[syzbot] [hfs?] WARNING in hfsplus_bnode_create (2)

[syzbot <syzbot+2bf21610eea63cb2ce93@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    eb3f4b7426cf Merge tag 'nfsd-7.1-2' of git://git.kernel.or..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=144f912e580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=bd38685893011045
dashboard link: https://syzkaller.appspot.com/bug?extid=2bf21610eea63cb2ce93
compiler:       Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=109c991f980000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=148dd97e580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/82ff9dc3956e/disk-eb3f4b74.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/be01a7a564dd/vmlinux-eb3f4b74.xz
kernel image: https://storage.googleapis.com/syzbot-assets/5d5168563228/bzImage-eb3f4b74.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/a4a0cfb0b4a1/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+2bf21610eea63cb2ce93@syzkaller.appspotmail.com

WARNING: The mand mount option has been deprecated and
         and is ignored by this kernel. Remove the mand
         option from the mount to silence this warning.
=======================================================
hfsplus: new node 0 already hashed?
------------[ cut here ]------------
1
WARNING: fs/hfsplus/bnode.c:634 at hfsplus_bnode_create+0x45d/0x4f0 fs/hfsplus/bnode.c:634, CPU#0: syz.0.17/5942
Modules linked in:
CPU: 0 UID: 0 PID: 5942 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:hfsplus_bnode_create+0x45d/0x4f0 fs/hfsplus/bnode.c:634
Code: 47 8b 89 ee e8 24 6f 83 fe e9 cf fc ff ff e8 da 88 20 ff 4c 89 f7 e8 92 d0 79 08 48 c7 c7 a0 52 47 8b 89 ee e8 04 6f 83 fe 90 <0f> 0b 90 49 c7 c5 ef ff ff ff eb a9 44 89 f9 80 e1 07 80 c1 03 38
RSP: 0018:ffffc90003a5f5a0 EFLAGS: 00010246
RAX: 0000000000000023 RBX: dffffc0000000000 RCX: 89c16ee503352d00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffff5200074be65 R12: 0000000000000000
R13: ffff888039ca0000 R14: ffff888039ca00d0 R15: ffff88802808fc00
FS:  00005555881da500(0000) GS:ffff888126386000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000038b22000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 hfs_bnode_split+0xd2/0x1090 fs/hfsplus/brec.c:248
 hfsplus_brec_insert+0x3bc/0xd70 fs/hfsplus/brec.c:100
 hfsplus_create_cat+0xa64/0x11f0 fs/hfsplus/catalog.c:308
 hfsplus_mknod+0x186/0x3f0 fs/hfsplus/dir.c:538
 hfsplus_mkdir+0x2c/0x40 fs/hfsplus/dir.c:579
 vfs_mkdir+0x40b/0x630 fs/namei.c:5261
 filename_mkdirat+0x289/0x520 fs/namei.c:5294
 __do_sys_mkdirat fs/namei.c:5315 [inline]
 __se_sys_mkdirat+0x35/0x150 fs/namei.c:5312
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7efc691dbcc7
Code: 00 66 90 48 89 f2 b9 00 01 00 00 48 89 fe bf 9c ff ff ff e9 db f7 ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 b8 02 01 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd3adf41f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007ffd3adf4280 RCX: 00007efc691dbcc7
RDX: 00000000000001ff RSI: 0000200000000440 RDI: 00000000ffffff9c
RBP: 0000200000000080 R08: 0000200000000140 R09: 0000000000000000
R10: 0000200000000080 R11: 0000000000000246 R12: 0000200000000440
R13: 00007ffd3adf4240 R14: 0000000000000000 R15: 0000000000000000
 </TASK>


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