Add some stuff that got missed along the way: - CONFIG_UNWIND_PATCH_PAC_INTO_SCS=y so SCS vs PAC is hardware selectable.
- CONFIG_X86_KERNEL_IBT=y while a default, just be sure. - CONFIG_CFI_CLANG=y for x86 and arm64. (And disable FINEIBT since it isn't as secure as straight KCFI.) - CONFIG_PAGE_TABLE_CHECK=y for userspace mapping sanity. Signed-off-by: Kees Cook <[email protected]> --- Cc: "Gustavo A. R. Silva" <[email protected]> Cc: Catalin Marinas <[email protected]> Cc: Will Deacon <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Dave Hansen <[email protected]> Cc: [email protected] Cc: "H. Peter Anvin" <[email protected]> Cc: Nathan Chancellor <[email protected]> Cc: Nick Desaulniers <[email protected]> Cc: Bill Wendling <[email protected]> Cc: Justin Stitt <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] --- arch/arm64/configs/hardening.config | 5 +++++ arch/x86/configs/hardening.config | 9 +++++++++ kernel/configs/hardening.config | 4 ++++ 3 files changed, 18 insertions(+) diff --git a/arch/arm64/configs/hardening.config b/arch/arm64/configs/hardening.config index b0e795208998..e8a18fec7a3e 100644 --- a/arch/arm64/configs/hardening.config +++ b/arch/arm64/configs/hardening.config @@ -5,6 +5,7 @@ CONFIG_ARM64_SW_TTBR0_PAN=y # Software Shadow Stack or PAC CONFIG_SHADOW_CALL_STACK=y +CONFIG_UNWIND_PATCH_PAC_INTO_SCS=y # Pointer authentication (ARMv8.3 and later). If hardware actually supports # it, one can turn off CONFIG_STACKPROTECTOR_STRONG with this enabled. @@ -20,3 +21,7 @@ CONFIG_ARM64_E0PD=y # Available in ARMv8.7 and later. CONFIG_ARM64_EPAN=y + +# Enable Kernel Control Flow Integrity (currently Clang only). +CONFIG_CFI_CLANG=y +# CONFIG_CFI_PERMISSIVE is not set diff --git a/arch/x86/configs/hardening.config b/arch/x86/configs/hardening.config index 7b497f3b7bc3..b47e5f411dd3 100644 --- a/arch/x86/configs/hardening.config +++ b/arch/x86/configs/hardening.config @@ -10,5 +10,14 @@ CONFIG_INTEL_IOMMU_DEFAULT_ON=y CONFIG_INTEL_IOMMU_SVM=y CONFIG_AMD_IOMMU=y +# Enforce CET Indirect Branch Tracking in the kernel. +CONFIG_X86_KERNEL_IBT=y + +# Enable Kernel Control Flow Integrity (currently Clang only), but disable +# weaker FINEIBT landing pads. +CONFIG_CFI_CLANG=y +# CONFIG_CFI_PERMISSIVE is not set +# CONFIG_FINEIBT is not set + # Enable CET Shadow Stack for userspace. CONFIG_X86_USER_SHADOW_STACK=y diff --git a/kernel/configs/hardening.config b/kernel/configs/hardening.config index 7a5bbfc024b7..4be0de1f085c 100644 --- a/kernel/configs/hardening.config +++ b/kernel/configs/hardening.config @@ -23,6 +23,10 @@ CONFIG_SLAB_FREELIST_HARDENED=y CONFIG_SHUFFLE_PAGE_ALLOCATOR=y CONFIG_RANDOM_KMALLOC_CACHES=y +# Sanity check userspace page table mappings. +CONFIG_PAGE_TABLE_CHECK=y +CONFIG_PAGE_TABLE_CHECK_ENFORCED=y + # Randomize kernel stack offset on syscall entry. CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT=y -- 2.34.1
