From: Ivan Vecera <ivec...@redhat.com> Date: Wed, 25 May 2016 21:21:52 +0200
> The team_device_event() notifier calls team_compute_features() to fix > vlan_features under team->lock to protect team->port_list. The problem is > that subsequent __team_compute_features() calls netdev_change_features() > to propagate vlan_features to upper vlan devices while team->lock is still > taken. This can lead to deadlock when NETIF_F_LRO is modified on lower > devices or team device itself. > > Example: > The team0 as active backup with eth0 and eth1 NICs. Both eth0 & eth1 are > LRO capable and LRO is enabled. Thus LRO is also enabled on team0. > > The command 'ethtool -K team0 lro off' now hangs due to this deadlock: ... > The bug is present in team from the beginning but it appeared after the commit > fd867d5 (net/core: generic support for disabling netdev features down stack) > that adds synchronization of features with lower devices. > > Fixes: fd867d5 (net/core: generic support for disabling netdev features down > stack) > Cc: Jiri Pirko <j...@resnulli.us> > Signed-off-by: Ivan Vecera <ivec...@redhat.com> Applied and queued up for -stable, thanks.
