[ python-Bugs-1590036 ] __getattr__ = getattr crash

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Bugs item #1590036, was opened at 2006-11-03 16:44
Message generated for change (Comment added) made by arigo
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Category: Python Interpreter Core
Group: Python 2.5
>Status: Closed
>Resolution: Duplicate
Priority: 6
Private: No
Submitted By: Brian Harring (ferringb)
Assigned to: Armin Rigo (arigo)
Summary: __getattr__ = getattr crash

Initial Comment:
class c(object):__getattr__ = getattr
c().spam

<segfault from overflowing the c stack>

Now granted... it's retarded to attempt this.  But out
of curiousity, I decided to be the retard, and noticed
the interpreter crashes instead of triggering a
RuntimeError for recursion.

As far as I know, getattr is instrumented with
Py_EnterRecursiveCall and Py_LEaveRecursiveCall... so a
bit curious as to how it's occuring.

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>Comment By: Armin Rigo (arigo)
Date: 2006-11-05 09:30

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This is a particular case of bug #1202533.

With Brett we arrived at a patch in #1202533 which
should solve a family of similar problems.  Can you
check that it also solves the __getattr__=getattr
attack?  If so, we should check in Brett's patch.

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Comment By: Brian Harring (ferringb)
Date: 2006-11-05 03:57

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can do the same trick with hasattr also (same type of fix)...

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Comment By: Neal Norwitz (nnorwitz)
Date: 2006-11-04 19:40

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The attached patch fixes this problem.  However, I'm
concerned there are more places like this.  I hope Armin has
some ideas if more things are needed to fix this problem.

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