hfs: new node 0 already hashed?
------------[ cut here ]------------
WARNING: fs/hfs/bnode.c:520 at hfs_bnode_create+0x461/0x4f0 fs/hfs/bnode.c:520, CPU#0: syz.8.258/7360
Modules linked in:
CPU: 0 UID: 0 PID: 7360 Comm: syz.8.258 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:hfs_bnode_create+0x461/0x4f0 fs/hfs/bnode.c:520
Code: c2 8b 89 ee e8 20 c3 8b fe e9 cf fc ff ff e8 16 e6 24 ff 4c 89 ef e8 4e 96 e5 08 48 c7 c7 e0 05 c2 8b 89 ee e8 00 c3 8b fe 90 <0f> 0b 90 eb b0 44 89 f1 80 e1 07 80 c1 03 38 c1 0f 8c d6 fb ff ff
RSP: 0018:ffffc9000aff6dc0 EFLAGS: 00010246
RAX: 000000000000001f RBX: ffff888053a42000 RCX: 83422e9b67071300
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffc9000aff6ae7 R09: 1ffff920015fed5c
R10: dffffc0000000000 R11: fffff520015fed5d R12: 0000000000000000
R13: ffff888053a420e0 R14: ffff8880293a5000 R15: dffffc0000000000
FS:  00007f8f7827f6c0(0000) GS:ffff8881259f7000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8f7825ed58 CR3: 000000004ec0e000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 hfs_bmap_alloc+0x5bb/0x640 fs/hfs/btree.c:326
 hfs_btree_inc_height+0xf6/0xac0 fs/hfs/brec.c:471
 hfs_brec_insert+0x743/0xbd0 fs/hfs/brec.c:148
 __hfs_ext_write_extent+0x2a1/0x470 fs/hfs/extent.c:124
 __hfs_ext_cache_extent+0x6b/0x9b0 fs/hfs/extent.c:174
 hfs_ext_read_extent fs/hfs/extent.c:202 [inline]
 hfs_extend_file+0x316/0x1230 fs/hfs/extent.c:401
 hfs_get_block+0x3d7/0xbd0 fs/hfs/extent.c:353
 __block_write_begin_int+0x6b5/0x1900 fs/buffer.c:2145
 block_write_begin fs/buffer.c:2256 [inline]
 cont_write_begin+0x789/0xb50 fs/buffer.c:2594
 hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:52
 cont_expand_zero fs/buffer.c:2522 [inline]
 cont_write_begin+0x2fd/0xb50 fs/buffer.c:2584
 hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:52
 hfs_file_truncate+0x190/0x9c0 fs/hfs/extent.c:494
 hfs_inode_setattr+0x4a9/0x670 fs/hfs/inode.c:654
 notify_change+0xc17/0xf40 fs/attr.c:546
 do_truncate+0x1a4/0x220 fs/open.c:68
 do_ftruncate+0x489/0x540 fs/open.c:195
 do_sys_ftruncate fs/open.c:210 [inline]
 __do_sys_ftruncate fs/open.c:215 [inline]
 __se_sys_ftruncate fs/open.c:213 [inline]
 __x64_sys_ftruncate+0x92/0xf0 fs/open.c:213
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8f7738ebe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f8f7827f038 EFLAGS: 00000246 ORIG_RAX: 000000000000004d
RAX: ffffffffffffffda RBX: 00007f8f775c5fa0 RCX: 00007f8f7738ebe9
RDX: 0000000000000000 RSI: 000000000000c17a RDI: 0000000000000004
RBP: 00007f8f77411e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8f775c6038 R14: 00007f8f775c5fa0 R15: 00007fffc27b91a8
 </TASK>