tests/ncdevmem: Fix double-free of queue array

netdev_bind_rx takes ownership of the queue array passed as parameter
and frees it, so a queue array buffer cannot be reused across multiple
netdev_bind_rx calls.

This commit fixes that by always passing in a newly created queue array
to all netdev_bind_rx calls in ncdevmem.

Fixes: 85585b4 ("selftests: add ncdevmem, netcat for devmem TCP")
Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Reviewed-by: Joe Damato <jdamato@fastly.com>
Reviewed-by: Mina Almasry <almasrymina@google.com>
Link: https://patch.msgid.link/20250508084434.1933069-1-cratiu@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

tools/testing/selftests/drivers/net/hw/ncdevmem.c

@@ -431,6 +431,22 @@ static int parse_address(const char *str, int port, struct sockaddr_in6 *sin6)
 	return 0;
 }
 
+static struct netdev_queue_id *create_queues(void)
+{
+	struct netdev_queue_id *queues;
+	size_t i = 0;
+
+	queues = calloc(num_queues, sizeof(*queues));
+	for (i = 0; i < num_queues; i++) {
+		queues[i]._present.type = 1;
+		queues[i]._present.id = 1;
+		queues[i].type = NETDEV_QUEUE_TYPE_RX;
+		queues[i].id = start_queue + i;
+	}
+
+	return queues;
+}
+
 int do_server(struct memory_buffer *mem)
 {
 	char ctrl_data[sizeof(int) * 20000];
@@ -448,7 +464,6 @@ int do_server(struct memory_buffer *mem)
 	char buffer[256];
 	int socket_fd;
 	int client_fd;
-	size_t i = 0;
 	int ret;
 
 	ret = parse_address(server_ip, atoi(port), &server_sin);
@@ -471,16 +486,7 @@ int do_server(struct memory_buffer *mem)
 
 	sleep(1);
 
-	queues = malloc(sizeof(*queues) * num_queues);
-
-	for (i = 0; i < num_queues; i++) {
-		queues[i]._present.type = 1;
-		queues[i]._present.id = 1;
-		queues[i].type = NETDEV_QUEUE_TYPE_RX;
-		queues[i].id = start_queue + i;
-	}
-
-	if (bind_rx_queue(ifindex, mem->fd, queues, num_queues, &ys))
+	if (bind_rx_queue(ifindex, mem->fd, create_queues(), num_queues, &ys))
 		error(1, 0, "Failed to bind\n");
 
 	tmp_mem = malloc(mem->size);
@@ -545,7 +551,6 @@ int do_server(struct memory_buffer *mem)
 			goto cleanup;
 		}
 
-		i++;
 		for (cm = CMSG_FIRSTHDR(&msg); cm; cm = CMSG_NXTHDR(&msg, cm)) {
 			if (cm->cmsg_level != SOL_SOCKET ||
 			    (cm->cmsg_type != SCM_DEVMEM_DMABUF &&
@@ -630,49 +635,33 @@ int do_server(struct memory_buffer *mem)
 
 void run_devmem_tests(void)
 {
-	struct netdev_queue_id *queues;
 	struct memory_buffer *mem;
 	struct ynl_sock *ys;
-	size_t i = 0;
 
 	mem = provider->alloc(getpagesize() * NUM_PAGES);
 
 	/* Configure RSS to divert all traffic from our devmem queues */
 	if (configure_rss())
 		error(1, 0, "rss error\n");
 
-	queues = calloc(num_queues, sizeof(*queues));
-
 	if (configure_headersplit(1))
 		error(1, 0, "Failed to configure header split\n");
 
-	if (!bind_rx_queue(ifindex, mem->fd, queues, num_queues, &ys))
+	if (!bind_rx_queue(ifindex, mem->fd,
+			   calloc(num_queues, sizeof(struct netdev_queue_id)),
+			   num_queues, &ys))
 		error(1, 0, "Binding empty queues array should have failed\n");
 
-	for (i = 0; i < num_queues; i++) {
-		queues[i]._present.type = 1;
-		queues[i]._present.id = 1;
-		queues[i].type = NETDEV_QUEUE_TYPE_RX;
-		queues[i].id = start_queue + i;
-	}
-
 	if (configure_headersplit(0))
 		error(1, 0, "Failed to configure header split\n");
 
-	if (!bind_rx_queue(ifindex, mem->fd, queues, num_queues, &ys))
+	if (!bind_rx_queue(ifindex, mem->fd, create_queues(), num_queues, &ys))
 		error(1, 0, "Configure dmabuf with header split off should have failed\n");
 
 	if (configure_headersplit(1))
 		error(1, 0, "Failed to configure header split\n");
 
-	for (i = 0; i < num_queues; i++) {
-		queues[i]._present.type = 1;
-		queues[i]._present.id = 1;
-		queues[i].type = NETDEV_QUEUE_TYPE_RX;
-		queues[i].id = start_queue + i;
-	}
-
-	if (bind_rx_queue(ifindex, mem->fd, queues, num_queues, &ys))
+	if (bind_rx_queue(ifindex, mem->fd, create_queues(), num_queues, &ys))
 		error(1, 0, "Failed to bind\n");
 
 	/* Deactivating a bound queue should not be legal */