On Wed, Jul 29, 2026 at 06:47:00PM +0200, Andreas Metzler wrote: > On 2026-07-29 Andrew Bower <[email protected]> wrote: > > I reproduced this condition absent systemd by running: > > > > unshare --mount > > mount -o ro /var/log /var/log > > /etc/cron.daily/locate systemd-timer
For completeness, my reproducer was missing "--bind" to the mount command. > > 3. The real worker, /usr/bin/updatedb.findutils, uses 'su' to become > > 'nobody'. This is not the right way to drop privileges. su is designed > > for human users, for a start. util-linux ships with 'runuser' which is > > more suitable for system scripts, has a minimal pam configuration and > > does not reproduce this problem! I tried this and it works, although it > > would need to be considered carefully by the 'locate' maintainers for > > unintended consequences. > > > > I suggest this is fixed via a shell function which falls back to 'su' so > > that 'locate' can still run on hurd (where there is no systemd anyway). > > I do not get hurd issue, while hurd has no systemd it still has runuser. Indeed. I falsely assumed that not being Linux, hurd had an alternative to util-linux that probably didn't have runuser. It seems a direct substitution would work for the whole of Debian! > d)'s "runas" is a typo, and should read "runuser", shouldn't it? (runas > exist, but is very niche and looks dead upstream) Yes, I meant to write 'runuser' but the 'runas' Windowsism crept in. > > I think 'locate' is probably the most accurate home for this bug! > > agreed. Thanks.
