Re: [PATCH] tcp: incoming connections might use wrong route undersynflood

From: David Miller
Date: Thu Apr 11 2013 - 13:18:13 EST


From: Dmitry Popov <dp@xxxxxxxxxxxxxxx>
Date: Thu, 11 Apr 2013 11:46:00 +0400

> There is a bug in cookie_v4_check (net/ipv4/syncookies.c):
> flowi4_init_output(&fl4, 0, sk->sk_mark, RT_CONN_FLAGS(sk),
> RT_SCOPE_UNIVERSE, IPPROTO_TCP,
> inet_sk_flowi_flags(sk),
> (opt && opt->srr) ? opt->faddr : ireq->rmt_addr,
> ireq->loc_addr, th->source, th->dest);
>
> Here we do not respect sk->sk_bound_dev_if, therefore wrong dst_entry may be
> taken. This dst_entry is used by new socket (get_cookie_sock ->
> tcp_v4_syn_recv_sock), so its packets may take the wrong path.
>
> Signed-off-by: Dmitry Popov <dp@xxxxxxxxxxxxxxx>

Do not top post, especially with patches! Because you top posted
the new version of the patch, my reply to you sits at the end of
the new patch.

Make a fresh, completely new, mailing list posting to post new versions
of patches. Never do so using replies.

Thanks.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/