gh-123657: Fix crash and refleak in `decimal.getcontext()` (GH-123703)

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neonene 2024-09-06 20:15:23 +09:00 committed by GitHub
parent 8311b11800
commit 853588e24c
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GPG Key ID: B5690EEEBB952194
2 changed files with 18 additions and 10 deletions

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@ -0,0 +1,2 @@
Fix crash and memory leak in :func:`decimal.getcontext`. It crashed when using
a thread-local context by ``--with-decimal-contextvar=no``.

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@ -76,8 +76,9 @@ typedef struct {
#ifndef WITH_DECIMAL_CONTEXTVAR
/* Key for thread state dictionary */
PyObject *tls_context_key;
/* Invariant: NULL or the most recently accessed thread local context */
struct PyDecContextObject *cached_context;
/* Invariant: NULL or a strong reference to the most recently accessed
thread local context. */
struct PyDecContextObject *cached_context; /* Not borrowed */
#else
PyObject *current_context_var;
#endif
@ -1419,12 +1420,6 @@ context_dealloc(PyDecContextObject *self)
{
PyTypeObject *tp = Py_TYPE(self);
PyObject_GC_UnTrack(self);
#ifndef WITH_DECIMAL_CONTEXTVAR
decimal_state *state = get_module_state_by_def(Py_TYPE(self));
if (self == state->cached_context) {
state->cached_context = NULL;
}
#endif
(void)context_clear(self);
tp->tp_free(self);
Py_DECREF(tp);
@ -1701,7 +1696,8 @@ current_context_from_dict(decimal_state *modstate)
/* Cache the context of the current thread, assuming that it
* will be accessed several times before a thread switch. */
modstate->cached_context = (PyDecContextObject *)tl_context;
Py_XSETREF(modstate->cached_context,
(PyDecContextObject *)Py_NewRef(tl_context));
modstate->cached_context->tstate = tstate;
/* Borrowed reference with refcount==1 */
@ -1769,7 +1765,7 @@ PyDec_SetCurrentContext(PyObject *self, PyObject *v)
Py_INCREF(v);
}
state->cached_context = NULL;
Py_CLEAR(state->cached_context);
if (PyDict_SetItem(dict, state->tls_context_key, v) < 0) {
Py_DECREF(v);
return NULL;
@ -6122,6 +6118,16 @@ decimal_traverse(PyObject *module, visitproc visit, void *arg)
Py_VISIT(state->Rational);
Py_VISIT(state->SignalTuple);
if (state->signal_map != NULL) {
for (DecCondMap *cm = state->signal_map; cm->name != NULL; cm++) {
Py_VISIT(cm->ex);
}
}
if (state->cond_map != NULL) {
for (DecCondMap *cm = state->cond_map + 1; cm->name != NULL; cm++) {
Py_VISIT(cm->ex);
}
}
return 0;
}