modules: limit the max amount of items in the protocol

For now, put a limit on the amount of items we can send and receive
over the native protocol. A more complex way of allocating and freeing
can be implemented later when we really need to raise the limits.

Fixes #2070

src/modules/module-client-device/protocol-native.c

@@ -32,6 +32,9 @@
 
 #include <pipewire/extensions/protocol-native.h>
 
+#define MAX_DICT	256
+#define MAX_PARAM_INFO	128
+
 static inline void push_item(struct spa_pod_builder *b, const struct spa_dict_item *item)
 {
 	const char *str;
@@ -62,6 +65,8 @@ do {												\
 			 SPA_POD_Int(&(d)->n_items), NULL) < 0)					\
 		return -EINVAL;									\
 	if ((d)->n_items > 0) {									\
+		if ((d)->n_items > MAX_DICT) 							\
+			return -ENOSPC;								\
 		(d)->items = alloca((d)->n_items * sizeof(struct spa_dict_item));		\
 		for (i = 0; i < (d)->n_items; i++) {						\
 			if (parse_item(prs, (struct spa_dict_item *) &(d)->items[i]) < 0)	\
@@ -77,6 +82,8 @@ do {												\
 			SPA_POD_Int(&(n_params)), NULL) < 0)					\
 		return -EINVAL;									\
 	if (n_params > 0) {									\
+		if (n_params > MAX_PARAM_INFO)							\
+			return -ENOSPC;								\
 		params = alloca(n_params * sizeof(struct spa_param_info));			\
 		for (i = 0; i < n_params; i++) {						\
 			if (spa_pod_parser_get(prs,						\

src/modules/module-client-node/client-node.c

@@ -755,6 +755,9 @@ do_port_use_buffers(struct impl *impl,
 	if (!CHECK_PORT(this, direction, port_id))
 		return n_buffers == 0 ? 0 : -EINVAL;
 
+	if (n_buffers > MAX_BUFFERS)
+		return -ENOSPC;
+
 	p = GET_PORT(this, direction, port_id);
 
 	spa_log_debug(this->log, "%p: %s port %d.%d use buffers %p %u flags:%08x", this,

src/modules/module-client-node/protocol-native.c

@@ -33,6 +33,13 @@
 #include <pipewire/extensions/protocol-native.h>
 #include <pipewire/extensions/client-node.h>
 
+#define MAX_DICT	256
+#define MAX_PARAMS	128
+#define MAX_PARAM_INFO	128
+#define MAX_BUFFERS	64
+#define MAX_METAS	16u
+#define MAX_DATAS	64u
+
 PW_LOG_TOPIC_EXTERN(mod_topic);
 #define PW_LOG_TOPIC_DEFAULT mod_topic
 
@@ -81,6 +88,8 @@ do {											\
 		return -EINVAL;								\
 	(d)->items = NULL;								\
 	if ((d)->n_items > 0) {								\
+		if ((d)->n_items > MAX_DICT) 						\
+			return -ENOSPC;							\
 		(d)->items = alloca((d)->n_items * sizeof(struct spa_dict_item));	\
 		for (i = 0; i < (d)->n_items; i++) {					\
 			if (parse_item(prs, (struct spa_dict_item *) &(d)->items[i]) < 0)	\
@@ -105,7 +114,9 @@ do {											\
 		return -EINVAL;								\
 	params = NULL;									\
 	if (n_params > 0) {								\
-		params = alloca(n_params * sizeof(struct spa_pos *));			\
+		if (n_params > MAX_PARAMS)						\
+			return -ENOSPC;							\
+		params = alloca(n_params * sizeof(struct spa_pod *));			\
 		for (i = 0; i < n_params; i++) {					\
 			if (spa_pod_parser_get(prs,					\
 					SPA_POD_PodObject(&params[i]), NULL) < 0)	\
@@ -122,6 +133,8 @@ do {											\
 		return -EINVAL;								\
 	params = NULL;									\
 	if (n_params > 0) {								\
+		if (n_params > MAX_PARAM_INFO)						\
+			return -ENOSPC;							\
 		params = alloca(n_params * sizeof(struct spa_param_info));		\
 		for (i = 0; i < n_params; i++) {					\
 			if (spa_pod_parser_get(prs,					\
@@ -518,6 +531,9 @@ static int client_node_demarshal_port_use_buffers(void *object, const struct pw_
 			SPA_POD_Int(&n_buffers), NULL) < 0)
 		return -EINVAL;
 
+	if (n_buffers > MAX_BUFFERS)
+		return -ENOSPC;
+
 	buffers = alloca(sizeof(struct pw_client_node_buffer) * n_buffers);
 	for (i = 0; i < n_buffers; i++) {
 		struct spa_buffer *buf = buffers[i].buffer = alloca(sizeof(struct spa_buffer));
@@ -529,6 +545,9 @@ static int client_node_demarshal_port_use_buffers(void *object, const struct pw_
 				      SPA_POD_Int(&buf->n_metas), NULL) < 0)
 			return -EINVAL;
 
+		if (buf->n_metas > MAX_METAS)
+			return -ENOSPC;
+
 		buf->metas = alloca(sizeof(struct spa_meta) * buf->n_metas);
 		for (j = 0; j < buf->n_metas; j++) {
 			struct spa_meta *m = &buf->metas[j];
@@ -542,6 +561,9 @@ static int client_node_demarshal_port_use_buffers(void *object, const struct pw_
 					SPA_POD_Int(&buf->n_datas), NULL) < 0)
 			return -EINVAL;
 
+		if (buf->n_datas > MAX_DATAS)
+			return -ENOSPC;
+
 		buf->datas = alloca(sizeof(struct spa_data) * buf->n_datas);
 		for (j = 0; j < buf->n_datas; j++) {
 			struct spa_data *d = &buf->datas[j];
@@ -1113,6 +1135,9 @@ static int client_node_demarshal_port_buffers(void *object, const struct pw_prot
 			SPA_POD_Int(&n_buffers), NULL) < 0)
 		return -EINVAL;
 
+	if (n_buffers > MAX_BUFFERS)
+		return -ENOSPC;
+
 	buffers = alloca(sizeof(struct spa_buffer*) * n_buffers);
 	for (i = 0; i < n_buffers; i++) {
 		struct spa_buffer *buf = buffers[i] = alloca(sizeof(struct spa_buffer));
@@ -1122,6 +1147,9 @@ static int client_node_demarshal_port_buffers(void *object, const struct pw_prot
 					SPA_POD_Int(&buf->n_datas), NULL) < 0)
 			return -EINVAL;
 
+		if (buf->n_datas > MAX_DATAS)
+			return -ENOSPC;
+
 		buf->datas = alloca(sizeof(struct spa_data) * buf->n_datas);
 		for (j = 0; j < buf->n_datas; j++) {
 			struct spa_data *d = &buf->datas[j];

src/modules/module-client-node/remote-node.c

@@ -41,7 +41,8 @@
 #include "pipewire/extensions/protocol-native.h"
 #include "pipewire/extensions/client-node.h"
 
-#define MAX_MIX	4096
+#define MAX_BUFFERS	64
+#define MAX_MIX		4096
 
 PW_LOG_TOPIC_EXTERN(mod_topic);
 #define PW_LOG_TOPIC_DEFAULT mod_topic
@@ -629,6 +630,9 @@ client_node_port_use_buffers(void *object,
 		goto error_exit;
 	}
 
+	if (n_buffers > MAX_BUFFERS)
+		return -ENOSPC;
+
 	prot = PW_MEMMAP_FLAG_READWRITE;
 
 	/* clear previous buffers */

src/modules/module-protocol-native/protocol-native.c

@@ -34,6 +34,10 @@
 
 #include "connection.h"
 
+#define MAX_DICT	256
+#define MAX_PARAM_INFO	128
+#define MAX_PERMISSIONS	1024
+
 PW_LOG_TOPIC_EXTERN(mod_topic);
 #define PW_LOG_TOPIC_DEFAULT mod_topic
 
@@ -175,6 +179,8 @@ do {												\
 	(d)->items = NULL;									\
 	if ((d)->n_items > 0) {									\
 		uint32_t i;									\
+		if ((d)->n_items > MAX_DICT)							\
+			return -ENOSPC;								\
 		(d)->items = alloca((d)->n_items * sizeof(struct spa_dict_item));		\
 		for (i = 0; i < (d)->n_items; i++) {						\
 			if (parse_item(prs, (struct spa_dict_item *) &(d)->items[i]) < 0)	\
@@ -216,6 +222,8 @@ do {											\
 	params = NULL;									\
 	if (n_params > 0) {								\
 		uint32_t i;								\
+		if (n_params > MAX_PARAM_INFO)						\
+			return -ENOSPC;							\
 		params = alloca(n_params * sizeof(struct spa_param_info));		\
 		for (i = 0; i < n_params; i++) {					\
 			if (spa_pod_parser_get(prs,					\
@@ -237,6 +245,8 @@ do {												\
 	permissions = NULL;									\
 	if (n_permissions > 0) {								\
 		uint32_t i;									\
+		if (n_permissions > MAX_PERMISSIONS)						\
+			return -ENOSPC;								\
 		permissions = alloca(n_permissions * sizeof(struct pw_permission));		\
 		for (i = 0; i < n_permissions; i++) {						\
 			if (spa_pod_parser_get(prs,						\

src/modules/module-session-manager/protocol-native.c

@@ -32,6 +32,10 @@
 #include <pipewire/extensions/session-manager.h>
 #include <pipewire/extensions/protocol-native.h>
 
+#define MAX_DICT	256
+#define MAX_PARAMS	128
+#define MAX_PARAM_INFO	128
+
 static void push_dict(struct spa_pod_builder *b, const struct spa_dict *dict)
 {
 	struct spa_pod_frame f;
@@ -61,6 +65,8 @@ do { \
 		return -EINVAL; \
 	\
 	if ((dict)->n_items > 0) { \
+		if ((dict)->n_items > MAX_DICT) \
+			return -ENOSPC; \
 		(dict)->items = alloca((dict)->n_items * sizeof(struct spa_dict_item)); \
 		for (i = 0; i < (dict)->n_items; i++) { \
 			if (spa_pod_parser_get(p, \
@@ -100,6 +106,8 @@ do { \
 		return -EINVAL; \
 	\
 	if (*(n_params_p) > 0) { \
+		if (*(n_params_p) > MAX_PARAM_INFO) \
+			return -ENOSPC; \
 		*(params_p) = alloca(*(n_params_p) * sizeof(struct spa_param_info)); \
 		for (i = 0; i < *(n_params_p); i++) { \
 			if (spa_pod_parser_get(p, \
@@ -553,6 +561,8 @@ static int client_endpoint_demarshal_update(void *object,
 			SPA_POD_Int(&n_params), NULL) < 0)
 		return -EINVAL;
 
+	if (n_params > MAX_PARAMS)
+		return -ENOSPC;
 	if (n_params > 0)
 		params = alloca(n_params * sizeof(struct spa_pod *));
 	for (i = 0; i < n_params; i++)
@@ -593,6 +603,8 @@ static int client_endpoint_demarshal_stream_update(void *object,
 			SPA_POD_Int(&n_params), NULL) < 0)
 		return -EINVAL;
 
+	if (n_params > MAX_PARAMS)
+		return -ENOSPC;
 	if (n_params > 0)
 		params = alloca(n_params * sizeof(struct spa_pod *));
 	for (i = 0; i < n_params; i++)
@@ -867,6 +879,8 @@ static int client_session_demarshal_update(void *object,
 			SPA_POD_Int(&n_params), NULL) < 0)
 		return -EINVAL;
 
+	if (n_params > MAX_PARAMS)
+		return -ENOSPC;
 	if (n_params > 0)
 		params = alloca(n_params * sizeof(struct spa_pod *));
 	for (i = 0; i < n_params; i++)
@@ -907,6 +921,8 @@ static int client_session_demarshal_link_update(void *object,
 			SPA_POD_Int(&n_params), NULL) < 0)
 		return -EINVAL;
 
+	if (n_params > MAX_PARAMS)
+		return -ENOSPC;
 	if (n_params > 0)
 		params = alloca(n_params * sizeof(struct spa_pod *));
 	for (i = 0; i < n_params; i++)