From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Michael S. Tsirkin" <mst@redhat.com>
Subject: Re: [BUG] acess_ok() missing from zerocopy_sg_from_iovec()
Date: Tue, 4 Jun 2013 08:30:04 +0300
Message-ID: <20130604053004.GA19433@redhat.com>
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Cc: netdev <netdev@vger.kernel.org>
To: Eric Dumazet <eric.dumazet@gmail.com>
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On Mon, Jun 03, 2013 at 05:34:12PM -0700, Eric Dumazet wrote:
> It looks like access_ok(VERIFY_READ, base, len) checks are missing in
> drivers/net/tun.c & drivers/net/macvtap.c before the
> get_user_pages_fast() calls.
> 
> Or am I missing something ?

These paths (zero-copy xmit) are only used through vhost-net which does
its own access_ok checks.

Needs a comment, I agree.