Jens Axboe 6b63308c28 io_uring/eventfd: ensure io_eventfd_signal() defers another RCU period
Commit c9a40292a44e78f71258b8522655bffaf5753bdb upstream.

io_eventfd_do_signal() is invoked from an RCU callback, but when
dropping the reference to the io_ev_fd, it calls io_eventfd_free()
directly if the refcount drops to zero. This isn't correct, as any
potential freeing of the io_ev_fd should be deferred another RCU grace
period.

Just call io_eventfd_put() rather than open-code the dec-and-test and
free, which will correctly defer it another RCU grace period.

Fixes: 21a091b970 ("io_uring: signal registered eventfd to process deferred task work")
Reported-by: Jann Horn <jannh@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-17 13:34:47 +01:00
2024-12-14 19:53:51 +01:00
2025-01-17 13:34:43 +01:00
2025-01-17 13:34:43 +01:00
2024-12-14 19:54:40 +01:00
2022-09-28 09:02:20 +02:00
2025-01-09 13:30:07 +01:00

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