[dpdk-stable] [PATCH 5/6] vhost: fix possible dead loop in vector filling
Tiwei Bie
tiwei.bie at intel.com
Fri Jan 4 05:06:41 CET 2019
Fix a possible dead loop which may happen, e.g. when driver
created a loop in the desc list and lens in descs are zero.
Fixes: fd68b4739d2c ("vhost: use buffer vectors in dequeue path")
Fixes: 2f3225a7d69b ("vhost: add vector filling support for packed ring")
Cc: stable at dpdk.org
Signed-off-by: Tiwei Bie <tiwei.bie at intel.com>
---
lib/librte_vhost/virtio_net.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c
index d64c355b9..0893a1d04 100644
--- a/lib/librte_vhost/virtio_net.c
+++ b/lib/librte_vhost/virtio_net.c
@@ -309,6 +309,7 @@ fill_vec_buf_split(struct virtio_net *dev, struct vhost_virtqueue *vq,
uint16_t vec_id = *vec_idx;
uint32_t len = 0;
uint64_t dlen;
+ uint32_t nr_descs = vq->size;
struct vring_desc *descs = vq->desc;
struct vring_desc *idesc = NULL;
@@ -319,6 +320,10 @@ fill_vec_buf_split(struct virtio_net *dev, struct vhost_virtqueue *vq,
if (vq->desc[idx].flags & VRING_DESC_F_INDIRECT) {
dlen = vq->desc[idx].len;
+ nr_descs = dlen / sizeof(struct vring_desc);
+ if (unlikely(nr_descs > vq->size))
+ return -1;
+
descs = (struct vring_desc *)(uintptr_t)
vhost_iova_to_vva(dev, vq, vq->desc[idx].addr,
&dlen,
@@ -348,6 +353,11 @@ fill_vec_buf_split(struct virtio_net *dev, struct vhost_virtqueue *vq,
return -1;
}
+ if (unlikely(nr_descs-- == 0)) {
+ free_ind_table(idesc);
+ return -1;
+ }
+
len += descs[idx].len;
if (unlikely(map_one_desc(dev, vq, buf_vec, &vec_id,
@@ -510,6 +520,9 @@ fill_vec_buf_packed(struct virtio_net *dev, struct vhost_virtqueue *vq,
if (unlikely(vec_id >= BUF_VECTOR_MAX))
return -1;
+ if (unlikely(*desc_count >= vq->size))
+ return -1;
+
*desc_count += 1;
*buf_id = descs[avail_idx].id;
--
2.17.1
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