- Issue #3845: In PyRun_SimpleFileExFlags avoid invalid memory access with
short file names.
diff --git a/Python/pythonrun.c b/Python/pythonrun.c
index b3866ce..8fc0ca1 100644
--- a/Python/pythonrun.c
+++ b/Python/pythonrun.c
@@ -898,7 +898,7 @@
{
PyObject *m, *d, *v;
const char *ext;
- int set_file_name = 0, ret;
+ int set_file_name = 0, ret, len;
m = PyImport_AddModule("__main__");
if (m == NULL)
@@ -915,7 +915,8 @@
set_file_name = 1;
Py_DECREF(f);
}
- ext = filename + strlen(filename) - 4;
+ len = strlen(filename);
+ ext = filename + len - (len > 4 ? 4 : 0);
if (maybe_pyc_file(fp, filename, ext, closeit)) {
/* Try to run a pyc file. First, re-open in binary */
if (closeit)