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* [Qemu-devel] [PATCH] filter-buffer: fix segfault while start qemu with status=off property
@ 2016-04-01  7:08 zhanghailiang
  2016-04-01  7:39 ` Jason Wang
  0 siblings, 1 reply; 6+ messages in thread
From: zhanghailiang @ 2016-04-01  7:08 UTC (permalink / raw)
  To: qemu-devel; +Cc: jasowang, zhanghailiang

After commit 338d3f, we support 'status' property for filter object.
The segfault can be triggered by starting qemu with 'status=off' property
for filter, when the s->incoming_queue is NULL, we reference it directly
in qemu_net_queue_flush().

Let's check the value of 's->incoming_queue' before calling
qemu_net_queue_flush().

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
---
 net/filter-buffer.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/filter-buffer.c b/net/filter-buffer.c
index cc6bd94..79e2ce3 100644
--- a/net/filter-buffer.c
+++ b/net/filter-buffer.c
@@ -34,7 +34,7 @@ static void filter_buffer_flush(NetFilterState *nf)
 {
     FilterBufferState *s = FILTER_BUFFER(nf);
 
-    if (!qemu_net_queue_flush(s->incoming_queue)) {
+    if (s->incoming_queue && !qemu_net_queue_flush(s->incoming_queue)) {
         /* Unable to empty the queue, purge remaining packets */
         qemu_net_queue_purge(s->incoming_queue, nf->netdev);
     }
-- 
1.8.3.1

^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [Qemu-devel] [PATCH] filter-buffer: fix segfault while start qemu with status=off property
  2016-04-01  7:08 [Qemu-devel] [PATCH] filter-buffer: fix segfault while start qemu with status=off property zhanghailiang
@ 2016-04-01  7:39 ` Jason Wang
  2016-04-01  8:24   ` Hailiang Zhang
  0 siblings, 1 reply; 6+ messages in thread
From: Jason Wang @ 2016-04-01  7:39 UTC (permalink / raw)
  To: zhanghailiang, qemu-devel



On 04/01/2016 03:08 PM, zhanghailiang wrote:
> After commit 338d3f, we support 'status' property for filter object.
> The segfault can be triggered by starting qemu with 'status=off' property
> for filter, when the s->incoming_queue is NULL, we reference it directly
> in qemu_net_queue_flush().
>
> Let's check the value of 's->incoming_queue' before calling
> qemu_net_queue_flush().
>
> Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
> ---
>  net/filter-buffer.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/filter-buffer.c b/net/filter-buffer.c
> index cc6bd94..79e2ce3 100644
> --- a/net/filter-buffer.c
> +++ b/net/filter-buffer.c
> @@ -34,7 +34,7 @@ static void filter_buffer_flush(NetFilterState *nf)
>  {
>      FilterBufferState *s = FILTER_BUFFER(nf);
>  
> -    if (!qemu_net_queue_flush(s->incoming_queue)) {
> +    if (s->incoming_queue && !qemu_net_queue_flush(s->incoming_queue)) {
>          /* Unable to empty the queue, purge remaining packets */
>          qemu_net_queue_purge(s->incoming_queue, nf->netdev);
>      }

We'd better handle this at generic layer and don't let a specific net
filter need to worry about this.

Looks like the issue is we may trigger status_changed() too early (even
before the the filter was initialized).

How about not call status_changed() if the initialization is not done?

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [Qemu-devel] [PATCH] filter-buffer: fix segfault while start qemu with status=off property
  2016-04-01  7:39 ` Jason Wang
@ 2016-04-01  8:24   ` Hailiang Zhang
  2016-04-01  9:10     ` Wen Congyang
  0 siblings, 1 reply; 6+ messages in thread
From: Hailiang Zhang @ 2016-04-01  8:24 UTC (permalink / raw)
  To: Jason Wang, qemu-devel; +Cc: peter.huangpeng

On 2016/4/1 15:39, Jason Wang wrote:
>
>
> On 04/01/2016 03:08 PM, zhanghailiang wrote:
>> After commit 338d3f, we support 'status' property for filter object.
>> The segfault can be triggered by starting qemu with 'status=off' property
>> for filter, when the s->incoming_queue is NULL, we reference it directly
>> in qemu_net_queue_flush().
>>
>> Let's check the value of 's->incoming_queue' before calling
>> qemu_net_queue_flush().
>>
>> Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
>> ---
>>   net/filter-buffer.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/net/filter-buffer.c b/net/filter-buffer.c
>> index cc6bd94..79e2ce3 100644
>> --- a/net/filter-buffer.c
>> +++ b/net/filter-buffer.c
>> @@ -34,7 +34,7 @@ static void filter_buffer_flush(NetFilterState *nf)
>>   {
>>       FilterBufferState *s = FILTER_BUFFER(nf);
>>
>> -    if (!qemu_net_queue_flush(s->incoming_queue)) {
>> +    if (s->incoming_queue && !qemu_net_queue_flush(s->incoming_queue)) {
>>           /* Unable to empty the queue, purge remaining packets */
>>           qemu_net_queue_purge(s->incoming_queue, nf->netdev);
>>       }
>
> We'd better handle this at generic layer and don't let a specific net
> filter need to worry about this.
>
> Looks like the issue is we may trigger status_changed() too early (even
> before the the filter was initialized).
>

Yes ~

> How about not call status_changed() if the initialization is not done?
>

But seems that it is difficult to confirm if the filter is initialized
or not ...

> .
>

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [Qemu-devel] [PATCH] filter-buffer: fix segfault while start qemu with status=off property
  2016-04-01  8:24   ` Hailiang Zhang
@ 2016-04-01  9:10     ` Wen Congyang
  2016-04-01  9:33       ` Hailiang Zhang
  0 siblings, 1 reply; 6+ messages in thread
From: Wen Congyang @ 2016-04-01  9:10 UTC (permalink / raw)
  To: Hailiang Zhang, Jason Wang, qemu-devel; +Cc: peter.huangpeng

On 04/01/2016 04:24 PM, Hailiang Zhang wrote:
> On 2016/4/1 15:39, Jason Wang wrote:
>>
>>
>> On 04/01/2016 03:08 PM, zhanghailiang wrote:
>>> After commit 338d3f, we support 'status' property for filter object.
>>> The segfault can be triggered by starting qemu with 'status=off' property
>>> for filter, when the s->incoming_queue is NULL, we reference it directly
>>> in qemu_net_queue_flush().
>>>
>>> Let's check the value of 's->incoming_queue' before calling
>>> qemu_net_queue_flush().
>>>
>>> Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
>>> ---
>>>   net/filter-buffer.c | 2 +-
>>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/net/filter-buffer.c b/net/filter-buffer.c
>>> index cc6bd94..79e2ce3 100644
>>> --- a/net/filter-buffer.c
>>> +++ b/net/filter-buffer.c
>>> @@ -34,7 +34,7 @@ static void filter_buffer_flush(NetFilterState *nf)
>>>   {
>>>       FilterBufferState *s = FILTER_BUFFER(nf);
>>>
>>> -    if (!qemu_net_queue_flush(s->incoming_queue)) {
>>> +    if (s->incoming_queue && !qemu_net_queue_flush(s->incoming_queue)) {
>>>           /* Unable to empty the queue, purge remaining packets */
>>>           qemu_net_queue_purge(s->incoming_queue, nf->netdev);
>>>       }
>>
>> We'd better handle this at generic layer and don't let a specific net
>> filter need to worry about this.
>>
>> Looks like the issue is we may trigger status_changed() too early (even
>> before the the filter was initialized).
>>
> 
> Yes ~
> 
>> How about not call status_changed() if the initialization is not done?
>>
> 
> But seems that it is difficult to confirm if the filter is initialized
> or not ...

If nfc->setup() is not called, nf->netdev is NULL.

Thanks
Wen Congyang

> 
>> .
>>
> 
> 
> 
> 
> 

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [Qemu-devel] [PATCH] filter-buffer: fix segfault while start qemu with status=off property
  2016-04-01  9:10     ` Wen Congyang
@ 2016-04-01  9:33       ` Hailiang Zhang
  2016-04-05  0:53         ` Jason Wang
  0 siblings, 1 reply; 6+ messages in thread
From: Hailiang Zhang @ 2016-04-01  9:33 UTC (permalink / raw)
  To: Wen Congyang, Jason Wang, qemu-devel; +Cc: peter.huangpeng

On 2016/4/1 17:10, Wen Congyang wrote:
> On 04/01/2016 04:24 PM, Hailiang Zhang wrote:
>> On 2016/4/1 15:39, Jason Wang wrote:
>>>
>>>
>>> On 04/01/2016 03:08 PM, zhanghailiang wrote:
>>>> After commit 338d3f, we support 'status' property for filter object.
>>>> The segfault can be triggered by starting qemu with 'status=off' property
>>>> for filter, when the s->incoming_queue is NULL, we reference it directly
>>>> in qemu_net_queue_flush().
>>>>
>>>> Let's check the value of 's->incoming_queue' before calling
>>>> qemu_net_queue_flush().
>>>>
>>>> Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
>>>> ---
>>>>    net/filter-buffer.c | 2 +-
>>>>    1 file changed, 1 insertion(+), 1 deletion(-)
>>>>
>>>> diff --git a/net/filter-buffer.c b/net/filter-buffer.c
>>>> index cc6bd94..79e2ce3 100644
>>>> --- a/net/filter-buffer.c
>>>> +++ b/net/filter-buffer.c
>>>> @@ -34,7 +34,7 @@ static void filter_buffer_flush(NetFilterState *nf)
>>>>    {
>>>>        FilterBufferState *s = FILTER_BUFFER(nf);
>>>>
>>>> -    if (!qemu_net_queue_flush(s->incoming_queue)) {
>>>> +    if (s->incoming_queue && !qemu_net_queue_flush(s->incoming_queue)) {
>>>>            /* Unable to empty the queue, purge remaining packets */
>>>>            qemu_net_queue_purge(s->incoming_queue, nf->netdev);
>>>>        }
>>>
>>> We'd better handle this at generic layer and don't let a specific net
>>> filter need to worry about this.
>>>
>>> Looks like the issue is we may trigger status_changed() too early (even
>>> before the the filter was initialized).
>>>
>>
>> Yes ~
>>
>>> How about not call status_changed() if the initialization is not done?
>>>
>>
>> But seems that it is difficult to confirm if the filter is initialized
>> or not ...
>
> If nfc->setup() is not called, nf->netdev is NULL.
>

Yes, you right, Jason, what's opinion ?

Thanks,
hailiang

> Thanks
> Wen Congyang
>
>>
>>> .
>>>
>>
>>
>>
>>
>>
>
>
>
>
> .
>

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [Qemu-devel] [PATCH] filter-buffer: fix segfault while start qemu with status=off property
  2016-04-01  9:33       ` Hailiang Zhang
@ 2016-04-05  0:53         ` Jason Wang
  0 siblings, 0 replies; 6+ messages in thread
From: Jason Wang @ 2016-04-05  0:53 UTC (permalink / raw)
  To: Hailiang Zhang, Wen Congyang, qemu-devel; +Cc: peter.huangpeng



On 04/01/2016 05:33 PM, Hailiang Zhang wrote:
> On 2016/4/1 17:10, Wen Congyang wrote:
>> On 04/01/2016 04:24 PM, Hailiang Zhang wrote:
>>> On 2016/4/1 15:39, Jason Wang wrote:
>>>>
>>>>
>>>> On 04/01/2016 03:08 PM, zhanghailiang wrote:
>>>>> After commit 338d3f, we support 'status' property for filter object.
>>>>> The segfault can be triggered by starting qemu with 'status=off'
>>>>> property
>>>>> for filter, when the s->incoming_queue is NULL, we reference it
>>>>> directly
>>>>> in qemu_net_queue_flush().
>>>>>
>>>>> Let's check the value of 's->incoming_queue' before calling
>>>>> qemu_net_queue_flush().
>>>>>
>>>>> Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
>>>>> ---
>>>>>    net/filter-buffer.c | 2 +-
>>>>>    1 file changed, 1 insertion(+), 1 deletion(-)
>>>>>
>>>>> diff --git a/net/filter-buffer.c b/net/filter-buffer.c
>>>>> index cc6bd94..79e2ce3 100644
>>>>> --- a/net/filter-buffer.c
>>>>> +++ b/net/filter-buffer.c
>>>>> @@ -34,7 +34,7 @@ static void filter_buffer_flush(NetFilterState *nf)
>>>>>    {
>>>>>        FilterBufferState *s = FILTER_BUFFER(nf);
>>>>>
>>>>> -    if (!qemu_net_queue_flush(s->incoming_queue)) {
>>>>> +    if (s->incoming_queue &&
>>>>> !qemu_net_queue_flush(s->incoming_queue)) {
>>>>>            /* Unable to empty the queue, purge remaining packets */
>>>>>            qemu_net_queue_purge(s->incoming_queue, nf->netdev);
>>>>>        }
>>>>
>>>> We'd better handle this at generic layer and don't let a specific net
>>>> filter need to worry about this.
>>>>
>>>> Looks like the issue is we may trigger status_changed() too early
>>>> (even
>>>> before the the filter was initialized).
>>>>
>>>
>>> Yes ~
>>>
>>>> How about not call status_changed() if the initialization is not done?
>>>>
>>>
>>> But seems that it is difficult to confirm if the filter is initialized
>>> or not ...
>>
>> If nfc->setup() is not called, nf->netdev is NULL.
>>
>
> Yes, you right, Jason, what's opinion ?
>
> Thanks,
> hailiang

Looks good. Please also add a comment of this in the patch.

Thanks

>
>> Thanks
>> Wen Congyang
>>
>>>
>>>> .
>>>>
>>>
>>>
>>>
>>>
>>>
>>
>>
>>
>>
>> .
>>
>
>

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2016-04-05  0:53 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2016-04-01  7:08 [Qemu-devel] [PATCH] filter-buffer: fix segfault while start qemu with status=off property zhanghailiang
2016-04-01  7:39 ` Jason Wang
2016-04-01  8:24   ` Hailiang Zhang
2016-04-01  9:10     ` Wen Congyang
2016-04-01  9:33       ` Hailiang Zhang
2016-04-05  0:53         ` Jason Wang

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