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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 56474C433DF for ; Mon, 29 Jun 2020 20:19:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2DAC620675 for ; Mon, 29 Jun 2020 20:19:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593461945; bh=48s3Xz4kc7u4FZNVKO6n+YOqtbnStGjUXYAV3in3A9Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=gcJriXSD3Ge1H87GkdkSTi60lgUSuOjUVXKejdEl10qJGu+hxWebLCsTx30qPN5wV JIEDxbMo3p/Fhke6NhiGqLN6En3/ucA8T/sLxWMHlBrRWlCV6pTSJ7cOmtAeQspHTm 6We8E/9Jz6PJw23eusgLh0PnTLCxCdROXsYP5ykE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729259AbgF2USc (ORCPT ); Mon, 29 Jun 2020 16:18:32 -0400 Received: from mail.kernel.org ([198.145.29.99]:37054 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732636AbgF2TZl (ORCPT ); Mon, 29 Jun 2020 15:25:41 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A68B425422; Mon, 29 Jun 2020 15:42:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593445374; bh=48s3Xz4kc7u4FZNVKO6n+YOqtbnStGjUXYAV3in3A9Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MeiOJc7HCZTnoEMp1pLZzWFlr4PL9JFQ54a7+Bzewn/A4co5/wL3MZ1MkgkJoPEyR CY511Y2Ivtar23qNBjifB8JGoXLV4IKIgWYTf0eodlHbhQfKkHIM3eEKVTjEu+40ZR Xn9BwRZEsgbuWTiQJYYXKl/0mW9e0YLLNyNTJyS8= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Ridge Kennedy , James Chapman , "David S . Miller" , Guenter Roeck , Greg Kroah-Hartman Subject: [PATCH 4.9 129/191] l2tp: Allow duplicate session creation with UDP Date: Mon, 29 Jun 2020 11:39:05 -0400 Message-Id: <20200629154007.2495120-130-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200629154007.2495120-1-sashal@kernel.org> References: <20200629154007.2495120-1-sashal@kernel.org> MIME-Version: 1.0 X-KernelTest-Patch: http://kernel.org/pub/linux/kernel/v4.x/stable-review/patch-4.9.229-rc1.gz X-KernelTest-Tree: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git X-KernelTest-Branch: linux-4.9.y X-KernelTest-Patches: git://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git X-KernelTest-Version: 4.9.229-rc1 X-KernelTest-Deadline: 2020-07-01T15:39+00:00 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ridge Kennedy commit 0d0d9a388a858e271bb70e71e99e7fe2a6fd6f64 upstream. In the past it was possible to create multiple L2TPv3 sessions with the same session id as long as the sessions belonged to different tunnels. The resulting sessions had issues when used with IP encapsulated tunnels, but worked fine with UDP encapsulated ones. Some applications began to rely on this behaviour to avoid having to negotiate unique session ids. Some time ago a change was made to require session ids to be unique across all tunnels, breaking the applications making use of this "feature". This change relaxes the duplicate session id check to allow duplicates if both of the colliding sessions belong to UDP encapsulated tunnels. Fixes: dbdbc73b4478 ("l2tp: fix duplicate session creation") Signed-off-by: Ridge Kennedy Acked-by: James Chapman Signed-off-by: David S. Miller Cc: Guenter Roeck Signed-off-by: Greg Kroah-Hartman --- net/l2tp/l2tp_core.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c index fdc1de1cb4fa6..c191ea65a6c7f 100644 --- a/net/l2tp/l2tp_core.c +++ b/net/l2tp/l2tp_core.c @@ -351,8 +351,13 @@ int l2tp_session_register(struct l2tp_session *session, spin_lock_bh(&pn->l2tp_session_hlist_lock); + /* IP encap expects session IDs to be globally unique, while + * UDP encap doesn't. + */ hlist_for_each_entry(session_walk, g_head, global_hlist) - if (session_walk->session_id == session->session_id) { + if (session_walk->session_id == session->session_id && + (session_walk->tunnel->encap == L2TP_ENCAPTYPE_IP || + tunnel->encap == L2TP_ENCAPTYPE_IP)) { err = -EEXIST; goto err_tlock_pnlock; } -- 2.25.1