From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754816AbdJINyY (ORCPT ); Mon, 9 Oct 2017 09:54:24 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:41927 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754245AbdJIMo6 (ORCPT ); Mon, 9 Oct 2017 08:44:58 -0400 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" , "=?UTF-8?q?Paul=20H=C3=BCber?=" Date: Mon, 09 Oct 2017 13:44:25 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 139/192] l2tp: avoid use-after-free caused by l2tp_ip_backlog_recv 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 3.16.49-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Paul Hüber commit 51fb60eb162ab84c5edf2ae9c63cf0b878e5547e upstream. l2tp_ip_backlog_recv may not return -1 if the packet gets dropped. The return value is passed up to ip_local_deliver_finish, which treats negative values as an IP protocol number for resubmission. Signed-off-by: Paul Hüber Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings --- net/l2tp/l2tp_ip.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/l2tp/l2tp_ip.c +++ b/net/l2tp/l2tp_ip.c @@ -390,7 +390,7 @@ static int l2tp_ip_backlog_recv(struct s drop: IP_INC_STATS(sock_net(sk), IPSTATS_MIB_INDISCARDS); kfree_skb(skb); - return -1; + return 0; } /* Userspace will call sendmsg() on the tunnel socket to send L2TP