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=-2.1 required=3.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID, USER_AGENT_MUTT 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 EA7A9ECE560 for ; Sat, 22 Sep 2018 14:31:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 908252146E for ; Sat, 22 Sep 2018 14:31:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="WS9iI+0F" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 908252146E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728871AbeIVUZc (ORCPT ); Sat, 22 Sep 2018 16:25:32 -0400 Received: from merlin.infradead.org ([205.233.59.134]:50454 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728733AbeIVUZb (ORCPT ); Sat, 22 Sep 2018 16:25:31 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=lSVbdL3HDTceWV3oqY2prchSt6K8Ab3m2RIQmqixTr8=; b=WS9iI+0F13cVwSO3Hx+UsnGE1 Kqx0ZpNmbpD4J0mIL8E1MRrhgNgOp3pDxCKDhsahSZwa/nASkXIP5nSbZgfQ7jT2RvHQUv9ui4rHB DlFXMVK7teok0QKrEjhjNDAQzaeQ/gMJN1VDMBBB8H1z8N59XcobUM36CUnNbdK7WOQifrGNXft3b 1EaVjwaCjUrQA6g1fw8P0KuaDl9kXsDcvIMa336El0CnTJfd2UtUyeux8XEubda3Bvcmg2LJdPCyt j4Ar/9ifwmz/esiZEg2G828bw+RoFVI+e0gkCydiFSuwVpK+d7j58AZZ2DG8MDtK4U/28Xweol5Qo zag3bGVrg==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1g3iwU-00051C-DP; Sat, 22 Sep 2018 14:31:31 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 1E42C2024E445; Sat, 22 Sep 2018 16:31:27 +0200 (CEST) Date: Sat, 22 Sep 2018 16:31:27 +0200 From: Peter Zijlstra To: Thomas Gleixner Cc: Jiri Kosina , "Schaufler, Casey" , Ingo Molnar , Josh Poimboeuf , Andrea Arcangeli , "Woodhouse, David" , Andi Kleen , Tim Chen , "linux-kernel@vger.kernel.org" , "x86@kernel.org" Subject: Re: [PATCH v6 0/3] Harden spectrev2 userspace-userspace protection Message-ID: <20180922143127.GJ24124@hirez.programming.kicks-ass.net> References: <99FC4B6EFCEFD44486C35F4C281DC6732144EA58@ORSMSX107.amr.corp.intel.com> <20180919154828.GJ24124@hirez.programming.kicks-ass.net> <20180922101844.GF24124@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.0 (2018-05-17) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Sep 22, 2018 at 03:30:07PM +0200, Thomas Gleixner wrote: > On Sat, 22 Sep 2018, Thomas Gleixner wrote: > > On Sat, 22 Sep 2018, Peter Zijlstra wrote: > > > This has some unfortunate duplication. > > > > > > Lets go with it for now, but I'll see if I can do something about that > > > later. > > > > Yes, I know. I tried to make the duplication smaller, but all attempts > > ended up being a convoluted mess. I'll try again after applying more > > coffee. > > Lunch and coffee indeed made brain work better. The simple solution was way > too obvious. > --- a/kernel/ptrace.c > +++ b/kernel/ptrace.c > @@ -261,6 +261,9 @@ static int ptrace_check_attach(struct ta > > static int ptrace_has_cap(struct user_namespace *ns, unsigned int mode) > { > + if (mode & PTRACE_MODE_SCHED) > + return false; > + > if (mode & PTRACE_MODE_NOAUDIT) > return has_ns_capability_noaudit(current, ns, CAP_SYS_PTRACE); > else > @@ -328,9 +331,16 @@ static int __ptrace_may_access(struct ta > !ptrace_has_cap(mm->user_ns, mode))) > return -EPERM; > > + if (mode & PTRACE_MODE_SCHED) > + return 0; > return security_ptrace_access_check(task, mode); > } > > +bool ptrace_may_access_sched(struct task_struct *task, unsigned int mode) > +{ > + return __ptrace_may_access(task, mode | PTRACE_MODE_SCHED); > +} Ha!, much nicer. Thanks!