[Bug 1950787] Re: systemd-sysusers cannot mount /dev in privileged containers (to pass credentials)
Lukas Märdian
1950787 at bugs.launchpad.net
Fri Nov 12 15:15:40 UTC 2021
I've implemented the workaround in systemd's debian/test/tests-in-lxd.
** Changed in: systemd (Ubuntu)
Status: New => Fix Committed
--
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to systemd in Ubuntu.
https://bugs.launchpad.net/bugs/1950787
Title:
systemd-sysusers cannot mount /dev in privileged containers (to pass
credentials)
Status in lxd package in Ubuntu:
Invalid
Status in systemd package in Ubuntu:
Fix Committed
Bug description:
systemd-sysusers.service/systemd.exec fails to start in privileged containers, due to being unable to properly mount /dev for passing credentials, caused by the following config in the .service unit:
```
# Optionally, pick up a root password and shell for the root user from a
# credential passed to the service manager. This is useful for importing this
# data from nspawn's --set-credential= switch.
LoadCredential=passwd.hashed-password.root
LoadCredential=passwd.plaintext-password.root
LoadCredential=passwd.shell.root
```
Reproducer:
$ lxc profile set default security.privileged "true"
$ lxc launch ubuntu-daily:jammy test
$ lxc exec test bash
# add-apt-repository ppa:ci-train-ppa-service/4704
# apt install systemd # install systemd 249.5-2ubuntu1
# systemctl restart systemd-sysusers
# systemctl status systemd-sysusers
# system --status=failed
$ lxc profile set default security.privileged "false"
A workaround is to disable it via:
$ cat /etc/systemd/system/systemd-sysusers.service.d/override.conf:
[Service]
LoadCredential=
Interesting logs:
Nov 12 12:09:44 test systemd[1]: systemd-journald.service: Added fd 42 (n/a) to fd store.
Nov 12 12:09:44 test systemd[431]: Mounting /dev (MS_REC|MS_SLAVE "")...
Nov 12 12:09:44 test systemd[431]: Failed to mount n/a (type n/a) on /dev (MS_REC|MS_SLAVE ""): Permission denied
Nov 12 12:09:44 test systemd[430]: (sd-mkdcreds) failed with exit status 1.
Nov 12 12:09:44 test systemd[430]: systemd-sysusers.service: Failed to set up credentials: Protocol error
Nov 12 12:09:44 test systemd[430]: systemd-sysusers.service: Failed at step CREDENTIALS spawning
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/lxd/+bug/1950787/+subscriptions
More information about the foundations-bugs
mailing list