Commit Graph
9819 Commits
Author SHA1 Message Date
Christian Brauner 9b62fd169e Extend W^X memory protection mechanism for RestrictFileSystemAccess (#43511)
Currently `RestrictFileSystemAccess` isn't trying hard enough to enforce
W^X and thus there are still places where an executable and writable
mapping can be created:

* `/proc/<pid>/mem` `FOLL_FORCE` writes
* `PTRACE_POKE{TEXT,DATA}` `FOLL_FORCE` writes
* `MAP_PRIVATE | MAP_EXECUTABLE` memory mappings

Let's block all of these mechanisms. Do note that
`RestrictFileSystemAccess` is still in very active development and also
cannot meaningfully be used on general purpose distros and systems.

Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-09-01 07:12:13 +02:00
Christian Brauner 62e665cacc core: check that proc_mem.force_override=never is active
The kernel silently ignores command line options it doesn't know. So a
kernel without CONFIG_PROC_MEM_* would pass the command line check while
still allowing FOLL_FORCE memory overwrites. Write one byte through
/proc/self/mem into a private read-only anonymous page. That can only
succeed with FOLL_FORCE writes supported.

Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-08-31 23:33:40 +02:00
Christian Brauner 0016132c3c core: block /proc/pid/mem FOLL_FORCE writes when RestrictFileSystemAccess= is enabled
In addition to PTRACE_POKE{TEXT,DATA} /proc/<pid>/mem can also be used
to FOLL_FORCE write into a trusted process's executable pages. Require
proc_mem.force_override=never.

Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-08-31 23:33:40 +02:00
Christian Brauner 4f4502ed23 core: block PTRACE_POKE{TEXT,DATA} when RestrictFileSystemAccess= is enabled
PTRACE_POKETEXT and PTRACE_POKEDATA use FOLL_FORCE to forcibly write
into a tracee's memory. That includes executable read-only pages. If we
restrict execution to trusted binaries PID 1 must enforce that it's
impossible to abuse this to get untrusted code execution. Note, that
usermodehelpers are not subject to PID 1's seccomp filters.

Install a ptrace seccomp filter from PID 1 if RestrictFileSystemAccess=
is requested. Every process it spawns will inherit it.

Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-08-31 23:33:40 +02:00
Christian Brauner 73e093d16d core: centralize RestrictFileSystemAccess= checks
Centralize the checks for RestrictFileSystemAccess= requirements.

Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-08-31 23:33:39 +02:00
Chris Down fdf0876bc7 core: Don't racily stop Type=dbus services when the bus broker restarts
If dbus dies, it is then immediately reactivated by dbus.socket as soon
as a client reconnects. In that case pid1's own connection to the bus
drops and is reestablished by manager_recheck_dbus() (which comes from
the unit_notify() when dbus.services goes back to being running).

As part of bringing the bus back up, bus_setup_api() issues
GetNameOwner() for every name we watch on behalf of a BusName= unit.

For a Type=dbus service this is a problem. Consider this scenario:

1. spearmint.service is Type=dbus, owns com.example.Spearmint, and is
   running.
2. The broker crashes and is re-activated through dbus.socket.
3. spearmint's client connection dropped too, so it is now reconnecting
   to the new broker to grab its name again.
4. pid1 racily reconnects first given it is triggered the moment
   dbus.service reaches SERVICE_RUNNING, whereas spearmint is an
   ordinary client that must first notice its own disconnection and thus
   when we do GetNameOwner() com.example.Spearmint is reported as having
   no owner.
5. service_bus_name_owner_change() sets bus_name_good = false, and since
   service_good() returns false for a Type=dbus service without its
   name, service_enter_running() stops the (perfectly healthy, other
   than dbus kicking the bucket temporarily) service.

In other words, a broker restart can tear down running Type=dbus
services that did nothing wrong, really.

So, to fix this, we can use the fact that a NameOwnerChanged signal is
definitive. That is, the name's owner changed while we were connected,
so a service that crashes or drops its name can still be stopped
immediately. By contrast a GetNameOwner() reply is less authoritative.

There is, importantly, no change to how losing the name on a live
connection works, we only give grace on reconnect.
2026-09-01 02:12:52 +09:00
Chris Down 00cf56abbd core: Add SERVICE_RUNNING_REVALIDATING state
For a Type=dbus service we sometimes want to keep treating it as running
while its bus name has briefly gone away (for example, due to a broker
restart).

SERVICE_RUNNING_REVALIDATING is active and keeps its main process like
SERVICE_RUNNING, but it's deliberately not part of the runtime timer
set, so RuntimeMaxSec= is paused while we sit in it.
2026-09-01 02:12:52 +09:00
Luca Boccassi b27a47207c core: minor PAM fixes (#43576)
Fixes: #39617
2026-08-31 16:57:19 +01:00
Konstantin Shkolnyy d1697c4ff8 kmod-setup: support early loading for virtio-ccw devices
Before this change, the code checked for presence of virtio-pci
devices to decide whether transport-agnostic virtio drivers needed
to be loaded early.

Do it also if virtio-ccw devices are present, that is, devices with
the control unit type (CU type) 0x3832, under /sys/devices/css0.
(This CU type value is documented in "Virtio Over Channel I/O" virtio
specification section.)

In other words, extend to virtio-ccw devices the fix previously
done for virtio-pci:
  #40161: commit 356cc4a1c3
  #40503: commit 6d36e5fae6

Tested-by: Marc Hartmayer <marc@linux.ibm.com>
Reviewed-by: Marc Hartmayer <marc@linux.ibm.com>
2026-08-31 19:40:33 +09:00
Lennart Poettering f5d545ab77 core: fix error code passed to pam_syslog_pam_error() 2026-08-31 12:02:58 +02:00
felix h a11144d0a9 tree-wide: format man page references as foo(1) 2026-08-28 06:34:45 +09:00
Zbigniew Jędrzejewski-Szmek 34d4d50d08 Another batch of conversions to COMMAND and additions of --introspect-cli (#43512) 2026-08-26 15:22:50 +02:00
Zbigniew Jędrzejewski-Szmek 4f2b0e977c core: convert to VERB_COMMAND and add --introspect-cli
--introspect-cli follows the same deferred pattern as --help: parse_argv()
only records the action, and it is executed in the same place where
ACTION_HELP and ACTION_VERSION are handled.

The help is looked up by explicit name: in the multicall configuration
the systemd and systemd-executor commands share one binary, so the
"first COMMAND" default would depend on link order.

The "This program takes no positional arguments." line is dropped from
the help output — the default "[OPTION…]" synopsis already says so.
(And also, this is not quite true. It does take positional args when
called as init.)
2026-08-26 12:22:15 +02:00
Zbigniew Jędrzejewski-Szmek 044ebd7e54 executor: convert to VERB_COMMAND and add --introspect-cli
The help is looked up by explicit name: in the multicall configuration
the systemd and systemd-executor commands share one binary.
2026-08-26 12:15:35 +02:00
David 'equinox' Lamparter 1aedc8fe5e core/service: document & improve STOPPING=1
`STOPPING=1` is final, explain in the sd_notify man page that this is
the case and log an error if a service attempts to get back out of
STOPPING with another notification.

Fixes #43465 / 98734ac74d
2026-08-24 22:46:01 +09:00
tunaichao 641c19e21e core: apply UnsetEnvironment= after command line expansion
UnsetEnvironment= was applied to the environment block before the
command line was expanded. Since the expansion looks the variables up
in that same block, any variable listed in UnsetEnvironment= was
already gone when $VAR in ExecStart= and friends was expanded, and a
whole-word $VAR reference was dropped from the command line.

Let the expansion see the full environment block, and apply the
unsetting only to the environment block passed to the executed
process. This way UnsetEnvironment= can hide variables from the
executed process without breaking command lines that reference them.

Extend the exec-unsetenvironment test accordingly: the whole-word
$VAR6 argument must be expanded into a positional parameter for the
shell, while ${VAR6-X} must evaluate to X in the executed process.

Also document in both the UnsetEnvironment= description and the
"Environment Variables in Spawned Processes" section that the
unsetting happens after command line variable expansion.

Fixes: #43343
2026-08-22 04:27:27 +09:00
Chris Ayoub 0b87becb0a core: clear dependency graph before freeing all units
When the manager tears down every unit during reload or shutdown,
unit_free() removes each dependency from both endpoints. This work is
redundant because every dependency map is about to disappear, and it
scales poorly with thousands of synthesized mount units.

Clear all unit dependency maps in one manager-wide pass before invoking
the existing unit_free() cleanup.

With 10,000 bind mounts, this reduced the mean daemon-reload time from
63.558s to 14.708s.
2026-08-22 04:21:35 +09:00
dongshengyuan 31ef154f15 core: fix integer truncation checks
Use explicit bounds checks for size_t and long conversions
so compilers cannot optimize away round-trip cast checks.

Follow-up for 78238fd7c9.
2026-08-19 02:28:19 +09:00
Yu Watanabe 90481c0b1b tree-wide: add missing assertions
Found by coccinelle.
2026-08-18 06:30:10 +09:00
dongshengyuan 507ba1e51c core: fix bind paths whitespace parsing
Stop warning on extra spaces in BindPaths= and BindReadOnlyPaths=.
Keep bind path parsing and serialization consistent.

Fixes: #43214
2026-08-15 00:26:40 +09:00
dongshengyuan f4284e9ceb path-lookup: reject empty env path components
Only trailing empty components have special meaning:
they request appending the built-in defaults.

Share the validation between normal path lookup and
systemd-analyze verify, so verify does not compose
values that path lookup later rejects.

Propagate generator path parse errors instead of
turning them into empty generator paths.

Follow-up for: cf7d80a5fe
2026-08-14 00:27:09 +09:00
dongshengyuan e98c68104b core: do not chown fd-passed TTYs
When stdio is passed as file descriptors, the provider of those
descriptors remains responsible for their ownership and access mode.

This keeps run0 in a pipeline from changing the caller's TTY ownership
to the target user, which can otherwise break later terminal access from
the original user.

Fixes #43336
2026-08-12 03:11:02 +09:00
Christian Brauner e37151765f core: gate bpf_real_data_inode() use on kernel support
Probe the kernel BTF for bpf_real_data_inode() and set the BPF program's
.rodata flag accordingly. The flag has to be written for every open of
the skeleton because .rodata is frozen once the object is loaded, so fold
the two open and load attempts into a common helper.

A positive BTF probe isn't a guarantee. It tells us that the function
exists, not that it is registered as an LSM kfunc with the signature we
expect. So if loading with resolution enabled fails anyway, retry with
the flag off. Files on union filesystems are then denied like they were
before which is a lot better than turning kernel drift into a boot
failure.

Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-08-10 16:09:06 +02:00
Yu Watanabe f8f2860750 core/service: Prevent accidental service termination during reload (#39692)
We currently blindly send the configured reload signal (e.g. SIGHUP or
SIGUSR1) to the main service PID for Type=notify-reload units, even if
the service hasn't installed a userspace handler. This can lead to
invoking unintended default behavior (typically process termination) in
daemons which later deprecate and remove their reload handler.

This is a real problem we have seen in production on multiple occasions.
In one particularly egregious instance, a production distributed storage
service had a large percentage of its nodes all terminate at once when
sent a reload signal. In this case a signal handler had been removed,
but another place still sending the signal was missed.

To mitigate this, introduce two new checks for Type=notify-reload
services:

1. On READY=1: When the service first sends READY=1 during initial
startup, we check for the handler. If it's missing, the service startup
is failed with SERVICE_FAILURE_PROTOCOL. This enforces the contract that
services *must* install their handler before signalling readiness.

2. On reload: Immediately before sending the reload signal, we check
again. If the handler is now missing, we log a warning but still send
the signal. This preserves the requested operator action while making
the missing handler visible.

The startup check catches definite static misconfiguration before the
service is accepted as ready. The reload check is advisory because the
service has already started successfully, but warns if its handler later
disappears. Together these provide a best-effort safety net while
preserving the agreed reload semantics.
2026-08-07 01:23:03 +09:00
Semyon Klintsov 0168430d91 dbus: allow FreezeUnit and ThawUnit D-Bus requests (#43292)
This change adds explicit D-Bus policy rules to allow calling the
Freeze and Thaw methods on the systemd interfaces.

- Add D-Bus policy rules for Manager interface FreezeUnit/ThawUnit methods
- Add D-Bus policy rules for Unit interface Freeze/Thaw methods
2026-08-05 14:44:25 +01:00
Chris Down d361e5ba34 core/service: Prevent accidental service termination during reload
We currently blindly send the configured reload signal (e.g. SIGHUP or
SIGUSR1) to the main service PID for Type=notify-reload units, even if
the service hasn't installed a userspace handler. This can lead to
invoking unintended default behavior (typically process termination) in
daemons which later deprecate and remove their reload handler.

This is a real problem we have seen in production on multiple occasions.
In one particularly egregious instance, a production distributed storage
service had a large percentage of its nodes all terminate at once when
sent a reload signal. In this case a signal handler had been removed, but
another place still sending the signal was missed.

To mitigate this, introduce signal handler validation for
Type=notify-reload services. We check both SigCgt (traditional handlers
via sigaction) and SigBlk (blocked signals for signalfd) to detect valid
handler configurations:

1. On first READY=1: When the service first sends READY=1 during initial
   startup, we check for the handler. If it's missing, the service
   startup is aborted with Result=protocol.

2. On reload: Immediately before sending the reload signal, we check
   again. If the handler is missing, we log a warning but still send
   the signal.

The rationale is that a missing handler at first startup represents a
definite misconfiguration that should be caught early. A missing handler
at reload time is warned about, but we defer to the operator's judgement
since the service already started successfully.

These checks are a best-effort, pragmatic safety net. They are naturally
racy, but in practice they prevent the common class of bugs from static
misconfiguration or software updates.
2026-08-04 16:51:37 -07:00
Yu Watanabe f4cb4596a3 core/bpf: avoid redundant BPF program loading (#43234)
Replaces #43211 and #43213.
2026-08-04 08:10:00 +09:00
Morteza Pourkazemi 5f0d98e728 Add ActivatingConcurrencyMax for slice startup pacing
Introduce Slice.ActivatingConcurrencyMax to limit how many units
within a slice hierarchy may be in activating state concurrently.

Expose the setting over D-Bus, support transient/property parsing,
enforce it during unit start dispatch, and re-check queued starts when
units leave activating state.

Document the new slice option and add a PID1 concurrency test covering
queued startup behavior.
2026-08-03 14:29:07 +09:00
dongshengyuan 78238fd7c9 socket: parse message queue size as IEC size
Allow MessageQueueMessageSize= to accept IEC size suffixes in socket unit files.
Support the same syntax for transient property assignments.
Keep MessageQueueMaxMessages= as a plain message count.
2026-08-02 19:17:51 +09:00
Zbigniew Jędrzejewski-Szmek 9eee40e687 selinux: alternate root support (#42768)
This PR changes some SELinux bits related to working with alternate
roots (specifically when using `--root` or `--image` on a bunch of
executables).

It addresses bug #42643 and it's hopefully the more whole approach than
the naive approach I PR'ed in #42644.

Before this PR the 'wrong' labels get applied because the path lookups
in the SELinux label database are prefixed with whatever the location of
the alternate root is (explained in more detail below).

Initially I had taken a very naive approach that did fix the issue by
stripping the alternate root from the path; however this still looks up
that path in the hosts' label database, which might differ from the one
contained in the alternate root.

So this expanded approach actually reads the label database from the
alternate root, strips the prefix *if* an alternate root is used
directly in `selinux-util.c` and then uses that to assign labels
instead.

See under the line for the behavior pre/post.

I've tried builds of this PR on both enforcing/non-enforcing/non-enabled
hosts *and* on enabled/non-enabled disk images and things seem to work
or at least fall back to ignoring MAC when required bits aren't present.

One thing is *if* an `/etc/selinux/config` is present that defines a
`SELINUXTYPE=` we *do* require the policy given to be present in the
image. This is the only new actual error in this code path that doesn't
get ignored.

We *could* verify that the path exists and also ignore it but I
personally don't think that's the right approach since the actual system
itself would likely also be broken anyhow. Let me know thoughts on that.

There's a tight coupling here still with the *hosts* SELinux policy in
that to set (potentially) unknown labels to the policy loaded in the
host kernel these executables would need to execute in a domain that
allows transitioning to `mac_admin`. I'd say that `install_t` is the
most likely candidate for that. See the first comment on this PR for
more explanation on it/request for input.

---

When mounting `a.raw` before running any tooling against it and showing
the `/etc/shadow` file labels we have:

```
€ sudo systemd-dissect --mount test/a.raw test/mnt/a
€ ls -Zlart test/mnt/a/etc/shadow
----------. 1 root root system_u:object_r:shadow_t:s0 520 Jun 27 07:55 test/mnt/a/etc/shadow
€ sudo systemd-dissect ---umount test/mnt/a
```

After running `systemd-firstboot` against the image, then remounting,
note the labels that have been changed to incorrect values:

```
€ sudo systemd-firstboot --image test/a.raw --root-password test    
/home/user/src/github.com/teamsbc/artifacts/test/a.raw: /etc/passwd written.
/home/user/src/github.com/teamsbc/artifacts/test/a.raw: /etc/shadow written.
€ sudo systemd-dissect --mount test/a.raw test/mnt/a           
€ ls -Zlart test/mnt/a/etc/shadow
----------. 1 root root system_u:object_r:init_var_run_t:s0 579 Jun 27 08:01 test/mnt/a/etc/shadow
```

The behavior before this PR looks up the labels in the label database of
the host, but the path that gets looked up is the path where the image
is temporarily mounted, or in the case of `--root` where the root is on
the host. Since that path doesn't define any labels we get the labels of
the location where the file was created on the host. In this case since
`--image` was used, which mounted things in a temporary location we end
up with `var_run_t`.

If this image is booted things that want to read `/etc/shadow` might not
be allowed to read files labeled this way; thus services fail to start,
and root can't login when SELinux is in enforcing mode.

After this PR is applied there are two main differences in how things
are handled. The first being that instead of reading the label database
from the host (which might have none, or have a different one from the
one contained inside an image or root) we read the label database from
inside the alternate root. This tries to make sure we get the correct
labels for given paths.

Second, and most importantly, if we did init SELinux with an alternate
root then any paths passed to the relevant label lookup functions strip
that alternate root from the path. While previously we'd look up a path
like `/run/dissect-XXXX/etc/shadow` we now look up a path like
`/etc/shadow` *and* this path gets looked up in the label database in
the alternate root.

Together these things give in my opinion better handling of SELinux in
alternate roots. To confirm things work here's the same operations on
the second copy of our image:

```
€ sudo systemd-dissect --mount test/b.raw test/mnt/b
artifacts € ls -Zlart test/mnt/b/etc/shadow
----------. 1 root root system_u:object_r:shadow_t:s0 520 Jun 27 07:55 test/mnt/b/etc/shadow
€ sudo ~/src/github.com/systemd/systemd/build/systemd-firstboot --image test/b.raw --root-password test
/home/user/src/github.com/teamsbc/artifacts/test/b.raw: /etc/passwd written.
/home/user/src/github.com/teamsbc/artifacts/test/b.raw: /etc/shadow written.
€ sudo systemd-dissect --mount test/b.raw test/mnt/b                                                  
€ ls -Zlart test/mnt/b/etc/shadow
----------. 1 root root system_u:object_r:shadow_t:s0 579 Jun 27 08:44 test/mnt/b/etc/shadow
```

Showing that we now have the correct labels applied.
2026-08-02 02:06:12 +02:00
Yu Watanabe 8bbbd71023 core/bpf-restrict-fsaccess: coding style fix 2026-08-01 03:23:40 +09:00
Yu WatanabeandEric Curtin 13d89ece2d core/bpf-restrict-fsaccess: merge bpf_restrict_fsaccess_supported() into bpf_restrict_fsaccess_setup()
Previously, bpf_restrict_fsaccess_prepare() is called twice in
bpf_restrict_fsaccess_setup(). One by through
bpf_restrict_fsaccess_supported() and one by itself directly.

In PID1, bpf_restrict_fsaccess_prepare() was only called by
bpf_restrict_fsaccess_setup(), hence it is not necessary to exist as a
separated function.

bpf_restrict_fsaccess_prepare() loads BPF program(s), hence it is
slightly slow operation.

Let's avoid redundant loading of BPF programs by merging
bpf_restrict_fsaccess_supported() into bpf_restrict_fsaccess_setup().

Co-authored-by: Eric Curtin <eric.curtin@docker.com>
2026-08-01 03:23:40 +09:00
Yu Watanabe 8292dfdca3 core/bpf-restrict-fs: use DEFINE_TRIVIAL_CLEANUP_FUNC_FULL_RENAME macro 2026-08-01 03:23:40 +09:00
Yu Watanabe dd7e148ed8 core/bpf-restrict-fs: merge three functions
This merges prepare_restrict_fs_bpf() and bpf_restrict_fs_supported()
into bpf_restrict_fs_setup().

Previously, bpf_restrict_fs_supported() was only called in
manager_new() and bpf_restrict_fs_cleanup(). However, it is not
necessary to call it in bpf_restrict_fs_cleanup(), as if the feature is
not supporetd, manager->restrict_fs is always NULL. In manager_new()
the function was always called with bpf_restrict_fs_setup(). Hence,
it is not necessary to keep bpf_restrict_fs_supported() and
bpf_restrict_fs_setup() as separated functions.

This also drops unnecessary '#if HAVE_LIBBPF' condition in
manager_new(), as bpf_restrict_fs_setup() is well defined also when
libbpf support is disabled.

Follow-up for c99678eeda.
2026-08-01 03:23:21 +09:00
Adam Dinwoodie 7b761dba0f core/timer: fix next trigger with RandomizedOffsetSec + Persistent (#42826)
When a calendar timer with RandomizedOffsetSec and Persistent=true fires a
catch-up activation, last_trigger is set to the current wall-clock time.
This inherently already includes any randomized offset, because the
trigger was that the activation time including the offset had passed.

When computing the next elapse, calendar_spec_next_usec() finds the next
calendar boundary after the base time, and then random_offset is added to the
result. If the base time already includes the offset, the next calendar
boundary is one period too far in the future, causing a scheduled activation
to be skipped.

Fix this by always subtracting random_offset from the base time before passing
it to calendar_spec_next_usec(), matching what the fallback branches (using
inactive_exit_timestamp or current time) already do. This puts the base into
"pre-offset calendar space" so that the next calendar match and subsequent
offset addition yield the correct next activation time.

Fixes #42337.
2026-08-01 00:53:33 +09:00
Sinity 3e04f8f450 core/dbus: do not flush a user manager's bus that is not RUNNING
destroy_bus() flushes unwritten data for unprivileged managers so that
queued messages are not lost when a connection is torn down. However,
sd_bus_flush() first drives the connection to completion via
bus_ensure_running(): for a connection still in OPENING or
AUTHENTICATING this blocks the manager synchronously - a single-fd
ppoll, the event loop is not running - until the peer answers or
BUS_AUTH_TIMEOUT (= DEFAULT_TIMEOUT_USEC, 90 s by default) expires; a
connection in HELLO blocks the same way on the Hello call's own
method timeout. destroy_bus() is reached from four places: the
disconnect handler, manager_recheck_dbus(), the failed-setup path in
api_bus_instance_id_reply(), and bus_done() during normal shutdown or
reexec (via manager_free()).

Such a peer legitimately never answers: during session teardown,
dbus.socket can be (or re-enter) listening while the D-Bus service
behind it is hung or already gone, so connect() succeeds against the
socket backlog and the authentication request is never read. The user
manager then freezes mid-shutdown - or mid-reexec - for 90 s, with
every remaining unit stop (or the reexec itself) gated behind it.

This is the block traced in #16471 (2020, v245): the reporter's
strace shows the manager hanging in a single-fd ppoll with an ~89 s
timeout right after SIGTERM - bus_ensure_running() driving an
AUTHENTICATING reconnection - and their summary attributes it to the
flush. Their tested sd-bus-level patch (breaking the wait via a
SIGTERM-set flag) was met with "a work-around once things are already
bad, but we shouldn't even get in that state"; the same reply stated
the expectation this commit implements - the manager "should normally
protect itself ... and not issue dbus messages when the dbus service
isn't fully up". bus_foreach_bus() already applies that principle in
the other direction, skipping enqueue for connections that "haven't
started yet" via the same sd_bus_is_ready() check. 1166f4472d
("core/dbus: do not block the manager on GetId during bus
(re-)connection") removed the connect-time instance of the same class
of block, in code added in 2025. The flush here is twelve years
older: it dates back to the libsystemd-bus conversion (718db96199,
2013).

Only flush when the connection is currently RUNNING. This does not
change what gets delivered in the failure case this fixes: whatever a
non-RUNNING connection's write queue holds (auth/Hello traffic, and
any subscriber signal a per-unit or per-job bus_track attached without
a readiness check) was never actually sent by the old code either -
sd_bus_flush() calls bus_ensure_running() before it ever looks at the
write queue, so a connection that times out without reaching RUNNING
had its queued data silently discarded on close exactly as before,
just after blocking for up to 90 s first rather than immediately. The
one narrowing is a connection that would have completed authentication
within the timeout window: previously such traffic could still reach
the peer after the block; now it will not. Every destroy_bus() call
site is reached only once the manager has already decided the
connection is being torn down (disconnected, recognized as down, or
the process itself exiting/reexecuting), so this narrowing does not
trade a working delivery for a broken one.

Fixes #16471
2026-07-31 23:57:09 +09:00
Simon de Vlieger 6b0e3ea222 label: plumb label_context through LabelOps
SELinux labeling with --root/--image needs per-call context to carry an
alternate policy database and root prefix. The current LabelOps interface
has no way to pass this, forcing any solution to rely on global state.

Add a LabelContext *label_context to the label_ops callbacks and all
intermediate layers. Generic filesystem functions that most callers use
(xopenat_full, write_string_file_full, etc.) get a _label variant
carrying the extra parameter, with inline wrappers preserving the
original signatures so the vast majority of call sites remain untouched.

Signed-off-by: Simon de Vlieger <cmdr@supakeen.com>
2026-07-31 09:49:41 +02:00
Yu Watanabe 3abe380d04 core/service: append the original error cause in the debugging logs 2026-07-31 11:30:32 +09:00
Michal Sekletar a3fee62707 core/service: ignore SELinux label errors in permissive mode
Return -ENODATA instead of the raw error when SELinux is permissive, so
the caller falls back to the default label. This is needed to allow
relabeling service to start on systems where file contexts maybe
invalid.
2026-07-31 11:30:32 +09:00
Yu Watanabe 71a2af43f9 core: quote each exec directory entry when serializing
Quote each serialized exec directory entry, and use extract flags
compatible with config_parse_exec_directories() when deserializing.
This allows paths containing spaces and escaped characters to round-trip
correctly.

Fixes #41853.
Replaces #42686.
2026-07-31 10:46:50 +09:00
Yu Watanabe 08ca33fdde core: postpone dbus queue dispatch while API bus setup is pending (#43200)
Since 1166f4472d the API bus setup
and the subscriber coldplug happen only once the asynchronous GetId
reply is processed by the event loop. After a daemon-reexec,
manager_dispatch_dbus_queue() runs before subscribers were registered
and consumed send_reloading_done, so the one-shot Reloading(false)
signal was never sent.

Clients that wait for this signal to detect that a reexec finished time out.

Track the pending setup and hold the flag until the reply handler has
re-added the subscriptions.

Also affects v261.2 via backport 26f3717e27f6f08347adf851c605d5fe1f52ac57.
2026-07-29 20:38:21 +09:00
r-vdp 266b3e5021 core: postpone D-Bus queue dispatch until the API bus is set up
Since 1166f4472d ("core/dbus: do not block the manager on GetId during
bus (re-)connection") the API bus setup and the subscriber coldplug
happen only once the asynchronous GetId reply is processed by the
event loop. After a daemon-reexec, manager_dispatch_dbus_queue() runs
before subscribers were re-added, so bus_foreach_bus() skipped the
API bus and queued messages were lost for subscribers. In particular
the one-shot Reloading(false) signal was never sent, and clients that
wait for it to detect that a reexec finished timed out.

Track whether bus_setup_api() has run for the current API bus
connection, and postpone dispatching the queue until then.
2026-07-29 09:52:57 +02:00
Eric Curtin c99678eeda core/bpf-restrict-fs: avoid loading the LSM BPF program twice at boot
bpf_restrict_fs_setup() is always called right after a successful
bpf_restrict_fs_supported(true) probe (see manager_setup() in
manager.c). Previously the probe independently opened, sized and
kernel-verifier-loaded the BPF object via prepare_restrict_fs_bpf(),
then did a trial LSM attach/detach via bpf_can_link_lsm_program() to
confirm the program *could* attach, and threw the whole object away
-- only for bpf_restrict_fs_setup() to build and verifier-load an
identical one from scratch again for the real, permanent attach.

The trial attach in the probe is redundant: if BPF_LSM_MAC attach
isn't actually usable (e.g. no BPF trampoline support on the running
architecture/kernel), bpf_restrict_fs_setup()'s own
sym_bpf_program__attach_lsm() call will simply fail, and that failure
is already logged and handled gracefully by its caller in manager.c
(logged as a warning, systemd continues without RestrictFileSystems=
enforcement). So bpf_restrict_fs_supported() only needs to check
whether the BPF LSM hook is enabled in the kernel at all
(lsm_supported("bpf")); it doesn't need to open/load/attach the BPF
program itself. Drop that from the probe, so the program is opened,
sized and verified by the kernel exactly once per boot instead of
twice.

Since the probe no longer verifies that the LSM BPF program can
actually attach, test-bpf-restrict-fs.c can no longer rely on
bpf_restrict_fs_supported(true) alone to skip on kernels/architectures
where the hook is listed but the real attach fails (e.g. missing BPF
trampoline support). Have the test also check m->restrict_fs after
manager_startup() and skip if the program never got attached, instead
of proceeding to hard-fail the enforcement assertions.
2026-07-28 21:33:38 +09:00
dongshengyuan 86168be51a core/namespace: split out bind mount retry helper
Move the bind mount retry path into a small helper so
apply_one_mount() no longer carries destination creation and
retry state inline.

Report destination creation and retry failures at debug level,
then return the error to apply_mounts(). The caller still reports
the final mount namespace failure with the cleaned-up mount path.
2026-07-26 19:57:43 +09:00
Tim Culverhouse 4517e7e4d9 core: support CollectMode in Varlink StartTransient
The io.systemd.Unit context exposes CollectMode, but StartTransient
rejects it as unsupported. This prevents Varlink clients from selecting
whether failed transient units should be garbage-collected.

Accept CollectMode when creating transient units and persist the setting
in the runtime unit configuration. Extend the integration test to verify
the value in both the Varlink response and the resulting unit.
2026-07-25 15:35:28 +09:00
gkehren 9d217e051b core: tolerate kernels without POSIX mqueue support
PrivateIPC= sets up a private mqueue mount for the service. When
CONFIG_POSIX_MQUEUE is disabled, mounting mqueue fails with ENODEV and
prevents the service from starting.

Treat ENODEV as an unavailable optional kernel feature while preserving
the private IPC namespace. Keep all other mount errors fatal.

Add coverage verifying that PrivateIPC= still creates a separate IPC
namespace when POSIX message queues are unavailable.

Fixes #42582
2026-07-24 13:44:59 +09:00
Ananth 34c60f113e timer: clamp future calendar base after clock jumps back
A calendar timer that is already waiting keeps the base timestamp it was
last armed from. When the wall clock is set backwards, that base can end
up in the future relative to the new realtime, and passing it to
calendar_spec_next_usec() schedules the next elapse relative to the old
future time instead of recalculating from now. systemctl list-timers
then keeps showing the stale pre-adjustment elapse (e.g. "3 years left"
after the clock moved back two years) and the timer never catches up.

Clamp the selected calendar base to the current realtime before asking
calendar_spec_next_usec() for the next occurrence. The clamp only kicks
in when the base is genuinely in the future, so Persistent=yes timers
whose last trigger is still in the past keep their catch-up behaviour and
we don't reintroduce the missed-run regression seen after suspend.

Fixes #6036.
2026-07-24 01:54:40 +09:00
Sinity 1166f4472d core/dbus: do not block the manager on GetId during bus (re-)connection
bus_init_api() issued a synchronous GetId call on every API bus
(re-)connection to decide whether saved subscription state could be
coldplugged onto the new connection.

If the D-Bus socket unit is listening while the message bus daemon
behind it is gone, connect() succeeds against the socket backlog but
nothing answers the authentication handshake. The synchronous call
then blocks PID 1 for BUS_AUTH_TIMEOUT (90 seconds by default), and
queued bus operations can trigger repeated reconnection attempts.
This was observed during shutdown as roughly 15 minutes of teardown
progressing only in 90-second intervals.

Query the instance ID asynchronously on every connection. Defer API
setup until the reply is processed, so saved subscriptions are
validated and coldplugged before new subscription requests can arrive.
If the query cannot be queued or its reply is invalid, discard the
unvalidated state and expose the API without blocking the manager.

Reset the live bus ID on every connection and serialize pending bus ID
and subscription state across reload and reexec. During daemon-reload,
preserve state that was already awaiting the asynchronous reply while
discarding the duplicate state produced by the reload itself.

Also remove the now-unused synchronous bus_get_instance_id() helper.
2026-07-20 11:53:34 +09:00
Yu Watanabe 661ab8b6fd tree-wide: drop DLOPEN_FOO() macros
Since 4c0d8d9673, most dlopen notes are
set at the beginning of the executables. Let's manage all dlopen notes
there, rather than setting them where dlopen is called.

Note that the only exceptions are the LIBBPF_NOTE for networkd and
nsresource. Since dlopen_bpf() is wrapped in an `#if` guard, the notes
are instead set within the corresponding functionality.

As a result, the DLOPEN_FOO() wrapper macros are no longer needed and
can be dropped completely.
2026-07-18 04:56:32 +09:00
Daan De Meyer 5a12005c83 copy: drop COPY_REFLINK
Reflinking is a safe optimization whenever the source and destination are
regular, seekable files on a filesystem that supports cloning. Requiring each
caller to opt in through COPY_REFLINK adds flag plumbing without changing the
necessary fallback behavior.

Drop COPY_REFLINK, renumber the remaining flags, and have copy_bytes_full()
unconditionally try FICLONE or FICLONERANGE before entering its normal copy
loop. Isolate the clone attempt and its file-offset bookkeeping in a helper so
copy_bytes_full() only has to handle its cloned, unavailable, and error results.
A successful clone therefore completes in one operation, while an unsupported
or rejected clone falls back to progress-limited copy_file_range(), sendfile(),
or buffered copying. Keep the public reflink helpers for operations that
specifically require clone semantics.

Existing test-copy coverage exercises both bounded and unbounded regular-file
copies through copy_bytes_full().

Signed-off-by: Daan De Meyer <daan@amutable.com>
2026-07-15 12:12:40 +02:00