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From: Cyrill Gorcunov <gorcunov@openvz.org>
To: Arvid Brodin <Arvid.Brodin@xdin.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Al Viro <viro@zeniv.linux.org.uk>,
	David Rientjes <rientjes@google.com>,
	"Eric W. Biederman" <ebiederm@xmission.com>
Subject: Re: fs/proc/base.c: text md5sums; tgid vs tid; and INF vs ONE?
Date: Wed, 31 Oct 2012 01:23:56 +0400	[thread overview]
Message-ID: <20121030212356.GP15657@moon> (raw)
In-Reply-To: <50904066.4060404@xdin.com>

On Tue, Oct 30, 2012 at 09:02:33PM +0000, Arvid Brodin wrote:
> Hi,
> 
> Below is a patch that adds a file /proc/PID/text_md5sum which when read returns the md5
> checksum of a process' text segment. (This would be used e.g. to make sure a process'
> code hasn't been tampered with.)
> 
> However, I have a few questions:
> 
> * What's the difference between the tgid_base_stuff and tid_base_stuff arrays? (One for
> processes and one for the process' threads? I haven't been able to find any info about
> this so I'm guessing.)
> 
> * When should I use the INF ("read") vs the ONE ("show") macro?
> 
> * Any other comments about the code?
> 
> Thanks!

I don't think this increments security by any means. start/end-code are rather
informative fields which are set when program being started, so one can ptrace
it, alloc new exec area, put evil code there, tuneup cs:ip and restore original
program contents, you won't even notice that.

  parent reply	other threads:[~2012-10-30 21:24 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-10-30 21:02 fs/proc/base.c: text md5sums; tgid vs tid; and INF vs ONE? Arvid Brodin
2012-10-30 21:22 ` Al Viro
2012-11-01 20:22   ` Arvid Brodin
2012-10-30 21:23 ` Cyrill Gorcunov [this message]
2012-10-30 22:45 ` Eric W. Biederman
2012-11-01 20:29   ` Arvid Brodin
2012-11-02 22:49     ` Arvid Brodin

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