ASoC: SOF: sof-audio: prepare_widgets: Check swidget for NULL on sink failure

If the swidget is NULL we skip the preparing of the widget and jump to
handle the sink path of the widget.
If the prepare fails in this case we would undo the prepare but the swidget
is NULL (we skipped the prepare for the widget).

To avoid NULL pointer dereference in this case we must check swidget
against NULL pointer once again.

Fixes: 0ad84b11f2f8 ("ASoC: SOF: sof-audio: skip prepare/unprepare if swidget is NULL")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20230120102125.30653-1-peter.ujfalusi@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/sof/sof-audio.c b/sound/soc/sof/sof-audio.c
index 275b1ae453062a80c6f9d65fb20f4033cdebfb6c..865c367eb2f2bfa3067444d570cff0d9cc989865 100644 (file)
--- a/sound/soc/sof/sof-audio.c
+++ b/sound/soc/sof/sof-audio.c
@@ -327,7 +327,8 @@ sink_prepare:
                        p->walking = false;
                        if (ret < 0) {
                                /* unprepare the source widget */
-                               if (widget_ops[widget->id].ipc_unprepare && swidget->prepared) {
+                               if (widget_ops[widget->id].ipc_unprepare &&
+                                   swidget && swidget->prepared) {
                                        widget_ops[widget->id].ipc_unprepare(swidget);
                                        swidget->prepared = false;
                                }