User=0day considered harmful in systemd

Posted Jul 15, 2017 1:07 UTC (Sat) by anselm (subscriber, #2796)
In reply to: User=0day considered harmful in systemd by rahvin
Parent article: User=0day considered harmful in systemd

Has anyone seriously argued systemd should treat a username starting with a number as root?

I don't think so. Where systemd goes out on a limb, as far as I'm concerned, is by assuming that a username that starts with a digit is invalid (and that therefore the directive could be ignored altogether, such that in the absence of a User= directive the unit is by default executed as root). We've heard Lennart claim that this is the “least common denominator” among various Linux distributions, but we've also heard from people who aver that digits at the beginning of a username (or even all-digit usernames) are perfectly acceptable. The paragraph on User= in systemd.exec(5) certainly doesn't mention that restriction but it probably should.