syzbot

==================================================================
BUG: KCSAN: data-race in lookup_fast / shrink_dentry_list

read-write to 0xffff8881056e6240 of 4 bytes by task 12359 on cpu 0:
 d_shrink_del fs/dcache.c:515 [inline]
 shrink_dentry_list+0x22d/0x3d0 fs/dcache.c:1133
 shrink_dcache_sb+0x14f/0x280 fs/dcache.c:1261
 reconfigure_super+0x46a/0x580 fs/super.c:1054
 do_remount fs/namespace.c:3279 [inline]
 path_mount+0xad2/0xb70 fs/namespace.c:4029
 do_mount fs/namespace.c:4050 [inline]
 __do_sys_mount fs/namespace.c:4238 [inline]
 __se_sys_mount+0x28c/0x2e0 fs/namespace.c:4215
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4215
 x64_sys_call+0x2b51/0x3000 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff8881056e6240 of 4 bytes by task 11791 on cpu 1:
 d_revalidate fs/namei.c:928 [inline]
 lookup_fast+0x72/0x320 fs/namei.c:1777
 lookup_fast_for_open fs/namei.c:3833 [inline]
 open_last_lookups fs/namei.c:3866 [inline]
 path_openat+0x43c/0x2170 fs/namei.c:4131
 do_filp_open+0x109/0x230 fs/namei.c:4161
 do_sys_openat2+0xa6/0x110 fs/open.c:1437
 do_sys_open fs/open.c:1452 [inline]
 __do_sys_openat fs/open.c:1468 [inline]
 __se_sys_openat fs/open.c:1463 [inline]
 __x64_sys_openat+0xf2/0x120 fs/open.c:1463
 x64_sys_call+0x2eab/0x3000 arch/x86/include/generated/asm/syscalls_64.h:258
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00240444 -> 0x00200044

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 11791 Comm: syz-executor Tainted: G        W           syzkaller #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
==================================================================