Illegal Instruction CentOS 6 Bug Fix

When updating yum or trying to install new packages or regular updates on a CentOS 6 system, you may run into an error like the following:

root@server [~]# yum update
Freeing read locks for locker 0x5: 425388/140510239045376
Freeing read locks for locker 0x7: 425388/140510239045376
Freeing read locks for locker 0x8: 425388/140510239045376
Freeing read locks for locker 0x15: 425388/140510239045376
Freeing read locks for locker 0x17: 425388/140510239045376
Loaded plugins: fastestmirror, rhnplugin
Setting up Update Process
Determining fastest mirrors
Illegal instruction

This is likely caused by a known bug in the nss-softokn package as described here: https://bugs.centos.org/view.php?id=10930

To resolve this, simply run the following command:

export NSS_DISABLE_HW_AES=1; yum upgrade

Once you have updated that package as part of the yum upgrade, the bug will be patched and you won't see it again.