From patchwork Wed Dec 14 23:26:03 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nathan Chancellor X-Patchwork-Id: 13073701 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 64042C4332F for ; Wed, 14 Dec 2022 23:29:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229812AbiLNX3O (ORCPT ); Wed, 14 Dec 2022 18:29:14 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58362 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229838AbiLNX2N (ORCPT ); Wed, 14 Dec 2022 18:28:13 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CB053511EE; Wed, 14 Dec 2022 15:26:38 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 568B361BF8; Wed, 14 Dec 2022 23:26:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2AB6DC433D2; Wed, 14 Dec 2022 23:26:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1671060397; bh=kkfEQgwWyo+kPv5VWEAu/1iunwHHV2AQpSwt9ibZlUY=; h=From:To:Cc:Subject:Date:From; b=dVVEHCmymGa2rwiZytT5fwntuTx84t4e8vd1gx8FET1GJQpYgyYAdH9sdZ6Fr0CMY PhprWN1t/BNlbT578Bu8t/D0NWQ8QYTm6GsFTklgMpS6nlzbg+MYzKdvZmzZfpEc5F GHfAWvSnHtPJSjQD4C6UE0FSwvw8m5ukX8KkqT1arsj6v6EwP93inuCfI8WbefQ3Tu u7sP8cx+q1AxHS0YUQ/L73VaoxaB/x/5q3azqCaC7N2uMJqgzv73aNDbqThJkg0z9j GhQDq3zEEr5mVG6lztAWvl8pfJ/0LoE25pd4Mlu5zfuNMVqjVCd/gPxyEeDBD0QZTm /TaWkt4hlXdGg== From: Nathan Chancellor To: Kees Cook , Nick Desaulniers Cc: Tom Rix , linux-hardening@vger.kernel.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev, patches@lists.linux.dev, Nathan Chancellor , stable@vger.kernel.org Subject: [PATCH] security: Restrict CONFIG_ZERO_CALL_USED_REGS to gcc or clang > 15.0.6 Date: Wed, 14 Dec 2022 16:26:03 -0700 Message-Id: <20221214232602.4118147-1-nathan@kernel.org> X-Mailer: git-send-email 2.39.0 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org A bad bug in clang's implementation of -fzero-call-used-regs can result in NULL pointer dereferences (see the links above the check for more information). Restrict CONFIG_CC_HAS_ZERO_CALL_USED_REGS to either a supported GCC version or a clang newer than 15.0.6, which will catch both a theoretical 15.0.7 and the upcoming 16.0.0, which will both have the bug fixed. Cc: stable@vger.kernel.org # v5.15+ Signed-off-by: Nathan Chancellor --- security/Kconfig.hardening | 3 +++ 1 file changed, 3 insertions(+) base-commit: 830b3c68c1fb1e9176028d02ef86f3cf76aa2476 diff --git a/security/Kconfig.hardening b/security/Kconfig.hardening index d766b7d0ffd1..53baa95cb644 100644 --- a/security/Kconfig.hardening +++ b/security/Kconfig.hardening @@ -257,6 +257,9 @@ config INIT_ON_FREE_DEFAULT_ON config CC_HAS_ZERO_CALL_USED_REGS def_bool $(cc-option,-fzero-call-used-regs=used-gpr) + # https://github.com/ClangBuiltLinux/linux/issues/1766 + # https://github.com/llvm/llvm-project/issues/59242 + depends on !CC_IS_CLANG || CLANG_VERSION > 150006 config ZERO_CALL_USED_REGS bool "Enable register zeroing on function exit"