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Pitfalls of Safe Rust

(corrode.dev)
168 points pjmlp | 2 comments | 04 Apr 25 17:55 UTC | HN request time: 0s | source
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nerdile ◴[06 Apr 25 17:56 UTC] No.43603402[source]▶
Title is slightly misleading but the content is good. It's the "Safe Rust" in the title that's weird to me. These apply to Rust altogether, you don't avoid them by writing unsafe Rust code. They also aren't unique to Rust.

A less baity title might be "Rust pitfalls: Runtime correctness beyond memory safety."

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burakemir ◴[06 Apr 25 18:33 UTC] No.43603739[source]▶
It is consistent with the way the Rust community uses "safe": as "passes static checks and thus protects from many runtime errors."

This regularly drives C++ programmers mad: the statement "C++ is all unsafe" is taken as some kind of hyperbole, attack or dogma, while the intent may well be to factually point out the lack of statically checked guarantees.

It is subtle but not inconsistent that strong static checks ("safe Rust") may still leave the possibility of runtime errors. So there is a legitimate, useful broader notion of "safety" where Rust's static checking is not enough. That's a bit hard to express in a title - "correctness" is not bad, but maybe a bit too strong.

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quotemstr ◴[06 Apr 25 18:47 UTC] No.43603876[source]▶
Safe Rust code doesn't have accidental remote code execution. C++ often does. C++ people need to stop pretending that "safety" is some nebulous and ill-defined thing. Everyone, even C++ people, shows perfectly damn well what it means. C++ people are just miffed that Rust built it while they slept.
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1. yjftsjthsd-h ◴[06 Apr 25 21:06 UTC] No.43604960[source]▶
Research I've seen seems to say that 70-80% of vulnerabilities come from memory safety problems[0]. Eliminating those is of course a huge improvement, but is rust doing something to kill the other 20-30%? Or is there something about RCE that makes it the exclusive domain of memory safety problems?

[0] For some reason I'm having trouble finding primary sources, but it's at least referenced in ex. https://security.googleblog.com/2024/09/eliminating-memory-s...

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2. Xylakant ◴[06 Apr 25 22:20 UTC] No.43605450[source]▶
Rust also provides guarantees that goe beyond mere memory safety. You get data-race safety as well, which avoids certain kinds of concurrency issues. You also get type-safety which is a step up when it comes to parsing untrusted input, at least compared to C for example. If untrusted inout can be parsed into your expected type system, it's more likely to not cause harm by confusing the program about what's in the variables. Rust doesn't straight up eliminate all source of error, but it makes major strides forward in areas that go beying mere memory safety.