From: Patrick McHardy <kaber@trash.net>
Date: Tue, 5 Jun 2007 12:14:22 +0000 (+0200)
Subject: [PATCH] NETFILTER: {ip, nf}_conntrack_sctp: fix remotely triggerable NULL ptr derefer... 
X-Git-Tag: v2.6.20.13~1
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=13ad357c616a85828fa224c0876a393d1dd6f59f;p=thirdparty%2Fkernel%2Fstable.git

[PATCH] NETFILTER: {ip, nf}_conntrack_sctp: fix remotely triggerable NULL ptr dereference (CVE-2007-2876)

When creating a new connection by sending an unknown chunk type, we
don't transition to a valid state, causing a NULL pointer dereference in
sctp_packet when accessing sctp_timeouts[SCTP_CONNTRACK_NONE].

Fix by don't creating new conntrack entry if initial state is invalid.

Noticed by Vilmos Nebehaj <vilmos.nebehaj@ramsys.hu>

CC: Kiran Kumar Immidi <immidi_kiran@yahoo.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
---

diff --git a/net/ipv4/netfilter/ip_conntrack_proto_sctp.c b/net/ipv4/netfilter/ip_conntrack_proto_sctp.c
index 2443322e4128a..ff483785ad4e8 100644
--- a/net/ipv4/netfilter/ip_conntrack_proto_sctp.c
+++ b/net/ipv4/netfilter/ip_conntrack_proto_sctp.c
@@ -461,7 +461,8 @@ static int sctp_new(struct ip_conntrack *conntrack,
 						SCTP_CONNTRACK_NONE, sch->type);
 
 		/* Invalid: delete conntrack */
-		if (newconntrack == SCTP_CONNTRACK_MAX) {
+		if (newconntrack == SCTP_CONNTRACK_NONE ||
+		    newconntrack == SCTP_CONNTRACK_MAX) {
 			DEBUGP("ip_conntrack_sctp: invalid new deleting.\n");
 			return 0;
 		}
diff --git a/net/netfilter/nf_conntrack_proto_sctp.c b/net/netfilter/nf_conntrack_proto_sctp.c
index 76e263668222c..fcc9152742dae 100644
--- a/net/netfilter/nf_conntrack_proto_sctp.c
+++ b/net/netfilter/nf_conntrack_proto_sctp.c
@@ -470,7 +470,8 @@ static int sctp_new(struct nf_conn *conntrack, const struct sk_buff *skb,
 					 SCTP_CONNTRACK_NONE, sch->type);
 
 		/* Invalid: delete conntrack */
-		if (newconntrack == SCTP_CONNTRACK_MAX) {
+		if (newconntrack == SCTP_CONNTRACK_NONE ||
+		    newconntrack == SCTP_CONNTRACK_MAX) {
 			DEBUGP("nf_conntrack_sctp: invalid new deleting.\n");
 			return 0;
 		}