I find stack overflow security bugs fascinating; and on Linux, compilers still don't protect against stack overflows by default when stack frames are bigger than stack guard pages.

So I went looking around in Android, and thanks to how Android's RPC mechanism allows recursive synchronous callbacks in some cases, I managed to find a way to jump a thread guard page in system_server from shell context and (with very low success rate) get instruction pointer control:
project-zero.issues.chromium.o

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