From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756180AbbLXPpN (ORCPT ); Thu, 24 Dec 2015 10:45:13 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:51387 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752502AbbLXPmb (ORCPT ); Thu, 24 Dec 2015 10:42:31 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Vlad Yasevich" , "David S. Miller" , "Eric Dumazet" , "Dmitry Vyukov" Date: Thu, 24 Dec 2015 15:37:42 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 69/77] ipv6: sctp: clone options to avoid use after free In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.247 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.75-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit 9470e24f35ab81574da54e69df90c1eb4a96b43f ] SCTP is lacking proper np->opt cloning at accept() time. TCP and DCCP use ipv6_dup_options() helper, do the same in SCTP. We might later factorize this code in a common helper to avoid future mistakes. Reported-by: Dmitry Vyukov Signed-off-by: Eric Dumazet Acked-by: Vlad Yasevich Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings --- net/sctp/ipv6.c | 8 ++++++++ 1 file changed, 8 insertions(+) --- a/net/sctp/ipv6.c +++ b/net/sctp/ipv6.c @@ -635,6 +635,7 @@ static struct sock *sctp_v6_create_accep struct sock *newsk; struct ipv6_pinfo *newnp, *np = inet6_sk(sk); struct sctp6_sock *newsctp6sk; + struct ipv6_txoptions *opt; newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot); if (!newsk) @@ -654,6 +655,13 @@ static struct sock *sctp_v6_create_accep memcpy(newnp, np, sizeof(struct ipv6_pinfo)); + rcu_read_lock(); + opt = rcu_dereference(np->opt); + if (opt) + opt = ipv6_dup_options(newsk, opt); + RCU_INIT_POINTER(newnp->opt, opt); + rcu_read_unlock(); + /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname() * and getpeername(). */