From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755662AbaELBy0 (ORCPT ); Sun, 11 May 2014 21:54:26 -0400 Received: from 1wt.eu ([62.212.114.60]:34709 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753884AbaELBnR (ORCPT ); Sun, 11 May 2014 21:43:17 -0400 Message-Id: <20140512003206.271246826@1wt.eu> User-Agent: quilt/0.48-1 Date: Mon, 12 May 2014 02:34:14 +0200 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Andrew Honig , Paolo Bonzini , Willy Tarreau Subject: [ 134/143] KVM: Improve create VCPU parameter (CVE-2013-4587) In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.32-longterm review patch. If anyone has any objections, please let me know. ------------------ From: Andy Honig commit 338c7dbadd2671189cec7faf64c84d01071b3f96 upstream In multiple functions the vcpu_id is used as an offset into a bitfield. Ag malicious user could specify a vcpu_id greater than 255 in order to set or clear bits in kernel memory. This could be used to elevate priveges in the kernel. This patch verifies that the vcpu_id provided is less than 255. The api documentation already specifies that the vcpu_id must be less than max_vcpus, but this is currently not checked. Reported-by: Andrew Honig Cc: stable@vger.kernel.org Signed-off-by: Andrew Honig Signed-off-by: Paolo Bonzini Signed-off-by: Willy Tarreau --- virt/kvm/kvm_main.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 82b6fdc..3b9443b 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1846,6 +1846,9 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id) int r; struct kvm_vcpu *vcpu, *v; + if (id >= KVM_MAX_VCPUS) + return -EINVAL; + vcpu = kvm_arch_vcpu_create(kvm, id); if (IS_ERR(vcpu)) return PTR_ERR(vcpu); -- 1.7.12.2.21.g234cd45.dirty