If you would like to chroot ssh user, you may installed Jailkit. It is not available on Ubuntu software repos but you can compile & build it in your own.

Before we build jailkit, we install the required software building tools first.

$ apt-get install build-essential autoconf automake1.11 libtool flex bison debhelper binutils

And then, we download, extract and build the Jailkit into a Debian/Ubuntu package.

$ cd /tmp
$ wget http://olivier.sessink.nl/jailkit/jailkit-2.19.tar.gz
$ tar xvfz jailkit-2.19.tar.gz
$ cd jailkit-2.19
$ ./debian/rules binary

After compiling source codes and created a Debian/Ubuntu binary package.

$ cd ..
$ dpkg -i jailkit_2.19-1_amd64.deb
$ rm -rf jailkit-2.19*