[patch 3/3] KVM: only clear irq_source_id if irqchip is present

[Marcelo Tosatti <mtosatti@redhat.com>]

[-- Attachment #1: free-irqsource-id --]
[-- Type: text/plain, Size: 911 bytes --]

Otherwise kvm might attempt to dereference a NULL pointer.

CC: stable@kernel.org
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

Index: kvm/virt/kvm/irq_comm.c
===================================================================
--- kvm.orig/virt/kvm/irq_comm.c
+++ kvm/virt/kvm/irq_comm.c
@@ -243,6 +243,10 @@ 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.vioapic->irq_states[i]);
 		if (i >= 16)
@@ -251,7 +255,6 @@ void kvm_free_irq_source_id(struct kvm *
 		clear_bit(irq_source_id, &pic_irqchip(kvm)->irq_states[i]);
 #endif
 	}
-	clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
 unlock:
 	mutex_unlock(&kvm->irq_lock);
 }