There are tons of git bisect howtos.  You will need to checkout the stable
kernel git tree, build and install it.  Here are the basics:

# 1. clone the git tree
git clone git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git
cd linux-stable
# 2. copy the config from your currently running kernel
cp /boot/config-4.0.4-<whatever> .config
# 3. start the bisect
git bisect start
git bisect good v4.0.4
git bisect bad v4.0.5
# 4. build and install the kernel
make
make modules_install
make install
# 5. reboot and test of the kernel is working
# 6a. if so mark the commit as good
git bisect good
# 6b. else mark it as bad
git bisect bad
# 7. repeat steps 4-6 until git has identified the problematic commit