vhost: check owner before we overwrite ubuf_info

If device has an owner, we shouldn't touch ubuf_info
since it might be in use.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index b07d96b8c0d1..8cf5aece8c84 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -1054,6 +1054,10 @@ static long vhost_net_set_owner(struct vhost_net *n)
         int r;
 
         mutex_lock(&n->dev.mutex);
+        if (vhost_dev_has_owner(&n->dev)) {
+                r = -EBUSY;
+                goto out;
+        }
         r = vhost_net_set_ubuf_info(n);
         if (r)
                 goto out;