Re: Linux 5.17-rc5

[Linus Torvalds]

On Mon, Feb 21, 2022 at 6:23 AM Woody Suwalski <wsuwalski@xxxxxxxxx> wrote:
>
> Compile failed like reported by Robert Gadson in
> https://lkml.org/lkml/2022/2/20/341
>
> As a workaround:
> nf_defrag_ipv6.patch
> --- a/net/netfilter/xt_socket.c    2022-02-21 07:29:21.938263397 -0500
> +++ b/net/netfilter/xt_socket.c    2022-02-21 07:40:16.730022272 -0500
> @@ -17,11 +17,11 @@
>   #include <net/inet_sock.h>
>   #include <net/netfilter/ipv4/nf_defrag_ipv4.h>
>
> -#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
> +//#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
>   #include <linux/netfilter_ipv6/ip6_tables.h>
...

Hmm. That may fix the compile failure, but it looks somewhat broken to me.

Other cases of nf_defrag_ipv6_disable() end up being protected by

   #if IS_ENABLED(CONFIG_NF_TABLES_IPV6)

at the use-point, not by just assuming it always exists even when
CONFIG_NF_TABLES_IPV6 is off.

So I think the proper fix is something along the lines of

  --- a/net/netfilter/xt_socket.c
  +++ b/net/netfilter/xt_socket.c
  @@ -220,8 +220,10 @@ static void socket_mt_destroy(const struct
xt_mtdtor_param *par)
   {
        if (par->family == NFPROTO_IPV4)
                nf_defrag_ipv4_disable(par->net);
  +#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
        else if (par->family == NFPROTO_IPV6)
                nf_defrag_ipv6_disable(par->net);
  +#endif
   }

instead. Entirely untested, because that's how I roll, but I suspect
the netfilter people will know what to do.

Added guilty parties and mailing list to the participants.

                Linus