diff options
| -rw-r--r-- | drivers/char/Kconfig | 50 | ||||
| -rw-r--r-- | drivers/char/random.c | 39 | ||||
| -rw-r--r-- | include/linux/crc-itu-t.h | 2 | ||||
| -rw-r--r-- | include/linux/random.h | 3 | ||||
| -rw-r--r-- | lib/crc-itu-t.c | 2 | ||||
| -rw-r--r-- | lib/vsprintf.c | 3 | ||||
| -rw-r--r-- | tools/testing/selftests/wireguard/qemu/Makefile | 28 | ||||
| -rw-r--r-- | tools/testing/selftests/wireguard/qemu/init.c | 3 | ||||
| -rw-r--r-- | tools/testing/selftests/wireguard/qemu/kernel.config | 3 |
9 files changed, 71 insertions, 62 deletions
diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig index 69fd31ffb847..0b6c03643ddc 100644 --- a/drivers/char/Kconfig +++ b/drivers/char/Kconfig @@ -429,28 +429,40 @@ config ADI driver include crash and makedumpfile. config RANDOM_TRUST_CPU - bool "Trust the CPU manufacturer to initialize Linux's CRNG" + bool "Initialize RNG using CPU RNG instructions" + default y depends on ARCH_RANDOM - default n help - Assume that CPU manufacturer (e.g., Intel or AMD for RDSEED or - RDRAND, IBM for the S390 and Power PC architectures) is trustworthy - for the purposes of initializing Linux's CRNG. Since this is not - something that can be independently audited, this amounts to trusting - that CPU manufacturer (perhaps with the insistence or mandate - of a Nation State's intelligence or law enforcement agencies) - has not installed a hidden back door to compromise the CPU's - random number generation facilities. This can also be configured - at boot with "random.trust_cpu=on/off". + Initialize the RNG using random numbers supplied by the CPU's + RNG instructions (e.g. RDRAND), if supported and available. These + random numbers are never used directly, but are rather hashed into + the main input pool, and this happens regardless of whether or not + this option is enabled. Instead, this option controls whether the + they are credited and hence can initialize the RNG. Additionally, + other sources of randomness are always used, regardless of this + setting. Enabling this implies trusting that the CPU can supply high + quality and non-backdoored random numbers. + + Say Y here unless you have reason to mistrust your CPU or believe + its RNG facilities may be faulty. This may also be configured at + boot time with "random.trust_cpu=on/off". config RANDOM_TRUST_BOOTLOADER - bool "Trust the bootloader to initialize Linux's CRNG" - help - Some bootloaders can provide entropy to increase the kernel's initial - device randomness. Say Y here to assume the entropy provided by the - booloader is trustworthy so it will be added to the kernel's entropy - pool. Otherwise, say N here so it will be regarded as device input that - only mixes the entropy pool. This can also be configured at boot with - "random.trust_bootloader=on/off". + bool "Initialize RNG using bootloader-supplied seed" + default y + help + Initialize the RNG using a seed supplied by the bootloader or boot + environment (e.g. EFI or a bootloader-generated device tree). This + seed is not used directly, but is rather hashed into the main input + pool, and this happens regardless of whether or not this option is + enabled. Instead, this option controls whether the seed is credited + and hence can initialize the RNG. Additionally, other sources of + randomness are always used, regardless of this setting. Enabling + this implies trusting that the bootloader can supply high quality and + non-backdoored seeds. + + Say Y here unless you have reason to mistrust your bootloader or + believe its RNG facilities may be faulty. This may also be configured + at boot time with "random.trust_bootloader=on/off". endmenu diff --git a/drivers/char/random.c b/drivers/char/random.c index b691b9d59503..655e327d425e 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -650,7 +650,8 @@ static void __cold _credit_init_bits(size_t bits) if (orig < POOL_READY_BITS && new >= POOL_READY_BITS) { crng_reseed(); /* Sets crng_init to CRNG_READY under base_crng.lock. */ - execute_in_process_context(crng_set_ready, &set_ready); + if (static_key_initialized) + execute_in_process_context(crng_set_ready, &set_ready); wake_up_interruptible(&crng_init_wait); kill_fasync(&fasync, SIGIO, POLL_IN); pr_notice("crng init done\n"); @@ -724,9 +725,8 @@ static void __cold _credit_init_bits(size_t bits) * **********************************************************************/ -static bool used_arch_random; -static bool trust_cpu __ro_after_init = IS_ENABLED(CONFIG_RANDOM_TRUST_CPU); -static bool trust_bootloader __ro_after_init = IS_ENABLED(CONFIG_RANDOM_TRUST_BOOTLOADER); +static bool trust_cpu __initdata = IS_ENABLED(CONFIG_RANDOM_TRUST_CPU); +static bool trust_bootloader __initdata = IS_ENABLED(CONFIG_RANDOM_TRUST_BOOTLOADER); static int __init parse_trust_cpu(char *arg) { return kstrtobool(arg, &trust_cpu); @@ -776,7 +776,7 @@ static struct notifier_block pm_notifier = { .notifier_call = random_pm_notifica int __init random_init(const char *command_line) { ktime_t now = ktime_get_real(); - unsigned int i, arch_bytes; + unsigned int i, arch_bits; unsigned long entropy; #if defined(LATENT_ENTROPY_PLUGIN) @@ -784,12 +784,12 @@ int __init random_init(const char *command_line) _mix_pool_bytes(compiletime_seed, sizeof(compiletime_seed)); #endif - for (i = 0, arch_bytes = BLAKE2S_BLOCK_SIZE; + for (i = 0, arch_bits = BLAKE2S_BLOCK_SIZE * 8; i < BLAKE2S_BLOCK_SIZE; i += sizeof(entropy)) { if (!arch_get_random_seed_long_early(&entropy) && !arch_get_random_long_early(&entropy)) { entropy = random_get_entropy(); - arch_bytes -= sizeof(entropy); + arch_bits -= sizeof(entropy) * 8; } _mix_pool_bytes(&entropy, sizeof(entropy)); } @@ -798,11 +798,18 @@ int __init random_init(const char *command_line) _mix_pool_bytes(command_line, strlen(command_line)); add_latent_entropy(); + /* + * If we were initialized by the bootloader before jump labels are + * initialized, then we should enable the static branch here, where + * it's guaranteed that jump labels have been initialized. + */ + if (!static_branch_likely(&crng_is_ready) && crng_init >= CRNG_READY) + crng_set_ready(NULL); + if (crng_ready()) crng_reseed(); else if (trust_cpu) - credit_init_bits(arch_bytes * 8); - used_arch_random = arch_bytes * 8 >= POOL_READY_BITS; + _credit_init_bits(arch_bits); WARN_ON(register_pm_notifier(&pm_notifier)); @@ -812,17 +819,6 @@ int __init random_init(const char *command_line) } /* - * Returns whether arch randomness has been mixed into the initial - * state of the RNG, regardless of whether or not that randomness - * was credited. Knowing this is only good for a very limited set - * of uses, such as early init printk pointer obfuscation. - */ -bool rng_has_arch_random(void) -{ - return used_arch_random; -} - -/* * Add device- or boot-specific data to the input pool to help * initialize it. * @@ -865,13 +861,12 @@ EXPORT_SYMBOL_GPL(add_hwgenerator_randomness); * Handle random seed passed by bootloader, and credit it if * CONFIG_RANDOM_TRUST_BOOTLOADER is set. */ -void __cold add_bootloader_randomness(const void *buf, size_t len) +void __init add_bootloader_randomness(const void *buf, size_t len) { mix_pool_bytes(buf, len); if (trust_bootloader) credit_init_bits(len * 8); } -EXPORT_SYMBOL_GPL(add_bootloader_randomness); #if IS_ENABLED(CONFIG_VMGENID) static BLOCKING_NOTIFIER_HEAD(vmfork_chain); diff --git a/include/linux/crc-itu-t.h b/include/linux/crc-itu-t.h index a4367051e192..2f991a427ade 100644 --- a/include/linux/crc-itu-t.h +++ b/include/linux/crc-itu-t.h @@ -4,7 +4,7 @@ * * Implements the standard CRC ITU-T V.41: * Width 16 - * Poly 0x1021 (x^16 + x^12 + x^15 + 1) + * Poly 0x1021 (x^16 + x^12 + x^5 + 1) * Init 0 */ diff --git a/include/linux/random.h b/include/linux/random.h index fae0c84027fd..20e389a14e5c 100644 --- a/include/linux/random.h +++ b/include/linux/random.h @@ -13,7 +13,7 @@ struct notifier_block; void add_device_randomness(const void *buf, size_t len); -void add_bootloader_randomness(const void *buf, size_t len); +void __init add_bootloader_randomness(const void *buf, size_t len); void add_input_randomness(unsigned int type, unsigned int code, unsigned int value) __latent_entropy; void add_interrupt_randomness(int irq) __latent_entropy; @@ -74,7 +74,6 @@ static inline unsigned long get_random_canary(void) int __init random_init(const char *command_line); bool rng_is_initialized(void); -bool rng_has_arch_random(void); int wait_for_random_bytes(void); /* Calls wait_for_random_bytes() and then calls get_random_bytes(buf, nbytes). diff --git a/lib/crc-itu-t.c b/lib/crc-itu-t.c index 1974b355c148..1d26a1647da5 100644 --- a/lib/crc-itu-t.c +++ b/lib/crc-itu-t.c @@ -7,7 +7,7 @@ #include <linux/module.h> #include <linux/crc-itu-t.h> -/** CRC table for the CRC ITU-T V.41 0x1021 (x^16 + x^12 + x^15 + 1) */ +/* CRC table for the CRC ITU-T V.41 0x1021 (x^16 + x^12 + x^5 + 1) */ const u16 crc_itu_t_table[256] = { 0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50a5, 0x60c6, 0x70e7, 0x8108, 0x9129, 0xa14a, 0xb16b, 0xc18c, 0xd1ad, 0xe1ce, 0xf1ef, diff --git a/lib/vsprintf.c b/lib/vsprintf.c index fb77f7bfd126..3c1853a9d1c0 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -769,8 +769,7 @@ static inline int __ptr_to_hashval(const void *ptr, unsigned long *hashval_out) static DECLARE_WORK(enable_ptr_key_work, enable_ptr_key_workfn); unsigned long flags; - if (!system_unbound_wq || - (!rng_is_initialized() && !rng_has_arch_random()) || + if (!system_unbound_wq || !rng_is_initialized() || !spin_trylock_irqsave(&filling, flags)) return -EAGAIN; diff --git a/tools/testing/selftests/wireguard/qemu/Makefile b/tools/testing/selftests/wireguard/qemu/Makefile index bca07b93eeb0..7d1b80988d8a 100644 --- a/tools/testing/selftests/wireguard/qemu/Makefile +++ b/tools/testing/selftests/wireguard/qemu/Makefile @@ -64,8 +64,8 @@ QEMU_VPORT_RESULT := virtio-serial-device ifeq ($(HOST_ARCH),$(ARCH)) QEMU_MACHINE := -cpu host -machine virt,gic_version=host,accel=kvm else -QEMU_MACHINE := -cpu cortex-a53 -machine virt -CFLAGS += -march=armv8-a -mtune=cortex-a53 +QEMU_MACHINE := -cpu max -machine virt +CFLAGS += -march=armv8-a endif else ifeq ($(ARCH),aarch64_be) CHOST := aarch64_be-linux-musl @@ -76,8 +76,8 @@ QEMU_VPORT_RESULT := virtio-serial-device ifeq ($(HOST_ARCH),$(ARCH)) QEMU_MACHINE := -cpu host -machine virt,gic_version=host,accel=kvm else -QEMU_MACHINE := -cpu cortex-a53 -machine virt -CFLAGS += -march=armv8-a -mtune=cortex-a53 +QEMU_MACHINE := -cpu max -machine virt +CFLAGS += -march=armv8-a endif else ifeq ($(ARCH),arm) CHOST := arm-linux-musleabi @@ -88,8 +88,8 @@ QEMU_VPORT_RESULT := virtio-serial-device ifeq ($(HOST_ARCH),$(ARCH)) QEMU_MACHINE := -cpu host -machine virt,gic_version=host,accel=kvm else -QEMU_MACHINE := -cpu cortex-a15 -machine virt -CFLAGS += -march=armv7-a -mtune=cortex-a15 -mabi=aapcs-linux +QEMU_MACHINE := -cpu max -machine virt +CFLAGS += -march=armv7-a -mabi=aapcs-linux endif else ifeq ($(ARCH),armeb) CHOST := armeb-linux-musleabi @@ -100,8 +100,8 @@ QEMU_VPORT_RESULT := virtio-serial-device ifeq ($(HOST_ARCH),$(ARCH)) QEMU_MACHINE := -cpu host -machine virt,gic_version=host,accel=kvm else -QEMU_MACHINE := -cpu cortex-a15 -machine virt -CFLAGS += -march=armv7-a -mabi=aapcs-linux # We don't pass -mtune=cortex-a15 due to a compiler bug on big endian. +QEMU_MACHINE := -cpu max -machine virt +CFLAGS += -march=armv7-a -mabi=aapcs-linux LDFLAGS += -Wl,--be8 endif else ifeq ($(ARCH),x86_64) @@ -112,8 +112,7 @@ KERNEL_BZIMAGE := $(KERNEL_BUILD_PATH)/arch/x86/boot/bzImage ifeq ($(HOST_ARCH),$(ARCH)) QEMU_MACHINE := -cpu host -machine q35,accel=kvm else -QEMU_MACHINE := -cpu Skylake-Server -machine q35 -CFLAGS += -march=skylake-avx512 +QEMU_MACHINE := -cpu max -machine q35 endif else ifeq ($(ARCH),i686) CHOST := i686-linux-musl @@ -123,8 +122,7 @@ KERNEL_BZIMAGE := $(KERNEL_BUILD_PATH)/arch/x86/boot/bzImage ifeq ($(subst x86_64,i686,$(HOST_ARCH)),$(ARCH)) QEMU_MACHINE := -cpu host -machine q35,accel=kvm else -QEMU_MACHINE := -cpu coreduo -machine q35 -CFLAGS += -march=prescott +QEMU_MACHINE := -cpu max -machine q35 endif else ifeq ($(ARCH),mips64) CHOST := mips64-linux-musl @@ -182,7 +180,7 @@ KERNEL_BZIMAGE := $(KERNEL_BUILD_PATH)/vmlinux ifeq ($(HOST_ARCH),$(ARCH)) QEMU_MACHINE := -cpu host,accel=kvm -machine pseries else -QEMU_MACHINE := -machine pseries +QEMU_MACHINE := -machine pseries -device spapr-rng,rng=rng -object rng-random,id=rng endif else ifeq ($(ARCH),powerpc64le) CHOST := powerpc64le-linux-musl @@ -192,7 +190,7 @@ KERNEL_BZIMAGE := $(KERNEL_BUILD_PATH)/vmlinux ifeq ($(HOST_ARCH),$(ARCH)) QEMU_MACHINE := -cpu host,accel=kvm -machine pseries else -QEMU_MACHINE := -machine pseries +QEMU_MACHINE := -machine pseries -device spapr-rng,rng=rng -object rng-random,id=rng endif else ifeq ($(ARCH),powerpc) CHOST := powerpc-linux-musl @@ -247,7 +245,7 @@ QEMU_VPORT_RESULT := virtio-serial-ccw ifeq ($(HOST_ARCH),$(ARCH)) QEMU_MACHINE := -cpu host,accel=kvm -machine s390-ccw-virtio -append $(KERNEL_CMDLINE) else -QEMU_MACHINE := -machine s390-ccw-virtio -append $(KERNEL_CMDLINE) +QEMU_MACHINE := -cpu max -machine s390-ccw-virtio -append $(KERNEL_CMDLINE) endif else $(error I only build: x86_64, i686, arm, armeb, aarch64, aarch64_be, mips, mipsel, mips64, mips64el, powerpc64, powerpc64le, powerpc, m68k, riscv64, riscv32, s390x) diff --git a/tools/testing/selftests/wireguard/qemu/init.c b/tools/testing/selftests/wireguard/qemu/init.c index 2a0f48fac925..c9e128436546 100644 --- a/tools/testing/selftests/wireguard/qemu/init.c +++ b/tools/testing/selftests/wireguard/qemu/init.c @@ -21,6 +21,7 @@ #include <sys/utsname.h> #include <sys/sendfile.h> #include <sys/sysmacros.h> +#include <sys/random.h> #include <linux/random.h> #include <linux/version.h> @@ -58,6 +59,8 @@ static void seed_rng(void) { int bits = 256, fd; + if (!getrandom(NULL, 0, GRND_NONBLOCK)) + return; pretty_message("[+] Fake seeding RNG..."); fd = open("/dev/random", O_WRONLY); if (fd < 0) diff --git a/tools/testing/selftests/wireguard/qemu/kernel.config b/tools/testing/selftests/wireguard/qemu/kernel.config index a9b5a520a1d2..bad88f4b0a03 100644 --- a/tools/testing/selftests/wireguard/qemu/kernel.config +++ b/tools/testing/selftests/wireguard/qemu/kernel.config @@ -31,6 +31,7 @@ CONFIG_TTY=y CONFIG_BINFMT_ELF=y CONFIG_BINFMT_SCRIPT=y CONFIG_VDSO=y +CONFIG_STRICT_KERNEL_RWX=y CONFIG_VIRTUALIZATION=y CONFIG_HYPERVISOR_GUEST=y CONFIG_PARAVIRT=y @@ -65,6 +66,8 @@ CONFIG_PROC_FS=y CONFIG_PROC_SYSCTL=y CONFIG_SYSFS=y CONFIG_TMPFS=y +CONFIG_RANDOM_TRUST_CPU=y +CONFIG_RANDOM_TRUST_BOOTLOADER=y CONFIG_CONSOLE_LOGLEVEL_DEFAULT=15 CONFIG_LOG_BUF_SHIFT=18 CONFIG_PRINTK_TIME=y |