From patchwork Fri Aug 27 07:50:15 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steffen Klassert X-Patchwork-Id: 12461449 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,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 AED36C43214 for ; Fri, 27 Aug 2021 07:50:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9239160F42 for ; Fri, 27 Aug 2021 07:50:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244512AbhH0HvN (ORCPT ); Fri, 27 Aug 2021 03:51:13 -0400 Received: from a.mx.secunet.com ([62.96.220.36]:41150 "EHLO a.mx.secunet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244480AbhH0HvL (ORCPT ); Fri, 27 Aug 2021 03:51:11 -0400 Received: from localhost (localhost [127.0.0.1]) by a.mx.secunet.com (Postfix) with ESMTP id 16D902049A; Fri, 27 Aug 2021 09:50:22 +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 zzlQuVotui2M; Fri, 27 Aug 2021 09:50:18 +0200 (CEST) Received: from mailout1.secunet.com (mailout1.secunet.com [62.96.220.44]) (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 6C827205A6; Fri, 27 Aug 2021 09:50:18 +0200 (CEST) Received: from cas-essen-02.secunet.de (unknown [10.53.40.202]) by mailout1.secunet.com (Postfix) with ESMTP id 5E15180004A; Fri, 27 Aug 2021 09:50:18 +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 15.1.2176.2; Fri, 27 Aug 2021 09:50:18 +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 15.1.2176.2; Fri, 27 Aug 2021 09:50:18 +0200 Received: by gauss2.secunet.de (Postfix, from userid 1000) id B13A53180727; Fri, 27 Aug 2021 09:50:17 +0200 (CEST) From: Steffen Klassert To: David Miller , Jakub Kicinski CC: Herbert Xu , Steffen Klassert , Subject: [PATCH 3/3] net: xfrm: fix shift-out-of-bounce Date: Fri, 27 Aug 2021 09:50:15 +0200 Message-ID: <20210827075015.2584560-4-steffen.klassert@secunet.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210827075015.2584560-1-steffen.klassert@secunet.com> References: <20210827075015.2584560-1-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: Pavel Skripkin We need to check up->dirmask to avoid shift-out-of-bounce bug, since up->dirmask comes from userspace. Also, added XFRM_USERPOLICY_DIRMASK_MAX constant to uapi to inform user-space that up->dirmask has maximum possible value Fixes: 2d151d39073a ("xfrm: Add possibility to set the default to block if we have no policy") Reported-and-tested-by: syzbot+9cd5837a045bbee5b810@syzkaller.appspotmail.com Signed-off-by: Pavel Skripkin Signed-off-by: Steffen Klassert --- include/uapi/linux/xfrm.h | 1 + net/xfrm/xfrm_user.c | 7 ++++++- 2 files changed, 7 insertions(+), 1 deletion(-) diff --git a/include/uapi/linux/xfrm.h b/include/uapi/linux/xfrm.h index 6e8095106192..b96c1ea7166d 100644 --- a/include/uapi/linux/xfrm.h +++ b/include/uapi/linux/xfrm.h @@ -514,6 +514,7 @@ struct xfrm_user_offload { #define XFRM_OFFLOAD_INBOUND 2 struct xfrm_userpolicy_default { +#define XFRM_USERPOLICY_DIRMASK_MAX (sizeof(__u8) * 8) __u8 dirmask; __u8 action; }; diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c index 4eafd1130c3e..127c99f71c99 100644 --- a/net/xfrm/xfrm_user.c +++ b/net/xfrm/xfrm_user.c @@ -1966,9 +1966,14 @@ static int xfrm_set_default(struct sk_buff *skb, struct nlmsghdr *nlh, { struct net *net = sock_net(skb->sk); struct xfrm_userpolicy_default *up = nlmsg_data(nlh); - u8 dirmask = (1 << up->dirmask) & XFRM_POL_DEFAULT_MASK; + u8 dirmask; u8 old_default = net->xfrm.policy_default; + if (up->dirmask >= XFRM_USERPOLICY_DIRMASK_MAX) + return -EINVAL; + + dirmask = (1 << up->dirmask) & XFRM_POL_DEFAULT_MASK; + net->xfrm.policy_default = (old_default & (0xff ^ dirmask)) | (up->action << up->dirmask);