Issue #27932: Prevent memory leak in win32_ver().

zooba · zooba · commit 74f4af7ac304 · 2016-09-17T17:27:48.000-07:00
diff --git a/Doc/library/sys.rst b/Doc/library/sys.rst
@@ -552,26 +552,15 @@ always available.
    Return a named tuple describing the Windows version
    currently running.  The named elements are *major*, *minor*,
    *build*, *platform*, *service_pack*, *service_pack_minor*,
-   *service_pack_major*, *suite_mask*, and *product_type*.
-   *service_pack* contains a string while all other values are
+   *service_pack_major*, *suite_mask*, *product_type* and
+   *platform_version*. *service_pack* contains a string,
+   *platform_version* a 3-tuple and all other values are
    integers. The components can also be accessed by name, so
    ``sys.getwindowsversion()[0]`` is equivalent to
    ``sys.getwindowsversion().major``. For compatibility with prior
    versions, only the first 5 elements are retrievable by indexing.
 
-   *platform* may be one of the following values:
-
-   +-----------------------------------------+-------------------------+
-   | Constant                                | Platform                |
-   +=========================================+=========================+
-   | :const:`0 (VER_PLATFORM_WIN32s)`        | Win32s on Windows 3.1   |
-   +-----------------------------------------+-------------------------+
-   | :const:`1 (VER_PLATFORM_WIN32_WINDOWS)` | Windows 95/98/ME        |
-   +-----------------------------------------+-------------------------+
-   | :const:`2 (VER_PLATFORM_WIN32_NT)`      | Windows NT/2000/XP/x64  |
-   +-----------------------------------------+-------------------------+
-   | :const:`3 (VER_PLATFORM_WIN32_CE)`      | Windows CE              |
-   +-----------------------------------------+-------------------------+
+   *platform* will be :const:`2 (VER_PLATFORM_WIN32_NT)`.
 
    *product_type* may be one of the following values:
 
@@ -587,17 +576,23 @@ always available.
    |                                       | a domain controller.            |
    +---------------------------------------+---------------------------------+
 
-
    This function wraps the Win32 :c:func:`GetVersionEx` function; see the
    Microsoft documentation on :c:func:`OSVERSIONINFOEX` for more information
    about these fields.
 
+   *platform_version* returns the accurate major version, minor version and
+   build number of the current operating system, rather than the version that
+   is being emulated for the process. It is intended for use in logging rather
+   than for feature detection.
+
    Availability: Windows.
 
    .. versionchanged:: 3.2
       Changed to a named tuple and added *service_pack_minor*,
       *service_pack_major*, *suite_mask*, and *product_type*.
 
+   .. versionchanged:: 3.6
+      Added *platform_version*
 
 .. function:: get_coroutine_wrapper()
 
diff --git a/Lib/platform.py b/Lib/platform.py
@@ -497,65 +497,6 @@ def _syscmd_ver(system='', release='', version='',
     (6, None): "post2012ServerR2",
 }
 
-def _get_real_winver(maj, min, build):
-    if maj < 6 or (maj == 6 and min < 2):
-        return maj, min, build
-
-    from ctypes import (c_buffer, POINTER, byref, create_unicode_buffer,
-                        Structure, WinDLL)
-    from ctypes.wintypes import DWORD, HANDLE
-
-    class VS_FIXEDFILEINFO(Structure):
-        _fields_ = [
-            ("dwSignature", DWORD),
-            ("dwStrucVersion", DWORD),
-            ("dwFileVersionMS", DWORD),
-            ("dwFileVersionLS", DWORD),
-            ("dwProductVersionMS", DWORD),
-            ("dwProductVersionLS", DWORD),
-            ("dwFileFlagsMask", DWORD),
-            ("dwFileFlags", DWORD),
-            ("dwFileOS", DWORD),
-            ("dwFileType", DWORD),
-            ("dwFileSubtype", DWORD),
-            ("dwFileDateMS", DWORD),
-            ("dwFileDateLS", DWORD),
-        ]
-
-    kernel32 = WinDLL('kernel32')
-    version = WinDLL('version')
-
-    # We will immediately double the length up to MAX_PATH, but the
-    # path may be longer, so we retry until the returned string is
-    # shorter than our buffer.
-    name_len = actual_len = 130
-    while actual_len == name_len:
-        name_len *= 2
-        name = create_unicode_buffer(name_len)
-        actual_len = kernel32.GetModuleFileNameW(HANDLE(kernel32._handle),
-                                                 name, len(name))
-        if not actual_len:
-            return maj, min, build
-
-    size = version.GetFileVersionInfoSizeW(name, None)
-    if not size:
-        return maj, min, build
-
-    ver_block = c_buffer(size)
-    if (not version.GetFileVersionInfoW(name, None, size, ver_block) or
-        not ver_block):
-        return maj, min, build
-
-    pvi = POINTER(VS_FIXEDFILEINFO)()
-    if not version.VerQueryValueW(ver_block, "", byref(pvi), byref(DWORD())):
-        return maj, min, build
-
-    maj = pvi.contents.dwProductVersionMS >> 16
-    min = pvi.contents.dwProductVersionMS & 0xFFFF
-    build = pvi.contents.dwProductVersionLS >> 16
-
-    return maj, min, build
-
 def win32_ver(release='', version='', csd='', ptype=''):
     try:
         from sys import getwindowsversion
@@ -567,7 +508,7 @@ def win32_ver(release='', version='', csd='', ptype=''):
         from _winreg import OpenKeyEx, QueryValueEx, CloseKey, HKEY_LOCAL_MACHINE
 
     winver = getwindowsversion()
-    maj, min, build = _get_real_winver(*winver[:3])
+    maj, min, build = winver.platform_version or winver[:3]
     version = '{0}.{1}.{2}'.format(maj, min, build)
 
     release = (_WIN32_CLIENT_RELEASES.get((maj, min)) or
diff --git a/Misc/NEWS b/Misc/NEWS
@@ -29,6 +29,8 @@ Core and Builtins
 Library
 -------
 
+- Issue #27932: Prevent memory leak in win32_ver().
+
 - Fix UnboundLocalError in socket._sendfile_use_sendfile.
 
 - Issue #28075: Check for ERROR_ACCESS_DENIED in Windows implementation of
diff --git a/PCbuild/pythoncore.vcxproj b/PCbuild/pythoncore.vcxproj
@@ -69,7 +69,7 @@
       <PreprocessorDefinitions>_USRDLL;Py_BUILD_CORE;Py_ENABLE_SHARED;MS_DLL_ID="$(SysWinVer)";%(PreprocessorDefinitions)</PreprocessorDefinitions>
     </ClCompile>
     <Link>
-      <AdditionalDependencies>shlwapi.lib;ws2_32.lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <AdditionalDependencies>version.lib;shlwapi.lib;ws2_32.lib;%(AdditionalDependencies)</AdditionalDependencies>
       <BaseAddress>0x1e000000</BaseAddress>
     </Link>
   </ItemDefinitionGroup>
diff --git a/Python/sysmodule.c b/Python/sysmodule.c
@@ -894,10 +894,11 @@ Return information about the running version of Windows as a named tuple.\n\
 The members are named: major, minor, build, platform, service_pack,\n\
 service_pack_major, service_pack_minor, suite_mask, and product_type. For\n\
 backward compatibility, only the first 5 items are available by indexing.\n\
-All elements are numbers, except service_pack which is a string. Platform\n\
-may be 0 for win32s, 1 for Windows 9x/ME, 2 for Windows NT/2000/XP/Vista/7,\n\
-3 for Windows CE. Product_type may be 1 for a workstation, 2 for a domain\n\
-controller, 3 for a server."
+All elements are numbers, except service_pack and platform_type which are\n\
+strings, and platform_version which is a 3-tuple. Platform is always 2.\n\
+Product_type may be 1 for a workstation, 2 for a domain controller, 3 for a\n\
+server. Platform_version is a 3-tuple containing a version number that is\n\
+intended for identifying the OS rather than feature detection."
 );
 
 static PyTypeObject WindowsVersionType = {0, 0, 0, 0, 0, 0};
@@ -912,6 +913,7 @@ static PyStructSequence_Field windows_version_fields[] = {
     {"service_pack_minor", "Service Pack minor version number"},
     {"suite_mask", "Bit mask identifying available product suites"},
     {"product_type", "System product type"},
+    {"platform_version", "Diagnostic version number"},
     {0}
 };
 
@@ -936,6 +938,12 @@ sys_getwindowsversion(PyObject *self)
     PyObject *version;
     int pos = 0;
     OSVERSIONINFOEX ver;
+    DWORD realMajor, realMinor, realBuild;
+    HANDLE hKernel32;
+    wchar_t kernel32_path[MAX_PATH];
+    LPVOID verblock;
+    DWORD verblock_size;
+
     ver.dwOSVersionInfoSize = sizeof(ver);
     if (!GetVersionEx((OSVERSIONINFO*) &ver))
         return PyErr_SetFromWindowsErr(0);
@@ -954,10 +962,40 @@ sys_getwindowsversion(PyObject *self)
     PyStructSequence_SET_ITEM(version, pos++, PyLong_FromLong(ver.wSuiteMask));
     PyStructSequence_SET_ITEM(version, pos++, PyLong_FromLong(ver.wProductType));
 
+    realMajor = ver.dwMajorVersion;
+    realMinor = ver.dwMinorVersion;
+    realBuild = ver.dwBuildNumber;
+
+    // GetVersion will lie if we are running in a compatibility mode.
+    // We need to read the version info from a system file resource
+    // to accurately identify the OS version. If we fail for any reason,
+    // just return whatever GetVersion said.
+    hKernel32 = GetModuleHandleW(L"kernel32.dll");
+    if (hKernel32 && GetModuleFileNameW(hKernel32, kernel32_path, MAX_PATH) &&
+        (verblock_size = GetFileVersionInfoSizeW(kernel32_path, NULL)) &&
+        (verblock = PyMem_RawMalloc(verblock_size))) {
+        VS_FIXEDFILEINFO *ffi;
+        UINT ffi_len;
+
+        if (GetFileVersionInfoW(kernel32_path, 0, verblock_size, verblock) &&
+            VerQueryValueW(verblock, L"", (LPVOID)&ffi, &ffi_len)) {
+            realMajor = HIWORD(ffi->dwProductVersionMS);
+            realMinor = LOWORD(ffi->dwProductVersionMS);
+            realBuild = HIWORD(ffi->dwProductVersionLS);
+        }
+        PyMem_RawFree(verblock);
+    }
+    PyStructSequence_SET_ITEM(version, pos++, PyTuple_Pack(3,
+        PyLong_FromLong(realMajor),
+        PyLong_FromLong(realMinor),
+        PyLong_FromLong(realBuild)
+    ));
+
     if (PyErr_Occurred()) {
         Py_DECREF(version);
         return NULL;
     }
+
     return version;
 }
 
