* [syzbot] [gfs2?] WARNING: kobject bug in __dlm_new_lockspace
@ 2026-08-17 8:57 syzbot
2026-10-17 21:21 ` syzbot
0 siblings, 1 reply; 2+ messages in thread
From: syzbot @ 2026-08-17 8:57 UTC (permalink / raw)
To: aahringo, gfs2, linux-kernel, syzkaller-bugs, teigland
Hello,
syzbot found the following issue on:
HEAD commit: 8d3ae59288f1 Linux 7.2
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=144ed6c6580000
kernel config: https://syzkaller.appspot.com/x/.config?x=4c9eb8e593cf8c5c
dashboard link: https://syzkaller.appspot.com/bug?extid=b2b8d04ec4914f618d23
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/e3213198af93/disk-8d3ae592.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ccb0eb1c86ad/vmlinux-8d3ae592.xz
kernel image: https://storage.googleapis.com/syzbot-assets/8c009fbdf753/bzImage-8d3ae592.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b2b8d04ec4914f618d23@syzkaller.appspotmail.com
dlm: Using TCP for communications
workqueue: Failed to create a rescuer kthread for wq "dlm_callback": -EINTR
dlm: can't start dlm_callback workqueue
dlm: mydomain: can't start dlm_callback -12
------------[ cut here ]------------
kobject: '(null)' (ffff888060a7c0c8): is not initialized, yet kobject_put() is being called.
WARNING: lib/kobject.c:736 at kobject_put+0x66/0x550 lib/kobject.c:734, CPU#1: syz.2.3/5785
Modules linked in:
CPU: 1 UID: 0 PID: 5785 Comm: syz.2.3 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:kobject_put+0x8e/0x550 lib/kobject.c:734
Code: 85 04 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 08 48 89 df e8 2b 7e f3 f6 48 8b 33 4c 89 f7 48 89 da <67> 48 0f b9 3a eb 05 e8 f6 f9 89 f6 4c 8d 73 38 4c 89 f7 be 04 00
RSP: 0018:ffffc90004347810 EFLAGS: 00010246
RAX: 1ffff1100c14f819 RBX: ffff888060a7c0c8 RCX: dffffc0000000000
RDX: ffff888060a7c0c8 RSI: 0000000000000000 RDI: ffffffff8fc1a5a0
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1f5f267 R12: 1ffff1100c14f820
R13: 00000000fffffff4 R14: ffffffff8fc1a5a0 R15: ffff888060a7c000
FS: 00007f3edfd866c0(0000) GS:ffff888125d3a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff044558000 CR3: 000000003c66c000 CR4: 00000000003526f0
Call Trace:
<TASK>
new_lockspace fs/dlm/lockspace.c:617 [inline]
__dlm_new_lockspace+0x19f0/0x2060 fs/dlm/lockspace.c:638
user_cluster_connect+0x231/0xcc0 fs/ocfs2/stack_user.c:976
ocfs2_cluster_connect+0x445/0x720 fs/ocfs2/stackglue.c:355
ocfs2_cluster_connect_agnostic+0x6e/0x90 fs/ocfs2/stackglue.c:385
user_dlm_register+0xd2/0x210 fs/ocfs2/dlmfs/userdlm.c:669
dlmfs_mkdir+0x13c/0x340 fs/ocfs2/dlmfs/dlmfs.c:434
vfs_mkdir+0x402/0x620 fs/namei.c:5276
filename_mkdirat+0x289/0x520 fs/namei.c:5309
__do_sys_mkdir fs/namei.c:5336 [inline]
__se_sys_mkdir+0x34/0x150 fs/namei.c:5333
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: 0033:0x7f3ee1b2e0d9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f3edfd86028 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00007f3ee1db5fa0 RCX: 00007f3ee1b2e0d9
RDX: 0000000000000000 RSI: 00000000000001ff RDI: 00002000000006c0
RBP: 00007f3ee1bc5024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3ee1db6038 R14: 00007f3ee1db5fa0 R15: 00007ffc09922098
</TASK>
----------------
Code disassembly (best guess):
0: 85 04 48 test %eax,(%rax,%rcx,2)
3: 89 d8 mov %ebx,%eax
5: 48 c1 e8 03 shr $0x3,%rax
9: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx
10: fc ff df
13: 80 3c 08 00 cmpb $0x0,(%rax,%rcx,1)
17: 74 08 je 0x21
19: 48 89 df mov %rbx,%rdi
1c: e8 2b 7e f3 f6 call 0xf6f37e4c
21: 48 8b 33 mov (%rbx),%rsi
24: 4c 89 f7 mov %r14,%rdi
27: 48 89 da mov %rbx,%rdx
* 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction
2f: eb 05 jmp 0x36
31: e8 f6 f9 89 f6 call 0xf689fa2c
36: 4c 8d 73 38 lea 0x38(%rbx),%r14
3a: 4c 89 f7 mov %r14,%rdi
3d: be .byte 0xbe
3e: 04 00 add $0x0,%al
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
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^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [syzbot] [gfs2?] WARNING: kobject bug in __dlm_new_lockspace
2026-08-17 8:57 [syzbot] [gfs2?] WARNING: kobject bug in __dlm_new_lockspace syzbot
@ 2026-10-17 21:21 ` syzbot
0 siblings, 0 replies; 2+ messages in thread
From: syzbot @ 2026-10-17 21:21 UTC (permalink / raw)
To: aahringo, gfs2, linux-kernel, syzkaller-bugs, teigland
syzbot has found a reproducer for the following issue on:
HEAD commit: 58161ead29e5 Merge tag 'drm-fixes-2026-10-17' of https://g..
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=121e9495580000
kernel config: https://syzkaller.appspot.com/x/.config?x=c4b098695335c89f
dashboard link: https://syzkaller.appspot.com/bug?extid=b2b8d04ec4914f618d23
compiler: Debian clang version 22.1.8 (1~deb13u4), Debian LLD 22.1.8
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=138e8d99580000
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b2b8d04ec4914f618d23@syzkaller.appspotmail.com
dlm: Using TCP for communications
workqueue: Failed to create a rescuer kthread for wq "dlm_callback": -EINTR
dlm: can't start dlm_callback workqueue
dlm: ls_6035_1: can't start dlm_callback -12
------------[ cut here ]------------
kobject: '(null)' (ffff888027a28088): is not initialized, yet kobject_put() is being called.
WARNING: lib/kobject.c:736 at kobject_put+0x66/0x550 lib/kobject.c:734, CPU#0: syz-executor183/6040
Modules linked in:
CPU: 0 UID: 0 PID: 6040 Comm: syz-executor183 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:kobject_put+0x8e/0x550 lib/kobject.c:734
Code: ae 05 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 08 48 89 df e8 ab 9f 59 f6 48 8b 33 4c 89 f7 48 89 da <67> 48 0f b9 3a eb 05 e8 56 c2 e8 f5 4c 8d 73 38 4c 89 f7 be 04 00
RSP: 0018:ffffc9000307f9f0 EFLAGS: 00010246
RAX: 1ffff11004f45011 RBX: ffff888027a28088 RCX: dffffc0000000000
RDX: ffff888027a28088 RSI: 0000000000000000 RDI: ffffffff918d8000
RBP: 0000000000000000 R08: ffffffff917a747f R09: 1ffffffff22f4e8f
R10: dffffc0000000000 R11: fffffbfff22f4e90 R12: 1ffff11004f45018
R13: ffffffff9bad9988 R14: ffffffff918d8000 R15: 00000000fffffff4
FS: 00005555573c3400(0000) GS:ffff888123abf000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6992404000 CR3: 00000000260fb000 CR4: 0000000000350ef0
Call Trace:
<TASK>
new_lockspace fs/dlm/lockspace.c:617 [inline]
__dlm_new_lockspace+0x1714/0x1cd0 fs/dlm/lockspace.c:638
device_create_lockspace+0xc7/0x350 fs/dlm/user.c:414
device_write+0x872/0xed0 fs/dlm/user.c:606
vfs_write+0x296/0xba0 fs/read_write.c:685
ksys_write+0x150/0x270 fs/read_write.c:739
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f69924444e9
Code: c0 79 93 eb d5 48 8d 7c 1d 00 eb 99 0f 1f 44 00 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 d8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd9a54bda8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f69924444e9
RDX: 0000000000000080 RSI: 00007ffd9a54be80 RDI: 0000000000000003
RBP: 00007ffd9a54be80 R08: 00000000ffffffff R09: 0000000084a559bf
R10: 00007ffd9a54beb8 R11: 0000000000000246 R12: 0000000000000002
R13: 00007ffd9a54bdd0 R14: 0000000000000001 R15: 00007f6992404000
</TASK>
----------------
Code disassembly (best guess):
0: ae scas %es:(%rdi),%al
1: 05 48 89 d8 48 add $0x48d88948,%eax
6: c1 e8 03 shr $0x3,%eax
9: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx
10: fc ff df
13: 80 3c 08 00 cmpb $0x0,(%rax,%rcx,1)
17: 74 08 je 0x21
19: 48 89 df mov %rbx,%rdi
1c: e8 ab 9f 59 f6 call 0xf6599fcc
21: 48 8b 33 mov (%rbx),%rsi
24: 4c 89 f7 mov %r14,%rdi
27: 48 89 da mov %rbx,%rdx
* 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction
2f: eb 05 jmp 0x36
31: e8 56 c2 e8 f5 call 0xf5e8c28c
36: 4c 8d 73 38 lea 0x38(%rbx),%r14
3a: 4c 89 f7 mov %r14,%rdi
3d: be .byte 0xbe
3e: 04 00 add $0x0,%al
---
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.
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2026-10-17 21:21 UTC | newest]
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2026-08-17 8:57 [syzbot] [gfs2?] WARNING: kobject bug in __dlm_new_lockspace syzbot
2026-10-17 21:21 ` syzbot
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