Fixes https://github.com/systemd/systemd/issues/28514.
Quoting https://github.com/systemd/systemd/issues/28514#issuecomment-1831781486:
> Whenever PAM is enabled for a service, we set up the PAM session and then
> fork off a process whose only job is to eventually close the PAM session when
> the service dies. That services we run with service privileges, both to
> minimize attack surface and because we want to use PR_SET_DEATHSIG to be get
> a notification via signal whenever the main process dies. But that only works
> if we have the same credentials as that main process.
>
> Now, if pam_systemd runs inside the PAM stack (which it normally does) it's
> session close hook will ask logind to synchronously end the session via a bus
> call. Currently that call is not accessible to unprivileged clients. And
> that's the part we need to relax: allow users to end their own sessions.
The check is implemented in a way that allows the kill if the sender is in
the target session.
I found 'sudo systemctl --user -M "zbyszek@" is-system-running' to
be a convenient reproducer.
Before:
May 16 16:25:26 x1c systemd[1]: run-u24754.service: Deactivated successfully.
May 16 16:25:26 x1c dbus-broker[1489]: A security policy denied :1.24757 to send method call /org/freedesktop/login1:org.freedesktop.login1.Manager.ReleaseSession to org.freedesktop.login1.
May 16 16:25:26 x1c (sd-pam)[3036470]: pam_systemd(login:session): Failed to release session: Access denied
May 16 16:25:26 x1c systemd[1]: Stopping session-114.scope...
May 16 16:25:26 x1c systemd[1]: session-114.scope: Deactivated successfully.
May 16 16:25:26 x1c systemd[1]: Stopped session-114.scope.
May 16 16:25:26 x1c systemd[1]: session-c151.scope: Deactivated successfully.
May 16 16:25:26 x1c systemd-logind[1513]: Session c151 logged out. Waiting for processes to exit.
May 16 16:25:26 x1c systemd-logind[1513]: Removed session c151.
After:
May 16 17:02:15 x1c systemd[1]: run-u24770.service: Deactivated successfully.
May 16 17:02:15 x1c systemd[1]: Stopping session-115.scope...
May 16 17:02:15 x1c systemd[1]: session-c153.scope: Deactivated successfully.
May 16 17:02:15 x1c systemd[1]: session-115.scope: Deactivated successfully.
May 16 17:02:15 x1c systemd[1]: Stopped session-115.scope.
May 16 17:02:15 x1c systemd-logind[1513]: Session c153 logged out. Waiting for processes to exit.
May 16 17:02:15 x1c systemd-logind[1513]: Removed session c153.
Edit: this seems to also fix https://github.com/systemd/systemd/issues/8598.
It seems that with the call to ReleaseSession, we wait for the pam session
close hooks to finish. I inserted a 'sleep(10)' after the call to ReleaseSession
in pam_systemd, and things block on that, nothing is killed prematurely.
Since signals can take arguments, let's suffix them with () as we
already do with functions. To make sure we remain consistent, make the
`update-dbus-docs.py` script check & fix any occurrences where this is
not the case.
Resolves: #31002
With the introduction of SetDisplay() method in 4885d7490b the Display
property emits a "properties changed" message every time the display is
changed using this method, so mark it appropriately.
Caught by systemd/systemd#30029:
systemd-logind[1366]: Got message type=method_call sender=:1.165 destination=org.freedesktop.login1 path=/org/freedesktop/login1/session/_310 interface=org.freedesktop.login1.Session member=SetDisplay cookie=8 reply_cookie=0 signature=s error-name=n/a error-message=n/a
systemd-logind[1366]: Assertion 'v->vtable->flags & SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE || v->vtable->flags & SD_BUS_VTABLE_PROPERTY_EMITS_INVALIDATION' failed at src/libsystemd/sd-bus/bus-objects.c:2141, function emit_properties_changed_on_interface(). Ignoring.
Follow-up to 4885d7490b.
Automatically softreboot if the nextroot has been set up with an OS
tree, or automatically kexec if a kernel has been loaded with kexec
--load.
Add SYSTEMCTL_SKIP_AUTO_KEXEC and SYSTEMCTL_SKIP_AUTO_SOFT_REBOOT to
skip the automated switchover.
The existing signal doesn't say which type of shutdown is going to happen.
With the introduction of soft-reboot, it is useful to have this information
broadcasted, so that clients can choose to do different things based on the
reboot type.
Add a{sv} as the payload so that more metadata can be added later if
needed, without needing to add yet another signal.
Send both old and new signal for backward compatibility, and send the new
one first so that clients can just wait for the first one on both old and
new systems.
Currently, the only way to set display name of a graphical session is to
pass it to CreateSession(). But modern display managers like gdm start
the display server as part of the user session, which means that the
display name isn't known yet when the session is being created. Hence,
let's make it possible to set it later.
This has the advantage that the executables are always in place and we don't
need any units to exist on the bus, so we can eventually hook this up into
a normal build system. (Probably as a build time check.)
Follow-up for f92c8d1c67.
directives.index:
- This index contains 3398 entries in 19 sections, referring to 333 individual
+ This index contains 4316 entries in 19 sections, referring to 333 individual
This replaces the api export tables with updated versions, and inserts
comments for all "undocumented" items. The slow work of documented them
is left for later ;)
lxml does some formatting changes that are not significant for lxml processing,
but generate spurious difference in the diff (namely: ulinks become one-line,
and double quotes are used instead of single quotes for element attribute
values). This should be a one-time thing: subsequent renegeration should be
idempotent with regards to this.