gh-111178: fix UBSan failures in Modules/_sre/sre.c (GH-128250)

fix UBSan failures for `PatternObject`, `MatchObject`, `TemplateObject`, `ScannerObject`

Author: picnixz

Modules/_sre/sre.c

@@ -395,6 +395,11 @@ static struct PyModuleDef sremodule;
 static PyObject*pattern_new_match(_sremodulestate *, PatternObject*, SRE_STATE*, Py_ssize_t);
 static PyObject *pattern_scanner(_sremodulestate *, PatternObject *, PyObject *, Py_ssize_t, Py_ssize_t);
 
+#define _PatternObject_CAST(op)     ((PatternObject *)(op))
+#define _MatchObject_CAST(op)       ((MatchObject *)(op))
+#define _TemplateObject_CAST(op)    ((TemplateObject *)(op))
+#define _ScannerObject_CAST(op)     ((ScannerObject *)(op))
+
 /*[clinic input]
 module _sre
 class _sre.SRE_Pattern "PatternObject *" "get_sre_module_state_by_class(tp)->Pattern_Type"
@@ -699,8 +704,9 @@ pattern_error(Py_ssize_t status)
 }
 
 static int
-pattern_traverse(PatternObject *self, visitproc visit, void *arg)
+pattern_traverse(PyObject *op, visitproc visit, void *arg)
 {
+    PatternObject *self = _PatternObject_CAST(op);
     Py_VISIT(Py_TYPE(self));
     Py_VISIT(self->groupindex);
     Py_VISIT(self->indexgroup);
@@ -712,8 +718,9 @@ pattern_traverse(PatternObject *self, visitproc visit, void *arg)
 }
 
 static int
-pattern_clear(PatternObject *self)
+pattern_clear(PyObject *op)
 {
+    PatternObject *self = _PatternObject_CAST(op);
     Py_CLEAR(self->groupindex);
     Py_CLEAR(self->indexgroup);
     Py_CLEAR(self->pattern);
@@ -724,13 +731,13 @@ pattern_clear(PatternObject *self)
 }
 
 static void
-pattern_dealloc(PatternObject* self)
+pattern_dealloc(PyObject *self)
 {
     PyTypeObject *tp = Py_TYPE(self);
-
     PyObject_GC_UnTrack(self);
-    if (self->weakreflist != NULL) {
-        PyObject_ClearWeakRefs((PyObject *) self);
+    PatternObject *obj = _PatternObject_CAST(self);
+    if (obj->weakreflist != NULL) {
+        PyObject_ClearWeakRefs(self);
     }
     (void)pattern_clear(self);
     tp->tp_free(self);
@@ -1497,7 +1504,7 @@ _sre_SRE_Pattern__fail_after_impl(PatternObject *self, int count,
 #endif /* Py_DEBUG */
 
 static PyObject *
-pattern_repr(PatternObject *obj)
+pattern_repr(PyObject *self)
 {
     static const struct {
         const char *name;
@@ -1512,6 +1519,8 @@ pattern_repr(PatternObject *obj)
         {"re.DEBUG", SRE_FLAG_DEBUG},
         {"re.ASCII", SRE_FLAG_ASCII},
     };
+
+    PatternObject *obj = _PatternObject_CAST(self);
     PyObject *result = NULL;
     PyObject *flag_items;
     size_t i;
@@ -1579,8 +1588,9 @@ PyDoc_STRVAR(pattern_doc, "Compiled regular expression object.");
 
 /* PatternObject's 'groupindex' method. */
 static PyObject *
-pattern_groupindex(PatternObject *self, void *Py_UNUSED(ignored))
+pattern_groupindex(PyObject *op, void *Py_UNUSED(ignored))
 {
+    PatternObject *self = _PatternObject_CAST(op);
     if (self->groupindex == NULL)
         return PyDict_New();
     return PyDictProxy_New(self->groupindex);
@@ -2245,8 +2255,9 @@ _validate(PatternObject *self)
 /* match methods */
 
 static int
-match_traverse(MatchObject *self, visitproc visit, void *arg)
+match_traverse(PyObject *op, visitproc visit, void *arg)
 {
+    MatchObject *self = _MatchObject_CAST(op);
     Py_VISIT(Py_TYPE(self));
     Py_VISIT(self->string);
     Py_VISIT(self->regs);
@@ -2255,19 +2266,19 @@ match_traverse(MatchObject *self, visitproc visit, void *arg)
 }
 
 static int
-match_clear(MatchObject *self)
+match_clear(PyObject *op)
 {
+    MatchObject *self = _MatchObject_CAST(op);
     Py_CLEAR(self->string);
     Py_CLEAR(self->regs);
     Py_CLEAR(self->pattern);
     return 0;
 }
 
 static void
-match_dealloc(MatchObject* self)
+match_dealloc(PyObject *self)
 {
     PyTypeObject *tp = Py_TYPE(self);
-
     PyObject_GC_UnTrack(self);
     (void)match_clear(self);
     tp->tp_free(self);
@@ -2376,8 +2387,9 @@ _sre_SRE_Match_expand_impl(MatchObject *self, PyObject *template)
 }
 
 static PyObject*
-match_group(MatchObject* self, PyObject* args)
+match_group(PyObject *op, PyObject* args)
 {
+    MatchObject *self = _MatchObject_CAST(op);
     PyObject* result;
     Py_ssize_t i, size;
 
@@ -2411,8 +2423,9 @@ match_group(MatchObject* self, PyObject* args)
 }
 
 static PyObject*
-match_getitem(MatchObject* self, PyObject* name)
+match_getitem(PyObject *op, PyObject* name)
 {
+    MatchObject *self = _MatchObject_CAST(op);
     return match_getslice(self, name, Py_None);
 }
 
@@ -2654,16 +2667,18 @@ PyDoc_STRVAR(match_group_doc,
     For 0 returns the entire match.");
 
 static PyObject *
-match_lastindex_get(MatchObject *self, void *Py_UNUSED(ignored))
+match_lastindex_get(PyObject *op, void *Py_UNUSED(ignored))
 {
+    MatchObject *self = _MatchObject_CAST(op);
     if (self->lastindex >= 0)
         return PyLong_FromSsize_t(self->lastindex);
     Py_RETURN_NONE;
 }
 
 static PyObject *
-match_lastgroup_get(MatchObject *self, void *Py_UNUSED(ignored))
+match_lastgroup_get(PyObject *op, void *Py_UNUSED(ignored))
 {
+    MatchObject *self = _MatchObject_CAST(op);
     if (self->pattern->indexgroup &&
         self->lastindex >= 0 &&
         self->lastindex < PyTuple_GET_SIZE(self->pattern->indexgroup))
@@ -2676,8 +2691,9 @@ match_lastgroup_get(MatchObject *self, void *Py_UNUSED(ignored))
 }
 
 static PyObject *
-match_regs_get(MatchObject *self, void *Py_UNUSED(ignored))
+match_regs_get(PyObject *op, void *Py_UNUSED(ignored))
 {
+    MatchObject *self = _MatchObject_CAST(op);
     if (self->regs) {
         return Py_NewRef(self->regs);
     } else
@@ -2780,27 +2796,29 @@ pattern_new_match(_sremodulestate* module_state,
 /* scanner methods (experimental) */
 
 static int
-scanner_traverse(ScannerObject *self, visitproc visit, void *arg)
+scanner_traverse(PyObject *op, visitproc visit, void *arg)
 {
+    ScannerObject *self = _ScannerObject_CAST(op);
     Py_VISIT(Py_TYPE(self));
     Py_VISIT(self->pattern);
     return 0;
 }
 
 static int
-scanner_clear(ScannerObject *self)
+scanner_clear(PyObject *op)
 {
+    ScannerObject *self = _ScannerObject_CAST(op);
     Py_CLEAR(self->pattern);
     return 0;
 }
 
 static void
-scanner_dealloc(ScannerObject* self)
+scanner_dealloc(PyObject *self)
 {
     PyTypeObject *tp = Py_TYPE(self);
-
     PyObject_GC_UnTrack(self);
-    state_fini(&self->state);
+    ScannerObject *scanner = _ScannerObject_CAST(self);
+    state_fini(&scanner->state);
     (void)scanner_clear(self);
     tp->tp_free(self);
     Py_DECREF(tp);
@@ -2957,8 +2975,9 @@ pattern_scanner(_sremodulestate *module_state,
 /* template methods */
 
 static int
-template_traverse(TemplateObject *self, visitproc visit, void *arg)
+template_traverse(PyObject *op, visitproc visit, void *arg)
 {
+    TemplateObject *self = _TemplateObject_CAST(op);
     Py_VISIT(Py_TYPE(self));
     Py_VISIT(self->literal);
     for (Py_ssize_t i = 0, n = Py_SIZE(self); i < n; i++) {
@@ -2968,8 +2987,9 @@ template_traverse(TemplateObject *self, visitproc visit, void *arg)
 }
 
 static int
-template_clear(TemplateObject *self)
+template_clear(PyObject *op)
 {
+    TemplateObject *self = _TemplateObject_CAST(op);
     Py_CLEAR(self->literal);
     for (Py_ssize_t i = 0, n = Py_SIZE(self); i < n; i++) {
         Py_CLEAR(self->items[i].literal);
@@ -2978,10 +2998,9 @@ template_clear(TemplateObject *self)
 }
 
 static void
-template_dealloc(TemplateObject *self)
+template_dealloc(PyObject *self)
 {
     PyTypeObject *tp = Py_TYPE(self);
-
     PyObject_GC_UnTrack(self);
     (void)template_clear(self);
     tp->tp_free(self);
@@ -3056,8 +3075,10 @@ expand_template(TemplateObject *self, MatchObject *match)
 
 
 static Py_hash_t
-pattern_hash(PatternObject *self)
+pattern_hash(PyObject *op)
 {
+    PatternObject *self = _PatternObject_CAST(op);
+
     Py_hash_t hash, hash2;
 
     hash = PyObject_Hash(self->pattern);
@@ -3148,7 +3169,7 @@ static PyMethodDef pattern_methods[] = {
 };
 
 static PyGetSetDef pattern_getset[] = {
-    {"groupindex", (getter)pattern_groupindex, (setter)NULL,
+    {"groupindex", pattern_groupindex, NULL,
       "A dictionary mapping group names to group numbers."},
     {NULL}  /* Sentinel */
 };
@@ -3166,9 +3187,9 @@ static PyMemberDef pattern_members[] = {
 };
 
 static PyType_Slot pattern_slots[] = {
-    {Py_tp_dealloc, (destructor)pattern_dealloc},
-    {Py_tp_repr, (reprfunc)pattern_repr},
-    {Py_tp_hash, (hashfunc)pattern_hash},
+    {Py_tp_dealloc, pattern_dealloc},
+    {Py_tp_repr, pattern_repr},
+    {Py_tp_hash, pattern_hash},
     {Py_tp_doc, (void *)pattern_doc},
     {Py_tp_richcompare, pattern_richcompare},
     {Py_tp_methods, pattern_methods},
@@ -3189,7 +3210,7 @@ static PyType_Spec pattern_spec = {
 };
 
 static PyMethodDef match_methods[] = {
-    {"group", (PyCFunction) match_group, METH_VARARGS, match_group_doc},
+    {"group", match_group, METH_VARARGS, match_group_doc},
     _SRE_SRE_MATCH_START_METHODDEF
     _SRE_SRE_MATCH_END_METHODDEF
     _SRE_SRE_MATCH_SPAN_METHODDEF
@@ -3204,11 +3225,11 @@ static PyMethodDef match_methods[] = {
 };
 
 static PyGetSetDef match_getset[] = {
-    {"lastindex", (getter)match_lastindex_get, (setter)NULL,
+    {"lastindex", match_lastindex_get, NULL,
      "The integer index of the last matched capturing group."},
-    {"lastgroup", (getter)match_lastgroup_get, (setter)NULL,
+    {"lastgroup", match_lastgroup_get, NULL,
      "The name of the last matched capturing group."},
-    {"regs",      (getter)match_regs_get,      (setter)NULL},
+    {"regs", match_regs_get, NULL, NULL},
     {NULL}
 };