[ python-Bugs-1185883 ] PyObject_Realloc bug in obmalloc.c

[SourceForge.net]

Bugs item #1185883, was opened at 2005-04-19 12:07
Message generated for change (Tracker Item Submitted) made by Item Submitter
You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=105470&aid=1185883&group_id=5470

Category: Python Interpreter Core
Group: Python 2.3
Status: Open
Resolution: None
Priority: 5
Submitted By: Kristján Valur (krisvale)
Assigned to: Nobody/Anonymous (nobody)
Summary: PyObject_Realloc bug in obmalloc.c

Initial Comment:
obmalloc.c:835
If the previous block was not handled by obmalloc, and 
the realloc is for growing the block, this memcpy may 
cross a page boundary and cause a segmentation 
fault.  This scenario can happen if a previous allocation 
failed to successfully allocate from the obmalloc pools, 
due to memory starvation or other reasons, but was 
successfully allocated by the c runtime.

The solution is to query the actual size of the allocated 
block, and copy only so much memory.  Most modern 
platforms provide size query functions complementing 
the malloc()/free() calls.  on Windows, this is the _msize
() function.

----------------------------------------------------------------------

You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=105470&aid=1185883&group_id=5470