10-link-restrictions.conf missing - removed by postinst

Status changed to 'Confirmed' because the bug affects multiple users.

Problem persist in Ubuntu 20.04 LTS stable release:

root@fpglinux:/var/cache# lsb_release -d
Description: Ubuntu 20.04 LTS

root@fpglinux:/var/cache# apt policy procps
procps:
  Instalados: 2:3.3.16-1ubuntu2
  Candidato: 2:3.3.16-1ubuntu2
  Tabla de versión:
 *** 2:3.3.16-1ubuntu2 500
        500 http://archive.ubuntu.com/ubuntu focal/main amd64 Packages
        100 /var/lib/dpkg/status

root@fpglinux:/var/cache# debsums -ac procps
debsums: missing file /etc/sysctl.d/10-link-restrictions.conf (from procps package)

Just found this, because I also noticed the debsums error. A quick look in the changelog finds this:
> procps (2:3.3.16-1ubuntu1) focal; urgency=low
> [...]
> * Dropped changes, no longer needed:
> ...
> - 10-link-restrictions.conf: this is redundant with link-protect.conf
> from Debian.
> * debian/procps.maintscript: handle migration of link-protect.conf from
> /etc to /usr.
>
> -- Steve Langasek <email address hidden> Thu, 13 Feb 2020 22:53:02 -0800

But apparently that file never arrived downstream? Neither find /usr ... nor apt-file search can find it. Having had a look at the contents of said file by opening the .deb archive has me a bit worried:

> # These settings eliminate an entire class of security vulnerability:
> # time-of-check-time-of-use cross-privilege attacks using guessable
> # filenames (generally seen as "/tmp file race" vulnerabilities).

This could very well warrant a bump in severity, given there are security implications.

A simple workaround is to just copy that file manually into /etc/sysctl.d under a different name, so postinst can't find it, should it try to murder it again. :P Of course it won't solve the debsums error but it solves the bigger problem of the file missing entirely.

Oh, I just found the file. It has a different name than suggested in the changelog:

/usr/lib/sysctl.d/protect-links.conf

And silly me didn't of just checking what sysctl returns for those values set in there. It's all good:
$ sudo sysctl fs.protected_fifos
fs.protected_fifos = 1
$ sudo sysctl fs.protected_hardlinks
fs.protected_hardlinks = 1
$ sudo sysctl fs.protected_regular
fs.protected_regular = 2
$ sudo sysctl fs.protected_symlinks
fs.protected_symlinks = 1

So, from my POV the debsums error, while technically correct, is a non-issue.