================================================================== BUG: KCSAN: data-race in __io_cqring_fill_event / io_drain_req write to 0xffff888108831400 of 4 bytes by task 19917 on cpu 1: io_get_cqe fs/io_uring.c:1397 [inline] __io_cqring_fill_event+0xfb/0x350 fs/io_uring.c:1576 io_req_complete_post+0x54/0x6a0 fs/io_uring.c:1600 __io_req_complete fs/io_uring.c:1652 [inline] __io_complete_rw+0x39d/0x460 fs/io_uring.c:2505 io_complete_rw+0x1b/0x20 fs/io_uring.c:2512 io_rw_done fs/io_uring.c:2764 [inline] kiocb_done+0x18a/0x3d0 fs/io_uring.c:2788 io_read fs/io_uring.c:3369 [inline] io_issue_sqe+0x3800/0x69f0 fs/io_uring.c:6182 io_wq_submit_work+0x113/0x270 fs/io_uring.c:6307 io_worker_handle_work+0x8cb/0xaf0 fs/io-wq.c:496 io_wqe_worker+0x184/0x4b0 fs/io-wq.c:545 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 read to 0xffff888108831400 of 4 bytes by task 19916 on cpu 0: req_need_defer fs/io_uring.c:1226 [inline] io_drain_req+0x4de/0x620 fs/io_uring.c:6066 io_queue_sqe fs/io_uring.c:6509 [inline] io_submit_sqe+0x2e66/0x3400 fs/io_uring.c:6668 io_submit_sqes+0x822/0xe50 fs/io_uring.c:6784 __do_sys_io_uring_enter fs/io_uring.c:9395 [inline] __se_sys_io_uring_enter+0x1c9/0x9e0 fs/io_uring.c:9338 __x64_sys_io_uring_enter+0x74/0x80 fs/io_uring.c:9338 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae value changed: 0x00000000 -> 0x00000001 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 19916 Comm: syz-executor.4 Not tainted 5.13.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================