diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c
index 1a736d28be..dfd62a61f5 100644
--- a/mm/kasan/generic.c
+++ b/mm/kasan/generic.c
@@ -268,10 +268,13 @@ void kasan_unregister(FAR void *addr)
     {
       if (g_region[i]->begin == (uintptr_t)addr)
         {
+          size_t size = g_region[i]->end - g_region[i]->begin;
           g_region_count--;
           memmove(&g_region[i], &g_region[i + 1],
                   (g_region_count - i) * sizeof(g_region[0]));
-          break;
+          spin_unlock_irqrestore(&g_lock, flags);
+          kasan_unpoison(addr, size);
+          return;
         }
     }
 
diff --git a/mm/kasan/sw_tags.c b/mm/kasan/sw_tags.c
index 8bfaa821a4..2df66485c1 100644
--- a/mm/kasan/sw_tags.c
+++ b/mm/kasan/sw_tags.c
@@ -217,10 +217,13 @@ void kasan_unregister(FAR void *addr)
     {
       if (g_region[i]->begin == (uintptr_t)addr)
         {
+          size_t size = g_region[i]->end - g_region[i]->begin;
           g_region_count--;
           memmove(&g_region[i], &g_region[i + 1],
                   (g_region_count - i) * sizeof(g_region[0]));
-          break;
+          spin_unlock_irqrestore(&g_lock, flags);
+          kasan_unpoison(addr, size);
+          return;
         }
     }