On Thu, Mar 23, 2017 at 01:13:50PM +0800, Jason Wang wrote:
> >From 312859b596e83a2164a8430343d31fce2a5ad808 Mon Sep 17 00:00:00 2001
> From: Jason Wang <jasow...@redhat.com>
> Date: Thu, 23 Mar 2017 13:07:16 +0800
> Subject: [PATCH] virtio_pci: fix out of bound access for msix_names
>
> Signed-off-by: Jason Wang <jasow...@redhat.com>
I tested this, and it does appear to fix the crashes in
vp_modern_find_vqs. Therefore:
Tested-by: Richard W.M. Jones <rjo...@redhat.com>
Thanks,
Rich.
> drivers/virtio/virtio_pci_common.c | 9 +++++----
> 1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/virtio/virtio_pci_common.c
> b/drivers/virtio/virtio_pci_common.c
> index df548a6..5905349 100644
> --- a/drivers/virtio/virtio_pci_common.c
> +++ b/drivers/virtio/virtio_pci_common.c
> @@ -147,7 +147,7 @@ static int vp_find_vqs_msix(struct virtio_device *vdev,
> unsigned nvqs,
> {
> struct virtio_pci_device *vp_dev = to_vp_device(vdev);
> const char *name = dev_name(&vp_dev->vdev.dev);
> - int i, err = -ENOMEM, allocated_vectors, nvectors;
> + int i, j, err = -ENOMEM, allocated_vectors, nvectors;
> unsigned flags = PCI_IRQ_MSIX;
> bool shared = false;
> u16 msix_vec;
> @@ -212,7 +212,7 @@ static int vp_find_vqs_msix(struct virtio_device *vdev,
> unsigned nvqs,
> if (!vp_dev->msix_vector_map)
> goto out_disable_config_irq;
>
> - allocated_vectors = 1; /* vector 0 is the config interrupt */
> + allocated_vectors = j = 1; /* vector 0 is the config interrupt */
> for (i = 0; i < nvqs; ++i) {
> if (!names[i]) {
> vqs[i] = NULL;
> @@ -236,18 +236,19 @@ static int vp_find_vqs_msix(struct virtio_device *vdev,
> unsigned nvqs,
> continue;
> }
>
> - snprintf(vp_dev->msix_names[i + 1],
> + snprintf(vp_dev->msix_names[j],
> sizeof(*vp_dev->msix_names), "%s-%s",
> dev_name(&vp_dev->vdev.dev), names[i]);
> err = request_irq(pci_irq_vector(vp_dev->pci_dev, msix_vec),
> vring_interrupt, IRQF_SHARED,
> - vp_dev->msix_names[i + 1], vqs[i]);
> + vp_dev->msix_names[j], vqs[i]);
> if (err) {
> /* don't free this irq on error */
> vp_dev->msix_vector_map[i] = VIRTIO_MSI_NO_VECTOR;
> goto out_remove_vqs;
> }
> vp_dev->msix_vector_map[i] = msix_vec;
> + j++;
>
> /*
> * Use a different vector for each queue if they are available,
> --
> 2.7.4
>
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
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