From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo1-f80.google.com (mail-oo1-f80.google.com [209.85.161.80]) (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 568F8355807 for ; Thu, 15 Jan 2026 09:15:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.161.80 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768468525; cv=none; b=HZc7gmkiJPoaQCaslruJo5shxszPS7zjU4xeNO0awU7D28PnjX5Sl223S4Xx4T5fba1iuRxE8n98SyDXQogo/GJd2IZ81+j/0vz0nvBe2YUiN/drUNjWCifu5T9HY+iHHu+2lEaAiCQT0jtHHRB60CfcMT8f+nBmcB3/vrKmHzs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768468525; c=relaxed/simple; bh=JO3r1AGUSaeclQ1le4igMTyX73HehkmcPf7CrCjlEhM=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=QoHD96j4xdo4603Siv62loEr9UPxcos6atqiLUUaoFcPAbHRX2u18PwfTueO/7WpnDEek9ABb8EByXSCLQFHDKTsLmtl+52v7iX1h0Ht7knXSVyOc8yUhmlo12JtyvvlhA9x1eiVPyxkh5VqCxSMGEV2feTAX48OkKEuZGiUWys= 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=209.85.161.80 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-oo1-f80.google.com with SMTP id 006d021491bc7-661125c8491so607920eaf.3 for ; Thu, 15 Jan 2026 01:15:22 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1768468521; x=1769073321; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=wdcygAQemIWGYaInbBbXcp/6UHNE5yO0hXqCDywHlzg=; b=D+XPFSKTWdu6l3Sj6AwsA3d7OKNy4J2XEKOWUSVdTemgGakgwtTlaQgtEMQrIg1039 5hwMzA6sb1kV+drDEWug3qRTx0ACUEGWRGP7nOAD7wKXjpUjoLF4AJDgCNxVt6EoapE3 gxb7q8nEeBhJIfUPmsuxpY54+rsqCAMbVYIh8yBZDmq3tBsUWuLQKFpAxE+3IIpPuuCj dHk4rN3JulLpSlVePscg/C2Bo1QR7UP0u8VXBuQ7Cn7hBpT43P5FDgb8jhrE+BLncA8k TtF5O+yvVd7PIwWsejVt40+KQp0nTU+ZkXUwh5BX3IsG07qzrOLAsOSBoTIrr0BUpMDT szNg== X-Forwarded-Encrypted: i=1; AJvYcCWMZD/PJX+ij5BzcyLgIGMmQTb2CmV54QkkU335KjS9TN+sHJ/C3S+yEXup4G+z+imTw2LMv0o=@vger.kernel.org X-Gm-Message-State: AOJu0YyfOi1Qb97zR+rYu6bzVgC25oMgn1pv4fNQRZVIaqShwGEJXuct /AzLnGqKWklv9uCBnkp1I+koHO0HBoMpPHmVV2PhCEiV617o7RsXjZ1zsvk5ZC5BrkKhg6B/+XY rkAHljJHc97OjmWFq95jzRk8Af3vD5QL2XXNQhNVDzrc2WMUUs5o24mtAmEQ= Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:2302:b0:65c:fff0:818e with SMTP id 006d021491bc7-6610070654bmr3533105eaf.63.1768468521216; Thu, 15 Jan 2026 01:15:21 -0800 (PST) Date: Thu, 15 Jan 2026 01:15:21 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6968b029.050a0220.58bed.0016.GAE@google.com> Subject: [syzbot] [net?] KCSAN: data-race in l2tp_tunnel_del_work / sk_common_release (7) From: syzbot To: davem@davemloft.net, dsahern@kernel.org, edumazet@google.com, horms@kernel.org, kuba@kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, pabeni@redhat.com, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 3609fa95fb0f Merge tag 'devicetree-fixes-for-6.19-2' of gi.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=17de2e9a580000 kernel config: https://syzkaller.appspot.com/x/.config?x=b319ff1b6a2797ca dashboard link: https://syzkaller.appspot.com/bug?extid=7312e82745f7fa2526db compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/3018b7ea95aa/disk-3609fa95.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/b7f25f6e87af/vmlinux-3609fa95.xz kernel image: https://storage.googleapis.com/syzbot-assets/13d7f9c6c13e/bzImage-3609fa95.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+7312e82745f7fa2526db@syzkaller.appspotmail.com ================================================================== BUG: KCSAN: data-race in l2tp_tunnel_del_work / sk_common_release write to 0xffff88811bce50e0 of 8 bytes by task 10132 on cpu 1: sk_set_socket include/net/sock.h:2092 [inline] sock_orphan include/net/sock.h:2118 [inline] sk_common_release+0xae/0x230 net/core/sock.c:4003 udp_lib_close+0x15/0x20 include/net/udp.h:325 inet_release+0xce/0xf0 net/ipv4/af_inet.c:437 __sock_release net/socket.c:662 [inline] sock_close+0x6b/0x150 net/socket.c:1455 __fput+0x29b/0x650 fs/file_table.c:468 ____fput+0x1c/0x30 fs/file_table.c:496 task_work_run+0x131/0x1a0 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:44 [inline] exit_to_user_mode_loop+0x1fe/0x740 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x1dd/0x2b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffff88811bce50e0 of 8 bytes by task 6117 on cpu 0: l2tp_tunnel_del_work+0x2f/0x1a0 net/l2tp/l2tp_core.c:1418 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0x4ce/0x9d0 kernel/workqueue.c:3340 worker_thread+0x582/0x770 kernel/workqueue.c:3421 kthread+0x489/0x510 kernel/kthread.c:463 ret_from_fork+0x149/0x290 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 value changed: 0xffff88811b477a80 -> 0x0000000000000000 Reported by Kernel Concurrency Sanitizer on: CPU: 0 UID: 0 PID: 6117 Comm: kworker/u8:55 Tainted: G W syzkaller #0 PREEMPT(voluntary) Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: l2tp l2tp_tunnel_del_work ================================================================== --- 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