tar: short read on linux-3.8.tar.xz

[John Spencer]

http://www.kernel.org/pub/linux/kernel/v3.0/linux-3.8.tar.xz

using busybox 1.20.2 and xz 5.0.3 or xz 5.0.4:

$ tar xf linux-3.8.tar.xz

i get: "short read" and exit status 1.
however the data seems to be there (at least partial).