From 01571bfa74f2d60ddfc0308f506efaec7dae3eda Mon Sep 17 00:00:00 2001
From: Victor Stinner <vstinner@python.org>
Date: Wed, 6 Nov 2024 14:24:46 +0100
Subject: [PATCH] gh-126461: Fix _Unpickler_ReadFromFile() error handling
 (GH-126485)

Handle _Unpickler_SetStringInput() failure.
(cherry picked from commit a1c57bcfd2bcbc55ff858407e09c1d8d8cee44e6)

Co-authored-by: Victor Stinner <vstinner@python.org>
---
 Modules/_pickle.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Modules/_pickle.c b/Modules/_pickle.c
index 879c18263d505e..179500d6956a78 100644
--- a/Modules/_pickle.c
+++ b/Modules/_pickle.c
@@ -1344,6 +1344,10 @@ _Unpickler_ReadFromFile(UnpicklerObject *self, Py_ssize_t n)
             else {
                 read_size = _Unpickler_SetStringInput(self, data);
                 Py_DECREF(data);
+                if (read_size < 0) {
+                    return -1;
+                }
+
                 self->prefetched_idx = 0;
                 if (n <= read_size)
                     return n;