Can someone shed some more light on the stability issues that this update 
addresses?  Is there a way to tell if a machine is having these problems? I had 
just updated my servers and would rather not have to do it again so soon.

thanks,

Steve Gaarder
System Administrator, Dept of Mathematics
Cornell University, Ithaca, NY, USA
[log in to unmask]

On Wed, 17 Jan 2018, Pat Riehecky wrote:

>  Synopsis:          Important: microcode_ctl security update
>  Advisory ID:       SLSA-2018:0093-1
>  Issue Date:        2018-01-16
>  CVE Numbers:       CVE-2017-5715
>  --
>
>  This update supersedes the previous microcode update provided with the
>  CVE-2017-5715 (Spectre) CPU branch injection vulnerability mitigation.
>  Further testing has uncovered problems with the microcode provided along
>  with the Spectre mitigation that could lead to system instabilities.
>
>  As a result, this microcode update reverts to the last known good
>  microcode version dated before 03 January 2018.
>
>  You should contact your hardware provider for the latest microcode updates.
>
>  IMPORTANT: If you are using Intel Skylake-, Broadwell-, and Haswell-based
>  platforms, obtain and install updated microcode from your hardware
>  vendor immediately. The "Spectre" mitigation requires both an updated
>  kernel and updated microcode from your hardware vendor.
>  --
>
>  SL6
>   x86_64
>     microcode_ctl-1.17-25.4.el6_9.x86_64.rpm
>     microcode_ctl-debuginfo-1.17-25.4.el6_9.x86_64.rpm
>     microcode_ctl-1.17-20.2.el6_7.x86_64.rpm
>     microcode_ctl-debuginfo-1.17-20.2.el6_7.x86_64.rpm
>     microcode_ctl-1.17-19.2.el6_6.x86_64.rpm
>     microcode_ctl-debuginfo-1.17-19.2.el6_6.x86_64.rpm
>   i386
>     microcode_ctl-1.17-25.4.el6_9.i686.rpm
>     microcode_ctl-debuginfo-1.17-25.4.el6_9.i686.rpm
>  SL7
>   x86_64
>     microcode_ctl-2.1-22.5.el7_4.x86_64.rpm
>     microcode_ctl-debuginfo-2.1-22.5.el7_4.x86_64.rpm
>     microcode_ctl-2.1-16.5.el7_3.x86_64.rpm
>     microcode_ctl-debuginfo-2.1-16.5.el7_3.x86_64.rpm
>     microcode_ctl-2.1-12.el7_2.3.x86_64.rpm
>     microcode_ctl-debuginfo-2.1-12.el7_2.3.x86_64.rpm
>
>  - Scientific Linux Development Team
>