rxrpc: Fix leak of rxrpc_peer objects

When a new client call is requested, an rxrpc_conn_parameters struct object
is passed in with a bunch of parameters set, such as the local endpoint to
use.  A pointer to the target peer record is also placed in there by
rxrpc_get_client_conn() - and this is removed if and only if a new
connection object is allocated.  Thus it leaks if a new connection object
isn't allocated.

Fix this by putting any peer object attached to the rxrpc_conn_parameters
object in the function that allocated it.

Fixes: 19ffa01c ("rxrpc: Use structs to hold connection params and protocol info")
Signed-off-by: David Howells <dhowells@redhat.com>

net/rxrpc/af_rxrpc.c

@@ -324,6 +324,7 @@ struct rxrpc_call *rxrpc_kernel_begin_call(struct socket *sock,
 		mutex_unlock(&call->user_mutex);
 	}
 
+	rxrpc_put_peer(cp.peer);
 	_leave(" = %p", call);
 	return call;
 }
@@ -447,6 +448,7 @@ int rxrpc_kernel_retry_call(struct socket *sock, struct rxrpc_call *call,
 		ret = rxrpc_retry_client_call(rx, call, &cp, srx, GFP_KERNEL);
 
 	mutex_unlock(&call->user_mutex);
+	rxrpc_put_peer(cp.peer);
 	_leave(" = %d", ret);
 	return ret;
 }

net/rxrpc/ar-internal.h

@@ -1041,6 +1041,7 @@ struct rxrpc_peer *rxrpc_lookup_peer(struct rxrpc_local *,
 struct rxrpc_peer *rxrpc_alloc_peer(struct rxrpc_local *, gfp_t);
 struct rxrpc_peer *rxrpc_lookup_incoming_peer(struct rxrpc_local *,
 					      struct rxrpc_peer *);
+void rxrpc_destroy_all_peers(struct rxrpc_net *);
 struct rxrpc_peer *rxrpc_get_peer(struct rxrpc_peer *);
 struct rxrpc_peer *rxrpc_get_peer_maybe(struct rxrpc_peer *);
 void rxrpc_put_peer(struct rxrpc_peer *);

net/rxrpc/net_ns.c

@@ -118,6 +118,7 @@ static __net_exit void rxrpc_exit_net(struct net *net)
 	cancel_work_sync(&rxnet->peer_keepalive_work);
 	rxrpc_destroy_all_calls(rxnet);
 	rxrpc_destroy_all_connections(rxnet);
+	rxrpc_destroy_all_peers(rxnet);
 	rxrpc_destroy_all_locals(rxnet);
 	proc_remove(rxnet->proc_net);
 }

net/rxrpc/peer_object.c

@@ -463,6 +463,27 @@ void rxrpc_put_peer(struct rxrpc_peer *peer)
 	}
 }
 
+/*
+ * Make sure all peer records have been discarded.
+ */
+void rxrpc_destroy_all_peers(struct rxrpc_net *rxnet)
+{
+	struct rxrpc_peer *peer;
+	int i;
+
+	for (i = 0; i < HASH_SIZE(rxnet->peer_hash); i++) {
+		if (hlist_empty(&rxnet->peer_hash[i]))
+			continue;
+
+		hlist_for_each_entry(peer, &rxnet->peer_hash[i], hash_link) {
+			pr_err("Leaked peer %u {%u} %pISp\n",
+			       peer->debug_id,
+			       atomic_read(&peer->usage),
+			       &peer->srx.transport);
+		}
+	}
+}
+
 /**
  * rxrpc_kernel_get_peer - Get the peer address of a call
  * @sock: The socket on which the call is in progress.

net/rxrpc/sendmsg.c

@@ -586,6 +586,7 @@ rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
 				     atomic_inc_return(&rxrpc_debug_id));
 	/* The socket is now unlocked */
 
+	rxrpc_put_peer(cp.peer);
 	_leave(" = %p\n", call);
 	return call;
 }