From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751982AbdASBbE (ORCPT ); Wed, 18 Jan 2017 20:31:04 -0500 Received: from mail-qt0-f178.google.com ([209.85.216.178]:34763 "EHLO mail-qt0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751798AbdASBao (ORCPT ); Wed, 18 Jan 2017 20:30:44 -0500 From: Laura Abbott To: Kees Cook Cc: Laura Abbott , Jason Wessel , Jonathan Corbet , Russell King , Catalin Marinas , Will Deacon , "James E.J. Bottomley" , Helge Deller , Martin Schwidefsky , Heiko Carstens , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, Rob Herring , "Rafael J. Wysocki" , Len Brown , Pavel Machek , Mark Rutland , Jessica Yu , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-parisc@vger.kernel.org, linux-s390@vger.kernel.org, linux-pm@vger.kernel.org, kernel-hardening@lists.openwall.com Subject: [PATCH 2/2] security: Change name of CONFIG_DEBUG_SET_MODULE_RONX Date: Wed, 18 Jan 2017 17:29:06 -0800 Message-Id: <1484789346-21012-3-git-send-email-labbott@redhat.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1484789346-21012-1-git-send-email-labbott@redhat.com> References: <1484789346-21012-1-git-send-email-labbott@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- Documentation/security/self-protection.txt | 2 +- arch/arm/Kconfig | 1 + arch/arm/Kconfig.debug | 11 ----------- arch/arm/configs/aspeed_g4_defconfig | 2 +- arch/arm/configs/aspeed_g5_defconfig | 2 +- arch/arm/kernel/patch.c | 2 +- arch/arm64/Kconfig | 1 + arch/arm64/Kconfig.debug | 11 ----------- arch/arm64/kernel/insn.c | 2 +- arch/s390/Kconfig | 1 + arch/s390/Kconfig.debug | 3 --- arch/x86/Kconfig | 1 + arch/x86/Kconfig.debug | 11 ----------- include/linux/filter.h | 4 ++-- include/linux/init.h | 2 +- include/linux/module.h | 2 +- init/main.c | 2 +- kernel/module.c | 6 +++--- security/Kconfig | 16 ++++++++++++++++ 19 files changed, 33 insertions(+), 49 deletions(-) diff --git a/Documentation/security/self-protection.txt b/Documentation/security/self-protection.txt index da8cb36..eb018a1 100644 --- a/Documentation/security/self-protection.txt +++ b/Documentation/security/self-protection.txt @@ -52,7 +52,7 @@ made writable during the update, and then returned to the original permissions.) In support of this are CONFIG_HARDENED_PAGE_MAPPINGS and -CONFIG_DEBUG_SET_MODULE_RONX, which seek to make sure that code is not +CONFIG_HARDENED_MODULE_MAPPINGS, which seek to make sure that code is not writable, data is not executable, and read-only data is neither writable nor executable. 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 diff --git a/arch/arm/configs/aspeed_g4_defconfig b/arch/arm/configs/aspeed_g4_defconfig index 8ccc216..ffe2656 100644 --- a/arch/arm/configs/aspeed_g4_defconfig +++ b/arch/arm/configs/aspeed_g4_defconfig @@ -79,7 +79,7 @@ CONFIG_DEBUG_LL_UART_8250=y CONFIG_DEBUG_UART_PHYS=0x1e784000 CONFIG_DEBUG_UART_VIRT=0xe8784000 CONFIG_EARLY_PRINTK=y -CONFIG_DEBUG_SET_MODULE_RONX=y +CONFIG_HARDENED_MODULE_MAPPINGS=y # CONFIG_XZ_DEC_X86 is not set # CONFIG_XZ_DEC_POWERPC is not set # CONFIG_XZ_DEC_IA64 is not set diff --git a/arch/arm/configs/aspeed_g5_defconfig b/arch/arm/configs/aspeed_g5_defconfig index 90c5ce4..2ea444e 100644 --- a/arch/arm/configs/aspeed_g5_defconfig +++ b/arch/arm/configs/aspeed_g5_defconfig @@ -81,7 +81,7 @@ CONFIG_DEBUG_LL_UART_8250=y CONFIG_DEBUG_UART_PHYS=0x1e784000 CONFIG_DEBUG_UART_VIRT=0xe8784000 CONFIG_EARLY_PRINTK=y -CONFIG_DEBUG_SET_MODULE_RONX=y +CONFIG_HARDENED_MODULE_MAPPINGS=y # CONFIG_XZ_DEC_X86 is not set # CONFIG_XZ_DEC_POWERPC is not set # CONFIG_XZ_DEC_IA64 is not set diff --git a/arch/arm/kernel/patch.c b/arch/arm/kernel/patch.c index 9da1bf5..eb73a76 100644 --- a/arch/arm/kernel/patch.c +++ b/arch/arm/kernel/patch.c @@ -24,7 +24,7 @@ static void __kprobes *patch_map(void *addr, int fixmap, unsigned long *flags) bool module = !core_kernel_text(uintaddr); struct page *page; - if (module && IS_ENABLED(CONFIG_DEBUG_SET_MODULE_RONX)) + if (module && IS_ENABLED(CONFIG_HARDENED_MODULE_MAPPINGS)) page = vmalloc_to_page(addr); else if (!module && IS_ENABLED(CONFIG_HARDENED_PAGE_MAPPINGS)) page = virt_to_page(addr); diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 06fed56..2fe0e98 100644 --- 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" diff --git a/arch/arm64/kernel/insn.c b/arch/arm64/kernel/insn.c index 94b62c1..31bd53f 100644 --- a/arch/arm64/kernel/insn.c +++ b/arch/arm64/kernel/insn.c @@ -93,7 +93,7 @@ static void __kprobes *patch_map(void *addr, int fixmap) bool module = !core_kernel_text(uintaddr); struct page *page; - if (module && IS_ENABLED(CONFIG_DEBUG_SET_MODULE_RONX)) + if (module && IS_ENABLED(CONFIG_HARDENED_MODULE_MAPPINGS)) page = vmalloc_to_page(addr); else if (!module) page = pfn_to_page(PHYS_PFN(__pa(addr))); diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index 8e70ae5..b1e6ed5 100644 --- 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 diff --git a/include/linux/filter.h b/include/linux/filter.h index e4eb254..5426940 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -545,7 +545,7 @@ static inline bool bpf_prog_was_classic(const struct bpf_prog *prog) #define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0])) -#ifdef CONFIG_DEBUG_SET_MODULE_RONX +#ifdef CONFIG_HARDENED_MODULE_MAPPINGS static inline void bpf_prog_lock_ro(struct bpf_prog *fp) { set_memory_ro((unsigned long)fp, fp->pages); @@ -563,7 +563,7 @@ static inline void bpf_prog_lock_ro(struct bpf_prog *fp) static inline void bpf_prog_unlock_ro(struct bpf_prog *fp) { } -#endif /* CONFIG_DEBUG_SET_MODULE_RONX */ +#endif /* CONFIG_HARDENED_MODULE_MAPPINGS */ int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap); static inline int sk_filter(struct sock *sk, struct sk_buff *skb) diff --git a/include/linux/init.h b/include/linux/init.h index 9967bc9..5d6b0b2 100644 --- a/include/linux/init.h +++ b/include/linux/init.h @@ -126,7 +126,7 @@ void prepare_namespace(void); void __init load_default_modules(void); int __init init_rootfs(void); -#if defined(CONFIG_HARDENED_PAGE_MAPPINGS) || defined(CONFIG_DEBUG_SET_MODULE_RONX) +#if defined(CONFIG_HARDENED_PAGE_MAPPINGS) || defined(CONFIG_HARDENED_MODULE_MAPPINGS) extern bool rodata_enabled; #endif #ifdef CONFIG_HARDENED_PAGE_MAPPINGS diff --git a/include/linux/module.h b/include/linux/module.h index 7c84273..a4f6926 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -764,7 +764,7 @@ extern int module_sysfs_initialized; #define __MODULE_STRING(x) __stringify(x) -#ifdef CONFIG_DEBUG_SET_MODULE_RONX +#ifdef CONFIG_HARDENED_MODULE_MAPPINGS extern void set_all_modules_text_rw(void); extern void set_all_modules_text_ro(void); extern void module_enable_ro(const struct module *mod, bool after_init); diff --git a/init/main.c b/init/main.c index 4b3bcc4..1545399 100644 --- a/init/main.c +++ b/init/main.c @@ -925,7 +925,7 @@ static int try_to_run_init_process(const char *init_filename) static noinline void __init kernel_init_freeable(void); -#if defined(CONFIG_HARDENED_PAGE_MAPPINGS) || defined(CONFIG_DEBUG_SET_MODULE_RONX) +#if defined(CONFIG_HARDENED_PAGE_MAPPINGS) || defined(CONFIG_HARDENED_MODULE_MAPPINGS) bool rodata_enabled __ro_after_init = true; static int __init set_debug_rodata(char *str) { diff --git a/kernel/module.c b/kernel/module.c index 38d4270..eb2f865 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -74,9 +74,9 @@ /* * Modules' sections will be aligned on page boundaries * to ensure complete separation of code and data, but - * only when CONFIG_DEBUG_SET_MODULE_RONX=y + * only when CONFIG_HARDENED_MODULE_MAPPINGS=y */ -#ifdef CONFIG_DEBUG_SET_MODULE_RONX +#ifdef CONFIG_HARDENED_MODULE_MAPPINGS # define debug_align(X) ALIGN(X, PAGE_SIZE) #else # define debug_align(X) (X) @@ -1847,7 +1847,7 @@ static void mod_sysfs_teardown(struct module *mod) mod_sysfs_fini(mod); } -#ifdef CONFIG_DEBUG_SET_MODULE_RONX +#ifdef CONFIG_HARDENED_MODULE_MAPPINGS /* * LKM RO/NX protection: protect module's text/ro-data * from modification and any data from execution. diff --git a/security/Kconfig b/security/Kconfig index ad6ce82..0f98d6b 100644 --- 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 + help + If this is set, module text and rodata memory will be made read-only, + and non-text memory will be made non-executable. This provides + protection against certain security vulnerabilities (e.g. modifying + code) + + Unless your system has known restrictions or performance issues, it + is recommended to say Y here. + source security/selinux/Kconfig source security/smack/Kconfig source security/tomoyo/Kconfig -- 2.7.4