trace.__main__ does not use io.open_code

[zooba]

When used as an entry point, the trace module opens code files without using io.open_code:

https://github.com/python/cpython/blob/main/Lib/trace.py#L719

This should use the io.open_code method instead of open(..., 'rb').

Linked PRs

• gh-103935: Use io.open_code() to open executable file #103947
• [3.11] gh-103935: Use io.open_code() when executing code in trace and profile modules (GH-103947) #103950
• [3.10] gh-103935: Use io.open_code() when executing code in trace and profile modules (GH-103947) #103952
• [3.9] gh-103935: Use io.open_code() when executing code in trace and profile modules (GH-103947) #103953
• [3.8] gh-103935: Use io.open_code() when executing code in trace and profile modules (GH-103947) #103954

[Agent-Hellboy]

Hi @zooba
I was exploring this and in the mean time i got this error
▶ ./python -m trace --trace Lib/calendar.py

  File "Lib/calendar.py", line 155, in monthrange
    ndays = mdays[month] + (month == FEBRUARY and isleap(year))
                                     ^^^^^^^^
NameError: name 'FEBRUARY' is not defined

FEBRUARY is a global attribute for this module which is made using the global_enum decorator over an enum but trace is throwing an exception that FEBRUARY is not defined

several std libs are throwing one or the other error

Btw, is the issue just about changing the open to io.open_code?

[gaogaotiantian]

Could you explain why this is a security issue? A similar PR was done for pdb a couple of days ago #103581.

[zooba]

Because we made a promise that files being opened for execution would go through open_code, and execution is a sensitive path. Plus it's something that anyone building their own security releases would want to backport, so we can save them all the work.

The pdb change should be backported as well.

(I removed 3.7 because this was all added in 3.8.)

[zooba]

I stand corrected - pdb was fine in 3.8-3.10, someone regressed it in 3.11, which has now been fixed.

[gaogaotiantian]

Thank you for the explanation! In that case, do you want me to submit a PR to fix profile and cProfile which also use raw open for executable code?

[zooba]

Sure, go ahead. They can all go in the same PR

[zooba]

Incidentally, I checked out the other open() calls in trace and they're all fine. It's just the one that I point out in the first message.

[gaogaotiantian]

I also did a quick scan for other similar usages, but did not find any Lib code that loads an executable file.