From patchwork Mon May 17 14:13:35 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johannes Berg X-Patchwork-Id: 12262155 X-Patchwork-Delegate: kuba@kernel.org 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 BCDF8C433ED for ; Mon, 17 May 2021 14:34:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 92C8561C7E for ; Mon, 17 May 2021 14:34:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240340AbhEQOeI (ORCPT ); Mon, 17 May 2021 10:34:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40968 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238661AbhEQOcH (ORCPT ); Mon, 17 May 2021 10:32:07 -0400 Received: from sipsolutions.net (s3.sipsolutions.net [IPv6:2a01:4f8:191:4433::2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E015CC06137F for ; Mon, 17 May 2021 07:13:41 -0700 (PDT) Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.94.2) (envelope-from ) id 1lie04-00AMa2-1S; Mon, 17 May 2021 16:13:40 +0200 From: Johannes Berg To: netdev@vger.kernel.org Cc: Jay Vosburgh , Veaceslav Falico , Andy Gospodarek , Johannes Berg , syzbot+bfda097c12a00c8cae67@syzkaller.appspotmail.com Subject: [PATCH] bonding: init notify_work earlier to avoid uninitialized use Date: Mon, 17 May 2021 16:13:35 +0200 Message-Id: <20210517161335.e40fea7f895a.I8b8487a9c0b8f54716cf44fdae02185381b1f64e@changeid> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From: Johannes Berg If bond_kobj_init() or later kzalloc() in bond_alloc_slave() fail, then we call kobject_put() on the slave->kobj. This in turn calls the release function slave_kobj_release() which will always try to cancel_delayed_work_sync(&slave->notify_work), which shouldn't be done on an uninitialized work struct. Always initialize the work struct earlier to avoid problems here. Syzbot bisected this down to a completely pointless commit, some fault injection may have been at work here that caused the alloc failure in the first place, which may interact badly with bisect. Reported-by: syzbot+bfda097c12a00c8cae67@syzkaller.appspotmail.com Signed-off-by: Johannes Berg Acked-by: Jay Vosburgh --- drivers/net/bonding/bond_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index 20bbda1b36e1..c5a646d06102 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -1526,6 +1526,7 @@ static struct slave *bond_alloc_slave(struct bonding *bond, slave->bond = bond; slave->dev = slave_dev; + INIT_DELAYED_WORK(&slave->notify_work, bond_netdev_notify_work); if (bond_kobj_init(slave)) return NULL; @@ -1538,7 +1539,6 @@ static struct slave *bond_alloc_slave(struct bonding *bond, return NULL; } } - INIT_DELAYED_WORK(&slave->notify_work, bond_netdev_notify_work); return slave; }