linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Andrew Morton <akpm@linux-foundation.org>
To: Kees Cook <keescook@chromium.org>
Cc: Kent Overstreet <kent.overstreet@linux.dev>,
	Matthew Wilcox <willy@infradead.org>,
	Suren Baghdasaryan <surenb@google.com>,
	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
Date: Thu, 25 Apr 2024 16:47:18 -0700	[thread overview]
Message-ID: <20240425164718.e8e187dd0c5b0a87371d8316@linux-foundation.org> (raw)
In-Reply-To: <202404251532.F8860056AE@keescook>

On Thu, 25 Apr 2024 15:42:30 -0700 Kees Cook <keescook@chromium.org> wrote:

> > The concern about leaking image layout could be addressed by sorting the
> > output before returning to userspace.
> 
> It's trivial to change permissions from the default 0400 at boot time.
> It can even have groups and ownership changed, etc. This is why we have
> per-mount-namespace /proc instances:
> 
> # chgrp sysmonitor /proc/allocinfo
> # chmod 0440 /proc/allocinfo
> 
> Poof, instant role-based access control. :)

Conversely, the paranoid could set it to 0400 at boot also.

> I'm just trying to make the _default_ safe.

Agree with this.

Semi-seriously, how about we set the permissions to 0000 and force
distributors/users to make a decision.



  parent reply	other threads:[~2024-04-25 23:47 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-04-25 20:08 Kees Cook
2024-04-25 20:45 ` Kent Overstreet
2024-04-25 20:51   ` Matthew Wilcox
2024-04-25 21:04     ` Kent Overstreet
2024-04-25 21:21       ` Suren Baghdasaryan
2024-04-25 21:25         ` Kent Overstreet
2024-04-25 21:38         ` Andrew Morton
2024-04-25 21:45           ` Kent Overstreet
2024-04-26  8:32         ` Pavel Machek
2024-04-26  8:46           ` Kent Overstreet
2024-04-25 22:42       ` Kees Cook
2024-04-25 23:02         ` Kent Overstreet
2024-04-25 23:47         ` Andrew Morton [this message]
2024-04-26  0:27           ` Kent Overstreet
2024-04-26  0:43             ` Kees Cook
2024-04-26  0:58               ` Kent Overstreet
2024-04-26  3:25                 ` Matthew Wilcox
2024-04-26  3:35                   ` Kent Overstreet
2024-04-26  8:34                   ` Pavel Machek
2024-04-26  0:39           ` Kees Cook
2024-04-25 20:57   ` Kees Cook

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20240425164718.e8e187dd0c5b0a87371d8316@linux-foundation.org \
    --to=akpm@linux-foundation.org \
    --cc=keescook@chromium.org \
    --cc=kent.overstreet@linux.dev \
    --cc=linux-hardening@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=surenb@google.com \
    --cc=willy@infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox