crypto: af_alg - Decrement struct key.usage in alg_set_by_key_serial()

commit 6b4b53ca0b7300ba2af98a49dbce22054bf034fe upstream.

Calls to lookup_user_key() require a corresponding key_put() to
decrement the usage counter. Once it reaches zero, we schedule key GC.
Therefore decrement struct key.usage in alg_set_by_key_serial().

Fixes: 7984ceb134bf ("crypto: af_alg - Support symmetric encryption via keyring keys")
Cc: <stable@vger.kernel.org>
Signed-off-by: Frederick Lawler <fred@cloudflare.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/crypto/af_alg.c b/crypto/af_alg.c
index 5f7252a5b7b44af2915913ef9ac35fddb369b3d5..703fb426ff5d159f0df64ab385de95b4f3cf928d 100644 (file)
--- a/crypto/af_alg.c
+++ b/crypto/af_alg.c
@@ -320,18 +320,21 @@ static int alg_setkey_by_key_serial(struct alg_sock *ask, sockptr_t optval,
 
        if (IS_ERR(ret)) {
                up_read(&key->sem);
+               key_put(key);
                return PTR_ERR(ret);
        }
 
        key_data = sock_kmalloc(&ask->sk, key_datalen, GFP_KERNEL);
        if (!key_data) {
                up_read(&key->sem);
+               key_put(key);
                return -ENOMEM;
        }
 
        memcpy(key_data, ret, key_datalen);
 
        up_read(&key->sem);
+       key_put(key);
 
        err = type->setkey(ask->private, key_data, key_datalen);