diff --git a/drivers/iommu/iommu-debug.c b/drivers/iommu/iommu-debug.c
index 5e2b42a326bf..2b719b69231a 100644
--- a/drivers/iommu/iommu-debug.c
+++ b/drivers/iommu/iommu-debug.c
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * Copyright (c) 2015-2020, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2015-2021, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -1546,6 +1546,11 @@ static ssize_t iommu_debug_atos_write(struct file *file,
 		return -EINVAL;
 	}
 
+	if (!ddev->domain) {
+		pr_err_ratelimited("No domain. Did you already attach?\n");
+		return -EINVAL;
+	}
+
 	phys = iommu_iova_to_phys(ddev->domain, iova);
 	pfn = __phys_to_pfn(phys);
 	if (!pfn_valid(pfn)) {