[PATCH 2/3] ntdll: Validate subheap's owner heap when validating heap.

[Jinoh Kang]

From: Jinoh Kang

---
 dlls/ntdll/heap.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/dlls/ntdll/heap.c b/dlls/ntdll/heap.c
index 9f786dab6f0..70926109547 100644
--- a/dlls/ntdll/heap.c
+++ b/dlls/ntdll/heap.c
@@ -1138,6 +1138,12 @@ static BOOL heap_validate_ptr( const struct heap *heap, const void *ptr )
         return validate_large_block( heap, block );
     }

+    if (subheap->user_value != heap)
+    {
+        ERR("subheap %p: owner heap mismatch (expected %p, got %p)\n", subheap, heap, subheap->user_value);
+        return FALSE;
+    }
+
     if (!validate_used_block( heap, subheap, block )) return FALSE;

/* validate_used_block() has checked the alignment; the block is now safe(r) to dereference.
@@ -1167,6 +1173,12 @@ static BOOL heap_validate( const struct heap *heap )
             return FALSE;
         }

+        if (subheap->user_value != heap)
+        {
+            ERR("subheap %p: owner heap mismatch (expected %p, got %p)\n", subheap, heap, subheap->user_value);
+            return FALSE;
+        }
+
         for (block = first_block( subheap ); block; block = next_block( subheap, block ))
         {
             if (block_get_flags( block ) & BLOCK_FLAG_FREE)