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=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 BE291C41514 for ; Wed, 4 Sep 2019 19:37:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A1CBB2077B for ; Wed, 4 Sep 2019 19:37:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731665AbfIDThA (ORCPT ); Wed, 4 Sep 2019 15:37:00 -0400 Received: from correo.us.es ([193.147.175.20]:37900 "EHLO mail.us.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731577AbfIDTg6 (ORCPT ); Wed, 4 Sep 2019 15:36:58 -0400 Received: from antivirus1-rhel7.int (unknown [192.168.2.11]) by mail.us.es (Postfix) with ESMTP id 4DEBD303D05 for ; Wed, 4 Sep 2019 21:36:55 +0200 (CEST) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id 421FCDA7B6 for ; Wed, 4 Sep 2019 21:36:55 +0200 (CEST) Received: by antivirus1-rhel7.int (Postfix, from userid 99) id 37AFAB8004; Wed, 4 Sep 2019 21:36:55 +0200 (CEST) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id 27AAFB7FFB; Wed, 4 Sep 2019 21:36:53 +0200 (CEST) Received: from 192.168.1.97 (192.168.1.97) by antivirus1-rhel7.int (F-Secure/fsigk_smtp/550/antivirus1-rhel7.int); Wed, 04 Sep 2019 21:36:53 +0200 (CEST) X-Virus-Status: clean(F-Secure/fsigk_smtp/550/antivirus1-rhel7.int) Received: from salvia.here (sys.soleta.eu [212.170.55.40]) (Authenticated sender: pneira@us.es) by entrada.int (Postfix) with ESMTPA id 002434265A5A; Wed, 4 Sep 2019 21:36:52 +0200 (CEST) X-SMTPAUTHUS: auth mail.us.es From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Cc: davem@davemloft.net, netdev@vger.kernel.org Subject: [PATCH 3/5] netfilter: nft_fib_netdev: Terminate rule eval if protocol=IPv6 and ipv6 module is disabled Date: Wed, 4 Sep 2019 21:36:44 +0200 Message-Id: <20190904193646.23830-4-pablo@netfilter.org> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20190904193646.23830-1-pablo@netfilter.org> References: <20190904193646.23830-1-pablo@netfilter.org> X-Virus-Scanned: ClamAV using ClamSMTP Sender: netfilter-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org From: Leonardo Bras If IPv6 is disabled on boot (ipv6.disable=1), but nft_fib_inet ends up dealing with a IPv6 packet, it causes a kernel panic in fib6_node_lookup_1(), crashing in bad_page_fault. The panic is caused by trying to deference a very low address (0x38 in ppc64le), due to ipv6.fib6_main_tbl = NULL. BUG: Kernel NULL pointer dereference at 0x00000038 The kernel panic was reproduced in a host that disabled IPv6 on boot and have to process guest packets (coming from a bridge) using it's ip6tables. Terminate rule evaluation when packet protocol is IPv6 but the ipv6 module is not loaded. Signed-off-by: Leonardo Bras Acked-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nft_fib_netdev.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/netfilter/nft_fib_netdev.c b/net/netfilter/nft_fib_netdev.c index 2cf3f32fe6d2..a2e726ae7f07 100644 --- a/net/netfilter/nft_fib_netdev.c +++ b/net/netfilter/nft_fib_netdev.c @@ -14,6 +14,7 @@ #include #include #include +#include #include @@ -34,6 +35,8 @@ static void nft_fib_netdev_eval(const struct nft_expr *expr, } break; case ETH_P_IPV6: + if (!ipv6_mod_enabled()) + break; switch (priv->result) { case NFT_FIB_RESULT_OIF: case NFT_FIB_RESULT_OIFNAME: -- 2.11.0