linux-kernel - Re: [ 02/42] TTY: do not update atime/mtime on read/write

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20130430013724.GA5358@kroah.com>
Date:	Mon, 29 Apr 2013 18:37:24 -0700
From:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:	Simon Kirby <sim@...tway.ca>
Cc:	Linus Torvalds <torvalds@...ux-foundation.org>,
	linux-kernel@...r.kernel.org, stable@...r.kernel.org,
	Jiri Slaby <jslaby@...e.cz>
Subject: Re: [ 02/42] TTY: do not update atime/mtime on read/write

On Mon, Apr 29, 2013 at 05:36:40PM -0700, Simon Kirby wrote:
> On Mon, Apr 29, 2013 at 05:21:17PM -0700, Greg Kroah-Hartman wrote:
> 
> > On Mon, Apr 29, 2013 at 05:14:45PM -0700, Simon Kirby wrote:
> > > On Mon, Apr 29, 2013 at 12:01:44PM -0700, Greg Kroah-Hartman wrote:
> > > 
> > > > 3.8-stable review patch.  If anyone has any objections, please let me know.
> > > 
> > > I object. This breaks functionality I use every day (seeing who else is
> > > working on stuff with "w").
> > > 
> > > Furthermore, the patch does not actually fix the hole referenced (see
> > > ptmx-keystroke-latency.c on http://vladz.devzero.fr/013_ptmx-timing.php).
> > > I can still reproduce the timing capture even with this patch applied
> > > (in 3.9-rc8).
> > 
> > How?  There are no keystrokes being reported to other users, or did we
> > miss something with this patch?
> 
> wget http://vladz.devzero.fr/svn/codes/PoC/ptmx-keystroke-latency.c
> gcc -O ptmx-keystroke-latency ptmx-keystroke-latency.c
> ./ptmx-keystroke-latency
> 
> Log in to another tty, as another user. See keystroke timing. 3.9-rc8.
> 
> Seems like it was missed. Meanwhile, idle times in "w" do not update.

Ah, it's using inotify on the /dev/ptmx device.  Jiri, your change
really doesn't affect that at all :(

Simon, you mention a grsec change somewhere that addresses this issue.
Any hints on where that would be?

thanks,

greg k-h
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/