sympl-firewall: "Another app is currently holding the xtables lock"
One user was reporting emails like this, coming from /usr/sbin/sympl-firewall and /usr/sbin/sympl-firewall-blacklist on two hosts.
From: Cron Daemon <root@hostname.fqdn>
Date: Mon, 14 Sep 2020 at 19:00
Subject: Cron <root@hostname> [ -x /usr/sbin/sympl-firewall ] &&
/usr/sbin/sympl-firewall
To: <root@hostname.fqdn>
Another app is currently holding the xtables lock. Perhaps you want to use
the -w option?
sympl-firewall: Firewall script failed.
sympl-firewall: Flushing /sbin/iptables rules and chains.
sympl-firewall: Flushing /sbin/ip6tables rules and chains.
sympl-firewall: Restoring old iptables rules and chains.
sympl-firewall: Restoring old ip6tables rules and chains.
sympl-firewall: Left firewall script in
/tmp/user/0/sympl-firewall-20200914-1505-1srb1j3-saved for inspection.The direct cause is unclear at the moment, and they don't happen all the time (once a day or so, apparently), so it may simply be a race condition.