Dear developers and maintainers,

We encountered a kernel warning with our modified Syzkaller. It is
tested on kernel 6.8.0-rc7. C repro and kernel config are attached to
this email. Bug report is listed below.

```
ODEBUG: init active (active state 0) object: ffff888063a28000 object
type: timer_list hint: mce_timer_fn+0x0/0x240
arch/x86/kernel/cpu/mce/core.c:2642
WARNING: CPU: 0 PID: 8120 at lib/debugobjects.c:514
debug_print_object+0x1a0/0x2a0 lib/debugobjects.c:514
Modules linked in:
CPU: 0 PID: 8120 Comm: syz-executor447 Not tainted 6.7.0-rc7 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
RIP: 0010:debug_print_object+0x1a0/0x2a0 lib/debugobjects.c:514
Code: fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 75 4c 48 8b 14 dd a0
aa 10 8b 41 56 4c 89 e6 48 c7 c7 a0 9d 10 8b e8 81 32 ef fc 90 <0f> 0b
90 90 58 83 05 28 9a bd 0a 01 48 83 c4 18 5b 5d 41 5c 41 5d
RSP: 0018:ffffc90002aef9a0 EFLAGS: 00010082
RAX: 0000000000000000 RBX: 0000000000000003 RCX: ffffffff814c00fa
RDX: ffff888108431940 RSI: ffffffff814c0107 RDI: 0000000000000001
RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: ffffffff8b10a380
R13: ffffffff8aaf6240 R14: ffffffff81334bf0 R15: ffff88801305ada8
FS:  000055555673c3c0(0000) GS:ffff888063a00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000080 CR3: 000000010635d000 CR4: 0000000000750ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
 <TASK>
 __debug_object_init+0x1cb/0x2a0 lib/debugobjects.c:651
 debug_timer_init kernel/time/timer.c:777 [inline]
 debug_init kernel/time/timer.c:825 [inline]
 init_timer_key+0x31/0x1e0 kernel/time/timer.c:869
 __mcheck_cpu_init_timer+0x70/0xf0 arch/x86/kernel/cpu/mce/core.c:2074
 mce_cpu_restart arch/x86/kernel/cpu/mce/core.c:2373 [inline]
 mce_cpu_restart+0x96/0xb0 arch/x86/kernel/cpu/mce/core.c:2367
 csd_do_func kernel/smp.c:133 [inline]
 smp_call_function_many_cond+0x121f/0x1570 kernel/smp.c:846
 on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1023
 on_each_cpu include/linux/smp.h:71 [inline]
 mce_restart arch/x86/kernel/cpu/mce/core.c:2380 [inline]
 set_bank+0x22a/0x370 arch/x86/kernel/cpu/mce/core.c:2450
 dev_attr_store+0x54/0x80 drivers/base/core.c:2366
 sysfs_kf_write+0x114/0x170 fs/sysfs/file.c:136
 kernfs_fop_write_iter+0x337/0x500 fs/kernfs/file.c:334
 call_write_iter include/linux/fs.h:2020 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x96a/0xd80 fs/read_write.c:584
 ksys_write+0x122/0x250 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x40/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7f2d0b70277d
Code: c3 e8 a7 1f 00 00 0f 1f 80 00 00 00 00 f3 0f 1e fa 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe0266ce18 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000000000000003e RCX: 00007f2d0b70277d
RDX: 0000000000000002 RSI: 00000000200000c0 RDI: 0000000000000003
RBP: 00000000000f4240 R08: 00007f2d0b757b75 R09: 00007f2d0b757b75
R10: 00007f2d0b757b75 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffe0266d078 R14: 00007ffe0266ce40 R15: 00007ffe0266ce30
 </TASK>
```

It seems that when restarting MCE the timer has been initialized
already. If you have any questions, please contact us.

Reported by: Yue Sun <samsun1006219@gmail.com>
Reported by: xingwei lee <xrivendell7@gmail.com>

Best Regards,
Yue