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Changes to multi-word pointers can cause UB due to race conditions in Go because only changes at the word level are atomic.

See: https://blog.stalkr.net/2015/04/golang-data-races-to-break-m...



Does Rust not have race conditions?


One of Rust's core guarantees is that a race condition in safe code will never cause UB. It might return a nondeterministic result, but that result will be safe and well-typed (for example, if it's a Vec, it will be a valid Vec that will behave as expected and, once you have a unique reference, is guaranteed not to change out from under you).


When talking about the kind that lead to torn memory writes, no it doesn't have those. To share between threads you need to go through atomics or mutexes or other protection methods.


Rust prevents data races, but not race conditions.


Rust has double free concurrency bugs

https://materialize.com/blog/rust-concurrency-bug-unbounded-...

Lockbud: project detailing memory, concurrency bugs and panics for Rust. https://github.com/BurtonQin/lockbud

USENIX paper on model checking for Rust OS kernels uncovered 20 concurrency bugs across 12 modules in projects like Redox OS and Tock, including data races, deadlocks, and livelocks

https://www.usenix.org/system/files/atc25-tang.pdf


You've linked to a bug that was unintentional and was fixed.

Go allowing torn writes for their slices and interfaces (their fat pointer types) is intentional behavior in the go implementation and has no sign of being fixed.

Some one getting unsafe code unintentionally wrong is not an indication that any language lacks memory safety.


I see, you wish to limit the domain. Do safety issues in the async runtime count ? Or is even "async Rust" out of your criteria ?

What about this one ? "Futurelock in Tokyo" ? https://rfd.shared.oxide.computer/rfd/0609


> What about this one ? "Futurelock in Tokyo" ?

Deadlocks are not memory safety issues by the definition used in the OP. Furthermore, safe Rust is only intended to guarantee protection against data races, not race conditions in general.


What about these ones ? They are considered memory-safety/soundness issues

'static closures/FnDefs/futures with non-'static return type are unsound https://github.com/rust-lang/rust/issues/84366

Resolve unsound interaction between noalias and self-referential data (incl. generators, async fn) https://github.com/rust-lang/rust/issues/63818


I think this is starting to wander rather far afield from where this thread started...

But anyways, at least from a quick glance those would at the very least seem to run into codys' unintentional bug vs. intentional behavior distinction. The bugs you linked are... well... bugs that the Rust devs fully intend to fix regardless of whether any in-the-wild exploits ever arise. The Go data race issue, on the other hand, is an intentional implementation decision and the devs have not indicated any interest in fixing it so far.


Neither set of issues is apposite to MemorySafety.org. The whole thing is just a dumb language war spat.




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