On Fri, Jun 22, 2018 at 11:09 AM, Andy Lutomirski <l...@amacapital.net> wrote: > One possible extra issue: IIRC /proc/.../mem uses FOLL_FORCE, which is not > what we want here. > > How about just adding an explicit “read/write the seccomp-trapped task’s > memory” primitive? That should be easier than a “open mem fd” primitive.
Uuugh. Can we avoid adding another "read/write remote process memory" interface? The point of this series was to provide a lightweight approach to what should normally be possible via the existing seccomp+ptrace interface. I do like Jann's context idea, but I agree with Andy: it can't be a handle to /proc/$pid/mem, since it's FOLL_FORCE. Is there any other kind of process context id we can use for this instead of pid? There was once an idea of pid-fd but it never landed... This would let us get rid of the "id" in the structure too. And if that existed, we could make process_vm_*v() safer too (taking a pid-fd instead of a pid). -Kees -- Kees Cook Pixel Security
