Issue #26494: Fixed crash on iterating exhausting iterators.

Affected classes are generic sequence iterators, iterators of str, bytes,
bytearray, list, tuple, set, frozenset, dict, OrderedDict, corresponding
views and os.scandir() iterator.

1 files changed, 10 insertions, 6 deletions

diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index 1cd0f24148..9013888f29 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -11956,13 +11956,15 @@ ScandirIterator_is_closed(ScandirIterator *iterator)
 static void
 ScandirIterator_closedir(ScandirIterator *iterator)
 {
-    if (iterator->handle == INVALID_HANDLE_VALUE)
+    HANDLE handle = iterator->handle;
+
+    if (handle == INVALID_HANDLE_VALUE)
         return;
 
+    iterator->handle = INVALID_HANDLE_VALUE;
     Py_BEGIN_ALLOW_THREADS
-    FindClose(iterator->handle);
+    FindClose(handle);
     Py_END_ALLOW_THREADS
-    iterator->handle = INVALID_HANDLE_VALUE;
 }
 
 static PyObject *
@@ -12018,13 +12020,15 @@ ScandirIterator_is_closed(ScandirIterator *iterator)
 static void
 ScandirIterator_closedir(ScandirIterator *iterator)
 {
-    if (!iterator->dirp)
+    DIR *dirp = iterator->dirp;
+
+    if (!dirp)
         return;
 
+    iterator->dirp = NULL;
     Py_BEGIN_ALLOW_THREADS
-    closedir(iterator->dirp);
+    closedir(dirp);
     Py_END_ALLOW_THREADS
-    iterator->dirp = NULL;
     return;
 }