From: Eric Biggers <ebiggers@xxxxxxxxxx>
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@xxxxxxxxxxxxxxx
Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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:
