On 10/2/22 12:46, Konstantin Khlebnikov wrote:
Fuzzing found that on some error paths vhost_memory_unmap() is called twice or
for NULL address. Let's reset pointers after unmap and ingnore unmap for NULL.
Signed-off-by: Konstantin Khlebnikov <[email protected]>
---
hw/virtio/vhost.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 7b03efccec..4e5d5f2ea4 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -335,7 +335,7 @@ static void vhost_memory_unmap(struct vhost_dev *dev, void
*buffer,
hwaddr len, int is_write,
hwaddr access_len)
{
- if (!vhost_dev_has_iommu(dev)) {
+ if (buffer && !vhost_dev_has_iommu(dev)) {
Shouldn't we simply add an "assert(buffer);" check here instead?
cpu_physical_memory_unmap(buffer, len, is_write, access_len);
}
}
@@ -1191,6 +1191,7 @@ fail_alloc_avail:
vhost_memory_unmap(dev, vq->desc, virtio_queue_get_desc_size(vdev, idx),
0, 0);
fail_alloc_desc:
+ vq->used = vq->avail = vq->desc = NULL;
return r;
}
@@ -1238,6 +1239,7 @@ static void vhost_virtqueue_stop(struct vhost_dev *dev,
0, virtio_queue_get_avail_size(vdev, idx));
vhost_memory_unmap(dev, vq->desc, virtio_queue_get_desc_size(vdev, idx),
0, virtio_queue_get_desc_size(vdev, idx));
+ vq->used = vq->avail = vq->desc = NULL;
}
This part is OK.
