syzbot

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BUG: KCSAN: data-race in wq_worker_tick / wq_worker_tick

read-write to 0xffff88810020dcb8 of 8 bytes by interrupt on cpu 1:
 wq_worker_tick+0x60/0x230 kernel/workqueue.c:1474
 sched_tick+0x11a/0x270 kernel/sched/core.c:5677
 update_process_times+0x15f/0x190 kernel/time/timer.c:2520
 tick_sched_handle kernel/time/tick-sched.c:276 [inline]
 tick_nohz_handler+0x249/0x2d0 kernel/time/tick-sched.c:297
 __run_hrtimer kernel/time/hrtimer.c:1761 [inline]
 __hrtimer_run_queues+0x20c/0x5a0 kernel/time/hrtimer.c:1825
 hrtimer_interrupt+0x21a/0x460 kernel/time/hrtimer.c:1887
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline]
 __sysvec_apic_timer_interrupt+0x5c/0x1d0 arch/x86/kernel/apic/apic.c:1055
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
 sysvec_apic_timer_interrupt+0x6f/0x80 arch/x86/kernel/apic/apic.c:1049
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
 get_current arch/x86/include/asm/current.h:25 [inline]
 get_ctx kernel/kcsan/core.c:206 [inline]
 kcsan_atomic_next+0x33/0x50 kernel/kcsan/core.c:896
 page_zonenum include/linux/mmzone.h:1155 [inline]
 page_zone include/linux/mm.h:1957 [inline]
 folio_zone include/linux/mm.h:1967 [inline]
 free_unref_folios+0x52d/0x6f0 mm/page_alloc.c:2802
 folios_put_refs+0x276/0x2d0 mm/swap.c:992
 release_pages+0x2a8/0x2f0 mm/swap.c:1032
 io_free_region+0x7b/0x160 io_uring/memmap.c:101
 io_rings_free io_uring/io_uring.c:2658 [inline]
 io_ring_ctx_free+0x1d0/0x360 io_uring/io_uring.c:2743
 io_ring_exit_work+0x529/0x560 io_uring/io_uring.c:2962
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x4cb/0x9d0 kernel/workqueue.c:3319
 worker_thread+0x582/0x770 kernel/workqueue.c:3400
 kthread+0x486/0x510 kernel/kthread.c:464
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read-write to 0xffff88810020dcb8 of 8 bytes by interrupt on cpu 0:
 wq_worker_tick+0x60/0x230 kernel/workqueue.c:1474
 sched_tick+0x11a/0x270 kernel/sched/core.c:5677
 update_process_times+0x15f/0x190 kernel/time/timer.c:2520
 tick_sched_handle kernel/time/tick-sched.c:276 [inline]
 tick_nohz_handler+0x249/0x2d0 kernel/time/tick-sched.c:297
 __run_hrtimer kernel/time/hrtimer.c:1761 [inline]
 __hrtimer_run_queues+0x20c/0x5a0 kernel/time/hrtimer.c:1825
 hrtimer_interrupt+0x21a/0x460 kernel/time/hrtimer.c:1887
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline]
 __sysvec_apic_timer_interrupt+0x5c/0x1d0 arch/x86/kernel/apic/apic.c:1055
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
 sysvec_apic_timer_interrupt+0x6f/0x80 arch/x86/kernel/apic/apic.c:1049
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
 __preempt_count_dec_and_test arch/x86/include/asm/preempt.h:95 [inline]
 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
 _raw_spin_unlock_irq+0x2f/0x50 kernel/locking/spinlock.c:202
 process_one_work kernel/workqueue.c:3207 [inline]
 process_scheduled_works+0x486/0x9d0 kernel/workqueue.c:3319
 worker_thread+0x582/0x770 kernel/workqueue.c:3400
 kthread+0x486/0x510 kernel/kthread.c:464
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0x00000000000249f0 -> 0x0000000000027100

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 9695 Comm: kworker/u8:67 Not tainted 6.15.0-rc5-syzkaller-00353-gcd802e7e5f1e #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
Workqueue: iou_exit io_ring_exit_work
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