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References: <1305147805-5756-1-git-send-email-shawn.p.huang@gmail.com>
	<20110513103202.GA27578@infradead.org>
Date: Fri, 13 May 2011 10:31:22 -0400
Message-ID: <BANLkTikeCHBe3OBpuyF6jd_UeF0az0BYcg@mail.gmail.com>
Subject: Re: [PATCH] nfs: check a crash in nfs_lookup_revalidate
From: Peng Huang <shawn.p.huang@gmail.com>
To: Christoph Hellwig <hch@infradead.org>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>, linux-nfs@vger.kernel.org,
        linux-kernel@vger.kernel.org
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I did not write any code to call lookup_one_len(). I just mounted an
ecryptfs on nfs, and then got the oops. So it should be a problem in
nfs or ecryptfs or both. At least it should not crash.

Peng

On Fri, May 13, 2011 at 6:32 AM, Christoph Hellwig <hch@infradead.org> wrote:
> On Wed, May 11, 2011 at 05:03:25PM -0400, Peng Huang wrote:
>> lookup_one_len() may call nfs_loopup_revalidate() with nd == NULL
>> indirectly, that causes the kernel crash.
>
> lookup_one_len must only be called by a filesystem or a library function
> called by the filesystem.  You are not allowed to call it on a random
> filesystem like nfs that doesn't support the underlying assumptions.
>
>
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