From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp153-165.sina.com.cn (smtp153-165.sina.com.cn [61.135.153.165]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4181A38DF9 for ; Sun, 31 Aug 2025 07:35:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=61.135.153.165 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756625728; cv=none; b=ATSWirWKVsTmacbqw4Qlp9HI/FzTks018X5/u3xhiygJ5y3sbZZ2zhzT3y7P8LdXCAPh0ckUtp35xVk+j4W3N9YcMNpwUdGJJ3rnOtHdGyMcwftJsJOTz7hj2JMjfamevnDYm/J1q/dA5x2jEIaaeDSWAiyLR/Y4Ff71HjbvmgE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756625728; c=relaxed/simple; bh=54ZcqTxbjRF/GUrSW27XJo4bQ9eFq5N76RS34fN24mw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=cCxk8MvNniADb9N8q4/vvuLKylFd9VSft+TTNs7A68e7Q3XYxsIixKtFDdyUtaBzNmMLkx2xuM1Pz7UTwS5gv4Gnm69xOPh9004bZpc92l5oxAfAUGWfS7bPIvyE4zcucJ+LFMZakmXQIvVYAFBYw0geOg9tSaHFKnnh4sdadf0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sina.com; spf=pass smtp.mailfrom=sina.com; dkim=pass (1024-bit key) header.d=sina.com header.i=@sina.com header.b=Xaw+phyO; arc=none smtp.client-ip=61.135.153.165 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sina.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sina.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=sina.com header.i=@sina.com header.b="Xaw+phyO" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sina.com; s=201208; t=1756625719; bh=D3JMiHMJt+hlYzkkSj/A+L6/r3z7BdOAei/uu00rQWI=; h=From:Subject:Date:Message-ID; b=Xaw+phyOIbF2gOliKcxCjO2xFDPPRSqTx/sXzdiZ4ZooyOAfRJVod6PBMNH/Y1xsS YKIaieMbpRbFqyGmWNzXLwl2hVhukldun5n3+wGLl1EQaPfcVY8Fs81O5Mz8In+7UV x3KNIcnnSiua7l9+bA2YI48u67lQ0VW8/vV1m0TU= X-SMAIL-HELO: localhost.localdomain Received: from unknown (HELO localhost.localdomain)([114.249.58.236]) by sina.com (10.54.253.32) with ESMTP id 68B3FB2C00003254; Sun, 31 Aug 2025 15:35:10 +0800 (CST) X-Sender: hdanton@sina.com X-Auth-ID: hdanton@sina.com Authentication-Results: sina.com; spf=none smtp.mailfrom=hdanton@sina.com; dkim=none header.i=none; dmarc=none action=none header.from=hdanton@sina.com X-SMAIL-MID: 1078774456683 X-SMAIL-UIID: 676ECD85FBBD4AEFA660F67C697207E5-20250831-153510-1 From: Hillf Danton To: syzbot Cc: linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Subject: Re: [syzbot] [net] [virt] INFO: task hung in __vhost_worker_flush Date: Sun, 31 Aug 2025 15:34:57 +0800 Message-ID: <20250831073458.6191-1-hdanton@sina.com> In-Reply-To: <68b3b1ac.a70a0220.1c57d1.028b.GAE@google.com> References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit > Date: Sat, 30 Aug 2025 19:21:32 -0700 [thread overview] > syzbot has found a reproducer for the following issue on: > > HEAD commit: 11e7861d680c Merge tag 'for-linus' of git://git.kernel.org.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=17c5c242580000 > 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 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1671ba62580000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1685aa62580000 #syz test --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -440,7 +440,9 @@ static bool vhost_run_work_list(void *da struct vhost_worker *worker = data; struct vhost_work *work, *work_next; struct llist_node *node; + bool did = false; +again: node = llist_del_all(&worker->work_list); if (node) { __set_current_state(TASK_RUNNING); @@ -455,9 +457,11 @@ static bool vhost_run_work_list(void *da kcov_remote_stop(); cond_resched(); } + did = true; + goto again; } - return !!node; + return did; } static void vhost_worker_killed(void *data) --