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

read to 0xffffffff85caf310 of 4 bytes by interrupt on cpu 1:
 tick_sched_do_timer+0x33/0xe0 kernel/time/tick-sched.c:128
 tick_sched_timer+0x43/0xe0 kernel/time/tick-sched.c:1289
 __run_hrtimer kernel/time/hrtimer.c:1389 [inline]
 __hrtimer_run_queues+0x288/0x600 kernel/time/hrtimer.c:1451
 hrtimer_interrupt+0x22a/0x480 kernel/time/hrtimer.c:1509
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline]
 smp_apic_timer_interrupt+0xdc/0x280 arch/x86/kernel/apic/apic.c:1135
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830
 is_enabled kernel/kcsan/core.c:209 [inline]
 __kcsan_check_watchpoint+0x51/0x180 kernel/kcsan/core.c:319
 __tsan_read2+0x15/0x30 kernel/kcsan/kcsan.c:29
 page_frag_alloc+0x52/0x2d0 mm/page_alloc.c:4844
 __napi_alloc_skb+0x172/0x210 net/core/skbuff.c:519
 napi_alloc_skb include/linux/skbuff.h:2813 [inline]
 page_to_skb+0x8d/0x480 drivers/net/virtio_net.c:384
 receive_mergeable drivers/net/virtio_net.c:924 [inline]
 receive_buf+0x17c7/0x30b0 drivers/net/virtio_net.c:1033
 virtnet_receive drivers/net/virtio_net.c:1323 [inline]
 virtnet_poll+0x436/0x7d0 drivers/net/virtio_net.c:1428
 napi_poll net/core/dev.c:6352 [inline]
 net_rx_action+0x3ae/0xa50 net/core/dev.c:6418

write to 0xffffffff85caf310 of 4 bytes by interrupt on cpu 0:
 tick_sched_do_timer+0xc0/0xe0 kernel/time/tick-sched.c:132
 tick_sched_timer+0x43/0xe0 kernel/time/tick-sched.c:1289
 __run_hrtimer kernel/time/hrtimer.c:1389 [inline]
 __hrtimer_run_queues+0x288/0x600 kernel/time/hrtimer.c:1451
 hrtimer_interrupt+0x22a/0x480 kernel/time/hrtimer.c:1509
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline]
 smp_apic_timer_interrupt+0xdc/0x280 arch/x86/kernel/apic/apic.c:1135
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 7350 Comm: syz-fuzzer Not tainted 5.3.0+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================