[PATCH][Unstable][Artful][SRU Zesty] scsi: hisi_sas: add null check before indirect pointer dereference

[dann frazier]

From: "Gustavo A. R. Silva" <garsilva at embeddedor.com>

BugLink: https://bugs.launchpad.net/bugs/1708714

Add null check before indirectly dereferencing pointer task->lldd_task
in statement u32 tag = slot->idx;

Addresses-Coverity-ID: 1373843
Signed-off-by: Gustavo A. R. Silva <garsilva at embeddedor.com>
Reviewed-by: John Garry <john.garry at huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen at oracle.com>
(cherry picked from commit eb045e046d5b2aab7710f82c2e5fb1403c69332b)
Signed-off-by: dann frazier <dann.frazier at canonical.com>
---
 drivers/scsi/hisi_sas/hisi_sas_main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c
index 7e6e8823a5c7..938a22f12868 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_main.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_main.c
@@ -963,7 +963,7 @@ static int hisi_sas_abort_task(struct sas_task *task)
 						     HISI_SAS_INT_ABT_DEV, 0);
 			rc = hisi_sas_softreset_ata_disk(device);
 		}
-	} else if (task->task_proto & SAS_PROTOCOL_SMP) {
+	} else if (task->lldd_task && task->task_proto & SAS_PROTOCOL_SMP) {
 		/* SMP */
 		struct hisi_sas_slot *slot = task->lldd_task;
 		u32 tag = slot->idx;
-- 
2.13.3