Use the CPU RNG for entropy (rhbz 1572944)

0001-random-add-a-config-option-to-trust-the-CPU-s-hwrng.patch

@@ -0,0 +1,78 @@
+From 39a8883a2b989d1d21bd8dd99f5557f0c5e89694 Mon Sep 17 00:00:00 2001
+From: Theodore Ts'o <tytso@mit.edu>
+Date: Tue, 17 Jul 2018 18:24:27 -0400
+Subject: [PATCH] random: add a config option to trust the CPU's hwrng
+
+This gives the user building their own kernel (or a Linux
+distribution) the option of deciding whether or not to trust the CPU's
+hardware random number generator (e.g., RDRAND for x86 CPU's) as being
+correctly implemented and not having a back door introduced (perhaps
+courtesy of a Nation State's law enforcement or intelligence
+agencies).
+
+This will prevent getrandom(2) from blocking, if there is a
+willingness to trust the CPU manufacturer.
+
+Signed-off-by: Theodore Ts'o <tytso@mit.edu>
+---
+ drivers/char/Kconfig  | 14 ++++++++++++++
+ drivers/char/random.c | 11 ++++++++++-
+ 2 files changed, 24 insertions(+), 1 deletion(-)
+
+diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
+index 212f447938ae..ce277ee0a28a 100644
+--- a/drivers/char/Kconfig
++++ b/drivers/char/Kconfig
+@@ -554,3 +554,17 @@ config ADI
+ 
+ endmenu
+ 
++config RANDOM_TRUST_CPU
++	bool "Trust the CPU manufacturer to initialize Linux's CRNG"
++	depends on X86 || S390 || PPC
++	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.
++
+diff --git a/drivers/char/random.c b/drivers/char/random.c
+index 34ddfd57419b..f4013b8a711b 100644
+--- a/drivers/char/random.c
++++ b/drivers/char/random.c
+@@ -782,6 +782,7 @@ static void invalidate_batched_entropy(void);
+ static void crng_initialize(struct crng_state *crng)
+ {
+ 	int		i;
++	int		arch_init = 1;
+ 	unsigned long	rv;
+ 
+ 	memcpy(&crng->state[0], "expand 32-byte k", 16);
+@@ -792,10 +793,18 @@ static void crng_initialize(struct crng_state *crng)
+ 		_get_random_bytes(&crng->state[4], sizeof(__u32) * 12);
+ 	for (i = 4; i < 16; i++) {
+ 		if (!arch_get_random_seed_long(&rv) &&
+-		    !arch_get_random_long(&rv))
++		    !arch_get_random_long(&rv)) {
+ 			rv = random_get_entropy();
++			arch_init = 0;
++		}
+ 		crng->state[i] ^= rv;
+ 	}
++#ifdef CONFIG_RANDOM_TRUST_CPU
++	if (arch_init) {
++		crng_init = 2;
++		pr_notice("random: crng done (trusting CPU's manufacturer)\n");
++	}
++#endif
+ 	crng->init_time = jiffies - CRNG_RESEED_INTERVAL - 1;
+ }
+ 
+-- 
+2.17.1
+

0001-random-make-CPU-trust-a-boot-parameter.patch

@@ -0,0 +1,82 @@
+From 9b25436662d5fb4c66eb527ead53cab15f596ee0 Mon Sep 17 00:00:00 2001
+From: Kees Cook <keescook@chromium.org>
+Date: Mon, 27 Aug 2018 14:51:54 -0700
+Subject: [PATCH] random: make CPU trust a boot parameter
+
+Instead of forcing a distro or other system builder to choose
+at build time whether the CPU is trusted for CRNG seeding via
+CONFIG_RANDOM_TRUST_CPU, provide a boot-time parameter for end users to
+control the choice. The CONFIG will set the default state instead.
+
+Signed-off-by: Kees Cook <keescook@chromium.org>
+Signed-off-by: Theodore Ts'o <tytso@mit.edu>
+---
+ Documentation/admin-guide/kernel-parameters.txt |  6 ++++++
+ drivers/char/Kconfig                            |  4 ++--
+ drivers/char/random.c                           | 11 ++++++++---
+ 3 files changed, 16 insertions(+), 5 deletions(-)
+
+diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
+index 0c8f7889efa1..227c5c6fa4c1 100644
+--- a/Documentation/admin-guide/kernel-parameters.txt
++++ b/Documentation/admin-guide/kernel-parameters.txt
+@@ -3390,6 +3390,12 @@
+ 	ramdisk_size=	[RAM] Sizes of RAM disks in kilobytes
+ 			See Documentation/blockdev/ramdisk.txt.
+ 
++	random.trust_cpu={on,off}
++			[KNL] Enable or disable trusting the use of the
++			CPU's random number generator (if available) to
++			fully seed the kernel's CRNG. Default is controlled
++			by CONFIG_RANDOM_TRUST_CPU.
++
+ 	ras=option[,option,...]	[KNL] RAS-specific options
+ 
+ 		cec_disable	[X86]
+diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
+index ce277ee0a28a..40728491f37b 100644
+--- a/drivers/char/Kconfig
++++ b/drivers/char/Kconfig
+@@ -566,5 +566,5 @@ config RANDOM_TRUST_CPU
+ 	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.
+-
++	random number generation facilities. This can also be configured
++	at boot with "random.trust_cpu=on/off".
+diff --git a/drivers/char/random.c b/drivers/char/random.c
+index bf5f99fc36f1..c75b6cdf0053 100644
+--- a/drivers/char/random.c
++++ b/drivers/char/random.c
+@@ -779,6 +779,13 @@ static struct crng_state **crng_node_pool __read_mostly;
+ 
+ static void invalidate_batched_entropy(void);
+ 
++static bool trust_cpu __ro_after_init = IS_ENABLED(CONFIG_RANDOM_TRUST_CPU);
++static int __init parse_trust_cpu(char *arg)
++{
++	return kstrtobool(arg, &trust_cpu);
++}
++early_param("random.trust_cpu", parse_trust_cpu);
++
+ static void crng_initialize(struct crng_state *crng)
+ {
+ 	int		i;
+@@ -799,12 +806,10 @@ static void crng_initialize(struct crng_state *crng)
+ 		}
+ 		crng->state[i] ^= rv;
+ 	}
+-#ifdef CONFIG_RANDOM_TRUST_CPU
+-	if (arch_init) {
++	if (trust_cpu && arch_init) {
+ 		crng_init = 2;
+ 		pr_notice("random: crng done (trusting CPU's manufacturer)\n");
+ 	}
+-#endif
+ 	crng->init_time = jiffies - CRNG_RESEED_INTERVAL - 1;
+ }
+ 
+-- 
+2.17.1
+

configs/fedora/generic/CONFIG_RANDOM_TRUST_CPU

@@ -0,0 +1 @@
+CONFIG_RANDOM_TRUST_CPU=y

kernel-aarch64-debug.config

@@ -4659,6 +4659,7 @@ CONFIG_RAID_ATTRS=m
 # CONFIG_RANDOM32_SELFTEST is not set
 CONFIG_RANDOMIZE_BASE=y
 CONFIG_RANDOMIZE_MODULE_REGION_FULL=y
+CONFIG_RANDOM_TRUST_CPU=y
 CONFIG_RAS_CEC=y
 CONFIG_RASPBERRYPI_FIRMWARE=y
 CONFIG_RASPBERRYPI_POWER=y

kernel-aarch64.config

@@ -4636,6 +4636,7 @@ CONFIG_RAID_ATTRS=m
 # CONFIG_RANDOM32_SELFTEST is not set
 CONFIG_RANDOMIZE_BASE=y
 CONFIG_RANDOMIZE_MODULE_REGION_FULL=y
+CONFIG_RANDOM_TRUST_CPU=y
 CONFIG_RAS_CEC=y
 CONFIG_RASPBERRYPI_FIRMWARE=y
 CONFIG_RASPBERRYPI_POWER=y

kernel-armv7hl-debug.config

@@ -4939,6 +4939,7 @@ CONFIG_RADIO_WL1273=m
 CONFIG_RADIO_ZOLTRIX=m
 CONFIG_RAID_ATTRS=m
 # CONFIG_RANDOM32_SELFTEST is not set
+CONFIG_RANDOM_TRUST_CPU=y
 CONFIG_RAS_CEC=y
 CONFIG_RASPBERRYPI_FIRMWARE=y
 CONFIG_RASPBERRYPI_POWER=y

kernel-armv7hl-lpae-debug.config

@@ -4663,6 +4663,7 @@ CONFIG_RADIO_WL1273=m
 CONFIG_RADIO_ZOLTRIX=m
 CONFIG_RAID_ATTRS=m
 # CONFIG_RANDOM32_SELFTEST is not set
+CONFIG_RANDOM_TRUST_CPU=y
 CONFIG_RAS_CEC=y
 CONFIG_RASPBERRYPI_FIRMWARE=y
 CONFIG_RASPBERRYPI_POWER=y

kernel-armv7hl-lpae.config

@@ -4640,6 +4640,7 @@ CONFIG_RADIO_WL1273=m
 CONFIG_RADIO_ZOLTRIX=m
 CONFIG_RAID_ATTRS=m
 # CONFIG_RANDOM32_SELFTEST is not set
+CONFIG_RANDOM_TRUST_CPU=y
 CONFIG_RAS_CEC=y
 CONFIG_RASPBERRYPI_FIRMWARE=y
 CONFIG_RASPBERRYPI_POWER=y

kernel-armv7hl.config

@@ -4916,6 +4916,7 @@ CONFIG_RADIO_WL1273=m
 CONFIG_RADIO_ZOLTRIX=m
 CONFIG_RAID_ATTRS=m
 # CONFIG_RANDOM32_SELFTEST is not set
+CONFIG_RANDOM_TRUST_CPU=y
 CONFIG_RAS_CEC=y
 CONFIG_RASPBERRYPI_FIRMWARE=y
 CONFIG_RASPBERRYPI_POWER=y

kernel-i686-PAE.config

@@ -4391,6 +4391,7 @@ CONFIG_RADIO_ZOLTRIX=m
 CONFIG_RAID_ATTRS=m
 # CONFIG_RANDOM32_SELFTEST is not set
 CONFIG_RANDOMIZE_BASE=y
+CONFIG_RANDOM_TRUST_CPU=y
 # CONFIG_RAPIDIO is not set
 CONFIG_RAS_CEC=y
 # CONFIG_RAVE_SP_CORE is not set

kernel-i686-PAEdebug.config

@@ -4415,6 +4415,7 @@ CONFIG_RADIO_ZOLTRIX=m
 CONFIG_RAID_ATTRS=m
 # CONFIG_RANDOM32_SELFTEST is not set
 CONFIG_RANDOMIZE_BASE=y
+CONFIG_RANDOM_TRUST_CPU=y
 # CONFIG_RAPIDIO is not set
 CONFIG_RAS_CEC=y
 # CONFIG_RAVE_SP_CORE is not set

kernel-i686-debug.config

@@ -4415,6 +4415,7 @@ CONFIG_RADIO_ZOLTRIX=m
 CONFIG_RAID_ATTRS=m
 # CONFIG_RANDOM32_SELFTEST is not set
 CONFIG_RANDOMIZE_BASE=y
+CONFIG_RANDOM_TRUST_CPU=y
 # CONFIG_RAPIDIO is not set
 CONFIG_RAS_CEC=y
 # CONFIG_RAVE_SP_CORE is not set

kernel-i686.config

@@ -4391,6 +4391,7 @@ CONFIG_RADIO_ZOLTRIX=m
 CONFIG_RAID_ATTRS=m
 # CONFIG_RANDOM32_SELFTEST is not set
 CONFIG_RANDOMIZE_BASE=y
+CONFIG_RANDOM_TRUST_CPU=y
 # CONFIG_RAPIDIO is not set
 CONFIG_RAS_CEC=y
 # CONFIG_RAVE_SP_CORE is not set

kernel-ppc64-debug.config

@@ -4221,6 +4221,7 @@ CONFIG_RADIO_WL1273=m
 CONFIG_RADIO_ZOLTRIX=m
 CONFIG_RAID_ATTRS=m
 # CONFIG_RANDOM32_SELFTEST is not set
+CONFIG_RANDOM_TRUST_CPU=y
 # CONFIG_RAPIDIO is not set
 CONFIG_RAS_CEC=y
 # CONFIG_RAVE_SP_CORE is not set

kernel-ppc64.config

@@ -4195,6 +4195,7 @@ CONFIG_RADIO_WL1273=m
 CONFIG_RADIO_ZOLTRIX=m
 CONFIG_RAID_ATTRS=m
 # CONFIG_RANDOM32_SELFTEST is not set
+CONFIG_RANDOM_TRUST_CPU=y
 # CONFIG_RAPIDIO is not set
 CONFIG_RAS_CEC=y
 # CONFIG_RAVE_SP_CORE is not set

kernel-ppc64le-debug.config

@@ -4159,6 +4159,7 @@ CONFIG_RADIO_WL1273=m
 CONFIG_RADIO_ZOLTRIX=m
 CONFIG_RAID_ATTRS=m
 # CONFIG_RANDOM32_SELFTEST is not set
+CONFIG_RANDOM_TRUST_CPU=y
 # CONFIG_RAPIDIO is not set
 CONFIG_RAS_CEC=y
 # CONFIG_RAVE_SP_CORE is not set

kernel-ppc64le.config

@@ -4133,6 +4133,7 @@ CONFIG_RADIO_WL1273=m
 CONFIG_RADIO_ZOLTRIX=m
 CONFIG_RAID_ATTRS=m
 # CONFIG_RANDOM32_SELFTEST is not set
+CONFIG_RANDOM_TRUST_CPU=y
 # CONFIG_RAPIDIO is not set
 CONFIG_RAS_CEC=y
 # CONFIG_RAVE_SP_CORE is not set

kernel-s390x-debug.config

@@ -4049,6 +4049,7 @@ CONFIG_RADIO_WL1273=m
 CONFIG_RADIO_ZOLTRIX=m
 CONFIG_RAID_ATTRS=m
 # CONFIG_RANDOM32_SELFTEST is not set
+CONFIG_RANDOM_TRUST_CPU=y
 CONFIG_RAS_CEC=y
 # CONFIG_RAVE_SP_CORE is not set
 CONFIG_RAW_DRIVER=y

kernel-s390x.config

@@ -4023,6 +4023,7 @@ CONFIG_RADIO_WL1273=m
 CONFIG_RADIO_ZOLTRIX=m
 CONFIG_RAID_ATTRS=m
 # CONFIG_RANDOM32_SELFTEST is not set
+CONFIG_RANDOM_TRUST_CPU=y
 CONFIG_RAS_CEC=y
 # CONFIG_RAVE_SP_CORE is not set
 CONFIG_RAW_DRIVER=y

kernel-x86_64-debug.config

@@ -4459,6 +4459,7 @@ CONFIG_RAID_ATTRS=m
 # CONFIG_RANDOM32_SELFTEST is not set
 CONFIG_RANDOMIZE_BASE=y
 CONFIG_RANDOMIZE_MEMORY=y
+CONFIG_RANDOM_TRUST_CPU=y
 # CONFIG_RAPIDIO is not set
 CONFIG_RAS_CEC=y
 # CONFIG_RAVE_SP_CORE is not set

kernel-x86_64.config

@@ -4435,6 +4435,7 @@ CONFIG_RAID_ATTRS=m
 # CONFIG_RANDOM32_SELFTEST is not set
 CONFIG_RANDOMIZE_BASE=y
 CONFIG_RANDOMIZE_MEMORY=y
+CONFIG_RANDOM_TRUST_CPU=y
 # CONFIG_RAPIDIO is not set
 CONFIG_RAS_CEC=y
 # CONFIG_RAVE_SP_CORE is not set

kernel.spec

@@ -627,6 +627,10 @@ Patch504: xsa270.patch
 # rhbz 1627963 1628715
 Patch505: HID-fixes.patch
 
+# rhbz 1572944
+Patch506: 0001-random-add-a-config-option-to-trust-the-CPU-s-hwrng.patch
+Patch507: 0001-random-make-CPU-trust-a-boot-parameter.patch
+
 # END OF PATCH DEFINITIONS
 
 %endif
@@ -1876,6 +1880,9 @@ fi
 #
 #
 %changelog
+* Thu Sep 13 2018 Laura Abbott <labbott@redhat.com>
+- Use the CPU RNG for entropy (rhbz 1572944)
+
 * Thu Sep 13 2018 Laura Abbott <labbott@redhat.com>
 - HID fixes (rhbz 1627963 1628715)