From: Assar <assar@permabit.com>
To: Marcelo Tosatti <marcelo.tosatti@cyclades.com>
Cc: 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: 13 Sep 2005 14:52:44 -0400 [thread overview]
Message-ID: <784q8okdfn.fsf@sober-counsel.permabit.com> (raw)
In-Reply-To: <20050913183948.GE14889@dmt.cnet>
Hi, Marcelo.
Marcelo Tosatti <marcelo.tosatti@cyclades.com> writes:
> > diff -u linux-2.4.31.orig/fs/nfs/nfs2xdr.c linux-2.4.31/fs/nfs/nfs2xdr.c
> > --- linux-2.4.31.orig/fs/nfs/nfs2xdr.c 2002-11-28 18:53:15.000000000 -0500
> > +++ linux-2.4.31/fs/nfs/nfs2xdr.c 2005-09-12 16:12:30.000000000 -0400
> > @@ -571,8 +571,8 @@
> > strlen = (u32*)kmap(rcvbuf->pages[0]);
> > /* Convert length of symlink */
> > len = ntohl(*strlen);
> > - if (len > rcvbuf->page_len)
> > - len = rcvbuf->page_len;
> > + if (len > rcvbuf->page_len - sizeof(*strlen) - 1)
> > + len = rcvbuf->page_len - sizeof(*strlen) - 1;
>
> So the problem is that the "len" variable encapsulated in (u32 *)rcvbuf->pages[0]
> does not account for its own length (4 bytes)?
That's one problem.
> If thats the reason, you don't need the "-1" there?
It also writes a 0 byte. I think it looks like this:
---- ------------ -
len string... 0
next prev parent reply other threads:[~2005-09-13 18:53 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 [this message]
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
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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