From mboxrd@z Thu Jan  1 00:00:00 1970
From: Maxime Coquelin <maxime.coquelin@redhat.com>
Subject: Re: [PATCH v4 05/19] vhost: fix error handling when mem
 table gets updated
Date: Tue, 9 Oct 2018 13:47:20 +0200
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References: <20181008152557.14275-1-maxime.coquelin@redhat.com>
 <20181008152557.14275-6-maxime.coquelin@redhat.com>
 <20181009113541.GA1548@debian>
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Cc: dev@dpdk.org, zhihong.wang@intel.com, jfreimann@redhat.com,
 nicknickolaev@gmail.com, i.maximets@samsung.com, bruce.richardson@intel.com,
 alejandro.lucero@netronome.com, dgilbert@redhat.com, stable@dpdk.org
To: Tiwei Bie <tiwei.bie@intel.com>
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On 10/09/2018 01:35 PM, Tiwei Bie wrote:
> On Mon, Oct 08, 2018 at 05:25:43PM +0200, Maxime Coquelin wrote:
>> When the memory table gets updated, the rings addresses need
>> to be translated again. If it fails, we need to exit cleanly
>> by unmapping memory regions.
>>
>> Fixes: d5022533c20a ("vhost: retranslate vring addr when memory table changes")
>> Cc: stable@dpdk.org
>>
>> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
>> Acked-by: Ilya Maximets <i.maximets@samsung.com>
>> ---
>>   lib/librte_vhost/vhost_user.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
>> index 71a0e7dd7..3f01926e2 100644
>> --- a/lib/librte_vhost/vhost_user.c
>> +++ b/lib/librte_vhost/vhost_user.c
>> @@ -964,7 +964,7 @@ vhost_user_set_mem_table(struct virtio_net **pdev, struct VhostUserMsg *msg)
>>   
>>   			dev = translate_ring_addresses(dev, i);
>>   			if (!dev)
>> -				return VH_RESULT_ERR;
>> +				goto err_mmap;
> 
> When dev is NULL, we can't just goto err_mmap directly,
> otherwise we will dereference the NULL pointer.

Indeed, thanks for catching it.
I think we should restore dev to *pdev value.

>>   
>>   			*pdev = dev;
>>   		}
>> -- 
>> 2.17.1
>>