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=-3.5 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no 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 22EBAC43461 for ; Thu, 17 Sep 2020 17:43:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CB73020872 for ; Thu, 17 Sep 2020 17:43:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=gmx.net header.i=@gmx.net header.b="AZ54eguB" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726402AbgIQRnp (ORCPT ); Thu, 17 Sep 2020 13:43:45 -0400 Received: from mout.gmx.net ([212.227.17.22]:34289 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726593AbgIQRlF (ORCPT ); Thu, 17 Sep 2020 13:41:05 -0400 X-Greylist: delayed 400 seconds by postgrey-1.27 at vger.kernel.org; Thu, 17 Sep 2020 13:40:46 EDT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1600364424; bh=AtpaLz5T0doiwW45rKTXhN9OPitxExJgCcjhtNz0x98=; h=X-UI-Sender-Class:Date:From:To:Cc:Subject:References:In-Reply-To; b=AZ54eguBjBVpgfrIyJQ0SsL2DbHWtMwIHELHexCYssWjgRYBO475Odahy/r27XRnm Ko3nlAolpxQqLoaPfZuDLPzAu76osTD6vmmgZAWj8rrYTPHYfElYy3nzEOB3yom1u1 pU/Ymjp7/OXsClocPacrbIv2nF3gNU9P0nV5ZqbI= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from ubuntu ([79.150.73.70]) by mail.gmx.com (mrgmx104 [212.227.17.174]) with ESMTPSA (Nemesis) id 1MOA3F-1k7jNd13M1-00OYlk; Thu, 17 Sep 2020 19:32:28 +0200 Date: Thu, 17 Sep 2020 19:32:09 +0200 From: John Wood To: Jann Horn Cc: Kees Cook , John Wood , Kernel Hardening , Matthew Wilcox , Jonathan Corbet , Alexander Viro , Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Luis Chamberlain , Iurii Zaikin , James Morris , "Serge E. Hallyn" , linux-doc@vger.kernel.org, kernel list , linux-fsdevel , linux-security-module Subject: Re: [RFC PATCH 1/6] security/fbfam: Add a Kconfig to enable the fbfam feature Message-ID: <20200917173209.GA3637@ubuntu> References: <20200910202107.3799376-1-keescook@chromium.org> <20200910202107.3799376-2-keescook@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Provags-ID: V03:K1:R5ZkovHXd6oUrfcKmVNF76tjDIn4TAPnGKJDjlfIyNZe9chhDUt Esh/G27SFDsxpGe3eTJoHTkEtlKWjMzGSWaf4NY77J0KknyMS4Kn3FifB6lpQ9wSsgJm6aR GWM1FOcKZJ7nuqitu7T9wYT0c/x3o41HPECfOOo6S21tnSwhYbEzXGPZ8NK/o/DFW7XB3Cr jdRHD05vg7a/XdyN7NGVA== X-UI-Out-Filterresults: notjunk:1;V03:K0:/6CMB5QJPcI=:X8wmKlFpZ253znFDwPLRvb YlZ/RdCI9xCVOBo9khl6lMLnAtBDlf5hMUNoOiyWZOv1J4QhAiinM2EoW6kY+qc8hjBJl2874 9bMUGQjsWdx4JH9U5brc4MuC19cin2DtZ29eZvfSI96b/elLNnR9aTov1mQB/C5Eimqy4fn+3 9Nf5mi/WXSFRHDUYdkLT8IszB7q6thtLFe2tvdQdPiPTRvVggd2/V0NX3n/t8N7/R+eCLy7lo 68v/prC3P0LDKQ+MsH3wLOPe1kT9PYMxyCYZsb5EN5iD67JB+g8PBu+1B0UA4Z048/10ti3SE WBTOV59GkNvF1RMmhH7mB7wW8J3GsMXdEfsTvEl98flGZc8dVunjEYCs8SNhdYTyUtklweh1b tSLoGPdXya8K0TH79aqwk++pYYNHLo9XWonep/6IkJBZCb32iDfJvruIeklbxHTtLgwJzuPpG 86NTtzC11WP5tG+UpwhgE1A6XzX0ItSGweTHyBkR20t1yP05fmU48TuhjvwJDnZzLxx+W9CKg 0ZmvuiW7I6Jrx5Vu26y4FLlWxROQn+C96iSZDx9M9G/hYncOeeY13LyUbh5wAVg1cblVy4QLD iQzVNhCq0J/ncRiijX1j7rDxLIFiwFZ5SI36ewts0CarJmfwiFE7lzIi+Xwg/+PeLHK8nnNLu DkN1N0tORU5izm1eHOOKBV208HzG4zOw/uTKyxEcsncBin1AKCVMaBFTJjV5WEKxvNjxU97mi zkLokRyZdGski1EAt1kPj3oG3AM2QZ7YRa6PeSsWKIPFqL4YeHgAxowfhHzQfNAAYTRFz6geZ Bn/7XX6nPF7sxU3E5mzUu643lR3FWnXR4STPrrP/P25HBZ6IYiQjGUzd11xrNx78P7H0yPm9S x9ii8+mMdTo+hTZ8ThfI2h5HyP40BIL2lFq5V7wafb8nRnoiq2Sdu3EvAhe8PRiReC8A8T7ci wSQf+RvoGk8M9D8n1TF4g5icDvjJsssP8O5usLHZAIIfum5N/qwYm0dRHsaGDwcEnS7lr2CY9 BUJxYj5K3maLD/TaiF4AOmUIqZ+8pL7UAzpKTFkXA+JqapWjrdFAlftP2UPCet8sAsd4M6WSX qS7gKahFwtQGMhnhzlsB2FF+5OciezSR/rQWZE6EoMRN6hqTok023YEUIjq28NmnUzBCwhjcy LEuRV4FCDPe0Y7DnC/SknZzc5eO758PryvZxDUo87FL3KE6/El5axTRhxOkyWI2+ou/MBoEqs DhSvYP2Mo0rcNzsdPPid0MuNieSbeSjCHLNBOaQ== Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 10, 2020 at 11:21:58PM +0200, Jann Horn wrote: > On Thu, Sep 10, 2020 at 10:21 PM Kees Cook wrote= : > > From: John Wood > > > > Add a menu entry under "Security options" to enable the "Fork brute > > force attack mitigation" feature. > [...] > > +config FBFAM > > Please give this a more descriptive name than FBFAM. Some name where, > if a random kernel developer sees an "#ifdef" with that name in some > random piece of kernel code, they immediately have a rough idea for > what kind of feature this is. > > Perhaps something like THROTTLE_FORK_CRASHES. Or something else that > is equally descriptive. Ok, understood. This will be fixed for the next version. Thanks. > > + bool "Fork brute force attack mitigation" > > + default n > > "default n" is superfluous and should AFAIK be omitted. Ok. I will remove it. Thanks. > > + help > > + This is a user defense that detects any fork brute force att= ack > > + based on the application's crashing rate. When this measure = is > > + triggered the fork system call is blocked. > > This help text claims that the mitigation will block fork(), but patch > 6/6 actually kills the process hierarchy. Sorry, it's a mistake. It was the first idea but finally the implementatio= n changed and this description not was modified. Apologies. It will be fixed for the next version. Thanks, John Wood