From 8c640bd0c68201dd0d71b78a07bb224973580ad3 Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Tue, 5 Jun 2007 14:14:22 +0200 Subject: [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 CC: Kiran Kumar Immidi Cc: David Miller Signed-off-by: Patrick McHardy Signed-off-by: Greg Kroah-Hartman Signed-off-by: Chris Wright --- net/ipv4/netfilter/ip_conntrack_proto_sctp.c | 3 ++- net/netfilter/nf_conntrack_proto_sctp.c | 3 ++- 2 files changed, 4 insertions(+), 2 deletions(-) diff --git a/net/ipv4/netfilter/ip_conntrack_proto_sctp.c b/net/ipv4/netfilter/ip_conntrack_proto_sctp.c index e6942992b2f6..b86479a3867d 100644 --- a/net/ipv4/netfilter/ip_conntrack_proto_sctp.c +++ b/net/ipv4/netfilter/ip_conntrack_proto_sctp.c @@ -460,7 +460,8 @@ 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 3c80558716a0..b53bc649f156 100644 --- a/net/netfilter/nf_conntrack_proto_sctp.c +++ b/net/netfilter/nf_conntrack_proto_sctp.c @@ -469,7 +469,8 @@ 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; } -- cgit v1.2.3