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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 71352C77B7C for ; Fri, 26 May 2023 22:27:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243227AbjEZW1R (ORCPT ); Fri, 26 May 2023 18:27:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43542 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244353AbjEZW1N (ORCPT ); Fri, 26 May 2023 18:27:13 -0400 Received: from mail-pl1-x649.google.com (mail-pl1-x649.google.com [IPv6:2607:f8b0:4864:20::649]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9F454E47 for ; Fri, 26 May 2023 15:27:10 -0700 (PDT) Received: by mail-pl1-x649.google.com with SMTP id d9443c01a7336-1ae79528ad4so8392175ad.3 for ; Fri, 26 May 2023 15:27:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1685140030; x=1687732030; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=E+kn5jvpzlh+utylQKrm+3JtysqFVAJXSZK4V7SHQK0=; b=LrJysw0bLgoRVpiuVdvbFTCyaw8iGCc0NyWU0iWouBiAQAUjsUqN9jJKiP2cGCreDB xemsueFR1JoUwQWpWwGZYcovVd0LmB1H0Yhs6GGvd0FkszbezXMrn6vD6vzXA5qQiznj GfJK4YjHrB+ux5NJgQgTyySjkF+q2vuLpy5wjXJl5hssH3TxR47HkR+FH0sX+BDztWe5 NC+/tXE5f3x4HoBYeDqKg6mo4rOTDoTddjxSWSsTKzT4HjqN92DbhS9IPPfoJ+EIJD9K d54R4zERsnCD+ho9k9iHNMtpfIMmwB3dxvaXVIom5hnkiJrfw5109lTawwiGZsc9R01C YZ/w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1685140030; x=1687732030; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=E+kn5jvpzlh+utylQKrm+3JtysqFVAJXSZK4V7SHQK0=; b=R9VcRYxSFEjvBFl6okOV+Da9ejpy+vSjPRNFMmRozCcFQAB9n0ltvmDiI3pfxrolqf ozb64VMilExhJk10iN2EBs9Rs7O42EIYOU3JIjVITQCVCRBBL6nBFJXOTsFYlGzyMwwz bTMh2ojv3FMaqJFltzPAe/A9XTsT9Yx36X3jPunznMIftYqh6daL4XZolyBazWEJ/ovH L1yChhCSkIzfV/lrW5wvchJTpx0hlBZBL2DQnlJnZtNWHkRJ2sn9516S+kAUvvhBIzXz fN8qkIw+MgB85y3L3aN+S+TeuJ3gGYYzd7oiy5NQmOfCWU7xa+w1sNCYpOmSVmsbf28f rLPw== X-Gm-Message-State: AC+VfDz8qsgUcaFEg3MB/N6tPvBQw4Y89oExTb/BH+KZ9JWW2ngv34xQ rhfuWg92i+OzV34AroCfm/QG/PmN8yo= X-Google-Smtp-Source: ACHHUZ4TYWcASHRXWe6Fi6LR2A+91ZBssr+QyfpjfRxDwnOBSS6XeqCRVPHw234WOwLCb5HXnjkb5CaOL4A= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a17:902:788d:b0:1ae:549f:af6e with SMTP id q13-20020a170902788d00b001ae549faf6emr920128pll.7.1685140030058; Fri, 26 May 2023 15:27:10 -0700 (PDT) Date: Fri, 26 May 2023 15:27:08 -0700 In-Reply-To: Mime-Version: 1.0 References: <20230525183347.2562472-1-mhal@rbox.co> <20230525183347.2562472-2-mhal@rbox.co> <016686aa-fedc-08bf-df42-9451bba9f82e@rbox.co> Message-ID: Subject: Re: [PATCH 1/3] KVM: x86: Fix out-of-bounds access in kvm_recalculate_phys_map() From: Sean Christopherson To: Michal Luczaj Cc: pbonzini@redhat.com, shuah@kernel.org, kvm@vger.kernel.org Content-Type: text/plain; charset="us-ascii" Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Fri, May 26, 2023, Michal Luczaj wrote: > On 5/26/23 18:17, Sean Christopherson wrote: > > On Fri, May 26, 2023, Michal Luczaj wrote: > >> Maybe it's not important, but what about moving xapic_id_mismatch > >> (re)initialization after "retry:"? > > > > Oof, good catch. I think it makes sense to move max_id (re)initialization too, > > even though I can't imagine it would matter in practice. > > Right, I forgot that max APIC ID can decrease along the way. Actually, we don't want to reset max_id. That would allow userspace or the guest to put KVM into an infinite loop, e.g. by toggling the APIC of the vCPU with the highest x2APIC ID between enabled and disabled. The downside of not shrinking the size is quite negligible.