On Sun, Jun 21, 2020 at 4:53 PM Philip Webb <purs...@ca.inter.net> wrote: > > 200621 Piotr Karbowski wrote: > > Title: xorg-server dropping default suid > ... > > The Gentoo X11 Team is announcing that starting with 15th of July, > > the x11-base/xorg-server will no longer default to suid > > and will default to using logind interface instead. This change > > makes xorg-server run as regular user rather than root by default, > > however those who do not have any logind interface provider > > -- either systemd or elogind -- will need to enable either > > to make it possible to run X session as unprivileged user. > > No action is required from systemd and desktop profile users, > > since systemd provides logind interface > > and desktop profile already enables 'elogind' USE flag globally. > > Rest of the non-systemd users is required to globally enable > > 'elogind' USE flag and apply it by 'emerge --newuse @world', > > after which, re-login is required so that PAM can allocate seat. > > One can confirm that a seat has been assigned upon login by running: > > $ loginctl user-status > > Those who for whatever reason want to preserve current state, > > while heavily discouraged, > > can still use x11-base/xorg-server with 'suid -elogind'. > > Gentoo Wiki says : > > elogind is the systemd project's logind, extracted to a standalone package. > It's designed for users who prefer a non-systemd init system, > but still want to use popular software such as KDE/Wayland or GNOME > that otherwise hard-depends on systemd. > > startx integration : To have an elogind session created > when using startx to start the X server (instead of a display manager), > add the following to the user's ~/.xinitrc file : FILE ~/.xinitrc > exec dbus-launch --exit-with-session <WINDOW_MANAGER> > WINDOW_MANAGER in the above example needs to be replaced > by a window manager or a single application. > > I want to use 'startx' to start X , because I don't want to be trapped > if some problem arises with X or KDE or the login manager > & I need to change config files or remerge pkgs (etc) to rescue myself. > With 'startx' I can do all that work from raw TTYs with no problems, > as I am not forced to go into an X session if I don't want to.
Thank you for actually participating in the discussion, unlike the last thread about this topic. > I don't want to use 'systemd', as I want to run a traditional UNIX version > of Linux + KDE (or Fluxbox) for a simple single-user desktop system. > > Why is running 'xorg-server' as root "heavily discouraged" ? > -- I've been doing that with Gentoo for > 16 yr without any problems. > AFAIK there are no problems re exploits via I/net browsers, > which are started by my user as all such user software always is. > What might go wrong, if I continue to 'startx' > with 'xorg-server' merged with 'suid -elogind' > & without the '.xinitrc' line show above in the Wiki ? For the majority of users (those that use a graphics driver with kernel modesetting support), X only needs root access for a small set of things: accessing the DRM device node, accessing the input device nodes, and some stuff around VTs. The rest of the time, X doesn't need root access but still must run as root for those cases I mention. With elogind, those bits are handled in a small daemon, and X no longer needs to run as root. Most people find that to be valuable, especially with the knowledge that there have been a number of security vulnerabilities found that would allow arbitrary code execution in the xserver over the years [1]. Our current default of USE=suid installs /usr/bin/Xorg with the setuid bit set, allowing it to be run *as root* by any user. This enables non-root users to execute startx, for example. I appreciate that Gentoo users are a diverse bunch, to say the least. This news item is about *defaults*. I'm happy to explain the value of the new default to people who are genuinely curious but I have no interest in trying to convince you or anyone else of anything. You're free to keep the status quo with a single line in /etc/portage/package.use. The people building and maintaining the distro think that the new defaults are better defaults for the vast majority of users, but again they're just defaults. [1] https://www.cvedetails.com/vulnerability-list/vendor_id-88/product_id-8600/X.org-Xorg-server.html
