From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:50174 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730278AbeKLFsQ (ORCPT ); Mon, 12 Nov 2018 00:48:16 -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: Sun, 11 Nov 2018 19:49:05 +0000 Message-ID: Subject: [PATCH 3.16 309/366] l2tp: fix missing refcount drop in pppol2tp_tunnel_ioctl() In-Reply-To: Sender: stable-owner@vger.kernel.org List-ID: 3.16.61-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Guillaume Nault commit f664e37dcc525768280cb94321424a09beb1c992 upstream. If 'session' is not NULL and is not a PPP pseudo-wire, then we fail to drop the reference taken by l2tp_session_get(). Fixes: ecd012e45ab5 ("l2tp: filter out non-PPP sessions in pppol2tp_tunnel_ioctl()") Signed-off-by: Guillaume Nault Signed-off-by: David S. Miller [bwh: Backported to 3.16: Also call session->deref in both cases] Signed-off-by: Ben Hutchings --- net/l2tp/l2tp_ppp.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) --- a/net/l2tp/l2tp_ppp.c +++ b/net/l2tp/l2tp_ppp.c @@ -1231,15 +1231,22 @@ static int pppol2tp_tunnel_ioctl(struct l2tp_session_get(sock_net(sk), tunnel, stats.session_id, true); - if (session && session->pwtype == L2TP_PWTYPE_PPP) { - err = pppol2tp_session_ioctl(session, cmd, - arg); + if (!session) { + err = -EBADR; + break; + } + if (session->pwtype != L2TP_PWTYPE_PPP) { if (session->deref) session->deref(session); l2tp_session_dec_refcount(session); - } else { err = -EBADR; + break; } + + err = pppol2tp_session_ioctl(session, cmd, arg); + if (session->deref) + session->deref(session); + l2tp_session_dec_refcount(session); break; } #ifdef CONFIG_XFRM