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BUG: KCSAN: data-race in tick_do_update_jiffies64 / tick_do_update_jiffies64

write to 0xffffffff86042008 of 8 bytes by interrupt on cpu 1:
 tick_do_update_jiffies64+0x105/0x260 kernel/time/tick-sched.c:73
 tick_sched_do_timer+0xd4/0xe0 kernel/time/tick-sched.c:138
 tick_sched_timer+0x43/0xe0 kernel/time/tick-sched.c:1292
 __run_hrtimer kernel/time/hrtimer.c:1514 [inline]
 __hrtimer_run_queues+0x288/0x600 kernel/time/hrtimer.c:1576
 hrtimer_interrupt+0x22a/0x480 kernel/time/hrtimer.c:1638
 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
 check_kcov_mode kernel/kcov.c:68 [inline]
 __sanitizer_cov_trace_pc+0x1a/0x50 kernel/kcov.c:102
 skb_cloned include/linux/skbuff.h:1586 [inline]
 skb_head_is_locked include/linux/skbuff.h:4463 [inline]
 skb_try_coalesce+0x468/0xbf0 net/core/skbuff.c:5059
 tcp_add_backlog+0x72b/0xcc0 net/ipv4/tcp_ipv4.c:1709
 tcp_v4_rcv+0x1a60/0x1bb0 net/ipv4/tcp_ipv4.c:1944
 ip_protocol_deliver_rcu+0x4d/0x420 net/ipv4/ip_input.c:204
 ip_local_deliver_finish+0x110/0x140 net/ipv4/ip_input.c:231
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ip_local_deliver+0x133/0x210 net/ipv4/ip_input.c:252

read to 0xffffffff86042008 of 8 bytes by interrupt on cpu 0:
 tick_do_update_jiffies64+0x2b/0x260 kernel/time/tick-sched.c:62
 tick_sched_do_timer+0xd4/0xe0 kernel/time/tick-sched.c:138
 tick_sched_timer+0x43/0xe0 kernel/time/tick-sched.c:1292
 __run_hrtimer kernel/time/hrtimer.c:1514 [inline]
 __hrtimer_run_queues+0x288/0x600 kernel/time/hrtimer.c:1576
 hrtimer_interrupt+0x22a/0x480 kernel/time/hrtimer.c:1638
 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
 __kcsan_setup_watchpoint+0x0/0x4a0 kernel/kcsan/core.c:279
 detach_buf_split+0x197/0x3d0 drivers/virtio/virtio_ring.c:640
 virtqueue_get_buf_ctx_split drivers/virtio/virtio_ring.c:720 [inline]
 virtqueue_get_buf_ctx+0x4b4/0x5c0 drivers/virtio/virtio_ring.c:1901
 virtqueue_get_buf+0x29/0x40 drivers/virtio/virtio_ring.c:1907
 free_old_xmit_skbs+0x9e/0x170 drivers/net/virtio_net.c:1359
 start_xmit+0xd3/0xbe0 drivers/net/virtio_net.c:1562

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 7278 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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