From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oi1-f207.google.com (mail-oi1-f207.google.com [209.85.167.207]) (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 91B012701C4 for ; Mon, 5 Jan 2026 23:13:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.207 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767654807; cv=none; b=faIrHYxi+98OlhSw1gEICf+hfSYDMSHhqG/wBDpAfa6ya9LuF6lggE/AoJfLVWW9qWzbHakyhZBZipQD0hiEv3r+U+rrEBLZqJ/4XYxvf0h0PJCezcraNj2UMQloFPGlaciy7F9Lp00MKXIR6qsuq4xB/WDs1JKfkp5J+T8TL74= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767654807; c=relaxed/simple; bh=6M6Ords2iBMktIWzFvHth89TMT9gBF/9t6DtdXzp3TE=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=LflxiPfJP2bsSK1gU+e4N4uVSFaHx4JSILsE20HyC5+XM9VWO2Xc5StWgI1IQdqdVp6Dyc3omIosKe8IwBKiRmI/vF4qPnYwoV4PuNgS54TthFa3ALWbkbW74vV+Oy44jdx9FswInW6Ry+Ta7HW/hohomyJb4docn2AgwGdNUVg= 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=209.85.167.207 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-f207.google.com with SMTP id 5614622812f47-459c305cd8fso791483b6e.2 for ; Mon, 05 Jan 2026 15:13:25 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1767654804; x=1768259604; h=to:from:subject:message-id:in-reply-to:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=HWq7HAirp8i7+S9f/l8O6fkkjpH0ekGDQYByySXDfOU=; b=FSwXIxT79P8qxPyNCuyNNfq8Kbe/3modeN0iNzOE5+jrL7MHbiExzlr+XSug9CPkzj 7esK/eSRzjQ1xMgJqQYMLBXlAj3JVYOsnBXFE2BGOQaSckFw90chLzCdtq2e3XyfLuxV knj7I7IyrzBi0cZxGAnkBJzsNMNheNOPPdwzrWzg/m7gaYfanbk9rsddTad+nmy6b/4h sDbI5PggM85DkgG+X1pZY8Gr2TTXHTp3645YO5xdxi1QazD4A2AmUYAWlZTAFJ375YDy KdNE2uHYSiaMZ/KqBoyl1q5Aq7GiA8K0WqTpVQ2H8gy3xfp5KnizTMcU7guCkTJns4VX 2RhQ== X-Forwarded-Encrypted: i=1; AJvYcCULrE/lg+7E2h6THONL30cmy1BPXMxnrargZcbcuTqsCUQVS/wGOGUlVPmNYoq5ZXxKviwhWRLEgx/YuUE=@vger.kernel.org X-Gm-Message-State: AOJu0YzsHtu2WQb/lq/0fLqiu1XQsq1NgnhPRNN9XLv6gd8/xTNwJTDL oyOT7afsix2Z/0sSl4/ccgmhyQXIjKLv7ZT7ElXKISZ7ma2ByBRdt8gZuZQWXn4CEdIjW1njUZB QwDHeOAtTyLXo/bVofYTs5Cn0yclisn/sW0HHTLxWfHyqUMFxOX9h0vNQ3do= X-Google-Smtp-Source: AGHT+IHaJZBYo4KstYwCd+SdHH13Y+EoW0OtcEn4HscFu9YplZzTv6kedyHmMDO4GAOzksmhM5x45ghRXDOJbBrOD05YK4c016zS Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:1c91:b0:65b:2a2c:2601 with SMTP id 006d021491bc7-65f47a69f79mr590246eaf.61.1767654804693; Mon, 05 Jan 2026 15:13:24 -0800 (PST) Date: Mon, 05 Jan 2026 15:13:24 -0800 In-Reply-To: <0000000000002ad5ee05e03568f4@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <695c4594.050a0220.318c5c.0133.GAE@google.com> Subject: Re: [syzbot] [net?] INFO: task can't die in vlan_ioctl_handler From: syzbot To: davem@davemloft.net, edumazet@google.com, horms@kernel.org, keescook@chromium.org, kuba@kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, pabeni@redhat.com, syzkaller-bugs@googlegroups.com, william.xuanziyang@huawei.com, zhudi21@huawei.com Content-Type: text/plain; charset="UTF-8" syzbot has found a reproducer for the following issue on: HEAD commit: c303e8b86d9d dt-bindings: net: mscc-miim: add microchip,la.. git tree: net-next console output: https://syzkaller.appspot.com/x/log.txt?x=13a4ae9a580000 kernel config: https://syzkaller.appspot.com/x/.config?x=a94030c847137a18 dashboard link: https://syzkaller.appspot.com/bug?extid=6db61674290152a463a0 compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13795efc580000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/fab8b6d30f06/disk-c303e8b8.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/362169306abb/vmlinux-c303e8b8.xz kernel image: https://storage.googleapis.com/syzbot-assets/fd793d32e1aa/bzImage-c303e8b8.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+6db61674290152a463a0@syzkaller.appspotmail.com INFO: task dhcpcd:5493 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:dhcpcd state:D stack:25208 pid:5493 tgid:5493 ppid:1 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776 vlan_ioctl_handler+0xd0/0x650 net/8021q/vlan.c:579 sock_ioctl+0x610/0x790 net/socket.c:1339 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fcf8811e378 RSP: 002b:00007ffdc6aa60d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00005605e1c82ba0 RCX: 00007fcf8811e378 RDX: 00007ffdc6aa60e0 RSI: 0000000000008982 RDI: 000000000000000f RBP: 00007ffdc6aa60e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00005605e1ddbd40 R14: 00007ffdc6aa6b30 R15: 00005605e1c82ba0 INFO: task kworker/u8:16:6446 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:16 state:D stack:25336 pid:6446 tgid:6446 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: ipv6_addrconf addrconf_dad_work Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776 rtnl_net_lock include/linux/rtnetlink.h:130 [inline] addrconf_dad_work+0x112/0x14b0 net/ipv6/addrconf.c:4194 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 INFO: task syz-executor:6457 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:22392 pid:6457 tgid:6457 ppid:1 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776 new_device_store+0x12c/0x6f0 drivers/net/netdevsim/bus.c:184 --- 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.