From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Leonardo Bras Date: Sat, 31 Aug 2019 01:40:33 -0300 Message-Id: <20190831044032.31931-1-leonardo@linux.ibm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Subject: [Bridge] [PATCH v5 1/1] net: br_netfiler_hooks: Drops IPv6 packets if IPv6 module is not loaded List-Id: Linux Ethernet Bridging List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: netfilter-devel@vger.kernel.org, coreteam@netfilter.org, bridge@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Nikolay Aleksandrov , Roopa Prabhu , Florian Westphal , Jozsef Kadlecsik , Leonardo Bras , "David S. Miller" , Pablo Neira Ayuso A kernel panic can happen if a host has disabled IPv6 on boot and have to process guest packets (coming from a bridge) using it's ip6tables. IPv6 packets need to be dropped if the IPv6 module is not loaded, and the host ip6tables will be used. Signed-off-by: Leonardo Bras --- Changes from v4: - Check if the host ip6tables is going to be used before testing ipv6 module presence - Adds a warning about ipv6 module disabled. net/bridge/br_netfilter_hooks.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/bridge/br_netfilter_hooks.c b/net/bridge/br_netfilter_hooks.c index d3f9592f4ff8..af7800103e51 100644 --- a/net/bridge/br_netfilter_hooks.c +++ b/net/bridge/br_netfilter_hooks.c @@ -496,6 +496,10 @@ static unsigned int br_nf_pre_routing(void *priv, if (!brnet->call_ip6tables && !br_opt_get(br, BROPT_NF_CALL_IP6TABLES)) return NF_ACCEPT; + if (!ipv6_mod_enabled()) { + pr_warn_once("Module ipv6 is disabled, so call_ip6tables is not supported."); + return NF_DROP; + } nf_bridge_pull_encap_header_rcsum(skb); return br_nf_pre_routing_ipv6(priv, skb, state); -- 2.20.1 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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=unavailable 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 203EDC3A59F for ; Sat, 31 Aug 2019 04:41:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EF31B23431 for ; Sat, 31 Aug 2019 04:41:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726074AbfHaElP (ORCPT ); Sat, 31 Aug 2019 00:41:15 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:48946 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725836AbfHaElO (ORCPT ); Sat, 31 Aug 2019 00:41:14 -0400 Received: from pps.filterd (m0098416.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x7V4bC3t010070; Sat, 31 Aug 2019 00:41:01 -0400 Received: from ppma02dal.us.ibm.com (a.bd.3ea9.ip4.static.sl-reverse.com [169.62.189.10]) by mx0b-001b2d01.pphosted.com with ESMTP id 2uqc4pgtgg-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Sat, 31 Aug 2019 00:41:01 -0400 Received: from pps.filterd (ppma02dal.us.ibm.com [127.0.0.1]) by ppma02dal.us.ibm.com (8.16.0.27/8.16.0.27) with SMTP id x7V4eTfb004166; Sat, 31 Aug 2019 04:41:00 GMT Received: from b01cxnp22034.gho.pok.ibm.com (b01cxnp22034.gho.pok.ibm.com [9.57.198.24]) by ppma02dal.us.ibm.com with ESMTP id 2uqgh68fpf-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Sat, 31 Aug 2019 04:41:00 +0000 Received: from b01ledav006.gho.pok.ibm.com (b01ledav006.gho.pok.ibm.com [9.57.199.111]) by b01cxnp22034.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x7V4exjP22544856 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Sat, 31 Aug 2019 04:40:59 GMT Received: from b01ledav006.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 6E5EFAC059; Sat, 31 Aug 2019 04:40:59 +0000 (GMT) Received: from b01ledav006.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 60978AC05B; Sat, 31 Aug 2019 04:40:56 +0000 (GMT) Received: from LeoBras.ibmuc.com (unknown [9.80.210.156]) by b01ledav006.gho.pok.ibm.com (Postfix) with ESMTP; Sat, 31 Aug 2019 04:40:56 +0000 (GMT) From: Leonardo Bras To: netfilter-devel@vger.kernel.org, coreteam@netfilter.org, bridge@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Leonardo Bras , Pablo Neira Ayuso , Jozsef Kadlecsik , Florian Westphal , Roopa Prabhu , Nikolay Aleksandrov , "David S. Miller" Subject: [PATCH v5 1/1] net: br_netfiler_hooks: Drops IPv6 packets if IPv6 module is not loaded Date: Sat, 31 Aug 2019 01:40:33 -0300 Message-Id: <20190831044032.31931-1-leonardo@linux.ibm.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-08-31_02:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound 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=8.0.1-1906280000 definitions=main-1908310051 Sender: netfilter-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org A kernel panic can happen if a host has disabled IPv6 on boot and have to process guest packets (coming from a bridge) using it's ip6tables. IPv6 packets need to be dropped if the IPv6 module is not loaded, and the host ip6tables will be used. Signed-off-by: Leonardo Bras --- Changes from v4: - Check if the host ip6tables is going to be used before testing ipv6 module presence - Adds a warning about ipv6 module disabled. net/bridge/br_netfilter_hooks.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/bridge/br_netfilter_hooks.c b/net/bridge/br_netfilter_hooks.c index d3f9592f4ff8..af7800103e51 100644 --- a/net/bridge/br_netfilter_hooks.c +++ b/net/bridge/br_netfilter_hooks.c @@ -496,6 +496,10 @@ static unsigned int br_nf_pre_routing(void *priv, if (!brnet->call_ip6tables && !br_opt_get(br, BROPT_NF_CALL_IP6TABLES)) return NF_ACCEPT; + if (!ipv6_mod_enabled()) { + pr_warn_once("Module ipv6 is disabled, so call_ip6tables is not supported."); + return NF_DROP; + } nf_bridge_pull_encap_header_rcsum(skb); return br_nf_pre_routing_ipv6(priv, skb, state); -- 2.20.1