Commit 91bd6b1e authored Oct 23, 2008 by Wei Yongjun Committed by David S. Miller Oct 23, 2008

sctp: Drop ICMP packet too big message with MTU larger than current PMTU



If ICMP packet too big message is received with MTU larger than current
PMTU, SCTP will still accept this ICMP message and sync the PMTU of assoc
with the wrong MTU.

Endpoing A                 Endpoint B
(ESTABLISHED)              (ESTABLISHED)
ICMP         --------->
(packet too big, MTU too larger)
                           sync PMTU

This patch fixed the problem by drop that ICMP message.

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent dcc51417

net/sctp/input.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -369,7 +369,7 @@ static void sctp_add_backlog(struct sock sk, struct sk_buff skb)
		void sctp_icmp_frag_needed(struct sock sk, struct sctp_association asoc,
		struct sctp_transport *t, __u32 pmtu)
		{
		if (!t \|\| (t->pathmtu == pmtu))
		if (!t \|\| (t->pathmtu <= pmtu))
		return;

		if (sock_owned_by_user(sk)) {

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