[PATCH v2 2/5] vhost: fix virtqueue access check in VDUSE setup

[David Marchand]

vring_translate and vring_invalidate change the vq access_ok field.
The access_ok field should only be updated under a (write) lock.

Fixes: a9120db8b98b ("vhost: add VDUSE device startup")
Fixes: ad67c65efda1 ("vhost: add VDUSE device stop")
Cc: stable at dpdk.org

Signed-off-by: David Marchand <david.marchand at redhat.com>
Acked-by: Eelco Chaudron <echaudro at redhat.com>
---
Changes since v1:
- moved fix out of patch 3,

---
 lib/vhost/vduse.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/vhost/vduse.c b/lib/vhost/vduse.c
index 080b58f7de..e198eeef64 100644
--- a/lib/vhost/vduse.c
+++ b/lib/vhost/vduse.c
@@ -196,6 +196,7 @@ vduse_vring_setup(struct virtio_net *dev, unsigned int index)
 				vq->size * sizeof(struct batch_copy_elem),
 				RTE_CACHE_LINE_SIZE, 0);
 
+	rte_rwlock_write_lock(&vq->access_lock);
 	vhost_user_iotlb_rd_lock(vq);
 	if (vring_translate(dev, vq))
 		VHOST_LOG_CONFIG(dev->ifname, ERR, "Failed to translate vring %d addresses\n",
@@ -206,6 +207,7 @@ vduse_vring_setup(struct virtio_net *dev, unsigned int index)
 				"Failed to disable guest notifications on vring %d\n",
 				index);
 	vhost_user_iotlb_rd_unlock(vq);
+	rte_rwlock_write_unlock(&vq->access_lock);
 
 	vq_efd.index = index;
 	vq_efd.fd = vq->kickfd;
@@ -259,7 +261,9 @@ vduse_vring_cleanup(struct virtio_net *dev, unsigned int index)
 	close(vq->kickfd);
 	vq->kickfd = VIRTIO_UNINITIALIZED_EVENTFD;
 
+	rte_rwlock_write_lock(&vq->access_lock);
 	vring_invalidate(dev, vq);
+	rte_rwlock_write_unlock(&vq->access_lock);
 
 	rte_free(vq->batch_copy_elems);
 	vq->batch_copy_elems = NULL;
-- 
2.42.0