Better living through software

Ben Hutchings's diary of life and technology

Email: ben@decadent.org.uk • Twitter: @benhutchingsuk • Debian: benh • Gitweb: git.decadent.org.uk • Github: github.com/bwhacks

Wed, 11 Apr 2018

Debian LTS work, March 2018

I was assigned 15 hours of work by Freexian's Debian LTS initiative and carried over 2 hours from February. I worked 15 hours and will again carry over 2 hours to April.

I made another two releases on the Linux 3.2 longterm stable branch (3.2.100 and 3.2.101), the latter including mitigations for Spectre on x86. I rebased the Debian package onto 3.2.101 but didn't upload an update to Debian this month. We will need to add gcc-4.9 to wheezy before we can enable all the mitigations for Spectre variant 2.

posted at: 21:41 | path: / | permanent link to this entry

Mon, 12 Mar 2018

Debian LTS work, February 2018

I was assigned 15 hours of work by Freexian's Debian LTS initiative and worked 13 hours. I will carry over 2 hours to March.

I made another release on the Linux 3.2 longterm stable branch (3.2.99) and started the review cycle for the next update (3.2.100). I rebased the Debian package onto 3.2.99 but didn't upload an update to Debian this month.

I also discussed the possibilities for cooperation between Debian LTS and CIP, briefly reviewed leptonlib for additional security issues, and updated the wiki page about the status of Spectre and Meltdown in Debian.

posted at: 00:51 | path: / | permanent link to this entry

Wed, 07 Feb 2018

Debian LTS work, January 2018

I was assigned 15 hours of work by Freexian's Debian LTS initiative and carried over 8 hours from December. I worked all these hours.

I put together and tested a more-or-less complete backport of KPTI/KAISER to Linux 3.2, based on work by Hugh Dickins and several others. This mitigates the Meltdown vulnerability on amd64 (only). I prepared and uploaded an update for wheezy with this and several other security fixes, and issued DLA-1232-1. I also released another update on the Linux 3.2 longterm stable branch (3.2.98), and started work on the next (3.2.99).

posted at: 19:41 | path: / | permanent link to this entry

Wed, 10 Jan 2018

Meltdown and Spectre in Debian

I'll assume everyone's already heard repeatedly about the Meltdown and Spectre security issues that affect many CPUs. If not, see meltdownattack.com. These primarily affect systems that run untrusted code - such as multi-tenant virtual hosting systems. Spectre is also a problem for web browsers with Javascript enabled.

Meltdown

Over the last week the Debian kernel team has worked to mitigate Meltdown in all suites. This mitigation is currently limited to kernels running in 64-bit mode (amd64 architecture), but the issue affects 32-bit mode as well.

You can see where this mitigation is applied on the security tracker. As of today, wheezy, jessie, jessie-backports, stretch and unstable/sid are fixed while stretch-backports, testing/buster and experimental are not.

Spectre

Spectre needs to be mitigated in the kernel, browsers, and potentially other software. Currently the kernel changes to mitigate it are still under discussion upstream. Mozilla has started mitigating Spectre in Firefox and some of these changes are now in Debian unstable (version 57.0.4-1). Chromium has also started mitigating Spectre but no such changes have landed in Debian yet.

posted at: 03:05 | path: / | permanent link to this entry

Debian LTS work, December 2017

I was assigned 14 hours of work by Freexian's Debian LTS initiative, but only worked 6 hours so I carried over 8 hours to January.

I prepared and uploaded an update to the Linux kernel to fix various security issues. I issued DLA-1200-1 for this update. I also prepared another update on the Linux 3.2 longterm stable branch, though most of that work was done while on holiday so I didn't count the hours. I spent some time following the closed mailing list used to coordinate backports of KPTI/KAISER.

posted at: 02:12 | path: / | permanent link to this entry