[NETFILTER]: {ip,nf}_conntrack_sctp: fix remotely triggerable NULL ptr dereference...

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>

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>

diff --git a/net/ipv4/netfilter/ip_conntrack_proto_sctp.c b/net/ipv4/netfilter/ip_conntrack_proto_sctp.c
index b82be9314f692c5169b6cbd06781439b89b60c78..ec54f3912abc4a4af17259a7087658004be4a9cf 100644 (file)
--- 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 7fcd1dd6eb9d07b4f744c97d415e5d2379d58f26..a8645412969c5498a995d1cdf7a7dc3e071eca26 100644 (file)
--- a/net/netfilter/nf_conntrack_proto_sctp.c
+++ b/net/netfilter/nf_conntrack_proto_sctp.c
@@ -467,7 +467,8 @@ 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;
                }