==================================================================
BUG: KCSAN: data-race in tick_nohz_idle_stop_tick / tick_sched_do_timer

write to 0xffffffff85d056d0 of 4 bytes by interrupt on cpu 0:
 tick_sched_do_timer+0xb4/0xd0 kernel/time/tick-sched.c:136
 tick_sched_timer+0x3f/0xd0 kernel/time/tick-sched.c:1307
 __run_hrtimer kernel/time/hrtimer.c:1517 [inline]
 __hrtimer_run_queues+0x271/0x600 kernel/time/hrtimer.c:1579
 hrtimer_interrupt+0x226/0x490 kernel/time/hrtimer.c:1641
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1119 [inline]
 smp_apic_timer_interrupt+0xd8/0x270 arch/x86/kernel/apic/apic.c:1144
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
 matching_access kernel/kcsan/encoding.h:90 [inline]
 find_watchpoint kernel/kcsan/core.c:125 [inline]
 check_access kernel/kcsan/core.c:554 [inline]
 __tsan_read8+0x1b/0x100 kernel/kcsan/core.c:703
 dev_net include/linux/netdevice.h:2206 [inline]
 __inet_lookup_skb include/net/inet_hashtables.h:389 [inline]
 tcp_v4_rcv+0x966/0x1d80 net/ipv4/tcp_ipv4.c:1902
 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:442 [inline]
 ip_sublist_rcv_finish+0xf0/0x140 net/ipv4/ip_input.c:549
 ip_list_rcv_finish net/ipv4/ip_input.c:599 [inline]
 ip_sublist_rcv+0x3f8/0x530 net/ipv4/ip_input.c:607
 ip_list_rcv+0x2f3/0x321 net/ipv4/ip_input.c:642
 __netif_receive_skb_list_ptype net/core/dev.c:5241 [inline]
 __netif_receive_skb_list_ptype net/core/dev.c:5230 [inline]
 __netif_receive_skb_list_core+0x368/0x5c0 net/core/dev.c:5289
 __netif_receive_skb_list net/core/dev.c:5341 [inline]
 netif_receive_skb_list_internal+0x5c7/0x810 net/core/dev.c:5436
 gro_normal_list.part.0+0x37/0xa0 net/core/dev.c:5547
 gro_normal_list net/core/dev.c:5560 [inline]
 gro_normal_one+0x14c/0x160 net/core/dev.c:5559
 napi_skb_finish net/core/dev.c:5887 [inline]
 napi_gro_receive+0x27d/0x2f0 net/core/dev.c:5919
 receive_buf+0x24e/0x2e20 drivers/net/virtio_net.c:1061
 virtnet_receive drivers/net/virtio_net.c:1323 [inline]
 virtnet_poll+0x343/0x790 drivers/net/virtio_net.c:1428
 napi_poll net/core/dev.c:6582 [inline]
 net_rx_action+0x3ad/0xac0 net/core/dev.c:6650
 __do_softirq+0x118/0x34a kernel/softirq.c:292
 run_ksoftirqd+0x41/0x60 kernel/softirq.c:603
 smpboot_thread_fn+0x374/0x4a0 kernel/smpboot.c:165
 kthread+0x1cb/0x1f0 kernel/kthread.c:255
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

read to 0xffffffff85d056d0 of 4 bytes by task 0 on cpu 1:
 tick_nohz_stop_tick kernel/time/tick-sched.c:774 [inline]
 __tick_nohz_idle_stop_tick kernel/time/tick-sched.c:967 [inline]
 tick_nohz_idle_stop_tick+0x191/0x680 kernel/time/tick-sched.c:988
 cpuidle_idle_call kernel/sched/idle.c:151 [inline]
 do_idle+0x1ad/0x290 kernel/sched/idle.c:269
 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:361
 start_secondary+0x164/0x1b0 arch/x86/kernel/smpboot.c:264
 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:242

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.6.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================