Commit 0bb29a84 authored by Theodore Ts'o's avatar Theodore Ts'o
Browse files

random: crng_reseed() should lock the crng instance that it is modifying 



Reported-by: default avatarJann Horn <jannh@google.com>
Fixes: 1e7f583a ("random: make /dev/urandom scalable for silly...")
Cc: stable@kernel.org # 4.8+
Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
Reviewed-by: default avatarJann Horn <jannh@google.com>
parent 8ef35c86

drivers/char/random.c

+2 −2
Original line number Diff line number Diff line
@@ -906,7 +906,7 @@ static void crng_reseed(struct crng_state *crng, struct entropy_store *r) 
		_crng_backtrack_protect(&primary_crng, buf.block,

					CHACHA20_KEY_SIZE);

	}

	spin_lock_irqsave(&primary_crng.lock, flags);

	spin_lock_irqsave(&crng->lock, flags);

	for (i = 0; i < 8; i++) {

		unsigned long	rv;

		if (!arch_get_random_seed_long(&rv) &&
@@ -916,7 +916,7 @@ static void crng_reseed(struct crng_state *crng, struct entropy_store *r) 
	}

	memzero_explicit(&buf, sizeof(buf));

	crng->init_time = jiffies;

	spin_unlock_irqrestore(&primary_crng.lock, flags);

	spin_unlock_irqrestore(&crng->lock, flags);

	if (crng == &primary_crng && crng_init < 2) {

		invalidate_batched_entropy();

		numa_crng_init();