> -----Original Message-----
> From: Bart Van Assche <bvanassche@xxxxxxx>
> Sent: Wednesday, May 31, 2023 6:04 PM
> To: Nilesh Javali <njavali@xxxxxxxxxxx>; martin.petersen@xxxxxxxxxx
> Cc: linux-scsi@xxxxxxxxxxxxxxx; GR-QLogic-Storage-Upstream <GR-QLogic-
> Storage-Upstream@xxxxxxxxxxx>; Bikash Hazarika <bhazarika@xxxxxxxxxxx>;
> Anil Gurumurthy <agurumurthy@xxxxxxxxxxx>; Shreyas Deodhar
> <sdeodhar@xxxxxxxxxxx>
> Subject: Re: [EXT] Re: [PATCH 2/8] qla2xxx: klocwork - Fix potential null pointer
> dereference
>
> On 5/31/23 04:43, Nilesh Javali wrote:
> > We can prevent the crash and notify the occurrence of this
> > rare case by adding warn_on like,
> >
> > + WARN_ON_ONCE(!cur_dsd);
> > + if (cur_dsd) {
> > + cur_dsd->address = 0;
> > + cur_dsd->length = 0;
> > + cur_dsd++;
> > + }
> > cmd_pkt->control_flags |= cpu_to_le16(CF_DATA_SEG_DESCR_ENABLE);
> > return 0;
> > }
>
> I think there is a much better solution: drop the new "if (cur_dsd) {"
> test and instead add the following code:
>
> diff --git a/drivers/scsi/qla2xxx/qla_iocb.c
> b/drivers/scsi/qla2xxx/qla_iocb.c
> index 6acfdcc48b16..a1675f056a5c 100644
> --- a/drivers/scsi/qla2xxx/qla_iocb.c
> +++ b/drivers/scsi/qla2xxx/qla_iocb.c
> @@ -607,7 +607,8 @@ qla24xx_build_scsi_type_6_iocbs(srb_t *sp, struct
> cmd_type_6 *cmd_pkt,
> put_unaligned_le32(COMMAND_TYPE_6, &cmd_pkt->entry_type);
>
> /* No data transfer */
> - if (!scsi_bufflen(cmd) || cmd->sc_data_direction == DMA_NONE) {
> + if (!scsi_bufflen(cmd) || cmd->sc_data_direction == DMA_NONE ||
> + tot_dsds == 0) {
> cmd_pkt->byte_count = cpu_to_le32(0);
> return 0;
> }
>
> Is the above change sufficient to suppress the Klocwork warning?
This looks good and does not generate any new klocwork warning.
I will re-send the series with this change included.
Thanks,
Nilesh
