io_uring: fail io_uring_register(2) on a dying io_uring instance

If we have multiple threads doing io_uring_register(2) on an io_uring
fd, then we can potentially try and kill the percpu reference while
someone else has already killed it.

Prevent this race by failing io_uring_register(2) if the ref is marked
dying. This is safe since we're inside the io_uring mutex.

Fixes: b19062a56726 ("io_uring: fix possible deadlock between io_uring_{enter,register}")
Reported-by: syzbot <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>

0 files changed, 0 insertions, 0 deletions