From: Andreas Gruenbacher <agruen@suse.de>
Subject: Re: [PATCH] NFS: nfsaclsvc_encode_getaclres() - Fix potential NULL deref and tiny optimization.
Date: Tue, 31 Oct 2006 17:26:00 +0100
Message-ID: <200610311726.00411.agruen@suse.de>
References: <200610272316.47089.jesper.juhl@gmail.com> <Pine.LNX.4.64N.0610271443500.31179@attu2.cs.washington.edu> <200610280001.49272.jesper.juhl@gmail.com>
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Cc: David Rientjes <rientjes@cs.washington.edu>,
	linux-kernel@vger.kernel.org, Neil Brown <neilb@cse.unsw.edu.au>,
	nfs@lists.sourceforge.net, Andrew Morton <akpm@osdl.org>
Return-path: <linux-kernel-owner+glk-linux-kernel-3=40m.gmane.org-S1423441AbWJaQZT@vger.kernel.org>
To: Jesper Juhl <jesper.juhl@gmail.com>
In-Reply-To: <200610280001.49272.jesper.juhl@gmail.com>
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <nfs.lists.sourceforge.net>

On Saturday 28 October 2006 00:01, Jesper Juhl wrote:
> > > 3) There are two locations in the function where we may return before
> > > we use the value of the variable 'w', but we compute it at the very top
> > > of the function. So in the case where we return early we have wasted a
> > > few cycles computing a value that was never used.

Computing w later in the function is fine.

> > w should be an unsigned int.
>
> Makes sense.

No, this breaks the while loop further below: with an unsigned int, the loop 
counter underflows and wraps.

Please fix this identically in fs/nfsd/nfs2acl.c and fs/nfsd/nfs3acl.c.

Thanks,
Andreas