Use struct_size() to calculate the output buffer length.
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
        spin_unlock(&dentry->d_lock);
        file_info->FileNameLength = cpu_to_le32(conv_len);
        rsp->OutputBufferLength =
-               cpu_to_le32(sizeof(struct smb2_file_alt_name_info) + conv_len);
+               cpu_to_le32(struct_size(file_info, FileName, conv_len));
 }
 
 static int get_file_stream_info(struct ksmbd_work *work,