Re: [kernel-hardening] Re: [RFC PATCH 2/2] mm: restrict access to /proc/slabinfo

From: Pekka Enberg
Date: Mon Sep 19 2011 - 13:31:45 EST


On Mon, Sep 19, 2011 at 7:18 PM, Vasiliy Kulikov <segoon@xxxxxxxxxxxx> wrote:
>> However, if the encryptfs and infoleaks really are serious enough to
>> hide /proc/slabinfo, I think you should consider switching over to
>> kmalloc() instead of kmem_cache_alloc() to make sure nobody can
>> gain access to the information.
>
> kmalloc() is still visible in slabinfo as kmalloc-128 or so.

Yes, but there's no way for users to know where the allocations came from
if you mix them up with other kmalloc-128 call-sites. That way the number
of private files will stay private to the user, no? Doesn't that give you even
better protection against the infoleak?

Pekka
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