Commit 30d0f6a9 authored by Eric Biggers's avatar Eric Biggers Committed by Herbert Xu
Browse files

crypto: rng - fix crypto_rng_reset() refcounting when !CRYPTO_STATS 



crypto_stats_get() is a no-op when the kernel is compiled without
CONFIG_CRYPTO_STATS, so pairing it with crypto_alg_put() unconditionally
(as crypto_rng_reset() does) is wrong.

Fix this by moving the call to crypto_stats_get() to just before the
actual algorithm operation which might need it.  This makes it always
paired with crypto_stats_rng_seed().

Fixes: eed74b3e ("crypto: rng - Fix a refcounting bug in crypto_rng_reset()")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 10cb823b

crypto/rng.c

+3 −7
Original line number Diff line number Diff line
@@ -34,22 +34,18 @@ int crypto_rng_reset(struct crypto_rng *tfm, const u8 *seed, unsigned int slen) 
	u8 *buf = NULL;

	int err;



	crypto_stats_get(alg);

	if (!seed && slen) {

		buf = kmalloc(slen, GFP_KERNEL);

		if (!buf) {

			crypto_alg_put(alg);

		if (!buf)

			return -ENOMEM;

		}



		err = get_random_bytes_wait(buf, slen);

		if (err) {

			crypto_alg_put(alg);

		if (err)

			goto out;

		}

		seed = buf;

	}



	crypto_stats_get(alg);

	err = crypto_rng_alg(tfm)->seed(tfm, seed, slen);

	crypto_stats_rng_seed(alg, err);

out: