From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-20.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EF015C433F5 for ; Mon, 20 Sep 2021 16:54:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D97256152B for ; Mon, 20 Sep 2021 16:54:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245054AbhITQzy (ORCPT ); Mon, 20 Sep 2021 12:55:54 -0400 Received: from mail.kernel.org ([198.145.29.99]:39722 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243599AbhITQv6 (ORCPT ); Mon, 20 Sep 2021 12:51:58 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id DA7BF61245; Mon, 20 Sep 2021 16:49:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1632156578; bh=JKb5xj6pEm3/ajHDs40qfOjoV8+Jz2PznN0JRk/mzaY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=U8oprgtt5Pfe8toyk3LMqnOZGzpI7Gno9i6+eqDOQph+dngNR5RQ/bEKU6rAJ4BAD S9Ks7vbBMF3hcNBL31xp+mC8TIsG/8r7gQLMbrHGPO70o7G8TtfAOFdyDpcMtys8yg lyrfBAeDO+hkWhpygz9cd6Owp0FAUyeTKZJqiQIE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Xiyu Yang , Xin Xiong , Xin Tan , "David S. Miller" Subject: [PATCH 4.4 122/133] net/l2tp: Fix reference count leak in l2tp_udp_recv_core Date: Mon, 20 Sep 2021 18:43:20 +0200 Message-Id: <20210920163916.611967028@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210920163912.603434365@linuxfoundation.org> References: <20210920163912.603434365@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Xiyu Yang commit 9b6ff7eb666415e1558f1ba8a742f5db6a9954de upstream. The reference count leak issue may take place in an error handling path. If both conditions of tunnel->version == L2TP_HDR_VER_3 and the return value of l2tp_v3_ensure_opt_in_linear is nonzero, the function would directly jump to label invalid, without decrementing the reference count of the l2tp_session object session increased earlier by l2tp_tunnel_get_session(). This may result in refcount leaks. Fix this issue by decrease the reference count before jumping to the label invalid. Fixes: 4522a70db7aa ("l2tp: fix reading optional fields of L2TPv3") Signed-off-by: Xiyu Yang Signed-off-by: Xin Xiong Signed-off-by: Xin Tan Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/l2tp/l2tp_core.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/net/l2tp/l2tp_core.c +++ b/net/l2tp/l2tp_core.c @@ -990,8 +990,10 @@ static int l2tp_udp_recv_core(struct l2t } if (tunnel->version == L2TP_HDR_VER_3 && - l2tp_v3_ensure_opt_in_linear(session, skb, &ptr, &optr)) + l2tp_v3_ensure_opt_in_linear(session, skb, &ptr, &optr)) { + l2tp_session_dec_refcount(session); goto error; + } l2tp_recv_common(session, skb, ptr, optr, hdrflags, length, payload_hook); l2tp_session_dec_refcount(session);