I've rebooted a second time without the oops/hang now.
I didn't notice any "error response NULL" messages though, and grep doesn't find any in /var/log.
Also note: handily, the backports module fixes an 11N bug for me (bug #305338 - can't get a DHCP address) but introduces a CRDA bug (bug #349001 - it always chooses the US regulatory domain).
I've rebooted a second time without the oops/hang now.
I didn't notice any "error response NULL" messages though, and grep doesn't find any in /var/log.
Also note: handily, the backports module fixes an 11N bug for me (bug #305338 - can't get a DHCP address) but introduces a CRDA bug (bug #349001 - it always chooses the US regulatory domain).