This is a note to let you know that I've just added the patch titled
random: group userspace read/write functions
to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
random-group-userspace-read-write-functions.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Thu Jun 16 07:08:33 PM CEST 2022
From: "Jason A. Donenfeld" <Jason@xxxxxxxxx>
Date: Fri, 11 Feb 2022 12:53:34 +0100
Subject: random: group userspace read/write functions
From: "Jason A. Donenfeld" <Jason@xxxxxxxxx>
commit a6adf8e7a605250b911e94793fd077933709ff9e upstream.
This pulls all of the userspace read/write-focused functions into the
fifth labeled section.
No functional changes.
Cc: Theodore Ts'o <tytso@xxxxxxx>
Reviewed-by: Eric Biggers <ebiggers@xxxxxxxxxx>
Reviewed-by: Dominik Brodowski <linux@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/char/random.c | 125 ++++++++++++++++++++++++++++++--------------------
1 file changed, 77 insertions(+), 48 deletions(-)
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -1472,30 +1472,61 @@ static void try_to_generate_entropy(void
mix_pool_bytes(&stack.now, sizeof(stack.now));
}
-static ssize_t urandom_read(struct file *file, char __user *buf, size_t nbytes,
- loff_t *ppos)
+
+/**********************************************************************
+ *
+ * Userspace reader/writer interfaces.
+ *
+ * getrandom(2) is the primary modern interface into the RNG and should
+ * be used in preference to anything else.
+ *
+ * Reading from /dev/random has the same functionality as calling
+ * getrandom(2) with flags=0. In earlier versions, however, it had
+ * vastly different semantics and should therefore be avoided, to
+ * prevent backwards compatibility issues.
+ *
+ * Reading from /dev/urandom has the same functionality as calling
+ * getrandom(2) with flags=GRND_INSECURE. Because it does not block
+ * waiting for the RNG to be ready, it should not be used.
+ *
+ * Writing to either /dev/random or /dev/urandom adds entropy to
+ * the input pool but does not credit it.
+ *
+ * Polling on /dev/random indicates when the RNG is initialized, on
+ * the read side, and when it wants new entropy, on the write side.
+ *
+ * Both /dev/random and /dev/urandom have the same set of ioctls for
+ * adding entropy, getting the entropy count, zeroing the count, and
+ * reseeding the crng.
+ *
+ **********************************************************************/
+
+SYSCALL_DEFINE3(getrandom, char __user *, buf, size_t, count, unsigned int,
+ flags)
{
- static int maxwarn = 10;
+ if (flags & ~(GRND_NONBLOCK | GRND_RANDOM | GRND_INSECURE))
+ return -EINVAL;
- if (!crng_ready() && maxwarn > 0) {
- maxwarn--;
- if (__ratelimit(&urandom_warning))
- pr_notice("%s: uninitialized urandom read (%zd bytes read)\n",
- current->comm, nbytes);
- }
+ /*
+ * Requesting insecure and blocking randomness at the same time makes
+ * no sense.
+ */
+ if ((flags & (GRND_INSECURE | GRND_RANDOM)) == (GRND_INSECURE | GRND_RANDOM))
+ return -EINVAL;
- return get_random_bytes_user(buf, nbytes);
-}
+ if (count > INT_MAX)
+ count = INT_MAX;
-static ssize_t random_read(struct file *file, char __user *buf, size_t nbytes,
- loff_t *ppos)
-{
- int ret;
+ if (!(flags & GRND_INSECURE) && !crng_ready()) {
+ int ret;
- ret = wait_for_random_bytes();
- if (ret != 0)
- return ret;
- return get_random_bytes_user(buf, nbytes);
+ if (flags & GRND_NONBLOCK)
+ return -EAGAIN;
+ ret = wait_for_random_bytes();
+ if (unlikely(ret))
+ return ret;
+ }
+ return get_random_bytes_user(buf, count);
}
static unsigned int random_poll(struct file *file, poll_table *wait)
@@ -1547,6 +1578,32 @@ static ssize_t random_write(struct file
return (ssize_t)count;
}
+static ssize_t urandom_read(struct file *file, char __user *buf, size_t nbytes,
+ loff_t *ppos)
+{
+ static int maxwarn = 10;
+
+ if (!crng_ready() && maxwarn > 0) {
+ maxwarn--;
+ if (__ratelimit(&urandom_warning))
+ pr_notice("%s: uninitialized urandom read (%zd bytes read)\n",
+ current->comm, nbytes);
+ }
+
+ return get_random_bytes_user(buf, nbytes);
+}
+
+static ssize_t random_read(struct file *file, char __user *buf, size_t nbytes,
+ loff_t *ppos)
+{
+ int ret;
+
+ ret = wait_for_random_bytes();
+ if (ret != 0)
+ return ret;
+ return get_random_bytes_user(buf, nbytes);
+}
+
static long random_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
{
int size, ent_count;
@@ -1555,7 +1612,7 @@ static long random_ioctl(struct file *f,
switch (cmd) {
case RNDGETENTCNT:
- /* inherently racy, no point locking */
+ /* Inherently racy, no point locking. */
if (put_user(input_pool.entropy_count, p))
return -EFAULT;
return 0;
@@ -1629,34 +1686,6 @@ const struct file_operations urandom_fop
.llseek = noop_llseek,
};
-SYSCALL_DEFINE3(getrandom, char __user *, buf, size_t, count, unsigned int,
- flags)
-{
- if (flags & ~(GRND_NONBLOCK | GRND_RANDOM | GRND_INSECURE))
- return -EINVAL;
-
- /*
- * Requesting insecure and blocking randomness at the same time makes
- * no sense.
- */
- if ((flags & (GRND_INSECURE | GRND_RANDOM)) == (GRND_INSECURE | GRND_RANDOM))
- return -EINVAL;
-
- if (count > INT_MAX)
- count = INT_MAX;
-
- if (!(flags & GRND_INSECURE) && !crng_ready()) {
- int ret;
-
- if (flags & GRND_NONBLOCK)
- return -EAGAIN;
- ret = wait_for_random_bytes();
- if (unlikely(ret))
- return ret;
- }
- return get_random_bytes_user(buf, count);
-}
-
/********************************************************************
*
* Sysctl interface
Patches currently in stable-queue which might be from Jason@xxxxxxxxx are
queue-4.14/random-do-not-take-pool-spinlock-at-boot.patch
queue-4.14/random-remove-kernel.random.read_wakeup_threshold.patch
queue-4.14/random-simplify-arithmetic-function-flow-in-account.patch
queue-4.14/random-order-timer-entropy-functions-below-interrupt-functions.patch
queue-4.14/random-introduce-drain_entropy-helper-to-declutter-crng_reseed.patch
queue-4.14/random-fix-locking-in-crng_fast_load.patch
queue-4.14/random-cleanup-uuid-handling.patch
queue-4.14/random-group-userspace-read-write-functions.patch
queue-4.14/random-make-credit_entropy_bits-always-safe.patch
queue-4.14/latent_entropy-avoid-build-error-when-plugin-cflags-are-not-set.patch
queue-4.14/revert-hwrng-core-freeze-khwrng-thread-during-suspend.patch
queue-4.14/drivers-char-random.c-make-primary_crng-static.patch
queue-4.14/random-do-not-re-init-if-crng_reseed-completes-before-primary-init.patch
queue-4.14/random-always-fill-buffer-in-get_random_bytes_wait.patch
queue-4.14/random-use-proper-jiffies-comparison-macro.patch
queue-4.14/init-call-time_init-before-rand_initialize.patch
queue-4.14/random-split-primary-secondary-crng-init-paths.patch
queue-4.14/random-pull-add_hwgenerator_randomness-declaration-into-random.h.patch
queue-4.14/random-unify-early-init-crng-load-accounting.patch
queue-4.14/drivers-char-random.c-remove-unused-stuct-poolinfo-poolbits.patch
queue-4.14/random-use-blake2s-instead-of-sha1-in-extraction.patch
queue-4.14/random-make-cpu-trust-a-boot-parameter.patch
queue-4.14/random-convert-to-using-fops-write_iter.patch
queue-4.14/random-initialize-chacha20-constants-with-correct-endianness.patch
queue-4.14/random-remove-incomplete-last_data-logic.patch
queue-4.14/random-group-entropy-extraction-functions.patch
queue-4.14/random-optimize-add_interrupt_randomness.patch
queue-4.14/random-add-proper-spdx-header.patch
queue-4.14/linux-random.h-remove-arch_has_random-arch_has_random_seed.patch
queue-4.14/random-rewrite-header-introductory-comment.patch
queue-4.14/random-make-dev-random-be-almost-like-dev-urandom.patch
queue-4.14/random-remove-ifdef-d-out-interrupt-bench.patch
queue-4.14/um-use-fallback-for-random_get_entropy-instead-of-zero.patch
queue-4.14/lib-crypto-sha1-re-roll-loops-to-reduce-code-size.patch
queue-4.14/random-tie-batched-entropy-generation-to-base_crng-generation.patch
queue-4.14/sparc-use-fallback-for-random_get_entropy-instead-of-zero.patch
queue-4.14/random-use-linear-min-entropy-accumulation-crediting.patch
queue-4.14/random-remove-batched-entropy-locking.patch
queue-4.14/xtensa-use-fallback-for-random_get_entropy-instead-of-zero.patch
queue-4.14/powerpc-remove-arch_has_random-arch_has_random_seed.patch
queue-4.14/fdt-add-support-for-rng-seed.patch
queue-4.14/random-continually-use-hwgenerator-randomness.patch
queue-4.14/random-access-input_pool_data-directly-rather-than-through-pointer.patch
queue-4.14/random-add-arch_get_random_-long_early.patch
queue-4.14/random-inline-leaves-of-rand_initialize.patch
queue-4.14/random-cleanup-poolinfo-abstraction.patch
queue-4.14/random-wire-up-fops-splice_-read-write-_iter.patch
queue-4.14/random-handle-latent-entropy-and-command-line-from-random_init.patch
queue-4.14/random-remove-use_input_pool-parameter-from-crng_reseed.patch
queue-4.14/random-credit-architectural-init-the-exact-amount.patch
queue-4.14/ia64-define-get_cycles-macro-for-arch-override.patch
queue-4.14/random-replace-custom-notifier-chain-with-standard-one.patch
queue-4.14/random-support-freezable-kthreads-in-add_hwgenerator_randomness.patch
queue-4.14/random-document-get_random_int-family.patch
queue-4.14/random-remove-the-blocking-pool.patch
queue-4.14/random-avoid-initializing-twice-in-credit-race.patch
queue-4.14/random-avoid-warnings-for-config_numa-builds.patch
queue-4.14/crypto-drbg-add-fips-140-2-ctrng-for-noise-source.patch
queue-4.14/random-mark-bootloader-randomness-code-as-__init.patch
queue-4.14/random-zero-buffer-after-reading-entropy-from-userspace.patch
queue-4.14/random-remove-whitespace-and-reorder-includes.patch
queue-4.14/random-ignore-grnd_random-in-getentropy-2.patch
queue-4.14/random-clear-fast-pool-crng-and-batches-in-cpuhp-bring-up.patch
queue-4.14/random-document-add_hwgenerator_randomness-with-other-input-functions.patch
queue-4.14/random-fix-typo-in-add_timer_randomness.patch
queue-4.14/random-do-crng-pre-init-loading-in-worker-rather-than-irq.patch
queue-4.14/powerpc-use-bool-in-archrandom.h.patch
queue-4.14/random-do-not-split-fast-init-input-in-add_hwgenerator_randomness.patch
queue-4.14/timekeeping-add-raw-clock-fallback-for-random_get_entropy.patch
queue-4.14/random-early-initialization-of-chacha-constants.patch
queue-4.14/crypto-drbg-prepare-for-more-fine-grained-tracking-of-seeding-state.patch
queue-4.14/random-delete-code-to-pull-data-into-pools.patch
queue-4.14/crypto-drbg-always-try-to-free-jitter-rng-instance.patch
queue-4.14/random-simplify-entropy-debiting.patch
queue-4.14/random-don-t-reset-crng_init_cnt-on-urandom_read.patch
queue-4.14/random-skip-fast_init-if-hwrng-provides-large-chunk-of-entropy.patch
queue-4.14/random-use-siphash-as-interrupt-entropy-accumulator.patch
queue-4.14/random-avoid-checking-crng_ready-twice-in-random_init.patch
queue-4.14/random-fix-soft-lockup-when-trying-to-read-from-an-uninitialized-blocking-pool.patch
queue-4.14/random-group-sysctl-functions.patch
queue-4.14/random-don-t-let-644-read-only-sysctls-be-written-to.patch
queue-4.14/random-document-crng_fast_key_erasure-destination-possibility.patch
queue-4.14/random-only-wake-up-writers-after-zap-if-threshold-was-passed.patch
queue-4.14/random-use-wait_event_freezable-in-add_hwgenerator_randomness.patch
queue-4.14/random-check-for-signal-and-try-earlier-when-generating-entropy.patch
queue-4.14/random-check-for-signals-every-page_size-chunk-of-dev-random.patch
queue-4.14/arm-use-fallback-for-random_get_entropy-instead-of-zero.patch
queue-4.14/random-absorb-fast-pool-into-input-pool-after-fast-load.patch
queue-4.14/random-give-sysctl_random_min_urandom_seed-a-more-sensible-value.patch
queue-4.14/crypto-blake2s-generic-c-library-implementation-and-selftest.patch
queue-4.14/random-cleanup-fractional-entropy-shift-constants.patch
queue-4.14/random-use-rdseed-instead-of-rdrand-in-entropy-extraction.patch
queue-4.14/random-move-rand_initialize-earlier.patch
queue-4.14/random-don-t-wake-crng_init_wait-when-crng_init-1.patch
queue-4.14/random-add-a-urandom_read_nowait-for-random-apis-that-don-t-warn.patch
queue-4.14/random-do-not-sign-extend-bytes-for-rotation-when-mixing.patch
queue-4.14/random-move-initialization-functions-out-of-hot-pages.patch
queue-4.14/random-remove-dead-code-left-over-from-blocking-pool.patch
queue-4.14/drivers-char-random.c-constify-poolinfo_table.patch
queue-4.14/crypto-drbg-track-whether-drbg-was-seeded-with-rng_is_initialized.patch
queue-4.14/random-use-computational-hash-for-entropy-extraction.patch
queue-4.14/random-add-and-use-pr_fmt.patch
queue-4.14/random-round-robin-registers-as-ulong-not-u32.patch
queue-4.14/random-always-wake-up-entropy-writers-after-extraction.patch
queue-4.14/s390-remove-arch_has_random-arch_has_random_seed.patch
queue-4.14/random-do-not-xor-rdrand-when-writing-into-dev-random.patch
queue-4.14/crypto-drbg-make-reseeding-from-get_random_bytes-synchronous.patch
queue-4.14/random-convert-to-entropy_bits-for-better-code-readability.patch
queue-4.14/char-random-add-a-newline-at-the-end-of-the-file.patch
queue-4.14/random-move-randomize_page-into-mm-where-it-belongs.patch
queue-4.14/random-only-call-crng_finalize_init-for-primary_crng.patch
queue-4.14/random-cleanup-integer-types.patch
queue-4.14/random-re-add-removed-comment-about-get_random_-u32-u64-reseeding.patch
queue-4.14/random-unify-cycles_t-and-jiffies-usage-and-types.patch
queue-4.14/random-insist-on-random_get_entropy-existing-in-order-to-simplify.patch
queue-4.14/random-group-initialization-wait-functions.patch
queue-4.14/linux-random.h-mark-config_arch_random-functions-__must_check.patch
queue-4.14/random-remove-unused-extract_entropy-reserved-argument.patch
queue-4.14/random-check-for-signal_pending-outside-of-need_resched-check.patch
queue-4.14/random-access-primary_pool-directly-rather-than-through-pointer.patch
queue-4.14/random-fix-sysctl-documentation-nits.patch
queue-4.14/random-remove-unused-tracepoints.patch
queue-4.14/random-only-read-from-dev-random-after-its-pool-has-received-128-bits.patch
queue-4.14/nios2-use-fallback-for-random_get_entropy-instead-of-zero.patch
queue-4.14/random-treat-bootloader-trust-toggle-the-same-way-as-cpu-trust-toggle.patch
queue-4.14/random-make-consistent-usage-of-crng_ready.patch
queue-4.14/lib-crypto-blake2s-move-hmac-construction-into-wireguard.patch
queue-4.14/parisc-define-get_cycles-macro-for-arch-override.patch
queue-4.14/x86-tsc-use-fallback-for-random_get_entropy-instead-of-zero.patch
queue-4.14/crypto-chacha20-fix-keystream-alignment-for-chacha20_block.patch
queue-4.14/random-add-grnd_insecure-to-return-best-effort-non-cryptographic-bytes.patch
queue-4.14/random-fix-whitespace-pre-random-bytes-work.patch
queue-4.14/crypto-drbg-move-dynamic-reseed_threshold-adjustments-to-__drbg_seed.patch
queue-4.14/random-check-for-signals-after-page-of-pool-writes.patch
queue-4.14/random-make-random_get_entropy-return-an-unsigned-long.patch
queue-4.14/random-check-for-crng_init-0-in-add_device_randomness.patch
queue-4.14/random-add-a-config-option-to-trust-the-cpu-s-hwrng.patch
queue-4.14/random-remove-unnecessary-unlikely.patch
queue-4.14/random-defer-fast-pool-mixing-to-worker.patch
queue-4.14/random-harmonize-crng-init-done-messages.patch
queue-4.14/crypto-blake2s-include-linux-bug.h-instead-of-asm-bug.h.patch
queue-4.14/random-use-static-branch-for-crng_ready.patch
queue-4.14/random-rather-than-entropy_store-abstraction-use-global.patch
queue-4.14/drivers-char-random.c-remove-unused-dont_count_entropy.patch
queue-4.14/random-remove-extern-from-functions-in-header.patch
queue-4.14/siphash-use-one-source-of-truth-for-siphash-permutations.patch
queue-4.14/random-group-entropy-collection-functions.patch
queue-4.14/random-de-duplicate-input_pool-constants.patch
queue-4.14/random-mix-build-time-latent-entropy-into-pool-at-init.patch
queue-4.14/random-remove-useless-header-comment.patch
queue-4.14/linux-random.h-use-false-with-bool.patch
queue-4.14/maintainers-co-maintain-random.c.patch
queue-4.14/random-remove-outdated-int_max-6-check-in-urandom_read.patch
queue-4.14/m68k-use-fallback-for-random_get_entropy-instead-of-zero.patch
queue-4.14/alpha-define-get_cycles-macro-for-arch-override.patch
queue-4.14/random-mix-bootloader-randomness-into-pool.patch
queue-4.14/random-remove-some-dead-code-of-poolinfo.patch
queue-4.14/random-do-not-use-batches-when-crng_ready.patch
queue-4.14/crypto-drbg-always-seeded-with-sp800-90b-compliant-noise-source.patch
queue-4.14/s390-define-get_cycles-macro-for-arch-override.patch
queue-4.14/random-do-not-pretend-to-handle-premature-next-security-model.patch
queue-4.14/random-avoid-arch_get_random_seed_long-when-collecting-irq-randomness.patch
queue-4.14/random-use-is_enabled-config_numa-instead-of-ifdefs.patch
queue-4.14/random-make-crng-state-queryable.patch
queue-4.14/random-avoid-superfluous-call-to-rdrand-in-crng-extraction.patch
queue-4.14/random-use-symbolic-constants-for-crng_init-states.patch
queue-4.14/random-reseed-more-often-immediately-after-booting.patch
queue-4.14/random-ensure-early-rdseed-goes-through-mixer-on-init.patch
queue-4.14/random-deobfuscate-irq-u32-u64-contributions.patch
queue-4.14/random-do-not-use-input-pool-from-hard-irqs.patch
queue-4.14/random-help-compiler-out-with-fast_mix-by-using-simpler-arguments.patch
queue-4.14/revert-random-use-static-branch-for-crng_ready.patch
queue-4.14/random-fix-crash-on-multiple-early-calls-to-add_bootloader_randomness.patch
queue-4.14/random-return-nbytes-filled-from-hw-rng.patch
queue-4.14/random-account-for-arch-randomness-in-bits.patch
queue-4.14/crypto-blake2s-adjust-include-guard-naming.patch
queue-4.14/random-do-not-allow-user-to-keep-crng-key-around-on-stack.patch
queue-4.14/x86-remove-arch_has_random-arch_has_random_seed.patch
queue-4.14/crypto-deduplicate-le32_to_cpu_array-and-cpu_to_le32_array.patch
queue-4.14/random-remove-ratelimiting-for-in-kernel-unseeded-randomness.patch
queue-4.14/random-remove-unused-irq_flags-argument-from-add_interrupt_randomness.patch
queue-4.14/random-prepend-remaining-pool-constants-with-pool_.patch
queue-4.14/powerpc-define-get_cycles-macro-for-arch-override.patch
queue-4.14/random-remove-unused-output_pool-constants.patch
queue-4.14/mips-use-fallback-for-random_get_entropy-instead-of-just-c0-random.patch
queue-4.14/random-use-hash-function-for-crng_slow_load.patch
queue-4.14/random-fix-typo-in-comments.patch
queue-4.14/random-remove-preempt-disabled-region.patch
queue-4.14/random-use-proper-return-types-on-get_random_-int-long-_wait.patch
