syzbot

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BUG: KCSAN: data-race in path_openat / shrink_dentry_list

read-write to 0xffff888106064cc0 of 4 bytes by task 3474 on cpu 1:
 d_shrink_del fs/dcache.c:506 [inline]
 shrink_dentry_list+0x226/0x3e0 fs/dcache.c:1124
 shrink_dcache_sb+0x156/0x280 fs/dcache.c:1252
 reconfigure_super+0x4c1/0x5b0 fs/super.c:1061
 do_remount fs/namespace.c:3365 [inline]
 path_mount+0x96a/0xb30 fs/namespace.c:4200
 do_mount fs/namespace.c:4221 [inline]
 __do_sys_mount fs/namespace.c:4432 [inline]
 __se_sys_mount+0x28f/0x2e0 fs/namespace.c:4409
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4409
 x64_sys_call+0xd11/0x2e10 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0x1a0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888106064cc0 of 4 bytes by task 3296 on cpu 0:
 __d_entry_type include/linux/dcache.h:409 [inline]
 d_is_reg include/linux/dcache.h:444 [inline]
 do_open fs/namei.c:3872 [inline]
 path_openat+0x194f/0x2000 fs/namei.c:4039
 do_filp_open+0x115/0x240 fs/namei.c:4066
 do_sys_openat2+0xaa/0x110 fs/open.c:1429
 do_sys_open fs/open.c:1444 [inline]
 __do_sys_openat fs/open.c:1460 [inline]
 __se_sys_openat fs/open.c:1455 [inline]
 __x64_sys_openat+0xf8/0x120 fs/open.c:1455
 x64_sys_call+0x1ac/0x2e10 arch/x86/include/generated/asm/syscalls_64.h:258
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0x1a0 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: 0 UID: 0 PID: 3296 Comm: udevd Not tainted 6.15.0-rc3-syzkaller-00019-gbc3372351d0c #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
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