Avoid potential DLL hijacking in Wintab code

Load Wintab32.dll from an absolute path. A proper Wintab32.dll, if
present, should be in the Windows system directory, so load it from
there.
This commit is contained in:
Tor Lillqvist 2010-09-09 15:44:12 +03:00
parent 7464a9ca08
commit e748334327

View File

@ -33,6 +33,8 @@
#include <windows.h>
#include <wintab.h>
#define WINTAB32_DLL "Wintab32.dll"
#define PACKETDATA (PK_CONTEXT | PK_CURSOR | PK_BUTTONS | PK_X | PK_Y | PK_NORMAL_PRESSURE | PK_ORIENTATION)
/* We want everything in absolute mode */
#define PACKETMODE (0)
@ -376,6 +378,9 @@ _gdk_input_wintab_init_check (GdkDeviceManagerWin32 *device_manager)
gchar *devname_utf8, *csrname_utf8, *device_name;
BOOL defcontext_done;
HMODULE wintab32;
char *wintab32_dll_path;
char dummy;
int n, k;
if (wintab_initialized)
return;
@ -387,7 +392,25 @@ _gdk_input_wintab_init_check (GdkDeviceManagerWin32 *device_manager)
if (_gdk_input_ignore_wintab)
return;
if ((wintab32 = LoadLibrary ("wintab32.dll")) == NULL)
n = GetSystemDirectory (&dummy, 0);
if (n <= 0)
return;
wintab32_dll_path = g_malloc (n + 1 + strlen (WINTAB32_DLL));
k = GetSystemDirectory (wintab32_dll_path, n);
if (k == 0 || k > n)
{
g_free (wintab32_dll_path);
return;
}
if (!G_IS_DIR_SEPARATOR (wintab32_dll_path[strlen (wintab32_dll_path) -1]))
strcat (wintab32_dll_path, G_DIR_SEPARATOR_S);
strcat (wintab32_dll_path, WINTAB32_DLL);
if ((wintab32 = LoadLibrary (wintab32_dll_path)) == NULL)
return;
if ((p_WTInfoA = (t_WTInfoA) GetProcAddress (wintab32, "WTInfoA")) == NULL)