Set UART rx_linger too high results in funny configuration?

I am playing with values of rx_linger in my app to do some tuning of response time vs. having to process partial messages.

On ESP32, I have noticed that setting the UART configuration so rx_linger is 200 and reading the configuration back out shows rx_linger=200 and rx_buf_size=256 (as expected), but setting rx_linger=201 and reading the configuration back out results in rx_buf_size=1073529920 and rx_linger_micros=4.

Have I uncovered a bug?