Merge remote-tracking branch 'raja/kargs'

This commit is contained in:
Patrick Schleizer
2024-07-17 08:38:23 -04:00
12 changed files with 340 additions and 157 deletions

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@ -1,99 +1,117 @@
## Copyright (C) 2019 - 2024 ENCRYPTED SUPPORT LP <adrelanos@whonix.org>
## See the file COPYING for copying conditions.
## Enables known mitigations for CPU vulnerabilities.
##
## Enable 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
## 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="$GRUB_CMDLINE_LINUX mitigations=auto,nosmt"
## Disable SMT as it has been the cause of and amplified numerous CPU exploits.
## The only full mitigation of cross-HT attacks is to disable SMT.
## Disabling will significantly decrease system performance on multi-threaded tasks.
## To enable SMT, remove this line all other occurrences of "nosmt" in this file.
##
## https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/core-scheduling.html
## https://forums.whonix.org/t/should-all-kernel-patches-for-cpu-bugs-be-unconditionally-enabled-vs-performance-vs-applicability/7647/17
## https://github.com/anthraxx/linux-hardened/issues/37#issuecomment-619597365
##
GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX nosmt=force"
## 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="$GRUB_CMDLINE_LINUX spectre_v2=on spectre_bhi=on"
##
GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX spectre_v2=on"
GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX spectre_bhi=on"
## Disable Speculative Store Bypass (Spectre Variant 4).
##
## https://www.suse.com/support/kb/doc/?id=000019189
##
GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX spec_store_bypass_disable=on"
## Enable mitigations for the L1TF vulnerability through disabling SMT
## and L1D flush runtime control.
##
## https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/l1tf.html
##
GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX l1tf=full,force"
## Enable mitigations for the MDS vulnerability through clearing buffer cache
## and disabling SMT.
##
## https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/mds.html
##
GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX mds=full,nosmt"
## Patches the TAA vulnerability by disabling TSX and enables mitigations using
## Patches the TAA vulnerability by disabling TSX and enable mitigations using
## TSX Async Abort along with disabling SMT.
##
## https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/tsx_async_abort.html
GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX tsx=off tsx_async_abort=full,nosmt"
##
GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX tsx=off"
GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX tsx_async_abort=full,nosmt"
## Mark all huge pages in the EPT as non-executable to mitigate iTLB multihit.
##
## https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/multihit.html
##
GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX kvm.nx_huge_pages=force"
## Enables mitigations for SRBDS to prevent MDS attacks on RDRAND and RDSEED instructions.
## Only mitigated through microcode updates from Intel.
## Mitigations for SRBDS to prevent MDS attacks on RDRAND and RDSEED instructions
## are only possible through microcode updates from Intel.
##
## https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/special-register-buffer-data-sampling.html
## https://access.redhat.com/solutions/5142691
## Force disable SMT as it has caused numerous CPU vulnerabilities.
## The only full mitigation of cross-HT attacks is to disable SMT.
##
## https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/core-scheduling.html
## https://forums.whonix.org/t/should-all-kernel-patches-for-cpu-bugs-be-unconditionally-enabled-vs-performance-vs-applicability/7647/17
GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX nosmt=force"
## Enables the prctl interface to prevent leaks from L1D on context switches.
## Enable the prctl() interface to prevent leaks from L1D on context switches.
##
## https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/l1d_flush.html
##
GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX l1d_flush=on"
## Mitigates numerous MMIO Stale Data vulnerabilities and disables SMT.
## Mitigate numerous MMIO Stale Data vulnerabilities and disable SMT.
##
## https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/processor_mmio_stale_data.html
##
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.
## The current default kernel parameter is 'spec_rstack_overflow=safe-ret'
## This default will used until provided sufficient evidence to modify.
##
## https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/srso.html
##
## The default kernel setting will be utilised until provided sufficient evidence to modify.
##
#GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX spec_rstack_overflow=safe-ret"
## Mitigates Gather Data Sampling (GDS) vulnerability.
## Enable Gather Data Sampling (GDS) mitigation.
## Note for systems that have not received a suitable microcode update this will
## entirely disable use of the AVX instructions set.
##
## https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/gather_data_sampling.html
##
GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX gather_data_sampling=force"
## Register File Data Sampling (RFDS) mitigation on Intel Atom CPUs which
## Enable 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="$GRUB_CMDLINE_LINUX reg_file_data_sampling=on"
##
GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX reg_file_data_sampling=on"

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## Copyright (C) 2019 - 2024 ENCRYPTED SUPPORT LP <adrelanos@whonix.org>
## See the file COPYING for copying conditions.
## Distrusts the bootloader for initial entropy at boot.
##
## https://lkml.org/lkml/2022/6/5/271
GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX random.trust_bootloader=off"

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## Copyright (C) 2019 - 2024 ENCRYPTED SUPPORT LP <adrelanos@whonix.org>
## See the file COPYING for copying conditions.
## Distrusts the CPU for initial entropy at boot as it is not possible to
## audit, may contain weaknesses or a backdoor.
##
## https://en.wikipedia.org/wiki/RDRAND#Reception
## https://twitter.com/pid_eins/status/1149649806056280069
## https://archive.nytimes.com/www.nytimes.com/interactive/2013/09/05/us/documents-reveal-nsa-campaign-against-encryption.html
## https://forums.whonix.org/t/entropy-config-random-trust-cpu-yes-or-no-rng-core-default-quality/8566
## https://lkml.org/lkml/2022/6/5/271
GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX random.trust_cpu=off"

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## Copyright (C) 2019 - 2024 ENCRYPTED SUPPORT LP <adrelanos@whonix.org>
## See the file COPYING for copying conditions.
## Enables IOMMU to prevent DMA attacks.
GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX intel_iommu=on amd_iommu=force_isolation"
## Disable the busmaster bit on all PCI bridges during very
## early boot to avoid holes in IOMMU.
##
## https://mjg59.dreamwidth.org/54433.html
## https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=4444f8541dad16fefd9b8807ad1451e806ef1d94
GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX efi=disable_early_pci_dma"
## Enables strict enforcement of IOMMU TLB invalidation so devices will never be able to access stale data contents
## https://github.com/torvalds/linux/blob/master/drivers/iommu/Kconfig#L97
## Page 11 of https://lenovopress.lenovo.com/lp1467.pdf
GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX iommu=force iommu.passthrough=0 iommu.strict=1"

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@ -5,58 +5,196 @@ kpkg="linux-image-$(dpkg --print-architecture)" || true
kver="$(dpkg-query --show --showformat='${Version}' "$kpkg")" 2>/dev/null || true
#echo "## kver: $kver"
## Disables the merging of slabs of similar sizes.
## Sometimes a slab can be used in a vulnerable way which an attacker can exploit.
## This configuration file is split into 3 sections:
## 1. Kernel Space
## 2. Direct Memory Access
## 3. Entropy
## 4. Networking
## See the documentation below for details on the majority of the selected commands.
## https://www.kernel.org/doc/html/latest/admin-guide/kernel-parameters.html
## https://wiki.archlinux.org/title/Kernel_parameters#GRUB
## 1. Kernel Space:
##
## https://madaidans-insecurities.github.io/guides/linux-hardening.html#boot-parameters
## Disable merging of slabs with similar size.
## Reduces the risk of triggering heap overflows.
## Prevents overwriting objects from merged caches and limits influencing slab cache layout.
##
## https://www.openwall.com/lists/kernel-hardening/2017/06/19/33
## https://www.openwall.com/lists/kernel-hardening/2017/06/20/10
##
GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX slab_nomerge"
## Enables sanity checks (F) and redzoning (Z).
## Disabled due to kernel deciding to implicitly disable kernel pointer hashing
## https://github.com/torvalds/linux/commit/792702911f581f7793962fbeb99d5c3a1b28f4c3
#GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX slub_debug=FZ"
## Zero memory at allocation time and free time.
## Fills newly allocated pages, freed pages, and heap objects with zeros.
## Mitigates use-after-free exploits by erasing sensitive information in memory.
##
## https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=6471384af2a6530696fc0203bafe4de41a23c9ef
##
GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX init_on_alloc=1"
GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX init_on_free=1"
## Zero memory at allocation and free time.
GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX init_on_alloc=1 init_on_free=1"
## Machine check exception handler decides whether the system should panic or not based on the exception that happened.
## https://forums.whonix.org/t/kernel-hardening/7296/494
#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"
## Vsyscalls are obsolete, are at fixed addresses and are a target for ROP.
GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX vsyscall=none"
## Enables page allocator freelist randomization.
## Enable the kernel page allocator to randomise free lists.
## During early boot the page allocator has predictable FIFO behaviour for physical pages.
## Limits some data exfiltration and ROP attacks that rely on inferring sensitive data location.
## Also improves performance by optimising memory-side cache utilisation.
##
## https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e900a918b0984ec8f2eb150b8477a47b75d17692
## https://en.wikipedia.org/wiki/Return-oriented_programming#Attacks
##
GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX page_alloc.shuffle=1"
## Enables randomisation of the kernel stack offset on syscall entries (introduced in kernel 5.13).
## Enable kernel page table isolation to harden against kernel ASLR (KASLR) bypasses.
## Mitigates the Meltdown CPU vulnerability.
##
## https://en.wikipedia.org/wiki/Kernel_page-table_isolation
##
GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX pti=on"
## Enable randomisation of the kernel stack offset on syscall entries.
## Hardens against memory corruption attacks due to increased entropy.
## Limits attacks relying on deterministic stack addresses or cross-syscall address exposure.
##
## https://lkml.org/lkml/2019/3/18/246
## https://a13xp0p0v.github.io/2020/02/15/CVE-2019-18683.html
##
GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX randomize_kstack_offset=on"
## Enables kernel lockdown.
## Disable vsyscalls to reduce attack surface as they have been replaced by vDSO.
## Vulnerable to ROP attacks as vsyscalls are located at fixed addresses in memory.
##
## Disabled for now as it enforces module signature verification which breaks
## too many things.
## https://forums.whonix.org/t/enforce-kernel-module-software-signature-verification-module-signing-disallow-kernel-module-loading-by-default/7880
## https://lwn.net/Articles/446528/
## https://en.wikipedia.org/wiki/VDSO
##
#if dpkg --compare-versions "${kver}" ge "5.4"; then
# GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX lockdown=confidentiality"
#fi
GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX vsyscall=none"
## Gather more entropy during boot.
## Restrict access to debugfs by not registering the file system.
## Deactivated since the file system can contain sensitive information.
##
## Requires linux-hardened kernel patch.
## https://github.com/anthraxx/linux-hardened
GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX extra_latent_entropy"
## Restrict access to debugfs since it can contain a lot of sensitive information.
## https://lkml.org/lkml/2020/7/16/122
## https://github.com/torvalds/linux/blob/fb1201aececc59990b75ef59fca93ae4aa1e1444/Documentation/admin-guide/kernel-parameters.txt#L835-L848
##
GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX debugfs=off"
## Force the kernel to panic on "oopses" (which may be due to false positives)
## Force the kernel to panic on "oopses".
## Can sometimes potentially indicate and thwart certain kernel exploitation attempts.
## Also cause panics on machine check exceptions.
## Panics may be due to false-positives such as bad drivers.
##
## https://forums.whonix.org/t/set-oops-panic-kernel-parameter-or-kernel-panic-on-oops-1-sysctl-for-better-security/7713
## Implemented differently:
## /usr/libexec/security-misc/panic-on-oops
##
## See /usr/libexec/security-misc/panic-on-oops for implementation.
##
#GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX oops=panic"
## Modify machine check exception handler.
## Can decide whether the system should panic or not based on the occurrence of an exception.
##
## https://www.kernel.org/doc/html/latest/arch/x86/x86_64/machinecheck.html
## https://www.kernel.org/doc/html/latest/arch/x86/x86_64/boot-options.html#machine-check
## https://forums.whonix.org/t/kernel-hardening/7296/494
##
## The default kernel setting will be utilised until provided sufficient evidence to modify.
##
#GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX mce=0"
## Prevent sensitive kernel information leaks in the console during boot.
## Must be used in combination with the kernel.printk sysctl.
## See /usr/lib/sysctl.d/30_silent-kernel-printk.conf for implementation.
##
## https://www.kernel.org/doc/html/latest/core-api/printk-basics.html
## https://wiki.archlinux.org/title/silent_boot
##
## See /etc/default/grub.d/41_quiet_boot.cfg for implementation.
##
#GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX loglevel=0"
#GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX quiet"
## Disable support for x86 processes and syscalls.
## Unconditionally disables IA32 emulation to substantially reduce attack surface.
##
## https://lore.kernel.org/all/20230623111409.3047467-7-nik.borisov@suse.com/
##
## Applicable when using Linux kernel >= 6.7 (retained here for future-proofing and completeness).
##
#ia32_emulation=0
## 2. Direct Memory Access:
##
## https://madaidans-insecurities.github.io/guides/linux-hardening.html#dma-attacks
## Enable CPU manufacturer-specific IOMMU drivers to protect against DMA attacks.
##
GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX amd_iommu=force_isolation"
GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX intel_iommu=on"
## Enable and force use of IOMMU translation to protect against DMA attacks.
## Strictly force DMA unmap operations to synchronously invalidate IOMMU hardware TLBs.
## Ensures devices will never be able to access stale data contents.
##
## https://en.wikipedia.org/wiki/Input%E2%80%93output_memory_management_unit
## https://en.wikipedia.org/wiki/DMA_attack
## https://lenovopress.lenovo.com/lp1467.pdf
##
GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX iommu=force"
GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX iommu.passthrough=0"
GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX iommu.strict=1"
## Disable the busmaster bit on all PCI bridges during the early boot process.
## Patches weak-point in some existing IOMMU implementations.
## May lead to issues such as complete system boot failure on certain devices.
##
## https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=4444f8541dad16fefd9b8807ad1451e806ef1d94
## https://mjg59.dreamwidth.org/54433.html
##
GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX efi=disable_early_pci_dma"
## 3. Entropy:
##
## https://madaidans-insecurities.github.io/guides/linux-hardening.html#rdrand
## Do not credit the CPU or bootloader seeds as entropy sources at boot.
## The RDRAND CPU (RNG) instructions are proprietary and closed-source.
## Numerous implementations of RDRAND have a long history of being defective.
## The RNG seed passed by the bootloader could also potentially be tampered.
## Maximising the entropy pool at boot is desirable for all cryptographic operations.
## These settings ensure additional entropy is obtained from other sources to initialise the RNG.
## Note that distrusting these (relatively fast) sources of entropy will increase boot time.
##
## https://en.wikipedia.org/wiki/RDRAND#Reception
## https://systemd.io/RANDOM_SEEDS/
## https://arstechnica.com/gadgets/2019/10/how-a-months-old-amd-microcode-bug-destroyed-my-weekend/
## https://x.com/pid_eins/status/1149649806056280069
## https://archive.nytimes.com/www.nytimes.com/interactive/2013/09/05/us/documents-reveal-nsa-campaign-against-encryption.html
## https://forums.whonix.org/t/entropy-config-random-trust-cpu-yes-or-no-rng-core-default-quality/8566
## https://github.com/NixOS/nixpkgs/pull/165355
## https://lkml.org/lkml/2022/6/5/271
##
GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX random.trust_bootloader=off"
GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX random.trust_cpu=off"
## Obtain more entropy during boot as the runtime memory allocator is being initialised.
## Entropy will be extracted from up to the first 4GB of RAM.
## Requires the linux-hardened kernel patch.
##
## https://www.kicksecure.com/wiki/Hardened-kernel#linux-hardened
## https://github.com/anthraxx/linux-hardened/commit/c3e7df1dba1eb8105d6d5143079a6a0ad9e9ebc7
## https://github.com/anthraxx/linux-hardened/commit/a04458f97fe1f7e95888c77c0165b646375db9c4
##
GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX extra_latent_entropy"
## 4. Networking
##
## https://madaidans-insecurities.github.io/guides/linux-hardening.html#kasr-boot-parameters
## Disable the entire IPv6 stack functionality.
## Removes attack surface associated with the IPv6 module.
##
## https://www.kernel.org/doc/html/latest/networking/ipv6.html
## https://wiki.archlinux.org/title/IPv6#Disable_IPv6
##
## Enabling makes redundant many network hardening sysctl's in usr/lib/sysctl.d/990-security-misc.conf.
##
#ipv6.disable=1

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@ -1,8 +0,0 @@
## Requires every module to be signed before being loaded.
## Any module that is unsigned or signed with an invalid key cannot be loaded.
## This makes it harder to load a malicious module.
##
## Not enabled by default yet due to issues:
## https://forums.whonix.org/t/enforce-kernel-module-software-signature-verification-module-signing-disallow-kernel-module-loading-by-default/7880/61
## https://github.com/dell/dkms/issues/359
#GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX module.sig_enforce=1"

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@ -1,16 +1,25 @@
## Copyright (C) 2023 - 2024 ENCRYPTED SUPPORT LP <adrelanos@whonix.org>
## See the file COPYING for copying conditions.
## Remount Secure provides enhanced security via mmount options:
## https://www.kicksecure.com/wiki/Security-misc#Remount_Secure
## Option A (No Security):
## Disable Remount Secure.
##
#GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX remountsecure=0"
## Re-mount with nodev, nosuid only.
## Option B (Low Security):
## Re-mount with nodev and nosuid only.
##
#GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX remountsecure=1"
## Re-mount with nodev, nosuid and most with noexec except for /home.
## Option C (Medium Security):
## Re-mount with nodev, nosuid, and noexec for most mount points, excluding /home.
##
#GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX remountsecure=2"
## Re-mount with nodev, nosuid and all with noexec including /home.
## Option D (Highest Security)
## Re-mount with nodev, nosuid, and noexec for all mount points including /home.
##
#GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX remountsecure=3"

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## Copyright (C) 2019 - 2024 ENCRYPTED SUPPORT LP <adrelanos@whonix.org>
## See the file COPYING for copying conditions.
## Require every kernel module to be signed before being loaded.
## Any module that is unsigned or signed with an invalid key cannot be loaded.
## This prevents all out-of-tree kernel modules unless signed.
## This makes it harder to load a malicious module.
##
## https://forums.whonix.org/t/enforce-kernel-module-software-signature-verification-module-signing-disallow-kernel-module-loading-by-default/7880/61
## https://github.com/dell/dkms/issues/359
##
## Not enabled by default yet due to several issues.
##
#GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX module.sig_enforce=1"
## Enable kernel lockdown to enforce security boundary between user and kernel space.
## Confidentiality mode enforces module signature verification.
##
## https://forums.whonix.org/t/enforce-kernel-module-software-signature-verification-module-signing-disallow-kernel-module-loading-by-default/7880
##
## ## Not enabled by default yet due to several issues.
##
#if dpkg --compare-versions "${kver}" ge "5.4"; then
# GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX lockdown=confidentiality"
#fi

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@ -1,27 +0,0 @@
## Copyright (C) 2019 - 2024 ENCRYPTED SUPPORT LP <adrelanos@whonix.org>
## See the file COPYING for copying conditions.
## Prevent kernel info leaks in console during boot.
## https://phabricator.whonix.org/T950
## LANG=C str_replace is provided by package helper-scripts.
## The following command actually removed "quiet" from the kernel command line.
## If verbosity is desired, the user might want to keep this line.
## Remove "quiet" from GRUB_CMDLINE_LINUX_DEFAULT because "quiet" must be first.
GRUB_CMDLINE_LINUX_DEFAULT="$(echo "$GRUB_CMDLINE_LINUX_DEFAULT" | LANG=C str_replace "quiet" "")"
## If verbosity is desired, the user might want to out-comment the following line.
GRUB_CMDLINE_LINUX_DEFAULT="$GRUB_CMDLINE_LINUX_DEFAULT quiet loglevel=0"
## NOTE:
## After editing this file, running:
## sudo update-grub
## is required.
##
## If higher verbosity is desired, the user might also want to delete file
## /etc/sysctl.d/30_silent-kernel-printk.conf
## (or out-comment its settings).
##
## Alternatively, the user could consider to install the debug-misc package,
## which will undo the settings found here.

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@ -0,0 +1,29 @@
## Copyright (C) 2019 - 2024 ENCRYPTED SUPPORT LP <adrelanos@whonix.org>
## See the file COPYING for copying conditions.
## Some default configuration files automatically include the "quiet" parameter.
## Thefore, first remove "quiet" from GRUB_CMDLINE_LINUX_DEFAULT since "quiet" must be first.
## LANG=C str_replace is provided by package helper-scripts.
##
## https://github.com/Kicksecure/security-misc/pull/233#issuecomment-2228792461
##
GRUB_CMDLINE_LINUX_DEFAULT="$(echo "$GRUB_CMDLINE_LINUX_DEFAULT" | LANG=C str_replace "quiet" "")"
## Prevent sensitive kernel information leaks in the console during boot.
## Must be used in combination with the kernel.printk sysctl.
## See /usr/lib/sysctl.d/30_silent-kernel-printk.conf for implementation.
##
## https://www.kernel.org/doc/html/latest/core-api/printk-basics.html
## https://wiki.archlinux.org/title/silent_boot
##
## For easier debugging, these are not applied to the recovery boot option.
## Switch the pair of commands to universally apply parameters to all boot options.
##
GRUB_CMDLINE_LINUX_DEFAULT="$GRUB_CMDLINE_LINUX_DEFAULT loglevel=0"
GRUB_CMDLINE_LINUX_DEFAULT="$GRUB_CMDLINE_LINUX_DEFAULT quiet"
#GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX loglevel=0"
#GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX quiet"
## For Increased Log Verbosity:
## Adjust (or comment out) the kernel.printk sysctl in /usr/lib/sysctl.d/30_silent-kernel-printk.conf.
## Alternatively, installing the debug-misc package will undo these settings.