From: Jason Wang <jasowang@redhat.com>
To: mst@redhat.com
Cc: ashish.kalra@amd.com, ak@linux.intel.com, file@sect.tu-berlin.de,
luto@kernel.org, kvm@vger.kernel.org, konrad.wilk@oracle.com,
linux-kernel@vger.kernel.org,
virtualization@lists.linux-foundation.org, hch@infradead.org,
xieyongji@bytedance.com, stefanha@redhat.com
Subject: [PATCH 4/7] virtio_ring: secure handling of mapping errors
Date: Fri, 4 Jun 2021 13:53:47 +0800 [thread overview]
Message-ID: <20210604055350.58753-5-jasowang@redhat.com> (raw)
In-Reply-To: <20210604055350.58753-1-jasowang@redhat.com>
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>
---
drivers/virtio/virtio_ring.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 0cdd965dba58..5509c2643fb1 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -1213,13 +1213,16 @@ 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;
--
2.25.1
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next prev parent reply other threads:[~2021-06-04 5:54 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-04 5:53 [PATCH 0/7] Do not read from descriptor ring Jason Wang
2021-06-04 5:53 ` [PATCH 1/7] virtio-ring: maintain next in extra state for packed virtqueue Jason Wang
2021-06-04 5:53 ` [PATCH 2/7] virtio_ring: rename vring_desc_extra_packed Jason Wang
2021-06-04 5:53 ` [PATCH 3/7] virtio-ring: factor out desc_extra allocation Jason Wang
2021-06-04 5:53 ` Jason Wang [this message]
2021-06-04 5:53 ` [PATCH 5/7] virtio_ring: introduce virtqueue_desc_add_split() Jason Wang
2021-06-04 5:53 ` [PATCH 6/7] virtio: use err label in __vring_new_virtqueue() Jason Wang
2021-06-04 5:53 ` [PATCH 7/7] virtio-ring: store DMA metadata in desc_extra for split virtqueue Jason Wang
2021-06-08 16:24 ` [PATCH 0/7] Do not read from descriptor ring Andy Lutomirski
2021-06-10 3:12 ` Jason Wang
2021-07-11 16:08 ` Michael S. Tsirkin
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