I've verified the fix in 4.15.0-89.89-generic. The sysrq help message is printed to the kernel log when trying to lift lockdown with the proof-of-concept and when trying to lift lockdown with alt+sysrq+x.
I've verified the fix in 4.15.0- 89.89-generic. The sysrq help message is printed to the kernel log when trying to lift lockdown with the proof-of-concept and when trying to lift lockdown with alt+sysrq+x.