1 files changed, 3 insertions, 0 deletions
diff --git a/Python/ast.c b/Python/ast.c
index da42a0e..79c9403 100644
--- a/Python/ast.c
+++ b/Python/ast.c
@@ -3145,6 +3145,9 @@ decode_unicode(struct compiling *c, const char *s, size_t len, int rawmode, cons
         buf = (char *)s;
         u = NULL;
     } else {
+        /* check for integer overflow */
+        if (len > PY_SIZE_MAX / 4)
+            return NULL;
         /* "\XX" may become "\u005c\uHHLL" (12 bytes) */
         u = PyBytes_FromStringAndSize((char *)NULL, len * 4);
         if (u == NULL)