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BUG: KCSAN: data-race in tick_nohz_next_event / tick_sched_do_timer

write to 0xffffffff85ebb050 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:1303
 __run_hrtimer kernel/time/hrtimer.c:1517 [inline]
 __hrtimer_run_queues+0x274/0x5f0 kernel/time/hrtimer.c:1579
 hrtimer_interrupt+0x22a/0x480 kernel/time/hrtimer.c:1641
 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:829
 kmalloc_type include/linux/slab.h:329 [inline]
 kmalloc_slab+0x3f/0x60 mm/slab_common.c:1151
 __kmalloc_reserve.isra.0+0x49/0xd0 net/core/skbuff.c:141
 __alloc_skb+0xc2/0x360 net/core/skbuff.c:209
 alloc_skb include/linux/skbuff.h:1049 [inline]
 __tcp_send_ack+0x7e/0x300 net/ipv4/tcp_output.c:3676
 tcp_send_ack+0x34/0x40 net/ipv4/tcp_output.c:3703
 tcp_cleanup_rbuf+0x130/0x360 net/ipv4/tcp.c:1578
 tcp_recvmsg+0x687/0x1c90 net/ipv4/tcp.c:2184
 inet_recvmsg+0xbb/0x250 net/ipv4/af_inet.c:838
 sock_recvmsg_nosec net/socket.c:873 [inline]
 sock_recvmsg net/socket.c:891 [inline]
 sock_recvmsg+0x92/0xb0 net/socket.c:887
 sock_read_iter+0x15f/0x1e0 net/socket.c:969
 call_read_iter include/linux/fs.h:1896 [inline]
 new_sync_read+0x4b1/0x4f0 fs/read_write.c:414
 __vfs_read+0xb1/0xc0 fs/read_write.c:427
 vfs_read fs/read_write.c:461 [inline]
 vfs_read+0x143/0x2c0 fs/read_write.c:446
 ksys_read+0x17b/0x1b0 fs/read_write.c:587
 __do_sys_read fs/read_write.c:597 [inline]
 __se_sys_read fs/read_write.c:595 [inline]
 __x64_sys_read+0x4c/0x60 fs/read_write.c:595
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffffffff85ebb050 of 4 bytes by task 0 on cpu 1:
 tick_nohz_next_event+0x19d/0x370 kernel/time/tick-sched.c:736
 __tick_nohz_idle_stop_tick kernel/time/tick-sched.c:954 [inline]
 tick_nohz_idle_stop_tick+0x3c2/0x670 kernel/time/tick-sched.c:984
 cpuidle_idle_call kernel/sched/idle.c:151 [inline]
 do_idle+0x1b8/0x290 kernel/sched/idle.c:269
 cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:361
 start_secondary+0x168/0x1b0 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 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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