From ed4be04b8fd80e8c47727191ee7385f418587652 Mon Sep 17 00:00:00 2001
From: Matthias Schiffer <mschiffer@universe-factory.net>
Date: Fri, 15 Apr 2011 16:04:10 +0200
Subject: Drop short packages

---
 quicktun.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/quicktun.c b/quicktun.c
index 6899a05..4c5c585 100644
--- a/quicktun.c
+++ b/quicktun.c
@@ -2,6 +2,7 @@
 #include <linux/ethtool.h>
 #include <linux/if_arp.h>
 #include <linux/ip.h>
+#include <linux/ipv6.h>
 #include <linux/netdevice.h>
 #include <linux/udp.h>
 #include <net/dst.h>
@@ -101,10 +102,15 @@ static void quicktun_udp_data_ready(struct sock *sk, int bytes)
 
 	switch (tun->flags & QUICKTUN_MODE_MASK) {
 	case QUICKTUN_MODE_ETHERNET:
+		if (len < ETH_HLEN)
+			goto drop;
 		skb->protocol = eth_type_trans(skb, tun->dev);
 		break;
 
 	case QUICKTUN_MODE_IP:
+		if (len < sizeof(struct iphdr))
+			goto drop;
+
 		__skb_tunnel_rx(skb, tun->dev);
 		skb_reset_network_header(skb);
 
@@ -113,6 +119,8 @@ static void quicktun_udp_data_ready(struct sock *sk, int bytes)
 			skb->protocol = htons(ETH_P_IP);
 			break;
 		case 0x60:
+			if (len < sizeof(struct ipv6hdr))
+				goto drop;
 			skb->protocol = htons(ETH_P_IPV6);
 			break;
 		default:
@@ -135,8 +143,7 @@ static void quicktun_udp_data_ready(struct sock *sk, int bytes)
 	kfree_skb(skb);
 }
 
-static int
-quicktun_net_change_mtu(struct net_device *dev, int new_mtu)
+static int quicktun_net_change_mtu(struct net_device *dev, int new_mtu)
 {
 	if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
 		return -EINVAL;
-- 
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