Linux 6.12-rc5 Disabling Intel's Linear Address Masking "LAM" Due To Security Concerns

Intel merged Linear Address Masking into the Linux kernel last year as a means of allowing user-space to store metadata within some bits of pointers without masking it out before use. LAM can be useful for virtual machines, sanitizers / profiling / memory tagging, and other uses. While the brand new Intel Arrow Lake and Lunar Lake CPUs support LAM, the Linux kernel is now disabling LAM out of security concerns...