Re: Soft lock-ups caused by iptables

From: Phil Sutter

Date: Wed Nov 19 2025 - 13:12:45 EST


On Wed, Nov 19, 2025 at 04:58:46PM +0100, Florian Westphal wrote:
> Phil Sutter <phil@xxxxxx> wrote:
> > On nftables side, maybe we could annotate chains with a depth value once
> > validated to skip digging into them again when revisiting from another
> > jump?
>
> Yes, but you also need to annotate the type of the last base chain origin,
> else you might skip validation of 'chain foo' because its depth value says its
> fine but new caller is coming from filter, not nat, and chain foo had
> masquerade expression.

There would need to be masks of valid types and hooks recording the
restrictions imposed on a non-base chain by its rules' expressions.
Maybe this even needs a matrix for cases where some hooks are OK in some
families/types but not others.

Cheers, Phil