Comment 0 for bug 1700373

NB: I am *not* directly affected by this bug.

Henrique emailed a warning to Debian devel today [1] on a potentially serious issue with (sky|kaby)lake processors. Excerpt:

"This warning advisory is relevant for users of systems with the Intel
processors code-named "Skylake" and "Kaby Lake". These are: the 6th and
7th generation Intel Core processors (desktop, embedded, mobile and
HEDT), their related server processors (such as Xeon v5 and Xeon v6), as
well as select Intel Pentium processor models.

TL;DR: unfixed Skylake and Kaby Lake processors could, in some
situations, dangerously misbehave when hyper-threading is enabled.
Disable hyper-threading immediately in BIOS/UEFI to work around the
problem. Read this advisory for instructions about an Intel-provided
fix."

It is probably a good idea to:
(1) issue a warning to our users about this;
(2) update intel-microcode on all our supported releases

I leave the discussion on whether this can have security implications to others.

[1] https://lists.debian.org/debian-devel/2017/06/msg00308.html

ProblemType: Bug
DistroRelease: Ubuntu 17.04
Package: intel-microcode 3.20161104.1
ProcVersionSignature: Ubuntu 4.10.0-24.28-generic 4.10.15
Uname: Linux 4.10.0-24-generic x86_64
ApportVersion: 2.20.4-0ubuntu4.1
Architecture: amd64
CurrentDesktop: Unity:Unity7
Date: Sun Jun 25 10:14:19 2017
InstallationDate: Installed on 2017-05-26 (30 days ago)
InstallationMedia: Ubuntu 17.04 "Zesty Zapus" - Release amd64 (20170412)
SourcePackage: intel-microcode
UpgradeStatus: No upgrade log present (probably fresh install)