To be able to run systemd in a Type=notify transient unit, the notify
socket can't be bind mounted to /run/systemd/notify as systemd in the
transient unit wants to use that as its own notify socket which
conflicts with systemd on the host.
Instead, for sandboxed units, let's bind mount the notify socket to
/run/host/notify as documented in the container interface. Since we
don't guarantee a stable location for the notify socket and insist users
use $NOTIFY_SOCKET to get its path, this is safe to do.
To be able to run systemd in a Type=notify transient unit, the notify
socket can't be bind mounted to /run/systemd/notify as systemd in the
transient unit wants to use that as its own notify socket which conflicts
with systemd on the host.
Instead, for sandboxed units, let's bind mount the notify socket to
/run/host/notify as documented in the container interface. Since we don't
guarantee a stable location for the notify socket and insist users use
$NOTIFY_SOCKET to get its path, this is safe to do.
Recently, PrivateUsers=identity was added to support mapping the first
65536 UIDs/GIDs from parent to the child namespace and mapping the other
UID/GIDs to the nobody user.
However, there are use cases where users have UIDs/GIDs > 65536 and need
to do a similar identity mapping. Moreover, in some of those cases,
users want a full identity mapping from 0 -> UID_MAX.
To support this, we add PrivateUsers=full that does identity mapping for
all available UID/GIDs.
Note to differentiate ourselves from the init user namespace, we need to
set up the uid_map/gid_map like:
```
0 0 1
1 1 UINT32_MAX - 1
```
as the init user namedspace uses `0 0 UINT32_MAX` and some applications
- like systemd itself - determine if its a non-init user namespace based
on uid_map/gid_map files.
Note systemd will remove this heuristic in running_in_userns() in
version 258 (https://github.com/systemd/systemd/pull/35382) and uses
namespace inode. But some users may be running a container image with
older systemd < 258 so we keep this hack until version 259 for version
N-1 compatibility.
In addition to mapping the whole UID/GID space, we also set
/proc/pid/setgroups to "allow". While we usually set "deny" to avoid
security issues with dropping supplementary groups
(https://lwn.net/Articles/626665/), this ends up breaking dbus-broker
when running /sbin/init in full OS containers.
Fixes: #35168Fixes: #35425
When trying to run dbus-broker in a systemd unit with PrivateUsers=full,
we see dbus-broker fails with EPERM at `util_audit_drop_permissions`.
The root cause is dbus-broker calls the setgroups() system call and this
is disallowed via systemd's implementation of PrivateUsers= by setting
/proc/pid/setgroups = deny. This is done to remediate potential privilege
escalation vulnerabilities in user namespaces where an attacker can remove
supplementary groups and gain access to resources where those groups are
restricted.
However, for OS-like containers, setgroups() is a pretty common API and
disabling it is not feasible. So we allow setgroups() by setting
/proc/pid/setgroups to allow in PrivateUsers=full. Note security conscious
users can still use SystemCallFilter= to disable setgroups() if they want
to specifically prevent this system call.
Fixes: #35425
TEST-75-RESOLVED fails on Ubuntu autopkgtest due to this warning from
knot:
notice: config, policy 'auto_rollover_nsec3' depends on default nsec3-salt-length=8, since version 3.5 the default becomes 0
Explicitly set nsec3-salt-length=8 to silence.
This PR allows an option for systemd exec units to enable UTS namespaces
but not restrict changing hostname via seccomp. Thus, units can change
hostname without affecting the host. This is useful for OS-like
containers running as units where they should have freedom to change
their container hostname if they want, but not the host's hostname.
Fixes: #30348
RestrictNamespaces= would accept "time" but would not actually apply
seccomp filters e.g. systemd-run -p RestrictNamespaces=time unshare -T true
should fail but it succeeded.
This commit actually enables time namespace seccomp filtering.
Previously if one service specified the same unit as their
success and failure handler we bailed out of resolving the triggering unit
even though it is still unique.
These new tests are flaky, so disable them temporarily, until after
the release, to avoid pushing out new flakiness to consumers. They
will be re-enabled immediately after.
Otherwise, if networkd is failed, e.g. .network files that triggered the
failure will remain, and the next test case will start with previous
.network files. So, most subsequent test will fail.
This makes sure all kernel log messages are logged to the console.
This should be helpful during shutdown to detect possible issues with
journald when the logs can't be written to the journal itself anymore
but are written to kmsg.
Currently, mkosi GitHub action complains the following:
===
Could not find 'setfiles' which is required to relabel files.
===
Let's tentatively disable SELinux test.
This allows an option for systemd exec units to enable UTS namespaces
but not restrict changing hostname via seccomp. Thus, units can change
hostname without affecting the host.
Fixes: #30348
We put a timeline of 257 to remove the old bash test runner so since
we're about to release 257, let's remove the old bash test runner in
favor of the meson + mkosi test runner.
Recently, PrivateUsers=identity was added to support mapping the first
65536 UIDs/GIDs from parent to the child namespace and mapping the other
UID/GIDs to the nobody user.
However, there are use cases where users have UIDs/GIDs > 65536 and need
to do a similar identity mapping. Moreover, in some of those cases, users
want a full identity mapping from 0 -> UID_MAX.
Note to differentiate ourselves from the init user namespace, we need to
set up the uid_map/gid_map like:
```
0 0 1
1 1 UINT32_MAX - 1
```
as the init user namedspace uses `0 0 UINT32_MAX` and some applications -
like systemd itself - determine if its a non-init user namespace based on
uid_map/gid_map files. Note systemd will remove this heuristic in
running_in_userns() in version 258 and uses namespace inode. But some users
may be running a container image with older systemd < 258 so we keep this
hack until version 259.
To support this, we add PrivateUsers=full that does identity mapping for
all available UID/GIDs.
Fixes: #35168
We want to make sure the integration tests that don't require qemu
can run successfully both in an nspawn container and in a qemu VM.
So let's add one more knob TEST_PREFER_QEMU=1 to run jobs that normally
require nspawn in qemu instead.
Running these tests in qemu is also possible by not running as root but
that's very implicit so we add an explicit knob instead to make it explicit
that we want to run these in qemu instead of nspawn.
Follow-up for c26948c6da
We only want to get rid of cred mount here, and RuntimeDirectory=
is documented to be retained for SERVICE_EXITED state.
Fixes#35427
- make udevd generate debugging logs for loopback and DM devices,
- insert 'udevadm wait' at several places to make the device processed
by udevd,
- cleanup generated integritysetup service before moving to next
algorithm,
- drop unnecessary exit on command failure,
- also test data splitting mode for all algorithms.
Otherwise the root inode will typically have what mkdtemp sets up, which
is something like 0700, which is weird and somewhat broken when trying
to look into containers from unpriv users.
Yu Watanabe
Daan De Meyer
Luca Boccassi
Ryan Wilson
Luca Boccassi
Nick Rosbrook
davjav
Ryan Wilson
Nils K
Zbigniew Jędrzejewski-Szmek
Mike Yuan
Lennart Poettering