Comment 14 for bug 1310586

Unfortunately I wont be able to test the mainline kernel any time soon. However, I see that the relevant patches described in the netdev thread are merged into the 3.13 tree:

bridge: multicast: add sanity check for query source addresses
bridge: multicast: add sanity check for general query destination
bridge: multicast: enable snooping on general queries only

Including these patches in the Ubuntu 14.04 kernel should resolve this issue.