diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
index dd9e26b7b718..14aa0d77df26 100644
--- a/drivers/iommu/amd/init.c
+++ b/drivers/iommu/amd/init.c
@@ -3664,6 +3664,14 @@ static int __init parse_ivrs_acpihid(char *str)
 	while (*uid == '0' && *(uid + 1))
 		uid++;
 
+	if (strlen(hid) >= ACPIHID_HID_LEN) {
+		pr_err("Invalid command line: hid is too long\n");
+		return 1;
+	} else if (strlen(uid) >= ACPIHID_UID_LEN) {
+		pr_err("Invalid command line: uid is too long\n");
+		return 1;
+	}
+
 	i = early_acpihid_map_size++;
 	memcpy(early_acpihid_map[i].hid, hid, strlen(hid));
 	memcpy(early_acpihid_map[i].uid, uid, strlen(uid));