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BUG: KCSAN: data-race in fasync_remove_entry / kill_fasync

write to 0xffff88812526e300 of 8 bytes by task 11270 on cpu 0:
 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 0xffff88812526e300 of 8 bytes by interrupt on cpu 1:
 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]
 check_kcov_mode kernel/kcov.c:155 [inline]
 write_comp_data+0x1e/0x70 kernel/kcov.c:208
 set_buffer_uptodate include/linux/buffer_head.h:120 [inline]
 __ext4_handle_dirty_metadata+0x16b/0x3d0 fs/ext4/ext4_jbd2.c:333
 ext4_do_update_inode fs/ext4/inode.c:5053 [inline]
 ext4_mark_iloc_dirty+0xda8/0x1580 fs/ext4/inode.c:5603
 ext4_mark_inode_dirty+0xe6/0x420 fs/ext4/inode.c:5796
 ext4_da_write_end+0x600/0x690 fs/ext4/inode.c:3080
 generic_perform_write+0x1d7/0x320 mm/filemap.c:3313
 ext4_buffered_write_iter+0x14e/0x280 fs/ext4/file.c:270
 ext4_file_write_iter+0xf4/0xd30 fs/ext4/file.c:642
 call_write_iter include/linux/fs.h:1907 [inline]
 do_iter_readv_writev+0x4a7/0x5d0 fs/read_write.c:694
 do_iter_write fs/read_write.c:999 [inline]
 do_iter_write+0x137/0x3a0 fs/read_write.c:980
 vfs_iter_write+0x56/0x80 fs/read_write.c:1040
 iter_file_splice_write+0x530/0x830 fs/splice.c:760
 do_splice_from fs/splice.c:863 [inline]
 direct_splice_actor+0x97/0xb0 fs/splice.c:1037
 splice_direct_to_actor+0x22f/0x540 fs/splice.c:992
 do_splice_direct+0x152/0x1d0 fs/splice.c:1080
 do_sendfile+0x380/0x800 fs/read_write.c:1521
 __do_sys_sendfile64 fs/read_write.c:1576 [inline]
 __se_sys_sendfile64 fs/read_write.c:1568 [inline]
 __x64_sys_sendfile64+0xb8/0x140 fs/read_write.c:1568
 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: 11271 Comm: syz-executor.3 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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