ptmalloc

Glibc dynamic memory allocator

What is ptmalloc2

ptmalloc2 is the dynamic memory allocator used by glibc since version 2.3.x. It is a fork of the original malloc with improved multi-threading support. It is also very fast (6 times faster) compared to the original malloc. Specifically, we are interested in the implementation of malloc.c. The very first step of getting into heap exploitation is reading malloc.c and understanding its algorithms.

Setup

Download and extract the latest glibc (the current version is 2.35):

cd /usr/src/glibc
sudo wget http://mirror.ibcp.fr/pub/gnu/libc/glibc-2.35.tar.xz
sudo tar xf glibc-2.35.tar.xz

The malloc.c file can be found at /usr/src/glibc/glibc-2.35/malloc.

Reference

堆概述 - CTF Wikictf-wiki.org

Heap - CTF Wiki