Messages in this thread | | | Date | Thu, 29 Sep 2011 21:25:31 +0400 | From | Vasiliy Kulikov <> | Subject | Re: [kernel-hardening] Re: [PATCH 2/2] mm: restrict access to /proc/meminfo |
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On Thu, Sep 29, 2011 at 12:57 -0400, Valdis.Kletnieks@vt.edu wrote: > But now he has to fly blind for the next 30 because the numbers will display > exactly the same, and he can't correct for somebody else allocating one so he > needs to only allocate 29...
You're still talking about "slabinfo", which is already restricted.
And meminfo can be still learned with the same race window (ala seq lock):
prepare_stuff(); fill_slabs(); // Here we know counters with KB granularity while (number_is_not_ok()) { prepare_stuff(); fill_slabs(); } do_exploit();
Thanks,
-- Vasiliy Kulikov http://www.openwall.com - bringing security into open computing environments
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