Very broken iptables 1.4.21 after upgrade to kernel 3.10.0-514.26.2.el7.x86_64

[simonautomatic]

I ran system update in WHM 64 Build 36, to upgrade some packages and also update the kernel to 3.10.0-514.26.2.el7.x86_64 (as advised by the security advisor).

The updates ran successsfully, but after a reboot I noticed that configServer (Csf) would no longer start. This turned out to be due to a problem with iptables. It seems that the newer kernel either doesn't have all the iptables modules loaded or doesn't even have support for them compiled in - I'm not quite sure which.

The error message when trying to start iptables (and thus when trying to start csf too) is:

iptables v1.4.21: can't initialize iptables table `filter': Table does not exist (do you need to insmod?)

I have tried various things such as issuing the modprobe command for iptables_filter and iptables_nat but to no avail. I also checked the netfilter directory (/lib/modules/3.10.0-514.26.2.el7.x86_64/kernel/net/ipv4/netfilter/) and it seems to contain all the correct files (I compared it with the previous kernel)

Am I right that the only solution here would be to recompile the kernel?

 

[cPanelMichael]

Hello,

Could you provide some more information about the server environment (OS, VPS software)? For instance, are you using a Linux Container (LXC)? Also, please post the output from the following commands:

runlevel
telnet 127.0.0.1

Thank you.

 

[simonautomatic]

Sure, it's a physical server running CENTOS 7.3 x86_64 standard (so no container)

[[email protected] /]# runlevel
N 3

[[email protected] /]# telnet 127.0.0.1
Trying 127.0.0.1...
telnet: connect to address 127.0.0.1: Connection refused

 

[cPanelMichael]

Hello,

Could you also run the "rpm -qa|grep iptables" command and let us know the output?

Thank you.

 

[simonautomatic]

Sure. Note that I installed the devel and services packages with yum, as part of various attempts to remedy the situation:

[[email protected] tmp]# rpm -qa|grep iptables
iptables-1.4.21-17.el7.x86_64
iptables-services-1.4.21-17.el7.x86_64
iptables-devel-1.4.21-17.el7.x86_64

 

[cPanelMichael]

Hello,

Could you open a support ticket using the link in my signature so we can take a closer look?

Thank you.

 

[simonautomatic]

I've done so. Hope you can help.