[NETFILTER]: PPTP conntrack: check call ID before changing state

For rejected calls the state is set to PPTP_CALL_NONE even for non-matching
call ids.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 13 insertions, 19 deletions

diff --git a/net/ipv4/netfilter/ip_conntrack_helper_pptp.c b/net/ipv4/netfilter/ip_conntrack_helper_pptp.c
index 7b6d5aaca4da..5cb6b61cd171 100644
--- a/net/ipv4/netfilter/ip_conntrack_helper_pptp.c
+++ b/net/ipv4/netfilter/ip_conntrack_helper_pptp.c
@@ -335,25 +335,19 @@ pptp_inbound_pkt(struct sk_buff **pskb,
                     info->cstate != PPTP_CALL_OUT_CONF)
                         goto invalid;
 
-                if (pptpReq->ocack.resultCode != PPTP_OUTCALL_CONNECT) {
-                        info->cstate = PPTP_CALL_NONE;
-                        break;
-                }
-
                 cid = pptpReq->ocack.callID;
                 pcid = pptpReq->ocack.peersCallID;
-
-                info->pac_call_id = cid;
-
                 if (info->pns_call_id != pcid)
                         goto invalid;
-
                 DEBUGP("%s, CID=%X, PCID=%X\n", pptp_msg_name[msg],
                         ntohs(cid), ntohs(pcid));
 
-                info->cstate = PPTP_CALL_OUT_CONF;
-
-                exp_gre(ct, cid, pcid);
+                if (pptpReq->ocack.resultCode == PPTP_OUTCALL_CONNECT) {
+                        info->cstate = PPTP_CALL_OUT_CONF;
+                        info->pac_call_id = cid;
+                        exp_gre(ct, cid, pcid);
+                } else
+                        info->cstate = PPTP_CALL_NONE;
                 break;
 
         case PPTP_IN_CALL_REQUEST:
@@ -464,17 +458,17 @@ pptp_outbound_pkt(struct sk_buff **pskb,
                     info->cstate != PPTP_CALL_IN_REP)
                         goto invalid;
 
-                if (pptpReq->icack.resultCode != PPTP_INCALL_ACCEPT) {
-                        info->cstate = PPTP_CALL_NONE;
-                        break;
-                }
                 pcid = pptpReq->icack.peersCallID;
                 if (info->pac_call_id != pcid)
                         goto invalid;
                 DEBUGP("%s, CID=%X\n", pptp_msg_name[msg], ntohs(pcid));
-                /* part two of the three-way handshake */
-                info->cstate = PPTP_CALL_IN_REP;
-                info->pns_call_id = pcid;
+
+                if (pptpReq->icack.resultCode == PPTP_INCALL_ACCEPT) {
+                        /* part two of the three-way handshake */
+                        info->cstate = PPTP_CALL_IN_REP;
+                        info->pns_call_id = pcid;
+                } else
+                        info->cstate = PPTP_CALL_NONE;
                 break;
 
         case PPTP_CALL_CLEAR_REQUEST: