## Copyright (C) 2019 - 2019 ENCRYPTED SUPPORT LP ## See the file COPYING for copying conditions. ## Disables the merging of slabs of similar sizes. Sometimes a slab can be used in a vulnerable way which an attacker can exploit. GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX slab_nomerge" ## Enables sanity checks (F), redzoning (Z) and poisoning (P). GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX slub_debug=FZP" if command -v "qubesdb-read" >/dev/null 2>&1 ; then ## https://github.com/QubesOS/qubes-issues/issues/5212#issuecomment-533873012 true "skip adding page_poison=1 in Qubes" else ## Wipes free memory so it can't leak in various ways and prevents some use-after-free vulnerabilites. GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX page_poison=1" fi ## Makes the kernel panic on uncorrectable errors in ECC memory that an attacker could exploit. GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX mce=0" ## Enables Kernel Page Table Isolation which mitigates Meltdown and improves KASLR. GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX pti=on" ## Enables all mitigations for the MDS vulnerability. ## Disables smt which can be used to exploit the MDS vulnerability. GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX mds=full,nosmt"