[PATCH 5.3 010/197] scsi: qla2xxx: Fix stale mem access on driver unload

[Greg Kroah-Hartman]

From: Quinn Tran <qutran@xxxxxxxxxxx>

[ Upstream commit fd5564ba54e0d8a9e3e823d311b764232e09eb5f ]

On driver unload, 'remove_one' thread was allowed to advance, while session
cleanup still lag behind.  This patch ensures session deletion will finish
before remove_one can advance.

Link: https://lore.kernel.org/r/20190912180918.6436-4-hmadhani@xxxxxxxxxxx
Signed-off-by: Quinn Tran <qutran@xxxxxxxxxxx>
Signed-off-by: Himanshu Madhani <hmadhani@xxxxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/scsi/qla2xxx/qla_os.c     |  1 +
 drivers/scsi/qla2xxx/qla_target.c | 21 ++++++++-------------
 2 files changed, 9 insertions(+), 13 deletions(-)

diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c
index 4fda308c3ef5c..084e39e415ff5 100644
--- a/drivers/scsi/qla2xxx/qla_os.c
+++ b/drivers/scsi/qla2xxx/qla_os.c
@@ -1153,6 +1153,7 @@ qla2x00_wait_for_sess_deletion(scsi_qla_host_t *vha)
 	qla2x00_mark_all_devices_lost(vha, 0);
 
 	wait_event_timeout(vha->fcport_waitQ, test_fcport_count(vha), 10*HZ);
+	flush_workqueue(vha->hw->wq);
 }
 
 /*
diff --git a/drivers/scsi/qla2xxx/qla_target.c b/drivers/scsi/qla2xxx/qla_target.c
index f77baf107024f..1bb0fc9324ead 100644
--- a/drivers/scsi/qla2xxx/qla_target.c
+++ b/drivers/scsi/qla2xxx/qla_target.c
@@ -954,7 +954,7 @@ void qlt_free_session_done(struct work_struct *work)
 	struct qla_hw_data *ha = vha->hw;
 	unsigned long flags;
 	bool logout_started = false;
-	scsi_qla_host_t *base_vha;
+	scsi_qla_host_t *base_vha = pci_get_drvdata(ha->pdev);
 	struct qlt_plogi_ack_t *own =
 		sess->plogi_link[QLT_PLOGI_LINK_SAME_WWN];
 
@@ -1106,6 +1106,7 @@ void qlt_free_session_done(struct work_struct *work)
 	}
 
 	spin_unlock_irqrestore(&ha->tgt.sess_lock, flags);
+	sess->free_pending = 0;
 
 	ql_dbg(ql_dbg_tgt_mgt, vha, 0xf001,
 	    "Unregistration of sess %p %8phC finished fcp_cnt %d\n",
@@ -1114,17 +1115,8 @@ void qlt_free_session_done(struct work_struct *work)
 	if (tgt && (tgt->sess_count == 0))
 		wake_up_all(&tgt->waitQ);
 
-	if (vha->fcport_count == 0)
-		wake_up_all(&vha->fcport_waitQ);
-
-	base_vha = pci_get_drvdata(ha->pdev);
-
-	sess->free_pending = 0;
-
-	if (test_bit(PFLG_DRIVER_REMOVING, &base_vha->pci_flags))
-		return;
-
-	if ((!tgt || !tgt->tgt_stop) && !LOOP_TRANSITION(vha)) {
+	if (!test_bit(PFLG_DRIVER_REMOVING, &base_vha->pci_flags) &&
+	    (!tgt || !tgt->tgt_stop) && !LOOP_TRANSITION(vha)) {
 		switch (vha->host->active_mode) {
 		case MODE_INITIATOR:
 		case MODE_DUAL:
@@ -1137,6 +1129,9 @@ void qlt_free_session_done(struct work_struct *work)
 			break;
 		}
 	}
+
+	if (vha->fcport_count == 0)
+		wake_up_all(&vha->fcport_waitQ);
 }
 
 /* ha->tgt.sess_lock supposed to be held on entry */
@@ -1166,7 +1161,7 @@ void qlt_unreg_sess(struct fc_port *sess)
 	sess->last_login_gen = sess->login_gen;
 
 	INIT_WORK(&sess->free_work, qlt_free_session_done);
-	schedule_work(&sess->free_work);
+	queue_work(sess->vha->hw->wq, &sess->free_work);
 }
 EXPORT_SYMBOL(qlt_unreg_sess);
 
-- 
2.20.1