From: Ilya Maximets <i.maximets@samsung.com>
Date: Wed, 3 Aug 2016 05:22:49 +0000 (+0300)
Subject: vhost: check for vhost_ops before using.
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=ca10203cde7cf37623e0e77da1696ba1fbce5d84;p=qemu.git

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>
---

diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
index dc61dc1c5f..f2d49ad7e7 100644
--- a/hw/net/vhost_net.c
+++ b/hw/net/vhost_net.c
@@ -428,7 +428,7 @@ int vhost_set_vring_enable(NetClientState *nc, int enable)
 
     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);
     }