bt full
#0  0x00007ffff64281d7 in __GI_raise (sig=sig@entry=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:56
        resultvar = 0
        pid = 13520
        selftid = 13526
#1  0x00007ffff64298c8 in __GI_abort () at abort.c:90
        save_stage = 2
        act = {__sigaction_handler = {sa_handler = 0x7fffffffe4f4, sa_sigaction = 0x7fffffffe4f4}, sa_mask = {__val = {140737326281904, 6593057, 224, 140737415839745, 140737324919459, 4,
              140737276347392, 51069858384, 140737018606174, 140737018606174, 0, 0, 0, 21474836480, 140737354104832, 140737326293928}}, sa_flags = 6593208,
          sa_restorer = 0x649be6 <__PRETTY_FUNCTION__.6214>}
        sigs = {__val = {32, 0 <repeats 15 times>}}
#2  0x00007ffff6421146 in __assert_fail_base (fmt=0x7ffff65723a8 "%s%s%s:%u: %s%sAssertion `%s' failed.\n%n", assertion=assertion@entry=0x649ab8 "( (sb)->sb_opts.lbo_valid == 0x3 )",
    file=file@entry=0x649a21 "io.c", line=line@entry=224, function=function@entry=0x649be6 <__PRETTY_FUNCTION__.6214> "ber_flush2") at assert.c:92
        str = 0x7fffe4116f70 ""
        total = 4096
#3  0x00007ffff64211f2 in __GI___assert_fail (assertion=assertion@entry=0x649ab8 "( (sb)->sb_opts.lbo_valid == 0x3 )", file=file@entry=0x649a21 "io.c", line=line@entry=224,
    function=function@entry=0x649be6 <__PRETTY_FUNCTION__.6214> "ber_flush2") at assert.c:101
No locals.
#4  0x00000000005b95d8 in ber_flush2 (sb=0x7fffe40000d8, ber=0x7fffe4119d40, freeit=freeit@entry=0) at io.c:224
        towrite = <optimized out>
        rc = <optimized out>
        __PRETTY_FUNCTION__ = "ber_flush2"
#5  0x00000000005a3491 in ldap_int_flush_request (ld=ld@entry=0x7fffe8102800, lr=lr@entry=0x7fffe410d570) at request.c:186
        lc = 0x7fffe4116f70
#6  0x00000000005a38fa in ldap_send_server_request (ld=ld@entry=0x7fffe8102800, ber=ber@entry=0x7fffe4119d40, msgid=msgid@entry=134, parentreq=parentreq@entry=0x0, srvlist=srvlist@entry=0x0,
    lc=0x7fffe4116f70, lc@entry=0x0, bind=bind@entry=0x0, m_noconn=m_noconn@entry=0, m_res=m_res@entry=0) at request.c:408
        lr = 0x7fffe410d570
        incparent = 0
        rc = 0
#7  0x00000000005a3aa8 in ldap_send_initial_request (ld=ld@entry=0x7fffe8102800, msgtype=msgtype@entry=99, dn=dn@entry=0x7fffe4002e48 "dc=corp,dc=de", ber=0x7fffe4119d40, msgid=134)
    at request.c:169
        rc = 1
        sd = 14
#8  0x00000000005946e4 in ldap_pvt_search (ld=0x7fffe8102800, base=0x7fffe4002e48 "dc=corp,dc=de", scope=2,
    filter=filter@entry=0x7fffe40031a8 "(&(objectClass=group)(gidNumber=20000)(&(OBJECTCATEGORY=group)(gidNumber=*)))", attrs=attrs@entry=0x7fffe4003170, attrsonly=0, sctrls=0x0,
    cctrls=cctrls@entry=0x0, timeout=0x7ffff35d07f0, sizelimit=1, deref=0, msgidp=msgidp@entry=0x7ffff35d07cc) at search.c:128
        rc = <optimized out>
        ber = <optimized out>
        timelimit = <optimized out>
        id = 134
        __PRETTY_FUNCTION__ = "ldap_pvt_search"
#9  0x00000000004c902d in ldap_back_search (op=0x7fffe40028e0, rs=<optimized out>) at search.c:233
        li = <optimized out>
        lc = 0x7fffe8000e40
        tv = {tv_sec = 10, tv_usec = 0}
        stoptime = 1494840996
        res = 0x7ffff67ac740 <_IO_str_jumps>
        e = <optimized out>
        rc = <optimized out>
        msgid = 0
        match = {bv_len = 0, bv_val = 0x0}
        filter = {bv_len = 77, bv_val = 0x7fffe40031a8 "(&(objectClass=group)(gidNumber=20000)(&(OBJECTCATEGORY=group)(gidNumber=*)))"}
        i = <optimized out>
        x = <optimized out>
        attrs = <optimized out>
        freetext = 0
        filter_undef = 1
        do_retry = 1
        dont_retry = 0
        ctrls = 0x0
        references = 0x0
        __PRETTY_FUNCTION__ = "ldap_back_search"
#10 0x0000000000442f41 in fe_op_search (op=0x7fffe40028e0, rs=0x7ffff35d19a0) at search.c:402
        bd = 0x894240 <slap_frontendDB>
#11 0x0000000000442926 in do_search (op=0x7fffe40028e0, rs=0x7ffff35d19a0) at search.c:247
        base = {bv_len = 13, bv_val = 0x7fffe4119288 "dc=corp,dc=de"}
        siz = 5
---Type <return> to continue, or q <return> to quit---
        off = 0
        i = <optimized out>
#12 0x00000000004407de in connection_operation (ctx=ctx@entry=0x7ffff35d1ad0, arg_v=arg_v@entry=0x7fffe40028e0) at connection.c:1158
        rc = 80
        cancel = <optimized out>
        op = 0x7fffe40028e0
        rs = {sr_type = REP_RESULT, sr_tag = 0, sr_msgid = 0, sr_err = -7, sr_matched = 0x0, sr_text = 0x0, sr_ref = 0x0, sr_ctrls = 0x0, sr_un = {sru_search = {r_entry = 0x0, r_attr_flags = 0,
              r_operational_attrs = 0x0, r_attrs = 0x0, r_nentries = 0, r_v2ref = 0x0}, sru_sasl = {r_sasldata = 0x0}, sru_extended = {r_rspoid = 0x0, r_rspdata = 0x0}}, sr_flags = 0}
        tag = 99
        opidx = SLAP_OP_SEARCH
        conn = 0x7ffff7f3a3d0
        memctx = 0x7fffe4000a80
        memctx_null = 0x0
        memsiz = 1048576
        __PRETTY_FUNCTION__ = "connection_operation"
#13 0x0000000000440aba in connection_read_thread (ctx=0x7ffff35d1ad0, argv=0xd) at connection.c:1294
        rc = <optimized out>
        cri = {op = 0x7fffe40028e0, func = 0x0, arg = 0x0, ctx = <optimized out>, nullop = <optimized out>}
        s = <optimized out>
#14 0x00000000005901c9 in ldap_int_thread_pool_wrapper (xpool=0x969360) at tpool.c:696
        pool = 0x969360
        task = 0x7fffec0008c0
        work_list = <optimized out>
        ctx = {ltu_id = 140737276356352, ltu_key = {{ltk_key = 0x43ece0 <conn_counter_init>, ltk_data = 0x7fffe4002730, ltk_free = 0x43eda0 <conn_counter_destroy>}, {
              ltk_key = 0x490c70 <slap_sl_mem_init>, ltk_data = 0x7fffe4000a80, ltk_free = 0x490b30 <slap_sl_mem_destroy>}, {ltk_key = 0x452e10 <slap_op_free>, ltk_data = 0x0,
              ltk_free = 0x452d70 <slap_op_q_destroy>}, {ltk_key = 0x0, ltk_data = 0x0, ltk_free = 0x0} <repeats 26 times>, {ltk_key = 0x0, ltk_data = 0x7ffff7897c4c <_L_unlock_3056+19>,
              ltk_free = 0x0}, {ltk_key = 0x0, ltk_data = 0x0, ltk_free = 0x0}, {ltk_key = 0x0, ltk_data = 0x0, ltk_free = 0x0}}}
        kctx = <optimized out>
        keyslot = 885
        hash = <optimized out>
        __PRETTY_FUNCTION__ = "ldap_int_thread_pool_wrapper"
#15 0x00007ffff7896dc5 in start_thread (arg=0x7ffff35d2700) at pthread_create.c:308
        __res = <optimized out>
        pd = 0x7ffff35d2700
        now = <optimized out>
        unwind_buf = {cancel_jmp_buf = {{jmp_buf = {140737276356352, -5529735075147983962, 1, 140737276357056, 140737276356352, 9699936, 5529727121998042022, 5529716852215993254},
              mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x0, 0x0}, data = {prev = 0x0, cleanup = 0x0, canceltype = 0}}}
        not_first_call = <optimized out>
        pagesize_m1 = <optimized out>
        sp = <optimized out>
        freesize = <optimized out>
#16 0x00007ffff64ea73d in clone