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R. Silva" Cc: Kees Cook , Catalin Marinas , Will Deacon , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Nathan Chancellor , Nick Desaulniers , Bill Wendling , Justin Stitt , linux-hardening@vger.kernel.org, linux-arm-kernel@lists.infradead.org, llvm@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH] hardening: Refresh KCFI options, add some more Date: Fri, 26 Apr 2024 15:29:44 -0700 Message-Id: <20240426222940.work.884-kees@kernel.org> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=3198; i=keescook@chromium.org; h=from:subject:message-id; bh=/JAZTw8Az0ztBUDk0sA4JmrZ5DFUfKzaFS+/N6fB7wg=; b=owEBbQKS/ZANAwAKAYly9N/cbcAmAcsmYgBmLCrX8Y9C46/LOVocPQD+qsoHgG7tK3cJ+oBHy rHReedMZSOJAjMEAAEKAB0WIQSlw/aPIp3WD3I+bhOJcvTf3G3AJgUCZiwq1wAKCRCJcvTf3G3A JsqaD/sHGOQsjFazK/JXw46/Wv4E4bcBtjgtHgo9OCskfnXNqnz0P4c9gHMNMWYw/p4ub+t4+bx wzzstZOSmhYV811Gx0vJ2ulo0jPPnh8y6/2x9nkGkvWgrtWxiNlHvOmJMSv9fGi8vP3exHn6CCG BUaxsodIlWT5neJdhD58ePBffk+31Og+gHc5/WD2Gng3env+B/4okSiDxsAqA1hgMmrvYbzFX3d EnzewxsoW2SV8Bwt/QP8QajLjiSy11N8sRwXD+rBRzJ/ay1lBJh9iGNMwRi+/b4yI3/tEiYfU1U FFwrNDQcr4zsU0LxFHx2PRjc44yfRrYYAJ3cp5gwpD6LpP8XcYyoio9gbIbe3wpTAcgIu1fsOQK d7mdnmP+1D6CNCQAOpVIk51N72SSC3cT7HTxCY/LjXycHo27tMZYehu6xV5ePlB75cUWq8bM4rC tGP/LbmOiQf9tg9vYWOSBi3Iyxu1sktbYrjp9HMToikeKYnbLz/5yVklefYALIS+z6RoQJPg3Ho vqV4lSwin4S08KSoVpJuAPdWTdt4XhpYTLl2avGVt0gsmcZpF2RQc6LdYIHIPq3A68lpxRztPRQ aRsWgfhBD2CTUhRRZjeJU4RwzGYeE27Orz5Ygo65aJqqmcuvlCIWtSVbc5Ns9QexMHAHLhzASPj hgh8L94 FruAYSaQ== X-Developer-Key: i=keescook@chromium.org; a=openpgp; fpr=A5C3F68F229DD60F723E6E138972F4DFDC6DC026 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240426_152948_820158_0EAF84B9 X-CRM114-Status: GOOD ( 13.72 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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 Reviewed-by: Nathan Chancellor --- Cc: "Gustavo A. R. Silva" Cc: Catalin Marinas Cc: Will Deacon Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: Dave Hansen Cc: x86@kernel.org Cc: "H. Peter Anvin" Cc: Nathan Chancellor Cc: Nick Desaulniers Cc: Bill Wendling Cc: Justin Stitt Cc: linux-hardening@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: llvm@lists.linux.dev --- 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