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Subject: Re: [PATCH net v2 01/11] net: core: limit nested device depth
From:   David Miller <davem@davemloft.net>
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From: Taehee Yoo <ap420073@gmail.com>
Date: Thu, 12 Sep 2019 12:56:19 +0900

> I tested with this reproducer commands without lockdep.
> 
>     ip link add dummy0 type dummy
>     ip link add link dummy0 name vlan1 type vlan id 1
>     ip link set vlan1 up
> 
>     for i in {2..200}
>     do
>             let A=$i-1
> 
>             ip link add name vlan$i link vlan$A type vlan id $i
>     done
>     ip link del vlan1 <-- this command is added.

Is there any other device type which allows arbitrary nesting depth
in this manner other than VLAN?  Perhaps it is the VLAN nesting
depth that we should limit instead of all of this extra code.