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Date: Thu, 25 Apr 2024 21:51:56 +0100
From: Matthew Wilcox <willy@infradead.org>
To: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Kees Cook <keescook@chromium.org>,
	Suren Baghdasaryan <surenb@google.com>,
	Andrew Morton <akpm@linux-foundation.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
Message-ID: <ZirCbPR1XwX2WJSX@casper.infradead.org>
References: <20240425200844.work.184-kees@kernel.org>
 <w6nbxvxt3itugrvtcvnayj5ducoxifwbffd7qh6vcastw77mse@2ugphwusgttz>
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On Thu, Apr 25, 2024 at 04:45:51PM -0400, Kent Overstreet wrote:
> On Thu, Apr 25, 2024 at 01:08:50PM -0700, Kees Cook wrote:
> > The /proc/allocinfo file exposes a tremendous about of information about
> > kernel build details, memory allocations (obviously), and potentially
> > even image layout (due to ordering). As this is intended to be consumed
> > by system owners (like /proc/slabinfo), use the same file permissions as
> > there: 0400.
> 
> Err...
> 
> 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