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authorKees Cook <keescook@chromium.org>2024-05-01 22:37:12 +0300
committerKees Cook <keescook@chromium.org>2024-05-01 22:38:14 +0300
commita284e43852380ab71eeb996389e01992d74a8dde (patch)
treed6e06644741e293066c71501f65c8b96dc73a7b6
parentfb28a8862dc4b5bf8e44578338f35d9c6c68339d (diff)
downloadlinux-a284e43852380ab71eeb996389e01992d74a8dde.tar.xz
hardening: Enable KCFI and some other options
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 globally. - CONFIG_PAGE_TABLE_CHECK=y for userspace mapping sanity. Reviewed-by: Nathan Chancellor <nathan@kernel.org> Link: https://lore.kernel.org/r/20240501193709.make.982-kees@kernel.org Signed-off-by: Kees Cook <keescook@chromium.org>
-rw-r--r--arch/arm64/configs/hardening.config1
-rw-r--r--arch/x86/configs/hardening.config3
-rw-r--r--kernel/configs/hardening.config8
3 files changed, 12 insertions, 0 deletions
diff --git a/arch/arm64/configs/hardening.config b/arch/arm64/configs/hardening.config
index b0e795208998..24179722927e 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.
diff --git a/arch/x86/configs/hardening.config b/arch/x86/configs/hardening.config
index 7b497f3b7bc3..de319852a1e9 100644
--- a/arch/x86/configs/hardening.config
+++ b/arch/x86/configs/hardening.config
@@ -10,5 +10,8 @@ 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 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..47e6564129c3 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
@@ -81,6 +85,10 @@ CONFIG_SECCOMP_FILTER=y
# Provides some protections against SYN flooding.
CONFIG_SYN_COOKIES=y
+# Enable Kernel Control Flow Integrity (currently Clang only).
+CONFIG_CFI_CLANG=y
+# CONFIG_CFI_PERMISSIVE is not set
+
# Attack surface reduction: do not autoload TTY line disciplines.
# CONFIG_LDISC_AUTOLOAD is not set