From: Stephen Hemminger <shemminger@vyatta.com>
To: David Miller <davem@davemloft.net>
Cc: netdev@vger.kernel.org, Pekka Savola <pekkas@netcore.fi>
Subject: [PATCH] TCP: check min TTL on received ICMP packets
Date: Thu, 18 Mar 2010 14:27:32 -0700 [thread overview]
Message-ID: <20100318142732.4de0f8d7@nehalam> (raw)
This adds RFC5082 checks for TTL on received ICMP packets.
It adds some security against spoofed ICMP packets
disrupting GTSM protected sessions.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
---
Please apply to 2.6.33 since it basically a "follow correct RFC"
fix to original GTSM patch.
--- a/net/ipv4/tcp_ipv4.c 2010-03-18 11:10:14.396384060 -0700
+++ b/net/ipv4/tcp_ipv4.c 2010-03-18 11:13:09.115759682 -0700
@@ -370,6 +370,11 @@ void tcp_v4_err(struct sk_buff *icmp_skb
if (sk->sk_state == TCP_CLOSE)
goto out;
+ if (unlikely(iph->ttl < inet_sk(sk)->min_ttl)) {
+ NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
+ goto out;
+ }
+
icsk = inet_csk(sk);
tp = tcp_sk(sk);
seq = ntohl(th->seq);
next reply other threads:[~2010-03-18 23:51 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-18 21:27 Stephen Hemminger [this message]
2010-03-20 4:08 ` [PATCH] TCP: check min TTL on received ICMP packets David Miller
2010-03-21 0:05 ` Stephen Hemminger
2010-03-22 1:12 ` David Miller
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