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BUG: KCSAN: data-race in run_timer_softirq / timer_reduce

write to 0xffff88812c01da88 of 8 bytes by interrupt on cpu 0:
 expire_timers kernel/time/timer.c:1445 [inline]
 __run_timers kernel/time/timer.c:1773 [inline]
 __run_timers kernel/time/timer.c:1740 [inline]
 run_timer_softirq+0x496/0xcd0 kernel/time/timer.c:1786
 __do_softirq+0x115/0x33f kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0xbb/0xe0 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:536 [inline]
 smp_apic_timer_interrupt+0xe6/0x280 arch/x86/kernel/apic/apic.c:1137
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
 arch_local_irq_restore arch/x86/include/asm/paravirt.h:752 [inline]
 kcsan_setup_watchpoint+0x1d4/0x460 kernel/kcsan/core.c:429
 check_access kernel/kcsan/core.c:459 [inline]
 __tsan_read8+0xc6/0x100 kernel/kcsan/core.c:589
 set_pte_at arch/x86/include/asm/paravirt.h:446 [inline]
 copy_one_pte mm/memory.c:798 [inline]
 copy_pte_range mm/memory.c:841 [inline]
 copy_pmd_range mm/memory.c:892 [inline]
 copy_pud_range mm/memory.c:926 [inline]
 copy_p4d_range mm/memory.c:948 [inline]
 copy_page_range+0xbcd/0x19b0 mm/memory.c:1010
 dup_mmap kernel/fork.c:604 [inline]
 dup_mm+0x74a/0xba0 kernel/fork.c:1360
 copy_mm kernel/fork.c:1416 [inline]
 copy_process+0x3138/0x3c40 kernel/fork.c:2072
 _do_fork+0xfe/0x7a0 kernel/fork.c:2421
 __do_sys_clone kernel/fork.c:2576 [inline]
 __se_sys_clone kernel/fork.c:2557 [inline]
 __x64_sys_clone+0x130/0x170 kernel/fork.c:2557
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88812c01da88 of 8 bytes by task 8264 on cpu 1:
 __mod_timer kernel/time/timer.c:1026 [inline]
 timer_reduce+0x25b/0x830 kernel/time/timer.c:1115
 srcu_queue_delayed_work_on+0x3d/0x90 kernel/rcu/srcutree.c:473
 srcu_schedule_cbs_sdp kernel/rcu/srcutree.c:482 [inline]
 srcu_schedule_cbs_snp kernel/rcu/srcutree.c:499 [inline]
 srcu_gp_end kernel/rcu/srcutree.c:558 [inline]
 srcu_advance_state kernel/rcu/srcutree.c:1146 [inline]
 process_srcu+0x58a/0x780 kernel/rcu/srcutree.c:1237
 process_one_work+0x3d4/0x890 kernel/workqueue.c:2264
 worker_thread+0xa0/0x800 kernel/workqueue.c:2410
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 8264 Comm: kworker/1:4 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: rcu_gp process_srcu
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