Submitted over the Christmas holidays by AMD engineer Tom Lendacky, the “x86/cpu, x86/pti: Do not enable PTI on AMD processors” patch has landed today in the Linux 4.14.12 kernel, disabling the kernel page table isolation (KPTI) for all AMD Radeon processors, which were treated as “insecure” until now. Linux kernel 4.14.12 also continues with the huge x86 PTI patches by adding two more, one that adds the ability to switch to kernel CR3 at early in entry_SYSCALL_compat() and another to make sure the user/kernel PTEs match. It also reverts the “xfrm: Fix stack-out-of-bounds read in xfrm_state_find” change, but it’s not bug-free yet.