From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-1524142-1518326644-2-15360548054203498764 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=1518326643; b=OcW0GGdCDV/I9aPDtao11KWNuxMd9o+8hLVX358XUzHoD5R kRbzJqsNOCniuIi6aGWAflp4j+V5RlWXqUmytSL6IcRVqr8CYvQpEXM+U6p9o6RB E/von5o4GYHa6Ci7kfs56sWGRzkKAqAvmo0fOkLn1LCShm8CYag11NlFqD8gJttV I3Na1A/E57lNMyr5s76KJh1IpVly1wsua+9UVOl7GYmaXrWEaZ8ytToti93/wbhd u9DfLwH3F+g653V88D7NzPlJydQ1TuhzjxYe/c45kpJkjI6/tsZyrCzFSasafCFO ecY0LbpEGsiIs2yw/iy88bh+fmglPOjkB5sCNfw== 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=1518326643; bh=ImHWs9ZxibUB76TVmc3 SkD6fjJdqyPUDbmODTYCa9rA=; b=SfEohdO68KDeoICy7YmPexftg9koE/Ywh8Z XCeaWnSCnMozFZsn7gMLu2UUX9NkE+3JJ8IEdIPYC7SpF2zOxapWlBAz3MV9Jpcf RYdF9qU+/b2Xarg3PwwOBrm3Hf72blwzz6vsEEky7WVe9aJZ9QCYrQK+yKdlNFF0 DA514XgUYQQJ4NsDqbTddN/W+ZRTS/XZI0mpd3vBkKBIIAJJIJAJ73ic5rsOMrpR 6OxCLV4Kl3mxpq4DBwntV4m7l82GcA7p7JC6V1rRqN8aqa397eKQZlkkew3cS5ma kzv0XG58Yil7Fe2I4qftLTC2lHaJXfyB4ezY4Lfe+PJlImZxEZA== ARC-Authentication-Results: i=1; mx1.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: mx1.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 S1752619AbeBKFXS (ORCPT ); Sun, 11 Feb 2018 00:23:18 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:41345 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752539AbeBKEdk (ORCPT ); Sat, 10 Feb 2018 23:33:40 -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 04:20:06 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 17/79] 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: 3.2.99-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 3.2: 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 @@ -466,11 +466,11 @@ 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); return; }