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=-1.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_PASS autolearn=unavailable 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 04944C43381 for ; Tue, 26 Mar 2019 19:21:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C35D02075D for ; Tue, 26 Mar 2019 19:21:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553628105; bh=3G5OLDJGt2VUj4PBtRdTYEfb1U+H5AzAVGZwalvrssE=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-ID:From; b=iKUyYh87ew0F8BfVHb2zH+leH7FiOK7RapfFUZyPuRe3bqcWT+4CzsqytA+fJGuo8 Kgfg9OXo4nINIFb08x86Doy/LRFqHVryjilm6lZrpzKgQ9AUvQe39iJwRu3NRaMVT4 mrxegOtw6GiDuooOiCMnUj9iGhk79fRcOpCBGVnQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731467AbfCZTVp (ORCPT ); Tue, 26 Mar 2019 15:21:45 -0400 Received: from mail.kernel.org ([198.145.29.99]:48780 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726266AbfCZTVi (ORCPT ); Tue, 26 Mar 2019 15:21:38 -0400 Received: from mail-wr1-f46.google.com (mail-wr1-f46.google.com [209.85.221.46]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 73BF8208E4 for ; Tue, 26 Mar 2019 19:21:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553628097; bh=3G5OLDJGt2VUj4PBtRdTYEfb1U+H5AzAVGZwalvrssE=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=ujWgSVmPTiCJxHUFiLdNFRIQ3LNz/y2sT6zjgX6M5tpeyZMPlFA7/kAhrZsRmfsEw BfqVVBiytLlSlOES3pK4D6WEj0zlUUELO7S2EfISBp5BLpATL8aSExwGrgqPQUNbvh ei7uRzKraSVTBZ4hUpujhNNzMk5rDWg3hnDrs07Y= Received: by mail-wr1-f46.google.com with SMTP id h4so106628wre.7 for ; Tue, 26 Mar 2019 12:21:37 -0700 (PDT) X-Gm-Message-State: APjAAAUyGM0VPRHV+nTOY1aRMWrBmMicknKXoVR2LL6Fr5/OHsKYSmmL +bQC76PQTHEIHi5GR+SG13UAWlH0JmzZSuQBrjET2A== X-Google-Smtp-Source: APXvYqxcunQWBDndSLRqy9+hfd85lsPv4VZV9ONiALbX5mgkPo4ruMBSbrDRvugQ9Go9DnUG8bauRTNb2ulhmq8wsgk= X-Received: by 2002:a5d:53d0:: with SMTP id a16mr185634wrw.309.1553628096107; Tue, 26 Mar 2019 12:21:36 -0700 (PDT) MIME-Version: 1.0 References: <20190326182742.16950-1-matthewgarrett@google.com> <20190326182742.16950-23-matthewgarrett@google.com> In-Reply-To: <20190326182742.16950-23-matthewgarrett@google.com> From: Andy Lutomirski Date: Tue, 26 Mar 2019 12:21:24 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH V31 22/25] bpf: Restrict bpf when kernel lockdown is in confidentiality mode To: Matthew Garrett Cc: James Morris , LSM List , LKML , David Howells , Linux API , Andrew Lutomirski , Alexei Starovoitov , Matthew Garrett , Network Development , Chun-Yi Lee , Daniel Borkmann Content-Type: text/plain; charset="UTF-8" Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: On Tue, Mar 26, 2019 at 11:28 AM 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. Disable them if the kernel has been locked down in > confidentiality mode. > :) This is yet another reason to get the new improved bpf_probe_user_read stuff landed!