EF6 按条件更新多行记录的值

using (var db = new MyDbContext())
{
  string fromUser = ""; //sender
  string toUser = ""; //receiver
  var messages = db.Message.Where(x => x.FromUser == fromUser && x.ToUser == toUser)
                 .ToList();
  messages.ForEach(m => m.IsRead = true);
  db.SaveChanges();
}