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BUG: KCSAN: data-race in __perf_event_overflow / fasync_remove_entry

write to 0xffff8880a63e4b00 of 8 bytes by task 14736 on cpu 1:
 fasync_remove_entry+0xba/0x120 fs/fcntl.c:882
 fasync_helper+0xcf/0xdc fs/fcntl.c:981
 perf_fasync+0x6c/0xa0 kernel/events/core.c:6002
 __fput+0x46a/0x520 fs/file_table.c:277
 ____fput+0x1f/0x30 fs/file_table.c:313
 task_work_run+0xf6/0x130 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop+0x2b4/0x2c0 arch/x86/entry/common.c:164
 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:278 [inline]
 do_syscall_64+0x384/0x3a0 arch/x86/entry/common.c:304
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8880a63e4b00 of 8 bytes by interrupt on cpu 0:
 __perf_event_overflow+0x11d/0x200 kernel/events/core.c:8429
 perf_swevent_hrtimer+0x261/0x280 kernel/events/core.c:9813
 __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
 kobject_uevent_env+0x1aa/0xc80 lib/kobject_uevent.c:529
 kobject_uevent+0x29/0x40 lib/kobject_uevent.c:641
 rx_queue_add_kobject net/core/net-sysfs.c:936 [inline]
 net_rx_queue_update_kobjects+0xf9/0x310 net/core/net-sysfs.c:958
 register_queue_kobjects net/core/net-sysfs.c:1533 [inline]
 netdev_register_kobject+0x198/0x240 net/core/net-sysfs.c:1756
 register_netdevice+0x34e/0xad0 net/core/dev.c:9316
 register_netdev+0x39/0x60 net/core/dev.c:9438
 vti6_init_net+0x25b/0x2c0 net/ipv6/ip6_vti.c:1122
 ops_init+0x8c/0x240 net/core/net_namespace.c:137
 setup_net+0x191/0x4b0 net/core/net_namespace.c:335
 copy_net_ns+0x1e7/0x400 net/core/net_namespace.c:476
 create_new_namespaces+0x2e2/0x550 kernel/nsproxy.c:103
 unshare_nsproxy_namespaces+0xb9/0x170 kernel/nsproxy.c:202
 ksys_unshare+0x2dc/0x710 kernel/fork.c:2935
 __do_sys_unshare kernel/fork.c:3003 [inline]
 __se_sys_unshare kernel/fork.c:3001 [inline]
 __x64_sys_unshare+0x28/0x40 kernel/fork.c:3001
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 14745 Comm: syz-executor.3 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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