From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oi1-f199.google.com (mail-oi1-f199.google.com [209.85.167.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 599893ED126 for ; Mon, 9 Mar 2026 17:57:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773079050; cv=none; b=tuilA1N71D2xBY/8Q4Yk8wUxH0Iwsb5/bLVuBkkdFYCxoiY3xGM7t00jhVKOdXPjeU8LDXRt1RA2Dq5+q2sNutSLKQkn7T3vpPQ04s6wz5T0pkLH+XBvL0ZfL5uqxjpm74Yml+eTmVCcpYh69qW8O48+MD+NvHVvz7OvACpf5Ug= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773079050; c=relaxed/simple; bh=fPyM8h+MWFzygmYwSmvI3rHWVDC32mlTJ+BU/NILccA=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=ISopYWOPDEIytOGhv7lDouzoQ0XspUgu3GSlFI8t8ieu6E+dI+wjud/yHH8FyR66Jf8sV/4nLuYaXbH44e+oDs5SrDidMRdUYb/DEDVsTx5v3xdZWVbhzyYtGVlugKxp8YG1bRZJhIK1czZEOj1JOlXYNvCsafABZrfl7pN5U+s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=209.85.167.199 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-oi1-f199.google.com with SMTP id 5614622812f47-466f705757bso7017351b6e.0 for ; Mon, 09 Mar 2026 10:57:26 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1773079045; x=1773683845; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=x5s79HsBAIIP/xnlkAUkUdpOkkY4Mxmchhv5/mpF0TA=; b=b2q8dNOSPB1NHlQ2YYjBYYa4YMfvC7KUD8ayRchnt9IAefxzb+8Nlj0ymh0Tt54EwN nhp7g4CbhmPtH6rMZZAyqGL5WUkD/lgrkXc+Y75WL7x9JpUZOZxqcLzXfdMDC1ZQPZBP 1svejf1Er0Os1F3YB5VQTTzrrs3doBJmXM/p4EqDpfUklaGhb1ftvVN4aUL8OYSVOkKp tG7zVxatwWBhvXyRiE+OMvfqsOYiLwCKnN6OqDzkCb9C8VQknx/lQNqo1ZAb2RJZhrmk J92bfugIed3z8szW8mYUA+zwlVtlvcJ5bfcM3EENYg3QNgMaognXkFJuutRJ8BBfHD6Z eMnA== X-Gm-Message-State: AOJu0YwXqpQ8RHsx6kiLo/WNVMpVQjacNHISMnC1QcygC3F35NCBo6qm LmNyBZEKKocRzDgvhMcz+ZFvGyshwjV1iHh4fEPFazPGUt3AIuwghOv8HS3m59rHNdweQEHG+BJ N8+alODmF696ZEMHw3ZNahzk94MrjqEpUNAsiHP+cG4nys5SRQ4DhaQF6ZNo= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:620:b0:67b:a971:fc88 with SMTP id 006d021491bc7-67ba9720025mr4285164eaf.40.1773079045187; Mon, 09 Mar 2026 10:57:25 -0700 (PDT) Date: Mon, 09 Mar 2026 10:57:25 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <69af0a05.050a0220.310d8.002f.GAE@google.com> Subject: [syzbot] [kernel?] WARNING in _cpu_down From: syzbot To: linux-kernel@vger.kernel.org, peterz@infradead.org, syzkaller-bugs@googlegroups.com, tglx@kernel.org Content-Type: text/plain; charset="UTF-8" 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+123e1b70473ce213f3af@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: 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 ---------------- 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 --- 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 syzkaller@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