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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_2 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 50B9EC06511 for ; Mon, 1 Jul 2019 19:57:18 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 243A121721 for ; Mon, 1 Jul 2019 19:57:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 243A121721 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id B5D7E6B0003; Mon, 1 Jul 2019 15:57:17 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B0E408E0003; Mon, 1 Jul 2019 15:57:17 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9FCB68E0002; Mon, 1 Jul 2019 15:57:17 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from mail-pg1-f205.google.com (mail-pg1-f205.google.com [209.85.215.205]) by kanga.kvack.org (Postfix) with ESMTP id 6B5DD6B0003 for ; Mon, 1 Jul 2019 15:57:17 -0400 (EDT) Received: by mail-pg1-f205.google.com with SMTP id f18so1585607pgb.10 for ; Mon, 01 Jul 2019 12:57:17 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-original-authentication-results:x-gm-message-state:message-id :subject:from:to:cc:date:in-reply-to:references:mime-version :content-transfer-encoding; bh=jXYUgVoeg0Ab1pwU7lf8dCL3mrqrPDKb0dW0TJUKuuU=; b=VaX2HRtFA/RAYCYiunRsSBxuVXwekmeTicK9gebQlyilYf4WyQD7UJcSElF7Topleh BjOZAtksvCInugx8teP4VuEq5gAUQQzmf2+7qhC6QmQVK0mTu5V87Rme3Kbl/a8fXEtO txD2mHlHoS4rFOvxM16h7oqbLUukP8t9ulEhVTBCqqtdDcDP4yAN37+KutsMHgZn1W/6 3ioiAQa9+gUuFFgcrGLvpvAFADk1+cYPUKIJy4y3cisPr/yRWeoM7eXyGdh7rcNk1ofN ANprgyABo+mLYkWMGVEdW4XJ+6laC9PvZcI+52tdZ86FdBZznUsbOAHw+o/NnPOH7+D7 /iVQ== X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of yu-cheng.yu@intel.com designates 134.134.136.24 as permitted sender) smtp.mailfrom=yu-cheng.yu@intel.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=intel.com X-Gm-Message-State: APjAAAXB4SKY3rtfV2RzcYyD6cJlvmUlSggImRsEMDzr1aF4MauOJWef c/X4BV7TcFy9Bv9BiDD6BL0iYWEp0/e4SWxnBdC/j+J12gEy8u4H66qZjtwP0Es8IaE3jM7yS36 RWcixTfTACrY4zZ1/y01Tv4WvjlWeMSZQHalqdrXC5N0xdK+25YNOCFmlgOuhmLCm4g== X-Received: by 2002:a63:f1c:: with SMTP id e28mr26104565pgl.147.1562011037003; Mon, 01 Jul 2019 12:57:17 -0700 (PDT) X-Google-Smtp-Source: APXvYqwSdxFJ5/gayf1jS0eCF8I/8XdAsMzHE/6iPGvW4gHSIaNobcjyVTAPRYk8j2++q6xfhjOm X-Received: by 2002:a63:f1c:: with SMTP id e28mr26104515pgl.147.1562011036322; Mon, 01 Jul 2019 12:57:16 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1562011036; cv=none; d=google.com; s=arc-20160816; b=tUAi+8t+kBelpF3rJq9yXmDZ7ac5+C4yGhpL4y2gIgxN8cJEbuxa7NAOJ/zXrCWdoB ax0RJx8IG5dYu1i+xk5/UD90+NupDu0Ic8Hogc70yK2uDBTAYIZja8mAn07ugCZZdkGn WxWWuW8VYig4jGSYu0gnASC8Vkaxa7BwrxNqJ25rwhtKHg7xfgsuGwr9l/qABILiui5F 7L8P02F4EnTbd2GPSlq5b2wLMpqDuanOulvCw80KVG+poXE3HgMDOrRExdEjwTC5YZ2R /tmty9VfB3DXmUfFhd0SZ3Cr+FpoelRfnRLv2tJJm24fgo46r/KsjmsaFt3/w5Lokqe7 VACg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:mime-version:references:in-reply-to:date :cc:to:from:subject:message-id; bh=jXYUgVoeg0Ab1pwU7lf8dCL3mrqrPDKb0dW0TJUKuuU=; b=gbuaLng5Odrixgq+IL3SMGXVd3LiWrL+TjNpp/ioPEa++1caOyQddBJuGGAWNH3La5 OUH77MlwzlCR9Gm9YHn/ZzdfUKB5hICTAtz2lvpgXjlJxwH8oY9Pu7t2fPc+7eEZPiXL 0LddQsjvgjpI3cKPGzDumDILqfKXGJWQaYWwQTzA4vx4+axyeJKFExk3S51c7SRq2Wz6 Xo5urj/adxUdizENrXyjOPtspnNUorh1MEBY7GWuUfHHbk6v/5YUT3heUwJY7iaG7gy9 dI3BZ/vIESgeKkIwKBaoSOk+XWMMKwyFllIr3PqoDTVmhw2ECpDND5OXWQUXGtZchzvq Ki5A== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of yu-cheng.yu@intel.com designates 134.134.136.24 as permitted sender) smtp.mailfrom=yu-cheng.yu@intel.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: from mga09.intel.com (mga09.intel.com. [134.134.136.24]) by mx.google.com with ESMTPS id z10si9965426pgh.30.2019.07.01.12.57.16 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 01 Jul 2019 12:57:16 -0700 (PDT) Received-SPF: pass (google.com: domain of yu-cheng.yu@intel.com designates 134.134.136.24 as permitted sender) client-ip=134.134.136.24; Authentication-Results: mx.google.com; spf=pass (google.com: domain of yu-cheng.yu@intel.com designates 134.134.136.24 as permitted sender) smtp.mailfrom=yu-cheng.yu@intel.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=intel.com X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 01 Jul 2019 12:57:15 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.63,440,1557212400"; d="scan'208";a="361947326" Received: from yyu32-desk1.sc.intel.com ([10.144.153.205]) by fmsmga005.fm.intel.com with ESMTP; 01 Jul 2019 12:57:15 -0700 Message-ID: Subject: Re: [RFC PATCH 3/3] Prevent user from writing to IBT bitmap. From: Yu-cheng Yu To: Andy Lutomirski Cc: X86 ML , "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , LKML , "open list:DOCUMENTATION" , Linux-MM , linux-arch , Linux API , Arnd Bergmann , Balbir Singh , Borislav Petkov , Cyrill Gorcunov , Dave Hansen , Eugene Syromiatnikov , Florian Weimer , "H.J. Lu" , Jann Horn , Jonathan Corbet , Kees Cook , Mike Kravetz , Nadav Amit , Oleg Nesterov , Pavel Machek , Peter Zijlstra , Randy Dunlap , "Ravi V. Shankar" , Vedvyas Shanbhogue , Dave Martin Date: Mon, 01 Jul 2019 12:48:56 -0700 In-Reply-To: References: <20190628194158.2431-1-yu-cheng.yu@intel.com> <20190628194158.2431-3-yu-cheng.yu@intel.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.28.1-2 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Sat, 2019-06-29 at 16:44 -0700, Andy Lutomirski wrote: > On Fri, Jun 28, 2019 at 12:50 PM Yu-cheng Yu wrote: > > > > The IBT bitmap is visiable from user-mode, but not writable. > > > > Signed-off-by: Yu-cheng Yu > > > > --- > > arch/x86/mm/fault.c | 7 +++++++ > > 1 file changed, 7 insertions(+) > > > > diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c > > index 59f4f66e4f2e..231196abb62e 100644 > > --- a/arch/x86/mm/fault.c > > +++ b/arch/x86/mm/fault.c > > @@ -1454,6 +1454,13 @@ void do_user_addr_fault(struct pt_regs *regs, > > * we can handle it.. > > */ > > good_area: > > +#define USER_MODE_WRITE (FAULT_FLAG_WRITE | FAULT_FLAG_USER) > > + if (((flags & USER_MODE_WRITE) == USER_MODE_WRITE) && > > + (vma->vm_flags & VM_IBT)) { > > + bad_area_access_error(regs, hw_error_code, address, vma); > > + return; > > + } > > + > > Just make the VMA have VM_WRITE and VM_MAYWRITE clear. No new code > like this should be required. Ok, I will work on that. Thanks, Yu-cheng