From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933331AbdKGAHi (ORCPT ); Mon, 6 Nov 2017 19:07:38 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:52585 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932782AbdKFXyb (ORCPT ); Mon, 6 Nov 2017 18:54:31 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "David S. Miller" , "Guillaume Nault" Date: Mon, 06 Nov 2017 23:03:02 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 159/294] l2tp: hold tunnel while handling genl tunnel updates In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.50-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Guillaume Nault commit 8c0e421525c9eb50d68e8f633f703ca31680b746 upstream. We need to make sure the tunnel is not going to be destroyed by l2tp_tunnel_destruct() concurrently. Fixes: 309795f4bec2 ("l2tp: Add netlink control API for L2TP") Signed-off-by: Guillaume Nault Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings --- net/l2tp/l2tp_netlink.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/net/l2tp/l2tp_netlink.c +++ b/net/l2tp/l2tp_netlink.c @@ -236,8 +236,8 @@ static int l2tp_nl_cmd_tunnel_modify(str } tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]); - tunnel = l2tp_tunnel_find(net, tunnel_id); - if (tunnel == NULL) { + tunnel = l2tp_tunnel_get(net, tunnel_id); + if (!tunnel) { ret = -ENODEV; goto out; } @@ -245,6 +245,8 @@ static int l2tp_nl_cmd_tunnel_modify(str if (info->attrs[L2TP_ATTR_DEBUG]) tunnel->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]); + l2tp_tunnel_dec_refcount(tunnel); + out: return ret; }