commit d3b73f32ef7c693a6ae8c54eb0e62df3b5315caf
author Christian Heimes <christian@python.org> Fri Apr 09 15:23:38 2021 +0200
committer GitHub <noreply@github.com> Fri Apr 09 15:23:38 2021 +0200
tree c2894776911d3bc7feec987f7d5167174c649e54
parent bd88ccb943c0ea672c14a87e76157fade4feae11

bpo-43789: OpenSSL 3.0.0 Don't call passwd callback again in error case (GH-25303)

Modules/_ssl.c

diff --git a/Modules/_ssl.c b/Modules/_ssl.c
index f3c3b20..94b06dd 100644
--- a/Modules/_ssl.c
+++ b/Modules/_ssl.c
@@ -3926,6 +3926,13 @@ _password_callback(char *buf, int size, int rwflag, void *userdata)
 
     PySSL_END_ALLOW_THREADS_S(pw_info->thread_state);
 
+    if (pw_info->error) {
+        /* already failed previously. OpenSSL 3.0.0-alpha14 invokes the
+         * callback multiple times which can lead to fatal Python error in
+         * exception check. */
+        goto error;
+    }
+
     if (pw_info->callable) {
         fn_ret = _PyObject_CallNoArg(pw_info->callable);
         if (!fn_ret) {