Re: nf_unregister_net_hook: hook not found!

[Joe Stringer]

On 30 December 2015 at 10:15, Sander Eikelenboom <linux@xxxxxxxxxxxxxx> wrote:
> On 2015-12-30 03:39, ebiederm@xxxxxxxxxxxx wrote:
>>
>> Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx> writes:
>>
>>> On Mon, Dec 28, 2015 at 09:05:03PM +0100, Sander Eikelenboom wrote:
>>>>
>>>> Hi,
>>>>
>>>> Running a 4.4.0-rc6 kernel i encountered the warning below.
>>>
>>>
>>> Cc'ing Eric Biederman.
>>>
>>> @Sander, could you provide a way to reproduce this?
>>
>>
>> I am on vacation until the new year, but if this is reproducible we
>> should be able to print out reg, reg->pf, reg->hooknum, reg->hook
>> to figure out which hook is having something very weird happen to it.
>>
>> This is happening in some network namespace exit.
>>
>> Eric
>>
>
> Unfortunately i have found no way to reproduce,
> 13 seconds implies it was at boot, but i only have seen this once.

How about this script?

#!/bin/sh

ip netns add at_ns0
ip netns del at_ns0
modprobe nf_conntrack_ipv4
modprobe -r nf_conntrack_ipv4