==================================================================
BUG: KCSAN: data-race in __d_lookup_done / __dentry_kill

write to 0xffff88810c3776c0 of 4 bytes by task 6671 on cpu 0:
 __d_lookup_done+0x8e/0x240 fs/dcache.c:2648
 d_lookup_done include/linux/dcache.h:369 [inline]
 __lookup_slow+0x206/0x250 fs/namei.c:1545
 lookup_slow fs/namei.c:1561 [inline]
 walk_component+0x2a5/0x350 fs/namei.c:1860
 link_path_walk+0x462/0x730 fs/namei.c:2179
 path_openat+0x199/0x20e0 fs/namei.c:3356
 do_filp_open+0xbd/0x1d0 fs/namei.c:3387
 do_sys_openat2+0x33c/0x4a0 fs/open.c:1179
 do_sys_open fs/open.c:1195 [inline]
 ksys_open include/linux/syscalls.h:1388 [inline]
 __do_sys_open fs/open.c:1201 [inline]
 __se_sys_open fs/open.c:1199 [inline]
 __x64_sys_open+0xe2/0x110 fs/open.c:1199
 do_syscall_64+0x51/0xb0 arch/x86/entry/common.c:359
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88810c3776c0 of 4 bytes by task 6895 on cpu 1:
 dentry_unlist fs/dcache.c:544 [inline]
 __dentry_kill+0x1ef/0x450 fs/dcache.c:575
 dentry_kill fs/dcache.c:692 [inline]
 dput+0x208/0x420 fs/dcache.c:878
 handle_mounts fs/namei.c:1389 [inline]
 step_into+0x448/0xe70 fs/namei.c:1690
 walk_component+0x190/0x350 fs/namei.c:1866
 link_path_walk+0x462/0x730 fs/namei.c:2179
 path_lookupat+0x7b/0x560 fs/namei.c:2332
 filename_lookup+0xf2/0x380 fs/namei.c:2366
 user_path_at_empty+0x3b/0x50 fs/namei.c:2646
 do_readlinkat+0x87/0x200 fs/stat.c:419
 __do_sys_readlinkat fs/stat.c:446 [inline]
 __se_sys_readlinkat fs/stat.c:443 [inline]
 __x64_sys_readlinkat+0x4f/0x60 fs/stat.c:443
 do_syscall_64+0x51/0xb0 arch/x86/entry/common.c:359
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 6895 Comm: systemd-udevd Not tainted 5.8.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================