my_secmalloc

C project that securely replicates malloc functionality in order to detect the exploitation of certain vulnerabilities such as double free, heap overflow or memory leak.

How to setup the project

Prerequisites

You'll need to check that each of these tools is installed on your device:

git
make
criterion build and installed in /usr with its dependencies
gef and valgrind for debugging, which will be a great help if you wish to contribute to the project.

Steps to build the project and use the allocator

How to build

git clone git@github.com:guyb27/my_secmalloc.git
cd my_secmalloc/my_secmalloc

Then you have several options for building the project:

make static which will give you the static library libmy_secmalloc.a in the ./build/lib folder
make dynamic, which gives you the dynamic library libmy_secmalloc.so in the ./build/lib folder
make test which gives you the test binary test in the ./build/test folder, it works thanks to the static lib
make script which will give you a my_secmalloc.sh script in the ./build folder, allowing you to run a program with the allocator without having to specify LD_PRELOAD.
make all, which builds the two libraries and, at the same time, executes the tests by building the test binary. (actually, make all doesn't build the dynamic library in the right way. dynamic library, you'll see that the malloc, free, realloc and calloc functions aren't present, so you'll need to do a make dynamic or make clean dynamic (if lib.so has already been built) to get a working dynamic library (a patch is currently under development).

You can also directly download the libraries on our repository here!

How to use the allocator with a utility/program?

By default, the program saves its logs in a default file named default_log.txt. The log file is determined by the MSM_OUTPUT environment variable, which you are free to modify.

There are two main options for using the allocator with a utility/program:

LD_PRELOAD, which loads the dynamic library before other libraries:

  LD_PRELOAD=./build/lib/libmy_secmalloc.so sl

Use the script at ./build/my_secmalloc.sh having been created via a make all or make script which allows you to launch a program with the allocator:

./build/my_secmalloc.sh python3

The script is currently not optimized.

Troubleshooting

Troubleshooting common problems

If you get compilation errors, you may not have installed the necessary dependencies to compile the project. Check that you have installed the necessary dependencies to compile the project.
If you find yourself running a make test and encounter a problem, make sure you've built the static library needed to run the tests. Make sure you've also installed criterion in /usr and its dependencies. You may also need to perform a make clean static before redoing a make test.
At present, the solution does not allow you to run every program, so check that you have the malloc, calloc, realloc and free symbols with this command: nm libmy_secmalloc.so | grep " T " | grep -v my_ | cut -f3 -d' ' | sort. If you don't have these symbols, do a make clean and then a make dynamic.
For any other error, don't hesitate to open an issue in accordance with the given template.

zxtNX / secure_linux_allocator