==================================================================
BUG: KCSAN: data-race in __d_lookup / __put_mountpoint

write to 0xffff88812b802840 of 4 bytes by task 32062 on cpu 1:
 __put_mountpoint+0xe2/0x1b0 fs/namespace.c:760
 put_mountpoint fs/namespace.c:771 [inline]
 attach_recursive_mnt+0x5eb/0x8a0 fs/namespace.c:2106
 graft_tree+0x107/0x160 fs/namespace.c:2179
 do_add_mount+0x130/0x1d0 fs/namespace.c:2734
 do_new_mount_fc fs/namespace.c:2771 [inline]
 do_new_mount fs/namespace.c:2824 [inline]
 do_mount+0x1291/0x14d0 fs/namespace.c:3107
 __do_sys_mount fs/namespace.c:3316 [inline]
 __se_sys_mount fs/namespace.c:3293 [inline]
 __x64_sys_mount+0x12b/0x1a0 fs/namespace.c:3293
 do_syscall_64+0xc7/0x390 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88812b802840 of 4 bytes by task 7761 on cpu 0:
 __d_lookup+0x164/0x3d0 fs/dcache.c:2380
 lookup_fast+0x282/0x6e0 fs/namei.c:1709
 walk_component+0x73/0x9a0 fs/namei.c:1911
 link_path_walk.part.0+0x5e5/0xa80 fs/namei.c:2241
 link_path_walk fs/namei.c:2387 [inline]
 path_lookupat.isra.0+0x66/0x2e0 fs/namei.c:2435
 filename_lookup+0x29e/0x2b0 fs/namei.c:2468
 user_path_at_empty+0x47/0x60 fs/namei.c:2746
 user_path_at include/linux/namei.h:58 [inline]
 vfs_statx+0xdb/0x190 fs/stat.c:197
 vfs_lstat include/linux/fs.h:3276 [inline]
 __do_sys_newlstat+0x50/0xb0 fs/stat.c:364
 __se_sys_newlstat fs/stat.c:358 [inline]
 __x64_sys_newlstat+0x37/0x50 fs/stat.c:358
 do_syscall_64+0xc7/0x390 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 7761 Comm: udevd Not tainted 5.6.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================