From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756323AbaHHUlm (ORCPT ); Fri, 8 Aug 2014 16:41:42 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:40025 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751745AbaHHUlg (ORCPT ); Fri, 8 Aug 2014 16:41:36 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Paolo Bonzini , Kamal Mostafa Subject: [PATCH 3.13 002/259] KVM: ioapic: fix assignment of ioapic->rtc_status.pending_eoi (CVE-2014-0155) Date: Fri, 8 Aug 2014 13:37:05 -0700 Message-Id: <1407530482-4483-3-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1407530482-4483-1-git-send-email-kamal@canonical.com> References: <1407530482-4483-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.13 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.13.11.6 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Paolo Bonzini commit 5678de3f15010b9022ee45673f33bcfc71d47b60 upstream. QE reported that they got the BUG_ON in ioapic_service to trigger. I cannot reproduce it, but there are two reasons why this could happen. The less likely but also easiest one, is when kvm_irq_delivery_to_apic does not deliver to any APIC and returns -1. Because irqe.shorthand == 0, the kvm_for_each_vcpu loop in that function is never reached. However, you can target the similar loop in kvm_irq_delivery_to_apic_fast; just program a zero logical destination address into the IOAPIC, or an out-of-range physical destination address. Signed-off-by: Paolo Bonzini Signed-off-by: Kamal Mostafa --- virt/kvm/ioapic.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c index 2d68297..39dc5bc 100644 --- a/virt/kvm/ioapic.c +++ b/virt/kvm/ioapic.c @@ -306,7 +306,7 @@ static int ioapic_deliver(struct kvm_ioapic *ioapic, int irq, bool line_status) BUG_ON(ioapic->rtc_status.pending_eoi != 0); ret = kvm_irq_delivery_to_apic(ioapic->kvm, NULL, &irqe, ioapic->rtc_status.dest_map); - ioapic->rtc_status.pending_eoi = ret; + ioapic->rtc_status.pending_eoi = (ret < 0 ? 0 : ret); } else ret = kvm_irq_delivery_to_apic(ioapic->kvm, NULL, &irqe, NULL); -- 1.9.1