units: further lock down our long-running services

Let's make this an excercise in dogfooding: let's turn on more security
features for all our long-running services.

Specifically:

- Turn on RestrictRealtime=yes for all of them

- Turn on ProtectKernelTunables=yes and ProtectControlGroups=yes for most of
  them

- Turn on RestrictAddressFamilies= for all of them, but different sets of
  address families for each

Also, always order settings in the unit files, that the various sandboxing
features are close together.

Add a couple of missing, older settings for a numbre of unit files.

Note that this change turns off AF_INET/AF_INET6 from udevd, thus effectively
turning of networking from udev rule commands. Since this might break stuff
(that is already broken I'd argue) this is documented in NEWS.

1 files changed, 3 insertions, 1 deletions

diff --git a/units/systemd-journald.service.in b/units/systemd-journald.service.in
index 08ace8ae44..712ce55483 100644
--- a/units/systemd-journald.service.in
+++ b/units/systemd-journald.service.in
@@ -21,10 +21,12 @@ Restart=always
 RestartSec=0
 NotifyAccess=all
 StandardOutput=null
-CapabilityBoundingSet=CAP_SYS_ADMIN CAP_DAC_OVERRIDE CAP_SYS_PTRACE CAP_SYSLOG CAP_AUDIT_CONTROL CAP_AUDIT_READ CAP_CHOWN CAP_DAC_READ_SEARCH CAP_FOWNER CAP_SETUID CAP_SETGID CAP_MAC_OVERRIDE
 WatchdogSec=3min
 FileDescriptorStoreMax=1024
+CapabilityBoundingSet=CAP_SYS_ADMIN CAP_DAC_OVERRIDE CAP_SYS_PTRACE CAP_SYSLOG CAP_AUDIT_CONTROL CAP_AUDIT_READ CAP_CHOWN CAP_DAC_READ_SEARCH CAP_FOWNER CAP_SETUID CAP_SETGID CAP_MAC_OVERRIDE
 MemoryDenyWriteExecute=yes
+RestrictRealtime=yes
+RestrictAddressFamilies=AF_UNIX AF_NETLINK
 SystemCallFilter=~@clock @cpu-emulation @debug @keyring @module @mount @obsolete @raw-io
 
 # Increase the default a bit in order to allow many simultaneous