From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936575AbdKPSKB (ORCPT ); Thu, 16 Nov 2017 13:10:01 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:35262 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S936216AbdKPRpu (ORCPT ); Thu, 16 Nov 2017 12:45:50 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Guillaume Nault , "David S. Miller" Subject: [PATCH 4.9 07/39] l2tp: check ps->sock before running pppol2tp_session_ioctl() Date: Thu, 16 Nov 2017 18:42:26 +0100 Message-Id: <20171116174213.613442027@linuxfoundation.org> X-Mailer: git-send-email 2.15.0 In-Reply-To: <20171116174213.321860523@linuxfoundation.org> References: <20171116174213.321860523@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Guillaume Nault [ Upstream commit 5903f594935a3841137c86b9d5b75143a5b7121c ] 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: Greg Kroah-Hartman --- net/l2tp/l2tp_ppp.c | 3 +++ 1 file changed, 3 insertions(+) --- a/net/l2tp/l2tp_ppp.c +++ b/net/l2tp/l2tp_ppp.c @@ -993,6 +993,9 @@ static int pppol2tp_session_ioctl(struct session->name, cmd, arg); sk = ps->sock; + if (!sk) + return -EBADR; + sock_hold(sk); switch (cmd) {