Re: [PATCH nf] netfilter: handle the connecting collision properly in nf_conntrack_proto_sctp

[Xin Long <lucien.xin@xxxxxxxxx>]

On Tue, Oct 3, 2023 at 8:51 AM Simon Horman <horms@xxxxxxxxxx> wrote:
>
> On Sun, Oct 01, 2023 at 11:07:48AM -0400, Xin Long wrote:
>
> ...
>
> > @@ -481,6 +486,24 @@ int nf_conntrack_sctp_packet(struct nf_conn *ct,
> >                           old_state == SCTP_CONNTRACK_CLOSED &&
> >                           nf_ct_is_confirmed(ct))
> >                               ignore = true;
> > +             } else if (sch->type == SCTP_CID_INIT_ACK) {
> > +                     struct sctp_inithdr _ih, *ih;
> > +                     u32 vtag;
> > +
> > +                     ih = skb_header_pointer(skb, offset + sizeof(_sch), sizeof(*ih), &_ih);
> > +                     if (ih == NULL)
> > +                             goto out_unlock;
> > +
> > +                     vtag = ct->proto.sctp.vtag[!dir];
> > +                     if (!ct->proto.sctp.init[!dir] && vtag && vtag != ih->init_tag)
> > +                             goto out_unlock;
> > +                     /* collision */
> > +                     if (ct->proto.sctp.init[dir] && ct->proto.sctp.init[!dir] &&
> > +                         vtag != ih->init_tag)
>
> The type of vtag is u32. But the type of ct->proto.sctp.vtag[!dir] and init_tag
> is __be32. This doesn't seem right (and makes Sparse unhappy).
You're right, I will fix it and re-post with tag:

Fixes: 9fb9cbb1082d ("[NETFILTER]: Add nf_conntrack subsystem.")

Thanks.
>
> > +                             goto out_unlock;
> > +
> > +                     pr_debug("Setting vtag %x for dir %d\n", ih->init_tag, !dir);
> > +                     ct->proto.sctp.vtag[!dir] = ih->init_tag;
> >               }
> >
> >               ct->proto.sctp.state = new_state;
> > --
> > 2.39.1
> >
> >