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From: Changli Gao <xiaosuo@gmail.com>
To: "David S. Miller" <davem@davemloft.net>
Cc: Patrick McHardy <kaber@trash.net>,
	Pablo Neira Ayuso <pablo@netfilter.org>,
	Eric Dumazet <eric.dumazet@gmail.com>,
	netfilter-devel@vger.kernel.org, netdev@vger.kernel.org,
	Changli Gao <xiaosuo@gmail.com>
Subject: [PATCH] net: check the length of the data before dereferencing it
Date: Mon,  2 Apr 2012 11:10:50 +0800	[thread overview]
Message-ID: <1333336250-4110-1-git-send-email-xiaosuo@gmail.com> (raw)

We should check the length of the data before dereferencing it when parsing
the TCP options.

Signed-off-by: Changli Gao <xiaosuo@gmail.com>
---
 net/ipv4/tcp_input.c |    2 ++
 1 file changed, 2 insertions(+)
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index e886e2f..5099f08 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -3845,6 +3845,8 @@ void tcp_parse_options(const struct sk_buff *skb, struct tcp_options_received *o
 			length--;
 			continue;
 		default:
+			if (length < 2)
+				return;
 			opsize = *ptr++;
 			if (opsize < 2) /* "silly options" */
 				return;

             reply	other threads:[~2012-04-02  3:10 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-04-02  3:10 Changli Gao [this message]
2012-04-02  3:19 ` [PATCH] net: check the length of the data before dereferencing it Eric Dumazet
2012-04-02  3:29   ` David Miller
2012-04-02  3:45     ` Changli Gao
2012-04-02  3:53       ` Eric Dumazet
2012-04-02  3:57         ` David Miller
2012-04-02  3:59           ` Eric Dumazet
2012-04-02  4:47         ` Changli Gao
2012-04-02  4:54           ` Eric Dumazet
2012-04-02  6:27             ` Changli Gao
2012-04-02  6:43               ` Eric Dumazet
2012-04-02  3:45     ` Eric Dumazet
2012-04-02  3:55       ` David Miller
2012-04-02  3:58         ` Eric Dumazet
2012-04-02  4:14           ` David Miller
2012-04-02  3:19 ` David Miller

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