From: Pablo Neira Ayuso <pablo@netfilter.org>
To: Florian Westphal <fw@strlen.de>
Cc: Taehee Yoo <ap420073@gmail.com>, netfilter-devel@vger.kernel.org
Subject: Re: [PATCH V2] netfilter: x_tables: Fix use-after-free in ipt_do_table.
Date: Wed, 26 Jul 2017 13:06:27 +0200 [thread overview]
Message-ID: <20170726110627.GC1607@salvia> (raw)
In-Reply-To: <20170726092716.GB28392@breakpoint.cc>
On Wed, Jul 26, 2017 at 11:27:16AM +0200, Florian Westphal wrote:
> Taehee Yoo <ap420073@gmail.com> wrote:
> > If verdict is NF_STOLEN in the SYNPROXY target,
> > the skb is consumed.
> > However, ipt_do_table() always tries to get ip header from the skb.
> > So that, KASAN triggers the use-after-free message.
>
> In case anyone wonders, ip6tables doesn't have this problem
> because we pass *skb, not ip6hdr to ip6_packet_match().
I think it would be good to make these code converge to what ip6tables
is doing while fixing up this?
> arptables has the same bug, it seems (no target returns STOLEN,
> but I think we should fix it there as well).
Yes, even if no target returns what triggers the problem, it's good if
we fix this now so we make sure whatever new extension gets in in the
future works accordingly.
Thanks!
next prev parent reply other threads:[~2017-07-26 11:06 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-26 9:16 [PATCH V2] netfilter: x_tables: Fix use-after-free in ipt_do_table Taehee Yoo
2017-07-26 9:27 ` Florian Westphal
2017-07-26 11:06 ` Pablo Neira Ayuso [this message]
2017-07-27 1:12 ` Taehee Yoo
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