diff --git a/fs/smb/client/cifsfs.c b/fs/smb/client/cifsfs.c
index 32d0305a1239..3e1dbc28af7d 100644
--- a/fs/smb/client/cifsfs.c
+++ b/fs/smb/client/cifsfs.c
@@ -1911,6 +1911,12 @@ init_cifs(void)
 {
 	int rc = 0;
 
+#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
+	rc = smb1_init_maperror();
+	if (rc)
+		return rc;
+#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
+
 	rc = smb2_init_maperror();
 	if (rc)
 		return rc;
diff --git a/fs/smb/client/smb1maperror.c b/fs/smb/client/smb1maperror.c
index fb985d2fc0d9..66ceebbe535e 100644
--- a/fs/smb/client/smb1maperror.c
+++ b/fs/smb/client/smb1maperror.c
@@ -256,3 +256,35 @@ map_and_check_smb_error(struct TCP_Server_Info *server,
 
 	return rc;
 }
+
+#define DEFINE_CHECK_SORT_FUNC(__array, __field)			\
+static int __init __array ## _is_sorted(void)				\
+{									\
+	unsigned int i;							\
+									\
+	/* Check whether the array is sorted in ascending order */	\
+	for (i = 1; i < ARRAY_SIZE(__array); i++) {			\
+		if (__array[i].__field >=				\
+		    __array[i - 1].__field)				\
+			continue;					\
+									\
+		pr_err(#__array " array order is incorrect\n");		\
+		return -EINVAL;						\
+	}								\
+									\
+	return 0;							\
+}
+
+/* ntstatus_to_dos_map_is_sorted */
+DEFINE_CHECK_SORT_FUNC(ntstatus_to_dos_map, ntstatus);
+
+int __init smb1_init_maperror(void)
+{
+	int rc;
+
+	rc = ntstatus_to_dos_map_is_sorted();
+	if (rc)
+		return rc;
+
+	return rc;
+}
diff --git a/fs/smb/client/smb1proto.h b/fs/smb/client/smb1proto.h
index 42569bbcf6fd..dd98d04e837a 100644
--- a/fs/smb/client/smb1proto.h
+++ b/fs/smb/client/smb1proto.h
@@ -234,6 +234,7 @@ int cifs_verify_signature(struct smb_rqst *rqst,
  * smb1maperror.c
  */
 int map_smb_to_linux_error(char *buf, bool logErr);
+int smb1_init_maperror(void);
 int map_and_check_smb_error(struct TCP_Server_Info *server,
 			    struct mid_q_entry *mid, bool logErr);