Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752901AbdDJQKo (ORCPT ); Mon, 10 Apr 2017 12:10:44 -0400 Received: from mx2.suse.de ([195.135.220.15]:37855 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754185AbdDJPeG (ORCPT ); Mon, 10 Apr 2017 11:34:06 -0400 X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "References" From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, =?UTF-8?q?Paul=20H=C3=BCber?= , "David S . Miller" , Jiri Slaby Subject: [PATCH 3.12 027/142] l2tp: avoid use-after-free caused by l2tp_ip_backlog_recv Date: Mon, 10 Apr 2017 17:31:48 +0200 Message-Id: <86cd0c73a229a79215ffdfddf2788cfb73b268cd.1491838390.git.jslaby@suse.cz> X-Mailer: git-send-email 2.12.2 In-Reply-To: References: In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1037 Lines: 34 From: Paul Hüber 3.12-stable review patch. If anyone has any objections, please let me know. =============== [ Upstream commit 51fb60eb162ab84c5edf2ae9c63cf0b878e5547e ] 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: Jiri Slaby --- net/l2tp/l2tp_ip.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/l2tp/l2tp_ip.c b/net/l2tp/l2tp_ip.c index b69b762159ad..c44b3742ae36 100644 --- a/net/l2tp/l2tp_ip.c +++ b/net/l2tp/l2tp_ip.c @@ -383,7 +383,7 @@ static int l2tp_ip_backlog_recv(struct sock *sk, struct sk_buff *skb) 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 -- 2.12.2