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>

1 files changed, 29 insertions, 0 deletions

diff --git a/crypto/algapi.c b/crypto/algapi.c
index 54dd4e3..9d4a9fe 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)
 {