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From: Pablo Neira Ayuso <pablo@netfilter.org>
To: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: Florian Westphal <fw@strlen.de>,
	netfilter-devel@vger.kernel.org, davem@davemloft.net,
	netdev@vger.kernel.org
Subject: Re: [PATCH 01/12] netfilter: avoid get_random_bytes calls
Date: Mon, 6 Jan 2014 13:58:23 +0100	[thread overview]
Message-ID: <20140106125823.GA8076@localhost> (raw)
In-Reply-To: <20140106124340.GC4611@order.stressinduktion.org>

On Mon, Jan 06, 2014 at 01:43:40PM +0100, Hannes Frederic Sowa wrote:
[...]
> > > Hmm, some of them look like good candidates for net_get_random_once. I don't
> > > see such a problem with draining entropy pool, especially as they don't run
> > > that early and they don't request so many random bits.
> > 
> > I specifically did not use net_get_random_once once because checkentry is
> > not a hotpath.
> > 
> > I don't see why get_random_bytes use increases the security margin, especially
> > considering none of these hashes have periodic run-time rehashing?
> > 
> > But sure, if you think this change is a problem, Pablo can just revert it.
> 
> I don't know if it is a real problem. Most of the time the initial seed
> should be enough, but I guess get_random_bytes would still be a more
> defensive choice. I would have used it. ;)

OK, I have reverted this patch, thanks.

  reply	other threads:[~2014-01-06 12:58 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-01-05 23:12 [PATCH 00/12] netfilter updates for net-next Pablo Neira Ayuso
2014-01-05 23:12 ` [PATCH 01/12] netfilter: avoid get_random_bytes calls Pablo Neira Ayuso
2014-01-05 23:41   ` Hannes Frederic Sowa
2014-01-06 11:54     ` Florian Westphal
2014-01-06 12:43       ` Hannes Frederic Sowa
2014-01-06 12:58         ` Pablo Neira Ayuso [this message]
2014-01-06 13:04         ` Florian Westphal
2014-01-06 13:06           ` Pablo Neira Ayuso
2014-01-06 13:07             ` Florian Westphal
2014-01-05 23:12 ` [PATCH 02/12] netfilter: ctnetlink: honor CTA_MARK_MASK when setting ctmark Pablo Neira Ayuso
2014-01-05 23:12 ` [PATCH 03/12] netfilter: nfnetlink_queue: enable UID/GID socket info retrieval Pablo Neira Ayuso
2014-01-06 15:32   ` Eric Dumazet
2014-01-06 16:36     ` Pablo Neira Ayuso
2014-01-06 18:36     ` David Miller
2014-01-05 23:12 ` [PATCH 04/12] netfilter: add IPv4/6 IPComp extension match support Pablo Neira Ayuso
2014-01-05 23:12 ` [PATCH 05/12] ipvs: Remove unused variable ret from sync_thread_master() Pablo Neira Ayuso
2014-01-05 23:13 ` [PATCH 06/12] netfilter: nf_nat: add full port randomization support Pablo Neira Ayuso
2014-01-05 23:13 ` [PATCH 07/12] netfilter: ipset: remove unused code Pablo Neira Ayuso
2014-01-05 23:13 ` [PATCH 08/12] netfilter: nf_conntrack: remove dead code Pablo Neira Ayuso
2014-01-05 23:13 ` [PATCH 09/12] netfilter: xt_CT: fix error value in xt_ct_tg_check() Pablo Neira Ayuso
2014-01-05 23:13 ` [PATCH 10/12] net: net_cls: move cgroupfs classid handling into core Pablo Neira Ayuso
2014-01-05 23:13 ` [PATCH 11/12] net: netprio: rename config to be more consistent with cgroup configs Pablo Neira Ayuso
2014-01-05 23:13 ` [PATCH 12/12] netfilter: x_tables: lightweight process control group matching Pablo Neira Ayuso
  -- strict thread matches above, loose matches on Subject: below --
2014-01-05 23:09 [PATCH 00/12] netfilter/IPVS updates for net-next Pablo Neira Ayuso
2014-01-05 23:09 ` [PATCH 01/12] netfilter: avoid get_random_bytes calls Pablo Neira Ayuso

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