[PATCH 0/1] MR2264: ntdll: Avoid shrinking large heap block to small block.

[Rémi Bernon]

Even though this is a waste of memory it seems to trip on some UAF with
some games.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=54475

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/2264

[PATCH 1/1] ntdll: Avoid shrinking large heap block to small block.

[Rémi Bernon]

From: Rémi Bernon <rbernon(a)codeweavers.com>

Even though this is a waste of memory it seems to trip on some UAF with
some games.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=54475
---
 dlls/ntdll/heap.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/dlls/ntdll/heap.c b/dlls/ntdll/heap.c
index afe38eddaa8..6688fab9690 100644
--- a/dlls/ntdll/heap.c
+++ b/dlls/ntdll/heap.c
@@ -2092,7 +2092,6 @@ static NTSTATUS heap_resize_large( struct heap *heap, ULONG flags, struct block
     SIZE_T old_block_size = large->block_size;
     *old_size = large->data_size;
 
-    if (block_size < HEAP_MIN_LARGE_BLOCK_SIZE / 4) return STATUS_NO_MEMORY;  /* shrinking large block to small block */
     if (old_block_size < block_size) return STATUS_NO_MEMORY;
 
     /* FIXME: we could remap zero-pages instead */
-- 
GitLab

https://gitlab.winehq.org/wine/wine/-/merge_requests/2264