apparmor="DENIED" operation="open" class="file" profile="rsyslogd" name="/run/systemd/sessions/"

[Martin Pitt]

There is an AppArmor regression in current noble. In cockpit we recently started to test on noble (to prevent the "major regressions after release" fiasco from 23.10 again).

For some weird reason, rsyslog is installed *by default* [1] in the cloud images. That is a rather pointless waste of CPU and disk space, as it's an unnecessary running daemon and duplicates all the written logs.

But more specifically, we noticed [2] an AppArmor rejection. Reproducer is simple:

    logger -p user.emerg --tag check-journal EMERGENCY_MESSAGE

this causes

    type=1400 audit(1710168739.345:108): apparmor="DENIED" operation="open" class="file" profile="rsyslogd" name="/run/systemd/sessions/" pid=714 comm=72733A6D61696E20513A526567 requested_mask="r" denied_mask="r" fsuid=102 ouid=0

Note that it doesn't actually fail, the "EMERGENCY_MESSAGE" does appear in the journal and also in /var/log/syslog. But it's some noise that triggers our (and presumbly other admin's) log detectors.

rsyslog 8.2312.0-3ubuntu3
apparmor 4.0.0~alpha4-0ubuntu1

[1] https://cloud-images.ubuntu.com/daily/server/noble/current/noble-server-cloudimg-amd64.manifest
[2] https://cockpit-logs.us-east-1.linodeobjects.com/pull-6048-20240311-125838-b465e9b2-ubuntu-stable-other-cockpit-project-cockpit/log.html#118

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.