From: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
Date: Thu, 18 Oct 2018 18:59:39 +0200
Subject: scsi: hisi_sas: Fix NULL pointer dereference
Patch-mainline: v4.20-rc1
Git-commit: f4445bb93d82a984657b469e63118c2794a4c3d3
References: FATE#326253
There is a NULL pointer dereference in case *slot* happens to be NULL at
lines 1053 and 1878:
struct hisi_sas_cq *cq =
&hisi_hba->cq[slot->dlvry_queue];
Notice that *slot* is being NULL checked at lines 1057 and 1881:
if (slot), which implies it may be NULL.
Fix this by placing the declaration and definition of variable cq, which
contains the pointer dereference slot->dlvry_queue, after slot has been
properly NULL checked.
Addresses-Coverity-ID: 1474515 ("Dereference before null check")
Addresses-Coverity-ID: 1474520 ("Dereference before null check")
Fixes: 584f53fe5f52 ("scsi: hisi_sas: Fix the race between IO completion and timeout for SMP/internal IO")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Johannes Thumshirn <jthumshirn@suse.de>
---
drivers/scsi/hisi_sas/hisi_sas_main.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c
index 2e5eaf1a73a0..b3f01d5b821b 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_main.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_main.c
@@ -1050,11 +1050,11 @@ static int hisi_sas_exec_internal_tmf_task(struct domain_device *device,
if ((task->task_state_flags & SAS_TASK_STATE_ABORTED)) {
if (!(task->task_state_flags & SAS_TASK_STATE_DONE)) {
struct hisi_sas_slot *slot = task->lldd_task;
- struct hisi_sas_cq *cq =
- &hisi_hba->cq[slot->dlvry_queue];
dev_err(dev, "abort tmf: TMF task timeout and not done\n");
if (slot) {
+ struct hisi_sas_cq *cq =
+ &hisi_hba->cq[slot->dlvry_queue];
/*
* flush tasklet to avoid free'ing task
* before using task in IO completion
@@ -1875,10 +1875,10 @@ hisi_sas_internal_task_abort(struct hisi_hba *hisi_hba,
if ((task->task_state_flags & SAS_TASK_STATE_ABORTED)) {
if (!(task->task_state_flags & SAS_TASK_STATE_DONE)) {
struct hisi_sas_slot *slot = task->lldd_task;
- struct hisi_sas_cq *cq =
- &hisi_hba->cq[slot->dlvry_queue];
if (slot) {
+ struct hisi_sas_cq *cq =
+ &hisi_hba->cq[slot->dlvry_queue];
/*
* flush tasklet to avoid free'ing task
* before using task in IO completion
--
2.12.3