Linux

47923 readers

1171 users here now

From Wikipedia, the free encyclopedia

Linux is a family of open source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991 by Linus Torvalds. Linux is typically packaged in a Linux distribution (or distro for short).

Distributions include the Linux kernel and supporting system software and libraries, many of which are provided by the GNU Project. Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name GNU/Linux to emphasize the importance of GNU software, causing some controversy.

Rules

Posts must be relevant to operating systems running the Linux kernel. GNU/Linux or otherwise.
No misinformation
No NSFW content
No hate speech, bigotry, etc

Related Communities

Community icon by Alpár-Etele Méder, licensed under CC BY 3.0

founded 5 years ago

MODERATORS

AgreeableLandscape@lemmy.ml

nooter692@lemmy.ml

MarcellusDrum@lemmy.ml

cypherpunks@lemmy.ml

cyclohexane@lemmy.ml

d3Xt3r@lemmy.nz

107

How the xz backdoor highlights a major flaw in Nix (shadeyg56.vercel.app)

submitted 6 months ago* (last edited 6 months ago) by d3Xt3r@lemmy.nz to c/linux@lemmy.ml

31 comments fedilink hide all child comments

The main issue is the handling of security updates within the Nixpkgs ecosystem, which relies on Nix's CI system, Hydra, to test and build packages. Due to the extensive number of packages in the Nixpkgs repository, the process can be slow, causing delays in the release of updates. As an example, the updated xz 5.4.6 package took nearly 5 days to become available in the unstable branch!

Fundamentally, there needs to be a change in how security fixes are handled in Hydra. As stated in the article, Nix was lucky to be unaffected, but multiple days to push out a security patch of this severity is concerning, even if there was no reason for concern.

you are viewing a single comment's thread
view the rest of the comments

[–] cypherpunks@lemmy.ml 5 points 6 months ago* (last edited 6 months ago)

As of today, NixOS (like most distros) has reverted to a version slightly prior to the release with the Debian-or-Redhat-specific sshd backdoor which was inserted into xz just two months ago. However, the saboteur had hundreds of commits prior to the insertion of that backdoor, and it is very likely that some of those contain subtle intentional vulnerabilities (aka "bugdoors") which have not yet been discovered.

As (retired) Debian developer Joey Hess explains here, the safest course is probably to switch to something based on the last version (5.3.1) released prior to Jia Tan getting push access.

Unfortunately, as explained in this debian issue, that is not entirely trivial because dependents of many recent pre-backdoor potentially-sabotaged versions require symbol(s) which are not present in older versions and also because those older versions contain at least two known vulnerabilities which were fixed during the multi-year period where the saboteur was contributing.

After reading Xz format inadequate for long-term archiving (first published eight years ago...) I'm convinced that migrating the many projects which use XZ today (including DPKG, RPM, and Linux itself) to an entirely different compression format is probably the best long-term plan. (Though we'll always still need tools to read XZ archives for historical purposes...)