From: Pablo Neira Ayuso <pablo@netfilter.org>
To: Phil Sutter <phil@nwl.cc>
Cc: netfilter-devel@vger.kernel.org
Subject: Re: [nft PATCH] libnftables: Fix for multiple context instances
Date: Mon, 20 Nov 2017 13:37:26 +0100 [thread overview]
Message-ID: <20171120123726.GA17459@salvia> (raw)
In-Reply-To: <20171116191024.18908-1-phil@nwl.cc>
On Thu, Nov 16, 2017 at 08:10:24PM +0100, Phil Sutter wrote:
> If a second context is created, the second call to nft_ctx_free() leads
> to freeing invalid pointers in nft_exit(). Fix this by introducing a
> reference counter so that neither nft_init() nor nft_exit() run more
> than once in a row.
>
> This reference counter has to be protected from parallel access. Do this
> using a mutex in a way that once nft_init() returns, the first call to
> that function running in parallel is guaranteed to be finished -
> otherwise it could happen that things being initialized in one thread
> are already accessed in another one.
I would prefer this table is placed into the context object, so they
are not global anymore. So I would prefer we fix this the right way(tm).
Let me know your thoughts, thanks!
next prev parent reply other threads:[~2017-11-20 12:37 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-16 19:10 [nft PATCH] libnftables: Fix for multiple context instances Phil Sutter
2017-11-20 12:37 ` Pablo Neira Ayuso [this message]
2017-11-20 12:54 ` Phil Sutter
2017-11-20 13:07 ` Pablo Neira Ayuso
2017-11-20 15:58 ` Phil Sutter
2017-11-20 16:53 ` Pablo Neira Ayuso
2017-11-22 17:49 ` Phil Sutter
2017-11-22 18:18 ` Pablo Neira Ayuso
[not found] ` <20171204100955.GA1822@salvia>
[not found] ` <20171204105324.GX32305@orbyte.nwl.cc>
[not found] ` <20171204110142.GA19776@salvia>
[not found] ` <20171204164327.GA32305@orbyte.nwl.cc>
[not found] ` <20171204184604.GA1556@salvia>
2017-12-05 13:43 ` libnftables extended API proposal (Was: Re: [nft PATCH] libnftables: Fix for multiple context instances) Phil Sutter
2017-12-07 0:05 ` Pablo Neira Ayuso
2017-12-07 11:34 ` Phil Sutter
2017-12-10 21:55 ` Pablo Neira Ayuso
2017-12-16 16:06 ` libnftables extended API proposal Phil Sutter
2017-12-18 23:00 ` Pablo Neira Ayuso
2017-12-20 12:32 ` Phil Sutter
2017-12-20 22:23 ` Pablo Neira Ayuso
2017-12-22 13:08 ` Phil Sutter
2017-12-22 13:49 ` Pablo Neira Ayuso
2017-12-22 15:30 ` Phil Sutter
2017-12-22 20:39 ` Pablo Neira Ayuso
2017-12-23 13:19 ` Phil Sutter
2017-12-28 19:21 ` Pablo Neira Ayuso
2017-12-29 14:58 ` Phil Sutter
2018-01-02 18:02 ` Pablo Neira Ayuso
2018-01-05 17:52 ` Phil Sutter
2018-01-09 23:31 ` Pablo Neira Ayuso
2018-01-10 4:46 ` mark diener
2018-01-10 10:39 ` Phil Sutter
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