[issue16212] mmap() dumps core upon resizing the underlying file

[Vladimir Ushakov]

New submission from Vladimir Ushakov:

The following code crashes the interpreter on Linux:

#!/usr/bin/python3

import mmap

with open('test', 'wb') as f:
    f.write(bytes(1))

with open('test', 'r+b') as f:
    m = mmap.mmap(f.fileno(), 0)
    f.truncate()
    a = m[:]

---

It's not specific to the zero size truncation, it's enough if the file size decreases beyond a page border.

----------
components: IO
messages: 172745
nosy: Vladimir.Ushakov
priority: normal
severity: normal
status: open
title: mmap() dumps core upon resizing the underlying file
type: crash
versions: Python 3.2

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue16212>
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