diff --git a/sys/x86/iommu/intel_ctx.c b/sys/x86/iommu/intel_ctx.c
--- a/sys/x86/iommu/intel_ctx.c
+++ b/sys/x86/iommu/intel_ctx.c
@@ -561,7 +561,7 @@
 			error = domain_init_rmrr(domain1, dev, bus,
 			    slot, func, dev_domain, dev_busno, dev_path,
 			    dev_path_len);
-			if (error == 0)
+			if (error == 0 && dev != NULL)
 				error = dmar_reserve_pci_regions(domain1, dev);
 			if (error != 0) {
 				dmar_domain_destroy(domain1);