This reminds me of the Intel SYSRET bug: https://blog.xenproject.org/2012/06/13/the-intel-sysret-privilege-escalation/ https://blog.xenproject.org/2012/06/13/th

This reminds me of the Intel SYSRET bug: https://blog.xenproject.org/2012/06/13/the-intel-sysret-privilege-escalation/ https://blog.xenproject.org/2012/06/13/the-intel-sysret-priv... In which AMD defines a new instruction, and Intel copies it with a subtle difference which trips up everyone (AMD's way is better IMO, and it came first).