27th
Unlocking Doug Lea’s Malloc
After a pretty long break from blogging activies here I come again with some fresh memory managing papers to read. I’ve started fooling around with Heap management exploitation for the GNU/Linux OS. There’s much more going on in each memory allocation than just a malloc() call and a return pointer. Therefore, if successful memory corruption is to happen, proper documentation is mandatory.
In order to get efficient memory allocation, Linux makes use of the Doug Lea’s Malloc implementation (dlmalloc from now on). This implementation makes use of some complex linking and asignation methods to make use of memory as efficient and agile as posibble. Papers on this matter are not very common despite the popularity of Heap Overflow vulnerabilities in todays software.
Two papers called my attention in their endeavour to illustrate the ups and downs of the dlmalloc implementation. Both of them where published a couple of years ago in the famous underground Phrack magazine. Both came to light in the 57th issue of the aforementioned publication. It’s a great read for these cold christmas days, give them a shot. Merry x-mas and happy new malloc(2008);
Vudo - An object superstitiously believed to embody magical powers
Once upon a free()...
Phrack.org
Doug Lea's site
