syzbot

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BUG: KCSAN: data-race in fsnotify_parent / vfs_rename

write to 0xffff8880830d0b40 of 4 bytes by task 28800 on cpu 1:
 dont_mount include/linux/dcache.h:354 [inline]
 vfs_rename+0x976/0xba0 fs/namei.c:4313
 do_renameat2+0x554/0x940 fs/namei.c:4450
 __do_sys_rename fs/namei.c:4496 [inline]
 __se_sys_rename fs/namei.c:4494 [inline]
 __x64_sys_rename+0x3a/0x40 fs/namei.c:4494
 do_syscall_64+0x51/0xb0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8880830d0b40 of 4 bytes by task 1 on cpu 0:
 fsnotify_parent+0x36/0x180 fs/notify/fsnotify.c:153
 fsnotify_file include/linux/fsnotify.h:74 [inline]
 fsnotify_perm+0x1b9/0x250 include/linux/fsnotify.h:103
 security_file_permission+0x87/0xa0 security/security.c:1450
 rw_verify_area+0x12c/0x240 fs/read_write.c:400
 vfs_read+0xf6/0x590 fs/read_write.c:472
 ksys_read+0xce/0x180 fs/read_write.c:607
 __do_sys_read fs/read_write.c:617 [inline]
 __se_sys_read fs/read_write.c:615 [inline]
 __x64_sys_read+0x3e/0x50 fs/read_write.c:615
 do_syscall_64+0x51/0xb0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 1 Comm: systemd Not tainted 5.8.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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