This bug, I believe, is indirectly caused by the Debian NVIDIA drivers in non-free. Those drivers force an older kernel (2.6.32-5-amd64) to be used that is presently shipped with 6.0.6 (linux 2.6.32-46-amd64). The kernel USB bug causing the panic still exists in those older kernels but I think the bug was fixed by the time of the 6.0.6's kernel.
This bug is rather severe and many launchpad bugs have been reported related to it such as https://bugs.launchpad.net/ubuntu/+source/linux/+bug/844957
