It has been a little while since LWN last surveyed tools for managing a digital music collection. In the intervening decades, many Linux users have moved on to music streaming services, found them wanting, and are looking to curate their own collection once again. There are plenty of choices when it comes to ripping, managing, and playing digital audio; so many, in fact, that it can be a bit daunting. After years of tinkering, I've found a few tools that work well for managing my digital library: the first I'd like to cover is the fre:ac free audio encoder for ripping music from CDs and converting between audio formats.

The NixOS project has announced a critical vulnerability in many versions of the Nix package manager's daemon. The flaw was introduced as part of a fix for a prior vulnerability in 2024. According to the advisory, all default configurations of NixOS and systems building untrusted derivations are impacted.

A bug in the fix for CVE-2024-27297 allowed for arbitrary overwrites of files writable by the Nix process orchestrating the builds (typically the Nix daemon running as root in multi-user installations) by following symlinks during fixed-output derivation output registration. This affects sandboxed Linux builds - sandboxed macOS builds are unaffected. The location of the temporary output used for the output copy was located inside the build chroot. A symlink, pointing to an arbitrary location in the filesystem, could be created by the derivation builder at that path. During output registration, the Nix process (running in the host mount namespace) would follow that symlink and overwrite the destination with the derivation's output contents.

In multi-user installations, this allows all users able to submit builds to the Nix daemon (allowed-users - defaulting to all users) to gain root privileges by modifying sensitive files.