[miah_]

Its because Selinux wasn't really designed for "sysadmins" it was designed for "governments" or organizations that need to meet a specific level of security as a contractual/legal requirement. Selinux came out of the NSA and is based around the Trusted Systems Criteria / Common Criteria, aka the Rainbow Books. If you look at 'Trusted Solaris' (or IRIX, AIX) you'll see very similar systems.

Is this poor design or simply, not designed _for_you_?

I agree, its a royal pain to manage, and it might be overkill for a small shop trying to lock down their web server. Thankfully there are other solutions, and operating systems that may better fit your use cases.

https://en.wikipedia.org/wiki/Common_Criteria

https://en.wikipedia.org/wiki/Trusted_Solaris

https://en.wikipedia.org/wiki/Security-Enhanced_Linux

[taikobo]

Well put, so to rephrase: SELinux is not for most people and cooperation, therefore, it is sensible to just disable it, making RHEL less secure than Debian in practice.

[ruthmarx]

Very much the wrong takeaway. SELinux is absolutely for people and corporations and has been for most of it's existence, and no, it doesn't make sense to disable it anymore than it makes sense to run as root because it's convenient.

If you are looking for a justification to excuse bad security practices, you won't find it in the origin story of SELinux.

[miah_]

Its very much for people who are trying to lock down their systems. Its also very much for people who want to meet the Common Criteria. It can be both. But for some people, its very much over kill.

[generalizations]

I mean yeah. It's software designed for compliance. It's technically capable of any kind of restriction a bureaucrat might envision, so it's the best thing available for the kind of checkbox security needed in a regulated industry.

I find it enlightening to read what kinds of justifications the proponents of SElinux use. It's never about the quality of the software; it's about how there's more band-aid tooling to make it easier to work with, or about how it's not as bad as it was, or that it gives you all these knobs and levers to have more control. It's not what you focus on when you're serious about quality software engineering.

Imagine if we were talking about something like Gnome or the Windows 11 interface: yeah, the interface is a real pain to navigate, but we added even more menus and buttons and the rightclick menu is twice as long now, so you can do even more stuff with it, and we even added Clippy back in to help you when you get stuck!

[SubjectToChange]

Yes, SELinux is enormously complex and typically obtuse. However, it's difficult to imagine a much more "elegant" solution for the role SELinux serves. Linux, and Unices in general, are simply not designed for security. Indeed, the virtualization movement was largely driven by process isolation being so poor in mainstream operating systems.

SELinux is designed to fulfill to primary goals. First, to secure the messy and complicated Linux architecture. And second, to be flexible enough to accommodate (highly) complex security architectures, as well as potentially unique and/or unforeseen needs. With that in mind, it's difficult to imagine any equivalent being practically more simple and/or elegant than SELinux.

The primary problem with SELinux is the broad lack of experience amongst users and sysadmins, opaque documentation, and primitive tooling. And in many ways, it is a negative feedback loop. If SELinux was used everywhere, improvements to its documentation and tooling would naturally follow.

[generalizations]

Some variants of Unix are designed for security; OpenBSD comes to mind. And Theo is on the record eviscerating the notion that virtualization be used as a security measure. Something about complexity being counterproductive to a secure system.

You're describing the linux architecture as messy and complicated, but that describes the SELinux architecture as well; if complexity & mess are bugs that should be squashed in pursuit of security, SELinux is ill-suited to the task.

> And second, to be flexible enough to accommodate (highly) complex security architectures, as well as potentially unique and/or unforeseen needs.

>> It's technically capable of any kind of restriction a bureaucrat might envision

Sounds like we're on the same page there. Or at least looking at the same phenomenon.

Your last paragraph is definitely outside the pattern of justifications I listed, but it's not much better: you're just blaming the users. Sysadmins use all kinds of complex software to accomplish any number of delicate tasks - if the tool is well-built, they don't tend to complain that it isn't. SELinux is not. Don't blame the user when the tool's at fault.

[ruthmarx]

> Some variants of Unix are designed for security; OpenBSD comes to mind.

This is fundamentally not true. Don't buy into the aggressive marketing. OpenBSD has a less secure design than pretty much any modern Linux. Their reputation for security is based on disabling things by default when it wasn't common 20 years ago, that's pretty much it.

[generalizations]

I trust soft sells over hard sells. SELinux depends on hard sells, from what I've seen; and OpenBSD stands on the logic of its own merits.

[ruthmarx]

This doesn't even make sense. At all.

First of all "OpenBSD stands on the logic of its own merits" what in the actual heck?

OpenBSD has had two remote holes in it's default install and importantly, *no mechanisms in place or restrict what can then be done*. That's not in line with a secure system.

You're vastly overstating and assuming the merits OpenBSD has, and then even worse, assuming logic exists based on that to support your position. I would say it doesn't, and I challenge you to show your work and demonstrate otherwise.

SELinux is a mature product that has seen widespread use in enterprise deployment and has real world examples of stopping attacks that OpenBSD couldn't hope to on it's best day.

If you want to go by merit and logic and not assumption and marketing, then SELinux will come out on top every time. It's actual, provable, tested security, not dreams and half-measures.

[pjmlp]

There are some talks on the actual security OpenBSD provides in practice.

[SubjectToChange]

...Theo is on the record eviscerating the notion that virtualization be used as a security measure. Something about complexity being counterproductive to a secure system.

Hypervisors predate Unix, in fact they practically predate general purpose operating systems as a whole. The reason hypervisors came first is because they are substantially more simple than an OS. Tens of billions of dollars has been spent on virtualization technologies because of its reliability.

Sure, a virtual machine running on a type-2 hypervisor like KVM looks like a complete mess. But the sad part is that such an architecture is easier to secure than an operating system, whether OpenBSD or otherwise. Raadt may disagree, but AWS, Azure, GCP, etc depend on hypervisors/virtualization, not OpenBSD.

You're describing the linux architecture as messy and complicated, but that describes the SELinux architecture as well...

Well, yes. SELinux has to cope with the deficiencies of Linux. I'm not pretending otherwise.

...if complexity & mess are bugs that should be squashed in pursuit of security, SELinux is ill-suited to the task.

The problem is that the market settled on Linux, despite its "complexity & mess". SELinux isn't nice but it's the most concrete solution available today. Indeed, after twenty years of criticism, no one has been able to design a competent replacement or alternative.

>> It's technically capable of any kind of restriction a bureaucrat might envision Sounds like we're on the same page there. Or at least looking at the same phenomenon.

There is a material difference between our viewpoints. The government has systems running in a dizzying amount of configurations and environments. Moreover, government agencies and government contractors operate in a far more dangerous security environment than the vast majority private companies. Perhaps your workplace doesn't need SELinux, but companies like Lockheed Martin or Aerojet Rocketdyne definitely do.

...you're just blaming the users.

Maybe it seems like splitting hairs, but I'm not blaming anyone. Rather, I was lamenting over the bad situation of things. After all, I've been there as a new sysadmin. Trying to grok SELinux for the first time is not a pleasant experience.

Don't blame the user when the tool's at fault.

Look, if security isn't important for someone and/or their organization, then fine, don't bother. However, we have seen time and time again that compromises in supposedly "unimportant" systems ends up causing quite a bit of harm.

Ultimately SELinux exists because of the shortcomings of Linux itself. Nothing has replaced SELinux because genuinely securing a Linux system is extremely difficult and it fundamentally cannot be made simple.

[generalizations]

> hypervisors

Yes, money has been spent, and cloud infrastructure built, on hypervisors because of their reliability, and because they are selling virtual machines. But reliability, while paramount, is not security, and the goal is to sell VMs. OpenBSD, with its focus on security over performance, is the wrong tool for the job.

> coping with the deficiencies of linux

Good designs can take a messy domain and provide a clean interface on top of it. SELinux does not.

SELinux is partly a big matrix of tags, with definable security associations between any two such tags. That's great when a bureaucrat in a defense contractor security department writes up some new policy definition - you never know what they might come up with - and I would not make the mistake of assuming security is well-informed on the internals of Linux when they write those rules. SELinux is elegantly designed to be as granular as needed to accommodate that. But that's what it's designed for: checkbox security within massive agencies.

> it's all we have

Yes, I agree, it's the only thing that can accommodate that kind of security; since few people outside regulated industries are interested in catering to it, there's not a lot of push to make something else to fill that niche.

> the user or the tool

Arguing that security is important is not relevant to justifying SELinux. I will agree though, it's definitely very hard to twist a Linux system into a shape that fits bureaucratic security policies.

[pjmlp]

Also SELinux was initially developed at NSA, which probably know a few things more about security than OpenBSD folks.

[argentier]

The NSA is about insecurity, not security. They're a SIGINT shop

[okasaki]

Poorly designed for general use?

[SubjectToChange]

Securing Linux, or practically any Unix system for that matter, is like nailing jello to the wall.