When try to update the kernel of Ubuntu and you’ve antivirus McAfee agent installed, you can have this error :

dpkg: error processing archive /tmp/apt-dpkg-install-CcwBQW/2-linux-image-5.13.0-35-generic_5.13.0-35.40_amd64.deb (--unpack):
unable to open '/boot/vmlinuz-5.13.0-35-generic.dpkg-new': Operation not permitted
Errors were encountered while processing:
/tmp/apt-dpkg-install-CcwBQW/2-linux-image-5.13.0-35-generic_5.13.0-35.40_amd64.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)

The antivirus prevents the installation of the packages as my system has already one (McAfee agent).

First of all, we need to check the status of the antivirus with the following commands if it is running or not:

# /opt/McAfee/ens/tp/init/mfetpd-control.sh status
# /opt/McAfee/ens/esp/init/mfeespd-control.sh status

If it is running then stop the services with these:

# /opt/McAfee/ens/tp/init/mfetpd-control.sh stop
# /opt/McAfee/ens/esp/init/mfeespd-control.sh stop

Then check the status again if it is stopped or not. If stopped then I started necessary updates and required installations by this:

sudo apt --fix-broken install

Finally, I started the antivirus again by these:

# /opt/McAfee/ens/esp/init/mfeespd-control.sh start
# /opt/McAfee/ens/tp/init/mfetpd-control.sh start

Reference: https://kc.mcafee.com/corporate/index?page=content&id=KB88223