From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753122AbYEQErG (ORCPT ); Sat, 17 May 2008 00:47:06 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751096AbYEQEqy (ORCPT ); Sat, 17 May 2008 00:46:54 -0400 Received: from ozlabs.org ([203.10.76.45]:37408 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751043AbYEQEqx (ORCPT ); Sat, 17 May 2008 00:46:53 -0400 From: Rusty Russell To: Johannes Berg Subject: Re: [PATCH 2/2] lguest: virtio-rng support Date: Sat, 17 May 2008 14:46:39 +1000 User-Agent: KMail/1.9.9 Cc: virtualization@lists.linux-foundation.org, Jeff Garzik , Herbert Xu , Christian Borntraeger , LKML , "H. Anvin" , Theodore Tso , Matt Mackall References: <482C8595.5030509@garzik.org> <200805161539.59739.rusty@rustcorp.com.au> <1210934981.6381.1.camel@johannes.berg> In-Reply-To: <1210934981.6381.1.camel@johannes.berg> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200805171446.39814.rusty@rustcorp.com.au> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Friday 16 May 2008 20:49:41 Johannes Berg wrote: > > + > > +/* Our random number generator device reads from /dev/urandom into the Guest's > > + * input buffers. The usual case is that the Guest doesn't want random numbers > > + * and so has no buffers although /dev/urandom is still readable, whereas > > + * console is the reverse. > > Is it really a good idea to use the hosts /dev/urandom to fill the > guests /dev/random? Technically it's up to rngd in the guest to decide whether to feed entropy or not (ie. /dev/urandom or /dev/random). If we use /dev/random in the host, we risk a DoS. But since /dev/random is 0666 on my system, perhaps noone actually cares? Cheers, Rusty.