Comment 4 for bug 1811580

I have exactly the same problem. I check and an auto update was made for systemd from 229-4ubuntu21.10 to 229-4ubuntu21.15 on many of my devices (Jetson TX2). Now devices rebooted doesn't start ssh and I lost complete communication with all those devices.

I were able to log in through serial console and confirm that this is the issue.

nvidia@tegra-ubuntu:~$ uname -a
Linux tegra-ubuntu 4.4.38-tegra #1 SMP PREEMPT Mon Oct 15 15:16:41 MDT 2018 aarch64 aarch64 aarch64 GNU/Linux

Start-Date: 2019-01-12 00:17:20
Commandline: /usr/bin/unattended-upgrade
Upgrade: libsystemd0:arm64 (229-4ubuntu21.10, 229-4ubuntu21.15), udev:arm64 (229-4ubuntu21.10, 229-4ubuntu21.15), libudev1:arm64 (229-4ubuntu21.10, 229-4ubuntu21.15), systemd-sysv:arm64 (229-4ubuntu21.10, 229-4ubuntu21.15), libpam-systemd:arm64 (229-4ubuntu21.10, 229-4ubuntu21.15), systemd:arm64 (229-4ubuntu21.10, 229-4ubuntu21.15)
End-Date: 2019-01-12 00:17:35

nvidia@tegra-ubuntu:~$ sudo systemd-tmpfiles --create |more
[sudo] password for nvidia:
[/usr/lib/tmpfiles.d/var.conf:14] Duplicate line for path "/var/log", ignoring.
Unsafe symlinks encountered in /var/log, refusing.
Unsafe symlinks encountered in /var/lib, refusing.
Unsafe symlinks encountered in /run/sendsigs.omit.d, refusing.
Unsafe symlinks encountered in /run/lock/subsys, refusing.
Unsafe symlinks encountered in /var/cache, refusing.
Unsafe symlinks encountered in /var/cache/man, refusing.
Unsafe symlinks encountered in /run/rpcbind, refusing.
Unsafe symlinks encountered in /run/rpcbind/rpcbind.xdr, refusing.
Unsafe symlinks encountered in /run/rpcbind/portmap.xdr, refusing.
Unsafe symlinks encountered in /var/run/sshd, refusing.
Unsafe symlinks encountered in /var/run/sudo, refusing.
Unsafe symlinks encountered in /var/run/sudo/ts, refusing.
Unsafe symlinks encountered in /run/user, refusing.
Unsafe symlinks encountered in /run/systemd/ask-password, refusing.
Unsafe symlinks encountered in /run/systemd/seats, refusing.
Unsafe symlinks encountered in /run/systemd/sessions, refusing.
Unsafe symlinks encountered in /run/systemd/users, refusing.
Unsafe symlinks encountered in /run/systemd/machines, refusing.
Unsafe symlinks encountered in /run/systemd/shutdown, refusing.
Unsafe symlinks encountered in /run/systemd/netif, refusing.
Unsafe symlinks encountered in /run/systemd/netif/links, refusing.
Unsafe symlinks encountered in /run/systemd/netif/leases, refusing.
Unsafe symlinks encountered in /run/log, refusing.
Unsafe symlinks encountered in /var/lib/systemd, refusing.
Unsafe symlinks encountered in /var/lib/systemd/coredump, refusing.
Unsafe symlinks encountered in /var/log/wtmp, refusing.
Unsafe symlinks encountered in /var/log/btmp, refusing.
Unsafe symlinks encountered in /var/spool, refusing.
Unsafe symlinks encountered in /tmp/.X11-unix, refusing.
Unsafe symlinks encountered in /tmp/.ICE-unix, refusing.
Unsafe symlinks encountered in /tmp/.XIM-unix, refusing.
Unsafe symlinks encountered in /tmp/.font-unix, refusing.
Unsafe symlinks encountered in /tmp/.Test-unix, refusing.
Unsafe symlinks encountered in /run/log/journal, refusing.
Unsafe symlinks encountered in /run/log/journal/ae15719763c84b35196c20a95728b806, refusing.