only dlopen from the defined search paths

Don't accept absolute library paths that are not in the search path,
skip the ../ in paths to avoid opening arbitrary libraries from
unexpected places.

Author: wtay

spa/plugins/filter-graph/plugin_ladspa.c

@@ -233,43 +233,49 @@ static inline const char *split_walk(const char *str, const char *delimiter, siz
 	return s;
 }
 
-static int load_ladspa_plugin(struct plugin *impl, const char *path)
+static void make_search_paths(const char **path, const char **search_dirs)
 {
-	int res = -ENOENT;
+	const char *p;
+
+	while ((p = strstr(*path, "../")) != NULL)
+		*path = p + 3;
 
-	if (path[0] != '/') {
-		const char *search_dirs, *p, *state = NULL;
-		char filename[PATH_MAX];
-		size_t len;
+	*search_dirs = getenv("LADSPA_PATH");
+	if (!*search_dirs)
+		*search_dirs = "/usr/lib64/ladspa:/usr/lib/ladspa:" LIBDIR;
+}
 
-		search_dirs = getenv("LADSPA_PATH");
-		if (!search_dirs)
-			search_dirs = "/usr/lib64/ladspa:/usr/lib/ladspa:" LIBDIR;
+static int load_ladspa_plugin(struct plugin *impl, const char *path, const char *search_dirs)
+{
+	int res = -ENOENT;
+	const char *p, *state = NULL;
+	char filename[PATH_MAX];
+	size_t len;
 
-		/*
-		 * set the errno for the case when `ladspa_handle_load_by_path()`
-		 * is never called, which can only happen if the supplied
-		 * LADSPA_PATH contains too long paths
-		 */
-		res = -ENAMETOOLONG;
+	/*
+	 * set the errno for the case when `ladspa_handle_load_by_path()`
+	 * is never called, which can only happen if the supplied
+	 * LADSPA_PATH contains too long paths
+	 */
+	res = -ENAMETOOLONG;
 
-		while ((p = split_walk(search_dirs, ":", &len, &state))) {
-			int namelen;
+	while ((p = split_walk(search_dirs, ":", &len, &state))) {
+		int namelen;
 
-			if (len >= sizeof(filename))
-				continue;
+		if (len >= sizeof(filename))
+			continue;
 
+		if (strncmp(path, p, len) == 0)
+			namelen = snprintf(filename, sizeof(filename), "%s", path);
+		else
 			namelen = snprintf(filename, sizeof(filename), "%.*s/%s.so", (int) len, p, path);
-			if (namelen < 0 || (size_t) namelen >= sizeof(filename))
-				continue;
 
-			res = ladspa_handle_load_by_path(impl, filename);
-			if (res >= 0)
-				break;
-		}
-	}
-	else {
-		res = ladspa_handle_load_by_path(impl, path);
+		if (namelen < 0 || (size_t) namelen >= sizeof(filename))
+			continue;
+
+		res = ladspa_handle_load_by_path(impl, filename);
+		if (res >= 0)
+			break;
 	}
 	return res;
 }
@@ -317,7 +323,7 @@ impl_init(const struct spa_handle_factory *factory,
 	struct plugin *impl;
 	uint32_t i;
 	int res;
-	const char *path = NULL;
+	const char *path = NULL, *search_dirs;
 
 	handle->get_interface = impl_get_interface;
 	handle->clear = impl_clear;
@@ -335,9 +341,11 @@ impl_init(const struct spa_handle_factory *factory,
 	if (path == NULL)
 		return -EINVAL;
 
-	if ((res = load_ladspa_plugin(impl, path)) < 0) {
-		spa_log_error(impl->log, "failed to load plugin '%s': %s",
-				path, spa_strerror(res));
+	make_search_paths(&path, &search_dirs);
+
+	if ((res = load_ladspa_plugin(impl, path, search_dirs)) < 0) {
+		spa_log_error(impl->log, "failed to load plugin '%s' in '%s': %s",
+				path, search_dirs, spa_strerror(res));
 		return res;
 	}
 

src/daemon/filter-chain/source-rnnoise.conf

@@ -21,7 +21,6 @@ context.modules = [
 			# listed in the environment variable LADSPA_PATH or 
 			# /usr/lib64/ladspa, /usr/lib/ladspa or the system library directory
 			# as a fallback.
-			# You might want to use an absolute path here to avoid problems.
                         plugin = "librnnoise_ladspa"
                         label  = noise_suppressor_stereo
                         control = {

src/modules/module-filter-chain.c

@@ -128,7 +128,7 @@ extern struct spa_handle_factory spa_filter_graph_factory;
  *             # an example ladspa plugin
  *             type = ladspa
  *             name = pitch
- *             plugin = "/usr/lib64/ladspa/ladspa-rubberband.so"
+ *             plugin = "ladspa-rubberband"
  *             label = "rubberband-r3-pitchshifter-mono"
  *             control = {
  *                 # controls are using the ladspa port names as seen in analyseplugin

src/modules/module-jack-tunnel.c

@@ -50,7 +50,6 @@
  *
  * - `jack.library`: the libjack to load, by default libjack.so.0 is searched in
  *			LIBJACK_PATH directories and then some standard library paths.
- *			Can be an absolute path.
  * - `jack.server`: the name of the JACK server to tunnel to.
  * - `jack.client-name`: the name of the JACK client.
  * - `jack.connect`: if jack ports should be connected automatically. Can also be

src/modules/module-jack-tunnel/weakjack.h

@@ -158,34 +158,36 @@ static inline int weakjack_load_by_path(struct weakjack *jack, const char *path)
 static inline int weakjack_load(struct weakjack *jack, const char *lib)
 {
 	int res = -ENOENT;
+	const char *search_dirs, *p, *state = NULL;
+	char path[PATH_MAX];
+	size_t len;
 
-	if (lib[0] != '/') {
-		const char *search_dirs, *p, *state = NULL;
-		char path[PATH_MAX];
-		size_t len;
+	while ((p = strstr(lib, "../")) != NULL)
+		lib = p + 3;
 
-		search_dirs = getenv("LIBJACK_PATH");
-		if (!search_dirs)
-			search_dirs = PREFIX "/lib64/:" PREFIX "/lib/:"
-				"/usr/lib64/:/usr/lib/:" LIBDIR;
+	search_dirs = getenv("LIBJACK_PATH");
+	if (!search_dirs)
+		search_dirs = PREFIX "/lib64/:" PREFIX "/lib/:"
+			"/usr/lib64/:/usr/lib/:" LIBDIR;
 
-		while ((p = pw_split_walk(search_dirs, ":", &len, &state))) {
-			int pathlen;
+	res = -ENAMETOOLONG;
 
-			if (len >= sizeof(path)) {
-				res = -ENAMETOOLONG;
-				continue;
-			}
+	while ((p = pw_split_walk(search_dirs, ":", &len, &state))) {
+		int pathlen;
+
+		if (len >= sizeof(path))
+			continue;
+
+		if (strncmp(lib, p, len) == 0)
+			pathlen = snprintf(path, sizeof(path), "%s", lib);
+		else
 			pathlen = snprintf(path, sizeof(path), "%.*s/%s", (int) len, p, lib);
-			if (pathlen < 0 || (size_t) pathlen >= sizeof(path)) {
-				res = -ENAMETOOLONG;
-				continue;
-			}
-			if ((res = weakjack_load_by_path(jack, path)) == 0)
-				break;
-		}
-	} else {
-		res = weakjack_load_by_path(jack, lib);
+
+		if (pathlen < 0 || (size_t) pathlen >= sizeof(path))
+			continue;
+
+		if ((res = weakjack_load_by_path(jack, path)) == 0)
+			break;
 	}
 	return res;
 }

src/pipewire/impl-module.c

@@ -154,6 +154,9 @@ pw_context_load_module(struct pw_context *context,
 		NULL
 	};
 
+	while ((p = strstr(name, "../")) != NULL)
+		name = p + 3;
+
 	pw_log_info("%p: name:%s args:%s", context, name, args);
 
 	module_dir = getenv("PIPEWIRE_MODULE_DIR");

src/pipewire/pipewire.c

@@ -232,6 +232,9 @@ static struct spa_handle *load_spa_handle(const char *lib,
 	if (lib == NULL)
 		lib = sup->support_lib;
 
+	while ((p = strstr(lib, "../")) != NULL)
+		lib = p + 3;
+
 	pw_log_debug("load lib:'%s' factory-name:'%s'", lib, factory_name);
 
 	plugin = NULL;