* Kees Cook <[email protected]> wrote:
> > That's the area in which we just map 1:1 to memory. Anything allocated
> > with
> > e.g. kmalloc() ends up with those addresses.
>
> Ah-ha! Yes, I see now when comparing the debug/kernel_page_tables reports.
> It's
> just the High Kernel Mapping that we care about. Addresses outside that range
> are less of a leak. Excellent, then GDT may not be a problem. Whew.
It's still an infoleak to worry about: any function pointers nearby matter, and
the x86 GDT is obviously full of useful and highly privilege-relevant function
pointers ...
I have no objections against read-only mapping the GDT as well.
Thanks,
Ingo
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