[New-bugs-announce] [issue14700] Integer overflow in classic string formatting

Serhiy Storchaka report at bugs.python.org
Mon Apr 30 18:55:26 CEST 2012


New submission from Serhiy Storchaka <storchaka at gmail.com>:

Check for integer overflow for width and precision is buggy.

Just a few examples (on platform with 32-bit int):

>>> '%.21d' % 123
'000000000000000000123'
>>> '%.2147483648d' % 123
'123'
>>> '%.2147483650d' % 123
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: prec too big

>>> '%.21f' % (1./7)
'0.142857142857142849213'
>>> '%.2147483648f' % (1./7)
'0.142857'
>>> '%.2147483650f' % (1./7)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: prec too big

----------
components: Interpreter Core
messages: 159707
nosy: storchaka
priority: normal
severity: normal
status: open
title: Integer overflow in classic string formatting
type: behavior
versions: Python 2.6, Python 2.7, Python 3.1, Python 3.2, Python 3.3

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue14700>
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