Before this patch the only way to prevent journald from reading the audit
messages was to mask systemd-journald-audit.socket. However this had main
drawback that downstream couldn't ship the socket disabled by default (beside
the fact that masking units is not supposed to be the usual way to disable
them).
Fixes#15777
We are basically already there, just need to add MONOTONIC_USEC= to the
RELOADING=1 message, and make sure the message is generated in really
all cases.
And send READY=1 again when we are done with it.
We do this not only for "daemon-reload" but also for "daemon-reexec" and
"switch-root", since from the perspective of an encapsulating service
manager these three operations are not that different.
This adds the same condition that systemd-networkd.service already
carries also to systemd-networkd-wait-online.service. Otherwise we'll
potentially see some logs we'd rather not see about a service we BindTo=
not running. Or in other words, if service X binds to Y then X should be
at least as conditioned as Y.
Note that this drops ProtectProc=invisible from
systemd-resolved.service.
This is done because othewise access to the booted "kernel" command line is not
necessarily available. That's because in containers we want to read
/proc/1/cmdline for that.
Fixes: #24103
This renames systemd-boot-system-token.service to
systemd-boot-random-seed.service and conditions it less strictly.
Previously, the job of the service was to write a "system token" EFI
variable if it was missing. It called "bootctl --graceful random-seed"
for that. With this change we condition it more liberally: instead of
calling it only when the "system token" EFI variable isn't set, we call
it whenever a boot loader interface compatible boot loader is used. This
means, previously it was invoked on the first boot only: now it is
invoked at every boot.
This doesn#t change the command that is invoked. That's because
previously already the "bootctl --graceful random-seed" did two things:
set the system token if not set yet *and* refresh the random seed in the
ESP. Previousy we put the focus on the former, now we shift the focus to
the latter.
With this simple change we can replace the logic
f913c784ad added, but from a service that
can run much later and doesn't keep the ESP pinned.
We want to make use of that when formatting file systems, hence let's
pull in these modules explicitly.
(This is necessary because we are an early boot service that might run
before systemd-tmpfiles-dev.service, which creates /dev/loop-control and
/dev/mapper/control.)
Alternatively we could just order ourselves after
systemd-tmpfiles-dev.service, but I think there's value in adding an
explicit minimal ordering here, since we know what we'll need.
Fixes: #25775
If everything points to the fact that TPM2 should work, but then the
driver fails to initialize we should handle this gracefully and not
cause failing services all over the place.
Fixes: #25700
We don't want systemd-networkd-wait-online to start if systemd-networkd
is skipped due to condition failures. This is only guaranteed by BindsTo=
and not Requires=, so let's use BindsTo=
sd-stub has an opportunity to handle the seed the same way sd-boot does,
which would have benefits for UKIs when sd-boot is not in use. This
commit wires that up.
It refactors the XBOOTLDR partition discovery to also find the ESP
partition, so that it access the random seed there.
Removing the virtualization check might not be the worst thing in the
world, and would potentially get many, many more systems properly seeded
rather than not seeded. There are a few reasons to consider this:
- In most QEMU setups and most guides on how to setup QEMU, a separate
pflash file is used for nvram variables, and this generally isn't
copied around.
- We're now hashing in a timestamp, which should provide some level of
differentiation, given that EFI_TIME has a nanoseconds field.
- The kernel itself will additionally hash in: a high resolution time
stamp, a cycle counter, RDRAND output, the VMGENID uniquely
identifying the virtual machine, any other seeds from the hypervisor
(like from FDT or setup_data).
- During early boot, the RNG is reseeded quite frequently to account for
the importance of early differentiation.
So maybe the mitigating factors make the actual feared problem
significantly less likely and therefore the pros of having file-based
seeding might outweigh the cons of weird misconfigured setups having a
hypothetical problem on first boot.
Rather than passing seeds up to userspace via EFI variables, pass seeds
directly to the kernel's EFI stub loader, via LINUX_EFI_RANDOM_SEED_TABLE_GUID.
EFI variables can potentially leak and suffer from forward secrecy
issues, and processing these with userspace means that they are
initialized much too late in boot to be useful. In contrast,
LINUX_EFI_RANDOM_SEED_TABLE_GUID uses EFI configuration tables, and so
is hidden from userspace entirely, and is parsed extremely early on by
the kernel, so that every single call to get_random_bytes() by the
kernel is seeded.
In order to do this properly, we use a bit more robust hashing scheme,
and make sure that each input is properly memzeroed out after use. The
scheme is:
key = HASH(LABEL || sizeof(input1) || input1 || ... || sizeof(inputN) || inputN)
new_disk_seed = HASH(key || 0)
seed_for_linux = HASH(key || 1)
The various inputs are:
- LINUX_EFI_RANDOM_SEED_TABLE_GUID from prior bootloaders
- 256 bits of seed from EFI's RNG
- The (immutable) system token, from its EFI variable
- The prior on-disk seed
- The UEFI monotonic counter
- A timestamp
This also adjusts the secure boot semantics, so that the operation is
only aborted if it's not possible to get random bytes from EFI's RNG or
a prior boot stage. With the proper hashing scheme, this should make
boot seeds safe even on secure boot.
There is currently a bug in Linux's EFI stub in which if the EFI stub
manages to generate random bytes on its own using EFI's RNG, it will
ignore what the bootloader passes. That's annoying, but it means that
either way, via systemd-boot or via EFI stub's mechanism, the RNG *does*
get initialized in a good safe way. And this bug is now fixed in the
efi.git tree, and will hopefully be backported to older kernels.
As the kernel recommends, the resultant seeds are 256 bits and are
allocated using pool memory of type EfiACPIReclaimMemory, so that it
gets freed at the right moment in boot.
As in most cases, tty device without input devices is meaningless.
This also swaps the priority of tty and net:
- input devices are often connected under USB bus, hence may take
slightly much time to be initialized. As, described in the above,
in most cases it is allowed that tty devices are initialized just
before input devices,
- network configuration usually requires much time, e.g. DHCP or RA,
hence it is better that network interfaces initialized. Then,
network services can start DHCP client or friends earlier.
Fixes#24026.
This adds two more phases to the PCR boot phase logic: "sysinit" +
"final".
The "sysinit" one is placed between sysinit.target and basic.target.
It's good to have a milestone in this place, since this is after all
file systems/LUKS volumes are in place (which sooner or later should
result in measurements of their own) and before services are started
(where we should be able to rely on them to be complete).
This is particularly useful to make certain secrets available for
mounting secondary file systems, but making them unavailable later.
This breaks API in a way (as measurements during runtime will change),
but given that the pcrphase stuff wasn't realeased yet should be OK.
With this, I can now easily do:
systemd-nspawn --load-credential=ssh.authorized_keys.root:/home/lennart/.ssh/authorized_keys --image=… --boot
To boot into an image with my SSH key copied in. Yay!
This partially reverts cabc1c6d7a.
The setting ProtectClock= implies DeviceAllow=, which is not suitable
for udevd. Although we are slowly removing cgropsv1 support, but
DeviceAllow= with cgroupsv1 is necessarily racy, and reloading PID1
during the early boot process may cause issues like #24668.
Let's disable ProtectClock= for udevd. And, if necessary, let's
explicitly drop CAP_SYS_TIME and CAP_WAKE_ALARM (and possibly others)
by using CapabilityBoundingSet= later.
Fixes#24668.
Normally we queue initrd-switch-root.target/isolate, which pulls in the
service via Wants= in the .target unit file. But if the service is instead
started directly, there may be nothing pulling in the target. Let's make
sure that the reference exists.
If we want to stop those services which would compete for access to
the console, we need to have an ordering so that they are actually
stopped before the other things starts, not asynchronously.
For shutdown, we queue shutdown.target/start, so in every unit which should be
stopped *before* shutdown, we need both Conflicts and an ordering dependency
with shutdown.target (either Before= or After= would work, because stop jobs
are always ordered before start jobs).
For initrd transition, we queue initrd-switch-root.service/isolate. This
automatically creates a /stop job for every running unit without
IgnoreOnIsolate. But no ordering dependency is created, unless the unit has a
(possibly transitive) ordering dependency on initrd-switch-root.service.
Since most units must stop before the transition, we should add the ordering
dependency. It is nicer to use Before=initrd-switch-root.target for this.
initrd-switch-root.target is ordered before initrd-switch-root.service, so
the effect it the same when both are in a transaction.
Fixes#23745.
To also cover the case where somebody is emergency mode in the initrd and
queues initrd-switch-root.service/start (not isolate), also add
Conflicts=initrd-switch-root.target, so various units are stopped properly.
This extends 2525682565 to cover all the other
services that are touched. It could be consider "operator error", but it's
easy to make and it's nicer if we can make this more foolproof.
The block is reordered and split to have:
1. description + documentation
2. (optionally) conditions
3. all the dependencies
I think it's easier to read the units this way.
Also, the Conflicts+Before is seperated out to separate lines.
The ordering dependency is "fake", because it could just as well be
After=, we are adding it to force ordering wrt. shutdown.target, and
it plays a different role than the other Before=, which are about a
real ordering on boot.
Commit 70e74a5997 ("pstore: Run after modules are loaded") added After=
and Wants= entries for all known kernel modules providing a pstore.
While adding these dependencies on systems where one of the modules is
not present, or not configured, should not have a real affect on the
system, it can produce annoying error messages in the kernel log. E.g.
"mtd device must be supplied (device name is empty)" when the mtdpstore
module is not configured correctly.
Since dependencies cannot be removed with drop-ins, if a distro wants to
remove some of these modules from systemd-pstore.service, they need to
patch units/systemd-pstore.service.in. On the other hand, if they want
to append to the dependencies this can be done by shipping a drop-in.
Since the original intent of the previous commit was to fix [1], which
only requires the efi_pstore module, remove all other kernel module
dependencies from systemd-pstore.service, and let distros ship drop-ins
to add dependencies if needed.
[1] https://github.com/systemd/systemd/issues/18540
Quoting https://github.com/systemd/systemd/pull/24054#issuecomment-1210501631:
> this would need a patch in dracut, specifically adding the
> systemd-sysroot-fstab-check to the list of installed stuff:
> fe8fa2b0ca/modules.d/00systemd/module-setup.sh (L47).
>
> I could do this manually in the CI (and I guess I'd have to do it anyway even
> if the patch lands in upstream, since it won't be available in C8S), but it
> should get there first before merging this PR, otherwise it's going to break
> Rawhide.
Let's remove the baud settings for the container getty units since
they don't have any effect there anyway. On top of that, when we're
dealing with container TTYs, we can handle all the setup involved
ourselves so let's prevent agetty/login from touching the container
tty at all.
One example where this helps is that it actually makes disabling
TTYVHangup have an effect since before, login would unconditionally
call vhangup() on the tty.
This makes use of the option switch that was added in the previous commit.
We used a pretty big hammer on a relatively small nail: we would do daemon-reload
and (in principle) allow any configuration to be changed. But in fact we only
made use of this in systemd-fstab-generator. systemd-fstab-generator filters
out all mountpoints except /usr and those marked with x-initrd.mount, i.e. on
a big majority of systems it wouldn't do anything.
Also, since systemd-fstab-generator first parses /proc/cmdline, and then
initrd's /etc/fstab, and only then /sysroot/etc/fstab, configuration in the
host would only matter if it the same mountpoint wasn't configured "earlier".
So the config in the host could be used for new mountpoints, but it couldn't
be used to amend configuration for existing mountpoints. And we wouldn't actually
remount anything, so mountpoints that were already mounted wouldn't be affected,
even if did change some config.
In the new scheme, we will parse /sysroot/etc/fstab and explicitly start
sysroot-usr.mount and other units that we just wrote. In most cases (as written
above), this will actually result in no units being created or started.
If the generator is invoked on a system with /sysroot/etc/fstab present,
behaviour is not changed and we'll create units as before. This is needed so
that if daemon-reload is later at some points, we don't "lose" those units.
There's a minor bugfix here: we honour x-initrd.mount for swaps, but we
wouldn't restart swap.target, i.e. the new swaps wouldn't necessarilly be
pulled in immediately.
