feature: out-of-bound write primitive and an exploit

[d1sgr4c3]

hello, @a13xp0p0v !

please have a look at these changes:

1. module has been patched to make OOBW happen, drill_test updated as well to prevent heap corruption
2. built a basic exploit
3. and carefully repaired modprobe_path
4. readme updated as well

also POC can bypass this mitigations:

• CONFIG_SLAB_MERGE_DEFAULT=n
• CONFIG_SLAB_FREELIST_RANDOM=y
• CONFIG_SLAB_FREELIST_HARDENED=y
• CONFIG_SLAB_BUCKETS=y