Re: [PATCH net] net: core: Fix the loop in default_device_exit_net()

[Jakub Kicinski]

On Fri, 18 Jul 2025 13:20:14 -0700 Haiyang Zhang wrote:
> The loop in default_device_exit_net() won't be able to properly detect the
> head then stop, and will hit NULL pointer, when a driver, like hv_netvsc,
> automatically moves the slave device together with the master device.
> 
> To fix this, add a helper function to return the first migratable netdev
> correctly, no matter one or two devices were removed from this net's list
> in the last iteration.

FTR I think that what the driver is trying to do is way too hacky, and
it should be fixed instead. But I defer to Kuniyuki for the final word,
maybe this change is useful for other reasons..