diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 37af23052470eff99b2c3a3fdcf05898c7312602..02e98f3131bda11433fd0081752bcb9be350afb5 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2935,7 +2935,7 @@ static long kvm_vm_ioctl(struct file *filp,
 	case KVM_SET_GSI_ROUTING: {
 		struct kvm_irq_routing routing;
 		struct kvm_irq_routing __user *urouting;
-		struct kvm_irq_routing_entry *entries;
+		struct kvm_irq_routing_entry *entries = NULL;
 
 		r = -EFAULT;
 		if (copy_from_user(&routing, argp, sizeof(routing)))
@@ -2945,15 +2945,17 @@ static long kvm_vm_ioctl(struct file *filp,
 			goto out;
 		if (routing.flags)
 			goto out;
-		r = -ENOMEM;
-		entries = vmalloc(routing.nr * sizeof(*entries));
-		if (!entries)
-			goto out;
-		r = -EFAULT;
-		urouting = argp;
-		if (copy_from_user(entries, urouting->entries,
-				   routing.nr * sizeof(*entries)))
-			goto out_free_irq_routing;
+		if (routing.nr) {
+			r = -ENOMEM;
+			entries = vmalloc(routing.nr * sizeof(*entries));
+			if (!entries)
+				goto out;
+			r = -EFAULT;
+			urouting = argp;
+			if (copy_from_user(entries, urouting->entries,
+					   routing.nr * sizeof(*entries)))
+				goto out_free_irq_routing;
+		}
 		r = kvm_set_irq_routing(kvm, entries, routing.nr,
 					routing.flags);
 out_free_irq_routing: