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=-5.1 required=3.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,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 F4178C433F4 for ; Wed, 19 Sep 2018 15:48:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8A7FB2151B for ; Wed, 19 Sep 2018 15:48:43 +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="Vq2xuS0Y" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8A7FB2151B 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 S1732589AbeISV1M (ORCPT ); Wed, 19 Sep 2018 17:27:12 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:37376 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732471AbeISV1M (ORCPT ); Wed, 19 Sep 2018 17:27:12 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.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=IdRFGzKgPx+mSTnrPlzqczQqyy1yZQVp2bL/yTgOAQI=; b=Vq2xuS0Y5YqnXuG0mopx8p+kk It7zUchJuzQhpSkYR141iuHsXezA/XtlmV4Z32VLDvFqUfmL0BoG0PnBaRqz3j0NUFDfwhjtSrBS0 SkbH2dPR5i4/2dWt1vocHyo3eCozD9QYf9td2bPUtGwWIWAOFSYlFdlqX+/N5+K9LM0uhIrYBtNF7 3vus5bXXHBX0I2YAnGxPSM/Cr/J5eD1Vuf/wsP4fW7yxAZvbgdA/reCCvvrW4+Gs1J1O+2b9yUw9c TLp+s89ELrLNy6/mb+Ex6X9goVIL+1VHh8VDa7PR9BO/HXFNWis7IzDQv4YN+/yxgqwlWGlH1zp4p c23OGM7Hw==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1g2eiN-00040C-Lj; Wed, 19 Sep 2018 15:48:32 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id D5B4E2024E441; Wed, 19 Sep 2018 17:48:28 +0200 (CEST) Date: Wed, 19 Sep 2018 17:48:28 +0200 From: Peter Zijlstra To: "Schaufler, Casey" Cc: Jiri Kosina , Thomas Gleixner , 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: <20180919154828.GJ24124@hirez.programming.kicks-ass.net> References: <99FC4B6EFCEFD44486C35F4C281DC6732144EA58@ORSMSX107.amr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <99FC4B6EFCEFD44486C35F4C281DC6732144EA58@ORSMSX107.amr.corp.intel.com> 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 Mon, Sep 17, 2018 at 04:09:33PM +0000, Schaufler, Casey wrote: > diff --git a/kernel/ptrace.c b/kernel/ptrace.c > index 5c5e7cb597cd..202a4d9c2af7 100644 > --- a/kernel/ptrace.c > +++ b/kernel/ptrace.c > @@ -330,9 +330,7 @@ int __ptrace_may_access(struct task_struct *task, unsigned int mode) > !ptrace_has_cap(mm->user_ns, mode)))) > return -EPERM; > > - if (!(mode & PTRACE_MODE_NOACCESS_CHK)) > - return security_ptrace_access_check(task, mode); > - return 0; > + return security_ptrace_access_check(task, mode); > } > > bool ptrace_may_access(struct task_struct *task, unsigned int mode) > diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c > index 161a4f29f860..30d21142e9fe 100644 > --- a/security/selinux/hooks.c > +++ b/security/selinux/hooks.c > @@ -2215,7 +2215,12 @@ static int selinux_ptrace_access_check(struct task_struct *child, > { > u32 sid = current_sid(); > u32 csid = task_sid(child); > + struct av_decision avd; > > + if (mode == PTRACE_MODE_IBPB) > + return avc_has_perm_noaudit(&selinux_state, sid, csid, > + SECCLASS_PROCESS, PROCESS__PTRACE, > + 0, &avd); > if (mode & PTRACE_MODE_READ) > return avc_has_perm(&selinux_state, > sid, csid, SECCLASS_FILE, FILE__READ, NULL); > As far as I can tell, this still has: avc_has_perm_noaudit() security_compute_av() read_lock(&state->ss->policy_rwlock); avc_insert() spin_lock_irqsave(); avc_denied() avc_update_node() spin_lock_irqsave(); under the scheduler's raw_spinlock_t, which are invalid lock nestings.