It appears Kees is able to reproduce this oops as reported in bug 585175, which I'll mark as a duplicate here.
"Trivial use of aufs doesn't crash, but trying to start up an aufs directory from schroot fails, and then the umount cannot even clean it up. During set up, it's /etc/schroot/setup.d/22nssdatabases that finally triggers the issue."
It appears Kees is able to reproduce this oops as reported in bug 585175, which I'll mark as a duplicate here.
"Trivial use of aufs doesn't crash, but trying to start up an aufs directory from schroot fails, and then the umount cannot even clean it up. During set up, it's /etc/schroot/ setup.d/ 22nssdatabases that finally triggers the issue."