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BUG: KCSAN: data-race in tick_nohz_next_event / tick_sched_timer

write to 0xffffffff86fc1a50 of 4 bytes by interrupt on cpu 1:
 tick_sched_do_timer kernel/time/tick-sched.c:141 [inline]
 tick_sched_timer+0x1f5/0x210 kernel/time/tick-sched.c:1321
 __run_hrtimer+0x133/0x420 kernel/time/hrtimer.c:1519
 __hrtimer_run_queues kernel/time/hrtimer.c:1583 [inline]
 hrtimer_interrupt+0x36e/0xa10 kernel/time/hrtimer.c:1645
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1080 [inline]
 __sysvec_apic_timer_interrupt+0x6f/0x200 arch/x86/kernel/apic/apic.c:1097
 run_sysvec_on_irqstack_cond arch/x86/include/asm/irq_stack.h:91 [inline]
 sysvec_apic_timer_interrupt+0x6f/0x90 arch/x86/kernel/apic/apic.c:1091
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:631
 watchpoint_slot kernel/kcsan/encoding.h:83 [inline]
 find_watchpoint kernel/kcsan/core.c:111 [inline]
 check_access kernel/kcsan/core.c:616 [inline]
 __tsan_read1+0x12/0x180 kernel/kcsan/core.c:839
 ip_packet_match net/ipv4/netfilter/ip_tables.c:76 [inline]
 ipt_do_table+0x509/0xce0 net/ipv4/netfilter/ip_tables.c:284
 iptable_mangle_hook+0x13b/0x270 net/ipv4/netfilter/iptable_mangle.c:82
 nf_hook_entry_hookfn include/linux/netfilter.h:136 [inline]
 nf_hook_slow net/netfilter/core.c:589 [inline]
 nf_hook_slow_list+0x133/0x340 net/netfilter/core.c:627
 NF_HOOK_LIST include/linux/netfilter.h:337 [inline]
 ip_sublist_rcv+0x56f/0x590 net/ipv4/ip_input.c:606
 ip_list_rcv+0x262/0x290 net/ipv4/ip_input.c:643
 __netif_receive_skb_list_ptype net/core/dev.c:5354 [inline]
 __netif_receive_skb_list_core+0x34b/0x450 net/core/dev.c:5402
 __netif_receive_skb_list+0x262/0x2e0 net/core/dev.c:5454
 netif_receive_skb_list_internal+0xda/0x330 net/core/dev.c:5564
 gro_normal_list net/core/dev.c:5718 [inline]
 napi_complete_done+0x1b2/0x420 net/core/dev.c:6443
 virtqueue_napi_complete+0x28/0x80 drivers/net/virtio_net.c:334
 virtnet_poll+0x607/0x730 drivers/net/virtio_net.c:1460
 napi_poll+0x178/0x4c0 net/core/dev.c:6759
 net_rx_action+0x17a/0x480 net/core/dev.c:6829
 __do_softirq+0x12c/0x2b1 kernel/softirq.c:298
 asm_call_irq_on_stack+0xf/0x20
 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline]
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline]
 do_softirq_own_stack+0x32/0x40 arch/x86/kernel/irq_64.c:77
 invoke_softirq kernel/softirq.c:393 [inline]
 __irq_exit_rcu+0xb2/0xc0 kernel/softirq.c:423
 common_interrupt+0xb5/0x130 arch/x86/kernel/irq.c:239
 asm_common_interrupt+0x1e/0x40 arch/x86/include/asm/idtentry.h:622

read to 0xffffffff86fc1a50 of 4 bytes by task 0 on cpu 0:
 tick_nohz_next_event+0x217/0x300 kernel/time/tick-sched.c:754
 tick_nohz_get_sleep_length+0x121/0x270 kernel/time/tick-sched.c:1107
 menu_select+0x2fa/0xf40 drivers/cpuidle/governors/menu.c:283
 cpuidle_select+0x3d/0x50 drivers/cpuidle/cpuidle.c:322
 cpuidle_idle_call kernel/sched/idle.c:232 [inline]
 do_idle+0x15f/0x230 kernel/sched/idle.c:299
 cpu_startup_entry+0x15/0x20 kernel/sched/idle.c:395
 rest_init+0xd7/0xe0 init/main.c:721
 arch_call_rest_init+0xa/0xb
 start_kernel+0x5a0/0x625 init/main.c:1061
 secondary_startup_64_no_verify+0xb0/0xbb

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.10.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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