Fabian Bläse [off-list ref] wrote:

To avoid unnecessary translations, I suggested the direction-specific checks.
Another option is to simplify them to:

     if (!(ct->status & IPS_NAT_MASK)) { … }

Yes, you can update the test from
        if (!ct || !(ct->status & IPS_SRC_NAT)) {

to
        if (!ct || !(ct->status & IPS_NAT_MASK)) {

Not related to your change:

I suspect there is a very small risk that kcsan could report a data
race here, given ct->status can be modified on other CPU.

But maybe, while at it, replace this with
READ_ONCE(ct->status) & ...

Correct — the change not only fixes SNAT-in-reply handling, but also adds
proper handling for DNAT in the reply direction, which was missing entirely.
I will update the commit message to reflect this.

Thanks!