[Python-Dev] Py2.4 _sre uses uninitialised memory (Bug 1088891)

[Gustavo Niemeyer]

Hello Andrew,

> _sre.c, data_stack_grow() in Py2.4 uses realloc()'ed memory without
> initialising the newly allocated memory. For complex regexps that
> require additional sre stack space, this ultimately results in a core
> dump or corrupted heap. Filling the newly allocated memory with 0x55
> makes the problem more obvious (dies on a reference to 0x55555558) for
> me.

As I just reported in the bug, the problem is not initializing the
allocated memory, but acknowledging memory reallocation in certain
situations where it's reallocated outside of the main matching
function.

Have a look at the bug at http://python.org/sf/1072259 for more
information and for a patch fixing the problem.

Thanks for the report,

-- 
Gustavo Niemeyer
http://niemeyer.net