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BUG: KCSAN: data-race in internal_add_timer / update_process_times

write to 0xffff888237c176d8 of 8 bytes by interrupt on cpu 1:
 enqueue_timer kernel/time/timer.c:598 [inline]
 internal_add_timer+0x14f/0x280 kernel/time/timer.c:611
 add_timer_on+0x262/0x2a0 kernel/time/timer.c:1182
 clocksource_watchdog+0xa74/0xac0 kernel/time/clocksource.c:478
 call_timer_fn+0x2e/0x1d0 kernel/time/timer.c:1421
 expire_timers+0x135/0x240 kernel/time/timer.c:1466
 __run_timers+0x378/0x440 kernel/time/timer.c:1734
 run_timer_softirq+0x19/0x30 kernel/time/timer.c:1747
 __do_softirq+0x12c/0x26e kernel/softirq.c:558
 invoke_softirq kernel/softirq.c:432 [inline]
 __irq_exit_rcu kernel/softirq.c:636 [inline]
 irq_exit_rcu+0x4e/0xa0 kernel/softirq.c:648
 sysvec_apic_timer_interrupt+0x69/0x80 arch/x86/kernel/apic/apic.c:1097
 asm_sysvec_apic_timer_interrupt+0x12/0x20
 native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
 arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
 acpi_safe_halt drivers/acpi/processor_idle.c:109 [inline]
 acpi_idle_do_entry drivers/acpi/processor_idle.c:553 [inline]
 acpi_idle_enter+0x258/0x2e0 drivers/acpi/processor_idle.c:688
 cpuidle_enter_state+0x2b4/0x760 drivers/cpuidle/cpuidle.c:237
 cpuidle_enter+0x3c/0x60 drivers/cpuidle/cpuidle.c:351
 call_cpuidle kernel/sched/idle.c:158 [inline]
 cpuidle_idle_call kernel/sched/idle.c:239 [inline]
 do_idle+0x1a3/0x250 kernel/sched/idle.c:306
 cpu_startup_entry+0x15/0x20 kernel/sched/idle.c:403
 secondary_startup_64_no_verify+0xb1/0xbb

read to 0xffff888237c176d8 of 8 bytes by interrupt on cpu 0:
 run_local_timers kernel/time/timer.c:1761 [inline]
 update_process_times+0x8c/0x150 kernel/time/timer.c:1784
 tick_sched_handle kernel/time/tick-sched.c:226 [inline]
 tick_sched_timer+0x191/0x210 kernel/time/tick-sched.c:1421
 __run_hrtimer+0x160/0x480 kernel/time/hrtimer.c:1685
 __hrtimer_run_queues kernel/time/hrtimer.c:1749 [inline]
 hrtimer_interrupt+0x380/0xaf0 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline]
 __sysvec_apic_timer_interrupt+0x6f/0x1c0 arch/x86/kernel/apic/apic.c:1103
 sysvec_apic_timer_interrupt+0x64/0x80 arch/x86/kernel/apic/apic.c:1097
 asm_sysvec_apic_timer_interrupt+0x12/0x20
 nf_ct_iterate_cleanup+0xd6/0x340 net/netfilter/nf_conntrack_core.c:2275
 nf_conntrack_cleanup_net_list+0x83/0x190 net/netfilter/nf_conntrack_core.c:2469
 nf_conntrack_pernet_exit+0x139/0x140 net/netfilter/nf_conntrack_standalone.c:1210
 ops_exit_list net/core/net_namespace.c:171 [inline]
 cleanup_net+0x4dc/0x8d0 net/core/net_namespace.c:591
 process_one_work+0x402/0x910 kernel/workqueue.c:2297
 worker_thread+0x636/0xae0 kernel/workqueue.c:2444
 kthread+0x262/0x280 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30

value changed: 0x000000010001c3b0 -> 0x000000010001c2fc

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 11580 Comm: kworker/u4:1 Tainted: G        W         5.15.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: netns cleanup_net
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