diff options
| -rw-r--r-- | Documentation/kbuild/reproducible-builds.rst | 7 | ||||
| -rw-r--r-- | arch/riscv/Kconfig | 2 | ||||
| -rw-r--r-- | arch/x86/mm/pti.c | 2 | ||||
| -rw-r--r-- | include/linux/compiler-gcc.h | 8 | ||||
| -rw-r--r-- | include/linux/compiler_types.h | 14 | ||||
| -rw-r--r-- | include/linux/vermagic.h | 8 | ||||
| -rw-r--r-- | kernel/panic.c | 2 | ||||
| -rw-r--r-- | scripts/Makefile.gcc-plugins | 4 | ||||
| -rw-r--r-- | scripts/gcc-plugins/Kconfig | 38 | ||||
| -rw-r--r-- | security/Kconfig.hardening | 62 |
10 files changed, 81 insertions, 66 deletions
diff --git a/Documentation/kbuild/reproducible-builds.rst b/Documentation/kbuild/reproducible-builds.rst index 3b25655e441b..81ff30505d35 100644 --- a/Documentation/kbuild/reproducible-builds.rst +++ b/Documentation/kbuild/reproducible-builds.rst @@ -99,10 +99,9 @@ unreproducible parts can be treated as sources: Structure randomisation ----------------------- -If you enable ``CONFIG_GCC_PLUGIN_RANDSTRUCT``, you will need to -pre-generate the random seed in -``scripts/gcc-plugins/randomize_layout_seed.h`` so the same value -is used in rebuilds. +If you enable ``CONFIG_RANDSTRUCT``, you will need to pre-generate +the random seed in ``scripts/gcc-plugins/randomize_layout_seed.h`` +so the same value is used in rebuilds. Debug info conflicts -------------------- diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 00fd9c548f26..3ac2a81a55eb 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -468,7 +468,7 @@ config CC_HAVE_STACKPROTECTOR_TLS config STACKPROTECTOR_PER_TASK def_bool y - depends on !GCC_PLUGIN_RANDSTRUCT + depends on !RANDSTRUCT depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS config PHYS_RAM_BASE_FIXED diff --git a/arch/x86/mm/pti.c b/arch/x86/mm/pti.c index 5d5c7bb50ce9..ffe3b3a087fe 100644 --- a/arch/x86/mm/pti.c +++ b/arch/x86/mm/pti.c @@ -540,7 +540,7 @@ static inline bool pti_kernel_image_global_ok(void) * cases where RANDSTRUCT is in use to help keep the layout a * secret. */ - if (IS_ENABLED(CONFIG_GCC_PLUGIN_RANDSTRUCT)) + if (IS_ENABLED(CONFIG_RANDSTRUCT)) return false; return true; diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h index 52299c957c98..a0c55eeaeaf1 100644 --- a/include/linux/compiler-gcc.h +++ b/include/linux/compiler-gcc.h @@ -66,14 +66,6 @@ __builtin_unreachable(); \ } while (0) -#if defined(RANDSTRUCT_PLUGIN) && !defined(__CHECKER__) -#define __randomize_layout __attribute__((randomize_layout)) -#define __no_randomize_layout __attribute__((no_randomize_layout)) -/* This anon struct can add padding, so only enable it under randstruct. */ -#define randomized_struct_fields_start struct { -#define randomized_struct_fields_end } __randomize_layout; -#endif - /* * GCC 'asm goto' miscompiles certain code sequences: * diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h index 1c2c33ae1b37..d08dfcb0ac68 100644 --- a/include/linux/compiler_types.h +++ b/include/linux/compiler_types.h @@ -242,15 +242,15 @@ struct ftrace_likely_data { # define __latent_entropy #endif -#ifndef __randomize_layout +#if defined(RANDSTRUCT) && !defined(__CHECKER__) +# define __randomize_layout __designated_init __attribute__((randomize_layout)) +# define __no_randomize_layout __attribute__((no_randomize_layout)) +/* This anon struct can add padding, so only enable it under randstruct. */ +# define randomized_struct_fields_start struct { +# define randomized_struct_fields_end } __randomize_layout; +#else # define __randomize_layout __designated_init -#endif - -#ifndef __no_randomize_layout # define __no_randomize_layout -#endif - -#ifndef randomized_struct_fields_start # define randomized_struct_fields_start # define randomized_struct_fields_end #endif diff --git a/include/linux/vermagic.h b/include/linux/vermagic.h index 329d63babaeb..efb51a2da599 100644 --- a/include/linux/vermagic.h +++ b/include/linux/vermagic.h @@ -32,11 +32,11 @@ #else #define MODULE_VERMAGIC_MODVERSIONS "" #endif -#ifdef RANDSTRUCT_PLUGIN +#ifdef RANDSTRUCT #include <generated/randomize_layout_hash.h> -#define MODULE_RANDSTRUCT_PLUGIN "RANDSTRUCT_PLUGIN_" RANDSTRUCT_HASHED_SEED +#define MODULE_RANDSTRUCT "RANDSTRUCT_" RANDSTRUCT_HASHED_SEED #else -#define MODULE_RANDSTRUCT_PLUGIN +#define MODULE_RANDSTRUCT #endif #define VERMAGIC_STRING \ @@ -44,6 +44,6 @@ MODULE_VERMAGIC_SMP MODULE_VERMAGIC_PREEMPT \ MODULE_VERMAGIC_MODULE_UNLOAD MODULE_VERMAGIC_MODVERSIONS \ MODULE_ARCH_VERMAGIC \ - MODULE_RANDSTRUCT_PLUGIN + MODULE_RANDSTRUCT #endif /* _LINUX_VERMAGIC_H */ diff --git a/kernel/panic.c b/kernel/panic.c index eb4dfb932c85..8355b19676f8 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -48,7 +48,7 @@ unsigned int __read_mostly sysctl_oops_all_cpu_backtrace; int panic_on_oops = CONFIG_PANIC_ON_OOPS_VALUE; static unsigned long tainted_mask = - IS_ENABLED(CONFIG_GCC_PLUGIN_RANDSTRUCT) ? (1 << TAINT_RANDSTRUCT) : 0; + IS_ENABLED(CONFIG_RANDSTRUCT) ? (1 << TAINT_RANDSTRUCT) : 0; static int pause_on_oops; static int pause_on_oops_flag; static DEFINE_SPINLOCK(pause_on_oops_lock); diff --git a/scripts/Makefile.gcc-plugins b/scripts/Makefile.gcc-plugins index 927c3dd57f84..827c47ce5c73 100644 --- a/scripts/Makefile.gcc-plugins +++ b/scripts/Makefile.gcc-plugins @@ -24,8 +24,8 @@ gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STRUCTLEAK) \ gcc-plugin-$(CONFIG_GCC_PLUGIN_RANDSTRUCT) += randomize_layout_plugin.so gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_RANDSTRUCT) \ - += -DRANDSTRUCT_PLUGIN -gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_RANDSTRUCT_PERFORMANCE) \ + += -DRANDSTRUCT +gcc-plugin-cflags-$(CONFIG_RANDSTRUCT_PERFORMANCE) \ += -fplugin-arg-randomize_layout_plugin-performance-mode gcc-plugin-$(CONFIG_GCC_PLUGIN_STACKLEAK) += stackleak_plugin.so diff --git a/scripts/gcc-plugins/Kconfig b/scripts/gcc-plugins/Kconfig index 51d81c3f03d6..e383cda05367 100644 --- a/scripts/gcc-plugins/Kconfig +++ b/scripts/gcc-plugins/Kconfig @@ -46,44 +46,6 @@ config GCC_PLUGIN_LATENT_ENTROPY * https://grsecurity.net/ * https://pax.grsecurity.net/ -config GCC_PLUGIN_RANDSTRUCT - bool "Randomize layout of sensitive kernel structures" - select MODVERSIONS if MODULES - help - If you say Y here, the layouts of structures that are entirely - function pointers (and have not been manually annotated with - __no_randomize_layout), or structures that have been explicitly - marked with __randomize_layout, will be randomized at compile-time. - This can introduce the requirement of an additional information - exposure vulnerability for exploits targeting these structure - types. - - Enabling this feature will introduce some performance impact, - slightly increase memory usage, and prevent the use of forensic - tools like Volatility against the system (unless the kernel - source tree isn't cleaned after kernel installation). - - The seed used for compilation is located at - scripts/gcc-plugins/randomize_layout_seed.h. It remains after - a make clean to allow for external modules to be compiled with - the existing seed and will be removed by a make mrproper or - make distclean. - - This plugin was ported from grsecurity/PaX. More information at: - * https://grsecurity.net/ - * https://pax.grsecurity.net/ - -config GCC_PLUGIN_RANDSTRUCT_PERFORMANCE - bool "Use cacheline-aware structure randomization" - depends on GCC_PLUGIN_RANDSTRUCT - depends on !COMPILE_TEST # do not reduce test coverage - help - If you say Y here, the RANDSTRUCT randomization will make a - best effort at restricting randomization to cacheline-sized - groups of elements. It will further not randomize bitfields - in structures. This reduces the performance hit of RANDSTRUCT - at the cost of weakened randomization. - config GCC_PLUGIN_ARM_SSP_PER_TASK bool depends on GCC_PLUGINS && ARM diff --git a/security/Kconfig.hardening b/security/Kconfig.hardening index ded4d7c0d132..364e3f8c6eea 100644 --- a/security/Kconfig.hardening +++ b/security/Kconfig.hardening @@ -266,4 +266,66 @@ config ZERO_CALL_USED_REGS endmenu +choice + prompt "Randomize layout of sensitive kernel structures" + default RANDSTRUCT_FULL if COMPILE_TEST && GCC_PLUGINS + default RANDSTRUCT_NONE + help + If you enable this, the layouts of structures that are entirely + function pointers (and have not been manually annotated with + __no_randomize_layout), or structures that have been explicitly + marked with __randomize_layout, will be randomized at compile-time. + This can introduce the requirement of an additional information + exposure vulnerability for exploits targeting these structure + types. + + Enabling this feature will introduce some performance impact, + slightly increase memory usage, and prevent the use of forensic + tools like Volatility against the system (unless the kernel + source tree isn't cleaned after kernel installation). + + The seed used for compilation is located at + scripts/randomize_layout_seed.h. It remains after a "make clean" + to allow for external modules to be compiled with the existing + seed and will be removed by a "make mrproper" or "make distclean". + + config RANDSTRUCT_NONE + bool "Disable structure layout randomization" + help + Build normally: no structure layout randomization. + + config RANDSTRUCT_FULL + bool "Fully randomize structure layout" + depends on GCC_PLUGINS + select MODVERSIONS if MODULES + help + Fully randomize the member layout of sensitive + structures as much as possible, which may have both a + memory size and performance impact. + + config RANDSTRUCT_PERFORMANCE + bool "Limit randomization of structure layout to cache-lines" + depends on GCC_PLUGINS + select MODVERSIONS if MODULES + help + Randomization of sensitive kernel structures will make a + best effort at restricting randomization to cacheline-sized + groups of members. It will further not randomize bitfields + in structures. This reduces the performance hit of RANDSTRUCT + at the cost of weakened randomization. +endchoice + +config RANDSTRUCT + def_bool !RANDSTRUCT_NONE + +config GCC_PLUGIN_RANDSTRUCT + def_bool GCC_PLUGINS && RANDSTRUCT + help + Use GCC plugin to randomize structure layout. + + This plugin was ported from grsecurity/PaX. More + information at: + * https://grsecurity.net/ + * https://pax.grsecurity.net/ + endmenu |