The function drw_fontset_free in drw.c was never called.
@ -95,6 +95,7 @@ drw_free(Drw *drw)
{
XFreePixmap(drw->dpy, drw->drawable);
XFreeGC(drw->dpy, drw->gc);
drw_fontset_free(drw->fonts);
free(drw);
}