#0  0x0807a972 in ast_channel_alloc (needqueue=0, state=1, cid_num=0x0, cid_name=0x0,
    acctcode=0xa13e150 "Zap/pseudo-1237072490", exten=0x154918d0 <Address 0x154918d0 out of bounds>, 
    context=0x9b50742 <Address 0x9b50742 out of bounds>, amaflag=90, name_fmt=0x1 <Address 0x1 out of bounds>) at strings.h:35
35              return (!s || (*s == '\0'));
(gdb) bt
#0  0x0807a972 in ast_channel_alloc (needqueue=0, state=1, cid_num=0x0, cid_name=0x0, 
    acctcode=0xa13e150 "Zap/pseudo-1237072490", exten=0x154918d0 <Address 0x154918d0 out of bounds>, 
    context=0x9b50742 <Address 0x9b50742 out of bounds>, amaflag=90, name_fmt=0x1 <Address 0x1 out of bounds>) at strings.h:35
#1  0xb73eb0a7 in zt_new (i=0xa159e08, state=1, startpbx=0, index=0, law=0, transfercapability=0) at chan_zap.c:5173
#2  0xb73fdfce in zt_request (type=0xb72126e4 "zap", format=64, data=0xb72126dd, cause=0xb6bddf90) at chan_zap.c:7815
#3  0x08081c72 in ast_request (type=0xb72126e4 "zap", format=64, data=0xb72126dd, cause=0xb6bddf90) at channel.c:3134
#4  0xb72033b9 in build_conf (confno=0xb6bde040 "1101", pin=0xb7212d28 "", pinadmin=0xb7212d28 "", make=1, dynamic=0, refcount=1)
    at app_meetme.c:756
#5  0xb72091c9 in find_conf (chan=0xa1672f0, confno=0xb6bde290 "1101", make=1, dynamic=0, dynamic_pin=0xb6bde210 "", 
    pin_buf_len=80, refcount=1, confflags=0xb6bde280) at strings.h:34
#6  0xb720a01e in conf_exec (chan=0xa1672f0, data=0xb6bde5ec) at app_meetme.c:2622
#7  0x080b5e33 in pbx_exec (c=0xa1672f0, app=0xa0a9620, data=0xb6bde5ec) at pbx.c:532
#8  0xb7cd53bd in handle_exec (chan=0xa1672f0, agi=0xb6bdee50, argc=3, argv=0xb6bde390) at res_agi.c:1116
#9  0xb7cd6500 in agi_handle_command (chan=0xa1672f0, agi=0xb6bdee50, buf=0xb6bde5e0 "EXEC") at res_agi.c:1812
#10 0xb7cd68da in run_agi (chan=0xa1672f0, request=0xb6bdee80 "inbound_call.php", agi=0xb6bdee50, pid=11845, status=0xb6bdee4c, 
    dead=0) at res_agi.c:1894
#11 0xb7cd7019 in agi_exec_full (chan=0xa1672f0, data=0xb6be3aa0, enhanced=0, dead=0) at res_agi.c:2038
#12 0xb7cd719c in agi_exec (chan=0xa1672f0, data=0xb6be3aa0) at res_agi.c:2069
#13 0x080b5e33 in pbx_exec (c=0xa1672f0, app=0x9ff35e8, data=0xb6be3aa0) at pbx.c:532
#14 0x080b9079 in pbx_extension_helper (c=0xa1672f0, con=0x0, context=0xa167470 "inbound_new", exten=0xa1674c0 "s", priority=5, 
    label=0x0, callerid=0xa140308 "NET24_E", action=E_SPAWN) at pbx.c:1833
#15 0x080ba13b in ast_spawn_extension (c=0xa1672f0, context=0xa167470 "inbound_new", exten=0xa1674c0 "s", priority=5, 
    callerid=0xa140308 "NET24_E") at pbx.c:2288
#16 0x080ba629 in __ast_pbx_run (c=0xa1672f0) at pbx.c:2388
#17 0x080bb326 in pbx_thread (data=0xa1672f0) at pbx.c:2601
#18 0x080f3665 in dummy_start (data=0xa0ac0f8) at utils.c:545
#19 0xb7f39ce1 in pthread_start_thread () from /lib/i686/libpthread.so.0
#20 0xb7eacd3a in clone () from /lib/i686/libc.so.6
(gdb) bt full
#0  0x0807a972 in ast_channel_alloc (needqueue=0, state=1, cid_num=0x0, cid_name=0x0, 
    acctcode=0xa13e150 "Zap/pseudo-1237072490", exten=0x154918d0 <Address 0x154918d0 out of bounds>, 
    context=0x9b50742 <Address 0x9b50742 out of bounds>, amaflag=90, name_fmt=0x1 <Address 0x1 out of bounds>) at strings.h:35
        tmp = (struct ast_channel *) 0xa176780
        x = 6
        flags = 1
        headp = (struct varshead *) 0xb7e2974b
        ap1 = 0xb6bddca8 "¸Ý½¶§°>·"
        ap2 = 0x1 <Address 0x1 out of bounds>
        __PRETTY_FUNCTION__ = "ast_channel_alloc"
#1  0xb73eb0a7 in zt_new (i=0xa159e08, state=1, startpbx=0, index=0, law=0, transfercapability=0) at chan_zap.c:5173
        tmp = Variable "tmp" is not available.
(gdb) thread apply all bt

Thread 43 (process 11503):
#0  0x00000296 in ?? ()
Cannot access memory at address 0x0
0x0807a972      35              return (!s || (*s == '\0'));