gistfile1.txt

diff --git a/crypto/af_alg.c b/crypto/af_alg.c
index a8e7aa3..b8fb45a 100644
--- a/crypto/af_alg.c
+++ b/crypto/af_alg.c
@@ -125,6 +125,23 @@ int af_alg_release(struct socket *sock)
 }
 EXPORT_SYMBOL_GPL(af_alg_release);
 
+void af_alg_release_parent(struct sock *sk)
+{
+	struct alg_sock *ask = alg_sk(sk);
+	bool last;
+
+	sk = ask->parent;
+	ask = alg_sk(sk);
+
+	lock_sock(sk);
+	last = !--ask->refcnt;
+	release_sock(sk);
+
+	if (last)
+		sock_put(sk);
+}
+EXPORT_SYMBOL_GPL(af_alg_release_parent);
+
 static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 {
 	const u32 forbidden = CRYPTO_ALG_INTERNAL;
@@ -133,6 +150,7 @@ static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 	struct sockaddr_alg *sa = (void *)uaddr;
 	const struct af_alg_type *type;
 	void *private;
+	int err;
 
 	if (sock->state == SS_CONNECTED)
 		return -EINVAL;
@@ -160,16 +178,22 @@ static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 		return PTR_ERR(private);
 	}
 
+	err = -EBUSY;
 	lock_sock(sk);
+	if (ask->refcnt)
+		goto unlock;
 
 	swap(ask->type, type);
 	swap(ask->private, private);
 
+	err = 0;
+
+unlock:
 	release_sock(sk);
 
 	alg_do_release(type, private);
 
-	return 0;
+	return err;
 }
 
 static int alg_setkey(struct sock *sk, char __user *ukey,
@@ -196,6 +220,16 @@ out:
 	return err;
 }
 
+static int alg_setauthsize(struct sock *sk, unsigned int size)
+{
+	int err;
+	struct alg_sock *ask = alg_sk(sk);
+	const struct af_alg_type *type = ask->type;
+
+	err = type->setauthsize(ask->private, size);
+	return err;
+}
+
 static int alg_setsockopt(struct socket *sock, int level, int optname,
 			  char __user *optval, unsigned int optlen)
 {
@@ -210,6 +244,11 @@ static int alg_setsockopt(struct socket *sock, int level, int optname,
 	if (level != SOL_ALG || !type)
 		goto unlock;
 
+	if (ask->refcnt) {
+		err = -EBUSY;
+		goto unlock;
+	}
+
 	switch (optname) {
 	case ALG_SET_KEY:
 		if (sock->state == SS_CONNECTED)
@@ -224,7 +263,7 @@ static int alg_setsockopt(struct socket *sock, int level, int optname,
 			goto unlock;
 		if (!type->setauthsize)
 			goto unlock;
-		err = type->setauthsize(ask->private, optlen);
+		err = alg_setauthsize(sk, optlen);
 	}
 
 unlock:
@@ -257,14 +296,13 @@ int af_alg_accept(struct sock *sk, struct socket *newsock)
 	security_sk_clone(sk, sk2);
 
 	err = type->accept(ask->private, sk2);
-	if (err) {
-		sk_free(sk2);
+	if (err)
 		goto unlock;
-	}
 
 	sk2->sk_family = PF_ALG;
 
-	sock_hold(sk);
+	if (!ask->refcnt++)
+		sock_hold(sk);
 	alg_sk(sk2)->parent = sk;
 	alg_sk(sk2)->type = type;
 
diff --git a/crypto/algif_skcipher.c b/crypto/algif_skcipher.c
index 634b4d1..df483f9 100644
--- a/crypto/algif_skcipher.c
+++ b/crypto/algif_skcipher.c
@@ -31,6 +31,11 @@ struct skcipher_sg_list {
 	struct scatterlist sg[0];
 };
 
+struct skcipher_tfm {
+	struct crypto_skcipher *skcipher;
+	bool has_key;
+};
+
 struct skcipher_ctx {
 	struct list_head tsgl;
 	struct af_alg_sgl rsgl;
@@ -750,17 +755,41 @@ static struct proto_ops algif_skcipher_ops = {
 
 static void *skcipher_bind(const char *name, u32 type, u32 mask)
 {
-	return crypto_alloc_skcipher(name, type, mask);
+	struct skcipher_tfm *tfm;
+	struct crypto_skcipher *skcipher;
+
+	tfm = kzalloc(sizeof(*tfm), GFP_KERNEL);
+	if (!tfm)
+		return ERR_PTR(-ENOMEM);
+
+	skcipher = crypto_alloc_skcipher(name, type, mask);
+	if (IS_ERR(skcipher)) {
+		kfree(tfm);
+		return ERR_CAST(skcipher);
+	}
+
+	tfm->skcipher = skcipher;
+
+	return tfm;
 }
 
 static void skcipher_release(void *private)
 {
-	crypto_free_skcipher(private);
+	struct skcipher_tfm *tfm = private;
+
+	crypto_free_skcipher(tfm->skcipher);
+	kfree(tfm);
 }
 
 static int skcipher_setkey(void *private, const u8 *key, unsigned int keylen)
 {
-	return crypto_skcipher_setkey(private, key, keylen);
+	struct skcipher_tfm *tfm = private;
+	int err;
+
+	err = crypto_skcipher_setkey(tfm->skcipher, key, keylen);
+	tfm->has_key = !err;
+
+	return err;
 }
 
 static void skcipher_wait(struct sock *sk)
@@ -792,20 +821,25 @@ static int skcipher_accept_parent(void *private, struct sock *sk)
 {
 	struct skcipher_ctx *ctx;
 	struct alg_sock *ask = alg_sk(sk);
-	unsigned int len = sizeof(*ctx) + crypto_skcipher_reqsize(private);
+	struct skcipher_tfm *tfm = private;
+	struct crypto_skcipher *skcipher = tfm->skcipher;
+	unsigned int len = sizeof(*ctx) + crypto_skcipher_reqsize(skcipher);
+
+	if (!tfm->has_key)
+		return -ENOKEY;
 
 	ctx = sock_kmalloc(sk, len, GFP_KERNEL);
 	if (!ctx)
 		return -ENOMEM;
 
-	ctx->iv = sock_kmalloc(sk, crypto_skcipher_ivsize(private),
+	ctx->iv = sock_kmalloc(sk, crypto_skcipher_ivsize(skcipher),
 			       GFP_KERNEL);
 	if (!ctx->iv) {
 		sock_kfree_s(sk, ctx, len);
 		return -ENOMEM;
 	}
 
-	memset(ctx->iv, 0, crypto_skcipher_ivsize(private));
+	memset(ctx->iv, 0, crypto_skcipher_ivsize(skcipher));
 
 	INIT_LIST_HEAD(&ctx->tsgl);
 	ctx->len = len;
@@ -818,7 +852,7 @@ static int skcipher_accept_parent(void *private, struct sock *sk)
 
 	ask->private = ctx;
 
-	skcipher_request_set_tfm(&ctx->req, private);
+	skcipher_request_set_tfm(&ctx->req, skcipher);
 	skcipher_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG,
 				      af_alg_complete, &ctx->completion);
 
diff --git a/include/crypto/if_alg.h b/include/crypto/if_alg.h
index 018afb2..589716f 100644
--- a/include/crypto/if_alg.h
+++ b/include/crypto/if_alg.h
@@ -30,6 +30,8 @@ struct alg_sock {
 
 	struct sock *parent;
 
+	unsigned int refcnt;
+
 	const struct af_alg_type *type;
 	void *private;
 };
@@ -67,6 +69,7 @@ int af_alg_register_type(const struct af_alg_type *type);
 int af_alg_unregister_type(const struct af_alg_type *type);
 
 int af_alg_release(struct socket *sock);
+void af_alg_release_parent(struct sock *sk);
 int af_alg_accept(struct sock *sk, struct socket *newsock);
 
 int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len);
@@ -83,11 +86,6 @@ static inline struct alg_sock *alg_sk(struct sock *sk)
 	return (struct alg_sock *)sk;
 }
 
-static inline void af_alg_release_parent(struct sock *sk)
-{
-	sock_put(alg_sk(sk)->parent);
-}
-
 static inline void af_alg_init_completion(struct af_alg_completion *completion)
 {
 	init_completion(&completion->completion);