diff --git a/etc/default/grub.d/40_cpu_mitigations.cfg b/etc/default/grub.d/40_cpu_mitigations.cfg index 667480e..fd997e4 100644 --- a/etc/default/grub.d/40_cpu_mitigations.cfg +++ b/etc/default/grub.d/40_cpu_mitigations.cfg @@ -1,21 +1,30 @@ ## Copyright (C) 2019 - 2023 ENCRYPTED SUPPORT LP ## See the file COPYING for copying conditions. -## Enables all known mitigations for CPU vulnerabilities. +## Enables known mitigations for CPU vulnerabilities. ## ## https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/index.html ## https://www.kernel.org/doc/html/latest/admin-guide/kernel-parameters.html ## https://forums.whonix.org/t/should-all-kernel-patches-for-cpu-bugs-be-unconditionally-enabled-vs-performance-vs-applicability/7647 -## Enable known mitigations for CPU vulnerabilities and disable SMT. +## Check for potential updates directly from AMD and Intel. +## +## https://www.amd.com/en/resources/product-security.html +## https://www.intel.com/content/www/us/en/developer/topic-technology/software-security-guidance/advisory-guidance.html +## https://www.intel.com/content/www/us/en/developer/topic-technology/software-security-guidance/disclosure-documentation.html + +## Enable a subset of known mitigations for CPU vulnerabilities and disable SMT. GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX mitigations=auto,nosmt" -## Enable mitigations for Spectre variant 2 (indirect branch speculation). +## Enable mitigations for both Spectre Variant 2 (indirect branch speculation) +## and Intel branch history injection (BHI) vulnerabilities. ## ## https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/spectre.html -GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX spectre_v2=on" +GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX spectre_v2=on spectre_bhi=on" -## Disable Speculative Store Bypass. +## Disable Speculative Store Bypass (Spectre Variant 4). +## +## https://www.suse.com/support/kb/doc/?id=000019189 GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX spec_store_bypass_disable=on" ## Enable mitigations for the L1TF vulnerability through disabling SMT @@ -67,6 +76,7 @@ GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX mmio_stale_data=full,nosmt" ## Enable mitigations for RETBleed (Arbitrary Speculative Code Execution with ## Return Instructions) vulnerability and disable SMT. ## +## https://www.suse.com/support/kb/doc/?id=000020693 GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX retbleed=auto,nosmt" ## Control RAS overflow mitigation on AMD Zen CPUs. @@ -75,8 +85,15 @@ GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX retbleed=auto,nosmt" ## ## https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/srso.html -## Enables mitigation of Branch History Injection vulnerabilities on Intel CPUs. +## Mitigates Gather Data Sampling (GDS) vulnerability. +## Note for systems that have not received a suitable microcode update this will +## entirely disable use of the AVX instructions set. ## -## https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=2bb69f5fc72183e1c62547d900f560d0e9334925 -## TODO: update the above link with better alternative when possible -GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX spectre_bhi=on" +## https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/gather_data_sampling.html +GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX gather_data_sampling=force" + +## Register File Data Sampling (RFDS) mitigation on Intel Atom CPUs which +## encompasses E-cores on hybrid architectures. +## +## https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/reg-file-data-sampling.html +GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX reg_file_data_sampling=on"