Re: [PATCH v16 1/5] mm: add VM_DROPPABLE for designating always lazily freeable mappings

Andy Lutomirski
2024-06-07T18:40:48Z

On Tue, May 28, 2024 at 5:24 AM Jason A. Donenfeld <Jason@zx2c4.com> wrote:
>
> The vDSO getrandom() implementation works with a buffer allocated with a
> new system call that has certain requirements:
>
> - It shouldn't be written to core dumps.
> * Easy: VM_DONTDUMP.

I'll bite: why shouldn't it be written to core dumps?

The implementation is supposed to be forward-secret: an attacker who
gets the state can't predict prior outputs. And a core-dumped process
is dead: there won't be future outputs.