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=-0.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 5661DC38A24 for ; Thu, 7 May 2020 18:53:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2ABB520575 for ; Thu, 7 May 2020 18:53:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="QDKy9YaZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728779AbgEGSxd (ORCPT ); Thu, 7 May 2020 14:53:33 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:57941 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728692AbgEGSxb (ORCPT ); Thu, 7 May 2020 14:53:31 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1588877610; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=3EhH1A9gQMpfXypIl8DH4medFGIIF5ti8TqIyHhZSE0=; b=QDKy9YaZbgJBAs07KOxXaJKW8PS2hP2HEOS9oBRpYujtfrda8VxsU4Fdzr2STiH7rSFITc 7t4fAxYWK1HPSYxSqze1AX/SSXhu2OJbzTy6BkQmKlG/0jMpH2BLn8Mndkg5aqRlVU8D9o 48uovEFB0POmDQcGNV2rpp+ZUCEK5Qg= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-17-Y-p7Je82PyWfiDY1P6m7tw-1; Thu, 07 May 2020 14:53:26 -0400 X-MC-Unique: Y-p7Je82PyWfiDY1P6m7tw-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 5E09E107ACCD; Thu, 7 May 2020 18:53:24 +0000 (UTC) Received: from optiplex-lnx (unknown [10.3.128.26]) by smtp.corp.redhat.com (Postfix) with ESMTPS id E7A721001B07; Thu, 7 May 2020 18:53:18 +0000 (UTC) Date: Thu, 7 May 2020 14:53:15 -0400 From: Rafael Aquini To: Luis Chamberlain Cc: linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, kexec@lists.infradead.org, linux-fsdevel@vger.kernel.org, dyoung@redhat.com, bhe@redhat.com, corbet@lwn.net, keescook@chromium.org, akpm@linux-foundation.org, cai@lca.pw, rdunlap@infradead.org Subject: Re: [PATCH v2] kernel: add panic_on_taint Message-ID: <20200507185315.GH205881@optiplex-lnx> References: <20200507180631.308441-1-aquini@redhat.com> <20200507185046.GY11244@42.do-not-panic.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200507185046.GY11244@42.do-not-panic.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, May 07, 2020 at 06:50:46PM +0000, Luis Chamberlain wrote: > On Thu, May 07, 2020 at 02:06:31PM -0400, Rafael Aquini wrote: > > Another, perhaps less frequent, use for this option would be > > as a mean for assuring a security policy (in paranoid mode) > > case where no single taint is allowed for the running system. > > If used for this purpose then we must add a new TAINT flag for > proc_taint() was used, otherwise we can cheat to show a taint > *did* happen, where in fact it never happened, some punk just > echo'd a value into the kernel's /proc/sys/kernel/tainted. > To accomplish that, the punk would need to be root, though, in which case everything else is doomed, already. > Forunately proc_taint() only allows to *increment* the taint, not > reduce. > > Luis >