IPTABLES Broken w/ Kernel Upgrade: "Can't initialize iptables table 'filter'" & "Could not insert 'iptable_filter': Operation not permitted"

Running Ubuntu 20.04 with freshly upgraded 5.11.0-34-generic (over 0-27). APT make the process of updating the kernel rather simple, but when attempting to initialize my VPN or simply checking the firewall status, I get:
Code:iptables v1.8.4 (legacy): can't initialize iptables table `filter': Table does not exist (do you need to insmod?)
Perhaps iptables or your kernel needs to be upgraded.I figured that it hadn't updated the module - and the iptables version is the one provided through apt, installed by default with ufw and ubuntu-standard. Modinfo said it was up-to-date, so I ran:
Code:sudo apt-get update
sudo apt-get reinstall linux-image-$(uname -r) linux-headers-$(uname -r) linux-modules-$(uname -r) linux-modules-extra-$(uname -r) iptables
sudo apt-get upgradeAfter this ran and I rebooted, the error persisted. Additionally, attempting to use modprobeon 'iptable_filter' or 'ip6table_filter' gives:
Code:modprobe: ERROR: could not insert 'iptable_filter': Operation not permittedSo I entered into recovery mode for 5.11.0-34. The system took a bit longer, understandably, and then I ran the 'dpkg Repair Broken Packages' recovery option. This found nothing broken, so I went into root terminal. Surprisingly? In recovery mode, the filter module was loaded fine into the kernel. However, the VPN still failed to load - likely due to the restrictions of recovery mode.

The output of 'modprobe -f -vvv iptable_filter' (after running modprobe -r) is:
Code:modprobe: INFO: ../libkmod/libkmod.c:365 kmod_set_log_fn() custom logging function 0x559fb9fa0b90 registered
modprobe: DEBUG: ../libkmod/libkmod-index.c:755 index_mm_open() file=/lib/modules/5.11.0-34-generic/modules.dep.bin
modprobe: DEBUG: ../libkmod/libkmod-index.c:755 index_mm_open() file=/lib/modules/5.11.0-34-generic/modules.alias.bin
modprobe: DEBUG: ../libkmod/libkmod-index.c:755 index_mm_open() file=/lib/modules/5.11.0-34-generic/modules.symbols.bin
modprobe: DEBUG: ../libkmod/libkmod-index.c:755 index_mm_open() file=/lib/modules/5.11.0-34-generic/modules.builtin.alias.bin
modprobe: DEBUG: ../libkmod/libkmod-index.c:755 index_mm_open() file=/lib/modules/5.11.0-34-generic/modules.builtin.bin
modprobe: DEBUG: ../libkmod/libkmod-module.c:556 kmod_module_new_from_lookup() input alias=iptable_filter, normalized=iptable_filter
modprobe: DEBUG: ../libkmod/libkmod-module.c:562 kmod_module_new_from_lookup() lookup modules.dep iptable_filter
modprobe: DEBUG: ../libkmod/libkmod.c:598 kmod_search_moddep() use mmaped index 'modules.dep' modname=iptable_filter
modprobe: DEBUG: ../libkmod/libkmod.c:403 kmod_pool_get_module() get module name='iptable_filter' found=(nil)
modprobe: DEBUG: ../libkmod/libkmod.c:411 kmod_pool_add_module() add 0x559fba860360 key='iptable_filter'
modprobe: DEBUG: ../libkmod/libkmod.c:403 kmod_pool_get_module() get module name='ip_tables' found=(nil)
modprobe: DEBUG: ../libkmod/libkmod.c:403 kmod_pool_get_module() get module name='ip_tables' found=(nil)
modprobe: DEBUG: ../libkmod/libkmod.c:411 kmod_pool_add_module() add 0x559fba8604d0 key='ip_tables'
modprobe: DEBUG: ../libkmod/libkmod-module.c:196 kmod_module_parse_depline() add dep: /lib/modules/5.11.0-34-generic/kernel/net/ipv4/netfilter/ip_tables.ko
modprobe: DEBUG: ../libkmod/libkmod.c:403 kmod_pool_get_module() get module name='x_tables' found=(nil)
modprobe: DEBUG: ../libkmod/libkmod.c:403 kmod_pool_get_module() get module name='x_tables' found=(nil)
modprobe: DEBUG: ../libkmod/libkmod.c:411 kmod_pool_add_module() add 0x559fba8605e0 key='x_tables'
modprobe: DEBUG: ../libkmod/libkmod-module.c:196 kmod_module_parse_depline() add dep: /lib/modules/5.11.0-34-generic/kernel/net/netfilter/x_tables.ko
modprobe: DEBUG: ../libkmod/libkmod-module.c:202 kmod_module_parse_depline() 2 dependencies for iptable_filter
modprobe: DEBUG: ../libkmod/libkmod-module.c:589 kmod_module_new_from_lookup() lookup iptable_filter=0, list=0x559fba85fd50
modprobe: DEBUG: ../libkmod/libkmod.c:500 lookup_builtin_file() use mmaped index 'modules.builtin' modname=iptable_filter
modprobe: DEBUG: ../libkmod/libkmod-module.c:1760 kmod_module_get_initstate() could not open '/sys/module/iptable_filter/initstate': No such file or directory
modprobe: DEBUG: ../libkmod/libkmod-module.c:1770 kmod_module_get_initstate() could not open '/sys/module/iptable_filter': No such file or directory
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_pcsp mod->name=x_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_usb_audio mod->name=x_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=cx88_alsa mod->name=x_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_atiixp_modem mod->name=x_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_intel8x0m mod->name=x_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_via82xx_modem mod->name=x_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=bt87x mod->name=x_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=cx88_alsa mod->name=x_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=saa7134_alsa mod->name=x_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_atiixp_modem mod->name=x_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_intel8x0m mod->name=x_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_via82xx_modem mod->name=x_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_usb_audio mod->name=x_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_usb_caiaq mod->name=x_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_usb_ua101 mod->name=x_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_usb_us122l mod->name=x_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_usb_usx2y mod->name=x_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_cmipci mod->name=x_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_pcsp mod->name=x_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_usb_audio mod->name=x_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=bonding mod->name=x_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=dummy mod->name=x_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=vt mod->name=x_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod.c:500 lookup_builtin_file() use mmaped index 'modules.builtin' modname=x_tables
modprobe: DEBUG: ../libkmod/libkmod-module.c:1316 kmod_module_probe_insert_module() Ignoring module 'x_tables': already loaded
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_pcsp mod->name=ip_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_usb_audio mod->name=ip_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=cx88_alsa mod->name=ip_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_atiixp_modem mod->name=ip_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_intel8x0m mod->name=ip_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_via82xx_modem mod->name=ip_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=bt87x mod->name=ip_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=cx88_alsa mod->name=ip_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=saa7134_alsa mod->name=ip_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_atiixp_modem mod->name=ip_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_intel8x0m mod->name=ip_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_via82xx_modem mod->name=ip_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_usb_audio mod->name=ip_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_usb_caiaq mod->name=ip_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_usb_ua101 mod->name=ip_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_usb_us122l mod->name=ip_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_usb_usx2y mod->name=ip_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_cmipci mod->name=ip_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_pcsp mod->name=ip_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_usb_audio mod->name=ip_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=bonding mod->name=ip_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=dummy mod->name=ip_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=vt mod->name=ip_tables mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod.c:500 lookup_builtin_file() use mmaped index 'modules.builtin' modname=ip_tables
modprobe: DEBUG: ../libkmod/libkmod-module.c:1316 kmod_module_probe_insert_module() Ignoring module 'ip_tables': already loaded
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_pcsp mod->name=iptable_filter mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_usb_audio mod->name=iptable_filter mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=cx88_alsa mod->name=iptable_filter mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_atiixp_modem mod->name=iptable_filter mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_intel8x0m mod->name=iptable_filter mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_via82xx_modem mod->name=iptable_filter mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=bt87x mod->name=iptable_filter mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=cx88_alsa mod->name=iptable_filter mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=saa7134_alsa mod->name=iptable_filter mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_atiixp_modem mod->name=iptable_filter mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_intel8x0m mod->name=iptable_filter mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_via82xx_modem mod->name=iptable_filter mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_usb_audio mod->name=iptable_filter mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_usb_caiaq mod->name=iptable_filter mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_usb_ua101 mod->name=iptable_filter mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_usb_us122l mod->name=iptable_filter mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_usb_usx2y mod->name=iptable_filter mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_cmipci mod->name=iptable_filter mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_pcsp mod->name=iptable_filter mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=snd_usb_audio mod->name=iptable_filter mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=bonding mod->name=iptable_filter mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=dummy mod->name=iptable_filter mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1404 kmod_module_get_options() modname=vt mod->name=iptable_filter mod->alias=(null)
modprobe: DEBUG: ../libkmod/libkmod-module.c:1760 kmod_module_get_initstate() could not open '/sys/module/iptable_filter/initstate': No such file or directory
modprobe: DEBUG: ../libkmod/libkmod-module.c:1770 kmod_module_get_initstate() could not open '/sys/module/iptable_filter': No such file or directory
modprobe: DEBUG: ../libkmod/libkmod-module.c:750 kmod_module_get_path() name='iptable_filter' path='/lib/modules/5.11.0-34-generic/kernel/net/ipv4/netfilter/iptable_filter.ko'
modprobe: DEBUG: ../libkmod/libkmod-module.c:750 kmod_module_get_path() name='iptable_filter' path='/lib/modules/5.11.0-34-generic/kernel/net/ipv4/netfilter/iptable_filter.ko'
insmod /lib/modules/5.11.0-34-generic/kernel/net/ipv4/netfilter/iptable_filter.ko
modprobe: DEBUG: ../libkmod/libkmod-module.c:750 kmod_module_get_path() name='iptable_filter' path='/lib/modules/5.11.0-34-generic/kernel/net/ipv4/netfilter/iptable_filter.ko'
modprobe: INFO: ../libkmod/libkmod-module.c:892 kmod_module_insert_module() Failed to insert module '/lib/modules/5.11.0-34-generic/kernel/net/ipv4/netfilter/iptable_filter.ko': Operation not permitted
modprobe: ERROR: could not insert 'iptable_filter': Operation not permitted
modprobe: DEBUG: ../libkmod/libkmod-module.c:468 kmod_module_unref() kmod_module 0x559fba860360 released
modprobe: DEBUG: ../libkmod/libkmod.c:419 kmod_pool_del_module() del 0x559fba860360 key='iptable_filter'
modprobe: DEBUG: ../libkmod/libkmod-module.c:468 kmod_module_unref() kmod_module 0x559fba8605e0 released
modprobe: DEBUG: ../libkmod/libkmod.c:419 kmod_pool_del_module() del 0x559fba8605e0 key='x_tables'
modprobe: DEBUG: ../libkmod/libkmod-module.c:468 kmod_module_unref() kmod_module 0x559fba8604d0 released
modprobe: DEBUG: ../libkmod/libkmod.c:419 kmod_pool_del_module() del 0x559fba8604d0 key='ip_tables'
modprobe: INFO: ../libkmod/libkmod.c:332 kmod_unref() context 0x559fba85f4a0 releasedI don't know much about these codes, but there isn't anything - to my knowledge - that says why loading the iptables filter is not permitted. Modinfo reports it as valid, so it isn't corrupt or anything, but nothing I seem to do can fix this, aside from what I had to do last month, which was a hard reinstall of Ubuntu.

Things I've looked at:
https://www.linuxquestions.org/quest...-exist-739550/
https://askubuntu.com/questions/7436...you-need-to-i/ (although it's angled for raspberry pi)
https://askubuntu.com/questions/2821...e-table-filter
https://www.tutorialspoint.com/unix_...s/modprobe.htm (just as reference for modprobe)
https://www.linuxquestions.org/quest...r'-577212/

Prior to the kernel upgrade, iptables and the VPN were working fine (i.e. using sudo iptables --list didn't make the terminal scream in figurative pain). This is getting in the way of a few smaller things, but I figured I needed to find out how - if possible - to fix this now and in the future, or if I should just... not touch apt-get dist-upgrade, depsite never having had problems with it until now.


Any ideas?