(gdb) bt
#0  0xb7f65410 in __kernel_vsyscall ()
#1  0x4f75a7d5 in raise () from /lib/tls/libc.so.6
#2  0x4f75c149 in abort () from /lib/tls/libc.so.6
#3  0x4f78e40a in __libc_message () from /lib/tls/libc.so.6
#4  0x4f79551c in _int_malloc () from /lib/tls/libc.so.6
#5  0x4f796f81 in malloc () from /lib/tls/libc.so.6
#6  0xb7cc1b99 in iks_malloc (size=312) at utility.c:21
#7  0xb7cc7ab4 in iks_base64_encode (buf=0xfffffff0 <Address 0xfffffff0 out of
bounds>, 
    len=0) at base64.c:69
#8  0xb7cc54aa in tagHook (data=0x819eb5c, name=0x8193a50 "challenge", atts=0x0,
type=1)
    at stream.c:213
#9  0xb7cc336e in iks_parse (prs=0x819eb9c, 
    data=0x81a7748 "<challenge
xmlns=\"urn:ietf:params:xml:ns:xmpp-sasl\">cmVhbG09InNydi1jb211bmlmaWVlIixub25jZT0iV0pOSkJIcmVYSkNXYU14MWQrK1lLK1g2ay9LS1hsOENhT25iNERjUiIscW9wPSJhdXRoIixjaGFyc2V0PXV0Zi04LGFsZ29yaXRobT1tZDUt"...,
len=220, finish=0) at sax.c:323
#10 0xb7cc4a84 in iks_recv (prs=0x819eb9c, timeout=1) at stream.c:465
#11 0xb7cdbc3e in aji_recv_loop (data=0x819e6e8) at res_jabber.c:1510
#12 0x080fa241 in dummy_start (data=0x819dce0) at utils.c:545
#13 0x4f8a1341 in start_thread () from /lib/tls/libpthread.so.0
#14 0x4f7fa6fe in clone () from /lib/tls/libc.so.6