Description of problem:

When using the ss binary from the iproute package on a machine with ipv6 disabled, ss segfaults.

Version-Release number of selected component (if applicable):

iproute-2.6.18-10.el5

How reproducible:

Always

Steps to Reproduce:

[root@localhost ~]# ss
State      Recv-Q Send-Q      Local Address:Port          Peer Address:Port   
Segmentation fault
[root@localhost ~]# strace ss
execve("/usr/sbin/ss", ["ss"], [/* 17 vars */]) = 0
brk(0)                                  = 0x856b000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY)      = 3

[...]
close(4)                                = 0
open("/proc/net/tcp6", O_RDONLY)        = -1 ENOENT (No such file or directory)
--- SIGSEGV (Segmentation fault) @ 0 (0) ---
+++ killed by SIGSEGV +++

[root@localhost ~]# rm /etc/modprobe.d/disable-ipv6 && modprobe ipv6
[root@localhost ~]# ss
State      Recv-Q Send-Q      Local Address:Port          Peer Address:Port   
[root@localhost ~]# exit

Actual results:

ss segfaults

Expected results:

ss does not segfault