[PATCH 3/6] user32: Zero initialize DEVMODE before passing it to EnumDisplaySettings(). - wine-devel

11 Aug 2020

EnumDisplaySettings() on Wine does not write beyond the end of DEVMODE because it doesn't use
dmDriverExtra currently, but this implementation detail should not be relied on.
Signed-off-by: Zhiyi Zhang zzhang@codeweavers.com
---
 dlls/user32/sysparams.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/dlls/user32/sysparams.c b/dlls/user32/sysparams.c
index 79f938a3c20..0c0f8fac5d1 100644
--- a/dlls/user32/sysparams.c
+++ b/dlls/user32/sysparams.c
@@ -3369,6 +3369,7 @@ LONG WINAPI ChangeDisplaySettingsExW( LPCWSTR devname, LPDEVMODEW devmode, HWND
if (def_mode)
     {
+        memset(&dm, 0, sizeof(dm));
         dm.dmSize = sizeof(dm);
         if (!EnumDisplaySettingsExW(devname, ENUM_REGISTRY_SETTINGS, &dm, 0))
         {
@@ -3428,6 +3429,8 @@ BOOL WINAPI EnumDisplaySettingsExA(LPCSTR lpszDeviceName, DWORD iModeNum,
     if (lpszDeviceName) RtlCreateUnicodeStringFromAsciiz(&nameW, lpszDeviceName);
     else nameW.Buffer = NULL;
+    memset(&devmodeW, 0, sizeof(devmodeW));
+    devmodeW.dmSize = sizeof(devmodeW);
     ret = EnumDisplaySettingsExW(nameW.Buffer,iModeNum,&devmodeW,dwFlags);
     if (ret)
     {
@@ -4808,6 +4811,7 @@ LONG WINAPI QueryDisplayConfig(UINT32 flags, UINT32 *numpathelements, DISPLAYCON
                                        &type, (BYTE *)device_name, sizeof(device_name), NULL, 0))
             goto done;
+        memset(&devmode, 0, sizeof(devmode));
         devmode.dmSize = sizeof(devmode);
         if (!EnumDisplaySettingsW(device_name, ENUM_CURRENT_SETTINGS, &devmode))
             goto done;
-- 
2.25.1



    