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BUG: KCSAN: data-race in tick_sched_do_timer / tick_sched_do_timer

write to 0xffffffff8764e210 of 4 bytes by interrupt on cpu 0:
 tick_sched_do_timer+0xb4/0xd0 kernel/time/tick-sched.c:141
 tick_sched_timer+0x3f/0xd0 kernel/time/tick-sched.c:1313
 __run_hrtimer kernel/time/hrtimer.c:1520 [inline]
 __hrtimer_run_queues+0x271/0x600 kernel/time/hrtimer.c:1584
 hrtimer_interrupt+0x226/0x490 kernel/time/hrtimer.c:1646
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1113 [inline]
 smp_apic_timer_interrupt+0xd8/0x270 arch/x86/kernel/apic/apic.c:1138
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
 arch_local_irq_restore arch/x86/include/asm/paravirt.h:759 [inline]
 kcsan_setup_watchpoint+0x25a/0x440 kernel/kcsan/core.c:542
 do_epoll_wait+0x143/0x180 fs/eventpoll.c:2317
 __do_sys_epoll_pwait fs/eventpoll.c:2351 [inline]
 __se_sys_epoll_pwait fs/eventpoll.c:2337 [inline]
 __x64_sys_epoll_pwait+0xc6/0x170 fs/eventpoll.c:2337
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffffffff8764e210 of 4 bytes by interrupt on cpu 1:
 tick_sched_do_timer+0x2e/0xd0 kernel/time/tick-sched.c:137
 tick_sched_timer+0x3f/0xd0 kernel/time/tick-sched.c:1313
 __run_hrtimer kernel/time/hrtimer.c:1520 [inline]
 __hrtimer_run_queues+0x271/0x600 kernel/time/hrtimer.c:1584
 hrtimer_interrupt+0x226/0x490 kernel/time/hrtimer.c:1646
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1113 [inline]
 smp_apic_timer_interrupt+0xd8/0x270 arch/x86/kernel/apic/apic.c:1138
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
 find_watchpoint kernel/kcsan/core.c:107 [inline]
 check_access kernel/kcsan/core.c:566 [inline]
 __tsan_unaligned_write8+0xd/0x110 kernel/kcsan/core.c:770
 tcp_try_coalesce net/ipv4/tcp_input.c:4455 [inline]
 tcp_try_coalesce+0x399/0x430 net/ipv4/tcp_input.c:4422
 tcp_queue_rcv+0x9b/0x380 net/ipv4/tcp_input.c:4697
 tcp_rcv_established+0xba3/0xee0 net/ipv4/tcp_input.c:5682
 tcp_v4_do_rcv+0x396/0x4f0 net/ipv4/tcp_ipv4.c:1621
 tcp_v4_rcv+0x1c55/0x1e10 net/ipv4/tcp_ipv4.c:2003
 ip_protocol_deliver_rcu+0x4b/0x410 net/ipv4/ip_input.c:204
 ip_local_deliver_finish+0xf3/0x120 net/ipv4/ip_input.c:231
 NF_HOOK include/linux/netfilter.h:307 [inline]
 NF_HOOK include/linux/netfilter.h:301 [inline]
 ip_local_deliver+0x135/0x220 net/ipv4/ip_input.c:252
 dst_input include/net/dst.h:441 [inline]
 ip_sublist_rcv_finish+0xf0/0x140 net/ipv4/ip_input.c:550
 ip_list_rcv_finish net/ipv4/ip_input.c:600 [inline]
 ip_sublist_rcv+0x3f8/0x530 net/ipv4/ip_input.c:608
 ip_list_rcv+0x2f3/0x321 net/ipv4/ip_input.c:643
 __netif_receive_skb_list_ptype net/core/dev.c:5230 [inline]
 __netif_receive_skb_list_ptype net/core/dev.c:5219 [inline]
 __netif_receive_skb_list_core+0x368/0x5c0 net/core/dev.c:5278
 __netif_receive_skb_list net/core/dev.c:5330 [inline]
 netif_receive_skb_list_internal+0x5c7/0x810 net/core/dev.c:5425
 gro_normal_list.part.0+0x37/0xa0 net/core/dev.c:5536
 gro_normal_list net/core/dev.c:5549 [inline]
 gro_normal_one+0x14c/0x160 net/core/dev.c:5548
 napi_skb_finish net/core/dev.c:5876 [inline]
 napi_gro_receive+0x27d/0x2f0 net/core/dev.c:5908
 receive_buf+0x24c/0x3420 drivers/net/virtio_net.c:1073
 virtnet_receive drivers/net/virtio_net.c:1335 [inline]
 virtnet_poll+0x343/0x790 drivers/net/virtio_net.c:1440
 napi_poll net/core/dev.c:6571 [inline]
 net_rx_action+0x3ad/0xac0 net/core/dev.c:6639
 __do_softirq+0x118/0x34a kernel/softirq.c:292
 run_ksoftirqd+0x41/0x60 kernel/softirq.c:604
 smpboot_thread_fn+0x374/0x4a0 kernel/smpboot.c:165
 kthread+0x203/0x230 kernel/kthread.c:268
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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