From: Patrick McHardy <kaber@trash.net>
Date: Tue, 10 Jan 2006 00:43:43 +0000 (-0800)
Subject: [NETFILTER]: Fix crash in ip_nat_pptp
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=15db34702cfafd24acc60295cf14861e497502ab;p=linux-beck.git

[NETFILTER]: Fix crash in ip_nat_pptp

When an inbound PPTP_IN_CALL_REQUEST packet is received the
PPTP NAT helper uses a NULL pointer in pointer arithmentic to
calculate the offset in the packet which needs to be mangled
and corrupts random memory or crashes.

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

diff --git a/net/ipv4/netfilter/ip_nat_helper_pptp.c b/net/ipv4/netfilter/ip_nat_helper_pptp.c
index e546203f5662..8ad7b36e242d 100644
--- a/net/ipv4/netfilter/ip_nat_helper_pptp.c
+++ b/net/ipv4/netfilter/ip_nat_helper_pptp.c
@@ -315,7 +315,7 @@ pptp_inbound_pkt(struct sk_buff **pskb,
 		break;
 	case PPTP_IN_CALL_REQUEST:
 		/* only need to nat in case PAC is behind NAT box */
-		break;
+		return NF_ACCEPT;
 	case PPTP_WAN_ERROR_NOTIFY:
 		pcid = &pptpReq->wanerr.peersCallID;
 		break;