Basically, we turn it on for most long-running services, with the
exception of machined (whose child processes need to join containers
here and there), and importd (which sandboxes tar in a CLONE_NEWNET
namespace). machined is left unrestricted, and importd is restricted to
use only "net"
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.
Add a line
SystemCallFilter=~@clock @module @mount @obsolete @raw-io ptrace
for daemons shipped by systemd. As an exception, systemd-timesyncd
needs @clock system calls and systemd-localed is not privileged.
ptrace(2) is blocked to prevent seccomp escapes.
Apparently, disk IO issues are more frequent than we hope, and 1min
waiting for disk IO happens, so let's increase the watchdog timeout a
bit, for all our services.
See #1353 for an example where this triggers.
Also, rename ProtectedHome= to ProtectHome=, to simplify things a bit.
With this in place we now have two neat options ProtectSystem= and
ProtectHome= for protecting the OS itself (and optionally its
configuration), and for protecting the user's data.
ReadOnlySystem= uses fs namespaces to mount /usr and /boot read-only for
a service.
ProtectedHome= uses fs namespaces to mount /home and /run/user
inaccessible or read-only for a service.
This patch also enables these settings for all our long-running services.
Together they should be good building block for a minimal service
sandbox, removing the ability for services to modify the operating
system or access the user's private data.
Adds a new call sd_event_set_watchdog() that can be used to hook up the
event loop with the watchdog supervision logic of systemd. If enabled
and $WATCHDOG_USEC is set the event loop will ping the invoking systemd
daemon right after coming back from epoll_wait() but not more often than
$WATCHDOG_USEC/4. The epoll_wait() will sleep no longer than
$WATCHDOG_USEC/4*3, to make sure the service manager is called in time.
This means that setting WatchdogSec= in a .service file and calling
sd_event_set_watchdog() in your daemon is enough to hook it up with the
watchdog logic.
This should help making the boot process a bit easier to explore and
understand for the administrator. The simple idea is that "systemctl
status" now shows a link to documentation alongside the other status and
decriptionary information of a service.
This patch adds the necessary fields to all our shipped units if we have
proper documentation for them.
We finally got the OK from all contributors with non-trivial commits to
relicense systemd from GPL2+ to LGPL2.1+.
Some udev bits continue to be GPL2+ for now, but we are looking into
relicensing them too, to allow free copy/paste of all code within
systemd.
The bits that used to be MIT continue to be MIT.
The big benefit of the relicensing is that closed source code may now
link against libsystemd-login.so and friends.
Lennart Poettering