syzbot


WARNING in hfs_mdb_commit

Status: upstream: reported C repro on 2026/05/13 17:28
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+2058ce469fb4ad897eae@syzkaller.appspotmail.com
First crash: 1d13h, last: 16h21m
Bug presence (1)
Date Name Commit Repro Result
2026/05/14 upstream (ToT) 66182ca873a4 C [report] WARNING in hfs_mdb_commit
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in hfs_mdb_commit hfs -1 1 5d03h 1d03h 0/29 upstream: reported on 2026/05/14 03:37

Sample crash report:
hfs: walked past end of dir
------------[ cut here ]------------
WARNING: CPU: 1 PID: 4375 at fs/buffer.c:1081 mark_buffer_dirty+0x383/0x7a0 fs/buffer.c:1081
Modules linked in:
CPU: 1 PID: 4375 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:mark_buffer_dirty+0x383/0x7a0 fs/buffer.c:1081
Code: 83 71 e2 ff 49 8b 3f be 04 00 00 00 5b 41 5c 41 5d 41 5e 41 5f 5d e9 fc a9 fc ff e8 27 65 91 ff e9 43 ff ff ff e8 1d 65 91 ff <0f> 0b e9 ba fc ff ff e8 11 65 91 ff 0f 0b e9 00 fd ff ff e8 05 65
RSP: 0018:ffffc90003db7c10 EFLAGS: 00010293
RAX: ffffffff81f11033 RBX: ffff888071520ae0 RCX: ffff888026048000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002
RBP: 1ffff1100f6ec001 R08: ffff888071520ae7 R09: 1ffff1100e2a415c
R10: dffffc0000000000 R11: ffffed100e2a415d R12: dffffc0000000000
R13: ffff88807b760678 R14: ffff88806a127c0b R15: ffff88806a233492
FS:  0000555577c71500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000d6283073e80 CR3: 000000002e215000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 hfs_mdb_commit+0x7cb/0x1100 fs/hfs/mdb.c:302
 hfs_sync_fs+0x11/0x20 fs/hfs/super.c:35
 sync_filesystem+0xe6/0x220 fs/sync.c:56
 generic_shutdown_super+0x6b/0x340 fs/super.c:474
 kill_block_super+0x7c/0xe0 fs/super.c:1470
 deactivate_locked_super+0x93/0xf0 fs/super.c:332
 cleanup_mnt+0x42c/0x4b0 fs/namespace.c:1191
 task_work_run+0x1d0/0x260 kernel/task_work.c:203
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f430699e097
Code: a2 c7 05 5c 06 25 00 00 00 00 00 eb 96 e8 e1 12 00 00 90 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffe7691d758 EFLAGS: 00000202 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000064 RCX: 00007f430699e097
RDX: 0000000000000200 RSI: 0000000000000009 RDI: 00007ffe7691e900
RBP: 00007f4306a321ca R08: 0000000000020590 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffe7691e900
R13: 00007f4306a321ca R14: 0000555577c714e8 R15: 00007ffe7691f9d0
 </TASK>

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/05/14 14:49 linux-6.1.y ad16b162f21d 6ccb967e .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan WARNING in hfs_mdb_commit
2026/05/14 13:32 linux-6.1.y ad16b162f21d 6ccb967e .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan WARNING in hfs_mdb_commit
2026/05/13 17:28 linux-6.1.y ad16b162f21d fec2a7ee .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in hfs_mdb_commit
2026/05/13 17:27 linux-6.1.y ad16b162f21d fec2a7ee .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in hfs_mdb_commit
* Struck through repros no longer work on HEAD.