[PATCH 1/1] user32: At least fail instantly on buffer overflow in winproc.

[Roman Pišl]

From: Roman Pišl

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=48559

Signed-off-by: Roman Pišl 
---
 dlls/user32/winproc.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/dlls/user32/winproc.c b/dlls/user32/winproc.c
index d2e4b29fc44..eff24bb3f2d 100644
--- a/dlls/user32/winproc.c
+++ b/dlls/user32/winproc.c
@@ -24,6 +24,7 @@
 #include "dbt.h"
 #include "wine/asm.h"
 #include "wine/debug.h"
+#include <assert.h>

WINE_DEFAULT_DEBUG_CHANNEL(msg);
 WINE_DECLARE_DEBUG_CHANNEL(relay);
@@ -332,7 +333,10 @@ LRESULT WINPROC_CallProcAtoW( winproc_callback_t callback, HWND hwnd, UINT msg,
         {
             WCHAR buffer[512];  /* FIXME: fixed sized buffer */

+            buffer[ARRAY_SIZE(buffer) - 1] = 0;
             ret = callback( hwnd, msg, wParam, (LPARAM)buffer, result, arg );
+            assert(!buffer[ARRAY_SIZE(buffer) - 1]);
+
             if (*result >= 0)
             {
                 DWORD len;
@@ -604,7 +608,10 @@ static LRESULT WINPROC_CallProcWtoA( winproc_callback_t callback, HWND hwnd, UIN
         {
             char buffer[512];  /* FIXME: fixed sized buffer */

+            buffer[ARRAY_SIZE(buffer) - 1] = 0;
             ret = callback( hwnd, msg, wParam, (LPARAM)buffer, result, arg );
+            assert(!buffer[ARRAY_SIZE(buffer) - 1]);
+
             if (*result >= 0)
             {
                 DWORD len;