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[209.132.180.67]) by mx.google.com with ESMTP id g186si16976182pfc.58.2019.03.26.12.22.24; Tue, 26 Mar 2019 12:22:39 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=ujWgSVmP; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732119AbfCZTVi (ORCPT + 99 others); Tue, 26 Mar 2019 15:21:38 -0400 Received: from mail.kernel.org ([198.145.29.99]:48804 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731467AbfCZTVi (ORCPT ); Tue, 26 Mar 2019 15:21:38 -0400 Received: from mail-wr1-f44.google.com (mail-wr1-f44.google.com [209.85.221.44]) (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 7B5222146F 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-f44.google.com with SMTP id w1so15788952wrp.2 for ; Tue, 26 Mar 2019 12:21:37 -0700 (PDT) X-Gm-Message-State: APjAAAX/HPnEpo6v8RJb1XeTV0stDKjMPuzg5NVFqLL4AuHN3R4XJtho 3G4WmKbrcw5nqyAKAZ7UTH2ffJBhtqGyzTZkgtzyGw== 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: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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!