python · miss-islington · Jun 22, 2020 · Jun 22, 2020
diff --git a/Misc/NEWS.d/next/Core and Builtins/2020-06-21-19-53-33.bpo-41056.IDu_EK.rst b/Misc/NEWS.d/next/Core and Builtins/2020-06-21-19-53-33.bpo-41056.IDu_EK.rst
@@ -0,0 +1 @@
+Fixes a reference to deallocated stack space during startup when constructing sys.path involving a relative symlink when code was supplied via -c.  (discovered via Coverity)
diff --git a/Python/pathconfig.c b/Python/pathconfig.c
@@ -679,6 +679,7 @@ _PyPathConfig_ComputeSysPath0(const PyWideStringList *argv, PyObject **path0_p)
 #ifdef HAVE_READLINK
    wchar_t link[MAXPATHLEN + 1];
    int nr = 0;
+    wchar_t path0copy[2 * MAXPATHLEN + 1];

    if (have_script_arg) {
        nr = _Py_wreadlink(path0, link, Py_ARRAY_LENGTH(link));
@@ -701,7 +702,6 @@ _PyPathConfig_ComputeSysPath0(const PyWideStringList *argv, PyObject **path0_p)
            }
            else {
                /* Must make a copy, path0copy has room for 2 * MAXPATHLEN */
-                wchar_t path0copy[2 * MAXPATHLEN + 1];
                wcsncpy(path0copy, path0, MAXPATHLEN);
                q = wcsrchr(path0copy, SEP);
                wcsncpy(q+1, link, MAXPATHLEN);
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1 @@
		Fixes a reference to deallocated stack space during startup when constructing sys.path involving a relative symlink when code was supplied via -c. (discovered via Coverity)