CPU hardware security issues: Meltdown and Spectre (updated 2018-03-08)

Researchers have published serious and widespread security issues relevant for all users of Intel (and other) CPUs for all products from the last decade. The bugs are known as “Meltdown” and “Spectre”. Both bugs have massive implications for the security of all applications both within an operating system as well as on hosted virtualised platforms like Amazon AWS, Google Compute Engine or the Flying Circus.

The security issues were intended to be under an embargo for another week but a couple of news outlets have already started reporting about them and forced the security researchers to publish the issues earlier than intended.

We’re watching the in-progress security patches as they arrive and will take appropriate measures. We’ll update our customers with more specific information over time but want you to know that we are aware of the issue and its implications.

Update Monday 2018-01-08

There is still progress happening and the most relevant security issue (Spectre, Variation 2, CVE 2017-5715) has no patch available yet. Some vendors and distributions are providing undocumented (and not publicly tested) patches that we are refraining from rolling out into our infrastructure. We’re in contact with Qemu and Linux kernel developers who are still working on reliable patches on both levels. We’ll keep you updated.

Update Monday, 2018-01-29

The situation remains complex. We have identified a small Linux kernel change that will ensure proper KVM/Qemu guest/host isolation. However, there are a number of other patches that keep finding their wait into this part of the Linux kernel code and Intel is still communicating very unclear messages and has retracted (some or all) µCode updates for their CPUs last week as well as other Vendors like Ubuntu, VMware, etc. Intel has announced another update for 2018-01-31 which we will review and consider after waiting for industry feedback on the performance and stability.

We are then planning to roll out an update Linux kernel on VM hosts and will likely enable the additional countermeasures (like KPTI) on the hosts. To validate that this does not have drastic performance impacts we are reviewing our baseline system and application performance using the Phoronix Test Suite.

More updates will follow here as the situation develops.

Update Thursday, 2018-03-08

A few weeks ago we have reviewed the status of the vanilla kernel fixes Spectre and Meltdown and have decided to update our Gentoo-based Linux 4.9 series hardware and virtual machines with the recent 4.9.85 update. The upstream developers have implemented sufficient mechanics at this point to selectively enable mitigations depending on hardware support and balance performance versus security. We started to roll out those updates in yesterday’s release and VMs and servers will perform required reboots within regular maintenance windows over the next days. Our host servers will enable mitigations for all variants (Meltdown and Spectre 1 and 2). Our guest systems will enable mitigations against Spectre 1 and 2 but not Meltdown, due to missing support for PCID and thus avoid KPTI which would have a big performance impact.

Due to the extent of mitigations available in the Linux kernel and a rough history of stability of Intel’s patches  we also decided to not apply µCode updates for the Intel CPUs at this point in time.

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