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=-5.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, 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 87394C04AB5 for ; Thu, 6 Jun 2019 18:18:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6D1052083D for ; Thu, 6 Jun 2019 18:18:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730511AbfFFSSh (ORCPT ); Thu, 6 Jun 2019 14:18:37 -0400 Received: from mga14.intel.com ([192.55.52.115]:43197 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727559AbfFFSSh (ORCPT ); Thu, 6 Jun 2019 14:18:37 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga103.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 06 Jun 2019 11:18:36 -0700 X-ExtLoop1: 1 Received: from sjchrist-coffee.jf.intel.com (HELO linux.intel.com) ([10.54.74.36]) by orsmga005.jf.intel.com with ESMTP; 06 Jun 2019 11:18:36 -0700 Date: Thu, 6 Jun 2019 11:18:36 -0700 From: Sean Christopherson To: Eugene Korenevsky , kvm@vger.kernel.org, Paolo Bonzini Subject: Re: [PATCH v4 1/2] kvm: vmx: fix limit checking in get_vmx_mem_address() Message-ID: <20190606181835.GH23169@linux.intel.com> References: <20190605211739.GA21798@dnote> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20190605211739.GA21798@dnote> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Thu, Jun 06, 2019 at 12:17:39AM +0300, Eugene Korenevsky wrote: > Intel SDM vol. 3, 5.3: > The processor causes a > general-protection exception (or, if the segment is SS, a stack-fault > exception) any time an attempt is made to access the following addresses > in a segment: > - A byte at an offset greater than the effective limit > - A word at an offset greater than the (effective-limit – 1) > - A doubleword at an offset greater than the (effective-limit – 3) > - A quadword at an offset greater than the (effective-limit – 7) > > Therefore, the generic limit checking error condition must be > > exn = (off > limit + 1 - access_len) = (off + access_len - 1 > limit) > > but not > > exn = (off + access_len > limit) > > as for now. > > Also avoid integer overflow of `off` at 32-bit KVM by casting it to u64. > > Note: access length is currently sizeof(u64) which is incorrect. This > will be fixed in the subsequent patch. > > Signed-off-by: Eugene Korenevsky > --- Reviewed-by: Sean Christopherson