diff --git a/Documentation/DocBook/kgdb.tmpl b/Documentation/DocBook/kgdb.tmpl
index f3abca7ec53d..856ac20bf367 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 3010576c9fca..141acfebe6ef 100644
--- a/Documentation/security/self-protection.txt
+++ b/Documentation/security/self-protection.txt
@@ -51,11 +51,17 @@ 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.
+Most architectures have these options on by default and not user selectable.
+For some architectures like arm that wish to have these be selectable,
+the architecture Kconfig can select ARCH_OPTIONAL_KERNEL_RWX to enable
+a Kconfig prompt. CONFIG_ARCH_OPTIONAL_KERNEL_RWX_DEFAULT determines
+the default setting when ARCH_OPTIONAL_KERNEL_RWX is enabled.
+
#### Function pointers and sensitive variables must not be writable
Vast areas of kernel memory contain function pointers that are looked
diff --git a/arch/Kconfig b/arch/Kconfig
index 99839c23d453..33f5a555c32a 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -781,4 +781,38 @@ config VMAP_STACK
the stack to map directly to the KASAN shadow map using a formula
that is incorrect if the stack is in vmalloc space.
+config ARCH_OPTIONAL_KERNEL_RWX
+ def_bool n
+
+config ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
+ def_bool n
+
+config ARCH_HAS_STRICT_KERNEL_RWX
+ def_bool n
+
+config STRICT_KERNEL_RWX
+ bool "Make kernel text and rodata read-only" if ARCH_OPTIONAL_KERNEL_RWX
+ depends on ARCH_HAS_STRICT_KERNEL_RWX
+ default !ARCH_OPTIONAL_KERNEL_RWX || ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
+ help
+ If this is set, kernel text and rodata memory will be made read-only,
+ and non-text memory will be made non-executable. This provides
+ protection against certain security exploits (e.g. executing the heap
+ or modifying text)
+
+ These features are considered standard security practice these days.
+ You should say Y here in almost all cases.
+
+config ARCH_HAS_STRICT_MODULE_RWX
+ def_bool n
+
+config STRICT_MODULE_RWX
+ bool "Set loadable kernel module data as NX and text as RO" if ARCH_OPTIONAL_KERNEL_RWX
+ depends on ARCH_HAS_STRICT_MODULE_RWX && MODULES
+ default !ARCH_OPTIONAL_KERNEL_RWX || ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
+ 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 exploits (e.g. writing to text)
+
source "kernel/gcov/Kconfig"
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 186c4c214e0a..8748353ed5e0 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -4,10 +4,14 @@ config ARM
select ARCH_CLOCKSOURCE_DATA
select ARCH_HAS_DEVMEM_IS_ALLOWED
select ARCH_HAS_ELF_RANDOMIZE
+ select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
+ select ARCH_HAS_STRICT_MODULE_RWX if MMU
select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
select ARCH_HAVE_CUSTOM_GPIO_H
select ARCH_HAS_GCOV_PROFILE_ALL
select ARCH_MIGHT_HAVE_PC_PARPORT
+ select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
+ select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT if CPU_V7
select ARCH_SUPPORTS_ATOMIC_RMW
select ARCH_USE_BUILTIN_BSWAP
select ARCH_USE_CMPXCHG_LOCKREF
diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug
index d83f7c369e51..426d2716f55d 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 ca39c04fec6b..05b99bc1c1ce 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 +78,8 @@ 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_STRICT_KERNEL_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 4f366b0370e9..05a16d53d03c 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 +80,8 @@ 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_STRICT_KERNEL_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 bdd283bc5842..02454fa15d2c 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 69bda1a5707e..020560b2dcb7 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 f7f55df0bf7b..ce18007f9e4e 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<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 885c3e6d0f9d..79af0962fd52 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 5cddadff2c25..f4f542ed3d92 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -763,7 +763,7 @@ 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 6d98664e843b..c8a00f0f10ff 100644
--- a/init/main.c
+++ b/init/main.c
@@ -924,7 +924,7 @@ 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)
{
@@ -933,7 +933,7 @@ 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 297756be369c..99127edc5204 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 1a17ec0c8ae7..a3889169a3ae 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -76,9 +76,9 @@
/*
* 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)
@@ -1846,7 +1846,7 @@ 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 b26dbc48c75b..86385af1080f 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 1dfa0da827d3..7fdc40d31b7d 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 2d8e2b227db8..905d5bbd595f 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 *);