From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756083AbbCXRJC (ORCPT ); Tue, 24 Mar 2015 13:09:02 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:33948 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756062AbbCXRIy (ORCPT ); Tue, 24 Mar 2015 13:08:54 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Dumazet , Pablo Neira Ayuso Subject: [PATCH 3.19 109/123] netfilter: xt_socket: fix a stack corruption bug Date: Tue, 24 Mar 2015 16:46:58 +0100 Message-Id: <20150324154428.886301904@linuxfoundation.org> X-Mailer: git-send-email 2.3.3 In-Reply-To: <20150324154423.655554012@linuxfoundation.org> References: <20150324154423.655554012@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet commit 78296c97ca1fd3b104f12e1f1fbc06c46635990b upstream. As soon as extract_icmp6_fields() returns, its local storage (automatic variables) is deallocated and can be overwritten. Lets add an additional parameter to make sure storage is valid long enough. While we are at it, adds some const qualifiers. Signed-off-by: Eric Dumazet Fixes: b64c9256a9b76 ("tproxy: added IPv6 support to the socket match") Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman --- net/netfilter/xt_socket.c | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-) --- a/net/netfilter/xt_socket.c +++ b/net/netfilter/xt_socket.c @@ -243,12 +243,13 @@ static int extract_icmp6_fields(const struct sk_buff *skb, unsigned int outside_hdrlen, int *protocol, - struct in6_addr **raddr, - struct in6_addr **laddr, + const struct in6_addr **raddr, + const struct in6_addr **laddr, __be16 *rport, - __be16 *lport) + __be16 *lport, + struct ipv6hdr *ipv6_var) { - struct ipv6hdr *inside_iph, _inside_iph; + const struct ipv6hdr *inside_iph; struct icmp6hdr *icmph, _icmph; __be16 *ports, _ports[2]; u8 inside_nexthdr; @@ -263,12 +264,14 @@ extract_icmp6_fields(const struct sk_buf if (icmph->icmp6_type & ICMPV6_INFOMSG_MASK) return 1; - inside_iph = skb_header_pointer(skb, outside_hdrlen + sizeof(_icmph), sizeof(_inside_iph), &_inside_iph); + inside_iph = skb_header_pointer(skb, outside_hdrlen + sizeof(_icmph), + sizeof(*ipv6_var), ipv6_var); if (inside_iph == NULL) return 1; inside_nexthdr = inside_iph->nexthdr; - inside_hdrlen = ipv6_skip_exthdr(skb, outside_hdrlen + sizeof(_icmph) + sizeof(_inside_iph), + inside_hdrlen = ipv6_skip_exthdr(skb, outside_hdrlen + sizeof(_icmph) + + sizeof(*ipv6_var), &inside_nexthdr, &inside_fragoff); if (inside_hdrlen < 0) return 1; /* hjm: Packet has no/incomplete transport layer headers. */ @@ -315,10 +318,10 @@ xt_socket_get_sock_v6(struct net *net, c static bool socket_mt6_v1_v2(const struct sk_buff *skb, struct xt_action_param *par) { - struct ipv6hdr *iph = ipv6_hdr(skb); + struct ipv6hdr ipv6_var, *iph = ipv6_hdr(skb); struct udphdr _hdr, *hp = NULL; struct sock *sk = skb->sk; - struct in6_addr *daddr = NULL, *saddr = NULL; + const struct in6_addr *daddr = NULL, *saddr = NULL; __be16 uninitialized_var(dport), uninitialized_var(sport); int thoff = 0, uninitialized_var(tproto); const struct xt_socket_mtinfo1 *info = (struct xt_socket_mtinfo1 *) par->matchinfo; @@ -342,7 +345,7 @@ socket_mt6_v1_v2(const struct sk_buff *s } else if (tproto == IPPROTO_ICMPV6) { if (extract_icmp6_fields(skb, thoff, &tproto, &saddr, &daddr, - &sport, &dport)) + &sport, &dport, &ipv6_var)) return false; } else { return false;