Messages in this thread | | | Subject | Re: [kernel-hardening] [RFC, PATCH] x86_64: KAISER - do not map kernel in user mode | From | Daniel Gruss <> | Date | Sat, 6 May 2017 10:28:30 +0200 |
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On 2017-05-05 17:53, Jann Horn wrote: > Ah, I think I understand. The kernel stacks are mapped, but > cpu_current_top_of_stack isn't, so you can't find the stack until after the CR3 > switch in the syscall handler?
That's the idea. Only the absolute minimum that is required for a context switch remains mapped (+ it is mapped at an offset which does not depend on KASLR -> we do not leak the KASLR offsets).
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