systemd locks up due to incorrect handling of time zone changes

Bug #1966800 reported by Matt Coleman
This bug affects 3 people
Affects Status Importance Assigned to Milestone
systemd (Fedora)
systemd (Ubuntu)
Fix Released
Fix Released

Bug Description


This bug can cause systemd timers to lock up systems using the Europe/Dublin timezone if certain OnCalendar values are used. If the timer is enabled at boot, this bug prevents the system from booting. If the timer is started later, systemd becomes unresponsive.

[Test Plan]

* Create a systemd service and corresponding timer scheduled for 01:00 on Sundays:

$ cat /etc/systemd/system/lp-1966800-reproducer.timer
 Description=LP 1966800 reproducer

 OnCalendar=Sun *-*-* 01:00:00


 $ cat /etc/systemd/system/lp-1966800-reproducer.service
 ExecStart=/usr/bin/echo "LP 1966800 reproducer"

 $ systemctl daemon-reload

* Set the date to 21 March, 2021 in the Europe/Dublin timezone (need to disable NTP first):

 $ timedatectl set-ntp false
 $ timedatectl set-time "2021-03-21"
 $ timedatectl set-timezone Europe/Dublin

* Try to start the timer, and observe that systemd becomes unresponsive. This command will time out, as will `systemctl status` etc.

 $ systemctl start lp-1966800-reproducer.timer

[Where problems could occur]

The patch makes changes in the calendar spec code, which is used by systemd timers to determine the next time to trigger a timer. If this patch breaks something, it would be related to the triggering of systemd timers.

[Original Description]

Recently on systems in Ireland, systemd became unresponsive due the change from GMT to Irish Standard Time. This is due to Ireland being unique in having their standard time during the summer, unlike most regions.

Related to:
Fixed by:

Related branches

Revision history for this message
Launchpad Janitor (janitor) wrote :

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

Changed in systemd (Ubuntu):
status: New → Confirmed
tags: added: rls-jj-incoming
tags: removed: rls-jj-incoming
Revision history for this message
Steve Langasek (vorlon) wrote :

This is fixed in the systemd present in Ubuntu 21.10 and later

Changed in systemd (Ubuntu):
status: Confirmed → Fix Released
tags: added: fr-2227
Nick Rosbrook (enr0n)
description: updated
Revision history for this message
Lukas Märdian (slyon) wrote :

A fix for this issue has been staged in git for the next Focal SRU:

Thank you @enr0n for providing the merge proposal!

Revision history for this message
Łukasz Zemczak (sil2100) wrote : Please test proposed package

Hello Matt, or anyone else affected,

Accepted systemd into focal-proposed. The package will build now and be available at in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, what testing has been performed on the package and change the tag from verification-needed-focal to verification-done-focal. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-focal. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

Changed in systemd (Ubuntu Focal):
status: New → Fix Committed
tags: added: verification-needed verification-needed-focal
Revision history for this message
Ubuntu SRU Bot (ubuntu-sru-bot) wrote : Autopkgtest regression report (systemd/245.4-4ubuntu3.18)

All autopkgtests for the newly accepted systemd (245.4-4ubuntu3.18) for focal have finished running.
The following regressions have been reported in tests triggered by the package:

linux-gke-5.15/5.15.0-1015.18~20.04.1 (arm64, amd64) (armhf)
linux-hwe-5.15/5.15.0-48.54~20.04.1 (armhf, amd64)
gvfs/1.44.1-1ubuntu1.1 (ppc64el)
linux-oracle-5.15/5.15.0-1016.20~20.04.1 (arm64)
linux-oracle-5.13/5.13.0-1036.43~20.04.1 (arm64)
linux-hwe-5.11/5.11.0-61.61 (arm64)
systemd/245.4-4ubuntu3.18 (armhf)

Please visit the excuses page listed below and investigate the failures, proceeding afterwards as per the StableReleaseUpdates policy regarding autopkgtest regressions [1].


Thank you!

Revision history for this message
Nick Rosbrook (enr0n) wrote :

The autopkgtest regressions were resolved by retries.

I have verified this fix on focal using the test plan above:

nr@clean-focal-amd64:~$ apt-cache policy systemd
  Installed: 245.4-4ubuntu3.18
  Candidate: 245.4-4ubuntu3.18
  Version table:
 *** 245.4-4ubuntu3.18 500
        500 focal-proposed/main amd64 Packages
        100 /var/lib/dpkg/status
     245.4-4ubuntu3.17 500
        500 focal-updates/main amd64 Packages
     245.4-4ubuntu3.15 500
        500 focal-security/main amd64 Packages
     245.4-4ubuntu3 500
        500 focal/main amd64 Packages

nr@clean-focal-amd64:~$ cat /etc/systemd/system/lp-1966800-reproducer.timer
Description=LP 1966800 reproducer

OnCalendar=Sun *-*-* 01:00:00


nr@clean-focal-amd64:~$ cat /etc/systemd/system/lp-1966800-reproducer.service
ExecStart=/usr/bin/echo "LP 1966800 reproducer"

nr@clean-focal-amd64:~$ sudo systemctl daemon-reload
nr@clean-focal-amd64:~$ sudo timedatectl set-ntp false
nr@clean-focal-amd64:~$ sudo timedatectl set-time "2021-03-21"
nr@clean-focal-amd64:~$ sudo timedatectl set-timezone Europe/Dublin
nr@clean-focal-amd64:~$ sudo systemctl start lp-1966800-reproducer.timer
nr@clean-focal-amd64:~$ sudo systemctl status
● clean-focal-amd64
    State: running
     Jobs: 0 queued
   Failed: 0 units
    Since: Thu 2022-09-08 18:08:29 IST; 1 years 5 months left
   CGroup: /
           │ └─user-1000.slice
           │ ├─user@1000.service …
           │ │ ├─gsd-xsettings.service
           │ │ │ └─1565 /usr/libexec/gsd-xsettings
           │ │ ├─gvfs-goa-volume-monitor.service
           │ │ │ └─1216 /usr/libexec/gvfs-goa-volume-monitor
           │ │ ├─gsd-power.service
           │ │ │ └─1531 /usr/libexec/gsd-power
           │ │ ├─xdg-permission-store.service
           │ │ │ └─1444 /usr/libexec/xdg-permission-store
           │ │ ├─gsd-sound.service
           │ │ │ └─1552 /usr/libexec/gsd-sound
           │ │ ├─gsd-rfkill.service
           │ │ │ └─1535 /usr/libexec/gsd-rfkill
           │ │ ├─gsd-usb-protection.service
           │ │ │ └─1555 /usr/libexec/gsd-usb-protection
           │ │ ├─gsd-print-notifications.service
           │ │ │ ├─1534 /usr/libexec/gsd-print-notifications
           │ │ │ └─1609 /usr/libexec/gsd-printer
           │ │ ├─evolution-calendar-factory.service
           │ │ │ └─1465 /usr/libexec/evolution-calendar-factory
           │ │ ├─gsd-a11y-settings.service
           │ │ │ └─1517 /usr/libexec/gsd-a11y-settings
           │ │ ├─gsd-wwan.service
           │ │ │ └─1563 /usr/libexec/gsd-wwan
           │ │ ├─pulseaudio.service
           │ │ │ └─1162 /usr/bin/pulseaudio --daemonize=no --log-target=journal
           │ │ ├─gsd-screensaver-proxy.service
           │ │ │ └─1537 /usr/libexec/gsd-screensaver-proxy
           │ │ ├─gsd-media-keys.service

tags: added: verification-done verification-done-focal
removed: verification-needed verification-needed-focal
Revision history for this message
Launchpad Janitor (janitor) wrote :

This bug was fixed in the package systemd - 245.4-4ubuntu3.18

systemd (245.4-4ubuntu3.18) focal; urgency=medium

  [ Nick Rosbrook ]
  * core: make sure we don't get confused when setting TERM for a tty fd
    (LP: #1959475)
    File: debian/patches/lp1959475-core-make-sure-we-don-t-get-confused-when-setting-TERM-fo.patch
  * shared/calendarspec: when mktime() moves us backwards, jump forward
    (LP: #1966800)
    File: debian/patches/lp1966800-shared-calendarspec-when-mktime-moves-us-backwards-jump-f.patch
  * network: do not remove localhost address (LP: #1979951)
    File: debian/patches/lp1979951-network-do-not-remove-localhost-address.patch
  * units: remove the restart limit on the modprobe@.service (LP: #1982462)
    File: debian/patches/lp1982462-units-remove-the-restart-limit-on-the-modprobe-.service.patch

  [ Mustafa Kemal Gilor ]
  * d/p/lp1978079-efi-pstore-not-cleared-on-boot.patch: pstore: Run after
    modules are loaded. Thanks to Alexander Graf <email address hidden>.
    (LP: #1978079)
    Author: Mustafa Kemal Gilor
    File: debian/patches/lp1978079-efi-pstore-not-cleared-on-boot.patch

 -- Nick Rosbrook <email address hidden> Wed, 31 Aug 2022 11:27:33 -0400

Changed in systemd (Ubuntu Focal):
status: Fix Committed → Fix Released
Revision history for this message
Łukasz Zemczak (sil2100) wrote : Update Released

The verification of the Stable Release Update for systemd has completed successfully and the package is now being released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.

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