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BUG: KCSAN: data-race in wq_worker_tick / wq_worker_tick

read-write to 0xffff888101217cb8 of 8 bytes by interrupt on cpu 0:
 wq_worker_tick+0x60/0x230 kernel/workqueue.c:1480
 sched_tick+0x11a/0x270 kernel/sched/core.c:5616
 update_process_times+0x15f/0x190 kernel/time/timer.c:2479
 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:1777 [inline]
 __hrtimer_run_queues+0x20f/0x5a0 kernel/time/hrtimer.c:1841
 hrtimer_interrupt+0x21a/0x460 kernel/time/hrtimer.c:1903
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline]
 __sysvec_apic_timer_interrupt+0x5f/0x1d0 arch/x86/kernel/apic/apic.c:1058
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
 sysvec_apic_timer_interrupt+0x6f/0x80 arch/x86/kernel/apic/apic.c:1052
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
 arch_atomic64_read arch/x86/include/asm/atomic64_64.h:15 [inline]
 raw_atomic64_read include/linux/atomic/atomic-arch-fallback.h:2583 [inline]
 raw_atomic_long_read include/linux/atomic/atomic-long.h:38 [inline]
 atomic_long_read include/linux/atomic/atomic-instrumented.h:3189 [inline]
 find_watchpoint kernel/kcsan/core.c:131 [inline]
 check_access kernel/kcsan/core.c:737 [inline]
 __tsan_unaligned_write8+0x2c/0x190 kernel/kcsan/core.c:1025
 ext4_put_nojournal fs/ext4/ext4_jbd2.c:59 [inline]
 __ext4_journal_stop+0x48/0x120 fs/ext4/ext4_jbd2.c:126
 ext4_do_writepages+0xa70/0x2750 fs/ext4/inode.c:2944
 ext4_writepages+0x176/0x300 fs/ext4/inode.c:3025
 do_writepages+0x1c6/0x310 mm/page-writeback.c:2604
 __writeback_single_inode+0x80/0x7c0 fs/fs-writeback.c:1719
 writeback_sb_inodes+0x48f/0xa30 fs/fs-writeback.c:2015
 wb_writeback+0x252/0x5c0 fs/fs-writeback.c:2195
 wb_do_writeback fs/fs-writeback.c:2342 [inline]
 wb_workfn+0x194/0x910 fs/fs-writeback.c:2382
 process_one_work kernel/workqueue.c:3263 [inline]
 process_scheduled_works+0x4ce/0x9d0 kernel/workqueue.c:3346
 worker_thread+0x582/0x770 kernel/workqueue.c:3427
 kthread+0x489/0x510 kernel/kthread.c:463
 ret_from_fork+0x122/0x1b0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read-write to 0xffff888101217cb8 of 8 bytes by interrupt on cpu 1:
 wq_worker_tick+0x60/0x230 kernel/workqueue.c:1480
 sched_tick+0x11a/0x270 kernel/sched/core.c:5616
 update_process_times+0x15f/0x190 kernel/time/timer.c:2479
 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:1777 [inline]
 __hrtimer_run_queues+0x20f/0x5a0 kernel/time/hrtimer.c:1841
 hrtimer_interrupt+0x21a/0x460 kernel/time/hrtimer.c:1903
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline]
 __sysvec_apic_timer_interrupt+0x5f/0x1d0 arch/x86/kernel/apic/apic.c:1058
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
 sysvec_apic_timer_interrupt+0x6f/0x80 arch/x86/kernel/apic/apic.c:1052
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
 get_ctx kernel/kcsan/core.c:206 [inline]
 check_access kernel/kcsan/core.c:750 [inline]
 __tsan_read8+0xe6/0x190 kernel/kcsan/core.c:1025
 folio_pos include/linux/pagemap.h:1029 [inline]
 mpage_prepare_extent_to_map+0x656/0xc00 fs/ext4/inode.c:2707
 ext4_do_writepages+0xa05/0x2750 fs/ext4/inode.c:2929
 ext4_writepages+0x176/0x300 fs/ext4/inode.c:3025
 do_writepages+0x1c6/0x310 mm/page-writeback.c:2604
 __writeback_single_inode+0x80/0x7c0 fs/fs-writeback.c:1719
 writeback_sb_inodes+0x48f/0xa30 fs/fs-writeback.c:2015
 wb_writeback+0x252/0x5c0 fs/fs-writeback.c:2195
 wb_do_writeback fs/fs-writeback.c:2342 [inline]
 wb_workfn+0x194/0x910 fs/fs-writeback.c:2382
 process_one_work kernel/workqueue.c:3263 [inline]
 process_scheduled_works+0x4ce/0x9d0 kernel/workqueue.c:3346
 worker_thread+0x582/0x770 kernel/workqueue.c:3427
 kthread+0x489/0x510 kernel/kthread.c:463
 ret_from_fork+0x122/0x1b0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0x00000000022af650 -> 0x00000000022b1d60

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 6515 Comm: kworker/u8:35 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Workqueue: writeback wb_workfn (flush-7:8)
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