[kernel-hardening] [PATCHv2 2/2] arch: Rename CONFIG_DEBUG_RODATA and CONFIG_DEBUG_MODULE_RONX

Laura Abbott
2017-02-03T17:52:22Z

Both of these options are poorly named. The features they provide are
necessary for system security and should not be considered debug only.
Change the name to something that accurately describes what these
options do.

Signed-off-by: Laura Abbott <labbott@redhat.com>
---
v2: This patch is now doing the renaming of CONFIG_DEBUG_RODATA and
CONFIG_DEBUG_MODULE_RONX
---
Documentation/DocBook/kgdb.tmpl | 8 ++++----
Documentation/security/self-protection.txt | 4 ++--
arch/Kconfig | 4 ++--
arch/arm/configs/aspeed_g4_defconfig | 3 +--
arch/arm/configs/aspeed_g5_defconfig | 3 +--
arch/arm/include/asm/cacheflush.h | 2 +-
arch/arm/kernel/patch.c | 4 ++--
arch/arm/kernel/vmlinux.lds.S | 8 ++++----
arch/arm/mm/Kconfig | 2 +-
arch/arm/mm/init.c | 4 ++--
arch/arm64/Kconfig.debug | 2 +-
arch/arm64/kernel/insn.c | 2 +-
arch/parisc/configs/712_defconfig | 1 -
arch/parisc/configs/c3000_defconfig | 1 -
arch/parisc/mm/init.c | 2 +-
include/linux/filter.h | 4 ++--
include/linux/init.h | 4 ++--
include/linux/module.h | 2 +-
init/main.c | 4 ++--
kernel/configs/android-recommended.config | 2 +-
kernel/module.c | 6 +++---
kernel/power/hibernate.c | 2 +-
kernel/power/power.h | 4 ++--
kernel/power/snapshot.c | 4 ++--
24 files changed, 39 insertions(+), 43 deletions(-)

diff --git a/Documentation/DocBook/kgdb.tmpl b/Documentation/DocBook/kgdb.tmpl
index f3abca7..856ac20 100644
--- a/Documentation/DocBook/kgdb.tmpl
+++ b/Documentation/DocBook/kgdb.tmpl
@@ -115,12 +115,12 @@


If the architecture that you are using supports the kernel option
- CONFIG_DEBUG_RODATA, you should consider turning it off. This
+ CONFIG_STRICT_KERNEL_RWX, you should consider turning it off. This
option will prevent the use of software breakpoints because it
marks certain regions of the kernel's memory space as read-only.
If kgdb supports it for the architecture you are using, you can
use hardware breakpoints if you desire to run with the
- CONFIG_DEBUG_RODATA option turned on, else you need to turn off
+ CONFIG_STRICT_KERNEL_RWX option turned on, else you need to turn off
this option.


@@ -135,7 +135,7 @@
Here is an example set of .config symbols to enable or
disable for kgdb:

- # CONFIG_DEBUG_RODATA is not set
+ # CONFIG_STRICT_KERNEL_RWX is not set
CONFIG_FRAME_POINTER=y
CONFIG_KGDB=y
CONFIG_KGDB_SERIAL_CONSOLE=y
@@ -166,7 +166,7 @@

Here is an example set of .config symbols to enable/disable kdb:

- # CONFIG_DEBUG_RODATA is not set
+ # CONFIG_STRICT_KERNEL_RWX is not set
CONFIG_FRAME_POINTER=y
CONFIG_KGDB=y
CONFIG_KGDB_SERIAL_CONSOLE=y
diff --git a/Documentation/security/self-protection.txt b/Documentation/security/self-protection.txt
index 3010576..dd2a3b1 100644
--- a/Documentation/security/self-protection.txt
+++ b/Documentation/security/self-protection.txt
@@ -51,8 +51,8 @@ kernel, they are implemented in a way where the memory is temporarily
made writable during the update, and then returned to the original
permissions.)

-In support of this are (the poorly named) CONFIG_DEBUG_RODATA and
-CONFIG_DEBUG_SET_MODULE_RONX, which seek to make sure that code is not
+In support of this are CONFIG_STRICT_KERNEL_RWX and
+CONFIG_STRICT_MODULE_RWX, 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/Kconfig b/arch/Kconfig
index 22ee01e..406f6cd 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -787,7 +787,7 @@ config ARCH_NO_STRICT_RWX_DEFAULTS
config ARCH_HAS_STRICT_KERNEL_RWX
def_bool n

-config DEBUG_RODATA
+config STRICT_KERNEL_RWX
def_bool y if !ARCH_NO_STRICT_RWX_DEFAULTS
prompt "Make kernel text and rodata read-only" if ARCH_NO_STRICT_RWX_DEFAULTS
depends on ARCH_HAS_STRICT_KERNEL_RWX
@@ -800,7 +800,7 @@ config DEBUG_RODATA
config ARCH_HAS_STRICT_MODULE_RWX
def_bool n

-config DEBUG_SET_MODULE_RONX
+config STRICT_MODULE_RWX
def_bool y if !ARCH_NO_STRICT_RWX_DEFAULTS
prompt "Set loadable kenrel module data as NX and text as RO" if ARCH_NO_STRICT_RWX_DEFAULTS
depends on ARCH_HAS_STRICT_MODULE_RWX && MODULES
diff --git a/arch/arm/configs/aspeed_g4_defconfig b/arch/arm/configs/aspeed_g4_defconfig
index ca39c04..beea2cc 100644
--- a/arch/arm/configs/aspeed_g4_defconfig
+++ b/arch/arm/configs/aspeed_g4_defconfig
@@ -25,7 +25,6 @@ CONFIG_MODULE_UNLOAD=y
# CONFIG_ARCH_MULTI_V7 is not set
CONFIG_ARCH_ASPEED=y
CONFIG_MACH_ASPEED_G4=y
-CONFIG_DEBUG_RODATA=y
CONFIG_AEABI=y
CONFIG_UACCESS_WITH_MEMCPY=y
CONFIG_SECCOMP=y
@@ -79,7 +78,7 @@ 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_STRICT_MODULE_RWX=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 4f366b0..0e245e5 100644
--- a/arch/arm/configs/aspeed_g5_defconfig
+++ b/arch/arm/configs/aspeed_g5_defconfig
@@ -26,7 +26,6 @@ CONFIG_ARCH_MULTI_V6=y
# CONFIG_ARCH_MULTI_V7 is not set
CONFIG_ARCH_ASPEED=y
CONFIG_MACH_ASPEED_G5=y
-CONFIG_DEBUG_RODATA=y
CONFIG_AEABI=y
CONFIG_UACCESS_WITH_MEMCPY=y
CONFIG_SECCOMP=y
@@ -81,7 +80,7 @@ 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_STRICT_MODULE_RWX=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/include/asm/cacheflush.h b/arch/arm/include/asm/cacheflush.h
index bdd283b..02454fa 100644
--- a/arch/arm/include/asm/cacheflush.h
+++ b/arch/arm/include/asm/cacheflush.h
@@ -490,7 +490,7 @@ static inline int set_memory_x(unsigned long addr, int numpages) { return 0; }
static inline int set_memory_nx(unsigned long addr, int numpages) { return 0; }
#endif

-#ifdef CONFIG_DEBUG_RODATA
+#ifdef CONFIG_STRICT_KERNEL_RWX
void set_kernel_text_rw(void);
void set_kernel_text_ro(void);
#else
diff --git a/arch/arm/kernel/patch.c b/arch/arm/kernel/patch.c
index 69bda1a..020560b 100644
--- a/arch/arm/kernel/patch.c
+++ b/arch/arm/kernel/patch.c
@@ -24,9 +24,9 @@ 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_STRICT_MODULE_RWX))
page = vmalloc_to_page(addr);
- else if (!module && IS_ENABLED(CONFIG_DEBUG_RODATA))
+ else if (!module && IS_ENABLED(CONFIG_STRICT_KERNEL_RWX))
page = virt_to_page(addr);
else
return addr;
diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S
index f7f55df..ce18007 100644
--- a/arch/arm/kernel/vmlinux.lds.S
+++ b/arch/arm/kernel/vmlinux.lds.S
@@ -97,7 +97,7 @@ SECTIONS
HEAD_TEXT
}

-#ifdef CONFIG_DEBUG_RODATA
+#ifdef CONFIG_STRICT_KERNEL_RWX
. = ALIGN(1<<SECTION_SHIFT);
#endif

@@ -158,7 +158,7 @@ SECTIONS

NOTES

-#ifdef CONFIG_DEBUG_RODATA
+#ifdef CONFIG_STRICT_KERNEL_RWX
. = ALIGN(1<<SECTION_SHIFT);
#else
. = ALIGN(PAGE_SIZE);
@@ -230,7 +230,7 @@ SECTIONS
PERCPU_SECTION(L1_CACHE_BYTES)
#endif

-#ifdef CONFIG_DEBUG_RODATA
+#ifdef CONFIG_STRICT_KERNEL_RWX
. = ALIGN(1<<SECTION_SHIFT);
#else
. = ALIGN(THREAD_SIZE);
@@ -325,7 +325,7 @@ SECTIONS
STABS_DEBUG
}

-#ifdef CONFIG_DEBUG_RODATA
+#ifdef CONFIG_STRICT_KERNEL_RWX
/*
* Without CONFIG_DEBUG_ALIGN_RODATA, __start_rodata_section_aligned will
* be the first section-aligned location after __start_rodata. Otherwise,
diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index 419a035..35e3a56 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -1053,7 +1053,7 @@ config ARCH_SUPPORTS_BIG_ENDIAN

config DEBUG_ALIGN_RODATA
bool "Make rodata strictly non-executable"
- depends on DEBUG_RODATA
+ depends on STRICT_KERNEL_RWX
default y
help
If this is set, rodata will be made explicitly non-executable. This
diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index 370581a..4be0bee 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -572,7 +572,7 @@ void __init mem_init(void)
}
}

-#ifdef CONFIG_DEBUG_RODATA
+#ifdef CONFIG_STRICT_KERNEL_RWX
struct section_perm {
const char *name;
unsigned long start;
@@ -741,7 +741,7 @@ void set_kernel_text_ro(void)

#else
static inline void fix_kernmem_perms(void) { }
-#endif /* CONFIG_DEBUG_RODATA */
+#endif /* CONFIG_STRICT_KERNEL_RWX */

void free_tcmmem(void)
{
diff --git a/arch/arm64/Kconfig.debug b/arch/arm64/Kconfig.debug
index 939815e..560a8d8 100644
--- a/arch/arm64/Kconfig.debug
+++ b/arch/arm64/Kconfig.debug
@@ -72,7 +72,7 @@ config DEBUG_WX
If in doubt, say "Y".

config DEBUG_ALIGN_RODATA
- depends on DEBUG_RODATA
+ depends on STRICT_KERNEL_RWX
bool "Align linker sections up to SECTION_SIZE"
help
If this option is enabled, sections that may potentially be marked as
diff --git a/arch/arm64/kernel/insn.c b/arch/arm64/kernel/insn.c
index 94b62c1..67f9cb9 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_STRICT_MODULE_RWX))
page = vmalloc_to_page(addr);
else if (!module)
page = pfn_to_page(PHYS_PFN(__pa(addr)));
diff --git a/arch/parisc/configs/712_defconfig b/arch/parisc/configs/712_defconfig
index db8f56b..143d026 100644
--- a/arch/parisc/configs/712_defconfig
+++ b/arch/parisc/configs/712_defconfig
@@ -182,7 +182,6 @@ CONFIG_DEBUG_FS=y
CONFIG_DEBUG_KERNEL=y
CONFIG_DEBUG_MUTEXES=y
# CONFIG_RCU_CPU_STALL_DETECTOR is not set
-CONFIG_DEBUG_RODATA=y
CONFIG_CRYPTO_NULL=m
CONFIG_CRYPTO_TEST=m
CONFIG_CRYPTO_HMAC=y
diff --git a/arch/parisc/configs/c3000_defconfig b/arch/parisc/configs/c3000_defconfig
index fb92b89..8e8f0e3 100644
--- a/arch/parisc/configs/c3000_defconfig
+++ b/arch/parisc/configs/c3000_defconfig
@@ -166,7 +166,6 @@ CONFIG_DEBUG_KERNEL=y
CONFIG_DEBUG_MUTEXES=y
# CONFIG_DEBUG_BUGVERBOSE is not set
# CONFIG_RCU_CPU_STALL_DETECTOR is not set
-CONFIG_DEBUG_RODATA=y
CONFIG_CRYPTO_NULL=m
CONFIG_CRYPTO_TEST=m
CONFIG_CRYPTO_MD5=m
diff --git a/arch/parisc/mm/init.c b/arch/parisc/mm/init.c
index e02ada3..a055e5b 100644
--- a/arch/parisc/mm/init.c
+++ b/arch/parisc/mm/init.c
@@ -545,7 +545,7 @@ void free_initmem(void)
}

-#ifdef CONFIG_DEBUG_RODATA
+#ifdef CONFIG_STRICT_KERNEL_RWX
void mark_rodata_ro(void)
{
/* rodata memory was already mapped with KERNEL_RO access rights by
diff --git a/include/linux/filter.h b/include/linux/filter.h
index e4eb254..c2d2827 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_STRICT_MODULE_RWX
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_STRICT_MODULE_RWX */

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 885c3e6..79af096 100644
--- a/include/linux/init.h
+++ b/include/linux/init.h
@@ -126,10 +126,10 @@ void prepare_namespace(void);
void __init load_default_modules(void);
int __init init_rootfs(void);

-#if defined(CONFIG_DEBUG_RODATA) || defined(CONFIG_DEBUG_SET_MODULE_RONX)
+#if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX)
extern bool rodata_enabled;
#endif
-#ifdef CONFIG_DEBUG_RODATA
+#ifdef CONFIG_STRICT_KERNEL_RWX
void mark_rodata_ro(void);
#endif

diff --git a/include/linux/module.h b/include/linux/module.h
index 7c84273..d5afd14 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_STRICT_MODULE_RWX
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 b0c9d6f..0b7bae2 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_DEBUG_RODATA) || defined(CONFIG_DEBUG_SET_MODULE_RONX)
+#if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX)
bool rodata_enabled __ro_after_init = true;
static int __init set_debug_rodata(char *str)
{
@@ -934,7 +934,7 @@ static int __init set_debug_rodata(char *str)
__setup("rodata=", set_debug_rodata);
#endif

-#ifdef CONFIG_DEBUG_RODATA
+#ifdef CONFIG_STRICT_KERNEL_RWX
static void mark_readonly(void)
{
if (rodata_enabled)
diff --git a/kernel/configs/android-recommended.config b/kernel/configs/android-recommended.config
index 297756b..99127ed 100644
--- a/kernel/configs/android-recommended.config
+++ b/kernel/configs/android-recommended.config
@@ -11,7 +11,7 @@ CONFIG_BLK_DEV_LOOP=y
CONFIG_BLK_DEV_RAM=y
CONFIG_BLK_DEV_RAM_SIZE=8192
CONFIG_COMPACTION=y
-CONFIG_DEBUG_RODATA=y
+CONFIG_STRICT_KERNEL_RWX=y
CONFIG_DM_CRYPT=y
CONFIG_DM_UEVENT=y
CONFIG_DM_VERITY=y
diff --git a/kernel/module.c b/kernel/module.c
index 38d4270..2643a14 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_STRICT_MODULE_RWX=y
*/
-#ifdef CONFIG_DEBUG_SET_MODULE_RONX
+#ifdef CONFIG_STRICT_MODULE_RWX
# 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_STRICT_MODULE_RWX
/*
* LKM RO/NX protection: protect module's text/ro-data
* from modification and any data from execution.
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index b26dbc4..86385af 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -1156,7 +1156,7 @@ static int __init hibernate_setup(char *str)
} else if (!strncmp(str, "no", 2)) {
noresume = 1;
nohibernate = 1;
- } else if (IS_ENABLED(CONFIG_DEBUG_RODATA)
+ } else if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)
&& !strncmp(str, "protect_image", 13)) {
enable_restore_image_protection();
}
diff --git a/kernel/power/power.h b/kernel/power/power.h
index 1dfa0da..7fdc40d 100644
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -61,12 +61,12 @@ extern int hibernation_snapshot(int platform_mode);
extern int hibernation_restore(int platform_mode);
extern int hibernation_platform_enter(void);

-#ifdef CONFIG_DEBUG_RODATA
+#ifdef CONFIG_STRICT_KERNEL_RWX
/* kernel/power/snapshot.c */
extern void enable_restore_image_protection(void);
#else
static inline void enable_restore_image_protection(void) {}
-#endif /* CONFIG_DEBUG_RODATA */
+#endif /* CONFIG_STRICT_KERNEL_RWX */

#else /* !CONFIG_HIBERNATION */

diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index 2d8e2b2..905d5bb 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -38,7 +38,7 @@

#include "power.h"

-#ifdef CONFIG_DEBUG_RODATA
+#ifdef CONFIG_STRICT_KERNEL_RWX
static bool hibernate_restore_protection;
static bool hibernate_restore_protection_active;

@@ -73,7 +73,7 @@ static inline void hibernate_restore_protection_begin(void) {}
static inline void hibernate_restore_protection_end(void) {}
static inline void hibernate_restore_protect_page(void *page_address) {}
static inline void hibernate_restore_unprotect_page(void *page_address) {}
-#endif /* CONFIG_DEBUG_RODATA */
+#endif /* CONFIG_STRICT_KERNEL_RWX */

static int swsusp_page_is_free(struct page *);
static void swsusp_set_page_forbidden(struct page *);
--
2.7.4