Index: kernel/generic/src/mm/backend_phys.c
===================================================================
--- kernel/generic/src/mm/backend_phys.c	(revision d99c1d2ba8c7b2c687d430f2e9fd237046606545)
+++ kernel/generic/src/mm/backend_phys.c	(revision c621f4aa64c16cb4d9c2b20dbf5be59c66c25ed3)
@@ -72,4 +72,7 @@
 	uintptr_t base = area->backend_data.base;
 
+	ASSERT(page_table_locked(AS));
+	ASSERT(mutex_locked(&area->lock));
+
 	if (!as_area_check_access(area, access))
 		return AS_PF_FAULT;
@@ -93,4 +96,6 @@
 void phys_share(as_area_t *area)
 {
+	ASSERT(mutex_locked(&area->as->lock));
+	ASSERT(mutex_locked(&area->lock));
 }