Ok, when suggesting the limits.conf file I was not paying attention to the fact that you are running RHEL 7. In that case, the limits for system services are managed by systemd on a per-service basis. You can find all available limit settings in the systemd.exec man page. To avoid having to modify the upstream .service file, it is recommended to use systemd's drop-in mechanism as described in the systemd.unit man page. In your case that would mean to add a file at the location /etc/systemd/system/kibana.conf.d/limits.conf containing something like
[service] LimitMEMLOCK=infinity LimitFSIZE=infinity LimitSTACK=8192
Don't forget to run systemctl daemon-reload after changing the file before systemctl restarting. In general I would advise to use sensible number values instead of infinity to preserve system stability.