Machine became unresponsive to ssh, systemd-networkd went crazy

My machine became unresponsive to ssh. My HTTP based services running in Docker were still responding OK. So I logged in physically to investigate.

I noticed that there were a large number of systemd-networkd processes, so I checked the logs and it looks like it has gone crazy and was unable to kill its own processes that it was creating. I’ve posted the full log here: systemd-networkd log · GitHub

I tried to restart sshd, but systemctl hung at that point and I couldn’t even kill it with Ctrl+C.