CHAIN_ADD failed (Device or resource busy) error

[larwilliams]

Hello,

For the last 24 hours or so, I've been getting e-mails saying that lfd failed to started due to a "CHAIN_ADD failed (Device or resource busy)" error. When I run the "test iptables" check in CSF inside WHM, it reports the following:

Testing ip_tables/iptable_filter...FAILED [FATAL Error: iptables v1.8.4 (nf_tables): CHAIN_ADD failed (Device or resource busy): chain INPUT] - Required for csf to function
Testing ipt_LOG...FAILED [FATAL Error: iptables v1.8.4 (nf_tables): CHAIN_ADD failed (Device or resource busy): chain INPUT] - Required for csf to function
Testing ipt_multiport/xt_multiport...FAILED [FATAL Error: iptables v1.8.4 (nf_tables): CHAIN_ADD failed (Device or resource busy): chain INPUT] - Required for csf to function
Testing ipt_REJECT...FAILED [FATAL Error: iptables v1.8.4 (nf_tables): CHAIN_ADD failed (Device or resource busy): chain INPUT] - Required for csf to function
Testing ipt_state/xt_state...FAILED [FATAL Error: iptables v1.8.4 (nf_tables): CHAIN_ADD failed (Device or resource busy): chain INPUT] - Required for csf to function
Testing ipt_limit/xt_limit...FAILED [FATAL Error: iptables v1.8.4 (nf_tables): CHAIN_ADD failed (Device or resource busy): chain INPUT] - Required for csf to function
Testing ipt_recent...FAILED [Error: iptables v1.8.4 (nf_tables): CHAIN_ADD failed (Device or resource busy): chain INPUT] - Required for PORTFLOOD and PORTKNOCKING features
Testing xt_connlimit...FAILED [Error: iptables v1.8.4 (nf_tables): CHAIN_ADD failed (Device or resource busy): chain INPUT] - Required for CONNLIMIT feature
Testing ipt_owner/xt_owner...FAILED [Error: iptables v1.8.4 (nf_tables): CHAIN_ADD failed (Device or resource busy): chain INPUT] - Required for SMTP_BLOCK and UID/GID blocking features
Testing iptable_nat/ipt_REDIRECT...OK
Testing iptable_nat/ipt_DNAT...OK

RESULT: csf will not function on this server due to FATAL errors from missing modules [6]

This is a VPS, so I'm wondering if this is an upstream host caused issue (they say it isn't) or not, and what could cause it. Google results are not helpful at all.

Below is the server info, with the hostname redacted:

[root@vps1 ~]# cat /etc/redhat-release
AlmaLinux release 8.6 (Sky Tiger)
[root@vps1 ~]# uname
Linux
[root@vps1 ~]# uname -a
Linux vps.domain.com 4.18.0 #1 SMP Tue Jan 25 12:49:12 MSK 2022 x86_64 x86_64 x86_64 GNU/Linux
[root@vps1 ~]# uname -r
4.18.0
[root@vps1 ~]# cat /proc/version
Linux version 4.18.0 (mockbuild@builder9.eng.sw.ru) (gcc version 4.8.5 20150623 (Red Hat 4.8.5-44) (GCC) ) #1 SMP Tue Jan 25 12:49:12 MSK 2022
[root@vps1 ~]#

[larwilliams]

To add: before I started getting these e-mails, everything worked fine.

[Sergio]

What is /var/log/lfd.log on that server showing?