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Rex is a safe kernel extension framework that allows Rust in the place of eBPF

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Re: Rex is a safe kernel extension framework that allows Rust in the place of eBPF

#31

Post by jacquesm »

testdelacc1 wrote: post #27
jacquesm wrote: post #19

Earlier quoted context omitted.

You may be correct but pjmlp is not one of those and if you had been here long enough you would have known that. You're the one creating an in-group here and putting yourself on the 'good' side. Perhaps that is too complex for you but I think it is intellectually lazy not to get who you're referring to before making comments such as these. Note that your strawman "See this is why I dislike the xyz community" wasn't p…

That dude said “even worse when coming from supposedly security conscious programming language community”. The comment is dripping with contempt, pointing out that the “community” makes tall claims that are unfounded. And he said this based purely on one comment. This contempt clearly indicated a dislike, which I generalised to “I dislike xyz community”. To which you reply with “strawman”. Sure. You’re then accusing…

Here's you:

https://news.ycombinator.com/item?id=46352728

So apparently it is fine for you to call out low karma accounts but I can't have you shit on a member in excellent standing here?

The Rust community has - rightly, in my opinion - flagged a number of serious concerns about language safety. Outside of that Rust is just another programming language and languages are just one of the parts of the security picture. There is process, general hygiene and a lot of hard learned lessons about how you keep systems secure regardless of what language a particular piece of code is written in.

Given the amount of Rust evangelization on HN (which is one of the reasons this link got posted in the first place) and the fact that they can't let any opportunity go by to shit on other languages and those that use them for reasons that are unclear to me (and this goes quite far, up to and including questioning the sanity of anybody writing in a systems language other than Rust) you can expect that that higher standard is applied to the Rust advocates in the same way.

Action begets reaction.

Your response is telling: you make a personal attack on a member of HN and then hide behind pointing out the flaws in 'the community' when in fact it is you that is poisoning the community with these kind of comments.

I've made it a rule since a couple of weeks that I'm tossing accounts like that onto my blacklist because really, life's too short. If you don't see value in HN discussing languages and their communities (and I have to give the Rust community some credit here, as the language matures they've become more realistic about their abilities and there is less zealotry, especially Steve Klabik deserves a mention) then it may be that you are in the wrong place. For me your account will cease to exist after this comment.

Re: Rex is a safe kernel extension framework that allows Rust in the place of eBPF

#32

Post by otabdeveloper4 »

calmingsolitude wrote: post #29

This is a pretty cool project and I think the comments here are being overly negative. Sure, removing the constraints that the eBPF verifier requires might encourage more complex and less performant code - but this is just another tool in the toolbox. For truly production systems, I can see the battle-tested eBPF being the top choice over a dubious kernel extension. But for quick prototyping? Rex can probably take th…

Sorry dude, I don't want you guys vibecoding my kernel modules while spouting cargocult platitudes that "it can't have bugs, it's written in Rust".

Re: Rex is a safe kernel extension framework that allows Rust in the place of eBPF

#33

Post by otabdeveloper4 »

bawolff wrote: post #3

> This approach avoids the overly restricted verification requirements (e.g., program complexity constraints) Maybe i'm missing something, but isn't that a bad thing?

"Bad thing" is an understatement.

Re: Rex is a safe kernel extension framework that allows Rust in the place of eBPF

#34

Post by testdelacc1 »

jacquesm wrote: post #31
testdelacc1 wrote: post #27

Earlier quoted context omitted.

That dude said “even worse when coming from supposedly security conscious programming language community”. The comment is dripping with contempt, pointing out that the “community” makes tall claims that are unfounded. And he said this based purely on one comment. This contempt clearly indicated a dislike, which I generalised to “I dislike xyz community”. To which you reply with “strawman”. Sure. You’re then accusing…

Here's you: https://news.ycombinator.com/item?id=46352728 So apparently it is fine for you to call out low karma accounts but I can't have you shit on a member in excellent standing here? The Rust community has - rightly, in my opinion - flagged a number of serious concerns about language safety. Outside of that Rust is just another programming language and languages are just one of the parts of the security picture.…

I didn’t make a personal attack on anyone, although you did to me.

Me calling out a sock puppet account (0 karma, created minutes before) is not the same as you saying that high karma accounts need to have their opinions respected simply because they are high karma. Coincidentally, I notice your account is very high karma.

You’re acting extraordinarily offended, like I’ve committed some major transgression here. I haven’t. I’ve re-read my comments and they’re frankly milquetoast.

Re: Rex is a safe kernel extension framework that allows Rust in the place of eBPF

#35

Post by IshKebab »

aliceryhl wrote: post #26
vlovich123 wrote: post #2

As a lover of Rust, ooo boy does this sound like a bad idea. The Rust compiler is not guaranteed to always output safe code against malicious inputs given that there’s numerous known soundness bugs that allow exploiting this. Unless I’m missing something this is a security nightmare of an idea. Also there’s reasons why eBPF programs aren’t allowed to run arbitrarily long and this just ignores that problem too.

I asked about this when they presented the project at the Linux Plumbers conference. They replied that it's not really intended to be a security boundary, and that you should not let anyone malicious load these programs. Given this thread model, I think their project is entirely reasonable. Safe Rust will prevent accidental mistakes even if you could technically circumvent it if you really try.

As I understand it eBPF has also given up on that due to Spectre. As a result you need root to use it on most distros anyway, and the kernel devs aren't going to expand its use (some systems are stuck on cBPF).

So it's not like eBPF is secure and this isn't. They're both insecure in different ways.

Re: Rex is a safe kernel extension framework that allows Rust in the place of eBPF

#36

Post by IshKebab »

bawolff wrote: post #3

> This approach avoids the overly restricted verification requirements (e.g., program complexity constraints) Maybe i'm missing something, but isn't that a bad thing?

The things you're missing:

1. This requires root.

2. eBPF also requires root usually. As I understand it it was originally meant to be secure enough to allow unprivileged use but Spectre ruined that and now they've given up on that.

Re: Rex is a safe kernel extension framework that allows Rust in the place of eBPF

#37

Post by pseudony »

NewJazz wrote: post #11
pjmlp wrote: post #6

Earlier quoted context omitted.

Yes, very bad, even worse when coming from supposedly security conscious programming language community.

They're not in the core language group... Do these people have influence in the stdlib, compiler, prominent libraries? Kernel community? Why judge the whole Rust community for the choices made by one minor subgroup?

This has been covered ad nauseam, but since rust advocacy has waded into enough discussions about code in other languages to lecture people on performance and safety, it has naturally pushed some to find a bit of satisfaction in commenting on shortcomings in rust projects.

And this is very much also something which is helped along by the community’s defining voices.

Re: Rex is a safe kernel extension framework that allows Rust in the place of eBPF

#38

Post by p-e-w »

IshKebab wrote: post #36
bawolff wrote: post #3

> This approach avoids the overly restricted verification requirements (e.g., program complexity constraints) Maybe i'm missing something, but isn't that a bad thing?

The things you're missing: 1. This requires root. 2. eBPF also requires root usually. As I understand it it was originally meant to be secure enough to allow unprivileged use but Spectre ruined that and now they've given up on that.

How would Spectre, a timing attack that does not require root, affect whether eBPF is safe to run as root?

Re: Rex is a safe kernel extension framework that allows Rust in the place of eBPF

#40

Post by IshKebab »

p-e-w wrote: post #38
IshKebab wrote: post #36

Earlier quoted context omitted.

The things you're missing: 1. This requires root. 2. eBPF also requires root usually. As I understand it it was originally meant to be secure enough to allow unprivileged use but Spectre ruined that and now they've given up on that.

How would Spectre, a timing attack that does not require root, affect whether eBPF is safe to run as root?

It doesn't. Spectre means unprivileged use of eBPF is insecure.
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