uuidd appears to be broken on Ubuntu 20.04 LTS

[vdbergh]

uuidgen -t returns a correct result when uuidd is _not_ running. See the following transcript

vdbergh@pl:~/$ sudo systemctl stop uuidd.service uuidd.socket
vdbergh@pl:~/$ uuidgen -t
ef485202-e275-11ec-b7ab-448500dea459 <---- (correct: last part is the MAC address)
vdbergh@pl:~/$ sudo systemctl start uuidd.service
vdbergh@pl:~/$ uuidgen -t
f8e7b3ca-e275-11ec-b074-1d42fae212d0 <---- (incorrect)

The same issue appears with every program that relies on libuuid.

Example: uuid.getnode() in python3 is supposed to return the MAC address but this only works if uuidd is not running.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: uuid-runtime 2.34-0.1ubuntu9.3
ProcVersionSignature: Ubuntu 5.13.0-44.49~20.04.1-generic 5.13.19
Uname: Linux 5.13.0-44-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.24
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: ubuntu:GNOME
Date: Thu Jun 2 15:59:10 2022
InstallationDate: Installed on 2020-12-06 (542 days ago)
InstallationMedia: Ubuntu 20.04.1 LTS "Focal Fossa" - Release amd64 (20200731)
SourcePackage: util-linux
UpgradeStatus: No upgrade log present (probably fresh install)

[vdbergh (michel-vandenbergh)]

I forgot to mention that a self compiled uuidd does not suffer from this bug(?).

[vdbergh (michel-vandenbergh)]

The previous comment was a red herring.

It turns out it doesn't matter if uuidd is self compiled or not. The system uuidd also works perfectly if it is started in the terminal simply by

sudo uuidd

However systemd starts uuidd with

/usr/sbin/uuidd --socket-activation

which probably makes a difference.

[vdbergh (michel-vandenbergh)]

I got a reply on the util-linux issue tracker

https://github.com/util-linux/util-linux/issues/1704#issuecomment-1144962011

So it seems te a systemd issue.

[vdbergh (michel-vandenbergh)]

This issue is now fixed upstream.

https://github.com/util-linux/util-linux/commit/304b4dc4936b115ca33af5325c3b04d0997c1353
https://github.com/util-linux/util-linux/commit/c9671a3cf7738bb81e1cbef2f56485a36c6e7623