I've analyzed the situation on Jammy, Impish and Focal and got the following result:
Jammy+Impish: /usr/lib/sysctl.d/50-default.conf:net.ipv4.conf.default.rp_filter = 2 => shadowed but equal value /usr/lib/sysctl.d/50-default.conf:net.ipv4.conf.*.rp_filter = 2 => shadows default.rp_filter & all.rp_filter (equal value) /usr/lib/sysctl.d/50-default.conf:-net.ipv4.conf.all.rp_filter /usr/lib/sysctl.d/50-default.conf:kernel.sysrq = 16 Focal (shadowed, but equal value): fs.protected_hardlinks = 1 fs.protected_symlinks = 1 So the critical ones seem to be kernel.sysrq = 16 and the removal of -net.ipv4.conf.all.rp_filter Settings shipped by procps: Jammy: root@jj:~# grep -v '^\s*$\|^\s*\#' -R /etc/sysctl.* # (excluding README.sysctl) /etc/sysctl.d/10-zeropage.conf:vm.mmap_min_addr = 65536 /etc/sysctl.d/10-network-security.conf:net.ipv4.conf.default.rp_filter=2 /etc/sysctl.d/10-network-security.conf:net.ipv4.conf.all.rp_filter=2 /etc/sysctl.d/10-kernel-hardening.conf:kernel.kptr_restrict = 1 /etc/sysctl.d/99-cloudimg-ipv6.conf:net.ipv6.conf.all.use_tempaddr = 0 /etc/sysctl.d/99-cloudimg-ipv6.conf:net.ipv6.conf.default.use_tempaddr = 0 /etc/sysctl.d/10-ptrace.conf:kernel.yama.ptrace_scope = 1 /etc/sysctl.d/10-console-messages.conf:kernel.printk = 4 4 1 7 /etc/sysctl.d/10-ipv6-privacy.conf:net.ipv6.conf.all.use_tempaddr = 2 /etc/sysctl.d/10-ipv6-privacy.conf:net.ipv6.conf.default.use_tempaddr = 2 /etc/sysctl.d/10-magic-sysrq.conf:kernel.sysrq = 176 Impish: - same as Jammy Focal: - same as Jammy, plus: /etc/sysctl.d/10-link-restrictions.conf:fs.protected_hardlinks = 1 /etc/sysctl.d/10-link-restrictions.conf:fs.protected_symlinks = 1 Settings shipped by systemd: Jammy: root@jj:~# grep -v '^\s*$\|^\s*\#' -R /usr/lib/sysctl* /usr/lib/sysctl.d/50-default.conf:kernel.sysrq = 16 /usr/lib/sysctl.d/50-default.conf:kernel.core_uses_pid = 1 /usr/lib/sysctl.d/50-default.conf:net.ipv4.conf.default.rp_filter = 2 /usr/lib/sysctl.d/50-default.conf:net.ipv4.conf.*.rp_filter = 2 /usr/lib/sysctl.d/50-default.conf:-net.ipv4.conf.all.rp_filter /usr/lib/sysctl.d/50-default.conf:net.ipv4.conf.default.accept_source_route = 0 /usr/lib/sysctl.d/50-default.conf:net.ipv4.conf.*.accept_source_route = 0 /usr/lib/sysctl.d/50-default.conf:-net.ipv4.conf.all.accept_source_route /usr/lib/sysctl.d/50-default.conf:net.ipv4.conf.default.promote_secondaries = 1 /usr/lib/sysctl.d/50-default.conf:net.ipv4.conf.*.promote_secondaries = 1 /usr/lib/sysctl.d/50-default.conf:-net.ipv4.conf.all.promote_secondaries /usr/lib/sysctl.d/50-default.conf:-net.ipv4.ping_group_range = 0 2147483647 /usr/lib/sysctl.d/50-default.conf:-net.core.default_qdisc = fq_codel /usr/lib/sysctl.d/50-default.conf:fs.protected_hardlinks = 1 /usr/lib/sysctl.d/50-default.conf:fs.protected_symlinks = 1 /usr/lib/sysctl.d/50-default.conf:fs.protected_regular = 1 /usr/lib/sysctl.d/50-default.conf:fs.protected_fifos = 1 /usr/lib/sysctl.d/50-pid-max.conf:kernel.pid_max = 4194304 Impish: - same as Jammy Focal: root@ff:~# grep -v '^\s*$\|^\s*\#' -R /usr/lib/sysctl* /usr/lib/sysctl.d/50-default.conf:net.ipv4.conf.default.promote_secondaries = 1 /usr/lib/sysctl.d/50-default.conf:net.ipv4.conf.*.promote_secondaries = 1 /usr/lib/sysctl.d/50-default.conf:-net.ipv4.conf.all.promote_secondaries /usr/lib/sysctl.d/50-default.conf:-net.ipv4.ping_group_range = 0 2147483647 /usr/lib/sysctl.d/50-default.conf:net.core.default_qdisc = fq_codel /usr/lib/sysctl.d/50-default.conf:fs.protected_regular = 1 /usr/lib/sysctl.d/50-default.conf:fs.protected_fifos = 1 /usr/lib/sysctl.d/50-pid-max.conf:kernel.pid_max = 4194304 /usr/lib/sysctl.d/protect-links.conf:fs.protected_fifos = 1 /usr/lib/sysctl.d/protect-links.conf:fs.protected_hardlinks = 1 /usr/lib/sysctl.d/protect-links.conf:fs.protected_regular = 2 /usr/lib/sysctl.d/protect-links.conf:fs.protected_symlinks = 1 => Focal changes: fs.protected_regular = 2 net.core.default_qdisc = fq_codel ** Changed in: systemd (Ubuntu) Status: New => Triaged -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, 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 systemd package in Ubuntu: Triaged Bug description: 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. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1962038/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp