From patchwork Thu Oct 7 05:55:24 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steffen Klassert X-Patchwork-Id: 12540959 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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DC504C433F5 for ; Thu, 7 Oct 2021 05:55:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C098E61245 for ; Thu, 7 Oct 2021 05:55:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240188AbhJGF5j (ORCPT ); Thu, 7 Oct 2021 01:57:39 -0400 Received: from a.mx.secunet.com ([62.96.220.36]:37696 "EHLO a.mx.secunet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240130AbhJGF5X (ORCPT ); Thu, 7 Oct 2021 01:57:23 -0400 Received: from localhost (localhost [127.0.0.1]) by a.mx.secunet.com (Postfix) with ESMTP id 211D220539; Thu, 7 Oct 2021 07:55:29 +0200 (CEST) X-Virus-Scanned: by secunet Received: from a.mx.secunet.com ([127.0.0.1]) by localhost (a.mx.secunet.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 9kfmzfv_fd0g; Thu, 7 Oct 2021 07:55:28 +0200 (CEST) Received: from mailout2.secunet.com (mailout2.secunet.com [62.96.220.49]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by a.mx.secunet.com (Postfix) with ESMTPS id 08FDC20460; Thu, 7 Oct 2021 07:55:28 +0200 (CEST) Received: from cas-essen-02.secunet.de (unknown [10.53.40.202]) by mailout2.secunet.com (Postfix) with ESMTP id EE62E80004A; Thu, 7 Oct 2021 07:55:27 +0200 (CEST) Received: from mbx-essen-01.secunet.de (10.53.40.197) by cas-essen-02.secunet.de (10.53.40.202) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.14; Thu, 7 Oct 2021 07:55:27 +0200 Received: from gauss2.secunet.de (10.182.7.193) by mbx-essen-01.secunet.de (10.53.40.197) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.14; Thu, 7 Oct 2021 07:55:27 +0200 Received: by gauss2.secunet.de (Postfix, from userid 1000) id B2B213183BF9; Thu, 7 Oct 2021 07:55:26 +0200 (CEST) From: Steffen Klassert To: David Miller , Jakub Kicinski CC: Herbert Xu , Steffen Klassert , Subject: [PATCH 5/5] xfrm: fix rcu lock in xfrm_notify_userpolicy() Date: Thu, 7 Oct 2021 07:55:24 +0200 Message-ID: <20211007055524.319785-6-steffen.klassert@secunet.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20211007055524.319785-1-steffen.klassert@secunet.com> References: <20211007055524.319785-1-steffen.klassert@secunet.com> MIME-Version: 1.0 X-ClientProxiedBy: cas-essen-02.secunet.de (10.53.40.202) To mbx-essen-01.secunet.de (10.53.40.197) X-EXCLAIMER-MD-CONFIG: 2c86f778-e09b-4440-8b15-867914633a10 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From: Nicolas Dichtel As stated in the comment above xfrm_nlmsg_multicast(), rcu read lock must be held before calling this function. Reported-by: syzbot+3d9866419b4aa8f985d6@syzkaller.appspotmail.com Fixes: 703b94b93c19 ("xfrm: notify default policy on update") Signed-off-by: Nicolas Dichtel Signed-off-by: Steffen Klassert --- net/xfrm/xfrm_user.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c index 0eba0c27c665..3a3cb09eec12 100644 --- a/net/xfrm/xfrm_user.c +++ b/net/xfrm/xfrm_user.c @@ -1967,6 +1967,7 @@ static int xfrm_notify_userpolicy(struct net *net) int len = NLMSG_ALIGN(sizeof(*up)); struct nlmsghdr *nlh; struct sk_buff *skb; + int err; skb = nlmsg_new(len, GFP_ATOMIC); if (skb == NULL) @@ -1988,7 +1989,11 @@ static int xfrm_notify_userpolicy(struct net *net) nlmsg_end(skb, nlh); - return xfrm_nlmsg_multicast(net, skb, 0, XFRMNLGRP_POLICY); + rcu_read_lock(); + err = xfrm_nlmsg_multicast(net, skb, 0, XFRMNLGRP_POLICY); + rcu_read_unlock(); + + return err; } static int xfrm_set_default(struct sk_buff *skb, struct nlmsghdr *nlh,