[PATCH v3] net/virtio: fix crash when dev is configured twice

[Xia, Chenbo]

> -----Original Message-----
> From: Xia, Chenbo <chenbo.xia at intel.com>
> Sent: Wednesday, September 28, 2022 12:47 PM
> To: Alexander Chernavin <achernavin at netgate.com>;
> maxime.coquelin at redhat.com
> Cc: dev at dpdk.org; stable at dpdk.org
> Subject: RE: [PATCH v3] net/virtio: fix crash when dev is configured twice
> 
> > -----Original Message-----
> > From: Alexander Chernavin <achernavin at netgate.com>
> > Sent: Tuesday, September 27, 2022 6:15 PM
> > To: Xia, Chenbo <chenbo.xia at intel.com>; maxime.coquelin at redhat.com
> > Cc: dev at dpdk.org; Alexander Chernavin <achernavin at netgate.com>;
> > stable at dpdk.org
> > Subject: [PATCH v3] net/virtio: fix crash when dev is configured twice
> >
> > When first attempt to configure a device with RX interrupt enabled fails
> > for some reason (e.g. because "Multiple intr vector not supported"),
> > second attempt to configure the device with RX interrupt disabled and
> > feature set unchanged will succeed but will leave virtio queues not
> > allocated. Accessing the queues will cause a segfault.
> >
> > First attempt:
> >   - virtio_dev_configure()
> >     - virtio_init_device() is called to reinit the device because
> >       "dev->data->dev_conf.intr_conf.rxq" is "1"
> >       - virtio_configure_intr() fails and returns an error
> >       - virtio_free_queues() frees previously allocated virtio queues
> >     - virtio_init_device() fails and returns an error
> >   - virtio_dev_configure() fails and returns an error
> >
> > Second attempt:
> >   - virtio_dev_configure()
> >     - This time virtio_init_device() is not called, virtio queues
> >       are not allocated
> >
> > With this fix, reinit the device during configuration if virtio queues
> > are not allocated.
> >
> > Fixes: 2b38151f745a ("net/virtio: fix queue memory leak on error")
> > Cc: stable at dpdk.org
> >
> > Signed-off-by: Alexander Chernavin <achernavin at netgate.com>
> > ---
> > v2: Add Cc: stable at dpdk.org
> > v3: Add Fixes: 2b38151f745a
> >
> >  drivers/net/virtio/virtio_ethdev.c | 7 +++++++
> >  1 file changed, 7 insertions(+)
> >
> > diff --git a/drivers/net/virtio/virtio_ethdev.c
> > b/drivers/net/virtio/virtio_ethdev.c
> > index d180162abd..38bfe050b5 100644
> > --- a/drivers/net/virtio/virtio_ethdev.c
> > +++ b/drivers/net/virtio/virtio_ethdev.c
> > @@ -2616,6 +2616,13 @@ virtio_dev_configure(struct rte_eth_dev *dev)
> >  			return ret;
> >  	}
> >
> > +	/* if queues are not allocated, reinit the device */
> > +	if (hw->vqs == NULL) {
> > +		ret = virtio_init_device(dev, hw->req_guest_features);
> > +		if (ret < 0)
> > +			return ret;
> > +	}
> > +
> >  	if ((rxmode->mq_mode & RTE_ETH_MQ_RX_RSS_FLAG) &&
> >  			!virtio_with_feature(hw, VIRTIO_NET_F_RSS)) {
> >  		PMD_DRV_LOG(ERR, "RSS support requested but not supported by
> > the device");
> > --
> > 2.25.1
> 
> Reviewed-by: Chenbo Xia <chenbo.xia at intel.com>

Applied to next-virtio/main, thanks