Note that same udevd rule exists as far back as 16.04 LTS:
ubuntu@xenial-test:~$ md5sum /lib/udev/rules.d/40-vm-hotadd.rules d8569b53b5bd1874a86b743b82a2a5b4 /lib/udev/rules.d/40-vm-hotadd.rules
ubuntu@focal-test:~$ md5sum /usr/lib/udev/rules.d/40-vm-hotadd.rules d8569b53b5bd1874a86b743b82a2a5b4 /usr/lib/udev/rules.d/40-vm-hotadd.rules
There is a previous bug, https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1518457 which addressed a different symptom but may be related.
Note that same udevd rule exists as far back as 16.04 LTS:
ubuntu@ xenial- test:~$ md5sum /lib/udev/ rules.d/ 40-vm-hotadd. rules 4a86b743b82a2a5 b4 /lib/udev/ rules.d/ 40-vm-hotadd. rules
d8569b53b5bd187
ubuntu@ focal-test: ~$ md5sum /usr/lib/ udev/rules. d/40-vm- hotadd. rules 4a86b743b82a2a5 b4 /usr/lib/ udev/rules. d/40-vm- hotadd. rules
d8569b53b5bd187
There is a previous bug, https:/ /bugs.launchpad .net/ubuntu/ +source/ linux/+ bug/1518457 which addressed a different symptom but may be related.