buildroot-2017.08-rc1/support/kconfig/confdata.c:853]: (error) Memory leak: opwd [buildroot-2017.08-rc1/support/kconfig/confdata.c:63]: (error) va_list 'ap' was opened but not closed by va_end().
This code comes from the upstream Linux kernel, so if there are any issues, please report them here. Thanks!