[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 e546203..8ad7b36 100644
--- a/net/ipv4/netfilter/ip_nat_helper_pptp.c
+++ b/net/ipv4/netfilter/ip_nat_helper_pptp.c
@@ -315,7 +315,7 @@
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;