Re: [PATCH nft] netlink_linearize: size nat register allocation by address expression

[Pablo Neira Ayuso <pablo@netfilter.org>]

On Thu, Aug 06, 2026 at 08:50:20PM +0200, Adrian Moisey wrote:
> nat statements with a literal concatenation of address and port, e.g.
> 
>   dnat ip6 addr . port to fd00:10:244::4 . 6443
> 
> allocated a fixed 128-bit register block for the address, but the ip6
> address . port concatenation is 144 bits (5 registers), so
> netlink_gen_concat overran into unallocated registers and hit the
> assertion 'dreg < ctx->reg_low' in netlink_gen_expr. IPv4 escaped by
> luck since its 48-bit concatenation fits into the padded block.
> 
> Allocate the register based on the address expression instead, which
> sizes by expr->len for concatenations, and add the matching
> release_register() call. Extend the nat_addr_port test with literal
> concatenation rules for ip and ip6.

Applied, thanks