[PATCH] infiniband: i40iw: fix potential NULL pointer dereferences

[Kangjie Lu]

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 <k...@umn.edu>
---
V2: add return value to capture the error code

 drivers/infiniband/hw/i40iw/i40iw.h      |  2 +-
 drivers/infiniband/hw/i40iw/i40iw_cm.c   | 19 ++++++++++++++++---
 drivers/infiniband/hw/i40iw/i40iw_main.c |  5 ++++-
 3 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/drivers/infiniband/hw/i40iw/i40iw.h 
b/drivers/infiniband/hw/i40iw/i40iw.h
index 2f2b4426ded7..8feec35f95a7 100644
--- 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_mem(struct 
i40iw_device *iwdev,
 
 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 *);
diff --git a/drivers/infiniband/hw/i40iw/i40iw_cm.c 
b/drivers/infiniband/hw/i40iw/i40iw_cm.c
index 206cfb0016f8..dda24f44239b 100644
--- 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_vsi *vsi, struct 
i40iw_puda_buf *rbuf)
  * 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;
 
@@ -3256,9 +3256,20 @@ void i40iw_setup_cm_core(struct i40iw_device *iwdev)
 
        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);
+       i40iw_pr_err("fail to setup CM core");
+
+       return return -ENOMEM;
 }
 
 /**
@@ -3278,8 +3289,10 @@ void i40iw_cleanup_cm_core(struct i40iw_cm_core *cm_core)
                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);
 }
 
 /**
diff --git a/drivers/infiniband/hw/i40iw/i40iw_main.c 
b/drivers/infiniband/hw/i40iw/i40iw_main.c
index 68095f00d08f..10932baee279 100644
--- 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 *ldev, struct 
i40e_client *client)
        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;
-- 
2.17.1