1 files changed, 29 insertions, 19 deletions

diff --git a/crypto/af_alg.c b/crypto/af_alg.c
index 879cf23f7489..1d4b0157ee5d 100644
--- a/crypto/af_alg.c
+++ b/crypto/af_alg.c
@@ -16,6 +16,7 @@
 #include <linux/module.h>
 #include <linux/net.h>
 #include <linux/rwsem.h>
+#include <linux/sched.h>
 #include <linux/sched/signal.h>
 #include <linux/security.h>
 
@@ -128,19 +129,15 @@ EXPORT_SYMBOL_GPL(af_alg_release);
 void af_alg_release_parent(struct sock *sk)
 {
 	struct alg_sock *ask = alg_sk(sk);
-	unsigned int nokey = ask->nokey_refcnt;
-	bool last = nokey && !ask->refcnt;
+	unsigned int nokey = atomic_read(&ask->nokey_refcnt);
 
 	sk = ask->parent;
 	ask = alg_sk(sk);
 
-	lock_sock(sk);
-	ask->nokey_refcnt -= nokey;
-	if (!last)
-		last = !--ask->refcnt;
-	release_sock(sk);
+	if (nokey)
+		atomic_dec(&ask->nokey_refcnt);
 
-	if (last)
+	if (atomic_dec_and_test(&ask->refcnt))
 		sock_put(sk);
 }
 EXPORT_SYMBOL_GPL(af_alg_release_parent);
@@ -185,7 +182,7 @@ static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 
 	err = -EBUSY;
 	lock_sock(sk);
-	if (ask->refcnt | ask->nokey_refcnt)
+	if (atomic_read(&ask->refcnt))
 		goto unlock;
 
 	swap(ask->type, type);
@@ -234,7 +231,7 @@ static int alg_setsockopt(struct socket *sock, int level, int optname,
 	int err = -EBUSY;
 
 	lock_sock(sk);
-	if (ask->refcnt)
+	if (atomic_read(&ask->refcnt) != atomic_read(&ask->nokey_refcnt))
 		goto unlock;
 
 	type = ask->type;
@@ -299,12 +296,14 @@ int af_alg_accept(struct sock *sk, struct socket *newsock, bool kern)
 	if (err)
 		goto unlock;
 
-	if (nokey || !ask->refcnt++)
+	if (atomic_inc_return_relaxed(&ask->refcnt) == 1)
 		sock_hold(sk);
-	ask->nokey_refcnt += nokey;
+	if (nokey) {
+		atomic_inc(&ask->nokey_refcnt);
+		atomic_set(&alg_sk(sk2)->nokey_refcnt, 1);
+	}
 	alg_sk(sk2)->parent = sk;
 	alg_sk(sk2)->type = type;
-	alg_sk(sk2)->nokey_refcnt = nokey;
 
 	newsock->ops = type->ops;
 	newsock->state = SS_CONNECTED;
@@ -637,6 +636,7 @@ void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst,
 
 	if (!ctx->used)
 		ctx->merge = 0;
+	ctx->init = ctx->more;
 }
 EXPORT_SYMBOL_GPL(af_alg_pull_tsgl);
 
@@ -736,9 +736,10 @@ EXPORT_SYMBOL_GPL(af_alg_wmem_wakeup);
  *
  * @sk socket of connection to user space
  * @flags If MSG_DONTWAIT is set, then only report if function would sleep
+ * @min Set to minimum request size if partial requests are allowed.
  * @return 0 when writable memory is available, < 0 upon error
  */
-int af_alg_wait_for_data(struct sock *sk, unsigned flags)
+int af_alg_wait_for_data(struct sock *sk, unsigned flags, unsigned min)
 {
 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
 	struct alg_sock *ask = alg_sk(sk);
@@ -756,7 +757,9 @@ int af_alg_wait_for_data(struct sock *sk, unsigned flags)
 		if (signal_pending(current))
 			break;
 		timeout = MAX_SCHEDULE_TIMEOUT;
-		if (sk_wait_event(sk, &timeout, (ctx->used || !ctx->more),
+		if (sk_wait_event(sk, &timeout,
+				  ctx->init && (!ctx->more ||
+						(min && ctx->used >= min)),
 				  &wait)) {
 			err = 0;
 			break;
@@ -845,10 +848,17 @@ int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
 	}
 
 	lock_sock(sk);
-	if (!ctx->more && ctx->used) {
-		err = -EINVAL;
-		goto unlock;
+	if (ctx->init && !ctx->more) {
+		if (ctx->used) {
+			err = -EINVAL;
+			goto unlock;
+		}
+
+		pr_info_once(
+			"%s sent an empty control message without MSG_MORE.\n",
+			current->comm);
 	}
+	ctx->init = true;
 
 	if (init) {
 		ctx->enc = enc;
@@ -1043,7 +1053,7 @@ void af_alg_async_cb(struct crypto_async_request *_req, int err)
 	af_alg_free_resources(areq);
 	sock_put(sk);
 
-	iocb->ki_complete(iocb, err ? err : resultlen, 0);
+	iocb->ki_complete(iocb, err ? err : (int)resultlen, 0);
 }
 EXPORT_SYMBOL_GPL(af_alg_async_cb);