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R. Silva" , linux-hardening@vger.kernel.org, Ingo Molnar , Christoph Hellwig , Andrey Konovalov , Andrey Ryabinin , Ard Biesheuvel , Masahiro Yamada , Nathan Chancellor , Nicolas Schier , Nick Desaulniers , Bill Wendling , Justin Stitt , linux-kernel@vger.kernel.org, x86@kernel.org, kasan-dev@googlegroups.com, linux-doc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-efi@vger.kernel.org, linux-kbuild@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kselftest@vger.kernel.org, sparclinux@vger.kernel.org, llvm@lists.linux.dev Subject: [PATCH v3 12/13] configs/hardening: Enable CONFIG_KSTACK_ERASE Date: Thu, 17 Jul 2025 16:25:17 -0700 Message-Id: <20250717232519.2984886-12-kees@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20250717231756.make.423-kees@kernel.org> References: <20250717231756.make.423-kees@kernel.org> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1038; i=kees@kernel.org; h=from:subject; bh=hftQ+JwDBzI0zRNacsurrBG64kHnxlfHAL+GJc3UtlU=; b=owGbwMvMwCVmps19z/KJym7G02pJDBmVbbFBctklSlm/hUWtYmesmm/+4Mz/o2oveebseJx+3 f2N065JHaUsDGJcDLJiiixBdu5xLh5v28Pd5yrCzGFlAhnCwMUpABPZrM/wT/+s9b/zj2UjKz2d 0opOWQdaqM192v1qrb5mpnFiz/LKFYwMM5YFnp723f9/aP7hJMnrxuH6yRfrcxYbWx+zavrULTm NDwA= X-Developer-Key: i=kees@kernel.org; a=openpgp; fpr=A5C3F68F229DD60F723E6E138972F4DFDC6DC026 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250717_162523_194722_2E206300 X-CRM114-Status: UNSURE ( 7.63 ) X-CRM114-Notice: Please train this message. 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 Since we can wipe the stack with both Clang and GCC plugins, enable this for the "hardening.config" for wider testing. Signed-off-by: Kees Cook --- Cc: "Gustavo A. R. Silva" Cc: --- kernel/configs/hardening.config | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/configs/hardening.config b/kernel/configs/hardening.config index dd7c32fb5ac1..d24c2772d04d 100644 --- a/kernel/configs/hardening.config +++ b/kernel/configs/hardening.config @@ -63,6 +63,9 @@ CONFIG_INIT_ON_ALLOC_DEFAULT_ON=y # Initialize all stack variables to zero on function entry. CONFIG_INIT_STACK_ALL_ZERO=y +# Wipe kernel stack after syscall completion to reduce stale data lifetime. +CONFIG_KSTACK_ERASE=y + # Wipe RAM at reboot via EFI. For more details, see: # https://trustedcomputinggroup.org/resource/pc-client-work-group-platform-reset-attack-mitigation-specification/ # https://bugzilla.redhat.com/show_bug.cgi?id=1532058 -- 2.34.1