From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-1431546-1518323694-2-9750910150772361404 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.001, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='US', FromHeader='uk', MailFrom='org' X-Spam-charsets: plain='UTF-8' X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: stable-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=arctest; t=1518323694; b=aDlmqzo9UmrQA5wAk+RE8Yo1j32gcS56ssf/j3LGmicFhk/ SCmzcwBJ5/DJg7zJpFe8lMKpw5wFBkbYcup1D174baEqkGDhHwUG9cUwuzZIRdQ3 +nmueh1NXX2mjGomDiOj0SzeA1RE61Bp07doJP9Y8EgItO1VkL+356dS9xDDJR1P /Gj0XsJzvmXyQRksqvKA+M06mXwnwv+Z2J9/elrnIKU8X1zSNtqzIed5HEjPOqye y3qOGJLikoHTEPLyzR+mWp987flmVAA8c1p8jZretm7a61mWtdgKfsPBJYfa0kfJ 0Psr4pxTPVRIR4MiMYowhhFvDS0aWOdvfndZ/Xw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=content-type:content-transfer-encoding :mime-version:from:to:cc:date:message-id:subject:in-reply-to :sender:list-id; s=arctest; t=1518323694; bh=0cqEIWE5e92yl511yjk iho/2yctmaOfKfzmLackuJHU=; b=qVfnRpCcGYyNur+dyAAv6c8a0ObZsbesKGB AZsccna1tmZkG6QcS0wKe94horwd/1IH08nLFL5RcXIqVDo+63EZoAtEC9JZ3mWB DPt4hmxWg6wTtkMPSKGNW6mSC2UaHDSrSJIkJTJ6WMVlvcvN3PvmT39SQEkGXT9c c9T4z+QLcjH5qlmuj9qfFY+PdxmjQL1k/U0+T+l9285+rECgY52Cck9DfyAlTEDg Q//cBri2Be9VHS04p0rjkpWPepQLkZ8sthFHY9roAIWzpiX611SdCTtkxNKGRA4j 4YvctaBQIy26RBASx1tgTxzY+OgwHTkcm+4G+i051PQpZ8Tulug== ARC-Authentication-Results: i=1; mx5.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=decadent.org.uk; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=decadent.org.uk header.result=pass header_is_org_domain=yes Authentication-Results: mx5.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=decadent.org.uk; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=decadent.org.uk header.result=pass header_is_org_domain=yes Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753047AbeBKEeU (ORCPT ); Sat, 10 Feb 2018 23:34:20 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:41671 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752929AbeBKEeG (ORCPT ); Sat, 10 Feb 2018 23:34:06 -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, "Guillaume Nault" , "David S. Miller" Date: Sun, 11 Feb 2018 04:31:11 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 032/136] l2tp: ensure sessions are freed after their PPPOL2TP socket 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: stable-owner@vger.kernel.org X-Mailing-List: stable@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 3.16.54-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Guillaume Nault commit cdd10c9627496ad25c87ce6394e29752253c69d3 upstream. If l2tp_tunnel_delete() or l2tp_tunnel_closeall() deletes a session right after pppol2tp_release() orphaned its socket, then the 'sock' variable of the pppol2tp_session_close() callback is NULL. Yet the session is still used by pppol2tp_release(). Therefore we need to take an extra reference in any case, to prevent l2tp_tunnel_delete() or l2tp_tunnel_closeall() from freeing the session. Since the pppol2tp_session_close() callback is only set if the session is associated to a PPPOL2TP socket and that both l2tp_tunnel_delete() and l2tp_tunnel_closeall() hold the PPPOL2TP socket before calling pppol2tp_session_close(), we're sure that pppol2tp_session_close() and pppol2tp_session_destruct() are paired and called in the right order. So the reference taken by the former will be released by the later. Signed-off-by: Guillaume Nault Signed-off-by: David S. Miller [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings --- net/l2tp/l2tp_ppp.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/net/l2tp/l2tp_ppp.c +++ b/net/l2tp/l2tp_ppp.c @@ -456,11 +456,11 @@ static void pppol2tp_session_close(struc BUG_ON(session->magic != L2TP_SESSION_MAGIC); - if (sock) { + if (sock) inet_shutdown(sock, 2); - /* Don't let the session go away before our socket does */ - l2tp_session_inc_refcount(session); - } + + /* Don't let the session go away before our socket does */ + l2tp_session_inc_refcount(session); } /* Really kill the session socket. (Called from sock_put() if