Re: [Qemu-devel] [PATCH] vmxnet3: Do not fill stats if device is inactive

[Jason Wang <jasowang@redhat.com>]

On 10/20/2015 03:11 PM, Dmitry Fleytman wrote:
> Hi Jason,
>
> Sure. No problem.
>
> Acked-by: Dmitry Fleytman <dmitry@daynix.com <mailto:dmitry@daynix.com>>
>
> Dmitry.

Thanks.

>
>> On 20 Oct 2015, at 06:08 AM, Jason Wang <jasowang@redhat.com
>> <mailto:jasowang@redhat.com>> wrote:
>>
>>
>>
>> On 10/18/2015 03:16 PM, Dmitry Fleytman wrote:
>>> ACK
>>
>> Hi Dmitry:
>>
>> Thanks a lot for the reviewing.
>>
>> As I want to add your "Acked-by" in the patch, could you pls add a
>> formal one in the future? (Which can make my life a little bit easier).
>>
>>>> On 15 Oct 2015, at 13:54 PM, Dana Rubin
>>>> <shmulik.ladkani@ravellosystems.com
>>>> <mailto:shmulik.ladkani@ravellosystems.com>> wrote:
>>>>
>>>> From: Shmulik Ladkani <shmulik.ladkani@ravellosystems.com
>>>> <mailto:shmulik.ladkani@ravellosystems.com>>
>>>>
>>>> Guest OS may issue VMXNET3_CMD_GET_STATS even before device was
>>>> activated (for example in linux, after insmod but prior net-dev open).
>>>>
>>>> Accessing shared descriptors prior device activation is illegal as the
>>>> VMXNET3State structures have not been fully initialized.
>>>>
>>>> As a result, guest memory gets corrupted and may lead to guest OS
>>>> crashes.
>>>>
>>>> Fix, by not filling the stats descriptors if device is inactive.
>>>>
>>>> Reported-by: Leonid Shatz <leonid.shatz@ravellosystems.com
>>>> <mailto:leonid.shatz@ravellosystems.com>>
>>>> Signed-off-by: Dana Rubin <dana.rubin@ravellosystems.com
>>>> <mailto:dana.rubin@ravellosystems.com>>
>>>> Signed-off-by: Shmulik Ladkani <shmulik.ladkani@ravellosystems.com
>>>> <mailto:shmulik.ladkani@ravellosystems.com>>
>>>> ---
>>>> hw/net/vmxnet3.c | 4 ++++
>>>> 1 file changed, 4 insertions(+)
>>>>
>>>> diff --git a/hw/net/vmxnet3.c b/hw/net/vmxnet3.c
>>>> index 3c5e10d..5e3a233 100644
>>>> --- a/hw/net/vmxnet3.c
>>>> +++ b/hw/net/vmxnet3.c
>>>> @@ -1289,6 +1289,10 @@ static uint32_t
>>>> vmxnet3_get_interrupt_config(VMXNET3State *s)
>>>> static void vmxnet3_fill_stats(VMXNET3State *s)
>>>> {
>>>>    int i;
>>>> +
>>>> +    if (!s->device_active)
>>>> +        return;
>>>> +
>>>>    for (i = 0; i < s->txq_num; i++) {
>>>>        cpu_physical_memory_write(s->txq_descr[i].tx_stats_pa,
>>>>                                  &s->txq_descr[i].txq_stats,
>>>> -- 
>>>> 1.9.1
>>>>
>>>
>>
>