Conversation

I've published sample releases of AOSP 9 with the next generation hardened malloc implementation and some other changes at seamlessupdate.app. It's at the domain I registered for the Updater app for the time being since I don't have a name for the OS hardening project yet.

Replying to

To better understand your efforts I would like to know the following:

Replying to

and

What makes you motivated to implement the OpenBSD pattern over extending the default google/Linux one to counter memory corruption?, is the default implement ation that bad ? Can you give a real life exploit use case?

Daniel Micay

@DanielMicay

Replying to

@ksuhiyb

If you're talking about the hardened memory allocator, the design is explained in github.com/AndroidHardeni including a list of the security properties it provides. A traditional allocator provides essentially zero of those security properties. It's not theoretical stuff either.

github.com

hardened_malloc/README.md at main · GrapheneOS/hardened_malloc

Hardened allocator designed for modern systems. It has integration into Android's Bionic libc and can be used externally with musl and glibc as a dynamic library for use on other Linux-base...

9:20 PM · Dec 22, 2018Twitter Web Client

Replying to

and

What is it that you're not understanding? I don't know what you mean by "implement the OpenBSD pattern" or "extending the default google/Linux one". The new allocator is not a port of OpenBSD malloc. The documentation explains that it's a successor to the previous port of it.

Replying to

and

You cannot bolt on security to an allocator design like dlmalloc and end up with a truly hardened allocator. You end up with a weak design with a few security features like canaries and zero filling on free sprinkled on. It doesn't provide these important security properties.

Show replies