New submission from Alexey Izbyshev <izbys...@ispras.ru>:
The compressor/decompressor classes from bz2 and lzma modules rely on __init__() for initialization, but it is not guaranteed to be called. Method calls on an uninitialized object crash: >>> from bz2 import BZ2Compressor as C >>> c = C.__new__(C) >>> c.compress(b'') Segmentation fault (core dumped) I see two ways to fix this: 1) Move some initialization (notably, for "lock" field) to __new__() and add initialization checks to other methods. This should be backwards-compatible. 2) Move all initialization to __new__(). Since compressor/decompressor classes are not subclassable, it'll break only code than repeatedly calls __init__() on the same object. The simplicity of the fix might outweigh the necessity to support such code. (However, in 2.7, classes in bz2 *are* subclassable; lzma is not present in 2.7). Which way is more preferable? ---------- components: Extension Modules messages: 325691 nosy: berker.peksag, izbyshev, serhiy.storchaka priority: normal severity: normal status: open title: bz2/lzma: Compressor/decompressor crash if __init__ is not called type: crash versions: Python 2.7, Python 3.6, Python 3.7, Python 3.8 _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue34729> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
