Rémi Bernon : wined3d: Add more padding to resource memory allocations.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: e7d7ac77087ed33958047dae34a2e9d66c473c21
URL:    https://gitlab.winehq.org/wine/wine/-/commit/e7d7ac77087ed33958047dae34a2e9d...

Author: Rémi Bernon <rbernon(a)codeweavers.com>
Date:   Fri Dec 15 18:46:17 2023 +0100

wined3d: Add more padding to resource memory allocations.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=55773

---

 dlls/wined3d/resource.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/dlls/wined3d/resource.c b/dlls/wined3d/resource.c
index 9d3fd0a426d..5351fbd3025 100644
--- a/dlls/wined3d/resource.c
+++ b/dlls/wined3d/resource.c
@@ -332,7 +332,11 @@ void CDECL wined3d_resource_preload(struct wined3d_resource *resource)
 static BOOL wined3d_resource_allocate_sysmem(struct wined3d_resource *resource)
 {
     void **p;
-    SIZE_T align = RESOURCE_ALIGNMENT - 1 + sizeof(*p);
+    /* Overallocate and add padding to the allocated pointer, to guard against
+     * games (for instance Railroad Tycoon 2) writing before the locked resource
+     * memory pointer.
+     */
+    SIZE_T align = RESOURCE_ALIGNMENT + sizeof(*p);
     void *mem;
 
     if (!(mem = heap_alloc_zero(resource->size + align)))