[PATCH v2] virtio/virtio_pci_legacy: debug checking for queue size
From: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Date: 2022-08-18 03:04:16
Subsystem:
the rest, virtio core · Maintainers:
Linus Torvalds, "Michael S. Tsirkin", Jason Wang, Eugenio Pérez
Legacy virtio pci has no way to communicate a change in vq size to the hypervisor. If ring sizes don't match hypervisor will happily corrupt memory. We add a check to vring size before calling vp_legacy_set_queue_address(). Checking the memory range directly is a bit cumbersome. Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> --- v2: replace BUG_ON with WARN_ON_ONCE. @Linus drivers/virtio/virtio_pci_legacy.c | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/drivers/virtio/virtio_pci_legacy.c b/drivers/virtio/virtio_pci_legacy.c
index 2257f1b3d8ae..091e73d74e94 100644
--- a/drivers/virtio/virtio_pci_legacy.c
+++ b/drivers/virtio/virtio_pci_legacy.c@@ -146,6 +146,15 @@ static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev, goto out_del_vq; } + /* Legacy virtio pci has no way to communicate a change in vq size to + * the hypervisor. If ring sizes don't match hypervisor will happily + * corrupt memory. + */ + if (WARN_ON_ONCE(num != virtqueue_get_vring_size(vq))) { + err = -EPERM; + goto out_del_vq; + } + /* activate the queue */ vp_legacy_set_queue_address(&vp_dev->ldev, index, q_pfn);
--
2.31.0
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