Comment 2 for bug 615177

Thomas, can you adjust these lines in /etc/apparmor.d/abstractions/user-tmp:
  owner /var/tmp/ rw,
  owner /tmp/ rw,

to be:
  /var/tmp/ rw,
  /tmp/ rw,

Then do:
$ sudo apparmor_parser -r -T -W /etc/apparmor.d/usr.sbin.mysqld

Then restart apparmor then mysql. Rebooting would be easiest (but make sure mysqld is still confined with 'sudo aa-status').

Please report back. I also recommend The abstraction is clearly too strict and will be fixed in the apparmor package, but after making the change an adjustment may still be needed for mysql.