From patchwork Thu Feb 25 09:53:46 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 387648 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=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT 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 6355BC433E0 for ; Thu, 25 Feb 2021 09:56:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0998964F36 for ; Thu, 25 Feb 2021 09:56:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235493AbhBYJ4M (ORCPT ); Thu, 25 Feb 2021 04:56:12 -0500 Received: from mail.kernel.org ([198.145.29.99]:32772 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235494AbhBYJyo (ORCPT ); Thu, 25 Feb 2021 04:54:44 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id B3FF964EF5; Thu, 25 Feb 2021 09:54:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1614246843; bh=iBNOvr58JQz924Lz8whUfoQyHyI302JA1X7nNfhZi04=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EKoLLHcZEJJC4KJl4T/DJzipKsIWmulD/UNqWhOiH5X+KVOjGmvGBwsvI2OIUMRLd rnBiUCPVUr64QvWSX9hINUMBmRi/oT3qWTM2SxAYi5G1lJksMGVdhivzP7gJ5LaCQ8 hl845N330VO3oUW9mpwmJJ7rBRzg8UcmNx2a+XYs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sean Christopherson , Paolo Bonzini Subject: [PATCH 5.11 12/12] KVM: Use kvm_pfn_t for local PFN variable in hva_to_pfn_remapped() Date: Thu, 25 Feb 2021 10:53:46 +0100 Message-Id: <20210225092515.573855820@linuxfoundation.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210225092515.015261674@linuxfoundation.org> References: <20210225092515.015261674@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Sean Christopherson commit a9545779ee9e9e103648f6f2552e73cfe808d0f4 upstream. Use kvm_pfn_t, a.k.a. u64, for the local 'pfn' variable when retrieving a so called "remapped" hva/pfn pair. In theory, the hva could resolve to a pfn in high memory on a 32-bit kernel. This bug was inadvertantly exposed by commit bd2fae8da794 ("KVM: do not assume PTE is writable after follow_pfn"), which added an error PFN value to the mix, causing gcc to comlain about overflowing the unsigned long. arch/x86/kvm/../../../virt/kvm/kvm_main.c: In function ‘hva_to_pfn_remapped’: include/linux/kvm_host.h:89:30: error: conversion from ‘long long unsigned int’ to ‘long unsigned int’ changes value from ‘9218868437227405314’ to ‘2’ [-Werror=overflow] 89 | #define KVM_PFN_ERR_RO_FAULT (KVM_PFN_ERR_MASK + 2) | ^ virt/kvm/kvm_main.c:1935:9: note: in expansion of macro ‘KVM_PFN_ERR_RO_FAULT’ Cc: stable@vger.kernel.org Fixes: add6a0cd1c5b ("KVM: MMU: try to fix up page faults before giving up") Signed-off-by: Sean Christopherson Message-Id: <20210208201940.1258328-1-seanjc@google.com> Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- virt/kvm/kvm_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1903,7 +1903,7 @@ static int hva_to_pfn_remapped(struct vm bool write_fault, bool *writable, kvm_pfn_t *p_pfn) { - unsigned long pfn; + kvm_pfn_t pfn; pte_t *ptep; spinlock_t *ptl; int r;