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

From: Vasiliy Kulikov
Date: Tue Sep 13 2011 - 02:29:23 EST


On Mon, Sep 12, 2011 at 19:06 +0400, Cyrill Gorcunov wrote:
> On Sat, Sep 10, 2011 at 08:41:34PM +0400, Vasiliy Kulikov wrote:
> > Historically /proc/slabinfo has 0444 permissions and is accessible to
> > the world. slabinfo contains rather private information related both to
> > the kernel and userspace tasks. Depending on the situation, it might
> > reveal either private information per se or information useful to make
> > another targeted attack. Some examples of what can be learned by
> > reading/watching for /proc/slabinfo entries:
> >
> ...
>
> Since this file is controversy point, probably its permissions might be
> configurable via setup option?

We could create DEBUG_PROC (of cource, defaults to =n) to keep current
relaxed procfs permissions, but I don't think a configure option is needed
for a thing which is trivially done via "chmod" in init scripts.

--
Vasiliy Kulikov
http://www.openwall.com - bringing security into open computing environments
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