Date: Sun, 23 Nov 2014 20:23:21 -0500 (EST)
Message-Id: <20141123.202321.1426718936320546377.davem@davemloft.net>
To: mst@redhat.com
Cc: pagupta@redhat.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
        jasowang@redhat.com, dgibson@redhat.com, vfalico@gmail.com,
        edumazet@google.com, vyasevic@redhat.com, hkchu@google.com,
        wuzhy@linux.vnet.ibm.com, xemul@parallels.com, therbert@google.com,
        bhutchings@solarflare.com, xii@google.com, stephen@networkplumber.org,
        jiri@resnulli.us, sergei.shtylyov@cogentembedded.com
Subject: Re: [PATCH net-net 0/4] Increase the limit of tuntap queues
From: David Miller <davem@davemloft.net>
In-Reply-To: <20141123203032.GA6286@redhat.com>
References: <20141123104623.GA31915@redhat.com>
	<20141123.134323.1154795102254868842.davem@davemloft.net>
	<20141123203032.GA6286@redhat.com>
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From: "Michael S. Tsirkin" <mst@redhat.com>
Date: Sun, 23 Nov 2014 22:30:32 +0200

> qemu runs in the host, but it's unpriveledged: it gets
> passed tun FDs by a priveledged daemon, and it only
> has the rights to some operations,
> in particular to attach and detach queues.
> 
> The assumption always was that this operation is safe
> and can't make kernel run out of resources.

This creates a rather rediculous situation in my opinion.

Configuring a network device is a privileged operation, the daemon
should be setting this thing up.

In no other context would we have to worry about something like this.
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