When a unit has a symlink that makes an alias in the filesystem,
but that name is not specified in [Install], it is confusing
is the unit is shown as "enabled". Look only for names specified
in Alias=.
Fixes#6338.
v2:
- Fix indentation.
- Fix checking for normal enablement, when the symlink name is the same as the
unit name. This case wasn't handled properly in v1.
v3:
- Rework the patch to also handle templates properly:
A template templ@.service with DefaultInstance=foo will be considered
enabled only when templ@foo.service symlink is found. Symlinks with
other instance names do not count, which matches the logic for aliases
to normal units. Tests are updated.
Let's rename all our functions that process IPv4 in_addr structures
in4_addr_xyz(), following the already establishing naming logic for
this.
Leave the in_addr_xyz() prefix for functions that process the IPv4/IPv6
in_addr_union union instead.
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
Current behavior is that %X where X is an unidentified specifier, then the result is
the same %X string. This was not the case when the string ended with a stray %, where
the character would have not been output. Lets add that missing character.
Fixes: #6374
When running through systemd-analyze verify or with --test, we would
not run generators (environment or unit). But at the end, we would nuke
the generator dirs anyway.
Simplify things by actually running generators of both types, but redirecting
their output to a temporary directory. This has the advantage that we test more
code, and the verification is more complete.
Since now we are not touching the real generator directories, we also don't
delete them, which fixes#5609.
This was added to make
https://bugs.freedesktop.org/show_bug.cgi?id=62558 work, which has long
been removed, hence let's revert to the original behaviour and fully
flush out the list when an empty string is assigned.
Given that sched_setattr/sched_setparam/sched_setscheduler are already
in the group the closely related nice + ioprio_set should also be
included.
Also, order things alphabetically.
Include the waid syscalls. If we permit forking then we should also
permit waiting for a process.
Similar to that: also permit determining the usage counters for
processes.
Include calls to determine process/thread identity. They have little
impact security-wise, but are very likely used when process management
of any form is done.
Also, add rt_sigqueueinfo + rt_tgsigqueueinfo as they are similar to
kill() and friends, but permit passing along a userdata ptr.
Let's add fremovexattr which was the only xattr syscall so far missing
from the group, even though lremovexattr and friends where included.
Add inotify_init, which is an older (but still supported) version of
inotify_init1.
Add oldfstat, oldlstat, oldstat which are old versions of the stat
syscalls on some archs.
Add utime, which is an older more limited version of utimes and
utimensat.
Enclose the "statx" entry in some ifdeffery to ensure libseccomp
actually knows the syscall. If libseccomp doesn't know it, then we'd get
EINVAL rather than EDOM (which is what is returned if a syscall is known
but not available on the local system) when resolving the syscall name
and we really don't want that, as we use the EDOM vs. EINVAL check for
determining whether a syscall makes sense at all.
Also, order things alphabetically.
Let's add _llseek which is the syscall name on some archs that on others
is simply lseek (due to 64bit vs 32bit off_t confusion). Also, let's
sort things alphabetically.
Let's add more of the most basic operations to "@default" as absolute
baseline needed by glibc and such to operate. Specifically:
futex, get_robust_list, get_thread_area, membarrier, set_robust_list,
set_thread_area, set_tid_address are all required to properly implement
mutexes and other thread synchronization logic. Given that a ton of
datastructures are protected by mutexes (such as stdio and such), let's
just whitelist this by default, so that things can just work.
restart_syscall is used to implement EAGAIN SA_RESTART stuff in some
archs, and synthesized by the kernel without any explicit user logic,
hence let's make this work out of the box.
With this setting we can explicitly unset specific variables for
processes of a unit, as last step of assembling the environment block
for them. This is useful to fix#6407.
While we are at it, greatly expand the documentation on how the
environment block for forked off processes is assembled.
We make copies (without O_CLOEXEC) of the fds anyway before using them,
hence let's be safe and create them with O_CLOEXEC first, so that we
don't run into issues should pager_open() be called in a threaded
environment where another thread fork()s at the wrong time and ends up
with fds not marked O_CLOEXEC.
Now that we have ported nspawn's seccomp code to the generic code in
seccomp-util, let's extend it to support whitelisting and blacklisting
of specific additional syscalls.
This uses similar syntax as PID1's support for system call filtering,
but in contrast to that always implements a blacklist (and not a
whitelist), as we prepopulate the filter with a blacklist, and the
unit's system call filter logic does not come with anything
prepopulated.
(Later on we might actually want to invert the logic here, and
whitelist rather than blacklist things, but at this point let's not do
that. In case we switch this over later, the syscall add/remove logic of
this commit should be compatible conceptually.)
Fixes: #5163
Replaces: #5944
Let's add a new helper function seccomp_add_syscall_filter_item() that
contains the inner loop code of seccomp_add_syscall_filter_set(). This
helper function we can then export and make use of elsewhere.
Add LockPersonality boolean to allow locking down personality(2)
system call so that the execution domain can't be changed.
This may be useful to improve security because odd emulations
may be poorly tested and source of vulnerabilities, while
system services shouldn't need any weird personalities.
This helps prevent symbol collisions with other programs and libraries. In particular,
because PAM modules are loaded into the process that is creating the session, and
systemd creates PAM sessions, the potential for collisions is high.
Disambiguate all systemd calls by tagging a 'version' SD_SHARED.
Fixes#6624
This patch adds two new special character prefixes to ExecStart= and
friends, in addition to the existing "-", "@" and "+":
"!" → much like "+", except with a much reduced effect as it only
disables the actual setresuid()/setresgid()/setgroups() calls, but
leaves all other security features on, including namespace
options. This is very useful in combination with
RuntimeDirectory= or DynamicUser= and similar option, as a user
is still allocated and used for the runtime directory, but the
actual UID/GID dropping is left to the daemon process itself.
This should make RuntimeDirectory= a lot more useful for daemons
which insist on doing their own privilege dropping.
"!!" → Similar to "!", but on systems supporting ambient caps this
becomes a NOP. This makes it relatively straightforward to write
unit files that make use of ambient capabilities to let systemd
drop all privs while retaining compatibility with systems that
lack ambient caps, where priv dropping is the left to the daemon
codes themselves.
This is an alternative approach to #6564 and related PRs.
This new group lists all UID/GID credential changing syscalls (which are
quite a number these days). This will become particularly useful in a
later commit, which uses this group to optionally permit user credential
changing to daemons in case ambient capabilities are not available.
Zbigniew Jędrzejewski-Szmek
Lennart Poettering
Daniel Mack
Felipe Sateler
Yu Watanabe
Topi Miettinen
Torstein Husebø