From: Nikolay Aleksandrov <razor@xxxxxxxxxxxxx>
Date: Fri, 15 Jan 2016 19:03:54 +0100
> From: Nikolay Aleksandrov <nikolay@xxxxxxxxxxxxxxxxxxx>
>
> After promisc mode management was introduced a bridge device could do
> dev_set_promiscuity from its ndo_change_rx_flags() callback which in
> turn can be called after the bridge's addr_list_lock has been taken
> (e.g. by dev_uc_add). This causes a false positive lockdep splat because
> the port interfaces' addr_list_lock is taken when br_manage_promisc()
> runs after the bridge's addr list lock was already taken.
> To remove the false positive introduce a custom bridge addr_list_lock
> class and set it on bridge init.
> A simple way to reproduce this is with the following:
> $ brctl addbr br0
> $ ip l add l br0 br0.100 type vlan id 100
> $ ip l set br0 up
> $ ip l set br0.100 up
> $ echo 1 > /sys/class/net/br0/bridge/vlan_filtering
> $ brctl addif br0 eth0
> Splat:
...
> CC: Vlad Yasevich <vyasevic@xxxxxxxxxx>
> CC: Stephen Hemminger <stephen@xxxxxxxxxxxxxxxxxx>
> CC: Bridge list <bridge@xxxxxxxxxxxxxxxxxxxxxxxxxx>
> CC: Andy Gospodarek <gospo@xxxxxxxxxxxxxxxxxxx>
> CC: Roopa Prabhu <roopa@xxxxxxxxxxxxxxxxxxx>
> Fixes: 2796d0c648c9 ("bridge: Automatically manage port promiscuous mode.")
> Reported-by: Andy Gospodarek <gospo@xxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Nikolay Aleksandrov <nikolay@xxxxxxxxxxxxxxxxxxx>
Applied and queued up for -stable, thanks Nikolay.
