==================================================================
BUG: KCSAN: data-race in d_alloc_parallel / d_set_d_op

read-write to 0xffff8881501d99c0 of 4 bytes by task 26404 on cpu 1:
 d_set_d_op+0xf0/0x1e0 fs/dcache.c:1932
 proc_ns_instantiate fs/proc/namespaces.c:114 [inline]
 proc_ns_dir_lookup+0x542/0x5d0 fs/proc/namespaces.c:172
 lookup_open fs/namei.c:3359 [inline]
 open_last_lookups fs/namei.c:3451 [inline]
 path_openat+0xb0f/0x1b30 fs/namei.c:3657
 do_filp_open+0x105/0x220 fs/namei.c:3687
 do_sys_openat2+0xb5/0x2a0 fs/open.c:1278
 do_sys_open fs/open.c:1294 [inline]
 __do_sys_openat fs/open.c:1310 [inline]
 __se_sys_openat fs/open.c:1305 [inline]
 __x64_sys_openat+0xef/0x110 fs/open.c:1305
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

read to 0xffff8881501d99c0 of 4 bytes by task 26405 on cpu 0:
 d_in_lookup include/linux/dcache.h:356 [inline]
 d_wait_lookup fs/dcache.c:2582 [inline]
 d_alloc_parallel+0x655/0xcc0 fs/dcache.c:2670
 lookup_open fs/namei.c:3305 [inline]
 open_last_lookups fs/namei.c:3451 [inline]
 path_openat+0x66f/0x1b30 fs/namei.c:3657
 do_filp_open+0x105/0x220 fs/namei.c:3687
 do_sys_openat2+0xb5/0x2a0 fs/open.c:1278
 do_sys_open fs/open.c:1294 [inline]
 __do_sys_openat fs/open.c:1310 [inline]
 __se_sys_openat fs/open.c:1305 [inline]
 __x64_sys_openat+0xef/0x110 fs/open.c:1305
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

value changed: 0x10000000 -> 0x1000000c

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 26405 Comm: syz-executor.1 Not tainted 5.18.0-syzkaller-11793-g8eca6b0a647a-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================