[PATCH BlueZ 7/7] profiles/audio: fix UAF on external media service teardown

["Frédéric Danis" <frederic.danis@collabora.com>]

Keep media_app endpoint/player queues in sync with object lifetime to
avoid stale pointers during proxy removal.

When admin allowlist reapply removes audio services, endpoint/player
objects may be destroyed through non-proxy paths first.
Later proxy_removed_cb calls queue_remove_if() and matching by path
can dereference freed endpoint/player memory.

Fix by:
- adding media_app back-references in media_endpoint/local_player
- unlinking from app queues inside media_endpoint_remove or
  local_player_remove
- setting ownership when app-registering endpoint/player objects

This prevents heap-use-after-free in match_endpoint_by_path or
match_player_by_path during service disconnect.

Assisted-by: GPT:GPT-5.3-Codex
---
 profiles/audio/media.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/profiles/audio/media.c b/profiles/audio/media.c
index 5d9ea2cbc..95f9580b0 100644
--- a/profiles/audio/media.c
+++ b/profiles/audio/media.c
@@ -136,12 +136,14 @@ struct media_endpoint {
 	guint			watch;
 	GSList			*requests;
 	struct media_adapter	*adapter;
+	struct media_app	*app;
 	GSList			*transports;
 	struct endpoint_features	features;
 };
 
 struct local_player {
 	struct media_adapter	*adapter;
+	struct media_app	*app;
 	char			*sender;	/* Player DBus bus id */
 	char			*path;		/* Player object path */
 	GHashTable		*settings;	/* Player settings */
@@ -305,6 +307,11 @@ static void media_endpoint_remove(void *data)
 	}
 #endif
 
+	if (endpoint->app) {
+		queue_remove(endpoint->app->endpoints, endpoint);
+		endpoint->app = NULL;
+	}
+
 	info("Endpoint unregistered: sender=%s path=%s", endpoint->sender,
 			endpoint->path);
 
@@ -2076,6 +2083,11 @@ static void local_player_remove(void *data)
 {
 	struct local_player *mp = data;
 
+	if (mp->app) {
+		queue_remove(mp->app->players, mp);
+		mp->app = NULL;
+	}
+
 	info("Player unregistered: sender=%s path=%s", mp->sender, mp->path);
 
 	local_player_destroy(mp);
@@ -3168,6 +3180,8 @@ static void app_register_endpoint(void *data, void *user_data)
 		return;
 	}
 
+	endpoint->app = app;
+
 	queue_push_tail(app->endpoints, endpoint);
 
 	return;
@@ -3196,6 +3210,8 @@ static void app_register_player(void *data, void *user_data)
 	if (!player)
 		return;
 
+	player->app = app;
+
 	if (g_dbus_proxy_get_property(proxy, "PlaybackStatus", &iter)) {
 		if (!set_status(player, &iter))
 			goto fail;
-- 
2.43.0