diff mbox

vhost: check for vhost_ops before using.

Message ID 1470201769-12344-1-git-send-email-i.maximets@samsung.com
State New
Headers show

Commit Message

Ilya Maximets Aug. 3, 2016, 5:22 a.m. UTC
'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>
---
 hw/net/vhost_net.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Marc-André Lureau Aug. 3, 2016, 8:37 a.m. UTC | #1
Hi

On Wed, Aug 3, 2016 at 9:25 AM Ilya Maximets <i.maximets@samsung.com> wrote:

> '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>
> ---
>  hw/net/vhost_net.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> 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 @@ 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);
>      }
>

would be nice for 2.7,

Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>

>
> --
> 2.7.4
>
>
> --
Marc-André Lureau
Marc-André Lureau Aug. 9, 2016, 10:27 a.m. UTC | #2
Hi

On Wed, Aug 3, 2016 at 12:37 PM Marc-André Lureau <
marcandre.lureau@gmail.com> wrote:

> Hi
>
> On Wed, Aug 3, 2016 at 9:25 AM Ilya Maximets <i.maximets@samsung.com>
> wrote:
>
>> '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>
>> ---
>>  hw/net/vhost_net.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> 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 @@ 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);
>>      }
>>
>
> would be nice for 2.7,
>

Michael, could you pick the fix for 2.7? thanks

>
> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
>
>>
>> --
>> 2.7.4
>>
>>
>> --
> Marc-André Lureau
>
diff mbox

Patch

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 @@  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);
     }