kernel BUG in hfs_write_inode

Status: upstream: reported C repro on 2025/06/16 18:04
Bug presence: origin:upstream
Labels: missing-backport
[Documentation on labels]
Reported-by: syzbot+905e5e4c2be48752878c@syzkaller.appspotmail.com
First crash: 417d, last: 2h37m
Fix commit to backport (bisect log) :
tree: upstream
commit 42b0ef01e6b5e9c77b383d32c25a0ec2a735d08a
Author: Arnd Bergmann <arnd@arndb.de>
Date: Fri Jul 11 08:46:51 2025 +0000

  block: fix FS_IOC_GETLBMD_CAP parsing in blkdev_common_ioctl()

  
▶ ▼ Bug presence (3)
Date Name Commit Repro Result
2025/08/03 linux-6.6.y (ToT) 3a8ababb8b6a C [report] kernel BUG in hfs_write_inode
2025/06/19 upstream (ToT) fb4d33ab452e C [report] kernel BUG in hfs_write_inode
2025/08/03 upstream (ToT) 186f3edfdd41 C Didn't crash
▶ ▼ Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 kernel BUG in hfs_write_inode origin:upstream missing-backport -1 syz, C inconclusive 29656 now 1221d 0/3 upstream: reported C repro on 2023/04/04 07:01
linux-4.14 kernel BUG in hfs_write_inode hfs -1 syz, C 3 1251d 1344d 0/1 upstream: reported C repro on 2022/12/02 20:03
linux-4.19 kernel BUG in hfs_write_inode hfs -1 syz, C 24 1250d 1350d 0/1 upstream: reported C repro on 2022/11/26 01:52
linux-5.15 kernel BUG in hfs_write_inode origin:upstream -1 syz, C error 21322 3h41m 1215d 0/3 upstream: reported C repro on 2023/04/10 13:50
upstream kernel BUG in hfs_write_inode prio:high hfs -1 syz, C error 238582 29m 1351d 0/29 upstream: reported C repro on 2022/11/25 09:45
▶ ▼ Fix bisection attempts (1)
Created Duration User Patch Repo Result
2025/12/31 11:28 7h34m fix candidate upstream OK (1) job log

Sample crash report:
wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50
------------[ cut here ]------------
kernel BUG at fs/hfs/inode.c:449!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 1135 Comm: kworker/u4:7 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: writeback wb_workfn (flush-7:0)
RIP: 0010:hfs_write_inode+0x87a/0x880 fs/hfs/inode.c:449
Code: c7 c1 00 73 31 97 80 e1 07 80 c1 03 38 c1 0f 8c 73 fe ff ff 48 c7 c7 00 73 31 97 e8 f0 f2 83 ff e9 62 fe ff ff e8 e6 b2 2b ff <0f> 0b 0f 1f 40 00 f3 0f 1e fa 55 41 57 41 56 41 54 53 48 89 fb 49
RSP: 0018:ffffc9000490f340 EFLAGS: 00010293
RAX: ffffffff825b78aa RBX: ffff88802d728ea8 RCX: ffff888023f81e00
RDX: 0000000000000000 RSI: ffffffff8d33a040 RDI: 0000000000000000
RBP: ffffc9000490f4d0 R08: ffff888023f81e00 R09: 0000000000000003
R10: 0000000000000004 R11: 0000000000000000 R12: dffffc0000000000
R13: 1ffff92000921e6c R14: ffff88802d728e58 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055557e130a38 CR3: 0000000031225000 CR4: 00000000003506e0
Call Trace:
 <TASK>
 write_inode fs/fs-writeback.c:1483 [inline]
 __writeback_single_inode+0x705/0xec0 fs/fs-writeback.c:1700
 writeback_sb_inodes+0x7cd/0xf50 fs/fs-writeback.c:1926
 wb_writeback+0x46a/0xbf0 fs/fs-writeback.c:2105
 wb_do_writeback fs/fs-writeback.c:2252 [inline]
 wb_workfn+0x400/0xe60 fs/fs-writeback.c:2292
 process_one_work kernel/workqueue.c:2653 [inline]
 process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730
 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:hfs_write_inode+0x87a/0x880 fs/hfs/inode.c:449
Code: c7 c1 00 73 31 97 80 e1 07 80 c1 03 38 c1 0f 8c 73 fe ff ff 48 c7 c7 00 73 31 97 e8 f0 f2 83 ff e9 62 fe ff ff e8 e6 b2 2b ff <0f> 0b 0f 1f 40 00 f3 0f 1e fa 55 41 57 41 56 41 54 53 48 89 fb 49
RSP: 0018:ffffc9000490f340 EFLAGS: 00010293
RAX: ffffffff825b78aa RBX: ffff88802d728ea8 RCX: ffff888023f81e00
RDX: 0000000000000000 RSI: ffffffff8d33a040 RDI: 0000000000000000
RBP: ffffc9000490f4d0 R08: ffff888023f81e00 R09: 0000000000000003
R10: 0000000000000004 R11: 0000000000000000 R12: dffffc0000000000
R13: 1ffff92000921e6c R14: ffff88802d728e58 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055557e130a38 CR3: 00000000309a8000 CR4: 00000000003506e0

Crashes (12868):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/06/16 05:12 linux-6.6.y 924b4a879cbb 50bb0618 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/03/07 12:28 linux-6.6.y 4fc00fe35d46 5cb44a80 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2025/11/27 07:12 linux-6.6.y 1e89a1be4fe9 d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2025/09/26 09:13 linux-6.6.y 147338df3487 0abd0691 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2025/06/17 18:56 linux-6.6.y c2603c511feb cfebc887 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/07 21:22 linux-6.6.y 6436c12a2ced e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/07 18:01 linux-6.6.y 6436c12a2ced e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/07 16:34 linux-6.6.y 6436c12a2ced e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/07 13:58 linux-6.6.y 6436c12a2ced e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/07 13:55 linux-6.6.y 6436c12a2ced e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/07 12:36 linux-6.6.y 6436c12a2ced e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/07 11:01 linux-6.6.y 6436c12a2ced e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/07 11:00 linux-6.6.y 6436c12a2ced e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/07 08:59 linux-6.6.y 6436c12a2ced c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/07 03:59 linux-6.6.y 80dfb0405055 c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/07 03:51 linux-6.6.y 80dfb0405055 c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/06 21:42 linux-6.6.y 80dfb0405055 c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/06 21:10 linux-6.6.y 80dfb0405055 c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/06 19:27 linux-6.6.y 80dfb0405055 c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/06 17:52 linux-6.6.y aa0e49877a2e c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/06 17:00 linux-6.6.y aa0e49877a2e c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/06 15:27 linux-6.6.y aa0e49877a2e c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/06 00:22 linux-6.6.y aa0e49877a2e cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/05 22:22 linux-6.6.y aa0e49877a2e cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/05 22:22 linux-6.6.y aa0e49877a2e cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/05 21:21 linux-6.6.y aa0e49877a2e cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/05 20:06 linux-6.6.y aa0e49877a2e cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/05 13:19 linux-6.6.y aa0e49877a2e 52aa2820 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/05 13:06 linux-6.6.y aa0e49877a2e 52aa2820 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/05 06:10 linux-6.6.y aa0e49877a2e 52aa2820 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/05 05:13 linux-6.6.y aa0e49877a2e 52aa2820 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/05 03:46 linux-6.6.y aa0e49877a2e 52aa2820 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/04 18:47 linux-6.6.y aa0e49877a2e d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/04 15:53 linux-6.6.y aa0e49877a2e d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/04 14:22 linux-6.6.y aa0e49877a2e d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/04 09:28 linux-6.6.y aa0e49877a2e 9451e17e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/04 07:20 linux-6.6.y aa0e49877a2e 9451e17e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/04 04:33 linux-6.6.y aa0e49877a2e 9451e17e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/04 01:16 linux-6.6.y aa0e49877a2e 9451e17e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/04 00:00 linux-6.6.y aa0e49877a2e 9451e17e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/03 19:51 linux-6.6.y aa0e49877a2e 6b7c9f71 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/03 18:00 linux-6.6.y aa0e49877a2e 6b7c9f71 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/03 12:57 linux-6.6.y aa0e49877a2e 6b7c9f71 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/03 12:57 linux-6.6.y aa0e49877a2e 6b7c9f71 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/03 11:21 linux-6.6.y aa0e49877a2e 6b7c9f71 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/03 01:58 linux-6.6.y a1153c0deb44 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/02 10:03 linux-6.6.y a1153c0deb44 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/02 02:20 linux-6.6.y a1153c0deb44 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/02 01:47 linux-6.6.y a1153c0deb44 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2026/08/02 01:44 linux-6.6.y a1153c0deb44 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
2025/06/16 18:04 linux-6.6.y c2603c511feb d1716036 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in hfs_write_inode
* Struck through repros no longer work on HEAD.