From owner-svn-src-head@freebsd.org  Mon Oct 17 23:25:32 2016
Return-Path: <owner-svn-src-head@freebsd.org>
Delivered-To: svn-src-head@mailman.ysv.freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org
 [IPv6:2001:1900:2254:206a::19:1])
 by mailman.ysv.freebsd.org (Postfix) with ESMTP id ED9FCC164E5;
 Mon, 17 Oct 2016 23:25:32 +0000 (UTC) (envelope-from gnn@FreeBSD.org)
Received: from repo.freebsd.org (repo.freebsd.org
 [IPv6:2610:1c1:1:6068::e6a:0])
 (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
 (Client did not present a certificate)
 by mx1.freebsd.org (Postfix) with ESMTPS id BFA4361C;
 Mon, 17 Oct 2016 23:25:32 +0000 (UTC) (envelope-from gnn@FreeBSD.org)
Received: from repo.freebsd.org ([127.0.1.37])
 by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id u9HNPV1p080226;
 Mon, 17 Oct 2016 23:25:31 GMT (envelope-from gnn@FreeBSD.org)
Received: (from gnn@localhost)
 by repo.freebsd.org (8.15.2/8.15.2/Submit) id u9HNPV91080225;
 Mon, 17 Oct 2016 23:25:31 GMT (envelope-from gnn@FreeBSD.org)
Message-Id: <201610172325.u9HNPV91080225@repo.freebsd.org>
X-Authentication-Warning: repo.freebsd.org: gnn set sender to gnn@FreeBSD.org
 using -f
From: "George V. Neville-Neil" <gnn@FreeBSD.org>
Date: Mon, 17 Oct 2016 23:25:31 +0000 (UTC)
To: src-committers@freebsd.org, svn-src-all@freebsd.org,
 svn-src-head@freebsd.org
Subject: svn commit: r307541 - head/sys/netinet6
X-SVN-Group: head
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
X-BeenThere: svn-src-head@freebsd.org
X-Mailman-Version: 2.1.23
Precedence: list
List-Id: SVN commit messages for the src tree for head/-current
 <svn-src-head.freebsd.org>
List-Unsubscribe: <https://lists.freebsd.org/mailman/options/svn-src-head>,
 <mailto:svn-src-head-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/svn-src-head/>
List-Post: <mailto:svn-src-head@freebsd.org>
List-Help: <mailto:svn-src-head-request@freebsd.org?subject=help>
List-Subscribe: <https://lists.freebsd.org/mailman/listinfo/svn-src-head>,
 <mailto:svn-src-head-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Mon, 17 Oct 2016 23:25:33 -0000

Author: gnn
Date: Mon Oct 17 23:25:31 2016
New Revision: 307541
URL: https://svnweb.freebsd.org/changeset/base/307541

Log:
  Limit the number of mbufs that can be allocated for IPV6_2292PKTOPTIONS
  (and IPV6_PKTOPTIONS).
  
  PR:		100219
  Submitted by:	Joseph Kong
  MFC after:	2 weeks
  Differential Revision:	https://reviews.freebsd.org/D5157

Modified:
  head/sys/netinet6/ip6_output.c

Modified: head/sys/netinet6/ip6_output.c
==============================================================================
--- head/sys/netinet6/ip6_output.c	Mon Oct 17 22:57:41 2016	(r307540)
+++ head/sys/netinet6/ip6_output.c	Mon Oct 17 23:25:31 2016	(r307541)
@@ -1393,6 +1393,15 @@ ip6_ctloutput(struct socket *so, struct 
 	int retval;
 #endif
 
+/*
+ * Don't use more than a quarter of mbuf clusters.  N.B.:
+ * nmbclusters is an int, but nmbclusters * MCLBYTES may overflow
+ * on LP64 architectures, so cast to u_long to avoid undefined
+ * behavior.  ILP32 architectures cannot have nmbclusters
+ * large enough to overflow for other reasons.
+ */
+#define IPV6_PKTOPTIONS_MBUF_LIMIT	((u_long)nmbclusters * MCLBYTES / 4)
+
 	level = sopt->sopt_level;
 	op = sopt->sopt_dir;
 	optname = sopt->sopt_name;
@@ -1448,6 +1457,12 @@ ip6_ctloutput(struct socket *so, struct 
 			{
 				struct mbuf *m;
 
+				if (optlen > IPV6_PKTOPTIONS_MBUF_LIMIT) {
+					printf("ip6_ctloutput: mbuf limit hit\n");
+					error = ENOBUFS;
+					break;
+				}
+
 				error = soopt_getm(sopt, &m); /* XXX */
 				if (error != 0)
 					break;