Temporary mitigation if you cannot reboot yet
The good news is that the same mitigation from the Dirty Frag article also inhibits Fragnesia because it uses the same esp4, esp6, and rxrpc modules to reach root. You are already safe against this one if you have already used it. Until you install the modified kernel, nothing else needs to be done.
Blacklisting the impacted modules will neutralize the attack surface if you haven't already. A normal workload does not require any of esp4, esp6, or rxrpc.
Blacklisting the impacted modules will neutralize the attack surface if you haven't already. A normal workload does not require any of esp4, esp6, or rxrpc.
sudo sh -c "printf 'install esp4 /bin/false\ninstall esp6 /bin/false\ninstall rxrpc /bin/false\n' > /etc/modprobe.d/fragnesia.conf; rmmod esp4 esp6 rxrpc 2>/dev/null; true"