From patchwork Fri Sep 3 16:30:20 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pablo Neira Ayuso X-Patchwork-Id: 506934 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, 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 BE637C433EF for ; Fri, 3 Sep 2021 16:30:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A552A610CF for ; Fri, 3 Sep 2021 16:30:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350044AbhICQbg (ORCPT ); Fri, 3 Sep 2021 12:31:36 -0400 Received: from mail.netfilter.org ([217.70.188.207]:58776 "EHLO mail.netfilter.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350005AbhICQbc (ORCPT ); Fri, 3 Sep 2021 12:31:32 -0400 Received: from localhost.localdomain (unknown [78.30.35.141]) by mail.netfilter.org (Postfix) with ESMTPSA id E412E600AD; Fri, 3 Sep 2021 18:29:28 +0200 (CEST) From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Cc: davem@davemloft.net, netdev@vger.kernel.org, kuba@kernel.org Subject: [PATCH net 5/5] netfilter: socket: icmp6: fix use-after-scope Date: Fri, 3 Sep 2021 18:30:20 +0200 Message-Id: <20210903163020.13741-6-pablo@netfilter.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210903163020.13741-1-pablo@netfilter.org> References: <20210903163020.13741-1-pablo@netfilter.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Benjamin Hesmans Bug reported by KASAN: BUG: KASAN: use-after-scope in inet6_ehashfn (net/ipv6/inet6_hashtables.c:40) Call Trace: (...) inet6_ehashfn (net/ipv6/inet6_hashtables.c:40) (...) nf_sk_lookup_slow_v6 (net/ipv6/netfilter/nf_socket_ipv6.c:91 net/ipv6/netfilter/nf_socket_ipv6.c:146) It seems that this bug has already been fixed by Eric Dumazet in the past in: commit 78296c97ca1f ("netfilter: xt_socket: fix a stack corruption bug") But a variant of the same issue has been introduced in commit d64d80a2cde9 ("netfilter: x_tables: don't extract flow keys on early demuxed sks in socket match") `daddr` and `saddr` potentially hold a reference to ipv6_var that is no longer in scope when the call to `nf_socket_get_sock_v6` is made. Fixes: d64d80a2cde9 ("netfilter: x_tables: don't extract flow keys on early demuxed sks in socket match") Acked-by: Matthieu Baerts Signed-off-by: Benjamin Hesmans Reviewed-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/ipv6/netfilter/nf_socket_ipv6.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/net/ipv6/netfilter/nf_socket_ipv6.c b/net/ipv6/netfilter/nf_socket_ipv6.c index 6fd54744cbc3..aa5bb8789ba0 100644 --- a/net/ipv6/netfilter/nf_socket_ipv6.c +++ b/net/ipv6/netfilter/nf_socket_ipv6.c @@ -99,7 +99,7 @@ struct sock *nf_sk_lookup_slow_v6(struct net *net, const struct sk_buff *skb, { __be16 dport, sport; const struct in6_addr *daddr = NULL, *saddr = NULL; - struct ipv6hdr *iph = ipv6_hdr(skb); + struct ipv6hdr *iph = ipv6_hdr(skb), ipv6_var; struct sk_buff *data_skb = NULL; int doff = 0; int thoff = 0, tproto; @@ -129,8 +129,6 @@ struct sock *nf_sk_lookup_slow_v6(struct net *net, const struct sk_buff *skb, thoff + sizeof(*hp); } else if (tproto == IPPROTO_ICMPV6) { - struct ipv6hdr ipv6_var; - if (extract_icmp6_fields(skb, thoff, &tproto, &saddr, &daddr, &sport, &dport, &ipv6_var)) return NULL;