crypto: Unlink and free instances when deleted

We leak the crypto instance when we unregister an instance with
crypto_del_alg(). Therefore we introduce crypto_unregister_instance()
to unlink the crypto instance from the template's instances list and
to free the recources of the instance properly.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

2 files changed, 30 insertions, 1 deletions

diff --git a/crypto/algapi.c b/crypto/algapi.c
index 54dd4e33b5d6..9d4a9fe913f8 100644
--- a/crypto/algapi.c
+++ b/crypto/algapi.c
@@ -518,6 +518,35 @@ err:
 }
 EXPORT_SYMBOL_GPL(crypto_register_instance);
 
+int crypto_unregister_instance(struct crypto_alg *alg)
+{
+        int err;
+        struct crypto_instance *inst = (void *)alg;
+        struct crypto_template *tmpl = inst->tmpl;
+        LIST_HEAD(users);
+
+        if (!(alg->cra_flags & CRYPTO_ALG_INSTANCE))
+                return -EINVAL;
+
+        BUG_ON(atomic_read(&alg->cra_refcnt) != 1);
+
+        down_write(&crypto_alg_sem);
+
+        hlist_del_init(&inst->list);
+        err = crypto_remove_alg(alg, &users);
+
+        up_write(&crypto_alg_sem);
+
+        if (err)
+                return err;
+
+        tmpl->free(inst);
+        crypto_remove_final(&users);
+
+        return 0;
+}
+EXPORT_SYMBOL_GPL(crypto_unregister_instance);
+
 int crypto_init_spawn(struct crypto_spawn *spawn, struct crypto_alg *alg,
                       struct crypto_instance *inst, u32 mask)
 {
diff --git a/crypto/crypto_user.c b/crypto/crypto_user.c
index 2abca780312d..edeebe1a84bb 100644
--- a/crypto/crypto_user.c
+++ b/crypto/crypto_user.c
@@ -301,7 +301,7 @@ static int crypto_del_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
         if (atomic_read(&alg->cra_refcnt) != 1)
                 return -EBUSY;
 
-        return crypto_unregister_alg(alg);
+        return crypto_unregister_instance(alg);
 }
 
 static int crypto_add_alg(struct sk_buff *skb, struct nlmsghdr *nlh,