[master,v2,1/2] vhost: fix possible denial of service on SET_VRING_NUM
Checks
Commit Message
vhost_user_set_vring_num() performs multiple allocations
without checking whether data were previously allocated.
It may cause a denial of service because of the memory leaks
that happen if a malicious vhost-user master keeps sending
VHOST_USER_SET_VRING_NUM request until the slave runs out
of memory.
This issue has been assigned CVE-2019-14818
Fixes: b0a985d1f340 ("vhost: add dequeue zero copy")
Reported-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
lib/librte_vhost/vhost_user.c | 8 ++++++++
1 file changed, 8 insertions(+)
Comments
On 12/11/2019 16:19, Maxime Coquelin wrote:
> vhost_user_set_vring_num() performs multiple allocations
> without checking whether data were previously allocated.
>
> It may cause a denial of service because of the memory leaks
> that happen if a malicious vhost-user master keeps sending
> VHOST_USER_SET_VRING_NUM request until the slave runs out
> of memory.
>
> This issue has been assigned CVE-2019-14818
>
> Fixes: b0a985d1f340 ("vhost: add dequeue zero copy")
>
> Reported-by: Jason Wang <jasowang@redhat.com>
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Applied, thanks.
@@ -348,6 +348,8 @@ vhost_user_set_vring_num(struct virtio_net **pdev,
vq->nr_zmbuf = 0;
vq->last_zmbuf_idx = 0;
vq->zmbuf_size = vq->size;
+ if (vq->zmbufs)
+ rte_free(vq->zmbufs);
vq->zmbufs = rte_zmalloc(NULL, vq->zmbuf_size *
sizeof(struct zcopy_mbuf), 0);
if (vq->zmbufs == NULL) {
@@ -360,6 +362,8 @@ vhost_user_set_vring_num(struct virtio_net **pdev,
}
if (vq_is_packed(dev)) {
+ if (vq->shadow_used_packed)
+ rte_free(vq->shadow_used_packed);
vq->shadow_used_packed = rte_malloc(NULL,
vq->size *
sizeof(struct vring_used_elem_packed),
@@ -371,6 +375,8 @@ vhost_user_set_vring_num(struct virtio_net **pdev,
}
} else {
+ if (vq->shadow_used_split)
+ rte_free(vq->shadow_used_split);
vq->shadow_used_split = rte_malloc(NULL,
vq->size * sizeof(struct vring_used_elem),
RTE_CACHE_LINE_SIZE);
@@ -381,6 +387,8 @@ vhost_user_set_vring_num(struct virtio_net **pdev,
}
}
+ if (vq->batch_copy_elems)
+ rte_free(vq->batch_copy_elems);
vq->batch_copy_elems = rte_malloc(NULL,
vq->size * sizeof(struct batch_copy_elem),
RTE_CACHE_LINE_SIZE);