Re: [PATCH] tun: orphan an skb on tx

From: Eric Dumazet
Date: Tue Apr 13 2010 - 14:31:28 EST


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

> > 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.



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