================================================================== BUG: KCSAN: data-race in __io_cqring_fill_event / io_req_defer write to 0xffff88812fc36c80 of 4 bytes by task 21309 on cpu 1: io_get_cqring fs/io_uring.c:1379 [inline] __io_cqring_fill_event+0xfd/0x350 fs/io_uring.c:1561 io_req_complete_post+0x58/0x540 fs/io_uring.c:1585 io_issue_sqe+0x4593/0x6750 fs/io_uring.c:1125 io_wq_submit_work+0x113/0x270 fs/io_uring.c:6252 io_worker_handle_work+0x8cb/0xaf0 fs/io-wq.c:496 io_wqe_worker+0x1c5/0x550 fs/io-wq.c:545 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 read to 0xffff88812fc36c80 of 4 bytes by task 21306 on cpu 0: req_need_defer fs/io_uring.c:1208 [inline] io_req_defer+0x358/0x4a0 fs/io_uring.c:6002 io_queue_sqe fs/io_uring.c:6451 [inline] io_submit_sqe+0x154d/0x3360 fs/io_uring.c:6626 io_submit_sqes+0x5bd/0xbd0 fs/io_uring.c:6734 __do_sys_io_uring_enter fs/io_uring.c:9330 [inline] __se_sys_io_uring_enter+0x1e1/0xa80 fs/io_uring.c:9272 __x64_sys_io_uring_enter+0x74/0x80 fs/io_uring.c:9272 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae value changed: 0x00000000 -> 0x00000001 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 21306 Comm: syz-executor.5 Not tainted 5.13.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================