Re: [PATCH] flow_offload: action should not be NULL when it is referenced

[Jamal Hadi Salim <jhs@mojatatu.com>]

On 2021-08-18 7:58 a.m., Ido Schimmel wrote:
> On Sat, Jun 26, 2021 at 04:56:06AM -0700, 13145886936@163.com wrote:
>> From: gushengxian <gushengxian@yulong.com>
>>
>> "action" should not be NULL when it is referenced.
>>
>> Signed-off-by: gushengxian <13145886936@163.com>
>> Signed-off-by: gushengxian <gushengxian@yulong.com>
>> ---
>>   include/net/flow_offload.h | 12 +++++++-----
>>   1 file changed, 7 insertions(+), 5 deletions(-)
>>
>> diff --git a/include/net/flow_offload.h b/include/net/flow_offload.h
>> index dc5c1e69cd9f..69c9eabf8325 100644
>> --- a/include/net/flow_offload.h
>> +++ b/include/net/flow_offload.h
>> @@ -319,12 +319,14 @@ flow_action_mixed_hw_stats_check(const struct flow_action *action,
>>   	if (flow_offload_has_one_action(action))
>>   		return true;
>>   
>> -	flow_action_for_each(i, action_entry, action) {
>> -		if (i && action_entry->hw_stats != last_hw_stats) {
>> -			NL_SET_ERR_MSG_MOD(extack, "Mixing HW stats types for actions is not supported");
>> -			return false;
>> +	if (action) {
> 
> This patch generates a smatch warning:
> 
> include/net/flow_offload.h:322 flow_action_mixed_hw_stats_check() warn: variable dereferenced before check 'action' (see line 319)
> 
> Why the patch is needed? 'action' is already dereferenced in
> flow_offload_has_one_action()
> 

Yep, doesnt make sense at all.

cheers,
jamal