1.51.5 (October 3rd, 2026)

Fixed

• fs: handle integer overflow in buffered relative seek (#8574)
• io: revert "always cleanup AsyncFd registration list on deregister" (#8540)
• process: unregister Windows wait before closing child handle (#8564)
• rt: drop blocking pool mutex before shutting down rejected task (#8562)
• sync: fix mpsc index wraparound in block reclamation (#8546)
• sync: forget mpsc Permit before sending value (#8560)
• sync: validate MAX_PERMITS in Semaphore::acquire (#8548)
• sync: wake broadcast Sender::closed outside mutex (#8558)
• task: drop replaced waker outside lock in JoinSet (#8554)
• time: drop timer lock before dropping waker in clear_entry (#8552)
• time: expire timers directly on shutdown without rotating wheel (#8570)

Fixed (unstable)

• rt: ignore current_thread task dumps from other runtimes (#8544)
• rt: preserve io_uring context if a completion waker panics (#8566)
• sync: fix semaphore use-after-free and permit leak on tracing panic (#8542)
• time: drop stored waker when cancelling alt timer entry (#8550)