Re: [PATCH nf v3 1/1] netfilter: validate L4 headers after userspace packet writes

Zhiling Zou <[email protected]> wrote:
> Extend NFQUEUE payload validation to check the final L4 protocol and
> known base headers after IPv4 options or IPv6 extension headers. Reject
> packets whose L4 protocol no longer matches an attached non-template
> conntrack entry, and validate TCP data offset before reinjection. Unknown
> L4 protocols are left to their normal protocol handlers.

Nfqueue part will need to check for the ip frag case as noted by AI review, but other than that this LGTM.

This also means we should return false (i.e. drop)  in case we have an
ip fragment with a conntrack attached to it.