Date: Wed, 1 Jun 2016 15:48:04 +0200
From: Lennart Poettering <mzerqung(a)0pointer.de>
Subject: Re: systemd 230 change - KillUserProcesses defaults to yes
To: Development discussions related to Fedora
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On Wed, 01.06.16 12:19, Howard Chu (hyc(a)symas.com) wrote:
> This is still looking at the problem back-asswards. The problem isn't that
> screen and tmux are special cases. The problem is that some handful of
> programs that got spawned in a GUI desktop environment are special cases,
> not exiting when they should.
> Fix the broken programs, don't force every well-behaved program in the
> universe to change to accommodate your broken GUI environment. This is
> Programming 101.
Again, this isn't just work-arounds around broken programs. It's a
security thing. It's privileged code (logind, PID 1) that enforces a
clear life-cycle on unprivileged programs.
Any scheme that relies on unprivileged programs "being nice" doesn't
fix the inherent security problem: after logout a user should not be
able consume further runtime resources on the system, regardless if he
does that because of a bug or on purpose.
Sure, having this as an option to be enabled in specific situations
is nice, but, it ignores how Linux is admined and used in the real
world 90% of the time. If you're going to enable this by default,
you enable something that may be needed 10% of the time but break
the other 90% of use cases. A sane default does not break the