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| author |   Jason Wang <jasowang@redhat.com> | 2021-06-04 13:53:47 +0800 |
|---|---|---|
| committer |   Michael S. Tsirkin <mst@redhat.com> | 2021-07-08 07:49:01 -0400 |
| commit | 44593865b7c5f55bf587f297c72d682c671eea2b (patch) | |
| tree | 591ca6616d1dd5472fb3f6d1f8416fa1345e9eb5 /drivers/virtio | |
| parent | virtio-ring: factor out desc_extra allocation (diff) | |
| download | linux-dev-44593865b7c5f55bf587f297c72d682c671eea2b.tar.xz linux-dev-44593865b7c5f55bf587f297c72d682c671eea2b.zip | |
virtio_ring: secure handling of mapping errors
We should not depend on the DMA address, length and flag of descriptor
table since they could be wrote with arbitrary value by the device. So
this patch switches to use the stored one in desc_extra.
Note that the indirect descriptors are fine since they are read-only
streaming mappings.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210604055350.58753-5-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'drivers/virtio')
| -rw-r--r-- | drivers/virtio/virtio_ring.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index f2f4a3b635f3..00e54115e29b 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -1219,13 +1219,16 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq, unmap_release: err_idx = i; i = head; + curr = vq->free_head; vq->packed.avail_used_flags = avail_used_flags; for (n = 0; n < total_sg; n++) { if (i == err_idx) break; - vring_unmap_desc_packed(vq, &desc[i]); + vring_unmap_state_packed(vq, + &vq->packed.desc_extra[curr]); + curr = vq->packed.desc_extra[curr].next; i++; if (i >= vq->packed.vring.num) i = 0; |