Subject: Re: [PATCH net-next] team: prevent adding a device which is already a team device lower

From: Hangbin Liu <[email-masked]>
Date: Thu, 2 Jan 2025 08:53:42 +0000

On Thu, Jan 02, 2025 at 08:50:42AM +0000, Hangbin Liu wrote:
> On Mon, Dec 30, 2024 at 12:56:47PM -0800, Octavian Purdila wrote:
> > Prevent adding a device which is already a team device lower,
> > e.g. adding veth0 if vlan1 was already added and veth0 is a lower of
> > vlan1.
> > 
> > This is not useful in practice and can lead to recursive locking:
> > 
> > $ ip link add veth0 type veth peer name veth1
> > $ ip link set veth0 up
> > $ ip link set veth1 up
> > $ ip link add link veth0 name veth0.1 type vlan protocol 802.1Q id 1
> > $ ip link add team0 type team
> > $ ip link set veth0.1 down
> > $ ip link set veth0.1 master team0
> > team0: Port device veth0.1 added
> > $ ip link set veth0 down
> > $ ip link set veth0 master team0
> > 

I didn't test, what if enslave veth0 first and then add enslave veth0.1 later.

Thanks
Hangbin