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GhostLock, a stack-UAF that has existed in all Linux distributions for 15 years

nebusec.ai

41–50 of 209 posts

Re: GhostLock, a stack-UAF that has existed in all Linux distributions for 15 years

#41

Earlier quoted context omitted.

Since this enables container escape, sounds like this might still impact quite a lot of us?

I guess, if you thought Docker/etc. was a security boundary

Runpod, digital ocean's gpu cloud, and at least a few others use Linux containers for isolation between tenants (look at Wiz's blog post about the nvidia container toolkit bug; digitalocean just puts everyone in a massive k8s cluster)

Re: GhostLock, a stack-UAF that has existed in all Linux distributions for 15 years

#42
post #32

Earlier quoted context omitted.

[flagged]

[flagged]

Hey guys - please don't do tit for tat spats on HN. I know how it feels (believe me, I know how it feels down to such a level that any hypothetical offspring would also know how it feels), but it only makes everything worse.

https://news.ycombinator.com/newsguidelines.html

Re: GhostLock, a stack-UAF that has existed in all Linux distributions for 15 years

#43
post #32

Earlier quoted context omitted.

[flagged]

[flagged]

Hey guys - please don't do tit for tat spats on HN. I know how it feels (believe me, I know how it feels down to such a level that any hypothetical offspring would also know how it feels), but it only makes everything worse.

https://news.ycombinator.com/newsguidelines.html

Re: GhostLock, a stack-UAF that has existed in all Linux distributions for 15 years

#44

Earlier quoted context omitted.

Since this enables container escape, sounds like this might still impact quite a lot of us?

I guess, if you thought Docker/etc. was a security boundary

I know there's a lot you can do in k8s to mitigate it, but I didn't think that prevented it outright.

Re: GhostLock, a stack-UAF that has existed in all Linux distributions for 15 years

#45

> This is the same shape as many other life-cycle bugs [...] Claude-ism detected. IME with Claude Code an object does not have a type or definition, apparently, but rather a shape (or at least it reaches for that word before more technically-accurate ones). Problems are not of a similar class or type, but of the same shape. Functions are not defined by their signatures but by their shape. Who talks like this and how…

I think you're probably right that the article was AI-assisted, but (if so) it's important not to confuse that with the thing the article is about. Google wouldn't pay $90k for a hallucination.

I don't mean that as a criticism—the question of how to receive AI-processed content is chaotic right now. I'm working on a post about that here: https://news.ycombinator.com/item?id=48887149.

Btw, Nebula Sec is a YC startup in the current batch. We've been working with them on how to launch on HN, and one of the things I've been trying to explain is that the HN audience won't respond well to LLM-generated reports. The underlying work, though, is impressive. These guys know what they're doing—the OP is by no means their only significant find—and the fact that they're doing it with an agent, rather than the traditional way, is significant.

Re: GhostLock, a stack-UAF that has existed in all Linux distributions for 15 years

#46

Has anyone in infosec ever seen the term "use after free" before LLMs? Or is this basically an acronym claude invented? I say this because I see claude use this term all the time like its common knowledge but in 15+ years in tech never seen it myself. I've seen all kinds of terms used to describe memory errors: memory corruption, heap corruption, stack corruption, whatever, just never this acronym.

Huh? That is a really common term. There have been even memes about it. I remember roughly 5 years ago I first heard the ironic; "Real men use after free" in a discussion about Rust's benefits as its borrowing checker would have also prevented this one.

"Use after free" is also described in most standard books about C as a thing you should never do, have you read one?

Re: GhostLock, a stack-UAF that has existed in all Linux distributions for 15 years

#47
post #39

Earlier quoted context omitted.

There is an interesting episode of This American Life about how everyone, everyone, has weird gaps in their knowledge that eventually get filled in sometimes fun or humiliating ways. You have these too.

Wow, what is that episode? I haven't listened to TAL in probably more than a decade but it was great for a long time, and for all I know still is.

"A Little Bit of Knowledge"

Re: GhostLock, a stack-UAF that has existed in all Linux distributions for 15 years

#48
post #45

> This is the same shape as many other life-cycle bugs [...] Claude-ism detected. IME with Claude Code an object does not have a type or definition, apparently, but rather a shape (or at least it reaches for that word before more technically-accurate ones). Problems are not of a similar class or type, but of the same shape. Functions are not defined by their signatures but by their shape. Who talks like this and how…

I think you're probably right that the article was AI-assisted, but (if so) it's important not to confuse that with the thing the article is about. Google wouldn't pay $90k for a hallucination. I don't mean that as a criticism—the question of how to receive AI-processed content is chaotic right now. I'm working on a post about that here: https://news.ycombinator.com/item?id=48887149 . Btw, Nebula Sec is a YC startup…

A thing that notably triggers my allergies is that if significant human effort went into something, a few paragraphs written by a human seems like a trivial additional investment; if that last touch is missing, it's really hard for me to extend the benefit of the doubt that there really is something there.

Obviously this is only one signal among many, one that can be overruled, but the ick remains regardless.

Re: GhostLock, a stack-UAF that has existed in all Linux distributions for 15 years

#49

Tested on three Android devices (version 9, 13, 16) with different Firefox versions under 150 (had to modify for older). Two boot looped, I had to enter recovery and the other just powered off [0]. The demo modifies the wallpaper on supported Pixel devices. [0] IonStack https://rootme.nebusec.ai ____ Tip: Install a Chromium flavor browser (Chromite) separate from the main browser. Disable Javascript and hardware acce…

I've been noodling with porting the kernel exploit to other devices, and the exploit is very sensitive to how the compiler happens to lay out stack frames, which varies between kernel builds. Once you figure out the right "stamp method" and offsets for a particular kernel build though, it's fairly reliable.

Re: GhostLock, a stack-UAF that has existed in all Linux distributions for 15 years

#50

> This is the same shape as many other life-cycle bugs [...] Claude-ism detected. IME with Claude Code an object does not have a type or definition, apparently, but rather a shape (or at least it reaches for that word before more technically-accurate ones). Problems are not of a similar class or type, but of the same shape. Functions are not defined by their signatures but by their shape. Who talks like this and how…

Isn't this just observation bias? "If I haven't encountered something, then it must not be real?" (Paraphrasing)
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