From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751950AbdAYLor (ORCPT ); Wed, 25 Jan 2017 06:44:47 -0500 Received: from mail-yb0-f181.google.com ([209.85.213.181]:36310 "EHLO mail-yb0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751421AbdAYLop (ORCPT ); Wed, 25 Jan 2017 06:44:45 -0500 Subject: Re: [PATCH 2/2] security: Change name of CONFIG_DEBUG_SET_MODULE_RONX To: Robin Murphy References: <1484789346-21012-1-git-send-email-labbott@redhat.com> <1484789346-21012-3-git-send-email-labbott@redhat.com> <5005f110-2279-9ac7-c9c5-1894b8f6387d@arm.com> Cc: Kees Cook , Mark Rutland , linux-doc@vger.kernel.org, Catalin Marinas , Heiko Carstens , "James E.J. Bottomley" , Pavel Machek , "H. Peter Anvin" , kernel-hardening@lists.openwall.com, Rob Herring , Jessica Yu , Jonathan Corbet , Helge Deller , x86@kernel.org, Russell King , Ingo Molnar , Len Brown , linux-s390@vger.kernel.org, Will Deacon , Thomas Gleixner , linux-arm-kernel@lists.infradead.org, linux-parisc@vger.kernel.org, linux-pm@vger.kernel.org, "Rafael J. Wysocki" , linux-kernel@vger.kernel.org, Jason Wessel , Martin Schwidefsky From: Laura Abbott Message-ID: Date: Wed, 25 Jan 2017 12:44:14 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.6.0 MIME-Version: 1.0 In-Reply-To: <5005f110-2279-9ac7-c9c5-1894b8f6387d@arm.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/19/2017 12:43 PM, Robin Murphy wrote: > Hi Laura, > > On 19/01/17 01:29, Laura Abbott wrote: >> >> Despite the word 'debug' in CONFIG_DEBUG_SET_MODULE_RONX, this kernel >> option provides key security features that are to be expected on a >> modern system. Change the name to CONFIG_HARDENED_MODULE_MAPPINGS which >> more accurately describes what this option is intended to do. >> >> Signed-off-by: Laura Abbott >> --- > > [...] > >> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig >> index 09aff28..ef852e4 100644 >> --- a/arch/arm/Kconfig >> +++ b/arch/arm/Kconfig >> @@ -8,6 +8,7 @@ config ARM >> select ARCH_HAVE_CUSTOM_GPIO_H >> select ARCH_HAS_GCOV_PROFILE_ALL >> select ARCH_HAS_HARDENED_MAPPINGS if MMU && !XIP_KERNEL >> + select ARCH_HAS_HARDENED_MODULE_MAPPINGS if MMU >> select ARCH_MIGHT_HAVE_PC_PARPORT >> select ARCH_SUPPORTS_ATOMIC_RMW >> select ARCH_USE_BUILTIN_BSWAP >> diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug >> index d83f7c3..426d271 100644 >> --- a/arch/arm/Kconfig.debug >> +++ b/arch/arm/Kconfig.debug >> @@ -1738,17 +1738,6 @@ config PID_IN_CONTEXTIDR >> additional instructions during context switch. Say Y here only if you >> are planning to use hardware trace tools with this kernel. >> >> -config DEBUG_SET_MODULE_RONX >> - bool "Set loadable kernel module data as NX and text as RO" >> - depends on MODULES && MMU >> - ---help--- >> - This option helps catch unintended modifications to loadable >> - kernel module's text and read-only data. It also prevents execution >> - of module data. Such protection may interfere with run-time code >> - patching and dynamic kernel tracing - and they might also protect >> - against certain classes of kernel exploits. >> - If in doubt, say "N". >> - >> source "drivers/hwtracing/coresight/Kconfig" >> >> endmenu > > [...] > >> --- a/arch/arm64/Kconfig >> +++ b/arch/arm64/Kconfig >> @@ -12,6 +12,7 @@ config ARM64 >> select ARCH_HAS_GCOV_PROFILE_ALL >> select ARCH_HAS_GIGANTIC_PAGE >> select ARCH_HAS_HARDENED_MAPPINGS >> + select ARCH_HAS_HARDENED_MODULE_MAPPINGS >> select ARCH_HAS_KCOV >> select ARCH_HAS_SG_CHAIN >> select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST >> diff --git a/arch/arm64/Kconfig.debug b/arch/arm64/Kconfig.debug >> index a26d27f..1eebe1f 100644 >> --- a/arch/arm64/Kconfig.debug >> +++ b/arch/arm64/Kconfig.debug >> @@ -71,17 +71,6 @@ config DEBUG_WX >> >> If in doubt, say "Y". >> >> -config DEBUG_SET_MODULE_RONX >> - bool "Set loadable kernel module data as NX and text as RO" >> - depends on MODULES >> - default y >> - help >> - Is this is set, kernel module text and rodata will be made read-only. >> - This is to help catch accidental or malicious attempts to change the >> - kernel's executable code. >> - >> - If in doubt, say Y. >> - >> config DEBUG_ALIGN_RODATA >> depends on ARCH_HAS_HARDENED_MAPPINGS >> bool "Align linker sections up to SECTION_SIZE" > > [...] > >> --- a/arch/s390/Kconfig >> +++ b/arch/s390/Kconfig >> @@ -69,6 +69,7 @@ config S390 >> select ARCH_HAS_GCOV_PROFILE_ALL >> select ARCH_HAS_GIGANTIC_PAGE >> select ARCH_HAS_HARDENED_MAPPINGS >> + select ARCH_HAS_HARDENED_MODULE_MAPPINGS >> select ARCH_HAS_KCOV >> select ARCH_HAS_SG_CHAIN >> select ARCH_HAS_UBSAN_SANITIZE_ALL >> diff --git a/arch/s390/Kconfig.debug b/arch/s390/Kconfig.debug >> index 26c5d5be..57f8ea9 100644 >> --- a/arch/s390/Kconfig.debug >> +++ b/arch/s390/Kconfig.debug >> @@ -17,7 +17,4 @@ config S390_PTDUMP >> kernel. >> If in doubt, say "N" >> >> -config DEBUG_SET_MODULE_RONX >> - def_bool y >> - depends on MODULES >> endmenu >> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig >> index 9d80cd8..38ce850 100644 >> --- a/arch/x86/Kconfig >> +++ b/arch/x86/Kconfig >> @@ -51,6 +51,7 @@ config X86 >> select ARCH_HAS_FAST_MULTIPLIER >> select ARCH_HAS_GCOV_PROFILE_ALL >> select ARCH_HAS_HARDENED_MAPPINGS >> + select ARCH_HAS_HARDENED_MODULE_MAPPINGS >> select ARCH_HAS_KCOV if X86_64 >> select ARCH_HAS_MMIO_FLUSH >> select ARCH_HAS_PMEM_API if X86_64 >> diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug >> index 67eec55..69cdd0b 100644 >> --- a/arch/x86/Kconfig.debug >> +++ b/arch/x86/Kconfig.debug >> @@ -109,17 +109,6 @@ config DEBUG_WX >> >> If in doubt, say "Y". >> >> -config DEBUG_SET_MODULE_RONX >> - bool "Set loadable kernel module data as NX and text as RO" >> - depends on MODULES >> - ---help--- >> - This option helps catch unintended modifications to loadable >> - kernel module's text and read-only data. It also prevents execution >> - of module data. Such protection may interfere with run-time code >> - patching and dynamic kernel tracing - and they might also protect >> - against certain classes of kernel exploits. >> - If in doubt, say "N". >> - >> config DEBUG_NX_TEST >> tristate "Testcase for the NX non-executable stack feature" >> depends on DEBUG_KERNEL && m > > [...] > >> --- a/security/Kconfig >> +++ b/security/Kconfig >> @@ -174,6 +174,22 @@ config HARDENED_PAGE_MAPPINGS >> Unless your system has known restrictions or performance issues, it >> is recommended to say Y here. >> >> +config ARCH_HAS_HARDENED_MODULE_MAPPINGS >> + def_bool n >> + >> +config HARDENED_MODULE_MAPPINGS >> + bool "Mark module mappings with stricter permissions (RO/W^X)" >> + default y >> + depends on ARCH_HAS_HARDENED_MODULE_MAPPINGS > > It would seem that this ends up losing the previous dependency on > MODULES - is that intentional? > > Robin. > (Apologies, my SMTP was set up incorrectly so this didn't actually get sent out when I thought it did) No, good catch. I missed re-adding that when doing the refactoring. Thanks, Laura >> >