focal: with the reproducer hack from the description (comment out the 'goto' line in the udev rule), and the system rebooted:
ubuntu@lp1876018-f:~$ dpkg -l systemd|grep systemd ii systemd 245.4-4ubuntu3.1 amd64 system and service manager ubuntu@lp1876018-f:~$ journalctl -g vm-hotadd -- Logs begin at Wed 2020-07-22 18:11:53 UTC, end at Wed 2020-07-22 18:46:23 UTC. -- Jul 22 18:45:15 lp1876018-f sudo[12380]: ubuntu : TTY=ttyS0 ; PWD=/home/ubuntu ; USER=root ; COMMAND=/usr/bin/vi /lib/udev/rules.d/40-vm-hotadd.rules -- Reboot -- Jul 22 18:45:48 lp1876018-f systemd-udevd[457]: memory0: /usr/lib/udev/rules.d/40-vm-hotadd.rules:9 Failed to write ATTR{/sys/devices/system/memory/memory0/state}, ignoring: Invalid argument Jul 22 18:45:48 lp1876018-f systemd-udevd[457]: memory1: /usr/lib/udev/rules.d/40-vm-hotadd.rules:9 Failed to write ATTR{/sys/devices/system/memory/memory1/state}, ignoring: Invalid argument Jul 22 18:45:48 lp1876018-f systemd-udevd[457]: memory10: /usr/lib/udev/rules.d/40-vm-hotadd.rules:9 Failed to write ATTR{/sys/devices/system/memory/memory10/state}, ignoring: Invalid argument ...(many more)... and with the udev rule again edited after the systemd upgrade (since it replaces the edited file), and the system rebooted: ubuntu@lp1876018-f:~$ dpkg -l systemd|grep systemd ii systemd 245.4-4ubuntu3.2 amd64 system and service manager ubuntu@lp1876018-f:~$ journalctl -b -g vm-hotadd -- Logs begin at Wed 2020-07-22 18:11:53 UTC, end at Wed 2020-07-22 18:50:00 UT> -- No entries -- ** Tags removed: verification-needed verification-needed-focal ** Tags added: verification-done verification-done-focal -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1876018 Title: 40-vm-hotadd.rules attempts to set non-existent sysfs parameters To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1876018/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs