==================================================================
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
 __read_once_size include/linux/compiler.h:232 [inline]
 arch_atomic64_read arch/x86/include/asm/atomic64_64.h:22 [inline]
 atomic64_read include/asm-generic/atomic-instrumented.h:838 [inline]
 atomic_long_read include/asm-generic/atomic-long.h:29 [inline]
 find_watchpoint kernel/kcsan/core.c:118 [inline]
 check_access kernel/kcsan/core.c:566 [inline]
 __tsan_read4+0x30/0x110 kernel/kcsan/core.c:769
 rcu_preempt_read_exit kernel/rcu/tree_plugin.h:360 [inline]
 __rcu_read_unlock+0x57/0x390 kernel/rcu/tree_plugin.h:394
 rcu_read_unlock include/linux/rcupdate.h:654 [inline]
 inet_gro_receive+0x734/0x770 net/ipv4/af_inet.c:1520
 dev_gro_receive+0x9d9/0x10f0 net/core/dev.c:5774
 napi_gro_receive+0x76/0x2f0 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

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
 should_watch kernel/kcsan/core.c:260 [inline]
 check_access kernel/kcsan/core.c:581 [inline]
 __tsan_read8+0xe4/0x110 kernel/kcsan/core.c:770
 task_stack_page include/linux/sched/task_stack.h:21 [inline]
 check_stack_object+0x31/0x90 mm/usercopy.c:36
 __check_object_size+0xd5/0x337 mm/usercopy.c:269
 check_object_size include/linux/thread_info.h:119 [inline]
 check_copy_size include/linux/thread_info.h:152 [inline]
 copy_to_iter include/linux/uio.h:135 [inline]
 simple_copy_to_iter+0x48/0x80 net/core/datagram.c:519
 __skb_datagram_iter+0x23f/0x470 net/core/datagram.c:448
 skb_copy_datagram_iter+0x65/0x160 net/core/datagram.c:533
 skb_copy_datagram_msg include/linux/skbuff.h:3537 [inline]
 tcp_recvmsg+0x109e/0x1ba0 net/ipv4/tcp.c:2137
 inet_recvmsg+0xc1/0x250 net/ipv4/af_inet.c:838
 sock_recvmsg_nosec net/socket.c:886 [inline]
 sock_recvmsg net/socket.c:904 [inline]
 sock_recvmsg+0x8e/0xb0 net/socket.c:900
 sock_read_iter+0x185/0x230 net/socket.c:982
 call_read_iter include/linux/fs.h:1901 [inline]
 new_sync_read+0x416/0x450 fs/read_write.c:415
 __vfs_read+0x9e/0xb0 fs/read_write.c:428
 vfs_read fs/read_write.c:462 [inline]
 vfs_read+0x13e/0x2b0 fs/read_write.c:447
 ksys_read+0x16a/0x1a0 fs/read_write.c:588
 __do_sys_read fs/read_write.c:598 [inline]
 __se_sys_read fs/read_write.c:596 [inline]
 __x64_sys_read+0x49/0x60 fs/read_write.c:596
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 8908 Comm: syz-fuzzer Not tainted 5.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================