From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755128AbdL1RvG (ORCPT ); Thu, 28 Dec 2017 12:51:06 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:58903 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754333AbdL1RN7 (ORCPT ); Thu, 28 Dec 2017 12:13:59 -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: Thu, 28 Dec 2017 17:05:44 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 116/204] l2tp: check ps->sock before running pppol2tp_session_ioctl() 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 3.16.52-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Guillaume Nault commit 5903f594935a3841137c86b9d5b75143a5b7121c upstream. When pppol2tp_session_ioctl() is called by pppol2tp_tunnel_ioctl(), the session may be unconnected. That is, it was created by pppol2tp_session_create() and hasn't been connected with pppol2tp_connect(). In this case, ps->sock is NULL, so we need to check for this case in order to avoid dereferencing a NULL pointer. 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_ppp.c | 3 +++ 1 file changed, 3 insertions(+) --- a/net/l2tp/l2tp_ppp.c +++ b/net/l2tp/l2tp_ppp.c @@ -1007,6 +1007,9 @@ static int pppol2tp_session_ioctl(struct session->name, cmd, arg); sk = ps->sock; + if (!sk) + return -EBADR; + sock_hold(sk); switch (cmd) {