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From: Cornelia Huck <cohuck@redhat.com>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>,
	qemu-devel@nongnu.org, Cindy Lu <lulu@redhat.com>
Subject: Re: [PATCH] virtio-net: check the existence of peer before accesing its config
Date: Mon, 27 Jul 2020 11:53:22 +0200	[thread overview]
Message-ID: <20200727115322.4e7fe1aa.cohuck@redhat.com> (raw)
In-Reply-To: <20200727053954-mutt-send-email-mst@kernel.org>

On Mon, 27 Jul 2020 05:41:17 -0400
"Michael S. Tsirkin" <mst@redhat.com> wrote:

> On Mon, Jul 27, 2020 at 03:43:28PM +0800, Jason Wang wrote:
> > We try to get config from peer unconditionally which may lead NULL
> > pointer dereference. Add a check before trying to access the config.
> > 
> > Fixes: 108a64818e69b ("vhost-vdpa: introduce vhost-vdpa backend")
> > Cc: Cindy Lu <lulu@redhat.com>
> > Tested-by: Cornelia Huck <cohuck@redhat.com>
> > Signed-off-by: Jason Wang <jasowang@redhat.com>  
> 
> I am a bit lost here. Isn't this invoked
> when guest attempts to read the config?
> With no peer, what do we return to guest?

Same as with a non-vdpa peer? It's the dereference that needs to be
guarded.

> A code comment might be helpful here.
> 
> > ---
> >  hw/net/virtio-net.c | 22 +++++++++++-----------
> >  1 file changed, 11 insertions(+), 11 deletions(-)



  parent reply	other threads:[~2020-07-27  9:54 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-27  7:43 [PATCH] virtio-net: check the existence of peer before accesing its config Jason Wang
2020-07-27  8:44 ` Cornelia Huck
2020-07-27  8:51   ` Jason Wang
2020-07-27  9:41 ` Michael S. Tsirkin
2020-07-27  9:49   ` Jason Wang
2020-07-27 10:17     ` Michael S. Tsirkin
2020-07-27 10:22       ` Jason Wang
2020-07-27 10:21     ` Michael S. Tsirkin
2020-07-27 10:23       ` Jason Wang
2020-07-27  9:53   ` Cornelia Huck [this message]
2020-07-27 10:13     ` Michael S. Tsirkin
2020-07-27 10:26       ` Jason Wang
2020-07-27 11:41         ` Michael S. Tsirkin
2020-07-27 12:44           ` Jason Wang

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