Re: [PATCH net] net: vlan: fix a UAF in vlan_dev_real_dev()

[Jakub Kicinski]

On Fri, 29 Oct 2021 09:13:24 -0300 Jason Gunthorpe wrote:
> Jakub's path would be to test vlan_dev->reg_state != NETREG_REGISTERED
> in the work queue, but that feels pretty hacky to me as the main point
> of the UNREGISTERING state is to keep the object alive enough that
> those with outstanding gets can compelte their work and release the
> get. Leaving a wrecked object in UNREGISTERING is a bad design.

That or we should investigate if we could hold the ref for real_dev all
the way until vlan_dev_free().