From f7faf5e8e57cebd2ed58d54c4a325d824932d599 Mon Sep 17 00:00:00 2001
From: Thibault Saunier <tsaunier@igalia.com>
Date: Thu, 29 Aug 2024 12:10:23 -0400
Subject: [PATCH] osxaudio: Avoid dangling pointer on shutdown

When tearing down the elements we were still referring to the ringbuffer unique_id
as our property while it was already freed, leading to potential segfaults when
accessing the property.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/7451>
---
 .../gst-plugins-good/sys/osxaudio/gstosxaudiosink.c      | 7 +++++++
 .../gst-plugins-good/sys/osxaudio/gstosxaudiosrc.c       | 9 +++++++++
 2 files changed, 16 insertions(+)

diff --git a/subprojects/gst-plugins-good/sys/osxaudio/gstosxaudiosink.c b/subprojects/gst-plugins-good/sys/osxaudio/gstosxaudiosink.c
index 4b48e0dd59..ac9183521c 100644
--- a/subprojects/gst-plugins-good/sys/osxaudio/gstosxaudiosink.c
+++ b/subprojects/gst-plugins-good/sys/osxaudio/gstosxaudiosink.c
@@ -239,6 +239,11 @@ gst_osx_audio_sink_change_state (GstElement * element,
   GstStateChangeReturn ret;
 
   switch (transition) {
+    case GST_STATE_CHANGE_READY_TO_NULL:
+      GST_OBJECT_LOCK (osxsink);
+      osxsink->device_id = kAudioDeviceUnknown;
+      GST_OBJECT_UNLOCK (osxsink);
+      break;
     default:
       break;
   }
@@ -256,7 +261,9 @@ gst_osx_audio_sink_change_state (GstElement * element,
       ringbuffer =
           GST_OSX_AUDIO_RING_BUFFER (GST_AUDIO_BASE_SINK (osxsink)->ringbuffer);
       if (ringbuffer->core_audio->device_id != osxsink->device_id) {
+        GST_OBJECT_LOCK (osxsink);
         osxsink->device_id = ringbuffer->core_audio->device_id;
+        GST_OBJECT_UNLOCK (osxsink);
         g_object_notify (G_OBJECT (osxsink), "device");
       }
       break;
diff --git a/subprojects/gst-plugins-good/sys/osxaudio/gstosxaudiosrc.c b/subprojects/gst-plugins-good/sys/osxaudio/gstosxaudiosrc.c
index 75793bb692..e519744dc1 100644
--- a/subprojects/gst-plugins-good/sys/osxaudio/gstosxaudiosrc.c
+++ b/subprojects/gst-plugins-good/sys/osxaudio/gstosxaudiosrc.c
@@ -210,6 +210,12 @@ gst_osx_audio_src_change_state (GstElement * element, GstStateChange transition)
   GstStateChangeReturn ret;
 
   switch (transition) {
+    case GST_STATE_CHANGE_READY_TO_NULL:{
+      GST_OBJECT_LOCK (osxsrc);
+      osxsrc->device_id = kAudioDeviceUnknown;
+      GST_OBJECT_UNLOCK (osxsrc);
+      break;
+    }
     default:
       break;
   }
@@ -224,7 +230,10 @@ gst_osx_audio_src_change_state (GstElement * element, GstStateChange transition)
       ringbuffer =
           GST_OSX_AUDIO_RING_BUFFER (GST_AUDIO_BASE_SRC (osxsrc)->ringbuffer);
       if (ringbuffer->core_audio->device_id != osxsrc->device_id) {
+        GST_OBJECT_LOCK (osxsrc);
         osxsrc->device_id = ringbuffer->core_audio->device_id;
+        GST_OBJECT_UNLOCK (osxsrc);
+
         g_object_notify (G_OBJECT (osxsrc), "device");
       }
       break;