[94/98] KVM: only clear irq_source_id if irqchip is present

[Greg KH]

2.6.32-stable review patch.  If anyone has any objections, please let us know.

------------------

From: Marcelo Tosatti <mtosatti@xxxxxxxxxx>

commit e50212bb51356f0df48d6cce0aae5acf41df336d upstream.

Otherwise kvm might attempt to dereference a NULL pointer.

Signed-off-by: Marcelo Tosatti <mtosatti@xxxxxxxxxx>
Signed-off-by: Avi Kivity <avi@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 virt/kvm/irq_comm.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/virt/kvm/irq_comm.c
+++ b/virt/kvm/irq_comm.c
@@ -233,9 +233,12 @@ void kvm_free_irq_source_id(struct kvm *
 		printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
 		goto unlock;
 	}
+	clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
+	if (!irqchip_in_kernel(kvm))
+		goto unlock;
+
 	for (i = 0; i < KVM_IOAPIC_NUM_PINS; i++)
 		clear_bit(irq_source_id, &kvm->arch.irq_states[i]);
-	clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
 unlock:
 	mutex_unlock(&kvm->irq_lock);
 }


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