Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933005AbbDGX1E (ORCPT ); Tue, 7 Apr 2015 19:27:04 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:55590 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754317AbbDGWw0 (ORCPT ); Tue, 7 Apr 2015 18:52:26 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Eric Dumazet , Pablo Neira Ayuso , Kamal Mostafa Subject: [PATCH 3.13.y-ckt 047/156] netfilter: xt_socket: fix a stack corruption bug Date: Tue, 7 Apr 2015 15:49:44 -0700 Message-Id: <1428447093-3282-48-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1428447093-3282-1-git-send-email-kamal@canonical.com> References: <1428447093-3282-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.13 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3456 Lines: 93 3.13.11-ckt19 -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: Kamal Mostafa --- net/netfilter/xt_socket.c | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-) diff --git a/net/netfilter/xt_socket.c b/net/netfilter/xt_socket.c index 1ba6793..13332db 100644 --- 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_buff *skb, 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, const u8 protocol, 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 *skb, struct xt_action_param *par) } 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; -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/