profile: Fail RegisterProfile if UUID already exists

If a process tries to register a profile implementation that is already
registered, RegisterProfile should fail.

This should help address issues when two instances of PulseAudio are
running at the same time, and the second instance tries to register an
audio profile implementation that has already been registered by the
first instance. Two situations where this may happen is when more than
one user is logged in, or during the transition between the GDM session
and the user session, when PulseAudio gets started on the new session
before the old session has been fully terminated.

https://gitlab.freedesktop.org/pulseaudio/pulseaudio/-/issues/303
https://gitlab.gnome.org/GNOME/gdm/-/issues/486

1 files changed, 30 insertions, 0 deletions

diff --git a/src/profile.c b/src/profile.c
index 5e460b639..60d17b6ae 100644
--- a/src/profile.c
+++ b/src/profile.c
@@ -749,6 +749,30 @@ void btd_profile_foreach(void (*func)(struct btd_profile *p, void *data),
 	}
 }
 
+static struct btd_profile *btd_profile_find_uuid(const char *uuid)
+{
+	GSList *l, *next;
+
+	for (l = profiles; l != NULL; l = next) {
+		struct btd_profile *p = l->data;
+
+		if (!g_strcmp0(p->local_uuid, uuid))
+			return p;
+		next = g_slist_next(l);
+	}
+
+	for (l = ext_profiles; l != NULL; l = next) {
+		struct ext_profile *ext = l->data;
+		struct btd_profile *p = &ext->p;
+
+		if (!g_strcmp0(p->local_uuid, uuid))
+			return p;
+		next = g_slist_next(l);
+	}
+
+	return NULL;
+}
+
 int btd_profile_register(struct btd_profile *profile)
 {
 	profiles = g_slist_append(profiles, profile);
@@ -2441,6 +2465,12 @@ static DBusMessage *register_profile(DBusConnection *conn,
 	dbus_message_iter_get_basic(&args, &uuid);
 	dbus_message_iter_next(&args);
 
+	if (btd_profile_find_uuid(uuid)) {
+		warn("%s tried to register %s which is already registered",
+								sender, uuid);
+		return btd_error_not_permitted(msg, "UUID already registered");
+	}
+
 	if (dbus_message_iter_get_arg_type(&args) != DBUS_TYPE_ARRAY)
 		return btd_error_invalid_args(msg);