On 3/6/20 3:15 PM, Pavel Begunkov wrote: > There is a recipe to deadlock the kernel: submit a timeout sqe with a > linked_timeout (e.g. test_single_link_timeout_ception() from liburing), > and SIGKILL the process. > > Then, io_kill_timeouts() takes @ctx->completion_lock, but the timeout > isn't flagged with REQ_F_COMP_LOCKED, and will try to double grab it > during io_put_free() to cancel the linked timeout. Probably, the same > can happen with another io_kill_timeout() call site, that is > io_commit_cqring(). Thanks, looks good, applied. -- Jens Axboe
