The mount option has special meaning when SELinux is enabled. To make
NoNewPrivileges=yes not break SELinux enabled systems, let's not set the
mount flag on such systems.
This reverts commit 1753d30215.
Let's re-enable that feature now. As reported when the original commit
was merged, this causes some trouble on SELinux enabled systems. So,
in the subsequent commit, the feature will be disabled when SELinux is enabled.
But, anyway, this commit just re-enable that feature unconditionally.
fd_duplicate_data_fd() is renamed to copy_data_fd(). This makes
the two functions have nicely similar names.
Now fd-util.[ch] is again about low-level file descriptor manipulations.
copy_data_fd() is a complex function that internally wraps the other
functions in copy.c. I want to move copy.c and the whole cluster of
related code from basic/ to shared/ later on, and this is a preparatory
step for that.
This reverts commit d8e3c31bd8.
A poorly documented fact is that SELinux unfortunately uses nosuid mount flag
to specify that also a fundamental feature of SELinux, domain transitions, must
not be allowed either. While this could be mitigated case by case by changing
the SELinux policy to use `nosuid_transition`, such mitigations would probably
have to be added everywhere if systemd used automatic nosuid mount flags when
`NoNewPrivileges=yes` would be implied. This isn't very desirable from SELinux
policy point of view since also untrusted mounts in service's mount namespaces
could start triggering domain transitions.
Alternatively there could be directives to override this behavior globally or
for each service (for example, new directives `SUIDPaths=`/`NoSUIDPaths=` or
more generic mount flag applicators), but since there's little value of the
commit by itself (setting NNP already disables most setuid functionality), it's
simpler to revert the commit. Such new directives could be used to implement
the original goal.
a70581ffb5 added ExecRuntime.ipcns_storage_socket[], and
serialization in exec_runtime_serialize(), and deserialization in exec_runtime_deserialize_one(),
but also deserialization in exec_runtime_deserialize_compat(). exec_runtime_deserialize_compat()
is for deserializating ExecRuntime when it was serialized as part of the unit before
e8a565cb66. There was never any code which would serialize
ExecRuntime.ipcns_storage_socket[] this way, so the deserialization attempts are pointless.
When `NoNewPrivileges=yes`, the service shouldn't have a need for any
setuid/setgid programs, so in case there will be a new mount namespace anyway,
mount the file systems with MS_NOSUID.
We recently started making more use of malloc_usable_size() and rely on
it (see the string_erase() story). Given that we don't really support
sytems where malloc_usable_size() cannot be trusted beyond statistics
anyway, let's go fully in and rework GREEDY_REALLOC() on top of it:
instead of passing around and maintaining the currenly allocated size
everywhere, let's just derive it automatically from
malloc_usable_size().
I am mostly after this for the simplicity this brings. It also brings
minor efficiency improvements I guess, but things become so much nicer
to look at if we can avoid these allocation size variables everywhere.
Note that the malloc_usable_size() man page says relying on it wasn't
"good programming practice", but I think it does this for reasons that
don't apply here: the greedy realloc logic specifically doesn't rely on
the returned extra size, beyond the fact that it is equal or larger than
what was requested.
(This commit was supposed to be a quick patch btw, but apparently we use
the greedy realloc stuff quite a bit across the codebase, so this ends
up touching *a*lot* of code.)
This commit applies the filtering imposed by LogLevelMax on a unit's
processes to messages logged by PID1 about the unit as well.
The target use case for this feature is a service that runs on a timer
many times an hour, where the system administrator decides that writing
a generic success message to the journal every few minutes or seconds
adds no diagnostic value and isn't worth the clutter or disk I/O.
With some versions of the compiler, the _cleanup_ attr makes it think
the variable might be freed/closed when uninitialized, even though it
cannot happen. The added cost is small enough to be worth the benefit,
and optimized builds will help reduce it even further.
Let's be a bit less strict when setting up credentials: if the service
manager didn't receieve a cred, and we shall propagate it down via
LoadCredentials= don't fail. Fail on all other errors though, as before,
and on explicitly listed paths.
The function already has a ridiculous amount of paramaters, let's drop
one that is either not used at all or has a constant value and let's
pick it internally.
Let's make use of the new dissection in all tools where this makes
sense, which are all tools that dissect images, except for those which
inherently operate on state/configuraiton and thus where an image
without state nor configuration is useless (e.g.
systemd-tmpfiles/systemd-firstboot/… --image= switch).
Clean up ignore_signals() + default_signals() + sigaction_many() a bit:
make it unnecessary to explicitly terminate the signal list with -1.
Merge all three calls into a single function that is just called with
slightly different parameters. And eliminate an unnecessary extra
iteration in its inner for() loop.
No change in behaviour.
Implement directives `NoExecPaths=` and `ExecPaths=` to control `MS_NOEXEC`
mount flag for the file system tree. This can be used to implement file system
W^X policies, and for example with allow-listing mode (NoExecPaths=/) a
compromised service would not be able to execute a shell, if that was not
explicitly allowed.
Example:
[Service]
NoExecPaths=/
ExecPaths=/usr/bin/daemon /usr/lib64 /usr/lib
Closes: #17942.
Previously if people enabled RootDirectory=/RootImage= and NotifyAccess=
together, things wouldn't work, they'd have to explicitly add
BindReadOnlyPaths=/run/systemd/notify too.
Let's make this implicit. Since both options are opt-in, if people use
them together it would be pointless not also defining the
BindReadOnlyPaths= entry, in which case we can just do it automatically.
See: #18051
Allow to setup new bind mounts for a service at runtime (via either
DBUS or a new 'systemctl bind' verb) with a new helper that forks into
the unit's mount namespace.
Add a new integration test to cover this.
Useful for zero-downtime addition to services that are running inside
mount namespaces, especially when using RootImage/RootDirectory.
If a service runs with a read-only root, a tmpfs is added on /run
to ensure we can create the airlock directory for incoming mounts
under /run/host/incoming.
This adds the ability to specify truncate:PATH for StandardOutput= and
StandardError=, similar to the existing append:PATH. The code is mostly
copied from the related append: code. Fixes#8983.
Michal Sekletar
Yu Watanabe
Zbigniew Jędrzejewski-Szmek
Topi Miettinen
Lennart Poettering
Mike Kazantsev
Ryan Hendrickson
Luca Boccassi
Xℹ Ruoyao
Anita Zhang
Susant Sahani
Lucas Werkmeister