bpfilter read fail

[fa]

hi,
With ufw installed on my linux mint 20.2, when linux starts, i have a lot of message saying :
bpfilter read fail 0

When i remove ufw, i haven't this messages.
My kernel is 5.15 and the problemn occurs since 5.13.15.

[Jamie Strandboge (jdstrand)]

This appears to be https://lore.kernel.org/lkml/20200727142114.uzxr4kl7xdj2ildi@wittgenstein/ and not an issue in ufw itself. You may be able to resolve it by using iptables-legacy on your system instead of iptables-nft, but this also might just be resolved with a newer kernel.

I'll separately mention that if you have multiple programs that are managing firewall rules (eg, ufw, docker, libvirt, lxd, etc) then they all must either use xtables (traditional iptables) or all use nftables (new nftables). iptables can be configured to use either the legacy or nft backends through the 'update-alternatives' command. ufw will follow whatever the system is using, but other software may not so you may want to verify what different software is using. Eg, the docker snap is known to use xtables which has been known to cause problems when the system is configured to use the nft iptables backend.

As this is not an issue with ufw itself, closing. Thanks for the report!