File linux-2.6-net-sctp-linearize-skb.patch of Package kernel

Date: Mon, 30 Oct 2006 23:41:46 +1100
From: Herbert Xu <herbert.xu@redhat.com>
Subject: [RHEL5 PATCH] RHBZ#212550 [SCTP]: Always linearise packet on input

RHBZ#:
------
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=212550

Description:
------------
[SCTP]: Always linearise packet on input

I was looking at a RHEL5 bug report involving Xen and SCTP
(https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=212550).
It turns out that SCTP wasn't written to handle skb fragments at
all.  The absence of any calls to skb_may_pull is testament to
that.

It just so happens that Xen creates fragmented packets more often
than other scenarios (header & data split when going from domU to
dom0).  That's what caused this bug to show up.

Until someone has the time sits down and audits the entire net/sctp
directory, here is a conservative and safe solution that simply
linearises all packets on input.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

RHEL Version Found:
-------------------
RHEL5

Upstream Status:
----------------
Accepted in Mainline.

-- 
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Email: Herbert Xu ~{PmV>HI~} <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
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--
Proposed Patch:
---------------

diff --git a/net/sctp/input.c b/net/sctp/input.c
index 64f6301..99c0501 100644
--- a/net/sctp/input.c
+++ b/net/sctp/input.c
@@ -135,6 +135,9 @@ int sctp_rcv(struct sk_buff *skb)
 
 	SCTP_INC_STATS_BH(SCTP_MIB_INSCTPPACKS);
 
+	if (skb_linearize(skb))
+		goto discard_it;
+
 	sh = (struct sctphdr *) skb->h.raw;
 
 	/* Pull up the IP and SCTP headers. */