From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-il1-f197.google.com (mail-il1-f197.google.com [209.85.166.197]) (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 244721E1DE9 for ; Mon, 1 Sep 2025 02:46:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.197 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756694765; cv=none; b=PYnjOOjzXlUlgEJTQ4WkgO56kLQ7OphfDwPT74I+YEp4BP0FxIvCfhORL7/6gLTkV6WS46GZAIYMaNs/wn3/ncvEbaNtQ14lY/8hAFyBRKfqkplI0fHm834VxAyYNC93NvPfv7abVe73w6k/svxhCrH9FcRDQrkz4bCboxQ1L5E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756694765; c=relaxed/simple; bh=InOIVVRqnM9v+OYFcO1yDIMQZ0Y4RuZMKc/QTUPbRK4=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=MN7UF4HwOl/biQFNN4A770Z5loDudkgBomlz5UhSDYcYyCUg0IhOoaUXQ0x4oQvXzVBAN/sJo59GRSGeoGb2rALYL+MVaD0RD30z4yWertSODeeJYf38fPis8EyAM5Nsy1L3Wz2yDbGa52pyw0W/JsRQY0q6G7fLHYO6W0sQXAk= 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=209.85.166.197 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-il1-f197.google.com with SMTP id e9e14a558f8ab-3f34562d2c6so27398445ab.0 for ; Sun, 31 Aug 2025 19:46:03 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1756694763; x=1757299563; 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=lfSqYf+3jtEOmaPgsllTgzT86MLg0ZfN5QrYeS5Wzrs=; b=AY4UQgyQJ+thcnvPDI7XLsPY1RuBRnc7oBkECrX979DpljPWhdUrgJyFH3Vjk0HUpn 3xK5k1ic9ECxOxRM2dX1HXoXRUoO2OAS5BnTyu72tZVbL+VIFgvv8Mo5H4ks4dS22PHg ULI1ghx45bcE1VQS4cZSv9kphiBPFT0vyDc5cHR5zqFldWs5zwRbKgF/dTDswjseHw3v sQui9vZdfOyqYl8uQ+Rn8Rlig24tJZyphFYYYSLM9h6ap/IDSL2rgyNaVjUrYtCnLgpa glEBW1iWK0fpgwWczqXdyfHwwzzk0yLeBii+WT0XRgIgaVNx29ZP6eW7eRXdIMIck2Ot /EjQ== X-Forwarded-Encrypted: i=1; AJvYcCUpQ03TrwV7SlwrT+j6PDJ050rgZthYkxrl3rGwDNKzRs8qkDBmArjVI8qLjH2FWdbZj5yeN6bWRJo+6SI=@vger.kernel.org X-Gm-Message-State: AOJu0Ywzo8f6azn9JN01cV2B3AGih1MYP+MJ+hFXa3UHBlJ29MwRB8zf UL3WAs53DRuWMEDC1MuE6yD9bC9D+f7j11o6tQjgKAmbnAdc3lAkWt/xmr92Q7j34Dz5/Tropyr KFD13mpOjPy+IlRgwiGcyvh1LrKAeEjXvmjy8OaTckRIRwbllpsRF22cYYTU= X-Google-Smtp-Source: AGHT+IH3RQ73iZcPiGNtMYDxz4bp0E6wiu3gHdYfrTHdYcO9nuVFR/bwbeO2y70AOtJ7MaskPrcmmkvdtZT4AUYJPPx80tslprXj Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6e02:1a03:b0:3f1:700a:3f78 with SMTP id e9e14a558f8ab-3f401ed81e4mr151221905ab.10.1756694763187; Sun, 31 Aug 2025 19:46:03 -0700 (PDT) Date: Sun, 31 Aug 2025 19:46:03 -0700 In-Reply-To: <20250901013758.6300-1-hdanton@sina.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <68b508eb.a70a0220.1c57d1.04d4.GAE@google.com> Subject: Re: [syzbot] [net] [virt] INFO: task hung in __vhost_worker_flush From: syzbot To: hdanton@sina.com, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot has tested the proposed patch but the reproducer is still triggering an issue: INFO: task hung in __vhost_worker_flush INFO: task syz.0.17:6484 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.17 state:D stack:27928 pid:6484 tgid:6484 ppid:6375 task_flags:0x400040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common+0x2fc/0x4e0 kernel/sched/completion.c:121 __vhost_worker_flush+0x1a8/0x1d0 drivers/vhost/vhost.c:296 vhost_worker_flush drivers/vhost/vhost.c:303 [inline] vhost_dev_flush+0xac/0x110 drivers/vhost/vhost.c:313 vhost_vsock_flush drivers/vhost/vsock.c:698 [inline] vhost_vsock_dev_release+0x19f/0x400 drivers/vhost/vsock.c:750 __fput+0x3ff/0xb70 fs/file_table.c:468 task_work_run+0x14d/0x240 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xeb/0x110 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x3f6/0x4c0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4ae478ebe9 RSP: 002b:00007ffe922fd5f8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f4ae49c7da0 RCX: 00007f4ae478ebe9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f4ae49c7da0 R08: 0000000000000000 R09: 00000008922fd8ef R10: 00007f4ae49c7cb0 R11: 0000000000000246 R12: 000000000001e366 R13: 00007ffe922fd6f0 R14: ffffffffffffffff R15: 00007ffe922fd710 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e5c1260 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e5c1260 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e5c1260 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:2/36: 1 lock held by klogd/5209: #0: ffff8880b853a318 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:636 2 locks held by getty/5608: #0: ffff88814df690a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900036bb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline] watchdog+0xf0e/0x1260 kernel/hung_task.c:491 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5911 Comm: kworker/0:5 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: 0x0 (wg-crypt-wg0) RIP: 0010:schedule_debug kernel/sched/core.c:5917 [inline] RIP: 0010:__schedule+0x1b2/0x5de0 kernel/sched/core.c:6838 Code: 80 3c 02 00 0f 85 1f 53 00 00 48 8b 85 10 ff ff ff 4c 8b 68 20 48 b8 00 00 00 00 00 fc ff df 4c 89 ea 48 c1 ea 03 80 3c 02 00 <0f> 85 ec 52 00 00 49 81 7d 00 9d 6e ac 57 0f 85 24 53 00 00 48 8b RSP: 0018:ffffc900041efbc8 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff8b94c176 RDX: 1ffff9200083d000 RSI: ffffffff8c162980 RDI: ffff88802740c8a0 RBP: ffffc900041efd80 R08: 0000000000000000 R09: fffffbfff2156a52 R10: ffffffff90ab5297 R11: 0000000000000000 R12: 0000000000000000 R13: ffffc900041e8000 R14: ffff8880b843a300 R15: ffff888033d59840 FS: 0000000000000000(0000) GS:ffff8881246b8000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005555588e15c8 CR3: 000000000e380000 CR4: 00000000003526f0 Call Trace: __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 worker_thread+0x2e5/0xf10 kernel/workqueue.c:3415 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Tested on: commit: b320789d Linux 6.17-rc4 git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=16446242580000 kernel config: https://syzkaller.appspot.com/x/.config?x=d4703ac89d9e185a dashboard link: https://syzkaller.appspot.com/bug?extid=7f3bbe59e8dd2328a990 compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 patch: https://syzkaller.appspot.com/x/patch.diff?x=127a4662580000