Description

kumaraditya303

opened on Sep 10, 2022

Issue body actions

Reproducer:

import struct
struct.unpack('!q', b'\xff\xff\xff\xff\xff\xff\xff\xff')

Error:

Modules/_struct.c:842:15: runtime error: left shift of 72057594037927935 by 8 places cannot be represented in type 'long long int'

Compiler options:

./configure -C --with-pydebug --with-address-sanitizer --with-undefined-behavior-sanitizer 

Python version: Python 3.12.0a0 (heads/main:30cc1901efa, Sep 10 2022, 10:14:58) [GCC 9.4.0] on linux

Reacted by Matthias Görgens

Activity

1. kumaraditya303

   added

   type-bugAn unexpected behavior, bug, or errorAn unexpected behavior, bug, or error

   extension-modulesC modules in the Modules dirC modules in the Modules dir

   3.11only security fixesonly security fixes

   3.10 (EOL)end of lifeend of life

   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

   on Sep 10, 2022
2. kumaraditya303 commented on Sep 10, 2022

   

   kumaraditya303

   on Sep 10, 2022

   ContributorAuthor

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   cc @mdickinson
3. mdickinson commented on Sep 10, 2022

   

   mdickinson

   on Sep 10, 2022

   Member

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   @kumaraditya303 Thanks; this should be an easy fix.
4. mdickinson

   self-assigned this

   on Sep 10, 2022
5. mdickinson

   added a commit that references this issue on Sep 25, 2022

   gh-96735: Fix undefined behaviour in struct unpacking functions (#96739)

   f5f047a
6. mdickinson commented on Sep 25, 2022

   

   mdickinson

   on Sep 25, 2022

   Member

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   Fixed for 3.12 in #96739. I agree with @matthiasgoergens that it's not worth fixing in 3.10 and 3.11, because the issue doesn't manifest itself in release builds, where -fwrapv is used.
7. mdickinson

   closed this as completedon Sep 25, 2022

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