Generic InsertOrUpdate method

I have a generic method to insert or update method that works but as I am a new to this. Are there any potential issues with my current implementation that are not handled here?

public class Repository<T> : IRepository<T> where T : BaseModel
{
    protected DbContext Context;
    protected readonly IDbSet<T> dbSet;

    public void InsertOrUpdate(T entity)
    {
        DbSet<T> dbSet = Context.Set<T>();
        var e = this.Find(entity.Id);

        if (e != null)
        {
            DbEntityEntry<T> entry;
            entry = Context.Entry(e);
            entry.CurrentValues.SetValues(entity);
            dbSet.Attach(entry.Entity);
            entry.State = EntityState.Modified;
        }
        else
        {
            dbSet.Add(entity);
        }
    }

    public T Find(object id)
    {
        return dbSet.Find(id);
    }
}