This bug was fixed in the package systemd - 237-3ubuntu10.52 --------------- systemd (237-3ubuntu10.52) bionic; urgency=medium
* d/extra/dhclient-enter-resolved-hook: Reset start limit counter for systemd-resolved in dhclient hook (LP: #1939255) https://git.launchpad.net/~ubuntu-core-dev/ubuntu/+source/systemd/commit/?id=ea6710476dde78e8595274c3c4ba7acca6d5162c * d/p/lp1934147/0001-core-add-a-new-unit-method-catchup.patch, d/p/lp1934147/0002-cgroup-do-catchup-for-unit-cgroup-inotify-watch-file.patch, d/p/lp1934147/0003-core-Make-sure-cgroup_oom_queue-is-flushed-on-manage.patch: Catch up on cgroup empty inotify after reexec/reload (LP: #1934147) https://git.launchpad.net/~ubuntu-core-dev/ubuntu/+source/systemd/commit/?id=5ef61bd930612a90ce3ed9105cbadc5ff97b6ffc * d/p/lp1934981-correct-suspend-then-sleep-string.patch: Fix sleep verb used by logind during suspend-then-hibernate (LP: #1934981) https://git.launchpad.net/~ubuntu-core-dev/ubuntu/+source/systemd/commit/?id=1ade873a41ad018a5e07f10775738c6eb8c82310 * d/extra/dhclient-enter-resolved-hook: Check is-enabled systemd-resolved in dhclient hook (LP: #1853164) https://git.launchpad.net/~ubuntu-core-dev/ubuntu/+source/systemd/commit/?id=774c2f82a39a88fa0fd8b2adbfa0b8a8c3cd1fb5 -- Dan Streetman <ddstr...@canonical.com> Thu, 26 Aug 2021 10:20:40 -0400 ** Changed in: systemd (Ubuntu Bionic) Status: Fix Committed => Fix Released ** Changed in: systemd (Ubuntu Focal) Status: Fix Committed => Fix Released -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to systemd in Ubuntu. https://bugs.launchpad.net/bugs/1934147 Title: systemd leaks abandoned session scopes Status in snapd: New Status in systemd: New Status in systemd package in Ubuntu: Fix Committed Status in systemd source package in Bionic: Fix Released Status in systemd source package in Focal: Fix Released Status in systemd source package in Groovy: Won't Fix Status in systemd source package in Hirsute: Fix Released Status in systemd source package in Impish: Fix Committed Bug description: [impact] systemd may leak sessions, leaving empty cgroups around as well as abandoned session scopes. [test case] on a system where the user has a ssh key that allows noninteractive login to localhost, and also has noninteractive sudo, run: $ for i in {1..100}; do sudo -b -i -u ubuntu ssh localhost -- sleep 1; done; for i in {1..20}; do echo 'Reloading...'; sudo systemctl daemon- reload; done check the sessions to see there have been leaked sessions: $ loginctl list-sessions SESSION UID USER SEAT TTY 1 1000 ubuntu ttyS0 350 1000 ubuntu 351 1000 ubuntu 360 1000 ubuntu ... to verify the sessions were leaked, clear them out with: $ echo '' | sudo tee /sys/fs/cgroup/unified/user.slice/user-1000.slice/session-*.scope/cgroup.events that should result in all the leaked sessions being cleaned up. [regression potential] issues during systemd pid1 reexec/reload, or issues while cleaning up sessions, including leaking sessions/cgroups [scope] this is needed for all releases upstream bug linked above, and upstream PR: https://github.com/systemd/systemd/pull/20199 [original description] On a system that is monitored via telegraf I found many abandoned systemd session which I believe are created by a potential race where systemd is reloading unit files and at the same time a user is connecting to the system via ssh or is executing the su command. The simple reproducer $ for i in {1..100}; do sleep 0.2; ssh localhost sudo systemctl daemon-reload & ssh localhost sleep 1 & done Wait > 1 second $ jobs -p | xargs --verbose --no-run-if-empty kill -KILL To clean out STOPPED jobs and $ systemctl status --all 2> /dev/null | grep --before-context 3 abandoned will produce something similar to │ ├─ 175 su - ubuntu │ ├─ 178 -su │ ├─62375 systemctl status --all │ └─62376 grep --color=auto --before-context 3 abandoned -- ● session-273.scope - Session 273 of user ubuntu Loaded: loaded (/run/systemd/transient/session-273.scope; transient) Transient: yes Active: active (abandoned) since Wed 2021-06-30 13:32:03 UTC; 4min 7s ago -- ● session-274.scope - Session 274 of user ubuntu Loaded: loaded (/run/systemd/transient/session-274.scope; transient) Transient: yes Active: active (abandoned) since Wed 2021-06-30 13:32:03 UTC; 4min 7s ago -- ● session-30.scope - Session 30 of user ubuntu Loaded: loaded (/run/systemd/transient/session-30.scope; transient) Transient: yes Active: active (abandoned) since Wed 2021-06-30 10:05:56 UTC; 3h 30min ago -- ● session-302.scope - Session 302 of user ubuntu Loaded: loaded (/run/systemd/transient/session-302.scope; transient) Transient: yes Active: active (abandoned) since Wed 2021-06-30 13:32:04 UTC; 4min 6s ago -- │ ├─ 175 su - ubuntu │ ├─ 178 -su │ ├─62375 systemctl status --all │ └─62376 grep --color=auto --before-context 3 abandoned The system in question is running Bionic, systemd-237-3ubuntu10.48 To manage notifications about this bug go to: https://bugs.launchpad.net/snapd/+bug/1934147/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp