CVE-2014-0155

Pulled from 3.10.23 stable for bug 110340.

>From a9ded882d5168e2fd5c0c20e2874f85c56016b4b Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini@redhat.com>
Date: Fri, 28 Mar 2014 20:41:50 +0100
Subject: KVM: ioapic: fix assignment of ioapic->rtc_status.pending_eoi
 (CVE-2014-0155)

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 <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 file changed