Are there better tools for finding this? It feels like the sort of thing static analysis should reliably find, but it's in the Linux kernel, so you'd think either coding standards or tooling around these sorts of C bugs would be mature.
Not the expert in the area, but "classic static analysis" (for lack of a better term) and concurrency bugs doesn't really check. There are specific modeling tools for concurrency, and they are an entirely different beast than static analysis that requires notation and language support to describe what threads access what data when. Concurrency bugs in static analysis probably requires a level of context and understanding that an LLM can easily churn through.
Some static analysis tools can detect use after free or memory leaks. But since this one requires reasoning about multiple threads, I think it would've been unlikely to be found by static analysis.