Description

brandtbucher

opened on Jun 9, 2023

Issue body actions

The generated code in Python-ast.c is missing error checks following the construction of C-level alias, arg, comprehension, keyword, match_item, and withitem nodes from their Python object counterparts. This means it's possible to crash the interpreter by attempting to compile an AST where a required member of these nodes is replaced with None:

>>> import ast
>>> tree = ast.parse("""
... match ...:
...     case THIS:
...         ...
... """)
>>> tree.body[0].cases[0].pattern = None
>>> compile(tree, "<crash>", "exec")
Segmentation fault

I'll have a PR up in a minute with the one-line fix.

Linked PRs

• GH-105588: Add missing error checks to some obj2ast_* converters #105589
• [3.12] GH-105588: Add missing error checks to some obj2ast_* converters (GH-105589) #105838
• [3.11] GH-105588: Add missing error checks to some obj2ast_* converters (GH-105589) #105839

Activity

1. brandtbucher

   added

   interpreter-core(Objects, Python, Grammar, and Parser dirs)(Objects, Python, Grammar, and Parser dirs)

   3.11only security fixesonly security fixes

   type-crashA hard crash of the interpreter, possibly with a core dumpA hard crash of the interpreter, possibly with a core dump

   3.12only security fixesonly security fixes

   triagedThe issue has been accepted as valid by a triager.The issue has been accepted as valid by a triager.

   3.13only security fixesonly security fixes

   on Jun 9, 2023
2. brandtbucher

   self-assigned this

   on Jun 9, 2023
3. brandtbucher

   added a commit that references this issue on Jun 15, 2023

   GH-105588: Add missing error checks to some obj2ast_* converters (GH-…

   a4056c8
4. miss-islington

   added 2 commits that reference this issue on Jun 15, 2023

   pythonGH-105588: Add missing error checks to some obj2ast_* converters (

   f8c3966

   pythonGH-105588: Add missing error checks to some obj2ast_* converters (

   3680071
5. brandtbucher

   closed this as completedon Jun 15, 2023
6. brandtbucher

   added 2 commits that reference this issue on Jun 15, 2023

   [3.12] GH-105588: Add missing error checks to some obj2ast_* converte…

   0add516

   [3.11] GH-105588: Add missing error checks to some obj2ast_* converte…

   c0c4186
7. carljm

   added a commit that references this issue on Jun 16, 2023

   Merge branch 'main' into modulelocals

   b096651
8. gvanrossum

   added a commit that references this issue on Jun 18, 2023

   pythonGH-105588: Add missing error checks to some obj2ast_* converters (

   524490c

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