syzbot


WARNING in hfs_bnode_create

Status: upstream: reported C repro on 2025/08/13 16:31
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+7aabff809b2149af6834@syzkaller.appspotmail.com
First crash: 9d11h, last: 2d03h
Bug presence (1)
Date Name Commit Repro Result
2025/08/14 upstream (ToT) 24ea63ea3877 C [report] WARNING in hfs_bnode_create
Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in hfs_bnode_create hfs -1 C done error 2683 now 2698d 0/29 upstream: reported C repro on 2018/04/04 03:02
linux-4.19 WARNING in hfs_bnode_create hfs -1 C 16 905d 1000d 0/1 upstream: reported C repro on 2022/11/26 06:17
linux-5.15 WARNING in hfs_bnode_create missing-backport origin:upstream -1 C error 624 4d13h 872d 0/3 upstream: reported C repro on 2023/04/04 01:35
linux-6.1 WARNING in hfs_bnode_create origin:upstream -1 C error 85 2d01h 873d 0/3 upstream: reported C repro on 2023/04/02 22:27
linux-4.14 WARNING in hfs_bnode_create -1 C 2 904d 986d 0/1 upstream: reported C repro on 2022/12/10 13:46

Sample crash report:
hfs: continuing without an alternate MDB
hfs: new node 0 already hashed?
------------[ cut here ]------------
WARNING: CPU: 0 PID: 10578 at fs/hfs/bnode.c:428 hfs_bnode_create+0x3b9/0x440 fs/hfs/bnode.c:427
Modules linked in:
CPU: 0 PID: 10578 Comm: syz.1.2276 Not tainted 6.6.101-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:hfs_bnode_create+0x3b9/0x440 fs/hfs/bnode.c:428
Code: c4 c0 8a 89 ee e8 a7 1b 0c 08 e9 73 fd ff ff e8 ed e5 2f ff 4c 89 ef e8 45 10 21 08 48 c7 c7 20 c5 c0 8a 89 ee e8 87 1b 0c 08 <0f> 0b eb b7 44 89 f1 80 e1 07 80 c1 03 38 c1 0f 8c 7f fc ff ff 4c
RSP: 0018:ffffc9000cfd6e18 EFLAGS: 00010246
RAX: 000000000000001f RBX: ffff8880774e4000 RCX: bacf591967246800
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffc9000cfd6b27 R09: 1ffff920019fad64
R10: dffffc0000000000 R11: fffff520019fad65 R12: 0000000000000000
R13: ffff8880774e40e0 R14: ffff888141743e00 R15: dffffc0000000000
FS:  00007f471765b6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3012d72020 CR3: 000000001a7fb000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 hfs_bmap_alloc+0x53b/0x5c0 fs/hfs/btree.c:291
 hfs_btree_inc_height+0xf7/0xac0 fs/hfs/brec.c:471
 hfs_brec_insert+0x742/0xbd0 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+0x317/0x1220 fs/hfs/extent.c:401
 hfs_get_block+0x3d8/0xbd0 fs/hfs/extent.c:353
 __block_write_begin_int+0x566/0x1ad0 fs/buffer.c:2124
 __block_write_begin fs/buffer.c:2173 [inline]
 block_write_begin+0x9a/0x1e0 fs/buffer.c:2234
 cont_write_begin+0x5c8/0x7e0 fs/buffer.c:2591
 hfs_write_begin+0x8b/0xd0 fs/hfs/inode.c:58
 cont_expand_zero fs/buffer.c:2518 [inline]
 cont_write_begin+0x2ad/0x7e0 fs/buffer.c:2581
 hfs_write_begin+0x8b/0xd0 fs/hfs/inode.c:58
 hfs_file_truncate+0x191/0x9b0 fs/hfs/extent.c:494
 hfs_inode_setattr+0x4af/0x6e0 fs/hfs/inode.c:659
 notify_change+0xb0d/0xe10 fs/attr.c:499
 do_truncate+0x19b/0x220 fs/open.c:66
 do_sys_ftruncate+0x325/0x3d0 fs/open.c:194
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f471678ebe9
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:00007f471765b038 EFLAGS: 00000246 ORIG_RAX: 000000000000004d
RAX: ffffffffffffffda RBX: 00007f47169b5fa0 RCX: 00007f471678ebe9
RDX: 0000000000000000 RSI: 000000000000c17a RDI: 0000000000000004
RBP: 00007f4716811e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f47169b6038 R14: 00007f47169b5fa0 R15: 00007fff5942e1a8
 </TASK>

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/13 20:38 linux-6.6.y 3a8ababb8b6a 22ec1469 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-6-kasan WARNING in hfs_bnode_create
2025/08/14 10:39 linux-6.6.y 3a8ababb8b6a 22ec1469 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-6-kasan WARNING in hfs_bnode_create
2025/08/13 22:12 linux-6.6.y 3a8ababb8b6a 22ec1469 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-6-kasan WARNING in hfs_bnode_create
2025/08/13 18:05 linux-6.6.y 3a8ababb8b6a 22ec1469 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-6-kasan WARNING in hfs_bnode_create
2025/08/21 00:27 linux-6.6.y bb9c90ab9c5a 0b9605c8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in hfs_bnode_create
2025/08/13 16:31 linux-6.6.y 3a8ababb8b6a 22ec1469 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in hfs_bnode_create
* Struck through repros no longer work on HEAD.