On 15.04.19 22:29, Andy Lutomirski wrote: <snip> > I would personally *love* it if distros started setting no_new_privs> for basically all processes. Maybe a pam module for that would be fine. But this should be configurable per-user, as so many things still rely on suid. Actually, I'd like to move all authentication / privilege switching to factotum (login(1), sshd, etc then also could run as unprivileged users). > And pidfd actually gets us part of the> way toward a straightforward way to make sudo and su still work in a> no_new_privs world: su could call into a daemon that would spawn the> privileged task, and su would get a (read-only!) pidfd back and then> wait for the fd and exit. How exactly would the pidfd improve this scenario ? IMHO, would just need to pass the inherited fd's to that daemon (eg. via unix socket) which then sets them up in the new child process. > I suppose that, done naively, this might> cause some odd effects with respect to tty handling, but I bet it's> solveable. Yes, signals and process groups would be a bit tricky. Some signals could be transmitted in a similar way as ssh does. But: how can we handle things like cgroups ? --mtx -- Enrico Weigelt, metux IT consult Free software and Linux embedded engineering info@xxxxxxxxx -- +49-151-27565287
