diff --git a/fs/shm/shmfs_alloc.c b/fs/shm/shmfs_alloc.c
index 4764c901e6849..7b68b763cf633 100644
--- a/fs/shm/shmfs_alloc.c
+++ b/fs/shm/shmfs_alloc.c
@@ -51,24 +51,26 @@ FAR struct shmfs_object_s *shmfs_alloc_object(size_t length)
    * chunk in kernel heap
    */
 
-  object = fs_heap_zalloc(sizeof(struct shmfs_object_s));
-  if (object)
+  size_t hdr_size = sizeof(struct shmfs_object_s);
+  size_t alloc_size = length;
+  size_t cachesize = up_get_dcache_linesize();
+
+  if (cachesize > 0)
     {
-      size_t cachesize = up_get_dcache_linesize();
-      if (cachesize > 0)
-        {
-          object->paddr = fs_heap_memalign(cachesize,
-                                           ALIGN_UP(length, cachesize));
-        }
-      else
-        {
-          object->paddr = fs_heap_malloc(length);
-        }
+      hdr_size = ALIGN_UP(hdr_size, cachesize);
+      alloc_size = ALIGN_UP(alloc_size, cachesize);
+      object = fs_heap_memalign(cachesize, hdr_size + alloc_size);
+    }
+  else
+    {
+      object = fs_heap_malloc(hdr_size + alloc_size);
+    }
 
-      if (object->paddr)
-        {
-           allocated = true;
-        }
+  if (object)
+    {
+      memset(object, 0, hdr_size + alloc_size);
+      object->paddr = (void *)((uintptr_t)object + hdr_size);
+      allocated = true;
     }
 
 #elif defined(CONFIG_BUILD_PROTECTED)
@@ -76,23 +78,27 @@ FAR struct shmfs_object_s *shmfs_alloc_object(size_t length)
    * memory in user heap
    */
 
+  size_t alloc_size = length;
+
   object = fs_heap_zalloc(sizeof(struct shmfs_object_s));
   if (object)
     {
       size_t cachesize = up_get_dcache_linesize();
+
       if (cachesize > 0)
         {
-          object->paddr = kumm_memalign(cachesize,
-                                        ALIGN_UP(length, cachesize));
+          alloc_size = ALIGN_UP(alloc_size, cachesize);
+          object->paddr = kumm_memalign(cachesize, alloc_size);
         }
       else
         {
-          object->paddr = kumm_malloc(length);
+          object->paddr = kumm_malloc(alloc_size);
         }
 
       if (object->paddr)
         {
-           allocated = true;
+          memset(object->paddr, 0, alloc_size);
+          allocated = true;
         }
     }
 
@@ -152,9 +158,7 @@ void shmfs_free_object(FAR struct shmfs_object_s *object)
 {
   if (object)
     {
-#if defined(CONFIG_BUILD_FLAT)
-      fs_heap_free(object->paddr);
-#elif defined(CONFIG_BUILD_PROTECTED)
+#if defined(CONFIG_BUILD_PROTECTED)
       kumm_free(object->paddr);
 #elif defined(CONFIG_BUILD_KERNEL)
       size_t i;