syzbot

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BUG: KCSAN: data-race in fsnotify / fsnotify_detach_mark

write to 0xffff88810672ae54 of 4 bytes by task 4670 on cpu 0:
 fsnotify_detach_mark+0x9a/0x160 fs/notify/mark.c:414
 fsnotify_clear_marks_by_group+0x280/0x320 fs/notify/mark.c:786
 fsnotify_destroy_group+0x6d/0x1b0 fs/notify/group.c:61
 inotify_release+0x21/0x30 fs/notify/inotify/inotify_user.c:286
 __fput+0x295/0x520 fs/file_table.c:280
 ____fput+0x11/0x20 fs/file_table.c:313
 task_work_run+0xae/0x130 kernel/task_work.c:164
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:175 [inline]
 exit_to_user_mode_prepare+0x156/0x190 kernel/entry/common.c:207
 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
 syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:300
 do_syscall_64+0x50/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88810672ae54 of 4 bytes by task 4671 on cpu 1:
 send_to_group fs/notify/fsnotify.c:335 [inline]
 fsnotify+0x836/0x11a0 fs/notify/fsnotify.c:541
 __fsnotify_parent+0x3bd/0x440 fs/notify/fsnotify.c:232
 fsnotify_parent include/linux/fsnotify.h:77 [inline]
 fsnotify_file include/linux/fsnotify.h:99 [inline]
 fsnotify_modify include/linux/fsnotify.h:264 [inline]
 do_iter_write+0x4e2/0x5c0 fs/read_write.c:859
 vfs_iter_write+0x4c/0x70 fs/read_write.c:896
 iter_file_splice_write+0x43a/0x790 fs/splice.c:689
 do_splice_from fs/splice.c:767 [inline]
 direct_splice_actor+0x80/0xa0 fs/splice.c:936
 splice_direct_to_actor+0x345/0x650 fs/splice.c:891
 do_splice_direct+0x106/0x190 fs/splice.c:979
 do_sendfile+0x63e/0xbb0 fs/read_write.c:1249
 __do_sys_sendfile64 fs/read_write.c:1308 [inline]
 __se_sys_sendfile64 fs/read_write.c:1300 [inline]
 __x64_sys_sendfile64+0xb9/0x140 fs/read_write.c:1300
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00000006 -> 0x00000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 4671 Comm: syz-executor.0 Not tainted 5.15.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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