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=-7.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 22347C433DB for ; Tue, 12 Jan 2021 08:07:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C166622D2C for ; Tue, 12 Jan 2021 08:07:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404484AbhALIHj (ORCPT ); Tue, 12 Jan 2021 03:07:39 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:25631 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729208AbhALIHj (ORCPT ); Tue, 12 Jan 2021 03:07:39 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1610438772; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=e98jFtAnO+UtW7Rwri+cMU4/wIA3Ib5qoGAOd0HCxb8=; b=Txbu8y7BPf1HL0vfozcTxckFkAv2Xu2VFjHEgXZgJwDWdQiZL9d7TueZQlNZdndWiEcL9e LHyzIKigGz05gVrzMXEGfE1RQpGZvMcHL8OzTN1iS+x/m8TEGcxIoPEbL6fsMyw7YEQsOD ID7zGxHhBge/CrcWfUVrY7/o65icbnQ= Received: from mail-ej1-f72.google.com (mail-ej1-f72.google.com [209.85.218.72]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-536-XSrdlajlORmAYo1AuudSVQ-1; Tue, 12 Jan 2021 03:06:11 -0500 X-MC-Unique: XSrdlajlORmAYo1AuudSVQ-1 Received: by mail-ej1-f72.google.com with SMTP id k3so684389ejr.16 for ; Tue, 12 Jan 2021 00:06:10 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=e98jFtAnO+UtW7Rwri+cMU4/wIA3Ib5qoGAOd0HCxb8=; b=muggxo79Ofg90tSpM5Jw/2IV8uOhEdOekWPqsTnUCneIi75WSQ6cO8sAeoIOuwpX2h +5NNUDpYfJkTN7cMk8UIQGTueVUe8ChI6ZnrR++WhZeuRmNuwnroXaihlnXLRgRq4re4 brl1p0CEYG2OQ8pAxmJjX36qpaj+dtkcupbJ/rF6jRv6RK7UUapH/2VQ2B95Jd623xmT 8DdSRjuIKL69o64fCjH+bMULGq3Jq4Q9fCucXGpYVgUHzad1ZpDKPC2oP555EaHV8sQu XaUpZBEh+wDp7T2j7kuD/ZhspUFwB85fIOiB2Xv7B5PKiVz/Axz7eFFsyhwsWYc9W1W7 dpfg== X-Gm-Message-State: AOAM530LfZ23wOayoBuei/myt6Eyl8cr79u+iRAII4hB3RI2QF/yrX6h 8VrUoCvjp8gLPhIZk7NRnBhMaLaah+xQlQseJt9HWzCmCSlZs24IvZNvF6i2z3uGxSZn2VgYW3H H+3uBaAM0ArzJdKzBlwHVzFwE X-Received: by 2002:a17:906:c10e:: with SMTP id do14mr2483308ejc.166.1610438769919; Tue, 12 Jan 2021 00:06:09 -0800 (PST) X-Google-Smtp-Source: ABdhPJxC9sIchIaPbpCd6LbN/mEZzRXK+530541sS7ArG8ztI+ctpVEyq5i7XV2NYKlXWG8KFV1ouA== X-Received: by 2002:a17:906:c10e:: with SMTP id do14mr2483289ejc.166.1610438769757; Tue, 12 Jan 2021 00:06:09 -0800 (PST) Received: from ?IPv6:2001:b07:6468:f312:c8dd:75d4:99ab:290a? ([2001:b07:6468:f312:c8dd:75d4:99ab:290a]) by smtp.gmail.com with ESMTPSA id zn5sm844167ejb.111.2021.01.12.00.06.08 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 12 Jan 2021 00:06:09 -0800 (PST) Subject: Re: UBSAN: shift-out-of-bounds in kvm_vcpu_after_set_cpuid To: Sean Christopherson , Jim Mattson Cc: syzbot , Borislav Petkov , "H . Peter Anvin" , Joerg Roedel , kvm list , LKML , Ingo Molnar , syzkaller-bugs , Thomas Gleixner , Vitaly Kuznetsov , Wanpeng Li , the arch/x86 maintainers References: <000000000000d5173d05b7097755@google.com> From: Paolo Bonzini Message-ID: Date: Tue, 12 Jan 2021 09:06:07 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.5.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/01/21 00:01, Sean Christopherson wrote: >> Perhaps cpuid_query_maxphyaddr() should just look at the low 5 bits of >> CPUID.80000008H:EAX? The low 6 bits I guess---yes, that would make sense and it would have also fixed the bug. (Nevertheless it's a good idea to make rsvd_bits more robust as well, as in the commit that Sean referenced. Paolo