Subject: Re: [PATCH] integrity: add ima_counts_put (updated)
From: Mimi Zohar <zohar@linux.vnet.ibm.com>
To: hooanon05@yahoo.co.jp
Cc: linux-kernel@vger.kernel.org, James Morris <jmorris@namei.org>,
       David Safford <safford@watson.ibm.com>, Mimi Zohar <zohar@us.ibm.com>
In-Reply-To: <7465.1246593761@jrobl>
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Date: Fri, 03 Jul 2009 14:37:59 -0400
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On Fri, 2009-07-03 at 13:02 +0900, hooanon05@yahoo.co.jp wrote:
> Mimi Zohar:
> > NFSv3 is an interesting example. Permission checking is done once,
> > followed by multiple open/read/close calls. Incrementing the counters in
> > nfsd_permission() once and decrementing the counters in close, multiple
> > times, resulted in imbalance messages.  True, the solution in this case
> > was to increment in open and decrement in close, but that was only part
> > of the solution.  The other part of the solution, the important part,
> > was to add a call to ima_path_check() to measure the file.
> 
> Let me make sure.
> Does "that was only part of the solution" mean IMA does not work for
> NFSD fully? To make IMA work fully, is incrementing before open
> absolutely necessary?
> 
> J. R. Okajima

The patch is fine.  It adds a call to ima_path_check() in
nfsd_permission(), but delays incrementing the counters to nfsd_open()
and decrementing the counters to nfsd_close() in order for the counters
to be balanced.

Mimi

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