From: Pablo Neira Ayuso <pablo@netfilter.org>
To: Florian Westphal <fw@strlen.de>
Cc: netfilter-devel@vger.kernel.org
Subject: Re: [PATCH nf-next v2 0/4] netfilter: handle race w. module removal and nfqueue
Date: Mon, 31 Jul 2017 19:10:16 +0200 [thread overview]
Message-ID: <20170731171016.GA4855@salvia> (raw)
In-Reply-To: <20170725220234.29354-1-fw@strlen.de>
On Wed, Jul 26, 2017 at 12:02:30AM +0200, Florian Westphal wrote:
> There is a long-standing race that occurs with module removal
> (such as helpers) nfqueue, and unconfirmed (not in hash table) conntracks.
>
> The main issue is that
> a). unconfirmed conntracks can't safely be mangled from other cpu (we assume
> exclusive access to grow/alter the extension area) and
> b). nfqueued skbs leave RCU protection
>
> This series address this by making the queue event similar to a
> confirm event:
>
> Just as we do not commit 'dying' conntracks to the main table, refuse to
> queue dying and unconfirmed conntracks to userspace.
>
> Combined with a 'drop queued skbs' when a module exit path calls the
> ct_iterate_destroy function this closes the hole, see patch #4 for details.
>
> The only change since v1 is a build error that occured in patch 4 when
> nfqueue is enabled but conntrack is not, as reported by kbuild test robot.
Series applied.
prev parent reply other threads:[~2017-07-31 17:10 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-25 22:02 [PATCH nf-next v2 0/4] netfilter: handle race w. module removal and nfqueue Florian Westphal
2017-07-25 22:02 ` [PATCH nf-next v2 1/4] netfilter: expect: add and use nf_ct_expect_iterate helpers Florian Westphal
2017-07-25 22:02 ` [PATCH nf-next v2 2/4] netfilter: add and use nf_ct_unconfirmed_destroy Florian Westphal
2017-07-25 22:02 ` [PATCH nf-next v2 3/4] netfilter: conntrack: destroy functions need to free queued packets Florian Westphal
2017-07-25 22:02 ` [PATCH nf-next v2 4/4] netfilter: nfnetlink_queue: don't queue dying conntracks to userspace Florian Westphal
2017-07-31 17:10 ` Pablo Neira Ayuso [this message]
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