () from /usr/local/lib/libsasl2.so.2
#16 0x00000000 in ?? ()
#17 0x00000000 in ?? ()
#18 0xbfbfe968 in ?? ()
#19 0xbfbfe954 in ?? ()
#20 0xbfbfe964 in ?? ()
#21 0xd7a3b2da in ?? ()
#22 0x283abad8 in ?? () from /lib/libc.so.7
#23 0x00000000 in ?? ()
#24 0x283ab730 in __stderrp () from /lib/libc.so.7
#25 0xbfbfe878 in ?? ()
#26 0x2838c764 in vfprintf () from /lib/libc.so.7
Previous frame inner to this frame (corrupt stack?)
I built openldap and cyrus-sasl on this machine from sources (not ports), and (after a long time of trying to find out how to run configure successfully in both installations) the outcome was exactly the same (meaning segfaults). So, one of my admins wrote a c program that overrides gss_release_buffer returning always 0 (what is expected after normal operation) and compiled it as a library. The program code is nothing more than just: 

int gss_release_buffer(void *a, void *b) {
  return 0;
}

we ld_preloaded the library, and when we ran ldapwhoami the outcome was:
SASL/GSSAPI authentication started
ldap_sasl_interactive_bind_s: Local error (-2)
additional info: SASL(-1): generic failure: GSSAPI Error: Miscellaneous failure (see text) (unknown mech-code 2529638919 for mech unknown) 

When we ran it with no kerberos tickets, we got:

SASL/GSSAPI authentication started
ldap_sasl_interactive_bind_s: Local error (-2)
additional info: SASL(-1): generic failure: GSSAPI Error: Miscellaneous failure (see text) (unknown mech-code 2 for mech unknown)
The exact same errors as the aforementioned client 4 (esxi, amd64)!!!!!!!!!!!!! 

What on earth is happening?!?!!?!?!
Now one can easily see that there is a definite problem regarding memory freeing, and after overcoming that the mech-code 2529638919 implies that some segment in memory is overwritten by some "random" value, so mech-code returns the number 2529638919 instead of a number of marginality 1.
What is more definite, is that openldap doesn't work out-of-the-box if gssapi support is required, and behaves randomly in different architectures/virtualHosts/platforms.
The problem may have been something related to line 96 in /usr/bin/krb5-config... I don't know.
What is sure, is that I am having second thoughts on using fbsd as my openldap/heimdal server for my setup, which would be quite disappointing for me, since I am using fbsd for the last many-many years, on all my laptops and servers. The only "good part" is that the only machine that works seamlessly (until now, at least) is the heimdal/ldap server.
Thank you all in advance and I hope that we will find an answer to all this. 

--
George Mamalakis

IT Officer
Electrical and Computer Engineer (Aristotle Un. of Thessaloniki),
MSc (Imperial College of London)

Department of Electrical and Computer Engineering
Faculty of Engineering
Aristotle University of Thessaloniki

phone number : +30 (2310) 994379