syzbot

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BUG: KCSAN: data-race in fsnotify / fsnotify_recalc_mask

write to 0xffff888101c92b6c of 4 bytes by task 25626 on cpu 0:
 __fsnotify_recalc_mask fs/notify/mark.c:132 [inline]
 fsnotify_recalc_mask+0x17d/0x1e0 fs/notify/mark.c:147
 fsnotify_add_mark_locked+0x9fa/0xbc0 fs/notify/mark.c:694
 fsnotify_add_inode_mark_locked include/linux/fsnotify_backend.h:626 [inline]
 inotify_new_watch fs/notify/inotify/inotify_user.c:601 [inline]
 inotify_update_watch fs/notify/inotify/inotify_user.c:628 [inline]
 __do_sys_inotify_add_watch fs/notify/inotify/inotify_user.c:766 [inline]
 __se_sys_inotify_add_watch+0x53b/0x680 fs/notify/inotify/inotify_user.c:709
 __x64_sys_inotify_add_watch+0x3f/0x50 fs/notify/inotify/inotify_user.c:709
 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

read to 0xffff888101c92b6c of 4 bytes by task 508 on cpu 1:
 fsnotify+0x1e2/0xf00 fs/notify/fsnotify.c:507
 __fsnotify_parent+0x33a/0x490 fs/notify/fsnotify.c:232
 fsnotify_parent include/linux/fsnotify.h:77 [inline]
 fsnotify_file include/linux/fsnotify.h:99 [inline]
 fsnotify_close include/linux/fsnotify.h:301 [inline]
 __fput+0x1d7/0x520 fs/file_table.c:266
 ____fput+0x11/0x20 fs/file_table.c:313
 task_work_run+0x8e/0x110 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+0x160/0x190 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

value changed: 0x00000000 -> 0x00002008

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 508 Comm: syz-executor.4 Not tainted 5.15.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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