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You gave me a u32. I gave you root. (io_uring ZCRX freelist LPE)

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Re: You gave me a u32. I gave you root. (io_uring ZCRX freelist LPE)

#41
post #34
post #31

[flagged]

Obviously the way to prevent this is by bounds checking, which is literally in the `770594e` patch. It's just a bug and they happen routinely in all languages. Since this is doing pointer arithmetic, it could just as easily happen in unsafe Rust, for example.

That's not prevention. That's remediation.

Re: You gave me a u32. I gave you root. (io_uring ZCRX freelist LPE)

#42
post #36

Earlier quoted context omitted.

Like they said, "no way to prevent this" (kind of bug from happening again).

Static analysis and other tools can find this, but they're expensive; wonder what the kernel team has access to?

If not static analysis what would ai tools be considered? They're operating off the same source code

Also nice the onion reference by op.

Re: You gave me a u32. I gave you root. (io_uring ZCRX freelist LPE)

#43

Earlier quoted context omitted.

Static analysis and other tools can find this, but they're expensive; wonder what the kernel team has access to?

If not static analysis what would ai tools be considered? They're operating off the same source code Also nice the onion reference by op.

"static analysis" is usually deterministic rules you can e.g. put in CI. AI is also somewhat dynamic in that it can execute commands to try stuff out. The best AI vuln finding harnesses work that way, by essentially putting the AI inside of a fuzzer-like environment and telling it to produce a crash.

Re: You gave me a u32. I gave you root. (io_uring ZCRX freelist LPE)

#44
Interesting, I haven't tested this myself but intuitively I think that a 4 byte OOB write is plenty for a data-only attack like [PageJack](https://i.blackhat.com/BH-US-24/Presentations/US24-Qian-Page...), so I don't think hardening against the KASLR leaks discussed in OP would necessarily save you from this attack.

Re: You gave me a u32. I gave you root. (io_uring ZCRX freelist LPE)

#46

Earlier quoted context omitted.

Static analysis and other tools can find this, but they're expensive; wonder what the kernel team has access to?

If not static analysis what would ai tools be considered? They're operating off the same source code Also nice the onion reference by op.

It's a reference to Xe Iaso's blog (e.g. https://xeiaso.net/shitposts/no-way-to-prevent-this/CVE-2025...), which is itself a reference to The Onion.

Re: You gave me a u32. I gave you root. (io_uring ZCRX freelist LPE)

#47
post #34
post #31

[flagged]

Obviously the way to prevent this is by bounds checking, which is literally in the `770594e` patch. It's just a bug and they happen routinely in all languages. Since this is doing pointer arithmetic, it could just as easily happen in unsafe Rust, for example.

But one would have to explicitly choose to use unsafe Rust for this instead of ordinary safe Rust. And safe Rust has no particular difficulty writing to slots in an array or slice or vector specified by their index.

Re: You gave me a u32. I gave you root. (io_uring ZCRX freelist LPE)

#48
post #47
post #34

Earlier quoted context omitted.

Obviously the way to prevent this is by bounds checking, which is literally in the `770594e` patch. It's just a bug and they happen routinely in all languages. Since this is doing pointer arithmetic, it could just as easily happen in unsafe Rust, for example.

But one would have to explicitly choose to use unsafe Rust for this instead of ordinary safe Rust. And safe Rust has no particular difficulty writing to slots in an array or slice or vector specified by their index.

except nearly everyone uses unsafe rust

Re: You gave me a u32. I gave you root. (io_uring ZCRX freelist LPE)

#49
post #10

What is happening? I see multiple outages and CVEs is being reported on HN's front page. I've never seen these many security/incident related posts on HN's front page.

Automated vulnerability discovery via LLM.

Anyone care to share which models and which prompts actually lead to finding these kinds of vulnerabilities? Or the narrowing-down workflow that can get an LLM to discover them? Surely just telling claude "Find all vulnerabilities in this project LOL" isn't enough? I hope?

Re: You gave me a u32. I gave you root. (io_uring ZCRX freelist LPE)

#50
post #34
post #31

[flagged]

Obviously the way to prevent this is by bounds checking, which is literally in the `770594e` patch. It's just a bug and they happen routinely in all languages. Since this is doing pointer arithmetic, it could just as easily happen in unsafe Rust, for example.

sure, but with unsafe Rust you have a very clear marking for the section of code that requires additional care and attention. it is also customary to include a "SAFETY" comment outlining why using unsafe is OK here
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