Hi linux-stable,

This is a request to backport

751eb6b6 ipv6: addrconf: fix dev refcont leak when DAD failed
https://github.com/torvalds/linux/commit/751eb6b6042a596b0080967c1a529a9fe98dac1d

to linux-stable 4.4.y branch.
It has already been applied to stable master, and 4.7.y, but not longterm 4.4.y

We often (1+/week) run into hosts hanging with errors like

[1637669.684652] unregister_netdevice: waiting for veth26dc718 to become free. Usage count = 1
[1637679.864366] unregister_netdevice: waiting for veth26dc718 to become free. Usage count = 1

and have been told that this patch likely fixes the problem.

I am not on the list so please keep me on CC for any followup.

Thanks!
Steven