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: kworker/u8:16/5927
Modules linked in:
CPU: 0 UID: 0 PID: 5927 Comm: kworker/u8:16 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: writeback wb_workfn (flush-7:4)
RIP: 0010:hfs_bnode_create+0x461/0x4f0 fs/hfs/bnode.c:520
Code: 02 8b 89 ee e8 30 9e 8f fe e9 cf fc ff ff e8 26 af 28 ff 4c 89 ef e8 1e 4b 3e 08 48 c7 c7 00 41 02 8b 89 ee e8 10 9e 8f 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:ffffc9000545ebe0 EFLAGS: 00010246
RAX: 000000000000001f RBX: ffff88803893e000 RCX: b7cf97b88aade000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffff52000a8bd21 R12: 0000000000000000
R13: ffff88803893e0d0 R14: ffff88803bd27a00 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff888126d01000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055558bfd25c8 CR3: 0000000033dfe000 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:490
 hfs_brec_insert+0x7ee/0xc80 fs/hfs/brec.c:148
 __hfs_ext_write_extent+0x2a1/0x470 fs/hfs/extent.c:124
 hfs_ext_write_extent+0x161/0x1e0 fs/hfs/extent.c:144
 hfs_write_inode+0xc6/0x8a0 fs/hfs/inode.c:441
 write_inode fs/fs-writeback.c:1582 [inline]
 __writeback_single_inode+0x7e4/0x1240 fs/fs-writeback.c:1802
 writeback_sb_inodes+0x8c8/0x1840 fs/fs-writeback.c:2030
 wb_writeback+0x42b/0xaa0 fs/fs-writeback.c:2216
 wb_do_writeback fs/fs-writeback.c:2363 [inline]
 wb_workfn+0x3fe/0xee0 fs/fs-writeback.c:2403
 process_one_work kernel/workqueue.c:3257 [inline]
 process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>