[PATCH v2 2/2] hardening: Enable i386 FORTIFY_SOURCE on Clang 16+
From: Kees Cook <kees@kernel.org>
Date: 2025-03-08 04:29:33
Also in:
linux-hardening, lkml, llvm
Subsystem:
kernel hardening (not covered by other areas), security subsystem, the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Kees Cook, Paul Moore, James Morris, "Serge E. Hallyn", Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
The i386 regparm bug exposed with FORTIFY_SOURCE with Clang was fixed in Clang 16[1]. Link: https://github.com/llvm/llvm-project/commit/c167c0a4dcdb998affb2756ce76903a12f7d8ca5 [1] Signed-off-by: Kees Cook <kees@kernel.org> --- arch/x86/Makefile | 2 +- security/Kconfig.hardening | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index d25ed25fb7d9..917459d1ad40 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile@@ -137,7 +137,7 @@ ifeq ($(CONFIG_X86_32),y) include $(srctree)/arch/x86/Makefile_32.cpu KBUILD_CFLAGS += $(cflags-y) - ifeq ($(CONFIG_CC_IS_CLANG),y) + ifneq ($(call clang-min-version, 160000),y) # temporary until string.h is fixed KBUILD_CFLAGS += -ffreestanding endif
diff --git a/security/Kconfig.hardening b/security/Kconfig.hardening
index 23ffb0d7c845..c17366ce8224 100644
--- a/security/Kconfig.hardening
+++ b/security/Kconfig.hardening@@ -286,7 +286,7 @@ config FORTIFY_SOURCE bool "Harden common str/mem functions against buffer overflows" depends on ARCH_HAS_FORTIFY_SOURCE # https://github.com/llvm/llvm-project/issues/53645 - depends on !CC_IS_CLANG || !X86_32 + depends on !X86_32 || !CC_IS_CLANG || CLANG_VERSION >= 160000 help Detect overflows of buffers in common string and memory functions where the compiler can determine and validate the buffer sizes.
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2.34.1