It was found that ntpd exits with a segmentation fault when a statistics type that was not enabled during compilation (e.g. timingstats) is referenced by the statistics or filegen configuration command, for example:

ntpq -c ':config statistics timingstats' ntpq -c ':config filegen timingstats'

Upstream patch:

http://bk.ntp.org/ntp-dev/?PAGE=patch&REV=4d253ed0A400LyhRQIV0u23NJwuGAA

(in 4.2.6, the code than handles NULL == filegen needs to be adjusted as the outer loop was changed from while to for)