doomlord has found a solution to root on xperia z on android 4.2.2 and i wonder if the same method applies here.the process is simple.if you have installed the 4.2.2 rom,flash via flashtool the kernel from .370,run this programm to root and then flash back the 4.2.2 kernel.if somebody could create a kernel only ftf package with the kernel of .370 rom and another one with the kernel of the latest 4.2.2 firmware i would test it and report back.