================================================================== BUG: KCSAN: data-race in __flush_work / __flush_work write to 0xffff888103d12be8 of 8 bytes by task 4224 on cpu 1: instrument_write include/linux/instrumented.h:41 [inline] ___set_bit include/asm-generic/bitops/instrumented-non-atomic.h:28 [inline] insert_wq_barrier kernel/workqueue.c:3790 [inline] start_flush_work kernel/workqueue.c:4142 [inline] __flush_work+0x30b/0x570 kernel/workqueue.c:4178 flush_work kernel/workqueue.c:4229 [inline] flush_delayed_work+0x66/0x70 kernel/workqueue.c:4251 io_fallback_tw+0x24b/0x320 io_uring/io_uring.c:1087 tctx_task_work_run+0xd1/0x1b0 io_uring/io_uring.c:1099 tctx_task_work+0x40/0x80 io_uring/io_uring.c:1124 task_work_run+0x13a/0x1a0 kernel/task_work.c:228 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x5dd/0x1720 kernel/exit.c:882 do_group_exit+0x102/0x150 kernel/exit.c:1031 get_signal+0xf2f/0x1080 kernel/signal.c:2917 arch_do_signal_or_restart+0x95/0x4b0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x59/0x130 kernel/entry/common.c:218 do_syscall_64+0xd6/0x1c0 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffff888103d12be8 of 8 bytes by task 56 on cpu 0: __flush_work+0x42a/0x570 kernel/workqueue.c:4188 flush_work kernel/workqueue.c:4229 [inline] flush_delayed_work+0x66/0x70 kernel/workqueue.c:4251 io_uring_try_cancel_requests+0x35b/0x370 io_uring/io_uring.c:3000 io_ring_exit_work+0x148/0x500 io_uring/io_uring.c:2779 process_one_work kernel/workqueue.c:3231 [inline] process_scheduled_works+0x483/0x9a0 kernel/workqueue.c:3312 worker_thread+0x526/0x700 kernel/workqueue.c:3390 kthread+0x1d1/0x210 kernel/kthread.c:389 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 value changed: 0x0000000000c00000 -> 0xffff88810006c20d Reported by Kernel Concurrency Sanitizer on: CPU: 0 UID: 0 PID: 56 Comm: kworker/u8:5 Not tainted 6.11.0-rc2-syzkaller-00315-g7006fe2f7f78 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 Workqueue: iou_exit io_ring_exit_work ==================================================================