From 2017a72c070033830b460d31cd4703f9d2ec0d56 Mon Sep 17 00:00:00 2001
From: Thomas Graf <tgraf@suug.ch>
Date: Mon, 10 Dec 2007 16:53:05 -0800
Subject: [IPv4] ESP: Discard dummy packets introduced in rfc4303

RFC4303 introduces dummy packets with a nexthdr value of 59
to implement traffic confidentiality. Such packets need to
be dropped silently and the payload may not be attempted to
be parsed as it consists of random chunk.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/ipv4/esp4.c | 5 +++++
 1 file changed, 5 insertions(+)

(limited to 'net/ipv4')

diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c
index c31bccb9b52..1738113268b 100644
--- a/net/ipv4/esp4.c
+++ b/net/ipv4/esp4.c
@@ -9,6 +9,7 @@
 #include <linux/pfkeyv2.h>
 #include <linux/random.h>
 #include <linux/spinlock.h>
+#include <linux/in6.h>
 #include <net/icmp.h>
 #include <net/protocol.h>
 #include <net/udp.h>
@@ -224,6 +225,10 @@ static int esp_input(struct xfrm_state *x, struct sk_buff *skb)
 
 	/* ... check padding bits here. Silly. :-) */
 
+	/* RFC4303: Drop dummy packets without any error */
+	if (nexthdr[1] == IPPROTO_NONE)
+		goto out;
+
 	iph = ip_hdr(skb);
 	ihl = iph->ihl * 4;
 
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