[2/4] vhost: fix potential use-after-free for zero copy mbuf
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Commit Message
Don't free the zero copy mbufs before they have been consumed,
otherwise there could be use-after-free.
Fixes: b0a985d1f340 ("vhost: add dequeue zero copy")
Cc: stable@dpdk.org
Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
---
lib/librte_vhost/vhost.h | 12 ++++++++++++
lib/librte_vhost/vhost_user.c | 3 +++
lib/librte_vhost/virtio_net.c | 12 ------------
3 files changed, 15 insertions(+), 12 deletions(-)
Comments
On 2/22/19 3:42 AM, Tiwei Bie wrote:
> Don't free the zero copy mbufs before they have been consumed,
> otherwise there could be use-after-free.
>
> Fixes: b0a985d1f340 ("vhost: add dequeue zero copy")
> Cc:stable@dpdk.org
>
> Signed-off-by: Tiwei Bie<tiwei.bie@intel.com>
> ---
> lib/librte_vhost/vhost.h | 12 ++++++++++++
> lib/librte_vhost/vhost_user.c | 3 +++
> lib/librte_vhost/virtio_net.c | 12 ------------
> 3 files changed, 15 insertions(+), 12 deletions(-)
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Thanks,
Maxime
@@ -757,4 +757,16 @@ restore_mbuf(struct rte_mbuf *m)
}
}
+static __rte_always_inline bool
+mbuf_is_consumed(struct rte_mbuf *m)
+{
+ while (m) {
+ if (rte_mbuf_refcnt_read(m) > 1)
+ return false;
+ m = m->next;
+ }
+
+ return true;
+}
+
#endif /* _VHOST_NET_CDEV_H_ */
@@ -1218,6 +1218,9 @@ free_zmbufs(struct vhost_virtqueue *vq)
zmbuf != NULL; zmbuf = next) {
next = TAILQ_NEXT(zmbuf, next);
+ while (!mbuf_is_consumed(zmbuf->mbuf))
+ usleep(1000);
+
restore_mbuf(zmbuf->mbuf);
rte_pktmbuf_free(zmbuf->mbuf);
TAILQ_REMOVE(&vq->zmbuf_list, zmbuf, next);
@@ -1306,18 +1306,6 @@ get_zmbuf(struct vhost_virtqueue *vq)
return NULL;
}
-static __rte_always_inline bool
-mbuf_is_consumed(struct rte_mbuf *m)
-{
- while (m) {
- if (rte_mbuf_refcnt_read(m) > 1)
- return false;
- m = m->next;
- }
-
- return true;
-}
-
static __rte_always_inline uint16_t
virtio_dev_tx_split(struct virtio_net *dev, struct vhost_virtqueue *vq,
struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count)