Harden memory copies between kernel and userspace

modulename: usercopy.ko

configname: CONFIG_HARDENED_USERCOPY

Linux Kernel Configuration
└─>Security options
└─>Harden memory copies between kernel and userspace
In linux kernel since version 3.10 (release Date: 2013-06-30)  
This option checks for obviously wrong memory regions when
copying memory to/from the kernel (via copy_to_user() and
copy_from_user() functions) by rejecting memory ranges that
are larger than the specified heap object, span multiple
separately allocated pages, are not on the process stack,
or are part of the kernel text. This prevents entire classes
of heap overflow exploits and similar kernel memory exposures.

source code: