From patchwork Fri Jan 31 11:10:30 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thadeu Lima de Souza Cascardo X-Patchwork-Id: 1231841 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lists.ubuntu.com (client-ip=91.189.94.19; helo=huckleberry.canonical.com; envelope-from=kernel-team-bounces@lists.ubuntu.com; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=canonical.com Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 488Dzh51ZSz9sRK; Fri, 31 Jan 2020 22:10:56 +1100 (AEDT) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.86_2) (envelope-from ) id 1ixUCK-000879-02; Fri, 31 Jan 2020 11:10:52 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1ixUCH-00084u-Af for kernel-team@lists.ubuntu.com; Fri, 31 Jan 2020 11:10:49 +0000 Received: from 1.general.cascardo.us.vpn ([10.172.70.58] helo=localhost.localdomain) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1ixUCF-0006R0-SF for kernel-team@lists.ubuntu.com; Fri, 31 Jan 2020 11:10:48 +0000 From: Thadeu Lima de Souza Cascardo To: kernel-team@lists.ubuntu.com Subject: [Disco 05/10] KVM: Properly check if "page" is valid in kvm_vcpu_unmap Date: Fri, 31 Jan 2020 08:10:30 -0300 Message-Id: <20200131111035.38050-6-cascardo@canonical.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20200131111035.38050-1-cascardo@canonical.com> References: <20200131111035.38050-1-cascardo@canonical.com> MIME-Version: 1.0 X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.20 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: "kernel-team" From: KarimAllah Ahmed CVE-2019-3016 CVE-2020-3016 The field "page" is initialized to KVM_UNMAPPED_PAGE when it is not used (i.e. when the memory lives outside kernel control). So this check will always end up using kunmap even for memremap regions. Fixes: e45adf665a53 ("KVM: Introduce a new guest mapping API") Cc: stable@vger.kernel.org Signed-off-by: KarimAllah Ahmed Signed-off-by: Paolo Bonzini (cherry picked from commit b614c6027896ff9ad6757122e84760d938cab15e) Signed-off-by: Thadeu Lima de Souza Cascardo --- virt/kvm/kvm_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 8d7585b99499..d40c8d70fd4e 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1841,7 +1841,7 @@ void kvm_vcpu_unmap(struct kvm_vcpu *vcpu, struct kvm_host_map *map, if (!map->hva) return; - if (map->page) + if (map->page != KVM_UNMAPPED_PAGE) kunmap(map->page); #ifdef CONFIG_HAS_IOMEM else