bpo-32890, os: Use errno instead of GetLastError() in execve() and truncate() (GH...

path_error() uses GetLastError() on Windows, but some os functions
are implemented via CRT APIs which report errors via errno.
This may result in raising OSError with invalid error code (such
as zero).

Introduce posix_path_error() function and use it where appropriate.
(cherry picked from commit 834603112e6ca35944dd21105b01fca562dc3241)

Co-authored-by: Alexey Izbyshev <izbyshev@ispras.ru>

diff --git a/Lib/test/test_os.py b/Lib/test/test_os.py
index cef4a09d7de994deed6e91f05aa94d26f23c1d0f..098d1d44fa3556defd745057dc18d91c3533f756 100644 (file)
--- a/Lib/test/test_os.py
+++ b/Lib/test/test_os.py
@@ -1589,6 +1589,16 @@ class ExecTests(unittest.TestCase):
         with self.assertRaises(ValueError):
             os.execve(args[0], args, newenv)
 
+    @unittest.skipUnless(sys.platform == "win32", "Win32-specific test")
+    def test_execve_with_empty_path(self):
+        # bpo-32890: Check GetLastError() misuse
+        try:
+            os.execve('', ['arg'], {})
+        except OSError as e:
+            self.assertTrue(e.winerror is None or e.winerror != 0)
+        else:
+            self.fail('No OSError raised')
+
 
 @unittest.skipUnless(sys.platform == "win32", "Win32 specific tests")
 class Win32ErrorTests(unittest.TestCase):

diff --git a/Misc/NEWS.d/next/Windows/2018-03-08-20-02-38.bpo-32890.3jzFzY.rst b/Misc/NEWS.d/next/Windows/2018-03-08-20-02-38.bpo-32890.3jzFzY.rst
new file mode 100644 (file)
index 0000000..e8a63b3
--- /dev/null
+++ b/Misc/NEWS.d/next/Windows/2018-03-08-20-02-38.bpo-32890.3jzFzY.rst
@@ -0,0 +1,2 @@
+Fix usage of GetLastError() instead of errno in os.execve() and
+os.truncate().

diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index bbbff1eca8ffbf7935826b1ebb9e518a2eb88978..0c48a66a64dd78a8397620ea0e1dec91c4e605cd 100644 (file)
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -1421,6 +1421,12 @@ win32_error_object(const char* function, PyObject* filename)
 
 #endif /* MS_WINDOWS */
 
+static PyObject *
+posix_path_object_error(PyObject *path)
+{
+    return PyErr_SetFromErrnoWithFilenameObject(PyExc_OSError, path);
+}
+
 static PyObject *
 path_object_error(PyObject *path)
 {
@@ -1428,7 +1434,7 @@ path_object_error(PyObject *path)
     return PyErr_SetExcFromWindowsErrWithFilenameObject(
                 PyExc_OSError, 0, path);
 #else
-    return PyErr_SetFromErrnoWithFilenameObject(PyExc_OSError, path);
+    return posix_path_object_error(path);
 #endif
 }
 
@@ -1449,6 +1455,12 @@ path_error(path_t *path)
     return path_object_error(path->object);
 }
 
+static PyObject *
+posix_path_error(path_t *path)
+{
+    return posix_path_object_error(path->object);
+}
+
 static PyObject *
 path_error2(path_t *path, path_t *path2)
 {
@@ -5097,7 +5109,7 @@ os_execve_impl(PyObject *module, path_t *path, PyObject *argv, PyObject *env)
 
     /* If we get here it's definitely an error */
 
-    path_error(path);
+    posix_path_error(path);
 
     free_string_array(envlist, envc);
   fail:
@@ -9060,7 +9072,7 @@ os_truncate_impl(PyObject *module, path_t *path, Py_off_t length)
     _Py_END_SUPPRESS_IPH
     Py_END_ALLOW_THREADS
     if (result < 0)
-        return path_error(path);
+        return posix_path_error(path);
 
     Py_RETURN_NONE;
 }