[Dovecot] dovecot cores

[dovecot at freakout.de]

Hi dovecot-community,

i have set up a new dovecot server - everything is self-compiled
and with newest versions. dovecot daemon dies every night:

Bugreport Mail - dovecot cores with sig11

my dovecot daemon cores every night - no message in log file.
Please help. It runs in an OpenVZ container - therefore reiserfs
is reported as filesystem.

root at glen ~]# cat /etc/dovecot/dovecot.conf
# 2.1.10: /etc/dovecot/dovecot.conf
# OS: Linux 2.6.18-308.8.2.el5.028stab101.1PAE i686 CentOS release 5.8 (Final) reiserfs
auth_mechanisms = plain login cram-md5 apop
default_login_user = nobody
disable_plaintext_auth = no
first_valid_uid = 300
listen = *
mail_gid = 332
mail_home = /var/dovecot
mail_location = maildir:/var/spool/mail/virtual/%d/%n
mail_plugins = quota
mail_uid = 332
passdb {
  driver = sql
  args = /etc/dovecot/sql.conf
}
plugin {
  quota = maildir:User quota
}
protocols = imap pop3
ssl_cert = </etc/exim/glen.ypack.de.pem
ssl_key = </etc/exim/glen.ypack.de.key
userdb {
  driver = prefetch
}
userdb {
  driver = sql
  args = /etc/dovecot/sql.conf
}
protocol pop3 {
  pop3_client_workarounds = outlook-no-nuls oe-ns-eoh
  pop3_enable_last = yes
  pop3_uidl_format = %08Xu%08Xv
}
protocol imap {
  imap_client_workarounds = delay-newmail
  mail_plugins = quota imap_quota
}

root at glen ~]# cat /etc/dovecot/sql.conf
driver = mysql
connect = host=much dbname=toarx user=exim password=xxxxxxxx
default_pass_scheme = PLAIN
password_query = select login as username, password, dbuser_uid, dbuser_gid, dbuser_home, dbuser_mail, userdb_quota_rule from vusers where email = '%u'
user_query = select login as username, password, dbuser_uid, dbuser_gid, dbuser_home, dbuser_mail, userdb_quota_rule from vusers where email = '%u'
iterate_query = select email as user from vusers where user != 'odmr'

root at glen run]# gdb /opt/dovecot/sbin/dovecot /var/dovecot/run/core.20049
GNU gdb (GDB) CentOS (7.0.1-42.el5.centos.1)
Copyright (C) 2009 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "i386-redhat-linux-gnu".
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>...
Reading symbols from /opt/dovecot-2.1.10-3/sbin/dovecot...(no debugging symbols found)...done.
 [New Thread 20049]
Reading symbols from /opt/mysql/lib/libmysqlclient.so.18...done.
Loaded symbols for /opt/mysql/lib/libmysqlclient.so.18
Reading symbols from /opt/dovecot/lib/libdovecot.so.0...done.
Loaded symbols for /opt/dovecot/lib/libdovecot.so.0
Reading symbols from /lib/libgcc_s.so.1...(no debugging symbols found)...done.
Loaded symbols for /lib/libgcc_s.so.1
Reading symbols from /lib/libc.so.6...(no debugging symbols found)...done.
Loaded symbols for /lib/libc.so.6
Reading symbols from /opt/mysql/lib/libstrings.so...done.
Loaded symbols for /opt/mysql/lib/libstrings.so
Reading symbols from /opt/zlib/lib/libz.so.1...(no debugging symbols found)...done.
Loaded symbols for /opt/zlib/lib/libz.so.1
Reading symbols from /lib/libdl.so.2...(no debugging symbols found)...done.
Loaded symbols for /lib/libdl.so.2
Reading symbols from /lib/libpthread.so.0...(no debugging symbols found)...done.
 [Thread debugging using libthread_db enabled]
Loaded symbols for /lib/libpthread.so.0
Reading symbols from /lib/libm.so.6...(no debugging symbols found)...done.
Loaded symbols for /lib/libm.so.6
Reading symbols from /opt/ssp/lib/libssp.so.0...done.
Loaded symbols for /opt/ssp/lib/libssp.so.0
Reading symbols from /lib/ld-linux.so.2...(no debugging symbols found)...done.
Loaded symbols for /lib/ld-linux.so.2
Reading symbols from /lib/libnss_files.so.2...(no debugging symbols found)...done.
Loaded symbols for /lib/libnss_files.so.2
Core was generated by `/opt/dovecot/sbin/dovecot'.
Program terminated with signal 11, Segmentation fault.
#0  0xb7f95fe4 in str_to_time () from /opt/mysql/lib/libmysqlclient.so.18
(gdb) bt
#0  0xb7f95fe4 in str_to_time () from /opt/mysql/lib/libmysqlclient.so.18
#1  0xb7f131c0 in master_instance_list_add_line (list=0x9d48880, line=0x9d540c8 "1349762052\tdovecot\t/var/dovecot/run\t")
    at master-instance.c:85
#2  0xb7f1331f in master_instance_list_refresh (list=0x9d48880) at master-instance.c:115
#3  0xb7f13620 in master_instance_write_init (list=0x9d48880, dotlock_r=0xbff6fb60) at master-instance.c:173
#4  0xb7f1390d in master_instance_list_set_name (list=0x9d48880, base_dir=0x8055300 "/var/dovecot/run", name=0x8055323 "dovecot")
    at master-instance.c:252
#5  0x0804c347 in net_accept () at network.c:502
#6  0xb7f3255b in io_loop_handle_timeouts_real (ioloop=0x9d465b0) at ioloop.c:354
#7  0xb7f325de in io_loop_handle_timeouts (ioloop=0x9d465b0) at ioloop.c:367
#8  0xb7f338b6 in io_loop_handler_run (ioloop=0x9d465b0) at ioloop-poll.c:171
#9  0xb7f326d3 in io_loop_run (ioloop=0x9d465b0) at ioloop.c:398
#10 0xb7f17304 in master_service_run (service=0x9d464e0, callback=0) at master-service.c:543
#11 0x0804d375 in net_accept () at network.c:502
#12 0xb7d84e9c in __libc_start_main () from /lib/libc.so.6
#13 0x0804b501 in net_accept () at network.c:502
(gdb) q

Regards
Axel