[Bug 1962038] Re: wrong sysrq value in /usr/lib/sysctl.d/50-default.conf

[Steve Langasek]

On Tue, Mar 08, 2022 at 04:11:45PM -0000, Lukas Märdian wrote:

> >> systemd should drop its setting to defer to the file that we have been
> >> carrying in procps for a very long time.

> > at some point it would be a better idea to drop the procps files and
> > adjust the systemd defaults where/if needed.  The sysctl configuration
> > hasn't been applied by procps since upstart; with systemd, the
> > systemd-sysctl service is what applies all the sysctl settings.

> We discussed this possibility during the Foundation team's meeting. But
> Steve wants to keep the policy in procps, as it has been in the past.

That's my current preference; but regardless, any moving of this to systemd
would need to handle a proper migration of the config files on upgrade,
which has not been done here today.

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to systemd in Ubuntu.
https://bugs.launchpad.net/bugs/1962038

Title:
  wrong sysrq value in /usr/lib/sysctl.d/50-default.conf

Status in procps package in Ubuntu:
  New
Status in systemd package in Ubuntu:
  In Progress
Status in procps source package in Impish:
  Won't Fix
Status in systemd source package in Impish:
  New
Status in procps source package in Jammy:
  New
Status in systemd source package in Jammy:
  In Progress

Bug description:
  [Impact]

  I've just learned that systemd is setting kernel.sysrq to 16 in
  /usr/lib/sysctl.d/50-default.conf.  This is inconsistent with
  /etc/sysctl.d/10-magic-sysrq.conf which intentionally sets it to 176
  by default.  systemd should drop its setting to defer to the file that
  we have been carrying in procps for a very long time.

  Therefore, users can only sync their storage but not do any other
  actions using the magic sysrq key.

  [Test Plan]

  $ sysctl kernel.sysrq
  => This should show "kernel.sysrq = 176" as set by /etc/sysctl.d/10-magic-sysrq.conf
  $ sysctl net.ipv4.conf.all.rp_filter
  => This should show "net.ipv4.conf.all.rp_filter=2" as set by /etc/sysctl.d/10-network-security.conf

  [Where problems could occur]

   * This patch changes systemd's sysctl configuration in /lib/sysctl.d/*.conf
   * If something is broken it could fail to apply any of systemd's sysctl configuration, but Ubuntu's defaults from /etc/sysctl.d/*.conf would still be in place.

  [Other Info]
   
   * None

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/procps/+bug/1962038/+subscriptions