CVE-2026-115567

### Summary On the multi-threaded runtime, there is a race condition between `Interval::poll_tick` and the runtime's time driver. This affects `Interval` only. `Sleep` and `Timeout` are **not** affected. ### Details In Tokio v1.54.0, a race condition between `tokio::time::Interval::poll_tick` (including `.tick().await`) and the runtime time driver can drop an internal timer entry without synchronizing with the driver thread that is firing it. This causes a data race and use-after-free on the timer's waker and task state in safe Rust, leading to assertion panics, task reference-count corruption, or heap memory corruption. This bug was introduced by https://github.com/tokio-rs/tokio/pull/8458, and it was fixed by https://github.com/tokio-rs/tokio/pull/8692. ### Impact This may lead to crashes and use-after-frees in applications using `Interval` on a multi-threaded runtime. Since this issue is known to lead to crashes in production systems, the v1.54.0 release of Tokio has been yanked. ### Credits Thank you to [creepycode](https://github.com/ByteZ1337) and [carabistouille](https://github.com/carabistouflette) for reporting this privately using the procedure outlined in our security policy. They both reported the issue independently of each other.

## Summary On the multi-threaded runtime, there is a race condition between `Interval::poll_tick` and the runtime's time driver. This affects `Interval` only. `Sleep` and `Timeout` are **not** affected. ## Details In Tokio v1.54.0, a race condition between `tokio::time::Interval::poll_tick` (including `.tick().await`) and the runtime time driver can drop an internal timer entry without synchronizing with the driver thread that is firing it. This causes a data race and use-after-free on the timer's waker and task state in safe Rust, leading to assertion panics, task reference-count corruption, or heap memory corruption. This bug was introduced by https://github.com/tokio-rs/tokio/pull/8458, and it was fixed by https://github.com/tokio-rs/tokio/pull/8692. ## Impact This may lead to crashes and use-after-frees in applications using `Interval` on a multi-threaded runtime. Since this issue is known to lead to crashes in production systems, the v1.54.0 release of Tokio has been yanked. ## Credits Thank you to [creepycode](https://github.com/ByteZ1337) and [carabistouille](https://github.com/carabistouflette) for reporting this privately using the procedure outlined in our security policy. They both reported the issue independently of each other.