[New-bugs-announce] [issue2629] _Py_ForgetReference crash when called from _PyUnicode_New on MemoryError

[Gregory P. Smith]

New submission from Gregory P. Smith <greg at krypto.org>:

In _PyUnicode_New() a unicode object is taken from the freelist but if
the unicode_resize() call fails and returns -1, the goto onerror calls
_Py_ForgetReference on the unicode object... But it has NULL _ob_prev
and _ob_next values causing a crash when they're used.

How to reproduce:

* Make a 32-bit --with-pydebug build of Python trunk.
* Run it on a machine with lots of ram (at least 3gigs recommended, or
lots of swap and a heap of patience):

./python
Python 2.6a2+ (trunk:62336M, Apr 13 2008, 18:51:30)
>>> msg = 'A'*2000111222
>>> x = msg.decode('utf8')

It segmentation faults in _Py_ForgetReference.

----------
messages: 65456
nosy: gregory.p.smith
severity: normal
status: open
title: _Py_ForgetReference crash when called from _PyUnicode_New on MemoryError
type: crash
versions: Python 2.6

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Tracker <report at bugs.python.org>
<http://bugs.python.org/issue2629>
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