public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Vojtech Pavlik <vojtech@suse.cz>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	torvalds@osdl.org, akpm@osdl.org, vojtech@suse.de
Subject: Re: Breakage from patch: Only root should be able to set the N_MOUSE line discipline.
Date: Tue, 1 Mar 2005 12:47:18 +0100	[thread overview]
Message-ID: <20050301114718.GA5375@ucw.cz> (raw)
In-Reply-To: <1109416402.2584.5.camel@localhost.localdomain>

On Sat, Feb 26, 2005 at 11:20:44AM +0000, Alan Cox wrote:

> On Gwe, 2005-01-28 at 16:12, Linux Kernel Mailing List wrote:
> > ChangeSet 1.1977.1.2, 2005/01/28 17:12:20+01:00, vojtech@suse.cz
> > 
> > 	input: Only root should be able to set the N_MOUSE line discipline.
> > 	
> 
> I finally had a chance to trace down why my mouse code for a little gui
> library started working differently and causing problems. This broken
> change breaks apps that use framebuffer in unpriviledged process form
> and want to use the mouse support in kernel and forces them to become
> setuid root or to revert to 2.4 style user space mouse drivers. If this
> functonality is root only kernel space it might as well be entirely
> deleted IMHO.
> 
> I can see no reason for this change - the ldisc is supposed to be
> configurable by non root users. It is reset on close/hangup in Linux so
> a user cannot jam a port up.
> 
> Can someone please justify this change. If not can it be reverted
 
A nonprivileged user could inject mouse movement and/or keystrokes
(using the sunkbd driver) into the input subsystem, taking over the
console/X, where another user is logged in.

Simply using a slightly modified inputattach on a PTY will do the trick.

-- 
Vojtech Pavlik
SuSE Labs, SuSE CR

  reply	other threads:[~2005-03-01 11:45 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <200502030209.j1329xTG013818@hera.kernel.org>
2005-02-26 11:20 ` Breakage from patch: Only root should be able to set the N_MOUSE line discipline Alan Cox
2005-03-01 11:47   ` Vojtech Pavlik [this message]
2005-03-01 15:57     ` Alan Cox
2005-03-01 16:17     ` Linus Torvalds
2005-03-01 16:33       ` Vojtech Pavlik

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=20050301114718.GA5375@ucw.cz \
    --to=vojtech@suse.cz \
    --cc=akpm@osdl.org \
    --cc=alan@lxorguk.ukuu.org.uk \
    --cc=linux-kernel@vger.kernel.org \
    --cc=torvalds@osdl.org \
    --cc=vojtech@suse.de \
    /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