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BUG: KCSAN: data-race in kick_pool / wq_worker_running

read-write to 0xffff888237c29d64 of 4 bytes by task 9 on cpu 0:
 wq_worker_running+0x95/0x120 kernel/workqueue.c:1404
 schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:7115
 __mutex_lock_common kernel/locking/mutex.c:676 [inline]
 __mutex_lock+0x467/0xcf0 kernel/locking/mutex.c:760
 __mutex_lock_slowpath+0xa/0x10 kernel/locking/mutex.c:1049
 mutex_lock+0x27/0x30 kernel/locking/mutex.c:274
 pcpu_balance_workfn+0x4a/0xc00 mm/percpu.c:2200
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0x4ce/0x9d0 kernel/workqueue.c:3319
 worker_thread+0x582/0x770 kernel/workqueue.c:3400
 kthread+0x486/0x510 kernel/kthread.c:463
 ret_from_fork+0xda/0x150 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffff888237c29d64 of 4 bytes by task 23219 on cpu 1:
 need_more_worker kernel/workqueue.c:938 [inline]
 kick_pool+0x49/0x2d0 kernel/workqueue.c:1244
 __queue_work+0x8cb/0xb50 kernel/workqueue.c:2340
 queue_work_on+0xd1/0x160 kernel/workqueue.c:2390
 queue_work include/linux/workqueue.h:669 [inline]
 schedule_work include/linux/workqueue.h:730 [inline]
 pcpu_schedule_balance_work mm/percpu.c:204 [inline]
 pcpu_alloc_noprof+0x9a4/0x1210 mm/percpu.c:1856
 percpu_ref_init+0x33/0x250 lib/percpu-refcount.c:72
 io_ring_ctx_alloc+0x1aa/0x6a0 io_uring/io_uring.c:319
 io_uring_create+0x10f/0x610 io_uring/io_uring.c:3743
 io_uring_setup io_uring/io_uring.c:3890 [inline]
 __do_sys_io_uring_setup io_uring/io_uring.c:3924 [inline]
 __se_sys_io_uring_setup+0x1f7/0x210 io_uring/io_uring.c:3915
 __x64_sys_io_uring_setup+0x31/0x40 io_uring/io_uring.c:3915
 x64_sys_call+0x2b21/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:426
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00000000 -> 0x00000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 23219 Comm: syz.4.6340 Not tainted 6.16.0-syzkaller-11952-g6e64f4580381 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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