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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 1A01AC32751 for ; Sat, 10 Aug 2019 20:54:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E1DAD20B7C for ; Sat, 10 Aug 2019 20:54:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727882AbfHJUyp (ORCPT ); Sat, 10 Aug 2019 16:54:45 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:53794 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726477AbfHJUns (ORCPT ); Sat, 10 Aug 2019 16:43:48 -0400 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1hwYDK-00053h-4F; Sat, 10 Aug 2019 21:43:46 +0100 Received: from ben by deadeye with local (Exim 4.92) (envelope-from ) id 1hwYDJ-0003Zl-9Z; Sat, 10 Aug 2019 21:43:45 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Hulk Robot" , "YueHaibing" , "David S. Miller" Date: Sat, 10 Aug 2019 21:40:07 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 029/157] net-sysfs: call dev_hold if kobject_init_and_add success In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.72-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: YueHaibing commit a3e23f719f5c4a38ffb3d30c8d7632a4ed8ccd9e upstream. In netdev_queue_add_kobject and rx_queue_add_kobject, if sysfs_create_group failed, kobject_put will call netdev_queue_release to decrease dev refcont, however dev_hold has not be called. So we will see this while unregistering dev: unregister_netdevice: waiting for bcsh0 to become free. Usage count = -1 Reported-by: Hulk Robot Fixes: d0d668371679 ("net: don't decrement kobj reference count on init failure") Signed-off-by: YueHaibing Signed-off-by: David S. Miller [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings --- net/core/net-sysfs.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -788,6 +788,8 @@ static int rx_queue_add_kobject(struct n if (error) return error; + dev_hold(queue->dev); + if (net->sysfs_rx_queue_group) { error = sysfs_create_group(kobj, net->sysfs_rx_queue_group); if (error) { @@ -797,7 +799,6 @@ static int rx_queue_add_kobject(struct n } kobject_uevent(kobj, KOBJ_ADD); - dev_hold(queue->dev); return error; } @@ -1146,6 +1147,8 @@ static int netdev_queue_add_kobject(stru if (error) return error; + dev_hold(queue->dev); + #ifdef CONFIG_BQL error = sysfs_create_group(kobj, &dql_group); if (error) { @@ -1155,7 +1158,6 @@ static int netdev_queue_add_kobject(stru #endif kobject_uevent(kobj, KOBJ_ADD); - dev_hold(queue->dev); return 0; }