[libvirt] [PATCH v4 2/2] libvirtd: fix crash on termination

[John Ferlan]

On 10/27/2017 02:32 AM, Nikolay Shirokovskiy wrote:
> 
> 
> On 27.10.2017 08:26, John Ferlan wrote:
>> From: Nikolay Shirokovskiy <nshirokovskiy at virtuozzo.com>
>>
>> The problem is incorrect order of qemu driver shutdown and shutdown
>> of netserver threads that serve client requests (thru qemu driver
>> particularly).
>>
>> Net server threads are shutdown upon dispose which is triggered
>> by last daemon object unref at the end of main function. At the same
>> time qemu driver is shutdown earlier in virStateCleanup. As a result
>> netserver threads see invalid driver object in the middle of request
>> processing.
>>
>> Let's move shutting down netserver threads earlier to virNetDaemonClose.
>>
>> Note: order of last daemon unref and virStateCleanup
>> is introduced in 85c3a182 for a valid reason.
>>
>> Signed-off-by: John Ferlan <jferlan at redhat.com>
>> ---
>>  src/rpc/virnetdaemon.c | 2 ++
>>  1 file changed, 2 insertions(+)
>>
>> diff --git a/src/rpc/virnetdaemon.c b/src/rpc/virnetdaemon.c
>> index d970c47ad4..7cb3214166 100644
>> --- a/src/rpc/virnetdaemon.c
>> +++ b/src/rpc/virnetdaemon.c
>> @@ -882,6 +882,8 @@ virNetDaemonClose(virNetDaemonPtr dmn)
>>      virObjectLock(dmn);
>>  
>>      virHashForEach(dmn->servers, daemonServerClose, NULL);
>> +    virHashRemoveAll(dmn->servers);
>> +    dmn->servers = NULL;
> 
> Setting NULL is not good, we leak hash table memory. Originally I call virHashFree instead of
> virHashRemoveAll thus this line. But calling virHashFree earlier then dispose is dangerous
> I agee with you here, virHashRemoveAll is better.
> 

See and I left the assignment from your patch.  Still, right
virHashRemoveAll doesn't do the VIR_FREE(table->table) and
VIR_FREE(table)...  I'll remove the assignment.

John

>>  
>>      virObjectUnlock(dmn);
>>  }
>>