Re: [Qemu-devel] [PATCH 1/3] net/colo: fix memory double free error

[Hailiang Zhang <zhang.zhanghailiang@huawei.com>]

On 2017/2/21 10:25, Zhang Chen wrote:
>
>
> On 02/20/2017 04:01 PM, zhanghailiang wrote:
>> The 'primary_list' and 'secondary_list' members of struct Connection
>> is not allocated through dynamically g_queue_new(), but we free it by using
>> g_queue_free(), which will lead to a double-free bug.
>>
>> Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
>> ---
>>    net/colo.c | 2 --
>>    1 file changed, 2 deletions(-)
>>
>> diff --git a/net/colo.c b/net/colo.c
>> index 6a6eacd..7d5c423 100644
>> --- a/net/colo.c
>> +++ b/net/colo.c
>> @@ -147,9 +147,7 @@ void connection_destroy(void *opaque)
>>        Connection *conn = opaque;
>>
>>        g_queue_foreach(&conn->primary_list, packet_destroy, NULL);
>> -    g_queue_free(&conn->primary_list);
>>        g_queue_foreach(&conn->secondary_list, packet_destroy, NULL);
>> -    g_queue_free(&conn->secondary_list);
>
> I think we need use g_queue_clear () here.
>

Ha, you are right, my original modification will introduce memory leak.
Will fix in next version.

> void
> g_queue_clear (GQueue *queue);
> Removes all the elements in queue . If queue elements contain
> dynamically-allocated memory, they should be freed first.
>
> Thanks
> Zhang Chen
>
>>        g_slice_free(Connection, conn);
>>    }
>>
>