From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Tue, 13 Mar 2018 09:56:00 +0000 (+0100)
Subject: fixup: sctp: verify size of a new chunk in _sctp_make_chunk()
X-Git-Tag: v3.18.100~1
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d8930f132b54a3abf0d12d506e9e9204ce23abb8;p=thirdparty%2Fkernel%2Fstable.git

fixup: sctp: verify size of a new chunk in _sctp_make_chunk()

Ben writes:
> > +	int chunklen;
> > +
> > +	chunklen = sizeof(*chunk_hdr) + paylen;
>
> I think this length still needs to be rounded up (with WORD_ROUND here,
> instead of SCTP_PAD4 upstream).

So here's a fix for this problem.


Reported-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c
index 6d48cbf6465d0..bbf6abb6ae3c3 100644
--- a/net/sctp/sm_make_chunk.c
+++ b/net/sctp/sm_make_chunk.c
@@ -1369,7 +1369,7 @@ static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc,
 	struct sock *sk;
 	int chunklen;
 
-	chunklen = sizeof(*chunk_hdr) + paylen;
+	chunklen = WORD_ROUND(sizeof(*chunk_hdr) + paylen);
 	if (chunklen > SCTP_MAX_CHUNK_LEN)
 		goto nodata;