commit ca10203cde7cf37623e0e77da1696ba1fbce5d84
author Ilya Maximets <i.maximets@samsung.com> Wed Aug 03 08:22:49 2016 +0300
committer Michael S. Tsirkin <mst@redhat.com> Wed Aug 10 17:47:29 2016 +0300
tree 24f87d97a7b5525d6be64260b0e605a7c1d94bb2
parent 53279c76cf071fed07a336948d37c72e3613e0b7

vhost: check for vhost_ops before using.

'vhost_set_vring_enable()' tries to call function using pointer to
'vhost_ops' which can be already zeroized in 'vhost_dev_cleanup()'
while vhost disconnection.

Fix that by checking 'vhost_ops' before using. This fixes QEMU crash
on calling 'ethtool -L eth0 combined 2' if vhost disconnected.

Signed-off-by: Ilya Maximets <i.maximets@samsung.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

hw/net/vhost_net.c

diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
index dc61dc1..f2d49ad 100644
--- a/hw/net/vhost_net.c
+++ b/hw/net/vhost_net.c
@@ -428,7 +428,7 @@
 
     nc->vring_enable = enable;
 
-    if (vhost_ops->vhost_set_vring_enable) {
+    if (vhost_ops && vhost_ops->vhost_set_vring_enable) {
         return vhost_ops->vhost_set_vring_enable(&net->dev, enable);
     }