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BUG: KCSAN: data-race in wq_worker_tick / wq_worker_tick

read-write to 0xffff888101075eb8 of 8 bytes by interrupt on cpu 1:
 wq_worker_tick+0x63/0x240 kernel/workqueue.c:1474
 sched_tick+0xd2/0x110 kernel/sched/core.c:5609
 update_process_times+0x15a/0x180 kernel/time/timer.c:2524
 tick_sched_handle kernel/time/tick-sched.c:276 [inline]
 tick_nohz_handler+0x250/0x2d0 kernel/time/tick-sched.c:297
 __run_hrtimer kernel/time/hrtimer.c:1691 [inline]
 __hrtimer_run_queues+0x20d/0x5e0 kernel/time/hrtimer.c:1755
 hrtimer_interrupt+0x210/0x7b0 kernel/time/hrtimer.c:1817
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1026 [inline]
 __sysvec_apic_timer_interrupt+0x5c/0x1a0 arch/x86/kernel/apic/apic.c:1043
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1037 [inline]
 sysvec_apic_timer_interrupt+0x6e/0x80 arch/x86/kernel/apic/apic.c:1037
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
 is_atomic kernel/kcsan/core.c:260 [inline]
 should_watch kernel/kcsan/core.c:277 [inline]
 check_access kernel/kcsan/core.c:752 [inline]
 __tsan_read4+0xf8/0x180 kernel/kcsan/core.c:1024
 mpage_add_bh_to_extent fs/ext4/inode.c:1966 [inline]
 mpage_process_page_bufs+0x1e6/0x5d0 fs/ext4/inode.c:2021
 mpage_prepare_extent_to_map+0x788/0xb80 fs/ext4/inode.c:2535
 ext4_do_writepages+0x6ea/0x2130 fs/ext4/inode.c:2677
 ext4_writepages+0x159/0x2e0 fs/ext4/inode.c:2813
 do_writepages+0x1d8/0x480 mm/page-writeback.c:2683
 __writeback_single_inode+0x89/0x850 fs/fs-writeback.c:1658
 writeback_sb_inodes+0x461/0xa30 fs/fs-writeback.c:1954
 wb_writeback+0x262/0x640 fs/fs-writeback.c:2134
 wb_do_writeback fs/fs-writeback.c:2281 [inline]
 wb_workfn+0x1a8/0x940 fs/fs-writeback.c:2321
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0x483/0x9a0 kernel/workqueue.c:3310
 worker_thread+0x51d/0x6f0 kernel/workqueue.c:3391
 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

read-write to 0xffff888101075eb8 of 8 bytes by interrupt on cpu 0:
 wq_worker_tick+0x63/0x240 kernel/workqueue.c:1474
 sched_tick+0xd2/0x110 kernel/sched/core.c:5609
 update_process_times+0x15a/0x180 kernel/time/timer.c:2524
 tick_sched_handle kernel/time/tick-sched.c:276 [inline]
 tick_nohz_handler+0x250/0x2d0 kernel/time/tick-sched.c:297
 __run_hrtimer kernel/time/hrtimer.c:1691 [inline]
 __hrtimer_run_queues+0x20d/0x5e0 kernel/time/hrtimer.c:1755
 hrtimer_interrupt+0x210/0x7b0 kernel/time/hrtimer.c:1817
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1026 [inline]
 __sysvec_apic_timer_interrupt+0x5c/0x1a0 arch/x86/kernel/apic/apic.c:1043
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1037 [inline]
 sysvec_apic_timer_interrupt+0x6e/0x80 arch/x86/kernel/apic/apic.c:1037
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
 lru_add_drain_cpu+0x42/0x260 mm/swap.c:657
 lru_add_drain mm/swap.c:743 [inline]
 __folio_batch_release+0x51/0xc0 mm/swap.c:1064
 folio_batch_release include/linux/pagevec.h:101 [inline]
 mpage_release_unused_pages+0x3be/0x440 fs/ext4/inode.c:1604
 ext4_do_writepages+0xb2d/0x2130 fs/ext4/inode.c:2742
 ext4_writepages+0x159/0x2e0 fs/ext4/inode.c:2813
 do_writepages+0x1d8/0x480 mm/page-writeback.c:2683
 __writeback_single_inode+0x89/0x850 fs/fs-writeback.c:1658
 writeback_sb_inodes+0x461/0xa30 fs/fs-writeback.c:1954
 wb_writeback+0x262/0x640 fs/fs-writeback.c:2134
 wb_do_writeback fs/fs-writeback.c:2281 [inline]
 wb_workfn+0x1a8/0x940 fs/fs-writeback.c:2321
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0x483/0x9a0 kernel/workqueue.c:3310
 worker_thread+0x51d/0x6f0 kernel/workqueue.c:3391
 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: 0x0000000001396a60 -> 0x0000000001399170

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 2331 Comm: kworker/u8:10 Not tainted 6.12.0-rc1-syzkaller-00330-gfc20a3e57247 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: writeback wb_workfn (flush-7:3)
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