From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-1091448-1522880385-2-8469102695688032541 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no ("Email failed DMARC policy for domain") X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.249, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='US', FromHeader='com', MailFrom='org' X-Spam-charsets: plain='us-ascii' X-IgnoreVacation: yes ("Email failed DMARC policy for domain") X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: linux-api-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=fm2; t= 1522880384; b=GmB6PqtHcdrSKgz6r6ZlneL/iVoLop7mvwxGngd+UT9H2ykP+Q NAyj0fndtcLSXbN5yOAQtHSf6mWd7K8grzYRKqgbzgTYvEQmfoIS2YFb/9E2GTuN jxfBHbBeUCIQSGCmUKOLDiJFMYSRx0zC87VzkqmsL5DgaHiBOq4O2AgGsZDxoEvS pA3Q4E3TtxfAprYH7pYGYmPeUZuwqn4+ZhZFD/gtK72PNqny6S8EEEKHOalG/FhW HZJlxp3/dwdoK1pxEp4XLZpjtCt85vfpDgnjxCDr8SJlvNXj0PUuFXKwwEJqkcTf 7h+Acn4L08VzCew20LxPuBm7e64zkqK5k5mw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=from:in-reply-to:references:to:cc:subject :mime-version:content-type:content-id:date:message-id:sender :list-id; s=fm2; t=1522880384; bh=iKXa7/nJwge7fvQtjvO2txoNZRWdop fpFFOCp2axUME=; b=WAd7hBu/v40OlUCnGwTKXVgjJhjy4Llf2vPHSyHa6YztQk m57BbFJXeaI96sKb+8GptKLhHZQKhv5xd8nmcacr3zKmWxhJvVJf+ODniM5vDOcd y07NlpykjK1wtC31qE+Gh5mYX4CzhMM016SrlUssjQi5D6cNum+FGybLNHnXhFxp SCa6Dn8AGXK8b6I+DH0umeWCqu/2eKqaPAlp17dWSyhI0fWIJvE/9+1Q3L11rxox SmhD3Iedwl2emrFpEPgb9BCmLVMsXKL5zdtTqGbLjwNb46p9BAIi+GFngYim7szi 9y8DfACIlyKJuGrEJD34yy5YR648VVlCBPLGBWYg== ARC-Authentication-Results: i=1; mx1.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=fail (p=none,has-list-id=yes,d=none) header.from=redhat.com; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=linux-api-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-cm=none score=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=redhat.com header.result=pass header_is_org_domain=yes; x-vs=clean score=-100 state=0 Authentication-Results: mx1.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=fail (p=none,has-list-id=yes,d=none) header.from=redhat.com; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=linux-api-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-cm=none score=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=redhat.com header.result=pass header_is_org_domain=yes; x-vs=clean score=-100 state=0 X-ME-VSCategory: clean X-CM-Envelope: MS4wfJuUdnXrMEbUlySRNLO1P4tqbB9JqG8IKNlUVZf1RCEX49P78nz+m6+4X9c3lvZ5Rc8boWsBk9ZiH5pG3VWcw3w838nppbj0R/E0rshiqrJwy82FMyCa M4RnN3n5HFUZxF5jJmh45x5mZLi0ooGflVmCP5zUBSzeDQ75f4TWztJivph12hXW8klhKw6DbAGBx2vo9cc6j18u0FfSFT03/RJwfymiZSYQcXG/q+6dr6g0 X-CM-Analysis: v=2.3 cv=WaUilXpX c=1 sm=1 tr=0 a=UK1r566ZdBxH71SXbqIOeA==:117 a=UK1r566ZdBxH71SXbqIOeA==:17 a=kj9zAlcOel0A:10 a=Kd1tUaAdevIA:10 a=1XWaLZrsAAAA:8 a=VwQbUJbxAAAA:8 a=gR4Rho1IovKi-j0URZMA:9 a=CjuIK1q_8ugA:10 a=x8gzFH9gYPwA:10 a=AjGcO6oz07-iQ99wixmX:22 X-ME-CMScore: 0 X-ME-CMCategory: none Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752366AbeDDWTd (ORCPT ); Wed, 4 Apr 2018 18:19:33 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:42548 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751749AbeDDWTb (ORCPT ); Wed, 4 Apr 2018 18:19:31 -0400 Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: References: <1119.1522858644@warthog.procyon.org.uk> To: Jann Horn Cc: dhowells@redhat.com, Alexei Starovoitov , Andy Lutomirski , Greg Kroah-Hartman , "Theodore Y. Ts'o" , Matthew Garrett , Linus Torvalds , Ard Biesheuvel , James Morris , Alan Cox , Linux Kernel Mailing List , Justin Forbes , linux-man , joeyli , LSM List , Linux API , Kees Cook , linux-efi Subject: Re: An actual suggestion (Re: [GIT PULL] Kernel lockdown for secure boot) MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <15405.1522880367.1@warthog.procyon.org.uk> Date: Wed, 04 Apr 2018 23:19:27 +0100 Message-ID: <15406.1522880367@warthog.procyon.org.uk> Sender: linux-api-owner@vger.kernel.org X-Mailing-List: linux-api@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: Jann Horn wrote: > > Uh, no. bpf, for example, can be used to modify kernel memory. > > I'm pretty sure bpf isn't supposed to be able to modify arbitrary > kernel memory. AFAIU if you can use BPF to write to arbitrary kernel > memory, that's a bug; with CAP_SYS_ADMIN, you can read from userspace, > write to userspace, and read from kernelspace, but you shouldn't be > able to write to kernelspace. Ah - you may be right. I seem to have misremembered what Joey Lee wrote in his patch description. David