From 78cad998e505b667d25ac42f8aaa24409f5031e1 Mon Sep 17 00:00:00 2001
From: Nikita Shulga <nshulga@meta.com>
Date: Thu, 17 Nov 2022 22:05:27 +0000
Subject: [PATCH] [JIT][Security] Do not blindly eval input string (#89189)

Introduce `_eval_no_call` method, that evaluates statement only if it
does not contain any calls(done by examining the bytecode), thus preventing command injection exploit

Added simple unit test to check for that
`torch.jit.annotations.get_signature` would not result in calling random
code.

Although, this code path exists for Python-2 compatibility, and perhaps
should be simply removed.

diff --git a/torch/jit/annotations.py b/torch/jit/annotations.py
index a4a36ce36a5e8..a6ff2d04d2076 100644
--- a/torch/jit/annotations.py
+++ b/torch/jit/annotations.py
@@ -1,4 +1,5 @@
 import ast
+import dis
 import enum
 import inspect
 import re
@@ -144,6 +145,15 @@ def check_fn(fn, loc):
         raise torch.jit.frontend.FrontendError(loc, "Expected a single top-level function")
 
 
+def _eval_no_call(stmt, glob, loc):
+    """Evaluate statement as long as it does not contain any method/function calls"""
+    bytecode = compile(stmt, "", mode="eval")
+    for insn in dis.get_instructions(bytecode):
+        if "CALL" in insn.opname:
+            raise RuntimeError(f"Type annotation should not contain calls, but '{stmt}' does")
+    return eval(bytecode, glob, loc)  # type: ignore[arg-type] # noqa: P204
+
+
 def parse_type_line(type_line, rcb, loc):
     """Parses a type annotation specified as a comment.
 
@@ -154,7 +164,7 @@ def parse_type_line(type_line, rcb, loc):
     arg_ann_str, ret_ann_str = split_type_line(type_line)
 
     try:
-        arg_ann = eval(arg_ann_str, {}, EvalEnv(rcb))  # type: ignore[arg-type] # noqa: P204
+        arg_ann = _eval_no_call(arg_ann_str, {}, EvalEnv(rcb))
     except (NameError, SyntaxError) as e:
         raise RuntimeError("Failed to parse the argument list of a type annotation") from e
 
@@ -162,7 +172,7 @@ def parse_type_line(type_line, rcb, loc):
         arg_ann = (arg_ann,)
 
     try:
-        ret_ann = eval(ret_ann_str, {}, EvalEnv(rcb))  # type: ignore[arg-type] # noqa: P204
+        ret_ann = _eval_no_call(ret_ann_str, {}, EvalEnv(rcb))
     except (NameError, SyntaxError) as e:
         raise RuntimeError("Failed to parse the return type of a type annotation") from e