public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Al Viro <viro@ZenIV.linux.org.uk>
To: Richard Weinberger <richard@nod.at>
Cc: user-mode-linux-devel@lists.sourceforge.net,
	user-mode-linux-user@lists.sourceforge.net,
	linux-kernel@vger.kernel.org, hch@lst.de
Subject: Re: [RFC][PATCH] um: Remove proc command from mconsole
Date: Sun, 21 May 2017 22:30:29 +0100	[thread overview]
Message-ID: <20170521213029.GB390@ZenIV.linux.org.uk> (raw)
In-Reply-To: <1495401543-6314-1-git-send-email-richard@nod.at>

On Sun, May 21, 2017 at 11:19:03PM +0200, Richard Weinberger wrote:
> This feature is another abuser of set_fs().
> Reading proc files from the host side is a debugging feature
> with no security checks at all. The path is not sanitized, therefore
> any file could be read.

ITYM "any file on procfs"

> Let's get rid of it.

Wait a sec - guest is not protected against anyone with mconsole access
anyway.

> Unless I miss something is feature is not ABI since it was addeded for
> debugging UML only. It is broken wrt. security and abuses set_fs().
> I think we can just remove it.

IDGI.  set_fs() abuses are trivial - just switch to kernel_read() and
be done with that...

      reply	other threads:[~2017-05-21 21:30 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-05-21 21:19 [RFC][PATCH] um: Remove proc command from mconsole Richard Weinberger
2017-05-21 21:30 ` Al Viro [this message]

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=20170521213029.GB390@ZenIV.linux.org.uk \
    --to=viro@zeniv.linux.org.uk \
    --cc=hch@lst.de \
    --cc=linux-kernel@vger.kernel.org \
    --cc=richard@nod.at \
    --cc=user-mode-linux-devel@lists.sourceforge.net \
    --cc=user-mode-linux-user@lists.sourceforge.net \
    /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