Index: kernel/generic/src/mm/backend_phys.c
===================================================================
--- kernel/generic/src/mm/backend_phys.c	(revision a17cced459351c09ce76e034323992c244cd80e6)
+++ kernel/generic/src/mm/backend_phys.c	(revision 89dcf93c3256fc08164f222f79051a1acaed5a2b)
@@ -93,6 +93,14 @@
 {
 	mem_backend_data_t *data = &area->backend_data;
+	bool last = true;
 
-	if (data->anonymous)
+	if (area->sh_info) {
+		mutex_lock(&area->sh_info->lock);
+		if (area->sh_info->refcount != 1)
+			last = false;
+		mutex_unlock(&area->sh_info->lock);
+	}
+	
+	if (last && data->anonymous)
 		frame_free(data->base, data->frames);
 }