KVM: properly check max PIC pin in irq route setup
Otherwise memory beyond irq_states[16] might be accessed.
Noticed by Juan Quintela.
Cc: stable@kernel.org
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Acked-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/virt/kvm/irq_comm.c b/virt/kvm/irq_comm.c
index 9b07734..9fd5b3e 100644
--- a/virt/kvm/irq_comm.c
+++ b/virt/kvm/irq_comm.c
@@ -302,6 +302,7 @@
{
int r = -EINVAL;
int delta;
+ unsigned max_pin;
struct kvm_kernel_irq_routing_entry *ei;
struct hlist_node *n;
@@ -322,12 +323,15 @@
switch (ue->u.irqchip.irqchip) {
case KVM_IRQCHIP_PIC_MASTER:
e->set = kvm_set_pic_irq;
+ max_pin = 16;
break;
case KVM_IRQCHIP_PIC_SLAVE:
e->set = kvm_set_pic_irq;
+ max_pin = 16;
delta = 8;
break;
case KVM_IRQCHIP_IOAPIC:
+ max_pin = KVM_IOAPIC_NUM_PINS;
e->set = kvm_set_ioapic_irq;
break;
default:
@@ -335,7 +339,7 @@
}
e->irqchip.irqchip = ue->u.irqchip.irqchip;
e->irqchip.pin = ue->u.irqchip.pin + delta;
- if (e->irqchip.pin >= KVM_IOAPIC_NUM_PINS)
+ if (e->irqchip.pin >= max_pin)
goto out;
rt->chip[ue->u.irqchip.irqchip][e->irqchip.pin] = ue->gsi;
break;