diff --git a/mm/mm_heap/mm_checkcorruption.c b/mm/mm_heap/mm_checkcorruption.c
index 5bafdbae0c..e45fe27bb5 100644
--- a/mm/mm_heap/mm_checkcorruption.c
+++ b/mm/mm_heap/mm_checkcorruption.c
@@ -66,15 +66,13 @@ void mm_checkcorruption(FAR struct mm_heap_s *heap)
   for (region = 0; region < heap_impl->mm_nregions; region++)
 #endif
     {
-      irqstate_t flags = 0;
-
       prev = NULL;
 
       /* Visit each node in the region
        * Retake the semaphore for each region to reduce latencies
        */
 
-      if (up_interrupt_context() || sched_idletask())
+      if (up_interrupt_context())
         {
           if (heap_impl->mm_counts_held)
             {
@@ -84,8 +82,13 @@ void mm_checkcorruption(FAR struct mm_heap_s *heap)
               return;
 #endif
             }
-
-          flags = enter_critical_section();
+        }
+      else if (sched_idletask())
+        {
+          if (mm_trysemaphore(heap))
+            {
+              return;
+            }
         }
       else
         {
@@ -122,11 +125,7 @@ void mm_checkcorruption(FAR struct mm_heap_s *heap)
 
       assert(node == heap_impl->mm_heapend[region]);
 
-      if (up_interrupt_context() || sched_idletask())
-        {
-          leave_critical_section(flags);
-        }
-      else
+      if (!up_interrupt_context())
         {
           mm_givesemaphore(heap);
         }
diff --git a/sched/init/nx_start.c b/sched/init/nx_start.c
index 109412546f..7840387e7f 100644
--- a/sched/init/nx_start.c
+++ b/sched/init/nx_start.c
@@ -805,19 +805,20 @@ void nx_start(void)
 
       /* Check stack in idle thread */
 
-      flags = enter_critical_section();
-
       for (i = 0; i < CONFIG_MAX_TASKS && g_pidhash[i].tcb; i++)
         {
+          flags = enter_critical_section();
+
           if (up_check_tcbstack_remain(g_pidhash[i].tcb) <= 0)
             {
               _alert("Stack check failed, pid %d, name %s\n",
                       g_pidhash[i].tcb->pid, g_pidhash[i].tcb->name);
               PANIC();
             }
+
+          leave_critical_section(flags);
         }
 
-      leave_critical_section(flags);
 #endif
 
       /* Check heap in idle thread */