[Qemu-devel] Re: [PATCH] tun: orphan an skb on tx

[Eric Dumazet]

Le mardi 13 avril 2010 à 20:39 +0300, Michael S. Tsirkin a écrit :

> > When a socket with inflight tx packets is closed, we dont block the
> > close, we only delay the socket freeing once all packets were delivered
> > and freed.
> > 
> 
> Which is wrong, since this is under userspace control, so you get
> unkillable processes.
> 

We do not get unkillable processes, at least with sockets I was thinking
about (TCP/UDP ones).

Maybe tun sockets can behave the same ?

Herbert Acked your patch, so I guess its OK, but I think it can be
dangerous.

Anyway my feeling is that we try to add various mechanisms to keep a
hostile user flooding another one.

For example, UDP got memory accounting quite recently, and we added
socket backlog limits very recently. It was considered not needed few
years ago.