staging: mmal-vchiq: Fix memory leak in error path

On error, vchiq_mmal_component_init could leave the
event context allocated for ports.
Clean them up in the error path.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

drivers/staging/vc04_services/vchiq-mmal/mmal-vchiq.c

@@ -1766,9 +1766,26 @@ static void free_event_context(struct vchiq_mmal_port *port)
 {
 	struct mmal_msg_context *ctx = port->event_context;
 
+	if (!ctx)
+		return;
+
 	kfree(ctx->u.bulk.buffer->buffer);
 	kfree(ctx->u.bulk.buffer);
 	release_msg_context(ctx);
+	port->event_context = NULL;
+}
+
+static void release_all_event_contexts(struct vchiq_mmal_component *component)
+{
+	int idx;
+
+	for (idx = 0; idx < component->inputs; idx++)
+		free_event_context(&component->input[idx]);
+	for (idx = 0; idx < component->outputs; idx++)
+		free_event_context(&component->output[idx]);
+	for (idx = 0; idx < component->clocks; idx++)
+		free_event_context(&component->clock[idx]);
+	free_event_context(&component->control);
 }
 
 /* Initialise a mmal component and its ports
@@ -1866,6 +1883,7 @@ int vchiq_mmal_component_init(struct vchiq_mmal_instance *instance,
 
 release_component:
 	destroy_component(instance, component);
+	release_all_event_contexts(component);
 unlock:
 	if (component)
 		component->in_use = false;
@@ -1881,7 +1899,7 @@ EXPORT_SYMBOL_GPL(vchiq_mmal_component_init);
 int vchiq_mmal_component_finalise(struct vchiq_mmal_instance *instance,
 				  struct vchiq_mmal_component *component)
 {
-	int ret, idx;
+	int ret;
 
 	if (mutex_lock_interruptible(&instance->vchiq_mutex))
 		return -EINTR;
@@ -1893,14 +1911,7 @@ int vchiq_mmal_component_finalise(struct vchiq_mmal_instance *instance,
 
 	component->in_use = false;
 
-	for (idx = 0; idx < component->inputs; idx++)
-		free_event_context(&component->input[idx]);
-	for (idx = 0; idx < component->outputs; idx++)
-		free_event_context(&component->output[idx]);
-	for (idx = 0; idx < component->clocks; idx++)
-		free_event_context(&component->clock[idx]);
-
-	free_event_context(&component->control);
+	release_all_event_contexts(component);
 
 	mutex_unlock(&instance->vchiq_mutex);