I've found it interesting that systemd and Linux user permissions/groups never come into the sandboxing discussions. They're both quite robust, offer a good deal of customization in concert,and by their nature, are fairly low cost.

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nextaccountic 2 hours ago | parent | next [-]

Unix permissions were written at a time where the (multi user) system was protecting itself from the user. Every program ran at the same privileges of the user, because it wasn't a security consideration that maybe the program doesn't do what the user thinks it does. That's why in the list of classic Unix tools there is nothing to sandbox programs or anything like that, it was a non issue

And today this is.. not sufficient. What we require today is to run software protected from each other. For quite some time I tried to use Unix permissions for this (one user per application I run), but it's totally unworkable. You need a capabilities model, not an user permission model

Anyway I already linked this elsewhere in this thread but in this comment it's a better fit https://xkcd.com/1200/

	▲	theteapot an hour ago \| parent \| next [-]
		I feel like apparmor is getting there, very, very slowly. Just need every package to come with a declarative profile or fallback to a strict default profile.
	▲	fsflover 2 hours ago \| parent \| prev [-]
		This is why my daily driver is https://qubes-os.org

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vbezhenar 2 hours ago | parent | prev | next [-]

Linux kernel is ridden with local privilege escalation vulnerabilities. This approach works for trusted software that you just want to contain, but it won't work for malicious software.

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viraptor an hour ago | parent [-]

Ridden? There are issues from time to time, but it's not like you can grab the latest, patched Ubuntu LTS and escalate from an unprivileged seccomp sandbox that doesn't include crazy device files.

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vbezhenar an hour ago | parent [-]

Any sandbox technology works fine until it isn't. It's not like you could escape Java sandbox, but Java applets were removed from the browsers due to issues being found regularly. In the end, browser sandbox is one of the few that billions of people use and run arbitrary code there every day, without even understanding that. The only comparable technology is qemu. I don't think there are many hosters who will hand off user account to a shared server and let you go wild there.

	▲	viraptor an hour ago \| parent [-]
		> Any sandbox technology works fine until it isn't. Tautology is tautology. > but Java applets were removed from the browsers Java applets provided more scope compared to the browser itself, not less. They're not really comparable to seccomp or namespaces. > hosters who will hand off user account to a shared server There's lots of CI or function runners that expose docker-like environments.

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moezd 3 hours ago | parent | prev | next [-]

This assumes people know more than just writing Dockerfiles and push straight to production. This is still a rarity.

	▲	ijustlovemath 2 hours ago \| parent [-]
		Nowadays, it's fairly simple to ask for a unit file and accompanying bash script/tests for correctness. I think the barrier in that sense has practically vanished.

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pjmlp 3 hours ago | parent | prev | next [-]

Because that is actually UNIX user permissions/groups, with a long history of what works, and what doesn't?

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hendry an hour ago | parent | prev | next [-]

Agreed! systemd nspawn is actually pretty awesome, though not many people use it.

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ape4 2 hours ago | parent | prev [-]

cgroups are part of whats used to implement docker and podman

	▲	ijustlovemath 2 hours ago \| parent [-]
		True, and they do indeed offer an additional layer of protection (but with some nontrivial costs). All (non-business killing) avenues should be used in pursuit of defense in depth when it comes to sandboxing. You could even throw a flatpak or firejail in, but that starts to degrade performance in noticeable ways (though I've found it's nice to strive for this in your CI).