Idk for the network stack, but for homed, I think it’s because it is up to the DEs to support it. As part of the Sovereign tech fund, GNOME is implementing support for it! I think this will be a great step forward for Linux desktop security when it lands
homed isn’t exactly a home directory replacement, more of an extension. You can mix and match homed and normal home directories like you want (on a per-user basis at least, not within a single user). It does have some nice things, such as user-password based encryption of the home directory, so the password is required to unlock it (no admin access) or automatically using subvolumes on btrfs.
user-password based encryption of the home directory, so the password is required to unlock it (no admin access)
That seems like a very niche feature given that it is only relevant if the admin isn’t the same person as the user but the admin would have to set it up and condemn themselves to hearing endless whining from users who lose their files when they forgot their password.
SElinux is a “global ACL.” You can stop root from doing anything you like with it. Usually by accident and without realizing it’s been done in my experience…
No, that is just not true. You can stop root from doing things without a reboot with SELinux but encrypting something with a password root does not know actually does stop them from doing it at all short of a brute force attack on the encryption.
Oh, I was specifically thinking that admins that have users either competent enough not to forget/lose their passwords or mature enough not to whine to the admin when that causes the loss of all their files are pretty niche.
I don’t know, unless I personally allow the admin to have that kinda access to my files I wouldn’t really want it. And for that case you can enroll recovery keys (which would need to be manually stored, but still) or a fido token or whatever other supported mechanism there is, its LUKS2 backed encryption after all. Then there is also the possibility to just not encrypt the home directory at all.
Agreed, this is a nice inclusion. I also hate sudoers with a passion - I already use doas but it’s not standard (in the Linux world anyway), but with systemd providing an alternative means that it’ll become a standard which most distros would adopt, and I hope this means we can finally ditch the convoluted sudoers file once and for all.
The thing with this is: its just a symlink to the systemd-run binary, which talks to PID1 to spawn new processes (in separate cgroups IIRC). Its one of the most fundamental parts of systemd. Even the debian systemd package includes systemd-run.
I guess the other question is if some tools the distro provides might switch to supporting it by default. For example on Arch there is makepkg that should never be executed as root, but does internally call some things with elevated privileges (mostly pacman to install and remove packages). Currently it checks for sudo and if not falls back to su, but maybe it might be worth considering changing su for run0 if its guaranteed to be there.
it does its authorization with polkit (which IIRC defaults to allow all wheel group members) and giving users that shouldn’t be allowed root access, root access, is not something you ever want. This is usually referred to as unauthorized privilege escalation. Also, it isn’t like sudo doesn’t need configuration.
Makes sense considering people who moved from one micro-blogging service to another instead of giving up on the idea completely are probably the ones deeply committed to that flawed idea.
Blame the Mastodon team, if you’re not running a fork, you have to go into the source and adjust the character limit manually.
Nobody has to do it like this, Mastodon supports longer posts since other servers and clients support more, it’s seemingly just a choice from upstream.
I admit, I’m not a big fan of putting more functionality into systemd (or just of systemd in general), but that is a well-reasoned argument for having sudo live in the init system.
doas is quite popular in the BSD world, and was ported to Linux a few years ago (via the OpenDoas project).
For starters, it’s is a lot smaller than sudo - under 2k lines of code vs sudo’s 132k - this makes it lot more easier to audit and maintain, and technically less likely to have vulnerabilities.
Another security advantage is that doas doesn’t pass on the environment variables by default (you’d have to explicitly declare the ones you want to pass, which you can do so in the config).
The config is also a lot simpler, and doesn’t force you to use visudo - which never made sense to me, visudo should’ve just generated the actual config, instead of checking it after the fact. Kinda like how grubby or grub2-mkconfig works. But no need for that complexity with doas.
Eg, the most basic doas config could just have one line in the file: permit: wheel. Maybe have another line for programs you want to run without a password, like permit nopass dexter cmd pacman.
Thanks for taking the time to explain. I was trying to get my head around on how this works but could not understand much of it. A lot of people here are very much against systemd in all senses, but this sounds like a better approach. Even if it not done as systemd, makes more sense than checking files and getting elevated privileges for a scope and use guardrails everywhere
When does systemd stop? Linux without it is increasingly looking unlikely in the future. Are we not worried about it being a single point of failure and attack vector?
This isn’t a moan about the unix philosophy btw, but a genuine curiosity about how we split responsibilities in todays linux environment.
@Olap
I agree. As someone who uses systemd on daily basis (I use Arch, BTW 😄) I really like it, but I am a bit worried about it being a single point of attack. Maybe just push doas as default instead? I never used doas but I watched few videos about it, so I guess it's fine and probably better than sudo (less bloated).
Just my few cents.
I don’t see how something would be inherently easier to attack if it is called systemd-foo instead of just foo. Attack surface and vectors do not depend on which project develops a particular tool.
SystemD will consume the entirety of Linux, bit by bit.
In 2032, SystemD announces they’re going to be introducing a new way to manage software on Linux
In 2035, SystemD will announce they’re making a display system to replace the ageing Wayland
In 2038, the SystemD team announces they’re making their own desktop environment
In 2039 SystemD’s codebase has grown to sixteen times its size in the 2020s. SystemD’s announces they’re going to release replacements for most other packages and ship their own vanilla distro.
In 2045 SystemD’s distro has become the standard Linux distribution. Most other distros have quietly faded away.
In 2047, SystemD announces they’re going to incorporate most of GNU into SystemD. Outrage ensues from the Free Software Foundation, which vehemently opposes this move.
In 2048, Richard Stallman dies of a heart attack after attempting to clone SystemD’s git repo. SystemD engages in a hostile takeover and all resistance within the FSF crumbles
In 2050, SystemD buys the struggling RedHat from IBM for $61 million.
In 2053, most world governments have been pressured into using SystemD.
In 2054, Linus Torvalds, fearing for his life, begins negotiations to merge kernel development into SystemD
In 2056, the final message on the Linux kernel development mailing list is sent.
In 2058, Torvalds dies under suspicious circumstances after his brand-new laptop battery explodes.
In 2060, SystemD agents assassinate the CEO of Microsoft.
In 2063, after immense pressure from SystemD-controlled human rights organisations, Arch developers discontinue development.
In 2064, the remaining living Debian developers release the next stable version of their clandestine and highly illegal distro.
Yes, because it’s easier to take care of octogenarians than people who might actually put up a fight to having their laptop batteries replaced with a pipe bomb.
Debian in many ways isn’t as slow-moving as people think.
For example, they moved to Wayland by default (for Gnome anyway) in 2019. A number of well-known distros likely won’t have that until 2025/2026 or beyond.
Sadly they’ve been dropping archs throughout the years, meaning they’re no longer the distro you can use to run on “anything” from a pi to a mainframe…
Doesn’t trixie still support like a dozen arches? I think one of the more recent deprecations was MIPS BE which is functionally obsolete in 2024, at least insofar as practically no one is using it to run a modern distribution.
Bookworm, Trixie, and Sid all currently support a total of 10 different architectures.
And looking through the Wikipedia article for Debian’s version history, most of the dropped architectures were functionally obsolete when they were dropped, or like the Motorola 68000, when support was added. (notable exceptions being IA-64 which was dropped 4 years before intel discontinued it, SPARC which is still supported by Oracle, and PowerPC.)
One way to notice a person has “systemd derangement syndrome” is by looking at how they write systemd: if they write it SystemD they are already in late stages of SDS and it isn’t curable anymore.
They seem to. Debian explicitly supports multiple init systems, sysvinit being the primary alternative, so packages have to handle systemd-init not being there.
Systemd is a bit of a hassle to be rid off, but thankfully it’s not actually that hard, the hardest part I found was converting systemd services to whatever init system I use.
Probably not much time, a lot of packages come with init scripts anyway, and they’re pretty trivial to write if not.
You can certainly argue it’s a philosophical choice, I’d say it’s more down to recognising the many poor architectural choices in systemd, rubbing agaist its many pain points and misfeatures and being alarmed at the size of the attack surface it exposes. I understand there is an effort underway to reduce the size and complexity of the main shared library to help address the last point, but just the fact that is necessary shows the scope of the problem.
Let’s agree to disagree on that point. Redhat switched because they invented it, and so took all the RHEL derivative distros with them. Debian switched to prefer it after a rather contentious vote and so took all the Debian derivative distros, including Ubuntu, with them. That just leaves a lot of the smaller distros, most of which seem to have stuck with sysvinit or similar as far as I can see.
The arguments against systemd are very unconvincing but more importantly, there is zero evidence that they actually matter.
And it works.
Further, in order to represent this as a nearly unilateral decision you failed to mention that arch, centos, and opensuse all opted in independently.
And no offense but angry Internet randos arguing software philosophy will never convince me to disagree with the creator of the Linux kernel.
Linus Torvalds said:
“I don’t actually have any particularly strong opinions on systemd itself. I’ve had issues with some of the core developers that I think are much too cavalier about bugs and compatibility, and I think some of the design details are insane (I dislike the binary logs, for example), but those are details, not big issues.”
I obviously find the arguments against systemd more persuasive than you do, and that’s fine, it’s all open source and we can all make our own choices about it. My experience with it over the years has been, and still is that it vastly over complicates things that used to be simple, often the less commonly used parts just don’t work right (the automounter is a particular bugbear of mine, and few distros seem to use the network management component). The arguments do matter in practical terms as they directly impact how it works.
Of the distros you mentioned, centos is a RHEL derivative and so wasn’t independent, arch packages multiple init systems, but yes, I’d forgotten opensuse, and they seem to be firmly in the systemd camp.
I may be an internet rando, but I’m not actually angry, more just disappointed. I’d agree with Mr Torvald’s opinion that some of the design details are insane, but I think they are more fundamental than just ‘details’ as many are to do with the fundamental concepts around what systemd is and how it works. Linus can be a real dragon around changes to the kernel, but he’s always tended to be more relaxed about the layers above it.
That the developers of systemd are ‘much too cavalier about bugs and compatibility’ is surely clear to anyone who follows the relevant mailing lists and bug trackers, and should alarm everyone.
That quote carries the opposite connotation of what you seem to take from it. He’s saying despite having issues with the devs, he acknowledges those issues probably don’t matter.
I admit I don’t understand the internals of any of these systems. But I do understand that if the creator of the kernel isn’t concerned about systemd, and that if the vast majority of distros use systemd, then it indeed works well enough. The systemd apocalypse never happened and likely never would happen.
I see this argument as software conservatism. The rest of us will be okay with the thousands of knowledgeable developers that seem to think systemd works just fine.
I’m not disputing that he doesn’t think the issues are major, as I said, he’s usually pretty ambivalent about what runs on the kernel, so they’re not issues he cares about. On the flip side, I do care what is running because I have to manage and support it.
I do wonder if we’re talking at cross purposes though. You seem to mostly be talking about the systemd init system, I’m mostly talking about all the other bits it, as a sort of umbrella project, tries to encompass. I don’t much like the init system, I prefer to be able to explicitly set the ordering of the steps, rather than having them inferred, and I prefer shell script that I can test to unit files, but it mostly works ok. So does every other init system though, so it’s not a selling point.
As I said, the big problem is around how they’ve tried to do everything, much of it less well than what they’re replacing. Yes, you can build a system that uses systemd-init and none of the other components, but that still drags in a load of other dependencies, so you might as well use a different init that’s smaller and cleaner.
We came close to the ‘systemd apocalypse’ recently, when distros hooked the systemd library into openssh without understanding just how bloated it is and how many poorly monitored dependencies it brought in. It was just luck that the right person spotted a slight change in timing and investigated.
Ultimately I suppose it comes down to the level you interact with your systems at. If you just want to install your OS, a few packages they directly support and let it get on with it, then you probably neither know nor care that you run systemd, and that’s great. On the other hand, in my experience, when you try to push the system past that and do anything more customized you start running into the sharp edges and misfeatures on the various systemd components.
took me about an hour to get started with artix originally, and maybe a couple more to really familiarize myself with the init. As for practicallity, it’s been a large improvement for me.
By this logic the Linux kernel is also a single point of failure and attack vector.
sudo isn’t going away, so does doas. run0 is just another alternative to use or not.
There are still distribution out there without systemd and if there ever won’t be any systemd-free distributions left and systemd would become a critical part of the Linux ecosystem, then it would get the same treatment as the Linux kernel with many professional maintainers.
plus, it isn’t like this isn’t exactly like adding another “door” to the “systemd building”. It’s a modular component of systemd, so more akin to replacing the sudo building with a new, but still separate, systemd sudo building
Those hacked together system-specific bash scripts were shit. Having a standard way of creating, starting, ensuring restarts,and logging services is so much better.
You can still get all the plain text logs you like.
Those hacked together system-specific bash scripts were shit.
With a different feature set per script as well. The systemd service files have often been pushed upstream.
Pretty sure people liking those scripts never really tried dealing with them across distributions. Though this just rehashes things that were said when distributions decided if to switch to systemd. Still the same strange claim that those scripts are somehow easier. It wasn’t, it is also way easier to package a systemd file from upstream than to maintain that stuff within a distribution.
Set ForwardToSyslog=yes in journald.conf and install a syslog daemon. Also optionally Storage=volatile (I wouldn’t set Storage=none unless you want systemd to no longer show you any logs anywhere including in systemctl status because I assume it will do that)
You know what's nice? Being able to sit down at any Linux distro and being able to set up and configure services without Googling how to use that particular distro's init system.
I don’t understand how this is any improvement over pkexec
That has the same problem as sudo: the SUID bit is set for it.
The fact that run0 uses polkit is more of a byproduct that this kinda authentication is already done with polkit all over the place in systemd. You can have individual subcommand accessible to different users (for example everyone can systemctl status, but systemctl reboot needs to be in the wheel group) which is why its generally used within systemd already. And it wouldn’t surprise me if again you can do it with this as well, limiting what commands can unconditionally run, need prompt or are completely blocked.
I mean it should kind of already be something like GNU/SystemD/X11/PipeWire/Linux, I guess.
It’s not like the GNU utils are the only massive integral part of the OS. I think GNU/Linux caught on squarely because many people follow Stallman, and that’s how he wants people to refer to it.
It definitely made way more sense at early on. I mean GNU made most of UX of using Linux at some point. Systemd, and the browser now make a much bigger portion than before, and the world is more than GNOME now too.
Not really, because you’re now going to make it do more, i.e. incorporate the functionality of sudo and expose it to user input. So unless you can prove that the newly written code is somehow inherently more secure than sudo’s existing code, the attack surface is exactly the same.
This is great. Not having the attack surface of sudo (and not even being a SUID binary) certainly are great additions.
And I hope people realize that systemd is not one large thing, but a (large) collection of tools.
XZ-utils rings a bell ? It was among others Debian wanting to pull in part of a systemd tool into openssh and that almost turned into a world wide disaster :(
You didn’t follow the XZ-utils story ? The malicious actor worked for years on that XZ backdoor that targeted the fact that some Linux distributions were modifying their openssh package to enable systemd notifications.
Ok true, it was a systemd dependent issue. But it only makes sense to have those notifications. The problem is dependency on small hardly maintained products, which systemd will improve by centralizing it.
And where do maintainers for the new parts of systemd come from? The larger systemd grows the more parts of it will be neglected. Also in regard to people checking commits, opening up doors for exploits like the one in xz.
But it only makes sense to have those notifications.
Maybe in your mind it makes sense. Going for ease of use rather than security is not something that OpenBSD would quickly do. If you read some more about what “jwz” has to say about all the screensaver bugs in Linux, like here : www.jwz.org/blog/…/i-told-you-so-2021-edition and realize what a mess that Linux maintainers are making again and again, and then have a look at Debian and their packaging of xscreensaver. Guess what ? Debian added some systemd thingie to xscreensaver. 🤯
I like Debian since a long time and I use it. But the tinkering of Debian package maintainers and always wanting to do things the Debian way is not something I am always very pleased with. Remember the OpenSSL Debian fiasco ? That shows a problem with Debian which may still exist. Too many packages, not enough maintainers with enough spare time, and no coherent team work of a security team.
You are talking about Debian holding back random packages for stability. This is of course not very cool but it needs to be tested.
I am very much in favor of isolate app environments controlled by upstream devs, containerized and with a permission system. The system is made by the distro, and can be stable and very tested, and the apps are simply isolated and made by upstream.
There is no xscreensaver on Wayland and I think this will not come back?
that systemd is not one large thing, but a (large) collection of tools.
Who don’t work without Systemd. And Systemd can’t coexist with tools in the same repo doing the same job in a portable way.
I think Chimera was it (?) which tried to have Systemd and Runit and others in the same repo. With lots of wrappers and shims. Not because of Runit & co.
Right. That reminds of the time I was visiting a friend who had broken his Linux computer (No, not “apt-get remove --purge systemd” but they did something slightly similar). When I booted from a live Linux, used chroot and wanted to use configure networking : FAIL because systemd was … not running. As he had no Internet because of his broken machine this caused some delays in fixing this but we got the job done eventually.
Kinda feels like writing a script that implements the sudo CLI but calls pkexec would be an easier way to do it. Given that so many systems already come with both sudo and pkexec, do we really need yet another option?
There seems to be misunderstanding about what Wayland is.
Wayland is set of protocols. They are implemented by wayland servers (compositors) and wayland clients (applications) themselves. There is no single “wayland binary” like in the X11 days. Servers or clients may choose to implement or not implement a specific protocol.
I think what they meant is that there are people that think: “Wayland is too fragmented, there should be 1 ‘Wayland Compositor’ and the rest should be window managers”
Nope, I meant that the wayland compositors are inflexible monoliths that are so tightly integrated into a DE that they can’t be replaced. Xorg might be bloated, but it follows the UNIX philosophy closely enough that each part of the stack above xorg can be trivially replaced.
Nothing in the protocol prevents you from splitting the server from the window manager, just everyone implementing the wayland server protocol didn’t see any benefit in splitting it out.
Sure, but that doesn’t change the fact that Wayland compositors are forced to be inflexible monoliths that need to be so tightly integrated into a DE that they can’t be replaced.
Edit: I’ve just learned that it’s not forced, but that every compositor used by popular DEs is an inflexible monolith by choice.
In xorg the server, wm, and compositor all do their own thing and can be replaced trivially. It took me like 5 minutes to replace xfwm4 with i3, and that included the research.
I think wayland has potential but in it’s current state it’s just half baked. Once more protocols get merged, maybe in a decades time Wayland should be quite flexible and robust.
The wildest thing is that current xorg package is maintained by the community and they’re still removing it completely because “xorg is taking up too much dev time”.
It does have potential. I think anyone denying that is simply wrong. the issue with wayland is purely how slowly it moves and the fragmentation. Now the fragmentation is actually in large part due to how slowly it moves. There are numerous WIP protocols that will greatly decrease fragmentation when all are merged.
I can’t wait because it seems like it will happen in the short future of one or two decades xD
Not that I’m opposed to a better sudo alternatives, but I find it rather ironic that one of the reason stated is the large attack surface, considering systemd is a massive attack surface already.
The attack surface is there either way, this is just functionality repackaged that existed already before (systemd-run, which is calling into PID1)
all compression libraries (actually most libraries at this point) are dlopened on demand (which was planned even before the attack, which is speculated that the attack was accelerated in timeline because he was on a timer before the change was released)
There’s a rewrite of sudo happening in rust, but he wants to throw out the SUID idea altogether?
when invoked under the “run0” name (via a symlink) it behaves a lot like a sudo clone. But with one key difference: it’s not in fact SUID. Instead it just asks the service manager to invoke a command or shell under the target user’s UID. It allocates a new PTY for that, and then shovels data back and forth from the originating TTY and this PTY.
That sounds like opening up the door to what windows is doing UAC and the wonderful vulnerability that the GOG Launcher had for privilege escalation.
I’m not a security researcher, but giving arbitrary users the ability to tel PID 1 to run a binary of the user’s choosing is… probably not what Pottering is suggesting, but opens up to such vulnerabilities. And if it’s written in C/C++ my trust is further reduced.
Giving users access to PID1 running binaries, giving users access to the kernel running binaries as root, I don’t see much difference. SUID was notorious in the past for being leaky, it only ended when distros got serious about fencing use of it in, giving it only to programs actually needing it, making sure that they drop privilege properly, etc.
If anything I’m in the PID1 camp because it’s more microkernely. But in any case broader userspace shouldn’t really care about the mechanism, only have an API to do it and that API being a bit in the file permissions is soooo 1960s.
invoking them is kind of a pain, my sole experience with it was meson/ninja using it but then that default was removed and I’ve never been able to put it back to satisfy my curiosity of how it’s done
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