From: Don Howard <dhoward@redhat.com> Subject: [rhel5.1 security patch] ip_conntrack_sctp: fix remotely triggerable NULL ptr dereference (243244) Date: Sun, 10 Jun 2007 15:38:06 -0700 (PDT) Bugzilla: 243244 Message-Id: <Pine.LNX.4.64.0706101522070.6012@sugarmagnolia.remotee.org> Changelog: [net] ip_conntrack_sctp: fix remotely triggerable NULL ptr dereference Fixes bz243244 / CVE-2007-2876 Built in brew. Patch is upstream in 2.6.21.4 diff-tree 8c640bd0c68201dd0d71b78a07bb224973580ad3 (from c23e7e4c94647c2c47d2c835b21cc7d745f62d05) Author: Patrick McHardy <kaber@trash.net> [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 e694299..b86479a 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 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 3c80558..b53bc64 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 *conn 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; } -- -Don dhoward@redhat.com