Since StandardOutput=file:path is more similar to StandardInput= than
StandardInputText=, and only StandardInput= is actually documented above
StandardOutput= whereas StandardInputText= is documented below it, I
assume the intention was to refer to the former.
Previously, reading through systemd.exec(5) one might get the idea that
XDG_SEAT and XDG_VTNR are part of the service management logic, but they
are not, they are only set if pam_systemd is part of a PAM stack an
pam_systemd is used.
Hence, let's drop these env vars from the list of env vars, and instead
add a paragraph after the list mentioning that pam_systemd might add
more systemd-specific env vars if included in the PAM stack for a
service that uses PAMName=.
Double newlines (i.e. one empty lines) are great to structure code. But
let's avoid triple newlines (i.e. two empty lines), quadruple newlines,
quintuple newlines, …, that's just spurious whitespace.
It's an easy way to drop 121 lines of code, and keeps the coding style
of our sources a bit tigther.
Files which are installed as-is (any .service and other unit files, .conf
files, .policy files, etc), are left as is. My assumption is that SPDX
identifiers are not yet that well known, so it's better to retain the
extended header to avoid any doubt.
I also kept any copyright lines. We can probably remove them, but it'd nice to
obtain explicit acks from all involved authors before doing that.
Before this change all unit types would default to "private" in the
system service manager and "inherit" to in the user service manager.
With this change this is slightly altered: non-service units of the
system service manager are now run with KeyringMode=shared. This appears
to be the more appropriate choice as isolation is not as desirable for
mount tools, which regularly consume key material. After all mounts are
a shared resource themselves as they appear system-wide hence it makes a
lot of sense to share their key material too.
Fixes: #8159
The VDSO provided by the kernel for x32, uses x86-64 syscalls instead of
x32 ones.
I think we can safely allow this; the set of x86-64 syscalls should be
very similar to the x32 ones. The real point is not to allow *x86*
syscalls, because some of those are inconveniently multiplexed and we're
apparently not able to block the specific actions we want to.
> Only system calls of the *specified* architectures will be permitted to
> processes of this unit.
(my emphasis)
> Note that setting this option to a non-empty list implies that
> native is included too.
Attempting to use "implies" in the later sentence, in a way that
contradicts the very clear meaning of the earlier sentence... it's too
much.
The long long list of settings is getting too confusing, let's add some
sections and reorder things in them.
This makes no changes regarding contents, it only reorders things,
sometimes reindents them, and adds sections that made sense to me to
some degree.
Within each sections the settings are ordered by relevance (at least
according to how relevant I personally find them), and not
alphabetically.
Let's clarify that these settings only apply to stdout/stderr logging.
Always mention the journal before syslog (as the latter is in most ways
just a legacy alias these days). Always mention the +console cases too.
MemoryDenyWriteExecution policy could be be bypassed by using pkey_mprotect
instead of mprotect to create an executable writable mapping.
The impact is mitigated by the fact that the man page says "Note that this
feature is fully available on x86-64, and partially on x86", so hopefully
people do not rely on it as a sole security measure.
Found by Karin Hossen and Thomas Imbert from Sogeti ESEC R&D.
https://bugs.launchpad.net/bugs/1725348
This makes each system call in SystemCallFilter= blacklist optionally
takes errno name or number after a colon. The errno takes precedence
over the one given by SystemCallErrorNumber=.
C.f. #7173.
Closes#7169.
This removes the '@credentials' syscall set that was added in commit
v234-468-gcd0ddf6f75.
Most of these syscalls are so simple that we do not want to filter them.
They work on the current calling process, doing only read operations,
they do not have a deep kernel path.
The problem may only be in 'capget' syscall since it can query arbitrary
processes, and used to discover processes, however sending signal 0 to
arbitrary processes can be used to discover if a process exists or not.
It is unfortunate that Linux allows to query processes of different
users. Lets put it now in '@process' syscall set, and later we may add
it to a new '@basic-process' set that allows most basic process
operations.
Usually, it's a good thing that we isolate the kernel session keyring
for the various services and disconnect them from the user keyring.
However, in case of the cryptsetup key caching we actually want that
multiple instances of the cryptsetup service can share the keys in the
root user's user keyring, hence we need to be able to disable this logic
for them.
This adds KeyringMode=inherit|private|shared:
inherit: don't do any keyring magic (this is the default in systemd --user)
private: a private keyring as before (default in systemd --system)
shared: the new setting
If two separate log streams are connected to stdout and stderr, let's
make sure $JOURNAL_STREAM points to the latter, as that's the preferred
log destination, and the environment variable has been created in order
to permit services to automatically upgrade from stderr based logging to
native journal logging.
Also, document this behaviour.
Fixes: #6800
Lennart Poettering