diff --git a/drivers/target/iscsi/iscsi_target_auth.c b/drivers/target/iscsi/iscsi_target_auth.c
index a3ad2d244dbe..5858cc308979 100644
--- a/drivers/target/iscsi/iscsi_target_auth.c
+++ b/drivers/target/iscsi/iscsi_target_auth.c
@@ -438,9 +438,11 @@ static int chap_server_compute_hash(
 	}
 
 	if (type == HEX)
-		ret = kstrtoul(&identifier[2], 0, &id);
+		ret = kstrtoul(identifier, 16, &id);
+	else if (type == DECIMAL)
+		ret = kstrtoul(identifier, 10, &id);
 	else
-		ret = kstrtoul(identifier, 0, &id);
+		ret = -EINVAL;
 
 	if (ret < 0) {
 		pr_err("kstrtoul() failed for CHAP identifier: %d\n", ret);