[PATCH 3/5][Bionic] scsi: hisi_sas: fix NULL check in SMP abort task path

[dann frazier]

From: Xiaofei Tan <tanxiaofei at huawei.com>

BugLink: https://bugs.launchpad.net/bugs/1739807

This patch adds a NULL check of task->lldd_task before freeing the
slot in SMP path.

This is to guard against the scenario of the slot being freed during
the from the preceding internal abort.

Signed-off-by: Xiaofei Tan <tanxiaofei at huawei.com>
Signed-off-by: John Garry <john.garry at huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen at oracle.com>
(cherry picked from commit 378c233bcb21dfb2d9c2548b9a1fa6a8d35c78dd)
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 4a5eface9e01..3384e7a5d4b1 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_main.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_main.c
@@ -1160,7 +1160,7 @@ static int hisi_sas_abort_task(struct sas_task *task)
 
 		rc = hisi_sas_internal_task_abort(hisi_hba, device,
 			     HISI_SAS_INT_ABT_CMD, tag);
-		if (rc == TMF_RESP_FUNC_FAILED) {
+		if (rc == TMF_RESP_FUNC_FAILED && task->lldd_task) {
 			spin_lock_irqsave(&hisi_hba->lock, flags);
 			hisi_sas_do_release_task(hisi_hba, task, slot);
 			spin_unlock_irqrestore(&hisi_hba->lock, flags);
-- 
2.15.1