From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH net] ip_tunnel: Don't allow to add the same tunnel multiple times. Date: Mon, 22 Sep 2014 16:45:56 -0400 (EDT) Message-ID: <20140922.164556.736459936247558402.davem@davemloft.net> References: <20140922071108.GY6390@secunet.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: steffen.klassert@secunet.com Return-path: Received: from shards.monkeyblade.net ([149.20.54.216]:53763 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754487AbaIVUp6 (ORCPT ); Mon, 22 Sep 2014 16:45:58 -0400 In-Reply-To: <20140922071108.GY6390@secunet.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Steffen Klassert Date: Mon, 22 Sep 2014 09:11:08 +0200 > When we try to add an already existing tunnel, we don't return > an error. Instead we continue and call ip_tunnel_update(). > This means that we can change existing tunnels by adding > the same tunnel multiple times. It is even possible to change > the tunnel endpoints of the fallback device. > > We fix this by returning an error if we try to add an existing > tunnel. > > Signed-off-by: Steffen Klassert > --- > > I was not able to find a commit that introduced this bug. > Looks like ipip and ip_gre had similar bugs already with > the initial git commit. I'm not so sure about this, perhaps the behavior of being able to change a configuration using an ADD call is intentional?