From: Eric Dumazet <eric.dumazet@gmail.com>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>,
"David S. Miller" <davem@davemloft.net>,
Herbert Xu <herbert@gondor.hengli.com.au>,
Paul Moore <paul.moore@hp.com>,
David Woodhouse <David.Woodhouse@intel.com>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
qemu-devel <qemu-devel@nongnu.org>
Subject: Re: [PATCH] tun: orphan an skb on tx
Date: Tue, 13 Apr 2010 20:31:03 +0200 [thread overview]
Message-ID: <1271183463.16881.545.camel@edumazet-laptop> (raw)
In-Reply-To: <20100413173919.GC26011@redhat.com>
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.
WARNING: multiple messages have this Message-ID (diff)
From: Eric Dumazet <eric.dumazet@gmail.com>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Paul Moore <paul.moore@hp.com>,
David Woodhouse <David.Woodhouse@intel.com>,
Jan Kiszka <jan.kiszka@siemens.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
qemu-devel <qemu-devel@nongnu.org>,
Herbert Xu <herbert@gondor.hengli.com.au>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
"David S. Miller" <davem@davemloft.net>
Subject: [Qemu-devel] Re: [PATCH] tun: orphan an skb on tx
Date: Tue, 13 Apr 2010 20:31:03 +0200 [thread overview]
Message-ID: <1271183463.16881.545.camel@edumazet-laptop> (raw)
In-Reply-To: <20100413173919.GC26011@redhat.com>
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.
next prev parent reply other threads:[~2010-04-13 18:31 UTC|newest]
Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-13 14:59 [PATCH] tun: orphan an skb on tx Michael S. Tsirkin
2010-04-13 14:59 ` [Qemu-devel] " Michael S. Tsirkin
2010-04-13 15:12 ` Herbert Xu
2010-04-13 15:12 ` [Qemu-devel] " Herbert Xu
2010-04-13 15:12 ` Herbert Xu
2010-04-13 15:36 ` Jan Kiszka
2010-04-13 15:36 ` [Qemu-devel] " Jan Kiszka
2010-04-13 16:40 ` Eric Dumazet
2010-04-13 16:40 ` [Qemu-devel] " Eric Dumazet
2010-04-13 16:52 ` Jan Kiszka
2010-04-13 16:52 ` [Qemu-devel] " Jan Kiszka
2010-04-13 17:39 ` Michael S. Tsirkin
2010-04-13 17:39 ` [Qemu-devel] " Michael S. Tsirkin
2010-04-13 18:31 ` Eric Dumazet [this message]
2010-04-13 18:31 ` Eric Dumazet
2010-04-13 20:25 ` Michael S. Tsirkin
2010-04-13 20:25 ` [Qemu-devel] " Michael S. Tsirkin
2010-04-13 20:38 ` Eric Dumazet
2010-04-13 20:38 ` [Qemu-devel] " Eric Dumazet
2010-04-13 20:43 ` Michael S. Tsirkin
2010-04-13 20:43 ` [Qemu-devel] " Michael S. Tsirkin
2010-04-14 0:58 ` Herbert Xu
2010-04-14 0:58 ` [Qemu-devel] " Herbert Xu
2010-04-14 0:58 ` Herbert Xu
2010-04-14 11:55 ` David Miller
2010-04-14 11:55 ` [Qemu-devel] " David Miller
2010-04-14 11:55 ` David Miller
2015-02-01 11:20 ` David Woodhouse
2015-02-01 11:20 ` [Qemu-devel] " David Woodhouse
2015-02-01 12:26 ` Michael S. Tsirkin
2015-02-01 12:26 ` [Qemu-devel] " Michael S. Tsirkin
2015-02-01 13:33 ` David Woodhouse
2015-02-01 13:33 ` [Qemu-devel] " David Woodhouse
2015-02-01 20:19 ` David Miller
2015-02-01 20:19 ` [Qemu-devel] " David Miller
2015-02-01 21:29 ` David Woodhouse
2015-02-01 21:29 ` [Qemu-devel] " David Woodhouse
2015-02-02 5:07 ` David Miller
2015-02-02 5:07 ` [Qemu-devel] " David Miller
2015-02-02 5:07 ` David Miller
2015-02-02 7:27 ` David Woodhouse
2015-02-02 7:27 ` [Qemu-devel] " David Woodhouse
2015-02-02 8:24 ` Steffen Klassert
2015-02-02 8:24 ` [Qemu-devel] " Steffen Klassert
2015-02-02 15:30 ` David Woodhouse
2015-02-02 15:30 ` [Qemu-devel] " David Woodhouse
2015-02-02 15:23 ` Phil Sutter
2015-02-02 15:23 ` [Qemu-devel] " Phil Sutter
2015-02-02 15:47 ` David Woodhouse
2015-02-02 15:47 ` [Qemu-devel] " David Woodhouse
2015-02-04 0:19 ` David Miller
2015-02-04 0:19 ` [Qemu-devel] " David Miller
2015-02-04 6:35 ` David Woodhouse
2015-02-04 6:35 ` [Qemu-devel] " David Woodhouse
2021-06-25 15:56 ` Bringing the SSL VPN data path back in-kernel David Woodhouse
2010-04-21 11:35 ` [PATCH] tun: orphan an skb on tx Michael S. Tsirkin
2010-04-21 11:35 ` [Qemu-devel] " Michael S. Tsirkin
2010-04-21 11:46 ` Jan Kiszka
2010-04-21 11:46 ` [Qemu-devel] " Jan Kiszka
2010-04-21 11:45 ` Michael S. Tsirkin
2010-04-21 11:45 ` [Qemu-devel] " Michael S. Tsirkin
2010-04-21 19:16 ` [stable] " Greg KH
2010-04-21 19:16 ` [Qemu-devel] " Greg KH
2010-09-14 15:20 ` Michael S. Tsirkin
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