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=-3.7 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 2A830C433DF for ; Tue, 9 Jun 2020 18:09:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 09EEE20691 for ; Tue, 9 Jun 2020 18:09:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388498AbgFISJb (ORCPT ); Tue, 9 Jun 2020 14:09:31 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:41428 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732185AbgFISF7 (ORCPT ); Tue, 9 Jun 2020 14:05:59 -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 1jiidF-0001oQ-13; Tue, 09 Jun 2020 19:05:53 +0100 Received: from ben by deadeye with local (Exim 4.94) (envelope-from ) id 1jiidE-006Vuv-Ca; Tue, 09 Jun 2020 19:05:52 +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 , "Tetsuo Handa" , "Lukas Bulwahn" , "David Miller" , "Jouni Hogander" , "syzbot" Date: Tue, 09 Jun 2020 19:04:01 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 10/61] net-sysfs: Call dev_hold always in rx_queue_add_kobject 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 3.16.85-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Jouni Hogander commit ddd9b5e3e765d8ed5a35786a6cb00111713fe161 upstream. Dev_hold has to be called always in rx_queue_add_kobject. Otherwise usage count drops below 0 in case of failure in kobject_init_and_add. Fixes: b8eb718348b8 ("net-sysfs: Fix reference count leak in rx|netdev_queue_add_kobject") Reported-by: syzbot Cc: Tetsuo Handa Cc: David Miller Cc: Lukas Bulwahn Signed-off-by: Jouni Hogander Signed-off-by: David S. Miller [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings --- net/core/net-sysfs.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -782,14 +782,17 @@ static int rx_queue_add_kobject(struct n struct kobject *kobj = &queue->kobj; int error = 0; + /* Kobject_put later will trigger rx_queue_release call which + * decreases dev refcount: Take that reference here + */ + dev_hold(queue->dev); + kobj->kset = net->queues_kset; error = kobject_init_and_add(kobj, &rx_queue_ktype, NULL, "rx-%u", index); if (error) goto err; - dev_hold(queue->dev); - if (net->sysfs_rx_queue_group) { error = sysfs_create_group(kobj, net->sysfs_rx_queue_group); if (error)