From patchwork Wed May 7 18:16:14 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 888305 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B8EA728EA67; Wed, 7 May 2025 18:16:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746641781; cv=none; b=jVfbP6shB6V7NU47m7AmYI/Fzmf0BJJT+lWwKs9m7FmYAtFHO9vHrfiaImI/DxlBl94jT6jz4/FcTHjMzxmFtS3YPX2sjgvpU3YbQ+i5Gfr0ky1HKxGPIqH1NUIKRYvZLwPnWhw6fwIjii67K88Bc8a9N4NzEr1l0a1AvEBXtJI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746641781; c=relaxed/simple; bh=JBC57/AJ4s9wnqVrwmV7BOpA+2zHUnfcHWTkMgWl8NU=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=cMLQaUh6HZR6PpwPPpeR0Ohfra6/Ue1MWAamPikBBPFSpYHKmlQ60SUOtnE9GsF9gHiwA8iDL0i9VLUkfWKJuE5V5GjNhUcZFBwPSL/J64QtRy9P2nJj0/qASzfKRnbt5mToWMtAOKGKenK2KyBZm6tqDz21VcndrYLw4c+M5hE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=F7UcDZXd; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="F7UcDZXd" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3EB66C4CEE2; Wed, 7 May 2025 18:16:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1746641781; bh=JBC57/AJ4s9wnqVrwmV7BOpA+2zHUnfcHWTkMgWl8NU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=F7UcDZXdXjx3KZ0l3mLTB+csre7VN6l1usVAnFYpDApDPAm06prvBdEhlADnkW6qA 6Ct662+QPW0P+8F0Oa58tF6i9aT/9MCvBj/FBr6/uU/vhZiR6R4zBCfysEenLCqUrE 6tHqabUzR/N/LG6jfquCv4eWd3RJ/h4rXkS1TFORy7r97wCz0ABguF/eGnXxW8zxIz ljfxv6OYRJ3vkc045YYhxP1/yI3w0ca03pTUHUMVgH8UIKM6xE/RhL/CRvTjpi4qn3 JyQH3je+lX/JEdGO+Fm75JCf/UdhCxfXNlzSyJ5TaUdz+qFXxrtWxAwoV/tmvZGTYw KMyTgtIMShNuw== From: Kees Cook To: Arnd Bergmann Cc: Kees Cook , "Gustavo A. R. Silva" , linux-hardening@vger.kernel.org, Christoph Hellwig , Marco Elver , 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 8/8] configs/hardening: Enable CONFIG_INIT_ON_FREE_DEFAULT_ON Date: Wed, 7 May 2025 11:16:14 -0700 Message-Id: <20250507181615.1947159-8-kees@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20250507180852.work.231-kees@kernel.org> References: <20250507180852.work.231-kees@kernel.org> Precedence: bulk X-Mailing-List: linux-efi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=961; i=kees@kernel.org; h=from:subject; bh=JBC57/AJ4s9wnqVrwmV7BOpA+2zHUnfcHWTkMgWl8NU=; b=owGbwMvMwCVmps19z/KJym7G02pJDBnSi3OdD7t0n7oULsejGJ/+9MQm/geGMg9cz00Vqajg/ sTnY3e9o5SFQYyLQVZMkSXIzj3OxeNte7j7XEWYOaxMIEMYuDgFYCJToxkZNsxfvyhx39Nzpiyy k1d9mfdaZ2I4d4Fed23ppfk+FmvT+Bn+V65ZP6cwRVHDaFl+g9uJIPvmT50TbXLDqlrmpn0pTfX nBAA= X-Developer-Key: i=kees@kernel.org; a=openpgp; fpr=A5C3F68F229DD60F723E6E138972F4DFDC6DC026 To reduce stale data lifetimes, enable CONFIG_INIT_ON_FREE_DEFAULT_ON as well. This matches the addition of CONFIG_STACKLEAK=y, which is doing similar for stack memory. 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 3da00926b4eb..7d92a740e490 100644 --- a/kernel/configs/hardening.config +++ b/kernel/configs/hardening.config @@ -60,6 +60,9 @@ CONFIG_LIST_HARDENED=y # Initialize all heap variables to zero on allocation. CONFIG_INIT_ON_ALLOC_DEFAULT_ON=y +# Initialize all heap variables to zero on free to reduce stale data lifetime. +CONFIG_INIT_ON_FREE_DEFAULT_ON=y + # Initialize all stack variables to zero on function entry. CONFIG_INIT_STACK_ALL_ZERO=y