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From: Peter Staubach <staubach@redhat.com>
To: Assar <assar@permabit.com>
Cc: Marcelo Tosatti <marcelo.tosatti@cyclades.com>,
	Trond Myklebust <trond.myklebust@fys.uio.no>,
	Valdis.Kletnieks@vt.edu, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] nfs client, kernel 2.4.31: readlink result overflow
Date: Wed, 14 Sep 2005 16:11:17 -0400	[thread overview]
Message-ID: <432883E5.6000004@redhat.com> (raw)
In-Reply-To: <7864t3h1xw.fsf@sober-counsel.permabit.com>

Assar wrote:

>>The 2.6 kernel code is also broken, but in a different, but once again,
>>similar fashions.
>>    
>>
>
>You mean for length > 1024 ?
>
>diff -u linux-2.6.13.orig/fs/nfs/nfs2xdr.c linux-2.6.13/fs/nfs/nfs2xdr.c
>--- linux-2.6.13.orig/fs/nfs/nfs2xdr.c	2005-08-28 19:41:01.000000000 -0400
>+++ linux-2.6.13/fs/nfs/nfs2xdr.c	2005-09-14 15:40:13.000000000 -0400
>@@ -557,7 +557,7 @@
> 		return -nfs_stat_to_errno(status);
> 	/* Convert length of symlink */
> 	len = ntohl(*p++);
>-	if (len >= rcvbuf->page_len || len <= 0) {
>+	if (len >= rcvbuf->page_len || len <= 0 || len > NFS2_MAXPATHLEN) {
> 		dprintk(KERN_WARNING "nfs: server returned giant symlink!\n");
> 		return -ENAMETOOLONG;
> 	}
>

This code appears to assume that rcvbuf->page_base is zero here, but then
uses rcvbuf->page_base when calculating where to place the null byte.  It
seems to me that it should either use rcvbuf->page_base in both
calculations or neither.

    Thanx...

       ps

  reply	other threads:[~2005-09-14 20:17 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-09-12 13:26 [PATCH] nfs client, kernel 2.4.31: readlink result overflow Assar
2005-09-12 18:46 ` Valdis.Kletnieks
2005-09-12 19:37   ` Assar
2005-09-12 20:01     ` Valdis.Kletnieks
2005-09-12 20:41       ` Assar
2005-09-12 20:53         ` Valdis.Kletnieks
2005-09-13 18:39         ` Marcelo Tosatti
2005-09-13 18:52           ` Assar
2005-09-13 19:35             ` Marcelo Tosatti
2005-09-13 20:01               ` Assar
2005-09-14 18:55                 ` Peter Staubach
2005-09-14 19:41                   ` Assar
2005-09-14 20:11                     ` Peter Staubach [this message]
2005-09-14 22:20                       ` Assar
2005-09-14 22:26                         ` Peter Staubach
2005-09-14 20:15                     ` Peter Staubach
2005-09-14 20:26                       ` Assar
2005-09-14 20:27                         ` Peter Staubach
2005-09-14 20:59                           ` Assar
2005-09-13 20:36             ` Peter Staubach
2005-09-13 20:55               ` Assar

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