This is establish the basic concepts for #35685, in the hope to get this
merged first.
This defines a special, fixed 64K UID range that is supposed to be used
by directory container images on disk, that is mapped to a dynamic UID
range at runtime (via idmapped mounts).
This enables a world where each container can run with a dynamic UID
range, but this in no way leaks onto the disk, thus making supposedly
dynamic, transient UID range assignments persistent.
This is infrastructure later used for the primary part of #35685: unpriv
container execution with directory images inside user's home dirs, that
are assigned to this special "foreign UID range".
This PR only defines the ranges, synthesizes NSS records for them via
userdb, and then exposes them in a new "systemd-dissect --shift" command
that can re-chown a container directory tree into this range (and in
fact any range).
This comes with docs. But no tests. There are tests in #35685 that cover
all this, but they are more comprehensive and also test nspawn's hook-up
with this, hence are excluded from this PR.
This makes sure when we are blocking signals in preparation for fork()
we'll not temporarily unblock any signals previously set, by mistake.
It's safe for us to block more, but not to unblock signals already
blocked. Fix that.
Fixes: #35470
This effectively reverts b8582198ca
as I can not get the testing farm bare metal machines working
downstream and even if I managed to, without also using the testing
farm bare metal machines upstream (for which there is no capacity),
the setup would very quickly bitrot anyway so we'll just run the
container based tests for now.
If we unexpectly disconnect from the bus, systemd would end up dropping
the list of subscribers, which breaks the ability of clients like logind
to monitor the state of units.
Stash the list of subscribers into the deserialized state in the event
of a disconnect so that when we recover we can renew the broken
subscriptions.
---
Fixes: #8672#26744
pam_systemd is used to create logind sessions and to apply extended
attributes from json user records. Not every application that creates a
pam session expects a login scope, but may be interested in the extended
attributes of json user records. Session class "none" implements this
service by disabling logind for this session altogether.
---
Closes: #34988
When running the integration tests downstream, it's useful to be able to
test that a new systemd version doesn't introduce any AVC denials, so
let's add a knob to make that possible.
When running the integration tests downstream, it's useful to be
able to test that a new systemd version doesn't introduce any AVC
denials, so let's add a knob to make that possible.
If we're not running interactively, there's no point in the features
from integration-test-setup.sh which are intended for interactive
development and debugging so lets skip adding it in that case.
This makes
- also cache sd_device for ACPI device.
- split fallback_chassis() into small pieces,
- use sd_device to reading sysfs attributes.
No functional change, just refactoring.
Even though udevadm accepts relative syspath, previously, udevadm
could not use relative path to device node:
===
$ cd /dev
$ udevadm info sda
Bad argument "sda", expected an absolute path in /dev/ or /sys/ or a unit name: Invalid argument
$ udevadm info /usr/../dev/sda
Unknown device "/usr/../dev/sda": No such device
===
With this change, both the above cases work fine.
Note, still sd_device_new_from_devname() requires absolute path starts
with /dev/, for safety.
Downstream we sometimes end up with machines with lots of CPUs which
leads to running out of memory when trying to run the tests in VMs.
So let's switch to a different heuristic when we have lots of CPUs to
avoid running out of memory.
If we unexpectly disconnect from the bus, systemd would end up dropping
the list of subscribers, which breaks the ability of clients like logind
to monitor the state of units.
Stash the list of subscribers into the deserialized state in the event
of a disconnect so that when we recover we can renew the broken
subscriptions.
This change adds a new firmware type device entry for the .hwids
section.
It also adds compile time validations and appropriate unit tests for
them.
chid_match() and related helpers have been updated accordingly.
Duplicate of https://github.com/systemd/systemd/pull/35281
Last review feedback's from this above PR has been incorporated and
merged.
@anonymix007
The need for -o was introduced in db6aeda to set the -p flag for login.
Setting -o overrides agettys built-in handling of arguments, so "-- \\u" was needed to mimic it.
This broke the autologin-feature, since the -f (noauth) flag is not passed to login [1].
But with 3d2157e, the -p flag is dropped, but the full change wasn't reverted,
leaving autologin still broken - But for no reason since agetty does the right thing.
Reference:
[1]: https://github.com/util-linux/util-linux/blob/4e14b57/term-utils/agetty.c#L529-L550
This makes the UID range configurable via build time options, but of
course it really shouldn't be changed. The default range I picked is
outside even of IPAs current (ridiculously large) allocation ranges,
hence hopefully minimizes conflicts.
We enforce quite strict rules on naming userns we assign uid ranges to
for users. So strict that they are hard to get right for clients. hence,
let's optionally mangle provided strings so that they work for us.
This should make it much easier to work with the API, as something
reasonable happens regarldess what kind of garbage a client sets as
name.
mangling the name is opt-in for clients, so that there's tight control
for the client on the name, but also "fire and forget".
This improves operation in unprivileged userns environments, where
unpriv user code might invoke a container with a delegated userns UID
range, and thus ends up with a subcgroup owned by another UID. With this
patch any user is always allowed to remove their own cgroups even if it
has subcgroups owned by other users.
This removes a DoS of sorts, and enforces the rule that users strictly
own everything below cgroups they own.
This is a test for the previous commits: we create an unpriv, delegated cgroup in
--user mode, then create a subcgroup that is owned by some other user
(to mimic the case where an unpriv user got a userns with delegated UIDs
assigned), and then try to stop the unit. traditionally this would fail,
because our unpriv systemd --user instance can't remove the subcrroup
owned by someone else. With the earlier patches this is addressed.
When running unprivileged containers, we run into a scenario where an
unpriv owned cgroup has a subcgroup delegated to another user (i.e. the
container's own UIDs). When the owner of that cgroup dies without
cleaning it up then the unpriv service manager might encounter a cgroup
it cannot delete anymore.
Let's address that: let's expose a method call on the service manager
(primarly in PID1) that can be used to delete a subcgroup of a unit one
owns. This would then allow the unpriv service manager to ask the priv
service manager to get rid of such a cgroup.
This commit only adds the method call, the next commit then adds the
code that makes use of this.
Let's liberalize process migration a bit. Previously, PID 1 would only
allow you to move processes into your own cgroups, if those processes
are owned by you too. This is now slightly relaxed: it's now also OK if
the processes are in a userns owned by you.
This makes process migration more useful in context of unpriv userns.
Lennart Poettering
Luca Boccassi
Daan De Meyer
Yu Watanabe
Ivan Kruglov
Ronan Pigott
Pontus Lundkvist
Mike Yuan