From owner-svn-src-head@freebsd.org  Sun Jan  8 18:46:02 2017
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 1A1ACCA59A7;
 Sun,  8 Jan 2017 18:46:02 +0000 (UTC)
 (envelope-from markj@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 D54D815EA;
 Sun,  8 Jan 2017 18:46:01 +0000 (UTC)
 (envelope-from markj@FreeBSD.org)
Received: from repo.freebsd.org ([127.0.1.37])
 by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id v08Ik10j022730;
 Sun, 8 Jan 2017 18:46:01 GMT (envelope-from markj@FreeBSD.org)
Received: (from markj@localhost)
 by repo.freebsd.org (8.15.2/8.15.2/Submit) id v08Ik1Ff022729;
 Sun, 8 Jan 2017 18:46:01 GMT (envelope-from markj@FreeBSD.org)
Message-Id: <201701081846.v08Ik1Ff022729@repo.freebsd.org>
X-Authentication-Warning: repo.freebsd.org: markj set sender to
 markj@FreeBSD.org using -f
From: Mark Johnston <markj@FreeBSD.org>
Date: Sun, 8 Jan 2017 18:46:01 +0000 (UTC)
To: src-committers@freebsd.org, svn-src-all@freebsd.org,
 svn-src-head@freebsd.org
Subject: svn commit: r311695 - 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: Sun, 08 Jan 2017 18:46:02 -0000

Author: markj
Date: Sun Jan  8 18:46:00 2017
New Revision: 311695
URL: https://svnweb.freebsd.org/changeset/base/311695

Log:
  Release the ND6 list lock before making a prefix off-link in nd6_timer().
  
  Reported by:	Jim <BM-2cWfdfG5CJsquqkJyry7hZT9LypbSEWEkQ@bitmessage.ch>
  X-MFC With:	r306829

Modified:
  head/sys/netinet6/nd6.c

Modified: head/sys/netinet6/nd6.c
==============================================================================
--- head/sys/netinet6/nd6.c	Sun Jan  8 18:33:13 2017	(r311694)
+++ head/sys/netinet6/nd6.c	Sun Jan  8 18:46:00 2017	(r311695)
@@ -910,7 +910,7 @@ nd6_timer(void *arg)
 	struct nd_defrouter *dr, *ndr;
 	struct nd_prefix *pr, *npr;
 	struct in6_ifaddr *ia6, *nia6;
-	bool onlink_locked;
+	uint64_t genid;
 
 	TAILQ_INIT(&drq);
 	LIST_INIT(&prl);
@@ -1022,7 +1022,6 @@ nd6_timer(void *arg)
 	}
 
 	ND6_WLOCK();
-	onlink_locked = false;
 restart:
 	LIST_FOREACH_SAFE(pr, &V_nd_prefix, ndpr_entry, npr) {
 		/*
@@ -1045,22 +1044,19 @@ restart:
 			continue;
 		}
 		if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0) {
-			if (!onlink_locked) {
-				onlink_locked = ND6_ONLINK_TRYLOCK();
-				if (!onlink_locked) {
-					ND6_WUNLOCK();
-					ND6_ONLINK_LOCK();
-					onlink_locked = true;
-					ND6_WLOCK();
-					goto restart;
-				}
-			}
+			genid = V_nd6_list_genid;
+			nd6_prefix_ref(pr);
+			ND6_WUNLOCK();
+			ND6_ONLINK_LOCK();
 			(void)nd6_prefix_offlink(pr);
+			ND6_ONLINK_UNLOCK();
+			ND6_WLOCK();
+			nd6_prefix_rele(pr);
+			if (genid != V_nd6_list_genid)
+				goto restart;
 		}
 	}
 	ND6_WUNLOCK();
-	if (onlink_locked)
-		ND6_ONLINK_UNLOCK();
 
 	while ((pr = LIST_FIRST(&prl)) != NULL) {
 		LIST_REMOVE(pr, ndpr_entry);