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=-4.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS 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 0D40BC43381 for ; Mon, 25 Mar 2019 23:42:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 54B4021473 for ; Mon, 25 Mar 2019 23:42:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=networkplumber-org.20150623.gappssmtp.com header.i=@networkplumber-org.20150623.gappssmtp.com header.b="Hr2sodvi" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730100AbfCYXm0 (ORCPT ); Mon, 25 Mar 2019 19:42:26 -0400 Received: from mail-pl1-f194.google.com ([209.85.214.194]:39908 "EHLO mail-pl1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726061AbfCYXm0 (ORCPT ); Mon, 25 Mar 2019 19:42:26 -0400 Received: by mail-pl1-f194.google.com with SMTP id b65so697980plb.6 for ; Mon, 25 Mar 2019 16:42:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=VSgTSStmyucgCQUG0l9SmzKEAqnVSFBHIEtJeqjh0Xs=; b=Hr2sodviulFCbh9JwInjMrl66OSdt4DR498G9P5YOCX1xfHEuql6GzifbTtbDa08u5 vrMuRFR9TRow0yDrd97cltle2gtcJJEeWaX5ZFTENNYSpqSzzqunQ/42or7ZVfDkBRgV cIbyKRltVv4V1XrTkO0q9LzEQIh5Z7LHdgyFRxruu1/fl+E14iPuVKlvaNAu+MTUe5Du 9KTe0bshsJAy/JMGKyq4JJiWRFe1T/mKxN4FwVQxxRP5yYAx1hr6rq97p+NJDJeiFcSI cK7vzk6D3qt7ywa6lfgx021X6EQpcKlaQUQCJJ2jkkgrUgjP28QS6zBNLE+il1jmsH8W 9MpQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=VSgTSStmyucgCQUG0l9SmzKEAqnVSFBHIEtJeqjh0Xs=; b=V6QxtzEDIUzlocVyCIkfaIapWbBXaKMdWShAuE7G7R4WvKFJXOEXRi87i54LsFrbdc 1EIGrmIrMTvctzgQKsJQZjeet1RtSelM9LAUMlewsgfZiELhuMgNSbMUCQxjSBBcVog3 c+Y4Z/rW6+ERZ6EPvaVK/lLVDyPEkXxdkObRd63w2lvqli52V5uwUDq0uRWy5WqyYnnU etIV9Z98dRbC0U8eoNd8AcCN5STf4Hw+qlzUz2miMyIi/pb0jT6Ijid+Zu3a7oF3OCoB QUxLDXre+7y+Yw1rLgn4g7Q1NLyZOydOKt8zzFmvzIFISdAAhd0JRIFfxZD5t9nQ47cu ga1Q== X-Gm-Message-State: APjAAAV8G3c4y0lM8NPV9SV6BYB21zS2vjaDq+iumQsX3q9T7ZUBUN2e TJUj6DLLNYq8hwAODg+qrGoBd6dfTj4CoA== X-Google-Smtp-Source: APXvYqx87hbg4Xed6wnjIWYIiKi+u3b5PK3yqnpj9m8ovw9xr0GeWVPIvLfGlpjDs6em7hjkgNlPAA== X-Received: by 2002:a17:902:1c9:: with SMTP id b67mr27150786plb.176.1553557345500; Mon, 25 Mar 2019 16:42:25 -0700 (PDT) Received: from shemminger-XPS-13-9360 (204-195-22-127.wavecable.com. [204.195.22.127]) by smtp.gmail.com with ESMTPSA id a13sm18829204pgw.91.2019.03.25.16.42.24 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 25 Mar 2019 16:42:25 -0700 (PDT) Date: Mon, 25 Mar 2019 16:42:21 -0700 From: Stephen Hemminger To: Matthew Garrett Cc: jmorris@namei.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, dhowells@redhat.com, Alexei Starovoitov , netdev@vger.kernel.org, Chun-Yi Lee , Daniel Borkmann , Kees Cook , Andy Lutomirski , Will Drewry Subject: Re: [PATCH 23/27] bpf: Restrict kernel image access functions when the kernel is locked down Message-ID: <20190325164221.5d8687bd@shemminger-XPS-13-9360> In-Reply-To: <20190325220954.29054-24-matthewgarrett@google.com> References: <20190325220954.29054-1-matthewgarrett@google.com> <20190325220954.29054-24-matthewgarrett@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: On Mon, 25 Mar 2019 15:09:50 -0700 Matthew Garrett wrote: > From: David Howells > > There are some bpf functions can be used to read kernel memory: > bpf_probe_read, bpf_probe_write_user and bpf_trace_printk. These allow > private keys in kernel memory (e.g. the hibernation image signing key) to > be read by an eBPF program and kernel memory to be altered without > restriction. > > Completely prohibit the use of BPF when the kernel is locked down. > > Suggested-by: Alexei Starovoitov > Signed-off-by: David Howells > cc: netdev@vger.kernel.org > cc: Chun-Yi Lee > cc: Alexei Starovoitov > Cc: Daniel Borkmann > Signed-off-by: Matthew Garrett Wouldn't this mean that Seccomp won't work in locked down mode?