re: kern/43541: Unaligned access in pf_normalize_tcpopt()

[Hisashi T Fujinaka <htodd%twofifty.com@localhost>]

I've switched to a sparc64 system and had a hard time causing the hang,
so I think I better ask for this to be closed. I still have the old
system, but I'm not sure how I'd trigger this.

Thanks.

On Tue, 29 Jun 2010, matthew green wrote:

> i wonder if this is the same problem as reported in:
>
>  port-sparc/40629: kernel panic under high network load using pf (and ipv6)
>
> hisashi, can you try the patch in this PR for your problem?
> (included below again.)
>
>
> .mrg.
>
>
> Index: sys/dist/pf/net/pf_norm.c
> ===================================================================
> --- sys/dist/pf/net/pf_norm.c
> +++ sys/dist/pf/net/pf_norm.c   (working copy)
> @@ -1878,7 +1878,7 @@
> pf_normalize_tcpopt(struct pf_rule *r, struct mbuf *m, struct tcphdr *th,
>     int off)
> {
> -       u_int16_t       *mss;
> +       u_int16_t        mss;
>         int              thoff;
>         int              opt, cnt, optlen = 0;
>         int              rewrite = 0;
> @@ -1903,11 +1903,12 @@
>                 }
>                 switch (opt) {
>                 case TCPOPT_MAXSEG:
> -                       mss = (u_int16_t *)(optp + 2);
> -                       if ((ntohs(*mss)) > r->max_mss) {
> +                       mss = (optp[2] << 8) | optp[3];
> +                       if (mss > r->max_mss) {
>                                 th->th_sum = pf_cksum_fixup(th->th_sum,
> -                                   *mss, htons(r->max_mss), 0);
> -                               *mss = htons(r->max_mss);
> +                                   htons(mss), htons(r->max_mss), 0);
> +                               optp[2] = (u_char)(r->max_mss >> 8) & 0xff;
> +                               optp[3] = (u_char)(r->max_mss) & 0xff;
>                                 rewrite = 1;
>                         }
>                         break;

--
Hisashi T Fujinaka - htodd%twofifty.com@localhost
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