syzbot

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BUG: KCSAN: data-race in __d_lookup_rcu / __d_rehash

read to 0xffff88810625f190 of 8 bytes by task 6549 on cpu 1:
 hlist_bl_unhashed include/linux/list_bl.h:54 [inline]
 d_unhashed include/linux/dcache.h:366 [inline]
 __d_lookup_rcu+0x105/0x2a0 fs/dcache.c:2267
 lookup_fast+0x99/0x320 fs/namei.c:1727
 walk_component fs/namei.c:2110 [inline]
 link_path_walk+0x472/0x830 fs/namei.c:2479
 path_openat+0x1af/0x1fc0 fs/namei.c:3985
 do_filp_open+0x107/0x230 fs/namei.c:4016
 do_sys_openat2+0xab/0x120 fs/open.c:1428
 do_sys_open fs/open.c:1443 [inline]
 __do_sys_openat fs/open.c:1459 [inline]
 __se_sys_openat fs/open.c:1454 [inline]
 __x64_sys_openat+0xf3/0x120 fs/open.c:1454
 x64_sys_call+0x2b30/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:258
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

write to 0xffff88810625f190 of 8 bytes by task 6617 on cpu 0:
 hlist_bl_add_head_rcu include/linux/rculist_bl.h:81 [inline]
 __d_rehash+0xa9/0x210 fs/dcache.c:2448
 __d_add+0x373/0x4a0 fs/dcache.c:2663
 d_add+0x45/0x50 fs/dcache.c:2686
 configfs_lookup+0x1ab/0x440 fs/configfs/dir.c:499
 lookup_one_qstr_excl+0xca/0x1c0 fs/namei.c:1693
 do_unlinkat+0x144/0x4d0 fs/namei.c:4577
 __do_sys_unlink fs/namei.c:4637 [inline]
 __se_sys_unlink fs/namei.c:4635 [inline]
 __x64_sys_unlink+0x2e/0x40 fs/namei.c:4635
 x64_sys_call+0x2329/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:88
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 6617 Comm: syz-executor Not tainted 6.14.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
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