New submission from Christian Heimes:

Coverity has found a potential buffer overflow in the unicodedata module. The 
function call _getcode() which calls _cmpname(). _cmpname() copies data into 
fixed size buffer of length NAME_MAXLEN. Neither lookup() nor _getcode() limit 
name_length to NAME_MAXLEN. Therefore the buffer could theoretical overflow.

In practice the buffer overflow can't be abused because 
Tools/unicode/makeunicodedata.py already limits max name length. I still like 
to fix the bug because it is a low hanging fruit. In most versions of Python 
the code already checks that name_length fits in INT_MAX.

CID 1295028 (#1 of 1): Out-of-bounds access (OVERRUN)
overrun-call: Overrunning callee's array of size 256 by passing argument 
(int)name_length (which evaluates to 2147483647) in call to _getcode

----------
files: unicode_name_maxlen.patch
keywords: patch
messages: 241461
nosy: benjamin.peterson, christian.heimes, ezio.melotti, haypo, lemburg, 
pitrou, serhiy.storchaka
priority: normal
severity: normal
stage: patch review
status: open
title: unicodedata_UCD_lookup() has theoretical buffer overflow
type: behavior
versions: Python 2.7, Python 3.3, Python 3.4, Python 3.5
Added file: http://bugs.python.org/file39109/unicode_name_maxlen.patch

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Python tracker <rep...@bugs.python.org>
<http://bugs.python.org/issue23997>
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