[lvc-project] [PATCH v2] scsi/cxgbi/libcxgbi: make sure sg is present before calling sg_next()

[Daniil Tatianin]

On 11/15/22 1:23 AM, Mike Christie wrote:
> On 11/14/22 9:09 AM, Daniil Tatianin wrote:
>> sg_next() dereferences the passed sg, therefore we have to verify that
>> it's present before calling it.
>>
>> Found by Linux Verification Center (linuxtesting.org) with the SVACE
>> static analysis tool.
>>
>> Signed-off-by: Daniil Tatianin <d-tatianin at yandex-team.ru>
>> ---
>>   drivers/scsi/cxgbi/libcxgbi.c | 3 +--
>>   1 file changed, 1 insertion(+), 2 deletions(-)
>>
>> diff --git a/drivers/scsi/cxgbi/libcxgbi.c b/drivers/scsi/cxgbi/libcxgbi.c
>> index af281e271f88..2ff9810f42a9 100644
>> --- a/drivers/scsi/cxgbi/libcxgbi.c
>> +++ b/drivers/scsi/cxgbi/libcxgbi.c
>> @@ -1196,8 +1196,7 @@ void cxgbi_ddp_set_one_ppod(struct cxgbi_pagepod *ppod,
>>   
>>   	if (offset == len) {
>>   		offset = 0;
>> -		sg = sg_next(sg);
>> -		if (sg) {
>> +		if (sg && (sg = sg_next(sg))) {
>>   			addr = sg_dma_address(sg);
>>   			len = sg_dma_len(sg);
>>   		}
> 
> Is cxgbit_set_one_ppod the same function but it already has the extra
> sg check?

Good catch! Certainly looks that way, albeit with messier indentation.

> Should it be a libcxgb function in libcxgb_ppm.c?

That makes sense to me. Should I just move both there?

Thanks