From: Stephen Hemminger <step...@networkplumber.org>
Date: Thu, 13 Sep 2018 08:03:43 -0700
> When netvsc device is removed it can call reschedule in RCU context.
> This happens because canceling the subchannel setup work could (in theory)
> cause a reschedule when manipulating the timer.
>
> To reproduce, run with lockdep enabled kernel and unbind
> a network device from hv_netvsc (via sysfs).
...
> Resolve this by getting RTNL earlier. This is safe because the subchannel
> work queue does trylock on RTNL and will detect the race.
>
> Fixes: 7b2ee50c0cd5 ("hv_netvsc: common detach logic")
> Signed-off-by: Stephen Hemminger <sthem...@microsoft.com>
Applied and queued up for -stable.
