syzbot

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BUG: KCSAN: data-race in __se_sys_inotify_add_watch / fsnotify

write to 0xffff888104e1ec80 of 4 bytes by task 4667 on cpu 0:
 inotify_update_watch fs/notify/inotify/inotify_user.c:625 [inline]
 __do_sys_inotify_add_watch fs/notify/inotify/inotify_user.c:766 [inline]
 __se_sys_inotify_add_watch+0x2a5/0x680 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+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888104e1ec80 of 4 bytes by task 4668 on cpu 1:
 send_to_group fs/notify/fsnotify.c:350 [inline]
 fsnotify+0xa19/0xf00 fs/notify/fsnotify.c:543
 __fsnotify_parent+0x40e/0x490 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:277 [inline]
 do_iter_write+0x4e2/0x5c0 fs/read_write.c:855
 vfs_iter_write+0x4c/0x70 fs/read_write.c:892
 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+0x675/0xc40 fs/read_write.c:1245
 __do_sys_sendfile64 fs/read_write.c:1304 [inline]
 __se_sys_sendfile64 fs/read_write.c:1296 [inline]
 __x64_sys_sendfile64+0xb9/0x140 fs/read_write.c:1296
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0c00217e -> 0x08002000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 4668 Comm: syz-executor.1 Not tainted 5.16.0-rc8-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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