diff options
| author | Dominik Brodowski <linux@dominikbrodowski.net> | 2022-02-09 19:57:06 +0100 |
|---|---|---|
| committer | Jason A. Donenfeld <Jason@zx2c4.com> | 2022-02-21 21:14:00 +0100 |
| commit | 7191c628fe07b70d3f37de736d173d1b115396ed (patch) | |
| tree | 158902b21e512d00d2f13d58367e8e37a1384e5b | |
| parent | 7b5164fb1279bf0251371848e40bae646b59b3a8 (diff) | |
| download | linux-stable-7191c628fe07b70d3f37de736d173d1b115396ed.tar.gz linux-stable-7191c628fe07b70d3f37de736d173d1b115396ed.zip | |
random: fix locking for crng_init in crng_reseed()
crng_init is protected by primary_crng->lock. Therefore, we need
to hold this lock when increasing crng_init to 2. As we shouldn't
hold this lock for too long, only hold it for those parts which
require protection.
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
| -rw-r--r-- | drivers/char/random.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c index 8ae7d0b30280..1ccd92efa8f4 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -502,6 +502,7 @@ static void crng_reseed(void) int entropy_count; unsigned long next_gen; u8 key[CHACHA_KEY_SIZE]; + bool finalize_init = false; /* * First we make sure we have POOL_MIN_BITS of entropy in the pool, @@ -529,12 +530,14 @@ static void crng_reseed(void) ++next_gen; WRITE_ONCE(base_crng.generation, next_gen); WRITE_ONCE(base_crng.birth, jiffies); - spin_unlock_irqrestore(&base_crng.lock, flags); - memzero_explicit(key, sizeof(key)); - if (crng_init < 2) { invalidate_batched_entropy(); crng_init = 2; + finalize_init = true; + } + spin_unlock_irqrestore(&base_crng.lock, flags); + memzero_explicit(key, sizeof(key)); + if (finalize_init) { process_random_ready_list(); wake_up_interruptible(&crng_init_wait); kill_fasync(&fasync, SIGIO, POLL_IN); |