linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Alexey Dobriyan <adobriyan@gmail.com>
To: Kees Cook <keescook@chromium.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Jann Horn <jann@thejh.net>,
	linux-kernel@vger.kernel.org
Subject: Re: + mm-relax-ptrace-mode-in-process_vm_readv2.patch added to -mm tree
Date: Tue, 6 Mar 2018 21:03:19 +0300	[thread overview]
Message-ID: <20180306180319.GC2080@avx2> (raw)
In-Reply-To: <20180306174218.GA2080@avx2>

On Tue, Mar 06, 2018 at 08:42:19PM +0300, Alexey Dobriyan wrote:
> On Mon, Mar 05, 2018 at 05:02:08PM -0800, Kees Cook wrote:
> > On Mon, Mar 5, 2018 at 4:07 PM,  <akpm@linux-foundation.org> wrote:
> 
> > > It is more natural to check for read-from-memory permissions in case of
> > > process_vm_readv() as PTRACE_MODE_ATTACH is equivalent to write
> > > permissions.
> > 
> > NAK, this weakens the existing permission model for reading
> 
> What if existing permission model is overezealous?
> 
> /proc/*/auxv, /proc/*/environ, /proc*/cmdline, /proc/*/mem opened
> for reading and process_vm_readv(2) should do PTRACE_MODE_READ and
> everything else should do PTRACE_MODE_ATTACH.

Or in other words:

what if there should be 3 levels:
1) permission to write to address space
2) permission to read arbitrarily from adress space
3) permission to read auxv, argv and envp

Current code conflates (1) and (2).

  reply	other threads:[~2018-03-06 18:03 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20180306000721.gx9qqFGe8%akpm@linux-foundation.org>
     [not found] ` <CAGXu5jKP03X7+XX9Oq+vVjQJhO1+A9ZyLDD+Gsxv2nRCgVD4wQ@mail.gmail.com>
2018-03-06 17:42   ` + mm-relax-ptrace-mode-in-process_vm_readv2.patch added to -mm tree Alexey Dobriyan
2018-03-06 18:03     ` Alexey Dobriyan [this message]
2018-03-06 22:31       ` 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=20180306180319.GC2080@avx2 \
    --to=adobriyan@gmail.com \
    --cc=akpm@linux-foundation.org \
    --cc=jann@thejh.net \
    --cc=keescook@chromium.org \
    --cc=linux-kernel@vger.kernel.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;
as well as URLs for NNTP newsgroup(s).