diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
index e93bcb5eef70..e7d7b4cb9337 100644
--- a/drivers/iommu/amd/init.c
+++ b/drivers/iommu/amd/init.c
@@ -3864,6 +3864,12 @@ static int __init parse_ivrs_acpihid(char *str)
 	return 1;
 
 found:
+	if (early_acpihid_map_size == EARLY_MAP_SIZE) {
+		pr_err("Early ACPI HID map overflow - ignoring ivrs_acpihid%s\n",
+		       str);
+		return 1;
+	}
+
 	p = acpiid;
 	hid = strsep(&p, ":");
 	uid = p;