From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752120AbeC0OLH (ORCPT ); Tue, 27 Mar 2018 10:11:07 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:52734 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751136AbeC0OLG (ORCPT ); Tue, 27 Mar 2018 10:11:06 -0400 Date: Tue, 27 Mar 2018 17:11:04 +0300 From: "Michael S. Tsirkin" To: Suzuki K Poulose Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, cdall@kernel.org, marc.zyngier@arm.com, punit.agrawal@arm.com, will.deacon@arm.com, catalin.marinas@arm.com, pbonzini@redhat.com, rkrcmar@redhat.com, ard.biesheuvel@linaro.org, peter.maydell@linaro.org, kristina.martsenko@arm.com, mark.rutland@arm.com, Jason Wang , Jean-Philippe Brucker Subject: Re: [PATCH v2 02/17] virtio: pci-legacy: Validate queue pfn Message-ID: <20180327170823-mutt-send-email-mst@kernel.org> References: <1522156531-28348-1-git-send-email-suzuki.poulose@arm.com> <1522156531-28348-3-git-send-email-suzuki.poulose@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1522156531-28348-3-git-send-email-suzuki.poulose@arm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Mar 27, 2018 at 02:15:12PM +0100, Suzuki K Poulose wrote: > Legacy PCI over virtio uses a 32bit PFN for the queue. If the > queue pfn is too large to fit in 32bits, which we could hit on > arm64 systems with 52bit physical addresses (even with 64K page > size), we simply miss out a proper link to the other side of > the queue. > > Add a check to validate the PFN, rather than silently breaking > the devices. > > Cc: "Michael S. Tsirkin" > Cc: Jason Wang > Cc: Marc Zyngier > Cc: Christoffer Dall > Cc: Peter Maydel > Cc: Jean-Philippe Brucker > Signed-off-by: Suzuki K Poulose > --- > drivers/virtio/virtio_pci_legacy.c | 12 ++++++++++-- > 1 file changed, 10 insertions(+), 2 deletions(-) > > diff --git a/drivers/virtio/virtio_pci_legacy.c b/drivers/virtio/virtio_pci_legacy.c > index 2780886..4b84a75 100644 > --- a/drivers/virtio/virtio_pci_legacy.c > +++ b/drivers/virtio/virtio_pci_legacy.c > @@ -122,6 +122,7 @@ static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev, > struct virtqueue *vq; > u16 num; > int err; > + u64 q_pfn; > > /* Select the queue we're interested in */ > iowrite16(index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL); > @@ -141,9 +142,15 @@ static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev, > if (!vq) > return ERR_PTR(-ENOMEM); > > + q_pfn = virtqueue_get_desc_addr(vq) >> VIRTIO_PCI_QUEUE_ADDR_SHIFT; > + if (q_pfn >> 32) { > + dev_err(&vp_dev->pci_dev->dev, "virtio-pci queue PFN too large\n"); > + err = -ENOMEM; ENOMEM seems wrong here. E2BIG? > + goto out_del_vq; > + } > + > /* activate the queue */ > - iowrite32(virtqueue_get_desc_addr(vq) >> VIRTIO_PCI_QUEUE_ADDR_SHIFT, > - vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN); > + iowrite32((u32)q_pfn, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN); Is the cast really necessary here? > > vq->priv = (void __force *)vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NOTIFY; > > @@ -160,6 +167,7 @@ static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev, > > out_deactivate: > iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN); > +out_del_vq: > vring_del_virtqueue(vq); > return ERR_PTR(err); > } > -- > 2.7.4