From patchwork Fri Aug 6 08:14:53 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 493347 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=-19.4 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 336A9C4320E for ; Fri, 6 Aug 2021 08:16:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 180F261131 for ; Fri, 6 Aug 2021 08:16:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243794AbhHFIQP (ORCPT ); Fri, 6 Aug 2021 04:16:15 -0400 Received: from mail.kernel.org ([198.145.29.99]:45706 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243659AbhHFIPr (ORCPT ); Fri, 6 Aug 2021 04:15:47 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id C1BAD61209; Fri, 6 Aug 2021 08:15:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1628237728; bh=xLBjq4gldfHI73hTK0Tka1mRhox3yHzQyBstCKafKGc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Btgx/BL+tBoO9HtXH4t0Xc8UjEzgdJM56dSClaPknmEYgMhYdvgxbYSt/3blzqI6+ /7VS1CVDtWWHuocsNeOE1uAWMwHDayu2P5USX1GDuZOy+G933wJZFQwWp8WakFRMJE nz0c3hKnJ4BEoPCOCRpcx93BNrqORnBUwTtxnRMI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sean Christopherson , Paolo Bonzini , Ovidiu Panait Subject: [PATCH 4.14 10/11] KVM: Use kvm_pfn_t for local PFN variable in hva_to_pfn_remapped() Date: Fri, 6 Aug 2021 10:14:53 +0200 Message-Id: <20210806081110.847017266@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210806081110.511221879@linuxfoundation.org> References: <20210806081110.511221879@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: Ovidiu Panait 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 @@ -1497,7 +1497,7 @@ 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;