Re: Do not run this code.

References	<CAPTjJmoSgX6_HO16b2WB=vT+y8tys0ZyvcD-XVS+=6hj=gtUTQ@mail.gmail.com> <mailman.56.1425537863.21433.python-list@python.org> <gi1gfalrm71kqju9qcmcgus5pbseit2eqo@4ax.com>
From	Ian Kelly <ian.g.kelly@gmail.com>
Date	2015-03-05 00:59 -0700
Subject	Re: Do not run this code.
Newsgroups	comp.lang.python
Message-ID	<mailman.58.1425542402.21433.python-list@python.org> (permalink)

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On Thu, Mar 5, 2015 at 12:39 AM, Dave Farrance
<DaveFarrance@omitthisyahooandthis.co.uk> wrote:
> Ben Finney <ben+python@benfinney.id.au> wrote:
>
>>Chris Angelico <rosuav@gmail.com> writes:
>>
>>> import base64; exec(…)
>>
>>That's all I need to know. Code with ‘exec()’ calls, I consider unsafe
>>by default.
>
> Indeed. replacing exec with print...
>
>>>> print(base64.b64decode(b"eD0neD0lcjsgZXhlYyh4JSV4KSc7IGV4ZWMoeCV4KQ=="))
> x='x=%r; exec(x%%x)'; exec(x%x)
>
> so, discarding that second exec...
>
>>>> x='x=%r; exec(x%%x)'
>>>> print(x)
> x=%r; exec(x%%x)
>
> So it recurses, and if that second exec had been left in then it would be
> a fork bomb.

In order to be a fork bomb, it would have to call fork at some point.
This is just a race to see whether you'll run out of memory before the
recursion limit is reached.

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Re: Do not run this code. Ben Finney <ben+python@benfinney.id.au> - 2015-03-05 17:44 +1100
  Re: Do not run this code. Dave Farrance <DaveFarrance@OMiTTHiSyahooANDTHiS.co.uk> - 2015-03-05 07:39 +0000
    Re: Do not run this code. Ian Kelly <ian.g.kelly@gmail.com> - 2015-03-05 00:59 -0700

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