[v6.6] kernel BUG in __ocfs2_flush_truncate_log

1 view
Skip to first unread message

syzbot

unread,
Jul 7, 2025, 2:01:25 AM7/7/25
to syzkaller...@googlegroups.com
Hello,

syzbot found the following issue on:

HEAD commit: a5df3a702b2c Linux 6.6.96
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=16b4cbd4580000
kernel config: https://syzkaller.appspot.com/x/.config?x=2632deddafa957e8
dashboard link: https://syzkaller.appspot.com/bug?extid=435ebc74366bec560db2
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/9ba5b19f9f4d/disk-a5df3a70.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/2cd779015729/vmlinux-a5df3a70.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b56fc39e5cb8/bzImage-a5df3a70.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+435ebc...@syzkaller.appspotmail.com

------------[ cut here ]------------
kernel BUG at fs/ocfs2/alloc.c:6012!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 15421 Comm: syz.5.2200 Not tainted 6.6.96-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:__ocfs2_flush_truncate_log+0xf7e/0x10b0 fs/ocfs2/alloc.c:6012
Code: ff 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c 28 fc ff ff 48 89 df e8 e3 d9 93 fe e9 1b fc ff ff e8 79 2a 3b fe 0f 0b e8 72 2a 3b fe <0f> 0b f3 0f 1e fa 65 44 8b 35 10 4e b9 7c bf 07 00 00 00 44 89 f6
RSP: 0018:ffffc90004acfb20 EFLAGS: 00010283
RAX: ffffffff834a6bee RBX: ffff88807e4cc000 RCX: 0000000000080000
RDX: ffffc9000d9ee000 RSI: 000000000000f044 RDI: 000000000000f045
RBP: ffffc90004acfd38 R08: ffffc90004acfaa7 R09: 1ffff92000959f54
R10: dffffc0000000000 R11: fffff52000959f55 R12: 00000000ffffffff
R13: ffff88805ed86c38 R14: ffff888058851a00 R15: ffff888028e66000
FS: 00007f37d48c66c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b33c0dff8 CR3: 000000002f539000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
ocfs2_flush_truncate_log+0x4f/0x60 fs/ocfs2/alloc.c:6077
ocfs2_sync_fs+0x117/0x310 fs/ocfs2/super.c:402
iterate_supers+0xb2/0x170 fs/super.c:979
ksys_sync+0xb3/0x150 fs/sync.c:104
__ia32_sys_sync+0xe/0x20 fs/sync.c:113
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: 0033:0x7f37d398e929
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:00007f37d48c6038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f37d3bb6080 RCX: 00007f37d398e929
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f37d3bb6080 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f37d3bb6080 R15: 00007ffd8ab62b08
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__ocfs2_flush_truncate_log+0xf7e/0x10b0 fs/ocfs2/alloc.c:6012
Code: ff 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c 28 fc ff ff 48 89 df e8 e3 d9 93 fe e9 1b fc ff ff e8 79 2a 3b fe 0f 0b e8 72 2a 3b fe <0f> 0b f3 0f 1e fa 65 44 8b 35 10 4e b9 7c bf 07 00 00 00 44 89 f6
RSP: 0018:ffffc90004acfb20 EFLAGS: 00010283
RAX: ffffffff834a6bee RBX: ffff88807e4cc000 RCX: 0000000000080000
RDX: ffffc9000d9ee000 RSI: 000000000000f044 RDI: 000000000000f045
RBP: ffffc90004acfd38 R08: ffffc90004acfaa7 R09: 1ffff92000959f54
R10: dffffc0000000000 R11: fffff52000959f55 R12: 00000000ffffffff
R13: ffff88805ed86c38 R14: ffff888058851a00 R15: ffff888028e66000
FS: 00007f37d48c66c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055c797356950 CR3: 000000002f539000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

syzbot

unread,
Dec 18, 2025, 7:38:30 PM12/18/25
to syzkaller...@googlegroups.com
syzbot has found a reproducer for the following issue on:

HEAD commit: 5fa4793a2d2d Linux 6.6.119
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=14ee4d58580000
kernel config: https://syzkaller.appspot.com/x/.config?x=691a6769a86ac817
dashboard link: https://syzkaller.appspot.com/bug?extid=435ebc74366bec560db2
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14a5dd92580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1173577c580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/63699875f1dd/disk-5fa4793a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/8506652fcb6f/vmlinux-5fa4793a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/1b30ceed1710/bzImage-5fa4793a.xz
mounted in repro #1: https://storage.googleapis.com/syzbot-assets/67e2fe9498a3/mount_0.gz
fsck result: OK (log: https://syzkaller.appspot.com/x/fsck.log?x=1673577c580000)
mounted in repro #2: https://storage.googleapis.com/syzbot-assets/7f90432f010e/mount_5.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+435ebc...@syzkaller.appspotmail.com

------------[ cut here ]------------
kernel BUG at fs/ocfs2/alloc.c:6012!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 5874 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__ocfs2_flush_truncate_log+0xf7e/0x10b0 fs/ocfs2/alloc.c:6012
Code: ff 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c 28 fc ff ff 48 89 df e8 d3 36 93 fe e9 1b fc ff ff e8 59 c8 3b fe 0f 0b e8 52 c8 3b fe <0f> 0b f3 0f 1e fa 65 44 8b 35 50 ed b9 7c bf 07 00 00 00 44 89 f6
RSP: 0018:ffffc900032379c0 EFLAGS: 00010293
RAX: ffffffff8349c86e RBX: ffff88807cddc000 RCX: ffff88802b2eda00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90003237bd8 R08: ffffc90003237947 R09: 1ffff92000646f28
R10: dffffc0000000000 R11: fffff52000646f29 R12: 0000000000000001
R13: ffff88805e95b338 R14: ffff88807cb87a00 R15: ffff88805e784c00
FS: 000055558a967500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffce4644f78 CR3: 0000000078faa000 CR4: 00000000003506e0
Call Trace:
<TASK>
ocfs2_flush_truncate_log+0x4f/0x60 fs/ocfs2/alloc.c:6077
ocfs2_sync_fs+0x117/0x310 fs/ocfs2/super.c:402
sync_filesystem+0x1c2/0x220 fs/sync.c:66
generic_shutdown_super+0x6f/0x2b0 fs/super.c:666
kill_block_super+0x44/0x90 fs/super.c:1660
deactivate_locked_super+0x97/0x100 fs/super.c:481
cleanup_mnt+0x429/0x4c0 fs/namespace.c:1259
task_work_run+0x1ce/0x250 kernel/task_work.c:239
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+0xf6/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f2167590a77
Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 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 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffc4f5f76a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f2167613d7d RCX: 00007f2167590a77
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc4f5f7760
RBP: 00007ffc4f5f7760 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffc4f5f87f0
R13: 00007f2167613d7d R14: 0000000000013ff6 R15: 00007ffc4f5f8830
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__ocfs2_flush_truncate_log+0xf7e/0x10b0 fs/ocfs2/alloc.c:6012
Code: ff 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c 28 fc ff ff 48 89 df e8 d3 36 93 fe e9 1b fc ff ff e8 59 c8 3b fe 0f 0b e8 52 c8 3b fe <0f> 0b f3 0f 1e fa 65 44 8b 35 50 ed b9 7c bf 07 00 00 00 44 89 f6
RSP: 0018:ffffc900032379c0 EFLAGS: 00010293
RAX: ffffffff8349c86e RBX: ffff88807cddc000 RCX: ffff88802b2eda00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90003237bd8 R08: ffffc90003237947 R09: 1ffff92000646f28
R10: dffffc0000000000 R11: fffff52000646f29 R12: 0000000000000001
R13: ffff88805e95b338 R14: ffff88807cb87a00 R15: ffff88805e784c00
FS: 000055558a967500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffce4644f78 CR3: 0000000078faa000 CR4: 00000000003506e0


---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
Reply all
Reply to author
Forward
0 new messages