From 87a4cd5fbebdd0e6166b421d2c3706bc2f2e5a11 Mon Sep 17 00:00:00 2001
From: Serhiy Storchaka <storchaka@gmail.com>
Date: Mon, 2 Mar 2020 09:58:48 +0200
Subject: bpo-38410: Properly handle PySys_Audit() failures (GH-18658)

_PyEval_SetAsyncGenFinalizer() and _PyEval_SetAsyncGenFirstiter()
didn't include proper error handling for their PySys_Audit() calls.

Co-authored-by: Zackery Spytz <zspytz@gmail.com>
---
 .../2019-10-09-08-14-25.bpo-38410._YyoMV.rst       |  2 +
 Python/ceval.c                                     | 26 ---------
 Python/sysmodule.c                                 | 61 +++++++++++++++++++---
 3 files changed, 57 insertions(+), 32 deletions(-)
 create mode 100644 Misc/NEWS.d/next/Library/2019-10-09-08-14-25.bpo-38410._YyoMV.rst

diff --git a/Misc/NEWS.d/next/Library/2019-10-09-08-14-25.bpo-38410._YyoMV.rst b/Misc/NEWS.d/next/Library/2019-10-09-08-14-25.bpo-38410._YyoMV.rst
new file mode 100644
index 0000000..fcfd793
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2019-10-09-08-14-25.bpo-38410._YyoMV.rst
@@ -0,0 +1,2 @@
+Properly handle :func:`sys.audit` failures in
+:func:`sys.set_asyncgen_hooks`. Based on patch by Zackery Spytz.
diff --git a/Python/ceval.c b/Python/ceval.c
index 3306fb9..5d78d5a 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -4742,19 +4742,6 @@ _PyEval_GetCoroutineOriginTrackingDepth(void)
     return tstate->coroutine_origin_tracking_depth;
 }
 
-void
-_PyEval_SetAsyncGenFirstiter(PyObject *firstiter)
-{
-    PyThreadState *tstate = _PyThreadState_GET();
-
-    if (PySys_Audit("sys.set_asyncgen_hook_firstiter", NULL) < 0) {
-        return;
-    }
-
-    Py_XINCREF(firstiter);
-    Py_XSETREF(tstate->async_gen_firstiter, firstiter);
-}
-
 PyObject *
 _PyEval_GetAsyncGenFirstiter(void)
 {
@@ -4762,19 +4749,6 @@ _PyEval_GetAsyncGenFirstiter(void)
     return tstate->async_gen_firstiter;
 }
 
-void
-_PyEval_SetAsyncGenFinalizer(PyObject *finalizer)
-{
-    PyThreadState *tstate = _PyThreadState_GET();
-
-    if (PySys_Audit("sys.set_asyncgen_hook_finalizer", NULL) < 0) {
-        return;
-    }
-
-    Py_XINCREF(finalizer);
-    Py_XSETREF(tstate->async_gen_finalizer, finalizer);
-}
-
 PyObject *
 _PyEval_GetAsyncGenFinalizer(void)
 {
diff --git a/Python/sysmodule.c b/Python/sysmodule.c
index da4b6e1..b544f2b 100644
--- a/Python/sysmodule.c
+++ b/Python/sysmodule.c
@@ -1178,6 +1178,51 @@ static PyStructSequence_Desc asyncgen_hooks_desc = {
     2
 };
 
+static int
+set_async_gen_firstiter(PyObject *firstiter)
+{
+    PyThreadState *tstate = _PyThreadState_GET();
+
+    if (PySys_Audit("sys.set_asyncgen_hook_firstiter", NULL) < 0) {
+        return -1;
+    }
+
+    Py_XINCREF(firstiter);
+    Py_XSETREF(tstate->async_gen_firstiter, firstiter);
+    return 0;
+}
+
+void
+_PyEval_SetAsyncGenFirstiter(PyObject *firstiter)
+{
+    if (set_async_gen_firstiter(firstiter) < 0) {
+        PyErr_WriteUnraisable(NULL);
+    }
+}
+
+static int
+set_async_gen_finalizer(PyObject *finalizer)
+{
+    PyThreadState *tstate = _PyThreadState_GET();
+
+    if (PySys_Audit("sys.set_asyncgen_hook_finalizer", NULL) < 0) {
+        return -1;
+    }
+
+    Py_XINCREF(finalizer);
+    Py_XSETREF(tstate->async_gen_finalizer, finalizer);
+    return 0;
+}
+
+void
+_PyEval_SetAsyncGenFinalizer(PyObject *finalizer)
+{
+    if (set_async_gen_finalizer(finalizer) < 0) {
+        PyErr_WriteUnraisable(NULL);
+    }
+}
+
+
 static PyObject *
 sys_set_asyncgen_hooks(PyObject *self, PyObject *args, PyObject *kw)
 {
@@ -1198,10 +1243,12 @@ sys_set_asyncgen_hooks(PyObject *self, PyObject *args, PyObject *kw)
                          Py_TYPE(finalizer)->tp_name);
             return NULL;
         }
-        _PyEval_SetAsyncGenFinalizer(finalizer);
+        if (set_async_gen_finalizer(finalizer) < 0) {
+            return NULL;
+        }
     }
-    else if (finalizer == Py_None) {
-        _PyEval_SetAsyncGenFinalizer(NULL);
+    else if (finalizer == Py_None && set_async_gen_finalizer(NULL) < 0) {
+        return NULL;
     }
 
     if (firstiter && firstiter != Py_None) {
@@ -1211,10 +1258,12 @@ sys_set_asyncgen_hooks(PyObject *self, PyObject *args, PyObject *kw)
                          Py_TYPE(firstiter)->tp_name);
             return NULL;
         }
-        _PyEval_SetAsyncGenFirstiter(firstiter);
+        if (set_async_gen_firstiter(firstiter) < 0) {
+            return NULL;
+        }
     }
-    else if (firstiter == Py_None) {
-        _PyEval_SetAsyncGenFirstiter(NULL);
+    else if (firstiter == Py_None && set_async_gen_firstiter(NULL) < 0) {
+        return NULL;
     }
 
     Py_RETURN_NONE;
-- 
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