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BUG: KCSAN: data-race in fasync_remove_entry / kill_fasync

write to 0xffff88811f79b300 of 8 bytes by task 13950 on cpu 1:
 fasync_remove_entry+0xb7/0x120 fs/fcntl.c:884
 fasync_helper+0xc9/0xd6 fs/fcntl.c:983
 perf_fasync+0x64/0x90 kernel/events/core.c:6187
 __fput+0x455/0x500 fs/file_table.c:277
 ____fput+0x1b/0x30 fs/file_table.c:313
 task_work_run+0xba/0x120 kernel/task_work.c:123
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop+0x2ae/0x2c0 arch/x86/entry/common.c:165
 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:279 [inline]
 do_syscall_64+0x38b/0x3b0 arch/x86/entry/common.c:305
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88811f79b300 of 8 bytes by interrupt on cpu 0:
 kill_fasync+0x3c/0x170 fs/fcntl.c:1021
 perf_event_wakeup+0x115/0x160 kernel/events/core.c:6227
 perf_pending_event+0x129/0x170 kernel/events/core.c:6283
 irq_work_run_list+0x13e/0x190 kernel/irq_work.c:157
 irq_work_run+0x43/0x90 kernel/irq_work.c:174
 smp_irq_work_interrupt+0x3b/0xf0 arch/x86/kernel/irq_work.c:21
 irq_work_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:860
 __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_read8+0x30/0x110 kernel/kcsan/core.c:770
 arch_local_irq_disable arch/x86/include/asm/paravirt.h:764 [inline]
 arch_local_irq_save arch/x86/include/asm/paravirt.h:777 [inline]
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:108 [inline]
 _raw_spin_lock_irqsave+0x40/0xb0 kernel/locking/spinlock.c:159
 rcu_report_qs_rdp kernel/rcu/tree.c:1993 [inline]
 rcu_check_quiescent_state kernel/rcu/tree.c:2058 [inline]
 rcu_core+0xda/0x9f0 kernel/rcu/tree.c:2417
 rcu_core_si+0x12/0x20 kernel/rcu/tree.c:2442
 __do_softirq+0x118/0x34a kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0xb5/0xd0 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:546 [inline]
 smp_apic_timer_interrupt+0xe2/0x270 arch/x86/kernel/apic/apic.c:1140
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
 __sanitizer_cov_trace_const_cmp4+0x4/0x20 kernel/kcov.c:274
 total_mapcount mm/huge_memory.c:2677 [inline]
 total_mapcount+0x111/0x2a0 mm/huge_memory.c:2664
 page_mapcount_is_zero+0x1c/0x40 mm/rmap.c:1717
 rmap_walk_anon+0x287/0x600 mm/rmap.c:1865
 rmap_walk+0x149/0x180 mm/rmap.c:1933
 try_to_unmap+0x14c/0x2e0 mm/rmap.c:1754
 __unmap_and_move mm/migrate.c:1123 [inline]
 unmap_and_move mm/migrate.c:1206 [inline]
 migrate_pages+0x12fd/0x1960 mm/migrate.c:1454
 do_mbind+0x8df/0x9f0 mm/mempolicy.c:1374
 kernel_mbind+0x10e/0x130 mm/mempolicy.c:1495
 __do_sys_mbind mm/mempolicy.c:1502 [inline]
 __se_sys_mbind mm/mempolicy.c:1498 [inline]
 __x64_sys_mbind+0x7e/0xa0 mm/mempolicy.c:1498
 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: 0 PID: 13963 Comm: syz-executor.5 Not tainted 5.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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