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=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_MUTT 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 5E870C10F06 for ; Sat, 6 Apr 2019 05:27:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1893A2173C for ; Sat, 6 Apr 2019 05:27:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="kU5dV5wb" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726310AbfDFF1V (ORCPT ); Sat, 6 Apr 2019 01:27:21 -0400 Received: from userp2130.oracle.com ([156.151.31.86]:42022 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725290AbfDFF1U (ORCPT ); Sat, 6 Apr 2019 01:27:20 -0400 Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x365F3MD188295; Sat, 6 Apr 2019 05:27:03 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : mime-version : content-type : in-reply-to; s=corp-2018-07-02; bh=Q2gYlnh069vO2f/dL2Z65Stz5BOFGSSFCPRM25/lNzQ=; b=kU5dV5wb+iMyv2vVUsGCHGMo8ELCS13seVTPOaG6SO3/kOuxhLlfEa83PRrFMknNOj0W +qCsgy5w85QQM7gSIh4cFcrgn6SujM0RD6qGr917REIKTouf7dLyH+bIbEtySOvKBoqR ZaBT9obpPBuL2RYJR5HY/1/oV0H3VnKt7BEJwQdxD7TvAG9DxYV92OPmrsuVD6OXsjFR aTH61FmkRF9hOFvSKppaf+AOqu469ZwJ7aEf+CrcZyW1Aa9Nw0ONi1miPkfqo1a7Gyjd RJAotQJvykaUgQMJar8tCARF3KmZwbvvWeR4FloSiNMojwEApyHf5a4MuvXXWTztqvXe iw== Received: from userp3030.oracle.com (userp3030.oracle.com [156.151.31.80]) by userp2130.oracle.com with ESMTP id 2rpkhsg4wr-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Sat, 06 Apr 2019 05:27:03 +0000 Received: from pps.filterd (userp3030.oracle.com [127.0.0.1]) by userp3030.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x365QJJv167608; Sat, 6 Apr 2019 05:27:03 GMT Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by userp3030.oracle.com with ESMTP id 2rph7rb0pn-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Sat, 06 Apr 2019 05:27:03 +0000 Received: from abhmp0005.oracle.com (abhmp0005.oracle.com [141.146.116.11]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id x365R0q2032003; Sat, 6 Apr 2019 05:27:01 GMT Received: from kadam (/41.202.241.49) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Fri, 05 Apr 2019 22:27:00 -0700 Date: Sat, 6 Apr 2019 08:26:52 +0300 From: Dan Carpenter To: Pablo Neira Ayuso Cc: Jozsef Kadlecsik , Florian Westphal , netfilter-devel@vger.kernel.org, coreteam@netfilter.org, kernel-janitors@vger.kernel.org Subject: [PATCH v2] netfilter: nf_tables: prevent shift wrap in nft_chain_parse_hook() Message-ID: <20190406052652.GA20963@kadam> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190402133038.GA18575@kadam> X-Mailer: git-send-email haha only kidding User-Agent: Mutt/1.9.4 (2018-02-28) X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9218 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1904060036 X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9218 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1904060036 Sender: netfilter-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org I believe that "hook->num" can be up to UINT_MAX. Shifting more than 31 bits would is undefined in C but in practice it would lead to shift wrapping. That would lead to an array overflow in nf_tables_addchain(): ops->hook = hook.type->hooks[ops->hooknum]; Fixes: fe19c04ca137 ("netfilter: nf_tables: remove nhooks field from struct nft_af_info") Signed-off-by: Dan Carpenter --- v2: In my original fix I thought making shifts unsigned was defined in C but it's not. My original patch didn't fix or change runtime at all. Thanks to Florian Westphal for his help on this. net/netfilter/nf_tables_api.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index ef7772e976cc..1606eaa5ae0d 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -1545,7 +1545,7 @@ static int nft_chain_parse_hook(struct net *net, if (IS_ERR(type)) return PTR_ERR(type); } - if (!(type->hook_mask & (1 << hook->num))) + if (hook->num > NF_MAX_HOOKS || !(type->hook_mask & (1 << hook->num))) return -EOPNOTSUPP; if (type->type == NFT_CHAIN_T_NAT && -- 2.17.1