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From: David Ahern <dsahern@gmail.com>
To: Kasper Dupont <kasperd@gczfm.28.feb.2009.kasperd.net>
Cc: netdev@vger.kernel.org,
	Thadeu Lima de Souza Cascardo <cascardo@canonical.com>,
	davem@davemloft.net, kuba@kernel.org, dsahern@kernel.org,
	Kasper Dupont <kasperd@gjkwv.06.feb.2021.kasperd.net>
Subject: Re: [PATCH 2/2] neighbour: allow NUD_NOARP entries to be forced GCed
Date: Mon, 19 Apr 2021 21:27:13 -0700	[thread overview]
Message-ID: <71ea409d-7065-821a-f958-1736d015e4ff@gmail.com> (raw)
In-Reply-To: <20210419175205.GA2375672@sniper.kasperd.net>

On 4/19/21 10:52 AM, Kasper Dupont wrote:
> On 19/04/21 10.10, David Ahern wrote:
>> On 4/19/21 9:44 AM, Kasper Dupont wrote:
>>>
>>> Is there any update regarding this change?
>>>
>>> I noticed this regression when it was used in a DoS attack on one of
>>> my servers which I had upgraded from Ubuntu 18.04 to 20.04.
>>>
>>> I have verified that Ubuntu 18.04 is not subject to this attack and
>>> Ubuntu 20.04 is vulnerable. I have also verified that the one-line
>>> change which Cascardo has provided fixes the vulnerability on Ubuntu
>>> 20.04.
>>>
>>
>> your testing included both patches or just this one?
> 
> I applied only this one line change on top of the kernel in Ubuntu
> 20.04. The behavior I observed was that without the patch the kernel
> was vulnerable and with that patch I was unable to reproduce the
> problem.

This patch should be re-submitted standalone for -net

> 
> The other longer patch is for a different issue which Cascardo
> discovered while working on the one I had reported. I don't have an
> environment set up where I can reproduce the issue addressed by that
> larger patch.
> 

The first patch is the one I have concerns about.

  reply	other threads:[~2021-04-20  4:27 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-17 18:53 [PATCH 1/2] neighbour: allow referenced neighbours to be removed Thadeu Lima de Souza Cascardo
2021-03-17 18:53 ` [PATCH 2/2] neighbour: allow NUD_NOARP entries to be forced GCed Thadeu Lima de Souza Cascardo
2021-04-19 16:44   ` Kasper Dupont
2021-04-19 17:10     ` David Ahern
2021-04-19 17:52       ` Kasper Dupont
2021-04-20  4:27         ` David Ahern [this message]
2021-03-17 23:42 ` [PATCH 1/2] neighbour: allow referenced neighbours to be removed David Ahern
2021-03-22 21:33   ` Thadeu Lima de Souza Cascardo

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