mongos always crash

[ocean-feng]

mongos Log:
Thu Feb 26 08:14:39.941 [mongosMain] connection accepted from 10.40.146.143:35420 #318154 (16 connections now open)
Received signal 11
Backtrace:

Mongos log show nothing about this crash.
Use the gdb to get the backtrace.
(gdb) bt
#0 0x00007fc255e8cc42 in backtrace () from /lib64/libc.so.6
#1 0x00000000008c6500 in mongo::printStackAndExit(int) ()
#2
#3 0x00007fc255e17abb in memcpy () from /lib64/libc.so.6
#4 0x00007fc256657b93 in std::basic_streambuf<char, std::char_traits >::xsgetn(char*, long) () from /usr/lib64/libstdc++.so.6
#5 0x00007fc25662e5ef in std::basic_filebuf<char, std::char_traits >::xsgetn(char*, long) () from /usr/lib64/libstdc++.so.6
#6 0x00007fc2566354a3 in std::basic_istream<char, std::char_traits >::read(char*, long) () from /usr/lib64/libstdc++.so.6
#7 0x0000000000c423d9 in mongo::InputStreamSecureRandom::nextInt64() ()
#8 0x0000000000000000 in ?? ()

Anybody know this crash?

tokumx version: tokumx-server-1.5.0-1.el6.x86_64.rpm