3 files changed, 28 insertions, 9 deletions

diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index ab47bf3ab66e..2ab43b2bba31 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -638,7 +638,7 @@ struct sock *__vsock_create(struct net *net,
 }
 EXPORT_SYMBOL_GPL(__vsock_create);
 
-static void __vsock_release(struct sock *sk)
+static void __vsock_release(struct sock *sk, int level)
 {
 	if (sk) {
 		struct sk_buff *skb;
@@ -648,9 +648,17 @@ static void __vsock_release(struct sock *sk)
 		vsk = vsock_sk(sk);
 		pending = NULL;	/* Compiler warning. */
 
+		/* The release call is supposed to use lock_sock_nested()
+		 * rather than lock_sock(), if a sock lock should be acquired.
+		 */
 		transport->release(vsk);
 
-		lock_sock(sk);
+		/* When "level" is SINGLE_DEPTH_NESTING, use the nested
+		 * version to avoid the warning "possible recursive locking
+		 * detected". When "level" is 0, lock_sock_nested(sk, level)
+		 * is the same as lock_sock(sk).
+		 */
+		lock_sock_nested(sk, level);
 		sock_orphan(sk);
 		sk->sk_shutdown = SHUTDOWN_MASK;
 
@@ -659,7 +667,7 @@ static void __vsock_release(struct sock *sk)
 
 		/* Clean up any sockets that never were accepted. */
 		while ((pending = vsock_dequeue_accept(sk)) != NULL) {
-			__vsock_release(pending);
+			__vsock_release(pending, SINGLE_DEPTH_NESTING);
 			sock_put(pending);
 		}
 
@@ -708,7 +716,7 @@ EXPORT_SYMBOL_GPL(vsock_stream_has_space);
 
 static int vsock_release(struct socket *sock)
 {
-	__vsock_release(sock->sk);
+	__vsock_release(sock->sk, 0);
 	sock->sk = NULL;
 	sock->state = SS_FREE;
 
diff --git a/net/vmw_vsock/hyperv_transport.c b/net/vmw_vsock/hyperv_transport.c
index 261521d286d6..c443db7af8d4 100644
--- a/net/vmw_vsock/hyperv_transport.c
+++ b/net/vmw_vsock/hyperv_transport.c
@@ -559,7 +559,7 @@ static void hvs_release(struct vsock_sock *vsk)
 	struct sock *sk = sk_vsock(vsk);
 	bool remove_sock;
 
-	lock_sock(sk);
+	lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
 	remove_sock = hvs_close_lock_held(vsk);
 	release_sock(sk);
 	if (remove_sock)
diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
index 5bb70c692b1e..481f7f8a1655 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c
@@ -204,10 +204,14 @@ static int virtio_transport_send_pkt_info(struct vsock_sock *vsk,
 	return virtio_transport_get_ops()->send_pkt(pkt);
 }
 
-static void virtio_transport_inc_rx_pkt(struct virtio_vsock_sock *vvs,
+static bool virtio_transport_inc_rx_pkt(struct virtio_vsock_sock *vvs,
 					struct virtio_vsock_pkt *pkt)
 {
+	if (vvs->rx_bytes + pkt->len > vvs->buf_alloc)
+		return false;
+
 	vvs->rx_bytes += pkt->len;
+	return true;
 }
 
 static void virtio_transport_dec_rx_pkt(struct virtio_vsock_sock *vvs,
@@ -458,6 +462,9 @@ void virtio_transport_set_buffer_size(struct vsock_sock *vsk, u64 val)
 		vvs->buf_size_max = val;
 	vvs->buf_size = val;
 	vvs->buf_alloc = val;
+
+	virtio_transport_send_credit_update(vsk, VIRTIO_VSOCK_TYPE_STREAM,
+					    NULL);
 }
 EXPORT_SYMBOL_GPL(virtio_transport_set_buffer_size);
 
@@ -820,7 +827,7 @@ void virtio_transport_release(struct vsock_sock *vsk)
 	struct sock *sk = &vsk->sk;
 	bool remove_sock = true;
 
-	lock_sock(sk);
+	lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
 	if (sk->sk_type == SOCK_STREAM)
 		remove_sock = virtio_transport_close(vsk);
 
@@ -876,14 +883,18 @@ virtio_transport_recv_enqueue(struct vsock_sock *vsk,
 			      struct virtio_vsock_pkt *pkt)
 {
 	struct virtio_vsock_sock *vvs = vsk->trans;
-	bool free_pkt = false;
+	bool can_enqueue, free_pkt = false;
 
 	pkt->len = le32_to_cpu(pkt->hdr.len);
 	pkt->off = 0;
 
 	spin_lock_bh(&vvs->rx_lock);
 
-	virtio_transport_inc_rx_pkt(vvs, pkt);
+	can_enqueue = virtio_transport_inc_rx_pkt(vvs, pkt);
+	if (!can_enqueue) {
+		free_pkt = true;
+		goto out;
+	}
 
 	/* Try to copy small packets into the buffer of last packet queued,
 	 * to avoid wasting memory queueing the entire buffer with a small