[PATCH 2/2] security: Change name of CONFIG_DEBUG_SET_MODULE_RONX
From: Laura Abbott
Date: Wed Jan 18 2017 - 20:31:30 EST
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 <labbott@xxxxxxxxxx>
---
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