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Date: Thu, 25 Apr 2024 14:38:42 -0700
From: Andrew Morton <akpm@linux-foundation.org>
To: Suren Baghdasaryan <surenb@google.com>
Cc: Kent Overstreet <kent.overstreet@linux.dev>, Matthew Wilcox
 <willy@infradead.org>, Kees Cook <keescook@chromium.org>,
 linux-mm@kvack.org, linux-kernel@vger.kernel.org,
 linux-hardening@vger.kernel.org
Subject: Re: [PATCH] alloc_tag: Tighten file permissions on /proc/allocinfo
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On Thu, 25 Apr 2024 14:21:39 -0700 Suren Baghdasaryan <surenb@google.com> wrote:

> > > > The side effect of locking down more and more reporting interfaces is
> > > > that programs that consume those interfaces now have to run as root.
> > >
> > > sudo cat /proc/allocinfo | analyse-that-fie
> >
> > Even that is still an annoyance, but I'm thinking more about a future
> > daemon to collect this every n seconds - that really shouldn't need to
> > be root.
> 
> Yeah, that would preclude some nice usecases. Could we maybe use
> CAP_SYS_ADMIN checks instead? That way we can still use it from a
> non-root process?

I'm inclined to keep Kees's 0400.  Yes it's a hassle but security is
always a hassle.  Let's not make Linux less secure, especially for
people who aren't even using /proc/allocinfo.

If someone really wants 0666 then they can chmod the thing from
initscripts, can't they?