From: Kangjie Lu <kjlu@umn.edu>
Date: Fri, 15 Mar 2019 01:57:14 -0500
Subject: RDMA/i40iw: Handle workqueue allocation failure
Patch-mainline: v5.2-rc1
Git-commit: e2a438bd7116889af36304903b92e56d0f347228
References: jsc#SLE-4793

alloc_ordered_workqueue may fail and return NULL.  The fix captures the
failure and handles it properly to avoid potential NULL pointer
dereferences.

Signed-off-by: Kangjie Lu <kjlu@umn.edu>
Reviewed-by: Shiraz, Saleem <shiraz.saleem@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/infiniband/hw/i40iw/i40iw.h      |    2 +-
 drivers/infiniband/hw/i40iw/i40iw_cm.c   |   18 +++++++++++++++---
 drivers/infiniband/hw/i40iw/i40iw_main.c |    5 ++++-
 3 files changed, 20 insertions(+), 5 deletions(-)

--- a/drivers/infiniband/hw/i40iw/i40iw.h
+++ b/drivers/infiniband/hw/i40iw/i40iw.h
@@ -552,7 +552,7 @@ enum i40iw_status_code i40iw_obj_aligned
 
 void i40iw_request_reset(struct i40iw_device *iwdev);
 void i40iw_destroy_rdma_device(struct i40iw_ib_device *iwibdev);
-void i40iw_setup_cm_core(struct i40iw_device *iwdev);
+int i40iw_setup_cm_core(struct i40iw_device *iwdev);
 void i40iw_cleanup_cm_core(struct i40iw_cm_core *cm_core);
 void i40iw_process_ceq(struct i40iw_device *, struct i40iw_ceq *iwceq);
 void i40iw_process_aeq(struct i40iw_device *);
--- a/drivers/infiniband/hw/i40iw/i40iw_cm.c
+++ b/drivers/infiniband/hw/i40iw/i40iw_cm.c
@@ -3237,7 +3237,7 @@ void i40iw_receive_ilq(struct i40iw_sc_v
  * core
  * @iwdev: iwarp device structure
  */
-void i40iw_setup_cm_core(struct i40iw_device *iwdev)
+int i40iw_setup_cm_core(struct i40iw_device *iwdev)
 {
 	struct i40iw_cm_core *cm_core = &iwdev->cm_core;
 
@@ -3257,9 +3257,19 @@ void i40iw_setup_cm_core(struct i40iw_de
 
 	cm_core->event_wq = alloc_ordered_workqueue("iwewq",
 						    WQ_MEM_RECLAIM);
+	if (!cm_core->event_wq)
+		goto error;
 
 	cm_core->disconn_wq = alloc_ordered_workqueue("iwdwq",
 						      WQ_MEM_RECLAIM);
+	if (!cm_core->disconn_wq)
+		goto error;
+
+	return 0;
+error:
+	i40iw_cleanup_cm_core(&iwdev->cm_core);
+
+	return -ENOMEM;
 }
 
 /**
@@ -3279,8 +3289,10 @@ void i40iw_cleanup_cm_core(struct i40iw_
 		del_timer_sync(&cm_core->tcp_timer);
 	spin_unlock_irqrestore(&cm_core->ht_lock, flags);
 
-	destroy_workqueue(cm_core->event_wq);
-	destroy_workqueue(cm_core->disconn_wq);
+	if (cm_core->event_wq)
+		destroy_workqueue(cm_core->event_wq);
+	if (cm_core->disconn_wq)
+		destroy_workqueue(cm_core->disconn_wq);
 }
 
 /**
--- a/drivers/infiniband/hw/i40iw/i40iw_main.c
+++ b/drivers/infiniband/hw/i40iw/i40iw_main.c
@@ -1641,7 +1641,10 @@ static int i40iw_open(struct i40e_info *
 	iwdev = &hdl->device;
 	iwdev->hdl = hdl;
 	dev = &iwdev->sc_dev;
-	i40iw_setup_cm_core(iwdev);
+	if (i40iw_setup_cm_core(iwdev)) {
+		kfree(iwdev->hdl);
+		return -ENOMEM;
+	}
 
 	dev->back_dev = (void *)iwdev;
 	iwdev->ldev = &hdl->ldev;