From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,T_DKIMWL_WL_HIGH,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 51C04C28EBD for ; Sun, 9 Jun 2019 16:57:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 21FCC204EC for ; Sun, 9 Jun 2019 16:57:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560099421; bh=GqXdJZl0PPXUTekBl3dZWFhm5s94SxROeP9DIvEdgYc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=vd9meZgWFkuK2AaKGKQSeVX4M8rZUSZffEbkutSOFRFIlbTSDfeVcm3mibbB/u+jM SApY3RowKWhj6tPaPBistfROdh9uumdhgxtyuvH4vvATr/zxvPkciWJlF2rq4/eXWj 0Rtp7Qt04VEi8qJj/3sk8dxB+lugFFPYlfWxDen0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733078AbfFIQ5A (ORCPT ); Sun, 9 Jun 2019 12:57:00 -0400 Received: from mail.kernel.org ([198.145.29.99]:59658 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733065AbfFIQ45 (ORCPT ); Sun, 9 Jun 2019 12:56:57 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 27F4A204EC; Sun, 9 Jun 2019 16:56:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560099416; bh=GqXdJZl0PPXUTekBl3dZWFhm5s94SxROeP9DIvEdgYc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gquK9qEEL724/EmGHCHyn63ErU+vbiF2qeMmLHKDjVsiexi0kwrfuVbxWjcH9GYcN PFgkhxsEKKBKOcisoaFG+Ib2C5e5akyL9g9rCL4caHlY1YGPjAkdEi6dGMpZdE0pGP sC172DWZaBKPwpHRdyS7IC9zE3RJiXMVZYWmNlbc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Dumazet , syzbot , "David S. Miller" Subject: [PATCH 4.4 032/241] net: avoid weird emergency message Date: Sun, 9 Jun 2019 18:39:34 +0200 Message-Id: <20190609164148.706912634@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190609164147.729157653@linuxfoundation.org> References: <20190609164147.729157653@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Eric Dumazet [ Upstream commit d7c04b05c9ca14c55309eb139430283a45c4c25f ] When host is under high stress, it is very possible thread running netdev_wait_allrefs() returns from msleep(250) 10 seconds late. This leads to these messages in the syslog : [...] unregister_netdevice: waiting for syz_tun to become free. Usage count = 0 If the device refcount is zero, the wait is over. Signed-off-by: Eric Dumazet Reported-by: syzbot Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/core/dev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/core/dev.c +++ b/net/core/dev.c @@ -6986,7 +6986,7 @@ static void netdev_wait_allrefs(struct n refcnt = netdev_refcnt_read(dev); - if (time_after(jiffies, warning_time + 10 * HZ)) { + if (refcnt && time_after(jiffies, warning_time + 10 * HZ)) { pr_emerg("unregister_netdevice: waiting for %s to become free. Usage count = %d\n", dev->name, refcnt); warning_time = jiffies;