This is a note to let you know that I've just added the patch titled
random: fix soft lockup when trying to read from an uninitialized blocking pool
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-fix-soft-lockup-when-trying-to-read-from-an-uninitialized-blocking-pool.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: Theodore Ts'o <tytso@xxxxxxx>
Date: Wed, 22 May 2019 12:02:16 -0400
Subject: random: fix soft lockup when trying to read from an uninitialized blocking pool
From: Theodore Ts'o <tytso@xxxxxxx>
commit 58be0106c5306b939b07b4b8bf00669a20593f4b upstream.
Fixes: eb9d1bf079bb: "random: only read from /dev/random after its pool has received 128 bits"
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/char/random.c | 16 +++++++++++++---
1 file changed, 13 insertions(+), 3 deletions(-)
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -773,8 +773,11 @@ retry:
if (cmpxchg(&r->entropy_count, orig, entropy_count) != orig)
goto retry;
- if (has_initialized)
+ if (has_initialized) {
r->initialized = 1;
+ wake_up_interruptible(&random_read_wait);
+ kill_fasync(&fasync, SIGIO, POLL_IN);
+ }
trace_credit_entropy_bits(r->name, nbits,
entropy_count >> ENTROPY_SHIFT, _RET_IP_);
@@ -790,6 +793,13 @@ retry:
entropy_bits = r->entropy_count >> ENTROPY_SHIFT;
}
+ /* initialize the blocking pool if necessary */
+ if (entropy_bits >= random_read_wakeup_bits &&
+ !other->initialized) {
+ schedule_work(&other->push_work);
+ return;
+ }
+
/* should we wake readers? */
if (entropy_bits >= random_read_wakeup_bits &&
wq_has_sleeper(&random_read_wait)) {
@@ -1939,8 +1949,8 @@ _random_read(int nonblock, char __user *
return -EAGAIN;
wait_event_interruptible(random_read_wait,
- ENTROPY_BITS(&input_pool) >=
- random_read_wakeup_bits);
+ blocking_pool.initialized &&
+ (ENTROPY_BITS(&input_pool) >= random_read_wakeup_bits));
if (signal_pending(current))
return -ERESTARTSYS;
}
Patches currently in stable-queue which might be from tytso@xxxxxxx are
queue-4.14/random-remove-kernel.random.read_wakeup_threshold.patch
queue-4.14/random-introduce-drain_entropy-helper-to-declutter-crng_reseed.patch
queue-4.14/random-group-userspace-read-write-functions.patch
queue-4.14/drivers-char-random.c-make-primary_crng-static.patch
queue-4.14/crypto-chacha20-fix-chacha20_block-keystream-alignment-again.patch
queue-4.14/random-always-fill-buffer-in-get_random_bytes_wait.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-initialize-chacha20-constants-with-correct-endianness.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/random-tie-batched-entropy-generation-to-base_crng-generation.patch
queue-4.14/random-use-linear-min-entropy-accumulation-crediting.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-add-arch_get_random_-long_early.patch
queue-4.14/random-inline-leaves-of-rand_initialize.patch
queue-4.14/random-replace-custom-notifier-chain-with-standard-one.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-warnings-for-config_numa-builds.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-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/timekeeping-add-raw-clock-fallback-for-random_get_entropy.patch
queue-4.14/random-delete-code-to-pull-data-into-pools.patch
queue-4.14/random-simplify-entropy-debiting.patch
queue-4.14/random-use-siphash-as-interrupt-entropy-accumulator.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-only-wake-up-writers-after-zap-if-threshold-was-passed.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/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/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-remove-dead-code-left-over-from-blocking-pool.patch
queue-4.14/drivers-char-random.c-constify-poolinfo_table.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/random-convert-to-entropy_bits-for-better-code-readability.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-tracepoints.patch
queue-4.14/random-only-read-from-dev-random-after-its-pool-has-received-128-bits.patch
queue-4.14/random-try-to-actively-add-entropy-rather-than-passively-wait-for-it.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/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/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-use-static-branch-for-crng_ready.patch
queue-4.14/drivers-char-random.c-remove-unused-dont_count_entropy.patch
queue-4.14/random-group-entropy-collection-functions.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/random-remove-some-dead-code-of-poolinfo.patch
queue-4.14/random-do-not-use-batches-when-crng_ready.patch
queue-4.14/random-do-not-pretend-to-handle-premature-next-security-model.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-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-return-nbytes-filled-from-hw-rng.patch
queue-4.14/char-random-silence-a-lockdep-splat-with-printk.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/random-remove-ratelimiting-for-in-kernel-unseeded-randomness.patch
queue-4.14/random-use-hash-function-for-crng_slow_load.patch
queue-4.14/random-remove-preempt-disabled-region.patch
