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Date: Tue, 09 Jul 2013 12:56:24 -0700 (PDT)
Message-Id: <20130709.125624.1456063645210971879.davem@davemloft.net>
To: mst@redhat.com
Cc: asias@redhat.com, jasowang@redhat.com, kvm@vger.kernel.org,
        virtualization@lists.linux-foundation.org, netdev@vger.kernel.org,
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Subject: Re: [PATCHv3] vhost-net: fix use-after-free in vhost_net_flush
From: David Miller <davem@davemloft.net>
In-Reply-To: <20130707112653.GA31232@redhat.com>
References: <20130707112653.GA31232@redhat.com>
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From: "Michael S. Tsirkin" <mst@redhat.com>
Date: Sun, 7 Jul 2013 14:26:53 +0300

> vhost_net_ubuf_put_and_wait has a confusing name:
> it will actually also free it's argument.
> Thus since commit 1280c27f8e29acf4af2da914e80ec27c3dbd5c01
>     "vhost-net: flush outstanding DMAs on memory change"
> vhost_net_flush tries to use the argument after passing it
> to vhost_net_ubuf_put_and_wait, this results
> in use after free.
> To fix, don't free the argument in vhost_net_ubuf_put_and_wait,
> add an new API for callers that want to free ubufs.
> 
> Acked-by: Asias He <asias@redhat.com>
> Acked-by: Jason Wang <jasowang@redhat.com>
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

Applied and queued up for -stable.