A buffer solution is composed of a weak acid (and its conjugate base) OR a weak base (and its conjugate acid). The pH of this solution changes very little upon the addition of small amounts of strong acid or base.
Homeostasis is a term defined to a system when it maintains its stable condition upon the application of stress.
Now, a buffer system can be defined as a chemical homeostasis system because it can regulate the pH of the system upon the addition of strong acid or strong base.
For example, our body is very sensitive to pH changes. Many buffer systems exists in our cells to prevent the abrupt change of our pH. If not maintained and the pH of our body becomes very high or very low, it may result in death.