From: Nikolay Aleksandrov <razor@blackwall.org>
Date: Wed, 22 Jul 2015 13:03:40 +0200

From: Nikolay Aleksandrov <redacted>

Since slave_changelink support was added there have been a few race
conditions when using br_setport() since some of the port functions it
uses require the bridge lock. It is very easy to trigger a lockup due to
some internal spin_lock() usage without bh disabled, also it's possible to
get the bridge into an inconsistent state.

Signed-off-by: Nikolay Aleksandrov <redacted>
Fixes: 3ac636b8591c ("bridge: implement rtnl_link_ops->slave_changelink")

Applied and queued up for -stable, thanks.