[syzbot] [kernel?] WARNING in _cpu_down

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 4ae12d8bd9a8 Merge tag 'kbuild-fixes-7.0-2' of git://git.k..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=177cca02580000
kernel config: https://syzkaller.appspot.com/x/.config?x=163cf0fb07ea84d3
dashboard link: https://syzkaller.appspot.com/bug?extid=123e1b70473ce213f3af
compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/5ef14578e4fb/disk-4ae12d8b.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/7d3000c5cbb9/vmlinux-4ae12d8b.xz
kernel image: https://storage.googleapis.com/syzbot-assets/6106927c4009/bzImage-4ae12d8b.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+123e1b...@syzkaller.appspotmail.com

smpboot: CPU 1 is now offline
smpboot: Booting Node 0 Processor 1 APIC 0x1
------------[ cut here ]------------
DEAD callback error for CPU1
WARNING: kernel/cpu.c:1463 at _cpu_down+0x759/0x1020 kernel/cpu.c:1463, CPU#0: syz.0.1960/14614
Modules linked in:
CPU: 0 UID: 0 PID: 14614 Comm: syz.0.1960 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:_cpu_down+0x75c/0x1020 kernel/cpu.c:1463
Code: c5 7a f6 89 ee bf 91 00 00 00 e8 1f c0 7a f6 81 fd 91 00 00 00 0f 84 6b 02 00 00 e8 5e c5 7a f6 48 8d 3d 67 73 4f 05 44 89 ee <67> 48 0f b9 3a e9 3a fa ff ff 45 31 ff e9 32 fa ff ff e8 3d c5 7a
RSP: 0018:ffffc900048f7aa8 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff8880b85242e0 RCX: ffffffff8b8d4a31
RDX: ffff88802e158000 RSI: 0000000000000001 RDI: ffffffff90dcbdb0
RBP: 0000000000000092 R08: 0000000000000005 R09: 0000000000000091
R10: 0000000000000092 R11: 0000000000000001 R12: 00000000000000ed
R13: 0000000000000001 R14: 0000000000000001 R15: 00000000fffffff5
FS: 00007f0d3e4e06c0(0000) GS:ffff88812434b000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000001b19000 CR3: 0000000059358000 CR4: 00000000003526f0
Call Trace:
<TASK>
cpu_down_maps_locked kernel/cpu.c:1483 [inline]
cpu_down kernel/cpu.c:1491 [inline]
cpu_device_down+0x82/0xc0 kernel/cpu.c:1508
device_offline drivers/base/core.c:4196 [inline]
device_offline+0x2a7/0x3c0 drivers/base/core.c:4180
online_store+0xd1/0x180 drivers/base/core.c:2809
dev_attr_store+0x58/0x80 drivers/base/core.c:2437
sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:142
kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:352
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x6ac/0x1070 fs/read_write.c:688
ksys_write+0x12a/0x250 fs/read_write.c:740
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0d3d59c799
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:00007f0d3e4e0028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f0d3d816180 RCX: 00007f0d3d59c799
RDX: 000000000000000b RSI: 00002000000002c0 RDI: 0000000000000003
RBP: 00007f0d3d632bd9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0d3d816218 R14: 00007f0d3d816180 R15: 00007ffd5aeaf7e8
</TASK>
----------------
Code disassembly (best guess), 1 bytes skipped:
0: 7a f6 jp 0xfffffff8
2: 89 ee mov %ebp,%esi
4: bf 91 00 00 00 mov $0x91,%edi
9: e8 1f c0 7a f6 call 0xf67ac02d
e: 81 fd 91 00 00 00 cmp $0x91,%ebp
14: 0f 84 6b 02 00 00 je 0x285
1a: e8 5e c5 7a f6 call 0xf67ac57d
1f: 48 8d 3d 67 73 4f 05 lea 0x54f7367(%rip),%rdi # 0x54f738d
26: 44 89 ee mov %r13d,%esi
* 29: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction
2e: e9 3a fa ff ff jmp 0xfffffa6d
33: 45 31 ff xor %r15d,%r15d
36: e9 32 fa ff ff jmp 0xfffffa6d
3b: e8 .byte 0xe8
3c: 3d .byte 0x3d
3d: c5 .byte 0xc5
3e: 7a .byte 0x7a


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