I will continue to talk about the exploitation of CVE-2017-7308. In this post, I will discuss the implementation details of buddy allocator and SLUB allocator in Linux-4.10.6. I will show how to put the victim object (struct packet_sock in this post) next adjacent to the vulnerable buffer (packet rv_ring buffer in previous post).
In , a general abstraction of Linux Kernel memory management is given as following picture. From the picture, we can find that two types of allocators (slab allocator and buddy allocator) are provided for Linux kernel functions. For both allocators, I will give some debugging info to give a straight view on how those objects are allocated and shaped in memory combined with some explanation on the source code.
Continue reading “Linux Kernel Exploitation Part 2: Buddy Allocator and SLUB Allocator”