[1.6.8] zabbix_agentd crashes - Red Hat 5.5 / LDAP

[NOB]

Hi

we can reproduce a crash of the zabbix_agentd on newly installed
RedHat 5.5 systems with LDAP authentication enabled and used.
The error message is Segmentation fault. I am not sure
whether the code in src/zbxnix/daemon.c was changed for 1.8.x or not.
A 1.6.8 zabbix_proxy on the same server executing the same daemon code
works fine, though !

According to our experiments and analysis the cause of the problem does
not seem to be the zabbix_agentd but the OS or its configuration wrt. LDAP.
I am no LDAP nor PAM expert, so I can't tell. The zabbix user is a local
user and belongs to a local group.

The agent crashes only, if started by user root and therefore it changes
internally to user zabbix.
If started by a normal user, this part of the code in daemon.c is not
executed.

The backtrace (see attached file) suggests, that the OS is accessing LDAP
regardless whether the user is local or not. The crash happens in initgroups()
and the subroutines called by it.

I checked the parameters to the initgroups call which the zabbix_agentd provides and everything is OK: user: zabbix, gid: 508.

Our workaround is to start the zabbix_agentd in the init script directly
as user zabbix (via su). And this works fine.
We don't experience those problems with 1.6.8 agents running on previous versions of RedHat
OS, i.e. 5,4, 5.3 or 4.x where LDAP is configured and used.

I hope this helps others to avoid some experiments.

Best regards

Norbert.

[NOB]

Solved !

Hi

solved: don't use static linking !

Using the option --enable-static for configure seems to be the culprit for
this crash.
Still don't know, exactly why, though.

HTH,

Norbert.

[neil]

static link libraries flag not recommended?

The 1.8 installation from source in manual indicates this flag must be added to build the agent from source once to copy easily to all other similar machines.

I used 1.9.5 source, added the flag to statically link, made and got the same "Segmentation Fault" after starting as root in /opt/zabbix-agent/zabbix-1.9.5/src/zabbix_agentd

How else to build from source where goal is to redistribute to same-architecture machines?

As a note, I did get plenty of (I ignored because I didn't understand implications and I am lame - even after googling):
../../src/libs/zbxcomms/libzbxcomms.a(comms.o): In function `zbx_gethost_by_ip':
/opt/zabbix-agent/zabbix-1.9.5/src/libs/zbxcomms/comms.c:125: warning: Using 'gethostbyaddr' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking