From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752548AbdGLWVH (ORCPT ); Wed, 12 Jul 2017 18:21:07 -0400 Received: from Chamillionaire.breakpoint.cc ([146.0.238.67]:57738 "EHLO Chamillionaire.breakpoint.cc" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752441AbdGLWVG (ORCPT ); Wed, 12 Jul 2017 18:21:06 -0400 Date: Thu, 13 Jul 2017 00:19:35 +0200 From: Florian Westphal To: Richard Weinberger Cc: Florian Westphal , "linux-kernel@vger.kernel.org" , Pablo Neira Ayuso , David Miller , netfilter-devel@vger.kernel.org, coreteam@netfilter.org, "netdev@vger.kernel.org" , David Gstir , kaber@trash.net, "keescook@chromium.org" Subject: Re: nf_conntrack: Infoleak via CTA_ID and CTA_EXPECT_ID Message-ID: <20170712221935.GC12347@breakpoint.cc> References: <20170630193544.GM9307@breakpoint.cc> <20170630195547.GN9307@breakpoint.cc> <20170701103504.GO9307@breakpoint.cc> <1daf1401-5009-df1c-a77a-a271811c0760@nod.at> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1daf1401-5009-df1c-a77a-a271811c0760@nod.at> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Richard Weinberger wrote: > Am 01.07.2017 um 12:35 schrieb Florian Westphal: > > The compare on removal is not needed afaics, and its also not used when > > doing lookup to begin with, so we can just recompute it? > > Isn't this a way too much overhead? I don't think so. This computation only occurs when we dump events to userspace. > I personally favor Pablo's per-cpu counter approach. > That way the IDs are unique again and we get rid of the info leak without > much effort. I have not seen these patches so can't really comment.