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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 19525C10F06 for ; Mon, 11 Mar 2019 22:50:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E4DCC2087C for ; Mon, 11 Mar 2019 22:50:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726504AbfCKWup (ORCPT ); Mon, 11 Mar 2019 18:50:45 -0400 Received: from mail.us.es ([193.147.175.20]:34552 "EHLO mail.us.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726187AbfCKWup (ORCPT ); Mon, 11 Mar 2019 18:50:45 -0400 Received: from antivirus1-rhel7.int (unknown [192.168.2.11]) by mail.us.es (Postfix) with ESMTP id 2446820991F for ; Mon, 11 Mar 2019 23:50:43 +0100 (CET) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id 150F6DA872 for ; Mon, 11 Mar 2019 23:50:43 +0100 (CET) Received: by antivirus1-rhel7.int (Postfix, from userid 99) id 0A4C0DA86E; Mon, 11 Mar 2019 23:50:43 +0100 (CET) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id D7E8EDA85D; Mon, 11 Mar 2019 23:50:40 +0100 (CET) Received: from 192.168.1.97 (192.168.1.97) by antivirus1-rhel7.int (F-Secure/fsigk_smtp/550/antivirus1-rhel7.int); Mon, 11 Mar 2019 23:50:40 +0100 (CET) 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 A92504265A2F; Mon, 11 Mar 2019 23:50:40 +0100 (CET) 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 1/5] netfilter: nat: don't register device notifier twice Date: Mon, 11 Mar 2019 23:50:31 +0100 Message-Id: <20190311225035.21250-2-pablo@netfilter.org> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20190311225035.21250-1-pablo@netfilter.org> References: <20190311225035.21250-1-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: Florian Westphal Otherwise, we get notifier list corruption. This is the most simple fix: remove the device notifier call chain from the ipv6 masquerade register function and handle it only in the ipv4 version. The better fix is merge nf_nat_masquerade_ipv4/6_(un)register_notifier into a single nf_nat_masquerade_(un)register_notifiers but to do this its needed to first merge the two masquerade modules into a single xt_MASQUERADE. Furthermore, we need to use different refcounts for ipv4/ipv6 until we can merge MASQUERADE. Fixes: d1aca8ab3104a ("netfilter: nat: merge ipv4 and ipv6 masquerade functionality") Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_nat_masquerade.c | 35 +++++++++++++++++++---------------- 1 file changed, 19 insertions(+), 16 deletions(-) diff --git a/net/netfilter/nf_nat_masquerade.c b/net/netfilter/nf_nat_masquerade.c index 86fa4dcc63c5..d85c4d902e7b 100644 --- a/net/netfilter/nf_nat_masquerade.c +++ b/net/netfilter/nf_nat_masquerade.c @@ -11,7 +11,8 @@ #include static DEFINE_MUTEX(masq_mutex); -static unsigned int masq_refcnt __read_mostly; +static unsigned int masq_refcnt4 __read_mostly; +static unsigned int masq_refcnt6 __read_mostly; unsigned int nf_nat_masquerade_ipv4(struct sk_buff *skb, unsigned int hooknum, @@ -141,8 +142,13 @@ int nf_nat_masquerade_ipv4_register_notifier(void) int ret = 0; mutex_lock(&masq_mutex); + if (WARN_ON_ONCE(masq_refcnt4 == UINT_MAX)) { + ret = -EOVERFLOW; + goto out_unlock; + } + /* check if the notifier was already set */ - if (++masq_refcnt > 1) + if (++masq_refcnt4 > 1) goto out_unlock; /* Register for device down reports */ @@ -160,7 +166,7 @@ int nf_nat_masquerade_ipv4_register_notifier(void) err_unregister: unregister_netdevice_notifier(&masq_dev_notifier); err_dec: - masq_refcnt--; + masq_refcnt4--; out_unlock: mutex_unlock(&masq_mutex); return ret; @@ -171,7 +177,7 @@ void nf_nat_masquerade_ipv4_unregister_notifier(void) { mutex_lock(&masq_mutex); /* check if the notifier still has clients */ - if (--masq_refcnt > 0) + if (--masq_refcnt4 > 0) goto out_unlock; unregister_netdevice_notifier(&masq_dev_notifier); @@ -321,25 +327,23 @@ int nf_nat_masquerade_ipv6_register_notifier(void) int ret = 0; mutex_lock(&masq_mutex); - /* check if the notifier is already set */ - if (++masq_refcnt > 1) + if (WARN_ON_ONCE(masq_refcnt6 == UINT_MAX)) { + ret = -EOVERFLOW; goto out_unlock; + } - ret = register_netdevice_notifier(&masq_dev_notifier); - if (ret) - goto err_dec; + /* check if the notifier is already set */ + if (++masq_refcnt6 > 1) + goto out_unlock; ret = register_inet6addr_notifier(&masq_inet6_notifier); if (ret) - goto err_unregister; + goto err_dec; mutex_unlock(&masq_mutex); return ret; - -err_unregister: - unregister_netdevice_notifier(&masq_dev_notifier); err_dec: - masq_refcnt--; + masq_refcnt6--; out_unlock: mutex_unlock(&masq_mutex); return ret; @@ -350,11 +354,10 @@ void nf_nat_masquerade_ipv6_unregister_notifier(void) { mutex_lock(&masq_mutex); /* check if the notifier still has clients */ - if (--masq_refcnt > 0) + if (--masq_refcnt6 > 0) goto out_unlock; unregister_inet6addr_notifier(&masq_inet6_notifier); - unregister_netdevice_notifier(&masq_dev_notifier); out_unlock: mutex_unlock(&masq_mutex); } -- 2.11.0