From: Eric Biggers ebiggers@google.com
commit 30d0f6a956fc74bb2e948398daf3278c6b08c7e9 upstream.
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: eed74b3eba9e ("crypto: rng - Fix a refcounting bug in crypto_rng_reset()") Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers ebiggers@google.com Signed-off-by: Herbert Xu herbert@gondor.apana.org.au Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- crypto/rng.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-)
--- a/crypto/rng.c +++ b/crypto/rng.c @@ -34,22 +34,18 @@ int crypto_rng_reset(struct crypto_rng * 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: