Thanks.

I just quickly tested it on my main workstation running 4.4.0-36, Jolla sbj1 running 3.4.0 and a fedora cloud image running 4.6.4-301 kernels using the above demo exploit.

On all of those devices the result was as expected, the user process was able to gain root using the leaking CoW.

Same thing applies as always; do not run unknown binaries in your system. Fortunately this is an exploit not easily used remotely.