This seems a bit nitpicky: you just move the threshold for where you might load a backdoored library from first exec to first use which dlopens that library (wh

This seems a bit nitpicky: you just move the threshold for where you might load a backdoored library from first exec to first use which dlopens that library (which might even just be at exec anyway, I haven't checked the source to see how systemd handles it). I think the focus on the specific means that the xz backdoor used to get into sshd is misdirected: it's code that is run in all kinds of priviledged contexts and has thousands of different ways to turn that into RCE. If sshd didn't load it directly the developers of the backdoor would have simply taken a different route.