bpo-35504: Fix segfaults and SystemErrors when deleting certain attrs. (GH-11175) (GH-11249)

(cherry picked from commit 842acaab1376c5c84fd5966bb6070e289880e1ca)

4 files changed, 16 insertions, 0 deletions

diff --git a/Modules/_ctypes/_ctypes.c b/Modules/_ctypes/_ctypes.c
index 9aa252d..8abcd30 100644
--- a/Modules/_ctypes/_ctypes.c
+++ b/Modules/_ctypes/_ctypes.c
@@ -1216,6 +1216,10 @@ CharArray_set_raw(CDataObject *self, PyObject *value)
 #if (PY_VERSION_HEX >= 0x02060000)
     Py_buffer view = { 0 };
 #endif
+    if (value == NULL) {
+        PyErr_SetString(PyExc_AttributeError, "cannot delete attribute");
+        return -1;
+    }
     if (PyBuffer_Check(value)) {
         size = Py_TYPE(value)->tp_as_buffer->bf_getreadbuffer(value, 0, (void *)&ptr);
         if (size < 0)
diff --git a/Modules/_io/textio.c b/Modules/_io/textio.c
index 5501da4..12a12f9 100644
--- a/Modules/_io/textio.c
+++ b/Modules/_io/textio.c
@@ -2593,6 +2593,10 @@ textiowrapper_chunk_size_set(textio *self, PyObject *arg, void *context)
 {
     Py_ssize_t n;
     CHECK_ATTACHED_INT(self);
+    if (arg == NULL) {
+        PyErr_SetString(PyExc_AttributeError, "cannot delete attribute");
+        return -1;
+    }
     n = PyNumber_AsSsize_t(arg, PyExc_TypeError);
     if (n == -1 && PyErr_Occurred())
         return -1;
diff --git a/Modules/_sqlite/connection.c b/Modules/_sqlite/connection.c
index 585453a..18a6b42 100644
--- a/Modules/_sqlite/connection.c
+++ b/Modules/_sqlite/connection.c
@@ -1131,6 +1131,10 @@ static int pysqlite_connection_set_isolation_level(pysqlite_Connection* self, Py
     PyObject* begin_statement;
     char* begin_statement_str;
 
+    if (isolation_level == NULL) {
+        PyErr_SetString(PyExc_AttributeError, "cannot delete attribute");
+        return -1;
+    }
     Py_XDECREF(self->isolation_level);
 
     if (self->begin_statement) {
diff --git a/Modules/cjkcodecs/multibytecodec.c b/Modules/cjkcodecs/multibytecodec.c
index 4b482bf..1ad0ea0 100644
--- a/Modules/cjkcodecs/multibytecodec.c
+++ b/Modules/cjkcodecs/multibytecodec.c
@@ -138,6 +138,10 @@ codecctx_errors_set(MultibyteStatefulCodecContext *self, PyObject *value,
 {
     PyObject *cb;
 
+    if (value == NULL) {
+        PyErr_SetString(PyExc_AttributeError, "cannot delete attribute");
+        return -1;
+    }
     if (!PyString_Check(value)) {
         PyErr_SetString(PyExc_TypeError, "errors must be a string");
         return -1;