[dpdk-dev,v3,7/8] vhost: do sanity check for desc->next against with vq->size
Commit Message
A malicious guest may easily forge some illegal vring desc buf.
To make our vhost robust, we need make sure desc->next will not
go beyond the vq->desc[] array.
Suggested-by: Rich Lane <rich.lane@bigswitch.com>
Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
---
lib/librte_vhost/vhost_rxtx.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
@@ -183,6 +183,8 @@ copy_mbuf_to_desc(struct virtio_net *dev, struct vhost_virtqueue *vq,
/* Room in vring buffer is not enough */
return -1;
}
+ if (unlikely(desc->next >= vq->size))
+ return -1;
desc = &vq->desc[desc->next];
desc_addr = gpa_to_vva(dev, desc->addr);
@@ -345,7 +347,7 @@ fill_vec_buf(struct vhost_virtqueue *vq, uint32_t avail_idx,
uint32_t len = *allocated;
while (1) {
- if (vec_id >= BUF_VECTOR_MAX)
+ if (unlikely(vec_id >= BUF_VECTOR_MAX || idx >= vq->size))
return -1;
len += vq->desc[idx].len;
@@ -759,6 +761,8 @@ copy_desc_to_mbuf(struct virtio_net *dev, struct vhost_virtqueue *vq,
while (desc_avail != 0 || (desc->flags & VRING_DESC_F_NEXT) != 0) {
/* This desc reaches to its end, get the next one */
if (desc_avail == 0) {
+ if (unlikely(desc->next >= vq->size))
+ return -1;
desc = &vq->desc[desc->next];
desc_addr = gpa_to_vva(dev, desc->addr);