Re: [PATCH] iscsi: Don't access non-existent scsi_lba_status_descriptor

[Peter Lieven]

Am 23.01.2020 um 21:38 schrieb John Snow <address@hidden>:
> 
> 
> 
>> On 1/23/20 12:05 PM, Kevin Wolf wrote:
>> In iscsi_co_block_status(), we may have received num_descriptors == 0
>> from the iscsi server. Therefore, we can't unconditionally access
>> lbas->descriptors[0]. Add the missing check.
>> 
>> Signed-off-by: Kevin Wolf <address@hidden>
>> ---
>> block/iscsi.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>> 
>> diff --git a/block/iscsi.c b/block/iscsi.c
>> index cbd57294ab..c8feaa2f0e 100644
>> --- a/block/iscsi.c
>> +++ b/block/iscsi.c
>> @@ -753,7 +753,7 @@ retry:
>>     }
>> 
>>     lbas = scsi_datain_unmarshall(iTask.task);
>> -    if (lbas == NULL) {
>> +    if (lbas == NULL || lbas->num_descriptors == 0) {
>>         ret = -EIO;
>>         goto out_unlock;
>>     }
>> 
> 
> Naive question: Does the specification allow for such a response? Is
> this inherently an error?

The spec says the answer SHALL contain at least one lbasd. So I think threating 
zero as an error is okay

Anyway,

Reviewed-by: Peter Lieven <address@hidden>

Peter